[chore] Validate/set account domain (#619)

* add miekg/dns dependency

* set/validate accountDomain

README.md

@@ -224,6 +224,7 @@ The following libraries and frameworks are used by GoToSocial, with gratitude
 - [jackc/pgx](https://github.com/jackc/pgx); Postgres driver. [MIT License](https://spdx.org/licenses/MIT.html).
 - [mcuadros/go-syslog](https://github.com/mcuadros/go-syslog); Syslog server library. [MIT License](https://spdx.org/licenses/MIT.html).
 - [microcosm-cc/bluemonday](https://github.com/microcosm-cc/bluemonday); HTML user-input sanitization. [BSD-3-Clause License](https://spdx.org/licenses/BSD-3-Clause.html).
+- [miekg/dns](https://github.com/miekg/dns); DNS utilities. [Go License](https://go.dev/LICENSE).
 - [mitchellh/mapstructure](https://github.com/mitchellh/mapstructure); Go interface => struct parsing. [MIT License](https://spdx.org/licenses/MIT.html).
 - [modernc.org/sqlite](https://gitlab.com/cznic/sqlite); cgo-free port of SQLite. [Other License](https://gitlab.com/cznic/sqlite/-/blob/master/LICENSE).
   - [modernc.org/ccgo](https://gitlab.com/cznic/ccgo); c99 AST -> Go translater. [BSD-3-Clause License](https://spdx.org/licenses/BSD-3-Clause.html).

go.mod

@@ -94,6 +94,7 @@ require (
 	github.com/leodido/go-urn v1.2.1 // indirect
 	github.com/magiconair/properties v1.8.6 // indirect
 	github.com/mattn/go-isatty v0.0.14 // indirect
+	github.com/miekg/dns v1.1.49 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pelletier/go-toml v1.9.5 // indirect

go.sum

@@ -391,6 +391,8 @@ github.com/mattn/go-sqlite3 v1.14.12/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4
 github.com/mattn/go-sqlite3 v2.0.3+incompatible h1:gXHsfypPkaMZrKbD5209QV9jbUTJKjyR5WD3HYQSd+U=
 github.com/microcosm-cc/bluemonday v1.0.18 h1:6HcxvXDAi3ARt3slx6nTesbvorIc3QeTzBNRvWktHBo=
 github.com/microcosm-cc/bluemonday v1.0.18/go.mod h1:Z0r70sCuXHig8YpBzCc5eGHAap2K7e/u082ZUpDRRqM=
+github.com/miekg/dns v1.1.49 h1:qe0mQU3Z/XpFeE+AEBo2rqaS1IPBJ3anmqZ4XiZJVG8=
+github.com/miekg/dns v1.1.49/go.mod h1:e3IlAVfNqAllflbibAZEWOXOQ+Ynzk/dDozDxY7XnME=
 github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
 github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -551,6 +553,7 @@ github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9de
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 github.com/zeebo/assert v1.1.0/go.mod h1:Pq9JiuJQpG8JLJdtkwrJESF0Foym2/D9XMU5ciN/wJ0=
 github.com/zeebo/blake3 v0.2.1/go.mod h1:TSQ0KjMH+pht+bRyvVooJ1rBpvvngSGaPISafq9MxJk=
 github.com/zeebo/pcg v1.0.1/go.mod h1:09F0S9iiKrwn9rlI5yjLkmrug154/YRW6KnnXVDM/l4=
@@ -622,6 +625,7 @@ golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 h1:6zppjxzCulZykYSLyVDYbneBfbaBIQPYMevg0bEwv2s=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -660,7 +664,9 @@ golang.org/x/net v0.0.0-20201031054903-ff519b6c9102/go.mod h1:sp8m0HH+o8qH0wwXwY
 golang.org/x/net v0.0.0-20201209123823-ac852fbbde11/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20201224014010-6772e930b67b/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/net v0.0.0-20210614182718-04defd469f4e/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20220127200216-cd36cc0744dd/go.mod h1:CfG3xpIq0wQ8r1q4Su4UZFWDARRcnwPjda9FqA0JpMk=
 golang.org/x/net v0.0.0-20220524220425-1d687d428aca h1:xTaFYiPROfpPhqrfTIDXj0ri1SpfueYT951s4bAuDO8=
@@ -687,6 +693,7 @@ golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -732,8 +739,10 @@ golang.org/x/sys v0.0.0-20201201145000-ef89a241ccb3/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210104204734-6f8348627aad/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210225134936-a50acf3fe073/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423185535-09eb48e85fd7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210806184541-e5e7981a1069/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -812,6 +821,7 @@ golang.org/x/tools v0.0.0-20201208233053-a543418bbed2/go.mod h1:emZCQorbCU4vsT4f
 golang.org/x/tools v0.0.0-20210105154028-b0ab187a4818/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.0.0-20210108195828-e2f9c7f1fc8e/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
+golang.org/x/tools v0.1.6-0.20210726203631-07bc1bf47fb2/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.10 h1:QjFRCZxdOhBJ/UNgnBZLbNV13DlbnK0quyivTnXJM20=
 golang.org/x/tools v0.1.10/go.mod h1:Uh6Zz+xoGYZom868N8YTex3t7RhtHDBrE8Gzo9bV56E=
 golang.org/x/xerrors v0.0.0-20190410155217-1f06c39b4373/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

internal/config/validate.go

@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/miekg/dns"
 	"github.com/sirupsen/logrus"
 )
 
@@ -31,10 +32,23 @@ func Validate() error {
 	errs := []error{}
 
 	// host
-	if GetHost() == "" {
+	host := GetHost()
+	if host == "" {
 		errs = append(errs, fmt.Errorf("%s must be set", HostFlag()))
 	}
 
+	// accountDomain; only check if host was set, otherwise there's no point
+	if host != "" {
+		switch ad := GetAccountDomain(); ad {
+		case "":
+			SetAccountDomain(GetHost())
+		default:
+			if !dns.IsSubDomain(ad, host) {
+				errs = append(errs, fmt.Errorf("%s was %s and %s was %s, but %s is not a valid subdomain of %s", HostFlag(), host, AccountDomainFlag(), ad, host, ad))
+			}
+		}
+	}
+
 	// protocol
 	switch proto := GetProtocol(); proto {
 	case "https":

internal/config/validate_test.go

@@ -46,6 +46,54 @@ func (suite *ConfigValidateTestSuite) TestValidateConfigNoHost() {
 	suite.EqualError(err, "host must be set")
 }
 
+func (suite *ConfigValidateTestSuite) TestValidateAccountDomainOK1() {
+	testrig.InitTestConfig()
+
+	err := config.Validate()
+	suite.NoError(err)
+
+	suite.Equal(config.GetHost(), config.GetAccountDomain())
+}
+
+func (suite *ConfigValidateTestSuite) TestValidateAccountDomainOK2() {
+	testrig.InitTestConfig()
+
+	config.SetAccountDomain("localhost:8080")
+
+	err := config.Validate()
+	suite.NoError(err)
+}
+
+func (suite *ConfigValidateTestSuite) TestValidateAccountDomainOK3() {
+	testrig.InitTestConfig()
+
+	config.SetHost("gts.example.org")
+	config.SetAccountDomain("example.org")
+
+	err := config.Validate()
+	suite.NoError(err)
+}
+
+func (suite *ConfigValidateTestSuite) TestValidateAccountDomainNotSubdomain1() {
+	testrig.InitTestConfig()
+
+	config.SetHost("gts.example.org")
+	config.SetAccountDomain("example.com")
+
+	err := config.Validate()
+	suite.EqualError(err, "host was gts.example.org and account-domain was example.com, but gts.example.org is not a valid subdomain of example.com")
+}
+
+func (suite *ConfigValidateTestSuite) TestValidateAccountDomainNotSubdomain2() {
+	testrig.InitTestConfig()
+
+	config.SetHost("example.org")
+	config.SetAccountDomain("gts.example.org")
+
+	err := config.Validate()
+	suite.EqualError(err, "host was example.org and account-domain was gts.example.org, but example.org is not a valid subdomain of gts.example.org")
+}
+
 func (suite *ConfigValidateTestSuite) TestValidateConfigNoProtocol() {
 	testrig.InitTestConfig()
 

vendor/github.com/miekg/dns/.codecov.yml

@@ -0,0 +1,8 @@
+coverage:
+  status:
+    project:
+      default:
+        target: 40%
+        threshold: null
+    patch: false
+    changes: false

vendor/github.com/miekg/dns/.gitignore

@@ -0,0 +1,4 @@
+*.6
+tags
+test.out
+a.out

vendor/github.com/miekg/dns/AUTHORS

@@ -0,0 +1 @@
+Miek Gieben <miek@miek.nl>

vendor/github.com/miekg/dns/CODEOWNERS

@@ -0,0 +1 @@
+* @miekg @tmthrgd

vendor/github.com/miekg/dns/CONTRIBUTORS

@@ -0,0 +1,10 @@
+Alex A. Skinner
+Andrew Tunnell-Jones
+Ask Bjørn Hansen
+Dave Cheney
+Dusty Wilson
+Marek Majkowski
+Peter van Dijk
+Omri Bahumi
+Alex Sergeyev
+James Hartig

vendor/github.com/miekg/dns/COPYRIGHT

@@ -0,0 +1,9 @@
+Copyright 2009 The Go Authors. All rights reserved. Use of this source code
+is governed by a BSD-style license that can be found in the LICENSE file.
+Extensions of the original work are copyright (c) 2011 Miek Gieben
+
+Copyright 2011 Miek Gieben. All rights reserved. Use of this source code is
+governed by a BSD-style license that can be found in the LICENSE file.
+
+Copyright 2014 CloudFlare. All rights reserved. Use of this source code is
+governed by a BSD-style license that can be found in the LICENSE file.

vendor/github.com/miekg/dns/LICENSE

@@ -0,0 +1,30 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+As this is fork of the official Go code the same license applies.
+Extensions of the original work are copyright (c) 2011 Miek Gieben

vendor/github.com/miekg/dns/Makefile.fuzz

@@ -0,0 +1,33 @@
+# Makefile for fuzzing
+#
+# Use go-fuzz and needs the tools installed.
+# See https://blog.cloudflare.com/dns-parser-meet-go-fuzzer/
+#
+# Installing go-fuzz:
+# $ make -f Makefile.fuzz get
+# Installs:
+# * github.com/dvyukov/go-fuzz/go-fuzz
+# * get github.com/dvyukov/go-fuzz/go-fuzz-build
+
+all: build
+
+.PHONY: build
+build:
+	go-fuzz-build -tags fuzz github.com/miekg/dns
+
+.PHONY: build-newrr
+build-newrr:
+	go-fuzz-build -func FuzzNewRR -tags fuzz github.com/miekg/dns
+
+.PHONY: fuzz
+fuzz:
+	go-fuzz -bin=dns-fuzz.zip -workdir=fuzz
+
+.PHONY: get
+get:
+	go get github.com/dvyukov/go-fuzz/go-fuzz
+	go get github.com/dvyukov/go-fuzz/go-fuzz-build
+
+.PHONY: clean
+clean:
+	rm *-fuzz.zip

vendor/github.com/miekg/dns/Makefile.release

@@ -0,0 +1,52 @@
+# Makefile for releasing.
+#
+# The release is controlled from version.go. The version found there is
+# used to tag the git repo, we're not building any artifacts so there is nothing
+# to upload to github.
+#
+# * Up the version in version.go
+# * Run: make -f Makefile.release release
+#   * will *commit* your change with 'Release $VERSION'
+#   * push to github
+#
+
+define GO
+//+build ignore
+
+package main
+
+import (
+	"fmt"
+
+	"github.com/miekg/dns"
+)
+
+func main() {
+	fmt.Println(dns.Version.String())
+}
+endef
+
+$(file > version_release.go,$(GO))
+VERSION:=$(shell go run version_release.go)
+TAG="v$(VERSION)"
+
+all:
+	@echo Use the \'release\' target to start a release $(VERSION)
+	rm -f version_release.go
+
+.PHONY: release
+release: commit push
+	@echo Released $(VERSION)
+	rm -f version_release.go
+
+.PHONY: commit
+commit:
+	@echo Committing release $(VERSION)
+	git commit -am"Release $(VERSION)"
+	git tag $(TAG)
+
+.PHONY: push
+push:
+	@echo Pushing release $(VERSION) to master
+	git push --tags
+	git push

vendor/github.com/miekg/dns/README.md

@@ -0,0 +1,186 @@
+[![Build Status](https://travis-ci.org/miekg/dns.svg?branch=master)](https://travis-ci.org/miekg/dns)
+[![Code Coverage](https://img.shields.io/codecov/c/github/miekg/dns/master.svg)](https://codecov.io/github/miekg/dns?branch=master)
+[![Go Report Card](https://goreportcard.com/badge/github.com/miekg/dns)](https://goreportcard.com/report/miekg/dns)
+[![](https://godoc.org/github.com/miekg/dns?status.svg)](https://godoc.org/github.com/miekg/dns)
+
+# Alternative (more granular) approach to a DNS library
+
+> Less is more.
+
+Complete and usable DNS library. All Resource Records are supported, including the DNSSEC types.
+It follows a lean and mean philosophy. If there is stuff you should know as a DNS programmer there
+isn't a convenience function for it. Server side and client side programming is supported, i.e. you
+can build servers and resolvers with it.
+
+We try to keep the "master" branch as sane as possible and at the bleeding edge of standards,
+avoiding breaking changes wherever reasonable. We support the last two versions of Go.
+
+# Goals
+
+* KISS;
+* Fast;
+* Small API. If it's easy to code in Go, don't make a function for it.
+
+# Users
+
+A not-so-up-to-date-list-that-may-be-actually-current:
+
+* https://github.com/coredns/coredns
+* https://github.com/abh/geodns
+* https://github.com/baidu/bfe
+* http://www.statdns.com/
+* http://www.dnsinspect.com/
+* https://github.com/chuangbo/jianbing-dictionary-dns
+* http://www.dns-lg.com/
+* https://github.com/fcambus/rrda
+* https://github.com/kenshinx/godns
+* https://github.com/skynetservices/skydns
+* https://github.com/hashicorp/consul
+* https://github.com/DevelopersPL/godnsagent
+* https://github.com/duedil-ltd/discodns
+* https://github.com/StalkR/dns-reverse-proxy
+* https://github.com/tianon/rawdns
+* https://mesosphere.github.io/mesos-dns/
+* https://github.com/fcambus/statzone
+* https://github.com/benschw/dns-clb-go
+* https://github.com/corny/dnscheck for <http://public-dns.info/>
+* https://github.com/miekg/unbound
+* https://github.com/miekg/exdns
+* https://dnslookup.org
+* https://github.com/looterz/grimd
+* https://github.com/phamhongviet/serf-dns
+* https://github.com/mehrdadrad/mylg
+* https://github.com/bamarni/dockness
+* https://github.com/fffaraz/microdns
+* https://github.com/ipdcode/hades <https://jd.com>
+* https://github.com/StackExchange/dnscontrol/
+* https://www.dnsperf.com/
+* https://dnssectest.net/
+* https://github.com/oif/apex
+* https://github.com/jedisct1/dnscrypt-proxy
+* https://github.com/jedisct1/rpdns
+* https://github.com/xor-gate/sshfp
+* https://github.com/rs/dnstrace
+* https://blitiri.com.ar/p/dnss ([github mirror](https://github.com/albertito/dnss))
+* https://render.com
+* https://github.com/peterzen/goresolver
+* https://github.com/folbricht/routedns
+* https://domainr.com/
+* https://zonedb.org/
+* https://router7.org/
+* https://github.com/fortio/dnsping
+* https://github.com/Luzilla/dnsbl_exporter
+* https://github.com/bodgit/tsig
+* https://github.com/v2fly/v2ray-core (test only)
+* https://kuma.io/
+* https://www.misaka.io/services/dns
+* https://ping.sx/dig
+* https://fleetdeck.io/
+* https://github.com/markdingo/autoreverse
+
+
+Send pull request if you want to be listed here.
+
+# Features
+
+* UDP/TCP queries, IPv4 and IPv6
+* RFC 1035 zone file parsing ($INCLUDE, $ORIGIN, $TTL and $GENERATE (for all record types) are supported
+* Fast
+* Server side programming (mimicking the net/http package)
+* Client side programming
+* DNSSEC: signing, validating and key generation for DSA, RSA, ECDSA and Ed25519
+* EDNS0, NSID, Cookies
+* AXFR/IXFR
+* TSIG, SIG(0)
+* DNS over TLS (DoT): encrypted connection between client and server over TCP
+* DNS name compression
+
+Have fun!
+
+Miek Gieben  -  2010-2012  -  <miek@miek.nl>
+DNS Authors 2012-
+
+# Building
+
+This library uses Go modules and uses semantic versioning. Building is done with the `go` tool, so
+the following should work:
+
+    go get github.com/miekg/dns
+    go build github.com/miekg/dns
+
+## Examples
+
+A short "how to use the API" is at the beginning of doc.go (this also will show when you call `godoc
+github.com/miekg/dns`).
+
+Example programs can be found in the `github.com/miekg/exdns` repository.
+
+## Supported RFCs
+
+*all of them*
+
+* 103{4,5} - DNS standard
+* 1348 - NSAP record (removed the record)
+* 1982 - Serial Arithmetic
+* 1876 - LOC record
+* 1995 - IXFR
+* 1996 - DNS notify
+* 2136 - DNS Update (dynamic updates)
+* 2181 - RRset definition - there is no RRset type though, just []RR
+* 2537 - RSAMD5 DNS keys
+* 2065 - DNSSEC (updated in later RFCs)
+* 2671 - EDNS record
+* 2782 - SRV record
+* 2845 - TSIG record
+* 2915 - NAPTR record
+* 2929 - DNS IANA Considerations
+* 3110 - RSASHA1 DNS keys
+* 3123 - APL record
+* 3225 - DO bit (DNSSEC OK)
+* 340{1,2,3} - NAPTR record
+* 3445 - Limiting the scope of (DNS)KEY
+* 3597 - Unknown RRs
+* 403{3,4,5} - DNSSEC + validation functions
+* 4255 - SSHFP record
+* 4343 - Case insensitivity
+* 4408 - SPF record
+* 4509 - SHA256 Hash in DS
+* 4592 - Wildcards in the DNS
+* 4635 - HMAC SHA TSIG
+* 4701 - DHCID
+* 4892 - id.server
+* 5001 - NSID
+* 5155 - NSEC3 record
+* 5205 - HIP record
+* 5702 - SHA2 in the DNS
+* 5936 - AXFR
+* 5966 - TCP implementation recommendations
+* 6605 - ECDSA
+* 6725 - IANA Registry Update
+* 6742 - ILNP DNS
+* 6840 - Clarifications and Implementation Notes for DNS Security
+* 6844 - CAA record
+* 6891 - EDNS0 update
+* 6895 - DNS IANA considerations
+* 6944 - DNSSEC DNSKEY Algorithm Status
+* 6975 - Algorithm Understanding in DNSSEC
+* 7043 - EUI48/EUI64 records
+* 7314 - DNS (EDNS) EXPIRE Option
+* 7477 - CSYNC RR
+* 7828 - edns-tcp-keepalive EDNS0 Option
+* 7553 - URI record
+* 7858 - DNS over TLS: Initiation and Performance Considerations
+* 7871 - EDNS0 Client Subnet
+* 7873 - Domain Name System (DNS) Cookies
+* 8080 - EdDSA for DNSSEC
+* 8499 - DNS Terminology
+* 8659 - DNS Certification Authority Authorization (CAA) Resource Record
+* 8914 - Extended DNS Errors
+* 8976 - Message Digest for DNS Zones (ZONEMD RR)
+
+## Loosely Based Upon
+
+* ldns - <https://nlnetlabs.nl/projects/ldns/about/>
+* NSD - <https://nlnetlabs.nl/projects/nsd/about/>
+* Net::DNS - <http://www.net-dns.org/>
+* GRONG - <https://github.com/bortzmeyer/grong>

vendor/github.com/miekg/dns/acceptfunc.go

@@ -0,0 +1,62 @@
+package dns
+
+// MsgAcceptFunc is used early in the server code to accept or reject a message with RcodeFormatError.
+// It returns a MsgAcceptAction to indicate what should happen with the message.
+type MsgAcceptFunc func(dh Header) MsgAcceptAction
+
+// DefaultMsgAcceptFunc checks the request and will reject if:
+//
+// * isn't a request (don't respond in that case)
+//
+// * opcode isn't OpcodeQuery or OpcodeNotify
+//
+// * Zero bit isn't zero
+//
+// * does not have exactly 1 question in the question section
+//
+// * has more than 1 RR in the Answer section
+//
+// * has more than 0 RRs in the Authority section
+//
+// * has more than 2 RRs in the Additional section
+//
+var DefaultMsgAcceptFunc MsgAcceptFunc = defaultMsgAcceptFunc
+
+// MsgAcceptAction represents the action to be taken.
+type MsgAcceptAction int
+
+// Allowed returned values from a MsgAcceptFunc.
+const (
+	MsgAccept               MsgAcceptAction = iota // Accept the message
+	MsgReject                                      // Reject the message with a RcodeFormatError
+	MsgIgnore                                      // Ignore the error and send nothing back.
+	MsgRejectNotImplemented                        // Reject the message with a RcodeNotImplemented
+)
+
+func defaultMsgAcceptFunc(dh Header) MsgAcceptAction {
+	if isResponse := dh.Bits&_QR != 0; isResponse {
+		return MsgIgnore
+	}
+
+	// Don't allow dynamic updates, because then the sections can contain a whole bunch of RRs.
+	opcode := int(dh.Bits>>11) & 0xF
+	if opcode != OpcodeQuery && opcode != OpcodeNotify {
+		return MsgRejectNotImplemented
+	}
+
+	if dh.Qdcount != 1 {
+		return MsgReject
+	}
+	// NOTIFY requests can have a SOA in the ANSWER section. See RFC 1996 Section 3.7 and 3.11.
+	if dh.Ancount > 1 {
+		return MsgReject
+	}
+	// IXFR request could have one SOA RR in the NS section. See RFC 1995, section 3.
+	if dh.Nscount > 1 {
+		return MsgReject
+	}
+	if dh.Arcount > 2 {
+		return MsgReject
+	}
+	return MsgAccept
+}

vendor/github.com/miekg/dns/client.go

@@ -0,0 +1,484 @@
+package dns
+
+// A client implementation.
+
+import (
+	"context"
+	"crypto/tls"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"net"
+	"strings"
+	"time"
+)
+
+const (
+	dnsTimeout     time.Duration = 2 * time.Second
+	tcpIdleTimeout time.Duration = 8 * time.Second
+)
+
+func isPacketConn(c net.Conn) bool {
+	if _, ok := c.(net.PacketConn); !ok {
+		return false
+	}
+
+	if ua, ok := c.LocalAddr().(*net.UnixAddr); ok {
+		return ua.Net == "unixgram"
+	}
+
+	return true
+}
+
+// A Conn represents a connection to a DNS server.
+type Conn struct {
+	net.Conn                         // a net.Conn holding the connection
+	UDPSize        uint16            // minimum receive buffer for UDP messages
+	TsigSecret     map[string]string // secret(s) for Tsig map[<zonename>]<base64 secret>, zonename must be in canonical form (lowercase, fqdn, see RFC 4034 Section 6.2)
+	TsigProvider   TsigProvider      // An implementation of the TsigProvider interface. If defined it replaces TsigSecret and is used for all TSIG operations.
+	tsigRequestMAC string
+}
+
+func (co *Conn) tsigProvider() TsigProvider {
+	if co.TsigProvider != nil {
+		return co.TsigProvider
+	}
+	// tsigSecretProvider will return ErrSecret if co.TsigSecret is nil.
+	return tsigSecretProvider(co.TsigSecret)
+}
+
+// A Client defines parameters for a DNS client.
+type Client struct {
+	Net       string      // if "tcp" or "tcp-tls" (DNS over TLS) a TCP query will be initiated, otherwise an UDP one (default is "" for UDP)
+	UDPSize   uint16      // minimum receive buffer for UDP messages
+	TLSConfig *tls.Config // TLS connection configuration
+	Dialer    *net.Dialer // a net.Dialer used to set local address, timeouts and more
+	// Timeout is a cumulative timeout for dial, write and read, defaults to 0 (disabled) - overrides DialTimeout, ReadTimeout,
+	// WriteTimeout when non-zero. Can be overridden with net.Dialer.Timeout (see Client.ExchangeWithDialer and
+	// Client.Dialer) or context.Context.Deadline (see ExchangeContext)
+	Timeout        time.Duration
+	DialTimeout    time.Duration     // net.DialTimeout, defaults to 2 seconds, or net.Dialer.Timeout if expiring earlier - overridden by Timeout when that value is non-zero
+	ReadTimeout    time.Duration     // net.Conn.SetReadTimeout value for connections, defaults to 2 seconds - overridden by Timeout when that value is non-zero
+	WriteTimeout   time.Duration     // net.Conn.SetWriteTimeout value for connections, defaults to 2 seconds - overridden by Timeout when that value is non-zero
+	TsigSecret     map[string]string // secret(s) for Tsig map[<zonename>]<base64 secret>, zonename must be in canonical form (lowercase, fqdn, see RFC 4034 Section 6.2)
+	TsigProvider   TsigProvider      // An implementation of the TsigProvider interface. If defined it replaces TsigSecret and is used for all TSIG operations.
+	SingleInflight bool              // if true suppress multiple outstanding queries for the same Qname, Qtype and Qclass
+	group          singleflight
+}
+
+// Exchange performs a synchronous UDP query. It sends the message m to the address
+// contained in a and waits for a reply. Exchange does not retry a failed query, nor
+// will it fall back to TCP in case of truncation.
+// See client.Exchange for more information on setting larger buffer sizes.
+func Exchange(m *Msg, a string) (r *Msg, err error) {
+	client := Client{Net: "udp"}
+	r, _, err = client.Exchange(m, a)
+	return r, err
+}
+
+func (c *Client) dialTimeout() time.Duration {
+	if c.Timeout != 0 {
+		return c.Timeout
+	}
+	if c.DialTimeout != 0 {
+		return c.DialTimeout
+	}
+	return dnsTimeout
+}
+
+func (c *Client) readTimeout() time.Duration {
+	if c.ReadTimeout != 0 {
+		return c.ReadTimeout
+	}
+	return dnsTimeout
+}
+
+func (c *Client) writeTimeout() time.Duration {
+	if c.WriteTimeout != 0 {
+		return c.WriteTimeout
+	}
+	return dnsTimeout
+}
+
+// Dial connects to the address on the named network.
+func (c *Client) Dial(address string) (conn *Conn, err error) {
+	return c.DialContext(context.Background(), address)
+}
+
+// DialContext connects to the address on the named network, with a context.Context.
+// For TLS over TCP (DoT) the context isn't used yet. This will be enabled when Go 1.18 is released.
+func (c *Client) DialContext(ctx context.Context, address string) (conn *Conn, err error) {
+	// create a new dialer with the appropriate timeout
+	var d net.Dialer
+	if c.Dialer == nil {
+		d = net.Dialer{Timeout: c.getTimeoutForRequest(c.dialTimeout())}
+	} else {
+		d = *c.Dialer
+	}
+
+	network := c.Net
+	if network == "" {
+		network = "udp"
+	}
+
+	useTLS := strings.HasPrefix(network, "tcp") && strings.HasSuffix(network, "-tls")
+
+	conn = new(Conn)
+	if useTLS {
+		network = strings.TrimSuffix(network, "-tls")
+
+		// TODO(miekg): Enable after Go 1.18 is released, to be able to support two prev. releases.
+		/*
+			tlsDialer := tls.Dialer{
+				NetDialer: &d,
+				Config:    c.TLSConfig,
+			}
+			conn.Conn, err = tlsDialer.DialContext(ctx, network, address)
+		*/
+		conn.Conn, err = tls.DialWithDialer(&d, network, address, c.TLSConfig)
+	} else {
+		conn.Conn, err = d.DialContext(ctx, network, address)
+	}
+	if err != nil {
+		return nil, err
+	}
+	conn.UDPSize = c.UDPSize
+	return conn, nil
+}
+
+// Exchange performs a synchronous query. It sends the message m to the address
+// contained in a and waits for a reply. Basic use pattern with a *dns.Client:
+//
+//	c := new(dns.Client)
+//	in, rtt, err := c.Exchange(message, "127.0.0.1:53")
+//
+// Exchange does not retry a failed query, nor will it fall back to TCP in
+// case of truncation.
+// It is up to the caller to create a message that allows for larger responses to be
+// returned. Specifically this means adding an EDNS0 OPT RR that will advertise a larger
+// buffer, see SetEdns0. Messages without an OPT RR will fallback to the historic limit
+// of 512 bytes
+// To specify a local address or a timeout, the caller has to set the `Client.Dialer`
+// attribute appropriately
+func (c *Client) Exchange(m *Msg, address string) (r *Msg, rtt time.Duration, err error) {
+	co, err := c.Dial(address)
+
+	if err != nil {
+		return nil, 0, err
+	}
+	defer co.Close()
+	return c.ExchangeWithConn(m, co)
+}
+
+// ExchangeWithConn has the same behavior as Exchange, just with a predetermined connection
+// that will be used instead of creating a new one.
+// Usage pattern with a *dns.Client:
+//
+//	c := new(dns.Client)
+//	// connection management logic goes here
+//
+//	conn := c.Dial(address)
+//	in, rtt, err := c.ExchangeWithConn(message, conn)
+//
+// This allows users of the library to implement their own connection management,
+// as opposed to Exchange, which will always use new connections and incur the added overhead
+// that entails when using "tcp" and especially "tcp-tls" clients.
+//
+// When the singleflight is set for this client the context is _not_ forwarded to the (shared) exchange, to
+// prevent one cancelation from canceling all outstanding requests.
+func (c *Client) ExchangeWithConn(m *Msg, conn *Conn) (r *Msg, rtt time.Duration, err error) {
+	return c.exchangeWithConnContext(context.Background(), m, conn)
+}
+
+func (c *Client) exchangeWithConnContext(ctx context.Context, m *Msg, conn *Conn) (r *Msg, rtt time.Duration, err error) {
+	if !c.SingleInflight {
+		return c.exchangeContext(ctx, m, conn)
+	}
+
+	q := m.Question[0]
+	key := fmt.Sprintf("%s:%d:%d", q.Name, q.Qtype, q.Qclass)
+	r, rtt, err, shared := c.group.Do(key, func() (*Msg, time.Duration, error) {
+		// When we're doing singleflight we don't want one context cancelation, cancel _all_ outstanding queries.
+		// Hence we ignore the context and use Background().
+		return c.exchangeContext(context.Background(), m, conn)
+	})
+	if r != nil && shared {
+		r = r.Copy()
+	}
+
+	return r, rtt, err
+}
+
+func (c *Client) exchangeContext(ctx context.Context, m *Msg, co *Conn) (r *Msg, rtt time.Duration, err error) {
+	opt := m.IsEdns0()
+	// If EDNS0 is used use that for size.
+	if opt != nil && opt.UDPSize() >= MinMsgSize {
+		co.UDPSize = opt.UDPSize()
+	}
+	// Otherwise use the client's configured UDP size.
+	if opt == nil && c.UDPSize >= MinMsgSize {
+		co.UDPSize = c.UDPSize
+	}
+
+	// write with the appropriate write timeout
+	t := time.Now()
+	writeDeadline := t.Add(c.getTimeoutForRequest(c.writeTimeout()))
+	readDeadline := t.Add(c.getTimeoutForRequest(c.readTimeout()))
+	if deadline, ok := ctx.Deadline(); ok {
+		if deadline.Before(writeDeadline) {
+			writeDeadline = deadline
+		}
+		if deadline.Before(readDeadline) {
+			readDeadline = deadline
+		}
+	}
+	co.SetWriteDeadline(writeDeadline)
+	co.SetReadDeadline(readDeadline)
+
+	co.TsigSecret, co.TsigProvider = c.TsigSecret, c.TsigProvider
+
+	if err = co.WriteMsg(m); err != nil {
+		return nil, 0, err
+	}
+
+	if isPacketConn(co.Conn) {
+		for {
+			r, err = co.ReadMsg()
+			// Ignore replies with mismatched IDs because they might be
+			// responses to earlier queries that timed out.
+			if err != nil || r.Id == m.Id {
+				break
+			}
+		}
+	} else {
+		r, err = co.ReadMsg()
+		if err == nil && r.Id != m.Id {
+			err = ErrId
+		}
+	}
+	rtt = time.Since(t)
+	return r, rtt, err
+}
+
+// ReadMsg reads a message from the connection co.
+// If the received message contains a TSIG record the transaction signature
+// is verified. This method always tries to return the message, however if an
+// error is returned there are no guarantees that the returned message is a
+// valid representation of the packet read.
+func (co *Conn) ReadMsg() (*Msg, error) {
+	p, err := co.ReadMsgHeader(nil)
+	if err != nil {
+		return nil, err
+	}
+
+	m := new(Msg)
+	if err := m.Unpack(p); err != nil {
+		// If an error was returned, we still want to allow the user to use
+		// the message, but naively they can just check err if they don't want
+		// to use an erroneous message
+		return m, err
+	}
+	if t := m.IsTsig(); t != nil {
+		// Need to work on the original message p, as that was used to calculate the tsig.
+		err = tsigVerifyProvider(p, co.tsigProvider(), co.tsigRequestMAC, false)
+	}
+	return m, err
+}
+
+// ReadMsgHeader reads a DNS message, parses and populates hdr (when hdr is not nil).
+// Returns message as a byte slice to be parsed with Msg.Unpack later on.
+// Note that error handling on the message body is not possible as only the header is parsed.
+func (co *Conn) ReadMsgHeader(hdr *Header) ([]byte, error) {
+	var (
+		p   []byte
+		n   int
+		err error
+	)
+
+	if isPacketConn(co.Conn) {
+		if co.UDPSize > MinMsgSize {
+			p = make([]byte, co.UDPSize)
+		} else {
+			p = make([]byte, MinMsgSize)
+		}
+		n, err = co.Read(p)
+	} else {
+		var length uint16
+		if err := binary.Read(co.Conn, binary.BigEndian, &length); err != nil {
+			return nil, err
+		}
+
+		p = make([]byte, length)
+		n, err = io.ReadFull(co.Conn, p)
+	}
+
+	if err != nil {
+		return nil, err
+	} else if n < headerSize {
+		return nil, ErrShortRead
+	}
+
+	p = p[:n]
+	if hdr != nil {
+		dh, _, err := unpackMsgHdr(p, 0)
+		if err != nil {
+			return nil, err
+		}
+		*hdr = dh
+	}
+	return p, err
+}
+
+// Read implements the net.Conn read method.
+func (co *Conn) Read(p []byte) (n int, err error) {
+	if co.Conn == nil {
+		return 0, ErrConnEmpty
+	}
+
+	if isPacketConn(co.Conn) {
+		// UDP connection
+		return co.Conn.Read(p)
+	}
+
+	var length uint16
+	if err := binary.Read(co.Conn, binary.BigEndian, &length); err != nil {
+		return 0, err
+	}
+	if int(length) > len(p) {
+		return 0, io.ErrShortBuffer
+	}
+
+	return io.ReadFull(co.Conn, p[:length])
+}
+
+// WriteMsg sends a message through the connection co.
+// If the message m contains a TSIG record the transaction
+// signature is calculated.
+func (co *Conn) WriteMsg(m *Msg) (err error) {
+	var out []byte
+	if t := m.IsTsig(); t != nil {
+		// Set tsigRequestMAC for the next read, although only used in zone transfers.
+		out, co.tsigRequestMAC, err = tsigGenerateProvider(m, co.tsigProvider(), co.tsigRequestMAC, false)
+	} else {
+		out, err = m.Pack()
+	}
+	if err != nil {
+		return err
+	}
+	_, err = co.Write(out)
+	return err
+}
+
+// Write implements the net.Conn Write method.
+func (co *Conn) Write(p []byte) (int, error) {
+	if len(p) > MaxMsgSize {
+		return 0, &Error{err: "message too large"}
+	}
+
+	if isPacketConn(co.Conn) {
+		return co.Conn.Write(p)
+	}
+
+	msg := make([]byte, 2+len(p))
+	binary.BigEndian.PutUint16(msg, uint16(len(p)))
+	copy(msg[2:], p)
+	return co.Conn.Write(msg)
+}
+
+// Return the appropriate timeout for a specific request
+func (c *Client) getTimeoutForRequest(timeout time.Duration) time.Duration {
+	var requestTimeout time.Duration
+	if c.Timeout != 0 {
+		requestTimeout = c.Timeout
+	} else {
+		requestTimeout = timeout
+	}
+	// net.Dialer.Timeout has priority if smaller than the timeouts computed so
+	// far
+	if c.Dialer != nil && c.Dialer.Timeout != 0 {
+		if c.Dialer.Timeout < requestTimeout {
+			requestTimeout = c.Dialer.Timeout
+		}
+	}
+	return requestTimeout
+}
+
+// Dial connects to the address on the named network.
+func Dial(network, address string) (conn *Conn, err error) {
+	conn = new(Conn)
+	conn.Conn, err = net.Dial(network, address)
+	if err != nil {
+		return nil, err
+	}
+	return conn, nil
+}
+
+// ExchangeContext performs a synchronous UDP query, like Exchange. It
+// additionally obeys deadlines from the passed Context.
+func ExchangeContext(ctx context.Context, m *Msg, a string) (r *Msg, err error) {
+	client := Client{Net: "udp"}
+	r, _, err = client.ExchangeContext(ctx, m, a)
+	// ignoring rtt to leave the original ExchangeContext API unchanged, but
+	// this function will go away
+	return r, err
+}
+
+// ExchangeConn performs a synchronous query. It sends the message m via the connection
+// c and waits for a reply. The connection c is not closed by ExchangeConn.
+// Deprecated: This function is going away, but can easily be mimicked:
+//
+//	co := &dns.Conn{Conn: c} // c is your net.Conn
+//	co.WriteMsg(m)
+//	in, _  := co.ReadMsg()
+//	co.Close()
+//
+func ExchangeConn(c net.Conn, m *Msg) (r *Msg, err error) {
+	println("dns: ExchangeConn: this function is deprecated")
+	co := new(Conn)
+	co.Conn = c
+	if err = co.WriteMsg(m); err != nil {
+		return nil, err
+	}
+	r, err = co.ReadMsg()
+	if err == nil && r.Id != m.Id {
+		err = ErrId
+	}
+	return r, err
+}
+
+// DialTimeout acts like Dial but takes a timeout.
+func DialTimeout(network, address string, timeout time.Duration) (conn *Conn, err error) {
+	client := Client{Net: network, Dialer: &net.Dialer{Timeout: timeout}}
+	return client.Dial(address)
+}
+
+// DialWithTLS connects to the address on the named network with TLS.
+func DialWithTLS(network, address string, tlsConfig *tls.Config) (conn *Conn, err error) {
+	if !strings.HasSuffix(network, "-tls") {
+		network += "-tls"
+	}
+	client := Client{Net: network, TLSConfig: tlsConfig}
+	return client.Dial(address)
+}
+
+// DialTimeoutWithTLS acts like DialWithTLS but takes a timeout.
+func DialTimeoutWithTLS(network, address string, tlsConfig *tls.Config, timeout time.Duration) (conn *Conn, err error) {
+	if !strings.HasSuffix(network, "-tls") {
+		network += "-tls"
+	}
+	client := Client{Net: network, Dialer: &net.Dialer{Timeout: timeout}, TLSConfig: tlsConfig}
+	return client.Dial(address)
+}
+
+// ExchangeContext acts like Exchange, but honors the deadline on the provided
+// context, if present. If there is both a context deadline and a configured
+// timeout on the client, the earliest of the two takes effect.
+func (c *Client) ExchangeContext(ctx context.Context, m *Msg, a string) (r *Msg, rtt time.Duration, err error) {
+	conn, err := c.DialContext(ctx, a)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer conn.Close()
+
+	return c.exchangeWithConnContext(ctx, m, conn)
+}

vendor/github.com/miekg/dns/clientconfig.go

@@ -0,0 +1,135 @@
+package dns
+
+import (
+	"bufio"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// ClientConfig wraps the contents of the /etc/resolv.conf file.
+type ClientConfig struct {
+	Servers  []string // servers to use
+	Search   []string // suffixes to append to local name
+	Port     string   // what port to use
+	Ndots    int      // number of dots in name to trigger absolute lookup
+	Timeout  int      // seconds before giving up on packet
+	Attempts int      // lost packets before giving up on server, not used in the package dns
+}
+
+// ClientConfigFromFile parses a resolv.conf(5) like file and returns
+// a *ClientConfig.
+func ClientConfigFromFile(resolvconf string) (*ClientConfig, error) {
+	file, err := os.Open(resolvconf)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	return ClientConfigFromReader(file)
+}
+
+// ClientConfigFromReader works like ClientConfigFromFile but takes an io.Reader as argument
+func ClientConfigFromReader(resolvconf io.Reader) (*ClientConfig, error) {
+	c := new(ClientConfig)
+	scanner := bufio.NewScanner(resolvconf)
+	c.Servers = make([]string, 0)
+	c.Search = make([]string, 0)
+	c.Port = "53"
+	c.Ndots = 1
+	c.Timeout = 5
+	c.Attempts = 2
+
+	for scanner.Scan() {
+		if err := scanner.Err(); err != nil {
+			return nil, err
+		}
+		line := scanner.Text()
+		f := strings.Fields(line)
+		if len(f) < 1 {
+			continue
+		}
+		switch f[0] {
+		case "nameserver": // add one name server
+			if len(f) > 1 {
+				// One more check: make sure server name is
+				// just an IP address.  Otherwise we need DNS
+				// to look it up.
+				name := f[1]
+				c.Servers = append(c.Servers, name)
+			}
+
+		case "domain": // set search path to just this domain
+			if len(f) > 1 {
+				c.Search = make([]string, 1)
+				c.Search[0] = f[1]
+			} else {
+				c.Search = make([]string, 0)
+			}
+
+		case "search": // set search path to given servers
+			c.Search = append([]string(nil), f[1:]...)
+
+		case "options": // magic options
+			for _, s := range f[1:] {
+				switch {
+				case len(s) >= 6 && s[:6] == "ndots:":
+					n, _ := strconv.Atoi(s[6:])
+					if n < 0 {
+						n = 0
+					} else if n > 15 {
+						n = 15
+					}
+					c.Ndots = n
+				case len(s) >= 8 && s[:8] == "timeout:":
+					n, _ := strconv.Atoi(s[8:])
+					if n < 1 {
+						n = 1
+					}
+					c.Timeout = n
+				case len(s) >= 9 && s[:9] == "attempts:":
+					n, _ := strconv.Atoi(s[9:])
+					if n < 1 {
+						n = 1
+					}
+					c.Attempts = n
+				case s == "rotate":
+					/* not imp */
+				}
+			}
+		}
+	}
+	return c, nil
+}
+
+// NameList returns all of the names that should be queried based on the
+// config. It is based off of go's net/dns name building, but it does not
+// check the length of the resulting names.
+func (c *ClientConfig) NameList(name string) []string {
+	// if this domain is already fully qualified, no append needed.
+	if IsFqdn(name) {
+		return []string{name}
+	}
+
+	// Check to see if the name has more labels than Ndots. Do this before making
+	// the domain fully qualified.
+	hasNdots := CountLabel(name) > c.Ndots
+	// Make the domain fully qualified.
+	name = Fqdn(name)
+
+	// Make a list of names based off search.
+	names := []string{}
+
+	// If name has enough dots, try that first.
+	if hasNdots {
+		names = append(names, name)
+	}
+	for _, s := range c.Search {
+		names = append(names, Fqdn(name+s))
+	}
+	// If we didn't have enough dots, try after suffixes.
+	if !hasNdots {
+		names = append(names, name)
+	}
+	return names
+}

vendor/github.com/miekg/dns/dane.go

@@ -0,0 +1,43 @@
+package dns
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"crypto/x509"
+	"encoding/hex"
+	"errors"
+)
+
+// CertificateToDANE converts a certificate to a hex string as used in the TLSA or SMIMEA records.
+func CertificateToDANE(selector, matchingType uint8, cert *x509.Certificate) (string, error) {
+	switch matchingType {
+	case 0:
+		switch selector {
+		case 0:
+			return hex.EncodeToString(cert.Raw), nil
+		case 1:
+			return hex.EncodeToString(cert.RawSubjectPublicKeyInfo), nil
+		}
+	case 1:
+		h := sha256.New()
+		switch selector {
+		case 0:
+			h.Write(cert.Raw)
+			return hex.EncodeToString(h.Sum(nil)), nil
+		case 1:
+			h.Write(cert.RawSubjectPublicKeyInfo)
+			return hex.EncodeToString(h.Sum(nil)), nil
+		}
+	case 2:
+		h := sha512.New()
+		switch selector {
+		case 0:
+			h.Write(cert.Raw)
+			return hex.EncodeToString(h.Sum(nil)), nil
+		case 1:
+			h.Write(cert.RawSubjectPublicKeyInfo)
+			return hex.EncodeToString(h.Sum(nil)), nil
+		}
+	}
+	return "", errors.New("dns: bad MatchingType or Selector")
+}

vendor/github.com/miekg/dns/defaults.go

@@ -0,0 +1,381 @@
+package dns
+
+import (
+	"errors"
+	"net"
+	"strconv"
+	"strings"
+)
+
+const hexDigit = "0123456789abcdef"
+
+// Everything is assumed in ClassINET.
+
+// SetReply creates a reply message from a request message.
+func (dns *Msg) SetReply(request *Msg) *Msg {
+	dns.Id = request.Id
+	dns.Response = true
+	dns.Opcode = request.Opcode
+	if dns.Opcode == OpcodeQuery {
+		dns.RecursionDesired = request.RecursionDesired // Copy rd bit
+		dns.CheckingDisabled = request.CheckingDisabled // Copy cd bit
+	}
+	dns.Rcode = RcodeSuccess
+	if len(request.Question) > 0 {
+		dns.Question = make([]Question, 1)
+		dns.Question[0] = request.Question[0]
+	}
+	return dns
+}
+
+// SetQuestion creates a question message, it sets the Question
+// section, generates an Id and sets the RecursionDesired (RD)
+// bit to true.
+func (dns *Msg) SetQuestion(z string, t uint16) *Msg {
+	dns.Id = Id()
+	dns.RecursionDesired = true
+	dns.Question = make([]Question, 1)
+	dns.Question[0] = Question{z, t, ClassINET}
+	return dns
+}
+
+// SetNotify creates a notify message, it sets the Question
+// section, generates an Id and sets the Authoritative (AA)
+// bit to true.
+func (dns *Msg) SetNotify(z string) *Msg {
+	dns.Opcode = OpcodeNotify
+	dns.Authoritative = true
+	dns.Id = Id()
+	dns.Question = make([]Question, 1)
+	dns.Question[0] = Question{z, TypeSOA, ClassINET}
+	return dns
+}
+
+// SetRcode creates an error message suitable for the request.
+func (dns *Msg) SetRcode(request *Msg, rcode int) *Msg {
+	dns.SetReply(request)
+	dns.Rcode = rcode
+	return dns
+}
+
+// SetRcodeFormatError creates a message with FormError set.
+func (dns *Msg) SetRcodeFormatError(request *Msg) *Msg {
+	dns.Rcode = RcodeFormatError
+	dns.Opcode = OpcodeQuery
+	dns.Response = true
+	dns.Authoritative = false
+	dns.Id = request.Id
+	return dns
+}
+
+// SetUpdate makes the message a dynamic update message. It
+// sets the ZONE section to: z, TypeSOA, ClassINET.
+func (dns *Msg) SetUpdate(z string) *Msg {
+	dns.Id = Id()
+	dns.Response = false
+	dns.Opcode = OpcodeUpdate
+	dns.Compress = false // BIND9 cannot handle compression
+	dns.Question = make([]Question, 1)
+	dns.Question[0] = Question{z, TypeSOA, ClassINET}
+	return dns
+}
+
+// SetIxfr creates message for requesting an IXFR.
+func (dns *Msg) SetIxfr(z string, serial uint32, ns, mbox string) *Msg {
+	dns.Id = Id()
+	dns.Question = make([]Question, 1)
+	dns.Ns = make([]RR, 1)
+	s := new(SOA)
+	s.Hdr = RR_Header{z, TypeSOA, ClassINET, defaultTtl, 0}
+	s.Serial = serial
+	s.Ns = ns
+	s.Mbox = mbox
+	dns.Question[0] = Question{z, TypeIXFR, ClassINET}
+	dns.Ns[0] = s
+	return dns
+}
+
+// SetAxfr creates message for requesting an AXFR.
+func (dns *Msg) SetAxfr(z string) *Msg {
+	dns.Id = Id()
+	dns.Question = make([]Question, 1)
+	dns.Question[0] = Question{z, TypeAXFR, ClassINET}
+	return dns
+}
+
+// SetTsig appends a TSIG RR to the message.
+// This is only a skeleton TSIG RR that is added as the last RR in the
+// additional section. The TSIG is calculated when the message is being send.
+func (dns *Msg) SetTsig(z, algo string, fudge uint16, timesigned int64) *Msg {
+	t := new(TSIG)
+	t.Hdr = RR_Header{z, TypeTSIG, ClassANY, 0, 0}
+	t.Algorithm = algo
+	t.Fudge = fudge
+	t.TimeSigned = uint64(timesigned)
+	t.OrigId = dns.Id
+	dns.Extra = append(dns.Extra, t)
+	return dns
+}
+
+// SetEdns0 appends a EDNS0 OPT RR to the message.
+// TSIG should always the last RR in a message.
+func (dns *Msg) SetEdns0(udpsize uint16, do bool) *Msg {
+	e := new(OPT)
+	e.Hdr.Name = "."
+	e.Hdr.Rrtype = TypeOPT
+	e.SetUDPSize(udpsize)
+	if do {
+		e.SetDo()
+	}
+	dns.Extra = append(dns.Extra, e)
+	return dns
+}
+
+// IsTsig checks if the message has a TSIG record as the last record
+// in the additional section. It returns the TSIG record found or nil.
+func (dns *Msg) IsTsig() *TSIG {
+	if len(dns.Extra) > 0 {
+		if dns.Extra[len(dns.Extra)-1].Header().Rrtype == TypeTSIG {
+			return dns.Extra[len(dns.Extra)-1].(*TSIG)
+		}
+	}
+	return nil
+}
+
+// IsEdns0 checks if the message has a EDNS0 (OPT) record, any EDNS0
+// record in the additional section will do. It returns the OPT record
+// found or nil.
+func (dns *Msg) IsEdns0() *OPT {
+	// RFC 6891, Section 6.1.1 allows the OPT record to appear
+	// anywhere in the additional record section, but it's usually at
+	// the end so start there.
+	for i := len(dns.Extra) - 1; i >= 0; i-- {
+		if dns.Extra[i].Header().Rrtype == TypeOPT {
+			return dns.Extra[i].(*OPT)
+		}
+	}
+	return nil
+}
+
+// popEdns0 is like IsEdns0, but it removes the record from the message.
+func (dns *Msg) popEdns0() *OPT {
+	// RFC 6891, Section 6.1.1 allows the OPT record to appear
+	// anywhere in the additional record section, but it's usually at
+	// the end so start there.
+	for i := len(dns.Extra) - 1; i >= 0; i-- {
+		if dns.Extra[i].Header().Rrtype == TypeOPT {
+			opt := dns.Extra[i].(*OPT)
+			dns.Extra = append(dns.Extra[:i], dns.Extra[i+1:]...)
+			return opt
+		}
+	}
+	return nil
+}
+
+// IsDomainName checks if s is a valid domain name, it returns the number of
+// labels and true, when a domain name is valid.  Note that non fully qualified
+// domain name is considered valid, in this case the last label is counted in
+// the number of labels.  When false is returned the number of labels is not
+// defined.  Also note that this function is extremely liberal; almost any
+// string is a valid domain name as the DNS is 8 bit protocol. It checks if each
+// label fits in 63 characters and that the entire name will fit into the 255
+// octet wire format limit.
+func IsDomainName(s string) (labels int, ok bool) {
+	// XXX: The logic in this function was copied from packDomainName and
+	// should be kept in sync with that function.
+
+	const lenmsg = 256
+
+	if len(s) == 0 { // Ok, for instance when dealing with update RR without any rdata.
+		return 0, false
+	}
+
+	s = Fqdn(s)
+
+	// Each dot ends a segment of the name. Except for escaped dots (\.), which
+	// are normal dots.
+
+	var (
+		off    int
+		begin  int
+		wasDot bool
+	)
+	for i := 0; i < len(s); i++ {
+		switch s[i] {
+		case '\\':
+			if off+1 > lenmsg {
+				return labels, false
+			}
+
+			// check for \DDD
+			if i+3 < len(s) && isDigit(s[i+1]) && isDigit(s[i+2]) && isDigit(s[i+3]) {
+				i += 3
+				begin += 3
+			} else {
+				i++
+				begin++
+			}
+
+			wasDot = false
+		case '.':
+			if wasDot {
+				// two dots back to back is not legal
+				return labels, false
+			}
+			wasDot = true
+
+			labelLen := i - begin
+			if labelLen >= 1<<6 { // top two bits of length must be clear
+				return labels, false
+			}
+
+			// off can already (we're in a loop) be bigger than lenmsg
+			// this happens when a name isn't fully qualified
+			off += 1 + labelLen
+			if off > lenmsg {
+				return labels, false
+			}
+
+			labels++
+			begin = i + 1
+		default:
+			wasDot = false
+		}
+	}
+
+	return labels, true
+}
+
+// IsSubDomain checks if child is indeed a child of the parent. If child and parent
+// are the same domain true is returned as well.
+func IsSubDomain(parent, child string) bool {
+	// Entire child is contained in parent
+	return CompareDomainName(parent, child) == CountLabel(parent)
+}
+
+// IsMsg sanity checks buf and returns an error if it isn't a valid DNS packet.
+// The checking is performed on the binary payload.
+func IsMsg(buf []byte) error {
+	// Header
+	if len(buf) < headerSize {
+		return errors.New("dns: bad message header")
+	}
+	// Header: Opcode
+	// TODO(miek): more checks here, e.g. check all header bits.
+	return nil
+}
+
+// IsFqdn checks if a domain name is fully qualified.
+func IsFqdn(s string) bool {
+	s2 := strings.TrimSuffix(s, ".")
+	if s == s2 {
+		return false
+	}
+
+	i := strings.LastIndexFunc(s2, func(r rune) bool {
+		return r != '\\'
+	})
+
+	// Test whether we have an even number of escape sequences before
+	// the dot or none.
+	return (len(s2)-i)%2 != 0
+}
+
+// IsRRset checks if a set of RRs is a valid RRset as defined by RFC 2181.
+// This means the RRs need to have the same type, name, and class. Returns true
+// if the RR set is valid, otherwise false.
+func IsRRset(rrset []RR) bool {
+	if len(rrset) == 0 {
+		return false
+	}
+	if len(rrset) == 1 {
+		return true
+	}
+	rrHeader := rrset[0].Header()
+	rrType := rrHeader.Rrtype
+	rrClass := rrHeader.Class
+	rrName := rrHeader.Name
+
+	for _, rr := range rrset[1:] {
+		curRRHeader := rr.Header()
+		if curRRHeader.Rrtype != rrType || curRRHeader.Class != rrClass || curRRHeader.Name != rrName {
+			// Mismatch between the records, so this is not a valid rrset for
+			//signing/verifying
+			return false
+		}
+	}
+
+	return true
+}
+
+// Fqdn return the fully qualified domain name from s.
+// If s is already fully qualified, it behaves as the identity function.
+func Fqdn(s string) string {
+	if IsFqdn(s) {
+		return s
+	}
+	return s + "."
+}
+
+// CanonicalName returns the domain name in canonical form. A name in canonical
+// form is lowercase and fully qualified. See Section 6.2 in RFC 4034.
+func CanonicalName(s string) string {
+	return strings.ToLower(Fqdn(s))
+}
+
+// Copied from the official Go code.
+
+// ReverseAddr returns the in-addr.arpa. or ip6.arpa. hostname of the IP
+// address suitable for reverse DNS (PTR) record lookups or an error if it fails
+// to parse the IP address.
+func ReverseAddr(addr string) (arpa string, err error) {
+	ip := net.ParseIP(addr)
+	if ip == nil {
+		return "", &Error{err: "unrecognized address: " + addr}
+	}
+	if v4 := ip.To4(); v4 != nil {
+		buf := make([]byte, 0, net.IPv4len*4+len("in-addr.arpa."))
+		// Add it, in reverse, to the buffer
+		for i := len(v4) - 1; i >= 0; i-- {
+			buf = strconv.AppendInt(buf, int64(v4[i]), 10)
+			buf = append(buf, '.')
+		}
+		// Append "in-addr.arpa." and return (buf already has the final .)
+		buf = append(buf, "in-addr.arpa."...)
+		return string(buf), nil
+	}
+	// Must be IPv6
+	buf := make([]byte, 0, net.IPv6len*4+len("ip6.arpa."))
+	// Add it, in reverse, to the buffer
+	for i := len(ip) - 1; i >= 0; i-- {
+		v := ip[i]
+		buf = append(buf, hexDigit[v&0xF], '.', hexDigit[v>>4], '.')
+	}
+	// Append "ip6.arpa." and return (buf already has the final .)
+	buf = append(buf, "ip6.arpa."...)
+	return string(buf), nil
+}
+
+// String returns the string representation for the type t.
+func (t Type) String() string {
+	if t1, ok := TypeToString[uint16(t)]; ok {
+		return t1
+	}
+	return "TYPE" + strconv.Itoa(int(t))
+}
+
+// String returns the string representation for the class c.
+func (c Class) String() string {
+	if s, ok := ClassToString[uint16(c)]; ok {
+		// Only emit mnemonics when they are unambiguous, specially ANY is in both.
+		if _, ok := StringToType[s]; !ok {
+			return s
+		}
+	}
+	return "CLASS" + strconv.Itoa(int(c))
+}
+
+// String returns the string representation for the name n.
+func (n Name) String() string {
+	return sprintName(string(n))
+}

vendor/github.com/miekg/dns/dns.go

@@ -0,0 +1,158 @@
+package dns
+
+import (
+	"encoding/hex"
+	"strconv"
+)
+
+const (
+	year68     = 1 << 31 // For RFC1982 (Serial Arithmetic) calculations in 32 bits.
+	defaultTtl = 3600    // Default internal TTL.
+
+	// DefaultMsgSize is the standard default for messages larger than 512 bytes.
+	DefaultMsgSize = 4096
+	// MinMsgSize is the minimal size of a DNS packet.
+	MinMsgSize = 512
+	// MaxMsgSize is the largest possible DNS packet.
+	MaxMsgSize = 65535
+)
+
+// Error represents a DNS error.
+type Error struct{ err string }
+
+func (e *Error) Error() string {
+	if e == nil {
+		return "dns: <nil>"
+	}
+	return "dns: " + e.err
+}
+
+// An RR represents a resource record.
+type RR interface {
+	// Header returns the header of an resource record. The header contains
+	// everything up to the rdata.
+	Header() *RR_Header
+	// String returns the text representation of the resource record.
+	String() string
+
+	// copy returns a copy of the RR
+	copy() RR
+
+	// len returns the length (in octets) of the compressed or uncompressed RR in wire format.
+	//
+	// If compression is nil, the uncompressed size will be returned, otherwise the compressed
+	// size will be returned and domain names will be added to the map for future compression.
+	len(off int, compression map[string]struct{}) int
+
+	// pack packs the records RDATA into wire format. The header will
+	// already have been packed into msg.
+	pack(msg []byte, off int, compression compressionMap, compress bool) (off1 int, err error)
+
+	// unpack unpacks an RR from wire format.
+	//
+	// This will only be called on a new and empty RR type with only the header populated. It
+	// will only be called if the record's RDATA is non-empty.
+	unpack(msg []byte, off int) (off1 int, err error)
+
+	// parse parses an RR from zone file format.
+	//
+	// This will only be called on a new and empty RR type with only the header populated.
+	parse(c *zlexer, origin string) *ParseError
+
+	// isDuplicate returns whether the two RRs are duplicates.
+	isDuplicate(r2 RR) bool
+}
+
+// RR_Header is the header all DNS resource records share.
+type RR_Header struct {
+	Name     string `dns:"cdomain-name"`
+	Rrtype   uint16
+	Class    uint16
+	Ttl      uint32
+	Rdlength uint16 // Length of data after header.
+}
+
+// Header returns itself. This is here to make RR_Header implements the RR interface.
+func (h *RR_Header) Header() *RR_Header { return h }
+
+// Just to implement the RR interface.
+func (h *RR_Header) copy() RR { return nil }
+
+func (h *RR_Header) String() string {
+	var s string
+
+	if h.Rrtype == TypeOPT {
+		s = ";"
+		// and maybe other things
+	}
+
+	s += sprintName(h.Name) + "\t"
+	s += strconv.FormatInt(int64(h.Ttl), 10) + "\t"
+	s += Class(h.Class).String() + "\t"
+	s += Type(h.Rrtype).String() + "\t"
+	return s
+}
+
+func (h *RR_Header) len(off int, compression map[string]struct{}) int {
+	l := domainNameLen(h.Name, off, compression, true)
+	l += 10 // rrtype(2) + class(2) + ttl(4) + rdlength(2)
+	return l
+}
+
+func (h *RR_Header) pack(msg []byte, off int, compression compressionMap, compress bool) (off1 int, err error) {
+	// RR_Header has no RDATA to pack.
+	return off, nil
+}
+
+func (h *RR_Header) unpack(msg []byte, off int) (int, error) {
+	panic("dns: internal error: unpack should never be called on RR_Header")
+}
+
+func (h *RR_Header) parse(c *zlexer, origin string) *ParseError {
+	panic("dns: internal error: parse should never be called on RR_Header")
+}
+
+// ToRFC3597 converts a known RR to the unknown RR representation from RFC 3597.
+func (rr *RFC3597) ToRFC3597(r RR) error {
+	buf := make([]byte, Len(r))
+	headerEnd, off, err := packRR(r, buf, 0, compressionMap{}, false)
+	if err != nil {
+		return err
+	}
+	buf = buf[:off]
+
+	*rr = RFC3597{Hdr: *r.Header()}
+	rr.Hdr.Rdlength = uint16(off - headerEnd)
+
+	if noRdata(rr.Hdr) {
+		return nil
+	}
+
+	_, err = rr.unpack(buf, headerEnd)
+	return err
+}
+
+// fromRFC3597 converts an unknown RR representation from RFC 3597 to the known RR type.
+func (rr *RFC3597) fromRFC3597(r RR) error {
+	hdr := r.Header()
+	*hdr = rr.Hdr
+
+	// Can't overflow uint16 as the length of Rdata is validated in (*RFC3597).parse.
+	// We can only get here when rr was constructed with that method.
+	hdr.Rdlength = uint16(hex.DecodedLen(len(rr.Rdata)))
+
+	if noRdata(*hdr) {
+		// Dynamic update.
+		return nil
+	}
+
+	// rr.pack requires an extra allocation and a copy so we just decode Rdata
+	// manually, it's simpler anyway.
+	msg, err := hex.DecodeString(rr.Rdata)
+	if err != nil {
+		return err
+	}
+
+	_, err = r.unpack(msg, 0)
+	return err
+}

vendor/github.com/miekg/dns/dnssec.go

@@ -0,0 +1,749 @@
+package dns
+
+import (
+	"bytes"
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	_ "crypto/sha1"   // need its init function
+	_ "crypto/sha256" // need its init function
+	_ "crypto/sha512" // need its init function
+	"encoding/asn1"
+	"encoding/binary"
+	"encoding/hex"
+	"math/big"
+	"sort"
+	"strings"
+	"time"
+)
+
+// DNSSEC encryption algorithm codes.
+const (
+	_ uint8 = iota
+	RSAMD5
+	DH
+	DSA
+	_ // Skip 4, RFC 6725, section 2.1
+	RSASHA1
+	DSANSEC3SHA1
+	RSASHA1NSEC3SHA1
+	RSASHA256
+	_ // Skip 9, RFC 6725, section 2.1
+	RSASHA512
+	_ // Skip 11, RFC 6725, section 2.1
+	ECCGOST
+	ECDSAP256SHA256
+	ECDSAP384SHA384
+	ED25519
+	ED448
+	INDIRECT   uint8 = 252
+	PRIVATEDNS uint8 = 253 // Private (experimental keys)
+	PRIVATEOID uint8 = 254
+)
+
+// AlgorithmToString is a map of algorithm IDs to algorithm names.
+var AlgorithmToString = map[uint8]string{
+	RSAMD5:           "RSAMD5",
+	DH:               "DH",
+	DSA:              "DSA",
+	RSASHA1:          "RSASHA1",
+	DSANSEC3SHA1:     "DSA-NSEC3-SHA1",
+	RSASHA1NSEC3SHA1: "RSASHA1-NSEC3-SHA1",
+	RSASHA256:        "RSASHA256",
+	RSASHA512:        "RSASHA512",
+	ECCGOST:          "ECC-GOST",
+	ECDSAP256SHA256:  "ECDSAP256SHA256",
+	ECDSAP384SHA384:  "ECDSAP384SHA384",
+	ED25519:          "ED25519",
+	ED448:            "ED448",
+	INDIRECT:         "INDIRECT",
+	PRIVATEDNS:       "PRIVATEDNS",
+	PRIVATEOID:       "PRIVATEOID",
+}
+
+// AlgorithmToHash is a map of algorithm crypto hash IDs to crypto.Hash's.
+// For newer algorithm that do their own hashing (i.e. ED25519) the returned value
+// is 0, implying no (external) hashing should occur. The non-exported identityHash is then
+// used.
+var AlgorithmToHash = map[uint8]crypto.Hash{
+	RSAMD5:           crypto.MD5, // Deprecated in RFC 6725
+	DSA:              crypto.SHA1,
+	RSASHA1:          crypto.SHA1,
+	RSASHA1NSEC3SHA1: crypto.SHA1,
+	RSASHA256:        crypto.SHA256,
+	ECDSAP256SHA256:  crypto.SHA256,
+	ECDSAP384SHA384:  crypto.SHA384,
+	RSASHA512:        crypto.SHA512,
+	ED25519:          0,
+}
+
+// DNSSEC hashing algorithm codes.
+const (
+	_      uint8 = iota
+	SHA1         // RFC 4034
+	SHA256       // RFC 4509
+	GOST94       // RFC 5933
+	SHA384       // Experimental
+	SHA512       // Experimental
+)
+
+// HashToString is a map of hash IDs to names.
+var HashToString = map[uint8]string{
+	SHA1:   "SHA1",
+	SHA256: "SHA256",
+	GOST94: "GOST94",
+	SHA384: "SHA384",
+	SHA512: "SHA512",
+}
+
+// DNSKEY flag values.
+const (
+	SEP    = 1
+	REVOKE = 1 << 7
+	ZONE   = 1 << 8
+)
+
+// The RRSIG needs to be converted to wireformat with some of the rdata (the signature) missing.
+type rrsigWireFmt struct {
+	TypeCovered uint16
+	Algorithm   uint8
+	Labels      uint8
+	OrigTtl     uint32
+	Expiration  uint32
+	Inception   uint32
+	KeyTag      uint16
+	SignerName  string `dns:"domain-name"`
+	/* No Signature */
+}
+
+// Used for converting DNSKEY's rdata to wirefmt.
+type dnskeyWireFmt struct {
+	Flags     uint16
+	Protocol  uint8
+	Algorithm uint8
+	PublicKey string `dns:"base64"`
+	/* Nothing is left out */
+}
+
+func divRoundUp(a, b int) int {
+	return (a + b - 1) / b
+}
+
+// KeyTag calculates the keytag (or key-id) of the DNSKEY.
+func (k *DNSKEY) KeyTag() uint16 {
+	if k == nil {
+		return 0
+	}
+	var keytag int
+	switch k.Algorithm {
+	case RSAMD5:
+		// This algorithm has been deprecated, but keep this key-tag calculation.
+		// Look at the bottom two bytes of the modules, which the last item in the pubkey.
+		// See https://www.rfc-editor.org/errata/eid193 .
+		modulus, _ := fromBase64([]byte(k.PublicKey))
+		if len(modulus) > 1 {
+			x := binary.BigEndian.Uint16(modulus[len(modulus)-3:])
+			keytag = int(x)
+		}
+	default:
+		keywire := new(dnskeyWireFmt)
+		keywire.Flags = k.Flags
+		keywire.Protocol = k.Protocol
+		keywire.Algorithm = k.Algorithm
+		keywire.PublicKey = k.PublicKey
+		wire := make([]byte, DefaultMsgSize)
+		n, err := packKeyWire(keywire, wire)
+		if err != nil {
+			return 0
+		}
+		wire = wire[:n]
+		for i, v := range wire {
+			if i&1 != 0 {
+				keytag += int(v) // must be larger than uint32
+			} else {
+				keytag += int(v) << 8
+			}
+		}
+		keytag += keytag >> 16 & 0xFFFF
+		keytag &= 0xFFFF
+	}
+	return uint16(keytag)
+}
+
+// ToDS converts a DNSKEY record to a DS record.
+func (k *DNSKEY) ToDS(h uint8) *DS {
+	if k == nil {
+		return nil
+	}
+	ds := new(DS)
+	ds.Hdr.Name = k.Hdr.Name
+	ds.Hdr.Class = k.Hdr.Class
+	ds.Hdr.Rrtype = TypeDS
+	ds.Hdr.Ttl = k.Hdr.Ttl
+	ds.Algorithm = k.Algorithm
+	ds.DigestType = h
+	ds.KeyTag = k.KeyTag()
+
+	keywire := new(dnskeyWireFmt)
+	keywire.Flags = k.Flags
+	keywire.Protocol = k.Protocol
+	keywire.Algorithm = k.Algorithm
+	keywire.PublicKey = k.PublicKey
+	wire := make([]byte, DefaultMsgSize)
+	n, err := packKeyWire(keywire, wire)
+	if err != nil {
+		return nil
+	}
+	wire = wire[:n]
+
+	owner := make([]byte, 255)
+	off, err1 := PackDomainName(CanonicalName(k.Hdr.Name), owner, 0, nil, false)
+	if err1 != nil {
+		return nil
+	}
+	owner = owner[:off]
+	// RFC4034:
+	// digest = digest_algorithm( DNSKEY owner name | DNSKEY RDATA);
+	// "|" denotes concatenation
+	// DNSKEY RDATA = Flags | Protocol | Algorithm | Public Key.
+
+	var hash crypto.Hash
+	switch h {
+	case SHA1:
+		hash = crypto.SHA1
+	case SHA256:
+		hash = crypto.SHA256
+	case SHA384:
+		hash = crypto.SHA384
+	case SHA512:
+		hash = crypto.SHA512
+	default:
+		return nil
+	}
+
+	s := hash.New()
+	s.Write(owner)
+	s.Write(wire)
+	ds.Digest = hex.EncodeToString(s.Sum(nil))
+	return ds
+}
+
+// ToCDNSKEY converts a DNSKEY record to a CDNSKEY record.
+func (k *DNSKEY) ToCDNSKEY() *CDNSKEY {
+	c := &CDNSKEY{DNSKEY: *k}
+	c.Hdr = k.Hdr
+	c.Hdr.Rrtype = TypeCDNSKEY
+	return c
+}
+
+// ToCDS converts a DS record to a CDS record.
+func (d *DS) ToCDS() *CDS {
+	c := &CDS{DS: *d}
+	c.Hdr = d.Hdr
+	c.Hdr.Rrtype = TypeCDS
+	return c
+}
+
+// Sign signs an RRSet. The signature needs to be filled in with the values:
+// Inception, Expiration, KeyTag, SignerName and Algorithm.  The rest is copied
+// from the RRset. Sign returns a non-nill error when the signing went OK.
+// There is no check if RRSet is a proper (RFC 2181) RRSet.  If OrigTTL is non
+// zero, it is used as-is, otherwise the TTL of the RRset is used as the
+// OrigTTL.
+func (rr *RRSIG) Sign(k crypto.Signer, rrset []RR) error {
+	if k == nil {
+		return ErrPrivKey
+	}
+	// s.Inception and s.Expiration may be 0 (rollover etc.), the rest must be set
+	if rr.KeyTag == 0 || len(rr.SignerName) == 0 || rr.Algorithm == 0 {
+		return ErrKey
+	}
+
+	h0 := rrset[0].Header()
+	rr.Hdr.Rrtype = TypeRRSIG
+	rr.Hdr.Name = h0.Name
+	rr.Hdr.Class = h0.Class
+	if rr.OrigTtl == 0 { // If set don't override
+		rr.OrigTtl = h0.Ttl
+	}
+	rr.TypeCovered = h0.Rrtype
+	rr.Labels = uint8(CountLabel(h0.Name))
+
+	if strings.HasPrefix(h0.Name, "*") {
+		rr.Labels-- // wildcard, remove from label count
+	}
+
+	sigwire := new(rrsigWireFmt)
+	sigwire.TypeCovered = rr.TypeCovered
+	sigwire.Algorithm = rr.Algorithm
+	sigwire.Labels = rr.Labels
+	sigwire.OrigTtl = rr.OrigTtl
+	sigwire.Expiration = rr.Expiration
+	sigwire.Inception = rr.Inception
+	sigwire.KeyTag = rr.KeyTag
+	// For signing, lowercase this name
+	sigwire.SignerName = CanonicalName(rr.SignerName)
+
+	// Create the desired binary blob
+	signdata := make([]byte, DefaultMsgSize)
+	n, err := packSigWire(sigwire, signdata)
+	if err != nil {
+		return err
+	}
+	signdata = signdata[:n]
+	wire, err := rawSignatureData(rrset, rr)
+	if err != nil {
+		return err
+	}
+
+	h, cryptohash, err := hashFromAlgorithm(rr.Algorithm)
+	if err != nil {
+		return err
+	}
+
+	switch rr.Algorithm {
+	case RSAMD5, DSA, DSANSEC3SHA1:
+		// See RFC 6944.
+		return ErrAlg
+	default:
+		h.Write(signdata)
+		h.Write(wire)
+
+		signature, err := sign(k, h.Sum(nil), cryptohash, rr.Algorithm)
+		if err != nil {
+			return err
+		}
+
+		rr.Signature = toBase64(signature)
+		return nil
+	}
+}
+
+func sign(k crypto.Signer, hashed []byte, hash crypto.Hash, alg uint8) ([]byte, error) {
+	signature, err := k.Sign(rand.Reader, hashed, hash)
+	if err != nil {
+		return nil, err
+	}
+
+	switch alg {
+	case RSASHA1, RSASHA1NSEC3SHA1, RSASHA256, RSASHA512, ED25519:
+		return signature, nil
+	case ECDSAP256SHA256, ECDSAP384SHA384:
+		ecdsaSignature := &struct {
+			R, S *big.Int
+		}{}
+		if _, err := asn1.Unmarshal(signature, ecdsaSignature); err != nil {
+			return nil, err
+		}
+
+		var intlen int
+		switch alg {
+		case ECDSAP256SHA256:
+			intlen = 32
+		case ECDSAP384SHA384:
+			intlen = 48
+		}
+
+		signature := intToBytes(ecdsaSignature.R, intlen)
+		signature = append(signature, intToBytes(ecdsaSignature.S, intlen)...)
+		return signature, nil
+	default:
+		return nil, ErrAlg
+	}
+}
+
+// Verify validates an RRSet with the signature and key. This is only the
+// cryptographic test, the signature validity period must be checked separately.
+// This function copies the rdata of some RRs (to lowercase domain names) for the validation to work.
+// It also checks that the Zone Key bit (RFC 4034 2.1.1) is set on the DNSKEY
+// and that the Protocol field is set to 3 (RFC 4034 2.1.2).
+func (rr *RRSIG) Verify(k *DNSKEY, rrset []RR) error {
+	// First the easy checks
+	if !IsRRset(rrset) {
+		return ErrRRset
+	}
+	if rr.KeyTag != k.KeyTag() {
+		return ErrKey
+	}
+	if rr.Hdr.Class != k.Hdr.Class {
+		return ErrKey
+	}
+	if rr.Algorithm != k.Algorithm {
+		return ErrKey
+	}
+	if !strings.EqualFold(rr.SignerName, k.Hdr.Name) {
+		return ErrKey
+	}
+	if k.Protocol != 3 {
+		return ErrKey
+	}
+	// RFC 4034 2.1.1 If bit 7 has value 0, then the DNSKEY record holds some
+	// other type of DNS public key and MUST NOT be used to verify RRSIGs that
+	// cover RRsets.
+	if k.Flags&ZONE == 0 {
+		return ErrKey
+	}
+
+	// IsRRset checked that we have at least one RR and that the RRs in
+	// the set have consistent type, class, and name. Also check that type and
+	// class matches the RRSIG record.
+	if h0 := rrset[0].Header(); h0.Class != rr.Hdr.Class || h0.Rrtype != rr.TypeCovered {
+		return ErrRRset
+	}
+
+	// RFC 4035 5.3.2.  Reconstructing the Signed Data
+	// Copy the sig, except the rrsig data
+	sigwire := new(rrsigWireFmt)
+	sigwire.TypeCovered = rr.TypeCovered
+	sigwire.Algorithm = rr.Algorithm
+	sigwire.Labels = rr.Labels
+	sigwire.OrigTtl = rr.OrigTtl
+	sigwire.Expiration = rr.Expiration
+	sigwire.Inception = rr.Inception
+	sigwire.KeyTag = rr.KeyTag
+	sigwire.SignerName = CanonicalName(rr.SignerName)
+	// Create the desired binary blob
+	signeddata := make([]byte, DefaultMsgSize)
+	n, err := packSigWire(sigwire, signeddata)
+	if err != nil {
+		return err
+	}
+	signeddata = signeddata[:n]
+	wire, err := rawSignatureData(rrset, rr)
+	if err != nil {
+		return err
+	}
+
+	sigbuf := rr.sigBuf()           // Get the binary signature data
+	if rr.Algorithm == PRIVATEDNS { // PRIVATEOID
+		// TODO(miek)
+		// remove the domain name and assume its ours?
+	}
+
+	h, cryptohash, err := hashFromAlgorithm(rr.Algorithm)
+	if err != nil {
+		return err
+	}
+
+	switch rr.Algorithm {
+	case RSASHA1, RSASHA1NSEC3SHA1, RSASHA256, RSASHA512:
+		// TODO(mg): this can be done quicker, ie. cache the pubkey data somewhere??
+		pubkey := k.publicKeyRSA() // Get the key
+		if pubkey == nil {
+			return ErrKey
+		}
+
+		h.Write(signeddata)
+		h.Write(wire)
+		return rsa.VerifyPKCS1v15(pubkey, cryptohash, h.Sum(nil), sigbuf)
+
+	case ECDSAP256SHA256, ECDSAP384SHA384:
+		pubkey := k.publicKeyECDSA()
+		if pubkey == nil {
+			return ErrKey
+		}
+
+		// Split sigbuf into the r and s coordinates
+		r := new(big.Int).SetBytes(sigbuf[:len(sigbuf)/2])
+		s := new(big.Int).SetBytes(sigbuf[len(sigbuf)/2:])
+
+		h.Write(signeddata)
+		h.Write(wire)
+		if ecdsa.Verify(pubkey, h.Sum(nil), r, s) {
+			return nil
+		}
+		return ErrSig
+
+	case ED25519:
+		pubkey := k.publicKeyED25519()
+		if pubkey == nil {
+			return ErrKey
+		}
+
+		if ed25519.Verify(pubkey, append(signeddata, wire...), sigbuf) {
+			return nil
+		}
+		return ErrSig
+
+	default:
+		return ErrAlg
+	}
+}
+
+// ValidityPeriod uses RFC1982 serial arithmetic to calculate
+// if a signature period is valid. If t is the zero time, the
+// current time is taken other t is. Returns true if the signature
+// is valid at the given time, otherwise returns false.
+func (rr *RRSIG) ValidityPeriod(t time.Time) bool {
+	var utc int64
+	if t.IsZero() {
+		utc = time.Now().UTC().Unix()
+	} else {
+		utc = t.UTC().Unix()
+	}
+	modi := (int64(rr.Inception) - utc) / year68
+	mode := (int64(rr.Expiration) - utc) / year68
+	ti := int64(rr.Inception) + modi*year68
+	te := int64(rr.Expiration) + mode*year68
+	return ti <= utc && utc <= te
+}
+
+// Return the signatures base64 encoding sigdata as a byte slice.
+func (rr *RRSIG) sigBuf() []byte {
+	sigbuf, err := fromBase64([]byte(rr.Signature))
+	if err != nil {
+		return nil
+	}
+	return sigbuf
+}
+
+// publicKeyRSA returns the RSA public key from a DNSKEY record.
+func (k *DNSKEY) publicKeyRSA() *rsa.PublicKey {
+	keybuf, err := fromBase64([]byte(k.PublicKey))
+	if err != nil {
+		return nil
+	}
+
+	if len(keybuf) < 1+1+64 {
+		// Exponent must be at least 1 byte and modulus at least 64
+		return nil
+	}
+
+	// RFC 2537/3110, section 2. RSA Public KEY Resource Records
+	// Length is in the 0th byte, unless its zero, then it
+	// it in bytes 1 and 2 and its a 16 bit number
+	explen := uint16(keybuf[0])
+	keyoff := 1
+	if explen == 0 {
+		explen = uint16(keybuf[1])<<8 | uint16(keybuf[2])
+		keyoff = 3
+	}
+
+	if explen > 4 || explen == 0 || keybuf[keyoff] == 0 {
+		// Exponent larger than supported by the crypto package,
+		// empty, or contains prohibited leading zero.
+		return nil
+	}
+
+	modoff := keyoff + int(explen)
+	modlen := len(keybuf) - modoff
+	if modlen < 64 || modlen > 512 || keybuf[modoff] == 0 {
+		// Modulus is too small, large, or contains prohibited leading zero.
+		return nil
+	}
+
+	pubkey := new(rsa.PublicKey)
+
+	var expo uint64
+	// The exponent of length explen is between keyoff and modoff.
+	for _, v := range keybuf[keyoff:modoff] {
+		expo <<= 8
+		expo |= uint64(v)
+	}
+	if expo > 1<<31-1 {
+		// Larger exponent than supported by the crypto package.
+		return nil
+	}
+
+	pubkey.E = int(expo)
+	pubkey.N = new(big.Int).SetBytes(keybuf[modoff:])
+	return pubkey
+}
+
+// publicKeyECDSA returns the Curve public key from the DNSKEY record.
+func (k *DNSKEY) publicKeyECDSA() *ecdsa.PublicKey {
+	keybuf, err := fromBase64([]byte(k.PublicKey))
+	if err != nil {
+		return nil
+	}
+	pubkey := new(ecdsa.PublicKey)
+	switch k.Algorithm {
+	case ECDSAP256SHA256:
+		pubkey.Curve = elliptic.P256()
+		if len(keybuf) != 64 {
+			// wrongly encoded key
+			return nil
+		}
+	case ECDSAP384SHA384:
+		pubkey.Curve = elliptic.P384()
+		if len(keybuf) != 96 {
+			// Wrongly encoded key
+			return nil
+		}
+	}
+	pubkey.X = new(big.Int).SetBytes(keybuf[:len(keybuf)/2])
+	pubkey.Y = new(big.Int).SetBytes(keybuf[len(keybuf)/2:])
+	return pubkey
+}
+
+func (k *DNSKEY) publicKeyED25519() ed25519.PublicKey {
+	keybuf, err := fromBase64([]byte(k.PublicKey))
+	if err != nil {
+		return nil
+	}
+	if len(keybuf) != ed25519.PublicKeySize {
+		return nil
+	}
+	return keybuf
+}
+
+type wireSlice [][]byte
+
+func (p wireSlice) Len() int      { return len(p) }
+func (p wireSlice) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
+func (p wireSlice) Less(i, j int) bool {
+	_, ioff, _ := UnpackDomainName(p[i], 0)
+	_, joff, _ := UnpackDomainName(p[j], 0)
+	return bytes.Compare(p[i][ioff+10:], p[j][joff+10:]) < 0
+}
+
+// Return the raw signature data.
+func rawSignatureData(rrset []RR, s *RRSIG) (buf []byte, err error) {
+	wires := make(wireSlice, len(rrset))
+	for i, r := range rrset {
+		r1 := r.copy()
+		h := r1.Header()
+		h.Ttl = s.OrigTtl
+		labels := SplitDomainName(h.Name)
+		// 6.2. Canonical RR Form. (4) - wildcards
+		if len(labels) > int(s.Labels) {
+			// Wildcard
+			h.Name = "*." + strings.Join(labels[len(labels)-int(s.Labels):], ".") + "."
+		}
+		// RFC 4034: 6.2.  Canonical RR Form. (2) - domain name to lowercase
+		h.Name = CanonicalName(h.Name)
+		// 6.2. Canonical RR Form. (3) - domain rdata to lowercase.
+		//   NS, MD, MF, CNAME, SOA, MB, MG, MR, PTR,
+		//   HINFO, MINFO, MX, RP, AFSDB, RT, SIG, PX, NXT, NAPTR, KX,
+		//   SRV, DNAME, A6
+		//
+		// RFC 6840 - Clarifications and Implementation Notes for DNS Security (DNSSEC):
+		//	Section 6.2 of [RFC4034] also erroneously lists HINFO as a record
+		//	that needs conversion to lowercase, and twice at that.  Since HINFO
+		//	records contain no domain names, they are not subject to case
+		//	conversion.
+		switch x := r1.(type) {
+		case *NS:
+			x.Ns = CanonicalName(x.Ns)
+		case *MD:
+			x.Md = CanonicalName(x.Md)
+		case *MF:
+			x.Mf = CanonicalName(x.Mf)
+		case *CNAME:
+			x.Target = CanonicalName(x.Target)
+		case *SOA:
+			x.Ns = CanonicalName(x.Ns)
+			x.Mbox = CanonicalName(x.Mbox)
+		case *MB:
+			x.Mb = CanonicalName(x.Mb)
+		case *MG:
+			x.Mg = CanonicalName(x.Mg)
+		case *MR:
+			x.Mr = CanonicalName(x.Mr)
+		case *PTR:
+			x.Ptr = CanonicalName(x.Ptr)
+		case *MINFO:
+			x.Rmail = CanonicalName(x.Rmail)
+			x.Email = CanonicalName(x.Email)
+		case *MX:
+			x.Mx = CanonicalName(x.Mx)
+		case *RP:
+			x.Mbox = CanonicalName(x.Mbox)
+			x.Txt = CanonicalName(x.Txt)
+		case *AFSDB:
+			x.Hostname = CanonicalName(x.Hostname)
+		case *RT:
+			x.Host = CanonicalName(x.Host)
+		case *SIG:
+			x.SignerName = CanonicalName(x.SignerName)
+		case *PX:
+			x.Map822 = CanonicalName(x.Map822)
+			x.Mapx400 = CanonicalName(x.Mapx400)
+		case *NAPTR:
+			x.Replacement = CanonicalName(x.Replacement)
+		case *KX:
+			x.Exchanger = CanonicalName(x.Exchanger)
+		case *SRV:
+			x.Target = CanonicalName(x.Target)
+		case *DNAME:
+			x.Target = CanonicalName(x.Target)
+		}
+		// 6.2. Canonical RR Form. (5) - origTTL
+		wire := make([]byte, Len(r1)+1) // +1 to be safe(r)
+		off, err1 := PackRR(r1, wire, 0, nil, false)
+		if err1 != nil {
+			return nil, err1
+		}
+		wire = wire[:off]
+		wires[i] = wire
+	}
+	sort.Sort(wires)
+	for i, wire := range wires {
+		if i > 0 && bytes.Equal(wire, wires[i-1]) {
+			continue
+		}
+		buf = append(buf, wire...)
+	}
+	return buf, nil
+}
+
+func packSigWire(sw *rrsigWireFmt, msg []byte) (int, error) {
+	// copied from zmsg.go RRSIG packing
+	off, err := packUint16(sw.TypeCovered, msg, 0)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint8(sw.Algorithm, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint8(sw.Labels, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint32(sw.OrigTtl, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint32(sw.Expiration, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint32(sw.Inception, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint16(sw.KeyTag, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = PackDomainName(sw.SignerName, msg, off, nil, false)
+	if err != nil {
+		return off, err
+	}
+	return off, nil
+}
+
+func packKeyWire(dw *dnskeyWireFmt, msg []byte) (int, error) {
+	// copied from zmsg.go DNSKEY packing
+	off, err := packUint16(dw.Flags, msg, 0)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint8(dw.Protocol, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint8(dw.Algorithm, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packStringBase64(dw.PublicKey, msg, off)
+	if err != nil {
+		return off, err
+	}
+	return off, nil
+}

vendor/github.com/miekg/dns/dnssec_keygen.go

@@ -0,0 +1,139 @@
+package dns
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	"math/big"
+)
+
+// Generate generates a DNSKEY of the given bit size.
+// The public part is put inside the DNSKEY record.
+// The Algorithm in the key must be set as this will define
+// what kind of DNSKEY will be generated.
+// The ECDSA algorithms imply a fixed keysize, in that case
+// bits should be set to the size of the algorithm.
+func (k *DNSKEY) Generate(bits int) (crypto.PrivateKey, error) {
+	switch k.Algorithm {
+	case RSASHA1, RSASHA256, RSASHA1NSEC3SHA1:
+		if bits < 512 || bits > 4096 {
+			return nil, ErrKeySize
+		}
+	case RSASHA512:
+		if bits < 1024 || bits > 4096 {
+			return nil, ErrKeySize
+		}
+	case ECDSAP256SHA256:
+		if bits != 256 {
+			return nil, ErrKeySize
+		}
+	case ECDSAP384SHA384:
+		if bits != 384 {
+			return nil, ErrKeySize
+		}
+	case ED25519:
+		if bits != 256 {
+			return nil, ErrKeySize
+		}
+	default:
+		return nil, ErrAlg
+	}
+
+	switch k.Algorithm {
+	case RSASHA1, RSASHA256, RSASHA512, RSASHA1NSEC3SHA1:
+		priv, err := rsa.GenerateKey(rand.Reader, bits)
+		if err != nil {
+			return nil, err
+		}
+		k.setPublicKeyRSA(priv.PublicKey.E, priv.PublicKey.N)
+		return priv, nil
+	case ECDSAP256SHA256, ECDSAP384SHA384:
+		var c elliptic.Curve
+		switch k.Algorithm {
+		case ECDSAP256SHA256:
+			c = elliptic.P256()
+		case ECDSAP384SHA384:
+			c = elliptic.P384()
+		}
+		priv, err := ecdsa.GenerateKey(c, rand.Reader)
+		if err != nil {
+			return nil, err
+		}
+		k.setPublicKeyECDSA(priv.PublicKey.X, priv.PublicKey.Y)
+		return priv, nil
+	case ED25519:
+		pub, priv, err := ed25519.GenerateKey(rand.Reader)
+		if err != nil {
+			return nil, err
+		}
+		k.setPublicKeyED25519(pub)
+		return priv, nil
+	default:
+		return nil, ErrAlg
+	}
+}
+
+// Set the public key (the value E and N)
+func (k *DNSKEY) setPublicKeyRSA(_E int, _N *big.Int) bool {
+	if _E == 0 || _N == nil {
+		return false
+	}
+	buf := exponentToBuf(_E)
+	buf = append(buf, _N.Bytes()...)
+	k.PublicKey = toBase64(buf)
+	return true
+}
+
+// Set the public key for Elliptic Curves
+func (k *DNSKEY) setPublicKeyECDSA(_X, _Y *big.Int) bool {
+	if _X == nil || _Y == nil {
+		return false
+	}
+	var intlen int
+	switch k.Algorithm {
+	case ECDSAP256SHA256:
+		intlen = 32
+	case ECDSAP384SHA384:
+		intlen = 48
+	}
+	k.PublicKey = toBase64(curveToBuf(_X, _Y, intlen))
+	return true
+}
+
+// Set the public key for Ed25519
+func (k *DNSKEY) setPublicKeyED25519(_K ed25519.PublicKey) bool {
+	if _K == nil {
+		return false
+	}
+	k.PublicKey = toBase64(_K)
+	return true
+}
+
+// Set the public key (the values E and N) for RSA
+// RFC 3110: Section 2. RSA Public KEY Resource Records
+func exponentToBuf(_E int) []byte {
+	var buf []byte
+	i := big.NewInt(int64(_E)).Bytes()
+	if len(i) < 256 {
+		buf = make([]byte, 1, 1+len(i))
+		buf[0] = uint8(len(i))
+	} else {
+		buf = make([]byte, 3, 3+len(i))
+		buf[0] = 0
+		buf[1] = uint8(len(i) >> 8)
+		buf[2] = uint8(len(i))
+	}
+	buf = append(buf, i...)
+	return buf
+}
+
+// Set the public key for X and Y for Curve. The two
+// values are just concatenated.
+func curveToBuf(_X, _Y *big.Int, intlen int) []byte {
+	buf := intToBytes(_X, intlen)
+	buf = append(buf, intToBytes(_Y, intlen)...)
+	return buf
+}

vendor/github.com/miekg/dns/dnssec_keyscan.go

@@ -0,0 +1,309 @@
+package dns
+
+import (
+	"bufio"
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/rsa"
+	"io"
+	"math/big"
+	"strconv"
+	"strings"
+)
+
+// NewPrivateKey returns a PrivateKey by parsing the string s.
+// s should be in the same form of the BIND private key files.
+func (k *DNSKEY) NewPrivateKey(s string) (crypto.PrivateKey, error) {
+	if s == "" || s[len(s)-1] != '\n' { // We need a closing newline
+		return k.ReadPrivateKey(strings.NewReader(s+"\n"), "")
+	}
+	return k.ReadPrivateKey(strings.NewReader(s), "")
+}
+
+// ReadPrivateKey reads a private key from the io.Reader q. The string file is
+// only used in error reporting.
+// The public key must be known, because some cryptographic algorithms embed
+// the public inside the privatekey.
+func (k *DNSKEY) ReadPrivateKey(q io.Reader, file string) (crypto.PrivateKey, error) {
+	m, err := parseKey(q, file)
+	if m == nil {
+		return nil, err
+	}
+	if _, ok := m["private-key-format"]; !ok {
+		return nil, ErrPrivKey
+	}
+	if m["private-key-format"] != "v1.2" && m["private-key-format"] != "v1.3" {
+		return nil, ErrPrivKey
+	}
+	// TODO(mg): check if the pubkey matches the private key
+	algo, err := strconv.ParseUint(strings.SplitN(m["algorithm"], " ", 2)[0], 10, 8)
+	if err != nil {
+		return nil, ErrPrivKey
+	}
+	switch uint8(algo) {
+	case RSASHA1, RSASHA1NSEC3SHA1, RSASHA256, RSASHA512:
+		priv, err := readPrivateKeyRSA(m)
+		if err != nil {
+			return nil, err
+		}
+		pub := k.publicKeyRSA()
+		if pub == nil {
+			return nil, ErrKey
+		}
+		priv.PublicKey = *pub
+		return priv, nil
+	case ECDSAP256SHA256, ECDSAP384SHA384:
+		priv, err := readPrivateKeyECDSA(m)
+		if err != nil {
+			return nil, err
+		}
+		pub := k.publicKeyECDSA()
+		if pub == nil {
+			return nil, ErrKey
+		}
+		priv.PublicKey = *pub
+		return priv, nil
+	case ED25519:
+		return readPrivateKeyED25519(m)
+	default:
+		return nil, ErrAlg
+	}
+}
+
+// Read a private key (file) string and create a public key. Return the private key.
+func readPrivateKeyRSA(m map[string]string) (*rsa.PrivateKey, error) {
+	p := new(rsa.PrivateKey)
+	p.Primes = []*big.Int{nil, nil}
+	for k, v := range m {
+		switch k {
+		case "modulus", "publicexponent", "privateexponent", "prime1", "prime2":
+			v1, err := fromBase64([]byte(v))
+			if err != nil {
+				return nil, err
+			}
+			switch k {
+			case "modulus":
+				p.PublicKey.N = new(big.Int).SetBytes(v1)
+			case "publicexponent":
+				i := new(big.Int).SetBytes(v1)
+				p.PublicKey.E = int(i.Int64()) // int64 should be large enough
+			case "privateexponent":
+				p.D = new(big.Int).SetBytes(v1)
+			case "prime1":
+				p.Primes[0] = new(big.Int).SetBytes(v1)
+			case "prime2":
+				p.Primes[1] = new(big.Int).SetBytes(v1)
+			}
+		case "exponent1", "exponent2", "coefficient":
+			// not used in Go (yet)
+		case "created", "publish", "activate":
+			// not used in Go (yet)
+		}
+	}
+	return p, nil
+}
+
+func readPrivateKeyECDSA(m map[string]string) (*ecdsa.PrivateKey, error) {
+	p := new(ecdsa.PrivateKey)
+	p.D = new(big.Int)
+	// TODO: validate that the required flags are present
+	for k, v := range m {
+		switch k {
+		case "privatekey":
+			v1, err := fromBase64([]byte(v))
+			if err != nil {
+				return nil, err
+			}
+			p.D.SetBytes(v1)
+		case "created", "publish", "activate":
+			/* not used in Go (yet) */
+		}
+	}
+	return p, nil
+}
+
+func readPrivateKeyED25519(m map[string]string) (ed25519.PrivateKey, error) {
+	var p ed25519.PrivateKey
+	// TODO: validate that the required flags are present
+	for k, v := range m {
+		switch k {
+		case "privatekey":
+			p1, err := fromBase64([]byte(v))
+			if err != nil {
+				return nil, err
+			}
+			if len(p1) != ed25519.SeedSize {
+				return nil, ErrPrivKey
+			}
+			p = ed25519.NewKeyFromSeed(p1)
+		case "created", "publish", "activate":
+			/* not used in Go (yet) */
+		}
+	}
+	return p, nil
+}
+
+// parseKey reads a private key from r. It returns a map[string]string,
+// with the key-value pairs, or an error when the file is not correct.
+func parseKey(r io.Reader, file string) (map[string]string, error) {
+	m := make(map[string]string)
+	var k string
+
+	c := newKLexer(r)
+
+	for l, ok := c.Next(); ok; l, ok = c.Next() {
+		// It should alternate
+		switch l.value {
+		case zKey:
+			k = l.token
+		case zValue:
+			if k == "" {
+				return nil, &ParseError{file, "no private key seen", l}
+			}
+
+			m[strings.ToLower(k)] = l.token
+			k = ""
+		}
+	}
+
+	// Surface any read errors from r.
+	if err := c.Err(); err != nil {
+		return nil, &ParseError{file: file, err: err.Error()}
+	}
+
+	return m, nil
+}
+
+type klexer struct {
+	br io.ByteReader
+
+	readErr error
+
+	line   int
+	column int
+
+	key bool
+
+	eol bool // end-of-line
+}
+
+func newKLexer(r io.Reader) *klexer {
+	br, ok := r.(io.ByteReader)
+	if !ok {
+		br = bufio.NewReaderSize(r, 1024)
+	}
+
+	return &klexer{
+		br: br,
+
+		line: 1,
+
+		key: true,
+	}
+}
+
+func (kl *klexer) Err() error {
+	if kl.readErr == io.EOF {
+		return nil
+	}
+
+	return kl.readErr
+}
+
+// readByte returns the next byte from the input
+func (kl *klexer) readByte() (byte, bool) {
+	if kl.readErr != nil {
+		return 0, false
+	}
+
+	c, err := kl.br.ReadByte()
+	if err != nil {
+		kl.readErr = err
+		return 0, false
+	}
+
+	// delay the newline handling until the next token is delivered,
+	// fixes off-by-one errors when reporting a parse error.
+	if kl.eol {
+		kl.line++
+		kl.column = 0
+		kl.eol = false
+	}
+
+	if c == '\n' {
+		kl.eol = true
+	} else {
+		kl.column++
+	}
+
+	return c, true
+}
+
+func (kl *klexer) Next() (lex, bool) {
+	var (
+		l lex
+
+		str strings.Builder
+
+		commt bool
+	)
+
+	for x, ok := kl.readByte(); ok; x, ok = kl.readByte() {
+		l.line, l.column = kl.line, kl.column
+
+		switch x {
+		case ':':
+			if commt || !kl.key {
+				break
+			}
+
+			kl.key = false
+
+			// Next token is a space, eat it
+			kl.readByte()
+
+			l.value = zKey
+			l.token = str.String()
+			return l, true
+		case ';':
+			commt = true
+		case '\n':
+			if commt {
+				// Reset a comment
+				commt = false
+			}
+
+			if kl.key && str.Len() == 0 {
+				// ignore empty lines
+				break
+			}
+
+			kl.key = true
+
+			l.value = zValue
+			l.token = str.String()
+			return l, true
+		default:
+			if commt {
+				break
+			}
+
+			str.WriteByte(x)
+		}
+	}
+
+	if kl.readErr != nil && kl.readErr != io.EOF {
+		// Don't return any tokens after a read error occurs.
+		return lex{value: zEOF}, false
+	}
+
+	if str.Len() > 0 {
+		// Send remainder
+		l.value = zValue
+		l.token = str.String()
+		return l, true
+	}
+
+	return lex{value: zEOF}, false
+}

vendor/github.com/miekg/dns/dnssec_privkey.go

@@ -0,0 +1,77 @@
+package dns
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/rsa"
+	"math/big"
+	"strconv"
+)
+
+const format = "Private-key-format: v1.3\n"
+
+var bigIntOne = big.NewInt(1)
+
+// PrivateKeyString converts a PrivateKey to a string. This string has the same
+// format as the private-key-file of BIND9 (Private-key-format: v1.3).
+// It needs some info from the key (the algorithm), so its a method of the DNSKEY.
+// It supports *rsa.PrivateKey, *ecdsa.PrivateKey and ed25519.PrivateKey.
+func (r *DNSKEY) PrivateKeyString(p crypto.PrivateKey) string {
+	algorithm := strconv.Itoa(int(r.Algorithm))
+	algorithm += " (" + AlgorithmToString[r.Algorithm] + ")"
+
+	switch p := p.(type) {
+	case *rsa.PrivateKey:
+		modulus := toBase64(p.PublicKey.N.Bytes())
+		e := big.NewInt(int64(p.PublicKey.E))
+		publicExponent := toBase64(e.Bytes())
+		privateExponent := toBase64(p.D.Bytes())
+		prime1 := toBase64(p.Primes[0].Bytes())
+		prime2 := toBase64(p.Primes[1].Bytes())
+		// Calculate Exponent1/2 and Coefficient as per: http://en.wikipedia.org/wiki/RSA#Using_the_Chinese_remainder_algorithm
+		// and from: http://code.google.com/p/go/issues/detail?id=987
+		p1 := new(big.Int).Sub(p.Primes[0], bigIntOne)
+		q1 := new(big.Int).Sub(p.Primes[1], bigIntOne)
+		exp1 := new(big.Int).Mod(p.D, p1)
+		exp2 := new(big.Int).Mod(p.D, q1)
+		coeff := new(big.Int).ModInverse(p.Primes[1], p.Primes[0])
+
+		exponent1 := toBase64(exp1.Bytes())
+		exponent2 := toBase64(exp2.Bytes())
+		coefficient := toBase64(coeff.Bytes())
+
+		return format +
+			"Algorithm: " + algorithm + "\n" +
+			"Modulus: " + modulus + "\n" +
+			"PublicExponent: " + publicExponent + "\n" +
+			"PrivateExponent: " + privateExponent + "\n" +
+			"Prime1: " + prime1 + "\n" +
+			"Prime2: " + prime2 + "\n" +
+			"Exponent1: " + exponent1 + "\n" +
+			"Exponent2: " + exponent2 + "\n" +
+			"Coefficient: " + coefficient + "\n"
+
+	case *ecdsa.PrivateKey:
+		var intlen int
+		switch r.Algorithm {
+		case ECDSAP256SHA256:
+			intlen = 32
+		case ECDSAP384SHA384:
+			intlen = 48
+		}
+		private := toBase64(intToBytes(p.D, intlen))
+		return format +
+			"Algorithm: " + algorithm + "\n" +
+			"PrivateKey: " + private + "\n"
+
+	case ed25519.PrivateKey:
+		private := toBase64(p.Seed())
+		return format +
+			"Algorithm: " + algorithm + "\n" +
+			"PrivateKey: " + private + "\n"
+
+	default:
+		return ""
+	}
+}

vendor/github.com/miekg/dns/doc.go

@@ -0,0 +1,292 @@
+/*
+Package dns implements a full featured interface to the Domain Name System.
+Both server- and client-side programming is supported. The package allows
+complete control over what is sent out to the DNS. The API follows the
+less-is-more principle, by presenting a small, clean interface.
+
+It supports (asynchronous) querying/replying, incoming/outgoing zone transfers,
+TSIG, EDNS0, dynamic updates, notifies and DNSSEC validation/signing.
+
+Note that domain names MUST be fully qualified before sending them, unqualified
+names in a message will result in a packing failure.
+
+Resource records are native types. They are not stored in wire format. Basic
+usage pattern for creating a new resource record:
+
+     r := new(dns.MX)
+     r.Hdr = dns.RR_Header{Name: "miek.nl.", Rrtype: dns.TypeMX, Class: dns.ClassINET, Ttl: 3600}
+     r.Preference = 10
+     r.Mx = "mx.miek.nl."
+
+Or directly from a string:
+
+     mx, err := dns.NewRR("miek.nl. 3600 IN MX 10 mx.miek.nl.")
+
+Or when the default origin (.) and TTL (3600) and class (IN) suit you:
+
+     mx, err := dns.NewRR("miek.nl MX 10 mx.miek.nl")
+
+Or even:
+
+     mx, err := dns.NewRR("$ORIGIN nl.\nmiek 1H IN MX 10 mx.miek")
+
+In the DNS messages are exchanged, these messages contain resource records
+(sets). Use pattern for creating a message:
+
+     m := new(dns.Msg)
+     m.SetQuestion("miek.nl.", dns.TypeMX)
+
+Or when not certain if the domain name is fully qualified:
+
+	m.SetQuestion(dns.Fqdn("miek.nl"), dns.TypeMX)
+
+The message m is now a message with the question section set to ask the MX
+records for the miek.nl. zone.
+
+The following is slightly more verbose, but more flexible:
+
+     m1 := new(dns.Msg)
+     m1.Id = dns.Id()
+     m1.RecursionDesired = true
+     m1.Question = make([]dns.Question, 1)
+     m1.Question[0] = dns.Question{"miek.nl.", dns.TypeMX, dns.ClassINET}
+
+After creating a message it can be sent. Basic use pattern for synchronous
+querying the DNS at a server configured on 127.0.0.1 and port 53:
+
+     c := new(dns.Client)
+     in, rtt, err := c.Exchange(m1, "127.0.0.1:53")
+
+Suppressing multiple outstanding queries (with the same question, type and
+class) is as easy as setting:
+
+	c.SingleInflight = true
+
+More advanced options are available using a net.Dialer and the corresponding API.
+For example it is possible to set a timeout, or to specify a source IP address
+and port to use for the connection:
+
+	c := new(dns.Client)
+	laddr := net.UDPAddr{
+		IP: net.ParseIP("[::1]"),
+		Port: 12345,
+		Zone: "",
+	}
+	c.Dialer := &net.Dialer{
+		Timeout: 200 * time.Millisecond,
+		LocalAddr: &laddr,
+	}
+	in, rtt, err := c.Exchange(m1, "8.8.8.8:53")
+
+If these "advanced" features are not needed, a simple UDP query can be sent,
+with:
+
+	in, err := dns.Exchange(m1, "127.0.0.1:53")
+
+When this functions returns you will get DNS message. A DNS message consists
+out of four sections.
+The question section: in.Question, the answer section: in.Answer,
+the authority section: in.Ns and the additional section: in.Extra.
+
+Each of these sections (except the Question section) contain a []RR. Basic
+use pattern for accessing the rdata of a TXT RR as the first RR in
+the Answer section:
+
+	if t, ok := in.Answer[0].(*dns.TXT); ok {
+		// do something with t.Txt
+	}
+
+Domain Name and TXT Character String Representations
+
+Both domain names and TXT character strings are converted to presentation form
+both when unpacked and when converted to strings.
+
+For TXT character strings, tabs, carriage returns and line feeds will be
+converted to \t, \r and \n respectively. Back slashes and quotations marks will
+be escaped. Bytes below 32 and above 127 will be converted to \DDD form.
+
+For domain names, in addition to the above rules brackets, periods, spaces,
+semicolons and the at symbol are escaped.
+
+DNSSEC
+
+DNSSEC (DNS Security Extension) adds a layer of security to the DNS. It uses
+public key cryptography to sign resource records. The public keys are stored in
+DNSKEY records and the signatures in RRSIG records.
+
+Requesting DNSSEC information for a zone is done by adding the DO (DNSSEC OK)
+bit to a request.
+
+     m := new(dns.Msg)
+     m.SetEdns0(4096, true)
+
+Signature generation, signature verification and key generation are all supported.
+
+DYNAMIC UPDATES
+
+Dynamic updates reuses the DNS message format, but renames three of the
+sections. Question is Zone, Answer is Prerequisite, Authority is Update, only
+the Additional is not renamed. See RFC 2136 for the gory details.
+
+You can set a rather complex set of rules for the existence of absence of
+certain resource records or names in a zone to specify if resource records
+should be added or removed. The table from RFC 2136 supplemented with the Go
+DNS function shows which functions exist to specify the prerequisites.
+
+ 3.2.4 - Table Of Metavalues Used In Prerequisite Section
+
+  CLASS    TYPE     RDATA    Meaning                    Function
+  --------------------------------------------------------------
+  ANY      ANY      empty    Name is in use             dns.NameUsed
+  ANY      rrset    empty    RRset exists (value indep) dns.RRsetUsed
+  NONE     ANY      empty    Name is not in use         dns.NameNotUsed
+  NONE     rrset    empty    RRset does not exist       dns.RRsetNotUsed
+  zone     rrset    rr       RRset exists (value dep)   dns.Used
+
+The prerequisite section can also be left empty. If you have decided on the
+prerequisites you can tell what RRs should be added or deleted. The next table
+shows the options you have and what functions to call.
+
+ 3.4.2.6 - Table Of Metavalues Used In Update Section
+
+  CLASS    TYPE     RDATA    Meaning                     Function
+  ---------------------------------------------------------------
+  ANY      ANY      empty    Delete all RRsets from name dns.RemoveName
+  ANY      rrset    empty    Delete an RRset             dns.RemoveRRset
+  NONE     rrset    rr       Delete an RR from RRset     dns.Remove
+  zone     rrset    rr       Add to an RRset             dns.Insert
+
+TRANSACTION SIGNATURE
+
+An TSIG or transaction signature adds a HMAC TSIG record to each message sent.
+The supported algorithms include: HmacSHA1, HmacSHA256 and HmacSHA512.
+
+Basic use pattern when querying with a TSIG name "axfr." (note that these key names
+must be fully qualified - as they are domain names) and the base64 secret
+"so6ZGir4GPAqINNh9U5c3A==":
+
+If an incoming message contains a TSIG record it MUST be the last record in
+the additional section (RFC2845 3.2).  This means that you should make the
+call to SetTsig last, right before executing the query.  If you make any
+changes to the RRset after calling SetTsig() the signature will be incorrect.
+
+	c := new(dns.Client)
+	c.TsigSecret = map[string]string{"axfr.": "so6ZGir4GPAqINNh9U5c3A=="}
+	m := new(dns.Msg)
+	m.SetQuestion("miek.nl.", dns.TypeMX)
+	m.SetTsig("axfr.", dns.HmacSHA256, 300, time.Now().Unix())
+	...
+	// When sending the TSIG RR is calculated and filled in before sending
+
+When requesting an zone transfer (almost all TSIG usage is when requesting zone
+transfers), with TSIG, this is the basic use pattern. In this example we
+request an AXFR for miek.nl. with TSIG key named "axfr." and secret
+"so6ZGir4GPAqINNh9U5c3A==" and using the server 176.58.119.54:
+
+	t := new(dns.Transfer)
+	m := new(dns.Msg)
+	t.TsigSecret = map[string]string{"axfr.": "so6ZGir4GPAqINNh9U5c3A=="}
+	m.SetAxfr("miek.nl.")
+	m.SetTsig("axfr.", dns.HmacSHA256, 300, time.Now().Unix())
+	c, err := t.In(m, "176.58.119.54:53")
+	for r := range c { ... }
+
+You can now read the records from the transfer as they come in. Each envelope
+is checked with TSIG. If something is not correct an error is returned.
+
+A custom TSIG implementation can be used. This requires additional code to
+perform any session establishment and signature generation/verification. The
+client must be configured with an implementation of the TsigProvider interface:
+
+	type Provider struct{}
+
+	func (*Provider) Generate(msg []byte, tsig *dns.TSIG) ([]byte, error) {
+		// Use tsig.Hdr.Name and tsig.Algorithm in your code to
+		// generate the MAC using msg as the payload.
+	}
+
+	func (*Provider) Verify(msg []byte, tsig *dns.TSIG) error {
+		// Use tsig.Hdr.Name and tsig.Algorithm in your code to verify
+		// that msg matches the value in tsig.MAC.
+	}
+
+	c := new(dns.Client)
+	c.TsigProvider = new(Provider)
+	m := new(dns.Msg)
+	m.SetQuestion("miek.nl.", dns.TypeMX)
+	m.SetTsig(keyname, dns.HmacSHA256, 300, time.Now().Unix())
+	...
+	// TSIG RR is calculated by calling your Generate method
+
+Basic use pattern validating and replying to a message that has TSIG set.
+
+	server := &dns.Server{Addr: ":53", Net: "udp"}
+	server.TsigSecret = map[string]string{"axfr.": "so6ZGir4GPAqINNh9U5c3A=="}
+	go server.ListenAndServe()
+	dns.HandleFunc(".", handleRequest)
+
+	func handleRequest(w dns.ResponseWriter, r *dns.Msg) {
+		m := new(dns.Msg)
+		m.SetReply(r)
+		if r.IsTsig() != nil {
+			if w.TsigStatus() == nil {
+				// *Msg r has an TSIG record and it was validated
+				m.SetTsig("axfr.", dns.HmacSHA256, 300, time.Now().Unix())
+			} else {
+				// *Msg r has an TSIG records and it was not validated
+			}
+		}
+		w.WriteMsg(m)
+	}
+
+PRIVATE RRS
+
+RFC 6895 sets aside a range of type codes for private use. This range is 65,280
+- 65,534 (0xFF00 - 0xFFFE). When experimenting with new Resource Records these
+can be used, before requesting an official type code from IANA.
+
+See https://miek.nl/2014/september/21/idn-and-private-rr-in-go-dns/ for more
+information.
+
+EDNS0
+
+EDNS0 is an extension mechanism for the DNS defined in RFC 2671 and updated by
+RFC 6891. It defines a new RR type, the OPT RR, which is then completely
+abused.
+
+Basic use pattern for creating an (empty) OPT RR:
+
+	o := new(dns.OPT)
+	o.Hdr.Name = "." // MUST be the root zone, per definition.
+	o.Hdr.Rrtype = dns.TypeOPT
+
+The rdata of an OPT RR consists out of a slice of EDNS0 (RFC 6891) interfaces.
+Currently only a few have been standardized: EDNS0_NSID (RFC 5001) and
+EDNS0_SUBNET (RFC 7871). Note that these options may be combined in an OPT RR.
+Basic use pattern for a server to check if (and which) options are set:
+
+	// o is a dns.OPT
+	for _, s := range o.Option {
+		switch e := s.(type) {
+		case *dns.EDNS0_NSID:
+			// do stuff with e.Nsid
+		case *dns.EDNS0_SUBNET:
+			// access e.Family, e.Address, etc.
+		}
+	}
+
+SIG(0)
+
+From RFC 2931:
+
+    SIG(0) provides protection for DNS transactions and requests ....
+    ... protection for glue records, DNS requests, protection for message headers
+    on requests and responses, and protection of the overall integrity of a response.
+
+It works like TSIG, except that SIG(0) uses public key cryptography, instead of
+the shared secret approach in TSIG. Supported algorithms: ECDSAP256SHA256,
+ECDSAP384SHA384, RSASHA1, RSASHA256 and RSASHA512.
+
+Signing subsequent messages in multi-message sessions is not implemented.
+*/
+package dns

vendor/github.com/miekg/dns/duplicate.go

@@ -0,0 +1,37 @@
+package dns
+
+//go:generate go run duplicate_generate.go
+
+// IsDuplicate checks of r1 and r2 are duplicates of each other, excluding the TTL.
+// So this means the header data is equal *and* the RDATA is the same. Returns true
+// if so, otherwise false. It's a protocol violation to have identical RRs in a message.
+func IsDuplicate(r1, r2 RR) bool {
+	// Check whether the record header is identical.
+	if !r1.Header().isDuplicate(r2.Header()) {
+		return false
+	}
+
+	// Check whether the RDATA is identical.
+	return r1.isDuplicate(r2)
+}
+
+func (r1 *RR_Header) isDuplicate(_r2 RR) bool {
+	r2, ok := _r2.(*RR_Header)
+	if !ok {
+		return false
+	}
+	if r1.Class != r2.Class {
+		return false
+	}
+	if r1.Rrtype != r2.Rrtype {
+		return false
+	}
+	if !isDuplicateName(r1.Name, r2.Name) {
+		return false
+	}
+	// ignore TTL
+	return true
+}
+
+// isDuplicateName checks if the domain names s1 and s2 are equal.
+func isDuplicateName(s1, s2 string) bool { return equal(s1, s2) }

vendor/github.com/miekg/dns/edns.go

@@ -0,0 +1,851 @@
+package dns
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"net"
+	"strconv"
+)
+
+// EDNS0 Option codes.
+const (
+	EDNS0LLQ          = 0x1     // long lived queries: http://tools.ietf.org/html/draft-sekar-dns-llq-01
+	EDNS0UL           = 0x2     // update lease draft: http://files.dns-sd.org/draft-sekar-dns-ul.txt
+	EDNS0NSID         = 0x3     // nsid (See RFC 5001)
+	EDNS0ESU          = 0x4     // ENUM Source-URI draft: https://datatracker.ietf.org/doc/html/draft-kaplan-enum-source-uri-00
+	EDNS0DAU          = 0x5     // DNSSEC Algorithm Understood
+	EDNS0DHU          = 0x6     // DS Hash Understood
+	EDNS0N3U          = 0x7     // NSEC3 Hash Understood
+	EDNS0SUBNET       = 0x8     // client-subnet (See RFC 7871)
+	EDNS0EXPIRE       = 0x9     // EDNS0 expire
+	EDNS0COOKIE       = 0xa     // EDNS0 Cookie
+	EDNS0TCPKEEPALIVE = 0xb     // EDNS0 tcp keep alive (See RFC 7828)
+	EDNS0PADDING      = 0xc     // EDNS0 padding (See RFC 7830)
+	EDNS0EDE          = 0xf     // EDNS0 extended DNS errors (See RFC 8914)
+	EDNS0LOCALSTART   = 0xFDE9  // Beginning of range reserved for local/experimental use (See RFC 6891)
+	EDNS0LOCALEND     = 0xFFFE  // End of range reserved for local/experimental use (See RFC 6891)
+	_DO               = 1 << 15 // DNSSEC OK
+)
+
+// makeDataOpt is used to unpack the EDNS0 option(s) from a message.
+func makeDataOpt(code uint16) EDNS0 {
+	// All the EDNS0.* constants above need to be in this switch.
+	switch code {
+	case EDNS0LLQ:
+		return new(EDNS0_LLQ)
+	case EDNS0UL:
+		return new(EDNS0_UL)
+	case EDNS0NSID:
+		return new(EDNS0_NSID)
+	case EDNS0DAU:
+		return new(EDNS0_DAU)
+	case EDNS0DHU:
+		return new(EDNS0_DHU)
+	case EDNS0N3U:
+		return new(EDNS0_N3U)
+	case EDNS0SUBNET:
+		return new(EDNS0_SUBNET)
+	case EDNS0EXPIRE:
+		return new(EDNS0_EXPIRE)
+	case EDNS0COOKIE:
+		return new(EDNS0_COOKIE)
+	case EDNS0TCPKEEPALIVE:
+		return new(EDNS0_TCP_KEEPALIVE)
+	case EDNS0PADDING:
+		return new(EDNS0_PADDING)
+	case EDNS0EDE:
+		return new(EDNS0_EDE)
+	case EDNS0ESU:
+		return &EDNS0_ESU{Code: EDNS0ESU}
+	default:
+		e := new(EDNS0_LOCAL)
+		e.Code = code
+		return e
+	}
+}
+
+// OPT is the EDNS0 RR appended to messages to convey extra (meta) information.
+// See RFC 6891.
+type OPT struct {
+	Hdr    RR_Header
+	Option []EDNS0 `dns:"opt"`
+}
+
+func (rr *OPT) String() string {
+	s := "\n;; OPT PSEUDOSECTION:\n; EDNS: version " + strconv.Itoa(int(rr.Version())) + "; "
+	if rr.Do() {
+		s += "flags: do; "
+	} else {
+		s += "flags: ; "
+	}
+	s += "udp: " + strconv.Itoa(int(rr.UDPSize()))
+
+	for _, o := range rr.Option {
+		switch o.(type) {
+		case *EDNS0_NSID:
+			s += "\n; NSID: " + o.String()
+			h, e := o.pack()
+			var r string
+			if e == nil {
+				for _, c := range h {
+					r += "(" + string(c) + ")"
+				}
+				s += "  " + r
+			}
+		case *EDNS0_SUBNET:
+			s += "\n; SUBNET: " + o.String()
+		case *EDNS0_COOKIE:
+			s += "\n; COOKIE: " + o.String()
+		case *EDNS0_TCP_KEEPALIVE:
+			s += "\n; KEEPALIVE: " + o.String()
+		case *EDNS0_UL:
+			s += "\n; UPDATE LEASE: " + o.String()
+		case *EDNS0_LLQ:
+			s += "\n; LONG LIVED QUERIES: " + o.String()
+		case *EDNS0_DAU:
+			s += "\n; DNSSEC ALGORITHM UNDERSTOOD: " + o.String()
+		case *EDNS0_DHU:
+			s += "\n; DS HASH UNDERSTOOD: " + o.String()
+		case *EDNS0_N3U:
+			s += "\n; NSEC3 HASH UNDERSTOOD: " + o.String()
+		case *EDNS0_LOCAL:
+			s += "\n; LOCAL OPT: " + o.String()
+		case *EDNS0_PADDING:
+			s += "\n; PADDING: " + o.String()
+		case *EDNS0_EDE:
+			s += "\n; EDE: " + o.String()
+		case *EDNS0_ESU:
+			s += "\n; ESU: " + o.String()
+		}
+	}
+	return s
+}
+
+func (rr *OPT) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	for _, o := range rr.Option {
+		l += 4 // Account for 2-byte option code and 2-byte option length.
+		lo, _ := o.pack()
+		l += len(lo)
+	}
+	return l
+}
+
+func (*OPT) parse(c *zlexer, origin string) *ParseError {
+	return &ParseError{err: "OPT records do not have a presentation format"}
+}
+
+func (rr *OPT) isDuplicate(r2 RR) bool { return false }
+
+// return the old value -> delete SetVersion?
+
+// Version returns the EDNS version used. Only zero is defined.
+func (rr *OPT) Version() uint8 {
+	return uint8(rr.Hdr.Ttl & 0x00FF0000 >> 16)
+}
+
+// SetVersion sets the version of EDNS. This is usually zero.
+func (rr *OPT) SetVersion(v uint8) {
+	rr.Hdr.Ttl = rr.Hdr.Ttl&0xFF00FFFF | uint32(v)<<16
+}
+
+// ExtendedRcode returns the EDNS extended RCODE field (the upper 8 bits of the TTL).
+func (rr *OPT) ExtendedRcode() int {
+	return int(rr.Hdr.Ttl&0xFF000000>>24) << 4
+}
+
+// SetExtendedRcode sets the EDNS extended RCODE field.
+//
+// If the RCODE is not an extended RCODE, will reset the extended RCODE field to 0.
+func (rr *OPT) SetExtendedRcode(v uint16) {
+	rr.Hdr.Ttl = rr.Hdr.Ttl&0x00FFFFFF | uint32(v>>4)<<24
+}
+
+// UDPSize returns the UDP buffer size.
+func (rr *OPT) UDPSize() uint16 {
+	return rr.Hdr.Class
+}
+
+// SetUDPSize sets the UDP buffer size.
+func (rr *OPT) SetUDPSize(size uint16) {
+	rr.Hdr.Class = size
+}
+
+// Do returns the value of the DO (DNSSEC OK) bit.
+func (rr *OPT) Do() bool {
+	return rr.Hdr.Ttl&_DO == _DO
+}
+
+// SetDo sets the DO (DNSSEC OK) bit.
+// If we pass an argument, set the DO bit to that value.
+// It is possible to pass 2 or more arguments. Any arguments after the 1st is silently ignored.
+func (rr *OPT) SetDo(do ...bool) {
+	if len(do) == 1 {
+		if do[0] {
+			rr.Hdr.Ttl |= _DO
+		} else {
+			rr.Hdr.Ttl &^= _DO
+		}
+	} else {
+		rr.Hdr.Ttl |= _DO
+	}
+}
+
+// Z returns the Z part of the OPT RR as a uint16 with only the 15 least significant bits used.
+func (rr *OPT) Z() uint16 {
+	return uint16(rr.Hdr.Ttl & 0x7FFF)
+}
+
+// SetZ sets the Z part of the OPT RR, note only the 15 least significant bits of z are used.
+func (rr *OPT) SetZ(z uint16) {
+	rr.Hdr.Ttl = rr.Hdr.Ttl&^0x7FFF | uint32(z&0x7FFF)
+}
+
+// EDNS0 defines an EDNS0 Option. An OPT RR can have multiple options appended to it.
+type EDNS0 interface {
+	// Option returns the option code for the option.
+	Option() uint16
+	// pack returns the bytes of the option data.
+	pack() ([]byte, error)
+	// unpack sets the data as found in the buffer. Is also sets
+	// the length of the slice as the length of the option data.
+	unpack([]byte) error
+	// String returns the string representation of the option.
+	String() string
+	// copy returns a deep-copy of the option.
+	copy() EDNS0
+}
+
+// EDNS0_NSID option is used to retrieve a nameserver
+// identifier. When sending a request Nsid must be set to the empty string
+// The identifier is an opaque string encoded as hex.
+// Basic use pattern for creating an nsid option:
+//
+//	o := new(dns.OPT)
+//	o.Hdr.Name = "."
+//	o.Hdr.Rrtype = dns.TypeOPT
+//	e := new(dns.EDNS0_NSID)
+//	e.Code = dns.EDNS0NSID
+//	e.Nsid = "AA"
+//	o.Option = append(o.Option, e)
+type EDNS0_NSID struct {
+	Code uint16 // Always EDNS0NSID
+	Nsid string // This string needs to be hex encoded
+}
+
+func (e *EDNS0_NSID) pack() ([]byte, error) {
+	h, err := hex.DecodeString(e.Nsid)
+	if err != nil {
+		return nil, err
+	}
+	return h, nil
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_NSID) Option() uint16        { return EDNS0NSID } // Option returns the option code.
+func (e *EDNS0_NSID) unpack(b []byte) error { e.Nsid = hex.EncodeToString(b); return nil }
+func (e *EDNS0_NSID) String() string        { return e.Nsid }
+func (e *EDNS0_NSID) copy() EDNS0           { return &EDNS0_NSID{e.Code, e.Nsid} }
+
+// EDNS0_SUBNET is the subnet option that is used to give the remote nameserver
+// an idea of where the client lives. See RFC 7871. It can then give back a different
+// answer depending on the location or network topology.
+// Basic use pattern for creating an subnet option:
+//
+//	o := new(dns.OPT)
+//	o.Hdr.Name = "."
+//	o.Hdr.Rrtype = dns.TypeOPT
+//	e := new(dns.EDNS0_SUBNET)
+//	e.Code = dns.EDNS0SUBNET
+//	e.Family = 1	// 1 for IPv4 source address, 2 for IPv6
+//	e.SourceNetmask = 32	// 32 for IPV4, 128 for IPv6
+//	e.SourceScope = 0
+//	e.Address = net.ParseIP("127.0.0.1").To4()	// for IPv4
+//	// e.Address = net.ParseIP("2001:7b8:32a::2")	// for IPV6
+//	o.Option = append(o.Option, e)
+//
+// This code will parse all the available bits when unpacking (up to optlen).
+// When packing it will apply SourceNetmask. If you need more advanced logic,
+// patches welcome and good luck.
+type EDNS0_SUBNET struct {
+	Code          uint16 // Always EDNS0SUBNET
+	Family        uint16 // 1 for IP, 2 for IP6
+	SourceNetmask uint8
+	SourceScope   uint8
+	Address       net.IP
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_SUBNET) Option() uint16 { return EDNS0SUBNET }
+
+func (e *EDNS0_SUBNET) pack() ([]byte, error) {
+	b := make([]byte, 4)
+	binary.BigEndian.PutUint16(b[0:], e.Family)
+	b[2] = e.SourceNetmask
+	b[3] = e.SourceScope
+	switch e.Family {
+	case 0:
+		// "dig" sets AddressFamily to 0 if SourceNetmask is also 0
+		// We might don't need to complain either
+		if e.SourceNetmask != 0 {
+			return nil, errors.New("dns: bad address family")
+		}
+	case 1:
+		if e.SourceNetmask > net.IPv4len*8 {
+			return nil, errors.New("dns: bad netmask")
+		}
+		if len(e.Address.To4()) != net.IPv4len {
+			return nil, errors.New("dns: bad address")
+		}
+		ip := e.Address.To4().Mask(net.CIDRMask(int(e.SourceNetmask), net.IPv4len*8))
+		needLength := (e.SourceNetmask + 8 - 1) / 8 // division rounding up
+		b = append(b, ip[:needLength]...)
+	case 2:
+		if e.SourceNetmask > net.IPv6len*8 {
+			return nil, errors.New("dns: bad netmask")
+		}
+		if len(e.Address) != net.IPv6len {
+			return nil, errors.New("dns: bad address")
+		}
+		ip := e.Address.Mask(net.CIDRMask(int(e.SourceNetmask), net.IPv6len*8))
+		needLength := (e.SourceNetmask + 8 - 1) / 8 // division rounding up
+		b = append(b, ip[:needLength]...)
+	default:
+		return nil, errors.New("dns: bad address family")
+	}
+	return b, nil
+}
+
+func (e *EDNS0_SUBNET) unpack(b []byte) error {
+	if len(b) < 4 {
+		return ErrBuf
+	}
+	e.Family = binary.BigEndian.Uint16(b)
+	e.SourceNetmask = b[2]
+	e.SourceScope = b[3]
+	switch e.Family {
+	case 0:
+		// "dig" sets AddressFamily to 0 if SourceNetmask is also 0
+		// It's okay to accept such a packet
+		if e.SourceNetmask != 0 {
+			return errors.New("dns: bad address family")
+		}
+		e.Address = net.IPv4(0, 0, 0, 0)
+	case 1:
+		if e.SourceNetmask > net.IPv4len*8 || e.SourceScope > net.IPv4len*8 {
+			return errors.New("dns: bad netmask")
+		}
+		addr := make(net.IP, net.IPv4len)
+		copy(addr, b[4:])
+		e.Address = addr.To16()
+	case 2:
+		if e.SourceNetmask > net.IPv6len*8 || e.SourceScope > net.IPv6len*8 {
+			return errors.New("dns: bad netmask")
+		}
+		addr := make(net.IP, net.IPv6len)
+		copy(addr, b[4:])
+		e.Address = addr
+	default:
+		return errors.New("dns: bad address family")
+	}
+	return nil
+}
+
+func (e *EDNS0_SUBNET) String() (s string) {
+	if e.Address == nil {
+		s = "<nil>"
+	} else if e.Address.To4() != nil {
+		s = e.Address.String()
+	} else {
+		s = "[" + e.Address.String() + "]"
+	}
+	s += "/" + strconv.Itoa(int(e.SourceNetmask)) + "/" + strconv.Itoa(int(e.SourceScope))
+	return
+}
+
+func (e *EDNS0_SUBNET) copy() EDNS0 {
+	return &EDNS0_SUBNET{
+		e.Code,
+		e.Family,
+		e.SourceNetmask,
+		e.SourceScope,
+		e.Address,
+	}
+}
+
+// The EDNS0_COOKIE option is used to add a DNS Cookie to a message.
+//
+//	o := new(dns.OPT)
+//	o.Hdr.Name = "."
+//	o.Hdr.Rrtype = dns.TypeOPT
+//	e := new(dns.EDNS0_COOKIE)
+//	e.Code = dns.EDNS0COOKIE
+//	e.Cookie = "24a5ac.."
+//	o.Option = append(o.Option, e)
+//
+// The Cookie field consists out of a client cookie (RFC 7873 Section 4), that is
+// always 8 bytes. It may then optionally be followed by the server cookie. The server
+// cookie is of variable length, 8 to a maximum of 32 bytes. In other words:
+//
+//	cCookie := o.Cookie[:16]
+//	sCookie := o.Cookie[16:]
+//
+// There is no guarantee that the Cookie string has a specific length.
+type EDNS0_COOKIE struct {
+	Code   uint16 // Always EDNS0COOKIE
+	Cookie string // Hex-encoded cookie data
+}
+
+func (e *EDNS0_COOKIE) pack() ([]byte, error) {
+	h, err := hex.DecodeString(e.Cookie)
+	if err != nil {
+		return nil, err
+	}
+	return h, nil
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_COOKIE) Option() uint16        { return EDNS0COOKIE }
+func (e *EDNS0_COOKIE) unpack(b []byte) error { e.Cookie = hex.EncodeToString(b); return nil }
+func (e *EDNS0_COOKIE) String() string        { return e.Cookie }
+func (e *EDNS0_COOKIE) copy() EDNS0           { return &EDNS0_COOKIE{e.Code, e.Cookie} }
+
+// The EDNS0_UL (Update Lease) (draft RFC) option is used to tell the server to set
+// an expiration on an update RR. This is helpful for clients that cannot clean
+// up after themselves. This is a draft RFC and more information can be found at
+// https://tools.ietf.org/html/draft-sekar-dns-ul-02
+//
+//	o := new(dns.OPT)
+//	o.Hdr.Name = "."
+//	o.Hdr.Rrtype = dns.TypeOPT
+//	e := new(dns.EDNS0_UL)
+//	e.Code = dns.EDNS0UL
+//	e.Lease = 120 // in seconds
+//	o.Option = append(o.Option, e)
+type EDNS0_UL struct {
+	Code     uint16 // Always EDNS0UL
+	Lease    uint32
+	KeyLease uint32
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_UL) Option() uint16 { return EDNS0UL }
+func (e *EDNS0_UL) String() string { return fmt.Sprintf("%d %d", e.Lease, e.KeyLease) }
+func (e *EDNS0_UL) copy() EDNS0    { return &EDNS0_UL{e.Code, e.Lease, e.KeyLease} }
+
+// Copied: http://golang.org/src/pkg/net/dnsmsg.go
+func (e *EDNS0_UL) pack() ([]byte, error) {
+	var b []byte
+	if e.KeyLease == 0 {
+		b = make([]byte, 4)
+	} else {
+		b = make([]byte, 8)
+		binary.BigEndian.PutUint32(b[4:], e.KeyLease)
+	}
+	binary.BigEndian.PutUint32(b, e.Lease)
+	return b, nil
+}
+
+func (e *EDNS0_UL) unpack(b []byte) error {
+	switch len(b) {
+	case 4:
+		e.KeyLease = 0
+	case 8:
+		e.KeyLease = binary.BigEndian.Uint32(b[4:])
+	default:
+		return ErrBuf
+	}
+	e.Lease = binary.BigEndian.Uint32(b)
+	return nil
+}
+
+// EDNS0_LLQ stands for Long Lived Queries: http://tools.ietf.org/html/draft-sekar-dns-llq-01
+// Implemented for completeness, as the EDNS0 type code is assigned.
+type EDNS0_LLQ struct {
+	Code      uint16 // Always EDNS0LLQ
+	Version   uint16
+	Opcode    uint16
+	Error     uint16
+	Id        uint64
+	LeaseLife uint32
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_LLQ) Option() uint16 { return EDNS0LLQ }
+
+func (e *EDNS0_LLQ) pack() ([]byte, error) {
+	b := make([]byte, 18)
+	binary.BigEndian.PutUint16(b[0:], e.Version)
+	binary.BigEndian.PutUint16(b[2:], e.Opcode)
+	binary.BigEndian.PutUint16(b[4:], e.Error)
+	binary.BigEndian.PutUint64(b[6:], e.Id)
+	binary.BigEndian.PutUint32(b[14:], e.LeaseLife)
+	return b, nil
+}
+
+func (e *EDNS0_LLQ) unpack(b []byte) error {
+	if len(b) < 18 {
+		return ErrBuf
+	}
+	e.Version = binary.BigEndian.Uint16(b[0:])
+	e.Opcode = binary.BigEndian.Uint16(b[2:])
+	e.Error = binary.BigEndian.Uint16(b[4:])
+	e.Id = binary.BigEndian.Uint64(b[6:])
+	e.LeaseLife = binary.BigEndian.Uint32(b[14:])
+	return nil
+}
+
+func (e *EDNS0_LLQ) String() string {
+	s := strconv.FormatUint(uint64(e.Version), 10) + " " + strconv.FormatUint(uint64(e.Opcode), 10) +
+		" " + strconv.FormatUint(uint64(e.Error), 10) + " " + strconv.FormatUint(e.Id, 10) +
+		" " + strconv.FormatUint(uint64(e.LeaseLife), 10)
+	return s
+}
+func (e *EDNS0_LLQ) copy() EDNS0 {
+	return &EDNS0_LLQ{e.Code, e.Version, e.Opcode, e.Error, e.Id, e.LeaseLife}
+}
+
+// EDNS0_DAU implements the EDNS0 "DNSSEC Algorithm Understood" option. See RFC 6975.
+type EDNS0_DAU struct {
+	Code    uint16 // Always EDNS0DAU
+	AlgCode []uint8
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_DAU) Option() uint16        { return EDNS0DAU }
+func (e *EDNS0_DAU) pack() ([]byte, error) { return e.AlgCode, nil }
+func (e *EDNS0_DAU) unpack(b []byte) error { e.AlgCode = b; return nil }
+
+func (e *EDNS0_DAU) String() string {
+	s := ""
+	for _, alg := range e.AlgCode {
+		if a, ok := AlgorithmToString[alg]; ok {
+			s += " " + a
+		} else {
+			s += " " + strconv.Itoa(int(alg))
+		}
+	}
+	return s
+}
+func (e *EDNS0_DAU) copy() EDNS0 { return &EDNS0_DAU{e.Code, e.AlgCode} }
+
+// EDNS0_DHU implements the EDNS0 "DS Hash Understood" option. See RFC 6975.
+type EDNS0_DHU struct {
+	Code    uint16 // Always EDNS0DHU
+	AlgCode []uint8
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_DHU) Option() uint16        { return EDNS0DHU }
+func (e *EDNS0_DHU) pack() ([]byte, error) { return e.AlgCode, nil }
+func (e *EDNS0_DHU) unpack(b []byte) error { e.AlgCode = b; return nil }
+
+func (e *EDNS0_DHU) String() string {
+	s := ""
+	for _, alg := range e.AlgCode {
+		if a, ok := HashToString[alg]; ok {
+			s += " " + a
+		} else {
+			s += " " + strconv.Itoa(int(alg))
+		}
+	}
+	return s
+}
+func (e *EDNS0_DHU) copy() EDNS0 { return &EDNS0_DHU{e.Code, e.AlgCode} }
+
+// EDNS0_N3U implements the EDNS0 "NSEC3 Hash Understood" option. See RFC 6975.
+type EDNS0_N3U struct {
+	Code    uint16 // Always EDNS0N3U
+	AlgCode []uint8
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_N3U) Option() uint16        { return EDNS0N3U }
+func (e *EDNS0_N3U) pack() ([]byte, error) { return e.AlgCode, nil }
+func (e *EDNS0_N3U) unpack(b []byte) error { e.AlgCode = b; return nil }
+
+func (e *EDNS0_N3U) String() string {
+	// Re-use the hash map
+	s := ""
+	for _, alg := range e.AlgCode {
+		if a, ok := HashToString[alg]; ok {
+			s += " " + a
+		} else {
+			s += " " + strconv.Itoa(int(alg))
+		}
+	}
+	return s
+}
+func (e *EDNS0_N3U) copy() EDNS0 { return &EDNS0_N3U{e.Code, e.AlgCode} }
+
+// EDNS0_EXPIRE implements the EDNS0 option as described in RFC 7314.
+type EDNS0_EXPIRE struct {
+	Code   uint16 // Always EDNS0EXPIRE
+	Expire uint32
+	Empty  bool // Empty is used to signal an empty Expire option in a backwards compatible way, it's not used on the wire.
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_EXPIRE) Option() uint16 { return EDNS0EXPIRE }
+func (e *EDNS0_EXPIRE) copy() EDNS0    { return &EDNS0_EXPIRE{e.Code, e.Expire, e.Empty} }
+
+func (e *EDNS0_EXPIRE) pack() ([]byte, error) {
+	if e.Empty {
+		return []byte{}, nil
+	}
+	b := make([]byte, 4)
+	binary.BigEndian.PutUint32(b, e.Expire)
+	return b, nil
+}
+
+func (e *EDNS0_EXPIRE) unpack(b []byte) error {
+	if len(b) == 0 {
+		// zero-length EXPIRE query, see RFC 7314 Section 2
+		e.Empty = true
+		return nil
+	}
+	if len(b) < 4 {
+		return ErrBuf
+	}
+	e.Expire = binary.BigEndian.Uint32(b)
+	e.Empty = false
+	return nil
+}
+
+func (e *EDNS0_EXPIRE) String() (s string) {
+	if e.Empty {
+		return ""
+	}
+	return strconv.FormatUint(uint64(e.Expire), 10)
+}
+
+// The EDNS0_LOCAL option is used for local/experimental purposes. The option
+// code is recommended to be within the range [EDNS0LOCALSTART, EDNS0LOCALEND]
+// (RFC6891), although any unassigned code can actually be used.  The content of
+// the option is made available in Data, unaltered.
+// Basic use pattern for creating a local option:
+//
+//	o := new(dns.OPT)
+//	o.Hdr.Name = "."
+//	o.Hdr.Rrtype = dns.TypeOPT
+//	e := new(dns.EDNS0_LOCAL)
+//	e.Code = dns.EDNS0LOCALSTART
+//	e.Data = []byte{72, 82, 74}
+//	o.Option = append(o.Option, e)
+type EDNS0_LOCAL struct {
+	Code uint16
+	Data []byte
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_LOCAL) Option() uint16 { return e.Code }
+func (e *EDNS0_LOCAL) String() string {
+	return strconv.FormatInt(int64(e.Code), 10) + ":0x" + hex.EncodeToString(e.Data)
+}
+func (e *EDNS0_LOCAL) copy() EDNS0 {
+	b := make([]byte, len(e.Data))
+	copy(b, e.Data)
+	return &EDNS0_LOCAL{e.Code, b}
+}
+
+func (e *EDNS0_LOCAL) pack() ([]byte, error) {
+	b := make([]byte, len(e.Data))
+	copied := copy(b, e.Data)
+	if copied != len(e.Data) {
+		return nil, ErrBuf
+	}
+	return b, nil
+}
+
+func (e *EDNS0_LOCAL) unpack(b []byte) error {
+	e.Data = make([]byte, len(b))
+	copied := copy(e.Data, b)
+	if copied != len(b) {
+		return ErrBuf
+	}
+	return nil
+}
+
+// EDNS0_TCP_KEEPALIVE is an EDNS0 option that instructs the server to keep
+// the TCP connection alive. See RFC 7828.
+type EDNS0_TCP_KEEPALIVE struct {
+	Code uint16 // Always EDNSTCPKEEPALIVE
+
+	// Timeout is an idle timeout value for the TCP connection, specified in
+	// units of 100 milliseconds, encoded in network byte order. If set to 0,
+	// pack will return a nil slice.
+	Timeout uint16
+
+	// Length is the option's length.
+	// Deprecated: this field is deprecated and is always equal to 0.
+	Length uint16
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_TCP_KEEPALIVE) Option() uint16 { return EDNS0TCPKEEPALIVE }
+
+func (e *EDNS0_TCP_KEEPALIVE) pack() ([]byte, error) {
+	if e.Timeout > 0 {
+		b := make([]byte, 2)
+		binary.BigEndian.PutUint16(b, e.Timeout)
+		return b, nil
+	}
+	return nil, nil
+}
+
+func (e *EDNS0_TCP_KEEPALIVE) unpack(b []byte) error {
+	switch len(b) {
+	case 0:
+	case 2:
+		e.Timeout = binary.BigEndian.Uint16(b)
+	default:
+		return fmt.Errorf("dns: length mismatch, want 0/2 but got %d", len(b))
+	}
+	return nil
+}
+
+func (e *EDNS0_TCP_KEEPALIVE) String() string {
+	s := "use tcp keep-alive"
+	if e.Timeout == 0 {
+		s += ", timeout omitted"
+	} else {
+		s += fmt.Sprintf(", timeout %dms", e.Timeout*100)
+	}
+	return s
+}
+
+func (e *EDNS0_TCP_KEEPALIVE) copy() EDNS0 { return &EDNS0_TCP_KEEPALIVE{e.Code, e.Timeout, e.Length} }
+
+// EDNS0_PADDING option is used to add padding to a request/response. The default
+// value of padding SHOULD be 0x0 but other values MAY be used, for instance if
+// compression is applied before encryption which may break signatures.
+type EDNS0_PADDING struct {
+	Padding []byte
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_PADDING) Option() uint16        { return EDNS0PADDING }
+func (e *EDNS0_PADDING) pack() ([]byte, error) { return e.Padding, nil }
+func (e *EDNS0_PADDING) unpack(b []byte) error { e.Padding = b; return nil }
+func (e *EDNS0_PADDING) String() string        { return fmt.Sprintf("%0X", e.Padding) }
+func (e *EDNS0_PADDING) copy() EDNS0 {
+	b := make([]byte, len(e.Padding))
+	copy(b, e.Padding)
+	return &EDNS0_PADDING{b}
+}
+
+// Extended DNS Error Codes (RFC 8914).
+const (
+	ExtendedErrorCodeOther uint16 = iota
+	ExtendedErrorCodeUnsupportedDNSKEYAlgorithm
+	ExtendedErrorCodeUnsupportedDSDigestType
+	ExtendedErrorCodeStaleAnswer
+	ExtendedErrorCodeForgedAnswer
+	ExtendedErrorCodeDNSSECIndeterminate
+	ExtendedErrorCodeDNSBogus
+	ExtendedErrorCodeSignatureExpired
+	ExtendedErrorCodeSignatureNotYetValid
+	ExtendedErrorCodeDNSKEYMissing
+	ExtendedErrorCodeRRSIGsMissing
+	ExtendedErrorCodeNoZoneKeyBitSet
+	ExtendedErrorCodeNSECMissing
+	ExtendedErrorCodeCachedError
+	ExtendedErrorCodeNotReady
+	ExtendedErrorCodeBlocked
+	ExtendedErrorCodeCensored
+	ExtendedErrorCodeFiltered
+	ExtendedErrorCodeProhibited
+	ExtendedErrorCodeStaleNXDOMAINAnswer
+	ExtendedErrorCodeNotAuthoritative
+	ExtendedErrorCodeNotSupported
+	ExtendedErrorCodeNoReachableAuthority
+	ExtendedErrorCodeNetworkError
+	ExtendedErrorCodeInvalidData
+)
+
+// ExtendedErrorCodeToString maps extended error info codes to a human readable
+// description.
+var ExtendedErrorCodeToString = map[uint16]string{
+	ExtendedErrorCodeOther:                      "Other",
+	ExtendedErrorCodeUnsupportedDNSKEYAlgorithm: "Unsupported DNSKEY Algorithm",
+	ExtendedErrorCodeUnsupportedDSDigestType:    "Unsupported DS Digest Type",
+	ExtendedErrorCodeStaleAnswer:                "Stale Answer",
+	ExtendedErrorCodeForgedAnswer:               "Forged Answer",
+	ExtendedErrorCodeDNSSECIndeterminate:        "DNSSEC Indeterminate",
+	ExtendedErrorCodeDNSBogus:                   "DNSSEC Bogus",
+	ExtendedErrorCodeSignatureExpired:           "Signature Expired",
+	ExtendedErrorCodeSignatureNotYetValid:       "Signature Not Yet Valid",
+	ExtendedErrorCodeDNSKEYMissing:              "DNSKEY Missing",
+	ExtendedErrorCodeRRSIGsMissing:              "RRSIGs Missing",
+	ExtendedErrorCodeNoZoneKeyBitSet:            "No Zone Key Bit Set",
+	ExtendedErrorCodeNSECMissing:                "NSEC Missing",
+	ExtendedErrorCodeCachedError:                "Cached Error",
+	ExtendedErrorCodeNotReady:                   "Not Ready",
+	ExtendedErrorCodeBlocked:                    "Blocked",
+	ExtendedErrorCodeCensored:                   "Censored",
+	ExtendedErrorCodeFiltered:                   "Filtered",
+	ExtendedErrorCodeProhibited:                 "Prohibited",
+	ExtendedErrorCodeStaleNXDOMAINAnswer:        "Stale NXDOMAIN Answer",
+	ExtendedErrorCodeNotAuthoritative:           "Not Authoritative",
+	ExtendedErrorCodeNotSupported:               "Not Supported",
+	ExtendedErrorCodeNoReachableAuthority:       "No Reachable Authority",
+	ExtendedErrorCodeNetworkError:               "Network Error",
+	ExtendedErrorCodeInvalidData:                "Invalid Data",
+}
+
+// StringToExtendedErrorCode is a map from human readable descriptions to
+// extended error info codes.
+var StringToExtendedErrorCode = reverseInt16(ExtendedErrorCodeToString)
+
+// EDNS0_EDE option is used to return additional information about the cause of
+// DNS errors.
+type EDNS0_EDE struct {
+	InfoCode  uint16
+	ExtraText string
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_EDE) Option() uint16 { return EDNS0EDE }
+func (e *EDNS0_EDE) copy() EDNS0    { return &EDNS0_EDE{e.InfoCode, e.ExtraText} }
+
+func (e *EDNS0_EDE) String() string {
+	info := strconv.FormatUint(uint64(e.InfoCode), 10)
+	if s, ok := ExtendedErrorCodeToString[e.InfoCode]; ok {
+		info += fmt.Sprintf(" (%s)", s)
+	}
+	return fmt.Sprintf("%s: (%s)", info, e.ExtraText)
+}
+
+func (e *EDNS0_EDE) pack() ([]byte, error) {
+	b := make([]byte, 2+len(e.ExtraText))
+	binary.BigEndian.PutUint16(b[0:], e.InfoCode)
+	copy(b[2:], []byte(e.ExtraText))
+	return b, nil
+}
+
+func (e *EDNS0_EDE) unpack(b []byte) error {
+	if len(b) < 2 {
+		return ErrBuf
+	}
+	e.InfoCode = binary.BigEndian.Uint16(b[0:])
+	e.ExtraText = string(b[2:])
+	return nil
+}
+
+// The EDNS0_ESU option for ENUM Source-URI Extension
+type EDNS0_ESU struct {
+	Code uint16
+	Uri  string
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_ESU) Option() uint16        { return EDNS0ESU }
+func (e *EDNS0_ESU) String() string        { return e.Uri }
+func (e *EDNS0_ESU) copy() EDNS0           { return &EDNS0_ESU{e.Code, e.Uri} }
+func (e *EDNS0_ESU) pack() ([]byte, error) { return []byte(e.Uri), nil }
+func (e *EDNS0_ESU) unpack(b []byte) error {
+	e.Uri = string(b)
+	return nil
+}

vendor/github.com/miekg/dns/format.go

@@ -0,0 +1,93 @@
+package dns
+
+import (
+	"net"
+	"reflect"
+	"strconv"
+)
+
+// NumField returns the number of rdata fields r has.
+func NumField(r RR) int {
+	return reflect.ValueOf(r).Elem().NumField() - 1 // Remove RR_Header
+}
+
+// Field returns the rdata field i as a string. Fields are indexed starting from 1.
+// RR types that holds slice data, for instance the NSEC type bitmap will return a single
+// string where the types are concatenated using a space.
+// Accessing non existing fields will cause a panic.
+func Field(r RR, i int) string {
+	if i == 0 {
+		return ""
+	}
+	d := reflect.ValueOf(r).Elem().Field(i)
+	switch d.Kind() {
+	case reflect.String:
+		return d.String()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return strconv.FormatInt(d.Int(), 10)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return strconv.FormatUint(d.Uint(), 10)
+	case reflect.Slice:
+		switch reflect.ValueOf(r).Elem().Type().Field(i).Tag {
+		case `dns:"a"`:
+			// TODO(miek): Hmm store this as 16 bytes
+			if d.Len() < net.IPv4len {
+				return ""
+			}
+			if d.Len() < net.IPv6len {
+				return net.IPv4(byte(d.Index(0).Uint()),
+					byte(d.Index(1).Uint()),
+					byte(d.Index(2).Uint()),
+					byte(d.Index(3).Uint())).String()
+			}
+			return net.IPv4(byte(d.Index(12).Uint()),
+				byte(d.Index(13).Uint()),
+				byte(d.Index(14).Uint()),
+				byte(d.Index(15).Uint())).String()
+		case `dns:"aaaa"`:
+			if d.Len() < net.IPv6len {
+				return ""
+			}
+			return net.IP{
+				byte(d.Index(0).Uint()),
+				byte(d.Index(1).Uint()),
+				byte(d.Index(2).Uint()),
+				byte(d.Index(3).Uint()),
+				byte(d.Index(4).Uint()),
+				byte(d.Index(5).Uint()),
+				byte(d.Index(6).Uint()),
+				byte(d.Index(7).Uint()),
+				byte(d.Index(8).Uint()),
+				byte(d.Index(9).Uint()),
+				byte(d.Index(10).Uint()),
+				byte(d.Index(11).Uint()),
+				byte(d.Index(12).Uint()),
+				byte(d.Index(13).Uint()),
+				byte(d.Index(14).Uint()),
+				byte(d.Index(15).Uint()),
+			}.String()
+		case `dns:"nsec"`:
+			if d.Len() == 0 {
+				return ""
+			}
+			s := Type(d.Index(0).Uint()).String()
+			for i := 1; i < d.Len(); i++ {
+				s += " " + Type(d.Index(i).Uint()).String()
+			}
+			return s
+		default:
+			// if it does not have a tag its a string slice
+			fallthrough
+		case `dns:"txt"`:
+			if d.Len() == 0 {
+				return ""
+			}
+			s := d.Index(0).String()
+			for i := 1; i < d.Len(); i++ {
+				s += " " + d.Index(i).String()
+			}
+			return s
+		}
+	}
+	return ""
+}

vendor/github.com/miekg/dns/fuzz.go

@@ -0,0 +1,32 @@
+// +build fuzz
+
+package dns
+
+import "strings"
+
+func Fuzz(data []byte) int {
+	msg := new(Msg)
+
+	if err := msg.Unpack(data); err != nil {
+		return 0
+	}
+	if _, err := msg.Pack(); err != nil {
+		return 0
+	}
+
+	return 1
+}
+
+func FuzzNewRR(data []byte) int {
+	str := string(data)
+	// Do not fuzz lines that include the $INCLUDE keyword and hint the fuzzer
+	// at avoiding them.
+	// See GH#1025 for context.
+	if strings.Contains(strings.ToUpper(str), "$INCLUDE") {
+		return -1
+	}
+	if _, err := NewRR(str); err != nil {
+		return 0
+	}
+	return 1
+}

vendor/github.com/miekg/dns/generate.go

@@ -0,0 +1,247 @@
+package dns
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+)
+
+// Parse the $GENERATE statement as used in BIND9 zones.
+// See http://www.zytrax.com/books/dns/ch8/generate.html for instance.
+// We are called after '$GENERATE '. After which we expect:
+// * the range (12-24/2)
+// * lhs (ownername)
+// * [[ttl][class]]
+// * type
+// * rhs (rdata)
+// But we are lazy here, only the range is parsed *all* occurrences
+// of $ after that are interpreted.
+func (zp *ZoneParser) generate(l lex) (RR, bool) {
+	token := l.token
+	step := int64(1)
+	if i := strings.IndexByte(token, '/'); i >= 0 {
+		if i+1 == len(token) {
+			return zp.setParseError("bad step in $GENERATE range", l)
+		}
+
+		s, err := strconv.ParseInt(token[i+1:], 10, 64)
+		if err != nil || s <= 0 {
+			return zp.setParseError("bad step in $GENERATE range", l)
+		}
+
+		step = s
+		token = token[:i]
+	}
+
+	sx := strings.SplitN(token, "-", 2)
+	if len(sx) != 2 {
+		return zp.setParseError("bad start-stop in $GENERATE range", l)
+	}
+
+	start, err := strconv.ParseInt(sx[0], 10, 64)
+	if err != nil {
+		return zp.setParseError("bad start in $GENERATE range", l)
+	}
+
+	end, err := strconv.ParseInt(sx[1], 10, 64)
+	if err != nil {
+		return zp.setParseError("bad stop in $GENERATE range", l)
+	}
+	if end < 0 || start < 0 || end < start || (end-start)/step > 65535 {
+		return zp.setParseError("bad range in $GENERATE range", l)
+	}
+
+	// _BLANK
+	l, ok := zp.c.Next()
+	if !ok || l.value != zBlank {
+		return zp.setParseError("garbage after $GENERATE range", l)
+	}
+
+	// Create a complete new string, which we then parse again.
+	var s string
+	for l, ok := zp.c.Next(); ok; l, ok = zp.c.Next() {
+		if l.err {
+			return zp.setParseError("bad data in $GENERATE directive", l)
+		}
+		if l.value == zNewline {
+			break
+		}
+
+		s += l.token
+	}
+
+	r := &generateReader{
+		s: s,
+
+		cur:   start,
+		start: start,
+		end:   end,
+		step:  step,
+
+		file: zp.file,
+		lex:  &l,
+	}
+	zp.sub = NewZoneParser(r, zp.origin, zp.file)
+	zp.sub.includeDepth, zp.sub.includeAllowed = zp.includeDepth, zp.includeAllowed
+	zp.sub.generateDisallowed = true
+	zp.sub.SetDefaultTTL(defaultTtl)
+	return zp.subNext()
+}
+
+type generateReader struct {
+	s  string
+	si int
+
+	cur   int64
+	start int64
+	end   int64
+	step  int64
+
+	mod bytes.Buffer
+
+	escape bool
+
+	eof bool
+
+	file string
+	lex  *lex
+}
+
+func (r *generateReader) parseError(msg string, end int) *ParseError {
+	r.eof = true // Make errors sticky.
+
+	l := *r.lex
+	l.token = r.s[r.si-1 : end]
+	l.column += r.si // l.column starts one zBLANK before r.s
+
+	return &ParseError{r.file, msg, l}
+}
+
+func (r *generateReader) Read(p []byte) (int, error) {
+	// NewZLexer, through NewZoneParser, should use ReadByte and
+	// not end up here.
+
+	panic("not implemented")
+}
+
+func (r *generateReader) ReadByte() (byte, error) {
+	if r.eof {
+		return 0, io.EOF
+	}
+	if r.mod.Len() > 0 {
+		return r.mod.ReadByte()
+	}
+
+	if r.si >= len(r.s) {
+		r.si = 0
+		r.cur += r.step
+
+		r.eof = r.cur > r.end || r.cur < 0
+		return '\n', nil
+	}
+
+	si := r.si
+	r.si++
+
+	switch r.s[si] {
+	case '\\':
+		if r.escape {
+			r.escape = false
+			return '\\', nil
+		}
+
+		r.escape = true
+		return r.ReadByte()
+	case '$':
+		if r.escape {
+			r.escape = false
+			return '$', nil
+		}
+
+		mod := "%d"
+
+		if si >= len(r.s)-1 {
+			// End of the string
+			fmt.Fprintf(&r.mod, mod, r.cur)
+			return r.mod.ReadByte()
+		}
+
+		if r.s[si+1] == '$' {
+			r.si++
+			return '$', nil
+		}
+
+		var offset int64
+
+		// Search for { and }
+		if r.s[si+1] == '{' {
+			// Modifier block
+			sep := strings.Index(r.s[si+2:], "}")
+			if sep < 0 {
+				return 0, r.parseError("bad modifier in $GENERATE", len(r.s))
+			}
+
+			var errMsg string
+			mod, offset, errMsg = modToPrintf(r.s[si+2 : si+2+sep])
+			if errMsg != "" {
+				return 0, r.parseError(errMsg, si+3+sep)
+			}
+			if r.start+offset < 0 || r.end+offset > 1<<31-1 {
+				return 0, r.parseError("bad offset in $GENERATE", si+3+sep)
+			}
+
+			r.si += 2 + sep // Jump to it
+		}
+
+		fmt.Fprintf(&r.mod, mod, r.cur+offset)
+		return r.mod.ReadByte()
+	default:
+		if r.escape { // Pretty useless here
+			r.escape = false
+			return r.ReadByte()
+		}
+
+		return r.s[si], nil
+	}
+}
+
+// Convert a $GENERATE modifier 0,0,d to something Printf can deal with.
+func modToPrintf(s string) (string, int64, string) {
+	// Modifier is { offset [ ,width [ ,base ] ] } - provide default
+	// values for optional width and type, if necessary.
+	var offStr, widthStr, base string
+	switch xs := strings.Split(s, ","); len(xs) {
+	case 1:
+		offStr, widthStr, base = xs[0], "0", "d"
+	case 2:
+		offStr, widthStr, base = xs[0], xs[1], "d"
+	case 3:
+		offStr, widthStr, base = xs[0], xs[1], xs[2]
+	default:
+		return "", 0, "bad modifier in $GENERATE"
+	}
+
+	switch base {
+	case "o", "d", "x", "X":
+	default:
+		return "", 0, "bad base in $GENERATE"
+	}
+
+	offset, err := strconv.ParseInt(offStr, 10, 64)
+	if err != nil {
+		return "", 0, "bad offset in $GENERATE"
+	}
+
+	width, err := strconv.ParseInt(widthStr, 10, 64)
+	if err != nil || width < 0 || width > 255 {
+		return "", 0, "bad width in $GENERATE"
+	}
+
+	if width == 0 {
+		return "%" + base, offset, ""
+	}
+
+	return "%0" + widthStr + base, offset, ""
+}

vendor/github.com/miekg/dns/hash.go

@@ -0,0 +1,31 @@
+package dns
+
+import (
+	"bytes"
+	"crypto"
+	"hash"
+)
+
+// identityHash will not hash, it only buffers the data written into it and returns it as-is.
+type identityHash struct {
+	b *bytes.Buffer
+}
+
+// Implement the hash.Hash interface.
+
+func (i identityHash) Write(b []byte) (int, error) { return i.b.Write(b) }
+func (i identityHash) Size() int                   { return i.b.Len() }
+func (i identityHash) BlockSize() int              { return 1024 }
+func (i identityHash) Reset()                      { i.b.Reset() }
+func (i identityHash) Sum(b []byte) []byte         { return append(b, i.b.Bytes()...) }
+
+func hashFromAlgorithm(alg uint8) (hash.Hash, crypto.Hash, error) {
+	hashnumber, ok := AlgorithmToHash[alg]
+	if !ok {
+		return nil, 0, ErrAlg
+	}
+	if hashnumber == 0 {
+		return identityHash{b: &bytes.Buffer{}}, hashnumber, nil
+	}
+	return hashnumber.New(), hashnumber, nil
+}

vendor/github.com/miekg/dns/labels.go

@@ -0,0 +1,212 @@
+package dns
+
+// Holds a bunch of helper functions for dealing with labels.
+
+// SplitDomainName splits a name string into it's labels.
+// www.miek.nl. returns []string{"www", "miek", "nl"}
+// .www.miek.nl. returns []string{"", "www", "miek", "nl"},
+// The root label (.) returns nil. Note that using
+// strings.Split(s) will work in most cases, but does not handle
+// escaped dots (\.) for instance.
+// s must be a syntactically valid domain name, see IsDomainName.
+func SplitDomainName(s string) (labels []string) {
+	if s == "" {
+		return nil
+	}
+	fqdnEnd := 0 // offset of the final '.' or the length of the name
+	idx := Split(s)
+	begin := 0
+	if IsFqdn(s) {
+		fqdnEnd = len(s) - 1
+	} else {
+		fqdnEnd = len(s)
+	}
+
+	switch len(idx) {
+	case 0:
+		return nil
+	case 1:
+		// no-op
+	default:
+		for _, end := range idx[1:] {
+			labels = append(labels, s[begin:end-1])
+			begin = end
+		}
+	}
+
+	return append(labels, s[begin:fqdnEnd])
+}
+
+// CompareDomainName compares the names s1 and s2 and
+// returns how many labels they have in common starting from the *right*.
+// The comparison stops at the first inequality. The names are downcased
+// before the comparison.
+//
+// www.miek.nl. and miek.nl. have two labels in common: miek and nl
+// www.miek.nl. and www.bla.nl. have one label in common: nl
+//
+// s1 and s2 must be syntactically valid domain names.
+func CompareDomainName(s1, s2 string) (n int) {
+	// the first check: root label
+	if s1 == "." || s2 == "." {
+		return 0
+	}
+
+	l1 := Split(s1)
+	l2 := Split(s2)
+
+	j1 := len(l1) - 1 // end
+	i1 := len(l1) - 2 // start
+	j2 := len(l2) - 1
+	i2 := len(l2) - 2
+	// the second check can be done here: last/only label
+	// before we fall through into the for-loop below
+	if equal(s1[l1[j1]:], s2[l2[j2]:]) {
+		n++
+	} else {
+		return
+	}
+	for {
+		if i1 < 0 || i2 < 0 {
+			break
+		}
+		if equal(s1[l1[i1]:l1[j1]], s2[l2[i2]:l2[j2]]) {
+			n++
+		} else {
+			break
+		}
+		j1--
+		i1--
+		j2--
+		i2--
+	}
+	return
+}
+
+// CountLabel counts the number of labels in the string s.
+// s must be a syntactically valid domain name.
+func CountLabel(s string) (labels int) {
+	if s == "." {
+		return
+	}
+	off := 0
+	end := false
+	for {
+		off, end = NextLabel(s, off)
+		labels++
+		if end {
+			return
+		}
+	}
+}
+
+// Split splits a name s into its label indexes.
+// www.miek.nl. returns []int{0, 4, 9}, www.miek.nl also returns []int{0, 4, 9}.
+// The root name (.) returns nil. Also see SplitDomainName.
+// s must be a syntactically valid domain name.
+func Split(s string) []int {
+	if s == "." {
+		return nil
+	}
+	idx := make([]int, 1, 3)
+	off := 0
+	end := false
+
+	for {
+		off, end = NextLabel(s, off)
+		if end {
+			return idx
+		}
+		idx = append(idx, off)
+	}
+}
+
+// NextLabel returns the index of the start of the next label in the
+// string s starting at offset.
+// The bool end is true when the end of the string has been reached.
+// Also see PrevLabel.
+func NextLabel(s string, offset int) (i int, end bool) {
+	if s == "" {
+		return 0, true
+	}
+	for i = offset; i < len(s)-1; i++ {
+		if s[i] != '.' {
+			continue
+		}
+		j := i - 1
+		for j >= 0 && s[j] == '\\' {
+			j--
+		}
+
+		if (j-i)%2 == 0 {
+			continue
+		}
+
+		return i + 1, false
+	}
+	return i + 1, true
+}
+
+// PrevLabel returns the index of the label when starting from the right and
+// jumping n labels to the left.
+// The bool start is true when the start of the string has been overshot.
+// Also see NextLabel.
+func PrevLabel(s string, n int) (i int, start bool) {
+	if s == "" {
+		return 0, true
+	}
+	if n == 0 {
+		return len(s), false
+	}
+
+	l := len(s) - 1
+	if s[l] == '.' {
+		l--
+	}
+
+	for ; l >= 0 && n > 0; l-- {
+		if s[l] != '.' {
+			continue
+		}
+		j := l - 1
+		for j >= 0 && s[j] == '\\' {
+			j--
+		}
+
+		if (j-l)%2 == 0 {
+			continue
+		}
+
+		n--
+		if n == 0 {
+			return l + 1, false
+		}
+	}
+
+	return 0, n > 1
+}
+
+// equal compares a and b while ignoring case. It returns true when equal otherwise false.
+func equal(a, b string) bool {
+	// might be lifted into API function.
+	la := len(a)
+	lb := len(b)
+	if la != lb {
+		return false
+	}
+
+	for i := la - 1; i >= 0; i-- {
+		ai := a[i]
+		bi := b[i]
+		if ai >= 'A' && ai <= 'Z' {
+			ai |= 'a' - 'A'
+		}
+		if bi >= 'A' && bi <= 'Z' {
+			bi |= 'a' - 'A'
+		}
+		if ai != bi {
+			return false
+		}
+	}
+	return true
+}

vendor/github.com/miekg/dns/listen_no_reuseport.go

@@ -0,0 +1,23 @@
+// +build !go1.11 !aix,!darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd
+
+package dns
+
+import "net"
+
+const supportsReusePort = false
+
+func listenTCP(network, addr string, reuseport bool) (net.Listener, error) {
+	if reuseport {
+		// TODO(tmthrgd): return an error?
+	}
+
+	return net.Listen(network, addr)
+}
+
+func listenUDP(network, addr string, reuseport bool) (net.PacketConn, error) {
+	if reuseport {
+		// TODO(tmthrgd): return an error?
+	}
+
+	return net.ListenPacket(network, addr)
+}

vendor/github.com/miekg/dns/listen_reuseport.go

@@ -0,0 +1,44 @@
+// +build go1.11
+// +build aix darwin dragonfly freebsd linux netbsd openbsd
+
+package dns
+
+import (
+	"context"
+	"net"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+const supportsReusePort = true
+
+func reuseportControl(network, address string, c syscall.RawConn) error {
+	var opErr error
+	err := c.Control(func(fd uintptr) {
+		opErr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
+	})
+	if err != nil {
+		return err
+	}
+
+	return opErr
+}
+
+func listenTCP(network, addr string, reuseport bool) (net.Listener, error) {
+	var lc net.ListenConfig
+	if reuseport {
+		lc.Control = reuseportControl
+	}
+
+	return lc.Listen(context.Background(), network, addr)
+}
+
+func listenUDP(network, addr string, reuseport bool) (net.PacketConn, error) {
+	var lc net.ListenConfig
+	if reuseport {
+		lc.Control = reuseportControl
+	}
+
+	return lc.ListenPacket(context.Background(), network, addr)
+}

vendor/github.com/miekg/dns/msg_helpers.go

@@ -0,0 +1,812 @@
+package dns
+
+import (
+	"encoding/base32"
+	"encoding/base64"
+	"encoding/binary"
+	"encoding/hex"
+	"net"
+	"sort"
+	"strings"
+)
+
+// helper functions called from the generated zmsg.go
+
+// These function are named after the tag to help pack/unpack, if there is no tag it is the name
+// of the type they pack/unpack (string, int, etc). We prefix all with unpackData or packData, so packDataA or
+// packDataDomainName.
+
+func unpackDataA(msg []byte, off int) (net.IP, int, error) {
+	if off+net.IPv4len > len(msg) {
+		return nil, len(msg), &Error{err: "overflow unpacking a"}
+	}
+	a := append(make(net.IP, 0, net.IPv4len), msg[off:off+net.IPv4len]...)
+	off += net.IPv4len
+	return a, off, nil
+}
+
+func packDataA(a net.IP, msg []byte, off int) (int, error) {
+	switch len(a) {
+	case net.IPv4len, net.IPv6len:
+		// It must be a slice of 4, even if it is 16, we encode only the first 4
+		if off+net.IPv4len > len(msg) {
+			return len(msg), &Error{err: "overflow packing a"}
+		}
+
+		copy(msg[off:], a.To4())
+		off += net.IPv4len
+	case 0:
+		// Allowed, for dynamic updates.
+	default:
+		return len(msg), &Error{err: "overflow packing a"}
+	}
+	return off, nil
+}
+
+func unpackDataAAAA(msg []byte, off int) (net.IP, int, error) {
+	if off+net.IPv6len > len(msg) {
+		return nil, len(msg), &Error{err: "overflow unpacking aaaa"}
+	}
+	aaaa := append(make(net.IP, 0, net.IPv6len), msg[off:off+net.IPv6len]...)
+	off += net.IPv6len
+	return aaaa, off, nil
+}
+
+func packDataAAAA(aaaa net.IP, msg []byte, off int) (int, error) {
+	switch len(aaaa) {
+	case net.IPv6len:
+		if off+net.IPv6len > len(msg) {
+			return len(msg), &Error{err: "overflow packing aaaa"}
+		}
+
+		copy(msg[off:], aaaa)
+		off += net.IPv6len
+	case 0:
+		// Allowed, dynamic updates.
+	default:
+		return len(msg), &Error{err: "overflow packing aaaa"}
+	}
+	return off, nil
+}
+
+// unpackHeader unpacks an RR header, returning the offset to the end of the header and a
+// re-sliced msg according to the expected length of the RR.
+func unpackHeader(msg []byte, off int) (rr RR_Header, off1 int, truncmsg []byte, err error) {
+	hdr := RR_Header{}
+	if off == len(msg) {
+		return hdr, off, msg, nil
+	}
+
+	hdr.Name, off, err = UnpackDomainName(msg, off)
+	if err != nil {
+		return hdr, len(msg), msg, err
+	}
+	hdr.Rrtype, off, err = unpackUint16(msg, off)
+	if err != nil {
+		return hdr, len(msg), msg, err
+	}
+	hdr.Class, off, err = unpackUint16(msg, off)
+	if err != nil {
+		return hdr, len(msg), msg, err
+	}
+	hdr.Ttl, off, err = unpackUint32(msg, off)
+	if err != nil {
+		return hdr, len(msg), msg, err
+	}
+	hdr.Rdlength, off, err = unpackUint16(msg, off)
+	if err != nil {
+		return hdr, len(msg), msg, err
+	}
+	msg, err = truncateMsgFromRdlength(msg, off, hdr.Rdlength)
+	return hdr, off, msg, err
+}
+
+// packHeader packs an RR header, returning the offset to the end of the header.
+// See PackDomainName for documentation about the compression.
+func (hdr RR_Header) packHeader(msg []byte, off int, compression compressionMap, compress bool) (int, error) {
+	if off == len(msg) {
+		return off, nil
+	}
+
+	off, err := packDomainName(hdr.Name, msg, off, compression, compress)
+	if err != nil {
+		return len(msg), err
+	}
+	off, err = packUint16(hdr.Rrtype, msg, off)
+	if err != nil {
+		return len(msg), err
+	}
+	off, err = packUint16(hdr.Class, msg, off)
+	if err != nil {
+		return len(msg), err
+	}
+	off, err = packUint32(hdr.Ttl, msg, off)
+	if err != nil {
+		return len(msg), err
+	}
+	off, err = packUint16(0, msg, off) // The RDLENGTH field will be set later in packRR.
+	if err != nil {
+		return len(msg), err
+	}
+	return off, nil
+}
+
+// helper helper functions.
+
+// truncateMsgFromRdLength truncates msg to match the expected length of the RR.
+// Returns an error if msg is smaller than the expected size.
+func truncateMsgFromRdlength(msg []byte, off int, rdlength uint16) (truncmsg []byte, err error) {
+	lenrd := off + int(rdlength)
+	if lenrd > len(msg) {
+		return msg, &Error{err: "overflowing header size"}
+	}
+	return msg[:lenrd], nil
+}
+
+var base32HexNoPadEncoding = base32.HexEncoding.WithPadding(base32.NoPadding)
+
+func fromBase32(s []byte) (buf []byte, err error) {
+	for i, b := range s {
+		if b >= 'a' && b <= 'z' {
+			s[i] = b - 32
+		}
+	}
+	buflen := base32HexNoPadEncoding.DecodedLen(len(s))
+	buf = make([]byte, buflen)
+	n, err := base32HexNoPadEncoding.Decode(buf, s)
+	buf = buf[:n]
+	return
+}
+
+func toBase32(b []byte) string {
+	return base32HexNoPadEncoding.EncodeToString(b)
+}
+
+func fromBase64(s []byte) (buf []byte, err error) {
+	buflen := base64.StdEncoding.DecodedLen(len(s))
+	buf = make([]byte, buflen)
+	n, err := base64.StdEncoding.Decode(buf, s)
+	buf = buf[:n]
+	return
+}
+
+func toBase64(b []byte) string { return base64.StdEncoding.EncodeToString(b) }
+
+// dynamicUpdate returns true if the Rdlength is zero.
+func noRdata(h RR_Header) bool { return h.Rdlength == 0 }
+
+func unpackUint8(msg []byte, off int) (i uint8, off1 int, err error) {
+	if off+1 > len(msg) {
+		return 0, len(msg), &Error{err: "overflow unpacking uint8"}
+	}
+	return msg[off], off + 1, nil
+}
+
+func packUint8(i uint8, msg []byte, off int) (off1 int, err error) {
+	if off+1 > len(msg) {
+		return len(msg), &Error{err: "overflow packing uint8"}
+	}
+	msg[off] = i
+	return off + 1, nil
+}
+
+func unpackUint16(msg []byte, off int) (i uint16, off1 int, err error) {
+	if off+2 > len(msg) {
+		return 0, len(msg), &Error{err: "overflow unpacking uint16"}
+	}
+	return binary.BigEndian.Uint16(msg[off:]), off + 2, nil
+}
+
+func packUint16(i uint16, msg []byte, off int) (off1 int, err error) {
+	if off+2 > len(msg) {
+		return len(msg), &Error{err: "overflow packing uint16"}
+	}
+	binary.BigEndian.PutUint16(msg[off:], i)
+	return off + 2, nil
+}
+
+func unpackUint32(msg []byte, off int) (i uint32, off1 int, err error) {
+	if off+4 > len(msg) {
+		return 0, len(msg), &Error{err: "overflow unpacking uint32"}
+	}
+	return binary.BigEndian.Uint32(msg[off:]), off + 4, nil
+}
+
+func packUint32(i uint32, msg []byte, off int) (off1 int, err error) {
+	if off+4 > len(msg) {
+		return len(msg), &Error{err: "overflow packing uint32"}
+	}
+	binary.BigEndian.PutUint32(msg[off:], i)
+	return off + 4, nil
+}
+
+func unpackUint48(msg []byte, off int) (i uint64, off1 int, err error) {
+	if off+6 > len(msg) {
+		return 0, len(msg), &Error{err: "overflow unpacking uint64 as uint48"}
+	}
+	// Used in TSIG where the last 48 bits are occupied, so for now, assume a uint48 (6 bytes)
+	i = uint64(msg[off])<<40 | uint64(msg[off+1])<<32 | uint64(msg[off+2])<<24 | uint64(msg[off+3])<<16 |
+		uint64(msg[off+4])<<8 | uint64(msg[off+5])
+	off += 6
+	return i, off, nil
+}
+
+func packUint48(i uint64, msg []byte, off int) (off1 int, err error) {
+	if off+6 > len(msg) {
+		return len(msg), &Error{err: "overflow packing uint64 as uint48"}
+	}
+	msg[off] = byte(i >> 40)
+	msg[off+1] = byte(i >> 32)
+	msg[off+2] = byte(i >> 24)
+	msg[off+3] = byte(i >> 16)
+	msg[off+4] = byte(i >> 8)
+	msg[off+5] = byte(i)
+	off += 6
+	return off, nil
+}
+
+func unpackUint64(msg []byte, off int) (i uint64, off1 int, err error) {
+	if off+8 > len(msg) {
+		return 0, len(msg), &Error{err: "overflow unpacking uint64"}
+	}
+	return binary.BigEndian.Uint64(msg[off:]), off + 8, nil
+}
+
+func packUint64(i uint64, msg []byte, off int) (off1 int, err error) {
+	if off+8 > len(msg) {
+		return len(msg), &Error{err: "overflow packing uint64"}
+	}
+	binary.BigEndian.PutUint64(msg[off:], i)
+	off += 8
+	return off, nil
+}
+
+func unpackString(msg []byte, off int) (string, int, error) {
+	if off+1 > len(msg) {
+		return "", off, &Error{err: "overflow unpacking txt"}
+	}
+	l := int(msg[off])
+	off++
+	if off+l > len(msg) {
+		return "", off, &Error{err: "overflow unpacking txt"}
+	}
+	var s strings.Builder
+	consumed := 0
+	for i, b := range msg[off : off+l] {
+		switch {
+		case b == '"' || b == '\\':
+			if consumed == 0 {
+				s.Grow(l * 2)
+			}
+			s.Write(msg[off+consumed : off+i])
+			s.WriteByte('\\')
+			s.WriteByte(b)
+			consumed = i + 1
+		case b < ' ' || b > '~': // unprintable
+			if consumed == 0 {
+				s.Grow(l * 2)
+			}
+			s.Write(msg[off+consumed : off+i])
+			s.WriteString(escapeByte(b))
+			consumed = i + 1
+		}
+	}
+	if consumed == 0 { // no escaping needed
+		return string(msg[off : off+l]), off + l, nil
+	}
+	s.Write(msg[off+consumed : off+l])
+	return s.String(), off + l, nil
+}
+
+func packString(s string, msg []byte, off int) (int, error) {
+	txtTmp := make([]byte, 256*4+1)
+	off, err := packTxtString(s, msg, off, txtTmp)
+	if err != nil {
+		return len(msg), err
+	}
+	return off, nil
+}
+
+func unpackStringBase32(msg []byte, off, end int) (string, int, error) {
+	if end > len(msg) {
+		return "", len(msg), &Error{err: "overflow unpacking base32"}
+	}
+	s := toBase32(msg[off:end])
+	return s, end, nil
+}
+
+func packStringBase32(s string, msg []byte, off int) (int, error) {
+	b32, err := fromBase32([]byte(s))
+	if err != nil {
+		return len(msg), err
+	}
+	if off+len(b32) > len(msg) {
+		return len(msg), &Error{err: "overflow packing base32"}
+	}
+	copy(msg[off:off+len(b32)], b32)
+	off += len(b32)
+	return off, nil
+}
+
+func unpackStringBase64(msg []byte, off, end int) (string, int, error) {
+	// Rest of the RR is base64 encoded value, so we don't need an explicit length
+	// to be set. Thus far all RR's that have base64 encoded fields have those as their
+	// last one. What we do need is the end of the RR!
+	if end > len(msg) {
+		return "", len(msg), &Error{err: "overflow unpacking base64"}
+	}
+	s := toBase64(msg[off:end])
+	return s, end, nil
+}
+
+func packStringBase64(s string, msg []byte, off int) (int, error) {
+	b64, err := fromBase64([]byte(s))
+	if err != nil {
+		return len(msg), err
+	}
+	if off+len(b64) > len(msg) {
+		return len(msg), &Error{err: "overflow packing base64"}
+	}
+	copy(msg[off:off+len(b64)], b64)
+	off += len(b64)
+	return off, nil
+}
+
+func unpackStringHex(msg []byte, off, end int) (string, int, error) {
+	// Rest of the RR is hex encoded value, so we don't need an explicit length
+	// to be set. NSEC and TSIG have hex fields with a length field.
+	// What we do need is the end of the RR!
+	if end > len(msg) {
+		return "", len(msg), &Error{err: "overflow unpacking hex"}
+	}
+
+	s := hex.EncodeToString(msg[off:end])
+	return s, end, nil
+}
+
+func packStringHex(s string, msg []byte, off int) (int, error) {
+	h, err := hex.DecodeString(s)
+	if err != nil {
+		return len(msg), err
+	}
+	if off+len(h) > len(msg) {
+		return len(msg), &Error{err: "overflow packing hex"}
+	}
+	copy(msg[off:off+len(h)], h)
+	off += len(h)
+	return off, nil
+}
+
+func unpackStringAny(msg []byte, off, end int) (string, int, error) {
+	if end > len(msg) {
+		return "", len(msg), &Error{err: "overflow unpacking anything"}
+	}
+	return string(msg[off:end]), end, nil
+}
+
+func packStringAny(s string, msg []byte, off int) (int, error) {
+	if off+len(s) > len(msg) {
+		return len(msg), &Error{err: "overflow packing anything"}
+	}
+	copy(msg[off:off+len(s)], s)
+	off += len(s)
+	return off, nil
+}
+
+func unpackStringTxt(msg []byte, off int) ([]string, int, error) {
+	txt, off, err := unpackTxt(msg, off)
+	if err != nil {
+		return nil, len(msg), err
+	}
+	return txt, off, nil
+}
+
+func packStringTxt(s []string, msg []byte, off int) (int, error) {
+	txtTmp := make([]byte, 256*4+1) // If the whole string consists out of \DDD we need this many.
+	off, err := packTxt(s, msg, off, txtTmp)
+	if err != nil {
+		return len(msg), err
+	}
+	return off, nil
+}
+
+func unpackDataOpt(msg []byte, off int) ([]EDNS0, int, error) {
+	var edns []EDNS0
+Option:
+	var code uint16
+	if off+4 > len(msg) {
+		return nil, len(msg), &Error{err: "overflow unpacking opt"}
+	}
+	code = binary.BigEndian.Uint16(msg[off:])
+	off += 2
+	optlen := binary.BigEndian.Uint16(msg[off:])
+	off += 2
+	if off+int(optlen) > len(msg) {
+		return nil, len(msg), &Error{err: "overflow unpacking opt"}
+	}
+	e := makeDataOpt(code)
+	if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
+		return nil, len(msg), err
+	}
+	edns = append(edns, e)
+	off += int(optlen)
+
+	if off < len(msg) {
+		goto Option
+	}
+
+	return edns, off, nil
+}
+
+func packDataOpt(options []EDNS0, msg []byte, off int) (int, error) {
+	for _, el := range options {
+		b, err := el.pack()
+		if err != nil || off+4 > len(msg) {
+			return len(msg), &Error{err: "overflow packing opt"}
+		}
+		binary.BigEndian.PutUint16(msg[off:], el.Option())      // Option code
+		binary.BigEndian.PutUint16(msg[off+2:], uint16(len(b))) // Length
+		off += 4
+		if off+len(b) > len(msg) {
+			return len(msg), &Error{err: "overflow packing opt"}
+		}
+		// Actual data
+		copy(msg[off:off+len(b)], b)
+		off += len(b)
+	}
+	return off, nil
+}
+
+func unpackStringOctet(msg []byte, off int) (string, int, error) {
+	s := string(msg[off:])
+	return s, len(msg), nil
+}
+
+func packStringOctet(s string, msg []byte, off int) (int, error) {
+	txtTmp := make([]byte, 256*4+1)
+	off, err := packOctetString(s, msg, off, txtTmp)
+	if err != nil {
+		return len(msg), err
+	}
+	return off, nil
+}
+
+func unpackDataNsec(msg []byte, off int) ([]uint16, int, error) {
+	var nsec []uint16
+	length, window, lastwindow := 0, 0, -1
+	for off < len(msg) {
+		if off+2 > len(msg) {
+			return nsec, len(msg), &Error{err: "overflow unpacking nsecx"}
+		}
+		window = int(msg[off])
+		length = int(msg[off+1])
+		off += 2
+		if window <= lastwindow {
+			// RFC 4034: Blocks are present in the NSEC RR RDATA in
+			// increasing numerical order.
+			return nsec, len(msg), &Error{err: "out of order NSEC block"}
+		}
+		if length == 0 {
+			// RFC 4034: Blocks with no types present MUST NOT be included.
+			return nsec, len(msg), &Error{err: "empty NSEC block"}
+		}
+		if length > 32 {
+			return nsec, len(msg), &Error{err: "NSEC block too long"}
+		}
+		if off+length > len(msg) {
+			return nsec, len(msg), &Error{err: "overflowing NSEC block"}
+		}
+
+		// Walk the bytes in the window and extract the type bits
+		for j, b := range msg[off : off+length] {
+			// Check the bits one by one, and set the type
+			if b&0x80 == 0x80 {
+				nsec = append(nsec, uint16(window*256+j*8+0))
+			}
+			if b&0x40 == 0x40 {
+				nsec = append(nsec, uint16(window*256+j*8+1))
+			}
+			if b&0x20 == 0x20 {
+				nsec = append(nsec, uint16(window*256+j*8+2))
+			}
+			if b&0x10 == 0x10 {
+				nsec = append(nsec, uint16(window*256+j*8+3))
+			}
+			if b&0x8 == 0x8 {
+				nsec = append(nsec, uint16(window*256+j*8+4))
+			}
+			if b&0x4 == 0x4 {
+				nsec = append(nsec, uint16(window*256+j*8+5))
+			}
+			if b&0x2 == 0x2 {
+				nsec = append(nsec, uint16(window*256+j*8+6))
+			}
+			if b&0x1 == 0x1 {
+				nsec = append(nsec, uint16(window*256+j*8+7))
+			}
+		}
+		off += length
+		lastwindow = window
+	}
+	return nsec, off, nil
+}
+
+// typeBitMapLen is a helper function which computes the "maximum" length of
+// a the NSEC Type BitMap field.
+func typeBitMapLen(bitmap []uint16) int {
+	var l int
+	var lastwindow, lastlength uint16
+	for _, t := range bitmap {
+		window := t / 256
+		length := (t-window*256)/8 + 1
+		if window > lastwindow && lastlength != 0 { // New window, jump to the new offset
+			l += int(lastlength) + 2
+			lastlength = 0
+		}
+		if window < lastwindow || length < lastlength {
+			// packDataNsec would return Error{err: "nsec bits out of order"} here, but
+			// when computing the length, we want do be liberal.
+			continue
+		}
+		lastwindow, lastlength = window, length
+	}
+	l += int(lastlength) + 2
+	return l
+}
+
+func packDataNsec(bitmap []uint16, msg []byte, off int) (int, error) {
+	if len(bitmap) == 0 {
+		return off, nil
+	}
+	if off > len(msg) {
+		return off, &Error{err: "overflow packing nsec"}
+	}
+	toZero := msg[off:]
+	if maxLen := typeBitMapLen(bitmap); maxLen < len(toZero) {
+		toZero = toZero[:maxLen]
+	}
+	for i := range toZero {
+		toZero[i] = 0
+	}
+	var lastwindow, lastlength uint16
+	for _, t := range bitmap {
+		window := t / 256
+		length := (t-window*256)/8 + 1
+		if window > lastwindow && lastlength != 0 { // New window, jump to the new offset
+			off += int(lastlength) + 2
+			lastlength = 0
+		}
+		if window < lastwindow || length < lastlength {
+			return len(msg), &Error{err: "nsec bits out of order"}
+		}
+		if off+2+int(length) > len(msg) {
+			return len(msg), &Error{err: "overflow packing nsec"}
+		}
+		// Setting the window #
+		msg[off] = byte(window)
+		// Setting the octets length
+		msg[off+1] = byte(length)
+		// Setting the bit value for the type in the right octet
+		msg[off+1+int(length)] |= byte(1 << (7 - t%8))
+		lastwindow, lastlength = window, length
+	}
+	off += int(lastlength) + 2
+	return off, nil
+}
+
+func unpackDataSVCB(msg []byte, off int) ([]SVCBKeyValue, int, error) {
+	var xs []SVCBKeyValue
+	var code uint16
+	var length uint16
+	var err error
+	for off < len(msg) {
+		code, off, err = unpackUint16(msg, off)
+		if err != nil {
+			return nil, len(msg), &Error{err: "overflow unpacking SVCB"}
+		}
+		length, off, err = unpackUint16(msg, off)
+		if err != nil || off+int(length) > len(msg) {
+			return nil, len(msg), &Error{err: "overflow unpacking SVCB"}
+		}
+		e := makeSVCBKeyValue(SVCBKey(code))
+		if e == nil {
+			return nil, len(msg), &Error{err: "bad SVCB key"}
+		}
+		if err := e.unpack(msg[off : off+int(length)]); err != nil {
+			return nil, len(msg), err
+		}
+		if len(xs) > 0 && e.Key() <= xs[len(xs)-1].Key() {
+			return nil, len(msg), &Error{err: "SVCB keys not in strictly increasing order"}
+		}
+		xs = append(xs, e)
+		off += int(length)
+	}
+	return xs, off, nil
+}
+
+func packDataSVCB(pairs []SVCBKeyValue, msg []byte, off int) (int, error) {
+	pairs = append([]SVCBKeyValue(nil), pairs...)
+	sort.Slice(pairs, func(i, j int) bool {
+		return pairs[i].Key() < pairs[j].Key()
+	})
+	prev := svcb_RESERVED
+	for _, el := range pairs {
+		if el.Key() == prev {
+			return len(msg), &Error{err: "repeated SVCB keys are not allowed"}
+		}
+		prev = el.Key()
+		packed, err := el.pack()
+		if err != nil {
+			return len(msg), err
+		}
+		off, err = packUint16(uint16(el.Key()), msg, off)
+		if err != nil {
+			return len(msg), &Error{err: "overflow packing SVCB"}
+		}
+		off, err = packUint16(uint16(len(packed)), msg, off)
+		if err != nil || off+len(packed) > len(msg) {
+			return len(msg), &Error{err: "overflow packing SVCB"}
+		}
+		copy(msg[off:off+len(packed)], packed)
+		off += len(packed)
+	}
+	return off, nil
+}
+
+func unpackDataDomainNames(msg []byte, off, end int) ([]string, int, error) {
+	var (
+		servers []string
+		s       string
+		err     error
+	)
+	if end > len(msg) {
+		return nil, len(msg), &Error{err: "overflow unpacking domain names"}
+	}
+	for off < end {
+		s, off, err = UnpackDomainName(msg, off)
+		if err != nil {
+			return servers, len(msg), err
+		}
+		servers = append(servers, s)
+	}
+	return servers, off, nil
+}
+
+func packDataDomainNames(names []string, msg []byte, off int, compression compressionMap, compress bool) (int, error) {
+	var err error
+	for _, name := range names {
+		off, err = packDomainName(name, msg, off, compression, compress)
+		if err != nil {
+			return len(msg), err
+		}
+	}
+	return off, nil
+}
+
+func packDataApl(data []APLPrefix, msg []byte, off int) (int, error) {
+	var err error
+	for i := range data {
+		off, err = packDataAplPrefix(&data[i], msg, off)
+		if err != nil {
+			return len(msg), err
+		}
+	}
+	return off, nil
+}
+
+func packDataAplPrefix(p *APLPrefix, msg []byte, off int) (int, error) {
+	if len(p.Network.IP) != len(p.Network.Mask) {
+		return len(msg), &Error{err: "address and mask lengths don't match"}
+	}
+
+	var err error
+	prefix, _ := p.Network.Mask.Size()
+	addr := p.Network.IP.Mask(p.Network.Mask)[:(prefix+7)/8]
+
+	switch len(p.Network.IP) {
+	case net.IPv4len:
+		off, err = packUint16(1, msg, off)
+	case net.IPv6len:
+		off, err = packUint16(2, msg, off)
+	default:
+		err = &Error{err: "unrecognized address family"}
+	}
+	if err != nil {
+		return len(msg), err
+	}
+
+	off, err = packUint8(uint8(prefix), msg, off)
+	if err != nil {
+		return len(msg), err
+	}
+
+	var n uint8
+	if p.Negation {
+		n = 0x80
+	}
+
+	// trim trailing zero bytes as specified in RFC3123 Sections 4.1 and 4.2.
+	i := len(addr) - 1
+	for ; i >= 0 && addr[i] == 0; i-- {
+	}
+	addr = addr[:i+1]
+
+	adflen := uint8(len(addr)) & 0x7f
+	off, err = packUint8(n|adflen, msg, off)
+	if err != nil {
+		return len(msg), err
+	}
+
+	if off+len(addr) > len(msg) {
+		return len(msg), &Error{err: "overflow packing APL prefix"}
+	}
+	off += copy(msg[off:], addr)
+
+	return off, nil
+}
+
+func unpackDataApl(msg []byte, off int) ([]APLPrefix, int, error) {
+	var result []APLPrefix
+	for off < len(msg) {
+		prefix, end, err := unpackDataAplPrefix(msg, off)
+		if err != nil {
+			return nil, len(msg), err
+		}
+		off = end
+		result = append(result, prefix)
+	}
+	return result, off, nil
+}
+
+func unpackDataAplPrefix(msg []byte, off int) (APLPrefix, int, error) {
+	family, off, err := unpackUint16(msg, off)
+	if err != nil {
+		return APLPrefix{}, len(msg), &Error{err: "overflow unpacking APL prefix"}
+	}
+	prefix, off, err := unpackUint8(msg, off)
+	if err != nil {
+		return APLPrefix{}, len(msg), &Error{err: "overflow unpacking APL prefix"}
+	}
+	nlen, off, err := unpackUint8(msg, off)
+	if err != nil {
+		return APLPrefix{}, len(msg), &Error{err: "overflow unpacking APL prefix"}
+	}
+
+	var ip []byte
+	switch family {
+	case 1:
+		ip = make([]byte, net.IPv4len)
+	case 2:
+		ip = make([]byte, net.IPv6len)
+	default:
+		return APLPrefix{}, len(msg), &Error{err: "unrecognized APL address family"}
+	}
+	if int(prefix) > 8*len(ip) {
+		return APLPrefix{}, len(msg), &Error{err: "APL prefix too long"}
+	}
+	afdlen := int(nlen & 0x7f)
+	if afdlen > len(ip) {
+		return APLPrefix{}, len(msg), &Error{err: "APL length too long"}
+	}
+	if off+afdlen > len(msg) {
+		return APLPrefix{}, len(msg), &Error{err: "overflow unpacking APL address"}
+	}
+
+	// Address MUST NOT contain trailing zero bytes per RFC3123 Sections 4.1 and 4.2.
+	off += copy(ip, msg[off:off+afdlen])
+	if afdlen > 0 {
+		last := ip[afdlen-1]
+		if last == 0 {
+			return APLPrefix{}, len(msg), &Error{err: "extra APL address bits"}
+		}
+	}
+	ipnet := net.IPNet{
+		IP:   ip,
+		Mask: net.CIDRMask(int(prefix), 8*len(ip)),
+	}
+
+	return APLPrefix{
+		Negation: (nlen & 0x80) != 0,
+		Network:  ipnet,
+	}, off, nil
+}

vendor/github.com/miekg/dns/msg_truncate.go

@@ -0,0 +1,117 @@
+package dns
+
+// Truncate ensures the reply message will fit into the requested buffer
+// size by removing records that exceed the requested size.
+//
+// It will first check if the reply fits without compression and then with
+// compression. If it won't fit with compression, Truncate then walks the
+// record adding as many records as possible without exceeding the
+// requested buffer size.
+//
+// If the message fits within the requested size without compression,
+// Truncate will set the message's Compress attribute to false. It is
+// the caller's responsibility to set it back to true if they wish to
+// compress the payload regardless of size.
+//
+// The TC bit will be set if any records were excluded from the message.
+// If the TC bit is already set on the message it will be retained.
+// TC indicates that the client should retry over TCP.
+//
+// According to RFC 2181, the TC bit should only be set if not all of the
+// "required" RRs can be included in the response. Unfortunately, we have
+// no way of knowing which RRs are required so we set the TC bit if any RR
+// had to be omitted from the response.
+//
+// The appropriate buffer size can be retrieved from the requests OPT
+// record, if present, and is transport specific otherwise. dns.MinMsgSize
+// should be used for UDP requests without an OPT record, and
+// dns.MaxMsgSize for TCP requests without an OPT record.
+func (dns *Msg) Truncate(size int) {
+	if dns.IsTsig() != nil {
+		// To simplify this implementation, we don't perform
+		// truncation on responses with a TSIG record.
+		return
+	}
+
+	// RFC 6891 mandates that the payload size in an OPT record
+	// less than 512 (MinMsgSize) bytes must be treated as equal to 512 bytes.
+	//
+	// For ease of use, we impose that restriction here.
+	if size < MinMsgSize {
+		size = MinMsgSize
+	}
+
+	l := msgLenWithCompressionMap(dns, nil) // uncompressed length
+	if l <= size {
+		// Don't waste effort compressing this message.
+		dns.Compress = false
+		return
+	}
+
+	dns.Compress = true
+
+	edns0 := dns.popEdns0()
+	if edns0 != nil {
+		// Account for the OPT record that gets added at the end,
+		// by subtracting that length from our budget.
+		//
+		// The EDNS(0) OPT record must have the root domain and
+		// it's length is thus unaffected by compression.
+		size -= Len(edns0)
+	}
+
+	compression := make(map[string]struct{})
+
+	l = headerSize
+	for _, r := range dns.Question {
+		l += r.len(l, compression)
+	}
+
+	var numAnswer int
+	if l < size {
+		l, numAnswer = truncateLoop(dns.Answer, size, l, compression)
+	}
+
+	var numNS int
+	if l < size {
+		l, numNS = truncateLoop(dns.Ns, size, l, compression)
+	}
+
+	var numExtra int
+	if l < size {
+		_, numExtra = truncateLoop(dns.Extra, size, l, compression)
+	}
+
+	// See the function documentation for when we set this.
+	dns.Truncated = dns.Truncated || len(dns.Answer) > numAnswer ||
+		len(dns.Ns) > numNS || len(dns.Extra) > numExtra
+
+	dns.Answer = dns.Answer[:numAnswer]
+	dns.Ns = dns.Ns[:numNS]
+	dns.Extra = dns.Extra[:numExtra]
+
+	if edns0 != nil {
+		// Add the OPT record back onto the additional section.
+		dns.Extra = append(dns.Extra, edns0)
+	}
+}
+
+func truncateLoop(rrs []RR, size, l int, compression map[string]struct{}) (int, int) {
+	for i, r := range rrs {
+		if r == nil {
+			continue
+		}
+
+		l += r.len(l, compression)
+		if l > size {
+			// Return size, rather than l prior to this record,
+			// to prevent any further records being added.
+			return size, i
+		}
+		if l == size {
+			return l, i + 1
+		}
+	}
+
+	return l, len(rrs)
+}

vendor/github.com/miekg/dns/nsecx.go

@@ -0,0 +1,95 @@
+package dns
+
+import (
+	"crypto/sha1"
+	"encoding/hex"
+	"strings"
+)
+
+// HashName hashes a string (label) according to RFC 5155. It returns the hashed string in uppercase.
+func HashName(label string, ha uint8, iter uint16, salt string) string {
+	if ha != SHA1 {
+		return ""
+	}
+
+	wireSalt := make([]byte, hex.DecodedLen(len(salt)))
+	n, err := packStringHex(salt, wireSalt, 0)
+	if err != nil {
+		return ""
+	}
+	wireSalt = wireSalt[:n]
+
+	name := make([]byte, 255)
+	off, err := PackDomainName(strings.ToLower(label), name, 0, nil, false)
+	if err != nil {
+		return ""
+	}
+	name = name[:off]
+
+	s := sha1.New()
+	// k = 0
+	s.Write(name)
+	s.Write(wireSalt)
+	nsec3 := s.Sum(nil)
+
+	// k > 0
+	for k := uint16(0); k < iter; k++ {
+		s.Reset()
+		s.Write(nsec3)
+		s.Write(wireSalt)
+		nsec3 = s.Sum(nsec3[:0])
+	}
+
+	return toBase32(nsec3)
+}
+
+// Cover returns true if a name is covered by the NSEC3 record.
+func (rr *NSEC3) Cover(name string) bool {
+	nameHash := HashName(name, rr.Hash, rr.Iterations, rr.Salt)
+	owner := strings.ToUpper(rr.Hdr.Name)
+	labelIndices := Split(owner)
+	if len(labelIndices) < 2 {
+		return false
+	}
+	ownerHash := owner[:labelIndices[1]-1]
+	ownerZone := owner[labelIndices[1]:]
+	if !IsSubDomain(ownerZone, strings.ToUpper(name)) { // name is outside owner zone
+		return false
+	}
+
+	nextHash := rr.NextDomain
+
+	// if empty interval found, try cover wildcard hashes so nameHash shouldn't match with ownerHash
+	if ownerHash == nextHash && nameHash != ownerHash { // empty interval
+		return true
+	}
+	if ownerHash > nextHash { // end of zone
+		if nameHash > ownerHash { // covered since there is nothing after ownerHash
+			return true
+		}
+		return nameHash < nextHash // if nameHash is before beginning of zone it is covered
+	}
+	if nameHash < ownerHash { // nameHash is before ownerHash, not covered
+		return false
+	}
+	return nameHash < nextHash // if nameHash is before nextHash is it covered (between ownerHash and nextHash)
+}
+
+// Match returns true if a name matches the NSEC3 record
+func (rr *NSEC3) Match(name string) bool {
+	nameHash := HashName(name, rr.Hash, rr.Iterations, rr.Salt)
+	owner := strings.ToUpper(rr.Hdr.Name)
+	labelIndices := Split(owner)
+	if len(labelIndices) < 2 {
+		return false
+	}
+	ownerHash := owner[:labelIndices[1]-1]
+	ownerZone := owner[labelIndices[1]:]
+	if !IsSubDomain(ownerZone, strings.ToUpper(name)) { // name is outside owner zone
+		return false
+	}
+	if ownerHash == nameHash {
+		return true
+	}
+	return false
+}

vendor/github.com/miekg/dns/privaterr.go

@@ -0,0 +1,113 @@
+package dns
+
+import "strings"
+
+// PrivateRdata is an interface used for implementing "Private Use" RR types, see
+// RFC 6895. This allows one to experiment with new RR types, without requesting an
+// official type code. Also see dns.PrivateHandle and dns.PrivateHandleRemove.
+type PrivateRdata interface {
+	// String returns the text presentation of the Rdata of the Private RR.
+	String() string
+	// Parse parses the Rdata of the private RR.
+	Parse([]string) error
+	// Pack is used when packing a private RR into a buffer.
+	Pack([]byte) (int, error)
+	// Unpack is used when unpacking a private RR from a buffer.
+	Unpack([]byte) (int, error)
+	// Copy copies the Rdata into the PrivateRdata argument.
+	Copy(PrivateRdata) error
+	// Len returns the length in octets of the Rdata.
+	Len() int
+}
+
+// PrivateRR represents an RR that uses a PrivateRdata user-defined type.
+// It mocks normal RRs and implements dns.RR interface.
+type PrivateRR struct {
+	Hdr  RR_Header
+	Data PrivateRdata
+
+	generator func() PrivateRdata // for copy
+}
+
+// Header return the RR header of r.
+func (r *PrivateRR) Header() *RR_Header { return &r.Hdr }
+
+func (r *PrivateRR) String() string { return r.Hdr.String() + r.Data.String() }
+
+// Private len and copy parts to satisfy RR interface.
+func (r *PrivateRR) len(off int, compression map[string]struct{}) int {
+	l := r.Hdr.len(off, compression)
+	l += r.Data.Len()
+	return l
+}
+
+func (r *PrivateRR) copy() RR {
+	// make new RR like this:
+	rr := &PrivateRR{r.Hdr, r.generator(), r.generator}
+
+	if err := r.Data.Copy(rr.Data); err != nil {
+		panic("dns: got value that could not be used to copy Private rdata: " + err.Error())
+	}
+
+	return rr
+}
+
+func (r *PrivateRR) pack(msg []byte, off int, compression compressionMap, compress bool) (int, error) {
+	n, err := r.Data.Pack(msg[off:])
+	if err != nil {
+		return len(msg), err
+	}
+	off += n
+	return off, nil
+}
+
+func (r *PrivateRR) unpack(msg []byte, off int) (int, error) {
+	off1, err := r.Data.Unpack(msg[off:])
+	off += off1
+	return off, err
+}
+
+func (r *PrivateRR) parse(c *zlexer, origin string) *ParseError {
+	var l lex
+	text := make([]string, 0, 2) // could be 0..N elements, median is probably 1
+Fetch:
+	for {
+		// TODO(miek): we could also be returning _QUOTE, this might or might not
+		// be an issue (basically parsing TXT becomes hard)
+		switch l, _ = c.Next(); l.value {
+		case zNewline, zEOF:
+			break Fetch
+		case zString:
+			text = append(text, l.token)
+		}
+	}
+
+	err := r.Data.Parse(text)
+	if err != nil {
+		return &ParseError{"", err.Error(), l}
+	}
+
+	return nil
+}
+
+func (r *PrivateRR) isDuplicate(r2 RR) bool { return false }
+
+// PrivateHandle registers a private resource record type. It requires
+// string and numeric representation of private RR type and generator function as argument.
+func PrivateHandle(rtypestr string, rtype uint16, generator func() PrivateRdata) {
+	rtypestr = strings.ToUpper(rtypestr)
+
+	TypeToRR[rtype] = func() RR { return &PrivateRR{RR_Header{}, generator(), generator} }
+	TypeToString[rtype] = rtypestr
+	StringToType[rtypestr] = rtype
+}
+
+// PrivateHandleRemove removes definitions required to support private RR type.
+func PrivateHandleRemove(rtype uint16) {
+	rtypestr, ok := TypeToString[rtype]
+	if ok {
+		delete(TypeToRR, rtype)
+		delete(TypeToString, rtype)
+		delete(StringToType, rtypestr)
+	}
+}

vendor/github.com/miekg/dns/reverse.go

@@ -0,0 +1,52 @@
+package dns
+
+// StringToType is the reverse of TypeToString, needed for string parsing.
+var StringToType = reverseInt16(TypeToString)
+
+// StringToClass is the reverse of ClassToString, needed for string parsing.
+var StringToClass = reverseInt16(ClassToString)
+
+// StringToOpcode is a map of opcodes to strings.
+var StringToOpcode = reverseInt(OpcodeToString)
+
+// StringToRcode is a map of rcodes to strings.
+var StringToRcode = reverseInt(RcodeToString)
+
+func init() {
+	// Preserve previous NOTIMP typo, see github.com/miekg/dns/issues/733.
+	StringToRcode["NOTIMPL"] = RcodeNotImplemented
+}
+
+// StringToAlgorithm is the reverse of AlgorithmToString.
+var StringToAlgorithm = reverseInt8(AlgorithmToString)
+
+// StringToHash is a map of names to hash IDs.
+var StringToHash = reverseInt8(HashToString)
+
+// StringToCertType is the reverseof CertTypeToString.
+var StringToCertType = reverseInt16(CertTypeToString)
+
+// Reverse a map
+func reverseInt8(m map[uint8]string) map[string]uint8 {
+	n := make(map[string]uint8, len(m))
+	for u, s := range m {
+		n[s] = u
+	}
+	return n
+}
+
+func reverseInt16(m map[uint16]string) map[string]uint16 {
+	n := make(map[string]uint16, len(m))
+	for u, s := range m {
+		n[s] = u
+	}
+	return n
+}
+
+func reverseInt(m map[int]string) map[string]int {
+	n := make(map[string]int, len(m))
+	for u, s := range m {
+		n[s] = u
+	}
+	return n
+}

vendor/github.com/miekg/dns/sanitize.go

@@ -0,0 +1,86 @@
+package dns
+
+// Dedup removes identical RRs from rrs. It preserves the original ordering.
+// The lowest TTL of any duplicates is used in the remaining one. Dedup modifies
+// rrs.
+// m is used to store the RRs temporary. If it is nil a new map will be allocated.
+func Dedup(rrs []RR, m map[string]RR) []RR {
+
+	if m == nil {
+		m = make(map[string]RR)
+	}
+	// Save the keys, so we don't have to call normalizedString twice.
+	keys := make([]*string, 0, len(rrs))
+
+	for _, r := range rrs {
+		key := normalizedString(r)
+		keys = append(keys, &key)
+		if mr, ok := m[key]; ok {
+			// Shortest TTL wins.
+			rh, mrh := r.Header(), mr.Header()
+			if mrh.Ttl > rh.Ttl {
+				mrh.Ttl = rh.Ttl
+			}
+			continue
+		}
+
+		m[key] = r
+	}
+	// If the length of the result map equals the amount of RRs we got,
+	// it means they were all different. We can then just return the original rrset.
+	if len(m) == len(rrs) {
+		return rrs
+	}
+
+	j := 0
+	for i, r := range rrs {
+		// If keys[i] lives in the map, we should copy and remove it.
+		if _, ok := m[*keys[i]]; ok {
+			delete(m, *keys[i])
+			rrs[j] = r
+			j++
+		}
+
+		if len(m) == 0 {
+			break
+		}
+	}
+
+	return rrs[:j]
+}
+
+// normalizedString returns a normalized string from r. The TTL
+// is removed and the domain name is lowercased. We go from this:
+// DomainName<TAB>TTL<TAB>CLASS<TAB>TYPE<TAB>RDATA to:
+// lowercasename<TAB>CLASS<TAB>TYPE...
+func normalizedString(r RR) string {
+	// A string Go DNS makes has: domainname<TAB>TTL<TAB>...
+	b := []byte(r.String())
+
+	// find the first non-escaped tab, then another, so we capture where the TTL lives.
+	esc := false
+	ttlStart, ttlEnd := 0, 0
+	for i := 0; i < len(b) && ttlEnd == 0; i++ {
+		switch {
+		case b[i] == '\\':
+			esc = !esc
+		case b[i] == '\t' && !esc:
+			if ttlStart == 0 {
+				ttlStart = i
+				continue
+			}
+			if ttlEnd == 0 {
+				ttlEnd = i
+			}
+		case b[i] >= 'A' && b[i] <= 'Z' && !esc:
+			b[i] += 32
+		default:
+			esc = false
+		}
+	}
+
+	// remove TTL.
+	copy(b[ttlStart:], b[ttlEnd:])
+	cut := ttlEnd - ttlStart
+	return string(b[:len(b)-cut])
+}

vendor/github.com/miekg/dns/serve_mux.go

@@ -0,0 +1,122 @@
+package dns
+
+import (
+	"sync"
+)
+
+// ServeMux is an DNS request multiplexer. It matches the zone name of
+// each incoming request against a list of registered patterns add calls
+// the handler for the pattern that most closely matches the zone name.
+//
+// ServeMux is DNSSEC aware, meaning that queries for the DS record are
+// redirected to the parent zone (if that is also registered), otherwise
+// the child gets the query.
+//
+// ServeMux is also safe for concurrent access from multiple goroutines.
+//
+// The zero ServeMux is empty and ready for use.
+type ServeMux struct {
+	z map[string]Handler
+	m sync.RWMutex
+}
+
+// NewServeMux allocates and returns a new ServeMux.
+func NewServeMux() *ServeMux {
+	return new(ServeMux)
+}
+
+// DefaultServeMux is the default ServeMux used by Serve.
+var DefaultServeMux = NewServeMux()
+
+func (mux *ServeMux) match(q string, t uint16) Handler {
+	mux.m.RLock()
+	defer mux.m.RUnlock()
+	if mux.z == nil {
+		return nil
+	}
+
+	q = CanonicalName(q)
+
+	var handler Handler
+	for off, end := 0, false; !end; off, end = NextLabel(q, off) {
+		if h, ok := mux.z[q[off:]]; ok {
+			if t != TypeDS {
+				return h
+			}
+			// Continue for DS to see if we have a parent too, if so delegate to the parent
+			handler = h
+		}
+	}
+
+	// Wildcard match, if we have found nothing try the root zone as a last resort.
+	if h, ok := mux.z["."]; ok {
+		return h
+	}
+
+	return handler
+}
+
+// Handle adds a handler to the ServeMux for pattern.
+func (mux *ServeMux) Handle(pattern string, handler Handler) {
+	if pattern == "" {
+		panic("dns: invalid pattern " + pattern)
+	}
+	mux.m.Lock()
+	if mux.z == nil {
+		mux.z = make(map[string]Handler)
+	}
+	mux.z[CanonicalName(pattern)] = handler
+	mux.m.Unlock()
+}
+
+// HandleFunc adds a handler function to the ServeMux for pattern.
+func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Msg)) {
+	mux.Handle(pattern, HandlerFunc(handler))
+}
+
+// HandleRemove deregisters the handler specific for pattern from the ServeMux.
+func (mux *ServeMux) HandleRemove(pattern string) {
+	if pattern == "" {
+		panic("dns: invalid pattern " + pattern)
+	}
+	mux.m.Lock()
+	delete(mux.z, CanonicalName(pattern))
+	mux.m.Unlock()
+}
+
+// ServeDNS dispatches the request to the handler whose pattern most
+// closely matches the request message.
+//
+// ServeDNS is DNSSEC aware, meaning that queries for the DS record
+// are redirected to the parent zone (if that is also registered),
+// otherwise the child gets the query.
+//
+// If no handler is found, or there is no question, a standard REFUSED
+// message is returned
+func (mux *ServeMux) ServeDNS(w ResponseWriter, req *Msg) {
+	var h Handler
+	if len(req.Question) >= 1 { // allow more than one question
+		h = mux.match(req.Question[0].Name, req.Question[0].Qtype)
+	}
+
+	if h != nil {
+		h.ServeDNS(w, req)
+	} else {
+		handleRefused(w, req)
+	}
+}
+
+// Handle registers the handler with the given pattern
+// in the DefaultServeMux. The documentation for
+// ServeMux explains how patterns are matched.
+func Handle(pattern string, handler Handler) { DefaultServeMux.Handle(pattern, handler) }
+
+// HandleRemove deregisters the handle with the given pattern
+// in the DefaultServeMux.
+func HandleRemove(pattern string) { DefaultServeMux.HandleRemove(pattern) }
+
+// HandleFunc registers the handler function with the given pattern
+// in the DefaultServeMux.
+func HandleFunc(pattern string, handler func(ResponseWriter, *Msg)) {
+	DefaultServeMux.HandleFunc(pattern, handler)
+}

vendor/github.com/miekg/dns/server.go

@@ -0,0 +1,836 @@
+// DNS server implementation.
+
+package dns
+
+import (
+	"context"
+	"crypto/tls"
+	"encoding/binary"
+	"errors"
+	"io"
+	"net"
+	"strings"
+	"sync"
+	"time"
+)
+
+// Default maximum number of TCP queries before we close the socket.
+const maxTCPQueries = 128
+
+// aLongTimeAgo is a non-zero time, far in the past, used for
+// immediate cancelation of network operations.
+var aLongTimeAgo = time.Unix(1, 0)
+
+// Handler is implemented by any value that implements ServeDNS.
+type Handler interface {
+	ServeDNS(w ResponseWriter, r *Msg)
+}
+
+// The HandlerFunc type is an adapter to allow the use of
+// ordinary functions as DNS handlers.  If f is a function
+// with the appropriate signature, HandlerFunc(f) is a
+// Handler object that calls f.
+type HandlerFunc func(ResponseWriter, *Msg)
+
+// ServeDNS calls f(w, r).
+func (f HandlerFunc) ServeDNS(w ResponseWriter, r *Msg) {
+	f(w, r)
+}
+
+// A ResponseWriter interface is used by an DNS handler to
+// construct an DNS response.
+type ResponseWriter interface {
+	// LocalAddr returns the net.Addr of the server
+	LocalAddr() net.Addr
+	// RemoteAddr returns the net.Addr of the client that sent the current request.
+	RemoteAddr() net.Addr
+	// WriteMsg writes a reply back to the client.
+	WriteMsg(*Msg) error
+	// Write writes a raw buffer back to the client.
+	Write([]byte) (int, error)
+	// Close closes the connection.
+	Close() error
+	// TsigStatus returns the status of the Tsig.
+	TsigStatus() error
+	// TsigTimersOnly sets the tsig timers only boolean.
+	TsigTimersOnly(bool)
+	// Hijack lets the caller take over the connection.
+	// After a call to Hijack(), the DNS package will not do anything with the connection.
+	Hijack()
+}
+
+// A ConnectionStater interface is used by a DNS Handler to access TLS connection state
+// when available.
+type ConnectionStater interface {
+	ConnectionState() *tls.ConnectionState
+}
+
+type response struct {
+	closed         bool // connection has been closed
+	hijacked       bool // connection has been hijacked by handler
+	tsigTimersOnly bool
+	tsigStatus     error
+	tsigRequestMAC string
+	tsigProvider   TsigProvider
+	udp            net.PacketConn // i/o connection if UDP was used
+	tcp            net.Conn       // i/o connection if TCP was used
+	udpSession     *SessionUDP    // oob data to get egress interface right
+	pcSession      net.Addr       // address to use when writing to a generic net.PacketConn
+	writer         Writer         // writer to output the raw DNS bits
+}
+
+// handleRefused returns a HandlerFunc that returns REFUSED for every request it gets.
+func handleRefused(w ResponseWriter, r *Msg) {
+	m := new(Msg)
+	m.SetRcode(r, RcodeRefused)
+	w.WriteMsg(m)
+}
+
+// HandleFailed returns a HandlerFunc that returns SERVFAIL for every request it gets.
+// Deprecated: This function is going away.
+func HandleFailed(w ResponseWriter, r *Msg) {
+	m := new(Msg)
+	m.SetRcode(r, RcodeServerFailure)
+	// does not matter if this write fails
+	w.WriteMsg(m)
+}
+
+// ListenAndServe Starts a server on address and network specified Invoke handler
+// for incoming queries.
+func ListenAndServe(addr string, network string, handler Handler) error {
+	server := &Server{Addr: addr, Net: network, Handler: handler}
+	return server.ListenAndServe()
+}
+
+// ListenAndServeTLS acts like http.ListenAndServeTLS, more information in
+// http://golang.org/pkg/net/http/#ListenAndServeTLS
+func ListenAndServeTLS(addr, certFile, keyFile string, handler Handler) error {
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+	if err != nil {
+		return err
+	}
+
+	config := tls.Config{
+		Certificates: []tls.Certificate{cert},
+	}
+
+	server := &Server{
+		Addr:      addr,
+		Net:       "tcp-tls",
+		TLSConfig: &config,
+		Handler:   handler,
+	}
+
+	return server.ListenAndServe()
+}
+
+// ActivateAndServe activates a server with a listener from systemd,
+// l and p should not both be non-nil.
+// If both l and p are not nil only p will be used.
+// Invoke handler for incoming queries.
+func ActivateAndServe(l net.Listener, p net.PacketConn, handler Handler) error {
+	server := &Server{Listener: l, PacketConn: p, Handler: handler}
+	return server.ActivateAndServe()
+}
+
+// Writer writes raw DNS messages; each call to Write should send an entire message.
+type Writer interface {
+	io.Writer
+}
+
+// Reader reads raw DNS messages; each call to ReadTCP or ReadUDP should return an entire message.
+type Reader interface {
+	// ReadTCP reads a raw message from a TCP connection. Implementations may alter
+	// connection properties, for example the read-deadline.
+	ReadTCP(conn net.Conn, timeout time.Duration) ([]byte, error)
+	// ReadUDP reads a raw message from a UDP connection. Implementations may alter
+	// connection properties, for example the read-deadline.
+	ReadUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *SessionUDP, error)
+}
+
+// PacketConnReader is an optional interface that Readers can implement to support using generic net.PacketConns.
+type PacketConnReader interface {
+	Reader
+
+	// ReadPacketConn reads a raw message from a generic net.PacketConn UDP connection. Implementations may
+	// alter connection properties, for example the read-deadline.
+	ReadPacketConn(conn net.PacketConn, timeout time.Duration) ([]byte, net.Addr, error)
+}
+
+// defaultReader is an adapter for the Server struct that implements the Reader and
+// PacketConnReader interfaces using the readTCP, readUDP and readPacketConn funcs
+// of the embedded Server.
+type defaultReader struct {
+	*Server
+}
+
+var _ PacketConnReader = defaultReader{}
+
+func (dr defaultReader) ReadTCP(conn net.Conn, timeout time.Duration) ([]byte, error) {
+	return dr.readTCP(conn, timeout)
+}
+
+func (dr defaultReader) ReadUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *SessionUDP, error) {
+	return dr.readUDP(conn, timeout)
+}
+
+func (dr defaultReader) ReadPacketConn(conn net.PacketConn, timeout time.Duration) ([]byte, net.Addr, error) {
+	return dr.readPacketConn(conn, timeout)
+}
+
+// DecorateReader is a decorator hook for extending or supplanting the functionality of a Reader.
+// Implementations should never return a nil Reader.
+// Readers should also implement the optional PacketConnReader interface.
+// PacketConnReader is required to use a generic net.PacketConn.
+type DecorateReader func(Reader) Reader
+
+// DecorateWriter is a decorator hook for extending or supplanting the functionality of a Writer.
+// Implementations should never return a nil Writer.
+type DecorateWriter func(Writer) Writer
+
+// A Server defines parameters for running an DNS server.
+type Server struct {
+	// Address to listen on, ":dns" if empty.
+	Addr string
+	// if "tcp" or "tcp-tls" (DNS over TLS) it will invoke a TCP listener, otherwise an UDP one
+	Net string
+	// TCP Listener to use, this is to aid in systemd's socket activation.
+	Listener net.Listener
+	// TLS connection configuration
+	TLSConfig *tls.Config
+	// UDP "Listener" to use, this is to aid in systemd's socket activation.
+	PacketConn net.PacketConn
+	// Handler to invoke, dns.DefaultServeMux if nil.
+	Handler Handler
+	// Default buffer size to use to read incoming UDP messages. If not set
+	// it defaults to MinMsgSize (512 B).
+	UDPSize int
+	// The net.Conn.SetReadTimeout value for new connections, defaults to 2 * time.Second.
+	ReadTimeout time.Duration
+	// The net.Conn.SetWriteTimeout value for new connections, defaults to 2 * time.Second.
+	WriteTimeout time.Duration
+	// TCP idle timeout for multiple queries, if nil, defaults to 8 * time.Second (RFC 5966).
+	IdleTimeout func() time.Duration
+	// An implementation of the TsigProvider interface. If defined it replaces TsigSecret and is used for all TSIG operations.
+	TsigProvider TsigProvider
+	// Secret(s) for Tsig map[<zonename>]<base64 secret>. The zonename must be in canonical form (lowercase, fqdn, see RFC 4034 Section 6.2).
+	TsigSecret map[string]string
+	// If NotifyStartedFunc is set it is called once the server has started listening.
+	NotifyStartedFunc func()
+	// DecorateReader is optional, allows customization of the process that reads raw DNS messages.
+	DecorateReader DecorateReader
+	// DecorateWriter is optional, allows customization of the process that writes raw DNS messages.
+	DecorateWriter DecorateWriter
+	// Maximum number of TCP queries before we close the socket. Default is maxTCPQueries (unlimited if -1).
+	MaxTCPQueries int
+	// Whether to set the SO_REUSEPORT socket option, allowing multiple listeners to be bound to a single address.
+	// It is only supported on go1.11+ and when using ListenAndServe.
+	ReusePort bool
+	// AcceptMsgFunc will check the incoming message and will reject it early in the process.
+	// By default DefaultMsgAcceptFunc will be used.
+	MsgAcceptFunc MsgAcceptFunc
+
+	// Shutdown handling
+	lock     sync.RWMutex
+	started  bool
+	shutdown chan struct{}
+	conns    map[net.Conn]struct{}
+
+	// A pool for UDP message buffers.
+	udpPool sync.Pool
+}
+
+func (srv *Server) tsigProvider() TsigProvider {
+	if srv.TsigProvider != nil {
+		return srv.TsigProvider
+	}
+	if srv.TsigSecret != nil {
+		return tsigSecretProvider(srv.TsigSecret)
+	}
+	return nil
+}
+
+func (srv *Server) isStarted() bool {
+	srv.lock.RLock()
+	started := srv.started
+	srv.lock.RUnlock()
+	return started
+}
+
+func makeUDPBuffer(size int) func() interface{} {
+	return func() interface{} {
+		return make([]byte, size)
+	}
+}
+
+func (srv *Server) init() {
+	srv.shutdown = make(chan struct{})
+	srv.conns = make(map[net.Conn]struct{})
+
+	if srv.UDPSize == 0 {
+		srv.UDPSize = MinMsgSize
+	}
+	if srv.MsgAcceptFunc == nil {
+		srv.MsgAcceptFunc = DefaultMsgAcceptFunc
+	}
+	if srv.Handler == nil {
+		srv.Handler = DefaultServeMux
+	}
+
+	srv.udpPool.New = makeUDPBuffer(srv.UDPSize)
+}
+
+func unlockOnce(l sync.Locker) func() {
+	var once sync.Once
+	return func() { once.Do(l.Unlock) }
+}
+
+// ListenAndServe starts a nameserver on the configured address in *Server.
+func (srv *Server) ListenAndServe() error {
+	unlock := unlockOnce(&srv.lock)
+	srv.lock.Lock()
+	defer unlock()
+
+	if srv.started {
+		return &Error{err: "server already started"}
+	}
+
+	addr := srv.Addr
+	if addr == "" {
+		addr = ":domain"
+	}
+
+	srv.init()
+
+	switch srv.Net {
+	case "tcp", "tcp4", "tcp6":
+		l, err := listenTCP(srv.Net, addr, srv.ReusePort)
+		if err != nil {
+			return err
+		}
+		srv.Listener = l
+		srv.started = true
+		unlock()
+		return srv.serveTCP(l)
+	case "tcp-tls", "tcp4-tls", "tcp6-tls":
+		if srv.TLSConfig == nil || (len(srv.TLSConfig.Certificates) == 0 && srv.TLSConfig.GetCertificate == nil) {
+			return errors.New("dns: neither Certificates nor GetCertificate set in Config")
+		}
+		network := strings.TrimSuffix(srv.Net, "-tls")
+		l, err := listenTCP(network, addr, srv.ReusePort)
+		if err != nil {
+			return err
+		}
+		l = tls.NewListener(l, srv.TLSConfig)
+		srv.Listener = l
+		srv.started = true
+		unlock()
+		return srv.serveTCP(l)
+	case "udp", "udp4", "udp6":
+		l, err := listenUDP(srv.Net, addr, srv.ReusePort)
+		if err != nil {
+			return err
+		}
+		u := l.(*net.UDPConn)
+		if e := setUDPSocketOptions(u); e != nil {
+			u.Close()
+			return e
+		}
+		srv.PacketConn = l
+		srv.started = true
+		unlock()
+		return srv.serveUDP(u)
+	}
+	return &Error{err: "bad network"}
+}
+
+// ActivateAndServe starts a nameserver with the PacketConn or Listener
+// configured in *Server. Its main use is to start a server from systemd.
+func (srv *Server) ActivateAndServe() error {
+	unlock := unlockOnce(&srv.lock)
+	srv.lock.Lock()
+	defer unlock()
+
+	if srv.started {
+		return &Error{err: "server already started"}
+	}
+
+	srv.init()
+
+	if srv.PacketConn != nil {
+		// Check PacketConn interface's type is valid and value
+		// is not nil
+		if t, ok := srv.PacketConn.(*net.UDPConn); ok && t != nil {
+			if e := setUDPSocketOptions(t); e != nil {
+				return e
+			}
+		}
+		srv.started = true
+		unlock()
+		return srv.serveUDP(srv.PacketConn)
+	}
+	if srv.Listener != nil {
+		srv.started = true
+		unlock()
+		return srv.serveTCP(srv.Listener)
+	}
+	return &Error{err: "bad listeners"}
+}
+
+// Shutdown shuts down a server. After a call to Shutdown, ListenAndServe and
+// ActivateAndServe will return.
+func (srv *Server) Shutdown() error {
+	return srv.ShutdownContext(context.Background())
+}
+
+// ShutdownContext shuts down a server. After a call to ShutdownContext,
+// ListenAndServe and ActivateAndServe will return.
+//
+// A context.Context may be passed to limit how long to wait for connections
+// to terminate.
+func (srv *Server) ShutdownContext(ctx context.Context) error {
+	srv.lock.Lock()
+	if !srv.started {
+		srv.lock.Unlock()
+		return &Error{err: "server not started"}
+	}
+
+	srv.started = false
+
+	if srv.PacketConn != nil {
+		srv.PacketConn.SetReadDeadline(aLongTimeAgo) // Unblock reads
+	}
+
+	if srv.Listener != nil {
+		srv.Listener.Close()
+	}
+
+	for rw := range srv.conns {
+		rw.SetReadDeadline(aLongTimeAgo) // Unblock reads
+	}
+
+	srv.lock.Unlock()
+
+	if testShutdownNotify != nil {
+		testShutdownNotify.Broadcast()
+	}
+
+	var ctxErr error
+	select {
+	case <-srv.shutdown:
+	case <-ctx.Done():
+		ctxErr = ctx.Err()
+	}
+
+	if srv.PacketConn != nil {
+		srv.PacketConn.Close()
+	}
+
+	return ctxErr
+}
+
+var testShutdownNotify *sync.Cond
+
+// getReadTimeout is a helper func to use system timeout if server did not intend to change it.
+func (srv *Server) getReadTimeout() time.Duration {
+	if srv.ReadTimeout != 0 {
+		return srv.ReadTimeout
+	}
+	return dnsTimeout
+}
+
+// serveTCP starts a TCP listener for the server.
+func (srv *Server) serveTCP(l net.Listener) error {
+	defer l.Close()
+
+	if srv.NotifyStartedFunc != nil {
+		srv.NotifyStartedFunc()
+	}
+
+	var wg sync.WaitGroup
+	defer func() {
+		wg.Wait()
+		close(srv.shutdown)
+	}()
+
+	for srv.isStarted() {
+		rw, err := l.Accept()
+		if err != nil {
+			if !srv.isStarted() {
+				return nil
+			}
+			if neterr, ok := err.(net.Error); ok && neterr.Temporary() {
+				continue
+			}
+			return err
+		}
+		srv.lock.Lock()
+		// Track the connection to allow unblocking reads on shutdown.
+		srv.conns[rw] = struct{}{}
+		srv.lock.Unlock()
+		wg.Add(1)
+		go srv.serveTCPConn(&wg, rw)
+	}
+
+	return nil
+}
+
+// serveUDP starts a UDP listener for the server.
+func (srv *Server) serveUDP(l net.PacketConn) error {
+	defer l.Close()
+
+	reader := Reader(defaultReader{srv})
+	if srv.DecorateReader != nil {
+		reader = srv.DecorateReader(reader)
+	}
+
+	lUDP, isUDP := l.(*net.UDPConn)
+	readerPC, canPacketConn := reader.(PacketConnReader)
+	if !isUDP && !canPacketConn {
+		return &Error{err: "PacketConnReader was not implemented on Reader returned from DecorateReader but is required for net.PacketConn"}
+	}
+
+	if srv.NotifyStartedFunc != nil {
+		srv.NotifyStartedFunc()
+	}
+
+	var wg sync.WaitGroup
+	defer func() {
+		wg.Wait()
+		close(srv.shutdown)
+	}()
+
+	rtimeout := srv.getReadTimeout()
+	// deadline is not used here
+	for srv.isStarted() {
+		var (
+			m    []byte
+			sPC  net.Addr
+			sUDP *SessionUDP
+			err  error
+		)
+		if isUDP {
+			m, sUDP, err = reader.ReadUDP(lUDP, rtimeout)
+		} else {
+			m, sPC, err = readerPC.ReadPacketConn(l, rtimeout)
+		}
+		if err != nil {
+			if !srv.isStarted() {
+				return nil
+			}
+			if netErr, ok := err.(net.Error); ok && netErr.Temporary() {
+				continue
+			}
+			return err
+		}
+		if len(m) < headerSize {
+			if cap(m) == srv.UDPSize {
+				srv.udpPool.Put(m[:srv.UDPSize])
+			}
+			continue
+		}
+		wg.Add(1)
+		go srv.serveUDPPacket(&wg, m, l, sUDP, sPC)
+	}
+
+	return nil
+}
+
+// Serve a new TCP connection.
+func (srv *Server) serveTCPConn(wg *sync.WaitGroup, rw net.Conn) {
+	w := &response{tsigProvider: srv.tsigProvider(), tcp: rw}
+	if srv.DecorateWriter != nil {
+		w.writer = srv.DecorateWriter(w)
+	} else {
+		w.writer = w
+	}
+
+	reader := Reader(defaultReader{srv})
+	if srv.DecorateReader != nil {
+		reader = srv.DecorateReader(reader)
+	}
+
+	idleTimeout := tcpIdleTimeout
+	if srv.IdleTimeout != nil {
+		idleTimeout = srv.IdleTimeout()
+	}
+
+	timeout := srv.getReadTimeout()
+
+	limit := srv.MaxTCPQueries
+	if limit == 0 {
+		limit = maxTCPQueries
+	}
+
+	for q := 0; (q < limit || limit == -1) && srv.isStarted(); q++ {
+		m, err := reader.ReadTCP(w.tcp, timeout)
+		if err != nil {
+			// TODO(tmthrgd): handle error
+			break
+		}
+		srv.serveDNS(m, w)
+		if w.closed {
+			break // Close() was called
+		}
+		if w.hijacked {
+			break // client will call Close() themselves
+		}
+		// The first read uses the read timeout, the rest use the
+		// idle timeout.
+		timeout = idleTimeout
+	}
+
+	if !w.hijacked {
+		w.Close()
+	}
+
+	srv.lock.Lock()
+	delete(srv.conns, w.tcp)
+	srv.lock.Unlock()
+
+	wg.Done()
+}
+
+// Serve a new UDP request.
+func (srv *Server) serveUDPPacket(wg *sync.WaitGroup, m []byte, u net.PacketConn, udpSession *SessionUDP, pcSession net.Addr) {
+	w := &response{tsigProvider: srv.tsigProvider(), udp: u, udpSession: udpSession, pcSession: pcSession}
+	if srv.DecorateWriter != nil {
+		w.writer = srv.DecorateWriter(w)
+	} else {
+		w.writer = w
+	}
+
+	srv.serveDNS(m, w)
+	wg.Done()
+}
+
+func (srv *Server) serveDNS(m []byte, w *response) {
+	dh, off, err := unpackMsgHdr(m, 0)
+	if err != nil {
+		// Let client hang, they are sending crap; any reply can be used to amplify.
+		return
+	}
+
+	req := new(Msg)
+	req.setHdr(dh)
+
+	switch action := srv.MsgAcceptFunc(dh); action {
+	case MsgAccept:
+		if req.unpack(dh, m, off) == nil {
+			break
+		}
+
+		fallthrough
+	case MsgReject, MsgRejectNotImplemented:
+		opcode := req.Opcode
+		req.SetRcodeFormatError(req)
+		req.Zero = false
+		if action == MsgRejectNotImplemented {
+			req.Opcode = opcode
+			req.Rcode = RcodeNotImplemented
+		}
+
+		// Are we allowed to delete any OPT records here?
+		req.Ns, req.Answer, req.Extra = nil, nil, nil
+
+		w.WriteMsg(req)
+		fallthrough
+	case MsgIgnore:
+		if w.udp != nil && cap(m) == srv.UDPSize {
+			srv.udpPool.Put(m[:srv.UDPSize])
+		}
+
+		return
+	}
+
+	w.tsigStatus = nil
+	if w.tsigProvider != nil {
+		if t := req.IsTsig(); t != nil {
+			w.tsigStatus = tsigVerifyProvider(m, w.tsigProvider, "", false)
+			w.tsigTimersOnly = false
+			w.tsigRequestMAC = t.MAC
+		}
+	}
+
+	if w.udp != nil && cap(m) == srv.UDPSize {
+		srv.udpPool.Put(m[:srv.UDPSize])
+	}
+
+	srv.Handler.ServeDNS(w, req) // Writes back to the client
+}
+
+func (srv *Server) readTCP(conn net.Conn, timeout time.Duration) ([]byte, error) {
+	// If we race with ShutdownContext, the read deadline may
+	// have been set in the distant past to unblock the read
+	// below. We must not override it, otherwise we may block
+	// ShutdownContext.
+	srv.lock.RLock()
+	if srv.started {
+		conn.SetReadDeadline(time.Now().Add(timeout))
+	}
+	srv.lock.RUnlock()
+
+	var length uint16
+	if err := binary.Read(conn, binary.BigEndian, &length); err != nil {
+		return nil, err
+	}
+
+	m := make([]byte, length)
+	if _, err := io.ReadFull(conn, m); err != nil {
+		return nil, err
+	}
+
+	return m, nil
+}
+
+func (srv *Server) readUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *SessionUDP, error) {
+	srv.lock.RLock()
+	if srv.started {
+		// See the comment in readTCP above.
+		conn.SetReadDeadline(time.Now().Add(timeout))
+	}
+	srv.lock.RUnlock()
+
+	m := srv.udpPool.Get().([]byte)
+	n, s, err := ReadFromSessionUDP(conn, m)
+	if err != nil {
+		srv.udpPool.Put(m)
+		return nil, nil, err
+	}
+	m = m[:n]
+	return m, s, nil
+}
+
+func (srv *Server) readPacketConn(conn net.PacketConn, timeout time.Duration) ([]byte, net.Addr, error) {
+	srv.lock.RLock()
+	if srv.started {
+		// See the comment in readTCP above.
+		conn.SetReadDeadline(time.Now().Add(timeout))
+	}
+	srv.lock.RUnlock()
+
+	m := srv.udpPool.Get().([]byte)
+	n, addr, err := conn.ReadFrom(m)
+	if err != nil {
+		srv.udpPool.Put(m)
+		return nil, nil, err
+	}
+	m = m[:n]
+	return m, addr, nil
+}
+
+// WriteMsg implements the ResponseWriter.WriteMsg method.
+func (w *response) WriteMsg(m *Msg) (err error) {
+	if w.closed {
+		return &Error{err: "WriteMsg called after Close"}
+	}
+
+	var data []byte
+	if w.tsigProvider != nil { // if no provider, dont check for the tsig (which is a longer check)
+		if t := m.IsTsig(); t != nil {
+			data, w.tsigRequestMAC, err = tsigGenerateProvider(m, w.tsigProvider, w.tsigRequestMAC, w.tsigTimersOnly)
+			if err != nil {
+				return err
+			}
+			_, err = w.writer.Write(data)
+			return err
+		}
+	}
+	data, err = m.Pack()
+	if err != nil {
+		return err
+	}
+	_, err = w.writer.Write(data)
+	return err
+}
+
+// Write implements the ResponseWriter.Write method.
+func (w *response) Write(m []byte) (int, error) {
+	if w.closed {
+		return 0, &Error{err: "Write called after Close"}
+	}
+
+	switch {
+	case w.udp != nil:
+		if u, ok := w.udp.(*net.UDPConn); ok {
+			return WriteToSessionUDP(u, m, w.udpSession)
+		}
+		return w.udp.WriteTo(m, w.pcSession)
+	case w.tcp != nil:
+		if len(m) > MaxMsgSize {
+			return 0, &Error{err: "message too large"}
+		}
+
+		msg := make([]byte, 2+len(m))
+		binary.BigEndian.PutUint16(msg, uint16(len(m)))
+		copy(msg[2:], m)
+		return w.tcp.Write(msg)
+	default:
+		panic("dns: internal error: udp and tcp both nil")
+	}
+}
+
+// LocalAddr implements the ResponseWriter.LocalAddr method.
+func (w *response) LocalAddr() net.Addr {
+	switch {
+	case w.udp != nil:
+		return w.udp.LocalAddr()
+	case w.tcp != nil:
+		return w.tcp.LocalAddr()
+	default:
+		panic("dns: internal error: udp and tcp both nil")
+	}
+}
+
+// RemoteAddr implements the ResponseWriter.RemoteAddr method.
+func (w *response) RemoteAddr() net.Addr {
+	switch {
+	case w.udpSession != nil:
+		return w.udpSession.RemoteAddr()
+	case w.pcSession != nil:
+		return w.pcSession
+	case w.tcp != nil:
+		return w.tcp.RemoteAddr()
+	default:
+		panic("dns: internal error: udpSession, pcSession and tcp are all nil")
+	}
+}
+
+// TsigStatus implements the ResponseWriter.TsigStatus method.
+func (w *response) TsigStatus() error { return w.tsigStatus }
+
+// TsigTimersOnly implements the ResponseWriter.TsigTimersOnly method.
+func (w *response) TsigTimersOnly(b bool) { w.tsigTimersOnly = b }
+
+// Hijack implements the ResponseWriter.Hijack method.
+func (w *response) Hijack() { w.hijacked = true }
+
+// Close implements the ResponseWriter.Close method
+func (w *response) Close() error {
+	if w.closed {
+		return &Error{err: "connection already closed"}
+	}
+	w.closed = true
+
+	switch {
+	case w.udp != nil:
+		// Can't close the udp conn, as that is actually the listener.
+		return nil
+	case w.tcp != nil:
+		return w.tcp.Close()
+	default:
+		panic("dns: internal error: udp and tcp both nil")
+	}
+}
+
+// ConnectionState() implements the ConnectionStater.ConnectionState() interface.
+func (w *response) ConnectionState() *tls.ConnectionState {
+	type tlsConnectionStater interface {
+		ConnectionState() tls.ConnectionState
+	}
+	if v, ok := w.tcp.(tlsConnectionStater); ok {
+		t := v.ConnectionState()
+		return &t
+	}
+	return nil
+}

vendor/github.com/miekg/dns/sig0.go

@@ -0,0 +1,194 @@
+package dns
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/rsa"
+	"encoding/binary"
+	"math/big"
+	"strings"
+	"time"
+)
+
+// Sign signs a dns.Msg. It fills the signature with the appropriate data.
+// The SIG record should have the SignerName, KeyTag, Algorithm, Inception
+// and Expiration set.
+func (rr *SIG) Sign(k crypto.Signer, m *Msg) ([]byte, error) {
+	if k == nil {
+		return nil, ErrPrivKey
+	}
+	if rr.KeyTag == 0 || rr.SignerName == "" || rr.Algorithm == 0 {
+		return nil, ErrKey
+	}
+
+	rr.Hdr = RR_Header{Name: ".", Rrtype: TypeSIG, Class: ClassANY, Ttl: 0}
+	rr.OrigTtl, rr.TypeCovered, rr.Labels = 0, 0, 0
+
+	buf := make([]byte, m.Len()+Len(rr))
+	mbuf, err := m.PackBuffer(buf)
+	if err != nil {
+		return nil, err
+	}
+	if &buf[0] != &mbuf[0] {
+		return nil, ErrBuf
+	}
+	off, err := PackRR(rr, buf, len(mbuf), nil, false)
+	if err != nil {
+		return nil, err
+	}
+	buf = buf[:off:cap(buf)]
+
+	h, cryptohash, err := hashFromAlgorithm(rr.Algorithm)
+	if err != nil {
+		return nil, err
+	}
+
+	// Write SIG rdata
+	h.Write(buf[len(mbuf)+1+2+2+4+2:])
+	// Write message
+	h.Write(buf[:len(mbuf)])
+
+	signature, err := sign(k, h.Sum(nil), cryptohash, rr.Algorithm)
+	if err != nil {
+		return nil, err
+	}
+
+	rr.Signature = toBase64(signature)
+
+	buf = append(buf, signature...)
+	if len(buf) > int(^uint16(0)) {
+		return nil, ErrBuf
+	}
+	// Adjust sig data length
+	rdoff := len(mbuf) + 1 + 2 + 2 + 4
+	rdlen := binary.BigEndian.Uint16(buf[rdoff:])
+	rdlen += uint16(len(signature))
+	binary.BigEndian.PutUint16(buf[rdoff:], rdlen)
+	// Adjust additional count
+	adc := binary.BigEndian.Uint16(buf[10:])
+	adc++
+	binary.BigEndian.PutUint16(buf[10:], adc)
+	return buf, nil
+}
+
+// Verify validates the message buf using the key k.
+// It's assumed that buf is a valid message from which rr was unpacked.
+func (rr *SIG) Verify(k *KEY, buf []byte) error {
+	if k == nil {
+		return ErrKey
+	}
+	if rr.KeyTag == 0 || rr.SignerName == "" || rr.Algorithm == 0 {
+		return ErrKey
+	}
+
+	h, cryptohash, err := hashFromAlgorithm(rr.Algorithm)
+	if err != nil {
+		return err
+	}
+
+	buflen := len(buf)
+	qdc := binary.BigEndian.Uint16(buf[4:])
+	anc := binary.BigEndian.Uint16(buf[6:])
+	auc := binary.BigEndian.Uint16(buf[8:])
+	adc := binary.BigEndian.Uint16(buf[10:])
+	offset := headerSize
+	for i := uint16(0); i < qdc && offset < buflen; i++ {
+		_, offset, err = UnpackDomainName(buf, offset)
+		if err != nil {
+			return err
+		}
+		// Skip past Type and Class
+		offset += 2 + 2
+	}
+	for i := uint16(1); i < anc+auc+adc && offset < buflen; i++ {
+		_, offset, err = UnpackDomainName(buf, offset)
+		if err != nil {
+			return err
+		}
+		// Skip past Type, Class and TTL
+		offset += 2 + 2 + 4
+		if offset+1 >= buflen {
+			continue
+		}
+		rdlen := binary.BigEndian.Uint16(buf[offset:])
+		offset += 2
+		offset += int(rdlen)
+	}
+	if offset >= buflen {
+		return &Error{err: "overflowing unpacking signed message"}
+	}
+
+	// offset should be just prior to SIG
+	bodyend := offset
+	// owner name SHOULD be root
+	_, offset, err = UnpackDomainName(buf, offset)
+	if err != nil {
+		return err
+	}
+	// Skip Type, Class, TTL, RDLen
+	offset += 2 + 2 + 4 + 2
+	sigstart := offset
+	// Skip Type Covered, Algorithm, Labels, Original TTL
+	offset += 2 + 1 + 1 + 4
+	if offset+4+4 >= buflen {
+		return &Error{err: "overflow unpacking signed message"}
+	}
+	expire := binary.BigEndian.Uint32(buf[offset:])
+	offset += 4
+	incept := binary.BigEndian.Uint32(buf[offset:])
+	offset += 4
+	now := uint32(time.Now().Unix())
+	if now < incept || now > expire {
+		return ErrTime
+	}
+	// Skip key tag
+	offset += 2
+	var signername string
+	signername, offset, err = UnpackDomainName(buf, offset)
+	if err != nil {
+		return err
+	}
+	// If key has come from the DNS name compression might
+	// have mangled the case of the name
+	if !strings.EqualFold(signername, k.Header().Name) {
+		return &Error{err: "signer name doesn't match key name"}
+	}
+	sigend := offset
+	h.Write(buf[sigstart:sigend])
+	h.Write(buf[:10])
+	h.Write([]byte{
+		byte((adc - 1) << 8),
+		byte(adc - 1),
+	})
+	h.Write(buf[12:bodyend])
+
+	hashed := h.Sum(nil)
+	sig := buf[sigend:]
+	switch k.Algorithm {
+	case RSASHA1, RSASHA256, RSASHA512:
+		pk := k.publicKeyRSA()
+		if pk != nil {
+			return rsa.VerifyPKCS1v15(pk, cryptohash, hashed, sig)
+		}
+	case ECDSAP256SHA256, ECDSAP384SHA384:
+		pk := k.publicKeyECDSA()
+		r := new(big.Int).SetBytes(sig[:len(sig)/2])
+		s := new(big.Int).SetBytes(sig[len(sig)/2:])
+		if pk != nil {
+			if ecdsa.Verify(pk, hashed, r, s) {
+				return nil
+			}
+			return ErrSig
+		}
+	case ED25519:
+		pk := k.publicKeyED25519()
+		if pk != nil {
+			if ed25519.Verify(pk, hashed, sig) {
+				return nil
+			}
+			return ErrSig
+		}
+	}
+	return ErrKeyAlg
+}

vendor/github.com/miekg/dns/singleinflight.go

@@ -0,0 +1,61 @@
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Adapted for dns package usage by Miek Gieben.
+
+package dns
+
+import "sync"
+import "time"
+
+// call is an in-flight or completed singleflight.Do call
+type call struct {
+	wg   sync.WaitGroup
+	val  *Msg
+	rtt  time.Duration
+	err  error
+	dups int
+}
+
+// singleflight represents a class of work and forms a namespace in
+// which units of work can be executed with duplicate suppression.
+type singleflight struct {
+	sync.Mutex                  // protects m
+	m          map[string]*call // lazily initialized
+
+	dontDeleteForTesting bool // this is only to be used by TestConcurrentExchanges
+}
+
+// Do executes and returns the results of the given function, making
+// sure that only one execution is in-flight for a given key at a
+// time. If a duplicate comes in, the duplicate caller waits for the
+// original to complete and receives the same results.
+// The return value shared indicates whether v was given to multiple callers.
+func (g *singleflight) Do(key string, fn func() (*Msg, time.Duration, error)) (v *Msg, rtt time.Duration, err error, shared bool) {
+	g.Lock()
+	if g.m == nil {
+		g.m = make(map[string]*call)
+	}
+	if c, ok := g.m[key]; ok {
+		c.dups++
+		g.Unlock()
+		c.wg.Wait()
+		return c.val, c.rtt, c.err, true
+	}
+	c := new(call)
+	c.wg.Add(1)
+	g.m[key] = c
+	g.Unlock()
+
+	c.val, c.rtt, c.err = fn()
+	c.wg.Done()
+
+	if !g.dontDeleteForTesting {
+		g.Lock()
+		delete(g.m, key)
+		g.Unlock()
+	}
+
+	return c.val, c.rtt, c.err, c.dups > 0
+}

vendor/github.com/miekg/dns/smimea.go

@@ -0,0 +1,44 @@
+package dns
+
+import (
+	"crypto/sha256"
+	"crypto/x509"
+	"encoding/hex"
+)
+
+// Sign creates a SMIMEA record from an SSL certificate.
+func (r *SMIMEA) Sign(usage, selector, matchingType int, cert *x509.Certificate) (err error) {
+	r.Hdr.Rrtype = TypeSMIMEA
+	r.Usage = uint8(usage)
+	r.Selector = uint8(selector)
+	r.MatchingType = uint8(matchingType)
+
+	r.Certificate, err = CertificateToDANE(r.Selector, r.MatchingType, cert)
+	return err
+}
+
+// Verify verifies a SMIMEA record against an SSL certificate. If it is OK
+// a nil error is returned.
+func (r *SMIMEA) Verify(cert *x509.Certificate) error {
+	c, err := CertificateToDANE(r.Selector, r.MatchingType, cert)
+	if err != nil {
+		return err // Not also ErrSig?
+	}
+	if r.Certificate == c {
+		return nil
+	}
+	return ErrSig // ErrSig, really?
+}
+
+// SMIMEAName returns the ownername of a SMIMEA resource record as per the
+// format specified in RFC 'draft-ietf-dane-smime-12' Section 2 and 3
+func SMIMEAName(email, domain string) (string, error) {
+	hasher := sha256.New()
+	hasher.Write([]byte(email))
+
+	// RFC Section 3: "The local-part is hashed using the SHA2-256
+	// algorithm with the hash truncated to 28 octets and
+	// represented in its hexadecimal representation to become the
+	// left-most label in the prepared domain name"
+	return hex.EncodeToString(hasher.Sum(nil)[:28]) + "." + "_smimecert." + domain, nil
+}

vendor/github.com/miekg/dns/svcb.go

@@ -0,0 +1,935 @@
+package dns
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"net"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// SVCBKey is the type of the keys used in the SVCB RR.
+type SVCBKey uint16
+
+// Keys defined in draft-ietf-dnsop-svcb-https-08 Section 14.3.2.
+const (
+	SVCB_MANDATORY SVCBKey = iota
+	SVCB_ALPN
+	SVCB_NO_DEFAULT_ALPN
+	SVCB_PORT
+	SVCB_IPV4HINT
+	SVCB_ECHCONFIG
+	SVCB_IPV6HINT
+	SVCB_DOHPATH // draft-ietf-add-svcb-dns-02 Section 9
+
+	svcb_RESERVED SVCBKey = 65535
+)
+
+var svcbKeyToStringMap = map[SVCBKey]string{
+	SVCB_MANDATORY:       "mandatory",
+	SVCB_ALPN:            "alpn",
+	SVCB_NO_DEFAULT_ALPN: "no-default-alpn",
+	SVCB_PORT:            "port",
+	SVCB_IPV4HINT:        "ipv4hint",
+	SVCB_ECHCONFIG:       "ech",
+	SVCB_IPV6HINT:        "ipv6hint",
+	SVCB_DOHPATH:         "dohpath",
+}
+
+var svcbStringToKeyMap = reverseSVCBKeyMap(svcbKeyToStringMap)
+
+func reverseSVCBKeyMap(m map[SVCBKey]string) map[string]SVCBKey {
+	n := make(map[string]SVCBKey, len(m))
+	for u, s := range m {
+		n[s] = u
+	}
+	return n
+}
+
+// String takes the numerical code of an SVCB key and returns its name.
+// Returns an empty string for reserved keys.
+// Accepts unassigned keys as well as experimental/private keys.
+func (key SVCBKey) String() string {
+	if x := svcbKeyToStringMap[key]; x != "" {
+		return x
+	}
+	if key == svcb_RESERVED {
+		return ""
+	}
+	return "key" + strconv.FormatUint(uint64(key), 10)
+}
+
+// svcbStringToKey returns the numerical code of an SVCB key.
+// Returns svcb_RESERVED for reserved/invalid keys.
+// Accepts unassigned keys as well as experimental/private keys.
+func svcbStringToKey(s string) SVCBKey {
+	if strings.HasPrefix(s, "key") {
+		a, err := strconv.ParseUint(s[3:], 10, 16)
+		// no leading zeros
+		// key shouldn't be registered
+		if err != nil || a == 65535 || s[3] == '0' || svcbKeyToStringMap[SVCBKey(a)] != "" {
+			return svcb_RESERVED
+		}
+		return SVCBKey(a)
+	}
+	if key, ok := svcbStringToKeyMap[s]; ok {
+		return key
+	}
+	return svcb_RESERVED
+}
+
+func (rr *SVCB) parse(c *zlexer, o string) *ParseError {
+	l, _ := c.Next()
+	i, e := strconv.ParseUint(l.token, 10, 16)
+	if e != nil || l.err {
+		return &ParseError{l.token, "bad SVCB priority", l}
+	}
+	rr.Priority = uint16(i)
+
+	c.Next()        // zBlank
+	l, _ = c.Next() // zString
+	rr.Target = l.token
+
+	name, nameOk := toAbsoluteName(l.token, o)
+	if l.err || !nameOk {
+		return &ParseError{l.token, "bad SVCB Target", l}
+	}
+	rr.Target = name
+
+	// Values (if any)
+	l, _ = c.Next()
+	var xs []SVCBKeyValue
+	// Helps require whitespace between pairs.
+	// Prevents key1000="a"key1001=...
+	canHaveNextKey := true
+	for l.value != zNewline && l.value != zEOF {
+		switch l.value {
+		case zString:
+			if !canHaveNextKey {
+				// The key we can now read was probably meant to be
+				// a part of the last value.
+				return &ParseError{l.token, "bad SVCB value quotation", l}
+			}
+
+			// In key=value pairs, value does not have to be quoted unless value
+			// contains whitespace. And keys don't need to have values.
+			// Similarly, keys with an equality signs after them don't need values.
+			// l.token includes at least up to the first equality sign.
+			idx := strings.IndexByte(l.token, '=')
+			var key, value string
+			if idx < 0 {
+				// Key with no value and no equality sign
+				key = l.token
+			} else if idx == 0 {
+				return &ParseError{l.token, "bad SVCB key", l}
+			} else {
+				key, value = l.token[:idx], l.token[idx+1:]
+
+				if value == "" {
+					// We have a key and an equality sign. Maybe we have nothing
+					// after "=" or we have a double quote.
+					l, _ = c.Next()
+					if l.value == zQuote {
+						// Only needed when value ends with double quotes.
+						// Any value starting with zQuote ends with it.
+						canHaveNextKey = false
+
+						l, _ = c.Next()
+						switch l.value {
+						case zString:
+							// We have a value in double quotes.
+							value = l.token
+							l, _ = c.Next()
+							if l.value != zQuote {
+								return &ParseError{l.token, "SVCB unterminated value", l}
+							}
+						case zQuote:
+							// There's nothing in double quotes.
+						default:
+							return &ParseError{l.token, "bad SVCB value", l}
+						}
+					}
+				}
+			}
+			kv := makeSVCBKeyValue(svcbStringToKey(key))
+			if kv == nil {
+				return &ParseError{l.token, "bad SVCB key", l}
+			}
+			if err := kv.parse(value); err != nil {
+				return &ParseError{l.token, err.Error(), l}
+			}
+			xs = append(xs, kv)
+		case zQuote:
+			return &ParseError{l.token, "SVCB key can't contain double quotes", l}
+		case zBlank:
+			canHaveNextKey = true
+		default:
+			return &ParseError{l.token, "bad SVCB values", l}
+		}
+		l, _ = c.Next()
+	}
+
+	// "In AliasMode, records SHOULD NOT include any SvcParams, and recipients MUST
+	// ignore any SvcParams that are present."
+	// However, we don't check rr.Priority == 0 && len(xs) > 0 here
+	// It is the responsibility of the user of the library to check this.
+	// This is to encourage the fixing of the source of this error.
+
+	rr.Value = xs
+	return nil
+}
+
+// makeSVCBKeyValue returns an SVCBKeyValue struct with the key or nil for reserved keys.
+func makeSVCBKeyValue(key SVCBKey) SVCBKeyValue {
+	switch key {
+	case SVCB_MANDATORY:
+		return new(SVCBMandatory)
+	case SVCB_ALPN:
+		return new(SVCBAlpn)
+	case SVCB_NO_DEFAULT_ALPN:
+		return new(SVCBNoDefaultAlpn)
+	case SVCB_PORT:
+		return new(SVCBPort)
+	case SVCB_IPV4HINT:
+		return new(SVCBIPv4Hint)
+	case SVCB_ECHCONFIG:
+		return new(SVCBECHConfig)
+	case SVCB_IPV6HINT:
+		return new(SVCBIPv6Hint)
+	case SVCB_DOHPATH:
+		return new(SVCBDoHPath)
+	case svcb_RESERVED:
+		return nil
+	default:
+		e := new(SVCBLocal)
+		e.KeyCode = key
+		return e
+	}
+}
+
+// SVCB RR. See RFC xxxx (https://tools.ietf.org/html/draft-ietf-dnsop-svcb-https-08).
+//
+// NOTE: The HTTPS/SVCB RFCs are in the draft stage.
+// The API, including constants and types related to SVCBKeyValues, may
+// change in future versions in accordance with the latest drafts.
+type SVCB struct {
+	Hdr      RR_Header
+	Priority uint16         // If zero, Value must be empty or discarded by the user of this library
+	Target   string         `dns:"domain-name"`
+	Value    []SVCBKeyValue `dns:"pairs"`
+}
+
+// HTTPS RR. Everything valid for SVCB applies to HTTPS as well.
+// Except that the HTTPS record is intended for use with the HTTP and HTTPS protocols.
+//
+// NOTE: The HTTPS/SVCB RFCs are in the draft stage.
+// The API, including constants and types related to SVCBKeyValues, may
+// change in future versions in accordance with the latest drafts.
+type HTTPS struct {
+	SVCB
+}
+
+func (rr *HTTPS) String() string {
+	return rr.SVCB.String()
+}
+
+func (rr *HTTPS) parse(c *zlexer, o string) *ParseError {
+	return rr.SVCB.parse(c, o)
+}
+
+// SVCBKeyValue defines a key=value pair for the SVCB RR type.
+// An SVCB RR can have multiple SVCBKeyValues appended to it.
+type SVCBKeyValue interface {
+	Key() SVCBKey          // Key returns the numerical key code.
+	pack() ([]byte, error) // pack returns the encoded value.
+	unpack([]byte) error   // unpack sets the value.
+	String() string        // String returns the string representation of the value.
+	parse(string) error    // parse sets the value to the given string representation of the value.
+	copy() SVCBKeyValue    // copy returns a deep-copy of the pair.
+	len() int              // len returns the length of value in the wire format.
+}
+
+// SVCBMandatory pair adds to required keys that must be interpreted for the RR
+// to be functional. If ignored, the whole RRSet must be ignored.
+// "port" and "no-default-alpn" are mandatory by default if present,
+// so they shouldn't be included here.
+//
+// It is incumbent upon the user of this library to reject the RRSet if
+// or avoid constructing such an RRSet that:
+// - "mandatory" is included as one of the keys of mandatory
+// - no key is listed multiple times in mandatory
+// - all keys listed in mandatory are present
+// - escape sequences are not used in mandatory
+// - mandatory, when present, lists at least one key
+//
+// Basic use pattern for creating a mandatory option:
+//
+//	s := &dns.SVCB{Hdr: dns.RR_Header{Name: ".", Rrtype: dns.TypeSVCB, Class: dns.ClassINET}}
+//	e := new(dns.SVCBMandatory)
+//	e.Code = []uint16{dns.SVCB_ALPN}
+//	s.Value = append(s.Value, e)
+//	t := new(dns.SVCBAlpn)
+//	t.Alpn = []string{"xmpp-client"}
+//	s.Value = append(s.Value, t)
+type SVCBMandatory struct {
+	Code []SVCBKey
+}
+
+func (*SVCBMandatory) Key() SVCBKey { return SVCB_MANDATORY }
+
+func (s *SVCBMandatory) String() string {
+	str := make([]string, len(s.Code))
+	for i, e := range s.Code {
+		str[i] = e.String()
+	}
+	return strings.Join(str, ",")
+}
+
+func (s *SVCBMandatory) pack() ([]byte, error) {
+	codes := append([]SVCBKey(nil), s.Code...)
+	sort.Slice(codes, func(i, j int) bool {
+		return codes[i] < codes[j]
+	})
+	b := make([]byte, 2*len(codes))
+	for i, e := range codes {
+		binary.BigEndian.PutUint16(b[2*i:], uint16(e))
+	}
+	return b, nil
+}
+
+func (s *SVCBMandatory) unpack(b []byte) error {
+	if len(b)%2 != 0 {
+		return errors.New("dns: svcbmandatory: value length is not a multiple of 2")
+	}
+	codes := make([]SVCBKey, 0, len(b)/2)
+	for i := 0; i < len(b); i += 2 {
+		// We assume strictly increasing order.
+		codes = append(codes, SVCBKey(binary.BigEndian.Uint16(b[i:])))
+	}
+	s.Code = codes
+	return nil
+}
+
+func (s *SVCBMandatory) parse(b string) error {
+	str := strings.Split(b, ",")
+	codes := make([]SVCBKey, 0, len(str))
+	for _, e := range str {
+		codes = append(codes, svcbStringToKey(e))
+	}
+	s.Code = codes
+	return nil
+}
+
+func (s *SVCBMandatory) len() int {
+	return 2 * len(s.Code)
+}
+
+func (s *SVCBMandatory) copy() SVCBKeyValue {
+	return &SVCBMandatory{
+		append([]SVCBKey(nil), s.Code...),
+	}
+}
+
+// SVCBAlpn pair is used to list supported connection protocols.
+// The user of this library must ensure that at least one protocol is listed when alpn is present.
+// Protocol IDs can be found at:
+// https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml#alpn-protocol-ids
+// Basic use pattern for creating an alpn option:
+//
+//	h := new(dns.HTTPS)
+//	h.Hdr = dns.RR_Header{Name: ".", Rrtype: dns.TypeHTTPS, Class: dns.ClassINET}
+//	e := new(dns.SVCBAlpn)
+//	e.Alpn = []string{"h2", "http/1.1"}
+//	h.Value = append(h.Value, e)
+type SVCBAlpn struct {
+	Alpn []string
+}
+
+func (*SVCBAlpn) Key() SVCBKey { return SVCB_ALPN }
+
+func (s *SVCBAlpn) String() string {
+	// An ALPN value is a comma-separated list of values, each of which can be
+	// an arbitrary binary value. In order to allow parsing, the comma and
+	// backslash characters are themselves excaped.
+	//
+	// However, this escaping is done in addition to the normal escaping which
+	// happens in zone files, meaning that these values must be
+	// double-escaped. This looks terrible, so if you see a never-ending
+	// sequence of backslash in a zone file this may be why.
+	//
+	// https://datatracker.ietf.org/doc/html/draft-ietf-dnsop-svcb-https-08#appendix-A.1
+	var str strings.Builder
+	for i, alpn := range s.Alpn {
+		// 4*len(alpn) is the worst case where we escape every character in the alpn as \123, plus 1 byte for the ',' separating the alpn from others
+		str.Grow(4*len(alpn) + 1)
+		if i > 0 {
+			str.WriteByte(',')
+		}
+		for j := 0; j < len(alpn); j++ {
+			e := alpn[j]
+			if ' ' > e || e > '~' {
+				str.WriteString(escapeByte(e))
+				continue
+			}
+			switch e {
+			// We escape a few characters which may confuse humans or parsers.
+			case '"', ';', ' ':
+				str.WriteByte('\\')
+				str.WriteByte(e)
+			// The comma and backslash characters themselves must be
+			// doubly-escaped. We use `\\` for the first backslash and
+			// the escaped numeric value for the other value. We especially
+			// don't want a comma in the output.
+			case ',':
+				str.WriteString(`\\\044`)
+			case '\\':
+				str.WriteString(`\\\092`)
+			default:
+				str.WriteByte(e)
+			}
+		}
+	}
+	return str.String()
+}
+
+func (s *SVCBAlpn) pack() ([]byte, error) {
+	// Liberally estimate the size of an alpn as 10 octets
+	b := make([]byte, 0, 10*len(s.Alpn))
+	for _, e := range s.Alpn {
+		if e == "" {
+			return nil, errors.New("dns: svcbalpn: empty alpn-id")
+		}
+		if len(e) > 255 {
+			return nil, errors.New("dns: svcbalpn: alpn-id too long")
+		}
+		b = append(b, byte(len(e)))
+		b = append(b, e...)
+	}
+	return b, nil
+}
+
+func (s *SVCBAlpn) unpack(b []byte) error {
+	// Estimate the size of the smallest alpn as 4 bytes
+	alpn := make([]string, 0, len(b)/4)
+	for i := 0; i < len(b); {
+		length := int(b[i])
+		i++
+		if i+length > len(b) {
+			return errors.New("dns: svcbalpn: alpn array overflowing")
+		}
+		alpn = append(alpn, string(b[i:i+length]))
+		i += length
+	}
+	s.Alpn = alpn
+	return nil
+}
+
+func (s *SVCBAlpn) parse(b string) error {
+	if len(b) == 0 {
+		s.Alpn = []string{}
+		return nil
+	}
+
+	alpn := []string{}
+	a := []byte{}
+	for p := 0; p < len(b); {
+		c, q := nextByte(b, p)
+		if q == 0 {
+			return errors.New("dns: svcbalpn: unterminated escape")
+		}
+		p += q
+		// If we find a comma, we have finished reading an alpn.
+		if c == ',' {
+			if len(a) == 0 {
+				return errors.New("dns: svcbalpn: empty protocol identifier")
+			}
+			alpn = append(alpn, string(a))
+			a = []byte{}
+			continue
+		}
+		// If it's a backslash, we need to handle a comma-separated list.
+		if c == '\\' {
+			dc, dq := nextByte(b, p)
+			if dq == 0 {
+				return errors.New("dns: svcbalpn: unterminated escape decoding comma-separated list")
+			}
+			if dc != '\\' && dc != ',' {
+				return errors.New("dns: svcbalpn: bad escaped character decoding comma-separated list")
+			}
+			p += dq
+			c = dc
+		}
+		a = append(a, c)
+	}
+	// Add the final alpn.
+	if len(a) == 0 {
+		return errors.New("dns: svcbalpn: last protocol identifier empty")
+	}
+	s.Alpn = append(alpn, string(a))
+	return nil
+}
+
+func (s *SVCBAlpn) len() int {
+	var l int
+	for _, e := range s.Alpn {
+		l += 1 + len(e)
+	}
+	return l
+}
+
+func (s *SVCBAlpn) copy() SVCBKeyValue {
+	return &SVCBAlpn{
+		append([]string(nil), s.Alpn...),
+	}
+}
+
+// SVCBNoDefaultAlpn pair signifies no support for default connection protocols.
+// Should be used in conjunction with alpn.
+// Basic use pattern for creating a no-default-alpn option:
+//
+//	s := &dns.SVCB{Hdr: dns.RR_Header{Name: ".", Rrtype: dns.TypeSVCB, Class: dns.ClassINET}}
+//	t := new(dns.SVCBAlpn)
+//	t.Alpn = []string{"xmpp-client"}
+//	s.Value = append(s.Value, t)
+//	e := new(dns.SVCBNoDefaultAlpn)
+//	s.Value = append(s.Value, e)
+type SVCBNoDefaultAlpn struct{}
+
+func (*SVCBNoDefaultAlpn) Key() SVCBKey          { return SVCB_NO_DEFAULT_ALPN }
+func (*SVCBNoDefaultAlpn) copy() SVCBKeyValue    { return &SVCBNoDefaultAlpn{} }
+func (*SVCBNoDefaultAlpn) pack() ([]byte, error) { return []byte{}, nil }
+func (*SVCBNoDefaultAlpn) String() string        { return "" }
+func (*SVCBNoDefaultAlpn) len() int              { return 0 }
+
+func (*SVCBNoDefaultAlpn) unpack(b []byte) error {
+	if len(b) != 0 {
+		return errors.New("dns: svcbnodefaultalpn: no-default-alpn must have no value")
+	}
+	return nil
+}
+
+func (*SVCBNoDefaultAlpn) parse(b string) error {
+	if b != "" {
+		return errors.New("dns: svcbnodefaultalpn: no-default-alpn must have no value")
+	}
+	return nil
+}
+
+// SVCBPort pair defines the port for connection.
+// Basic use pattern for creating a port option:
+//
+//	s := &dns.SVCB{Hdr: dns.RR_Header{Name: ".", Rrtype: dns.TypeSVCB, Class: dns.ClassINET}}
+//	e := new(dns.SVCBPort)
+//	e.Port = 80
+//	s.Value = append(s.Value, e)
+type SVCBPort struct {
+	Port uint16
+}
+
+func (*SVCBPort) Key() SVCBKey         { return SVCB_PORT }
+func (*SVCBPort) len() int             { return 2 }
+func (s *SVCBPort) String() string     { return strconv.FormatUint(uint64(s.Port), 10) }
+func (s *SVCBPort) copy() SVCBKeyValue { return &SVCBPort{s.Port} }
+
+func (s *SVCBPort) unpack(b []byte) error {
+	if len(b) != 2 {
+		return errors.New("dns: svcbport: port length is not exactly 2 octets")
+	}
+	s.Port = binary.BigEndian.Uint16(b)
+	return nil
+}
+
+func (s *SVCBPort) pack() ([]byte, error) {
+	b := make([]byte, 2)
+	binary.BigEndian.PutUint16(b, s.Port)
+	return b, nil
+}
+
+func (s *SVCBPort) parse(b string) error {
+	port, err := strconv.ParseUint(b, 10, 16)
+	if err != nil {
+		return errors.New("dns: svcbport: port out of range")
+	}
+	s.Port = uint16(port)
+	return nil
+}
+
+// SVCBIPv4Hint pair suggests an IPv4 address which may be used to open connections
+// if A and AAAA record responses for SVCB's Target domain haven't been received.
+// In that case, optionally, A and AAAA requests can be made, after which the connection
+// to the hinted IP address may be terminated and a new connection may be opened.
+// Basic use pattern for creating an ipv4hint option:
+//
+//	h := new(dns.HTTPS)
+//	h.Hdr = dns.RR_Header{Name: ".", Rrtype: dns.TypeHTTPS, Class: dns.ClassINET}
+//	e := new(dns.SVCBIPv4Hint)
+//	e.Hint = []net.IP{net.IPv4(1,1,1,1).To4()}
+//
+//  Or
+//
+//	e.Hint = []net.IP{net.ParseIP("1.1.1.1").To4()}
+//	h.Value = append(h.Value, e)
+type SVCBIPv4Hint struct {
+	Hint []net.IP
+}
+
+func (*SVCBIPv4Hint) Key() SVCBKey { return SVCB_IPV4HINT }
+func (s *SVCBIPv4Hint) len() int   { return 4 * len(s.Hint) }
+
+func (s *SVCBIPv4Hint) pack() ([]byte, error) {
+	b := make([]byte, 0, 4*len(s.Hint))
+	for _, e := range s.Hint {
+		x := e.To4()
+		if x == nil {
+			return nil, errors.New("dns: svcbipv4hint: expected ipv4, hint is ipv6")
+		}
+		b = append(b, x...)
+	}
+	return b, nil
+}
+
+func (s *SVCBIPv4Hint) unpack(b []byte) error {
+	if len(b) == 0 || len(b)%4 != 0 {
+		return errors.New("dns: svcbipv4hint: ipv4 address byte array length is not a multiple of 4")
+	}
+	x := make([]net.IP, 0, len(b)/4)
+	for i := 0; i < len(b); i += 4 {
+		x = append(x, net.IP(b[i:i+4]))
+	}
+	s.Hint = x
+	return nil
+}
+
+func (s *SVCBIPv4Hint) String() string {
+	str := make([]string, len(s.Hint))
+	for i, e := range s.Hint {
+		x := e.To4()
+		if x == nil {
+			return "<nil>"
+		}
+		str[i] = x.String()
+	}
+	return strings.Join(str, ",")
+}
+
+func (s *SVCBIPv4Hint) parse(b string) error {
+	if strings.Contains(b, ":") {
+		return errors.New("dns: svcbipv4hint: expected ipv4, got ipv6")
+	}
+	str := strings.Split(b, ",")
+	dst := make([]net.IP, len(str))
+	for i, e := range str {
+		ip := net.ParseIP(e).To4()
+		if ip == nil {
+			return errors.New("dns: svcbipv4hint: bad ip")
+		}
+		dst[i] = ip
+	}
+	s.Hint = dst
+	return nil
+}
+
+func (s *SVCBIPv4Hint) copy() SVCBKeyValue {
+	hint := make([]net.IP, len(s.Hint))
+	for i, ip := range s.Hint {
+		hint[i] = copyIP(ip)
+	}
+
+	return &SVCBIPv4Hint{
+		Hint: hint,
+	}
+}
+
+// SVCBECHConfig pair contains the ECHConfig structure defined in draft-ietf-tls-esni [RFC xxxx].
+// Basic use pattern for creating an ech option:
+//
+//	h := new(dns.HTTPS)
+//	h.Hdr = dns.RR_Header{Name: ".", Rrtype: dns.TypeHTTPS, Class: dns.ClassINET}
+//	e := new(dns.SVCBECHConfig)
+//	e.ECH = []byte{0xfe, 0x08, ...}
+//	h.Value = append(h.Value, e)
+type SVCBECHConfig struct {
+	ECH []byte // Specifically ECHConfigList including the redundant length prefix
+}
+
+func (*SVCBECHConfig) Key() SVCBKey     { return SVCB_ECHCONFIG }
+func (s *SVCBECHConfig) String() string { return toBase64(s.ECH) }
+func (s *SVCBECHConfig) len() int       { return len(s.ECH) }
+
+func (s *SVCBECHConfig) pack() ([]byte, error) {
+	return append([]byte(nil), s.ECH...), nil
+}
+
+func (s *SVCBECHConfig) copy() SVCBKeyValue {
+	return &SVCBECHConfig{
+		append([]byte(nil), s.ECH...),
+	}
+}
+
+func (s *SVCBECHConfig) unpack(b []byte) error {
+	s.ECH = append([]byte(nil), b...)
+	return nil
+}
+func (s *SVCBECHConfig) parse(b string) error {
+	x, err := fromBase64([]byte(b))
+	if err != nil {
+		return errors.New("dns: svcbech: bad base64 ech")
+	}
+	s.ECH = x
+	return nil
+}
+
+// SVCBIPv6Hint pair suggests an IPv6 address which may be used to open connections
+// if A and AAAA record responses for SVCB's Target domain haven't been received.
+// In that case, optionally, A and AAAA requests can be made, after which the
+// connection to the hinted IP address may be terminated and a new connection may be opened.
+// Basic use pattern for creating an ipv6hint option:
+//
+//	h := new(dns.HTTPS)
+//	h.Hdr = dns.RR_Header{Name: ".", Rrtype: dns.TypeHTTPS, Class: dns.ClassINET}
+//	e := new(dns.SVCBIPv6Hint)
+//	e.Hint = []net.IP{net.ParseIP("2001:db8::1")}
+//	h.Value = append(h.Value, e)
+type SVCBIPv6Hint struct {
+	Hint []net.IP
+}
+
+func (*SVCBIPv6Hint) Key() SVCBKey { return SVCB_IPV6HINT }
+func (s *SVCBIPv6Hint) len() int   { return 16 * len(s.Hint) }
+
+func (s *SVCBIPv6Hint) pack() ([]byte, error) {
+	b := make([]byte, 0, 16*len(s.Hint))
+	for _, e := range s.Hint {
+		if len(e) != net.IPv6len || e.To4() != nil {
+			return nil, errors.New("dns: svcbipv6hint: expected ipv6, hint is ipv4")
+		}
+		b = append(b, e...)
+	}
+	return b, nil
+}
+
+func (s *SVCBIPv6Hint) unpack(b []byte) error {
+	if len(b) == 0 || len(b)%16 != 0 {
+		return errors.New("dns: svcbipv6hint: ipv6 address byte array length not a multiple of 16")
+	}
+	x := make([]net.IP, 0, len(b)/16)
+	for i := 0; i < len(b); i += 16 {
+		ip := net.IP(b[i : i+16])
+		if ip.To4() != nil {
+			return errors.New("dns: svcbipv6hint: expected ipv6, got ipv4")
+		}
+		x = append(x, ip)
+	}
+	s.Hint = x
+	return nil
+}
+
+func (s *SVCBIPv6Hint) String() string {
+	str := make([]string, len(s.Hint))
+	for i, e := range s.Hint {
+		if x := e.To4(); x != nil {
+			return "<nil>"
+		}
+		str[i] = e.String()
+	}
+	return strings.Join(str, ",")
+}
+
+func (s *SVCBIPv6Hint) parse(b string) error {
+	str := strings.Split(b, ",")
+	dst := make([]net.IP, len(str))
+	for i, e := range str {
+		ip := net.ParseIP(e)
+		if ip == nil {
+			return errors.New("dns: svcbipv6hint: bad ip")
+		}
+		if ip.To4() != nil {
+			return errors.New("dns: svcbipv6hint: expected ipv6, got ipv4-mapped-ipv6")
+		}
+		dst[i] = ip
+	}
+	s.Hint = dst
+	return nil
+}
+
+func (s *SVCBIPv6Hint) copy() SVCBKeyValue {
+	hint := make([]net.IP, len(s.Hint))
+	for i, ip := range s.Hint {
+		hint[i] = copyIP(ip)
+	}
+
+	return &SVCBIPv6Hint{
+		Hint: hint,
+	}
+}
+
+// SVCBDoHPath pair is used to indicate the URI template that the
+// clients may use to construct a DNS over HTTPS URI.
+//
+// See RFC xxxx (https://datatracker.ietf.org/doc/html/draft-ietf-add-svcb-dns-02)
+// and RFC yyyy (https://datatracker.ietf.org/doc/html/draft-ietf-add-ddr-06).
+//
+// A basic example of using the dohpath option together with the alpn
+// option to indicate support for DNS over HTTPS on a certain path:
+//
+//	s := new(dns.SVCB)
+//	s.Hdr = dns.RR_Header{Name: ".", Rrtype: dns.TypeSVCB, Class: dns.ClassINET}
+//	e := new(dns.SVCBAlpn)
+//	e.Alpn = []string{"h2", "h3"}
+//	p := new(dns.SVCBDoHPath)
+//	p.Template = "/dns-query{?dns}"
+//	s.Value = append(s.Value, e, p)
+//
+// The parsing currently doesn't validate that Template is a valid
+// RFC 6570 URI template.
+type SVCBDoHPath struct {
+	Template string
+}
+
+func (*SVCBDoHPath) Key() SVCBKey            { return SVCB_DOHPATH }
+func (s *SVCBDoHPath) String() string        { return svcbParamToStr([]byte(s.Template)) }
+func (s *SVCBDoHPath) len() int              { return len(s.Template) }
+func (s *SVCBDoHPath) pack() ([]byte, error) { return []byte(s.Template), nil }
+
+func (s *SVCBDoHPath) unpack(b []byte) error {
+	s.Template = string(b)
+	return nil
+}
+
+func (s *SVCBDoHPath) parse(b string) error {
+	template, err := svcbParseParam(b)
+	if err != nil {
+		return fmt.Errorf("dns: svcbdohpath: %w", err)
+	}
+	s.Template = string(template)
+	return nil
+}
+
+func (s *SVCBDoHPath) copy() SVCBKeyValue {
+	return &SVCBDoHPath{
+		Template: s.Template,
+	}
+}
+
+// SVCBLocal pair is intended for experimental/private use. The key is recommended
+// to be in the range [SVCB_PRIVATE_LOWER, SVCB_PRIVATE_UPPER].
+// Basic use pattern for creating a keyNNNNN option:
+//
+//	h := new(dns.HTTPS)
+//	h.Hdr = dns.RR_Header{Name: ".", Rrtype: dns.TypeHTTPS, Class: dns.ClassINET}
+//	e := new(dns.SVCBLocal)
+//	e.KeyCode = 65400
+//	e.Data = []byte("abc")
+//	h.Value = append(h.Value, e)
+type SVCBLocal struct {
+	KeyCode SVCBKey // Never 65535 or any assigned keys.
+	Data    []byte  // All byte sequences are allowed.
+}
+
+func (s *SVCBLocal) Key() SVCBKey          { return s.KeyCode }
+func (s *SVCBLocal) String() string        { return svcbParamToStr(s.Data) }
+func (s *SVCBLocal) pack() ([]byte, error) { return append([]byte(nil), s.Data...), nil }
+func (s *SVCBLocal) len() int              { return len(s.Data) }
+
+func (s *SVCBLocal) unpack(b []byte) error {
+	s.Data = append([]byte(nil), b...)
+	return nil
+}
+
+func (s *SVCBLocal) parse(b string) error {
+	data, err := svcbParseParam(b)
+	if err != nil {
+		return fmt.Errorf("dns: svcblocal: svcb private/experimental key %w", err)
+	}
+	s.Data = data
+	return nil
+}
+
+func (s *SVCBLocal) copy() SVCBKeyValue {
+	return &SVCBLocal{s.KeyCode,
+		append([]byte(nil), s.Data...),
+	}
+}
+
+func (rr *SVCB) String() string {
+	s := rr.Hdr.String() +
+		strconv.Itoa(int(rr.Priority)) + " " +
+		sprintName(rr.Target)
+	for _, e := range rr.Value {
+		s += " " + e.Key().String() + "=\"" + e.String() + "\""
+	}
+	return s
+}
+
+// areSVCBPairArraysEqual checks if SVCBKeyValue arrays are equal after sorting their
+// copies. arrA and arrB have equal lengths, otherwise zduplicate.go wouldn't call this function.
+func areSVCBPairArraysEqual(a []SVCBKeyValue, b []SVCBKeyValue) bool {
+	a = append([]SVCBKeyValue(nil), a...)
+	b = append([]SVCBKeyValue(nil), b...)
+	sort.Slice(a, func(i, j int) bool { return a[i].Key() < a[j].Key() })
+	sort.Slice(b, func(i, j int) bool { return b[i].Key() < b[j].Key() })
+	for i, e := range a {
+		if e.Key() != b[i].Key() {
+			return false
+		}
+		b1, err1 := e.pack()
+		b2, err2 := b[i].pack()
+		if err1 != nil || err2 != nil || !bytes.Equal(b1, b2) {
+			return false
+		}
+	}
+	return true
+}
+
+// svcbParamStr converts the value of an SVCB parameter into a DNS presentation-format string.
+func svcbParamToStr(s []byte) string {
+	var str strings.Builder
+	str.Grow(4 * len(s))
+	for _, e := range s {
+		if ' ' <= e && e <= '~' {
+			switch e {
+			case '"', ';', ' ', '\\':
+				str.WriteByte('\\')
+				str.WriteByte(e)
+			default:
+				str.WriteByte(e)
+			}
+		} else {
+			str.WriteString(escapeByte(e))
+		}
+	}
+	return str.String()
+}
+
+// svcbParseParam parses a DNS presentation-format string into an SVCB parameter value.
+func svcbParseParam(b string) ([]byte, error) {
+	data := make([]byte, 0, len(b))
+	for i := 0; i < len(b); {
+		if b[i] != '\\' {
+			data = append(data, b[i])
+			i++
+			continue
+		}
+		if i+1 == len(b) {
+			return nil, errors.New("escape unterminated")
+		}
+		if isDigit(b[i+1]) {
+			if i+3 < len(b) && isDigit(b[i+2]) && isDigit(b[i+3]) {
+				a, err := strconv.ParseUint(b[i+1:i+4], 10, 8)
+				if err == nil {
+					i += 4
+					data = append(data, byte(a))
+					continue
+				}
+			}
+			return nil, errors.New("bad escaped octet")
+		} else {
+			data = append(data, b[i+1])
+			i += 2
+		}
+	}
+	return data, nil
+}

vendor/github.com/miekg/dns/tlsa.go

@@ -0,0 +1,44 @@
+package dns
+
+import (
+	"crypto/x509"
+	"net"
+	"strconv"
+)
+
+// Sign creates a TLSA record from an SSL certificate.
+func (r *TLSA) Sign(usage, selector, matchingType int, cert *x509.Certificate) (err error) {
+	r.Hdr.Rrtype = TypeTLSA
+	r.Usage = uint8(usage)
+	r.Selector = uint8(selector)
+	r.MatchingType = uint8(matchingType)
+
+	r.Certificate, err = CertificateToDANE(r.Selector, r.MatchingType, cert)
+	return err
+}
+
+// Verify verifies a TLSA record against an SSL certificate. If it is OK
+// a nil error is returned.
+func (r *TLSA) Verify(cert *x509.Certificate) error {
+	c, err := CertificateToDANE(r.Selector, r.MatchingType, cert)
+	if err != nil {
+		return err // Not also ErrSig?
+	}
+	if r.Certificate == c {
+		return nil
+	}
+	return ErrSig // ErrSig, really?
+}
+
+// TLSAName returns the ownername of a TLSA resource record as per the
+// rules specified in RFC 6698, Section 3.
+func TLSAName(name, service, network string) (string, error) {
+	if !IsFqdn(name) {
+		return "", ErrFqdn
+	}
+	p, err := net.LookupPort(network, service)
+	if err != nil {
+		return "", err
+	}
+	return "_" + strconv.Itoa(p) + "._" + network + "." + name, nil
+}

vendor/github.com/miekg/dns/tools.go

@@ -0,0 +1,9 @@
+// +build tools
+
+// We include our tool dependencies for `go generate` here to ensure they're
+// properly tracked by the go tool. See the Go Wiki for the rationale behind this:
+// https://github.com/golang/go/wiki/Modules#how-can-i-track-tool-dependencies-for-a-module.
+
+package dns
+
+import _ "golang.org/x/tools/go/packages"

vendor/github.com/miekg/dns/tsig.go

@@ -0,0 +1,456 @@
+package dns
+
+import (
+	"crypto/hmac"
+	"crypto/sha1"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/binary"
+	"encoding/hex"
+	"hash"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// HMAC hashing codes. These are transmitted as domain names.
+const (
+	HmacSHA1   = "hmac-sha1."
+	HmacSHA224 = "hmac-sha224."
+	HmacSHA256 = "hmac-sha256."
+	HmacSHA384 = "hmac-sha384."
+	HmacSHA512 = "hmac-sha512."
+
+	HmacMD5 = "hmac-md5.sig-alg.reg.int." // Deprecated: HmacMD5 is no longer supported.
+)
+
+// TsigProvider provides the API to plug-in a custom TSIG implementation.
+type TsigProvider interface {
+	// Generate is passed the DNS message to be signed and the partial TSIG RR. It returns the signature and nil, otherwise an error.
+	Generate(msg []byte, t *TSIG) ([]byte, error)
+	// Verify is passed the DNS message to be verified and the TSIG RR. If the signature is valid it will return nil, otherwise an error.
+	Verify(msg []byte, t *TSIG) error
+}
+
+type tsigHMACProvider string
+
+func (key tsigHMACProvider) Generate(msg []byte, t *TSIG) ([]byte, error) {
+	// If we barf here, the caller is to blame
+	rawsecret, err := fromBase64([]byte(key))
+	if err != nil {
+		return nil, err
+	}
+	var h hash.Hash
+	switch CanonicalName(t.Algorithm) {
+	case HmacSHA1:
+		h = hmac.New(sha1.New, rawsecret)
+	case HmacSHA224:
+		h = hmac.New(sha256.New224, rawsecret)
+	case HmacSHA256:
+		h = hmac.New(sha256.New, rawsecret)
+	case HmacSHA384:
+		h = hmac.New(sha512.New384, rawsecret)
+	case HmacSHA512:
+		h = hmac.New(sha512.New, rawsecret)
+	default:
+		return nil, ErrKeyAlg
+	}
+	h.Write(msg)
+	return h.Sum(nil), nil
+}
+
+func (key tsigHMACProvider) Verify(msg []byte, t *TSIG) error {
+	b, err := key.Generate(msg, t)
+	if err != nil {
+		return err
+	}
+	mac, err := hex.DecodeString(t.MAC)
+	if err != nil {
+		return err
+	}
+	if !hmac.Equal(b, mac) {
+		return ErrSig
+	}
+	return nil
+}
+
+type tsigSecretProvider map[string]string
+
+func (ts tsigSecretProvider) Generate(msg []byte, t *TSIG) ([]byte, error) {
+	key, ok := ts[t.Hdr.Name]
+	if !ok {
+		return nil, ErrSecret
+	}
+	return tsigHMACProvider(key).Generate(msg, t)
+}
+
+func (ts tsigSecretProvider) Verify(msg []byte, t *TSIG) error {
+	key, ok := ts[t.Hdr.Name]
+	if !ok {
+		return ErrSecret
+	}
+	return tsigHMACProvider(key).Verify(msg, t)
+}
+
+// TSIG is the RR the holds the transaction signature of a message.
+// See RFC 2845 and RFC 4635.
+type TSIG struct {
+	Hdr        RR_Header
+	Algorithm  string `dns:"domain-name"`
+	TimeSigned uint64 `dns:"uint48"`
+	Fudge      uint16
+	MACSize    uint16
+	MAC        string `dns:"size-hex:MACSize"`
+	OrigId     uint16
+	Error      uint16
+	OtherLen   uint16
+	OtherData  string `dns:"size-hex:OtherLen"`
+}
+
+// TSIG has no official presentation format, but this will suffice.
+
+func (rr *TSIG) String() string {
+	s := "\n;; TSIG PSEUDOSECTION:\n; " // add another semi-colon to signify TSIG does not have a presentation format
+	s += rr.Hdr.String() +
+		" " + rr.Algorithm +
+		" " + tsigTimeToString(rr.TimeSigned) +
+		" " + strconv.Itoa(int(rr.Fudge)) +
+		" " + strconv.Itoa(int(rr.MACSize)) +
+		" " + strings.ToUpper(rr.MAC) +
+		" " + strconv.Itoa(int(rr.OrigId)) +
+		" " + strconv.Itoa(int(rr.Error)) + // BIND prints NOERROR
+		" " + strconv.Itoa(int(rr.OtherLen)) +
+		" " + rr.OtherData
+	return s
+}
+
+func (*TSIG) parse(c *zlexer, origin string) *ParseError {
+	return &ParseError{err: "TSIG records do not have a presentation format"}
+}
+
+// The following values must be put in wireformat, so that the MAC can be calculated.
+// RFC 2845, section 3.4.2. TSIG Variables.
+type tsigWireFmt struct {
+	// From RR_Header
+	Name  string `dns:"domain-name"`
+	Class uint16
+	Ttl   uint32
+	// Rdata of the TSIG
+	Algorithm  string `dns:"domain-name"`
+	TimeSigned uint64 `dns:"uint48"`
+	Fudge      uint16
+	// MACSize, MAC and OrigId excluded
+	Error     uint16
+	OtherLen  uint16
+	OtherData string `dns:"size-hex:OtherLen"`
+}
+
+// If we have the MAC use this type to convert it to wiredata. Section 3.4.3. Request MAC
+type macWireFmt struct {
+	MACSize uint16
+	MAC     string `dns:"size-hex:MACSize"`
+}
+
+// 3.3. Time values used in TSIG calculations
+type timerWireFmt struct {
+	TimeSigned uint64 `dns:"uint48"`
+	Fudge      uint16
+}
+
+// TsigGenerate fills out the TSIG record attached to the message.
+// The message should contain
+// a "stub" TSIG RR with the algorithm, key name (owner name of the RR),
+// time fudge (defaults to 300 seconds) and the current time
+// The TSIG MAC is saved in that Tsig RR.
+// When TsigGenerate is called for the first time requestMAC is set to the empty string and
+// timersOnly is false.
+// If something goes wrong an error is returned, otherwise it is nil.
+func TsigGenerate(m *Msg, secret, requestMAC string, timersOnly bool) ([]byte, string, error) {
+	return tsigGenerateProvider(m, tsigHMACProvider(secret), requestMAC, timersOnly)
+}
+
+func tsigGenerateProvider(m *Msg, provider TsigProvider, requestMAC string, timersOnly bool) ([]byte, string, error) {
+	if m.IsTsig() == nil {
+		panic("dns: TSIG not last RR in additional")
+	}
+
+	rr := m.Extra[len(m.Extra)-1].(*TSIG)
+	m.Extra = m.Extra[0 : len(m.Extra)-1] // kill the TSIG from the msg
+	mbuf, err := m.Pack()
+	if err != nil {
+		return nil, "", err
+	}
+
+	buf, err := tsigBuffer(mbuf, rr, requestMAC, timersOnly)
+	if err != nil {
+		return nil, "", err
+	}
+
+	t := new(TSIG)
+	// Copy all TSIG fields except MAC, its size, and time signed which are filled when signing.
+	*t = *rr
+	t.TimeSigned = 0
+	t.MAC = ""
+	t.MACSize = 0
+
+	// Sign unless there is a key or MAC validation error (RFC 8945 5.3.2)
+	if rr.Error != RcodeBadKey && rr.Error != RcodeBadSig {
+		mac, err := provider.Generate(buf, rr)
+		if err != nil {
+			return nil, "", err
+		}
+		t.TimeSigned = rr.TimeSigned
+		t.MAC = hex.EncodeToString(mac)
+		t.MACSize = uint16(len(t.MAC) / 2) // Size is half!
+	}
+
+	tbuf := make([]byte, Len(t))
+	off, err := PackRR(t, tbuf, 0, nil, false)
+	if err != nil {
+		return nil, "", err
+	}
+	mbuf = append(mbuf, tbuf[:off]...)
+	// Update the ArCount directly in the buffer.
+	binary.BigEndian.PutUint16(mbuf[10:], uint16(len(m.Extra)+1))
+
+	return mbuf, t.MAC, nil
+}
+
+// TsigVerify verifies the TSIG on a message.
+// If the signature does not validate err contains the
+// error, otherwise it is nil.
+func TsigVerify(msg []byte, secret, requestMAC string, timersOnly bool) error {
+	return tsigVerify(msg, tsigHMACProvider(secret), requestMAC, timersOnly, uint64(time.Now().Unix()))
+}
+
+func tsigVerifyProvider(msg []byte, provider TsigProvider, requestMAC string, timersOnly bool) error {
+	return tsigVerify(msg, provider, requestMAC, timersOnly, uint64(time.Now().Unix()))
+}
+
+// actual implementation of TsigVerify, taking the current time ('now') as a parameter for the convenience of tests.
+func tsigVerify(msg []byte, provider TsigProvider, requestMAC string, timersOnly bool, now uint64) error {
+	// Strip the TSIG from the incoming msg
+	stripped, tsig, err := stripTsig(msg)
+	if err != nil {
+		return err
+	}
+
+	buf, err := tsigBuffer(stripped, tsig, requestMAC, timersOnly)
+	if err != nil {
+		return err
+	}
+
+	if err := provider.Verify(buf, tsig); err != nil {
+		return err
+	}
+
+	// Fudge factor works both ways. A message can arrive before it was signed because
+	// of clock skew.
+	// We check this after verifying the signature, following draft-ietf-dnsop-rfc2845bis
+	// instead of RFC2845, in order to prevent a security vulnerability as reported in CVE-2017-3142/3143.
+	ti := now - tsig.TimeSigned
+	if now < tsig.TimeSigned {
+		ti = tsig.TimeSigned - now
+	}
+	if uint64(tsig.Fudge) < ti {
+		return ErrTime
+	}
+
+	return nil
+}
+
+// Create a wiredata buffer for the MAC calculation.
+func tsigBuffer(msgbuf []byte, rr *TSIG, requestMAC string, timersOnly bool) ([]byte, error) {
+	var buf []byte
+	if rr.TimeSigned == 0 {
+		rr.TimeSigned = uint64(time.Now().Unix())
+	}
+	if rr.Fudge == 0 {
+		rr.Fudge = 300 // Standard (RFC) default.
+	}
+
+	// Replace message ID in header with original ID from TSIG
+	binary.BigEndian.PutUint16(msgbuf[0:2], rr.OrigId)
+
+	if requestMAC != "" {
+		m := new(macWireFmt)
+		m.MACSize = uint16(len(requestMAC) / 2)
+		m.MAC = requestMAC
+		buf = make([]byte, len(requestMAC)) // long enough
+		n, err := packMacWire(m, buf)
+		if err != nil {
+			return nil, err
+		}
+		buf = buf[:n]
+	}
+
+	tsigvar := make([]byte, DefaultMsgSize)
+	if timersOnly {
+		tsig := new(timerWireFmt)
+		tsig.TimeSigned = rr.TimeSigned
+		tsig.Fudge = rr.Fudge
+		n, err := packTimerWire(tsig, tsigvar)
+		if err != nil {
+			return nil, err
+		}
+		tsigvar = tsigvar[:n]
+	} else {
+		tsig := new(tsigWireFmt)
+		tsig.Name = CanonicalName(rr.Hdr.Name)
+		tsig.Class = ClassANY
+		tsig.Ttl = rr.Hdr.Ttl
+		tsig.Algorithm = CanonicalName(rr.Algorithm)
+		tsig.TimeSigned = rr.TimeSigned
+		tsig.Fudge = rr.Fudge
+		tsig.Error = rr.Error
+		tsig.OtherLen = rr.OtherLen
+		tsig.OtherData = rr.OtherData
+		n, err := packTsigWire(tsig, tsigvar)
+		if err != nil {
+			return nil, err
+		}
+		tsigvar = tsigvar[:n]
+	}
+
+	if requestMAC != "" {
+		x := append(buf, msgbuf...)
+		buf = append(x, tsigvar...)
+	} else {
+		buf = append(msgbuf, tsigvar...)
+	}
+	return buf, nil
+}
+
+// Strip the TSIG from the raw message.
+func stripTsig(msg []byte) ([]byte, *TSIG, error) {
+	// Copied from msg.go's Unpack() Header, but modified.
+	var (
+		dh  Header
+		err error
+	)
+	off, tsigoff := 0, 0
+
+	if dh, off, err = unpackMsgHdr(msg, off); err != nil {
+		return nil, nil, err
+	}
+	if dh.Arcount == 0 {
+		return nil, nil, ErrNoSig
+	}
+
+	// Rcode, see msg.go Unpack()
+	if int(dh.Bits&0xF) == RcodeNotAuth {
+		return nil, nil, ErrAuth
+	}
+
+	for i := 0; i < int(dh.Qdcount); i++ {
+		_, off, err = unpackQuestion(msg, off)
+		if err != nil {
+			return nil, nil, err
+		}
+	}
+
+	_, off, err = unpackRRslice(int(dh.Ancount), msg, off)
+	if err != nil {
+		return nil, nil, err
+	}
+	_, off, err = unpackRRslice(int(dh.Nscount), msg, off)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	rr := new(TSIG)
+	var extra RR
+	for i := 0; i < int(dh.Arcount); i++ {
+		tsigoff = off
+		extra, off, err = UnpackRR(msg, off)
+		if err != nil {
+			return nil, nil, err
+		}
+		if extra.Header().Rrtype == TypeTSIG {
+			rr = extra.(*TSIG)
+			// Adjust Arcount.
+			arcount := binary.BigEndian.Uint16(msg[10:])
+			binary.BigEndian.PutUint16(msg[10:], arcount-1)
+			break
+		}
+	}
+	if rr == nil {
+		return nil, nil, ErrNoSig
+	}
+	return msg[:tsigoff], rr, nil
+}
+
+// Translate the TSIG time signed into a date. There is no
+// need for RFC1982 calculations as this date is 48 bits.
+func tsigTimeToString(t uint64) string {
+	ti := time.Unix(int64(t), 0).UTC()
+	return ti.Format("20060102150405")
+}
+
+func packTsigWire(tw *tsigWireFmt, msg []byte) (int, error) {
+	// copied from zmsg.go TSIG packing
+	// RR_Header
+	off, err := PackDomainName(tw.Name, msg, 0, nil, false)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint16(tw.Class, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint32(tw.Ttl, msg, off)
+	if err != nil {
+		return off, err
+	}
+
+	off, err = PackDomainName(tw.Algorithm, msg, off, nil, false)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint48(tw.TimeSigned, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint16(tw.Fudge, msg, off)
+	if err != nil {
+		return off, err
+	}
+
+	off, err = packUint16(tw.Error, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint16(tw.OtherLen, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packStringHex(tw.OtherData, msg, off)
+	if err != nil {
+		return off, err
+	}
+	return off, nil
+}
+
+func packMacWire(mw *macWireFmt, msg []byte) (int, error) {
+	off, err := packUint16(mw.MACSize, msg, 0)
+	if err != nil {
+		return off, err
+	}
+	off, err = packStringHex(mw.MAC, msg, off)
+	if err != nil {
+		return off, err
+	}
+	return off, nil
+}
+
+func packTimerWire(tw *timerWireFmt, msg []byte) (int, error) {
+	off, err := packUint48(tw.TimeSigned, msg, 0)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint16(tw.Fudge, msg, off)
+	if err != nil {
+		return off, err
+	}
+	return off, nil
+}

vendor/github.com/miekg/dns/udp.go

@@ -0,0 +1,102 @@
+// +build !windows
+
+package dns
+
+import (
+	"net"
+
+	"golang.org/x/net/ipv4"
+	"golang.org/x/net/ipv6"
+)
+
+// This is the required size of the OOB buffer to pass to ReadMsgUDP.
+var udpOOBSize = func() int {
+	// We can't know whether we'll get an IPv4 control message or an
+	// IPv6 control message ahead of time. To get around this, we size
+	// the buffer equal to the largest of the two.
+
+	oob4 := ipv4.NewControlMessage(ipv4.FlagDst | ipv4.FlagInterface)
+	oob6 := ipv6.NewControlMessage(ipv6.FlagDst | ipv6.FlagInterface)
+
+	if len(oob4) > len(oob6) {
+		return len(oob4)
+	}
+
+	return len(oob6)
+}()
+
+// SessionUDP holds the remote address and the associated
+// out-of-band data.
+type SessionUDP struct {
+	raddr   *net.UDPAddr
+	context []byte
+}
+
+// RemoteAddr returns the remote network address.
+func (s *SessionUDP) RemoteAddr() net.Addr { return s.raddr }
+
+// ReadFromSessionUDP acts just like net.UDPConn.ReadFrom(), but returns a session object instead of a
+// net.UDPAddr.
+func ReadFromSessionUDP(conn *net.UDPConn, b []byte) (int, *SessionUDP, error) {
+	oob := make([]byte, udpOOBSize)
+	n, oobn, _, raddr, err := conn.ReadMsgUDP(b, oob)
+	if err != nil {
+		return n, nil, err
+	}
+	return n, &SessionUDP{raddr, oob[:oobn]}, err
+}
+
+// WriteToSessionUDP acts just like net.UDPConn.WriteTo(), but uses a *SessionUDP instead of a net.Addr.
+func WriteToSessionUDP(conn *net.UDPConn, b []byte, session *SessionUDP) (int, error) {
+	oob := correctSource(session.context)
+	n, _, err := conn.WriteMsgUDP(b, oob, session.raddr)
+	return n, err
+}
+
+func setUDPSocketOptions(conn *net.UDPConn) error {
+	// Try setting the flags for both families and ignore the errors unless they
+	// both error.
+	err6 := ipv6.NewPacketConn(conn).SetControlMessage(ipv6.FlagDst|ipv6.FlagInterface, true)
+	err4 := ipv4.NewPacketConn(conn).SetControlMessage(ipv4.FlagDst|ipv4.FlagInterface, true)
+	if err6 != nil && err4 != nil {
+		return err4
+	}
+	return nil
+}
+
+// parseDstFromOOB takes oob data and returns the destination IP.
+func parseDstFromOOB(oob []byte) net.IP {
+	// Start with IPv6 and then fallback to IPv4
+	// TODO(fastest963): Figure out a way to prefer one or the other. Looking at
+	// the lvl of the header for a 0 or 41 isn't cross-platform.
+	cm6 := new(ipv6.ControlMessage)
+	if cm6.Parse(oob) == nil && cm6.Dst != nil {
+		return cm6.Dst
+	}
+	cm4 := new(ipv4.ControlMessage)
+	if cm4.Parse(oob) == nil && cm4.Dst != nil {
+		return cm4.Dst
+	}
+	return nil
+}
+
+// correctSource takes oob data and returns new oob data with the Src equal to the Dst
+func correctSource(oob []byte) []byte {
+	dst := parseDstFromOOB(oob)
+	if dst == nil {
+		return nil
+	}
+	// If the dst is definitely an IPv6, then use ipv6's ControlMessage to
+	// respond otherwise use ipv4's because ipv6's marshal ignores ipv4
+	// addresses.
+	if dst.To4() == nil {
+		cm := new(ipv6.ControlMessage)
+		cm.Src = dst
+		oob = cm.Marshal()
+	} else {
+		cm := new(ipv4.ControlMessage)
+		cm.Src = dst
+		oob = cm.Marshal()
+	}
+	return oob
+}

vendor/github.com/miekg/dns/udp_windows.go

@@ -0,0 +1,35 @@
+// +build windows
+
+package dns
+
+import "net"
+
+// SessionUDP holds the remote address
+type SessionUDP struct {
+	raddr *net.UDPAddr
+}
+
+// RemoteAddr returns the remote network address.
+func (s *SessionUDP) RemoteAddr() net.Addr { return s.raddr }
+
+// ReadFromSessionUDP acts just like net.UDPConn.ReadFrom(), but returns a session object instead of a
+// net.UDPAddr.
+// TODO(fastest963): Once go1.10 is released, use ReadMsgUDP.
+func ReadFromSessionUDP(conn *net.UDPConn, b []byte) (int, *SessionUDP, error) {
+	n, raddr, err := conn.ReadFrom(b)
+	if err != nil {
+		return n, nil, err
+	}
+	return n, &SessionUDP{raddr.(*net.UDPAddr)}, err
+}
+
+// WriteToSessionUDP acts just like net.UDPConn.WriteTo(), but uses a *SessionUDP instead of a net.Addr.
+// TODO(fastest963): Once go1.10 is released, use WriteMsgUDP.
+func WriteToSessionUDP(conn *net.UDPConn, b []byte, session *SessionUDP) (int, error) {
+	return conn.WriteTo(b, session.raddr)
+}
+
+// TODO(fastest963): Once go1.10 is released and we can use *MsgUDP methods
+// use the standard method in udp.go for these.
+func setUDPSocketOptions(*net.UDPConn) error { return nil }
+func parseDstFromOOB([]byte, net.IP) net.IP  { return nil }

vendor/github.com/miekg/dns/update.go

@@ -0,0 +1,112 @@
+package dns
+
+// NameUsed sets the RRs in the prereq section to
+// "Name is in use" RRs. RFC 2136 section 2.4.4.
+func (u *Msg) NameUsed(rr []RR) {
+	if u.Answer == nil {
+		u.Answer = make([]RR, 0, len(rr))
+	}
+	for _, r := range rr {
+		u.Answer = append(u.Answer, &ANY{Hdr: RR_Header{Name: r.Header().Name, Ttl: 0, Rrtype: TypeANY, Class: ClassANY}})
+	}
+}
+
+// NameNotUsed sets the RRs in the prereq section to
+// "Name is in not use" RRs. RFC 2136 section 2.4.5.
+func (u *Msg) NameNotUsed(rr []RR) {
+	if u.Answer == nil {
+		u.Answer = make([]RR, 0, len(rr))
+	}
+	for _, r := range rr {
+		u.Answer = append(u.Answer, &ANY{Hdr: RR_Header{Name: r.Header().Name, Ttl: 0, Rrtype: TypeANY, Class: ClassNONE}})
+	}
+}
+
+// Used sets the RRs in the prereq section to
+// "RRset exists (value dependent -- with rdata)" RRs. RFC 2136 section 2.4.2.
+func (u *Msg) Used(rr []RR) {
+	if len(u.Question) == 0 {
+		panic("dns: empty question section")
+	}
+	if u.Answer == nil {
+		u.Answer = make([]RR, 0, len(rr))
+	}
+	for _, r := range rr {
+		hdr := r.Header()
+		hdr.Class = u.Question[0].Qclass
+		hdr.Ttl = 0
+		u.Answer = append(u.Answer, r)
+	}
+}
+
+// RRsetUsed sets the RRs in the prereq section to
+// "RRset exists (value independent -- no rdata)" RRs. RFC 2136 section 2.4.1.
+func (u *Msg) RRsetUsed(rr []RR) {
+	if u.Answer == nil {
+		u.Answer = make([]RR, 0, len(rr))
+	}
+	for _, r := range rr {
+		h := r.Header()
+		u.Answer = append(u.Answer, &ANY{Hdr: RR_Header{Name: h.Name, Ttl: 0, Rrtype: h.Rrtype, Class: ClassANY}})
+	}
+}
+
+// RRsetNotUsed sets the RRs in the prereq section to
+// "RRset does not exist" RRs. RFC 2136 section 2.4.3.
+func (u *Msg) RRsetNotUsed(rr []RR) {
+	if u.Answer == nil {
+		u.Answer = make([]RR, 0, len(rr))
+	}
+	for _, r := range rr {
+		h := r.Header()
+		u.Answer = append(u.Answer, &ANY{Hdr: RR_Header{Name: h.Name, Ttl: 0, Rrtype: h.Rrtype, Class: ClassNONE}})
+	}
+}
+
+// Insert creates a dynamic update packet that adds an complete RRset, see RFC 2136 section 2.5.1.
+func (u *Msg) Insert(rr []RR) {
+	if len(u.Question) == 0 {
+		panic("dns: empty question section")
+	}
+	if u.Ns == nil {
+		u.Ns = make([]RR, 0, len(rr))
+	}
+	for _, r := range rr {
+		r.Header().Class = u.Question[0].Qclass
+		u.Ns = append(u.Ns, r)
+	}
+}
+
+// RemoveRRset creates a dynamic update packet that deletes an RRset, see RFC 2136 section 2.5.2.
+func (u *Msg) RemoveRRset(rr []RR) {
+	if u.Ns == nil {
+		u.Ns = make([]RR, 0, len(rr))
+	}
+	for _, r := range rr {
+		h := r.Header()
+		u.Ns = append(u.Ns, &ANY{Hdr: RR_Header{Name: h.Name, Ttl: 0, Rrtype: h.Rrtype, Class: ClassANY}})
+	}
+}
+
+// RemoveName creates a dynamic update packet that deletes all RRsets of a name, see RFC 2136 section 2.5.3
+func (u *Msg) RemoveName(rr []RR) {
+	if u.Ns == nil {
+		u.Ns = make([]RR, 0, len(rr))
+	}
+	for _, r := range rr {
+		u.Ns = append(u.Ns, &ANY{Hdr: RR_Header{Name: r.Header().Name, Ttl: 0, Rrtype: TypeANY, Class: ClassANY}})
+	}
+}
+
+// Remove creates a dynamic update packet deletes RR from a RRSset, see RFC 2136 section 2.5.4
+func (u *Msg) Remove(rr []RR) {
+	if u.Ns == nil {
+		u.Ns = make([]RR, 0, len(rr))
+	}
+	for _, r := range rr {
+		h := r.Header()
+		h.Class = ClassNONE
+		h.Ttl = 0
+		u.Ns = append(u.Ns, r)
+	}
+}

vendor/github.com/miekg/dns/version.go

@@ -0,0 +1,15 @@
+package dns
+
+import "fmt"
+
+// Version is current version of this library.
+var Version = v{1, 1, 49}
+
+// v holds the version of this library.
+type v struct {
+	Major, Minor, Patch int
+}
+
+func (v v) String() string {
+	return fmt.Sprintf("%d.%d.%d", v.Major, v.Minor, v.Patch)
+}

vendor/github.com/miekg/dns/xfr.go

@@ -0,0 +1,271 @@
+package dns
+
+import (
+	"fmt"
+	"time"
+)
+
+// Envelope is used when doing a zone transfer with a remote server.
+type Envelope struct {
+	RR    []RR  // The set of RRs in the answer section of the xfr reply message.
+	Error error // If something went wrong, this contains the error.
+}
+
+// A Transfer defines parameters that are used during a zone transfer.
+type Transfer struct {
+	*Conn
+	DialTimeout    time.Duration     // net.DialTimeout, defaults to 2 seconds
+	ReadTimeout    time.Duration     // net.Conn.SetReadTimeout value for connections, defaults to 2 seconds
+	WriteTimeout   time.Duration     // net.Conn.SetWriteTimeout value for connections, defaults to 2 seconds
+	TsigProvider   TsigProvider      // An implementation of the TsigProvider interface. If defined it replaces TsigSecret and is used for all TSIG operations.
+	TsigSecret     map[string]string // Secret(s) for Tsig map[<zonename>]<base64 secret>, zonename must be in canonical form (lowercase, fqdn, see RFC 4034 Section 6.2)
+	tsigTimersOnly bool
+}
+
+func (t *Transfer) tsigProvider() TsigProvider {
+	if t.TsigProvider != nil {
+		return t.TsigProvider
+	}
+	if t.TsigSecret != nil {
+		return tsigSecretProvider(t.TsigSecret)
+	}
+	return nil
+}
+
+// TODO: Think we need to away to stop the transfer
+
+// In performs an incoming transfer with the server in a.
+// If you would like to set the source IP, or some other attribute
+// of a Dialer for a Transfer, you can do so by specifying the attributes
+// in the Transfer.Conn:
+//
+//	d := net.Dialer{LocalAddr: transfer_source}
+//	con, err := d.Dial("tcp", master)
+//	dnscon := &dns.Conn{Conn:con}
+//	transfer = &dns.Transfer{Conn: dnscon}
+//	channel, err := transfer.In(message, master)
+//
+func (t *Transfer) In(q *Msg, a string) (env chan *Envelope, err error) {
+	switch q.Question[0].Qtype {
+	case TypeAXFR, TypeIXFR:
+	default:
+		return nil, &Error{"unsupported question type"}
+	}
+
+	timeout := dnsTimeout
+	if t.DialTimeout != 0 {
+		timeout = t.DialTimeout
+	}
+
+	if t.Conn == nil {
+		t.Conn, err = DialTimeout("tcp", a, timeout)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if err := t.WriteMsg(q); err != nil {
+		return nil, err
+	}
+
+	env = make(chan *Envelope)
+	switch q.Question[0].Qtype {
+	case TypeAXFR:
+		go t.inAxfr(q, env)
+	case TypeIXFR:
+		go t.inIxfr(q, env)
+	}
+
+	return env, nil
+}
+
+func (t *Transfer) inAxfr(q *Msg, c chan *Envelope) {
+	first := true
+	defer t.Close()
+	defer close(c)
+	timeout := dnsTimeout
+	if t.ReadTimeout != 0 {
+		timeout = t.ReadTimeout
+	}
+	for {
+		t.Conn.SetReadDeadline(time.Now().Add(timeout))
+		in, err := t.ReadMsg()
+		if err != nil {
+			c <- &Envelope{nil, err}
+			return
+		}
+		if q.Id != in.Id {
+			c <- &Envelope{in.Answer, ErrId}
+			return
+		}
+		if first {
+			if in.Rcode != RcodeSuccess {
+				c <- &Envelope{in.Answer, &Error{err: fmt.Sprintf(errXFR, in.Rcode)}}
+				return
+			}
+			if !isSOAFirst(in) {
+				c <- &Envelope{in.Answer, ErrSoa}
+				return
+			}
+			first = !first
+			// only one answer that is SOA, receive more
+			if len(in.Answer) == 1 {
+				t.tsigTimersOnly = true
+				c <- &Envelope{in.Answer, nil}
+				continue
+			}
+		}
+
+		if !first {
+			t.tsigTimersOnly = true // Subsequent envelopes use this.
+			if isSOALast(in) {
+				c <- &Envelope{in.Answer, nil}
+				return
+			}
+			c <- &Envelope{in.Answer, nil}
+		}
+	}
+}
+
+func (t *Transfer) inIxfr(q *Msg, c chan *Envelope) {
+	var serial uint32 // The first serial seen is the current server serial
+	axfr := true
+	n := 0
+	qser := q.Ns[0].(*SOA).Serial
+	defer t.Close()
+	defer close(c)
+	timeout := dnsTimeout
+	if t.ReadTimeout != 0 {
+		timeout = t.ReadTimeout
+	}
+	for {
+		t.SetReadDeadline(time.Now().Add(timeout))
+		in, err := t.ReadMsg()
+		if err != nil {
+			c <- &Envelope{nil, err}
+			return
+		}
+		if q.Id != in.Id {
+			c <- &Envelope{in.Answer, ErrId}
+			return
+		}
+		if in.Rcode != RcodeSuccess {
+			c <- &Envelope{in.Answer, &Error{err: fmt.Sprintf(errXFR, in.Rcode)}}
+			return
+		}
+		if n == 0 {
+			// Check if the returned answer is ok
+			if !isSOAFirst(in) {
+				c <- &Envelope{in.Answer, ErrSoa}
+				return
+			}
+			// This serial is important
+			serial = in.Answer[0].(*SOA).Serial
+			// Check if there are no changes in zone
+			if qser >= serial {
+				c <- &Envelope{in.Answer, nil}
+				return
+			}
+		}
+		// Now we need to check each message for SOA records, to see what we need to do
+		t.tsigTimersOnly = true
+		for _, rr := range in.Answer {
+			if v, ok := rr.(*SOA); ok {
+				if v.Serial == serial {
+					n++
+					// quit if it's a full axfr or the the servers' SOA is repeated the third time
+					if axfr && n == 2 || n == 3 {
+						c <- &Envelope{in.Answer, nil}
+						return
+					}
+				} else if axfr {
+					// it's an ixfr
+					axfr = false
+				}
+			}
+		}
+		c <- &Envelope{in.Answer, nil}
+	}
+}
+
+// Out performs an outgoing transfer with the client connecting in w.
+// Basic use pattern:
+//
+//	ch := make(chan *dns.Envelope)
+//	tr := new(dns.Transfer)
+//	var wg sync.WaitGroup
+//	go func() {
+//		tr.Out(w, r, ch)
+//		wg.Done()
+//	}()
+//	ch <- &dns.Envelope{RR: []dns.RR{soa, rr1, rr2, rr3, soa}}
+//	close(ch)
+//	wg.Wait() // wait until everything is written out
+//	w.Close() // close connection
+//
+// The server is responsible for sending the correct sequence of RRs through the channel ch.
+func (t *Transfer) Out(w ResponseWriter, q *Msg, ch chan *Envelope) error {
+	for x := range ch {
+		r := new(Msg)
+		// Compress?
+		r.SetReply(q)
+		r.Authoritative = true
+		// assume it fits TODO(miek): fix
+		r.Answer = append(r.Answer, x.RR...)
+		if tsig := q.IsTsig(); tsig != nil && w.TsigStatus() == nil {
+			r.SetTsig(tsig.Hdr.Name, tsig.Algorithm, tsig.Fudge, time.Now().Unix())
+		}
+		if err := w.WriteMsg(r); err != nil {
+			return err
+		}
+		w.TsigTimersOnly(true)
+	}
+	return nil
+}
+
+// ReadMsg reads a message from the transfer connection t.
+func (t *Transfer) ReadMsg() (*Msg, error) {
+	m := new(Msg)
+	p := make([]byte, MaxMsgSize)
+	n, err := t.Read(p)
+	if err != nil && n == 0 {
+		return nil, err
+	}
+	p = p[:n]
+	if err := m.Unpack(p); err != nil {
+		return nil, err
+	}
+	if ts, tp := m.IsTsig(), t.tsigProvider(); ts != nil && tp != nil {
+		// Need to work on the original message p, as that was used to calculate the tsig.
+		err = tsigVerifyProvider(p, tp, t.tsigRequestMAC, t.tsigTimersOnly)
+		t.tsigRequestMAC = ts.MAC
+	}
+	return m, err
+}
+
+// WriteMsg writes a message through the transfer connection t.
+func (t *Transfer) WriteMsg(m *Msg) (err error) {
+	var out []byte
+	if ts, tp := m.IsTsig(), t.tsigProvider(); ts != nil && tp != nil {
+		out, t.tsigRequestMAC, err = tsigGenerateProvider(m, tp, t.tsigRequestMAC, t.tsigTimersOnly)
+	} else {
+		out, err = m.Pack()
+	}
+	if err != nil {
+		return err
+	}
+	_, err = t.Write(out)
+	return err
+}
+
+func isSOAFirst(in *Msg) bool {
+	return len(in.Answer) > 0 &&
+		in.Answer[0].Header().Rrtype == TypeSOA
+}
+
+func isSOALast(in *Msg) bool {
+	return len(in.Answer) > 0 &&
+		in.Answer[len(in.Answer)-1].Header().Rrtype == TypeSOA
+}
+
+const errXFR = "bad xfr rcode: %d"

vendor/github.com/miekg/dns/ztypes.go

@@ -0,0 +1,952 @@
+// Code generated by "go run types_generate.go"; DO NOT EDIT.
+
+package dns
+
+import (
+	"encoding/base64"
+	"net"
+)
+
+// TypeToRR is a map of constructors for each RR type.
+var TypeToRR = map[uint16]func() RR{
+	TypeA:          func() RR { return new(A) },
+	TypeAAAA:       func() RR { return new(AAAA) },
+	TypeAFSDB:      func() RR { return new(AFSDB) },
+	TypeANY:        func() RR { return new(ANY) },
+	TypeAPL:        func() RR { return new(APL) },
+	TypeAVC:        func() RR { return new(AVC) },
+	TypeCAA:        func() RR { return new(CAA) },
+	TypeCDNSKEY:    func() RR { return new(CDNSKEY) },
+	TypeCDS:        func() RR { return new(CDS) },
+	TypeCERT:       func() RR { return new(CERT) },
+	TypeCNAME:      func() RR { return new(CNAME) },
+	TypeCSYNC:      func() RR { return new(CSYNC) },
+	TypeDHCID:      func() RR { return new(DHCID) },
+	TypeDLV:        func() RR { return new(DLV) },
+	TypeDNAME:      func() RR { return new(DNAME) },
+	TypeDNSKEY:     func() RR { return new(DNSKEY) },
+	TypeDS:         func() RR { return new(DS) },
+	TypeEID:        func() RR { return new(EID) },
+	TypeEUI48:      func() RR { return new(EUI48) },
+	TypeEUI64:      func() RR { return new(EUI64) },
+	TypeGID:        func() RR { return new(GID) },
+	TypeGPOS:       func() RR { return new(GPOS) },
+	TypeHINFO:      func() RR { return new(HINFO) },
+	TypeHIP:        func() RR { return new(HIP) },
+	TypeHTTPS:      func() RR { return new(HTTPS) },
+	TypeKEY:        func() RR { return new(KEY) },
+	TypeKX:         func() RR { return new(KX) },
+	TypeL32:        func() RR { return new(L32) },
+	TypeL64:        func() RR { return new(L64) },
+	TypeLOC:        func() RR { return new(LOC) },
+	TypeLP:         func() RR { return new(LP) },
+	TypeMB:         func() RR { return new(MB) },
+	TypeMD:         func() RR { return new(MD) },
+	TypeMF:         func() RR { return new(MF) },
+	TypeMG:         func() RR { return new(MG) },
+	TypeMINFO:      func() RR { return new(MINFO) },
+	TypeMR:         func() RR { return new(MR) },
+	TypeMX:         func() RR { return new(MX) },
+	TypeNAPTR:      func() RR { return new(NAPTR) },
+	TypeNID:        func() RR { return new(NID) },
+	TypeNIMLOC:     func() RR { return new(NIMLOC) },
+	TypeNINFO:      func() RR { return new(NINFO) },
+	TypeNS:         func() RR { return new(NS) },
+	TypeNSAPPTR:    func() RR { return new(NSAPPTR) },
+	TypeNSEC:       func() RR { return new(NSEC) },
+	TypeNSEC3:      func() RR { return new(NSEC3) },
+	TypeNSEC3PARAM: func() RR { return new(NSEC3PARAM) },
+	TypeNULL:       func() RR { return new(NULL) },
+	TypeOPENPGPKEY: func() RR { return new(OPENPGPKEY) },
+	TypeOPT:        func() RR { return new(OPT) },
+	TypePTR:        func() RR { return new(PTR) },
+	TypePX:         func() RR { return new(PX) },
+	TypeRKEY:       func() RR { return new(RKEY) },
+	TypeRP:         func() RR { return new(RP) },
+	TypeRRSIG:      func() RR { return new(RRSIG) },
+	TypeRT:         func() RR { return new(RT) },
+	TypeSIG:        func() RR { return new(SIG) },
+	TypeSMIMEA:     func() RR { return new(SMIMEA) },
+	TypeSOA:        func() RR { return new(SOA) },
+	TypeSPF:        func() RR { return new(SPF) },
+	TypeSRV:        func() RR { return new(SRV) },
+	TypeSSHFP:      func() RR { return new(SSHFP) },
+	TypeSVCB:       func() RR { return new(SVCB) },
+	TypeTA:         func() RR { return new(TA) },
+	TypeTALINK:     func() RR { return new(TALINK) },
+	TypeTKEY:       func() RR { return new(TKEY) },
+	TypeTLSA:       func() RR { return new(TLSA) },
+	TypeTSIG:       func() RR { return new(TSIG) },
+	TypeTXT:        func() RR { return new(TXT) },
+	TypeUID:        func() RR { return new(UID) },
+	TypeUINFO:      func() RR { return new(UINFO) },
+	TypeURI:        func() RR { return new(URI) },
+	TypeX25:        func() RR { return new(X25) },
+	TypeZONEMD:     func() RR { return new(ZONEMD) },
+}
+
+// TypeToString is a map of strings for each RR type.
+var TypeToString = map[uint16]string{
+	TypeA:          "A",
+	TypeAAAA:       "AAAA",
+	TypeAFSDB:      "AFSDB",
+	TypeANY:        "ANY",
+	TypeAPL:        "APL",
+	TypeATMA:       "ATMA",
+	TypeAVC:        "AVC",
+	TypeAXFR:       "AXFR",
+	TypeCAA:        "CAA",
+	TypeCDNSKEY:    "CDNSKEY",
+	TypeCDS:        "CDS",
+	TypeCERT:       "CERT",
+	TypeCNAME:      "CNAME",
+	TypeCSYNC:      "CSYNC",
+	TypeDHCID:      "DHCID",
+	TypeDLV:        "DLV",
+	TypeDNAME:      "DNAME",
+	TypeDNSKEY:     "DNSKEY",
+	TypeDS:         "DS",
+	TypeEID:        "EID",
+	TypeEUI48:      "EUI48",
+	TypeEUI64:      "EUI64",
+	TypeGID:        "GID",
+	TypeGPOS:       "GPOS",
+	TypeHINFO:      "HINFO",
+	TypeHIP:        "HIP",
+	TypeHTTPS:      "HTTPS",
+	TypeISDN:       "ISDN",
+	TypeIXFR:       "IXFR",
+	TypeKEY:        "KEY",
+	TypeKX:         "KX",
+	TypeL32:        "L32",
+	TypeL64:        "L64",
+	TypeLOC:        "LOC",
+	TypeLP:         "LP",
+	TypeMAILA:      "MAILA",
+	TypeMAILB:      "MAILB",
+	TypeMB:         "MB",
+	TypeMD:         "MD",
+	TypeMF:         "MF",
+	TypeMG:         "MG",
+	TypeMINFO:      "MINFO",
+	TypeMR:         "MR",
+	TypeMX:         "MX",
+	TypeNAPTR:      "NAPTR",
+	TypeNID:        "NID",
+	TypeNIMLOC:     "NIMLOC",
+	TypeNINFO:      "NINFO",
+	TypeNS:         "NS",
+	TypeNSEC:       "NSEC",
+	TypeNSEC3:      "NSEC3",
+	TypeNSEC3PARAM: "NSEC3PARAM",
+	TypeNULL:       "NULL",
+	TypeNXT:        "NXT",
+	TypeNone:       "None",
+	TypeOPENPGPKEY: "OPENPGPKEY",
+	TypeOPT:        "OPT",
+	TypePTR:        "PTR",
+	TypePX:         "PX",
+	TypeRKEY:       "RKEY",
+	TypeRP:         "RP",
+	TypeRRSIG:      "RRSIG",
+	TypeRT:         "RT",
+	TypeReserved:   "Reserved",
+	TypeSIG:        "SIG",
+	TypeSMIMEA:     "SMIMEA",
+	TypeSOA:        "SOA",
+	TypeSPF:        "SPF",
+	TypeSRV:        "SRV",
+	TypeSSHFP:      "SSHFP",
+	TypeSVCB:       "SVCB",
+	TypeTA:         "TA",
+	TypeTALINK:     "TALINK",
+	TypeTKEY:       "TKEY",
+	TypeTLSA:       "TLSA",
+	TypeTSIG:       "TSIG",
+	TypeTXT:        "TXT",
+	TypeUID:        "UID",
+	TypeUINFO:      "UINFO",
+	TypeUNSPEC:     "UNSPEC",
+	TypeURI:        "URI",
+	TypeX25:        "X25",
+	TypeZONEMD:     "ZONEMD",
+	TypeNSAPPTR:    "NSAP-PTR",
+}
+
+func (rr *A) Header() *RR_Header          { return &rr.Hdr }
+func (rr *AAAA) Header() *RR_Header       { return &rr.Hdr }
+func (rr *AFSDB) Header() *RR_Header      { return &rr.Hdr }
+func (rr *ANY) Header() *RR_Header        { return &rr.Hdr }
+func (rr *APL) Header() *RR_Header        { return &rr.Hdr }
+func (rr *AVC) Header() *RR_Header        { return &rr.Hdr }
+func (rr *CAA) Header() *RR_Header        { return &rr.Hdr }
+func (rr *CDNSKEY) Header() *RR_Header    { return &rr.Hdr }
+func (rr *CDS) Header() *RR_Header        { return &rr.Hdr }
+func (rr *CERT) Header() *RR_Header       { return &rr.Hdr }
+func (rr *CNAME) Header() *RR_Header      { return &rr.Hdr }
+func (rr *CSYNC) Header() *RR_Header      { return &rr.Hdr }
+func (rr *DHCID) Header() *RR_Header      { return &rr.Hdr }
+func (rr *DLV) Header() *RR_Header        { return &rr.Hdr }
+func (rr *DNAME) Header() *RR_Header      { return &rr.Hdr }
+func (rr *DNSKEY) Header() *RR_Header     { return &rr.Hdr }
+func (rr *DS) Header() *RR_Header         { return &rr.Hdr }
+func (rr *EID) Header() *RR_Header        { return &rr.Hdr }
+func (rr *EUI48) Header() *RR_Header      { return &rr.Hdr }
+func (rr *EUI64) Header() *RR_Header      { return &rr.Hdr }
+func (rr *GID) Header() *RR_Header        { return &rr.Hdr }
+func (rr *GPOS) Header() *RR_Header       { return &rr.Hdr }
+func (rr *HINFO) Header() *RR_Header      { return &rr.Hdr }
+func (rr *HIP) Header() *RR_Header        { return &rr.Hdr }
+func (rr *HTTPS) Header() *RR_Header      { return &rr.Hdr }
+func (rr *KEY) Header() *RR_Header        { return &rr.Hdr }
+func (rr *KX) Header() *RR_Header         { return &rr.Hdr }
+func (rr *L32) Header() *RR_Header        { return &rr.Hdr }
+func (rr *L64) Header() *RR_Header        { return &rr.Hdr }
+func (rr *LOC) Header() *RR_Header        { return &rr.Hdr }
+func (rr *LP) Header() *RR_Header         { return &rr.Hdr }
+func (rr *MB) Header() *RR_Header         { return &rr.Hdr }
+func (rr *MD) Header() *RR_Header         { return &rr.Hdr }
+func (rr *MF) Header() *RR_Header         { return &rr.Hdr }
+func (rr *MG) Header() *RR_Header         { return &rr.Hdr }
+func (rr *MINFO) Header() *RR_Header      { return &rr.Hdr }
+func (rr *MR) Header() *RR_Header         { return &rr.Hdr }
+func (rr *MX) Header() *RR_Header         { return &rr.Hdr }
+func (rr *NAPTR) Header() *RR_Header      { return &rr.Hdr }
+func (rr *NID) Header() *RR_Header        { return &rr.Hdr }
+func (rr *NIMLOC) Header() *RR_Header     { return &rr.Hdr }
+func (rr *NINFO) Header() *RR_Header      { return &rr.Hdr }
+func (rr *NS) Header() *RR_Header         { return &rr.Hdr }
+func (rr *NSAPPTR) Header() *RR_Header    { return &rr.Hdr }
+func (rr *NSEC) Header() *RR_Header       { return &rr.Hdr }
+func (rr *NSEC3) Header() *RR_Header      { return &rr.Hdr }
+func (rr *NSEC3PARAM) Header() *RR_Header { return &rr.Hdr }
+func (rr *NULL) Header() *RR_Header       { return &rr.Hdr }
+func (rr *OPENPGPKEY) Header() *RR_Header { return &rr.Hdr }
+func (rr *OPT) Header() *RR_Header        { return &rr.Hdr }
+func (rr *PTR) Header() *RR_Header        { return &rr.Hdr }
+func (rr *PX) Header() *RR_Header         { return &rr.Hdr }
+func (rr *RFC3597) Header() *RR_Header    { return &rr.Hdr }
+func (rr *RKEY) Header() *RR_Header       { return &rr.Hdr }
+func (rr *RP) Header() *RR_Header         { return &rr.Hdr }
+func (rr *RRSIG) Header() *RR_Header      { return &rr.Hdr }
+func (rr *RT) Header() *RR_Header         { return &rr.Hdr }
+func (rr *SIG) Header() *RR_Header        { return &rr.Hdr }
+func (rr *SMIMEA) Header() *RR_Header     { return &rr.Hdr }
+func (rr *SOA) Header() *RR_Header        { return &rr.Hdr }
+func (rr *SPF) Header() *RR_Header        { return &rr.Hdr }
+func (rr *SRV) Header() *RR_Header        { return &rr.Hdr }
+func (rr *SSHFP) Header() *RR_Header      { return &rr.Hdr }
+func (rr *SVCB) Header() *RR_Header       { return &rr.Hdr }
+func (rr *TA) Header() *RR_Header         { return &rr.Hdr }
+func (rr *TALINK) Header() *RR_Header     { return &rr.Hdr }
+func (rr *TKEY) Header() *RR_Header       { return &rr.Hdr }
+func (rr *TLSA) Header() *RR_Header       { return &rr.Hdr }
+func (rr *TSIG) Header() *RR_Header       { return &rr.Hdr }
+func (rr *TXT) Header() *RR_Header        { return &rr.Hdr }
+func (rr *UID) Header() *RR_Header        { return &rr.Hdr }
+func (rr *UINFO) Header() *RR_Header      { return &rr.Hdr }
+func (rr *URI) Header() *RR_Header        { return &rr.Hdr }
+func (rr *X25) Header() *RR_Header        { return &rr.Hdr }
+func (rr *ZONEMD) Header() *RR_Header     { return &rr.Hdr }
+
+// len() functions
+func (rr *A) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	if len(rr.A) != 0 {
+		l += net.IPv4len
+	}
+	return l
+}
+func (rr *AAAA) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	if len(rr.AAAA) != 0 {
+		l += net.IPv6len
+	}
+	return l
+}
+func (rr *AFSDB) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Subtype
+	l += domainNameLen(rr.Hostname, off+l, compression, false)
+	return l
+}
+func (rr *ANY) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	return l
+}
+func (rr *APL) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	for _, x := range rr.Prefixes {
+		l += x.len()
+	}
+	return l
+}
+func (rr *AVC) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	for _, x := range rr.Txt {
+		l += len(x) + 1
+	}
+	return l
+}
+func (rr *CAA) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l++ // Flag
+	l += len(rr.Tag) + 1
+	l += len(rr.Value)
+	return l
+}
+func (rr *CERT) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Type
+	l += 2 // KeyTag
+	l++    // Algorithm
+	l += base64.StdEncoding.DecodedLen(len(rr.Certificate))
+	return l
+}
+func (rr *CNAME) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Target, off+l, compression, true)
+	return l
+}
+func (rr *DHCID) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += base64.StdEncoding.DecodedLen(len(rr.Digest))
+	return l
+}
+func (rr *DNAME) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Target, off+l, compression, false)
+	return l
+}
+func (rr *DNSKEY) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Flags
+	l++    // Protocol
+	l++    // Algorithm
+	l += base64.StdEncoding.DecodedLen(len(rr.PublicKey))
+	return l
+}
+func (rr *DS) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // KeyTag
+	l++    // Algorithm
+	l++    // DigestType
+	l += len(rr.Digest) / 2
+	return l
+}
+func (rr *EID) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += len(rr.Endpoint) / 2
+	return l
+}
+func (rr *EUI48) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 6 // Address
+	return l
+}
+func (rr *EUI64) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 8 // Address
+	return l
+}
+func (rr *GID) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 4 // Gid
+	return l
+}
+func (rr *GPOS) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += len(rr.Longitude) + 1
+	l += len(rr.Latitude) + 1
+	l += len(rr.Altitude) + 1
+	return l
+}
+func (rr *HINFO) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += len(rr.Cpu) + 1
+	l += len(rr.Os) + 1
+	return l
+}
+func (rr *HIP) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l++    // HitLength
+	l++    // PublicKeyAlgorithm
+	l += 2 // PublicKeyLength
+	l += len(rr.Hit) / 2
+	l += base64.StdEncoding.DecodedLen(len(rr.PublicKey))
+	for _, x := range rr.RendezvousServers {
+		l += domainNameLen(x, off+l, compression, false)
+	}
+	return l
+}
+func (rr *KX) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Preference
+	l += domainNameLen(rr.Exchanger, off+l, compression, false)
+	return l
+}
+func (rr *L32) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Preference
+	if len(rr.Locator32) != 0 {
+		l += net.IPv4len
+	}
+	return l
+}
+func (rr *L64) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Preference
+	l += 8 // Locator64
+	return l
+}
+func (rr *LOC) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l++    // Version
+	l++    // Size
+	l++    // HorizPre
+	l++    // VertPre
+	l += 4 // Latitude
+	l += 4 // Longitude
+	l += 4 // Altitude
+	return l
+}
+func (rr *LP) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Preference
+	l += domainNameLen(rr.Fqdn, off+l, compression, false)
+	return l
+}
+func (rr *MB) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Mb, off+l, compression, true)
+	return l
+}
+func (rr *MD) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Md, off+l, compression, true)
+	return l
+}
+func (rr *MF) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Mf, off+l, compression, true)
+	return l
+}
+func (rr *MG) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Mg, off+l, compression, true)
+	return l
+}
+func (rr *MINFO) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Rmail, off+l, compression, true)
+	l += domainNameLen(rr.Email, off+l, compression, true)
+	return l
+}
+func (rr *MR) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Mr, off+l, compression, true)
+	return l
+}
+func (rr *MX) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Preference
+	l += domainNameLen(rr.Mx, off+l, compression, true)
+	return l
+}
+func (rr *NAPTR) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Order
+	l += 2 // Preference
+	l += len(rr.Flags) + 1
+	l += len(rr.Service) + 1
+	l += len(rr.Regexp) + 1
+	l += domainNameLen(rr.Replacement, off+l, compression, false)
+	return l
+}
+func (rr *NID) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Preference
+	l += 8 // NodeID
+	return l
+}
+func (rr *NIMLOC) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += len(rr.Locator) / 2
+	return l
+}
+func (rr *NINFO) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	for _, x := range rr.ZSData {
+		l += len(x) + 1
+	}
+	return l
+}
+func (rr *NS) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Ns, off+l, compression, true)
+	return l
+}
+func (rr *NSAPPTR) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Ptr, off+l, compression, false)
+	return l
+}
+func (rr *NSEC3PARAM) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l++    // Hash
+	l++    // Flags
+	l += 2 // Iterations
+	l++    // SaltLength
+	l += len(rr.Salt) / 2
+	return l
+}
+func (rr *NULL) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += len(rr.Data)
+	return l
+}
+func (rr *OPENPGPKEY) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += base64.StdEncoding.DecodedLen(len(rr.PublicKey))
+	return l
+}
+func (rr *PTR) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Ptr, off+l, compression, true)
+	return l
+}
+func (rr *PX) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Preference
+	l += domainNameLen(rr.Map822, off+l, compression, false)
+	l += domainNameLen(rr.Mapx400, off+l, compression, false)
+	return l
+}
+func (rr *RFC3597) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += len(rr.Rdata) / 2
+	return l
+}
+func (rr *RKEY) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Flags
+	l++    // Protocol
+	l++    // Algorithm
+	l += base64.StdEncoding.DecodedLen(len(rr.PublicKey))
+	return l
+}
+func (rr *RP) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Mbox, off+l, compression, false)
+	l += domainNameLen(rr.Txt, off+l, compression, false)
+	return l
+}
+func (rr *RRSIG) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // TypeCovered
+	l++    // Algorithm
+	l++    // Labels
+	l += 4 // OrigTtl
+	l += 4 // Expiration
+	l += 4 // Inception
+	l += 2 // KeyTag
+	l += domainNameLen(rr.SignerName, off+l, compression, false)
+	l += base64.StdEncoding.DecodedLen(len(rr.Signature))
+	return l
+}
+func (rr *RT) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Preference
+	l += domainNameLen(rr.Host, off+l, compression, false)
+	return l
+}
+func (rr *SMIMEA) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l++ // Usage
+	l++ // Selector
+	l++ // MatchingType
+	l += len(rr.Certificate) / 2
+	return l
+}
+func (rr *SOA) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Ns, off+l, compression, true)
+	l += domainNameLen(rr.Mbox, off+l, compression, true)
+	l += 4 // Serial
+	l += 4 // Refresh
+	l += 4 // Retry
+	l += 4 // Expire
+	l += 4 // Minttl
+	return l
+}
+func (rr *SPF) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	for _, x := range rr.Txt {
+		l += len(x) + 1
+	}
+	return l
+}
+func (rr *SRV) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Priority
+	l += 2 // Weight
+	l += 2 // Port
+	l += domainNameLen(rr.Target, off+l, compression, false)
+	return l
+}
+func (rr *SSHFP) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l++ // Algorithm
+	l++ // Type
+	l += len(rr.FingerPrint) / 2
+	return l
+}
+func (rr *SVCB) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Priority
+	l += domainNameLen(rr.Target, off+l, compression, false)
+	for _, x := range rr.Value {
+		l += 4 + int(x.len())
+	}
+	return l
+}
+func (rr *TA) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // KeyTag
+	l++    // Algorithm
+	l++    // DigestType
+	l += len(rr.Digest) / 2
+	return l
+}
+func (rr *TALINK) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.PreviousName, off+l, compression, false)
+	l += domainNameLen(rr.NextName, off+l, compression, false)
+	return l
+}
+func (rr *TKEY) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Algorithm, off+l, compression, false)
+	l += 4 // Inception
+	l += 4 // Expiration
+	l += 2 // Mode
+	l += 2 // Error
+	l += 2 // KeySize
+	l += len(rr.Key) / 2
+	l += 2 // OtherLen
+	l += len(rr.OtherData) / 2
+	return l
+}
+func (rr *TLSA) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l++ // Usage
+	l++ // Selector
+	l++ // MatchingType
+	l += len(rr.Certificate) / 2
+	return l
+}
+func (rr *TSIG) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += domainNameLen(rr.Algorithm, off+l, compression, false)
+	l += 6 // TimeSigned
+	l += 2 // Fudge
+	l += 2 // MACSize
+	l += len(rr.MAC) / 2
+	l += 2 // OrigId
+	l += 2 // Error
+	l += 2 // OtherLen
+	l += len(rr.OtherData) / 2
+	return l
+}
+func (rr *TXT) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	for _, x := range rr.Txt {
+		l += len(x) + 1
+	}
+	return l
+}
+func (rr *UID) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 4 // Uid
+	return l
+}
+func (rr *UINFO) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += len(rr.Uinfo) + 1
+	return l
+}
+func (rr *URI) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 2 // Priority
+	l += 2 // Weight
+	l += len(rr.Target)
+	return l
+}
+func (rr *X25) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += len(rr.PSDNAddress) + 1
+	return l
+}
+func (rr *ZONEMD) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	l += 4 // Serial
+	l++    // Scheme
+	l++    // Hash
+	l += len(rr.Digest) / 2
+	return l
+}
+
+// copy() functions
+func (rr *A) copy() RR {
+	return &A{rr.Hdr, copyIP(rr.A)}
+}
+func (rr *AAAA) copy() RR {
+	return &AAAA{rr.Hdr, copyIP(rr.AAAA)}
+}
+func (rr *AFSDB) copy() RR {
+	return &AFSDB{rr.Hdr, rr.Subtype, rr.Hostname}
+}
+func (rr *ANY) copy() RR {
+	return &ANY{rr.Hdr}
+}
+func (rr *APL) copy() RR {
+	Prefixes := make([]APLPrefix, len(rr.Prefixes))
+	for i, e := range rr.Prefixes {
+		Prefixes[i] = e.copy()
+	}
+	return &APL{rr.Hdr, Prefixes}
+}
+func (rr *AVC) copy() RR {
+	Txt := make([]string, len(rr.Txt))
+	copy(Txt, rr.Txt)
+	return &AVC{rr.Hdr, Txt}
+}
+func (rr *CAA) copy() RR {
+	return &CAA{rr.Hdr, rr.Flag, rr.Tag, rr.Value}
+}
+func (rr *CDNSKEY) copy() RR {
+	return &CDNSKEY{*rr.DNSKEY.copy().(*DNSKEY)}
+}
+func (rr *CDS) copy() RR {
+	return &CDS{*rr.DS.copy().(*DS)}
+}
+func (rr *CERT) copy() RR {
+	return &CERT{rr.Hdr, rr.Type, rr.KeyTag, rr.Algorithm, rr.Certificate}
+}
+func (rr *CNAME) copy() RR {
+	return &CNAME{rr.Hdr, rr.Target}
+}
+func (rr *CSYNC) copy() RR {
+	TypeBitMap := make([]uint16, len(rr.TypeBitMap))
+	copy(TypeBitMap, rr.TypeBitMap)
+	return &CSYNC{rr.Hdr, rr.Serial, rr.Flags, TypeBitMap}
+}
+func (rr *DHCID) copy() RR {
+	return &DHCID{rr.Hdr, rr.Digest}
+}
+func (rr *DLV) copy() RR {
+	return &DLV{*rr.DS.copy().(*DS)}
+}
+func (rr *DNAME) copy() RR {
+	return &DNAME{rr.Hdr, rr.Target}
+}
+func (rr *DNSKEY) copy() RR {
+	return &DNSKEY{rr.Hdr, rr.Flags, rr.Protocol, rr.Algorithm, rr.PublicKey}
+}
+func (rr *DS) copy() RR {
+	return &DS{rr.Hdr, rr.KeyTag, rr.Algorithm, rr.DigestType, rr.Digest}
+}
+func (rr *EID) copy() RR {
+	return &EID{rr.Hdr, rr.Endpoint}
+}
+func (rr *EUI48) copy() RR {
+	return &EUI48{rr.Hdr, rr.Address}
+}
+func (rr *EUI64) copy() RR {
+	return &EUI64{rr.Hdr, rr.Address}
+}
+func (rr *GID) copy() RR {
+	return &GID{rr.Hdr, rr.Gid}
+}
+func (rr *GPOS) copy() RR {
+	return &GPOS{rr.Hdr, rr.Longitude, rr.Latitude, rr.Altitude}
+}
+func (rr *HINFO) copy() RR {
+	return &HINFO{rr.Hdr, rr.Cpu, rr.Os}
+}
+func (rr *HIP) copy() RR {
+	RendezvousServers := make([]string, len(rr.RendezvousServers))
+	copy(RendezvousServers, rr.RendezvousServers)
+	return &HIP{rr.Hdr, rr.HitLength, rr.PublicKeyAlgorithm, rr.PublicKeyLength, rr.Hit, rr.PublicKey, RendezvousServers}
+}
+func (rr *HTTPS) copy() RR {
+	return &HTTPS{*rr.SVCB.copy().(*SVCB)}
+}
+func (rr *KEY) copy() RR {
+	return &KEY{*rr.DNSKEY.copy().(*DNSKEY)}
+}
+func (rr *KX) copy() RR {
+	return &KX{rr.Hdr, rr.Preference, rr.Exchanger}
+}
+func (rr *L32) copy() RR {
+	return &L32{rr.Hdr, rr.Preference, copyIP(rr.Locator32)}
+}
+func (rr *L64) copy() RR {
+	return &L64{rr.Hdr, rr.Preference, rr.Locator64}
+}
+func (rr *LOC) copy() RR {
+	return &LOC{rr.Hdr, rr.Version, rr.Size, rr.HorizPre, rr.VertPre, rr.Latitude, rr.Longitude, rr.Altitude}
+}
+func (rr *LP) copy() RR {
+	return &LP{rr.Hdr, rr.Preference, rr.Fqdn}
+}
+func (rr *MB) copy() RR {
+	return &MB{rr.Hdr, rr.Mb}
+}
+func (rr *MD) copy() RR {
+	return &MD{rr.Hdr, rr.Md}
+}
+func (rr *MF) copy() RR {
+	return &MF{rr.Hdr, rr.Mf}
+}
+func (rr *MG) copy() RR {
+	return &MG{rr.Hdr, rr.Mg}
+}
+func (rr *MINFO) copy() RR {
+	return &MINFO{rr.Hdr, rr.Rmail, rr.Email}
+}
+func (rr *MR) copy() RR {
+	return &MR{rr.Hdr, rr.Mr}
+}
+func (rr *MX) copy() RR {
+	return &MX{rr.Hdr, rr.Preference, rr.Mx}
+}
+func (rr *NAPTR) copy() RR {
+	return &NAPTR{rr.Hdr, rr.Order, rr.Preference, rr.Flags, rr.Service, rr.Regexp, rr.Replacement}
+}
+func (rr *NID) copy() RR {
+	return &NID{rr.Hdr, rr.Preference, rr.NodeID}
+}
+func (rr *NIMLOC) copy() RR {
+	return &NIMLOC{rr.Hdr, rr.Locator}
+}
+func (rr *NINFO) copy() RR {
+	ZSData := make([]string, len(rr.ZSData))
+	copy(ZSData, rr.ZSData)
+	return &NINFO{rr.Hdr, ZSData}
+}
+func (rr *NS) copy() RR {
+	return &NS{rr.Hdr, rr.Ns}
+}
+func (rr *NSAPPTR) copy() RR {
+	return &NSAPPTR{rr.Hdr, rr.Ptr}
+}
+func (rr *NSEC) copy() RR {
+	TypeBitMap := make([]uint16, len(rr.TypeBitMap))
+	copy(TypeBitMap, rr.TypeBitMap)
+	return &NSEC{rr.Hdr, rr.NextDomain, TypeBitMap}
+}
+func (rr *NSEC3) copy() RR {
+	TypeBitMap := make([]uint16, len(rr.TypeBitMap))
+	copy(TypeBitMap, rr.TypeBitMap)
+	return &NSEC3{rr.Hdr, rr.Hash, rr.Flags, rr.Iterations, rr.SaltLength, rr.Salt, rr.HashLength, rr.NextDomain, TypeBitMap}
+}
+func (rr *NSEC3PARAM) copy() RR {
+	return &NSEC3PARAM{rr.Hdr, rr.Hash, rr.Flags, rr.Iterations, rr.SaltLength, rr.Salt}
+}
+func (rr *NULL) copy() RR {
+	return &NULL{rr.Hdr, rr.Data}
+}
+func (rr *OPENPGPKEY) copy() RR {
+	return &OPENPGPKEY{rr.Hdr, rr.PublicKey}
+}
+func (rr *OPT) copy() RR {
+	Option := make([]EDNS0, len(rr.Option))
+	for i, e := range rr.Option {
+		Option[i] = e.copy()
+	}
+	return &OPT{rr.Hdr, Option}
+}
+func (rr *PTR) copy() RR {
+	return &PTR{rr.Hdr, rr.Ptr}
+}
+func (rr *PX) copy() RR {
+	return &PX{rr.Hdr, rr.Preference, rr.Map822, rr.Mapx400}
+}
+func (rr *RFC3597) copy() RR {
+	return &RFC3597{rr.Hdr, rr.Rdata}
+}
+func (rr *RKEY) copy() RR {
+	return &RKEY{rr.Hdr, rr.Flags, rr.Protocol, rr.Algorithm, rr.PublicKey}
+}
+func (rr *RP) copy() RR {
+	return &RP{rr.Hdr, rr.Mbox, rr.Txt}
+}
+func (rr *RRSIG) copy() RR {
+	return &RRSIG{rr.Hdr, rr.TypeCovered, rr.Algorithm, rr.Labels, rr.OrigTtl, rr.Expiration, rr.Inception, rr.KeyTag, rr.SignerName, rr.Signature}
+}
+func (rr *RT) copy() RR {
+	return &RT{rr.Hdr, rr.Preference, rr.Host}
+}
+func (rr *SIG) copy() RR {
+	return &SIG{*rr.RRSIG.copy().(*RRSIG)}
+}
+func (rr *SMIMEA) copy() RR {
+	return &SMIMEA{rr.Hdr, rr.Usage, rr.Selector, rr.MatchingType, rr.Certificate}
+}
+func (rr *SOA) copy() RR {
+	return &SOA{rr.Hdr, rr.Ns, rr.Mbox, rr.Serial, rr.Refresh, rr.Retry, rr.Expire, rr.Minttl}
+}
+func (rr *SPF) copy() RR {
+	Txt := make([]string, len(rr.Txt))
+	copy(Txt, rr.Txt)
+	return &SPF{rr.Hdr, Txt}
+}
+func (rr *SRV) copy() RR {
+	return &SRV{rr.Hdr, rr.Priority, rr.Weight, rr.Port, rr.Target}
+}
+func (rr *SSHFP) copy() RR {
+	return &SSHFP{rr.Hdr, rr.Algorithm, rr.Type, rr.FingerPrint}
+}
+func (rr *SVCB) copy() RR {
+	Value := make([]SVCBKeyValue, len(rr.Value))
+	for i, e := range rr.Value {
+		Value[i] = e.copy()
+	}
+	return &SVCB{rr.Hdr, rr.Priority, rr.Target, Value}
+}
+func (rr *TA) copy() RR {
+	return &TA{rr.Hdr, rr.KeyTag, rr.Algorithm, rr.DigestType, rr.Digest}
+}
+func (rr *TALINK) copy() RR {
+	return &TALINK{rr.Hdr, rr.PreviousName, rr.NextName}
+}
+func (rr *TKEY) copy() RR {
+	return &TKEY{rr.Hdr, rr.Algorithm, rr.Inception, rr.Expiration, rr.Mode, rr.Error, rr.KeySize, rr.Key, rr.OtherLen, rr.OtherData}
+}
+func (rr *TLSA) copy() RR {
+	return &TLSA{rr.Hdr, rr.Usage, rr.Selector, rr.MatchingType, rr.Certificate}
+}
+func (rr *TSIG) copy() RR {
+	return &TSIG{rr.Hdr, rr.Algorithm, rr.TimeSigned, rr.Fudge, rr.MACSize, rr.MAC, rr.OrigId, rr.Error, rr.OtherLen, rr.OtherData}
+}
+func (rr *TXT) copy() RR {
+	Txt := make([]string, len(rr.Txt))
+	copy(Txt, rr.Txt)
+	return &TXT{rr.Hdr, Txt}
+}
+func (rr *UID) copy() RR {
+	return &UID{rr.Hdr, rr.Uid}
+}
+func (rr *UINFO) copy() RR {
+	return &UINFO{rr.Hdr, rr.Uinfo}
+}
+func (rr *URI) copy() RR {
+	return &URI{rr.Hdr, rr.Priority, rr.Weight, rr.Target}
+}
+func (rr *X25) copy() RR {
+	return &X25{rr.Hdr, rr.PSDNAddress}
+}
+func (rr *ZONEMD) copy() RR {
+	return &ZONEMD{rr.Hdr, rr.Serial, rr.Scheme, rr.Hash, rr.Digest}
+}

vendor/golang.org/x/net/bpf/asm.go

@@ -0,0 +1,41 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bpf
+
+import "fmt"
+
+// Assemble converts insts into raw instructions suitable for loading
+// into a BPF virtual machine.
+//
+// Currently, no optimization is attempted, the assembled program flow
+// is exactly as provided.
+func Assemble(insts []Instruction) ([]RawInstruction, error) {
+	ret := make([]RawInstruction, len(insts))
+	var err error
+	for i, inst := range insts {
+		ret[i], err = inst.Assemble()
+		if err != nil {
+			return nil, fmt.Errorf("assembling instruction %d: %s", i+1, err)
+		}
+	}
+	return ret, nil
+}
+
+// Disassemble attempts to parse raw back into
+// Instructions. Unrecognized RawInstructions are assumed to be an
+// extension not implemented by this package, and are passed through
+// unchanged to the output. The allDecoded value reports whether insts
+// contains no RawInstructions.
+func Disassemble(raw []RawInstruction) (insts []Instruction, allDecoded bool) {
+	insts = make([]Instruction, len(raw))
+	allDecoded = true
+	for i, r := range raw {
+		insts[i] = r.Disassemble()
+		if _, ok := insts[i].(RawInstruction); ok {
+			allDecoded = false
+		}
+	}
+	return insts, allDecoded
+}

vendor/golang.org/x/net/bpf/constants.go

@@ -0,0 +1,222 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bpf
+
+// A Register is a register of the BPF virtual machine.
+type Register uint16
+
+const (
+	// RegA is the accumulator register. RegA is always the
+	// destination register of ALU operations.
+	RegA Register = iota
+	// RegX is the indirection register, used by LoadIndirect
+	// operations.
+	RegX
+)
+
+// An ALUOp is an arithmetic or logic operation.
+type ALUOp uint16
+
+// ALU binary operation types.
+const (
+	ALUOpAdd ALUOp = iota << 4
+	ALUOpSub
+	ALUOpMul
+	ALUOpDiv
+	ALUOpOr
+	ALUOpAnd
+	ALUOpShiftLeft
+	ALUOpShiftRight
+	aluOpNeg // Not exported because it's the only unary ALU operation, and gets its own instruction type.
+	ALUOpMod
+	ALUOpXor
+)
+
+// A JumpTest is a comparison operator used in conditional jumps.
+type JumpTest uint16
+
+// Supported operators for conditional jumps.
+// K can be RegX for JumpIfX
+const (
+	// K == A
+	JumpEqual JumpTest = iota
+	// K != A
+	JumpNotEqual
+	// K > A
+	JumpGreaterThan
+	// K < A
+	JumpLessThan
+	// K >= A
+	JumpGreaterOrEqual
+	// K <= A
+	JumpLessOrEqual
+	// K & A != 0
+	JumpBitsSet
+	// K & A == 0
+	JumpBitsNotSet
+)
+
+// An Extension is a function call provided by the kernel that
+// performs advanced operations that are expensive or impossible
+// within the BPF virtual machine.
+//
+// Extensions are only implemented by the Linux kernel.
+//
+// TODO: should we prune this list? Some of these extensions seem
+// either broken or near-impossible to use correctly, whereas other
+// (len, random, ifindex) are quite useful.
+type Extension int
+
+// Extension functions available in the Linux kernel.
+const (
+	// extOffset is the negative maximum number of instructions used
+	// to load instructions by overloading the K argument.
+	extOffset = -0x1000
+	// ExtLen returns the length of the packet.
+	ExtLen Extension = 1
+	// ExtProto returns the packet's L3 protocol type.
+	ExtProto Extension = 0
+	// ExtType returns the packet's type (skb->pkt_type in the kernel)
+	//
+	// TODO: better documentation. How nice an API do we want to
+	// provide for these esoteric extensions?
+	ExtType Extension = 4
+	// ExtPayloadOffset returns the offset of the packet payload, or
+	// the first protocol header that the kernel does not know how to
+	// parse.
+	ExtPayloadOffset Extension = 52
+	// ExtInterfaceIndex returns the index of the interface on which
+	// the packet was received.
+	ExtInterfaceIndex Extension = 8
+	// ExtNetlinkAttr returns the netlink attribute of type X at
+	// offset A.
+	ExtNetlinkAttr Extension = 12
+	// ExtNetlinkAttrNested returns the nested netlink attribute of
+	// type X at offset A.
+	ExtNetlinkAttrNested Extension = 16
+	// ExtMark returns the packet's mark value.
+	ExtMark Extension = 20
+	// ExtQueue returns the packet's assigned hardware queue.
+	ExtQueue Extension = 24
+	// ExtLinkLayerType returns the packet's hardware address type
+	// (e.g. Ethernet, Infiniband).
+	ExtLinkLayerType Extension = 28
+	// ExtRXHash returns the packets receive hash.
+	//
+	// TODO: figure out what this rxhash actually is.
+	ExtRXHash Extension = 32
+	// ExtCPUID returns the ID of the CPU processing the current
+	// packet.
+	ExtCPUID Extension = 36
+	// ExtVLANTag returns the packet's VLAN tag.
+	ExtVLANTag Extension = 44
+	// ExtVLANTagPresent returns non-zero if the packet has a VLAN
+	// tag.
+	//
+	// TODO: I think this might be a lie: it reads bit 0x1000 of the
+	// VLAN header, which changed meaning in recent revisions of the
+	// spec - this extension may now return meaningless information.
+	ExtVLANTagPresent Extension = 48
+	// ExtVLANProto returns 0x8100 if the frame has a VLAN header,
+	// 0x88a8 if the frame has a "Q-in-Q" double VLAN header, or some
+	// other value if no VLAN information is present.
+	ExtVLANProto Extension = 60
+	// ExtRand returns a uniformly random uint32.
+	ExtRand Extension = 56
+)
+
+// The following gives names to various bit patterns used in opcode construction.
+
+const (
+	opMaskCls uint16 = 0x7
+	// opClsLoad masks
+	opMaskLoadDest  = 0x01
+	opMaskLoadWidth = 0x18
+	opMaskLoadMode  = 0xe0
+	// opClsALU & opClsJump
+	opMaskOperand  = 0x08
+	opMaskOperator = 0xf0
+)
+
+const (
+	// +---------------+-----------------+---+---+---+
+	// | AddrMode (3b) | LoadWidth (2b)  | 0 | 0 | 0 |
+	// +---------------+-----------------+---+---+---+
+	opClsLoadA uint16 = iota
+	// +---------------+-----------------+---+---+---+
+	// | AddrMode (3b) | LoadWidth (2b)  | 0 | 0 | 1 |
+	// +---------------+-----------------+---+---+---+
+	opClsLoadX
+	// +---+---+---+---+---+---+---+---+
+	// | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
+	// +---+---+---+---+---+---+---+---+
+	opClsStoreA
+	// +---+---+---+---+---+---+---+---+
+	// | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
+	// +---+---+---+---+---+---+---+---+
+	opClsStoreX
+	// +---------------+-----------------+---+---+---+
+	// | Operator (4b) | OperandSrc (1b) | 1 | 0 | 0 |
+	// +---------------+-----------------+---+---+---+
+	opClsALU
+	// +-----------------------------+---+---+---+---+
+	// |      TestOperator (4b)      | 0 | 1 | 0 | 1 |
+	// +-----------------------------+---+---+---+---+
+	opClsJump
+	// +---+-------------------------+---+---+---+---+
+	// | 0 | 0 | 0 |   RetSrc (1b)   | 0 | 1 | 1 | 0 |
+	// +---+-------------------------+---+---+---+---+
+	opClsReturn
+	// +---+-------------------------+---+---+---+---+
+	// | 0 | 0 | 0 |  TXAorTAX (1b)  | 0 | 1 | 1 | 1 |
+	// +---+-------------------------+---+---+---+---+
+	opClsMisc
+)
+
+const (
+	opAddrModeImmediate uint16 = iota << 5
+	opAddrModeAbsolute
+	opAddrModeIndirect
+	opAddrModeScratch
+	opAddrModePacketLen // actually an extension, not an addressing mode.
+	opAddrModeMemShift
+)
+
+const (
+	opLoadWidth4 uint16 = iota << 3
+	opLoadWidth2
+	opLoadWidth1
+)
+
+// Operand for ALU and Jump instructions
+type opOperand uint16
+
+// Supported operand sources.
+const (
+	opOperandConstant opOperand = iota << 3
+	opOperandX
+)
+
+// An jumpOp is a conditional jump condition.
+type jumpOp uint16
+
+// Supported jump conditions.
+const (
+	opJumpAlways jumpOp = iota << 4
+	opJumpEqual
+	opJumpGT
+	opJumpGE
+	opJumpSet
+)
+
+const (
+	opRetSrcConstant uint16 = iota << 4
+	opRetSrcA
+)
+
+const (
+	opMiscTAX = 0x00
+	opMiscTXA = 0x80
+)

vendor/golang.org/x/net/bpf/doc.go

@@ -0,0 +1,80 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package bpf implements marshaling and unmarshaling of programs for the
+Berkeley Packet Filter virtual machine, and provides a Go implementation
+of the virtual machine.
+
+BPF's main use is to specify a packet filter for network taps, so that
+the kernel doesn't have to expensively copy every packet it sees to
+userspace. However, it's been repurposed to other areas where running
+user code in-kernel is needed. For example, Linux's seccomp uses BPF
+to apply security policies to system calls. For simplicity, this
+documentation refers only to packets, but other uses of BPF have their
+own data payloads.
+
+BPF programs run in a restricted virtual machine. It has almost no
+access to kernel functions, and while conditional branches are
+allowed, they can only jump forwards, to guarantee that there are no
+infinite loops.
+
+# The virtual machine
+
+The BPF VM is an accumulator machine. Its main register, called
+register A, is an implicit source and destination in all arithmetic
+and logic operations. The machine also has 16 scratch registers for
+temporary storage, and an indirection register (register X) for
+indirect memory access. All registers are 32 bits wide.
+
+Each run of a BPF program is given one packet, which is placed in the
+VM's read-only "main memory". LoadAbsolute and LoadIndirect
+instructions can fetch up to 32 bits at a time into register A for
+examination.
+
+The goal of a BPF program is to produce and return a verdict (uint32),
+which tells the kernel what to do with the packet. In the context of
+packet filtering, the returned value is the number of bytes of the
+packet to forward to userspace, or 0 to ignore the packet. Other
+contexts like seccomp define their own return values.
+
+In order to simplify programs, attempts to read past the end of the
+packet terminate the program execution with a verdict of 0 (ignore
+packet). This means that the vast majority of BPF programs don't need
+to do any explicit bounds checking.
+
+In addition to the bytes of the packet, some BPF programs have access
+to extensions, which are essentially calls to kernel utility
+functions. Currently, the only extensions supported by this package
+are the Linux packet filter extensions.
+
+# Examples
+
+This packet filter selects all ARP packets.
+
+	bpf.Assemble([]bpf.Instruction{
+		// Load "EtherType" field from the ethernet header.
+		bpf.LoadAbsolute{Off: 12, Size: 2},
+		// Skip over the next instruction if EtherType is not ARP.
+		bpf.JumpIf{Cond: bpf.JumpNotEqual, Val: 0x0806, SkipTrue: 1},
+		// Verdict is "send up to 4k of the packet to userspace."
+		bpf.RetConstant{Val: 4096},
+		// Verdict is "ignore packet."
+		bpf.RetConstant{Val: 0},
+	})
+
+This packet filter captures a random 1% sample of traffic.
+
+	bpf.Assemble([]bpf.Instruction{
+		// Get a 32-bit random number from the Linux kernel.
+		bpf.LoadExtension{Num: bpf.ExtRand},
+		// 1% dice roll?
+		bpf.JumpIf{Cond: bpf.JumpLessThan, Val: 2^32/100, SkipFalse: 1},
+		// Capture.
+		bpf.RetConstant{Val: 4096},
+		// Ignore.
+		bpf.RetConstant{Val: 0},
+	})
+*/
+package bpf // import "golang.org/x/net/bpf"

vendor/golang.org/x/net/bpf/instructions.go

@@ -0,0 +1,726 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bpf
+
+import "fmt"
+
+// An Instruction is one instruction executed by the BPF virtual
+// machine.
+type Instruction interface {
+	// Assemble assembles the Instruction into a RawInstruction.
+	Assemble() (RawInstruction, error)
+}
+
+// A RawInstruction is a raw BPF virtual machine instruction.
+type RawInstruction struct {
+	// Operation to execute.
+	Op uint16
+	// For conditional jump instructions, the number of instructions
+	// to skip if the condition is true/false.
+	Jt uint8
+	Jf uint8
+	// Constant parameter. The meaning depends on the Op.
+	K uint32
+}
+
+// Assemble implements the Instruction Assemble method.
+func (ri RawInstruction) Assemble() (RawInstruction, error) { return ri, nil }
+
+// Disassemble parses ri into an Instruction and returns it. If ri is
+// not recognized by this package, ri itself is returned.
+func (ri RawInstruction) Disassemble() Instruction {
+	switch ri.Op & opMaskCls {
+	case opClsLoadA, opClsLoadX:
+		reg := Register(ri.Op & opMaskLoadDest)
+		sz := 0
+		switch ri.Op & opMaskLoadWidth {
+		case opLoadWidth4:
+			sz = 4
+		case opLoadWidth2:
+			sz = 2
+		case opLoadWidth1:
+			sz = 1
+		default:
+			return ri
+		}
+		switch ri.Op & opMaskLoadMode {
+		case opAddrModeImmediate:
+			if sz != 4 {
+				return ri
+			}
+			return LoadConstant{Dst: reg, Val: ri.K}
+		case opAddrModeScratch:
+			if sz != 4 || ri.K > 15 {
+				return ri
+			}
+			return LoadScratch{Dst: reg, N: int(ri.K)}
+		case opAddrModeAbsolute:
+			if ri.K > extOffset+0xffffffff {
+				return LoadExtension{Num: Extension(-extOffset + ri.K)}
+			}
+			return LoadAbsolute{Size: sz, Off: ri.K}
+		case opAddrModeIndirect:
+			return LoadIndirect{Size: sz, Off: ri.K}
+		case opAddrModePacketLen:
+			if sz != 4 {
+				return ri
+			}
+			return LoadExtension{Num: ExtLen}
+		case opAddrModeMemShift:
+			return LoadMemShift{Off: ri.K}
+		default:
+			return ri
+		}
+
+	case opClsStoreA:
+		if ri.Op != opClsStoreA || ri.K > 15 {
+			return ri
+		}
+		return StoreScratch{Src: RegA, N: int(ri.K)}
+
+	case opClsStoreX:
+		if ri.Op != opClsStoreX || ri.K > 15 {
+			return ri
+		}
+		return StoreScratch{Src: RegX, N: int(ri.K)}
+
+	case opClsALU:
+		switch op := ALUOp(ri.Op & opMaskOperator); op {
+		case ALUOpAdd, ALUOpSub, ALUOpMul, ALUOpDiv, ALUOpOr, ALUOpAnd, ALUOpShiftLeft, ALUOpShiftRight, ALUOpMod, ALUOpXor:
+			switch operand := opOperand(ri.Op & opMaskOperand); operand {
+			case opOperandX:
+				return ALUOpX{Op: op}
+			case opOperandConstant:
+				return ALUOpConstant{Op: op, Val: ri.K}
+			default:
+				return ri
+			}
+		case aluOpNeg:
+			return NegateA{}
+		default:
+			return ri
+		}
+
+	case opClsJump:
+		switch op := jumpOp(ri.Op & opMaskOperator); op {
+		case opJumpAlways:
+			return Jump{Skip: ri.K}
+		case opJumpEqual, opJumpGT, opJumpGE, opJumpSet:
+			cond, skipTrue, skipFalse := jumpOpToTest(op, ri.Jt, ri.Jf)
+			switch operand := opOperand(ri.Op & opMaskOperand); operand {
+			case opOperandX:
+				return JumpIfX{Cond: cond, SkipTrue: skipTrue, SkipFalse: skipFalse}
+			case opOperandConstant:
+				return JumpIf{Cond: cond, Val: ri.K, SkipTrue: skipTrue, SkipFalse: skipFalse}
+			default:
+				return ri
+			}
+		default:
+			return ri
+		}
+
+	case opClsReturn:
+		switch ri.Op {
+		case opClsReturn | opRetSrcA:
+			return RetA{}
+		case opClsReturn | opRetSrcConstant:
+			return RetConstant{Val: ri.K}
+		default:
+			return ri
+		}
+
+	case opClsMisc:
+		switch ri.Op {
+		case opClsMisc | opMiscTAX:
+			return TAX{}
+		case opClsMisc | opMiscTXA:
+			return TXA{}
+		default:
+			return ri
+		}
+
+	default:
+		panic("unreachable") // switch is exhaustive on the bit pattern
+	}
+}
+
+func jumpOpToTest(op jumpOp, skipTrue uint8, skipFalse uint8) (JumpTest, uint8, uint8) {
+	var test JumpTest
+
+	// Decode "fake" jump conditions that don't appear in machine code
+	// Ensures the Assemble -> Disassemble stage recreates the same instructions
+	// See https://github.com/golang/go/issues/18470
+	if skipTrue == 0 {
+		switch op {
+		case opJumpEqual:
+			test = JumpNotEqual
+		case opJumpGT:
+			test = JumpLessOrEqual
+		case opJumpGE:
+			test = JumpLessThan
+		case opJumpSet:
+			test = JumpBitsNotSet
+		}
+
+		return test, skipFalse, 0
+	}
+
+	switch op {
+	case opJumpEqual:
+		test = JumpEqual
+	case opJumpGT:
+		test = JumpGreaterThan
+	case opJumpGE:
+		test = JumpGreaterOrEqual
+	case opJumpSet:
+		test = JumpBitsSet
+	}
+
+	return test, skipTrue, skipFalse
+}
+
+// LoadConstant loads Val into register Dst.
+type LoadConstant struct {
+	Dst Register
+	Val uint32
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a LoadConstant) Assemble() (RawInstruction, error) {
+	return assembleLoad(a.Dst, 4, opAddrModeImmediate, a.Val)
+}
+
+// String returns the instruction in assembler notation.
+func (a LoadConstant) String() string {
+	switch a.Dst {
+	case RegA:
+		return fmt.Sprintf("ld #%d", a.Val)
+	case RegX:
+		return fmt.Sprintf("ldx #%d", a.Val)
+	default:
+		return fmt.Sprintf("unknown instruction: %#v", a)
+	}
+}
+
+// LoadScratch loads scratch[N] into register Dst.
+type LoadScratch struct {
+	Dst Register
+	N   int // 0-15
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a LoadScratch) Assemble() (RawInstruction, error) {
+	if a.N < 0 || a.N > 15 {
+		return RawInstruction{}, fmt.Errorf("invalid scratch slot %d", a.N)
+	}
+	return assembleLoad(a.Dst, 4, opAddrModeScratch, uint32(a.N))
+}
+
+// String returns the instruction in assembler notation.
+func (a LoadScratch) String() string {
+	switch a.Dst {
+	case RegA:
+		return fmt.Sprintf("ld M[%d]", a.N)
+	case RegX:
+		return fmt.Sprintf("ldx M[%d]", a.N)
+	default:
+		return fmt.Sprintf("unknown instruction: %#v", a)
+	}
+}
+
+// LoadAbsolute loads packet[Off:Off+Size] as an integer value into
+// register A.
+type LoadAbsolute struct {
+	Off  uint32
+	Size int // 1, 2 or 4
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a LoadAbsolute) Assemble() (RawInstruction, error) {
+	return assembleLoad(RegA, a.Size, opAddrModeAbsolute, a.Off)
+}
+
+// String returns the instruction in assembler notation.
+func (a LoadAbsolute) String() string {
+	switch a.Size {
+	case 1: // byte
+		return fmt.Sprintf("ldb [%d]", a.Off)
+	case 2: // half word
+		return fmt.Sprintf("ldh [%d]", a.Off)
+	case 4: // word
+		if a.Off > extOffset+0xffffffff {
+			return LoadExtension{Num: Extension(a.Off + 0x1000)}.String()
+		}
+		return fmt.Sprintf("ld [%d]", a.Off)
+	default:
+		return fmt.Sprintf("unknown instruction: %#v", a)
+	}
+}
+
+// LoadIndirect loads packet[X+Off:X+Off+Size] as an integer value
+// into register A.
+type LoadIndirect struct {
+	Off  uint32
+	Size int // 1, 2 or 4
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a LoadIndirect) Assemble() (RawInstruction, error) {
+	return assembleLoad(RegA, a.Size, opAddrModeIndirect, a.Off)
+}
+
+// String returns the instruction in assembler notation.
+func (a LoadIndirect) String() string {
+	switch a.Size {
+	case 1: // byte
+		return fmt.Sprintf("ldb [x + %d]", a.Off)
+	case 2: // half word
+		return fmt.Sprintf("ldh [x + %d]", a.Off)
+	case 4: // word
+		return fmt.Sprintf("ld [x + %d]", a.Off)
+	default:
+		return fmt.Sprintf("unknown instruction: %#v", a)
+	}
+}
+
+// LoadMemShift multiplies the first 4 bits of the byte at packet[Off]
+// by 4 and stores the result in register X.
+//
+// This instruction is mainly useful to load into X the length of an
+// IPv4 packet header in a single instruction, rather than have to do
+// the arithmetic on the header's first byte by hand.
+type LoadMemShift struct {
+	Off uint32
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a LoadMemShift) Assemble() (RawInstruction, error) {
+	return assembleLoad(RegX, 1, opAddrModeMemShift, a.Off)
+}
+
+// String returns the instruction in assembler notation.
+func (a LoadMemShift) String() string {
+	return fmt.Sprintf("ldx 4*([%d]&0xf)", a.Off)
+}
+
+// LoadExtension invokes a linux-specific extension and stores the
+// result in register A.
+type LoadExtension struct {
+	Num Extension
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a LoadExtension) Assemble() (RawInstruction, error) {
+	if a.Num == ExtLen {
+		return assembleLoad(RegA, 4, opAddrModePacketLen, 0)
+	}
+	return assembleLoad(RegA, 4, opAddrModeAbsolute, uint32(extOffset+a.Num))
+}
+
+// String returns the instruction in assembler notation.
+func (a LoadExtension) String() string {
+	switch a.Num {
+	case ExtLen:
+		return "ld #len"
+	case ExtProto:
+		return "ld #proto"
+	case ExtType:
+		return "ld #type"
+	case ExtPayloadOffset:
+		return "ld #poff"
+	case ExtInterfaceIndex:
+		return "ld #ifidx"
+	case ExtNetlinkAttr:
+		return "ld #nla"
+	case ExtNetlinkAttrNested:
+		return "ld #nlan"
+	case ExtMark:
+		return "ld #mark"
+	case ExtQueue:
+		return "ld #queue"
+	case ExtLinkLayerType:
+		return "ld #hatype"
+	case ExtRXHash:
+		return "ld #rxhash"
+	case ExtCPUID:
+		return "ld #cpu"
+	case ExtVLANTag:
+		return "ld #vlan_tci"
+	case ExtVLANTagPresent:
+		return "ld #vlan_avail"
+	case ExtVLANProto:
+		return "ld #vlan_tpid"
+	case ExtRand:
+		return "ld #rand"
+	default:
+		return fmt.Sprintf("unknown instruction: %#v", a)
+	}
+}
+
+// StoreScratch stores register Src into scratch[N].
+type StoreScratch struct {
+	Src Register
+	N   int // 0-15
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a StoreScratch) Assemble() (RawInstruction, error) {
+	if a.N < 0 || a.N > 15 {
+		return RawInstruction{}, fmt.Errorf("invalid scratch slot %d", a.N)
+	}
+	var op uint16
+	switch a.Src {
+	case RegA:
+		op = opClsStoreA
+	case RegX:
+		op = opClsStoreX
+	default:
+		return RawInstruction{}, fmt.Errorf("invalid source register %v", a.Src)
+	}
+
+	return RawInstruction{
+		Op: op,
+		K:  uint32(a.N),
+	}, nil
+}
+
+// String returns the instruction in assembler notation.
+func (a StoreScratch) String() string {
+	switch a.Src {
+	case RegA:
+		return fmt.Sprintf("st M[%d]", a.N)
+	case RegX:
+		return fmt.Sprintf("stx M[%d]", a.N)
+	default:
+		return fmt.Sprintf("unknown instruction: %#v", a)
+	}
+}
+
+// ALUOpConstant executes A = A <Op> Val.
+type ALUOpConstant struct {
+	Op  ALUOp
+	Val uint32
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a ALUOpConstant) Assemble() (RawInstruction, error) {
+	return RawInstruction{
+		Op: opClsALU | uint16(opOperandConstant) | uint16(a.Op),
+		K:  a.Val,
+	}, nil
+}
+
+// String returns the instruction in assembler notation.
+func (a ALUOpConstant) String() string {
+	switch a.Op {
+	case ALUOpAdd:
+		return fmt.Sprintf("add #%d", a.Val)
+	case ALUOpSub:
+		return fmt.Sprintf("sub #%d", a.Val)
+	case ALUOpMul:
+		return fmt.Sprintf("mul #%d", a.Val)
+	case ALUOpDiv:
+		return fmt.Sprintf("div #%d", a.Val)
+	case ALUOpMod:
+		return fmt.Sprintf("mod #%d", a.Val)
+	case ALUOpAnd:
+		return fmt.Sprintf("and #%d", a.Val)
+	case ALUOpOr:
+		return fmt.Sprintf("or #%d", a.Val)
+	case ALUOpXor:
+		return fmt.Sprintf("xor #%d", a.Val)
+	case ALUOpShiftLeft:
+		return fmt.Sprintf("lsh #%d", a.Val)
+	case ALUOpShiftRight:
+		return fmt.Sprintf("rsh #%d", a.Val)
+	default:
+		return fmt.Sprintf("unknown instruction: %#v", a)
+	}
+}
+
+// ALUOpX executes A = A <Op> X
+type ALUOpX struct {
+	Op ALUOp
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a ALUOpX) Assemble() (RawInstruction, error) {
+	return RawInstruction{
+		Op: opClsALU | uint16(opOperandX) | uint16(a.Op),
+	}, nil
+}
+
+// String returns the instruction in assembler notation.
+func (a ALUOpX) String() string {
+	switch a.Op {
+	case ALUOpAdd:
+		return "add x"
+	case ALUOpSub:
+		return "sub x"
+	case ALUOpMul:
+		return "mul x"
+	case ALUOpDiv:
+		return "div x"
+	case ALUOpMod:
+		return "mod x"
+	case ALUOpAnd:
+		return "and x"
+	case ALUOpOr:
+		return "or x"
+	case ALUOpXor:
+		return "xor x"
+	case ALUOpShiftLeft:
+		return "lsh x"
+	case ALUOpShiftRight:
+		return "rsh x"
+	default:
+		return fmt.Sprintf("unknown instruction: %#v", a)
+	}
+}
+
+// NegateA executes A = -A.
+type NegateA struct{}
+
+// Assemble implements the Instruction Assemble method.
+func (a NegateA) Assemble() (RawInstruction, error) {
+	return RawInstruction{
+		Op: opClsALU | uint16(aluOpNeg),
+	}, nil
+}
+
+// String returns the instruction in assembler notation.
+func (a NegateA) String() string {
+	return fmt.Sprintf("neg")
+}
+
+// Jump skips the following Skip instructions in the program.
+type Jump struct {
+	Skip uint32
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a Jump) Assemble() (RawInstruction, error) {
+	return RawInstruction{
+		Op: opClsJump | uint16(opJumpAlways),
+		K:  a.Skip,
+	}, nil
+}
+
+// String returns the instruction in assembler notation.
+func (a Jump) String() string {
+	return fmt.Sprintf("ja %d", a.Skip)
+}
+
+// JumpIf skips the following Skip instructions in the program if A
+// <Cond> Val is true.
+type JumpIf struct {
+	Cond      JumpTest
+	Val       uint32
+	SkipTrue  uint8
+	SkipFalse uint8
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a JumpIf) Assemble() (RawInstruction, error) {
+	return jumpToRaw(a.Cond, opOperandConstant, a.Val, a.SkipTrue, a.SkipFalse)
+}
+
+// String returns the instruction in assembler notation.
+func (a JumpIf) String() string {
+	return jumpToString(a.Cond, fmt.Sprintf("#%d", a.Val), a.SkipTrue, a.SkipFalse)
+}
+
+// JumpIfX skips the following Skip instructions in the program if A
+// <Cond> X is true.
+type JumpIfX struct {
+	Cond      JumpTest
+	SkipTrue  uint8
+	SkipFalse uint8
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a JumpIfX) Assemble() (RawInstruction, error) {
+	return jumpToRaw(a.Cond, opOperandX, 0, a.SkipTrue, a.SkipFalse)
+}
+
+// String returns the instruction in assembler notation.
+func (a JumpIfX) String() string {
+	return jumpToString(a.Cond, "x", a.SkipTrue, a.SkipFalse)
+}
+
+// jumpToRaw assembles a jump instruction into a RawInstruction
+func jumpToRaw(test JumpTest, operand opOperand, k uint32, skipTrue, skipFalse uint8) (RawInstruction, error) {
+	var (
+		cond jumpOp
+		flip bool
+	)
+	switch test {
+	case JumpEqual:
+		cond = opJumpEqual
+	case JumpNotEqual:
+		cond, flip = opJumpEqual, true
+	case JumpGreaterThan:
+		cond = opJumpGT
+	case JumpLessThan:
+		cond, flip = opJumpGE, true
+	case JumpGreaterOrEqual:
+		cond = opJumpGE
+	case JumpLessOrEqual:
+		cond, flip = opJumpGT, true
+	case JumpBitsSet:
+		cond = opJumpSet
+	case JumpBitsNotSet:
+		cond, flip = opJumpSet, true
+	default:
+		return RawInstruction{}, fmt.Errorf("unknown JumpTest %v", test)
+	}
+	jt, jf := skipTrue, skipFalse
+	if flip {
+		jt, jf = jf, jt
+	}
+	return RawInstruction{
+		Op: opClsJump | uint16(cond) | uint16(operand),
+		Jt: jt,
+		Jf: jf,
+		K:  k,
+	}, nil
+}
+
+// jumpToString converts a jump instruction to assembler notation
+func jumpToString(cond JumpTest, operand string, skipTrue, skipFalse uint8) string {
+	switch cond {
+	// K == A
+	case JumpEqual:
+		return conditionalJump(operand, skipTrue, skipFalse, "jeq", "jneq")
+	// K != A
+	case JumpNotEqual:
+		return fmt.Sprintf("jneq %s,%d", operand, skipTrue)
+	// K > A
+	case JumpGreaterThan:
+		return conditionalJump(operand, skipTrue, skipFalse, "jgt", "jle")
+	// K < A
+	case JumpLessThan:
+		return fmt.Sprintf("jlt %s,%d", operand, skipTrue)
+	// K >= A
+	case JumpGreaterOrEqual:
+		return conditionalJump(operand, skipTrue, skipFalse, "jge", "jlt")
+	// K <= A
+	case JumpLessOrEqual:
+		return fmt.Sprintf("jle %s,%d", operand, skipTrue)
+	// K & A != 0
+	case JumpBitsSet:
+		if skipFalse > 0 {
+			return fmt.Sprintf("jset %s,%d,%d", operand, skipTrue, skipFalse)
+		}
+		return fmt.Sprintf("jset %s,%d", operand, skipTrue)
+	// K & A == 0, there is no assembler instruction for JumpBitNotSet, use JumpBitSet and invert skips
+	case JumpBitsNotSet:
+		return jumpToString(JumpBitsSet, operand, skipFalse, skipTrue)
+	default:
+		return fmt.Sprintf("unknown JumpTest %#v", cond)
+	}
+}
+
+func conditionalJump(operand string, skipTrue, skipFalse uint8, positiveJump, negativeJump string) string {
+	if skipTrue > 0 {
+		if skipFalse > 0 {
+			return fmt.Sprintf("%s %s,%d,%d", positiveJump, operand, skipTrue, skipFalse)
+		}
+		return fmt.Sprintf("%s %s,%d", positiveJump, operand, skipTrue)
+	}
+	return fmt.Sprintf("%s %s,%d", negativeJump, operand, skipFalse)
+}
+
+// RetA exits the BPF program, returning the value of register A.
+type RetA struct{}
+
+// Assemble implements the Instruction Assemble method.
+func (a RetA) Assemble() (RawInstruction, error) {
+	return RawInstruction{
+		Op: opClsReturn | opRetSrcA,
+	}, nil
+}
+
+// String returns the instruction in assembler notation.
+func (a RetA) String() string {
+	return fmt.Sprintf("ret a")
+}
+
+// RetConstant exits the BPF program, returning a constant value.
+type RetConstant struct {
+	Val uint32
+}
+
+// Assemble implements the Instruction Assemble method.
+func (a RetConstant) Assemble() (RawInstruction, error) {
+	return RawInstruction{
+		Op: opClsReturn | opRetSrcConstant,
+		K:  a.Val,
+	}, nil
+}
+
+// String returns the instruction in assembler notation.
+func (a RetConstant) String() string {
+	return fmt.Sprintf("ret #%d", a.Val)
+}
+
+// TXA copies the value of register X to register A.
+type TXA struct{}
+
+// Assemble implements the Instruction Assemble method.
+func (a TXA) Assemble() (RawInstruction, error) {
+	return RawInstruction{
+		Op: opClsMisc | opMiscTXA,
+	}, nil
+}
+
+// String returns the instruction in assembler notation.
+func (a TXA) String() string {
+	return fmt.Sprintf("txa")
+}
+
+// TAX copies the value of register A to register X.
+type TAX struct{}
+
+// Assemble implements the Instruction Assemble method.
+func (a TAX) Assemble() (RawInstruction, error) {
+	return RawInstruction{
+		Op: opClsMisc | opMiscTAX,
+	}, nil
+}
+
+// String returns the instruction in assembler notation.
+func (a TAX) String() string {
+	return fmt.Sprintf("tax")
+}
+
+func assembleLoad(dst Register, loadSize int, mode uint16, k uint32) (RawInstruction, error) {
+	var (
+		cls uint16
+		sz  uint16
+	)
+	switch dst {
+	case RegA:
+		cls = opClsLoadA
+	case RegX:
+		cls = opClsLoadX
+	default:
+		return RawInstruction{}, fmt.Errorf("invalid target register %v", dst)
+	}
+	switch loadSize {
+	case 1:
+		sz = opLoadWidth1
+	case 2:
+		sz = opLoadWidth2
+	case 4:
+		sz = opLoadWidth4
+	default:
+		return RawInstruction{}, fmt.Errorf("invalid load byte length %d", sz)
+	}
+	return RawInstruction{
+		Op: cls | sz | mode,
+		K:  k,
+	}, nil
+}

vendor/golang.org/x/net/bpf/setter.go

@@ -0,0 +1,10 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bpf
+
+// A Setter is a type which can attach a compiled BPF filter to itself.
+type Setter interface {
+	SetBPF(filter []RawInstruction) error
+}

vendor/golang.org/x/net/bpf/vm.go

@@ -0,0 +1,150 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bpf
+
+import (
+	"errors"
+	"fmt"
+)
+
+// A VM is an emulated BPF virtual machine.
+type VM struct {
+	filter []Instruction
+}
+
+// NewVM returns a new VM using the input BPF program.
+func NewVM(filter []Instruction) (*VM, error) {
+	if len(filter) == 0 {
+		return nil, errors.New("one or more Instructions must be specified")
+	}
+
+	for i, ins := range filter {
+		check := len(filter) - (i + 1)
+		switch ins := ins.(type) {
+		// Check for out-of-bounds jumps in instructions
+		case Jump:
+			if check <= int(ins.Skip) {
+				return nil, fmt.Errorf("cannot jump %d instructions; jumping past program bounds", ins.Skip)
+			}
+		case JumpIf:
+			if check <= int(ins.SkipTrue) {
+				return nil, fmt.Errorf("cannot jump %d instructions in true case; jumping past program bounds", ins.SkipTrue)
+			}
+			if check <= int(ins.SkipFalse) {
+				return nil, fmt.Errorf("cannot jump %d instructions in false case; jumping past program bounds", ins.SkipFalse)
+			}
+		case JumpIfX:
+			if check <= int(ins.SkipTrue) {
+				return nil, fmt.Errorf("cannot jump %d instructions in true case; jumping past program bounds", ins.SkipTrue)
+			}
+			if check <= int(ins.SkipFalse) {
+				return nil, fmt.Errorf("cannot jump %d instructions in false case; jumping past program bounds", ins.SkipFalse)
+			}
+		// Check for division or modulus by zero
+		case ALUOpConstant:
+			if ins.Val != 0 {
+				break
+			}
+
+			switch ins.Op {
+			case ALUOpDiv, ALUOpMod:
+				return nil, errors.New("cannot divide by zero using ALUOpConstant")
+			}
+		// Check for unknown extensions
+		case LoadExtension:
+			switch ins.Num {
+			case ExtLen:
+			default:
+				return nil, fmt.Errorf("extension %d not implemented", ins.Num)
+			}
+		}
+	}
+
+	// Make sure last instruction is a return instruction
+	switch filter[len(filter)-1].(type) {
+	case RetA, RetConstant:
+	default:
+		return nil, errors.New("BPF program must end with RetA or RetConstant")
+	}
+
+	// Though our VM works using disassembled instructions, we
+	// attempt to assemble the input filter anyway to ensure it is compatible
+	// with an operating system VM.
+	_, err := Assemble(filter)
+
+	return &VM{
+		filter: filter,
+	}, err
+}
+
+// Run runs the VM's BPF program against the input bytes.
+// Run returns the number of bytes accepted by the BPF program, and any errors
+// which occurred while processing the program.
+func (v *VM) Run(in []byte) (int, error) {
+	var (
+		// Registers of the virtual machine
+		regA       uint32
+		regX       uint32
+		regScratch [16]uint32
+
+		// OK is true if the program should continue processing the next
+		// instruction, or false if not, causing the loop to break
+		ok = true
+	)
+
+	// TODO(mdlayher): implement:
+	// - NegateA:
+	//   - would require a change from uint32 registers to int32
+	//     registers
+
+	// TODO(mdlayher): add interop tests that check signedness of ALU
+	// operations against kernel implementation, and make sure Go
+	// implementation matches behavior
+
+	for i := 0; i < len(v.filter) && ok; i++ {
+		ins := v.filter[i]
+
+		switch ins := ins.(type) {
+		case ALUOpConstant:
+			regA = aluOpConstant(ins, regA)
+		case ALUOpX:
+			regA, ok = aluOpX(ins, regA, regX)
+		case Jump:
+			i += int(ins.Skip)
+		case JumpIf:
+			jump := jumpIf(ins, regA)
+			i += jump
+		case JumpIfX:
+			jump := jumpIfX(ins, regA, regX)
+			i += jump
+		case LoadAbsolute:
+			regA, ok = loadAbsolute(ins, in)
+		case LoadConstant:
+			regA, regX = loadConstant(ins, regA, regX)
+		case LoadExtension:
+			regA = loadExtension(ins, in)
+		case LoadIndirect:
+			regA, ok = loadIndirect(ins, in, regX)
+		case LoadMemShift:
+			regX, ok = loadMemShift(ins, in)
+		case LoadScratch:
+			regA, regX = loadScratch(ins, regScratch, regA, regX)
+		case RetA:
+			return int(regA), nil
+		case RetConstant:
+			return int(ins.Val), nil
+		case StoreScratch:
+			regScratch = storeScratch(ins, regScratch, regA, regX)
+		case TAX:
+			regX = regA
+		case TXA:
+			regA = regX
+		default:
+			return 0, fmt.Errorf("unknown Instruction at index %d: %T", i, ins)
+		}
+	}
+
+	return 0, nil
+}

vendor/golang.org/x/net/bpf/vm_instructions.go

@@ -0,0 +1,182 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bpf
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+func aluOpConstant(ins ALUOpConstant, regA uint32) uint32 {
+	return aluOpCommon(ins.Op, regA, ins.Val)
+}
+
+func aluOpX(ins ALUOpX, regA uint32, regX uint32) (uint32, bool) {
+	// Guard against division or modulus by zero by terminating
+	// the program, as the OS BPF VM does
+	if regX == 0 {
+		switch ins.Op {
+		case ALUOpDiv, ALUOpMod:
+			return 0, false
+		}
+	}
+
+	return aluOpCommon(ins.Op, regA, regX), true
+}
+
+func aluOpCommon(op ALUOp, regA uint32, value uint32) uint32 {
+	switch op {
+	case ALUOpAdd:
+		return regA + value
+	case ALUOpSub:
+		return regA - value
+	case ALUOpMul:
+		return regA * value
+	case ALUOpDiv:
+		// Division by zero not permitted by NewVM and aluOpX checks
+		return regA / value
+	case ALUOpOr:
+		return regA | value
+	case ALUOpAnd:
+		return regA & value
+	case ALUOpShiftLeft:
+		return regA << value
+	case ALUOpShiftRight:
+		return regA >> value
+	case ALUOpMod:
+		// Modulus by zero not permitted by NewVM and aluOpX checks
+		return regA % value
+	case ALUOpXor:
+		return regA ^ value
+	default:
+		return regA
+	}
+}
+
+func jumpIf(ins JumpIf, regA uint32) int {
+	return jumpIfCommon(ins.Cond, ins.SkipTrue, ins.SkipFalse, regA, ins.Val)
+}
+
+func jumpIfX(ins JumpIfX, regA uint32, regX uint32) int {
+	return jumpIfCommon(ins.Cond, ins.SkipTrue, ins.SkipFalse, regA, regX)
+}
+
+func jumpIfCommon(cond JumpTest, skipTrue, skipFalse uint8, regA uint32, value uint32) int {
+	var ok bool
+
+	switch cond {
+	case JumpEqual:
+		ok = regA == value
+	case JumpNotEqual:
+		ok = regA != value
+	case JumpGreaterThan:
+		ok = regA > value
+	case JumpLessThan:
+		ok = regA < value
+	case JumpGreaterOrEqual:
+		ok = regA >= value
+	case JumpLessOrEqual:
+		ok = regA <= value
+	case JumpBitsSet:
+		ok = (regA & value) != 0
+	case JumpBitsNotSet:
+		ok = (regA & value) == 0
+	}
+
+	if ok {
+		return int(skipTrue)
+	}
+
+	return int(skipFalse)
+}
+
+func loadAbsolute(ins LoadAbsolute, in []byte) (uint32, bool) {
+	offset := int(ins.Off)
+	size := int(ins.Size)
+
+	return loadCommon(in, offset, size)
+}
+
+func loadConstant(ins LoadConstant, regA uint32, regX uint32) (uint32, uint32) {
+	switch ins.Dst {
+	case RegA:
+		regA = ins.Val
+	case RegX:
+		regX = ins.Val
+	}
+
+	return regA, regX
+}
+
+func loadExtension(ins LoadExtension, in []byte) uint32 {
+	switch ins.Num {
+	case ExtLen:
+		return uint32(len(in))
+	default:
+		panic(fmt.Sprintf("unimplemented extension: %d", ins.Num))
+	}
+}
+
+func loadIndirect(ins LoadIndirect, in []byte, regX uint32) (uint32, bool) {
+	offset := int(ins.Off) + int(regX)
+	size := int(ins.Size)
+
+	return loadCommon(in, offset, size)
+}
+
+func loadMemShift(ins LoadMemShift, in []byte) (uint32, bool) {
+	offset := int(ins.Off)
+
+	// Size of LoadMemShift is always 1 byte
+	if !inBounds(len(in), offset, 1) {
+		return 0, false
+	}
+
+	// Mask off high 4 bits and multiply low 4 bits by 4
+	return uint32(in[offset]&0x0f) * 4, true
+}
+
+func inBounds(inLen int, offset int, size int) bool {
+	return offset+size <= inLen
+}
+
+func loadCommon(in []byte, offset int, size int) (uint32, bool) {
+	if !inBounds(len(in), offset, size) {
+		return 0, false
+	}
+
+	switch size {
+	case 1:
+		return uint32(in[offset]), true
+	case 2:
+		return uint32(binary.BigEndian.Uint16(in[offset : offset+size])), true
+	case 4:
+		return uint32(binary.BigEndian.Uint32(in[offset : offset+size])), true
+	default:
+		panic(fmt.Sprintf("invalid load size: %d", size))
+	}
+}
+
+func loadScratch(ins LoadScratch, regScratch [16]uint32, regA uint32, regX uint32) (uint32, uint32) {
+	switch ins.Dst {
+	case RegA:
+		regA = regScratch[ins.N]
+	case RegX:
+		regX = regScratch[ins.N]
+	}
+
+	return regA, regX
+}
+
+func storeScratch(ins StoreScratch, regScratch [16]uint32, regA uint32, regX uint32) [16]uint32 {
+	switch ins.Src {
+	case RegA:
+		regScratch[ins.N] = regA
+	case RegX:
+		regScratch[ins.N] = regX
+	}
+
+	return regScratch
+}

vendor/golang.org/x/net/internal/iana/const.go

@@ -0,0 +1,223 @@
+// go generate gen.go
+// Code generated by the command above; DO NOT EDIT.
+
+// Package iana provides protocol number resources managed by the Internet Assigned Numbers Authority (IANA).
+package iana // import "golang.org/x/net/internal/iana"
+
+// Differentiated Services Field Codepoints (DSCP), Updated: 2018-05-04
+const (
+	DiffServCS0           = 0x00 // CS0
+	DiffServCS1           = 0x20 // CS1
+	DiffServCS2           = 0x40 // CS2
+	DiffServCS3           = 0x60 // CS3
+	DiffServCS4           = 0x80 // CS4
+	DiffServCS5           = 0xa0 // CS5
+	DiffServCS6           = 0xc0 // CS6
+	DiffServCS7           = 0xe0 // CS7
+	DiffServAF11          = 0x28 // AF11
+	DiffServAF12          = 0x30 // AF12
+	DiffServAF13          = 0x38 // AF13
+	DiffServAF21          = 0x48 // AF21
+	DiffServAF22          = 0x50 // AF22
+	DiffServAF23          = 0x58 // AF23
+	DiffServAF31          = 0x68 // AF31
+	DiffServAF32          = 0x70 // AF32
+	DiffServAF33          = 0x78 // AF33
+	DiffServAF41          = 0x88 // AF41
+	DiffServAF42          = 0x90 // AF42
+	DiffServAF43          = 0x98 // AF43
+	DiffServEF            = 0xb8 // EF
+	DiffServVOICEADMIT    = 0xb0 // VOICE-ADMIT
+	NotECNTransport       = 0x00 // Not-ECT (Not ECN-Capable Transport)
+	ECNTransport1         = 0x01 // ECT(1) (ECN-Capable Transport(1))
+	ECNTransport0         = 0x02 // ECT(0) (ECN-Capable Transport(0))
+	CongestionExperienced = 0x03 // CE (Congestion Experienced)
+)
+
+// Protocol Numbers, Updated: 2017-10-13
+const (
+	ProtocolIP             = 0   // IPv4 encapsulation, pseudo protocol number
+	ProtocolHOPOPT         = 0   // IPv6 Hop-by-Hop Option
+	ProtocolICMP           = 1   // Internet Control Message
+	ProtocolIGMP           = 2   // Internet Group Management
+	ProtocolGGP            = 3   // Gateway-to-Gateway
+	ProtocolIPv4           = 4   // IPv4 encapsulation
+	ProtocolST             = 5   // Stream
+	ProtocolTCP            = 6   // Transmission Control
+	ProtocolCBT            = 7   // CBT
+	ProtocolEGP            = 8   // Exterior Gateway Protocol
+	ProtocolIGP            = 9   // any private interior gateway (used by Cisco for their IGRP)
+	ProtocolBBNRCCMON      = 10  // BBN RCC Monitoring
+	ProtocolNVPII          = 11  // Network Voice Protocol
+	ProtocolPUP            = 12  // PUP
+	ProtocolEMCON          = 14  // EMCON
+	ProtocolXNET           = 15  // Cross Net Debugger
+	ProtocolCHAOS          = 16  // Chaos
+	ProtocolUDP            = 17  // User Datagram
+	ProtocolMUX            = 18  // Multiplexing
+	ProtocolDCNMEAS        = 19  // DCN Measurement Subsystems
+	ProtocolHMP            = 20  // Host Monitoring
+	ProtocolPRM            = 21  // Packet Radio Measurement
+	ProtocolXNSIDP         = 22  // XEROX NS IDP
+	ProtocolTRUNK1         = 23  // Trunk-1
+	ProtocolTRUNK2         = 24  // Trunk-2
+	ProtocolLEAF1          = 25  // Leaf-1
+	ProtocolLEAF2          = 26  // Leaf-2
+	ProtocolRDP            = 27  // Reliable Data Protocol
+	ProtocolIRTP           = 28  // Internet Reliable Transaction
+	ProtocolISOTP4         = 29  // ISO Transport Protocol Class 4
+	ProtocolNETBLT         = 30  // Bulk Data Transfer Protocol
+	ProtocolMFENSP         = 31  // MFE Network Services Protocol
+	ProtocolMERITINP       = 32  // MERIT Internodal Protocol
+	ProtocolDCCP           = 33  // Datagram Congestion Control Protocol
+	Protocol3PC            = 34  // Third Party Connect Protocol
+	ProtocolIDPR           = 35  // Inter-Domain Policy Routing Protocol
+	ProtocolXTP            = 36  // XTP
+	ProtocolDDP            = 37  // Datagram Delivery Protocol
+	ProtocolIDPRCMTP       = 38  // IDPR Control Message Transport Proto
+	ProtocolTPPP           = 39  // TP++ Transport Protocol
+	ProtocolIL             = 40  // IL Transport Protocol
+	ProtocolIPv6           = 41  // IPv6 encapsulation
+	ProtocolSDRP           = 42  // Source Demand Routing Protocol
+	ProtocolIPv6Route      = 43  // Routing Header for IPv6
+	ProtocolIPv6Frag       = 44  // Fragment Header for IPv6
+	ProtocolIDRP           = 45  // Inter-Domain Routing Protocol
+	ProtocolRSVP           = 46  // Reservation Protocol
+	ProtocolGRE            = 47  // Generic Routing Encapsulation
+	ProtocolDSR            = 48  // Dynamic Source Routing Protocol
+	ProtocolBNA            = 49  // BNA
+	ProtocolESP            = 50  // Encap Security Payload
+	ProtocolAH             = 51  // Authentication Header
+	ProtocolINLSP          = 52  // Integrated Net Layer Security  TUBA
+	ProtocolNARP           = 54  // NBMA Address Resolution Protocol
+	ProtocolMOBILE         = 55  // IP Mobility
+	ProtocolTLSP           = 56  // Transport Layer Security Protocol using Kryptonet key management
+	ProtocolSKIP           = 57  // SKIP
+	ProtocolIPv6ICMP       = 58  // ICMP for IPv6
+	ProtocolIPv6NoNxt      = 59  // No Next Header for IPv6
+	ProtocolIPv6Opts       = 60  // Destination Options for IPv6
+	ProtocolCFTP           = 62  // CFTP
+	ProtocolSATEXPAK       = 64  // SATNET and Backroom EXPAK
+	ProtocolKRYPTOLAN      = 65  // Kryptolan
+	ProtocolRVD            = 66  // MIT Remote Virtual Disk Protocol
+	ProtocolIPPC           = 67  // Internet Pluribus Packet Core
+	ProtocolSATMON         = 69  // SATNET Monitoring
+	ProtocolVISA           = 70  // VISA Protocol
+	ProtocolIPCV           = 71  // Internet Packet Core Utility
+	ProtocolCPNX           = 72  // Computer Protocol Network Executive
+	ProtocolCPHB           = 73  // Computer Protocol Heart Beat
+	ProtocolWSN            = 74  // Wang Span Network
+	ProtocolPVP            = 75  // Packet Video Protocol
+	ProtocolBRSATMON       = 76  // Backroom SATNET Monitoring
+	ProtocolSUNND          = 77  // SUN ND PROTOCOL-Temporary
+	ProtocolWBMON          = 78  // WIDEBAND Monitoring
+	ProtocolWBEXPAK        = 79  // WIDEBAND EXPAK
+	ProtocolISOIP          = 80  // ISO Internet Protocol
+	ProtocolVMTP           = 81  // VMTP
+	ProtocolSECUREVMTP     = 82  // SECURE-VMTP
+	ProtocolVINES          = 83  // VINES
+	ProtocolTTP            = 84  // Transaction Transport Protocol
+	ProtocolIPTM           = 84  // Internet Protocol Traffic Manager
+	ProtocolNSFNETIGP      = 85  // NSFNET-IGP
+	ProtocolDGP            = 86  // Dissimilar Gateway Protocol
+	ProtocolTCF            = 87  // TCF
+	ProtocolEIGRP          = 88  // EIGRP
+	ProtocolOSPFIGP        = 89  // OSPFIGP
+	ProtocolSpriteRPC      = 90  // Sprite RPC Protocol
+	ProtocolLARP           = 91  // Locus Address Resolution Protocol
+	ProtocolMTP            = 92  // Multicast Transport Protocol
+	ProtocolAX25           = 93  // AX.25 Frames
+	ProtocolIPIP           = 94  // IP-within-IP Encapsulation Protocol
+	ProtocolSCCSP          = 96  // Semaphore Communications Sec. Pro.
+	ProtocolETHERIP        = 97  // Ethernet-within-IP Encapsulation
+	ProtocolENCAP          = 98  // Encapsulation Header
+	ProtocolGMTP           = 100 // GMTP
+	ProtocolIFMP           = 101 // Ipsilon Flow Management Protocol
+	ProtocolPNNI           = 102 // PNNI over IP
+	ProtocolPIM            = 103 // Protocol Independent Multicast
+	ProtocolARIS           = 104 // ARIS
+	ProtocolSCPS           = 105 // SCPS
+	ProtocolQNX            = 106 // QNX
+	ProtocolAN             = 107 // Active Networks
+	ProtocolIPComp         = 108 // IP Payload Compression Protocol
+	ProtocolSNP            = 109 // Sitara Networks Protocol
+	ProtocolCompaqPeer     = 110 // Compaq Peer Protocol
+	ProtocolIPXinIP        = 111 // IPX in IP
+	ProtocolVRRP           = 112 // Virtual Router Redundancy Protocol
+	ProtocolPGM            = 113 // PGM Reliable Transport Protocol
+	ProtocolL2TP           = 115 // Layer Two Tunneling Protocol
+	ProtocolDDX            = 116 // D-II Data Exchange (DDX)
+	ProtocolIATP           = 117 // Interactive Agent Transfer Protocol
+	ProtocolSTP            = 118 // Schedule Transfer Protocol
+	ProtocolSRP            = 119 // SpectraLink Radio Protocol
+	ProtocolUTI            = 120 // UTI
+	ProtocolSMP            = 121 // Simple Message Protocol
+	ProtocolPTP            = 123 // Performance Transparency Protocol
+	ProtocolISIS           = 124 // ISIS over IPv4
+	ProtocolFIRE           = 125 // FIRE
+	ProtocolCRTP           = 126 // Combat Radio Transport Protocol
+	ProtocolCRUDP          = 127 // Combat Radio User Datagram
+	ProtocolSSCOPMCE       = 128 // SSCOPMCE
+	ProtocolIPLT           = 129 // IPLT
+	ProtocolSPS            = 130 // Secure Packet Shield
+	ProtocolPIPE           = 131 // Private IP Encapsulation within IP
+	ProtocolSCTP           = 132 // Stream Control Transmission Protocol
+	ProtocolFC             = 133 // Fibre Channel
+	ProtocolRSVPE2EIGNORE  = 134 // RSVP-E2E-IGNORE
+	ProtocolMobilityHeader = 135 // Mobility Header
+	ProtocolUDPLite        = 136 // UDPLite
+	ProtocolMPLSinIP       = 137 // MPLS-in-IP
+	ProtocolMANET          = 138 // MANET Protocols
+	ProtocolHIP            = 139 // Host Identity Protocol
+	ProtocolShim6          = 140 // Shim6 Protocol
+	ProtocolWESP           = 141 // Wrapped Encapsulating Security Payload
+	ProtocolROHC           = 142 // Robust Header Compression
+	ProtocolReserved       = 255 // Reserved
+)
+
+// Address Family Numbers, Updated: 2018-04-02
+const (
+	AddrFamilyIPv4                          = 1     // IP (IP version 4)
+	AddrFamilyIPv6                          = 2     // IP6 (IP version 6)
+	AddrFamilyNSAP                          = 3     // NSAP
+	AddrFamilyHDLC                          = 4     // HDLC (8-bit multidrop)
+	AddrFamilyBBN1822                       = 5     // BBN 1822
+	AddrFamily802                           = 6     // 802 (includes all 802 media plus Ethernet "canonical format")
+	AddrFamilyE163                          = 7     // E.163
+	AddrFamilyE164                          = 8     // E.164 (SMDS, Frame Relay, ATM)
+	AddrFamilyF69                           = 9     // F.69 (Telex)
+	AddrFamilyX121                          = 10    // X.121 (X.25, Frame Relay)
+	AddrFamilyIPX                           = 11    // IPX
+	AddrFamilyAppletalk                     = 12    // Appletalk
+	AddrFamilyDecnetIV                      = 13    // Decnet IV
+	AddrFamilyBanyanVines                   = 14    // Banyan Vines
+	AddrFamilyE164withSubaddress            = 15    // E.164 with NSAP format subaddress
+	AddrFamilyDNS                           = 16    // DNS (Domain Name System)
+	AddrFamilyDistinguishedName             = 17    // Distinguished Name
+	AddrFamilyASNumber                      = 18    // AS Number
+	AddrFamilyXTPoverIPv4                   = 19    // XTP over IP version 4
+	AddrFamilyXTPoverIPv6                   = 20    // XTP over IP version 6
+	AddrFamilyXTPnativemodeXTP              = 21    // XTP native mode XTP
+	AddrFamilyFibreChannelWorldWidePortName = 22    // Fibre Channel World-Wide Port Name
+	AddrFamilyFibreChannelWorldWideNodeName = 23    // Fibre Channel World-Wide Node Name
+	AddrFamilyGWID                          = 24    // GWID
+	AddrFamilyL2VPN                         = 25    // AFI for L2VPN information
+	AddrFamilyMPLSTPSectionEndpointID       = 26    // MPLS-TP Section Endpoint Identifier
+	AddrFamilyMPLSTPLSPEndpointID           = 27    // MPLS-TP LSP Endpoint Identifier
+	AddrFamilyMPLSTPPseudowireEndpointID    = 28    // MPLS-TP Pseudowire Endpoint Identifier
+	AddrFamilyMTIPv4                        = 29    // MT IP: Multi-Topology IP version 4
+	AddrFamilyMTIPv6                        = 30    // MT IPv6: Multi-Topology IP version 6
+	AddrFamilyEIGRPCommonServiceFamily      = 16384 // EIGRP Common Service Family
+	AddrFamilyEIGRPIPv4ServiceFamily        = 16385 // EIGRP IPv4 Service Family
+	AddrFamilyEIGRPIPv6ServiceFamily        = 16386 // EIGRP IPv6 Service Family
+	AddrFamilyLISPCanonicalAddressFormat    = 16387 // LISP Canonical Address Format (LCAF)
+	AddrFamilyBGPLS                         = 16388 // BGP-LS
+	AddrFamily48bitMAC                      = 16389 // 48-bit MAC
+	AddrFamily64bitMAC                      = 16390 // 64-bit MAC
+	AddrFamilyOUI                           = 16391 // OUI
+	AddrFamilyMACFinal24bits                = 16392 // MAC/24
+	AddrFamilyMACFinal40bits                = 16393 // MAC/40
+	AddrFamilyIPv6Initial64bits             = 16394 // IPv6/64
+	AddrFamilyRBridgePortID                 = 16395 // RBridge Port ID
+	AddrFamilyTRILLNickname                 = 16396 // TRILL Nickname
+)

vendor/golang.org/x/net/internal/socket/cmsghdr.go

@@ -0,0 +1,12 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
+
+package socket
+
+func (h *cmsghdr) len() int { return int(h.Len) }
+func (h *cmsghdr) lvl() int { return int(h.Level) }
+func (h *cmsghdr) typ() int { return int(h.Type) }

vendor/golang.org/x/net/internal/socket/cmsghdr_bsd.go

@@ -0,0 +1,14 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || netbsd || openbsd
+// +build aix darwin dragonfly freebsd netbsd openbsd
+
+package socket
+
+func (h *cmsghdr) set(l, lvl, typ int) {
+	h.Len = uint32(l)
+	h.Level = int32(lvl)
+	h.Type = int32(typ)
+}

vendor/golang.org/x/net/internal/socket/cmsghdr_linux_32bit.go

@@ -0,0 +1,15 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build (arm || mips || mipsle || 386 || ppc) && linux
+// +build arm mips mipsle 386 ppc
+// +build linux
+
+package socket
+
+func (h *cmsghdr) set(l, lvl, typ int) {
+	h.Len = uint32(l)
+	h.Level = int32(lvl)
+	h.Type = int32(typ)
+}

vendor/golang.org/x/net/internal/socket/cmsghdr_linux_64bit.go

@@ -0,0 +1,15 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build (arm64 || amd64 || loong64 || ppc64 || ppc64le || mips64 || mips64le || riscv64 || s390x) && linux
+// +build arm64 amd64 loong64 ppc64 ppc64le mips64 mips64le riscv64 s390x
+// +build linux
+
+package socket
+
+func (h *cmsghdr) set(l, lvl, typ int) {
+	h.Len = uint64(l)
+	h.Level = int32(lvl)
+	h.Type = int32(typ)
+}

vendor/golang.org/x/net/internal/socket/cmsghdr_solaris_64bit.go

@@ -0,0 +1,14 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build amd64 && solaris
+// +build amd64,solaris
+
+package socket
+
+func (h *cmsghdr) set(l, lvl, typ int) {
+	h.Len = uint32(l)
+	h.Level = int32(lvl)
+	h.Type = int32(typ)
+}

vendor/golang.org/x/net/internal/socket/cmsghdr_stub.go

@@ -0,0 +1,28 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !aix && !darwin && !dragonfly && !freebsd && !linux && !netbsd && !openbsd && !solaris && !zos
+// +build !aix,!darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd,!solaris,!zos
+
+package socket
+
+func controlHeaderLen() int {
+	return 0
+}
+
+func controlMessageLen(dataLen int) int {
+	return 0
+}
+
+func controlMessageSpace(dataLen int) int {
+	return 0
+}
+
+type cmsghdr struct{}
+
+func (h *cmsghdr) len() int { return 0 }
+func (h *cmsghdr) lvl() int { return 0 }
+func (h *cmsghdr) typ() int { return 0 }
+
+func (h *cmsghdr) set(l, lvl, typ int) {}

vendor/golang.org/x/net/internal/socket/cmsghdr_unix.go

@@ -0,0 +1,22 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
+
+package socket
+
+import "golang.org/x/sys/unix"
+
+func controlHeaderLen() int {
+	return unix.CmsgLen(0)
+}
+
+func controlMessageLen(dataLen int) int {
+	return unix.CmsgLen(dataLen)
+}
+
+func controlMessageSpace(dataLen int) int {
+	return unix.CmsgSpace(dataLen)
+}

vendor/golang.org/x/net/internal/socket/cmsghdr_zos_s390x.go

@@ -0,0 +1,11 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package socket
+
+func (h *cmsghdr) set(l, lvl, typ int) {
+	h.Len = int32(l)
+	h.Level = int32(lvl)
+	h.Type = int32(typ)
+}

vendor/golang.org/x/net/internal/socket/complete_dontwait.go

@@ -0,0 +1,26 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package socket
+
+import (
+	"syscall"
+)
+
+// ioComplete checks the flags and result of a syscall, to be used as return
+// value in a syscall.RawConn.Read or Write callback.
+func ioComplete(flags int, operr error) bool {
+	if flags&syscall.MSG_DONTWAIT != 0 {
+		// Caller explicitly said don't wait, so always return immediately.
+		return true
+	}
+	if operr == syscall.EAGAIN || operr == syscall.EWOULDBLOCK {
+		// No data available, block for I/O and try again.
+		return false
+	}
+	return true
+}

vendor/golang.org/x/net/internal/socket/complete_nodontwait.go

@@ -0,0 +1,22 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || windows || zos
+// +build aix windows zos
+
+package socket
+
+import (
+	"syscall"
+)
+
+// ioComplete checks the flags and result of a syscall, to be used as return
+// value in a syscall.RawConn.Read or Write callback.
+func ioComplete(flags int, operr error) bool {
+	if operr == syscall.EAGAIN || operr == syscall.EWOULDBLOCK {
+		// No data available, block for I/O and try again.
+		return false
+	}
+	return true
+}

vendor/golang.org/x/net/internal/socket/empty.s

@@ -0,0 +1,8 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build darwin && go1.12
+// +build darwin,go1.12
+
+// This exists solely so we can linkname in symbols from syscall.

vendor/golang.org/x/net/internal/socket/error_unix.go

@@ -0,0 +1,32 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris || zos
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris zos
+
+package socket
+
+import "syscall"
+
+var (
+	errEAGAIN error = syscall.EAGAIN
+	errEINVAL error = syscall.EINVAL
+	errENOENT error = syscall.ENOENT
+)
+
+// errnoErr returns common boxed Errno values, to prevent allocations
+// at runtime.
+func errnoErr(errno syscall.Errno) error {
+	switch errno {
+	case 0:
+		return nil
+	case syscall.EAGAIN:
+		return errEAGAIN
+	case syscall.EINVAL:
+		return errEINVAL
+	case syscall.ENOENT:
+		return errENOENT
+	}
+	return errno
+}

vendor/golang.org/x/net/internal/socket/error_windows.go

@@ -0,0 +1,26 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package socket
+
+import "syscall"
+
+var (
+	errERROR_IO_PENDING error = syscall.ERROR_IO_PENDING
+	errEINVAL           error = syscall.EINVAL
+)
+
+// errnoErr returns common boxed Errno values, to prevent allocations
+// at runtime.
+func errnoErr(errno syscall.Errno) error {
+	switch errno {
+	case 0:
+		return nil
+	case syscall.ERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	case syscall.EINVAL:
+		return errEINVAL
+	}
+	return errno
+}

vendor/golang.org/x/net/internal/socket/iovec_32bit.go

@@ -0,0 +1,20 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build (arm || mips || mipsle || 386 || ppc) && (darwin || dragonfly || freebsd || linux || netbsd || openbsd)
+// +build arm mips mipsle 386 ppc
+// +build darwin dragonfly freebsd linux netbsd openbsd
+
+package socket
+
+import "unsafe"
+
+func (v *iovec) set(b []byte) {
+	l := len(b)
+	if l == 0 {
+		return
+	}
+	v.Base = (*byte)(unsafe.Pointer(&b[0]))
+	v.Len = uint32(l)
+}

vendor/golang.org/x/net/internal/socket/iovec_64bit.go

@@ -0,0 +1,20 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build (arm64 || amd64 || loong64 || ppc64 || ppc64le || mips64 || mips64le || riscv64 || s390x) && (aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || zos)
+// +build arm64 amd64 loong64 ppc64 ppc64le mips64 mips64le riscv64 s390x
+// +build aix darwin dragonfly freebsd linux netbsd openbsd zos
+
+package socket
+
+import "unsafe"
+
+func (v *iovec) set(b []byte) {
+	l := len(b)
+	if l == 0 {
+		return
+	}
+	v.Base = (*byte)(unsafe.Pointer(&b[0]))
+	v.Len = uint64(l)
+}

vendor/golang.org/x/net/internal/socket/iovec_solaris_64bit.go

@@ -0,0 +1,19 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build amd64 && solaris
+// +build amd64,solaris
+
+package socket
+
+import "unsafe"
+
+func (v *iovec) set(b []byte) {
+	l := len(b)
+	if l == 0 {
+		return
+	}
+	v.Base = (*int8)(unsafe.Pointer(&b[0]))
+	v.Len = uint64(l)
+}

vendor/golang.org/x/net/internal/socket/iovec_stub.go

@@ -0,0 +1,12 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !aix && !darwin && !dragonfly && !freebsd && !linux && !netbsd && !openbsd && !solaris && !zos
+// +build !aix,!darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd,!solaris,!zos
+
+package socket
+
+type iovec struct{}
+
+func (v *iovec) set(b []byte) {}

vendor/golang.org/x/net/internal/socket/mmsghdr_stub.go

@@ -0,0 +1,22 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !aix && !linux && !netbsd
+// +build !aix,!linux,!netbsd
+
+package socket
+
+import "net"
+
+type mmsghdr struct{}
+
+type mmsghdrs []mmsghdr
+
+func (hs mmsghdrs) pack(ms []Message, parseFn func([]byte, string) (net.Addr, error), marshalFn func(net.Addr) []byte) error {
+	return nil
+}
+
+func (hs mmsghdrs) unpack(ms []Message, parseFn func([]byte, string) (net.Addr, error), hint string) error {
+	return nil
+}

vendor/golang.org/x/net/internal/socket/mmsghdr_unix.go

@@ -0,0 +1,180 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || linux || netbsd
+// +build aix linux netbsd
+
+package socket
+
+import (
+	"net"
+	"os"
+	"sync"
+	"syscall"
+)
+
+type mmsghdrs []mmsghdr
+
+func (hs mmsghdrs) unpack(ms []Message, parseFn func([]byte, string) (net.Addr, error), hint string) error {
+	for i := range hs {
+		ms[i].N = int(hs[i].Len)
+		ms[i].NN = hs[i].Hdr.controllen()
+		ms[i].Flags = hs[i].Hdr.flags()
+		if parseFn != nil {
+			var err error
+			ms[i].Addr, err = parseFn(hs[i].Hdr.name(), hint)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// mmsghdrsPacker packs Message-slices into mmsghdrs (re-)using pre-allocated buffers.
+type mmsghdrsPacker struct {
+	// hs are the pre-allocated mmsghdrs.
+	hs mmsghdrs
+	// sockaddrs is the pre-allocated buffer for the Hdr.Name buffers.
+	// We use one large buffer for all messages and slice it up.
+	sockaddrs []byte
+	// vs are the pre-allocated iovecs.
+	// We allocate one large buffer for all messages and slice it up. This allows to reuse the buffer
+	// if the number of buffers per message is distributed differently between calls.
+	vs []iovec
+}
+
+func (p *mmsghdrsPacker) prepare(ms []Message) {
+	n := len(ms)
+	if n <= cap(p.hs) {
+		p.hs = p.hs[:n]
+	} else {
+		p.hs = make(mmsghdrs, n)
+	}
+	if n*sizeofSockaddrInet6 <= cap(p.sockaddrs) {
+		p.sockaddrs = p.sockaddrs[:n*sizeofSockaddrInet6]
+	} else {
+		p.sockaddrs = make([]byte, n*sizeofSockaddrInet6)
+	}
+
+	nb := 0
+	for _, m := range ms {
+		nb += len(m.Buffers)
+	}
+	if nb <= cap(p.vs) {
+		p.vs = p.vs[:nb]
+	} else {
+		p.vs = make([]iovec, nb)
+	}
+}
+
+func (p *mmsghdrsPacker) pack(ms []Message, parseFn func([]byte, string) (net.Addr, error), marshalFn func(net.Addr, []byte) int) mmsghdrs {
+	p.prepare(ms)
+	hs := p.hs
+	vsRest := p.vs
+	saRest := p.sockaddrs
+	for i := range hs {
+		nvs := len(ms[i].Buffers)
+		vs := vsRest[:nvs]
+		vsRest = vsRest[nvs:]
+
+		var sa []byte
+		if parseFn != nil {
+			sa = saRest[:sizeofSockaddrInet6]
+			saRest = saRest[sizeofSockaddrInet6:]
+		} else if marshalFn != nil {
+			n := marshalFn(ms[i].Addr, saRest)
+			if n > 0 {
+				sa = saRest[:n]
+				saRest = saRest[n:]
+			}
+		}
+		hs[i].Hdr.pack(vs, ms[i].Buffers, ms[i].OOB, sa)
+	}
+	return hs
+}
+
+// syscaller is a helper to invoke recvmmsg and sendmmsg via the RawConn.Read/Write interface.
+// It is reusable, to amortize the overhead of allocating a closure for the function passed to
+// RawConn.Read/Write.
+type syscaller struct {
+	n     int
+	operr error
+	hs    mmsghdrs
+	flags int
+
+	boundRecvmmsgF func(uintptr) bool
+	boundSendmmsgF func(uintptr) bool
+}
+
+func (r *syscaller) init() {
+	r.boundRecvmmsgF = r.recvmmsgF
+	r.boundSendmmsgF = r.sendmmsgF
+}
+
+func (r *syscaller) recvmmsg(c syscall.RawConn, hs mmsghdrs, flags int) (int, error) {
+	r.n = 0
+	r.operr = nil
+	r.hs = hs
+	r.flags = flags
+	if err := c.Read(r.boundRecvmmsgF); err != nil {
+		return r.n, err
+	}
+	if r.operr != nil {
+		return r.n, os.NewSyscallError("recvmmsg", r.operr)
+	}
+	return r.n, nil
+}
+
+func (r *syscaller) recvmmsgF(s uintptr) bool {
+	r.n, r.operr = recvmmsg(s, r.hs, r.flags)
+	return ioComplete(r.flags, r.operr)
+}
+
+func (r *syscaller) sendmmsg(c syscall.RawConn, hs mmsghdrs, flags int) (int, error) {
+	r.n = 0
+	r.operr = nil
+	r.hs = hs
+	r.flags = flags
+	if err := c.Write(r.boundSendmmsgF); err != nil {
+		return r.n, err
+	}
+	if r.operr != nil {
+		return r.n, os.NewSyscallError("sendmmsg", r.operr)
+	}
+	return r.n, nil
+}
+
+func (r *syscaller) sendmmsgF(s uintptr) bool {
+	r.n, r.operr = sendmmsg(s, r.hs, r.flags)
+	return ioComplete(r.flags, r.operr)
+}
+
+// mmsgTmps holds reusable temporary helpers for recvmmsg and sendmmsg.
+type mmsgTmps struct {
+	packer    mmsghdrsPacker
+	syscaller syscaller
+}
+
+var defaultMmsgTmpsPool = mmsgTmpsPool{
+	p: sync.Pool{
+		New: func() interface{} {
+			tmps := new(mmsgTmps)
+			tmps.syscaller.init()
+			return tmps
+		},
+	},
+}
+
+type mmsgTmpsPool struct {
+	p sync.Pool
+}
+
+func (p *mmsgTmpsPool) Get() *mmsgTmps {
+	return p.p.Get().(*mmsgTmps)
+}
+
+func (p *mmsgTmpsPool) Put(tmps *mmsgTmps) {
+	p.p.Put(tmps)
+}

vendor/golang.org/x/net/internal/socket/msghdr_bsd.go

@@ -0,0 +1,40 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || netbsd || openbsd
+// +build aix darwin dragonfly freebsd netbsd openbsd
+
+package socket
+
+import "unsafe"
+
+func (h *msghdr) pack(vs []iovec, bs [][]byte, oob []byte, sa []byte) {
+	for i := range vs {
+		vs[i].set(bs[i])
+	}
+	h.setIov(vs)
+	if len(oob) > 0 {
+		h.Control = (*byte)(unsafe.Pointer(&oob[0]))
+		h.Controllen = uint32(len(oob))
+	}
+	if sa != nil {
+		h.Name = (*byte)(unsafe.Pointer(&sa[0]))
+		h.Namelen = uint32(len(sa))
+	}
+}
+
+func (h *msghdr) name() []byte {
+	if h.Name != nil && h.Namelen > 0 {
+		return (*[sizeofSockaddrInet6]byte)(unsafe.Pointer(h.Name))[:h.Namelen]
+	}
+	return nil
+}
+
+func (h *msghdr) controllen() int {
+	return int(h.Controllen)
+}
+
+func (h *msghdr) flags() int {
+	return int(h.Flags)
+}

vendor/golang.org/x/net/internal/socket/msghdr_bsdvar.go

@@ -0,0 +1,17 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || netbsd
+// +build aix darwin dragonfly freebsd netbsd
+
+package socket
+
+func (h *msghdr) setIov(vs []iovec) {
+	l := len(vs)
+	if l == 0 {
+		return
+	}
+	h.Iov = &vs[0]
+	h.Iovlen = int32(l)
+}

vendor/golang.org/x/net/internal/socket/msghdr_linux.go

@@ -0,0 +1,39 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package socket
+
+import "unsafe"
+
+func (h *msghdr) pack(vs []iovec, bs [][]byte, oob []byte, sa []byte) {
+	for i := range vs {
+		vs[i].set(bs[i])
+	}
+	h.setIov(vs)
+	if len(oob) > 0 {
+		h.setControl(oob)
+	}
+	if sa != nil {
+		h.Name = (*byte)(unsafe.Pointer(&sa[0]))
+		h.Namelen = uint32(len(sa))
+	} else {
+		h.Name = nil
+		h.Namelen = 0
+	}
+}
+
+func (h *msghdr) name() []byte {
+	if h.Name != nil && h.Namelen > 0 {
+		return (*[sizeofSockaddrInet6]byte)(unsafe.Pointer(h.Name))[:h.Namelen]
+	}
+	return nil
+}
+
+func (h *msghdr) controllen() int {
+	return int(h.Controllen)
+}
+
+func (h *msghdr) flags() int {
+	return int(h.Flags)
+}

vendor/golang.org/x/net/internal/socket/msghdr_linux_32bit.go

@@ -0,0 +1,25 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build (arm || mips || mipsle || 386 || ppc) && linux
+// +build arm mips mipsle 386 ppc
+// +build linux
+
+package socket
+
+import "unsafe"
+
+func (h *msghdr) setIov(vs []iovec) {
+	l := len(vs)
+	if l == 0 {
+		return
+	}
+	h.Iov = &vs[0]
+	h.Iovlen = uint32(l)
+}
+
+func (h *msghdr) setControl(b []byte) {
+	h.Control = (*byte)(unsafe.Pointer(&b[0]))
+	h.Controllen = uint32(len(b))
+}

vendor/golang.org/x/net/internal/socket/msghdr_linux_64bit.go

@@ -0,0 +1,25 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build (arm64 || amd64 || loong64 || ppc64 || ppc64le || mips64 || mips64le || riscv64 || s390x) && linux
+// +build arm64 amd64 loong64 ppc64 ppc64le mips64 mips64le riscv64 s390x
+// +build linux
+
+package socket
+
+import "unsafe"
+
+func (h *msghdr) setIov(vs []iovec) {
+	l := len(vs)
+	if l == 0 {
+		return
+	}
+	h.Iov = &vs[0]
+	h.Iovlen = uint64(l)
+}
+
+func (h *msghdr) setControl(b []byte) {
+	h.Control = (*byte)(unsafe.Pointer(&b[0]))
+	h.Controllen = uint64(len(b))
+}

vendor/golang.org/x/net/internal/socket/msghdr_openbsd.go

@@ -0,0 +1,14 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package socket
+
+func (h *msghdr) setIov(vs []iovec) {
+	l := len(vs)
+	if l == 0 {
+		return
+	}
+	h.Iov = &vs[0]
+	h.Iovlen = uint32(l)
+}

vendor/golang.org/x/net/internal/socket/msghdr_solaris_64bit.go

@@ -0,0 +1,36 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build amd64 && solaris
+// +build amd64,solaris
+
+package socket
+
+import "unsafe"
+
+func (h *msghdr) pack(vs []iovec, bs [][]byte, oob []byte, sa []byte) {
+	for i := range vs {
+		vs[i].set(bs[i])
+	}
+	if len(vs) > 0 {
+		h.Iov = &vs[0]
+		h.Iovlen = int32(len(vs))
+	}
+	if len(oob) > 0 {
+		h.Accrights = (*int8)(unsafe.Pointer(&oob[0]))
+		h.Accrightslen = int32(len(oob))
+	}
+	if sa != nil {
+		h.Name = (*byte)(unsafe.Pointer(&sa[0]))
+		h.Namelen = uint32(len(sa))
+	}
+}
+
+func (h *msghdr) controllen() int {
+	return int(h.Accrightslen)
+}
+
+func (h *msghdr) flags() int {
+	return int(NativeEndian.Uint32(h.Pad_cgo_2[:]))
+}

vendor/golang.org/x/net/internal/socket/msghdr_stub.go

@@ -0,0 +1,15 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !aix && !darwin && !dragonfly && !freebsd && !linux && !netbsd && !openbsd && !solaris && !zos
+// +build !aix,!darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd,!solaris,!zos
+
+package socket
+
+type msghdr struct{}
+
+func (h *msghdr) pack(vs []iovec, bs [][]byte, oob []byte, sa []byte) {}
+func (h *msghdr) name() []byte                                        { return nil }
+func (h *msghdr) controllen() int                                     { return 0 }
+func (h *msghdr) flags() int                                          { return 0 }

vendor/golang.org/x/net/internal/socket/msghdr_zos_s390x.go

@@ -0,0 +1,36 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build s390x && zos
+// +build s390x,zos
+
+package socket
+
+import "unsafe"
+
+func (h *msghdr) pack(vs []iovec, bs [][]byte, oob []byte, sa []byte) {
+	for i := range vs {
+		vs[i].set(bs[i])
+	}
+	if len(vs) > 0 {
+		h.Iov = &vs[0]
+		h.Iovlen = int32(len(vs))
+	}
+	if len(oob) > 0 {
+		h.Control = (*byte)(unsafe.Pointer(&oob[0]))
+		h.Controllen = uint32(len(oob))
+	}
+	if sa != nil {
+		h.Name = (*byte)(unsafe.Pointer(&sa[0]))
+		h.Namelen = uint32(len(sa))
+	}
+}
+
+func (h *msghdr) controllen() int {
+	return int(h.Controllen)
+}
+
+func (h *msghdr) flags() int {
+	return int(h.Flags)
+}

vendor/golang.org/x/net/internal/socket/norace.go

@@ -0,0 +1,13 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !race
+// +build !race
+
+package socket
+
+func (m *Message) raceRead() {
+}
+func (m *Message) raceWrite() {
+}

vendor/golang.org/x/net/internal/socket/race.go

@@ -0,0 +1,38 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build race
+// +build race
+
+package socket
+
+import (
+	"runtime"
+	"unsafe"
+)
+
+// This package reads and writes the Message buffers using a
+// direct system call, which the race detector can't see.
+// These functions tell the race detector what is going on during the syscall.
+
+func (m *Message) raceRead() {
+	for _, b := range m.Buffers {
+		if len(b) > 0 {
+			runtime.RaceReadRange(unsafe.Pointer(&b[0]), len(b))
+		}
+	}
+	if b := m.OOB; len(b) > 0 {
+		runtime.RaceReadRange(unsafe.Pointer(&b[0]), len(b))
+	}
+}
+func (m *Message) raceWrite() {
+	for _, b := range m.Buffers {
+		if len(b) > 0 {
+			runtime.RaceWriteRange(unsafe.Pointer(&b[0]), len(b))
+		}
+	}
+	if b := m.OOB; len(b) > 0 {
+		runtime.RaceWriteRange(unsafe.Pointer(&b[0]), len(b))
+	}
+}