78 lines
1.7 KiB
Go
78 lines
1.7 KiB
Go
// Copyright 2020 Lauris BH. All rights reserved.
|
|
// Use of this source code is governed by a MIT-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package proxy
|
|
|
|
// Ported from Goji's middleware, source:
|
|
// https://github.com/zenazn/goji/tree/master/web/middleware
|
|
|
|
import (
|
|
"net"
|
|
"net/http"
|
|
"strings"
|
|
)
|
|
|
|
var xForwardedFor = http.CanonicalHeaderKey("X-Forwarded-For")
|
|
var xRealIP = http.CanonicalHeaderKey("X-Real-IP")
|
|
|
|
// ForwardedHeaders is a middleware that sets a http.Request's RemoteAddr to the results
|
|
// of parsing either the X-Real-IP header or the X-Forwarded-For header (in that
|
|
// order).
|
|
func ForwardedHeaders(options ...*ForwardedHeadersOptions) func(h http.Handler) http.Handler {
|
|
opt := defaultOptions
|
|
if len(options) > 0 {
|
|
opt = options[0]
|
|
}
|
|
return func(h http.Handler) http.Handler {
|
|
fn := func(w http.ResponseWriter, r *http.Request) {
|
|
// Treat unix socket as 127.0.0.1
|
|
if r.RemoteAddr == "@" {
|
|
r.RemoteAddr = "127.0.0.1:0"
|
|
}
|
|
if rip := realIP(r, opt); len(rip) > 0 {
|
|
r.RemoteAddr = net.JoinHostPort(rip, "0")
|
|
}
|
|
|
|
h.ServeHTTP(w, r)
|
|
}
|
|
|
|
return http.HandlerFunc(fn)
|
|
}
|
|
}
|
|
|
|
func realIP(r *http.Request, options *ForwardedHeadersOptions) string {
|
|
host, _, err := net.SplitHostPort(r.RemoteAddr)
|
|
if err != nil {
|
|
return ""
|
|
}
|
|
|
|
if !options.isTrustedProxy(net.ParseIP(host)) {
|
|
return ""
|
|
}
|
|
|
|
var ip string
|
|
|
|
if xrip := r.Header.Get(xRealIP); xrip != "" {
|
|
ip = xrip
|
|
} else if xff := r.Header.Get(xForwardedFor); xff != "" {
|
|
p := 0
|
|
for i := options.ForwardLimit; i > 0; i-- {
|
|
if p > 0 {
|
|
xff = xff[:p-2]
|
|
}
|
|
p = strings.LastIndex(xff, ", ")
|
|
if p < 0 {
|
|
p = 0
|
|
break
|
|
} else {
|
|
p += 2
|
|
}
|
|
}
|
|
|
|
ip = xff[p:]
|
|
}
|
|
|
|
return ip
|
|
}
|