forked from gitea/gitea
1
0
Fork 0
gitea/vendor/github.com/chi-middleware/proxy/middleware.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
}