|
- // Copyright 2015 Google Inc. All rights reserved.
- //
- // Licensed under the Apache License, Version 2.0 (the "License");
- // you may not use this file except in compliance with the License.
- // You may obtain a copy of the License at
- //
- // http://www.apache.org/licenses/LICENSE-2.0
- //
- // Unless required by applicable law or agreed to in writing, software
- // distributed under the License is distributed on an "AS IS" BASIS,
- // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- // See the License for the specific language governing permissions and
- // limitations under the License.
-
- package header
-
- import (
- "net"
- "net/http"
-
- "github.com/google/martian"
- )
-
- // NewForwardedModifier sets the X-Forwarded-For, X-Forwarded-Proto,
- // X-Forwarded-Host, and X-Forwarded-Url headers.
- //
- // If X-Forwarded-For is already present, the client IP is appended to
- // the existing value. X-Forwarded-Proto, X-Forwarded-Host, and
- // X-Forwarded-Url are preserved if already present.
- //
- // TODO: Support "Forwarded" header.
- // see: http://tools.ietf.org/html/rfc7239
- func NewForwardedModifier() martian.RequestModifier {
- return martian.RequestModifierFunc(
- func(req *http.Request) error {
- if v := req.Header.Get("X-Forwarded-Proto"); v == "" {
- req.Header.Set("X-Forwarded-Proto", req.URL.Scheme)
- }
- if v := req.Header.Get("X-Forwarded-Host"); v == "" {
- req.Header.Set("X-Forwarded-Host", req.Host)
- }
- if v := req.Header.Get("X-Forwarded-Url"); v == "" {
- req.Header.Set("X-Forwarded-Url", req.URL.String())
- }
-
- xff, _, err := net.SplitHostPort(req.RemoteAddr)
- if err != nil {
- xff = req.RemoteAddr
- }
-
- if v := req.Header.Get("X-Forwarded-For"); v != "" {
- xff = v + ", " + xff
- }
-
- req.Header.Set("X-Forwarded-For", xff)
-
- return nil
- })
- }
|