mirror of https://github.com/caddyserver/caddy.git
127 lines
3.6 KiB
Go
127 lines
3.6 KiB
Go
// Copyright 2015 Matthew Holt and The Caddy Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package headers
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import (
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"net/http"
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"strings"
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"github.com/caddyserver/caddy"
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"github.com/caddyserver/caddy/modules/caddyhttp"
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)
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func init() {
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caddy.RegisterModule(caddy.Module{
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Name: "http.middleware.headers",
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New: func() interface{} { return new(Headers) },
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})
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}
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// Headers is a middleware which can mutate HTTP headers.
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type Headers struct {
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Request *HeaderOps `json:"request,omitempty"`
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Response *RespHeaderOps `json:"response,omitempty"`
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}
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// HeaderOps defines some operations to
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// perform on HTTP headers.
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type HeaderOps struct {
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Add http.Header `json:"add,omitempty"`
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Set http.Header `json:"set,omitempty"`
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Delete []string `json:"delete,omitempty"`
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}
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// RespHeaderOps is like HeaderOps, but
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// optionally deferred until response time.
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type RespHeaderOps struct {
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*HeaderOps
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Require *caddyhttp.ResponseMatcher `json:"require,omitempty"`
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Deferred bool `json:"deferred,omitempty"`
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}
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func (h Headers) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
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repl := r.Context().Value(caddy.ReplacerCtxKey).(caddy.Replacer)
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apply(h.Request, r.Header, repl)
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if h.Response != nil {
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if h.Response.Deferred || h.Response.Require != nil {
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w = &responseWriterWrapper{
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ResponseWriterWrapper: &caddyhttp.ResponseWriterWrapper{ResponseWriter: w},
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replacer: repl,
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require: h.Response.Require,
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headerOps: h.Response.HeaderOps,
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}
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} else {
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apply(h.Response.HeaderOps, w.Header(), repl)
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}
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}
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return next.ServeHTTP(w, r)
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}
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func apply(ops *HeaderOps, hdr http.Header, repl caddy.Replacer) {
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if ops == nil {
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return
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}
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for fieldName, vals := range ops.Add {
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fieldName = repl.ReplaceAll(fieldName, "")
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for _, v := range vals {
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hdr.Add(fieldName, repl.ReplaceAll(v, ""))
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}
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}
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for fieldName, vals := range ops.Set {
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fieldName = repl.ReplaceAll(fieldName, "")
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for i := range vals {
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vals[i] = repl.ReplaceAll(vals[i], "")
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}
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hdr.Set(fieldName, strings.Join(vals, ","))
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}
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for _, fieldName := range ops.Delete {
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hdr.Del(repl.ReplaceAll(fieldName, ""))
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}
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}
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// responseWriterWrapper defers response header
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// operations until WriteHeader is called.
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type responseWriterWrapper struct {
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*caddyhttp.ResponseWriterWrapper
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replacer caddy.Replacer
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require *caddyhttp.ResponseMatcher
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headerOps *HeaderOps
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wroteHeader bool
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}
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func (rww *responseWriterWrapper) WriteHeader(status int) {
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if rww.wroteHeader {
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return
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}
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rww.wroteHeader = true
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if rww.require == nil || rww.require.Match(status, rww.ResponseWriterWrapper.Header()) {
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apply(rww.headerOps, rww.ResponseWriterWrapper.Header(), rww.replacer)
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}
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rww.ResponseWriterWrapper.WriteHeader(status)
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}
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func (rww *responseWriterWrapper) Write(d []byte) (int, error) {
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if !rww.wroteHeader {
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rww.WriteHeader(http.StatusOK)
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}
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return rww.ResponseWriterWrapper.Write(d)
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}
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// Interface guards
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var (
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_ caddyhttp.MiddlewareHandler = (*Headers)(nil)
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_ caddyhttp.HTTPInterfaces = (*responseWriterWrapper)(nil)
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)
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