caddy/modules/caddyhttp/headers/caddyfile.go
Matthew Holt 005a11cf4b
headers: New 'request_header' directive; handle Host header specially
Before this change, only response headers could be manipulated with the
Caddyfile's 'header' directive.

Also handle the request Host header specially, since the Go standard
library treats it separately from the other header fields...
2019-09-11 18:48:37 -06:00

133 lines
3.4 KiB
Go

// Copyright 2015 Matthew Holt and The Caddy Authors
//
// 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 headers
import (
"net/http"
"strings"
"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
)
func init() {
httpcaddyfile.RegisterHandlerDirective("headers", parseCaddyfile)
httpcaddyfile.RegisterHandlerDirective("request_header", parseReqHdrCaddyfile)
}
// parseCaddyfile sets up the handler for response headers from
// Caddyfile tokens. Syntax:
//
// headers [<matcher>] [[+|-]<field> <value>] {
// [+][<field>] [<value>]
// [-<field>]
// }
//
// Either a block can be opened or a single header field can be configured
// in the first line, but not both in the same directive.
func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) {
hdr := new(Headers)
for h.Next() {
// first see if headers are in the initial line
var hasArgs bool
if h.NextArg() {
hasArgs = true
field := h.Val()
var value string
if h.NextArg() {
value = h.Val()
}
processCaddyfileLineRespHdr(hdr, field, value)
}
// if not, they should be in a block
for h.NextBlock(0) {
if hasArgs {
return nil, h.Err("cannot specify headers in both arguments and block")
}
field := h.Val()
var value string
if h.NextArg() {
value = h.Val()
}
processCaddyfileLineRespHdr(hdr, field, value)
}
}
return hdr, nil
}
// parseReqHdrCaddyfile sets up the handler for request headers
// from Caddyfile tokens. Syntax:
//
// request_header [<matcher>] [[+|-]<field> <value>]
//
func parseReqHdrCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) {
hdr := new(Headers)
for h.Next() {
if !h.NextArg() {
return nil, h.ArgErr()
}
field := h.Val()
var value string
if h.NextArg() {
value = h.Val()
}
if hdr.Request == nil {
hdr.Request = new(HeaderOps)
}
if strings.HasPrefix(field, "+") {
if hdr.Request.Add == nil {
hdr.Request.Add = make(http.Header)
}
hdr.Request.Add.Set(field[1:], value)
} else if strings.HasPrefix(field, "-") {
hdr.Request.Delete = append(hdr.Request.Delete, field[1:])
} else {
if hdr.Request.Set == nil {
hdr.Request.Set = make(http.Header)
}
hdr.Request.Set.Set(field, value)
}
if h.NextArg() {
return nil, h.ArgErr()
}
}
return hdr, nil
}
func processCaddyfileLineRespHdr(hdr *Headers, field, value string) {
if hdr.Response == nil {
hdr.Response = &RespHeaderOps{
HeaderOps: new(HeaderOps),
Deferred: true,
}
}
if strings.HasPrefix(field, "+") {
if hdr.Response.Add == nil {
hdr.Response.Add = make(http.Header)
}
hdr.Response.Add.Set(field[1:], value)
} else if strings.HasPrefix(field, "-") {
hdr.Response.Delete = append(hdr.Response.Delete, field[1:])
} else {
if hdr.Response.Set == nil {
hdr.Response.Set = make(http.Header)
}
hdr.Response.Set.Set(field, value)
}
}