mirror of
https://github.com/etcd-io/etcd.git
synced 2024-09-27 06:25:44 +00:00
94 lines
2.4 KiB
Go
94 lines
2.4 KiB
Go
/*
|
|
Copyright 2014 CoreOS, Inc.
|
|
|
|
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 pkg
|
|
|
|
import (
|
|
"fmt"
|
|
"net/http"
|
|
"net/url"
|
|
"strings"
|
|
)
|
|
|
|
type CORSInfo map[string]bool
|
|
|
|
// CORSInfo implements the flag.Value interface to allow users to define a list of CORS origins
|
|
func (ci *CORSInfo) Set(s string) error {
|
|
m := make(map[string]bool)
|
|
for _, v := range strings.Split(s, ",") {
|
|
v = strings.TrimSpace(v)
|
|
if v == "" {
|
|
continue
|
|
}
|
|
if v != "*" {
|
|
if _, err := url.Parse(v); err != nil {
|
|
return fmt.Errorf("Invalid CORS origin: %s", err)
|
|
}
|
|
}
|
|
m[v] = true
|
|
|
|
}
|
|
*ci = CORSInfo(m)
|
|
return nil
|
|
}
|
|
|
|
func (ci *CORSInfo) String() string {
|
|
o := make([]string, 0)
|
|
for k, _ := range *ci {
|
|
o = append(o, k)
|
|
}
|
|
return strings.Join(o, ",")
|
|
}
|
|
|
|
// OriginAllowed determines whether the server will allow a given CORS origin.
|
|
func (c CORSInfo) OriginAllowed(origin string) bool {
|
|
return c["*"] || c[origin]
|
|
}
|
|
|
|
type CORSHandler struct {
|
|
Handler http.Handler
|
|
Info *CORSInfo
|
|
}
|
|
|
|
// addHeader adds the correct cors headers given an origin
|
|
func (h *CORSHandler) addHeader(w http.ResponseWriter, origin string) {
|
|
w.Header().Add("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
|
|
w.Header().Add("Access-Control-Allow-Origin", origin)
|
|
w.Header().Add("Access-Control-Allow-Headers", "accept, content-type")
|
|
}
|
|
|
|
// ServeHTTP adds the correct CORS headers based on the origin and returns immediately
|
|
// with a 200 OK if the method is OPTIONS.
|
|
func (h *CORSHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
|
|
// It is important to flush before leaving the goroutine.
|
|
// Or it may miss the latest info written.
|
|
defer w.(http.Flusher).Flush()
|
|
|
|
// Write CORS header.
|
|
if h.Info.OriginAllowed("*") {
|
|
h.addHeader(w, "*")
|
|
} else if origin := req.Header.Get("Origin"); h.Info.OriginAllowed(origin) {
|
|
h.addHeader(w, origin)
|
|
}
|
|
|
|
if req.Method == "OPTIONS" {
|
|
w.WriteHeader(http.StatusOK)
|
|
return
|
|
}
|
|
|
|
h.Handler.ServeHTTP(w, req)
|
|
}
|