cloudflared-mirror/streamhandler/request.go

70 lines
1.8 KiB
Go

package streamhandler
import (
"fmt"
"net/http"
"net/url"
"strconv"
"strings"
"github.com/cloudflare/cloudflared/h2mux"
"github.com/pkg/errors"
)
const (
lbProbeUserAgentPrefix = "Mozilla/5.0 (compatible; Cloudflare-Traffic-Manager/1.0; +https://www.cloudflare.com/traffic-manager/;"
)
func FindCfRayHeader(h1 *http.Request) string {
return h1.Header.Get("Cf-Ray")
}
func IsLBProbeRequest(req *http.Request) bool {
return strings.HasPrefix(req.UserAgent(), lbProbeUserAgentPrefix)
}
func CreateRequest(stream *h2mux.MuxedStream, originAddr string) (*http.Request, error) {
req, err := http.NewRequest(http.MethodGet, originAddr, h2mux.MuxedStreamReader{MuxedStream: stream})
if err != nil {
return nil, errors.Wrap(err, "unexpected error from http.NewRequest")
}
err = H2RequestHeadersToH1Request(stream.Headers, req)
if err != nil {
return nil, errors.Wrap(err, "invalid request received")
}
return req, nil
}
func H2RequestHeadersToH1Request(h2 []h2mux.Header, h1 *http.Request) error {
for _, header := range h2 {
switch header.Name {
case ":method":
h1.Method = header.Value
case ":scheme":
case ":authority":
// Otherwise the host header will be based on the origin URL
h1.Host = header.Value
case ":path":
u, err := url.Parse(header.Value)
if err != nil {
return fmt.Errorf("unparseable path")
}
resolved := h1.URL.ResolveReference(u)
// prevent escaping base URL
if !strings.HasPrefix(resolved.String(), h1.URL.String()) {
return fmt.Errorf("invalid path")
}
h1.URL = resolved
case "content-length":
contentLength, err := strconv.ParseInt(header.Value, 10, 64)
if err != nil {
return fmt.Errorf("unparseable content length")
}
h1.ContentLength = contentLength
default:
h1.Header.Add(http.CanonicalHeaderKey(header.Name), header.Value)
}
}
return nil
}