TUN-2717: Function to serialize/deserialize HTTP headers

streamhandler/request.go

@@ -1,10 +1,8 @@
 package streamhandler
 
 import (
-	"fmt"
 	"net/http"
 	"net/url"
-	"strconv"
 	"strings"
 
 	"github.com/cloudflare/cloudflared/h2mux"
@@ -28,65 +26,9 @@ func createRequest(stream *h2mux.MuxedStream, url *url.URL) (*http.Request, erro
 	if err != nil {
 		return nil, errors.Wrap(err, "unexpected error from http.NewRequest")
 	}
-	err = H2RequestHeadersToH1Request(stream.Headers, req)
+	err = h2mux.H2RequestHeadersToH1Request(stream.Headers, req)
 	if err != nil {
 		return nil, errors.Wrap(err, "invalid request received")
 	}
 	return req, nil
 }
-
-// H2RequestHeadersToH1Request converts the HTTP/2 headers to an HTTP/1 Request
-// object. This includes conversion of the pseudo-headers into their closest
-// HTTP/1 equivalents. See https://tools.ietf.org/html/rfc7540#section-8.1.2.3
-func H2RequestHeadersToH1Request(h2 []h2mux.Header, h1 *http.Request) error {
-	for _, header := range h2 {
-		switch header.Name {
-		case ":method":
-			h1.Method = header.Value
-		case ":scheme":
-			// noop - use the preexisting scheme from h1.URL
-		case ":authority":
-			// Otherwise the host header will be based on the origin URL
-			h1.Host = header.Value
-		case ":path":
-			// We don't want to be an "opinionated" proxy, so ideally we would use :path as-is.
-			// However, this HTTP/1 Request object belongs to the Go standard library,
-			// whose URL package makes some opinionated decisions about the encoding of
-			// URL characters: see the docs of https://godoc.org/net/url#URL,
-			// in particular the EscapedPath method https://godoc.org/net/url#URL.EscapedPath,
-			// which is always used when computing url.URL.String(), whether we'd like it or not.
-			//
-			// Well, not *always*. We could circumvent this by using url.URL.Opaque. But
-			// that would present unusual difficulties when using an HTTP proxy: url.URL.Opaque
-			// is treated differently when HTTP_PROXY is set!
-			// See https://github.com/golang/go/issues/5684#issuecomment-66080888
-			//
-			// This means we are subject to the behavior of net/url's function `shouldEscape`
-			// (as invoked with mode=encodePath): https://github.com/golang/go/blob/go1.12.7/src/net/url/url.go#L101
-
-			if header.Value == "*" {
-				h1.URL.Path = "*"
-				continue
-			}
-			// Due to the behavior of validation.ValidateUrl, h1.URL may
-			// already have a partial value, with or without a trailing slash.
-			base := h1.URL.String()
-			base = strings.TrimRight(base, "/")
-			// But we know :path begins with '/', because we handled '*' above - see RFC7540
-			url, err := url.Parse(base + header.Value)
-			if err != nil {
-				return errors.Wrap(err, fmt.Sprintf("invalid path '%v'", header.Value))
-			}
-			h1.URL = url
-		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
-}