dlna: fix SOAP action header parsing - fixes #6354

Changes in github.com/anacrolix/dms changed upnp.ServiceURN to include a
namespace identifier. This identifier was previously hardcoded, but is
now parsed out of the URN. The old SOAP action header parsing logic was
duplicated in rclone and did not handle this field. Resulting responses
included a URN with an empty namespace identifier, breaking clients.

cmd/serve/dlna/dlna.go

@@ -186,7 +186,7 @@ func (s *server) rootDescHandler(w http.ResponseWriter, r *http.Request) {
 // Handle a service control HTTP request.
 func (s *server) serviceControlHandler(w http.ResponseWriter, r *http.Request) {
 	soapActionString := r.Header.Get("SOAPACTION")
-	soapAction, err := parseActionHTTPHeader(soapActionString)
+	soapAction, err := upnp.ParseActionHTTPHeader(soapActionString)
 	if err != nil {
 		serveError(s, w, "Could not parse SOAPACTION header", err)
 		return

cmd/serve/dlna/dlna_test.go

@@ -119,6 +119,8 @@ func TestContentDirectoryBrowseMetadata(t *testing.T) {
 	assert.Equal(t, http.StatusOK, resp.StatusCode)
 	body, err := ioutil.ReadAll(resp.Body)
 	require.NoError(t, err)
+	// should contain an appropriate URN
+	require.Contains(t, string(body), "urn:schemas-upnp-org:service:ContentDirectory:1")
 	// expect a <container> element
 	require.Contains(t, string(body), html.EscapeString("<container "))
 	require.NotContains(t, string(body), html.EscapeString("<item "))

cmd/serve/dlna/dlna_util.go

@@ -3,7 +3,6 @@ package dlna
 import (
 	"crypto/md5"
 	"encoding/xml"
-	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -12,9 +11,6 @@ import (
 	"net/http/httptest"
 	"net/http/httputil"
 	"os"
-	"regexp"
-	"strconv"
-	"strings"
 
 	"github.com/anacrolix/dms/soap"
 	"github.com/anacrolix/dms/upnp"
@@ -89,36 +85,6 @@ func marshalSOAPResponse(sa upnp.SoapAction, args map[string]string) []byte {
 		sa.Action, sa.ServiceURN.String(), mustMarshalXML(soapArgs)))
 }
 
-var serviceURNRegexp = regexp.MustCompile(`:service:(\w+):(\d+)$`)
-
-func parseServiceType(s string) (ret upnp.ServiceURN, err error) {
-	matches := serviceURNRegexp.FindStringSubmatch(s)
-	if matches == nil {
-		err = errors.New(s)
-		return
-	}
-	if len(matches) != 3 {
-		log.Panicf("Invalid serviceURNRegexp ?")
-	}
-	ret.Type = matches[1]
-	ret.Version, err = strconv.ParseUint(matches[2], 0, 0)
-	return
-}
-
-func parseActionHTTPHeader(s string) (ret upnp.SoapAction, err error) {
-	if s[0] != '"' || s[len(s)-1] != '"' {
-		return
-	}
-	s = s[1 : len(s)-1]
-	hashIndex := strings.LastIndex(s, "#")
-	if hashIndex == -1 {
-		return
-	}
-	ret.Action = s[hashIndex+1:]
-	ret.ServiceURN, err = parseServiceType(s[:hashIndex])
-	return
-}
-
 type loggingResponseWriter struct {
 	http.ResponseWriter
 	request   *http.Request