Implement parsing/serialization of a=bundle-only.
This CL doesn't start *using* a=bundle-only; it just adds support for
parsing it. We need to do this first, because otherwise old versions of
WebRTC will interpret a zero port value as a rejected m= section.
BUG=webrtc:4674
Review-Url: https://codereview.webrtc.org/2562183002
Cr-Commit-Position: refs/heads/master@{#15558}
diff --git a/webrtc/api/webrtcsdp.cc b/webrtc/api/webrtcsdp.cc
index 69a1af2..43fdc68 100644
--- a/webrtc/api/webrtcsdp.cc
+++ b/webrtc/api/webrtcsdp.cc
@@ -108,6 +108,7 @@
static const char kAttributeGroup[] = "group";
static const char kAttributeMid[] = "mid";
static const char kAttributeMsid[] = "msid";
+static const char kAttributeBundleOnly[] = "bundle-only";
static const char kAttributeRtcpMux[] = "rtcp-mux";
static const char kAttributeRtcpReducedSize[] = "rtcp-rsize";
static const char kAttributeSsrc[] = "ssrc";
@@ -275,6 +276,7 @@
const std::vector<int>& payload_types,
size_t* pos,
std::string* content_name,
+ bool* bundle_only,
MediaContentDescription* media_desc,
TransportDescription* transport,
std::vector<JsepIceCandidate*>* candidates,
@@ -1282,13 +1284,19 @@
fmt = " 0";
}
- // The port number in the m line will be updated later when associate with
+ // The port number in the m line will be updated later when associated with
// the candidates.
+ //
+ // A port value of 0 indicates that the m= section is rejected.
// RFC 3264
// To reject an offered stream, the port number in the corresponding stream in
// the answer MUST be set to zero.
- const std::string& port = content_info->rejected ?
- kMediaPortRejected : kDummyPort;
+ //
+ // However, the BUNDLE draft adds a new meaning to port zero, when used along
+ // with a=bundle-only.
+ const std::string& port =
+ (content_info->rejected || content_info->bundle_only) ? kMediaPortRejected
+ : kDummyPort;
rtc::SSLFingerprint* fp = (transport_info) ?
transport_info->description.identity_fingerprint.get() : NULL;
@@ -1307,6 +1315,12 @@
AddLine(os.str(), message);
}
+ // Add the a=bundle-only line.
+ if (content_info->bundle_only) {
+ InitAttrLine(kAttributeBundleOnly, &os);
+ AddLine(os.str(), message);
+ }
+
// Add the a=rtcp line.
if (IsRtp(media_desc->protocol())) {
std::string rtcp_line = GetRtcpLine(candidates);
@@ -2210,6 +2224,7 @@
const std::vector<int>& payload_types,
size_t* pos,
std::string* content_name,
+ bool* bundle_only,
TransportDescription* transport,
std::vector<JsepIceCandidate*>* candidates,
webrtc::SdpParseError* error) {
@@ -2229,8 +2244,8 @@
break;
}
if (!ParseContent(message, media_type, mline_index, protocol, payload_types,
- pos, content_name, media_desc, transport, candidates,
- error)) {
+ pos, content_name, bundle_only, media_desc, transport,
+ candidates, error)) {
delete media_desc;
return NULL;
}
@@ -2277,12 +2292,12 @@
if (fields.size() < expected_min_fields) {
return ParseFailedExpectMinFieldNum(line, expected_min_fields, error);
}
- bool rejected = false;
+ bool port_rejected = false;
// RFC 3264
// To reject an offered stream, the port number in the corresponding stream
// in the answer MUST be set to zero.
if (fields[1] == kMediaPortRejected) {
- rejected = true;
+ port_rejected = true;
}
std::string protocol = fields[2];
@@ -2314,19 +2329,23 @@
std::unique_ptr<MediaContentDescription> content;
std::string content_name;
+ bool bundle_only = false;
if (HasAttribute(line, kMediaTypeVideo)) {
content.reset(ParseContentDescription<VideoContentDescription>(
message, cricket::MEDIA_TYPE_VIDEO, mline_index, protocol,
- payload_types, pos, &content_name, &transport, candidates, error));
+ payload_types, pos, &content_name, &bundle_only, &transport,
+ candidates, error));
} else if (HasAttribute(line, kMediaTypeAudio)) {
content.reset(ParseContentDescription<AudioContentDescription>(
message, cricket::MEDIA_TYPE_AUDIO, mline_index, protocol,
- payload_types, pos, &content_name, &transport, candidates, error));
+ payload_types, pos, &content_name, &bundle_only, &transport,
+ candidates, error));
} else if (HasAttribute(line, kMediaTypeData)) {
DataContentDescription* data_desc =
ParseContentDescription<DataContentDescription>(
message, cricket::MEDIA_TYPE_DATA, mline_index, protocol,
- payload_types, pos, &content_name, &transport, candidates, error);
+ payload_types, pos, &content_name, &bundle_only, &transport,
+ candidates, error);
content.reset(data_desc);
int p;
@@ -2343,6 +2362,22 @@
return false;
}
+ bool content_rejected = false;
+ if (bundle_only) {
+ // A port of 0 is not interpreted as a rejected m= section when it's
+ // used along with a=bundle-only.
+ if (!port_rejected) {
+ return ParseFailed(
+ "a=bundle-only",
+ "a=bundle-only MUST only be used in combination with a 0 port.",
+ error);
+ }
+ } else {
+ // If not using bundle-only, interpret port 0 in the normal way; the m=
+ // section is being rejected.
+ content_rejected = port_rejected;
+ }
+
if (IsRtp(protocol)) {
// Set the extmap.
if (!session_extmaps.empty() &&
@@ -2358,10 +2393,9 @@
}
content->set_protocol(protocol);
desc->AddContent(content_name,
- IsDtlsSctp(protocol) ? cricket::NS_JINGLE_DRAFT_SCTP :
- cricket::NS_JINGLE_RTP,
- rejected,
- content.release());
+ IsDtlsSctp(protocol) ? cricket::NS_JINGLE_DRAFT_SCTP
+ : cricket::NS_JINGLE_RTP,
+ content_rejected, bundle_only, content.release());
// Create TransportInfo with the media level "ice-pwd" and "ice-ufrag".
TransportInfo transport_info(content_name, transport);
@@ -2537,6 +2571,7 @@
const std::vector<int>& payload_types,
size_t* pos,
std::string* content_name,
+ bool* bundle_only,
MediaContentDescription* media_desc,
TransportDescription* transport,
std::vector<JsepIceCandidate*>* candidates,
@@ -2619,6 +2654,8 @@
return false;
}
*content_name = mline_id;
+ } else if (HasAttribute(line, kAttributeBundleOnly)) {
+ *bundle_only = true;
} else if (HasAttribute(line, kAttributeCandidate)) {
Candidate candidate;
if (!ParseCandidate(line, &candidate, error, false)) {