admin/webrtc_m130
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

sdp: document existing mid backfill cornercases

Browse Source 
mids get backfilled starting with 0 which means they are always
present in the answer (even though JSEP says otherwise) and may
even be backfilled in a manner compatible with their usage in a
BUNDLE group. Those cases are ok-ish but should be documented by
tests.

BUG=None

Change-Id: I69f0475c279da5022109a56f0006169dbc2de147
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/349380
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Commit-Queue: Philipp Hancke <phancke@meta.com>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42234}
This commit is contained in:
Philipp Hancke 2024-05-03 09:12:41 -07:00 committed by WebRTC LUCI CQ
parent 01ff41e594
commit 89679bfd02
1 changed files with 71 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
pc/sdp_offer_answer_unittest.cc
View File

@ -1242,4 +1242,75 @@ TEST_F(SdpOfferAnswerTest, OfferWithRejectedMlineWithoutFingerprintIsAccepted) {
EXPECT_TRUE(pc->SetLocalDescription(std::move(answer)));
}
TEST_F(SdpOfferAnswerTest, MidBackfillAnswer) {
auto pc = CreatePeerConnection();
// An offer without a mid backfills the mid. This is currently
// done with a per-peerconnection counter that starts from 0.
// JSEP says to only include the mid in the answer if it was in the offer
// but due to backfill it is always present.
// TODO: https://issues.webrtc.org/issues/338529222 - don't respond with mid.
std::string sdp =
"v=0\r\n"
"o=- 0 3 IN IP4 127.0.0.1\r\n"
"s=-\r\n"
"t=0 0\r\n"
"a=setup:actpass\r\n"
"a=ice-ufrag:ETEn\r\n"
"a=ice-pwd:OtSK0WpNtpUjkY4+86js7Z/l\r\n"
"a=fingerprint:sha-1 "
"4A:AD:B9:B1:3F:82:18:3B:54:02:12:DF:3E:5D:49:6B:19:E5:7C:AB\r\n"
"a=setup:actpass\r\n"
"m=audio 9 RTP/SAVPF 111\r\n"
"c=IN IP4 0.0.0.0\r\n"
"a=sendrecv\r\n"
"a=rtpmap:111 opus/48000/2\r\n"
// "a=mid:0\r\n"
"a=rtcp-mux\r\n";
auto desc = CreateSessionDescription(SdpType::kOffer, sdp);
ASSERT_NE(desc, nullptr);
RTCError error;
pc->SetRemoteDescription(std::move(desc), &error);
EXPECT_TRUE(error.ok());
auto offer_contents =
pc->pc()->remote_description()->description()->contents();
ASSERT_EQ(offer_contents.size(), 1u);
EXPECT_EQ(offer_contents[0].mid(), "0");
auto answer = pc->CreateAnswerAndSetAsLocal();
auto answer_contents = answer->description()->contents();
ASSERT_EQ(answer_contents.size(), 1u);
EXPECT_EQ(answer_contents[0].mid(), offer_contents[0].mid());
}
TEST_F(SdpOfferAnswerTest, MidBackfillDoesNotCheckAgainstBundleGroup) {
auto pc = CreatePeerConnection();
// An offer with a BUNDLE group specifying a mid that is not present
// in the offer. This is not rejected due to the mid being backfilled
// starting at 0.
// TODO: https://issues.webrtc.org/issues/338528603 - reject this.
std::string sdp =
"v=0\r\n"
"o=- 0 3 IN IP4 127.0.0.1\r\n"
"s=-\r\n"
"t=0 0\r\n"
"a=setup:actpass\r\n"
"a=ice-ufrag:ETEn\r\n"
"a=ice-pwd:OtSK0WpNtpUjkY4+86js7Z/l\r\n"
"a=fingerprint:sha-1 "
"4A:AD:B9:B1:3F:82:18:3B:54:02:12:DF:3E:5D:49:6B:19:E5:7C:AB\r\n"
"a=setup:actpass\r\n"
"a=group:BUNDLE 0\r\n"
"m=audio 9 RTP/SAVPF 111\r\n"
"c=IN IP4 0.0.0.0\r\n"
"a=sendrecv\r\n"
"a=rtpmap:111 opus/48000/2\r\n"
// "a=mid:0\r\n"
"a=rtcp-mux\r\n";
auto desc = CreateSessionDescription(SdpType::kOffer, sdp);
ASSERT_NE(desc, nullptr);
RTCError error;
pc->SetRemoteDescription(std::move(desc), &error);
EXPECT_TRUE(error.ok());
EXPECT_TRUE(pc->CreateAnswerAndSetAsLocal());
}
} // namespace webrtc