sdp: reject large number of channels

the maximum used in practice is multiopus with
6 or 8 channels. 24 is the maximum number of channels
supported in the audio decoder.

BUG=chromium:1265806

Change-Id: Iba8e3185a1f235b846fed9c154e66fb3983664ed
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/238980
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Philipp Hancke <phancke@nvidia.com>
Cr-Commit-Position: refs/heads/main@{#35440}
This commit is contained in:
Philipp Hancke 2021-11-25 08:57:54 +01:00 committed by WebRTC LUCI CQ
parent 6c167d8278
commit d58ac5adf8
2 changed files with 19 additions and 0 deletions

View file

@ -257,6 +257,9 @@ static const char kDefaultSctpmapProtocol[] = "webrtc-datachannel";
// types.
const int kWildcardPayloadType = -1;
// Maximum number of channels allowed.
static const size_t kMaxNumberOfChannels = 24;
struct SsrcInfo {
uint32_t ssrc_id;
std::string cname;
@ -3628,6 +3631,10 @@ bool ParseRtpmapAttribute(const std::string& line,
return false;
}
}
if (channels > kMaxNumberOfChannels) {
return ParseFailed(line, "At most 24 channels are supported.", error);
}
AudioContentDescription* audio_desc = media_desc->as_audio();
UpdateCodec(payload_type, encoding_name, clock_rate, 0, channels,
audio_desc);

View file

@ -4694,3 +4694,15 @@ TEST_F(WebRtcSdpTest, IllegalMidCharacterValue) {
Replace("a=mid:", "a=mid:[]", &sdp);
ExpectParseFailure(std::string(sdp), "a=mid:[]");
}
TEST_F(WebRtcSdpTest, MaxChannels) {
std::string sdp =
"v=0\r\n"
"o=- 11 22 IN IP4 127.0.0.1\r\n"
"s=-\r\n"
"t=0 0\r\n"
"m=audio 49232 RTP/AVP 108\r\n"
"a=rtpmap:108 ISAC/16000/512\r\n";
ExpectParseFailure(sdp, "a=rtpmap:108 ISAC/16000/512");
}