| /* |
| * libjingle |
| * Copyright 2004 Google Inc. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright notice, |
| * this list of conditions and the following disclaimer in the documentation |
| * and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
| * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "talk/session/media/rtcpmuxfilter.h" |
| |
| #include "webrtc/base/logging.h" |
| |
| namespace cricket { |
| |
| RtcpMuxFilter::RtcpMuxFilter() : state_(ST_INIT), offer_enable_(false) { |
| } |
| |
| bool RtcpMuxFilter::IsActive() const { |
| return state_ == ST_SENTPRANSWER || |
| state_ == ST_RECEIVEDPRANSWER || |
| state_ == ST_ACTIVE; |
| } |
| |
| bool RtcpMuxFilter::SetOffer(bool offer_enable, ContentSource src) { |
| if (!ExpectOffer(offer_enable, src)) { |
| LOG(LS_ERROR) << "Invalid state for change of RTCP mux offer"; |
| return false; |
| } |
| |
| offer_enable_ = offer_enable; |
| state_ = (src == CS_LOCAL) ? ST_SENTOFFER : ST_RECEIVEDOFFER; |
| return true; |
| } |
| |
| bool RtcpMuxFilter::SetProvisionalAnswer(bool answer_enable, |
| ContentSource src) { |
| if (!ExpectAnswer(src)) { |
| LOG(LS_ERROR) << "Invalid state for RTCP mux provisional answer"; |
| return false; |
| } |
| |
| if (offer_enable_) { |
| if (answer_enable) { |
| if (src == CS_REMOTE) |
| state_ = ST_RECEIVEDPRANSWER; |
| else // CS_LOCAL |
| state_ = ST_SENTPRANSWER; |
| } else { |
| // The provisional answer doesn't want to use RTCP mux. |
| // Go back to the original state after the offer was set and wait for next |
| // provisional or final answer. |
| if (src == CS_REMOTE) |
| state_ = ST_SENTOFFER; |
| else // CS_LOCAL |
| state_ = ST_RECEIVEDOFFER; |
| } |
| } else if (answer_enable) { |
| // If the offer didn't specify RTCP mux, the answer shouldn't either. |
| LOG(LS_WARNING) << "Invalid parameters in RTCP mux provisional answer"; |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool RtcpMuxFilter::SetAnswer(bool answer_enable, ContentSource src) { |
| if (!ExpectAnswer(src)) { |
| LOG(LS_ERROR) << "Invalid state for RTCP mux answer"; |
| return false; |
| } |
| |
| if (offer_enable_ && answer_enable) { |
| state_ = ST_ACTIVE; |
| } else if (answer_enable) { |
| // If the offer didn't specify RTCP mux, the answer shouldn't either. |
| LOG(LS_WARNING) << "Invalid parameters in RTCP mux answer"; |
| return false; |
| } else { |
| state_ = ST_INIT; |
| } |
| return true; |
| } |
| |
| bool RtcpMuxFilter::DemuxRtcp(const char* data, int len) { |
| // If we're muxing RTP/RTCP, we must inspect each packet delivered and |
| // determine whether it is RTP or RTCP. We do so by checking the packet type, |
| // and assuming RTP if type is 0-63 or 96-127. For additional details, see |
| // http://tools.ietf.org/html/rfc5761. |
| // Note that if we offer RTCP mux, we may receive muxed RTCP before we |
| // receive the answer, so we operate in that state too. |
| if (!offer_enable_ || state_ < ST_SENTOFFER) { |
| return false; |
| } |
| |
| int type = (len >= 2) ? (static_cast<uint8>(data[1]) & 0x7F) : 0; |
| return (type >= 64 && type < 96); |
| } |
| |
| bool RtcpMuxFilter::ExpectOffer(bool offer_enable, ContentSource source) { |
| return ((state_ == ST_INIT) || |
| (state_ == ST_ACTIVE && offer_enable == offer_enable_) || |
| (state_ == ST_SENTOFFER && source == CS_LOCAL) || |
| (state_ == ST_RECEIVEDOFFER && source == CS_REMOTE)); |
| } |
| |
| bool RtcpMuxFilter::ExpectAnswer(ContentSource source) { |
| return ((state_ == ST_SENTOFFER && source == CS_REMOTE) || |
| (state_ == ST_RECEIVEDOFFER && source == CS_LOCAL) || |
| (state_ == ST_SENTPRANSWER && source == CS_LOCAL) || |
| (state_ == ST_RECEIVEDPRANSWER && source == CS_REMOTE)); |
| } |
| |
| } // namespace cricket |