1 /* 2 * libjingle 3 * Copyright 2004--2010, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "talk/session/phone/rtcpmuxfilter.h" 29 30 #include "talk/base/logging.h" 31 32 namespace cricket { 33 34 RtcpMuxFilter::RtcpMuxFilter() : state_(ST_INIT), offer_enable_(false) { 35 } 36 37 bool RtcpMuxFilter::IsActive() const { 38 // We can receive muxed media prior to the accept, so we have to be able to 39 // deal with that. 40 return (state_ == ST_SENTOFFER || state_ == ST_ACTIVE); 41 } 42 43 bool RtcpMuxFilter::SetOffer(bool offer_enable, ContentSource source) { 44 bool ret = false; 45 if (state_ == ST_INIT) { 46 offer_enable_ = offer_enable; 47 state_ = (source == CS_LOCAL) ? ST_SENTOFFER : ST_RECEIVEDOFFER; 48 ret = true; 49 } else { 50 LOG(LS_ERROR) << "Invalid state for RTCP mux offer"; 51 } 52 return ret; 53 } 54 55 bool RtcpMuxFilter::SetAnswer(bool answer_enable, ContentSource source) { 56 bool ret = false; 57 if ((state_ == ST_SENTOFFER && source == CS_REMOTE) || 58 (state_ == ST_RECEIVEDOFFER && source == CS_LOCAL)) { 59 if (offer_enable_) { 60 state_ = (answer_enable) ? ST_ACTIVE : ST_INIT; 61 ret = true; 62 } else { 63 // If the offer didn't specify RTCP mux, the answer shouldn't either. 64 if (!answer_enable) { 65 ret = true; 66 state_ = ST_INIT; 67 } else { 68 LOG(LS_WARNING) << "Invalid parameters in RTCP mux answer"; 69 } 70 } 71 } else { 72 LOG(LS_ERROR) << "Invalid state for RTCP mux answer"; 73 } 74 return ret; 75 } 76 77 bool RtcpMuxFilter::DemuxRtcp(const char* data, int len) { 78 // If we're muxing RTP/RTCP, we must inspect each packet delivered and 79 // determine whether it is RTP or RTCP. We do so by checking the packet type, 80 // and assuming RTP if type is 0-63 or 96-127. For additional details, see 81 // http://tools.ietf.org/html/rfc5761. 82 // Note that if we offer RTCP mux, we may receive muxed RTCP before we 83 // receive the answer, so we operate in that state too. 84 if (!IsActive()) { 85 return false; 86 } 87 88 int type = (len >= 2) ? (static_cast<uint8>(data[1]) & 0x7F) : 0; 89 return (type >= 64 && type < 96); 90 } 91 92 } // namespace cricket 93
