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      1 /*
      2  * libjingle
      3  * Copyright 2004 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/media/bundlefilter.h"
     29 
     30 #include "talk/media/base/rtputils.h"
     31 #include "webrtc/base/logging.h"
     32 
     33 namespace cricket {
     34 
     35 static const uint32 kSsrc01 = 0x01;
     36 
     37 BundleFilter::BundleFilter() {
     38 }
     39 
     40 BundleFilter::~BundleFilter() {
     41 }
     42 
     43 bool BundleFilter::DemuxPacket(const char* data, size_t len, bool rtcp) {
     44   // For rtp packets, we check whether the payload type can be found.
     45   // For rtcp packets, we check whether the ssrc can be found or is the special
     46   // value 1 except for SDES packets which always pass through. Plus, if
     47   // |streams_| is empty, we will allow all rtcp packets pass through provided
     48   // that they are valid rtcp packets in case that they are for early media.
     49   if (!rtcp) {
     50     // It may not be a RTP packet (e.g. SCTP).
     51     if (!IsRtpPacket(data, len))
     52       return false;
     53 
     54     int payload_type = 0;
     55     if (!GetRtpPayloadType(data, len, &payload_type)) {
     56       return false;
     57     }
     58     return FindPayloadType(payload_type);
     59   }
     60 
     61   // Rtcp packets using ssrc filter.
     62   int pl_type = 0;
     63   uint32 ssrc = 0;
     64   if (!GetRtcpType(data, len, &pl_type)) return false;
     65   if (pl_type == kRtcpTypeSDES) {
     66     // SDES packet parsing not supported.
     67     LOG(LS_INFO) << "SDES packet received for demux.";
     68     return true;
     69   } else {
     70     if (!GetRtcpSsrc(data, len, &ssrc)) return false;
     71     if (ssrc == kSsrc01) {
     72       // SSRC 1 has a special meaning and indicates generic feedback on
     73       // some systems and should never be dropped.  If it is forwarded
     74       // incorrectly it will be ignored by lower layers anyway.
     75       return true;
     76     }
     77   }
     78   // Pass through if |streams_| is empty to allow early rtcp packets in.
     79   return !HasStreams() || FindStream(ssrc);
     80 }
     81 
     82 void BundleFilter::AddPayloadType(int payload_type) {
     83   payload_types_.insert(payload_type);
     84 }
     85 
     86 bool BundleFilter::AddStream(const StreamParams& stream) {
     87   if (GetStreamBySsrc(streams_, stream.first_ssrc(), NULL)) {
     88       LOG(LS_WARNING) << "Stream already added to filter";
     89       return false;
     90   }
     91   streams_.push_back(stream);
     92   return true;
     93 }
     94 
     95 bool BundleFilter::RemoveStream(uint32 ssrc) {
     96   return RemoveStreamBySsrc(&streams_, ssrc);
     97 }
     98 
     99 bool BundleFilter::HasStreams() const {
    100   return !streams_.empty();
    101 }
    102 
    103 bool BundleFilter::FindStream(uint32 ssrc) const {
    104   if (ssrc == 0) {
    105     return false;
    106   }
    107   return (GetStreamBySsrc(streams_, ssrc, NULL));
    108 }
    109 
    110 bool BundleFilter::FindPayloadType(int pl_type) const {
    111   return payload_types_.find(pl_type) != payload_types_.end();
    112 }
    113 
    114 void BundleFilter::ClearAllPayloadTypes() {
    115   payload_types_.clear();
    116 }
    117 
    118 }  // namespace cricket
    119