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#ifndef TALK_SESSION_MEDIA_RTCPMUXFILTER_H_
29#define TALK_SESSION_MEDIA_RTCPMUXFILTER_H_
30
31#include "webrtc/p2p/base/sessiondescription.h"
32#include "webrtc/base/basictypes.h"
33
34namespace cricket {
35
36// RTCP Muxer, as defined in RFC 5761 (http://tools.ietf.org/html/rfc5761)
37class RtcpMuxFilter {
38 public:
39  RtcpMuxFilter();
40
41  // Whether the filter is active, i.e. has RTCP mux been properly negotiated.
42  bool IsActive() const;
43
44  // Make the filter active, regardless of the current state.
45  void SetActive();
46
47  // Specifies whether the offer indicates the use of RTCP mux.
48  bool SetOffer(bool offer_enable, ContentSource src);
49
50  // Specifies whether the provisional answer indicates the use of RTCP mux.
51  bool SetProvisionalAnswer(bool answer_enable, ContentSource src);
52
53  // Specifies whether the answer indicates the use of RTCP mux.
54  bool SetAnswer(bool answer_enable, ContentSource src);
55
56  // Determines whether the specified packet is RTCP.
57  bool DemuxRtcp(const char* data, int len);
58
59 private:
60  bool ExpectOffer(bool offer_enable, ContentSource source);
61  bool ExpectAnswer(ContentSource source);
62  enum State {
63    // RTCP mux filter unused.
64    ST_INIT,
65    // Offer with RTCP mux enabled received.
66    // RTCP mux filter is not active.
67    ST_RECEIVEDOFFER,
68    // Offer with RTCP mux enabled sent.
69    // RTCP mux filter can demux incoming packets but is not active.
70    ST_SENTOFFER,
71    // RTCP mux filter is active but the sent answer is only provisional.
72    // When the final answer is set, the state transitions to ST_ACTIVE or
73    // ST_INIT.
74    ST_SENTPRANSWER,
75    // RTCP mux filter is active but the received answer is only provisional.
76    // When the final answer is set, the state transitions to ST_ACTIVE or
77    // ST_INIT.
78    ST_RECEIVEDPRANSWER,
79    // Offer and answer set, RTCP mux enabled. It is not possible to de-activate
80    // the filter.
81    ST_ACTIVE
82  };
83  State state_;
84  bool offer_enable_;
85};
86
87}  // namespace cricket
88
89#endif  // TALK_SESSION_MEDIA_RTCPMUXFILTER_H_
90