1/*
2 * libjingle
3 * Copyright 2004--2005, 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// P2PTransportChannel wraps up the state management of the connection between
29// two P2P clients.  Clients have candidate ports for connecting, and
30// connections which are combinations of candidates from each end (Alice and
31// Bob each have candidates, one candidate from Alice and one candidate from
32// Bob are used to make a connection, repeat to make many connections).
33//
34// When all of the available connections become invalid (non-writable), we
35// kick off a process of determining more candidates and more connections.
36//
37#ifndef TALK_P2P_BASE_P2PTRANSPORTCHANNEL_H_
38#define TALK_P2P_BASE_P2PTRANSPORTCHANNEL_H_
39
40#include <map>
41#include <string>
42#include <vector>
43#include "talk/p2p/base/candidate.h"
44#include "talk/p2p/base/p2ptransport.h"
45#include "talk/p2p/base/portallocator.h"
46#include "talk/p2p/base/portinterface.h"
47#include "talk/p2p/base/transport.h"
48#include "talk/p2p/base/transportchannelimpl.h"
49#include "webrtc/base/asyncpacketsocket.h"
50#include "webrtc/base/sigslot.h"
51
52namespace cricket {
53
54// Adds the port on which the candidate originated.
55class RemoteCandidate : public Candidate {
56 public:
57  RemoteCandidate(const Candidate& c, PortInterface* origin_port)
58      : Candidate(c), origin_port_(origin_port) {}
59
60  PortInterface* origin_port() { return origin_port_; }
61
62 private:
63  PortInterface* origin_port_;
64};
65
66// P2PTransportChannel manages the candidates and connection process to keep
67// two P2P clients connected to each other.
68class P2PTransportChannel : public TransportChannelImpl,
69                            public rtc::MessageHandler {
70 public:
71  P2PTransportChannel(const std::string& content_name,
72                      int component,
73                      P2PTransport* transport,
74                      PortAllocator *allocator);
75  virtual ~P2PTransportChannel();
76
77  // From TransportChannelImpl:
78  virtual Transport* GetTransport() { return transport_; }
79  virtual void SetIceRole(IceRole role);
80  virtual IceRole GetIceRole() const { return ice_role_; }
81  virtual void SetIceTiebreaker(uint64 tiebreaker);
82  virtual size_t GetConnectionCount() const { return connections_.size(); }
83  virtual bool GetIceProtocolType(IceProtocolType* type) const;
84  virtual void SetIceProtocolType(IceProtocolType type);
85  virtual void SetIceCredentials(const std::string& ice_ufrag,
86                                 const std::string& ice_pwd);
87  virtual void SetRemoteIceCredentials(const std::string& ice_ufrag,
88                                       const std::string& ice_pwd);
89  virtual void SetRemoteIceMode(IceMode mode);
90  virtual void Connect();
91  virtual void Reset();
92  virtual void OnSignalingReady();
93  virtual void OnCandidate(const Candidate& candidate);
94
95  // From TransportChannel:
96  virtual int SendPacket(const char *data, size_t len,
97                         const rtc::PacketOptions& options, int flags);
98  virtual int SetOption(rtc::Socket::Option opt, int value);
99  virtual int GetError() { return error_; }
100  virtual bool GetStats(std::vector<ConnectionInfo>* stats);
101
102  const Connection* best_connection() const { return best_connection_; }
103  void set_incoming_only(bool value) { incoming_only_ = value; }
104
105  // Note: This is only for testing purpose.
106  // |ports_| should not be changed from outside.
107  const std::vector<PortInterface *>& ports() { return ports_; }
108
109  IceMode remote_ice_mode() const { return remote_ice_mode_; }
110
111  // DTLS methods.
112  virtual bool IsDtlsActive() const { return false; }
113
114  // Default implementation.
115  virtual bool GetSslRole(rtc::SSLRole* role) const {
116    return false;
117  }
118
119  virtual bool SetSslRole(rtc::SSLRole role) {
120    return false;
121  }
122
123  // Set up the ciphers to use for DTLS-SRTP.
124  virtual bool SetSrtpCiphers(const std::vector<std::string>& ciphers) {
125    return false;
126  }
127
128  // Find out which DTLS-SRTP cipher was negotiated
129  virtual bool GetSrtpCipher(std::string* cipher) {
130    return false;
131  }
132
133  // Returns false because the channel is not encrypted by default.
134  virtual bool GetLocalIdentity(rtc::SSLIdentity** identity) const {
135    return false;
136  }
137
138  virtual bool GetRemoteCertificate(rtc::SSLCertificate** cert) const {
139    return false;
140  }
141
142  // Allows key material to be extracted for external encryption.
143  virtual bool ExportKeyingMaterial(
144      const std::string& label,
145      const uint8* context,
146      size_t context_len,
147      bool use_context,
148      uint8* result,
149      size_t result_len) {
150    return false;
151  }
152
153  virtual bool SetLocalIdentity(rtc::SSLIdentity* identity) {
154    return false;
155  }
156
157  // Set DTLS Remote fingerprint. Must be after local identity set.
158  virtual bool SetRemoteFingerprint(
159    const std::string& digest_alg,
160    const uint8* digest,
161    size_t digest_len) {
162    return false;
163  }
164
165  // Helper method used only in unittest.
166  rtc::DiffServCodePoint DefaultDscpValue() const;
167
168 private:
169  rtc::Thread* thread() { return worker_thread_; }
170  PortAllocatorSession* allocator_session() {
171    return allocator_sessions_.back();
172  }
173
174  void Allocate();
175  void UpdateConnectionStates();
176  void RequestSort();
177  void SortConnections();
178  void SwitchBestConnectionTo(Connection* conn);
179  void UpdateChannelState();
180  void HandleWritable();
181  void HandleNotWritable();
182  void HandleAllTimedOut();
183
184  Connection* GetBestConnectionOnNetwork(rtc::Network* network);
185  bool CreateConnections(const Candidate &remote_candidate,
186                         PortInterface* origin_port, bool readable);
187  bool CreateConnection(PortInterface* port, const Candidate& remote_candidate,
188                        PortInterface* origin_port, bool readable);
189  bool FindConnection(cricket::Connection* connection) const;
190
191  uint32 GetRemoteCandidateGeneration(const Candidate& candidate);
192  bool IsDuplicateRemoteCandidate(const Candidate& candidate);
193  void RememberRemoteCandidate(const Candidate& remote_candidate,
194                               PortInterface* origin_port);
195  bool IsPingable(Connection* conn);
196  Connection* FindNextPingableConnection();
197  void PingConnection(Connection* conn);
198  void AddAllocatorSession(PortAllocatorSession* session);
199  void AddConnection(Connection* connection);
200
201  void OnPortReady(PortAllocatorSession *session, PortInterface* port);
202  void OnCandidatesReady(PortAllocatorSession *session,
203                         const std::vector<Candidate>& candidates);
204  void OnCandidatesAllocationDone(PortAllocatorSession* session);
205  void OnUnknownAddress(PortInterface* port,
206                        const rtc::SocketAddress& addr,
207                        ProtocolType proto,
208                        IceMessage* stun_msg,
209                        const std::string& remote_username,
210                        bool port_muxed);
211  void OnPortDestroyed(PortInterface* port);
212  void OnRoleConflict(PortInterface* port);
213
214  void OnConnectionStateChange(Connection* connection);
215  void OnReadPacket(Connection *connection, const char *data, size_t len,
216                    const rtc::PacketTime& packet_time);
217  void OnReadyToSend(Connection* connection);
218  void OnConnectionDestroyed(Connection *connection);
219
220  void OnUseCandidate(Connection* conn);
221
222  virtual void OnMessage(rtc::Message *pmsg);
223  void OnSort();
224  void OnPing();
225
226  P2PTransport* transport_;
227  PortAllocator *allocator_;
228  rtc::Thread *worker_thread_;
229  bool incoming_only_;
230  bool waiting_for_signaling_;
231  int error_;
232  std::vector<PortAllocatorSession*> allocator_sessions_;
233  std::vector<PortInterface *> ports_;
234  std::vector<Connection *> connections_;
235  Connection* best_connection_;
236  // Connection selected by the controlling agent. This should be used only
237  // at controlled side when protocol type is RFC5245.
238  Connection* pending_best_connection_;
239  std::vector<RemoteCandidate> remote_candidates_;
240  bool sort_dirty_;  // indicates whether another sort is needed right now
241  bool was_writable_;
242  typedef std::map<rtc::Socket::Option, int> OptionMap;
243  OptionMap options_;
244  std::string ice_ufrag_;
245  std::string ice_pwd_;
246  std::string remote_ice_ufrag_;
247  std::string remote_ice_pwd_;
248  IceProtocolType protocol_type_;
249  IceMode remote_ice_mode_;
250  IceRole ice_role_;
251  uint64 tiebreaker_;
252  uint32 remote_candidate_generation_;
253
254  DISALLOW_EVIL_CONSTRUCTORS(P2PTransportChannel);
255};
256
257}  // namespace cricket
258
259#endif  // TALK_P2P_BASE_P2PTRANSPORTCHANNEL_H_
260