1 /*
2  * libjingle
3  * Copyright 2012 Google Inc. and Robin Seggelmann
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_MEDIA_SCTP_SCTPDATAENGINE_H_
29 #define TALK_MEDIA_SCTP_SCTPDATAENGINE_H_
30 
31 #include <errno.h>
32 #include <string>
33 #include <vector>
34 
35 namespace cricket {
36 // Some ERRNO values get re-#defined to WSA* equivalents in some talk/
37 // headers.  We save the original ones in an enum.
38 enum PreservedErrno {
39   SCTP_EINPROGRESS = EINPROGRESS,
40   SCTP_EWOULDBLOCK = EWOULDBLOCK
41 };
42 }  // namespace cricket
43 
44 #include "talk/media/base/codec.h"
45 #include "talk/media/base/mediachannel.h"
46 #include "talk/media/base/mediaengine.h"
47 #include "webrtc/base/buffer.h"
48 #include "webrtc/base/scoped_ptr.h"
49 
50 // Defined by "usrsctplib/usrsctp.h"
51 struct sockaddr_conn;
52 struct sctp_assoc_change;
53 struct sctp_stream_reset_event;
54 // Defined by <sys/socket.h>
55 struct socket;
56 namespace cricket {
57 // The highest stream ID (Sid) that SCTP allows, and the number of streams we
58 // tell SCTP we're going to use.
59 const uint32_t kMaxSctpSid = 1023;
60 
61 // This is the default SCTP port to use. It is passed along the wire and the
62 // connectee and connector must be using the same port. It is not related to the
63 // ports at the IP level. (Corresponds to: sockaddr_conn.sconn_port in
64 // usrsctp.h)
65 const int kSctpDefaultPort = 5000;
66 
67 class SctpDataMediaChannel;
68 
69 // A DataEngine that interacts with usrsctp.
70 //
71 // From channel calls, data flows like this:
72 // [worker thread (although it can in princple be another thread)]
73 //  1.  SctpDataMediaChannel::SendData(data)
74 //  2.  usrsctp_sendv(data)
75 // [worker thread returns; sctp thread then calls the following]
76 //  3.  OnSctpOutboundPacket(wrapped_data)
77 // [sctp thread returns having posted a message for the worker thread]
78 //  4.  SctpDataMediaChannel::OnMessage(wrapped_data)
79 //  5.  SctpDataMediaChannel::OnPacketFromSctpToNetwork(wrapped_data)
80 //  6.  NetworkInterface::SendPacket(wrapped_data)
81 //  7.  ... across network ... a packet is sent back ...
82 //  8.  SctpDataMediaChannel::OnPacketReceived(wrapped_data)
83 //  9.  usrsctp_conninput(wrapped_data)
84 // [worker thread returns; sctp thread then calls the following]
85 //  10.  OnSctpInboundData(data)
86 // [sctp thread returns having posted a message fot the worker thread]
87 //  11. SctpDataMediaChannel::OnMessage(inboundpacket)
88 //  12. SctpDataMediaChannel::OnInboundPacketFromSctpToChannel(inboundpacket)
89 //  13. SctpDataMediaChannel::OnDataFromSctpToChannel(data)
90 //  14. SctpDataMediaChannel::SignalDataReceived(data)
91 // [from the same thread, methods registered/connected to
92 //  SctpDataMediaChannel are called with the recieved data]
93 class SctpDataEngine : public DataEngineInterface, public sigslot::has_slots<> {
94  public:
95   SctpDataEngine();
96   virtual ~SctpDataEngine();
97 
98   virtual DataMediaChannel* CreateChannel(DataChannelType data_channel_type);
99 
data_codecs()100   virtual const std::vector<DataCodec>& data_codecs() { return codecs_; }
101 
102   static int SendThresholdCallback(struct socket* sock, uint32_t sb_free);
103 
104  private:
105   static int usrsctp_engines_count;
106   std::vector<DataCodec> codecs_;
107 
108   static SctpDataMediaChannel* GetChannelFromSocket(struct socket* sock);
109 };
110 
111 // TODO(ldixon): Make into a special type of TypedMessageData.
112 // Holds data to be passed on to a channel.
113 struct SctpInboundPacket;
114 
115 class SctpDataMediaChannel : public DataMediaChannel,
116                              public rtc::MessageHandler {
117  public:
118   // DataMessageType is used for the SCTP "Payload Protocol Identifier", as
119   // defined in http://tools.ietf.org/html/rfc4960#section-14.4
120   //
121   // For the list of IANA approved values see:
122   // http://www.iana.org/assignments/sctp-parameters/sctp-parameters.xml
123   // The value is not used by SCTP itself. It indicates the protocol running
124   // on top of SCTP.
125   enum PayloadProtocolIdentifier {
126     PPID_NONE = 0,  // No protocol is specified.
127     // Matches the PPIDs in mozilla source and
128     // https://datatracker.ietf.org/doc/draft-ietf-rtcweb-data-protocol Sec. 9
129     // They're not yet assigned by IANA.
130     PPID_CONTROL = 50,
131     PPID_BINARY_PARTIAL = 52,
132     PPID_BINARY_LAST = 53,
133     PPID_TEXT_PARTIAL = 54,
134     PPID_TEXT_LAST = 51
135   };
136 
137   typedef std::set<uint32_t> StreamSet;
138 
139   // Given a thread which will be used to post messages (received data) to this
140   // SctpDataMediaChannel instance.
141   explicit SctpDataMediaChannel(rtc::Thread* thread);
142   virtual ~SctpDataMediaChannel();
143 
144   // When SetSend is set to true, connects. When set to false, disconnects.
145   // Calling: "SetSend(true); SetSend(false); SetSend(true);" will connect,
146   // disconnect, and reconnect.
147   virtual bool SetSend(bool send);
148   // Unless SetReceive(true) is called, received packets will be discarded.
149   virtual bool SetReceive(bool receive);
150 
151   virtual bool SetSendParameters(const DataSendParameters& params);
152   virtual bool SetRecvParameters(const DataRecvParameters& params);
153   virtual bool AddSendStream(const StreamParams& sp);
154   virtual bool RemoveSendStream(uint32_t ssrc);
155   virtual bool AddRecvStream(const StreamParams& sp);
156   virtual bool RemoveRecvStream(uint32_t ssrc);
157 
158   // Called when Sctp gets data. The data may be a notification or data for
159   // OnSctpInboundData. Called from the worker thread.
160   virtual void OnMessage(rtc::Message* msg);
161   // Send data down this channel (will be wrapped as SCTP packets then given to
162   // sctp that will then post the network interface by OnMessage).
163   // Returns true iff successful data somewhere on the send-queue/network.
164   virtual bool SendData(const SendDataParams& params,
165                         const rtc::Buffer& payload,
166                         SendDataResult* result = NULL);
167   // A packet is received from the network interface. Posted to OnMessage.
168   virtual void OnPacketReceived(rtc::Buffer* packet,
169                                 const rtc::PacketTime& packet_time);
170 
171   // Exposed to allow Post call from c-callbacks.
worker_thread()172   rtc::Thread* worker_thread() const { return worker_thread_; }
173 
174   // Many of these things are unused by SCTP, but are needed to fulfill
175   // the MediaChannel interface.
OnRtcpReceived(rtc::Buffer * packet,const rtc::PacketTime & packet_time)176   virtual void OnRtcpReceived(rtc::Buffer* packet,
177                               const rtc::PacketTime& packet_time) {}
OnReadyToSend(bool ready)178   virtual void OnReadyToSend(bool ready) {}
179 
180   void OnSendThresholdCallback();
181   // Helper for debugging.
set_debug_name(const std::string & debug_name)182   void set_debug_name(const std::string& debug_name) {
183     debug_name_ = debug_name;
184   }
debug_name()185   const std::string& debug_name() const { return debug_name_; }
socket()186   const struct socket* socket() const { return sock_; }
187  private:
188   sockaddr_conn GetSctpSockAddr(int port);
189 
190   bool SetSendCodecs(const std::vector<DataCodec>& codecs);
191   bool SetRecvCodecs(const std::vector<DataCodec>& codecs);
192 
193   // Creates the socket and connects. Sets sending_ to true.
194   bool Connect();
195   // Closes the socket. Sets sending_ to false.
196   void Disconnect();
197 
198   // Returns false when openning the socket failed; when successfull sets
199   // sending_ to true
200   bool OpenSctpSocket();
201   // Sets sending_ to false and sock_ to NULL.
202   void CloseSctpSocket();
203 
204   // Sends a SCTP_RESET_STREAM for all streams in closing_ssids_.
205   bool SendQueuedStreamResets();
206 
207   // Adds a stream.
208   bool AddStream(const StreamParams &sp);
209   // Queues a stream for reset.
210   bool ResetStream(uint32_t ssrc);
211 
212   // Called by OnMessage to send packet on the network.
213   void OnPacketFromSctpToNetwork(rtc::Buffer* buffer);
214   // Called by OnMessage to decide what to do with the packet.
215   void OnInboundPacketFromSctpToChannel(SctpInboundPacket* packet);
216   void OnDataFromSctpToChannel(const ReceiveDataParams& params,
217                                rtc::Buffer* buffer);
218   void OnNotificationFromSctp(rtc::Buffer* buffer);
219   void OnNotificationAssocChange(const sctp_assoc_change& change);
220 
221   void OnStreamResetEvent(const struct sctp_stream_reset_event* evt);
222 
223   // Responsible for marshalling incoming data to the channels listeners, and
224   // outgoing data to the network interface.
225   rtc::Thread* worker_thread_;
226   // The local and remote SCTP port to use. These are passed along the wire
227   // and the listener and connector must be using the same port. It is not
228   // related to the ports at the IP level.  If set to -1, we default to
229   // kSctpDefaultPort.
230   int local_port_;
231   int remote_port_;
232   struct socket* sock_;  // The socket created by usrsctp_socket(...).
233 
234   // sending_ is true iff there is a connected socket.
235   bool sending_;
236   // receiving_ controls whether inbound packets are thrown away.
237   bool receiving_;
238 
239   // When a data channel opens a stream, it goes into open_streams_.  When we
240   // want to close it, the stream's ID goes into queued_reset_streams_.  When
241   // we actually transmit a RE-CONFIG chunk with that stream ID, the ID goes
242   // into sent_reset_streams_.  When we get a response RE-CONFIG chunk back
243   // acknowledging the reset, we remove the stream ID from
244   // sent_reset_streams_.  We use sent_reset_streams_ to differentiate
245   // between acknowledgment RE-CONFIG and peer-initiated RE-CONFIGs.
246   StreamSet open_streams_;
247   StreamSet queued_reset_streams_;
248   StreamSet sent_reset_streams_;
249 
250   // A human-readable name for debugging messages.
251   std::string debug_name_;
252 };
253 
254 }  // namespace cricket
255 
256 #endif  // TALK_MEDIA_SCTP_SCTPDATAENGINE_H_
257