blob: 6591383916b0f25e534baf626ad06fd8134a70b4 [file] [log] [blame]
* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
#include <errno.h>
#include <string>
#include <vector>
namespace cricket {
// Some ERRNO values get re-#defined to WSA* equivalents in some talk/
// headers. We save the original ones in an enum.
enum PreservedErrno {
} // namespace cricket
#include "webrtc/base/copyonwritebuffer.h"
#include "webrtc/base/gtest_prod_util.h"
#include "webrtc/media/base/codec.h"
#include "webrtc/media/base/mediachannel.h"
#include "webrtc/media/base/mediaengine.h"
// Defined by "usrsctplib/usrsctp.h"
struct sockaddr_conn;
struct sctp_assoc_change;
struct sctp_stream_reset_event;
// Defined by <sys/socket.h>
struct socket;
namespace cricket {
// The number of outgoing streams that we'll negotiate. Since stream IDs (SIDs)
// are 0-based, the highest usable SID is 1023.
// It's recommended to use the maximum of 65535 in:
// However, we use 1024 in order to save memory. usrsctp allocates 104 bytes
// for each pair of incoming/outgoing streams (on a 64-bit system), so 65535
// streams would waste ~6MB.
// Note: "max" and "min" here are inclusive.
constexpr uint16_t kMaxSctpStreams = 1024;
constexpr uint16_t kMaxSctpSid = kMaxSctpStreams - 1;
constexpr uint16_t kMinSctpSid = 0;
// This is the default SCTP port to use. It is passed along the wire and the
// connectee and connector must be using the same port. It is not related to the
// ports at the IP level. (Corresponds to: sockaddr_conn.sconn_port in
// usrsctp.h)
const int kSctpDefaultPort = 5000;
class SctpDataMediaChannel;
// A DataEngine that interacts with usrsctp.
// From channel calls, data flows like this:
// [worker thread (although it can in princple be another thread)]
// 1. SctpDataMediaChannel::SendData(data)
// 2. usrsctp_sendv(data)
// [worker thread returns; sctp thread then calls the following]
// 3. OnSctpOutboundPacket(wrapped_data)
// [sctp thread returns having posted a message for the worker thread]
// 4. SctpDataMediaChannel::OnMessage(wrapped_data)
// 5. SctpDataMediaChannel::OnPacketFromSctpToNetwork(wrapped_data)
// 6. NetworkInterface::SendPacket(wrapped_data)
// 7. ... across network ... a packet is sent back ...
// 8. SctpDataMediaChannel::OnPacketReceived(wrapped_data)
// 9. usrsctp_conninput(wrapped_data)
// [worker thread returns; sctp thread then calls the following]
// 10. OnSctpInboundData(data)
// [sctp thread returns having posted a message fot the worker thread]
// 11. SctpDataMediaChannel::OnMessage(inboundpacket)
// 12. SctpDataMediaChannel::OnInboundPacketFromSctpToChannel(inboundpacket)
// 13. SctpDataMediaChannel::OnDataFromSctpToChannel(data)
// 14. SctpDataMediaChannel::SignalDataReceived(data)
// [from the same thread, methods registered/connected to
// SctpDataMediaChannel are called with the recieved data]
class SctpDataEngine : public DataEngineInterface, public sigslot::has_slots<> {
~SctpDataEngine() override;
DataMediaChannel* CreateChannel(DataChannelType data_channel_type) override;
const std::vector<DataCodec>& data_codecs() override { return codecs_; }
const std::vector<DataCodec> codecs_;
// TODO(ldixon): Make into a special type of TypedMessageData.
// Holds data to be passed on to a channel.
struct SctpInboundPacket;
class SctpDataMediaChannel : public DataMediaChannel,
public rtc::MessageHandler {
// DataMessageType is used for the SCTP "Payload Protocol Identifier", as
// defined in
// For the list of IANA approved values see:
// The value is not used by SCTP itself. It indicates the protocol running
// on top of SCTP.
enum PayloadProtocolIdentifier {
PPID_NONE = 0, // No protocol is specified.
// Matches the PPIDs in mozilla source and
// Sec. 9
// They're not yet assigned by IANA.
typedef std::set<uint32_t> StreamSet;
// Given a thread which will be used to post messages (received data) to this
// SctpDataMediaChannel instance.
explicit SctpDataMediaChannel(rtc::Thread* thread);
virtual ~SctpDataMediaChannel();
// When SetSend is set to true, connects. When set to false, disconnects.
// Calling: "SetSend(true); SetSend(false); SetSend(true);" will connect,
// disconnect, and reconnect.
virtual bool SetSend(bool send);
// Unless SetReceive(true) is called, received packets will be discarded.
virtual bool SetReceive(bool receive);
virtual bool SetSendParameters(const DataSendParameters& params);
virtual bool SetRecvParameters(const DataRecvParameters& params);
virtual bool AddSendStream(const StreamParams& sp);
virtual bool RemoveSendStream(uint32_t ssrc);
virtual bool AddRecvStream(const StreamParams& sp);
virtual bool RemoveRecvStream(uint32_t ssrc);
// Called when Sctp gets data. The data may be a notification or data for
// OnSctpInboundData. Called from the worker thread.
virtual void OnMessage(rtc::Message* msg);
// Send data down this channel (will be wrapped as SCTP packets then given to
// sctp that will then post the network interface by OnMessage).
// Returns true iff successful data somewhere on the send-queue/network.
virtual bool SendData(const SendDataParams& params,
const rtc::CopyOnWriteBuffer& payload,
SendDataResult* result = NULL);
// A packet is received from the network interface. Posted to OnMessage.
virtual void OnPacketReceived(rtc::CopyOnWriteBuffer* packet,
const rtc::PacketTime& packet_time);
// Exposed to allow Post call from c-callbacks.
rtc::Thread* worker_thread() const { return worker_thread_; }
// Many of these things are unused by SCTP, but are needed to fulfill
// the MediaChannel interface.
virtual void OnRtcpReceived(rtc::CopyOnWriteBuffer* packet,
const rtc::PacketTime& packet_time) {}
virtual void OnReadyToSend(bool ready) {}
void OnSendThresholdCallback();
// Helper for debugging.
void set_debug_name_for_testing(const char* debug_name) {
debug_name_ = debug_name;
const struct socket* socket() const { return sock_; }
FRIEND_TEST_ALL_PREFIXES(SctpDataMediaChannelTest, EngineSignalsRightChannel);
static int SendThresholdCallback(struct socket* sock, uint32_t sb_free);
static SctpDataMediaChannel* GetChannelFromSocket(struct socket* sock);
sockaddr_conn GetSctpSockAddr(int port);
bool SetSendCodecs(const std::vector<DataCodec>& codecs);
bool SetRecvCodecs(const std::vector<DataCodec>& codecs);
// Creates the socket and connects. Sets sending_ to true.
bool Connect();
// Closes the socket. Sets sending_ to false.
void Disconnect();
// Returns false when openning the socket failed; when successfull sets
// sending_ to true
bool OpenSctpSocket();
// Sets sending_ to false and sock_ to NULL.
void CloseSctpSocket();
// Sends a SCTP_RESET_STREAM for all streams in closing_ssids_.
bool SendQueuedStreamResets();
// Adds a stream.
bool AddStream(const StreamParams &sp);
// Queues a stream for reset.
bool ResetStream(uint32_t ssrc);
// Called by OnMessage to send packet on the network.
void OnPacketFromSctpToNetwork(rtc::CopyOnWriteBuffer* buffer);
// Called by OnMessage to decide what to do with the packet.
void OnInboundPacketFromSctpToChannel(SctpInboundPacket* packet);
void OnDataFromSctpToChannel(const ReceiveDataParams& params,
const rtc::CopyOnWriteBuffer& buffer);
void OnNotificationFromSctp(const rtc::CopyOnWriteBuffer& buffer);
void OnNotificationAssocChange(const sctp_assoc_change& change);
void OnStreamResetEvent(const struct sctp_stream_reset_event* evt);
// Responsible for marshalling incoming data to the channels listeners, and
// outgoing data to the network interface.
rtc::Thread* worker_thread_;
// The local and remote SCTP port to use. These are passed along the wire
// and the listener and connector must be using the same port. It is not
// related to the ports at the IP level. If set to -1, we default to
// kSctpDefaultPort.
int local_port_;
int remote_port_;
struct socket* sock_; // The socket created by usrsctp_socket(...).
// sending_ is true iff there is a connected socket.
bool sending_;
// receiving_ controls whether inbound packets are thrown away.
bool receiving_;
// When a data channel opens a stream, it goes into open_streams_. When we
// want to close it, the stream's ID goes into queued_reset_streams_. When
// we actually transmit a RE-CONFIG chunk with that stream ID, the ID goes
// into sent_reset_streams_. When we get a response RE-CONFIG chunk back
// acknowledging the reset, we remove the stream ID from
// sent_reset_streams_. We use sent_reset_streams_ to differentiate
// between acknowledgment RE-CONFIG and peer-initiated RE-CONFIGs.
StreamSet open_streams_;
StreamSet queued_reset_streams_;
StreamSet sent_reset_streams_;
// A static human-readable name for debugging messages.
const char* debug_name_;
} // namespace cricket