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/*
* libjingle
* Copyright 2012 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "talk/app/webrtc/datachannel.h"
#include <string>
#include "talk/app/webrtc/mediastreamprovider.h"
#include "talk/app/webrtc/sctputils.h"
#include "webrtc/base/logging.h"
#include "webrtc/base/refcount.h"
namespace webrtc {
static size_t kMaxQueuedReceivedDataBytes = 16 * 1024 * 1024;
static size_t kMaxQueuedSendDataBytes = 16 * 1024 * 1024;
enum {
MSG_CHANNELREADY,
};
DataChannel::PacketQueue::PacketQueue() : byte_count_(0) {}
DataChannel::PacketQueue::~PacketQueue() {
Clear();
}
bool DataChannel::PacketQueue::Empty() const {
return packets_.empty();
}
DataBuffer* DataChannel::PacketQueue::Front() {
return packets_.front();
}
void DataChannel::PacketQueue::Pop() {
if (packets_.empty()) {
return;
}
byte_count_ -= packets_.front()->size();
packets_.pop_front();
}
void DataChannel::PacketQueue::Push(DataBuffer* packet) {
byte_count_ += packet->size();
packets_.push_back(packet);
}
void DataChannel::PacketQueue::Clear() {
while (!packets_.empty()) {
delete packets_.front();
packets_.pop_front();
}
byte_count_ = 0;
}
void DataChannel::PacketQueue::Swap(PacketQueue* other) {
size_t other_byte_count = other->byte_count_;
other->byte_count_ = byte_count_;
byte_count_ = other_byte_count;
other->packets_.swap(packets_);
}
rtc::scoped_refptr<DataChannel> DataChannel::Create(
DataChannelProviderInterface* provider,
cricket::DataChannelType dct,
const std::string& label,
const InternalDataChannelInit& config) {
rtc::scoped_refptr<DataChannel> channel(
new rtc::RefCountedObject<DataChannel>(provider, dct, label));
if (!channel->Init(config)) {
return NULL;
}
return channel;
}
DataChannel::DataChannel(
DataChannelProviderInterface* provider,
cricket::DataChannelType dct,
const std::string& label)
: label_(label),
observer_(NULL),
state_(kConnecting),
data_channel_type_(dct),
provider_(provider),
handshake_state_(kHandshakeInit),
connected_to_provider_(false),
send_ssrc_set_(false),
receive_ssrc_set_(false),
writable_(false),
send_ssrc_(0),
receive_ssrc_(0) {
}
bool DataChannel::Init(const InternalDataChannelInit& config) {
if (data_channel_type_ == cricket::DCT_RTP) {
if (config.reliable ||
config.id != -1 ||
config.maxRetransmits != -1 ||
config.maxRetransmitTime != -1) {
LOG(LS_ERROR) << "Failed to initialize the RTP data channel due to "
<< "invalid DataChannelInit.";
return false;
}
handshake_state_ = kHandshakeReady;
} else if (data_channel_type_ == cricket::DCT_SCTP) {
if (config.id < -1 ||
config.maxRetransmits < -1 ||
config.maxRetransmitTime < -1) {
LOG(LS_ERROR) << "Failed to initialize the SCTP data channel due to "
<< "invalid DataChannelInit.";
return false;
}
if (config.maxRetransmits != -1 && config.maxRetransmitTime != -1) {
LOG(LS_ERROR) <<
"maxRetransmits and maxRetransmitTime should not be both set.";
return false;
}
config_ = config;
switch (config_.open_handshake_role) {
case webrtc::InternalDataChannelInit::kNone: // pre-negotiated
handshake_state_ = kHandshakeReady;
break;
case webrtc::InternalDataChannelInit::kOpener:
handshake_state_ = kHandshakeShouldSendOpen;
break;
case webrtc::InternalDataChannelInit::kAcker:
handshake_state_ = kHandshakeShouldSendAck;
break;
};
// Try to connect to the transport in case the transport channel already
// exists.
OnTransportChannelCreated();
// Checks if the transport is ready to send because the initial channel
// ready signal may have been sent before the DataChannel creation.
// This has to be done async because the upper layer objects (e.g.
// Chrome glue and WebKit) are not wired up properly until after this
// function returns.
if (provider_->ReadyToSendData()) {
rtc::Thread::Current()->Post(this, MSG_CHANNELREADY, NULL);
}
}
return true;
}
DataChannel::~DataChannel() {}
void DataChannel::RegisterObserver(DataChannelObserver* observer) {
observer_ = observer;
DeliverQueuedReceivedData();
}
void DataChannel::UnregisterObserver() {
observer_ = NULL;
}
bool DataChannel::reliable() const {
if (data_channel_type_ == cricket::DCT_RTP) {
return false;
} else {
return config_.maxRetransmits == -1 &&
config_.maxRetransmitTime == -1;
}
}
uint64 DataChannel::buffered_amount() const {
return queued_send_data_.byte_count();
}
void DataChannel::Close() {
if (state_ == kClosed)
return;
send_ssrc_ = 0;
send_ssrc_set_ = false;
SetState(kClosing);
UpdateState();
}
bool DataChannel::Send(const DataBuffer& buffer) {
if (state_ != kOpen) {
return false;
}
// TODO(jiayl): the spec is unclear about if the remote side should get the
// onmessage event. We need to figure out the expected behavior and change the
// code accordingly.
if (buffer.size() == 0) {
return true;
}
// If the queue is non-empty, we're waiting for SignalReadyToSend,
// so just add to the end of the queue and keep waiting.
if (!queued_send_data_.Empty()) {
// Only SCTP DataChannel queues the outgoing data when the transport is
// blocked.
ASSERT(data_channel_type_ == cricket::DCT_SCTP);
if (!QueueSendDataMessage(buffer)) {
Close();
}
return true;
}
bool success = SendDataMessage(buffer, true);
if (data_channel_type_ == cricket::DCT_RTP) {
return success;
}
// Always return true for SCTP DataChannel per the spec.
return true;
}
void DataChannel::SetReceiveSsrc(uint32 receive_ssrc) {
ASSERT(data_channel_type_ == cricket::DCT_RTP);
if (receive_ssrc_set_) {
return;
}
receive_ssrc_ = receive_ssrc;
receive_ssrc_set_ = true;
UpdateState();
}
// The remote peer request that this channel shall be closed.
void DataChannel::RemotePeerRequestClose() {
DoClose();
}
void DataChannel::SetSctpSid(int sid) {
ASSERT(config_.id < 0 && sid >= 0 && data_channel_type_ == cricket::DCT_SCTP);
if (config_.id == sid)
return;
config_.id = sid;
provider_->AddSctpDataStream(sid);
}
void DataChannel::OnTransportChannelCreated() {
ASSERT(data_channel_type_ == cricket::DCT_SCTP);
if (!connected_to_provider_) {
connected_to_provider_ = provider_->ConnectDataChannel(this);
}
// The sid may have been unassigned when provider_->ConnectDataChannel was
// done. So always add the streams even if connected_to_provider_ is true.
if (config_.id >= 0) {
provider_->AddSctpDataStream(config_.id);
}
}
void DataChannel::SetSendSsrc(uint32 send_ssrc) {
ASSERT(data_channel_type_ == cricket::DCT_RTP);
if (send_ssrc_set_) {
return;
}
send_ssrc_ = send_ssrc;
send_ssrc_set_ = true;
UpdateState();
}
void DataChannel::OnMessage(rtc::Message* msg) {
switch (msg->message_id) {
case MSG_CHANNELREADY:
OnChannelReady(true);
break;
}
}
// The underlaying data engine is closing.
// This function makes sure the DataChannel is disconnected and changes state to
// kClosed.
void DataChannel::OnDataEngineClose() {
DoClose();
}
void DataChannel::OnDataReceived(cricket::DataChannel* channel,
const cricket::ReceiveDataParams& params,
const rtc::Buffer& payload) {
uint32 expected_ssrc =
(data_channel_type_ == cricket::DCT_RTP) ? receive_ssrc_ : config_.id;
if (params.ssrc != expected_ssrc) {
return;
}
if (params.type == cricket::DMT_CONTROL) {
ASSERT(data_channel_type_ == cricket::DCT_SCTP);
if (handshake_state_ != kHandshakeWaitingForAck) {
// Ignore it if we are not expecting an ACK message.
LOG(LS_WARNING) << "DataChannel received unexpected CONTROL message, "
<< "sid = " << params.ssrc;
return;
}
if (ParseDataChannelOpenAckMessage(payload)) {
// We can send unordered as soon as we receive the ACK message.
handshake_state_ = kHandshakeReady;
LOG(LS_INFO) << "DataChannel received OPEN_ACK message, sid = "
<< params.ssrc;
} else {
LOG(LS_WARNING) << "DataChannel failed to parse OPEN_ACK message, sid = "
<< params.ssrc;
}
return;
}
ASSERT(params.type == cricket::DMT_BINARY ||
params.type == cricket::DMT_TEXT);
LOG(LS_VERBOSE) << "DataChannel received DATA message, sid = " << params.ssrc;
// We can send unordered as soon as we receive any DATA message since the
// remote side must have received the OPEN (and old clients do not send
// OPEN_ACK).
if (handshake_state_ == kHandshakeWaitingForAck) {
handshake_state_ = kHandshakeReady;
}
bool binary = (params.type == cricket::DMT_BINARY);
rtc::scoped_ptr<DataBuffer> buffer(new DataBuffer(payload, binary));
if (state_ == kOpen && observer_) {
observer_->OnMessage(*buffer.get());
} else {
if (queued_received_data_.byte_count() + payload.size() >
kMaxQueuedReceivedDataBytes) {
LOG(LS_ERROR) << "Queued received data exceeds the max buffer size.";
queued_received_data_.Clear();
if (data_channel_type_ != cricket::DCT_RTP) {
Close();
}
return;
}
queued_received_data_.Push(buffer.release());
}
}
void DataChannel::OnChannelReady(bool writable) {
writable_ = writable;
if (!writable) {
return;
}
SendQueuedControlMessages();
SendQueuedDataMessages();
UpdateState();
}
void DataChannel::DoClose() {
if (state_ == kClosed)
return;
receive_ssrc_set_ = false;
send_ssrc_set_ = false;
SetState(kClosing);
UpdateState();
}
void DataChannel::UpdateState() {
// UpdateState determines what to do from a few state variables. Include
// all conditions required for each state transition here for
// clarity. OnChannelReady(true) will send any queued data and then invoke
// UpdateState().
switch (state_) {
case kConnecting: {
if (send_ssrc_set_ == receive_ssrc_set_) {
if (data_channel_type_ == cricket::DCT_RTP && !connected_to_provider_) {
connected_to_provider_ = provider_->ConnectDataChannel(this);
}
if (connected_to_provider_) {
if (handshake_state_ == kHandshakeShouldSendOpen) {
rtc::Buffer payload;
WriteDataChannelOpenMessage(label_, config_, &payload);
SendControlMessage(payload);
} else if (handshake_state_ == kHandshakeShouldSendAck) {
rtc::Buffer payload;
WriteDataChannelOpenAckMessage(&payload);
SendControlMessage(payload);
}
if (writable_ &&
(handshake_state_ == kHandshakeReady ||
handshake_state_ == kHandshakeWaitingForAck)) {
SetState(kOpen);
// If we have received buffers before the channel got writable.
// Deliver them now.
DeliverQueuedReceivedData();
}
}
}
break;
}
case kOpen: {
break;
}
case kClosing: {
if (queued_send_data_.Empty() && queued_control_data_.Empty()) {
if (connected_to_provider_) {
DisconnectFromProvider();
}
if (!connected_to_provider_ && !send_ssrc_set_ && !receive_ssrc_set_) {
SetState(kClosed);
}
}
break;
}
case kClosed:
break;
}
}
void DataChannel::SetState(DataState state) {
if (state_ == state)
return;
state_ = state;
if (observer_) {
observer_->OnStateChange();
}
}
void DataChannel::DisconnectFromProvider() {
if (!connected_to_provider_)
return;
provider_->DisconnectDataChannel(this);
connected_to_provider_ = false;
if (data_channel_type_ == cricket::DCT_SCTP && config_.id >= 0) {
provider_->RemoveSctpDataStream(config_.id);
}
}
void DataChannel::DeliverQueuedReceivedData() {
if (!observer_) {
return;
}
while (!queued_received_data_.Empty()) {
rtc::scoped_ptr<DataBuffer> buffer(queued_received_data_.Front());
observer_->OnMessage(*buffer);
queued_received_data_.Pop();
}
}
void DataChannel::SendQueuedDataMessages() {
if (queued_send_data_.Empty()) {
return;
}
ASSERT(state_ == kOpen || state_ == kClosing);
uint64 start_buffered_amount = buffered_amount();
while (!queued_send_data_.Empty()) {
DataBuffer* buffer = queued_send_data_.Front();
if (!SendDataMessage(*buffer, false)) {
// Leave the message in the queue if sending is aborted.
break;
}
queued_send_data_.Pop();
delete buffer;
}
if (observer_ && buffered_amount() < start_buffered_amount) {
observer_->OnBufferedAmountChange(start_buffered_amount);
}
}
bool DataChannel::SendDataMessage(const DataBuffer& buffer,
bool queue_if_blocked) {
cricket::SendDataParams send_params;
if (data_channel_type_ == cricket::DCT_SCTP) {
send_params.ordered = config_.ordered;
// Send as ordered if it is still going through OPEN/ACK signaling.
if (handshake_state_ != kHandshakeReady && !config_.ordered) {
send_params.ordered = true;
LOG(LS_VERBOSE) << "Sending data as ordered for unordered DataChannel "
<< "because the OPEN_ACK message has not been received.";
}
send_params.max_rtx_count = config_.maxRetransmits;
send_params.max_rtx_ms = config_.maxRetransmitTime;
send_params.ssrc = config_.id;
} else {
send_params.ssrc = send_ssrc_;
}
send_params.type = buffer.binary ? cricket::DMT_BINARY : cricket::DMT_TEXT;
cricket::SendDataResult send_result = cricket::SDR_SUCCESS;
bool success = provider_->SendData(send_params, buffer.data, &send_result);
if (success) {
return true;
}
if (data_channel_type_ != cricket::DCT_SCTP) {
return false;
}
if (send_result == cricket::SDR_BLOCK) {
if (!queue_if_blocked || QueueSendDataMessage(buffer)) {
return false;
}
}
// Close the channel if the error is not SDR_BLOCK, or if queuing the
// message failed.
LOG(LS_ERROR) << "Closing the DataChannel due to a failure to send data, "
<< "send_result = " << send_result;
Close();
return false;
}
bool DataChannel::QueueSendDataMessage(const DataBuffer& buffer) {
size_t start_buffered_amount = buffered_amount();
if (start_buffered_amount >= kMaxQueuedSendDataBytes) {
LOG(LS_ERROR) << "Can't buffer any more data for the data channel.";
return false;
}
queued_send_data_.Push(new DataBuffer(buffer));
// The buffer can have length zero, in which case there is no change.
if (observer_ && buffered_amount() > start_buffered_amount) {
observer_->OnBufferedAmountChange(start_buffered_amount);
}
return true;
}
void DataChannel::SendQueuedControlMessages() {
PacketQueue control_packets;
control_packets.Swap(&queued_control_data_);
while (!control_packets.Empty()) {
rtc::scoped_ptr<DataBuffer> buf(control_packets.Front());
SendControlMessage(buf->data);
control_packets.Pop();
}
}
void DataChannel::QueueControlMessage(const rtc::Buffer& buffer) {
queued_control_data_.Push(new DataBuffer(buffer, true));
}
bool DataChannel::SendControlMessage(const rtc::Buffer& buffer) {
bool is_open_message = handshake_state_ == kHandshakeShouldSendOpen;
ASSERT(data_channel_type_ == cricket::DCT_SCTP &&
writable_ &&
config_.id >= 0 &&
(!is_open_message || !config_.negotiated));
cricket::SendDataParams send_params;
send_params.ssrc = config_.id;
// Send data as ordered before we receive any message from the remote peer to
// make sure the remote peer will not receive any data before it receives the
// OPEN message.
send_params.ordered = config_.ordered || is_open_message;
send_params.type = cricket::DMT_CONTROL;
cricket::SendDataResult send_result = cricket::SDR_SUCCESS;
bool retval = provider_->SendData(send_params, buffer, &send_result);
if (retval) {
LOG(LS_INFO) << "Sent CONTROL message on channel " << config_.id;
if (handshake_state_ == kHandshakeShouldSendAck) {
handshake_state_ = kHandshakeReady;
} else if (handshake_state_ == kHandshakeShouldSendOpen) {
handshake_state_ = kHandshakeWaitingForAck;
}
} else if (send_result == cricket::SDR_BLOCK) {
QueueControlMessage(buffer);
} else {
LOG(LS_ERROR) << "Closing the DataChannel due to a failure to send"
<< " the CONTROL message, send_result = " << send_result;
Close();
}
return retval;
}
} // namespace webrtc