| /* | 
 |  *  Copyright 2004 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. | 
 |  */ | 
 |  | 
 | /* | 
 |  *  This is a diagram of how TCP reconnect works for the active side. The | 
 |  *  passive side just waits for an incoming connection. | 
 |  * | 
 |  *  - Connected: Indicate whether the TCP socket is connected. | 
 |  * | 
 |  *  - Writable: Whether the stun binding is completed. Sending a data packet | 
 |  *    before stun binding completed will trigger IPC socket layer to shutdown | 
 |  *    the connection. | 
 |  * | 
 |  *  - PendingTCP: |connection_pending_| indicates whether there is an | 
 |  *    outstanding TCP connection in progress. | 
 |  * | 
 |  *  - PretendWri: Tracked by |pretending_to_be_writable_|. Marking connection as | 
 |  *    WRITE_TIMEOUT will cause the connection be deleted. Instead, we're | 
 |  *    "pretending" we're still writable for a period of time such that reconnect | 
 |  *    could work. | 
 |  * | 
 |  *  Data could only be sent in state 3. Sening data during state 2 & 6 will get | 
 |  *  EWOULDBLOCK, 4 & 5 EPIPE. | 
 |  * | 
 |  *         OS Timeout         7 -------------+ | 
 |  *   +----------------------->|Connected: N  | | 
 |  *   |                        |Writable:  N  |     Timeout | 
 |  *   |       Timeout          |Connection is |<----------------+ | 
 |  *   |   +------------------->|Dead          |                 | | 
 |  *   |   |                    +--------------+                 | | 
 |  *   |   |                               ^                     | | 
 |  *   |   |            OnClose            |                     | | 
 |  *   |   |    +-----------------------+  |                     | | 
 |  *   |   |    |                       |  |Timeout              | | 
 |  *   |   |    v                       |  |                     | | 
 |  *   | 4 +----------+          5 -----+--+--+           6 -----+-----+ | 
 |  *   | |Connected: N|Send() or |Connected: N|           |Connected: Y| | 
 |  *   | |Writable:  Y|Ping()    |Writable:  Y|OnConnect  |Writable:  Y| | 
 |  *   | |PendingTCP:N+--------> |PendingTCP:Y+---------> |PendingTCP:N| | 
 |  *   | |PretendWri:Y|          |PretendWri:Y|           |PretendWri:Y| | 
 |  *   | +-----+------+          +------------+           +---+--+-----+ | 
 |  *   |   ^   ^                                              |  | | 
 |  *   |   |   |                     OnClose                  |  | | 
 |  *   |   |   +----------------------------------------------+  | | 
 |  *   |   |                                                     | | 
 |  *   |   |                              Stun Binding Completed | | 
 |  *   |   |                                                     | | 
 |  *   |   |                    OnClose                          | | 
 |  *   |   +------------------------------------------------+    | | 
 |  *   |                                                    |    v | 
 |  *  1 -----------+           2 -----------+Stun      3 -----------+ | 
 |  *  |Connected: N|           |Connected: Y|Binding   |Connected: Y| | 
 |  *  |Writable:  N|OnConnect  |Writable:  N|Completed |Writable:  Y| | 
 |  *  |PendingTCP:Y+---------> |PendingTCP:N+--------> |PendingTCP:N| | 
 |  *  |PretendWri:N|           |PretendWri:N|          |PretendWri:N| | 
 |  *  +------------+           +------------+          +------------+ | 
 |  * | 
 |  */ | 
 |  | 
 | #include "webrtc/p2p/base/tcpport.h" | 
 |  | 
 | #include "webrtc/p2p/base/common.h" | 
 | #include "webrtc/base/common.h" | 
 | #include "webrtc/base/logging.h" | 
 |  | 
 | namespace cricket { | 
 |  | 
 | TCPPort::TCPPort(rtc::Thread* thread, | 
 |                  rtc::PacketSocketFactory* factory, | 
 |                  rtc::Network* network, | 
 |                  const rtc::IPAddress& ip, | 
 |                  uint16_t min_port, | 
 |                  uint16_t max_port, | 
 |                  const std::string& username, | 
 |                  const std::string& password, | 
 |                  bool allow_listen) | 
 |     : Port(thread, | 
 |            LOCAL_PORT_TYPE, | 
 |            factory, | 
 |            network, | 
 |            ip, | 
 |            min_port, | 
 |            max_port, | 
 |            username, | 
 |            password), | 
 |       incoming_only_(false), | 
 |       allow_listen_(allow_listen), | 
 |       socket_(NULL), | 
 |       error_(0) { | 
 |   // TODO(mallinath) - Set preference value as per RFC 6544. | 
 |   // http://b/issue?id=7141794 | 
 | } | 
 |  | 
 | bool TCPPort::Init() { | 
 |   if (allow_listen_) { | 
 |     // Treat failure to create or bind a TCP socket as fatal.  This | 
 |     // should never happen. | 
 |     socket_ = socket_factory()->CreateServerTcpSocket( | 
 |         rtc::SocketAddress(ip(), 0), min_port(), max_port(), | 
 |         false /* ssl */); | 
 |     if (!socket_) { | 
 |       LOG_J(LS_ERROR, this) << "TCP socket creation failed."; | 
 |       return false; | 
 |     } | 
 |     socket_->SignalNewConnection.connect(this, &TCPPort::OnNewConnection); | 
 |     socket_->SignalAddressReady.connect(this, &TCPPort::OnAddressReady); | 
 |   } | 
 |   return true; | 
 | } | 
 |  | 
 | TCPPort::~TCPPort() { | 
 |   delete socket_; | 
 |   std::list<Incoming>::iterator it; | 
 |   for (it = incoming_.begin(); it != incoming_.end(); ++it) | 
 |     delete it->socket; | 
 |   incoming_.clear(); | 
 | } | 
 |  | 
 | Connection* TCPPort::CreateConnection(const Candidate& address, | 
 |                                       CandidateOrigin origin) { | 
 |   if (!SupportsProtocol(address.protocol())) { | 
 |     return NULL; | 
 |   } | 
 |  | 
 |   if (address.tcptype() == TCPTYPE_ACTIVE_STR || | 
 |       (address.tcptype().empty() && address.address().port() == 0)) { | 
 |     // It's active only candidate, we should not try to create connections | 
 |     // for these candidates. | 
 |     return NULL; | 
 |   } | 
 |  | 
 |   // We can't accept TCP connections incoming on other ports | 
 |   if (origin == ORIGIN_OTHER_PORT) | 
 |     return NULL; | 
 |  | 
 |   // Check if we are allowed to make outgoing TCP connections | 
 |   if (incoming_only_ && (origin == ORIGIN_MESSAGE)) | 
 |     return NULL; | 
 |  | 
 |   // We don't know how to act as an ssl server yet | 
 |   if ((address.protocol() == SSLTCP_PROTOCOL_NAME) && | 
 |       (origin == ORIGIN_THIS_PORT)) { | 
 |     return NULL; | 
 |   } | 
 |  | 
 |   if (!IsCompatibleAddress(address.address())) { | 
 |     return NULL; | 
 |   } | 
 |  | 
 |   TCPConnection* conn = NULL; | 
 |   if (rtc::AsyncPacketSocket* socket = | 
 |       GetIncoming(address.address(), true)) { | 
 |     socket->SignalReadPacket.disconnect(this); | 
 |     conn = new TCPConnection(this, address, socket); | 
 |   } else { | 
 |     conn = new TCPConnection(this, address); | 
 |   } | 
 |   AddConnection(conn); | 
 |   return conn; | 
 | } | 
 |  | 
 | void TCPPort::PrepareAddress() { | 
 |   if (socket_) { | 
 |     // If socket isn't bound yet the address will be added in | 
 |     // OnAddressReady(). Socket may be in the CLOSED state if Listen() | 
 |     // failed, we still want to add the socket address. | 
 |     LOG(LS_VERBOSE) << "Preparing TCP address, current state: " | 
 |                     << socket_->GetState(); | 
 |     if (socket_->GetState() == rtc::AsyncPacketSocket::STATE_BOUND || | 
 |         socket_->GetState() == rtc::AsyncPacketSocket::STATE_CLOSED) | 
 |       AddAddress(socket_->GetLocalAddress(), socket_->GetLocalAddress(), | 
 |                  rtc::SocketAddress(), TCP_PROTOCOL_NAME, "", | 
 |                  TCPTYPE_PASSIVE_STR, LOCAL_PORT_TYPE, | 
 |                  ICE_TYPE_PREFERENCE_HOST_TCP, 0, true); | 
 |   } else { | 
 |     LOG_J(LS_INFO, this) << "Not listening due to firewall restrictions."; | 
 |     // Note: We still add the address, since otherwise the remote side won't | 
 |     // recognize our incoming TCP connections. According to | 
 |     // https://tools.ietf.org/html/rfc6544#section-4.5, for active candidate, | 
 |     // the port must be set to the discard port, i.e. 9. | 
 |     AddAddress(rtc::SocketAddress(ip(), DISCARD_PORT), | 
 |                rtc::SocketAddress(ip(), 0), rtc::SocketAddress(), | 
 |                TCP_PROTOCOL_NAME, "", TCPTYPE_ACTIVE_STR, LOCAL_PORT_TYPE, | 
 |                ICE_TYPE_PREFERENCE_HOST_TCP, 0, true); | 
 |   } | 
 | } | 
 |  | 
 | int TCPPort::SendTo(const void* data, size_t size, | 
 |                     const rtc::SocketAddress& addr, | 
 |                     const rtc::PacketOptions& options, | 
 |                     bool payload) { | 
 |   rtc::AsyncPacketSocket * socket = NULL; | 
 |   TCPConnection* conn = static_cast<TCPConnection*>(GetConnection(addr)); | 
 |  | 
 |   // For Connection, this is the code path used by Ping() to establish | 
 |   // WRITABLE. It has to send through the socket directly as TCPConnection::Send | 
 |   // checks writability. | 
 |   if (conn) { | 
 |     if (!conn->connected()) { | 
 |       conn->MaybeReconnect(); | 
 |       return SOCKET_ERROR; | 
 |     } | 
 |     socket = conn->socket(); | 
 |   } else { | 
 |     socket = GetIncoming(addr); | 
 |   } | 
 |   if (!socket) { | 
 |     LOG_J(LS_ERROR, this) << "Attempted to send to an unknown destination, " | 
 |                           << addr.ToSensitiveString(); | 
 |     return SOCKET_ERROR;  // TODO(tbd): Set error_ | 
 |   } | 
 |  | 
 |   int sent = socket->Send(data, size, options); | 
 |   if (sent < 0) { | 
 |     error_ = socket->GetError(); | 
 |     // Error from this code path for a Connection (instead of from a bare | 
 |     // socket) will not trigger reconnecting. In theory, this shouldn't matter | 
 |     // as OnClose should always be called and set connected to false. | 
 |     LOG_J(LS_ERROR, this) << "TCP send of " << size | 
 |                           << " bytes failed with error " << error_; | 
 |   } | 
 |   return sent; | 
 | } | 
 |  | 
 | int TCPPort::GetOption(rtc::Socket::Option opt, int* value) { | 
 |   if (socket_) { | 
 |     return socket_->GetOption(opt, value); | 
 |   } else { | 
 |     return SOCKET_ERROR; | 
 |   } | 
 | } | 
 |  | 
 | int TCPPort::SetOption(rtc::Socket::Option opt, int value) { | 
 |   if (socket_) { | 
 |     return socket_->SetOption(opt, value); | 
 |   } else { | 
 |     return SOCKET_ERROR; | 
 |   } | 
 | } | 
 |  | 
 | int TCPPort::GetError() { | 
 |   return error_; | 
 | } | 
 |  | 
 | void TCPPort::OnNewConnection(rtc::AsyncPacketSocket* socket, | 
 |                               rtc::AsyncPacketSocket* new_socket) { | 
 |   ASSERT(socket == socket_); | 
 |  | 
 |   Incoming incoming; | 
 |   incoming.addr = new_socket->GetRemoteAddress(); | 
 |   incoming.socket = new_socket; | 
 |   incoming.socket->SignalReadPacket.connect(this, &TCPPort::OnReadPacket); | 
 |   incoming.socket->SignalReadyToSend.connect(this, &TCPPort::OnReadyToSend); | 
 |   incoming.socket->SignalSentPacket.connect(this, &TCPPort::OnSentPacket); | 
 |  | 
 |   LOG_J(LS_VERBOSE, this) << "Accepted connection from " | 
 |                           << incoming.addr.ToSensitiveString(); | 
 |   incoming_.push_back(incoming); | 
 | } | 
 |  | 
 | rtc::AsyncPacketSocket* TCPPort::GetIncoming( | 
 |     const rtc::SocketAddress& addr, bool remove) { | 
 |   rtc::AsyncPacketSocket* socket = NULL; | 
 |   for (std::list<Incoming>::iterator it = incoming_.begin(); | 
 |        it != incoming_.end(); ++it) { | 
 |     if (it->addr == addr) { | 
 |       socket = it->socket; | 
 |       if (remove) | 
 |         incoming_.erase(it); | 
 |       break; | 
 |     } | 
 |   } | 
 |   return socket; | 
 | } | 
 |  | 
 | void TCPPort::OnReadPacket(rtc::AsyncPacketSocket* socket, | 
 |                            const char* data, size_t size, | 
 |                            const rtc::SocketAddress& remote_addr, | 
 |                            const rtc::PacketTime& packet_time) { | 
 |   Port::OnReadPacket(data, size, remote_addr, PROTO_TCP); | 
 | } | 
 |  | 
 | void TCPPort::OnSentPacket(rtc::AsyncPacketSocket* socket, | 
 |                            const rtc::SentPacket& sent_packet) { | 
 |   PortInterface::SignalSentPacket(sent_packet); | 
 | } | 
 |  | 
 | void TCPPort::OnReadyToSend(rtc::AsyncPacketSocket* socket) { | 
 |   Port::OnReadyToSend(); | 
 | } | 
 |  | 
 | void TCPPort::OnAddressReady(rtc::AsyncPacketSocket* socket, | 
 |                              const rtc::SocketAddress& address) { | 
 |   AddAddress(address, address, rtc::SocketAddress(), TCP_PROTOCOL_NAME, "", | 
 |              TCPTYPE_PASSIVE_STR, LOCAL_PORT_TYPE, ICE_TYPE_PREFERENCE_HOST_TCP, | 
 |              0, true); | 
 | } | 
 |  | 
 | TCPConnection::TCPConnection(TCPPort* port, | 
 |                              const Candidate& candidate, | 
 |                              rtc::AsyncPacketSocket* socket) | 
 |     : Connection(port, 0, candidate), | 
 |       socket_(socket), | 
 |       error_(0), | 
 |       outgoing_(socket == NULL), | 
 |       connection_pending_(false), | 
 |       pretending_to_be_writable_(false), | 
 |       reconnection_timeout_(cricket::CONNECTION_WRITE_CONNECT_TIMEOUT) { | 
 |   if (outgoing_) { | 
 |     CreateOutgoingTcpSocket(); | 
 |   } else { | 
 |     // Incoming connections should match the network address. | 
 |     LOG_J(LS_VERBOSE, this) | 
 |         << "socket ipaddr: " << socket_->GetLocalAddress().ToString() | 
 |         << ",port() ip:" << port->ip().ToString(); | 
 |     ASSERT(socket_->GetLocalAddress().ipaddr() == port->ip()); | 
 |     ConnectSocketSignals(socket); | 
 |   } | 
 | } | 
 |  | 
 | TCPConnection::~TCPConnection() { | 
 | } | 
 |  | 
 | int TCPConnection::Send(const void* data, size_t size, | 
 |                         const rtc::PacketOptions& options) { | 
 |   if (!socket_) { | 
 |     error_ = ENOTCONN; | 
 |     return SOCKET_ERROR; | 
 |   } | 
 |  | 
 |   // Sending after OnClose on active side will trigger a reconnect for a | 
 |   // outgoing connection. Note that the write state is still WRITABLE as we want | 
 |   // to spend a few seconds attempting a reconnect before saying we're | 
 |   // unwritable. | 
 |   if (!connected()) { | 
 |     MaybeReconnect(); | 
 |     return SOCKET_ERROR; | 
 |   } | 
 |  | 
 |   // Note that this is important to put this after the previous check to give | 
 |   // the connection a chance to reconnect. | 
 |   if (pretending_to_be_writable_ || write_state() != STATE_WRITABLE) { | 
 |     // TODO: Should STATE_WRITE_TIMEOUT return a non-blocking error? | 
 |     error_ = EWOULDBLOCK; | 
 |     return SOCKET_ERROR; | 
 |   } | 
 |   sent_packets_total_++; | 
 |   int sent = socket_->Send(data, size, options); | 
 |   if (sent < 0) { | 
 |     sent_packets_discarded_++; | 
 |     error_ = socket_->GetError(); | 
 |   } else { | 
 |     send_rate_tracker_.AddSamples(sent); | 
 |   } | 
 |   return sent; | 
 | } | 
 |  | 
 | int TCPConnection::GetError() { | 
 |   return error_; | 
 | } | 
 |  | 
 | void TCPConnection::OnConnectionRequestResponse(ConnectionRequest* req, | 
 |                                                 StunMessage* response) { | 
 |   // Process the STUN response before we inform upper layer ready to send. | 
 |   Connection::OnConnectionRequestResponse(req, response); | 
 |  | 
 |   // If we're in the state of pretending to be writeable, we should inform the | 
 |   // upper layer it's ready to send again as previous EWOULDLBLOCK from socket | 
 |   // would have stopped the outgoing stream. | 
 |   if (pretending_to_be_writable_) { | 
 |     Connection::OnReadyToSend(); | 
 |   } | 
 |   pretending_to_be_writable_ = false; | 
 |   ASSERT(write_state() == STATE_WRITABLE); | 
 | } | 
 |  | 
 | void TCPConnection::OnConnect(rtc::AsyncPacketSocket* socket) { | 
 |   ASSERT(socket == socket_.get()); | 
 |   // Do not use this connection if the socket bound to a different address than | 
 |   // the one we asked for. This is seen in Chrome, where TCP sockets cannot be | 
 |   // given a binding address, and the platform is expected to pick the | 
 |   // correct local address. | 
 |   const rtc::SocketAddress& socket_addr = socket->GetLocalAddress(); | 
 |   if (socket_addr.ipaddr() == port()->ip()) { | 
 |     LOG_J(LS_VERBOSE, this) << "Connection established to " | 
 |                             << socket->GetRemoteAddress().ToSensitiveString(); | 
 |   } else if (IPIsAny(port()->ip())) { | 
 |     LOG(LS_WARNING) << "Socket is bound to a different address:" | 
 |                     << socket_addr.ipaddr().ToString() | 
 |                     << ", rather then the local port:" | 
 |                     << port()->ip().ToString() | 
 |                     << ". Still allowing it since it's any address" | 
 |                     << ", possibly caused by multi-routes being disabled."; | 
 |   } else if (socket_addr.IsLoopbackIP()) { | 
 |     LOG(LS_WARNING) << "Socket is bound to a different address:" | 
 |                     << socket_addr.ipaddr().ToString() | 
 |                     << ", rather then the local port:" | 
 |                     << port()->ip().ToString() | 
 |                     << ". Still allowing it since it's localhost."; | 
 |   } else { | 
 |     LOG_J(LS_WARNING, this) << "Dropping connection as TCP socket bound to IP " | 
 |                             << socket_addr.ipaddr().ToSensitiveString() | 
 |                             << ", different from the local candidate IP " | 
 |                             << port()->ip().ToSensitiveString(); | 
 |     OnClose(socket, 0); | 
 |     return; | 
 |   } | 
 |  | 
 |   // Connection is established successfully. | 
 |   set_connected(true); | 
 |   connection_pending_ = false; | 
 | } | 
 |  | 
 | void TCPConnection::OnClose(rtc::AsyncPacketSocket* socket, int error) { | 
 |   ASSERT(socket == socket_.get()); | 
 |   LOG_J(LS_INFO, this) << "Connection closed with error " << error; | 
 |  | 
 |   // Guard against the condition where IPC socket will call OnClose for every | 
 |   // packet it can't send. | 
 |   if (connected()) { | 
 |     set_connected(false); | 
 |  | 
 |     // Prevent the connection from being destroyed by redundant SignalClose | 
 |     // events. | 
 |     pretending_to_be_writable_ = true; | 
 |  | 
 |     // We don't attempt reconnect right here. This is to avoid a case where the | 
 |     // shutdown is intentional and reconnect is not necessary. We only reconnect | 
 |     // when the connection is used to Send() or Ping(). | 
 |     port()->thread()->PostDelayed(reconnection_timeout(), this, | 
 |                                   MSG_TCPCONNECTION_DELAYED_ONCLOSE); | 
 |   } else if (!pretending_to_be_writable_) { | 
 |     // OnClose could be called when the underneath socket times out during the | 
 |     // initial connect() (i.e. |pretending_to_be_writable_| is false) . We have | 
 |     // to manually destroy here as this connection, as never connected, will not | 
 |     // be scheduled for ping to trigger destroy. | 
 |     Destroy(); | 
 |   } | 
 | } | 
 |  | 
 | void TCPConnection::OnMessage(rtc::Message* pmsg) { | 
 |   switch (pmsg->message_id) { | 
 |     case MSG_TCPCONNECTION_DELAYED_ONCLOSE: | 
 |       // If this connection can't become connected and writable again in 5 | 
 |       // seconds, it's time to tear this down. This is the case for the original | 
 |       // TCP connection on passive side during a reconnect. | 
 |       if (pretending_to_be_writable_) { | 
 |         Destroy(); | 
 |       } | 
 |       break; | 
 |     default: | 
 |       Connection::OnMessage(pmsg); | 
 |   } | 
 | } | 
 |  | 
 | void TCPConnection::MaybeReconnect() { | 
 |   // Only reconnect for an outgoing TCPConnection when OnClose was signaled and | 
 |   // no outstanding reconnect is pending. | 
 |   if (connected() || connection_pending_ || !outgoing_) { | 
 |     return; | 
 |   } | 
 |  | 
 |   LOG_J(LS_INFO, this) << "TCP Connection with remote is closed, " | 
 |                        << "trying to reconnect"; | 
 |  | 
 |   CreateOutgoingTcpSocket(); | 
 |   error_ = EPIPE; | 
 | } | 
 |  | 
 | void TCPConnection::OnReadPacket( | 
 |   rtc::AsyncPacketSocket* socket, const char* data, size_t size, | 
 |   const rtc::SocketAddress& remote_addr, | 
 |   const rtc::PacketTime& packet_time) { | 
 |   ASSERT(socket == socket_.get()); | 
 |   Connection::OnReadPacket(data, size, packet_time); | 
 | } | 
 |  | 
 | void TCPConnection::OnReadyToSend(rtc::AsyncPacketSocket* socket) { | 
 |   ASSERT(socket == socket_.get()); | 
 |   Connection::OnReadyToSend(); | 
 | } | 
 |  | 
 | void TCPConnection::CreateOutgoingTcpSocket() { | 
 |   ASSERT(outgoing_); | 
 |   // TODO(guoweis): Handle failures here (unlikely since TCP). | 
 |   int opts = (remote_candidate().protocol() == SSLTCP_PROTOCOL_NAME) | 
 |                  ? rtc::PacketSocketFactory::OPT_SSLTCP | 
 |                  : 0; | 
 |   socket_.reset(port()->socket_factory()->CreateClientTcpSocket( | 
 |       rtc::SocketAddress(port()->ip(), 0), remote_candidate().address(), | 
 |       port()->proxy(), port()->user_agent(), opts)); | 
 |   if (socket_) { | 
 |     LOG_J(LS_VERBOSE, this) | 
 |         << "Connecting from " << socket_->GetLocalAddress().ToSensitiveString() | 
 |         << " to " << remote_candidate().address().ToSensitiveString(); | 
 |     set_connected(false); | 
 |     connection_pending_ = true; | 
 |     ConnectSocketSignals(socket_.get()); | 
 |   } else { | 
 |     LOG_J(LS_WARNING, this) << "Failed to create connection to " | 
 |                             << remote_candidate().address().ToSensitiveString(); | 
 |   } | 
 | } | 
 |  | 
 | void TCPConnection::ConnectSocketSignals(rtc::AsyncPacketSocket* socket) { | 
 |   if (outgoing_) { | 
 |     socket->SignalConnect.connect(this, &TCPConnection::OnConnect); | 
 |   } | 
 |   socket->SignalReadPacket.connect(this, &TCPConnection::OnReadPacket); | 
 |   socket->SignalReadyToSend.connect(this, &TCPConnection::OnReadyToSend); | 
 |   socket->SignalClose.connect(this, &TCPConnection::OnClose); | 
 | } | 
 |  | 
 | }  // namespace cricket |