/*
* 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);
}
AddOrReplaceConnection(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;
}
stats_.sent_total_packets++;
int sent = socket_->Send(data, size, options);
if (sent < 0) {
stats_.sent_discarded_packets++;
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(RTC_FROM_HERE, 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