content/browser/renderer_host/p2p/socket_host_tcp.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/renderer_host/p2p/socket_host_tcp.h"
   6
   7 #include "base/location.h"
   8 #include "base/single_thread_task_runner.h"
   9 #include "base/sys_byteorder.h"
  10 #include "content/common/p2p_messages.h"
  11 #include "ipc/ipc_sender.h"
  12 #include "jingle/glue/fake_ssl_client_socket.h"
  13 #include "jingle/glue/proxy_resolving_client_socket.h"
  14 #include "net/base/io_buffer.h"
  15 #include "net/base/net_errors.h"
  16 #include "net/base/net_util.h"
  17 #include "net/socket/client_socket_factory.h"
  18 #include "net/socket/client_socket_handle.h"
  19 #include "net/socket/ssl_client_socket.h"
  20 #include "net/socket/tcp_client_socket.h"
  21 #include "net/url_request/url_request_context.h"
  22 #include "net/url_request/url_request_context_getter.h"
  23 #include "third_party/webrtc/base/asyncpacketsocket.h"
  24
  25 namespace {
  26
  27 typedef uint16 PacketLength;
  28 const int kPacketHeaderSize = sizeof(PacketLength);
  29 const int kReadBufferSize = 4096;
  30 const int kPacketLengthOffset = 2;
  31 const int kTurnChannelDataHeaderSize = 4;
  32 const int kRecvSocketBufferSize = 128 * 1024;
  33 const int kSendSocketBufferSize = 128 * 1024;
  34
  35 bool IsTlsClientSocket(content::P2PSocketType type) {
  36   return (type == content::P2P_SOCKET_STUN_TLS_CLIENT ||
  37           type == content::P2P_SOCKET_TLS_CLIENT);
  38 }
  39
  40 bool IsPseudoTlsClientSocket(content::P2PSocketType type) {
  41   return (type == content::P2P_SOCKET_SSLTCP_CLIENT ||
  42           type == content::P2P_SOCKET_STUN_SSLTCP_CLIENT);
  43 }
  44
  45 }  // namespace
  46
  47 namespace content {
  48
  49 P2PSocketHostTcpBase::P2PSocketHostTcpBase(
  50     IPC::Sender* message_sender,
  51     int socket_id,
  52     P2PSocketType type,
  53     net::URLRequestContextGetter* url_context)
  54     : P2PSocketHost(message_sender, socket_id, P2PSocketHost::TCP),
  55       write_pending_(false),
  56       connected_(false),
  57       type_(type),
  58       url_context_(url_context) {
  59 }
  60
  61 P2PSocketHostTcpBase::~P2PSocketHostTcpBase() {
  62   if (state_ == STATE_OPEN) {
  63     DCHECK(socket_.get());
  64     socket_.reset();
  65   }
  66 }
  67
  68 bool P2PSocketHostTcpBase::InitAccepted(const net::IPEndPoint& remote_address,
  69                                         net::StreamSocket* socket) {
  70   DCHECK(socket);
  71   DCHECK_EQ(state_, STATE_UNINITIALIZED);
  72
  73   remote_address_.ip_address = remote_address;
  74   // TODO(ronghuawu): Add FakeSSLServerSocket.
  75   socket_.reset(socket);
  76   state_ = STATE_OPEN;
  77   DoRead();
  78   return state_ != STATE_ERROR;
  79 }
  80
  81 bool P2PSocketHostTcpBase::Init(const net::IPEndPoint& local_address,
  82                                 const P2PHostAndIPEndPoint& remote_address) {
  83   DCHECK_EQ(state_, STATE_UNINITIALIZED);
  84
  85   remote_address_ = remote_address;
  86   state_ = STATE_CONNECTING;
  87
  88   net::HostPortPair dest_host_port_pair;
  89   // If there is a domain name, let's try it first, it's required by some proxy
  90   // to only take hostname for CONNECT. If it has been DNS resolved, the result
  91   // is likely cached and shouldn't cause 2nd DNS resolution in the case of
  92   // direct connect (i.e. no proxy).
  93   if (!remote_address.hostname.empty()) {
  94     dest_host_port_pair = net::HostPortPair(remote_address.hostname,
  95                                             remote_address.ip_address.port());
  96   } else {
  97     DCHECK(!remote_address.ip_address.address().empty());
  98     dest_host_port_pair = net::HostPortPair::FromIPEndPoint(
  99         remote_address.ip_address);
 100   }
 101
 102   // TODO(mallinath) - We are ignoring local_address altogether. We should
 103   // find a way to inject this into ProxyResolvingClientSocket. This could be
 104   // a problem on multi-homed host.
 105
 106   // The default SSLConfig is good enough for us for now.
 107   const net::SSLConfig ssl_config;
 108   socket_.reset(new jingle_glue::ProxyResolvingClientSocket(
 109                     NULL,     // Default socket pool provided by the net::Proxy.
 110                     url_context_,
 111                     ssl_config,
 112                     dest_host_port_pair));
 113
 114   int status = socket_->Connect(
 115       base::Bind(&P2PSocketHostTcpBase::OnConnected,
 116                  base::Unretained(this)));
 117   if (status != net::ERR_IO_PENDING) {
 118     // We defer execution of ProcessConnectDone instead of calling it
 119     // directly here as the caller may not expect an error/close to
 120     // happen here.  This is okay, as from the caller's point of view,
 121     // the connect always happens asynchronously.
 122     base::MessageLoop* message_loop = base::MessageLoop::current();
 123     CHECK(message_loop);
 124     message_loop->task_runner()->PostTask(
 125         FROM_HERE, base::Bind(&P2PSocketHostTcpBase::OnConnected,
 126                               base::Unretained(this), status));
 127   }
 128
 129   return state_ != STATE_ERROR;
 130 }
 131
 132 void P2PSocketHostTcpBase::OnError() {
 133   socket_.reset();
 134
 135   if (state_ == STATE_UNINITIALIZED || state_ == STATE_CONNECTING ||
 136       state_ == STATE_TLS_CONNECTING || state_ == STATE_OPEN) {
 137     message_sender_->Send(new P2PMsg_OnError(id_));
 138   }
 139
 140   state_ = STATE_ERROR;
 141 }
 142
 143 void P2PSocketHostTcpBase::OnConnected(int result) {
 144   DCHECK_EQ(state_, STATE_CONNECTING);
 145   DCHECK_NE(result, net::ERR_IO_PENDING);
 146
 147   if (result != net::OK) {
 148     LOG(WARNING) << "Error from connecting socket, result=" << result;
 149     OnError();
 150     return;
 151   }
 152
 153   if (IsTlsClientSocket(type_)) {
 154     state_ = STATE_TLS_CONNECTING;
 155     StartTls();
 156   } else if (IsPseudoTlsClientSocket(type_)) {
 157     scoped_ptr<net::StreamSocket> transport_socket = socket_.Pass();
 158     socket_.reset(
 159         new jingle_glue::FakeSSLClientSocket(transport_socket.Pass()));
 160     state_ = STATE_TLS_CONNECTING;
 161     int status = socket_->Connect(
 162         base::Bind(&P2PSocketHostTcpBase::ProcessTlsSslConnectDone,
 163                    base::Unretained(this)));
 164     if (status != net::ERR_IO_PENDING) {
 165       ProcessTlsSslConnectDone(status);
 166     }
 167   } else {
 168     // If we are not doing TLS, we are ready to send data now.
 169     // In case of TLS, SignalConnect will be sent only after TLS handshake is
 170     // successfull. So no buffering will be done at socket handlers if any
 171     // packets sent before that by the application.
 172     OnOpen();
 173   }
 174 }
 175
 176 void P2PSocketHostTcpBase::StartTls() {
 177   DCHECK_EQ(state_, STATE_TLS_CONNECTING);
 178   DCHECK(socket_.get());
 179
 180   scoped_ptr<net::ClientSocketHandle> socket_handle(
 181       new net::ClientSocketHandle());
 182   socket_handle->SetSocket(socket_.Pass());
 183
 184   net::SSLClientSocketContext context;
 185   context.cert_verifier = url_context_->GetURLRequestContext()->cert_verifier();
 186   context.transport_security_state =
 187       url_context_->GetURLRequestContext()->transport_security_state();
 188   DCHECK(context.transport_security_state);
 189
 190   // Default ssl config.
 191   const net::SSLConfig ssl_config;
 192   net::HostPortPair dest_host_port_pair;
 193
 194   // Calling net::HostPortPair::FromIPEndPoint will crash if the IP address is
 195   // empty.
 196   if (!remote_address_.ip_address.address().empty()) {
 197       net::HostPortPair::FromIPEndPoint(remote_address_.ip_address);
 198   } else {
 199     dest_host_port_pair.set_port(remote_address_.ip_address.port());
 200   }
 201   if (!remote_address_.hostname.empty())
 202     dest_host_port_pair.set_host(remote_address_.hostname);
 203
 204   net::ClientSocketFactory* socket_factory =
 205       net::ClientSocketFactory::GetDefaultFactory();
 206   DCHECK(socket_factory);
 207
 208   socket_ = socket_factory->CreateSSLClientSocket(
 209       socket_handle.Pass(), dest_host_port_pair, ssl_config, context);
 210   int status = socket_->Connect(
 211       base::Bind(&P2PSocketHostTcpBase::ProcessTlsSslConnectDone,
 212                  base::Unretained(this)));
 213
 214   if (status != net::ERR_IO_PENDING) {
 215     ProcessTlsSslConnectDone(status);
 216   }
 217 }
 218
 219 void P2PSocketHostTcpBase::ProcessTlsSslConnectDone(int status) {
 220   DCHECK_NE(status, net::ERR_IO_PENDING);
 221   DCHECK_EQ(state_, STATE_TLS_CONNECTING);
 222   if (status != net::OK) {
 223     LOG(WARNING) << "Error from connecting TLS socket, status=" << status;
 224     OnError();
 225     return;
 226   }
 227   OnOpen();
 228 }
 229
 230 void P2PSocketHostTcpBase::OnOpen() {
 231   state_ = STATE_OPEN;
 232   // Setting socket send and receive buffer size.
 233   if (net::OK != socket_->SetReceiveBufferSize(kRecvSocketBufferSize)) {
 234     LOG(WARNING) << "Failed to set socket receive buffer size to "
 235                  << kRecvSocketBufferSize;
 236   }
 237
 238   if (net::OK != socket_->SetSendBufferSize(kSendSocketBufferSize)) {
 239     LOG(WARNING) << "Failed to set socket send buffer size to "
 240                  << kSendSocketBufferSize;
 241   }
 242
 243   if (!DoSendSocketCreateMsg())
 244     return;
 245
 246   DCHECK_EQ(state_, STATE_OPEN);
 247   DoRead();
 248 }
 249
 250 bool P2PSocketHostTcpBase::DoSendSocketCreateMsg() {
 251   DCHECK(socket_.get());
 252
 253   net::IPEndPoint local_address;
 254   int result = socket_->GetLocalAddress(&local_address);
 255   if (result < 0) {
 256     LOG(ERROR) << "P2PSocketHostTcpBase::OnConnected: unable to get local"
 257                << " address: " << result;
 258     OnError();
 259     return false;
 260   }
 261
 262   VLOG(1) << "Local address: " << local_address.ToString();
 263
 264   net::IPEndPoint remote_address;
 265
 266   // GetPeerAddress returns ERR_NAME_NOT_RESOLVED if the socket is connected
 267   // through a proxy.
 268   result = socket_->GetPeerAddress(&remote_address);
 269   if (result < 0 && result != net::ERR_NAME_NOT_RESOLVED) {
 270     LOG(ERROR) << "P2PSocketHostTcpBase::OnConnected: unable to get peer"
 271                << " address: " << result;
 272     OnError();
 273     return false;
 274   }
 275
 276   if (!remote_address.address().empty()) {
 277     VLOG(1) << "Remote address: " << remote_address.ToString();
 278     if (remote_address_.ip_address.address().empty()) {
 279       // Save |remote_address| if address is empty.
 280       remote_address_.ip_address = remote_address;
 281     }
 282   } else {
 283     VLOG(1) << "Remote address is unknown since connection is proxied";
 284   }
 285
 286   // If we are not doing TLS, we are ready to send data now.
 287   // In case of TLS SignalConnect will be sent only after TLS handshake is
 288   // successful. So no buffering will be done at socket handlers if any
 289   // packets sent before that by the application.
 290   message_sender_->Send(new P2PMsg_OnSocketCreated(
 291       id_, local_address, remote_address));
 292   return true;
 293 }
 294
 295 void P2PSocketHostTcpBase::DoRead() {
 296   int result;
 297   do {
 298     if (!read_buffer_.get()) {
 299       read_buffer_ = new net::GrowableIOBuffer();
 300       read_buffer_->SetCapacity(kReadBufferSize);
 301     } else if (read_buffer_->RemainingCapacity() < kReadBufferSize) {
 302       // Make sure that we always have at least kReadBufferSize of
 303       // remaining capacity in the read buffer. Normally all packets
 304       // are smaller than kReadBufferSize, so this is not really
 305       // required.
 306       read_buffer_->SetCapacity(read_buffer_->capacity() + kReadBufferSize -
 307                                 read_buffer_->RemainingCapacity());
 308     }
 309     result = socket_->Read(
 310         read_buffer_.get(),
 311         read_buffer_->RemainingCapacity(),
 312         base::Bind(&P2PSocketHostTcp::OnRead, base::Unretained(this)));
 313     DidCompleteRead(result);
 314   } while (result > 0);
 315 }
 316
 317 void P2PSocketHostTcpBase::OnRead(int result) {
 318   DidCompleteRead(result);
 319   if (state_ == STATE_OPEN) {
 320     DoRead();
 321   }
 322 }
 323
 324 void P2PSocketHostTcpBase::OnPacket(const std::vector<char>& data) {
 325   if (!connected_) {
 326     P2PSocketHost::StunMessageType type;
 327     bool stun = GetStunPacketType(&*data.begin(), data.size(), &type);
 328     if (stun && IsRequestOrResponse(type)) {
 329       connected_ = true;
 330     } else if (!stun || type == STUN_DATA_INDICATION) {
 331       LOG(ERROR) << "Received unexpected data packet from "
 332                  << remote_address_.ip_address.ToString()
 333                  << " before STUN binding is finished. "
 334                  << "Terminating connection.";
 335       OnError();
 336       return;
 337     }
 338   }
 339
 340   message_sender_->Send(new P2PMsg_OnDataReceived(
 341       id_, remote_address_.ip_address, data, base::TimeTicks::Now()));
 342
 343   if (dump_incoming_rtp_packet_)
 344     DumpRtpPacket(&data[0], data.size(), true);
 345 }
 346
 347 // Note: dscp is not actually used on TCP sockets as this point,
 348 // but may be honored in the future.
 349 void P2PSocketHostTcpBase::Send(const net::IPEndPoint& to,
 350                                 const std::vector<char>& data,
 351                                 const rtc::PacketOptions& options,
 352                                 uint64 packet_id) {
 353   if (!socket_) {
 354     // The Send message may be sent after the an OnError message was
 355     // sent by hasn't been processed the renderer.
 356     return;
 357   }
 358
 359   if (!(to == remote_address_.ip_address)) {
 360     // Renderer should use this socket only to send data to |remote_address_|.
 361     NOTREACHED();
 362     OnError();
 363     return;
 364   }
 365
 366   if (!connected_) {
 367     P2PSocketHost::StunMessageType type = P2PSocketHost::StunMessageType();
 368     bool stun = GetStunPacketType(&*data.begin(), data.size(), &type);
 369     if (!stun || type == STUN_DATA_INDICATION) {
 370       LOG(ERROR) << "Page tried to send a data packet to " << to.ToString()
 371                  << " before STUN binding is finished.";
 372       OnError();
 373       return;
 374     }
 375   }
 376
 377   DoSend(to, data, options);
 378 }
 379
 380 void P2PSocketHostTcpBase::WriteOrQueue(
 381     scoped_refptr<net::DrainableIOBuffer>& buffer) {
 382   IncrementTotalSentPackets();
 383   if (write_buffer_.get()) {
 384     write_queue_.push(buffer);
 385     IncrementDelayedPackets();
 386     IncrementDelayedBytes(buffer->size());
 387     return;
 388   }
 389
 390   write_buffer_ = buffer;
 391   DoWrite();
 392 }
 393
 394 void P2PSocketHostTcpBase::DoWrite() {
 395   while (write_buffer_.get() && state_ == STATE_OPEN && !write_pending_) {
 396     int result = socket_->Write(
 397         write_buffer_.get(),
 398         write_buffer_->BytesRemaining(),
 399         base::Bind(&P2PSocketHostTcp::OnWritten, base::Unretained(this)));
 400     HandleWriteResult(result);
 401   }
 402 }
 403
 404 void P2PSocketHostTcpBase::OnWritten(int result) {
 405   DCHECK(write_pending_);
 406   DCHECK_NE(result, net::ERR_IO_PENDING);
 407
 408   write_pending_ = false;
 409   HandleWriteResult(result);
 410   DoWrite();
 411 }
 412
 413 void P2PSocketHostTcpBase::HandleWriteResult(int result) {
 414   DCHECK(write_buffer_.get());
 415   if (result >= 0) {
 416     write_buffer_->DidConsume(result);
 417     if (write_buffer_->BytesRemaining() == 0) {
 418       message_sender_->Send(
 419           new P2PMsg_OnSendComplete(id_, P2PSendPacketMetrics()));
 420       if (write_queue_.empty()) {
 421         write_buffer_ = NULL;
 422       } else {
 423         write_buffer_ = write_queue_.front();
 424         write_queue_.pop();
 425         // Update how many bytes are still waiting to be sent.
 426         DecrementDelayedBytes(write_buffer_->size());
 427       }
 428     }
 429   } else if (result == net::ERR_IO_PENDING) {
 430     write_pending_ = true;
 431   } else {
 432     LOG(ERROR) << "Error when sending data in TCP socket: " << result;
 433     OnError();
 434   }
 435 }
 436
 437 P2PSocketHost* P2PSocketHostTcpBase::AcceptIncomingTcpConnection(
 438     const net::IPEndPoint& remote_address, int id) {
 439   NOTREACHED();
 440   OnError();
 441   return NULL;
 442 }
 443
 444 void P2PSocketHostTcpBase::DidCompleteRead(int result) {
 445   DCHECK_EQ(state_, STATE_OPEN);
 446
 447   if (result == net::ERR_IO_PENDING) {
 448     return;
 449   } else if (result < 0) {
 450     LOG(ERROR) << "Error when reading from TCP socket: " << result;
 451     OnError();
 452     return;
 453   } else if (result == 0) {
 454     LOG(WARNING) << "Remote peer has shutdown TCP socket.";
 455     OnError();
 456     return;
 457   }
 458
 459   read_buffer_->set_offset(read_buffer_->offset() + result);
 460   char* head = read_buffer_->StartOfBuffer();  // Purely a convenience.
 461   int pos = 0;
 462   while (pos <= read_buffer_->offset() && state_ == STATE_OPEN) {
 463     int consumed = ProcessInput(head + pos, read_buffer_->offset() - pos);
 464     if (!consumed)
 465       break;
 466     pos += consumed;
 467   }
 468   // We've consumed all complete packets from the buffer; now move any remaining
 469   // bytes to the head of the buffer and set offset to reflect this.
 470   if (pos && pos <= read_buffer_->offset()) {
 471     memmove(head, head + pos, read_buffer_->offset() - pos);
 472     read_buffer_->set_offset(read_buffer_->offset() - pos);
 473   }
 474 }
 475
 476 bool P2PSocketHostTcpBase::SetOption(P2PSocketOption option, int value) {
 477   DCHECK_EQ(STATE_OPEN, state_);
 478   switch (option) {
 479     case P2P_SOCKET_OPT_RCVBUF:
 480       return socket_->SetReceiveBufferSize(value) == net::OK;
 481     case P2P_SOCKET_OPT_SNDBUF:
 482       return socket_->SetSendBufferSize(value) == net::OK;
 483     case P2P_SOCKET_OPT_DSCP:
 484       return false;  // For TCP sockets DSCP setting is not available.
 485     default:
 486       NOTREACHED();
 487       return false;
 488   }
 489 }
 490
 491 P2PSocketHostTcp::P2PSocketHostTcp(IPC::Sender* message_sender,
 492                                    int socket_id,
 493                                    P2PSocketType type,
 494                                    net::URLRequestContextGetter* url_context)
 495     : P2PSocketHostTcpBase(message_sender, socket_id, type, url_context) {
 496   DCHECK(type == P2P_SOCKET_TCP_CLIENT ||
 497          type == P2P_SOCKET_SSLTCP_CLIENT ||
 498          type == P2P_SOCKET_TLS_CLIENT);
 499 }
 500
 501 P2PSocketHostTcp::~P2PSocketHostTcp() {
 502 }
 503
 504 int P2PSocketHostTcp::ProcessInput(char* input, int input_len) {
 505   if (input_len < kPacketHeaderSize)
 506     return 0;
 507   int packet_size = base::NetToHost16(*reinterpret_cast<uint16*>(input));
 508   if (input_len < packet_size + kPacketHeaderSize)
 509     return 0;
 510
 511   int consumed = kPacketHeaderSize;
 512   char* cur = input + consumed;
 513   std::vector<char> data(cur, cur + packet_size);
 514   OnPacket(data);
 515   consumed += packet_size;
 516   return consumed;
 517 }
 518
 519 void P2PSocketHostTcp::DoSend(const net::IPEndPoint& to,
 520                               const std::vector<char>& data,
 521                               const rtc::PacketOptions& options) {
 522   int size = kPacketHeaderSize + data.size();
 523   scoped_refptr<net::DrainableIOBuffer> buffer =
 524       new net::DrainableIOBuffer(new net::IOBuffer(size), size);
 525   *reinterpret_cast<uint16*>(buffer->data()) = base::HostToNet16(data.size());
 526   memcpy(buffer->data() + kPacketHeaderSize, &data[0], data.size());
 527
 528   packet_processing_helpers::ApplyPacketOptions(
 529       buffer->data() + kPacketHeaderSize,
 530       buffer->BytesRemaining() - kPacketHeaderSize,
 531       options, 0);
 532
 533   WriteOrQueue(buffer);
 534 }
 535
 536 // P2PSocketHostStunTcp
 537 P2PSocketHostStunTcp::P2PSocketHostStunTcp(
 538     IPC::Sender* message_sender,
 539     int socket_id,
 540     P2PSocketType type,
 541     net::URLRequestContextGetter* url_context)
 542     : P2PSocketHostTcpBase(message_sender, socket_id, type, url_context) {
 543   DCHECK(type == P2P_SOCKET_STUN_TCP_CLIENT ||
 544          type == P2P_SOCKET_STUN_SSLTCP_CLIENT ||
 545          type == P2P_SOCKET_STUN_TLS_CLIENT);
 546 }
 547
 548 P2PSocketHostStunTcp::~P2PSocketHostStunTcp() {
 549 }
 550
 551 int P2PSocketHostStunTcp::ProcessInput(char* input, int input_len) {
 552   if (input_len < kPacketHeaderSize + kPacketLengthOffset)
 553     return 0;
 554
 555   int pad_bytes;
 556   int packet_size = GetExpectedPacketSize(
 557       input, input_len, &pad_bytes);
 558
 559   if (input_len < packet_size + pad_bytes)
 560     return 0;
 561
 562   // We have a complete packet. Read through it.
 563   int consumed = 0;
 564   char* cur = input;
 565   std::vector<char> data(cur, cur + packet_size);
 566   OnPacket(data);
 567   consumed += packet_size;
 568   consumed += pad_bytes;
 569   return consumed;
 570 }
 571
 572 void P2PSocketHostStunTcp::DoSend(const net::IPEndPoint& to,
 573                                   const std::vector<char>& data,
 574                                   const rtc::PacketOptions& options) {
 575   // Each packet is expected to have header (STUN/TURN ChannelData), where
 576   // header contains message type and and length of message.
 577   if (data.size() < kPacketHeaderSize + kPacketLengthOffset) {
 578     NOTREACHED();
 579     OnError();
 580     return;
 581   }
 582
 583   int pad_bytes;
 584   size_t expected_len = GetExpectedPacketSize(
 585       &data[0], data.size(), &pad_bytes);
 586
 587   // Accepts only complete STUN/TURN packets.
 588   if (data.size() != expected_len) {
 589     NOTREACHED();
 590     OnError();
 591     return;
 592   }
 593
 594   // Add any pad bytes to the total size.
 595   int size = data.size() + pad_bytes;
 596
 597   scoped_refptr<net::DrainableIOBuffer> buffer =
 598       new net::DrainableIOBuffer(new net::IOBuffer(size), size);
 599   memcpy(buffer->data(), &data[0], data.size());
 600
 601   packet_processing_helpers::ApplyPacketOptions(
 602       buffer->data(), data.size(), options, 0);
 603
 604   if (pad_bytes) {
 605     char padding[4] = {0};
 606     DCHECK_LE(pad_bytes, 4);
 607     memcpy(buffer->data() + data.size(), padding, pad_bytes);
 608   }
 609   WriteOrQueue(buffer);
 610
 611   if (dump_outgoing_rtp_packet_)
 612     DumpRtpPacket(buffer->data(), data.size(), false);
 613 }
 614
 615 int P2PSocketHostStunTcp::GetExpectedPacketSize(
 616     const char* data, int len, int* pad_bytes) {
 617   DCHECK_LE(kTurnChannelDataHeaderSize, len);
 618   // Both stun and turn had length at offset 2.
 619   int packet_size = base::NetToHost16(*reinterpret_cast<const uint16*>(
 620       data + kPacketLengthOffset));
 621
 622   // Get packet type (STUN or TURN).
 623   uint16 msg_type = base::NetToHost16(*reinterpret_cast<const uint16*>(data));
 624
 625   *pad_bytes = 0;
 626   // Add heder length to packet length.
 627   if ((msg_type & 0xC000) == 0) {
 628     packet_size += kStunHeaderSize;
 629   } else {
 630     packet_size += kTurnChannelDataHeaderSize;
 631     // Calculate any padding if present.
 632     if (packet_size % 4)
 633       *pad_bytes = 4 - packet_size % 4;
 634   }
 635   return packet_size;
 636 }
 637
 638 }  // namespace content