remoting/signaling/xmpp_signal_strategy.cc

   1 // Copyright 2014 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 "remoting/signaling/xmpp_signal_strategy.h"
   6
   7 #include <vector>
   8
   9 #include "base/bind.h"
  10 #include "base/location.h"
  11 #include "base/logging.h"
  12 #include "base/observer_list.h"
  13 #include "base/rand_util.h"
  14 #include "base/single_thread_task_runner.h"
  15 #include "base/strings/string_number_conversions.h"
  16 #include "base/thread_task_runner_handle.h"
  17 #include "base/threading/thread_checker.h"
  18 #include "base/time/time.h"
  19 #include "base/timer/timer.h"
  20 #include "jingle/glue/proxy_resolving_client_socket.h"
  21 #include "net/cert/cert_verifier.h"
  22 #include "net/http/transport_security_state.h"
  23 #include "net/socket/client_socket_factory.h"
  24 #include "net/socket/client_socket_handle.h"
  25 #include "net/socket/ssl_client_socket.h"
  26 #include "net/url_request/url_request_context_getter.h"
  27 #include "remoting/base/buffered_socket_writer.h"
  28 #include "remoting/signaling/xmpp_login_handler.h"
  29 #include "remoting/signaling/xmpp_stream_parser.h"
  30 #include "third_party/webrtc/libjingle/xmllite/xmlelement.h"
  31
  32 // Use 50 seconds keep-alive interval, in case routers terminate
  33 // connections that are idle for more than a minute.
  34 const int kKeepAliveIntervalSeconds = 50;
  35
  36 const int kReadBufferSize = 4096;
  37
  38 const int kDefaultXmppPort = 5222;
  39 const int kDefaultHttpsPort = 443;
  40
  41 namespace remoting {
  42
  43 XmppSignalStrategy::XmppServerConfig::XmppServerConfig()
  44     : port(kDefaultXmppPort), use_tls(true) {
  45 }
  46
  47 XmppSignalStrategy::XmppServerConfig::~XmppServerConfig() {
  48 }
  49
  50 class XmppSignalStrategy::Core : public XmppLoginHandler::Delegate {
  51  public:
  52   Core(
  53       net::ClientSocketFactory* socket_factory,
  54       const scoped_refptr<net::URLRequestContextGetter>& request_context_getter,
  55       const XmppServerConfig& xmpp_server_config);
  56   ~Core() override;
  57
  58   void Connect();
  59   void Disconnect();
  60   State GetState() const;
  61   Error GetError() const;
  62   std::string GetLocalJid() const;
  63   void AddListener(Listener* listener);
  64   void RemoveListener(Listener* listener);
  65   bool SendStanza(scoped_ptr<buzz::XmlElement> stanza);
  66
  67   void SetAuthInfo(const std::string& username,
  68                    const std::string& auth_token);
  69
  70  private:
  71   enum class TlsState {
  72     // StartTls() hasn't been called. |socket_| is not encrypted.
  73     NOT_REQUESTED,
  74
  75     // StartTls() has been called. Waiting for |writer_| to finish writing
  76     // data before starting TLS.
  77     WAITING_FOR_FLUSH,
  78
  79     // TLS has been started, waiting for TLS handshake to finish.
  80     CONNECTING,
  81
  82     // TLS is connected.
  83     CONNECTED,
  84   };
  85
  86   void OnSocketConnected(int result);
  87   void OnTlsConnected(int result);
  88
  89   void ReadSocket();
  90   void OnReadResult(int result);
  91   void HandleReadResult(int result);
  92
  93   // XmppLoginHandler::Delegate interface.
  94   void SendMessage(const std::string& message) override;
  95   void StartTls() override;
  96   void OnHandshakeDone(const std::string& jid,
  97                        scoped_ptr<XmppStreamParser> parser) override;
  98   void OnLoginHandlerError(SignalStrategy::Error error) override;
  99
 100   // Callback for BufferedSocketWriter.
 101   void OnMessageSent();
 102
 103   // Event handlers for XmppStreamParser.
 104   void OnStanza(const scoped_ptr<buzz::XmlElement> stanza);
 105   void OnParserError();
 106
 107   void OnNetworkError(int error);
 108
 109   void SendKeepAlive();
 110
 111   net::ClientSocketFactory* socket_factory_;
 112   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
 113   XmppServerConfig xmpp_server_config_;
 114
 115   // Used by the |socket_|.
 116   scoped_ptr<net::CertVerifier> cert_verifier_;
 117   scoped_ptr<net::TransportSecurityState> transport_security_state_;
 118
 119   scoped_ptr<net::StreamSocket> socket_;
 120   scoped_ptr<BufferedSocketWriter> writer_;
 121   int pending_writes_ = 0;
 122   scoped_refptr<net::IOBuffer> read_buffer_;
 123   bool read_pending_ = false;
 124
 125   TlsState tls_state_ = TlsState::NOT_REQUESTED;
 126
 127   scoped_ptr<XmppLoginHandler> login_handler_;
 128   scoped_ptr<XmppStreamParser> stream_parser_;
 129   std::string jid_;
 130
 131   Error error_ = OK;
 132
 133   base::ObserverList<Listener, true> listeners_;
 134
 135   base::Timer keep_alive_timer_;
 136
 137   base::ThreadChecker thread_checker_;
 138
 139   DISALLOW_COPY_AND_ASSIGN(Core);
 140 };
 141
 142 XmppSignalStrategy::Core::Core(
 143     net::ClientSocketFactory* socket_factory,
 144     const scoped_refptr<net::URLRequestContextGetter>& request_context_getter,
 145     const XmppSignalStrategy::XmppServerConfig& xmpp_server_config)
 146     : socket_factory_(socket_factory),
 147       request_context_getter_(request_context_getter),
 148       xmpp_server_config_(xmpp_server_config),
 149       keep_alive_timer_(
 150           FROM_HERE,
 151           base::TimeDelta::FromSeconds(kKeepAliveIntervalSeconds),
 152           base::Bind(&Core::SendKeepAlive, base::Unretained(this)),
 153           true) {
 154 #if defined(NDEBUG)
 155   // Non-secure connections are allowed only for debugging.
 156   CHECK(xmpp_server_config_.use_tls);
 157 #endif
 158 }
 159
 160 XmppSignalStrategy::Core::~Core() {
 161   Disconnect();
 162 }
 163
 164 void XmppSignalStrategy::Core::Connect() {
 165   DCHECK(thread_checker_.CalledOnValidThread());
 166
 167   // Disconnect first if we are currently connected.
 168   Disconnect();
 169
 170   error_ = OK;
 171
 172   FOR_EACH_OBSERVER(Listener, listeners_,
 173                     OnSignalStrategyStateChange(CONNECTING));
 174
 175   socket_.reset(new jingle_glue::ProxyResolvingClientSocket(
 176       socket_factory_, request_context_getter_, net::SSLConfig(),
 177       net::HostPortPair(xmpp_server_config_.host, xmpp_server_config_.port)));
 178
 179   int result = socket_->Connect(base::Bind(
 180       &Core::OnSocketConnected, base::Unretained(this)));
 181   if (result != net::ERR_IO_PENDING)
 182     OnSocketConnected(result);
 183 }
 184
 185 void XmppSignalStrategy::Core::Disconnect() {
 186   DCHECK(thread_checker_.CalledOnValidThread());
 187
 188   if (socket_) {
 189     login_handler_.reset();
 190     stream_parser_.reset();
 191     writer_.reset();
 192     socket_.reset();
 193     tls_state_ = TlsState::NOT_REQUESTED;
 194
 195     FOR_EACH_OBSERVER(Listener, listeners_,
 196                       OnSignalStrategyStateChange(DISCONNECTED));
 197   }
 198 }
 199
 200 SignalStrategy::State XmppSignalStrategy::Core::GetState() const {
 201   DCHECK(thread_checker_.CalledOnValidThread());
 202
 203   if (stream_parser_) {
 204     DCHECK(socket_);
 205     return CONNECTED;
 206   } else if (socket_) {
 207     return CONNECTING;
 208   } else {
 209     return DISCONNECTED;
 210   }
 211 }
 212
 213 SignalStrategy::Error XmppSignalStrategy::Core::GetError() const {
 214   DCHECK(thread_checker_.CalledOnValidThread());
 215   return error_;
 216 }
 217
 218 std::string XmppSignalStrategy::Core::GetLocalJid() const {
 219   DCHECK(thread_checker_.CalledOnValidThread());
 220   return jid_;
 221 }
 222
 223 void XmppSignalStrategy::Core::AddListener(Listener* listener) {
 224   DCHECK(thread_checker_.CalledOnValidThread());
 225   listeners_.AddObserver(listener);
 226 }
 227
 228 void XmppSignalStrategy::Core::RemoveListener(Listener* listener) {
 229   DCHECK(thread_checker_.CalledOnValidThread());
 230   listeners_.RemoveObserver(listener);
 231 }
 232
 233 bool XmppSignalStrategy::Core::SendStanza(scoped_ptr<buzz::XmlElement> stanza) {
 234   DCHECK(thread_checker_.CalledOnValidThread());
 235
 236   if (!stream_parser_) {
 237     VLOG(0) << "Dropping signalling message because XMPP "
 238                "connection has been terminated.";
 239     return false;
 240   }
 241
 242   SendMessage(stanza->Str());
 243   return true;
 244 }
 245
 246 void XmppSignalStrategy::Core::SetAuthInfo(const std::string& username,
 247                                            const std::string& auth_token) {
 248   DCHECK(thread_checker_.CalledOnValidThread());
 249   xmpp_server_config_.username = username;
 250   xmpp_server_config_.auth_token = auth_token;
 251 }
 252
 253 void XmppSignalStrategy::Core::SendMessage(const std::string& message) {
 254   DCHECK(thread_checker_.CalledOnValidThread());
 255   DCHECK(tls_state_ == TlsState::NOT_REQUESTED ||
 256          tls_state_ == TlsState::CONNECTED);
 257
 258   scoped_refptr<net::IOBufferWithSize> buffer =
 259       new net::IOBufferWithSize(message.size());
 260   memcpy(buffer->data(), message.data(), message.size());
 261   writer_->Write(buffer,
 262                  base::Bind(&Core::OnMessageSent, base::Unretained(this)));
 263 }
 264
 265 void XmppSignalStrategy::Core::StartTls() {
 266   DCHECK(thread_checker_.CalledOnValidThread());
 267   DCHECK(login_handler_);
 268   DCHECK(tls_state_ == TlsState::NOT_REQUESTED ||
 269          tls_state_ == TlsState::WAITING_FOR_FLUSH);
 270
 271   if (writer_->has_data_pending()) {
 272     tls_state_ = TlsState::WAITING_FOR_FLUSH;
 273     return;
 274   }
 275
 276   tls_state_ = TlsState::CONNECTING;
 277
 278   // Reset the writer so we don't try to write to the raw socket anymore.
 279   writer_.reset();
 280
 281   DCHECK(!read_pending_);
 282
 283   scoped_ptr<net::ClientSocketHandle> socket_handle(
 284       new net::ClientSocketHandle());
 285   socket_handle->SetSocket(socket_.Pass());
 286
 287   cert_verifier_.reset(net::CertVerifier::CreateDefault());
 288   transport_security_state_.reset(new net::TransportSecurityState());
 289   net::SSLClientSocketContext context;
 290   context.cert_verifier = cert_verifier_.get();
 291   context.transport_security_state = transport_security_state_.get();
 292
 293   socket_ = socket_factory_->CreateSSLClientSocket(
 294       socket_handle.Pass(),
 295       net::HostPortPair(xmpp_server_config_.host, kDefaultHttpsPort),
 296       net::SSLConfig(), context);
 297
 298   int result = socket_->Connect(
 299       base::Bind(&Core::OnTlsConnected, base::Unretained(this)));
 300   if (result != net::ERR_IO_PENDING)
 301     OnTlsConnected(result);
 302 }
 303
 304 void XmppSignalStrategy::Core::OnHandshakeDone(
 305     const std::string& jid,
 306     scoped_ptr<XmppStreamParser> parser) {
 307   DCHECK(thread_checker_.CalledOnValidThread());
 308
 309   jid_ = jid;
 310   stream_parser_ = parser.Pass();
 311   stream_parser_->SetCallbacks(
 312       base::Bind(&Core::OnStanza, base::Unretained(this)),
 313       base::Bind(&Core::OnParserError, base::Unretained(this)));
 314
 315   // Don't need |login_handler_| anymore.
 316   login_handler_.reset();
 317
 318   FOR_EACH_OBSERVER(Listener, listeners_,
 319                     OnSignalStrategyStateChange(CONNECTED));
 320 }
 321
 322 void XmppSignalStrategy::Core::OnLoginHandlerError(
 323     SignalStrategy::Error error) {
 324   DCHECK(thread_checker_.CalledOnValidThread());
 325
 326   error_ = error;
 327   Disconnect();
 328 }
 329
 330 void XmppSignalStrategy::Core::OnMessageSent() {
 331   DCHECK(thread_checker_.CalledOnValidThread());
 332
 333   if (tls_state_ == TlsState::WAITING_FOR_FLUSH &&
 334       !writer_->has_data_pending()) {
 335     StartTls();
 336   }
 337 }
 338
 339 void XmppSignalStrategy::Core::OnStanza(
 340     const scoped_ptr<buzz::XmlElement> stanza) {
 341   DCHECK(thread_checker_.CalledOnValidThread());
 342
 343   base::ObserverListBase<Listener>::Iterator it(&listeners_);
 344   for (Listener* listener = it.GetNext(); listener; listener = it.GetNext()) {
 345     if (listener->OnSignalStrategyIncomingStanza(stanza.get()))
 346       return;
 347   }
 348 }
 349
 350 void XmppSignalStrategy::Core::OnParserError() {
 351   DCHECK(thread_checker_.CalledOnValidThread());
 352
 353   error_ = NETWORK_ERROR;
 354   Disconnect();
 355 }
 356
 357 void XmppSignalStrategy::Core::OnSocketConnected(int result) {
 358   DCHECK(thread_checker_.CalledOnValidThread());
 359
 360   if (result != net::OK) {
 361     OnNetworkError(result);
 362     return;
 363   }
 364
 365   writer_.reset(new BufferedSocketWriter());
 366   writer_->Init(socket_.get(), base::Bind(&Core::OnNetworkError,
 367                                           base::Unretained(this)));
 368
 369   XmppLoginHandler::TlsMode tls_mode;
 370   if (xmpp_server_config_.use_tls) {
 371     tls_mode = (xmpp_server_config_.port == kDefaultXmppPort)
 372                    ? XmppLoginHandler::TlsMode::WITH_HANDSHAKE
 373                    : XmppLoginHandler::TlsMode::WITHOUT_HANDSHAKE;
 374   } else {
 375     tls_mode = XmppLoginHandler::TlsMode::NO_TLS;
 376   }
 377
 378   // The server name is passed as to attribute in the <stream>. When connecting
 379   // to talk.google.com it affects the certificate the server will use for TLS:
 380   // talk.google.com uses gmail certificate when specified server is gmail.com
 381   // or googlemail.com and google.com cert otherwise. In the same time it
 382   // doesn't accept talk.google.com as target server. Here we use google.com
 383   // server name when authenticating to talk.google.com. This ensures that the
 384   // server will use google.com cert which will be accepted by the TLS
 385   // implementation in Chrome (TLS API doesn't allow specifying domain other
 386   // than the one that was passed to connect()).
 387   std::string server = xmpp_server_config_.host;
 388   if (server == "talk.google.com")
 389     server = "google.com";
 390
 391   login_handler_.reset(
 392       new XmppLoginHandler(server, xmpp_server_config_.username,
 393                            xmpp_server_config_.auth_token, tls_mode, this));
 394   login_handler_->Start();
 395
 396   ReadSocket();
 397 }
 398
 399 void XmppSignalStrategy::Core::OnTlsConnected(int result) {
 400   DCHECK(thread_checker_.CalledOnValidThread());
 401   DCHECK(tls_state_ == TlsState::CONNECTING);
 402   tls_state_ = TlsState::CONNECTED;
 403
 404   if (result != net::OK) {
 405     OnNetworkError(result);
 406     return;
 407   }
 408
 409   writer_.reset(new BufferedSocketWriter());
 410   writer_->Init(socket_.get(), base::Bind(&Core::OnNetworkError,
 411                                           base::Unretained(this)));
 412
 413   login_handler_->OnTlsStarted();
 414
 415   ReadSocket();
 416 }
 417
 418 void XmppSignalStrategy::Core::ReadSocket() {
 419   DCHECK(thread_checker_.CalledOnValidThread());
 420
 421   while (socket_ && !read_pending_ && (tls_state_ == TlsState::NOT_REQUESTED ||
 422                                        tls_state_ == TlsState::CONNECTED)) {
 423     read_buffer_ = new net::IOBuffer(kReadBufferSize);
 424     int result = socket_->Read(
 425         read_buffer_.get(), kReadBufferSize,
 426         base::Bind(&Core::OnReadResult, base::Unretained(this)));
 427     HandleReadResult(result);
 428   }
 429 }
 430
 431 void XmppSignalStrategy::Core::OnReadResult(int result) {
 432   DCHECK(thread_checker_.CalledOnValidThread());
 433   DCHECK(read_pending_);
 434   read_pending_ = false;
 435   HandleReadResult(result);
 436   ReadSocket();
 437 }
 438
 439 void XmppSignalStrategy::Core::HandleReadResult(int result) {
 440   DCHECK(thread_checker_.CalledOnValidThread());
 441
 442   if (result == net::ERR_IO_PENDING) {
 443     read_pending_ = true;
 444     return;
 445   }
 446
 447   if (result < 0) {
 448     OnNetworkError(result);
 449     return;
 450   }
 451
 452   if (result == 0) {
 453     // Connection was closed by the server.
 454     error_ = OK;
 455     Disconnect();
 456     return;
 457   }
 458
 459   if (stream_parser_) {
 460     stream_parser_->AppendData(std::string(read_buffer_->data(), result));
 461   } else {
 462     login_handler_->OnDataReceived(std::string(read_buffer_->data(), result));
 463   }
 464 }
 465
 466 void XmppSignalStrategy::Core::OnNetworkError(int error) {
 467   DCHECK(thread_checker_.CalledOnValidThread());
 468
 469   LOG(ERROR) << "XMPP socket error " << error;
 470   error_ = NETWORK_ERROR;
 471   Disconnect();
 472 }
 473
 474 void XmppSignalStrategy::Core::SendKeepAlive() {
 475   DCHECK(thread_checker_.CalledOnValidThread());
 476
 477   if (GetState() == CONNECTED)
 478     SendMessage(" ");
 479 }
 480
 481 XmppSignalStrategy::XmppSignalStrategy(
 482     net::ClientSocketFactory* socket_factory,
 483     const scoped_refptr<net::URLRequestContextGetter>& request_context_getter,
 484     const XmppServerConfig& xmpp_server_config)
 485     : core_(new Core(socket_factory,
 486                      request_context_getter,
 487                      xmpp_server_config)) {
 488 }
 489
 490 XmppSignalStrategy::~XmppSignalStrategy() {
 491   // All listeners should be removed at this point, so it's safe to detach
 492   // |core_|.
 493   base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, core_.release());
 494 }
 495
 496 void XmppSignalStrategy::Connect() {
 497   core_->Connect();
 498 }
 499
 500 void XmppSignalStrategy::Disconnect() {
 501   core_->Disconnect();
 502 }
 503
 504 SignalStrategy::State XmppSignalStrategy::GetState() const {
 505   return core_->GetState();
 506 }
 507
 508 SignalStrategy::Error XmppSignalStrategy::GetError() const {
 509   return core_->GetError();
 510 }
 511
 512 std::string XmppSignalStrategy::GetLocalJid() const {
 513   return core_->GetLocalJid();
 514 }
 515
 516 void XmppSignalStrategy::AddListener(Listener* listener) {
 517   core_->AddListener(listener);
 518 }
 519
 520 void XmppSignalStrategy::RemoveListener(Listener* listener) {
 521   core_->RemoveListener(listener);
 522 }
 523 bool XmppSignalStrategy::SendStanza(scoped_ptr<buzz::XmlElement> stanza) {
 524   return core_->SendStanza(stanza.Pass());
 525 }
 526
 527 std::string XmppSignalStrategy::GetNextId() {
 528   return base::Uint64ToString(base::RandUint64());
 529 }
 530
 531 void XmppSignalStrategy::SetAuthInfo(const std::string& username,
 532                                      const std::string& auth_token) {
 533   core_->SetAuthInfo(username, auth_token);
 534 }
 535
 536 }  // namespace remoting