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     read_pending_ = false;
 195
 196     FOR_EACH_OBSERVER(Listener, listeners_,
 197                       OnSignalStrategyStateChange(DISCONNECTED));
 198   }
 199 }
 200
 201 SignalStrategy::State XmppSignalStrategy::Core::GetState() const {
 202   DCHECK(thread_checker_.CalledOnValidThread());
 203
 204   if (stream_parser_) {
 205     DCHECK(socket_);
 206     return CONNECTED;
 207   } else if (socket_) {
 208     return CONNECTING;
 209   } else {
 210     return DISCONNECTED;
 211   }
 212 }
 213
 214 SignalStrategy::Error XmppSignalStrategy::Core::GetError() const {
 215   DCHECK(thread_checker_.CalledOnValidThread());
 216   return error_;
 217 }
 218
 219 std::string XmppSignalStrategy::Core::GetLocalJid() const {
 220   DCHECK(thread_checker_.CalledOnValidThread());
 221   return jid_;
 222 }
 223
 224 void XmppSignalStrategy::Core::AddListener(Listener* listener) {
 225   DCHECK(thread_checker_.CalledOnValidThread());
 226   listeners_.AddObserver(listener);
 227 }
 228
 229 void XmppSignalStrategy::Core::RemoveListener(Listener* listener) {
 230   DCHECK(thread_checker_.CalledOnValidThread());
 231   listeners_.RemoveObserver(listener);
 232 }
 233
 234 bool XmppSignalStrategy::Core::SendStanza(scoped_ptr<buzz::XmlElement> stanza) {
 235   DCHECK(thread_checker_.CalledOnValidThread());
 236
 237   if (!stream_parser_) {
 238     VLOG(0) << "Dropping signalling message because XMPP is not connected.";
 239     return false;
 240   }
 241
 242   SendMessage(stanza->Str());
 243
 244   // Return false if the SendMessage() call above resulted in the SignalStrategy
 245   // being disconnected.
 246   return stream_parser_ != nullptr;
 247 }
 248
 249 void XmppSignalStrategy::Core::SetAuthInfo(const std::string& username,
 250                                            const std::string& auth_token) {
 251   DCHECK(thread_checker_.CalledOnValidThread());
 252   xmpp_server_config_.username = username;
 253   xmpp_server_config_.auth_token = auth_token;
 254 }
 255
 256 void XmppSignalStrategy::Core::SendMessage(const std::string& message) {
 257   DCHECK(thread_checker_.CalledOnValidThread());
 258   DCHECK(tls_state_ == TlsState::NOT_REQUESTED ||
 259          tls_state_ == TlsState::CONNECTED);
 260
 261   scoped_refptr<net::IOBufferWithSize> buffer =
 262       new net::IOBufferWithSize(message.size());
 263   memcpy(buffer->data(), message.data(), message.size());
 264   writer_->Write(buffer,
 265                  base::Bind(&Core::OnMessageSent, base::Unretained(this)));
 266 }
 267
 268 void XmppSignalStrategy::Core::StartTls() {
 269   DCHECK(thread_checker_.CalledOnValidThread());
 270   DCHECK(login_handler_);
 271   DCHECK(tls_state_ == TlsState::NOT_REQUESTED ||
 272          tls_state_ == TlsState::WAITING_FOR_FLUSH);
 273
 274   if (writer_->has_data_pending()) {
 275     tls_state_ = TlsState::WAITING_FOR_FLUSH;
 276     return;
 277   }
 278
 279   tls_state_ = TlsState::CONNECTING;
 280
 281   // Reset the writer so we don't try to write to the raw socket anymore.
 282   writer_.reset();
 283
 284   DCHECK(!read_pending_);
 285
 286   scoped_ptr<net::ClientSocketHandle> socket_handle(
 287       new net::ClientSocketHandle());
 288   socket_handle->SetSocket(socket_.Pass());
 289
 290   cert_verifier_ = net::CertVerifier::CreateDefault();
 291   transport_security_state_.reset(new net::TransportSecurityState());
 292   net::SSLClientSocketContext context;
 293   context.cert_verifier = cert_verifier_.get();
 294   context.transport_security_state = transport_security_state_.get();
 295
 296   socket_ = socket_factory_->CreateSSLClientSocket(
 297       socket_handle.Pass(),
 298       net::HostPortPair(xmpp_server_config_.host, kDefaultHttpsPort),
 299       net::SSLConfig(), context);
 300
 301   int result = socket_->Connect(
 302       base::Bind(&Core::OnTlsConnected, base::Unretained(this)));
 303   if (result != net::ERR_IO_PENDING)
 304     OnTlsConnected(result);
 305 }
 306
 307 void XmppSignalStrategy::Core::OnHandshakeDone(
 308     const std::string& jid,
 309     scoped_ptr<XmppStreamParser> parser) {
 310   DCHECK(thread_checker_.CalledOnValidThread());
 311
 312   jid_ = jid;
 313   stream_parser_ = parser.Pass();
 314   stream_parser_->SetCallbacks(
 315       base::Bind(&Core::OnStanza, base::Unretained(this)),
 316       base::Bind(&Core::OnParserError, base::Unretained(this)));
 317
 318   // Don't need |login_handler_| anymore.
 319   login_handler_.reset();
 320
 321   FOR_EACH_OBSERVER(Listener, listeners_,
 322                     OnSignalStrategyStateChange(CONNECTED));
 323 }
 324
 325 void XmppSignalStrategy::Core::OnLoginHandlerError(
 326     SignalStrategy::Error error) {
 327   DCHECK(thread_checker_.CalledOnValidThread());
 328
 329   error_ = error;
 330   Disconnect();
 331 }
 332
 333 void XmppSignalStrategy::Core::OnMessageSent() {
 334   DCHECK(thread_checker_.CalledOnValidThread());
 335
 336   if (tls_state_ == TlsState::WAITING_FOR_FLUSH &&
 337       !writer_->has_data_pending()) {
 338     StartTls();
 339   }
 340 }
 341
 342 void XmppSignalStrategy::Core::OnStanza(
 343     const scoped_ptr<buzz::XmlElement> stanza) {
 344   DCHECK(thread_checker_.CalledOnValidThread());
 345
 346   base::ObserverListBase<Listener>::Iterator it(&listeners_);
 347   for (Listener* listener = it.GetNext(); listener; listener = it.GetNext()) {
 348     if (listener->OnSignalStrategyIncomingStanza(stanza.get()))
 349       return;
 350   }
 351 }
 352
 353 void XmppSignalStrategy::Core::OnParserError() {
 354   DCHECK(thread_checker_.CalledOnValidThread());
 355
 356   error_ = NETWORK_ERROR;
 357   Disconnect();
 358 }
 359
 360 void XmppSignalStrategy::Core::OnSocketConnected(int result) {
 361   DCHECK(thread_checker_.CalledOnValidThread());
 362
 363   if (result != net::OK) {
 364     OnNetworkError(result);
 365     return;
 366   }
 367
 368   writer_ = BufferedSocketWriter::CreateForSocket(
 369       socket_.get(), base::Bind(&Core::OnNetworkError, base::Unretained(this)));
 370
 371   XmppLoginHandler::TlsMode tls_mode;
 372   if (xmpp_server_config_.use_tls) {
 373     tls_mode = (xmpp_server_config_.port == kDefaultXmppPort)
 374                    ? XmppLoginHandler::TlsMode::WITH_HANDSHAKE
 375                    : XmppLoginHandler::TlsMode::WITHOUT_HANDSHAKE;
 376   } else {
 377     tls_mode = XmppLoginHandler::TlsMode::NO_TLS;
 378   }
 379
 380   // The server name is passed as to attribute in the <stream>. When connecting
 381   // to talk.google.com it affects the certificate the server will use for TLS:
 382   // talk.google.com uses gmail certificate when specified server is gmail.com
 383   // or googlemail.com and google.com cert otherwise. In the same time it
 384   // doesn't accept talk.google.com as target server. Here we use google.com
 385   // server name when authenticating to talk.google.com. This ensures that the
 386   // server will use google.com cert which will be accepted by the TLS
 387   // implementation in Chrome (TLS API doesn't allow specifying domain other
 388   // than the one that was passed to connect()).
 389   std::string server = xmpp_server_config_.host;
 390   if (server == "talk.google.com")
 391     server = "google.com";
 392
 393   login_handler_.reset(
 394       new XmppLoginHandler(server, xmpp_server_config_.username,
 395                            xmpp_server_config_.auth_token, tls_mode, this));
 396   login_handler_->Start();
 397
 398   ReadSocket();
 399 }
 400
 401 void XmppSignalStrategy::Core::OnTlsConnected(int result) {
 402   DCHECK(thread_checker_.CalledOnValidThread());
 403   DCHECK(tls_state_ == TlsState::CONNECTING);
 404   tls_state_ = TlsState::CONNECTED;
 405
 406   if (result != net::OK) {
 407     OnNetworkError(result);
 408     return;
 409   }
 410
 411   writer_ = BufferedSocketWriter::CreateForSocket(
 412       socket_.get(), base::Bind(&Core::OnNetworkError, base::Unretained(this)));
 413
 414   login_handler_->OnTlsStarted();
 415
 416   ReadSocket();
 417 }
 418
 419 void XmppSignalStrategy::Core::ReadSocket() {
 420   DCHECK(thread_checker_.CalledOnValidThread());
 421
 422   while (socket_ && !read_pending_ && (tls_state_ == TlsState::NOT_REQUESTED ||
 423                                        tls_state_ == TlsState::CONNECTED)) {
 424     read_buffer_ = new net::IOBuffer(kReadBufferSize);
 425     int result = socket_->Read(
 426         read_buffer_.get(), kReadBufferSize,
 427         base::Bind(&Core::OnReadResult, base::Unretained(this)));
 428     HandleReadResult(result);
 429   }
 430 }
 431
 432 void XmppSignalStrategy::Core::OnReadResult(int result) {
 433   DCHECK(thread_checker_.CalledOnValidThread());
 434   DCHECK(read_pending_);
 435   read_pending_ = false;
 436   HandleReadResult(result);
 437   ReadSocket();
 438 }
 439
 440 void XmppSignalStrategy::Core::HandleReadResult(int result) {
 441   DCHECK(thread_checker_.CalledOnValidThread());
 442
 443   if (result == net::ERR_IO_PENDING) {
 444     read_pending_ = true;
 445     return;
 446   }
 447
 448   if (result < 0) {
 449     OnNetworkError(result);
 450     return;
 451   }
 452
 453   if (result == 0) {
 454     // Connection was closed by the server.
 455     error_ = OK;
 456     Disconnect();
 457     return;
 458   }
 459
 460   if (stream_parser_) {
 461     stream_parser_->AppendData(std::string(read_buffer_->data(), result));
 462   } else {
 463     login_handler_->OnDataReceived(std::string(read_buffer_->data(), result));
 464   }
 465 }
 466
 467 void XmppSignalStrategy::Core::OnNetworkError(int error) {
 468   DCHECK(thread_checker_.CalledOnValidThread());
 469
 470   LOG(ERROR) << "XMPP socket error " << error;
 471   error_ = NETWORK_ERROR;
 472   Disconnect();
 473 }
 474
 475 void XmppSignalStrategy::Core::SendKeepAlive() {
 476   DCHECK(thread_checker_.CalledOnValidThread());
 477
 478   if (GetState() == CONNECTED)
 479     SendMessage(" ");
 480 }
 481
 482 XmppSignalStrategy::XmppSignalStrategy(
 483     net::ClientSocketFactory* socket_factory,
 484     const scoped_refptr<net::URLRequestContextGetter>& request_context_getter,
 485     const XmppServerConfig& xmpp_server_config)
 486     : core_(new Core(socket_factory,
 487                      request_context_getter,
 488                      xmpp_server_config)) {
 489 }
 490
 491 XmppSignalStrategy::~XmppSignalStrategy() {
 492   // All listeners should be removed at this point, so it's safe to detach
 493   // |core_|.
 494   base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, core_.release());
 495 }
 496
 497 void XmppSignalStrategy::Connect() {
 498   core_->Connect();
 499 }
 500
 501 void XmppSignalStrategy::Disconnect() {
 502   core_->Disconnect();
 503 }
 504
 505 SignalStrategy::State XmppSignalStrategy::GetState() const {
 506   return core_->GetState();
 507 }
 508
 509 SignalStrategy::Error XmppSignalStrategy::GetError() const {
 510   return core_->GetError();
 511 }
 512
 513 std::string XmppSignalStrategy::GetLocalJid() const {
 514   return core_->GetLocalJid();
 515 }
 516
 517 void XmppSignalStrategy::AddListener(Listener* listener) {
 518   core_->AddListener(listener);
 519 }
 520
 521 void XmppSignalStrategy::RemoveListener(Listener* listener) {
 522   core_->RemoveListener(listener);
 523 }
 524 bool XmppSignalStrategy::SendStanza(scoped_ptr<buzz::XmlElement> stanza) {
 525   return core_->SendStanza(stanza.Pass());
 526 }
 527
 528 std::string XmppSignalStrategy::GetNextId() {
 529   return base::Uint64ToString(base::RandUint64());
 530 }
 531
 532 void XmppSignalStrategy::SetAuthInfo(const std::string& username,
 533                                      const std::string& auth_token) {
 534   core_->SetAuthInfo(username, auth_token);
 535 }
 536
 537 }  // namespace remoting