net/quic/quic_dispatcher.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 "net/quic/quic_dispatcher.h"
   6
   7 #include <errno.h>
   8
   9 #include "base/debug/stack_trace.h"
  10 #include "base/logging.h"
  11 #include "base/stl_util.h"
  12 #include "net/quic/quic_blocked_writer_interface.h"
  13 #include "net/quic/quic_connection_helper.h"
  14 #include "net/quic/quic_flags.h"
  15 #include "net/quic/quic_time_wait_list_manager.h"
  16 #include "net/quic/quic_utils.h"
  17
  18 namespace net {
  19
  20 using base::StringPiece;
  21 using std::make_pair;
  22 using std::find;
  23
  24 class DeleteSessionsAlarm : public QuicAlarm::Delegate {
  25  public:
  26   explicit DeleteSessionsAlarm(QuicDispatcher* dispatcher)
  27       : dispatcher_(dispatcher) {
  28   }
  29
  30   virtual QuicTime OnAlarm() OVERRIDE {
  31     dispatcher_->DeleteSessions();
  32     return QuicTime::Zero();
  33   }
  34
  35  private:
  36   QuicDispatcher* dispatcher_;
  37 };
  38
  39 class QuicDispatcher::QuicFramerVisitor : public QuicFramerVisitorInterface {
  40  public:
  41   explicit QuicFramerVisitor(QuicDispatcher* dispatcher)
  42       : dispatcher_(dispatcher),
  43         connection_id_(0) {}
  44
  45   // QuicFramerVisitorInterface implementation
  46   virtual void OnPacket() OVERRIDE {}
  47   virtual bool OnUnauthenticatedPublicHeader(
  48       const QuicPacketPublicHeader& header) OVERRIDE {
  49     connection_id_ = header.connection_id;
  50     return dispatcher_->OnUnauthenticatedPublicHeader(header);
  51   }
  52   virtual bool OnUnauthenticatedHeader(
  53       const QuicPacketHeader& header) OVERRIDE {
  54     dispatcher_->OnUnauthenticatedHeader(header);
  55     return false;
  56   }
  57   virtual void OnError(QuicFramer* framer) OVERRIDE {
  58     DVLOG(1) << QuicUtils::ErrorToString(framer->error());
  59   }
  60
  61   virtual bool OnProtocolVersionMismatch(
  62       QuicVersion /*received_version*/) OVERRIDE {
  63     if (dispatcher_->time_wait_list_manager()->IsConnectionIdInTimeWait(
  64             connection_id_)) {
  65       // Keep processing after protocol mismatch - this will be dealt with by
  66       // the TimeWaitListManager.
  67       return true;
  68     } else {
  69       DLOG(DFATAL) << "Version mismatch, connection ID (" << connection_id_
  70                    << ") not in time wait list.";
  71       return false;
  72     }
  73   }
  74
  75   // The following methods should never get called because we always return
  76   // false from OnUnauthenticatedHeader().  As a result, we never process the
  77   // payload of the packet.
  78   virtual void OnPublicResetPacket(
  79       const QuicPublicResetPacket& /*packet*/) OVERRIDE {
  80     DCHECK(false);
  81   }
  82   virtual void OnVersionNegotiationPacket(
  83       const QuicVersionNegotiationPacket& /*packet*/) OVERRIDE {
  84     DCHECK(false);
  85   }
  86   virtual void OnDecryptedPacket(EncryptionLevel level) OVERRIDE {
  87     DCHECK(false);
  88   }
  89   virtual bool OnPacketHeader(const QuicPacketHeader& /*header*/) OVERRIDE {
  90     DCHECK(false);
  91     return false;
  92   }
  93   virtual void OnRevivedPacket() OVERRIDE {
  94     DCHECK(false);
  95   }
  96   virtual void OnFecProtectedPayload(StringPiece /*payload*/) OVERRIDE {
  97     DCHECK(false);
  98   }
  99   virtual bool OnStreamFrame(const QuicStreamFrame& /*frame*/) OVERRIDE {
 100     DCHECK(false);
 101     return false;
 102   }
 103   virtual bool OnAckFrame(const QuicAckFrame& /*frame*/) OVERRIDE {
 104     DCHECK(false);
 105     return false;
 106   }
 107   virtual bool OnCongestionFeedbackFrame(
 108       const QuicCongestionFeedbackFrame& /*frame*/) OVERRIDE {
 109     DCHECK(false);
 110     return false;
 111   }
 112   virtual bool OnStopWaitingFrame(
 113       const QuicStopWaitingFrame& /*frame*/) OVERRIDE {
 114     DCHECK(false);
 115     return false;
 116   }
 117   virtual bool OnPingFrame(const QuicPingFrame& /*frame*/) OVERRIDE {
 118     DCHECK(false);
 119     return false;
 120   }
 121   virtual bool OnRstStreamFrame(const QuicRstStreamFrame& /*frame*/) OVERRIDE {
 122     DCHECK(false);
 123     return false;
 124   }
 125   virtual bool OnConnectionCloseFrame(
 126       const QuicConnectionCloseFrame & /*frame*/) OVERRIDE {
 127     DCHECK(false);
 128     return false;
 129   }
 130   virtual bool OnGoAwayFrame(const QuicGoAwayFrame& /*frame*/) OVERRIDE {
 131     DCHECK(false);
 132     return false;
 133   }
 134   virtual bool OnWindowUpdateFrame(const QuicWindowUpdateFrame& /*frame*/)
 135       OVERRIDE {
 136     DCHECK(false);
 137     return false;
 138   }
 139   virtual bool OnBlockedFrame(const QuicBlockedFrame& frame) OVERRIDE {
 140     DCHECK(false);
 141     return false;
 142   }
 143   virtual void OnFecData(const QuicFecData& /*fec*/) OVERRIDE {
 144     DCHECK(false);
 145   }
 146   virtual void OnPacketComplete() OVERRIDE {
 147     DCHECK(false);
 148   }
 149
 150  private:
 151   QuicDispatcher* dispatcher_;
 152
 153   // Latched in OnUnauthenticatedPublicHeader for use later.
 154   QuicConnectionId connection_id_;
 155 };
 156
 157 QuicDispatcher::QuicDispatcher(const QuicConfig& config,
 158                                const QuicCryptoServerConfig& crypto_config,
 159                                const QuicVersionVector& supported_versions,
 160                                QuicConnectionHelperInterface* helper)
 161     : config_(config),
 162       crypto_config_(crypto_config),
 163       helper_(helper),
 164       delete_sessions_alarm_(
 165           helper_->CreateAlarm(new DeleteSessionsAlarm(this))),
 166       supported_versions_(supported_versions),
 167       supported_versions_no_connection_flow_control_(supported_versions),
 168       current_packet_(NULL),
 169       framer_(supported_versions, /*unused*/ QuicTime::Zero(), true),
 170       framer_visitor_(new QuicFramerVisitor(this)) {
 171   framer_.set_visitor(framer_visitor_.get());
 172 }
 173
 174 QuicDispatcher::~QuicDispatcher() {
 175   STLDeleteValues(&session_map_);
 176   STLDeleteElements(&closed_session_list_);
 177 }
 178
 179 void QuicDispatcher::Initialize(QuicServerPacketWriter* writer) {
 180   DCHECK(writer_ == NULL);
 181   writer_.reset(writer);
 182   time_wait_list_manager_.reset(CreateQuicTimeWaitListManager());
 183
 184   // Remove all versions > QUIC_VERSION_18 from the
 185   // supported_versions_no_connection_flow_control_ vector.
 186   QuicVersionVector::iterator connection_it =
 187       find(supported_versions_no_connection_flow_control_.begin(),
 188            supported_versions_no_connection_flow_control_.end(),
 189            QUIC_VERSION_19);
 190   if (connection_it != supported_versions_no_connection_flow_control_.end()) {
 191     supported_versions_no_connection_flow_control_.erase(
 192         supported_versions_no_connection_flow_control_.begin(),
 193         connection_it + 1);
 194   }
 195   CHECK(!supported_versions_no_connection_flow_control_.empty());
 196 }
 197
 198 void QuicDispatcher::ProcessPacket(const IPEndPoint& server_address,
 199                                    const IPEndPoint& client_address,
 200                                    const QuicEncryptedPacket& packet) {
 201   current_server_address_ = server_address;
 202   current_client_address_ = client_address;
 203   current_packet_ = &packet;
 204   // ProcessPacket will cause the packet to be dispatched in
 205   // OnUnauthenticatedPublicHeader, or sent to the time wait list manager
 206   // in OnAuthenticatedHeader.
 207   framer_.ProcessPacket(packet);
 208   // TODO(rjshade): Return a status describing if/why a packet was dropped,
 209   //                and log somehow.  Maybe expose as a varz.
 210 }
 211
 212 bool QuicDispatcher::OnUnauthenticatedPublicHeader(
 213     const QuicPacketPublicHeader& header) {
 214   QuicSession* session = NULL;
 215
 216   QuicConnectionId connection_id = header.connection_id;
 217   SessionMap::iterator it = session_map_.find(connection_id);
 218   if (it == session_map_.end()) {
 219     if (header.reset_flag) {
 220       return false;
 221     }
 222     if (time_wait_list_manager_->IsConnectionIdInTimeWait(connection_id)) {
 223       return HandlePacketForTimeWait(header);
 224     }
 225
 226     // Ensure the packet has a version negotiation bit set before creating a new
 227     // session for it.  All initial packets for a new connection are required to
 228     // have the flag set.  Otherwise it may be a stray packet.
 229     if (header.version_flag) {
 230       session = CreateQuicSession(connection_id, current_server_address_,
 231                                   current_client_address_);
 232     }
 233
 234     if (session == NULL) {
 235       DVLOG(1) << "Failed to create session for " << connection_id;
 236       // Add this connection_id fo the time-wait state, to safely reject future
 237       // packets.
 238
 239       if (header.version_flag &&
 240           !framer_.IsSupportedVersion(header.versions.front())) {
 241         // TODO(ianswett): Produce a no-version version negotiation packet.
 242         return false;
 243       }
 244
 245       // Use the version in the packet if possible, otherwise assume the latest.
 246       QuicVersion version = header.version_flag ? header.versions.front() :
 247           supported_versions_.front();
 248       time_wait_list_manager_->AddConnectionIdToTimeWait(
 249           connection_id, version, NULL);
 250       DCHECK(time_wait_list_manager_->IsConnectionIdInTimeWait(connection_id));
 251       return HandlePacketForTimeWait(header);
 252     }
 253     DVLOG(1) << "Created new session for " << connection_id;
 254     session_map_.insert(make_pair(connection_id, session));
 255   } else {
 256     session = it->second;
 257   }
 258
 259   session->connection()->ProcessUdpPacket(
 260       current_server_address_, current_client_address_, *current_packet_);
 261
 262   // Do not parse the packet further.  The session will process it completely.
 263   return false;
 264 }
 265
 266 void QuicDispatcher::OnUnauthenticatedHeader(const QuicPacketHeader& header) {
 267   DCHECK(time_wait_list_manager_->IsConnectionIdInTimeWait(
 268       header.public_header.connection_id));
 269   time_wait_list_manager_->ProcessPacket(current_server_address_,
 270                                          current_client_address_,
 271                                          header.public_header.connection_id,
 272                                          header.packet_sequence_number,
 273                                          *current_packet_);
 274 }
 275
 276 void QuicDispatcher::CleanUpSession(SessionMap::iterator it) {
 277   QuicConnection* connection = it->second->connection();
 278   QuicEncryptedPacket* connection_close_packet =
 279       connection->ReleaseConnectionClosePacket();
 280   write_blocked_list_.erase(connection);
 281   time_wait_list_manager_->AddConnectionIdToTimeWait(it->first,
 282                                                      connection->version(),
 283                                                      connection_close_packet);
 284   session_map_.erase(it);
 285 }
 286
 287 void QuicDispatcher::DeleteSessions() {
 288   STLDeleteElements(&closed_session_list_);
 289 }
 290
 291 void QuicDispatcher::OnCanWrite() {
 292   // We finished a write: the socket should not be blocked.
 293   writer_->SetWritable();
 294
 295   // Give all the blocked writers one chance to write, until we're blocked again
 296   // or there's no work left.
 297   while (!write_blocked_list_.empty() && !writer_->IsWriteBlocked()) {
 298     QuicBlockedWriterInterface* blocked_writer =
 299         write_blocked_list_.begin()->first;
 300     write_blocked_list_.erase(write_blocked_list_.begin());
 301     blocked_writer->OnCanWrite();
 302   }
 303 }
 304
 305 bool QuicDispatcher::HasPendingWrites() const {
 306   return !write_blocked_list_.empty();
 307 }
 308
 309 void QuicDispatcher::Shutdown() {
 310   while (!session_map_.empty()) {
 311     QuicSession* session = session_map_.begin()->second;
 312     session->connection()->SendConnectionClose(QUIC_PEER_GOING_AWAY);
 313     // Validate that the session removes itself from the session map on close.
 314     DCHECK(session_map_.empty() || session_map_.begin()->second != session);
 315   }
 316   DeleteSessions();
 317 }
 318
 319 void QuicDispatcher::OnConnectionClosed(QuicConnectionId connection_id,
 320                                         QuicErrorCode error) {
 321   SessionMap::iterator it = session_map_.find(connection_id);
 322   if (it == session_map_.end()) {
 323     LOG(DFATAL) << "ConnectionId " << connection_id
 324                 << " does not exist in the session map.  "
 325                 << "Error: " << QuicUtils::ErrorToString(error);
 326     LOG(DFATAL) << base::debug::StackTrace().ToString();
 327     return;
 328   }
 329   DVLOG_IF(1, error != QUIC_NO_ERROR) << "Closing connection ("
 330                                       << connection_id
 331                                       << ") due to error: "
 332                                       << QuicUtils::ErrorToString(error);
 333   if (closed_session_list_.empty()) {
 334     delete_sessions_alarm_->Set(helper_->GetClock()->ApproximateNow());
 335   }
 336   closed_session_list_.push_back(it->second);
 337   CleanUpSession(it);
 338 }
 339
 340 void QuicDispatcher::OnWriteBlocked(
 341     QuicBlockedWriterInterface* blocked_writer) {
 342   if (!writer_->IsWriteBlocked()) {
 343     LOG(DFATAL) <<
 344         "QuicDispatcher::OnWriteBlocked called when the writer is not blocked.";
 345     // Return without adding the connection to the blocked list, to avoid
 346     // infinite loops in OnCanWrite.
 347     return;
 348   }
 349   write_blocked_list_.insert(make_pair(blocked_writer, true));
 350 }
 351
 352 QuicSession* QuicDispatcher::CreateQuicSession(
 353     QuicConnectionId connection_id,
 354     const IPEndPoint& server_address,
 355     const IPEndPoint& client_address) {
 356   QuicPerConnectionPacketWriter* per_connection_packet_writer =
 357       new QuicPerConnectionPacketWriter(writer_.get());
 358   QuicConnection* connection =
 359       CreateQuicConnection(connection_id,
 360                            server_address,
 361                            client_address,
 362                            per_connection_packet_writer);
 363   QuicServerSession* session = new QuicServerSession(
 364       config_,
 365       connection,
 366       per_connection_packet_writer,
 367       this);
 368   session->InitializeSession(crypto_config_);
 369   return session;
 370 }
 371
 372 QuicConnection* QuicDispatcher::CreateQuicConnection(
 373     QuicConnectionId connection_id,
 374     const IPEndPoint& server_address,
 375     const IPEndPoint& client_address,
 376     QuicPerConnectionPacketWriter* writer) {
 377   QuicConnection* connection;
 378   if (FLAGS_enable_quic_connection_flow_control_2) {
 379     DVLOG(1) << "Creating QuicDispatcher with all versions.";
 380     connection = new QuicConnection(connection_id, client_address, helper_,
 381                                     writer, true, supported_versions_);
 382   } else {
 383     DVLOG(1) << "Connection flow control disabled, creating QuicDispatcher "
 384              << "WITHOUT version 19 or higher.";
 385     connection = new QuicConnection(
 386         connection_id, client_address, helper_, writer, true,
 387         supported_versions_no_connection_flow_control_);
 388   }
 389   writer->set_connection(connection);
 390   return connection;
 391 }
 392
 393 QuicTimeWaitListManager* QuicDispatcher::CreateQuicTimeWaitListManager() {
 394   return new QuicTimeWaitListManager(
 395       writer_.get(), this, helper_, supported_versions());
 396 }
 397
 398 bool QuicDispatcher::HandlePacketForTimeWait(
 399     const QuicPacketPublicHeader& header) {
 400   if (header.reset_flag) {
 401     // Public reset packets do not have sequence numbers, so ignore the packet.
 402     return false;
 403   }
 404
 405   // Switch the framer to the correct version, so that the sequence number can
 406   // be parsed correctly.
 407   framer_.set_version(time_wait_list_manager_->GetQuicVersionFromConnectionId(
 408       header.connection_id));
 409
 410   // Continue parsing the packet to extract the sequence number.  Then
 411   // send it to the time wait manager in OnUnathenticatedHeader.
 412   return true;
 413 }
 414
 415 }  // namespace net