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