net/tools/quic/quic_dispatcher.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 "net/tools/quic/quic_dispatcher.h"
   6
   7 #include <utility>
   8
   9 #include "base/debug/stack_trace.h"
  10 #include "base/logging.h"
  11 #include "base/stl_util.h"
  12 #include "net/quic/quic_utils.h"
  13 #include "net/tools/quic/quic_per_connection_packet_writer.h"
  14 #include "net/tools/quic/quic_time_wait_list_manager.h"
  15
  16 namespace net {
  17
  18 namespace tools {
  19
  20 using base::StringPiece;
  21
  22 namespace {
  23
  24 // An alarm that informs the QuicDispatcher to delete old sessions.
  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     // Let the dispatcher register the alarm at appropriate time.
  34     return QuicTime::Zero();
  35   }
  36
  37  private:
  38   // Not owned.
  39   QuicDispatcher* dispatcher_;
  40
  41   DISALLOW_COPY_AND_ASSIGN(DeleteSessionsAlarm);
  42 };
  43
  44 }  // namespace
  45
  46 class QuicDispatcher::QuicFramerVisitor : public QuicFramerVisitorInterface {
  47  public:
  48   explicit QuicFramerVisitor(QuicDispatcher* dispatcher)
  49       : dispatcher_(dispatcher),
  50         connection_id_(0) {}
  51
  52   // QuicFramerVisitorInterface implementation
  53   void OnPacket() override {}
  54   bool OnUnauthenticatedPublicHeader(
  55       const QuicPacketPublicHeader& header) override {
  56     connection_id_ = header.connection_id;
  57     return dispatcher_->OnUnauthenticatedPublicHeader(header);
  58   }
  59   bool OnUnauthenticatedHeader(const QuicPacketHeader& header) override {
  60     dispatcher_->OnUnauthenticatedHeader(header);
  61     return false;
  62   }
  63   void OnError(QuicFramer* framer) override {
  64     DVLOG(1) << QuicUtils::ErrorToString(framer->error());
  65   }
  66
  67   bool OnProtocolVersionMismatch(QuicVersion /*received_version*/) override {
  68     if (dispatcher_->time_wait_list_manager()->IsConnectionIdInTimeWait(
  69             connection_id_)) {
  70       // Keep processing after protocol mismatch - this will be dealt with by
  71       // the TimeWaitListManager.
  72       return true;
  73     } else {
  74       DLOG(DFATAL) << "Version mismatch, connection ID (" << connection_id_
  75                    << ") not in time wait list.";
  76       return false;
  77     }
  78   }
  79
  80   // The following methods should never get called because we always return
  81   // false from OnUnauthenticatedHeader().  As a result, we never process the
  82   // payload of the packet.
  83   void OnPublicResetPacket(const QuicPublicResetPacket& /*packet*/) override {
  84     DCHECK(false);
  85   }
  86   void OnVersionNegotiationPacket(
  87       const QuicVersionNegotiationPacket& /*packet*/) override {
  88     DCHECK(false);
  89   }
  90   void OnDecryptedPacket(EncryptionLevel level) override { DCHECK(false); }
  91   bool OnPacketHeader(const QuicPacketHeader& /*header*/) override {
  92     DCHECK(false);
  93     return false;
  94   }
  95   void OnRevivedPacket() override { DCHECK(false); }
  96   void OnFecProtectedPayload(StringPiece /*payload*/) override {
  97     DCHECK(false);
  98   }
  99   bool OnStreamFrame(const QuicStreamFrame& /*frame*/) override {
 100     DCHECK(false);
 101     return false;
 102   }
 103   bool OnAckFrame(const QuicAckFrame& /*frame*/) override {
 104     DCHECK(false);
 105     return false;
 106   }
 107   bool OnStopWaitingFrame(const QuicStopWaitingFrame& /*frame*/) override {
 108     DCHECK(false);
 109     return false;
 110   }
 111   bool OnPingFrame(const QuicPingFrame& /*frame*/) override {
 112     DCHECK(false);
 113     return false;
 114   }
 115   bool OnRstStreamFrame(const QuicRstStreamFrame& /*frame*/) override {
 116     DCHECK(false);
 117     return false;
 118   }
 119   bool OnConnectionCloseFrame(
 120       const QuicConnectionCloseFrame& /*frame*/) override {
 121     DCHECK(false);
 122     return false;
 123   }
 124   bool OnGoAwayFrame(const QuicGoAwayFrame& /*frame*/) override {
 125     DCHECK(false);
 126     return false;
 127   }
 128   bool OnWindowUpdateFrame(const QuicWindowUpdateFrame& /*frame*/) override {
 129     DCHECK(false);
 130     return false;
 131   }
 132   bool OnBlockedFrame(const QuicBlockedFrame& frame) override {
 133     DCHECK(false);
 134     return false;
 135   }
 136   void OnFecData(const QuicFecData& /*fec*/) override { DCHECK(false); }
 137   void OnPacketComplete() override { DCHECK(false); }
 138
 139  private:
 140   QuicDispatcher* dispatcher_;
 141
 142   // Latched in OnUnauthenticatedPublicHeader for use later.
 143   QuicConnectionId connection_id_;
 144 };
 145
 146 QuicPacketWriter* QuicDispatcher::DefaultPacketWriterFactory::Create(
 147     QuicPacketWriter* writer,
 148     QuicConnection* connection) {
 149   return new QuicPerConnectionPacketWriter(writer, connection);
 150 }
 151
 152 QuicDispatcher::PacketWriterFactoryAdapter::PacketWriterFactoryAdapter(
 153     QuicDispatcher* dispatcher)
 154     : dispatcher_(dispatcher) {}
 155
 156 QuicDispatcher::PacketWriterFactoryAdapter::~PacketWriterFactoryAdapter() {}
 157
 158 QuicPacketWriter* QuicDispatcher::PacketWriterFactoryAdapter::Create(
 159     QuicConnection* connection) const {
 160   return dispatcher_->packet_writer_factory_->Create(
 161       dispatcher_->writer_.get(),
 162       connection);
 163 }
 164
 165 QuicDispatcher::QuicDispatcher(const QuicConfig& config,
 166                                const QuicCryptoServerConfig& crypto_config,
 167                                const QuicVersionVector& supported_versions,
 168                                PacketWriterFactory* packet_writer_factory,
 169                                QuicConnectionHelperInterface* helper)
 170     : config_(config),
 171       crypto_config_(crypto_config),
 172       helper_(helper),
 173       delete_sessions_alarm_(
 174           helper_->CreateAlarm(new DeleteSessionsAlarm(this))),
 175       packet_writer_factory_(packet_writer_factory),
 176       connection_writer_factory_(this),
 177       supported_versions_(supported_versions),
 178       current_packet_(nullptr),
 179       framer_(supported_versions,
 180               /*unused*/ QuicTime::Zero(),
 181               Perspective::IS_SERVER),
 182       framer_visitor_(new QuicFramerVisitor(this)) {
 183   framer_.set_visitor(framer_visitor_.get());
 184 }
 185
 186 QuicDispatcher::~QuicDispatcher() {
 187   STLDeleteValues(&session_map_);
 188   STLDeleteElements(&closed_session_list_);
 189 }
 190
 191 void QuicDispatcher::InitializeWithWriter(QuicPacketWriter* writer) {
 192   DCHECK(writer_ == nullptr);
 193   writer_.reset(writer);
 194   time_wait_list_manager_.reset(CreateQuicTimeWaitListManager());
 195 }
 196
 197 void QuicDispatcher::ProcessPacket(const IPEndPoint& server_address,
 198                                    const IPEndPoint& client_address,
 199                                    const QuicEncryptedPacket& packet) {
 200   current_server_address_ = server_address;
 201   current_client_address_ = client_address;
 202   current_packet_ = &packet;
 203   // ProcessPacket will cause the packet to be dispatched in
 204   // OnUnauthenticatedPublicHeader, or sent to the time wait list manager
 205   // in OnAuthenticatedHeader.
 206   framer_.ProcessPacket(packet);
 207   // TODO(rjshade): Return a status describing if/why a packet was dropped,
 208   //                and log somehow.  Maybe expose as a varz.
 209 }
 210
 211 bool QuicDispatcher::OnUnauthenticatedPublicHeader(
 212     const QuicPacketPublicHeader& header) {
 213   // Port zero is only allowed for unidirectional UDP, so is disallowed by QUIC.
 214   // Given that we can't even send a reply rejecting the packet, just black hole
 215   // it.
 216   if (current_client_address_.port() == 0) {
 217     return false;
 218   }
 219
 220   // The session that we have identified as the one to which this packet
 221   // belongs.
 222   QuicServerSession* session = nullptr;
 223   QuicConnectionId connection_id = header.connection_id;
 224   SessionMap::iterator it = session_map_.find(connection_id);
 225   if (it == session_map_.end()) {
 226     if (time_wait_list_manager_->IsConnectionIdInTimeWait(connection_id)) {
 227       return HandlePacketForTimeWait(header);
 228     }
 229
 230     // The packet has an unknown connection ID.
 231     // If the packet is a public reset, there is nothing we must do or can do.
 232     if (header.reset_flag) {
 233       return false;
 234     }
 235
 236     // All packets within a connection sent by a client before receiving a
 237     // response from the server are required to have the version negotiation
 238     // flag set.  Since this may be a client continuing a connection we lost
 239     // track of via server restart, send a rejection to fast-fail the
 240     // connection.
 241     if (!header.version_flag) {
 242       DVLOG(1) << "Packet without version arrived for unknown connection ID "
 243                << connection_id;
 244       // Add this connection_id fo the time-wait state, to safely reject future
 245       // packets.
 246       QuicVersion version = supported_versions_.front();
 247       time_wait_list_manager_->AddConnectionIdToTimeWait(connection_id, version,
 248                                                          nullptr);
 249       DCHECK(time_wait_list_manager_->IsConnectionIdInTimeWait(connection_id));
 250       return HandlePacketForTimeWait(header);
 251     }
 252
 253     session = AdditionalValidityChecksThenCreateSession(header, connection_id);
 254     if (session == nullptr) {
 255       return false;
 256     }
 257   } else {
 258     session = it->second;
 259   }
 260
 261   session->connection()->ProcessUdpPacket(
 262       current_server_address_, current_client_address_, *current_packet_);
 263
 264   // Do not parse the packet further.  The session methods called above have
 265   // processed it completely.
 266   return false;
 267 }
 268
 269 QuicServerSession* QuicDispatcher::AdditionalValidityChecksThenCreateSession(
 270     const QuicPacketPublicHeader& header,
 271     QuicConnectionId connection_id) {
 272   QuicServerSession* session = CreateQuicSession(
 273       connection_id, current_server_address_, current_client_address_);
 274
 275   if (session == nullptr) {
 276     DVLOG(1) << "Failed to create session for " << connection_id;
 277
 278     if (!framer_.IsSupportedVersion(header.versions.front())) {
 279       // TODO(ianswett): Produce packet saying "no supported version".
 280       return nullptr;
 281     }
 282
 283     // Add this connection_id to the time-wait state, to safely reject future
 284     // packets.
 285     QuicVersion version = header.versions.front();
 286     time_wait_list_manager_->AddConnectionIdToTimeWait(connection_id, version,
 287                                                        nullptr);
 288     DCHECK(time_wait_list_manager_->IsConnectionIdInTimeWait(connection_id));
 289     HandlePacketForTimeWait(header);
 290
 291     return nullptr;
 292   }
 293
 294   DVLOG(1) << "Created new session for connection ID " << connection_id;
 295   session_map_.insert(std::make_pair(connection_id, session));
 296
 297   return session;
 298 }
 299
 300 void QuicDispatcher::OnUnauthenticatedHeader(const QuicPacketHeader& header) {
 301   DCHECK(time_wait_list_manager_->IsConnectionIdInTimeWait(
 302       header.public_header.connection_id));
 303   time_wait_list_manager_->ProcessPacket(current_server_address_,
 304                                          current_client_address_,
 305                                          header.public_header.connection_id,
 306                                          header.packet_sequence_number,
 307                                          *current_packet_);
 308 }
 309
 310 void QuicDispatcher::CleanUpSession(SessionMap::iterator it) {
 311   QuicConnection* connection = it->second->connection();
 312   QuicEncryptedPacket* connection_close_packet =
 313       connection->ReleaseConnectionClosePacket();
 314   write_blocked_list_.erase(connection);
 315   time_wait_list_manager_->AddConnectionIdToTimeWait(it->first,
 316                                                      connection->version(),
 317                                                      connection_close_packet);
 318   session_map_.erase(it);
 319 }
 320
 321 void QuicDispatcher::DeleteSessions() {
 322   STLDeleteElements(&closed_session_list_);
 323 }
 324
 325 void QuicDispatcher::OnCanWrite() {
 326   // We got an EPOLLOUT: the socket should not be blocked.
 327   writer_->SetWritable();
 328
 329   // Give all the blocked writers one chance to write, until we're blocked again
 330   // or there's no work left.
 331   while (!write_blocked_list_.empty() && !writer_->IsWriteBlocked()) {
 332     QuicBlockedWriterInterface* blocked_writer =
 333         write_blocked_list_.begin()->first;
 334     write_blocked_list_.erase(write_blocked_list_.begin());
 335     blocked_writer->OnCanWrite();
 336   }
 337 }
 338
 339 bool QuicDispatcher::HasPendingWrites() const {
 340   return !write_blocked_list_.empty();
 341 }
 342
 343 void QuicDispatcher::Shutdown() {
 344   while (!session_map_.empty()) {
 345     QuicServerSession* session = session_map_.begin()->second;
 346     session->connection()->SendConnectionClose(QUIC_PEER_GOING_AWAY);
 347     // Validate that the session removes itself from the session map on close.
 348     DCHECK(session_map_.empty() || session_map_.begin()->second != session);
 349   }
 350   DeleteSessions();
 351 }
 352
 353 void QuicDispatcher::OnConnectionClosed(QuicConnectionId connection_id,
 354                                         QuicErrorCode error) {
 355   SessionMap::iterator it = session_map_.find(connection_id);
 356   if (it == session_map_.end()) {
 357     LOG(DFATAL) << "ConnectionId " << connection_id
 358                 << " does not exist in the session map.  "
 359                 << "Error: " << QuicUtils::ErrorToString(error);
 360     LOG(DFATAL) << base::debug::StackTrace().ToString();
 361     return;
 362   }
 363
 364   DVLOG_IF(1, error != QUIC_NO_ERROR) << "Closing connection ("
 365                                       << connection_id
 366                                       << ") due to error: "
 367                                       << QuicUtils::ErrorToString(error);
 368
 369   if (closed_session_list_.empty()) {
 370     delete_sessions_alarm_->Cancel();
 371     delete_sessions_alarm_->Set(helper()->GetClock()->ApproximateNow());
 372   }
 373   closed_session_list_.push_back(it->second);
 374   CleanUpSession(it);
 375 }
 376
 377 void QuicDispatcher::OnWriteBlocked(
 378     QuicBlockedWriterInterface* blocked_writer) {
 379   if (!writer_->IsWriteBlocked()) {
 380     LOG(DFATAL) <<
 381         "QuicDispatcher::OnWriteBlocked called when the writer is not blocked.";
 382     // Return without adding the connection to the blocked list, to avoid
 383     // infinite loops in OnCanWrite.
 384     return;
 385   }
 386   write_blocked_list_.insert(std::make_pair(blocked_writer, true));
 387 }
 388
 389 void QuicDispatcher::OnConnectionAddedToTimeWaitList(
 390     QuicConnectionId connection_id) {
 391   DVLOG(1) << "Connection " << connection_id << " added to time wait list.";
 392 }
 393
 394 void QuicDispatcher::OnConnectionRemovedFromTimeWaitList(
 395     QuicConnectionId connection_id) {
 396   DVLOG(1) << "Connection " << connection_id << " removed from time wait list.";
 397 }
 398
 399 QuicServerSession* QuicDispatcher::CreateQuicSession(
 400     QuicConnectionId connection_id,
 401     const IPEndPoint& server_address,
 402     const IPEndPoint& client_address) {
 403   // The QuicServerSession takes ownership of |connection| below.
 404   QuicConnection* connection = new QuicConnection(
 405       connection_id, client_address, helper_.get(), connection_writer_factory_,
 406       /* owns_writer= */ true, Perspective::IS_SERVER,
 407       crypto_config_.HasProofSource(), supported_versions_);
 408
 409   QuicServerSession* session = new QuicServerSession(config_, connection, this);
 410   session->InitializeSession(&crypto_config_);
 411   return session;
 412 }
 413
 414 QuicTimeWaitListManager* QuicDispatcher::CreateQuicTimeWaitListManager() {
 415   return new QuicTimeWaitListManager(
 416       writer_.get(), this, helper_.get(), supported_versions());
 417 }
 418
 419 bool QuicDispatcher::HandlePacketForTimeWait(
 420     const QuicPacketPublicHeader& header) {
 421   if (header.reset_flag) {
 422     // Public reset packets do not have sequence numbers, so ignore the packet.
 423     return false;
 424   }
 425
 426   // Switch the framer to the correct version, so that the sequence number can
 427   // be parsed correctly.
 428   framer_.set_version(time_wait_list_manager_->GetQuicVersionFromConnectionId(
 429       header.connection_id));
 430
 431   // Continue parsing the packet to extract the sequence number.  Then
 432   // send it to the time wait manager in OnUnathenticatedHeader.
 433   return true;
 434 }
 435
 436 }  // namespace tools
 437 }  // namespace net