src/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 <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_flags.h"
  14 #include "net/quic/quic_utils.h"
  15 #include "net/tools/epoll_server/epoll_server.h"
  16 #include "net/tools/quic/quic_default_packet_writer.h"
  17 #include "net/tools/quic/quic_epoll_connection_helper.h"
  18 #include "net/tools/quic/quic_per_connection_packet_writer.h"
  19 #include "net/tools/quic/quic_socket_utils.h"
  20 #include "net/tools/quic/quic_time_wait_list_manager.h"
  21
  22 namespace net {
  23
  24 namespace tools {
  25
  26 using base::StringPiece;
  27 using std::make_pair;
  28
  29 class DeleteSessionsAlarm : public EpollAlarm {
  30  public:
  31   explicit DeleteSessionsAlarm(QuicDispatcher* dispatcher)
  32       : dispatcher_(dispatcher) {
  33   }
  34
  35   int64 OnAlarm() override {
  36     EpollAlarm::OnAlarm();
  37     dispatcher_->DeleteSessions();
  38     return 0;
  39   }
  40
  41  private:
  42   QuicDispatcher* dispatcher_;
  43 };
  44
  45 class QuicDispatcher::QuicFramerVisitor : public QuicFramerVisitorInterface {
  46  public:
  47   explicit QuicFramerVisitor(QuicDispatcher* dispatcher)
  48       : dispatcher_(dispatcher),
  49         connection_id_(0) {}
  50
  51   // QuicFramerVisitorInterface implementation
  52   void OnPacket() override {}
  53   bool OnUnauthenticatedPublicHeader(
  54       const QuicPacketPublicHeader& header) override {
  55     connection_id_ = header.connection_id;
  56     return dispatcher_->OnUnauthenticatedPublicHeader(header);
  57   }
  58   bool OnUnauthenticatedHeader(const QuicPacketHeader& header) override {
  59     dispatcher_->OnUnauthenticatedHeader(header);
  60     return false;
  61   }
  62   void OnError(QuicFramer* framer) override {
  63     DVLOG(1) << QuicUtils::ErrorToString(framer->error());
  64   }
  65
  66   bool OnProtocolVersionMismatch(QuicVersion /*received_version*/) override {
  67     if (dispatcher_->time_wait_list_manager()->IsConnectionIdInTimeWait(
  68             connection_id_)) {
  69       // Keep processing after protocol mismatch - this will be dealt with by
  70       // the TimeWaitListManager.
  71       return true;
  72     } else {
  73       DLOG(DFATAL) << "Version mismatch, connection ID (" << connection_id_
  74                    << ") not in time wait list.";
  75       return false;
  76     }
  77   }
  78
  79   // The following methods should never get called because we always return
  80   // false from OnUnauthenticatedHeader().  As a result, we never process the
  81   // payload of the packet.
  82   void OnPublicResetPacket(const QuicPublicResetPacket& /*packet*/) override {
  83     DCHECK(false);
  84   }
  85   void OnVersionNegotiationPacket(
  86       const QuicVersionNegotiationPacket& /*packet*/) override {
  87     DCHECK(false);
  88   }
  89   void OnDecryptedPacket(EncryptionLevel level) override { DCHECK(false); }
  90   bool OnPacketHeader(const QuicPacketHeader& /*header*/) override {
  91     DCHECK(false);
  92     return false;
  93   }
  94   void OnRevivedPacket() override { DCHECK(false); }
  95   void OnFecProtectedPayload(StringPiece /*payload*/) override {
  96     DCHECK(false);
  97   }
  98   bool OnStreamFrame(const QuicStreamFrame& /*frame*/) override {
  99     DCHECK(false);
 100     return false;
 101   }
 102   bool OnAckFrame(const QuicAckFrame& /*frame*/) override {
 103     DCHECK(false);
 104     return false;
 105   }
 106   bool OnCongestionFeedbackFrame(
 107       const QuicCongestionFeedbackFrame& /*frame*/) override {
 108     DCHECK(false);
 109     return false;
 110   }
 111   bool OnStopWaitingFrame(const QuicStopWaitingFrame& /*frame*/) override {
 112     DCHECK(false);
 113     return false;
 114   }
 115   bool OnPingFrame(const QuicPingFrame& /*frame*/) override {
 116     DCHECK(false);
 117     return false;
 118   }
 119   bool OnRstStreamFrame(const QuicRstStreamFrame& /*frame*/) override {
 120     DCHECK(false);
 121     return false;
 122   }
 123   bool OnConnectionCloseFrame(
 124       const QuicConnectionCloseFrame& /*frame*/) override {
 125     DCHECK(false);
 126     return false;
 127   }
 128   bool OnGoAwayFrame(const QuicGoAwayFrame& /*frame*/) override {
 129     DCHECK(false);
 130     return false;
 131   }
 132   bool OnWindowUpdateFrame(const QuicWindowUpdateFrame& /*frame*/) override {
 133     DCHECK(false);
 134     return false;
 135   }
 136   bool OnBlockedFrame(const QuicBlockedFrame& frame) override {
 137     DCHECK(false);
 138     return false;
 139   }
 140   void OnFecData(const QuicFecData& /*fec*/) override { DCHECK(false); }
 141   void OnPacketComplete() override { DCHECK(false); }
 142
 143  private:
 144   QuicDispatcher* dispatcher_;
 145
 146   // Latched in OnUnauthenticatedPublicHeader for use later.
 147   QuicConnectionId connection_id_;
 148 };
 149
 150 QuicPacketWriter* QuicDispatcher::DefaultPacketWriterFactory::Create(
 151     QuicPacketWriter* writer,
 152     QuicConnection* connection) {
 153   return new QuicPerConnectionPacketWriter(writer, connection);
 154 }
 155
 156 QuicDispatcher::PacketWriterFactoryAdapter::PacketWriterFactoryAdapter(
 157     QuicDispatcher* dispatcher)
 158     : dispatcher_(dispatcher) {}
 159
 160 QuicDispatcher::PacketWriterFactoryAdapter::~PacketWriterFactoryAdapter() {}
 161
 162 QuicPacketWriter* QuicDispatcher::PacketWriterFactoryAdapter::Create(
 163     QuicConnection* connection) const {
 164   return dispatcher_->packet_writer_factory_->Create(
 165       dispatcher_->writer_.get(),
 166       connection);
 167 }
 168
 169 QuicDispatcher::QuicDispatcher(const QuicConfig& config,
 170                                const QuicCryptoServerConfig& crypto_config,
 171                                const QuicVersionVector& supported_versions,
 172                                PacketWriterFactory* packet_writer_factory,
 173                                EpollServer* epoll_server)
 174     : config_(config),
 175       crypto_config_(crypto_config),
 176       delete_sessions_alarm_(new DeleteSessionsAlarm(this)),
 177       epoll_server_(epoll_server),
 178       helper_(new QuicEpollConnectionHelper(epoll_server_)),
 179       packet_writer_factory_(packet_writer_factory),
 180       connection_writer_factory_(this),
 181       supported_versions_(supported_versions),
 182       current_packet_(nullptr),
 183       framer_(supported_versions, /*unused*/ QuicTime::Zero(), true),
 184       framer_visitor_(new QuicFramerVisitor(this)) {
 185   framer_.set_visitor(framer_visitor_.get());
 186 }
 187
 188 QuicDispatcher::~QuicDispatcher() {
 189   STLDeleteValues(&session_map_);
 190   STLDeleteElements(&closed_session_list_);
 191 }
 192
 193 void QuicDispatcher::Initialize(int fd) {
 194   DCHECK(writer_ == nullptr);
 195   writer_.reset(CreateWriter(fd));
 196   time_wait_list_manager_.reset(CreateQuicTimeWaitListManager());
 197 }
 198
 199 void QuicDispatcher::ProcessPacket(const IPEndPoint& server_address,
 200                                    const IPEndPoint& client_address,
 201                                    const QuicEncryptedPacket& packet) {
 202   current_server_address_ = server_address;
 203   current_client_address_ = client_address;
 204   current_packet_ = &packet;
 205   // ProcessPacket will cause the packet to be dispatched in
 206   // OnUnauthenticatedPublicHeader, or sent to the time wait list manager
 207   // in OnAuthenticatedHeader.
 208   framer_.ProcessPacket(packet);
 209   // TODO(rjshade): Return a status describing if/why a packet was dropped,
 210   //                and log somehow.  Maybe expose as a varz.
 211 }
 212
 213 bool QuicDispatcher::OnUnauthenticatedPublicHeader(
 214     const QuicPacketPublicHeader& header) {
 215   QuicSession* session = nullptr;
 216
 217   QuicConnectionId connection_id = header.connection_id;
 218   SessionMap::iterator it = session_map_.find(connection_id);
 219   if (it == session_map_.end()) {
 220     if (header.reset_flag) {
 221       return false;
 222     }
 223     if (time_wait_list_manager_->IsConnectionIdInTimeWait(connection_id)) {
 224       return HandlePacketForTimeWait(header);
 225     }
 226
 227     // Ensure the packet has a version negotiation bit set before creating a new
 228     // session for it.  All initial packets for a new connection are required to
 229     // have the flag set.  Otherwise it may be a stray packet.
 230     if (header.version_flag) {
 231       session = CreateQuicSession(connection_id, current_server_address_,
 232                                   current_client_address_);
 233     }
 234
 235     if (session == nullptr) {
 236       DVLOG(1) << "Failed to create session for " << connection_id;
 237       // Add this connection_id fo the time-wait state, to safely reject future
 238       // packets.
 239
 240       if (header.version_flag &&
 241           !framer_.IsSupportedVersion(header.versions.front())) {
 242         // TODO(ianswett): Produce a no-version version negotiation packet.
 243         return false;
 244       }
 245
 246       // Use the version in the packet if possible, otherwise assume the latest.
 247       QuicVersion version = header.version_flag ? header.versions.front() :
 248           supported_versions_.front();
 249       time_wait_list_manager_->AddConnectionIdToTimeWait(connection_id, version,
 250                                                          nullptr);
 251       DCHECK(time_wait_list_manager_->IsConnectionIdInTimeWait(connection_id));
 252       return HandlePacketForTimeWait(header);
 253     }
 254     DVLOG(1) << "Created new session for " << connection_id;
 255     session_map_.insert(make_pair(connection_id, session));
 256   } else {
 257     session = it->second;
 258   }
 259
 260   session->connection()->ProcessUdpPacket(
 261       current_server_address_, current_client_address_, *current_packet_);
 262
 263   // Do not parse the packet further.  The session will process it completely.
 264   return false;
 265 }
 266
 267 void QuicDispatcher::OnUnauthenticatedHeader(const QuicPacketHeader& header) {
 268   DCHECK(time_wait_list_manager_->IsConnectionIdInTimeWait(
 269       header.public_header.connection_id));
 270   time_wait_list_manager_->ProcessPacket(current_server_address_,
 271                                          current_client_address_,
 272                                          header.public_header.connection_id,
 273                                          header.packet_sequence_number,
 274                                          *current_packet_);
 275 }
 276
 277 void QuicDispatcher::CleanUpSession(SessionMap::iterator it) {
 278   QuicConnection* connection = it->second->connection();
 279   QuicEncryptedPacket* connection_close_packet =
 280       connection->ReleaseConnectionClosePacket();
 281   write_blocked_list_.erase(connection);
 282   time_wait_list_manager_->AddConnectionIdToTimeWait(it->first,
 283                                                      connection->version(),
 284                                                      connection_close_packet);
 285   session_map_.erase(it);
 286 }
 287
 288 void QuicDispatcher::DeleteSessions() {
 289   STLDeleteElements(&closed_session_list_);
 290 }
 291
 292 void QuicDispatcher::OnCanWrite() {
 293   // We got an EPOLLOUT: the socket should not be blocked.
 294   writer_->SetWritable();
 295
 296   // Give all the blocked writers one chance to write, until we're blocked again
 297   // or there's no work left.
 298   while (!write_blocked_list_.empty() && !writer_->IsWriteBlocked()) {
 299     QuicBlockedWriterInterface* blocked_writer =
 300         write_blocked_list_.begin()->first;
 301     write_blocked_list_.erase(write_blocked_list_.begin());
 302     blocked_writer->OnCanWrite();
 303   }
 304 }
 305
 306 bool QuicDispatcher::HasPendingWrites() const {
 307   return !write_blocked_list_.empty();
 308 }
 309
 310 void QuicDispatcher::Shutdown() {
 311   while (!session_map_.empty()) {
 312     QuicSession* session = session_map_.begin()->second;
 313     session->connection()->SendConnectionClose(QUIC_PEER_GOING_AWAY);
 314     // Validate that the session removes itself from the session map on close.
 315     DCHECK(session_map_.empty() || session_map_.begin()->second != session);
 316   }
 317   DeleteSessions();
 318 }
 319
 320 void QuicDispatcher::OnConnectionClosed(QuicConnectionId connection_id,
 321                                         QuicErrorCode error) {
 322   SessionMap::iterator it = session_map_.find(connection_id);
 323   if (it == session_map_.end()) {
 324     LOG(DFATAL) << "ConnectionId " << connection_id
 325                 << " does not exist in the session map.  "
 326                 << "Error: " << QuicUtils::ErrorToString(error);
 327     LOG(DFATAL) << base::debug::StackTrace().ToString();
 328     return;
 329   }
 330
 331   DLOG_IF(INFO, error != QUIC_NO_ERROR) << "Closing connection ("
 332                                         << connection_id
 333                                         << ") due to error: "
 334                                         << QuicUtils::ErrorToString(error);
 335
 336   if (closed_session_list_.empty()) {
 337     epoll_server_->RegisterAlarmApproximateDelta(
 338         0, delete_sessions_alarm_.get());
 339   }
 340   closed_session_list_.push_back(it->second);
 341   CleanUpSession(it);
 342 }
 343
 344 void QuicDispatcher::OnWriteBlocked(
 345     QuicBlockedWriterInterface* blocked_writer) {
 346   if (!writer_->IsWriteBlocked()) {
 347     LOG(DFATAL) <<
 348         "QuicDispatcher::OnWriteBlocked called when the writer is not blocked.";
 349     // Return without adding the connection to the blocked list, to avoid
 350     // infinite loops in OnCanWrite.
 351     return;
 352   }
 353   write_blocked_list_.insert(make_pair(blocked_writer, true));
 354 }
 355
 356 QuicPacketWriter* QuicDispatcher::CreateWriter(int fd) {
 357   return new QuicDefaultPacketWriter(fd);
 358 }
 359
 360 QuicSession* QuicDispatcher::CreateQuicSession(
 361     QuicConnectionId connection_id,
 362     const IPEndPoint& server_address,
 363     const IPEndPoint& client_address) {
 364   QuicServerSession* session = new QuicServerSession(
 365       config_,
 366       CreateQuicConnection(connection_id, server_address, client_address),
 367       this,
 368       crypto_config_.HasProofSource());
 369   session->InitializeSession(crypto_config_);
 370   return session;
 371 }
 372
 373 QuicConnection* QuicDispatcher::CreateQuicConnection(
 374     QuicConnectionId connection_id,
 375     const IPEndPoint& server_address,
 376     const IPEndPoint& client_address) {
 377   return new QuicConnection(connection_id,
 378                             client_address,
 379                             helper_.get(),
 380                             connection_writer_factory_,
 381                             /* owns_writer= */ true,
 382                             /* is_server= */ true,
 383                             supported_versions_);
 384 }
 385
 386 QuicTimeWaitListManager* QuicDispatcher::CreateQuicTimeWaitListManager() {
 387   return new QuicTimeWaitListManager(
 388       writer_.get(), this, epoll_server(), supported_versions());
 389 }
 390
 391 bool QuicDispatcher::HandlePacketForTimeWait(
 392     const QuicPacketPublicHeader& header) {
 393   if (header.reset_flag) {
 394     // Public reset packets do not have sequence numbers, so ignore the packet.
 395     return false;
 396   }
 397
 398   // Switch the framer to the correct version, so that the sequence number can
 399   // be parsed correctly.
 400   framer_.set_version(time_wait_list_manager_->GetQuicVersionFromConnectionId(
 401       header.connection_id));
 402
 403   // Continue parsing the packet to extract the sequence number.  Then
 404   // send it to the time wait manager in OnUnathenticatedHeader.
 405   return true;
 406 }
 407
 408 }  // namespace tools
 409 }  // namespace net