google_apis/gcm/engine/connection_factory_impl.cc

   1 // Copyright (c) 2013 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 "google_apis/gcm/engine/connection_factory_impl.h"
   6
   7 #include "base/message_loop/message_loop.h"
   8 #include "base/metrics/histogram.h"
   9 #include "base/metrics/sparse_histogram.h"
  10 #include "google_apis/gcm/engine/connection_handler_impl.h"
  11 #include "google_apis/gcm/protocol/mcs.pb.h"
  12 #include "net/base/net_errors.h"
  13 #include "net/http/http_network_session.h"
  14 #include "net/http/http_request_headers.h"
  15 #include "net/proxy/proxy_info.h"
  16 #include "net/socket/client_socket_handle.h"
  17 #include "net/socket/client_socket_pool_manager.h"
  18 #include "net/ssl/ssl_config_service.h"
  19
  20 namespace gcm {
  21
  22 namespace {
  23
  24 // The amount of time a Socket read should wait before timing out.
  25 const int kReadTimeoutMs = 30000;  // 30 seconds.
  26
  27 // If a connection is reset after succeeding within this window of time,
  28 // the previous backoff entry is restored (and the connection success is treated
  29 // as if it was transient).
  30 const int kConnectionResetWindowSecs = 10;  // 10 seconds.
  31
  32 // Backoff policy.
  33 const net::BackoffEntry::Policy kConnectionBackoffPolicy = {
  34   // Number of initial errors (in sequence) to ignore before applying
  35   // exponential back-off rules.
  36   0,
  37
  38   // Initial delay for exponential back-off in ms.
  39   10000,  // 10 seconds.
  40
  41   // Factor by which the waiting time will be multiplied.
  42   2,
  43
  44   // Fuzzing percentage. ex: 10% will spread requests randomly
  45   // between 90%-100% of the calculated time.
  46   0.5,  // 50%.
  47
  48   // Maximum amount of time we are willing to delay our request in ms.
  49   1000 * 60 * 5, // 5 minutes.
  50
  51   // Time to keep an entry from being discarded even when it
  52   // has no significant state, -1 to never discard.
  53   -1,
  54
  55   // Don't use initial delay unless the last request was an error.
  56   false,
  57 };
  58
  59 }  // namespace
  60
  61 ConnectionFactoryImpl::ConnectionFactoryImpl(
  62     const GURL& mcs_endpoint,
  63     scoped_refptr<net::HttpNetworkSession> network_session,
  64     net::NetLog* net_log)
  65   : mcs_endpoint_(mcs_endpoint),
  66     network_session_(network_session),
  67     net_log_(net_log),
  68     connecting_(false),
  69     weak_ptr_factory_(this) {
  70 }
  71
  72 ConnectionFactoryImpl::~ConnectionFactoryImpl() {
  73 }
  74
  75 void ConnectionFactoryImpl::Initialize(
  76     const BuildLoginRequestCallback& request_builder,
  77     const ConnectionHandler::ProtoReceivedCallback& read_callback,
  78     const ConnectionHandler::ProtoSentCallback& write_callback) {
  79   DCHECK(!connection_handler_);
  80
  81   previous_backoff_ = CreateBackoffEntry(&kConnectionBackoffPolicy);
  82   backoff_entry_ = CreateBackoffEntry(&kConnectionBackoffPolicy);
  83   request_builder_ = request_builder;
  84
  85   net::NetworkChangeNotifier::AddIPAddressObserver(this);
  86   net::NetworkChangeNotifier::AddConnectionTypeObserver(this);
  87   connection_handler_.reset(
  88       new ConnectionHandlerImpl(
  89           base::TimeDelta::FromMilliseconds(kReadTimeoutMs),
  90           read_callback,
  91           write_callback,
  92           base::Bind(&ConnectionFactoryImpl::ConnectionHandlerCallback,
  93                      weak_ptr_factory_.GetWeakPtr())));
  94 }
  95
  96 ConnectionHandler* ConnectionFactoryImpl::GetConnectionHandler() const {
  97   return connection_handler_.get();
  98 }
  99
 100 void ConnectionFactoryImpl::Connect() {
 101   DCHECK(connection_handler_);
 102
 103   connecting_ = true;
 104   if (backoff_entry_->ShouldRejectRequest()) {
 105     DVLOG(1) << "Delaying MCS endpoint connection for "
 106              << backoff_entry_->GetTimeUntilRelease().InMilliseconds()
 107              << " milliseconds.";
 108     base::MessageLoop::current()->PostDelayedTask(
 109         FROM_HERE,
 110         base::Bind(&ConnectionFactoryImpl::Connect,
 111                    weak_ptr_factory_.GetWeakPtr()),
 112         backoff_entry_->GetTimeUntilRelease());
 113     return;
 114   }
 115
 116   DVLOG(1) << "Attempting connection to MCS endpoint.";
 117   ConnectImpl();
 118 }
 119
 120 bool ConnectionFactoryImpl::IsEndpointReachable() const {
 121   return connection_handler_ &&
 122       connection_handler_->CanSendMessage() &&
 123       !connecting_;
 124 }
 125
 126 void ConnectionFactoryImpl::SignalConnectionReset() {
 127   if (connecting_)
 128     return;  // Already attempting to reconnect.
 129
 130   if (!backoff_reset_time_.is_null() &&
 131       NowTicks() - backoff_reset_time_ <=
 132           base::TimeDelta::FromSeconds(kConnectionResetWindowSecs)) {
 133     backoff_entry_.swap(previous_backoff_);
 134     backoff_entry_->InformOfRequest(false);
 135   }
 136   backoff_reset_time_ = base::TimeTicks();
 137   previous_backoff_->Reset();
 138   Connect();
 139 }
 140
 141 base::TimeTicks ConnectionFactoryImpl::NextRetryAttempt() const {
 142   if (!backoff_entry_)
 143     return base::TimeTicks();
 144   return backoff_entry_->GetReleaseTime();
 145 }
 146
 147 void ConnectionFactoryImpl::OnConnectionTypeChanged(
 148     net::NetworkChangeNotifier::ConnectionType type) {
 149   if (type == net::NetworkChangeNotifier::CONNECTION_NONE)
 150     return;
 151
 152   // TODO(zea): implement different backoff/retry policies based on connection
 153   // type.
 154   DVLOG(1) << "Connection type changed to " << type << ", resetting backoff.";
 155   backoff_entry_->Reset();
 156   // Connect(..) should be retrying with backoff already if a connection is
 157   // necessary, so no need to call again.
 158 }
 159
 160 void ConnectionFactoryImpl::OnIPAddressChanged() {
 161   DVLOG(1) << "IP Address changed, resetting backoff.";
 162   backoff_entry_->Reset();
 163   // Connect(..) should be retrying with backoff already if a connection is
 164   // necessary, so no need to call again.
 165 }
 166
 167 void ConnectionFactoryImpl::ConnectImpl() {
 168   if (socket_handle_.socket() && socket_handle_.socket()->IsConnected())
 169     socket_handle_.socket()->Disconnect();
 170   socket_handle_.Reset();
 171
 172   // TODO(zea): resolve proxies.
 173   net::ProxyInfo proxy_info;
 174   proxy_info.UseDirect();
 175   net::SSLConfig ssl_config;
 176   network_session_->ssl_config_service()->GetSSLConfig(&ssl_config);
 177
 178   int status = net::InitSocketHandleForTlsConnect(
 179       net::HostPortPair::FromURL(mcs_endpoint_),
 180       network_session_.get(),
 181       proxy_info,
 182       ssl_config,
 183       ssl_config,
 184       net::kPrivacyModeDisabled,
 185       net::BoundNetLog::Make(net_log_, net::NetLog::SOURCE_SOCKET),
 186       &socket_handle_,
 187       base::Bind(&ConnectionFactoryImpl::OnConnectDone,
 188                  weak_ptr_factory_.GetWeakPtr()));
 189   if (status != net::ERR_IO_PENDING)
 190     OnConnectDone(status);
 191 }
 192
 193 void ConnectionFactoryImpl::InitHandler() {
 194   // May be null in tests.
 195   mcs_proto::LoginRequest login_request;
 196   if (!request_builder_.is_null()) {
 197     request_builder_.Run(&login_request);
 198     DCHECK(login_request.IsInitialized());
 199   }
 200
 201   connection_handler_->Init(login_request, socket_handle_.socket());
 202 }
 203
 204 scoped_ptr<net::BackoffEntry> ConnectionFactoryImpl::CreateBackoffEntry(
 205     const net::BackoffEntry::Policy* const policy) {
 206   return scoped_ptr<net::BackoffEntry>(new net::BackoffEntry(policy));
 207 }
 208
 209 base::TimeTicks ConnectionFactoryImpl::NowTicks() {
 210   return base::TimeTicks::Now();
 211 }
 212
 213 void ConnectionFactoryImpl::OnConnectDone(int result) {
 214   if (result != net::OK) {
 215     LOG(ERROR) << "Failed to connect to MCS endpoint with error " << result;
 216     backoff_entry_->InformOfRequest(false);
 217     UMA_HISTOGRAM_SPARSE_SLOWLY("GCM.ConnectionFailureErrorCode", result);
 218     Connect();
 219     return;
 220   }
 221
 222   DVLOG(1) << "MCS endpoint socket connection success, starting handshake.";
 223   InitHandler();
 224 }
 225
 226 void ConnectionFactoryImpl::ConnectionHandlerCallback(int result) {
 227   if (result == net::OK) {
 228     // Handshake succeeded, reset the backoff.
 229     connecting_ = false;
 230     backoff_reset_time_ = NowTicks();
 231     previous_backoff_.swap(backoff_entry_);
 232     backoff_entry_->Reset();
 233     return;
 234   }
 235
 236   if (!connecting_)
 237     UMA_HISTOGRAM_SPARSE_SLOWLY("GCM.ConnectionDisconnectErrorCode", result);
 238
 239   // TODO(zea): Consider how to handle errors that may require some sort of
 240   // user intervention (login page, etc.).
 241   LOG(ERROR) << "Connection reset with error " << result;
 242   backoff_entry_->InformOfRequest(false);
 243   Connect();
 244 }
 245
 246 }  // namespace gcm