net/socket/transport_client_socket_pool.h

   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 #ifndef NET_SOCKET_TRANSPORT_CLIENT_SOCKET_POOL_H_
   6 #define NET_SOCKET_TRANSPORT_CLIENT_SOCKET_POOL_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/time/time.h"
  14 #include "base/timer/timer.h"
  15 #include "net/base/host_port_pair.h"
  16 #include "net/dns/host_resolver.h"
  17 #include "net/dns/single_request_host_resolver.h"
  18 #include "net/socket/client_socket_pool.h"
  19 #include "net/socket/client_socket_pool_base.h"
  20 #include "net/socket/client_socket_pool_histograms.h"
  21
  22 namespace net {
  23
  24 class ClientSocketFactory;
  25
  26 typedef base::Callback<int(const AddressList&, const BoundNetLog& net_log)>
  27 OnHostResolutionCallback;
  28
  29 class NET_EXPORT_PRIVATE TransportSocketParams
  30     : public base::RefCounted<TransportSocketParams> {
  31  public:
  32   // CombineConnectAndWrite currently translates to using TCP FastOpen.
  33   // TCP FastOpen should not be used if the first write to the socket may
  34   // be non-idempotent, as the underlying socket could retransmit the data
  35   // on failure of the first transmission.
  36   // NOTE: Currently, COMBINE_CONNECT_AND_WRITE_DESIRED is used if the data in
  37   // the write is known to be idempotent, and COMBINE_CONNECT_AND_WRITE_DEFAULT
  38   // is used as a default for other cases (including non-idempotent writes).
  39   enum CombineConnectAndWritePolicy {
  40     COMBINE_CONNECT_AND_WRITE_DEFAULT,    // Default policy, implemented in
  41                                           // TransportSocketParams constructor.
  42     COMBINE_CONNECT_AND_WRITE_DESIRED,    // Combine if supported by socket.
  43     COMBINE_CONNECT_AND_WRITE_PROHIBITED  // Do not combine.
  44   };
  45
  46   // |host_resolution_callback| will be invoked after the the hostname is
  47   // resolved.  If |host_resolution_callback| does not return OK, then the
  48   // connection will be aborted with that value. |combine_connect_and_write|
  49   // defines the policy for use of TCP FastOpen on this socket.
  50   TransportSocketParams(
  51       const HostPortPair& host_port_pair,
  52       bool disable_resolver_cache,
  53       bool ignore_limits,
  54       const OnHostResolutionCallback& host_resolution_callback,
  55       CombineConnectAndWritePolicy combine_connect_and_write);
  56
  57   const HostResolver::RequestInfo& destination() const { return destination_; }
  58   bool ignore_limits() const { return ignore_limits_; }
  59   const OnHostResolutionCallback& host_resolution_callback() const {
  60     return host_resolution_callback_;
  61   }
  62
  63   CombineConnectAndWritePolicy combine_connect_and_write() const {
  64     return combine_connect_and_write_;
  65   }
  66
  67  private:
  68   friend class base::RefCounted<TransportSocketParams>;
  69   ~TransportSocketParams();
  70
  71   HostResolver::RequestInfo destination_;
  72   bool ignore_limits_;
  73   const OnHostResolutionCallback host_resolution_callback_;
  74   CombineConnectAndWritePolicy combine_connect_and_write_;
  75
  76   DISALLOW_COPY_AND_ASSIGN(TransportSocketParams);
  77 };
  78
  79 // Common data and logic shared between TransportConnectJob and
  80 // WebSocketTransportConnectJob.
  81 class NET_EXPORT_PRIVATE TransportConnectJobHelper {
  82  public:
  83   enum State {
  84     STATE_RESOLVE_HOST,
  85     STATE_RESOLVE_HOST_COMPLETE,
  86     STATE_TRANSPORT_CONNECT,
  87     STATE_TRANSPORT_CONNECT_COMPLETE,
  88     STATE_NONE,
  89   };
  90
  91   // For recording the connection time in the appropriate bucket.
  92   enum ConnectionLatencyHistogram {
  93     CONNECTION_LATENCY_UNKNOWN,
  94     CONNECTION_LATENCY_IPV4_WINS_RACE,
  95     CONNECTION_LATENCY_IPV4_NO_RACE,
  96     CONNECTION_LATENCY_IPV6_RACEABLE,
  97     CONNECTION_LATENCY_IPV6_SOLO,
  98   };
  99
 100   TransportConnectJobHelper(const scoped_refptr<TransportSocketParams>& params,
 101                             ClientSocketFactory* client_socket_factory,
 102                             HostResolver* host_resolver,
 103                             LoadTimingInfo::ConnectTiming* connect_timing);
 104   ~TransportConnectJobHelper();
 105
 106   ClientSocketFactory* client_socket_factory() {
 107     return client_socket_factory_;
 108   }
 109
 110   const AddressList& addresses() const { return addresses_; }
 111   State next_state() const { return next_state_; }
 112   void set_next_state(State next_state) { next_state_ = next_state; }
 113   CompletionCallback on_io_complete() const { return on_io_complete_; }
 114   const TransportSocketParams* params() { return params_.get(); }
 115
 116   int DoResolveHost(RequestPriority priority, const BoundNetLog& net_log);
 117   int DoResolveHostComplete(int result, const BoundNetLog& net_log);
 118
 119   template <class T>
 120   int DoConnectInternal(T* job);
 121
 122   template <class T>
 123   void SetOnIOComplete(T* job);
 124
 125   template <class T>
 126   void OnIOComplete(T* job, int result);
 127
 128   // Record the histograms Net.DNS_Resolution_And_TCP_Connection_Latency2 and
 129   // Net.TCP_Connection_Latency and return the connect duration.
 130   base::TimeDelta HistogramDuration(ConnectionLatencyHistogram race_result);
 131
 132   static const int kIPv6FallbackTimerInMs;
 133
 134  private:
 135   template <class T>
 136   int DoLoop(T* job, int result);
 137
 138   scoped_refptr<TransportSocketParams> params_;
 139   ClientSocketFactory* const client_socket_factory_;
 140   SingleRequestHostResolver resolver_;
 141   AddressList addresses_;
 142   State next_state_;
 143   CompletionCallback on_io_complete_;
 144   LoadTimingInfo::ConnectTiming* connect_timing_;
 145
 146   DISALLOW_COPY_AND_ASSIGN(TransportConnectJobHelper);
 147 };
 148
 149 // TransportConnectJob handles the host resolution necessary for socket creation
 150 // and the transport (likely TCP) connect. TransportConnectJob also has fallback
 151 // logic for IPv6 connect() timeouts (which may happen due to networks / routers
 152 // with broken IPv6 support). Those timeouts take 20s, so rather than make the
 153 // user wait 20s for the timeout to fire, we use a fallback timer
 154 // (kIPv6FallbackTimerInMs) and start a connect() to a IPv4 address if the timer
 155 // fires. Then we race the IPv4 connect() against the IPv6 connect() (which has
 156 // a headstart) and return the one that completes first to the socket pool.
 157 class NET_EXPORT_PRIVATE TransportConnectJob : public ConnectJob {
 158  public:
 159   TransportConnectJob(const std::string& group_name,
 160                       RequestPriority priority,
 161                       const scoped_refptr<TransportSocketParams>& params,
 162                       base::TimeDelta timeout_duration,
 163                       ClientSocketFactory* client_socket_factory,
 164                       HostResolver* host_resolver,
 165                       Delegate* delegate,
 166                       NetLog* net_log);
 167   ~TransportConnectJob() override;
 168
 169   // ConnectJob methods.
 170   LoadState GetLoadState() const override;
 171
 172   // Rolls |addrlist| forward until the first IPv4 address, if any.
 173   // WARNING: this method should only be used to implement the prefer-IPv4 hack.
 174   static void MakeAddressListStartWithIPv4(AddressList* addrlist);
 175
 176  private:
 177   enum ConnectInterval {
 178     CONNECT_INTERVAL_LE_10MS,
 179     CONNECT_INTERVAL_LE_20MS,
 180     CONNECT_INTERVAL_GT_20MS,
 181   };
 182
 183   friend class TransportConnectJobHelper;
 184
 185   int DoResolveHost();
 186   int DoResolveHostComplete(int result);
 187   int DoTransportConnect();
 188   int DoTransportConnectComplete(int result);
 189
 190   // Not part of the state machine.
 191   void DoIPv6FallbackTransportConnect();
 192   void DoIPv6FallbackTransportConnectComplete(int result);
 193
 194   // Begins the host resolution and the TCP connect.  Returns OK on success
 195   // and ERR_IO_PENDING if it cannot immediately service the request.
 196   // Otherwise, it returns a net error code.
 197   int ConnectInternal() override;
 198
 199   TransportConnectJobHelper helper_;
 200
 201   scoped_ptr<StreamSocket> transport_socket_;
 202
 203   scoped_ptr<StreamSocket> fallback_transport_socket_;
 204   scoped_ptr<AddressList> fallback_addresses_;
 205   base::TimeTicks fallback_connect_start_time_;
 206   base::OneShotTimer<TransportConnectJob> fallback_timer_;
 207
 208   // Track the interval between this connect and previous connect.
 209   ConnectInterval interval_between_connects_;
 210
 211   DISALLOW_COPY_AND_ASSIGN(TransportConnectJob);
 212 };
 213
 214 class NET_EXPORT_PRIVATE TransportClientSocketPool : public ClientSocketPool {
 215  public:
 216   typedef TransportSocketParams SocketParams;
 217
 218   TransportClientSocketPool(
 219       int max_sockets,
 220       int max_sockets_per_group,
 221       ClientSocketPoolHistograms* histograms,
 222       HostResolver* host_resolver,
 223       ClientSocketFactory* client_socket_factory,
 224       NetLog* net_log);
 225
 226   ~TransportClientSocketPool() override;
 227
 228   // ClientSocketPool implementation.
 229   int RequestSocket(const std::string& group_name,
 230                     const void* resolve_info,
 231                     RequestPriority priority,
 232                     ClientSocketHandle* handle,
 233                     const CompletionCallback& callback,
 234                     const BoundNetLog& net_log) override;
 235   void RequestSockets(const std::string& group_name,
 236                       const void* params,
 237                       int num_sockets,
 238                       const BoundNetLog& net_log) override;
 239   void CancelRequest(const std::string& group_name,
 240                      ClientSocketHandle* handle) override;
 241   void ReleaseSocket(const std::string& group_name,
 242                      scoped_ptr<StreamSocket> socket,
 243                      int id) override;
 244   void FlushWithError(int error) override;
 245   void CloseIdleSockets() override;
 246   int IdleSocketCount() const override;
 247   int IdleSocketCountInGroup(const std::string& group_name) const override;
 248   LoadState GetLoadState(const std::string& group_name,
 249                          const ClientSocketHandle* handle) const override;
 250   base::DictionaryValue* GetInfoAsValue(
 251       const std::string& name,
 252       const std::string& type,
 253       bool include_nested_pools) const override;
 254   base::TimeDelta ConnectionTimeout() const override;
 255   ClientSocketPoolHistograms* histograms() const override;
 256
 257   // HigherLayeredPool implementation.
 258   bool IsStalled() const override;
 259   void AddHigherLayeredPool(HigherLayeredPool* higher_pool) override;
 260   void RemoveHigherLayeredPool(HigherLayeredPool* higher_pool) override;
 261
 262  protected:
 263   // Methods shared with WebSocketTransportClientSocketPool
 264   void NetLogTcpClientSocketPoolRequestedSocket(
 265       const BoundNetLog& net_log,
 266       const scoped_refptr<TransportSocketParams>* casted_params);
 267
 268  private:
 269   typedef ClientSocketPoolBase<TransportSocketParams> PoolBase;
 270
 271   class TransportConnectJobFactory
 272       : public PoolBase::ConnectJobFactory {
 273    public:
 274     TransportConnectJobFactory(ClientSocketFactory* client_socket_factory,
 275                          HostResolver* host_resolver,
 276                          NetLog* net_log)
 277         : client_socket_factory_(client_socket_factory),
 278           host_resolver_(host_resolver),
 279           net_log_(net_log) {}
 280
 281     ~TransportConnectJobFactory() override {}
 282
 283     // ClientSocketPoolBase::ConnectJobFactory methods.
 284
 285     scoped_ptr<ConnectJob> NewConnectJob(
 286         const std::string& group_name,
 287         const PoolBase::Request& request,
 288         ConnectJob::Delegate* delegate) const override;
 289
 290     base::TimeDelta ConnectionTimeout() const override;
 291
 292    private:
 293     ClientSocketFactory* const client_socket_factory_;
 294     HostResolver* const host_resolver_;
 295     NetLog* net_log_;
 296
 297     DISALLOW_COPY_AND_ASSIGN(TransportConnectJobFactory);
 298   };
 299
 300   PoolBase base_;
 301
 302   DISALLOW_COPY_AND_ASSIGN(TransportClientSocketPool);
 303 };
 304
 305 template <class T>
 306 int TransportConnectJobHelper::DoConnectInternal(T* job) {
 307   next_state_ = STATE_RESOLVE_HOST;
 308   return this->DoLoop(job, OK);
 309 }
 310
 311 template <class T>
 312 void TransportConnectJobHelper::SetOnIOComplete(T* job) {
 313   // These usages of base::Unretained() are safe because IO callbacks are
 314   // guaranteed not to be called after the object is destroyed.
 315   on_io_complete_ = base::Bind(&TransportConnectJobHelper::OnIOComplete<T>,
 316                                base::Unretained(this),
 317                                base::Unretained(job));
 318 }
 319
 320 template <class T>
 321 void TransportConnectJobHelper::OnIOComplete(T* job, int result) {
 322   result = this->DoLoop(job, result);
 323   if (result != ERR_IO_PENDING)
 324     job->NotifyDelegateOfCompletion(result);  // Deletes |job| and |this|
 325 }
 326
 327 template <class T>
 328 int TransportConnectJobHelper::DoLoop(T* job, int result) {
 329   DCHECK_NE(next_state_, STATE_NONE);
 330
 331   int rv = result;
 332   do {
 333     State state = next_state_;
 334     next_state_ = STATE_NONE;
 335     switch (state) {
 336       case STATE_RESOLVE_HOST:
 337         DCHECK_EQ(OK, rv);
 338         rv = job->DoResolveHost();
 339         break;
 340       case STATE_RESOLVE_HOST_COMPLETE:
 341         rv = job->DoResolveHostComplete(rv);
 342         break;
 343       case STATE_TRANSPORT_CONNECT:
 344         DCHECK_EQ(OK, rv);
 345         rv = job->DoTransportConnect();
 346         break;
 347       case STATE_TRANSPORT_CONNECT_COMPLETE:
 348         rv = job->DoTransportConnectComplete(rv);
 349         break;
 350       default:
 351         NOTREACHED();
 352         rv = ERR_FAILED;
 353         break;
 354     }
 355   } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
 356
 357   return rv;
 358 }
 359
 360 }  // namespace net
 361
 362 #endif  // NET_SOCKET_TRANSPORT_CLIENT_SOCKET_POOL_H_