net/http/http_proxy_client_socket_pool.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/http/http_proxy_client_socket_pool.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/compiler_specific.h"
  10 #include "base/time/time.h"
  11 #include "base/values.h"
  12 #include "net/base/load_flags.h"
  13 #include "net/base/net_errors.h"
  14 #include "net/base/proxy_delegate.h"
  15 #include "net/http/http_network_session.h"
  16 #include "net/http/http_proxy_client_socket.h"
  17 #include "net/socket/client_socket_factory.h"
  18 #include "net/socket/client_socket_handle.h"
  19 #include "net/socket/client_socket_pool_base.h"
  20 #include "net/socket/ssl_client_socket.h"
  21 #include "net/socket/ssl_client_socket_pool.h"
  22 #include "net/socket/transport_client_socket_pool.h"
  23 #include "net/spdy/spdy_proxy_client_socket.h"
  24 #include "net/spdy/spdy_session.h"
  25 #include "net/spdy/spdy_session_pool.h"
  26 #include "net/spdy/spdy_stream.h"
  27 #include "net/ssl/ssl_cert_request_info.h"
  28 #include "url/gurl.h"
  29
  30 namespace net {
  31
  32 HttpProxySocketParams::HttpProxySocketParams(
  33     const scoped_refptr<TransportSocketParams>& transport_params,
  34     const scoped_refptr<SSLSocketParams>& ssl_params,
  35     const GURL& request_url,
  36     const std::string& user_agent,
  37     const HostPortPair& endpoint,
  38     HttpAuthCache* http_auth_cache,
  39     HttpAuthHandlerFactory* http_auth_handler_factory,
  40     SpdySessionPool* spdy_session_pool,
  41     bool tunnel,
  42     ProxyDelegate* proxy_delegate)
  43     : transport_params_(transport_params),
  44       ssl_params_(ssl_params),
  45       spdy_session_pool_(spdy_session_pool),
  46       request_url_(request_url),
  47       user_agent_(user_agent),
  48       endpoint_(endpoint),
  49       http_auth_cache_(tunnel ? http_auth_cache : NULL),
  50       http_auth_handler_factory_(tunnel ? http_auth_handler_factory : NULL),
  51       tunnel_(tunnel),
  52       proxy_delegate_(proxy_delegate) {
  53   DCHECK((transport_params.get() == NULL && ssl_params.get() != NULL) ||
  54          (transport_params.get() != NULL && ssl_params.get() == NULL));
  55   if (transport_params_.get()) {
  56     ignore_limits_ = transport_params->ignore_limits();
  57   } else {
  58     ignore_limits_ = ssl_params->ignore_limits();
  59   }
  60 }
  61
  62 const HostResolver::RequestInfo& HttpProxySocketParams::destination() const {
  63   if (transport_params_.get() == NULL) {
  64     return ssl_params_->GetDirectConnectionParams()->destination();
  65   } else {
  66     return transport_params_->destination();
  67   }
  68 }
  69
  70 HttpProxySocketParams::~HttpProxySocketParams() {}
  71
  72 // HttpProxyConnectJobs will time out after this many seconds.  Note this is on
  73 // top of the timeout for the transport socket.
  74 // TODO(kundaji): Proxy connect timeout should be independent of platform and be
  75 // based on proxy. Bug http://crbug.com/407446.
  76 #if defined(OS_ANDROID) || defined(OS_IOS)
  77 static const int kHttpProxyConnectJobTimeoutInSeconds = 10;
  78 #else
  79 static const int kHttpProxyConnectJobTimeoutInSeconds = 30;
  80 #endif
  81
  82 HttpProxyConnectJob::HttpProxyConnectJob(
  83     const std::string& group_name,
  84     RequestPriority priority,
  85     const scoped_refptr<HttpProxySocketParams>& params,
  86     const base::TimeDelta& timeout_duration,
  87     TransportClientSocketPool* transport_pool,
  88     SSLClientSocketPool* ssl_pool,
  89     Delegate* delegate,
  90     NetLog* net_log)
  91     : ConnectJob(group_name, timeout_duration, priority, delegate,
  92                  BoundNetLog::Make(net_log, NetLog::SOURCE_CONNECT_JOB)),
  93       params_(params),
  94       transport_pool_(transport_pool),
  95       ssl_pool_(ssl_pool),
  96       using_spdy_(false),
  97       protocol_negotiated_(kProtoUnknown),
  98       weak_ptr_factory_(this) {
  99     callback_= base::Bind(&HttpProxyConnectJob::OnIOComplete,
 100                            weak_ptr_factory_.GetWeakPtr());
 101 }
 102
 103 HttpProxyConnectJob::~HttpProxyConnectJob() {}
 104
 105 LoadState HttpProxyConnectJob::GetLoadState() const {
 106   switch (next_state_) {
 107     case STATE_TCP_CONNECT:
 108     case STATE_TCP_CONNECT_COMPLETE:
 109     case STATE_SSL_CONNECT:
 110     case STATE_SSL_CONNECT_COMPLETE:
 111       return transport_socket_handle_->GetLoadState();
 112     case STATE_HTTP_PROXY_CONNECT:
 113     case STATE_HTTP_PROXY_CONNECT_COMPLETE:
 114     case STATE_SPDY_PROXY_CREATE_STREAM:
 115     case STATE_SPDY_PROXY_CREATE_STREAM_COMPLETE:
 116       return LOAD_STATE_ESTABLISHING_PROXY_TUNNEL;
 117     default:
 118       NOTREACHED();
 119       return LOAD_STATE_IDLE;
 120   }
 121 }
 122
 123 void HttpProxyConnectJob::GetAdditionalErrorState(ClientSocketHandle * handle) {
 124   if (error_response_info_.cert_request_info.get()) {
 125     handle->set_ssl_error_response_info(error_response_info_);
 126     handle->set_is_ssl_error(true);
 127   }
 128 }
 129
 130 void HttpProxyConnectJob::OnIOComplete(int result) {
 131   // TODO(pkasting): Remove ScopedTracker below once crbug.com/455884 is fixed.
 132   tracked_objects::ScopedTracker tracking_profile(
 133       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 134           "455884 HttpProxyConnectJob::OnIOComplete"));
 135   int rv = DoLoop(result);
 136   if (rv != ERR_IO_PENDING) {
 137     NotifyProxyDelegateOfCompletion(rv);
 138     NotifyDelegateOfCompletion(rv);  // Deletes |this|
 139   }
 140 }
 141
 142 int HttpProxyConnectJob::DoLoop(int result) {
 143   DCHECK_NE(next_state_, STATE_NONE);
 144
 145   int rv = result;
 146   do {
 147     State state = next_state_;
 148     next_state_ = STATE_NONE;
 149     switch (state) {
 150       case STATE_TCP_CONNECT:
 151         DCHECK_EQ(OK, rv);
 152         rv = DoTransportConnect();
 153         break;
 154       case STATE_TCP_CONNECT_COMPLETE:
 155         rv = DoTransportConnectComplete(rv);
 156         break;
 157       case STATE_SSL_CONNECT:
 158         DCHECK_EQ(OK, rv);
 159         rv = DoSSLConnect();
 160         break;
 161       case STATE_SSL_CONNECT_COMPLETE:
 162         rv = DoSSLConnectComplete(rv);
 163         break;
 164       case STATE_HTTP_PROXY_CONNECT:
 165         DCHECK_EQ(OK, rv);
 166         rv = DoHttpProxyConnect();
 167         break;
 168       case STATE_HTTP_PROXY_CONNECT_COMPLETE:
 169         rv = DoHttpProxyConnectComplete(rv);
 170         break;
 171       case STATE_SPDY_PROXY_CREATE_STREAM:
 172         DCHECK_EQ(OK, rv);
 173         rv = DoSpdyProxyCreateStream();
 174         break;
 175       case STATE_SPDY_PROXY_CREATE_STREAM_COMPLETE:
 176         rv = DoSpdyProxyCreateStreamComplete(rv);
 177         break;
 178       default:
 179         NOTREACHED() << "bad state";
 180         rv = ERR_FAILED;
 181         break;
 182     }
 183   } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
 184
 185   return rv;
 186 }
 187
 188 int HttpProxyConnectJob::DoTransportConnect() {
 189   next_state_ = STATE_TCP_CONNECT_COMPLETE;
 190   transport_socket_handle_.reset(new ClientSocketHandle());
 191   return transport_socket_handle_->Init(group_name(),
 192                                         params_->transport_params(),
 193                                         priority(),
 194                                         callback_,
 195                                         transport_pool_,
 196                                         net_log());
 197 }
 198
 199 int HttpProxyConnectJob::DoTransportConnectComplete(int result) {
 200   if (result != OK)
 201     return ERR_PROXY_CONNECTION_FAILED;
 202
 203   // Reset the timer to just the length of time allowed for HttpProxy handshake
 204   // so that a fast TCP connection plus a slow HttpProxy failure doesn't take
 205   // longer to timeout than it should.
 206   ResetTimer(base::TimeDelta::FromSeconds(
 207       kHttpProxyConnectJobTimeoutInSeconds));
 208
 209   next_state_ = STATE_HTTP_PROXY_CONNECT;
 210   return result;
 211 }
 212
 213 int HttpProxyConnectJob::DoSSLConnect() {
 214   if (params_->tunnel()) {
 215     SpdySessionKey key(params_->destination().host_port_pair(),
 216                        ProxyServer::Direct(),
 217                        PRIVACY_MODE_DISABLED);
 218     if (params_->spdy_session_pool()->FindAvailableSession(key, net_log())) {
 219       using_spdy_ = true;
 220       next_state_ = STATE_SPDY_PROXY_CREATE_STREAM;
 221       return OK;
 222     }
 223   }
 224   next_state_ = STATE_SSL_CONNECT_COMPLETE;
 225   transport_socket_handle_.reset(new ClientSocketHandle());
 226   return transport_socket_handle_->Init(
 227       group_name(), params_->ssl_params(), priority(), callback_,
 228       ssl_pool_, net_log());
 229 }
 230
 231 int HttpProxyConnectJob::DoSSLConnectComplete(int result) {
 232   if (result == ERR_SSL_CLIENT_AUTH_CERT_NEEDED) {
 233     error_response_info_ = transport_socket_handle_->ssl_error_response_info();
 234     DCHECK(error_response_info_.cert_request_info.get());
 235     error_response_info_.cert_request_info->is_proxy = true;
 236     return result;
 237   }
 238   if (IsCertificateError(result)) {
 239     if (params_->ssl_params()->load_flags() & LOAD_IGNORE_ALL_CERT_ERRORS) {
 240       result = OK;
 241     } else {
 242       // TODO(rch): allow the user to deal with proxy cert errors in the
 243       // same way as server cert errors.
 244       transport_socket_handle_->socket()->Disconnect();
 245       return ERR_PROXY_CERTIFICATE_INVALID;
 246     }
 247   }
 248   // A SPDY session to the proxy completed prior to resolving the proxy
 249   // hostname. Surface this error, and allow the delegate to retry.
 250   // See crbug.com/334413.
 251   if (result == ERR_SPDY_SESSION_ALREADY_EXISTS) {
 252     DCHECK(!transport_socket_handle_->socket());
 253     return ERR_SPDY_SESSION_ALREADY_EXISTS;
 254   }
 255   if (result < 0) {
 256     if (transport_socket_handle_->socket())
 257       transport_socket_handle_->socket()->Disconnect();
 258     return ERR_PROXY_CONNECTION_FAILED;
 259   }
 260
 261   SSLClientSocket* ssl =
 262       static_cast<SSLClientSocket*>(transport_socket_handle_->socket());
 263   using_spdy_ = ssl->was_spdy_negotiated();
 264   protocol_negotiated_ = ssl->GetNegotiatedProtocol();
 265
 266   // Reset the timer to just the length of time allowed for HttpProxy handshake
 267   // so that a fast SSL connection plus a slow HttpProxy failure doesn't take
 268   // longer to timeout than it should.
 269   ResetTimer(base::TimeDelta::FromSeconds(
 270       kHttpProxyConnectJobTimeoutInSeconds));
 271   // TODO(rch): If we ever decide to implement a "trusted" SPDY proxy
 272   // (one that we speak SPDY over SSL to, but to which we send HTTPS
 273   // request directly instead of through CONNECT tunnels, then we
 274   // need to add a predicate to this if statement so we fall through
 275   // to the else case. (HttpProxyClientSocket currently acts as
 276   // a "trusted" SPDY proxy).
 277   if (using_spdy_ && params_->tunnel()) {
 278     next_state_ = STATE_SPDY_PROXY_CREATE_STREAM;
 279   } else {
 280     next_state_ = STATE_HTTP_PROXY_CONNECT;
 281   }
 282   return result;
 283 }
 284
 285 int HttpProxyConnectJob::DoHttpProxyConnect() {
 286   next_state_ = STATE_HTTP_PROXY_CONNECT_COMPLETE;
 287   const HostResolver::RequestInfo& tcp_destination = params_->destination();
 288   const HostPortPair& proxy_server = tcp_destination.host_port_pair();
 289
 290   // Add a HttpProxy connection on top of the tcp socket.
 291   transport_socket_.reset(
 292       new HttpProxyClientSocket(transport_socket_handle_.release(),
 293                                 params_->request_url(),
 294                                 params_->user_agent(),
 295                                 params_->endpoint(),
 296                                 proxy_server,
 297                                 params_->http_auth_cache(),
 298                                 params_->http_auth_handler_factory(),
 299                                 params_->tunnel(),
 300                                 using_spdy_,
 301                                 protocol_negotiated_,
 302                                 params_->proxy_delegate(),
 303                                 params_->ssl_params().get() != NULL));
 304   return transport_socket_->Connect(callback_);
 305 }
 306
 307 int HttpProxyConnectJob::DoHttpProxyConnectComplete(int result) {
 308   if (result == OK || result == ERR_PROXY_AUTH_REQUESTED ||
 309       result == ERR_HTTPS_PROXY_TUNNEL_RESPONSE) {
 310     SetSocket(transport_socket_.Pass());
 311   }
 312
 313   if (result == ERR_HTTP_1_1_REQUIRED)
 314     return ERR_PROXY_HTTP_1_1_REQUIRED;
 315
 316   return result;
 317 }
 318
 319 int HttpProxyConnectJob::DoSpdyProxyCreateStream() {
 320   DCHECK(using_spdy_);
 321   DCHECK(params_->tunnel());
 322   SpdySessionKey key(params_->destination().host_port_pair(),
 323                      ProxyServer::Direct(),
 324                      PRIVACY_MODE_DISABLED);
 325   SpdySessionPool* spdy_pool = params_->spdy_session_pool();
 326   base::WeakPtr<SpdySession> spdy_session =
 327       spdy_pool->FindAvailableSession(key, net_log());
 328   // It's possible that a session to the proxy has recently been created
 329   if (spdy_session) {
 330     if (transport_socket_handle_.get()) {
 331       if (transport_socket_handle_->socket())
 332         transport_socket_handle_->socket()->Disconnect();
 333       transport_socket_handle_->Reset();
 334     }
 335   } else {
 336     // Create a session direct to the proxy itself
 337     spdy_session =
 338         spdy_pool->CreateAvailableSessionFromSocket(
 339             key, transport_socket_handle_.Pass(),
 340             net_log(), OK, /*using_ssl_*/ true);
 341     DCHECK(spdy_session);
 342   }
 343
 344   next_state_ = STATE_SPDY_PROXY_CREATE_STREAM_COMPLETE;
 345   return spdy_stream_request_.StartRequest(SPDY_BIDIRECTIONAL_STREAM,
 346                                            spdy_session,
 347                                            params_->request_url(),
 348                                            priority(),
 349                                            spdy_session->net_log(),
 350                                            callback_);
 351 }
 352
 353 int HttpProxyConnectJob::DoSpdyProxyCreateStreamComplete(int result) {
 354   if (result < 0)
 355     return result;
 356
 357   next_state_ = STATE_HTTP_PROXY_CONNECT_COMPLETE;
 358   base::WeakPtr<SpdyStream> stream = spdy_stream_request_.ReleaseStream();
 359   DCHECK(stream.get());
 360   // |transport_socket_| will set itself as |stream|'s delegate.
 361   transport_socket_.reset(
 362       new SpdyProxyClientSocket(stream,
 363                                 params_->user_agent(),
 364                                 params_->endpoint(),
 365                                 params_->request_url(),
 366                                 params_->destination().host_port_pair(),
 367                                 net_log(),
 368                                 params_->http_auth_cache(),
 369                                 params_->http_auth_handler_factory()));
 370   return transport_socket_->Connect(callback_);
 371 }
 372
 373 void HttpProxyConnectJob::NotifyProxyDelegateOfCompletion(int result) {
 374   if (!params_->proxy_delegate())
 375     return;
 376
 377   const HostPortPair& proxy_server = params_->destination().host_port_pair();
 378   params_->proxy_delegate()->OnTunnelConnectCompleted(params_->endpoint(),
 379                                                       proxy_server,
 380                                                       result);
 381 }
 382
 383 int HttpProxyConnectJob::ConnectInternal() {
 384   if (params_->transport_params().get()) {
 385     next_state_ = STATE_TCP_CONNECT;
 386   } else {
 387     next_state_ = STATE_SSL_CONNECT;
 388   }
 389
 390   int rv = DoLoop(OK);
 391   if (rv != ERR_IO_PENDING) {
 392     NotifyProxyDelegateOfCompletion(rv);
 393   }
 394
 395   return rv;
 396 }
 397
 398 HttpProxyClientSocketPool::
 399 HttpProxyConnectJobFactory::HttpProxyConnectJobFactory(
 400     TransportClientSocketPool* transport_pool,
 401     SSLClientSocketPool* ssl_pool,
 402     NetLog* net_log)
 403     : transport_pool_(transport_pool),
 404       ssl_pool_(ssl_pool),
 405       net_log_(net_log) {
 406   base::TimeDelta max_pool_timeout = base::TimeDelta();
 407
 408 // TODO(kundaji): Proxy connect timeout should be independent of platform and be
 409 // based on proxy. Bug http://crbug.com/407446.
 410 #if (defined(OS_ANDROID) || defined(OS_IOS))
 411 #else
 412   if (transport_pool_)
 413     max_pool_timeout = transport_pool_->ConnectionTimeout();
 414   if (ssl_pool_)
 415     max_pool_timeout = std::max(max_pool_timeout,
 416                                 ssl_pool_->ConnectionTimeout());
 417 #endif
 418   timeout_ = max_pool_timeout +
 419     base::TimeDelta::FromSeconds(kHttpProxyConnectJobTimeoutInSeconds);
 420 }
 421
 422
 423 scoped_ptr<ConnectJob>
 424 HttpProxyClientSocketPool::HttpProxyConnectJobFactory::NewConnectJob(
 425     const std::string& group_name,
 426     const PoolBase::Request& request,
 427     ConnectJob::Delegate* delegate) const {
 428   return scoped_ptr<ConnectJob>(new HttpProxyConnectJob(group_name,
 429                                                         request.priority(),
 430                                                         request.params(),
 431                                                         ConnectionTimeout(),
 432                                                         transport_pool_,
 433                                                         ssl_pool_,
 434                                                         delegate,
 435                                                         net_log_));
 436 }
 437
 438 base::TimeDelta
 439 HttpProxyClientSocketPool::HttpProxyConnectJobFactory::ConnectionTimeout(
 440     ) const {
 441   return timeout_;
 442 }
 443
 444 HttpProxyClientSocketPool::HttpProxyClientSocketPool(
 445     int max_sockets,
 446     int max_sockets_per_group,
 447     ClientSocketPoolHistograms* histograms,
 448     TransportClientSocketPool* transport_pool,
 449     SSLClientSocketPool* ssl_pool,
 450     NetLog* net_log)
 451     : transport_pool_(transport_pool),
 452       ssl_pool_(ssl_pool),
 453       base_(this, max_sockets, max_sockets_per_group, histograms,
 454             ClientSocketPool::unused_idle_socket_timeout(),
 455             ClientSocketPool::used_idle_socket_timeout(),
 456             new HttpProxyConnectJobFactory(transport_pool,
 457                                            ssl_pool,
 458                                            net_log)) {
 459   // We should always have a |transport_pool_| except in unit tests.
 460   if (transport_pool_)
 461     base_.AddLowerLayeredPool(transport_pool_);
 462   if (ssl_pool_)
 463     base_.AddLowerLayeredPool(ssl_pool_);
 464 }
 465
 466 HttpProxyClientSocketPool::~HttpProxyClientSocketPool() {
 467 }
 468
 469 int HttpProxyClientSocketPool::RequestSocket(
 470     const std::string& group_name, const void* socket_params,
 471     RequestPriority priority, ClientSocketHandle* handle,
 472     const CompletionCallback& callback, const BoundNetLog& net_log) {
 473   const scoped_refptr<HttpProxySocketParams>* casted_socket_params =
 474       static_cast<const scoped_refptr<HttpProxySocketParams>*>(socket_params);
 475
 476   return base_.RequestSocket(group_name, *casted_socket_params, priority,
 477                              handle, callback, net_log);
 478 }
 479
 480 void HttpProxyClientSocketPool::RequestSockets(
 481     const std::string& group_name,
 482     const void* params,
 483     int num_sockets,
 484     const BoundNetLog& net_log) {
 485   const scoped_refptr<HttpProxySocketParams>* casted_params =
 486       static_cast<const scoped_refptr<HttpProxySocketParams>*>(params);
 487
 488   base_.RequestSockets(group_name, *casted_params, num_sockets, net_log);
 489 }
 490
 491 void HttpProxyClientSocketPool::CancelRequest(
 492     const std::string& group_name,
 493     ClientSocketHandle* handle) {
 494   base_.CancelRequest(group_name, handle);
 495 }
 496
 497 void HttpProxyClientSocketPool::ReleaseSocket(const std::string& group_name,
 498                                               scoped_ptr<StreamSocket> socket,
 499                                               int id) {
 500   base_.ReleaseSocket(group_name, socket.Pass(), id);
 501 }
 502
 503 void HttpProxyClientSocketPool::FlushWithError(int error) {
 504   base_.FlushWithError(error);
 505 }
 506
 507 void HttpProxyClientSocketPool::CloseIdleSockets() {
 508   base_.CloseIdleSockets();
 509 }
 510
 511 int HttpProxyClientSocketPool::IdleSocketCount() const {
 512   return base_.idle_socket_count();
 513 }
 514
 515 int HttpProxyClientSocketPool::IdleSocketCountInGroup(
 516     const std::string& group_name) const {
 517   return base_.IdleSocketCountInGroup(group_name);
 518 }
 519
 520 LoadState HttpProxyClientSocketPool::GetLoadState(
 521     const std::string& group_name, const ClientSocketHandle* handle) const {
 522   return base_.GetLoadState(group_name, handle);
 523 }
 524
 525 base::DictionaryValue* HttpProxyClientSocketPool::GetInfoAsValue(
 526     const std::string& name,
 527     const std::string& type,
 528     bool include_nested_pools) const {
 529   base::DictionaryValue* dict = base_.GetInfoAsValue(name, type);
 530   if (include_nested_pools) {
 531     base::ListValue* list = new base::ListValue();
 532     if (transport_pool_) {
 533       list->Append(transport_pool_->GetInfoAsValue("transport_socket_pool",
 534                                                    "transport_socket_pool",
 535                                                    true));
 536     }
 537     if (ssl_pool_) {
 538       list->Append(ssl_pool_->GetInfoAsValue("ssl_socket_pool",
 539                                              "ssl_socket_pool",
 540                                              true));
 541     }
 542     dict->Set("nested_pools", list);
 543   }
 544   return dict;
 545 }
 546
 547 base::TimeDelta HttpProxyClientSocketPool::ConnectionTimeout() const {
 548   return base_.ConnectionTimeout();
 549 }
 550
 551 ClientSocketPoolHistograms* HttpProxyClientSocketPool::histograms() const {
 552   return base_.histograms();
 553 }
 554
 555 bool HttpProxyClientSocketPool::IsStalled() const {
 556   return base_.IsStalled();
 557 }
 558
 559 void HttpProxyClientSocketPool::AddHigherLayeredPool(
 560     HigherLayeredPool* higher_pool) {
 561   base_.AddHigherLayeredPool(higher_pool);
 562 }
 563
 564 void HttpProxyClientSocketPool::RemoveHigherLayeredPool(
 565     HigherLayeredPool* higher_pool) {
 566   base_.RemoveHigherLayeredPool(higher_pool);
 567 }
 568
 569 bool HttpProxyClientSocketPool::CloseOneIdleConnection() {
 570   if (base_.CloseOneIdleSocket())
 571     return true;
 572   return base_.CloseOneIdleConnectionInHigherLayeredPool();
 573 }
 574
 575 }  // namespace net