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     HostResolver* host_resolver,
  90     Delegate* delegate,
  91     NetLog* net_log)
  92     : ConnectJob(group_name, timeout_duration, priority, delegate,
  93                  BoundNetLog::Make(net_log, NetLog::SOURCE_CONNECT_JOB)),
  94       params_(params),
  95       transport_pool_(transport_pool),
  96       ssl_pool_(ssl_pool),
  97       resolver_(host_resolver),
  98       using_spdy_(false),
  99       protocol_negotiated_(kProtoUnknown),
 100       weak_ptr_factory_(this) {
 101     callback_= base::Bind(&HttpProxyConnectJob::OnIOComplete,
 102                            weak_ptr_factory_.GetWeakPtr());
 103 }
 104
 105 HttpProxyConnectJob::~HttpProxyConnectJob() {}
 106
 107 LoadState HttpProxyConnectJob::GetLoadState() const {
 108   switch (next_state_) {
 109     case STATE_TCP_CONNECT:
 110     case STATE_TCP_CONNECT_COMPLETE:
 111     case STATE_SSL_CONNECT:
 112     case STATE_SSL_CONNECT_COMPLETE:
 113       return transport_socket_handle_->GetLoadState();
 114     case STATE_HTTP_PROXY_CONNECT:
 115     case STATE_HTTP_PROXY_CONNECT_COMPLETE:
 116     case STATE_SPDY_PROXY_CREATE_STREAM:
 117     case STATE_SPDY_PROXY_CREATE_STREAM_COMPLETE:
 118       return LOAD_STATE_ESTABLISHING_PROXY_TUNNEL;
 119     default:
 120       NOTREACHED();
 121       return LOAD_STATE_IDLE;
 122   }
 123 }
 124
 125 void HttpProxyConnectJob::GetAdditionalErrorState(ClientSocketHandle * handle) {
 126   if (error_response_info_.cert_request_info.get()) {
 127     handle->set_ssl_error_response_info(error_response_info_);
 128     handle->set_is_ssl_error(true);
 129   }
 130 }
 131
 132 void HttpProxyConnectJob::OnIOComplete(int result) {
 133   int rv = DoLoop(result);
 134   if (rv != ERR_IO_PENDING) {
 135     NotifyProxyDelegateOfCompletion(rv);
 136     NotifyDelegateOfCompletion(rv);  // Deletes |this|
 137   }
 138 }
 139
 140 int HttpProxyConnectJob::DoLoop(int result) {
 141   DCHECK_NE(next_state_, STATE_NONE);
 142
 143   int rv = result;
 144   do {
 145     State state = next_state_;
 146     next_state_ = STATE_NONE;
 147     switch (state) {
 148       case STATE_TCP_CONNECT:
 149         DCHECK_EQ(OK, rv);
 150         rv = DoTransportConnect();
 151         break;
 152       case STATE_TCP_CONNECT_COMPLETE:
 153         rv = DoTransportConnectComplete(rv);
 154         break;
 155       case STATE_SSL_CONNECT:
 156         DCHECK_EQ(OK, rv);
 157         rv = DoSSLConnect();
 158         break;
 159       case STATE_SSL_CONNECT_COMPLETE:
 160         rv = DoSSLConnectComplete(rv);
 161         break;
 162       case STATE_HTTP_PROXY_CONNECT:
 163         DCHECK_EQ(OK, rv);
 164         rv = DoHttpProxyConnect();
 165         break;
 166       case STATE_HTTP_PROXY_CONNECT_COMPLETE:
 167         rv = DoHttpProxyConnectComplete(rv);
 168         break;
 169       case STATE_SPDY_PROXY_CREATE_STREAM:
 170         DCHECK_EQ(OK, rv);
 171         rv = DoSpdyProxyCreateStream();
 172         break;
 173       case STATE_SPDY_PROXY_CREATE_STREAM_COMPLETE:
 174         rv = DoSpdyProxyCreateStreamComplete(rv);
 175         break;
 176       default:
 177         NOTREACHED() << "bad state";
 178         rv = ERR_FAILED;
 179         break;
 180     }
 181   } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
 182
 183   return rv;
 184 }
 185
 186 int HttpProxyConnectJob::DoTransportConnect() {
 187   next_state_ = STATE_TCP_CONNECT_COMPLETE;
 188   transport_socket_handle_.reset(new ClientSocketHandle());
 189   return transport_socket_handle_->Init(group_name(),
 190                                         params_->transport_params(),
 191                                         priority(),
 192                                         callback_,
 193                                         transport_pool_,
 194                                         net_log());
 195 }
 196
 197 int HttpProxyConnectJob::DoTransportConnectComplete(int result) {
 198   if (result != OK)
 199     return ERR_PROXY_CONNECTION_FAILED;
 200
 201   // Reset the timer to just the length of time allowed for HttpProxy handshake
 202   // so that a fast TCP connection plus a slow HttpProxy failure doesn't take
 203   // longer to timeout than it should.
 204   ResetTimer(base::TimeDelta::FromSeconds(
 205       kHttpProxyConnectJobTimeoutInSeconds));
 206
 207   next_state_ = STATE_HTTP_PROXY_CONNECT;
 208   return result;
 209 }
 210
 211 int HttpProxyConnectJob::DoSSLConnect() {
 212   if (params_->tunnel()) {
 213     SpdySessionKey key(params_->destination().host_port_pair(),
 214                        ProxyServer::Direct(),
 215                        PRIVACY_MODE_DISABLED);
 216     if (params_->spdy_session_pool()->FindAvailableSession(key, net_log())) {
 217       using_spdy_ = true;
 218       next_state_ = STATE_SPDY_PROXY_CREATE_STREAM;
 219       return OK;
 220     }
 221   }
 222   next_state_ = STATE_SSL_CONNECT_COMPLETE;
 223   transport_socket_handle_.reset(new ClientSocketHandle());
 224   return transport_socket_handle_->Init(
 225       group_name(), params_->ssl_params(), priority(), callback_,
 226       ssl_pool_, net_log());
 227 }
 228
 229 int HttpProxyConnectJob::DoSSLConnectComplete(int result) {
 230   if (result == ERR_SSL_CLIENT_AUTH_CERT_NEEDED) {
 231     error_response_info_ = transport_socket_handle_->ssl_error_response_info();
 232     DCHECK(error_response_info_.cert_request_info.get());
 233     error_response_info_.cert_request_info->is_proxy = true;
 234     return result;
 235   }
 236   if (IsCertificateError(result)) {
 237     if (params_->ssl_params()->load_flags() & LOAD_IGNORE_ALL_CERT_ERRORS) {
 238       result = OK;
 239     } else {
 240       // TODO(rch): allow the user to deal with proxy cert errors in the
 241       // same way as server cert errors.
 242       transport_socket_handle_->socket()->Disconnect();
 243       return ERR_PROXY_CERTIFICATE_INVALID;
 244     }
 245   }
 246   // A SPDY session to the proxy completed prior to resolving the proxy
 247   // hostname. Surface this error, and allow the delegate to retry.
 248   // See crbug.com/334413.
 249   if (result == ERR_SPDY_SESSION_ALREADY_EXISTS) {
 250     DCHECK(!transport_socket_handle_->socket());
 251     return ERR_SPDY_SESSION_ALREADY_EXISTS;
 252   }
 253   if (result < 0) {
 254     if (transport_socket_handle_->socket())
 255       transport_socket_handle_->socket()->Disconnect();
 256     return ERR_PROXY_CONNECTION_FAILED;
 257   }
 258
 259   SSLClientSocket* ssl =
 260       static_cast<SSLClientSocket*>(transport_socket_handle_->socket());
 261   using_spdy_ = ssl->was_spdy_negotiated();
 262   protocol_negotiated_ = ssl->GetNegotiatedProtocol();
 263
 264   // Reset the timer to just the length of time allowed for HttpProxy handshake
 265   // so that a fast SSL connection plus a slow HttpProxy failure doesn't take
 266   // longer to timeout than it should.
 267   ResetTimer(base::TimeDelta::FromSeconds(
 268       kHttpProxyConnectJobTimeoutInSeconds));
 269   // TODO(rch): If we ever decide to implement a "trusted" SPDY proxy
 270   // (one that we speak SPDY over SSL to, but to which we send HTTPS
 271   // request directly instead of through CONNECT tunnels, then we
 272   // need to add a predicate to this if statement so we fall through
 273   // to the else case. (HttpProxyClientSocket currently acts as
 274   // a "trusted" SPDY proxy).
 275   if (using_spdy_ && params_->tunnel()) {
 276     next_state_ = STATE_SPDY_PROXY_CREATE_STREAM;
 277   } else {
 278     next_state_ = STATE_HTTP_PROXY_CONNECT;
 279   }
 280   return result;
 281 }
 282
 283 int HttpProxyConnectJob::DoHttpProxyConnect() {
 284   next_state_ = STATE_HTTP_PROXY_CONNECT_COMPLETE;
 285   const HostResolver::RequestInfo& tcp_destination = params_->destination();
 286   const HostPortPair& proxy_server = tcp_destination.host_port_pair();
 287
 288   // Add a HttpProxy connection on top of the tcp socket.
 289   transport_socket_.reset(
 290       new HttpProxyClientSocket(transport_socket_handle_.release(),
 291                                 params_->request_url(),
 292                                 params_->user_agent(),
 293                                 params_->endpoint(),
 294                                 proxy_server,
 295                                 params_->http_auth_cache(),
 296                                 params_->http_auth_handler_factory(),
 297                                 params_->tunnel(),
 298                                 using_spdy_,
 299                                 protocol_negotiated_,
 300                                 params_->proxy_delegate(),
 301                                 params_->ssl_params().get() != NULL));
 302   return transport_socket_->Connect(callback_);
 303 }
 304
 305 int HttpProxyConnectJob::DoHttpProxyConnectComplete(int result) {
 306   if (result == OK || result == ERR_PROXY_AUTH_REQUESTED ||
 307       result == ERR_HTTPS_PROXY_TUNNEL_RESPONSE) {
 308     SetSocket(transport_socket_.Pass());
 309   }
 310
 311   return result;
 312 }
 313
 314 int HttpProxyConnectJob::DoSpdyProxyCreateStream() {
 315   DCHECK(using_spdy_);
 316   DCHECK(params_->tunnel());
 317   SpdySessionKey key(params_->destination().host_port_pair(),
 318                      ProxyServer::Direct(),
 319                      PRIVACY_MODE_DISABLED);
 320   SpdySessionPool* spdy_pool = params_->spdy_session_pool();
 321   base::WeakPtr<SpdySession> spdy_session =
 322       spdy_pool->FindAvailableSession(key, net_log());
 323   // It's possible that a session to the proxy has recently been created
 324   if (spdy_session) {
 325     if (transport_socket_handle_.get()) {
 326       if (transport_socket_handle_->socket())
 327         transport_socket_handle_->socket()->Disconnect();
 328       transport_socket_handle_->Reset();
 329     }
 330   } else {
 331     // Create a session direct to the proxy itself
 332     spdy_session =
 333         spdy_pool->CreateAvailableSessionFromSocket(
 334             key, transport_socket_handle_.Pass(),
 335             net_log(), OK, /*using_ssl_*/ true);
 336     DCHECK(spdy_session);
 337   }
 338
 339   next_state_ = STATE_SPDY_PROXY_CREATE_STREAM_COMPLETE;
 340   return spdy_stream_request_.StartRequest(SPDY_BIDIRECTIONAL_STREAM,
 341                                            spdy_session,
 342                                            params_->request_url(),
 343                                            priority(),
 344                                            spdy_session->net_log(),
 345                                            callback_);
 346 }
 347
 348 int HttpProxyConnectJob::DoSpdyProxyCreateStreamComplete(int result) {
 349   if (result < 0)
 350     return result;
 351
 352   next_state_ = STATE_HTTP_PROXY_CONNECT_COMPLETE;
 353   base::WeakPtr<SpdyStream> stream = spdy_stream_request_.ReleaseStream();
 354   DCHECK(stream.get());
 355   // |transport_socket_| will set itself as |stream|'s delegate.
 356   transport_socket_.reset(
 357       new SpdyProxyClientSocket(stream,
 358                                 params_->user_agent(),
 359                                 params_->endpoint(),
 360                                 params_->request_url(),
 361                                 params_->destination().host_port_pair(),
 362                                 net_log(),
 363                                 params_->http_auth_cache(),
 364                                 params_->http_auth_handler_factory()));
 365   return transport_socket_->Connect(callback_);
 366 }
 367
 368 void HttpProxyConnectJob::NotifyProxyDelegateOfCompletion(int result) {
 369   if (!params_->proxy_delegate())
 370     return;
 371
 372   const HostPortPair& proxy_server = params_->destination().host_port_pair();
 373   params_->proxy_delegate()->OnTunnelConnectCompleted(params_->endpoint(),
 374                                                       proxy_server,
 375                                                       result);
 376 }
 377
 378 int HttpProxyConnectJob::ConnectInternal() {
 379   if (params_->transport_params().get()) {
 380     next_state_ = STATE_TCP_CONNECT;
 381   } else {
 382     next_state_ = STATE_SSL_CONNECT;
 383   }
 384
 385   int rv = DoLoop(OK);
 386   if (rv != ERR_IO_PENDING) {
 387     NotifyProxyDelegateOfCompletion(rv);
 388   }
 389
 390   return rv;
 391 }
 392
 393 HttpProxyClientSocketPool::
 394 HttpProxyConnectJobFactory::HttpProxyConnectJobFactory(
 395     TransportClientSocketPool* transport_pool,
 396     SSLClientSocketPool* ssl_pool,
 397     HostResolver* host_resolver,
 398     const ProxyDelegate* proxy_delegate,
 399     NetLog* net_log)
 400     : transport_pool_(transport_pool),
 401       ssl_pool_(ssl_pool),
 402       host_resolver_(host_resolver),
 403       proxy_delegate_(proxy_delegate),
 404       net_log_(net_log) {
 405   base::TimeDelta max_pool_timeout = base::TimeDelta();
 406
 407 // TODO(kundaji): Proxy connect timeout should be independent of platform and be
 408 // based on proxy. Bug http://crbug.com/407446.
 409 #if (defined(OS_ANDROID) || defined(OS_IOS))
 410 #else
 411   if (transport_pool_)
 412     max_pool_timeout = transport_pool_->ConnectionTimeout();
 413   if (ssl_pool_)
 414     max_pool_timeout = std::max(max_pool_timeout,
 415                                 ssl_pool_->ConnectionTimeout());
 416 #endif
 417   timeout_ = max_pool_timeout +
 418     base::TimeDelta::FromSeconds(kHttpProxyConnectJobTimeoutInSeconds);
 419 }
 420
 421
 422 scoped_ptr<ConnectJob>
 423 HttpProxyClientSocketPool::HttpProxyConnectJobFactory::NewConnectJob(
 424     const std::string& group_name,
 425     const PoolBase::Request& request,
 426     ConnectJob::Delegate* delegate) const {
 427   return scoped_ptr<ConnectJob>(new HttpProxyConnectJob(group_name,
 428                                                         request.priority(),
 429                                                         request.params(),
 430                                                         ConnectionTimeout(),
 431                                                         transport_pool_,
 432                                                         ssl_pool_,
 433                                                         host_resolver_,
 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     HostResolver* host_resolver,
 449     TransportClientSocketPool* transport_pool,
 450     SSLClientSocketPool* ssl_pool,
 451     const ProxyDelegate* proxy_delegate,
 452     NetLog* net_log)
 453     : transport_pool_(transport_pool),
 454       ssl_pool_(ssl_pool),
 455       base_(this, max_sockets, max_sockets_per_group, histograms,
 456             ClientSocketPool::unused_idle_socket_timeout(),
 457             ClientSocketPool::used_idle_socket_timeout(),
 458             new HttpProxyConnectJobFactory(transport_pool,
 459                                            ssl_pool,
 460                                            host_resolver,
 461                                            proxy_delegate,
 462                                            net_log)) {
 463   // We should always have a |transport_pool_| except in unit tests.
 464   if (transport_pool_)
 465     base_.AddLowerLayeredPool(transport_pool_);
 466   if (ssl_pool_)
 467     base_.AddLowerLayeredPool(ssl_pool_);
 468 }
 469
 470 HttpProxyClientSocketPool::~HttpProxyClientSocketPool() {
 471 }
 472
 473 int HttpProxyClientSocketPool::RequestSocket(
 474     const std::string& group_name, const void* socket_params,
 475     RequestPriority priority, ClientSocketHandle* handle,
 476     const CompletionCallback& callback, const BoundNetLog& net_log) {
 477   const scoped_refptr<HttpProxySocketParams>* casted_socket_params =
 478       static_cast<const scoped_refptr<HttpProxySocketParams>*>(socket_params);
 479
 480   return base_.RequestSocket(group_name, *casted_socket_params, priority,
 481                              handle, callback, net_log);
 482 }
 483
 484 void HttpProxyClientSocketPool::RequestSockets(
 485     const std::string& group_name,
 486     const void* params,
 487     int num_sockets,
 488     const BoundNetLog& net_log) {
 489   const scoped_refptr<HttpProxySocketParams>* casted_params =
 490       static_cast<const scoped_refptr<HttpProxySocketParams>*>(params);
 491
 492   base_.RequestSockets(group_name, *casted_params, num_sockets, net_log);
 493 }
 494
 495 void HttpProxyClientSocketPool::CancelRequest(
 496     const std::string& group_name,
 497     ClientSocketHandle* handle) {
 498   base_.CancelRequest(group_name, handle);
 499 }
 500
 501 void HttpProxyClientSocketPool::ReleaseSocket(const std::string& group_name,
 502                                               scoped_ptr<StreamSocket> socket,
 503                                               int id) {
 504   base_.ReleaseSocket(group_name, socket.Pass(), id);
 505 }
 506
 507 void HttpProxyClientSocketPool::FlushWithError(int error) {
 508   base_.FlushWithError(error);
 509 }
 510
 511 void HttpProxyClientSocketPool::CloseIdleSockets() {
 512   base_.CloseIdleSockets();
 513 }
 514
 515 int HttpProxyClientSocketPool::IdleSocketCount() const {
 516   return base_.idle_socket_count();
 517 }
 518
 519 int HttpProxyClientSocketPool::IdleSocketCountInGroup(
 520     const std::string& group_name) const {
 521   return base_.IdleSocketCountInGroup(group_name);
 522 }
 523
 524 LoadState HttpProxyClientSocketPool::GetLoadState(
 525     const std::string& group_name, const ClientSocketHandle* handle) const {
 526   return base_.GetLoadState(group_name, handle);
 527 }
 528
 529 base::DictionaryValue* HttpProxyClientSocketPool::GetInfoAsValue(
 530     const std::string& name,
 531     const std::string& type,
 532     bool include_nested_pools) const {
 533   base::DictionaryValue* dict = base_.GetInfoAsValue(name, type);
 534   if (include_nested_pools) {
 535     base::ListValue* list = new base::ListValue();
 536     if (transport_pool_) {
 537       list->Append(transport_pool_->GetInfoAsValue("transport_socket_pool",
 538                                                    "transport_socket_pool",
 539                                                    true));
 540     }
 541     if (ssl_pool_) {
 542       list->Append(ssl_pool_->GetInfoAsValue("ssl_socket_pool",
 543                                              "ssl_socket_pool",
 544                                              true));
 545     }
 546     dict->Set("nested_pools", list);
 547   }
 548   return dict;
 549 }
 550
 551 base::TimeDelta HttpProxyClientSocketPool::ConnectionTimeout() const {
 552   return base_.ConnectionTimeout();
 553 }
 554
 555 ClientSocketPoolHistograms* HttpProxyClientSocketPool::histograms() const {
 556   return base_.histograms();
 557 }
 558
 559 bool HttpProxyClientSocketPool::IsStalled() const {
 560   return base_.IsStalled();
 561 }
 562
 563 void HttpProxyClientSocketPool::AddHigherLayeredPool(
 564     HigherLayeredPool* higher_pool) {
 565   base_.AddHigherLayeredPool(higher_pool);
 566 }
 567
 568 void HttpProxyClientSocketPool::RemoveHigherLayeredPool(
 569     HigherLayeredPool* higher_pool) {
 570   base_.RemoveHigherLayeredPool(higher_pool);
 571 }
 572
 573 bool HttpProxyClientSocketPool::CloseOneIdleConnection() {
 574   if (base_.CloseOneIdleSocket())
 575     return true;
 576   return base_.CloseOneIdleConnectionInHigherLayeredPool();
 577 }
 578
 579 }  // namespace net