Race TCP connection to proxies with QUIC connections

net/http/http_stream_factory_impl_job.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/http/http_stream_factory_impl_job.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/trace_event.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "net/base/port_util.h"
+#include "net/base/proxy_delegate.h"
 #include "net/cert/cert_verifier.h"
 #include "net/http/bidirectional_stream_impl.h"
 #include "net/http/http_basic_stream.h"
 #include "net/http/http_network_session.h"
 #include "net/http/http_proxy_client_socket.h"
 #include "net/http/http_proxy_client_socket_pool.h"
 #include "net/http/http_request_info.h"
 #include "net/http/http_server_properties.h"
 #include "net/http/http_stream_factory.h"
 #include "net/http/http_stream_factory_impl_request.h"
@@ skipping 116 matching lines @@
     : Job(delegate,
           job_type,
           session,
           request_info,
           priority,
           server_ssl_config,
           proxy_ssl_config,
           destination,
           origin_url,
           AlternativeService(),
+          ProxyServer(),
           net_log) {}
 
 HttpStreamFactoryImpl::Job::Job(Delegate* delegate,
                                 JobType job_type,
                                 HttpNetworkSession* session,
                                 const HttpRequestInfo& request_info,
                                 RequestPriority priority,
                                 const SSLConfig& server_ssl_config,
                                 const SSLConfig& proxy_ssl_config,
                                 HostPortPair destination,
                                 GURL origin_url,
                                 AlternativeService alternative_service,
+                                const ProxyServer& alternative_proxy_server,
                                 NetLog* net_log)
     : request_info_(request_info),
       priority_(priority),
       server_ssl_config_(server_ssl_config),
       proxy_ssl_config_(proxy_ssl_config),
       net_log_(BoundNetLog::Make(net_log, NetLog::SOURCE_HTTP_STREAM_JOB)),
       io_callback_(base::Bind(&Job::OnIOComplete, base::Unretained(this))),
       connection_(new ClientSocketHandle),
       session_(session),
       next_state_(STATE_NONE),
       pac_request_(NULL),
       destination_(destination),
       origin_url_(origin_url),
       alternative_service_(alternative_service),
       delegate_(delegate),
+      alternative_proxy_server_(alternative_proxy_server),
       job_type_(job_type),
       using_ssl_(false),
       using_spdy_(false),
       using_quic_(false),
       quic_request_(session_->quic_stream_factory()),
       using_existing_quic_session_(false),
       spdy_certificate_error_(OK),
       establishing_tunnel_(false),
       was_npn_negotiated_(false),
       negotiated_protocol_(kProtoUnknown),
       num_streams_(0),
       spdy_session_direct_(false),
       job_status_(STATUS_RUNNING),
       other_job_status_(STATUS_RUNNING),
       stream_type_(HttpStreamRequest::BIDIRECTIONAL_STREAM),
       ptr_factory_(this) {
   DCHECK(session);
+  // The job can't have alternative service and alternative proxy server set at
+  // the same time since alternative services are used for requests that are
+  // fetched directly, while the alternative proxy server is used for requests
+  // that should be fetched using proxy.
+  DCHECK(alternative_service_.protocol == UNINITIALIZED_ALTERNATE_PROTOCOL ||
+         !alternative_proxy_server_.is_valid());
+  DCHECK(!alternative_proxy_server_.is_valid() ||
+         !(IsSpdyAlternative() || IsQuicAlternative()));
+
   if (IsSpdyAlternative()) {
     DCHECK(origin_url_.SchemeIs("https"));
   }
   if (IsQuicAlternative()) {
     DCHECK(session_->params().enable_quic);
     using_quic_ = true;
   }
 }
 
 HttpStreamFactoryImpl::Job::~Job() {
@@ skipping 476 matching lines @@
   DCHECK(!pac_request_);
   DCHECK(session_);
 
   next_state_ = STATE_RESOLVE_PROXY_COMPLETE;
 
   if (request_info_.load_flags & LOAD_BYPASS_PROXY) {
     proxy_info_.UseDirect();
     return OK;
   }
 
+  // If an alternative proxy server was provided, use that.
+  if (alternative_proxy_server_.is_valid()) {

[Zhongyi Shi, 2016/08/20 06:15:40]

nit: DCHECK_EQ(job_type_, ALTERNATIVE);

[tbansal1, 2016/08/22 15:42:33]

good idea, I added a similar DCHECK in the constructor of the Job above.

+    proxy_info_.UseProxyServer(alternative_proxy_server_);
+    return OK;
+  }
+
   return session_->proxy_service()->ResolveProxy(
       origin_url_, request_info_.method, &proxy_info_, io_callback_,
       &pac_request_, session_->params().proxy_delegate, net_log_);
 }
 
 int HttpStreamFactoryImpl::Job::DoResolveProxyComplete(int result) {
   pac_request_ = NULL;
 
   if (result == OK) {
     // Remove unsupported proxies from the list.
@@ skipping 17 matching lines @@
       // user visible, because the non-alternative Job should be resumed.
       result = ERR_NO_SUPPORTED_PROXIES;
     }
   }
 
   if (result != OK) {
     return result;
   }
 
   next_state_ = STATE_WAIT;
+
+  delegate_->OnResolveProxyComplete(this, request_info_, priority_,
+                                    server_ssl_config_, proxy_ssl_config_,
+                                    stream_type_);
+
   return OK;
 }
 
 bool HttpStreamFactoryImpl::Job::ShouldForceQuic() const {
   return session_->params().enable_quic &&
          (base::ContainsKey(session_->params().origins_to_force_quic_on,
                             HostPortPair()) ||
           base::ContainsKey(session_->params().origins_to_force_quic_on,
                             destination_)) &&
          proxy_info_.is_direct() && origin_url_.SchemeIs("https");
@@ skipping 636 matching lines @@
       return error;
   }
 
   // Do not bypass non-QUIC proxy on ERR_MSG_TOO_BIG.
   if (!proxy_info_.is_quic() && error == ERR_MSG_TOO_BIG)
     return error;
 
   if (request_info_.load_flags & LOAD_BYPASS_PROXY)
     return error;
 
+  // Alternative proxy server job should not use fallback proxies, and instead
+  // return. This would resume the main job (if possible) which may try the
+  // fallback proxies.
+  if (alternative_proxy_server_.is_valid()) {
+    DCHECK_EQ(STATE_NONE, next_state_);
+    return error;
+  }
+
   if (proxy_info_.is_https() && proxy_ssl_config_.send_client_cert) {
     session_->ssl_client_auth_cache()->Remove(
         proxy_info_.proxy_server().host_port_pair());
   }
 
   int rv = session_->proxy_service()->ReconsiderProxyAfterError(
       request_info_.url, request_info_.method, error, &proxy_info_,
       io_callback_, &pac_request_, session_->params().proxy_delegate, net_log_);
   if (rv == OK || rv == ERR_IO_PENDING) {
     // If the error was during connection setup, there is no socket to
@@ skipping 60 matching lines @@
     // This Job was the alternative Job, and hence won the race.
     HistogramAlternateProtocolUsage(ALTERNATE_PROTOCOL_USAGE_WON_RACE);
   } else {
     // This Job was the normal Job, and hence the alternative Job lost the race.
     HistogramAlternateProtocolUsage(ALTERNATE_PROTOCOL_USAGE_LOST_RACE);
   }
 }
 
 void HttpStreamFactoryImpl::Job::MarkOtherJobComplete(const Job& job) {
   DCHECK_EQ(STATUS_RUNNING, other_job_status_);
+  DCHECK(!other_job_alternative_proxy_server_.is_valid());
+
   other_job_status_ = job.job_status_;
   other_job_alternative_service_ = job.alternative_service_;
+  other_job_alternative_proxy_server_ = job.alternative_proxy_server_;
+
+  // At most one job can have a valid |alternative_proxy_server_|.
+  DCHECK(!alternative_proxy_server_.is_valid() ||
+         !other_job_alternative_proxy_server_.is_valid());
+
   MaybeMarkAlternativeServiceBroken();
 }
 
 void HttpStreamFactoryImpl::Job::MaybeMarkAlternativeServiceBroken() {
   if (job_status_ == STATUS_RUNNING || other_job_status_ == STATUS_RUNNING)
     return;
 
+  MaybeNotifyAlternativeProxyServerBroken();
+
   if (IsSpdyAlternative() || IsQuicAlternative()) {
     if (job_status_ == STATUS_BROKEN && other_job_status_ == STATUS_SUCCEEDED) {
       HistogramBrokenAlternateProtocolLocation(
           BROKEN_ALTERNATE_PROTOCOL_LOCATION_HTTP_STREAM_FACTORY_IMPL_JOB_ALT);
       session_->http_server_properties()->MarkAlternativeServiceBroken(
           alternative_service_);
     }
     return;
   }
 
   session_->quic_stream_factory()->OnTcpJobCompleted(job_status_ ==
                                                      STATUS_SUCCEEDED);
   if (job_status_ == STATUS_SUCCEEDED && other_job_status_ == STATUS_BROKEN) {
     HistogramBrokenAlternateProtocolLocation(
         BROKEN_ALTERNATE_PROTOCOL_LOCATION_HTTP_STREAM_FACTORY_IMPL_JOB_MAIN);
     session_->http_server_properties()->MarkAlternativeServiceBroken(
         other_job_alternative_service_);
   }
 }
 
+void HttpStreamFactoryImpl::Job::MaybeNotifyAlternativeProxyServerBroken()
+    const {
+  if (!alternative_proxy_server_.is_valid() &&
+      !other_job_alternative_proxy_server_.is_valid()) {

[Zhongyi Shi, 2016/08/20 06:15:40]

nit:
DCHECK_EQ(alternative_service_.protocol != UNINITIALIZED_ALTERNATE_PROTOCOL ||
other_job_alternative_service_.protocol != UNINITIALIZED_ALTERNATE_PROTOCOL);

[tbansal1, 2016/08/22 15:42:33]

Isn't this the same as the DCHECKs in lInes 1558-1560 below?

[Zhongyi Shi, 2016/08/23 05:42:33]

You won't be able to run the checks on line 1558-1560 if you are early return
here, right?

[Zhongyi Shi, 2016/08/23 05:42:33]

I don't think those two checks has any correlation. Checking on line 1558-1560
doesn't guarantee the checks in this early return. I was trying to confirm that
one of the two jobs are using alternative service. 

[tbansal1, 2016/08/23 20:56:40]

I think what you meant was:
DCHECK(alternative_service_.protocol == UNINITIALIZED_ALTERNATE_PROTOCOL ||
         other_job_alternative_service_.protocol ==
             UNINITIALIZED_ALTERNATE_PROTOCOL);

Done.

+    // Neither of the two jobs used an alternative proxy server.
+    return;
+  }
+
+  // Neither this job, nor the other job should have used the alternative
+  // service.
+  DCHECK_EQ(UNINITIALIZED_ALTERNATE_PROTOCOL, alternative_service_.protocol);
+  DCHECK_EQ(UNINITIALIZED_ALTERNATE_PROTOCOL,
+            other_job_alternative_service_.protocol);
+
+  ProxyDelegate* proxy_delegate = session_->params().proxy_delegate;
+  if (!proxy_delegate)
+    return;
+
+  if (alternative_proxy_server_.is_valid()) {
+    // |this| connected to the alternative proxy server.
+    if ((job_status_ == STATUS_BROKEN || job_status_ == STATUS_FAILED) &&
+        other_job_status_ == STATUS_SUCCEEDED) {
+      // Notify ProxyDelegate.
+      proxy_delegate->OnAlternativeProxyBroken(alternative_proxy_server_);
+    }
+    return;
+  }
+
+  if (other_job_alternative_proxy_server_.is_valid()) {
+    // Other job connected to the alternative proxy server.
+    if (job_status_ == STATUS_SUCCEEDED &&
+        (other_job_status_ == STATUS_BROKEN ||
+         other_job_status_ == STATUS_FAILED)) {
+      // Notify ProxyDelegate.
+      proxy_delegate->OnAlternativeProxyBroken(
+          other_job_alternative_proxy_server_);
+    }
+    return;
+  }
+}
+
 ClientSocketPoolManager::SocketGroupType
 HttpStreamFactoryImpl::Job::GetSocketGroup() const {
   std::string scheme = origin_url_.scheme();
   if (scheme == "https" || scheme == "wss" || IsSpdyAlternative())
     return ClientSocketPoolManager::SSL_GROUP;
 
   if (scheme == "ftp")
     return ClientSocketPoolManager::FTP_GROUP;
 
   return ClientSocketPoolManager::NORMAL_GROUP;
@@ skipping 11 matching lines @@
 
   ConnectionAttempts socket_attempts = connection_->connection_attempts();
   if (connection_->socket()) {
     connection_->socket()->GetConnectionAttempts(&socket_attempts);
   }
 
   delegate_->AddConnectionAttemptsToRequest(this, socket_attempts);
 }
 
 }  // namespace net