chromecast/net/connectivity_checker.cc

   1 // Copyright 2015 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 "chromecast/net/connectivity_checker.h"
   6
   7 #include "base/command_line.h"
   8 #include "base/logging.h"
   9 #include "base/message_loop/message_loop.h"
  10 #include "chromecast/net/net_switches.h"
  11 #include "net/base/request_priority.h"
  12 #include "net/http/http_response_headers.h"
  13 #include "net/http/http_response_info.h"
  14 #include "net/http/http_status_code.h"
  15 #include "net/proxy/proxy_config.h"
  16 #include "net/proxy/proxy_config_service_fixed.h"
  17 #include "net/url_request/url_request_context.h"
  18 #include "net/url_request/url_request_context_builder.h"
  19
  20 namespace chromecast {
  21
  22 namespace {
  23
  24 // How often connectivity checks are performed in seconds
  25 const unsigned int kConnectivityPeriodSeconds = 1;
  26
  27 // Number of consecutive bad responses received before connectivity status is
  28 // changed to offline
  29 const unsigned int kNumBadResponses = 3;
  30
  31 // Default url for connectivity checking.
  32 const char kDefaultConnectivityCheckUrl[] =
  33     "https://clients3.google.com/generate_204";
  34
  35 }  // namespace
  36
  37 ConnectivityChecker::ConnectivityChecker(
  38     const scoped_refptr<base::MessageLoopProxy>& loop_proxy)
  39     : connectivity_observer_list_(
  40           new ObserverListThreadSafe<ConnectivityObserver>()),
  41       loop_proxy_(loop_proxy),
  42       connected_(false),
  43       bad_responses_(0) {
  44   DCHECK(loop_proxy_.get());
  45   loop_proxy->PostTask(FROM_HERE,
  46                        base::Bind(&ConnectivityChecker::Initialize, this));
  47 }
  48
  49 void ConnectivityChecker::Initialize() {
  50   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  51   base::CommandLine::StringType check_url_str =
  52       command_line->GetSwitchValueNative(switches::kConnectivityCheckUrl);
  53   connectivity_check_url_.reset(new GURL(
  54       check_url_str.empty() ? kDefaultConnectivityCheckUrl : check_url_str));
  55
  56   net::URLRequestContextBuilder builder;
  57   builder.set_proxy_config_service(
  58       new net::ProxyConfigServiceFixed(net::ProxyConfig::CreateDirect()));
  59   builder.DisableHttpCache();
  60   url_request_context_.reset(builder.Build());
  61
  62   net::NetworkChangeNotifier::AddConnectionTypeObserver(this);
  63   loop_proxy_->PostTask(FROM_HERE,
  64                         base::Bind(&ConnectivityChecker::Check, this));
  65 }
  66
  67 ConnectivityChecker::~ConnectivityChecker() {
  68   DCHECK(loop_proxy_.get());
  69   loop_proxy_->DeleteSoon(FROM_HERE, url_request_context_.release());
  70   loop_proxy_->DeleteSoon(FROM_HERE, url_request_.release());
  71 }
  72
  73 void ConnectivityChecker::AddConnectivityObserver(
  74     ConnectivityObserver* observer) {
  75   connectivity_observer_list_->AddObserver(observer);
  76 }
  77
  78 void ConnectivityChecker::RemoveConnectivityObserver(
  79     ConnectivityObserver* observer) {
  80   connectivity_observer_list_->RemoveObserver(observer);
  81 }
  82
  83 bool ConnectivityChecker::Connected() const {
  84   return connected_;
  85 }
  86
  87 void ConnectivityChecker::SetConnectivity(bool connected) {
  88   if (connected_ == connected)
  89     return;
  90
  91   connected_ = connected;
  92   connectivity_observer_list_->Notify(
  93       FROM_HERE, &ConnectivityObserver::OnConnectivityChanged, connected);
  94   LOG(INFO) << "Global connection is: " << (connected ? "Up" : "Down");
  95 }
  96
  97 void ConnectivityChecker::Check() {
  98   if (!loop_proxy_->BelongsToCurrentThread()) {
  99     loop_proxy_->PostTask(FROM_HERE,
 100                           base::Bind(&ConnectivityChecker::Check, this));
 101     return;
 102   }
 103   DCHECK(url_request_context_.get());
 104
 105   // If url_request_ is non-null, there is already a check going on. Don't
 106   // start another.
 107   if (url_request_.get())
 108     return;
 109
 110   VLOG(1) << "Connectivity check: url=" << *connectivity_check_url_;
 111   url_request_ = url_request_context_->CreateRequest(
 112       *connectivity_check_url_, net::MAXIMUM_PRIORITY, this, NULL);
 113   url_request_->set_method("HEAD");
 114   url_request_->Start();
 115 }
 116
 117 void ConnectivityChecker::OnConnectionTypeChanged(
 118     net::NetworkChangeNotifier::ConnectionType type) {
 119   if (type == net::NetworkChangeNotifier::CONNECTION_NONE)
 120     SetConnectivity(false);
 121
 122   Cancel();
 123   Check();
 124 }
 125
 126 void ConnectivityChecker::OnResponseStarted(net::URLRequest* request) {
 127   int http_response_code =
 128       (request->status().is_success() &&
 129        request->response_info().headers.get() != NULL)
 130           ? request->response_info().headers->response_code()
 131           : net::HTTP_BAD_REQUEST;
 132
 133   // Clears resources.
 134   url_request_.reset(NULL);  // URLRequest::Cancel() is called in destructor.
 135
 136   if (http_response_code < 400) {
 137     VLOG(1) << "Connectivity check succeeded";
 138     bad_responses_ = 0;
 139     SetConnectivity(true);
 140     return;
 141   }
 142
 143   VLOG(1) << "Connectivity check failed: " << http_response_code;
 144   ++bad_responses_;
 145   if (bad_responses_ > kNumBadResponses) {
 146     bad_responses_ = kNumBadResponses;
 147     SetConnectivity(false);
 148   }
 149
 150   // Check again
 151   loop_proxy_->PostDelayedTask(
 152       FROM_HERE, base::Bind(&ConnectivityChecker::Check, this),
 153       base::TimeDelta::FromSeconds(kConnectivityPeriodSeconds));
 154 }
 155
 156 void ConnectivityChecker::OnReadCompleted(net::URLRequest* request,
 157                                           int bytes_read) {
 158   NOTREACHED();
 159 }
 160
 161 void ConnectivityChecker::Cancel() {
 162   if (url_request_.get()) {
 163     VLOG(2) << "Cancel connectivity check in progress";
 164     url_request_.reset(NULL);  // URLRequest::Cancel() is called in destructor.
 165   }
 166 }
 167
 168 }  // namespace chromecast