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// Copyright 2015 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 "chromecast/net/connectivity_checker_impl.h"
#include "base/command_line.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/message_loop/message_loop.h"
#include "chromecast/net/net_switches.h"
#include "net/base/request_priority.h"
#include "net/http/http_response_headers.h"
#include "net/http/http_response_info.h"
#include "net/http/http_status_code.h"
#include "net/proxy/proxy_config.h"
#include "net/proxy/proxy_config_service_fixed.h"
#include "net/socket/ssl_client_socket.h"
#include "net/url_request/url_request_context.h"
#include "net/url_request/url_request_context_builder.h"
namespace chromecast {
namespace {
// How often connectivity checks are performed in seconds.
const unsigned int kConnectivityPeriodSeconds = 1;
// Number of consecutive connectivity check errors before status is changed
// to offline.
const unsigned int kNumErrorsToNotifyOffline = 3;
// Request timeout value in seconds.
const unsigned int kRequestTimeoutInSeconds = 3;
// Default url for connectivity checking.
const char kDefaultConnectivityCheckUrl[] =
"https://clients3.google.com/generate_204";
// Delay notification of network change events to smooth out rapid flipping.
// Histogram "Cast.Network.Down.Duration.In.Seconds" shows 40% of network
// downtime is less than 3 seconds.
const char kNetworkChangedDelayInSeconds = 3;
} // namespace
ConnectivityCheckerImpl::ConnectivityCheckerImpl(
const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
: ConnectivityChecker(),
task_runner_(task_runner),
connected_(false),
connection_type_(net::NetworkChangeNotifier::CONNECTION_NONE),
check_errors_(0),
network_changed_pending_(false) {
DCHECK(task_runner_.get());
task_runner->PostTask(FROM_HERE,
base::Bind(&ConnectivityCheckerImpl::Initialize, this));
}
void ConnectivityCheckerImpl::Initialize() {
base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
base::CommandLine::StringType check_url_str =
command_line->GetSwitchValueNative(switches::kConnectivityCheckUrl);
connectivity_check_url_.reset(new GURL(
check_url_str.empty() ? kDefaultConnectivityCheckUrl : check_url_str));
net::URLRequestContextBuilder builder;
builder.set_proxy_config_service(base::WrapUnique(
new net::ProxyConfigServiceFixed(net::ProxyConfig::CreateDirect())));
builder.DisableHttpCache();
url_request_context_ = builder.Build();
net::NetworkChangeNotifier::AddNetworkChangeObserver(this);
task_runner_->PostTask(FROM_HERE,
base::Bind(&ConnectivityCheckerImpl::Check, this));
}
ConnectivityCheckerImpl::~ConnectivityCheckerImpl() {
DCHECK(task_runner_.get());
net::NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
task_runner_->DeleteSoon(FROM_HERE, url_request_.release());
task_runner_->DeleteSoon(FROM_HERE, url_request_context_.release());
}
bool ConnectivityCheckerImpl::Connected() const {
return connected_;
}
void ConnectivityCheckerImpl::SetConnected(bool connected) {
if (connected_ == connected)
return;
connected_ = connected;
Notify(connected);
LOG(INFO) << "Global connection is: " << (connected ? "Up" : "Down");
}
void ConnectivityCheckerImpl::Check() {
if (!task_runner_->BelongsToCurrentThread()) {
task_runner_->PostTask(FROM_HERE,
base::Bind(&ConnectivityCheckerImpl::Check, this));
return;
}
DCHECK(url_request_context_.get());
// Don't check connectivity if network is offline, because Internet could be
// accessible via netifs ignored.
if (net::NetworkChangeNotifier::IsOffline())
return;
// If url_request_ is non-null, there is already a check going on. Don't
// start another.
if (url_request_.get())
return;
VLOG(1) << "Connectivity check: url=" << *connectivity_check_url_;
url_request_ = url_request_context_->CreateRequest(
*connectivity_check_url_, net::MAXIMUM_PRIORITY, this);
url_request_->set_method("HEAD");
url_request_->Start();
timeout_.Reset(base::Bind(&ConnectivityCheckerImpl::OnUrlRequestTimeout,
this));
// Exponential backoff for timeout in 3, 6 and 12 sec.
const int timeout = kRequestTimeoutInSeconds
<< (check_errors_ > 2 ? 2 : check_errors_);
base::MessageLoop::current()->PostDelayedTask(
FROM_HERE,
timeout_.callback(),
base::TimeDelta::FromSeconds(timeout));
}
void ConnectivityCheckerImpl::OnNetworkChanged(
net::NetworkChangeNotifier::ConnectionType type) {
VLOG(2) << "OnNetworkChanged " << type;
connection_type_ = type;
if (network_changed_pending_)
return;
network_changed_pending_ = true;
base::MessageLoop::current()->PostDelayedTask(
FROM_HERE,
base::Bind(&ConnectivityCheckerImpl::OnNetworkChangedInternal, this),
base::TimeDelta::FromSeconds(kNetworkChangedDelayInSeconds));
}
void ConnectivityCheckerImpl::OnNetworkChangedInternal() {
network_changed_pending_ = false;
Cancel();
if (connection_type_ == net::NetworkChangeNotifier::CONNECTION_NONE) {
SetConnected(false);
return;
}
Check();
}
void ConnectivityCheckerImpl::OnResponseStarted(net::URLRequest* request) {
int http_response_code =
(request->status().is_success() &&
request->response_info().headers.get() != nullptr)
? request->response_info().headers->response_code()
: net::HTTP_BAD_REQUEST;
// Clears resources.
url_request_.reset(nullptr); // URLRequest::Cancel() is called in destructor.
if (http_response_code < 400) {
VLOG(1) << "Connectivity check succeeded";
check_errors_ = 0;
SetConnected(true);
timeout_.Cancel();
return;
}
VLOG(1) << "Connectivity check failed: " << http_response_code;
OnUrlRequestError();
timeout_.Cancel();
}
void ConnectivityCheckerImpl::OnReadCompleted(net::URLRequest* request,
int bytes_read) {
NOTREACHED();
}
void ConnectivityCheckerImpl::OnSSLCertificateError(
net::URLRequest* request,
const net::SSLInfo& ssl_info,
bool fatal) {
LOG(ERROR) << "OnSSLCertificateError: cert_status=" << ssl_info.cert_status;
net::SSLClientSocket::ClearSessionCache();
OnUrlRequestError();
timeout_.Cancel();
}
void ConnectivityCheckerImpl::OnUrlRequestError() {
++check_errors_;
if (check_errors_ > kNumErrorsToNotifyOffline) {
check_errors_ = kNumErrorsToNotifyOffline;
SetConnected(false);
}
url_request_.reset(nullptr);
// Check again.
task_runner_->PostDelayedTask(
FROM_HERE, base::Bind(&ConnectivityCheckerImpl::Check, this),
base::TimeDelta::FromSeconds(kConnectivityPeriodSeconds));
}
void ConnectivityCheckerImpl::OnUrlRequestTimeout() {
LOG(ERROR) << "time out";
OnUrlRequestError();
}
void ConnectivityCheckerImpl::Cancel() {
if (!url_request_.get())
return;
VLOG(2) << "Cancel connectivity check in progress";
url_request_.reset(nullptr); // URLRequest::Cancel() is called in destructor.
timeout_.Cancel();
}
} // namespace chromecast
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