// Copyright 2015 The Chromium Authors
// 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 <algorithm>
#include "base/command_line.h"
#include "base/functional/bind.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/task/single_thread_task_runner.h"
#include "chromecast/base/metrics/cast_metrics_helper.h"
#include "chromecast/net/net_switches.h"
#include "chromecast/net/time_sync_tracker.h"
#include "net/base/request_priority.h"
#include "net/http/http_response_headers.h"
#include "net/http/http_status_code.h"
#include "services/network/public/cpp/resource_request.h"
#include "services/network/public/cpp/shared_url_loader_factory.h"
#include "services/network/public/cpp/simple_url_loader.h"
#include "services/network/public/mojom/url_response_head.mojom.h"
namespace chromecast {
namespace {
// How often connectivity checks are performed while not connected.
constexpr base::TimeDelta kDisconnectedProbePeriod = base::Seconds(1);
// How often connectivity checks are performed while connected.
constexpr base::TimeDelta kConnectedProbePeriod = base::Seconds(60);
// Number of consecutive connectivity check errors before status is changed
// to offline.
const unsigned int kNumErrorsToNotifyOffline = 3;
// Request timeout value.
constexpr base::TimeDelta kRequestTimeout = base::Seconds(3);
const char kMetricNameNetworkConnectivityCheckingErrorType[] =
"Network.ConnectivityChecking.ErrorType";
} // namespace
// static
scoped_refptr<ConnectivityCheckerImpl> ConnectivityCheckerImpl::Create(
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
std::unique_ptr<network::PendingSharedURLLoaderFactory>
pending_url_loader_factory,
network::NetworkConnectionTracker* network_connection_tracker,
TimeSyncTracker* time_sync_tracker) {
DCHECK(task_runner);
return Create(task_runner, std::move(pending_url_loader_factory),
network_connection_tracker, kDisconnectedProbePeriod,
kConnectedProbePeriod, time_sync_tracker);
}
// static
scoped_refptr<ConnectivityCheckerImpl> ConnectivityCheckerImpl::Create(
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
std::unique_ptr<network::PendingSharedURLLoaderFactory>
pending_url_loader_factory,
network::NetworkConnectionTracker* network_connection_tracker,
base::TimeDelta disconnected_probe_period,
base::TimeDelta connected_probe_period,
TimeSyncTracker* time_sync_tracker) {
DCHECK(task_runner);
auto connectivity_checker = base::WrapRefCounted(new ConnectivityCheckerImpl(
task_runner, network_connection_tracker, disconnected_probe_period,
connected_probe_period, time_sync_tracker));
task_runner->PostTask(
FROM_HERE,
base::BindOnce(&ConnectivityCheckerImpl::Initialize, connectivity_checker,
std::move(pending_url_loader_factory)));
return connectivity_checker;
}
ConnectivityCheckerImpl::ConnectivityCheckerImpl(
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
network::NetworkConnectionTracker* network_connection_tracker,
base::TimeDelta disconnected_probe_period,
base::TimeDelta connected_probe_period,
TimeSyncTracker* time_sync_tracker)
: ConnectivityChecker(task_runner),
task_runner_(std::move(task_runner)),
network_connection_tracker_(network_connection_tracker),
time_sync_tracker_(time_sync_tracker),
cast_metrics_helper_(metrics::CastMetricsHelper::GetInstance()),
connected_and_time_synced_(false),
network_connected_(false),
connection_type_(network::mojom::ConnectionType::CONNECTION_NONE),
check_errors_(0),
network_changed_pending_(false),
disconnected_probe_period_(disconnected_probe_period),
connected_probe_period_(connected_probe_period),
weak_factory_(this) {
DCHECK(task_runner_);
DCHECK(network_connection_tracker_);
DCHECK(cast_metrics_helper_);
DCHECK(!disconnected_probe_period_.is_zero());
DCHECK(!connected_probe_period_.is_zero());
weak_this_ = weak_factory_.GetWeakPtr();
if (time_sync_tracker_) {
time_sync_tracker_->AddObserver(this);
}
}
void ConnectivityCheckerImpl::Initialize(
std::unique_ptr<network::PendingSharedURLLoaderFactory>
pending_url_loader_factory) {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(pending_url_loader_factory);
url_loader_factory_ = network::SharedURLLoaderFactory::Create(
std::move(pending_url_loader_factory));
base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
base::CommandLine::StringType check_url_str =
command_line->GetSwitchValueNative(switches::kConnectivityCheckUrl);
connectivity_check_url_ = std::make_unique<GURL>(
check_url_str.empty() ? kDefaultConnectivityCheckUrl : check_url_str);
network_connection_tracker_->AddNetworkConnectionObserver(this);
Check();
}
ConnectivityCheckerImpl::~ConnectivityCheckerImpl() {
DCHECK(task_runner_);
DCHECK(task_runner_->BelongsToCurrentThread());
network_connection_tracker_->RemoveNetworkConnectionObserver(this);
}
bool ConnectivityCheckerImpl::Connected() const {
base::AutoLock auto_lock(connected_lock_);
return connected_and_time_synced_;
}
void ConnectivityCheckerImpl::SetConnected(bool connected) {
DCHECK(task_runner_->BelongsToCurrentThread());
{
base::AutoLock auto_lock(connected_lock_);
network_connected_ = connected;
// If a time_sync_tracker is not provided, is it assumed that network
// connectivity is equivalent to time being synced.
bool connected_and_time_synced = network_connected_;
if (time_sync_tracker_) {
connected_and_time_synced &= time_sync_tracker_->IsTimeSynced();
}
if (connected_and_time_synced_ == connected_and_time_synced) {
return;
}
connected_and_time_synced_ = connected_and_time_synced;
}
base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
base::CommandLine::StringType check_url_str =
command_line->GetSwitchValueNative(switches::kConnectivityCheckUrl);
if (check_url_str.empty()) {
connectivity_check_url_ = std::make_unique<GURL>(
connected_and_time_synced_ ? kHttpConnectivityCheckUrl
: kDefaultConnectivityCheckUrl);
LOG(INFO) << "Change check url=" << *connectivity_check_url_;
}
Notify(connected_and_time_synced_);
LOG(INFO) << "Global connection is: "
<< (connected_and_time_synced_ ? "Up" : "Down");
}
void ConnectivityCheckerImpl::Check() {
task_runner_->PostTask(
FROM_HERE,
base::BindOnce(&ConnectivityCheckerImpl::CheckInternal, weak_this_));
}
void ConnectivityCheckerImpl::CheckInternal() {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(url_loader_factory_);
auto connection_type = network::mojom::ConnectionType::CONNECTION_UNKNOWN;
bool is_sync = network_connection_tracker_->GetConnectionType(
&connection_type,
base::BindOnce(&ConnectivityCheckerImpl::OnConnectionChanged,
weak_this_));
// Don't check connectivity if network is offline.
// Also don't check connectivity if the connection_type cannot be
// synchronously retrieved, since OnConnectionChanged will be triggered later
// which will cause duplicate checks.
if (!is_sync ||
connection_type == network::mojom::ConnectionType::CONNECTION_NONE) {
return;
}
// If url_loader_ is non-null, there is already a check going on. Don't
// start another.
if (url_loader_) {
return;
}
VLOG(1) << "Connectivity check: url=" << *connectivity_check_url_;
auto resource_request = std::make_unique<network::ResourceRequest>();
resource_request->url = GURL(*connectivity_check_url_);
resource_request->method = "HEAD";
resource_request->priority = net::MAXIMUM_PRIORITY;
url_loader_ = network::SimpleURLLoader::Create(std::move(resource_request),
MISSING_TRAFFIC_ANNOTATION);
// To enable ssl_info in the response.
url_loader_->SetURLLoaderFactoryOptions(
network::mojom::kURLLoadOptionSendSSLInfoWithResponse |
network::mojom::kURLLoadOptionSendSSLInfoForCertificateError);
// Configure the loader to treat HTTP error status codes as successful loads.
// This setting allows us to inspect the status code and log it as an error.
url_loader_->SetAllowHttpErrorResults(true);
network::SimpleURLLoader::HeadersOnlyCallback callback = base::BindOnce(
&ConnectivityCheckerImpl::OnConnectivityCheckComplete, weak_this_);
url_loader_->DownloadHeadersOnly(url_loader_factory_.get(),
std::move(callback));
// Exponential backoff for timeout in 3, 6 and 12 sec.
const base::TimeDelta timeout =
kRequestTimeout *
std::pow(2, std::min(check_errors_, static_cast<unsigned int>(2)));
timeout_.Reset(base::BindOnce(&ConnectivityCheckerImpl::OnUrlRequestTimeout,
weak_this_, timeout));
base::SingleThreadTaskRunner::GetCurrentDefault()->PostDelayedTask(
FROM_HERE, timeout_.callback(), timeout);
}
void ConnectivityCheckerImpl::SetCastMetricsHelperForTesting(
metrics::CastMetricsHelper* cast_metrics_helper) {
DCHECK(cast_metrics_helper);
cast_metrics_helper_ = cast_metrics_helper;
}
void ConnectivityCheckerImpl::OnConnectionChanged(
network::mojom::ConnectionType type) {
DVLOG(2) << "OnConnectionChanged " << type;
connection_type_ = type;
if (network_changed_pending_) {
return;
}
if (std::exchange(first_connection_, false)) {
OnConnectionChangedInternal();
return;
}
network_changed_pending_ = true;
base::SingleThreadTaskRunner::GetCurrentDefault()->PostDelayedTask(
FROM_HERE,
base::BindOnce(&ConnectivityCheckerImpl::OnConnectionChangedInternal,
weak_this_),
kNetworkChangedDelay);
}
void ConnectivityCheckerImpl::OnConnectionChangedInternal() {
network_changed_pending_ = false;
Cancel();
if (connection_type_ == network::mojom::ConnectionType::CONNECTION_NONE) {
SetConnected(false);
return;
}
Check();
}
void ConnectivityCheckerImpl::OnTimeSynced() {
SetConnected(network_connected_);
}
void ConnectivityCheckerImpl::OnConnectivityCheckComplete(
scoped_refptr<net::HttpResponseHeaders> headers) {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(url_loader_);
// Move url_loader_ onto the stack to ensure it gets deleted when this
// function completes.
std::unique_ptr<network::SimpleURLLoader> url_loader = std::move(url_loader_);
timeout_.Cancel();
int error = url_loader->NetError();
if (error == net::ERR_INSECURE_RESPONSE && url_loader->ResponseInfo() &&
url_loader->ResponseInfo()->ssl_info) {
LOG(ERROR) << "OnSSLCertificateError: cert_status="
<< url_loader->ResponseInfo()->ssl_info->cert_status;
OnUrlRequestError(ErrorType::SSL_CERTIFICATE_ERROR);
return;
}
if (error != net::OK) {
// Captures non-HTTP errors here. All HTTP status codes (including error
// codes) are treated as network success and won't be logged here. HTTP
// errors are handled further below to provide more precise granularity.
LOG(ERROR) << "Connectivity check failed: net_error=" << error;
OnUrlRequestError(ErrorType::NET_ERROR);
return;
}
// At this point, network connection is considered successful, but we still
// need to check HTTP response for errors. If headers are empty, use an
// implicit zero status code.
int http_response_code = headers ? headers->response_code() : 0;
if (http_response_code != kConnectivitySuccessStatusCode) {
LOG(ERROR) << "Connectivity check failed: http_response_code="
<< http_response_code;
OnUrlRequestError(ErrorType::BAD_HTTP_STATUS);
return;
}
DVLOG(1) << "Connectivity check succeeded";
check_errors_ = 0;
SetConnected(true);
// Some products don't have an idle screen that makes periodic network
// requests. Schedule another check to ensure connectivity hasn't dropped.
delayed_check_.Reset(
base::BindOnce(&ConnectivityCheckerImpl::CheckInternal, weak_this_));
task_runner_->PostDelayedTask(FROM_HERE, delayed_check_.callback(),
connected_probe_period_);
}
void ConnectivityCheckerImpl::OnUrlRequestError(ErrorType type) {
DCHECK(task_runner_->BelongsToCurrentThread());
++check_errors_;
if (check_errors_ > kNumErrorsToNotifyOffline) {
LOG(INFO) << "Notify connectivity check failure.";
NotifyCheckFailure();
// Only record event on the connectivity transition.
if (connected_and_time_synced_) {
cast_metrics_helper_->RecordEventWithValue(
kMetricNameNetworkConnectivityCheckingErrorType,
static_cast<int>(type));
}
check_errors_ = kNumErrorsToNotifyOffline;
SetConnected(false);
}
// Check again.
delayed_check_.Reset(
base::BindOnce(&ConnectivityCheckerImpl::CheckInternal, weak_this_));
task_runner_->PostDelayedTask(FROM_HERE, delayed_check_.callback(),
disconnected_probe_period_);
}
void ConnectivityCheckerImpl::OnUrlRequestTimeout(base::TimeDelta timeout) {
DCHECK(task_runner_->BelongsToCurrentThread());
DCHECK(url_loader_);
url_loader_ = nullptr;
LOG(WARNING) << "timed out after " << timeout;
OnUrlRequestError(ErrorType::REQUEST_TIMEOUT);
}
void ConnectivityCheckerImpl::Cancel() {
DCHECK(task_runner_->BelongsToCurrentThread());
if (!url_loader_) {
return;
}
VLOG(2) << "Cancel connectivity check in progress";
url_loader_ = nullptr;
timeout_.Cancel();
}
} // namespace chromecast
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