blob: 98c30af148c527239205bdc6da48312f787c36df [file] [log] [blame]
// Copyright (c) 2013 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 "google_apis/gcm/engine/connection_factory_impl.h"
#include <string>
#include "base/location.h"
#include "base/memory/ptr_util.h"
#include "base/metrics/histogram.h"
#include "base/metrics/histogram_functions.h"
#include "base/metrics/histogram_macros.h"
#include "base/threading/thread_task_runner_handle.h"
#include "google_apis/gcm/engine/connection_handler_impl.h"
#include "google_apis/gcm/monitoring/gcm_stats_recorder.h"
#include "google_apis/gcm/protocol/mcs.pb.h"
#include "net/base/net_errors.h"
#include "net/http/http_request_headers.h"
#include "net/http/proxy_fallback.h"
#include "net/log/net_log_source_type.h"
#include "net/proxy_resolution/proxy_info.h"
#include "net/socket/client_socket_handle.h"
#include "net/socket/client_socket_pool_manager.h"
#include "net/ssl/ssl_config_service.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
namespace gcm {
namespace {
// The amount of time a Socket read should wait before timing out.
const int kReadTimeoutMs = 30000; // 30 seconds.
// If a connection is reset after succeeding within this window of time,
// the previous backoff entry is restored (and the connection success is treated
// as if it was transient).
const int kConnectionResetWindowSecs = 10; // 10 seconds.
// Decides whether the last login was within kConnectionResetWindowSecs of now
// or not.
bool ShouldRestorePreviousBackoff(const base::TimeTicks& login_time,
const base::TimeTicks& now_ticks) {
return !login_time.is_null() &&
now_ticks - login_time <=
base::TimeDelta::FromSeconds(kConnectionResetWindowSecs);
}
} // namespace
ConnectionFactoryImpl::ConnectionFactoryImpl(
const std::vector<GURL>& mcs_endpoints,
const net::BackoffEntry::Policy& backoff_policy,
GetProxyResolvingFactoryCallback get_socket_factory_callback,
GCMStatsRecorder* recorder)
: mcs_endpoints_(mcs_endpoints),
next_endpoint_(0),
last_successful_endpoint_(0),
backoff_policy_(backoff_policy),
get_socket_factory_callback_(get_socket_factory_callback),
connecting_(false),
waiting_for_backoff_(false),
waiting_for_network_online_(false),
handshake_in_progress_(false),
recorder_(recorder),
listener_(NULL),
weak_ptr_factory_(this) {
DCHECK_GE(mcs_endpoints_.size(), 1U);
}
ConnectionFactoryImpl::~ConnectionFactoryImpl() {
CloseSocket();
net::NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
}
void ConnectionFactoryImpl::Initialize(
const BuildLoginRequestCallback& request_builder,
const ConnectionHandler::ProtoReceivedCallback& read_callback,
const ConnectionHandler::ProtoSentCallback& write_callback) {
DCHECK(!connection_handler_);
DCHECK(read_callback_.is_null());
DCHECK(write_callback_.is_null());
previous_backoff_ = CreateBackoffEntry(&backoff_policy_);
backoff_entry_ = CreateBackoffEntry(&backoff_policy_);
request_builder_ = request_builder;
read_callback_ = read_callback;
write_callback_ = write_callback;
net::NetworkChangeNotifier::AddNetworkChangeObserver(this);
waiting_for_network_online_ = net::NetworkChangeNotifier::IsOffline();
}
ConnectionHandler* ConnectionFactoryImpl::GetConnectionHandler() const {
return connection_handler_.get();
}
void ConnectionFactoryImpl::Connect() {
if (!connection_handler_) {
connection_handler_ = CreateConnectionHandler(
base::TimeDelta::FromMilliseconds(kReadTimeoutMs), read_callback_,
write_callback_,
base::Bind(&ConnectionFactoryImpl::ConnectionHandlerCallback,
weak_ptr_factory_.GetWeakPtr()));
}
if (connecting_ || waiting_for_backoff_)
return; // Connection attempt already in progress or pending.
if (IsEndpointReachable())
return; // Already connected.
ConnectWithBackoff();
}
ConnectionEventTracker* ConnectionFactoryImpl::GetEventTrackerForTesting() {
return &event_tracker_;
}
void ConnectionFactoryImpl::ConnectWithBackoff() {
// If a canary managed to connect while a backoff expiration was pending,
// just cleanup the internal state.
if (connecting_ || handshake_in_progress_ || IsEndpointReachable()) {
waiting_for_backoff_ = false;
return;
}
if (backoff_entry_->ShouldRejectRequest()) {
DVLOG(1) << "Delaying MCS endpoint connection for "
<< backoff_entry_->GetTimeUntilRelease().InMilliseconds()
<< " milliseconds.";
waiting_for_backoff_ = true;
recorder_->RecordConnectionDelayedDueToBackoff(
backoff_entry_->GetTimeUntilRelease().InMilliseconds());
base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
FROM_HERE,
base::Bind(&ConnectionFactoryImpl::ConnectWithBackoff,
weak_ptr_factory_.GetWeakPtr()),
backoff_entry_->GetTimeUntilRelease());
return;
}
DVLOG(1) << "Attempting connection to MCS endpoint.";
waiting_for_backoff_ = false;
// It's necessary to close the socket before attempting any new connection,
// otherwise it's possible to hit a use-after-free in the connection handler.
// crbug.com/462319
CloseSocket();
ConnectImpl();
}
bool ConnectionFactoryImpl::IsEndpointReachable() const {
return connection_handler_ && connection_handler_->CanSendMessage();
}
std::string ConnectionFactoryImpl::GetConnectionStateString() const {
if (IsEndpointReachable())
return "CONNECTED";
if (handshake_in_progress_)
return "HANDSHAKE IN PROGRESS";
if (connecting_)
return "CONNECTING";
if (waiting_for_backoff_)
return "WAITING FOR BACKOFF";
if (waiting_for_network_online_)
return "WAITING FOR NETWORK CHANGE";
return "NOT CONNECTED";
}
void ConnectionFactoryImpl::SignalConnectionReset(
ConnectionResetReason reason) {
if (!connection_handler_) {
// No initial connection has been made. No need to do anything.
return;
}
// A failure can trigger multiple resets, so no need to do anything if a
// connection is already in progress.
if (connecting_) {
DVLOG(1) << "Connection in progress, ignoring reset.";
return;
}
if (listener_)
listener_->OnDisconnected();
UMA_HISTOGRAM_ENUMERATION("GCM.ConnectionResetReason",
reason,
CONNECTION_RESET_COUNT);
recorder_->RecordConnectionResetSignaled(reason);
if (!last_login_time_.is_null()) {
UMA_HISTOGRAM_CUSTOM_TIMES("GCM.ConnectionUpTime",
NowTicks() - last_login_time_,
base::TimeDelta::FromSeconds(1),
base::TimeDelta::FromHours(24),
50);
// |last_login_time_| will be reset below, before attempting the new
// connection.
}
// SignalConnectionReset can be called at any time without regard to whether
// a connection attempt is currently in progress. Only notify the event
// tracker if there is an event in progress.
if (event_tracker_.IsEventInProgress()) {
if (reason == LOGIN_FAILURE)
event_tracker_.ConnectionLoginFailed();
event_tracker_.EndConnectionAttempt();
}
CloseSocket();
DCHECK(!IsEndpointReachable());
// TODO(zea): if the network is offline, don't attempt to connect.
// See crbug.com/396687
// Network changes get special treatment as they can trigger a one-off canary
// request that bypasses backoff (but does nothing if a connection is in
// progress). Other connection reset events can be ignored as a connection
// is already awaiting backoff expiration.
if (waiting_for_backoff_ && reason != NETWORK_CHANGE) {
DVLOG(1) << "Backoff expiration pending, ignoring reset.";
return;
}
if (reason == NETWORK_CHANGE) {
// Canary attempts bypass backoff without resetting it. These will have no
// effect if we're already in the process of connecting.
ConnectImpl();
return;
} else if (handshake_in_progress_) {
// Failures prior to handshake completion reuse the existing backoff entry.
handshake_in_progress_ = false;
backoff_entry_->InformOfRequest(false);
} else if (reason == LOGIN_FAILURE ||
ShouldRestorePreviousBackoff(last_login_time_, NowTicks())) {
// Failures due to login, or within the reset window of a login, restore
// the backoff entry that was saved off at login completion time.
backoff_entry_.swap(previous_backoff_);
backoff_entry_->InformOfRequest(false);
} else {
// We shouldn't be in backoff in thise case.
DCHECK_EQ(0, backoff_entry_->failure_count());
}
// At this point the last login time has been consumed or deemed irrelevant,
// reset it.
last_login_time_ = base::TimeTicks();
Connect();
}
void ConnectionFactoryImpl::SetConnectionListener(
ConnectionListener* listener) {
listener_ = listener;
}
base::TimeTicks ConnectionFactoryImpl::NextRetryAttempt() const {
if (!backoff_entry_)
return base::TimeTicks();
return backoff_entry_->GetReleaseTime();
}
void ConnectionFactoryImpl::OnNetworkChanged(
net::NetworkChangeNotifier::ConnectionType type) {
if (type == net::NetworkChangeNotifier::CONNECTION_NONE) {
DVLOG(1) << "Network lost, resettion connection.";
waiting_for_network_online_ = true;
// Will do nothing due to |waiting_for_network_online_ == true|.
// TODO(zea): make the above statement actually true. See crbug.com/396687
SignalConnectionReset(NETWORK_CHANGE);
return;
}
DVLOG(1) << "Connection type changed to " << type << ", reconnecting.";
waiting_for_network_online_ = false;
SignalConnectionReset(NETWORK_CHANGE);
}
GURL ConnectionFactoryImpl::GetCurrentEndpoint() const {
// Note that IsEndpointReachable() returns false anytime connecting_ is true,
// so while connecting this always uses |next_endpoint_|.
if (IsEndpointReachable())
return mcs_endpoints_[last_successful_endpoint_];
return mcs_endpoints_[next_endpoint_];
}
void ConnectionFactoryImpl::ConnectImpl() {
event_tracker_.StartConnectionAttempt();
StartConnection();
}
void ConnectionFactoryImpl::StartConnection() {
DCHECK(!IsEndpointReachable());
// TODO(zea): Make this a dcheck again. crbug.com/462319
CHECK(!socket_);
// TODO(zea): if the network is offline, don't attempt to connect.
// See crbug.com/396687
connecting_ = true;
GURL current_endpoint = GetCurrentEndpoint();
recorder_->RecordConnectionInitiated(current_endpoint.host());
get_socket_factory_callback_.Run(mojo::MakeRequest(&socket_factory_));
net::NetworkTrafficAnnotationTag traffic_annotation =
net::DefineNetworkTrafficAnnotation("gcm_connection_factory", R"(
semantics {
sender: "GCM Connection Factory"
description:
"TCP connection to the Google Cloud Messaging notification "
"servers. Supports reliable bi-directional messaging and push "
"notifications for multiple consumers."
trigger:
"The connection is created when an application (e.g. Chrome Sync) "
"or a website using Web Push starts the GCM service, and is kept "
"alive as long as there are valid applications registered. "
"Messaging is application/website controlled."
data:
"Arbitrary application-specific data."
destination: GOOGLE_OWNED_SERVICE
}
policy {
cookies_allowed: NO
setting:
"Users can stop messages related to Sync by disabling Sync for "
"everything in settings. Messages related to Web Push can be "
"stopped by revoking the site permissions in settings. Messages "
"related to extensions can be stopped by uninstalling the "
"extension."
chrome_policy {
SyncDisabled {
SyncDisabled: True
}
}
}
comments:
"'SyncDisabled' policy disables messages that are based on Sync, "
"but does not have any effect on other Google Cloud messages."
)");
socket_factory_->CreateProxyResolvingSocket(
current_endpoint, true /* use_tls */,
net::MutableNetworkTrafficAnnotationTag(traffic_annotation),
mojo::MakeRequest(&socket_),
base::BindOnce(&ConnectionFactoryImpl::OnConnectDone,
base::Unretained(this)));
}
void ConnectionFactoryImpl::InitHandler(
mojo::ScopedDataPipeConsumerHandle receive_stream,
mojo::ScopedDataPipeProducerHandle send_stream) {
mcs_proto::LoginRequest login_request;
// May be null in tests.
if (!request_builder_.is_null()) {
request_builder_.Run(&login_request);
DCHECK(login_request.IsInitialized());
event_tracker_.WriteToLoginRequest(&login_request);
}
connection_handler_->Init(login_request, std::move(receive_stream),
std::move(send_stream));
}
std::unique_ptr<net::BackoffEntry> ConnectionFactoryImpl::CreateBackoffEntry(
const net::BackoffEntry::Policy* const policy) {
return std::unique_ptr<net::BackoffEntry>(new net::BackoffEntry(policy));
}
std::unique_ptr<ConnectionHandler>
ConnectionFactoryImpl::CreateConnectionHandler(
base::TimeDelta read_timeout,
const ConnectionHandler::ProtoReceivedCallback& read_callback,
const ConnectionHandler::ProtoSentCallback& write_callback,
const ConnectionHandler::ConnectionChangedCallback& connection_callback) {
return base::WrapUnique<ConnectionHandler>(new ConnectionHandlerImpl(
read_timeout, read_callback, write_callback, connection_callback));
}
base::TimeTicks ConnectionFactoryImpl::NowTicks() {
return base::TimeTicks::Now();
}
void ConnectionFactoryImpl::OnConnectDone(
int result,
const base::Optional<net::IPEndPoint>& local_addr,
const base::Optional<net::IPEndPoint>& peer_addr,
mojo::ScopedDataPipeConsumerHandle receive_stream,
mojo::ScopedDataPipeProducerHandle send_stream) {
DCHECK_NE(net::ERR_IO_PENDING, result);
if (result != net::OK) {
LOG(ERROR) << "Failed to connect to MCS endpoint with error " << result;
UMA_HISTOGRAM_BOOLEAN("GCM.ConnectionSuccessRate", false);
recorder_->RecordConnectionFailure(result);
CloseSocket();
backoff_entry_->InformOfRequest(false);
base::UmaHistogramSparse("GCM.ConnectionFailureErrorCode", result);
event_tracker_.ConnectionAttemptFailed(result);
event_tracker_.EndConnectionAttempt();
// If there are other endpoints available, use the next endpoint on the
// subsequent retry.
next_endpoint_++;
if (next_endpoint_ >= mcs_endpoints_.size())
next_endpoint_ = 0;
connecting_ = false;
Connect();
return;
}
UMA_HISTOGRAM_BOOLEAN("GCM.ConnectionSuccessRate", true);
UMA_HISTOGRAM_COUNTS("GCM.ConnectionEndpoint", next_endpoint_);
recorder_->RecordConnectionSuccess();
// Reset the endpoint back to the default.
// TODO(zea): consider prioritizing endpoints more intelligently based on
// which ones succeed most for this client? Although that will affect
// measuring the success rate of the default endpoint vs fallback.
last_successful_endpoint_ = next_endpoint_;
next_endpoint_ = 0;
connecting_ = false;
handshake_in_progress_ = true;
DVLOG(1) << "MCS endpoint socket connection success, starting login.";
// |peer_addr| is only non-null if result == net::OK and the connection is not
// through a proxy.
if (peer_addr)
peer_addr_ = peer_addr.value();
InitHandler(std::move(receive_stream), std::move(send_stream));
}
void ConnectionFactoryImpl::ConnectionHandlerCallback(int result) {
DCHECK(!connecting_);
if (result != net::OK) {
// TODO(zea): Consider how to handle errors that may require some sort of
// user intervention (login page, etc.).
base::UmaHistogramSparse("GCM.ConnectionDisconnectErrorCode", result);
SignalConnectionReset(SOCKET_FAILURE);
return;
}
// Handshake complete, reset backoff. If the login failed with an error,
// the client should invoke SignalConnectionReset(LOGIN_FAILURE), which will
// restore the previous backoff.
DVLOG(1) << "Handshake complete.";
last_login_time_ = NowTicks();
previous_backoff_.swap(backoff_entry_);
backoff_entry_->Reset();
handshake_in_progress_ = false;
event_tracker_.ConnectionAttemptSucceeded();
if (listener_)
listener_->OnConnected(GetCurrentEndpoint(), peer_addr_);
}
void ConnectionFactoryImpl::CloseSocket() {
// The connection handler needs to be reset, else it'll attempt to keep using
// the destroyed socket.
if (connection_handler_)
connection_handler_->Reset();
socket_.reset();
peer_addr_ = net::IPEndPoint();
}
} // namespace gcm