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// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chromeos/ash/components/tether/crash_recovery_manager_impl.h"
#include <memory>
#include "base/functional/bind.h"
#include "base/memory/ptr_util.h"
#include "base/memory/weak_ptr.h"
#include "chromeos/ash/components/multidevice/logging/logging.h"
#include "chromeos/ash/components/multidevice/remote_device_ref.h"
#include "chromeos/ash/components/network/network_state.h"
#include "chromeos/ash/components/network/network_state_handler.h"
#include "chromeos/ash/components/tether/host_scan_cache.h"
namespace ash {
namespace tether {
// static
CrashRecoveryManagerImpl::Factory*
CrashRecoveryManagerImpl::Factory::factory_instance_ = nullptr;
// static
std::unique_ptr<CrashRecoveryManager> CrashRecoveryManagerImpl::Factory::Create(
NetworkStateHandler* network_state_handler,
ActiveHost* active_host,
HostScanCache* host_scan_cache) {
if (factory_instance_) {
return factory_instance_->CreateInstance(network_state_handler, active_host,
host_scan_cache);
}
return base::WrapUnique(new CrashRecoveryManagerImpl(
network_state_handler, active_host, host_scan_cache));
}
// static
void CrashRecoveryManagerImpl::Factory::SetFactoryForTesting(Factory* factory) {
factory_instance_ = factory;
}
CrashRecoveryManagerImpl::Factory::~Factory() = default;
CrashRecoveryManagerImpl::CrashRecoveryManagerImpl(
NetworkStateHandler* network_state_handler,
ActiveHost* active_host,
HostScanCache* host_scan_cache)
: network_state_handler_(network_state_handler),
active_host_(active_host),
host_scan_cache_(host_scan_cache) {}
CrashRecoveryManagerImpl::~CrashRecoveryManagerImpl() = default;
void CrashRecoveryManagerImpl::RestorePreCrashStateIfNecessary(
base::OnceClosure on_restoration_finished) {
ActiveHost::ActiveHostStatus status = active_host_->GetActiveHostStatus();
std::string active_host_device_id = active_host_->GetActiveHostDeviceId();
std::string wifi_network_guid = active_host_->GetWifiNetworkGuid();
std::string tether_network_guid = active_host_->GetTetherNetworkGuid();
if (status == ActiveHost::ActiveHostStatus::DISCONNECTED) {
// There was no active Tether session, so either the last TetherComponent
// shutdown occurred normally (i.e., without a crash), or it occurred due
// to a crash and there was no active host at the time of the crash.
std::move(on_restoration_finished).Run();
return;
}
if (status == ActiveHost::ActiveHostStatus::CONNECTING) {
// If a connection attempt was in progress when the crash occurred, abandon
// the connection attempt. Set ActiveHost back to DISCONNECTED; the user can
// attempt another connection if desired.
// TODO(khorimoto): Explore whether we should attempt to restore an
// in-progress connection attempt. This is a low-priority edge case which is
// difficult to solve.
PA_LOG(WARNING) << "Browser crashed while Tether connection attempt was in "
<< "progress. Abandoning connection attempt.";
active_host_->SetActiveHostDisconnected();
std::move(on_restoration_finished).Run();
return;
}
RestoreConnectedState(std::move(on_restoration_finished),
active_host_device_id, tether_network_guid,
wifi_network_guid);
}
void CrashRecoveryManagerImpl::RestoreConnectedState(
base::OnceClosure on_restoration_finished,
const std::string& active_host_device_id,
const std::string& tether_network_guid,
const std::string& wifi_network_guid) {
// Since the host was connected, both a Wi-Fi and Tether network GUID are
// expected to be present.
DCHECK(!wifi_network_guid.empty() && !tether_network_guid.empty());
if (!host_scan_cache_->ExistsInCache(tether_network_guid)) {
// If a crash occurred, HostScanCache is expected to have restored its state
// via its persistent scan results. If that did not happen correctly, there
// is no way to restore the active host, so abandon the connection. Note
// that this is not an expected error condition.
PA_LOG(ERROR)
<< "Browser crashed while a Tether connection was active, "
<< "but the scan result for the active host was lost. Setting "
<< "the active host to DISCONNECTED.";
active_host_->SetActiveHostDisconnected();
std::move(on_restoration_finished).Run();
return;
}
// Since the associated scan result exists in the cache, it is expected to be
// present in the network stack.
const NetworkState* tether_state =
network_state_handler_->GetNetworkStateFromGuid(tether_network_guid);
DCHECK(tether_state);
const NetworkState* wifi_state =
network_state_handler_->GetNetworkStateFromGuid(wifi_network_guid);
if (!wifi_state || !wifi_state->IsConnectedState()) {
// If the Wi-Fi network corresponding to the Tether hotspot is not present
// or is no longer connected, then this device is no longer truly connected
// to the active host.
PA_LOG(ERROR) << "Browser crashed while a Tether connection was active, "
<< "but underlying Wi-Fi network corresponding to the Tether "
<< "connection is no longer present. Setting the active host "
<< "to DISCONNECTED.";
active_host_->SetActiveHostDisconnected();
std::move(on_restoration_finished).Run();
return;
}
// Because the NetworkState object representing the Wi-Fi network was lost
// during the crash, the association between it and the Tether NetworkState
// has been broken. Restore it now.
DCHECK(wifi_state->tether_guid().empty());
network_state_handler_->AssociateTetherNetworkStateWithWifiNetwork(
tether_network_guid, wifi_network_guid);
active_host_->GetActiveHost(base::BindOnce(
&CrashRecoveryManagerImpl::OnActiveHostFetched,
weak_ptr_factory_.GetWeakPtr(), std::move(on_restoration_finished)));
}
void CrashRecoveryManagerImpl::OnActiveHostFetched(
base::OnceClosure on_restoration_finished,
ActiveHost::ActiveHostStatus active_host_status,
std::optional<multidevice::RemoteDeviceRef> active_host,
const std::string& tether_network_guid,
const std::string& wifi_network_guid) {
DCHECK(ActiveHost::ActiveHostStatus::CONNECTED == active_host_status);
DCHECK(active_host_);
// Even though the active host has not actually changed, fire an active host
// changed update so that classes listening on ActiveHost (e.g.,
// ActiveHostNetworkStateUpdater and KeepAliveScheduler) will be notified
// that there is an active connection.
//
// Note: SendActiveHostChangedUpdate() is a protected function of ActiveHost
// which is only invoked here because CrashRecoveryManagerImpl is a friend
// class.
// It is invoked directly here because we are sending out a "fake" change
// event which has equal old and new values.
active_host_->SendActiveHostChangedUpdate(
ActiveHost::ActiveHostStatus::CONNECTED /* old_status */,
active_host ? active_host->GetDeviceId()
: std::string() /* old_active_host_id */,
tether_network_guid /* old_tether_network_guid */,
wifi_network_guid /* old_wifi_network_guid */,
ActiveHost::ActiveHostStatus::CONNECTED /* new_status */,
active_host /* new_active_host */,
tether_network_guid /* new_tether_network_guid */,
wifi_network_guid /* new_wifi_network_guid */);
std::move(on_restoration_finished).Run();
}
} // namespace tether
} // namespace ash
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