bluetooth/bluetooth_hal/debug/debug_monitor.cc

/*
 * Copyright 2025 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "bluetooth_hal.debug_monitor"

#include "bluetooth_hal/debug/debug_monitor.h"

#include <cstdint>

#include "android-base/logging.h"
#include "bluetooth_hal/debug/debug_central.h"
#include "bluetooth_hal/hal_packet.h"
#include "bluetooth_hal/hal_types.h"
#include "bluetooth_hal/hci_monitor.h"
#include "bluetooth_hal/hci_router_client.h"
#include "bluetooth_hal/util/power/wakelock_watchdog.h"
#include "com_android_bluetooth_bluetooth_hal_flags.h"

namespace bluetooth_hal::debug {
namespace {

using ::bluetooth_hal::hci::CommandOpCode;
using ::bluetooth_hal::hci::EventCode;
using ::bluetooth_hal::hci::GoogleEventSubCode;
using ::bluetooth_hal::hci::HalPacket;
using ::bluetooth_hal::hci::HciCommandMonitor;
using ::bluetooth_hal::hci::HciEventMonitor;
using ::bluetooth_hal::hci::HciPacketType;
using ::bluetooth_hal::hci::HciRouterClient;
using ::bluetooth_hal::hci::MonitorMode;
using ::bluetooth_hal::hci::PacketSource;
using ::bluetooth_hal::util::power::WakelockWatchdog;

namespace hal_flags = ::com::android::bluetooth::bluetooth_hal::flags;

constexpr uint8_t kGoogleSubEventOffset = 3;
constexpr uint8_t kLoopbackModeEnabledOffset = 4;
constexpr uint8_t kLoopbackModeByteEnabled = 0x01;

}  // namespace

DebugMonitor::DebugMonitor()
    : debug_info_command_monitor_(
              HciCommandMonitor(static_cast<uint16_t>(CommandOpCode::kGoogleDebugInfo))),
      debug_info_event_monitor_(
              HciEventMonitor(static_cast<uint8_t>(EventCode::kVendorSpecific),
                              static_cast<uint8_t>(GoogleEventSubCode::kControllerDebugInfo),
                              kGoogleSubEventOffset)),
      loopback_command_monitor_(
              HciCommandMonitor(static_cast<uint16_t>(CommandOpCode::kLoopbackMode))) {
    RegisterMonitor(debug_info_command_monitor_, MonitorMode::kMonitor);
    RegisterMonitor(debug_info_event_monitor_, MonitorMode::kIntercept);
    RegisterMonitor(loopback_command_monitor_, MonitorMode::kMonitor);
}

MonitorMode DebugMonitor::OnPacketCallback(const HalPacket& packet) {
    auto monitor_mode = HciRouterClient::OnPacketCallback(packet);

    if (monitor_mode == MonitorMode::kNone && loopback_mode_enabled_ &&
        packet.GetType() == HciPacketType::kCommand && packet.GetSource() == PacketSource::kStack) {
        // When loopback mode is enabled, intercept command packets from the stack
        // and send them to the controller as non-ack commands.
        SendCommandNoAck(packet);
        return MonitorMode::kIntercept;
    }
    return monitor_mode;
}

void DebugMonitor::OnMonitorPacketCallback([[maybe_unused]] MonitorMode mode,
                                           const HalPacket& packet) {
    if (packet.GetCommandOpcode() == static_cast<uint16_t>(CommandOpCode::kGoogleDebugInfo)) {
        LOG(ERROR) << "Debug Info command detected!";
        DebugCentral::Get().HandleDebugInfoCommand();
        return;
    }
    if (packet.GetCommandOpcode() == static_cast<uint16_t>(CommandOpCode::kLoopbackMode)) {
        if (packet.At(kLoopbackModeEnabledOffset) == kLoopbackModeByteEnabled) {
            LOG(WARNING) << "Loopback mode is enabled, disabling HCI flow control in the HAL.";
            loopback_mode_enabled_ = true;
            WakelockWatchdog::GetWatchdog().Pause();
        } else {
            LOG(INFO) << "Loopback mode disabled by command.";
            loopback_mode_enabled_ = false;
            WakelockWatchdog::GetWatchdog().Resume();
        }
        return;
    }
    if (packet.IsVendorEvent() && packet.size() > kGoogleSubEventOffset &&
        packet.At(kGoogleSubEventOffset) ==
                static_cast<uint8_t>(GoogleEventSubCode::kControllerDebugInfo)) {
        DebugCentral::Get().HandleDebugInfoEvent(packet);
    }
}

bool DebugMonitor::IsBluetoothEnabled() {
    return HciRouterClient::IsBluetoothEnabled();
}

void DebugMonitor::OnBluetoothEnabled() {
    DebugCentral::Get().ResetCoredumpGenerator();
}

void DebugMonitor::OnBluetoothDisabled() {
    DebugCentral::Get().ResetCoredumpGenerator();

    if (loopback_mode_enabled_) {
        loopback_mode_enabled_ = false;
        WakelockWatchdog::GetWatchdog().Resume();
    }
}

}  // namespace bluetooth_hal::debug