/*
 * Copyright (C) 2018 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.
 */
package com.android.server.adb;

import static com.android.internal.util.function.pooled.PooledLambda.obtainMessage;

import android.annotation.NonNull;
import android.annotation.UserIdInt;
import android.content.ContentResolver;
import android.content.Context;
import android.content.pm.PackageManager;
import android.database.ContentObserver;
import android.debug.AdbManagerInternal;
import android.debug.AdbTransportType;
import android.debug.FingerprintAndPairDevice;
import android.debug.IAdbCallback;
import android.debug.IAdbManager;
import android.debug.IAdbTransport;
import android.debug.PairDevice;
import android.hardware.usb.UsbManager;
import android.net.Uri;
import android.net.wifi.WifiManager;
import android.os.Binder;
import android.os.IBinder;
import android.os.ParcelFileDescriptor;
import android.os.RemoteCallbackList;
import android.os.RemoteException;
import android.os.SystemProperties;
import android.provider.Settings;
import android.service.adb.AdbServiceDumpProto;
import android.util.ArrayMap;
import android.util.ArraySet;
import android.util.Slog;
import android.util.proto.ProtoOutputStream;

import com.android.internal.util.DumpUtils;
import com.android.internal.util.IndentingPrintWriter;
import com.android.internal.util.Preconditions;
import com.android.internal.util.dump.DualDumpOutputStream;
import com.android.server.FgThread;
import com.android.server.LocalServices;
import com.android.server.SystemService;
import com.android.server.testharness.TestHarnessModeService;

import java.io.File;
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.util.Collections;
import java.util.Map;

/**
 * The Android Debug Bridge (ADB) service. This controls the availability of ADB and authorization
 * of devices allowed to connect to ADB.
 */
public class AdbService extends IAdbManager.Stub {
    /** Adb native daemon. */
    static final String ADBD = "adbd";

    /** Command to start native service. */
    static final String CTL_START = "ctl.start";

    /** Command to start native service. */
    static final String CTL_STOP = "ctl.stop";

    private final RemoteCallbackList<IAdbCallback> mCallbacks = new RemoteCallbackList<>();

    /** Manages the service lifecycle for {@code AdbService} in {@code SystemServer}. */
    public static class Lifecycle extends SystemService {
        private AdbService mAdbService;

        public Lifecycle(Context context) {
            super(context);
        }

        @Override
        public void onStart() {
            mAdbService = new AdbService(getContext());
            publishBinderService(Context.ADB_SERVICE, mAdbService);
        }

        @Override
        public void onBootPhase(int phase) {
            if (phase == SystemService.PHASE_ACTIVITY_MANAGER_READY) {
                mAdbService.systemReady();
            } else if (phase == SystemService.PHASE_BOOT_COMPLETED) {
                FgThread.getHandler()
                        .sendMessage(obtainMessage(AdbService::bootCompleted, mAdbService));
            }
        }
    }

    private class AdbManagerInternalImpl extends AdbManagerInternal {
        @Override
        public void registerTransport(IAdbTransport transport) {
            mTransports.put(transport.asBinder(), transport);
        }

        @Override
        public void unregisterTransport(IAdbTransport transport) {
            mTransports.remove(transport.asBinder());
        }

        @Override
        public boolean isAdbEnabled(byte transportType) {
            switch (transportType) {
                case AdbTransportType.USB:
                    return mIsAdbUsbEnabled;
                case AdbTransportType.WIFI:
                    return mIsAdbWifiEnabled;
                case AdbTransportType.VSOCK:
                    throw new IllegalArgumentException(
                            "AdbTransportType.VSOCK is not yet supported here");
                default:
                    throw new IllegalArgumentException(
                            "isAdbEnabled called with unimplemented transport type="
                                    + transportType);
            }
        }

        @Override
        public File getAdbKeysFile() {
            return mDebuggingManager.getUserKeyFile();
        }

        @Override
        public File getAdbTempKeysFile() {
            return mDebuggingManager.getAdbTempKeysFile();
        }

        @Override
        public void notifyKeyFilesUpdated() {
            mDebuggingManager.notifyKeyFilesUpdated();
        }
    }

    private void registerContentObservers() {
        try {
            // register observer to listen for settings changes
            mObserver = new AdbSettingsObserver();
            mContentResolver.registerContentObserver(
                    Settings.Global.getUriFor(Settings.Global.ADB_ENABLED), false, mObserver);
            mContentResolver.registerContentObserver(
                    Settings.Global.getUriFor(Settings.Global.ADB_WIFI_ENABLED), false, mObserver);
        } catch (Exception e) {
            Slog.e(TAG, "Error in registerContentObservers", e);
        }
    }

    private static boolean containsFunction(String functions, String function) {
        int index = functions.indexOf(function);
        if (index < 0) return false;
        if (index > 0 && functions.charAt(index - 1) != ',') return false;
        int charAfter = index + function.length();
        if (charAfter < functions.length() && functions.charAt(charAfter) != ',') return false;
        return true;
    }

    private class AdbSettingsObserver extends ContentObserver {
        private final Uri mAdbUsbUri = Settings.Global.getUriFor(Settings.Global.ADB_ENABLED);
        private final Uri mAdbWifiUri = Settings.Global.getUriFor(Settings.Global.ADB_WIFI_ENABLED);

        AdbSettingsObserver() {
            super(null);
        }

        @Override
        public void onChange(boolean selfChange, @NonNull Uri uri, @UserIdInt int userId) {
            Slog.d("AdbSettingsObserver", "onChange " + uri.toString());
            if (mAdbUsbUri.equals(uri)) {
                boolean shouldEnable =
                        (Settings.Global.getInt(mContentResolver, Settings.Global.ADB_ENABLED, 0)
                                > 0);
                setAdbEnabled(shouldEnable, AdbTransportType.USB);
            } else if (mAdbWifiUri.equals(uri)) {
                boolean shouldEnable =
                        (Settings.Global.getInt(
                                        mContentResolver, Settings.Global.ADB_WIFI_ENABLED, 0)
                                > 0);
                setAdbEnabled(shouldEnable, AdbTransportType.WIFI);
            }
        }
    }

    private static final String TAG = AdbService.class.getSimpleName();

    /**
     * The persistent property which stores whether adb is enabled or not. May also contain
     * vendor-specific default functions for testing purposes.
     */
    private static final String USB_PERSISTENT_CONFIG_PROPERTY = "persist.sys.usb.config";

    /**
     * The system property used by both framework and adbd to set if ADB Wifi should be enabled when
     * either system starts up.
     */
    private static final String WIFI_PERSISTENT_CONFIG_PROPERTY = "persist.adb.tls_server.enable";

    private final Context mContext;
    private final ContentResolver mContentResolver;
    private final ArrayMap<IBinder, IAdbTransport> mTransports = new ArrayMap<>();

    private boolean mIsAdbUsbEnabled;
    private boolean mIsAdbWifiEnabled;
    private final AdbDebuggingManager mDebuggingManager;

    private ContentObserver mObserver;

    private AdbService(Context context) {
        mContext = context;
        mContentResolver = context.getContentResolver();
        mDebuggingManager = new AdbDebuggingManager(context);

        registerContentObservers();
        LocalServices.addService(AdbManagerInternal.class, new AdbManagerInternalImpl());
    }

    /**
     * Called in response to {@code SystemService.PHASE_ACTIVITY_MANAGER_READY} from {@code
     * SystemServer}.
     */
    public void systemReady() {
        Slog.d(TAG, "systemReady");

        /*
         * Use the normal bootmode persistent prop to maintain state of adb across
         * all boot modes.
         */
        mIsAdbUsbEnabled =
                containsFunction(
                        SystemProperties.get(USB_PERSISTENT_CONFIG_PROPERTY, ""),
                        UsbManager.USB_FUNCTION_ADB);
        boolean shouldEnableAdbUsb =
                mIsAdbUsbEnabled
                        || SystemProperties.getBoolean(
                                TestHarnessModeService.TEST_HARNESS_MODE_PROPERTY, false);
        mIsAdbWifiEnabled = "1".equals(SystemProperties.get(WIFI_PERSISTENT_CONFIG_PROPERTY, "0"));

        // make sure the ADB_ENABLED setting value matches the current state
        try {
            Settings.Global.putInt(
                    mContentResolver, Settings.Global.ADB_ENABLED, shouldEnableAdbUsb ? 1 : 0);
            Settings.Global.putInt(
                    mContentResolver, Settings.Global.ADB_WIFI_ENABLED, mIsAdbWifiEnabled ? 1 : 0);
        } catch (SecurityException e) {
            // If UserManager.DISALLOW_DEBUGGING_FEATURES is on, that this setting can't be changed.
            Slog.d(TAG, "ADB_ENABLED is restricted.");
        }
    }

    /**
     * Called in response to {@code SystemService.PHASE_BOOT_COMPLETED} from {@code SystemServer}.
     */
    public void bootCompleted() {
        Slog.d(TAG, "boot completed");
        mDebuggingManager.setAdbEnabled(mIsAdbUsbEnabled, AdbTransportType.USB);
        mDebuggingManager.setAdbEnabled(mIsAdbWifiEnabled, AdbTransportType.WIFI);
    }

    @Override
    public void allowDebugging(boolean alwaysAllow, @NonNull String publicKey) {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        Preconditions.checkStringNotEmpty(publicKey);
        mDebuggingManager.allowDebugging(alwaysAllow, publicKey);
    }

    @Override
    public void denyDebugging() {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        mDebuggingManager.denyDebugging();
    }

    @Override
    public void clearDebuggingKeys() {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        mDebuggingManager.clearDebuggingKeys();
    }

    /**
     * @return true if the device supports secure ADB over Wi-Fi or Ethernet.
     * @hide
     */
    @Override
    public boolean isAdbWifiSupported() {
        mContext.enforceCallingPermission(
                android.Manifest.permission.MANAGE_DEBUGGING, "AdbService");
        return mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_WIFI)
                || mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_ETHERNET);
    }

    /**
     * @return true if the device supports secure ADB over Wi-Fi and device pairing by QR code.
     * @hide
     */
    @Override
    public boolean isAdbWifiQrSupported() {
        mContext.enforceCallingPermission(
                android.Manifest.permission.MANAGE_DEBUGGING, "AdbService");
        return isAdbWifiSupported()
                && mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_ANY);
    }

    @Override
    public void allowWirelessDebugging(boolean alwaysAllow, @NonNull String bssid) {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        Preconditions.checkStringNotEmpty(bssid);
        mDebuggingManager.allowWirelessDebugging(alwaysAllow, bssid);
    }

    @Override
    public void denyWirelessDebugging() {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        mDebuggingManager.denyWirelessDebugging();
    }

    @Override
    public FingerprintAndPairDevice[] getPairedDevices() {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        Map<String, PairDevice> map = mDebuggingManager.getPairedDevices();
        FingerprintAndPairDevice[] ret = new FingerprintAndPairDevice[map.size()];
        int i = 0;
        for (Map.Entry<String, PairDevice> entry : map.entrySet()) {
            ret[i] = new FingerprintAndPairDevice();
            ret[i].keyFingerprint = entry.getKey();
            ret[i].device = entry.getValue();
            i++;
        }
        return ret;
    }

    @Override
    public void unpairDevice(@NonNull String fingerprint) {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        Preconditions.checkStringNotEmpty(fingerprint);
        mDebuggingManager.unpairDevice(fingerprint);
    }

    @Override
    public void enablePairingByPairingCode() {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        mDebuggingManager.enablePairingByPairingCode();
    }

    @Override
    public void enablePairingByQrCode(@NonNull String serviceName, @NonNull String password) {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        Preconditions.checkStringNotEmpty(serviceName);
        Preconditions.checkStringNotEmpty(password);
        mDebuggingManager.enablePairingByQrCode(serviceName, password);
    }

    @Override
    public void disablePairing() {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        mDebuggingManager.disablePairing();
    }

    @Override
    public int getAdbWirelessPort() {
        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_DEBUGGING, null);
        return mDebuggingManager.getAdbWirelessPort();
    }

    @Override
    public void registerCallback(IAdbCallback callback) throws RemoteException {
        Slog.d(TAG, "Registering callback " + callback);
        mCallbacks.register(callback);
    }

    @Override
    public void unregisterCallback(IAdbCallback callback) throws RemoteException {
        Slog.d(TAG, "Unregistering callback " + callback);
        mCallbacks.unregister(callback);
    }

    private void startAdbd() {
        SystemProperties.set(CTL_START, ADBD);
    }

    private void stopAdbd() {
        if (!mIsAdbUsbEnabled && !mIsAdbWifiEnabled) {
            SystemProperties.set(CTL_STOP, ADBD);
        }
    }

    private WifiManager.MulticastLock mAdbMulticastLock = null;

    private void acquireMulticastLock() {
        if (mAdbMulticastLock == null) {
            WifiManager wifiManager =
                    (WifiManager)
                            mContext.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
            mAdbMulticastLock = wifiManager.createMulticastLock("AdbMulticastLock");
        }

        if (!mAdbMulticastLock.isHeld()) {
            mAdbMulticastLock.acquire();
            Slog.d(TAG, "Acquired multicast lock");
        }
    }

    private void releaseMulticastLock() {
        if (mAdbMulticastLock != null && mAdbMulticastLock.isHeld()) {
            mAdbMulticastLock.release();
            Slog.d(TAG, "Released multicast lock");
        }
    }

    private void setAdbEnabled(boolean enable, byte transportType) {
        FgThread.getHandler()
                .sendMessage(
                        obtainMessage(
                                AdbService::setAdbEnabledDoNotCallDirectly,
                                this,
                                enable,
                                transportType));
    }

    static void enableADBdWifi() {
        Slog.d(TAG, "Enabling ADBd Wifi property");
        SystemProperties.set(WIFI_PERSISTENT_CONFIG_PROPERTY, "1");
    }

    static void disableADBdWifi() {
        Slog.d(TAG, "Disabling ADBd Wifi property");
        SystemProperties.set(WIFI_PERSISTENT_CONFIG_PROPERTY, "0");
    }

    private void setAdbEnabledDoNotCallDirectly(boolean enable, byte transportType) {
        Slog.d(
                TAG,
                "setAdbEnabled("
                        + enable
                        + "), mIsAdbUsbEnabled="
                        + mIsAdbUsbEnabled
                        + ", mIsAdbWifiEnabled="
                        + mIsAdbWifiEnabled
                        + ", transportType="
                        + transportType);

        switch (transportType) {
            case AdbTransportType.USB:
                if (enable == mIsAdbUsbEnabled) {
                    return;
                }
                mIsAdbUsbEnabled = enable;
                break;
            case AdbTransportType.WIFI:
                if (enable == mIsAdbWifiEnabled) {
                    return;
                }
                mIsAdbWifiEnabled = enable;
                if (mIsAdbWifiEnabled) {
                    // Start adb over WiFi.
                    enableADBdWifi();
                    acquireMulticastLock();
                } else {
                    // Stop adb over WiFi.
                    disableADBdWifi();
                    releaseMulticastLock();
                }
                break;
            case AdbTransportType.VSOCK:
                Slog.e(TAG, "AdbTransportType.VSOCK is not yet supported here");
                return;
            default:
                Slog.e(TAG, "Unknown transport type=" + transportType);
                return;
        }

        if (enable) {
            startAdbd();
        } else {
            stopAdbd();
        }

        for (IAdbTransport transport : mTransports.values()) {
            try {
                transport.onAdbEnabled(enable, transportType);
            } catch (RemoteException e) {
                Slog.w(TAG, "Unable to send onAdbEnabled to transport " + transport.toString());
            }
        }

        mDebuggingManager.setAdbEnabled(enable, transportType);

        Slog.d(TAG, "Broadcasting enable = " + enable + ", type = " + transportType);
        mCallbacks.broadcast(
                (callback) -> {
                    Slog.d(
                            TAG,
                            "Sending enable = "
                                    + enable
                                    + ", type = "
                                    + transportType
                                    + " to "
                                    + callback);
                    try {
                        callback.onDebuggingChanged(enable, transportType);
                    } catch (RemoteException ex) {
                        Slog.w(TAG, "Unable to send onDebuggingChanged:", ex);
                    }
                });
    }

    @Override
    public int handleShellCommand(
            ParcelFileDescriptor in,
            ParcelFileDescriptor out,
            ParcelFileDescriptor err,
            String[] args) {
        return new AdbShellCommand(this)
                .exec(
                        this,
                        in.getFileDescriptor(),
                        out.getFileDescriptor(),
                        err.getFileDescriptor(),
                        args);
    }

    @Override
    public void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
        if (!DumpUtils.checkDumpPermission(mContext, TAG, writer)) return;

        final IndentingPrintWriter pw = new IndentingPrintWriter(writer, "  ");
        final long ident = Binder.clearCallingIdentity();
        try {
            ArraySet<String> argsSet = new ArraySet<>();
            Collections.addAll(argsSet, args);

            boolean dumpAsProto = false;
            if (argsSet.contains("--proto")) {
                dumpAsProto = true;
            }

            if (argsSet.size() == 0 || argsSet.contains("-a") || dumpAsProto) {
                DualDumpOutputStream dump;
                if (dumpAsProto) {
                    dump = new DualDumpOutputStream(new ProtoOutputStream(fd));
                } else {
                    pw.println("ADB MANAGER STATE (dumpsys adb):");

                    dump = new DualDumpOutputStream(new IndentingPrintWriter(pw, "  "));
                }

                mDebuggingManager.dump(
                        dump, "debugging_manager", AdbServiceDumpProto.DEBUGGING_MANAGER);
                dump.flush();
            } else {
                pw.println("Dump current ADB state");
                pw.println("  No commands available");
            }
        } finally {
            Binder.restoreCallingIdentity(ident);
        }
    }
}