Leftovers of SELinux policy update mechanism.

            </intent-filter>

        </receiver>

        <receiver android:name="com.android.server.updates.SELinuxPolicyInstallReceiver"

                android:permission="android.permission.UPDATE_CONFIG">

            <intent-filter>

                <action android:name="android.intent.action.UPDATE_SEPOLICY" />

                <data android:scheme="content" android:host="*" android:mimeType="*/*" />

            </intent-filter>

        </receiver>

        <receiver android:name="com.android.server.MasterClearReceiver"

            android:permission="android.permission.MASTER_CLEAR">

            <intent-filter

/*

 * Copyright (C) 2013 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.updates;

import android.content.Context;

import android.content.Intent;

import android.os.SystemProperties;

import android.system.ErrnoException;

import android.system.Os;

import android.util.Base64;

import android.util.Slog;

import java.io.BufferedInputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import libcore.io.IoUtils;

public class SELinuxPolicyInstallReceiver extends ConfigUpdateInstallReceiver {

    private static final String TAG = "SELinuxPolicyInstallReceiver";

    private static final String sepolicyPath = "sepolicy";

    private static final String fileContextsPath = "file_contexts.bin";

    private static final String propertyContextsPath = "property_contexts";

    private static final String seappContextsPath = "seapp_contexts";

    private static final String versionPath = "selinux_version";

    private static final String macPermissionsPath = "mac_permissions.xml";

    private static final String serviceContextsPath = "service_contexts";

    public SELinuxPolicyInstallReceiver() {

        super("/data/security/bundle", "sepolicy_bundle", "metadata/", "version");

    }

    private int readInt(BufferedInputStream reader) throws IOException {

        int value = 0;

        for (int i=0; i < 4; i++) {

            value = (value << 8) | reader.read();

        }

        return value;

    }

    private int[] readChunkLengths(BufferedInputStream bundle) throws IOException {

        int[] chunks = new int[7];

        chunks[0] = readInt(bundle);

        chunks[1] = readInt(bundle);

        chunks[2] = readInt(bundle);

        chunks[3] = readInt(bundle);

        chunks[4] = readInt(bundle);

        chunks[5] = readInt(bundle);

        chunks[6] = readInt(bundle);

        return chunks;

    }

    private void installFile(File destination, BufferedInputStream stream, int length)

            throws IOException {

        byte[] chunk = new byte[length];

        stream.read(chunk, 0, length);

        writeUpdate(updateDir, destination, Base64.decode(chunk, Base64.DEFAULT));

    }

    private void deleteRecursive(File fileOrDirectory) {

        if (fileOrDirectory.isDirectory())

            for (File child : fileOrDirectory.listFiles())

                deleteRecursive(child);

        fileOrDirectory.delete();

    }

    private void unpackBundle() throws IOException {

        BufferedInputStream stream = new BufferedInputStream(new FileInputStream(updateContent));

        File tmp = new File(updateDir.getParentFile(), "tmp");

        try {

            int[] chunkLengths = readChunkLengths(stream);

            deleteRecursive(tmp);

            tmp.mkdirs();

            installFile(new File(tmp, versionPath), stream, chunkLengths[0]);

            installFile(new File(tmp, macPermissionsPath), stream, chunkLengths[1]);

            installFile(new File(tmp, seappContextsPath), stream, chunkLengths[2]);

            installFile(new File(tmp, propertyContextsPath), stream, chunkLengths[3]);

            installFile(new File(tmp, fileContextsPath), stream, chunkLengths[4]);

            installFile(new File(tmp, sepolicyPath), stream, chunkLengths[5]);

            installFile(new File(tmp, serviceContextsPath), stream, chunkLengths[6]);

        } finally {

            IoUtils.closeQuietly(stream);

        }

    }

    private void applyUpdate() throws IOException, ErrnoException {

        Slog.i(TAG, "Applying SELinux policy");

        File backup = new File(updateDir.getParentFile(), "backup");

        File current = new File(updateDir.getParentFile(), "current");

        File tmp = new File(updateDir.getParentFile(), "tmp");

        if (current.exists()) {

            deleteRecursive(backup);

            Os.rename(current.getPath(), backup.getPath());

        }

        try {

            Os.rename(tmp.getPath(), current.getPath());

            SystemProperties.set("selinux.reload_policy", "1");

        } catch (ErrnoException e) {

            Slog.e(TAG, "Could not update selinux policy: ", e);

            if (backup.exists()) {

                Os.rename(backup.getPath(), current.getPath());

            }

        }

    }

    @Override

    protected void postInstall(Context context, Intent intent) {

        try {

            unpackBundle();

            applyUpdate();

        } catch (IllegalArgumentException e) {

            Slog.e(TAG, "SELinux policy update malformed: ", e);

        } catch (IOException e) {

            Slog.e(TAG, "Could not update selinux policy: ", e);

        } catch (ErrnoException e) {

            Slog.e(TAG, "Could not update selinux policy: ", e);

        }

    }

}