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Commit 44f61309 authored by Junyu Lai's avatar Junyu Lai
Browse files

[MS59.1] Add NetworkStatsDataMigrationUtils

Once the data usage part moves into the module, the OEM would
lose the ability to modify the code, thus we need a mechanism
to prevent data loss during migration. Hence, provide a
helper class to read old version of persistent network
statistics, the implementation is intended to be modified
by OEM partners to accommodate their custom changes.

This interface will be invoked by NetworkStatsService during
the boot up phase in the migration process which will be
introduced in follow-up changes.

Test: atest NetworkStatsDataMigrationUtilsTest
Bug: 204830222
Change-Id: I4a9c8a04761b530ce0b31869f0d7fc191b00438f
parent dbaa056d
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/*
 * Copyright (C) 2022 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 android.net.netstats;

import static android.app.usage.NetworkStatsManager.PREFIX_UID;
import static android.app.usage.NetworkStatsManager.PREFIX_UID_TAG;
import static android.app.usage.NetworkStatsManager.PREFIX_XT;
import static android.net.ConnectivityManager.TYPE_MOBILE;
import static android.net.ConnectivityManager.TYPE_MOBILE_DUN;
import static android.net.ConnectivityManager.TYPE_MOBILE_HIPRI;
import static android.net.ConnectivityManager.TYPE_MOBILE_MMS;
import static android.net.ConnectivityManager.TYPE_MOBILE_SUPL;
import static android.net.NetworkStats.SET_DEFAULT;
import static android.net.NetworkStats.TAG_NONE;

import android.annotation.NonNull;
import android.net.NetworkIdentity;
import android.net.NetworkStatsCollection;
import android.net.NetworkStatsHistory;
import android.net.NetworkTemplate;
import android.os.Environment;
import android.util.AtomicFile;

import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.util.FastDataInput;

import libcore.io.IoUtils;

import java.io.BufferedInputStream;
import java.io.DataInput;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.ProtocolException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;

/**
 * Helper class to read old version of persistent network statistics, the implementation is
 * intended to be modified by OEM partners to accommodate their custom changes.
 * @hide
 */
// @SystemApi(client = MODULE_LIBRARIES)
public class NetworkStatsDataMigrationUtils {

    private static final HashMap<String, String> sPrefixLegacyFileNameMap =
            new HashMap<String, String>() {{
                put(PREFIX_XT, "netstats_xt.bin");
                put(PREFIX_UID, "netstats_uid.bin");
                put(PREFIX_UID_TAG, "netstats_uid.bin");
            }};

    // These version constants are copied from NetworkStatsCollection/History, which is okay for
    // OEMs to modify to adapt their own logic.
    private static class CollectionVersion {
        static final int VERSION_NETWORK_INIT = 1;

        static final int VERSION_UID_INIT = 1;
        static final int VERSION_UID_WITH_IDENT = 2;
        static final int VERSION_UID_WITH_TAG = 3;
        static final int VERSION_UID_WITH_SET = 4;

        static final int VERSION_UNIFIED_INIT = 16;
    }

    private static class HistoryVersion {
        static final int VERSION_INIT = 1;
        static final int VERSION_ADD_PACKETS = 2;
        static final int VERSION_ADD_ACTIVE = 3;
    }

    private static class IdentitySetVersion {
        static final int VERSION_INIT = 1;
        static final int VERSION_ADD_ROAMING = 2;
        static final int VERSION_ADD_NETWORK_ID = 3;
        static final int VERSION_ADD_METERED = 4;
        static final int VERSION_ADD_DEFAULT_NETWORK = 5;
        static final int VERSION_ADD_OEM_MANAGED_NETWORK = 6;
    }

    /**
     * File header magic number: "ANET". The definition is copied from NetworkStatsCollection,
     * but it is fine for OEM to re-define to their own value to adapt the legacy file reading
     * logic.
     */
    private static final int FILE_MAGIC = 0x414E4554;
    /** Default buffer size from BufferedInputStream */
    private static final int BUFFER_SIZE = 8192;

    // Constructing this object is not allowed.
    private NetworkStatsDataMigrationUtils() {
    }

    // Used to read files at /data/system/netstats_*.bin.
    @NonNull
    private static File getPlatformSystemDir() {
        return new File(Environment.getDataDirectory(), "system");
    }

    // Used to read files at /data/system/netstats/<tag>.<start>-<end>.
    @NonNull
    private static File getPlatformBaseDir() {
        File baseDir = new File(getPlatformSystemDir(), "netstats");
        baseDir.mkdirs();
        return baseDir;
    }

    // Get /data/system/netstats_*.bin legacy files. Does not check for existence.
    @NonNull
    private static File getLegacyBinFileForPrefix(@NonNull String prefix) {
        return new File(getPlatformSystemDir(), sPrefixLegacyFileNameMap.get(prefix));
    }

    // List /data/system/netstats/[xt|uid|uid_tag].<start>-<end> legacy files.
    @NonNull
    private static ArrayList<File> getPlatformFileListForPrefix(@NonNull String prefix) {
        final ArrayList<File> list = new ArrayList<>();
        final File platformFiles = new File(getPlatformBaseDir(), "netstats");
        if (platformFiles.exists()) {
            for (String name : platformFiles.list()) {
                // Skip when prefix doesn't match.
                if (!name.startsWith(prefix + ".")) continue;

                list.add(new File(platformFiles, name));
            }
        }
        return list;
    }

    /**
     * Read legacy persisted network stats from disk. This function provides a default
     * implementation to read persisted network stats from two different locations.
     * And this is intended to be modified by OEM to read from custom file format or
     * locations if necessary.
     *
     * @param prefix         Type of data which is being read by the service.
     * @param bucketDuration Duration of the buckets of the object, in milliseconds.
     * @return {@link NetworkStatsCollection} instance.
     */
    @NonNull
    public static NetworkStatsCollection readPlatformCollectionLocked(
            @NonNull String prefix, long bucketDuration) throws IOException {
        final NetworkStatsCollection.Builder builder =
                new NetworkStatsCollection.Builder(bucketDuration);

        // Import /data/system/netstats_uid.bin legacy files if exists.
        switch (prefix) {
            case PREFIX_UID:
            case PREFIX_UID_TAG:
                final File uidFile = getLegacyBinFileForPrefix(prefix);
                if (uidFile.exists()) {
                    readLegacyUid(builder, uidFile, PREFIX_UID_TAG.equals(prefix) ? true : false);
                }
                break;
            default:
                // Ignore other types.
        }

        // Import /data/system/netstats/[xt|uid|uid_tag].<start>-<end> legacy files if exists.
        final ArrayList<File> platformFiles = getPlatformFileListForPrefix(prefix);
        for (final File platformFile : platformFiles) {
            if (platformFile.exists()) {
                readPlatformCollection(builder, platformFile);
            }
        }

        return builder.build();
    }

    private static void readPlatformCollection(@NonNull NetworkStatsCollection.Builder builder,
            @NonNull File file) throws IOException {
        final FileInputStream is = new FileInputStream(file);
        final FastDataInput dataIn = new FastDataInput(is, BUFFER_SIZE);
        try {
            readPlatformCollection(builder, dataIn);
        } finally {
            IoUtils.closeQuietly(dataIn);
        }
    }

    /**
     * Helper function to read old version of NetworkStatsCollections that resided in the platform.
     *
     * @hide
     */
    @VisibleForTesting
    public static void readPlatformCollection(@NonNull NetworkStatsCollection.Builder builder,
            @NonNull DataInput in) throws IOException {
        // verify file magic header intact
        final int magic = in.readInt();
        if (magic != FILE_MAGIC) {
            throw new ProtocolException("unexpected magic: " + magic);
        }

        final int version = in.readInt();
        switch (version) {
            case CollectionVersion.VERSION_UNIFIED_INIT: {
                // uid := size *(NetworkIdentitySet size *(uid set tag NetworkStatsHistory))
                final int identSize = in.readInt();
                for (int i = 0; i < identSize; i++) {
                    final Set<NetworkIdentity> ident = readPlatformNetworkIdentitySet(in);

                    final int size = in.readInt();
                    for (int j = 0; j < size; j++) {
                        final int uid = in.readInt();
                        final int set = in.readInt();
                        final int tag = in.readInt();

                        final NetworkStatsCollection.Key key = new NetworkStatsCollection.Key(
                                ident, uid, set, tag);
                        final NetworkStatsHistory history = readPlatformHistory(in);
                        builder.addEntry(key, history);
                    }
                }
                break;
            }
            default: {
                throw new ProtocolException("unexpected version: " + version);
            }
        }
    }

    // Copied from NetworkStatsHistory#DataStreamUtils.
    private static long[] readFullLongArray(DataInput in) throws IOException {
        final int size = in.readInt();
        if (size < 0) throw new ProtocolException("negative array size");
        final long[] values = new long[size];
        for (int i = 0; i < values.length; i++) {
            values[i] = in.readLong();
        }
        return values;
    }

    // Copied from NetworkStatsHistory#DataStreamUtils.
    private static long[] readVarLongArray(@NonNull DataInput in) throws IOException {
        final int size = in.readInt();
        if (size == -1) return null;
        if (size < 0) throw new ProtocolException("negative array size");
        final long[] values = new long[size];
        for (int i = 0; i < values.length; i++) {
            values[i] = readVarLong(in);
        }
        return values;
    }

    /**
     * Read variable-length {@link Long} using protobuf-style approach.
     */
    // Copied from NetworkStatsHistory#DataStreamUtils.
    private static long readVarLong(DataInput in) throws IOException {
        int shift = 0;
        long result = 0;
        while (shift < 64) {
            byte b = in.readByte();
            result |= (long) (b & 0x7F) << shift;
            if ((b & 0x80) == 0) {
                return result;
            }
            shift += 7;
        }
        throw new ProtocolException("malformed var long");
    }

    // Copied from NetworkIdentitySet.
    private static String readOptionalString(DataInput in) throws IOException {
        if (in.readByte() != 0) {
            return in.readUTF();
        } else {
            return null;
        }
    }

    /**
     * This is copied from NetworkStatsHistory#NetworkStatsHistory(DataInput in). But it is fine
     * for OEM to re-write the logic to adapt the legacy file reading.
     */
    @NonNull
    private static NetworkStatsHistory readPlatformHistory(@NonNull DataInput in)
            throws IOException {
        final long bucketDuration;
        final long[] bucketStart;
        final long[] rxBytes;
        final long[] rxPackets;
        final long[] txBytes;
        final long[] txPackets;
        final long[] operations;
        final int bucketCount;
        long[] activeTime = new long[0];

        final int version = in.readInt();
        switch (version) {
            case HistoryVersion.VERSION_INIT: {
                bucketDuration = in.readLong();
                bucketStart = readFullLongArray(in);
                rxBytes = readFullLongArray(in);
                rxPackets = new long[bucketStart.length];
                txBytes = readFullLongArray(in);
                txPackets = new long[bucketStart.length];
                operations = new long[bucketStart.length];
                bucketCount = bucketStart.length;
                break;
            }
            case HistoryVersion.VERSION_ADD_PACKETS:
            case HistoryVersion.VERSION_ADD_ACTIVE: {
                bucketDuration = in.readLong();
                bucketStart = readVarLongArray(in);
                activeTime = (version >= HistoryVersion.VERSION_ADD_ACTIVE)
                        ? readVarLongArray(in)
                        : new long[bucketStart.length];
                rxBytes = readVarLongArray(in);
                rxPackets = readVarLongArray(in);
                txBytes = readVarLongArray(in);
                txPackets = readVarLongArray(in);
                operations = readVarLongArray(in);
                bucketCount = bucketStart.length;
                break;
            }
            default: {
                throw new ProtocolException("unexpected version: " + version);
            }
        }

        final NetworkStatsHistory.Builder historyBuilder =
                new NetworkStatsHistory.Builder(bucketDuration, bucketCount);
        for (int i = 0; i < bucketCount; i++) {
            final NetworkStatsHistory.Entry entry = new NetworkStatsHistory.Entry(
                    bucketStart[i], activeTime[i],
                    rxBytes[i], rxPackets[i], txBytes[i], txPackets[i], operations[i]);
            historyBuilder.addEntry(entry);
        }

        return historyBuilder.build();
    }

    @NonNull
    private static Set<NetworkIdentity> readPlatformNetworkIdentitySet(@NonNull DataInput in)
            throws IOException {
        final int version = in.readInt();
        final int size = in.readInt();
        final Set<NetworkIdentity> set = new HashSet<>();
        for (int i = 0; i < size; i++) {
            if (version <= IdentitySetVersion.VERSION_INIT) {
                final int ignored = in.readInt();
            }
            final int type = in.readInt();
            final int ratType = in.readInt();
            final String subscriberId = readOptionalString(in);
            final String networkId;
            if (version >= IdentitySetVersion.VERSION_ADD_NETWORK_ID) {
                networkId = readOptionalString(in);
            } else {
                networkId = null;
            }
            final boolean roaming;
            if (version >= IdentitySetVersion.VERSION_ADD_ROAMING) {
                roaming = in.readBoolean();
            } else {
                roaming = false;
            }

            final boolean metered;
            if (version >= IdentitySetVersion.VERSION_ADD_METERED) {
                metered = in.readBoolean();
            } else {
                // If this is the old data and the type is mobile, treat it as metered. (Note that
                // if this is a mobile network, TYPE_MOBILE is the only possible type that could be
                // used.)
                metered = (type == TYPE_MOBILE);
            }

            final boolean defaultNetwork;
            if (version >= IdentitySetVersion.VERSION_ADD_DEFAULT_NETWORK) {
                defaultNetwork = in.readBoolean();
            } else {
                defaultNetwork = true;
            }

            final int oemNetCapabilities;
            if (version >= IdentitySetVersion.VERSION_ADD_OEM_MANAGED_NETWORK) {
                oemNetCapabilities = in.readInt();
            } else {
                oemNetCapabilities = NetworkIdentity.OEM_NONE;
            }

            // Legacy files might contain TYPE_MOBILE_* types which were deprecated in later
            // releases. For backward compatibility, record them as TYPE_MOBILE instead.
            final int collapsedLegacyType = getCollapsedLegacyType(type);
            final NetworkIdentity.Builder builder = new NetworkIdentity.Builder()
                    .setType(collapsedLegacyType)
                    .setSubscriberId(subscriberId)
                    .setWifiNetworkKey(networkId)
                    .setRoaming(roaming).setMetered(metered)
                    .setDefaultNetwork(defaultNetwork)
                    .setOemManaged(oemNetCapabilities);
            if (type == TYPE_MOBILE && ratType != NetworkTemplate.NETWORK_TYPE_ALL) {
                builder.setRatType(ratType);
            }
            set.add(builder.build());
        }
        return set;
    }

    private static int getCollapsedLegacyType(int networkType) {
        // The constants are referenced from ConnectivityManager#TYPE_MOBILE_*.
        switch (networkType) {
            case TYPE_MOBILE:
            case TYPE_MOBILE_SUPL:
            case TYPE_MOBILE_MMS:
            case TYPE_MOBILE_DUN:
            case TYPE_MOBILE_HIPRI:
            case 10 /* TYPE_MOBILE_FOTA */:
            case 11 /* TYPE_MOBILE_IMS */:
            case 12 /* TYPE_MOBILE_CBS */:
            case 14 /* TYPE_MOBILE_IA */:
            case 15 /* TYPE_MOBILE_EMERGENCY */:
                return TYPE_MOBILE;
        }
        return networkType;
    }

    private static void readLegacyUid(@NonNull NetworkStatsCollection.Builder builder,
            @NonNull File uidFile, boolean onlyTaggedData) throws IOException {
        final AtomicFile inputFile = new AtomicFile(uidFile);
        DataInputStream in = new DataInputStream(new BufferedInputStream(inputFile.openRead()));
        try {
            readLegacyUid(builder, in, onlyTaggedData);
        } finally {
            IoUtils.closeQuietly(in);
        }
    }

    /**
     * Read legacy Uid statistics file format into the collection.
     *
     * This is copied from {@code NetworkStatsCollection#readLegacyUid}.
     * See {@code NetworkStatsService#maybeUpgradeLegacyStatsLocked}.
     *
     * @param taggedData whether to read tagged data. For legacy uid files, the tagged
     *                   data was stored in the same binary file with non-tagged data.
     *                   But in later releases, these data should be kept in different
     *                   recorders.
     * @hide
     */
    @VisibleForTesting
    public static void readLegacyUid(@NonNull NetworkStatsCollection.Builder builder,
            @NonNull DataInput in, boolean taggedData) throws IOException {
        try {
            // verify file magic header intact
            final int magic = in.readInt();
            if (magic != FILE_MAGIC) {
                throw new ProtocolException("unexpected magic: " + magic);
            }

            final int version = in.readInt();
            switch (version) {
                case CollectionVersion.VERSION_UID_INIT: {
                    // uid := size *(UID NetworkStatsHistory)
                    // drop this data version, since we don't have a good
                    // mapping into NetworkIdentitySet.
                    break;
                }
                case CollectionVersion.VERSION_UID_WITH_IDENT: {
                    // uid := size *(NetworkIdentitySet size *(UID NetworkStatsHistory))
                    // drop this data version, since this version only existed
                    // for a short time.
                    break;
                }
                case CollectionVersion.VERSION_UID_WITH_TAG:
                case CollectionVersion.VERSION_UID_WITH_SET: {
                    // uid := size *(NetworkIdentitySet size *(uid set tag NetworkStatsHistory))
                    final int identSize = in.readInt();
                    for (int i = 0; i < identSize; i++) {
                        final Set<NetworkIdentity> ident = readPlatformNetworkIdentitySet(in);

                        final int size = in.readInt();
                        for (int j = 0; j < size; j++) {
                            final int uid = in.readInt();
                            final int set = (version >= CollectionVersion.VERSION_UID_WITH_SET)
                                    ? in.readInt()
                                    : SET_DEFAULT;
                            final int tag = in.readInt();

                            final NetworkStatsCollection.Key key = new NetworkStatsCollection.Key(
                                    ident, uid, set, tag);
                            final NetworkStatsHistory history = readPlatformHistory(in);

                            if ((tag == TAG_NONE) != taggedData) {
                                builder.addEntry(key, history);
                            }
                        }
                    }
                    break;
                }
                default: {
                    throw new ProtocolException("unknown version: " + version);
                }
            }
        } catch (FileNotFoundException | ProtocolException e) {
            // missing stats is okay, probably first boot
        }
    }
}