Merge changes Ife1279ca,Ib1eb78c4 into tm-dev am: 8c0f73cb35
Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Nearby/+/17252245
Change-Id: Ie0cf98d08f7ba9b66ef8d78455de0abb9805047a
diff --git a/nearby/service/java/com/android/server/nearby/util/FastPairDecoder.java b/nearby/service/java/com/android/server/nearby/util/FastPairDecoder.java
deleted file mode 100644
index 6021ff6..0000000
--- a/nearby/service/java/com/android/server/nearby/util/FastPairDecoder.java
+++ /dev/null
@@ -1,258 +0,0 @@
-/*
- * 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 com.android.server.nearby.util;
-
-import android.annotation.Nullable;
-import android.bluetooth.le.ScanRecord;
-import android.os.ParcelUuid;
-import android.util.SparseArray;
-
-import com.android.server.nearby.common.ble.BleFilter;
-import com.android.server.nearby.common.ble.BleRecord;
-
-import java.util.Arrays;
-
-/**
- * Parses Fast Pair information out of {@link BleRecord}s.
- *
- * <p>There are 2 different packet formats that are supported, which is used can be determined by
- * packet length:
- *
- * <p>For 3-byte packets, the full packet is the model ID.
- *
- * <p>For all other packets, the first byte is the header, followed by the model ID, followed by
- * zero or more extra fields. Each field has its own header byte followed by the field value. The
- * packet header is formatted as 0bVVVLLLLR (V = version, L = model ID length, R = reserved) and
- * each extra field header is 0bLLLLTTTT (L = field length, T = field type).
- */
-public class FastPairDecoder {
-
- private static final int FIELD_TYPE_BLOOM_FILTER = 0;
- private static final int FIELD_TYPE_BLOOM_FILTER_SALT = 1;
- private static final int FIELD_TYPE_BLOOM_FILTER_NO_NOTIFICATION = 2;
- private static final int FIELD_TYPE_BATTERY = 3;
- private static final int FIELD_TYPE_BATTERY_NO_NOTIFICATION = 4;
- public static final int FIELD_TYPE_CONNECTION_STATE = 5;
- private static final int FIELD_TYPE_RANDOM_RESOLVABLE_DATA = 6;
-
-
- /** FE2C is the 16-bit Service UUID. The rest is the base UUID. See BluetoothUuid (hidden). */
- private static final ParcelUuid FAST_PAIR_SERVICE_PARCEL_UUID =
- ParcelUuid.fromString("0000FE2C-0000-1000-8000-00805F9B34FB");
-
- /** The filter you use to scan for Fast Pair BLE advertisements. */
- public static final BleFilter FILTER =
- new BleFilter.Builder().setServiceData(FAST_PAIR_SERVICE_PARCEL_UUID,
- new byte[0]).build();
-
- // NOTE: Ensure that all bitmasks are always ints, not bytes so that bitshifting works correctly
- // without needing worry about signing errors.
- private static final int HEADER_VERSION_BITMASK = 0b11100000;
- private static final int HEADER_LENGTH_BITMASK = 0b00011110;
- private static final int HEADER_VERSION_OFFSET = 5;
- private static final int HEADER_LENGTH_OFFSET = 1;
-
- private static final int EXTRA_FIELD_LENGTH_BITMASK = 0b11110000;
- private static final int EXTRA_FIELD_TYPE_BITMASK = 0b00001111;
- private static final int EXTRA_FIELD_LENGTH_OFFSET = 4;
- private static final int EXTRA_FIELD_TYPE_OFFSET = 0;
-
- private static final int MIN_ID_LENGTH = 3;
- private static final int MAX_ID_LENGTH = 14;
- private static final int HEADER_INDEX = 0;
- private static final int HEADER_LENGTH = 1;
- private static final int FIELD_HEADER_LENGTH = 1;
-
- // Not using java.util.IllegalFormatException because it is unchecked.
- private static class IllegalFormatException extends Exception {
- private IllegalFormatException(String message) {
- super(message);
- }
- }
-
- /**
- * Gets model id data from broadcast
- */
- @Nullable
- public static byte[] getModelId(@Nullable byte[] serviceData) {
- if (serviceData == null) {
- return null;
- }
-
- if (serviceData.length >= MIN_ID_LENGTH) {
- if (serviceData.length == MIN_ID_LENGTH) {
- // If the length == 3, all bytes are the ID. See flag docs for more about
- // endianness.
- return serviceData;
- } else {
- // Otherwise, the first byte is a header which contains the length of the big-endian
- // model ID that follows. The model ID will be trimmed if it contains leading zeros.
- int idIndex = 1;
- int end = idIndex + getIdLength(serviceData);
- while (serviceData[idIndex] == 0 && end - idIndex > MIN_ID_LENGTH) {
- idIndex++;
- }
- return Arrays.copyOfRange(serviceData, idIndex, end);
- }
- }
- return null;
- }
-
- /** Gets the FastPair service data array if available, otherwise returns null. */
- @Nullable
- public static byte[] getServiceDataArray(BleRecord bleRecord) {
- return bleRecord.getServiceData(FAST_PAIR_SERVICE_PARCEL_UUID);
- }
-
- /** Gets the FastPair service data array if available, otherwise returns null. */
- @Nullable
- public static byte[] getServiceDataArray(ScanRecord scanRecord) {
- return scanRecord.getServiceData(FAST_PAIR_SERVICE_PARCEL_UUID);
- }
-
- /** Gets the bloom filter from the extra fields if available, otherwise returns null. */
- @Nullable
- public static byte[] getBloomFilter(@Nullable byte[] serviceData) {
- return getExtraField(serviceData, FIELD_TYPE_BLOOM_FILTER);
- }
-
- /** Gets the bloom filter salt from the extra fields if available, otherwise returns null. */
- @Nullable
- public static byte[] getBloomFilterSalt(byte[] serviceData) {
- return getExtraField(serviceData, FIELD_TYPE_BLOOM_FILTER_SALT);
- }
-
- /**
- * Gets the suppress notification with bloom filter from the extra fields if available,
- * otherwise returns null.
- */
- @Nullable
- public static byte[] getBloomFilterNoNotification(@Nullable byte[] serviceData) {
- return getExtraField(serviceData, FIELD_TYPE_BLOOM_FILTER_NO_NOTIFICATION);
- }
-
- /**
- * Get random resolvableData
- */
- @Nullable
- public static byte[] getRandomResolvableData(byte[] serviceData) {
- return getExtraField(serviceData, FIELD_TYPE_RANDOM_RESOLVABLE_DATA);
- }
-
- @Nullable
- private static byte[] getExtraField(@Nullable byte[] serviceData, int fieldId) {
- if (serviceData == null || serviceData.length < HEADER_INDEX + HEADER_LENGTH) {
- return null;
- }
- try {
- return getExtraFields(serviceData).get(fieldId);
- } catch (IllegalFormatException e) {
- return null;
- }
- }
-
- /** Gets extra field data at the end of the packet, defined by the extra field header. */
- private static SparseArray<byte[]> getExtraFields(byte[] serviceData)
- throws IllegalFormatException {
- SparseArray<byte[]> extraFields = new SparseArray<>();
- if (getVersion(serviceData) != 0) {
- return extraFields;
- }
- int headerIndex = getFirstExtraFieldHeaderIndex(serviceData);
- while (headerIndex < serviceData.length) {
- int length = getExtraFieldLength(serviceData, headerIndex);
- int index = headerIndex + FIELD_HEADER_LENGTH;
- int type = getExtraFieldType(serviceData, headerIndex);
- int end = index + length;
- if (extraFields.get(type) == null) {
- if (end <= serviceData.length) {
- extraFields.put(type, Arrays.copyOfRange(serviceData, index, end));
- } else {
- throw new IllegalFormatException(
- "Invalid length, " + end + " is longer than service data size "
- + serviceData.length);
- }
- }
- headerIndex = end;
- }
- return extraFields;
- }
-
- /** Checks whether or not a valid ID is included in the service data packet. */
- public static boolean hasBeaconIdBytes(BleRecord bleRecord) {
- byte[] serviceData = bleRecord.getServiceData(FAST_PAIR_SERVICE_PARCEL_UUID);
- return checkModelId(serviceData);
- }
-
- /** Check whether byte array is FastPair model id or not. */
- public static boolean checkModelId(@Nullable byte[] scanResult) {
- return scanResult != null
- // The 3-byte format has no header byte (all bytes are the ID).
- && (scanResult.length == MIN_ID_LENGTH
- // Header byte exists. We support only format version 0. (A different version
- // indicates
- // a breaking change in the format.)
- || (scanResult.length > MIN_ID_LENGTH
- && getVersion(scanResult) == 0
- && isIdLengthValid(scanResult)));
- }
-
- /** Checks whether or not bloom filter is included in the service data packet. */
- public static boolean hasBloomFilter(BleRecord bleRecord) {
- return (getBloomFilter(getServiceDataArray(bleRecord)) != null
- || getBloomFilterNoNotification(getServiceDataArray(bleRecord)) != null);
- }
-
- /** Checks whether or not bloom filter is included in the service data packet. */
- public static boolean hasBloomFilter(ScanRecord scanRecord) {
- return (getBloomFilter(getServiceDataArray(scanRecord)) != null
- || getBloomFilterNoNotification(getServiceDataArray(scanRecord)) != null);
- }
-
- private static int getVersion(byte[] serviceData) {
- return serviceData.length == MIN_ID_LENGTH
- ? 0
- : (serviceData[HEADER_INDEX] & HEADER_VERSION_BITMASK) >> HEADER_VERSION_OFFSET;
- }
-
- private static int getIdLength(byte[] serviceData) {
- return serviceData.length == MIN_ID_LENGTH
- ? MIN_ID_LENGTH
- : (serviceData[HEADER_INDEX] & HEADER_LENGTH_BITMASK) >> HEADER_LENGTH_OFFSET;
- }
-
- private static int getFirstExtraFieldHeaderIndex(byte[] serviceData) {
- return HEADER_INDEX + HEADER_LENGTH + getIdLength(serviceData);
- }
-
- private static int getExtraFieldLength(byte[] serviceData, int extraFieldIndex) {
- return (serviceData[extraFieldIndex] & EXTRA_FIELD_LENGTH_BITMASK)
- >> EXTRA_FIELD_LENGTH_OFFSET;
- }
-
- private static int getExtraFieldType(byte[] serviceData, int extraFieldIndex) {
- return (serviceData[extraFieldIndex] & EXTRA_FIELD_TYPE_BITMASK) >> EXTRA_FIELD_TYPE_OFFSET;
- }
-
- private static boolean isIdLengthValid(byte[] serviceData) {
- int idLength = getIdLength(serviceData);
- return MIN_ID_LENGTH <= idLength
- && idLength <= MAX_ID_LENGTH
- && idLength + HEADER_LENGTH <= serviceData.length;
- }
-}
-