1 /* 2 * Copyright 2021 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.libraries.testing.deviceshadower.internal.utils; 18 19 import android.bluetooth.BluetoothAdapter; 20 21 import com.android.internal.annotations.VisibleForTesting; 22 23 import java.util.Locale; 24 25 import javax.annotation.concurrent.GuardedBy; 26 27 /** 28 * A class which generates and converts valid Bluetooth MAC addresses. 29 */ 30 public class MacAddressGenerator { 31 32 @GuardedBy("MacAddressGenerator.class") 33 private static MacAddressGenerator sInstance = new MacAddressGenerator(); 34 35 @VisibleForTesting setInstanceForTest(MacAddressGenerator generator)36 public static synchronized void setInstanceForTest(MacAddressGenerator generator) { 37 sInstance = generator; 38 } 39 get()40 public static synchronized MacAddressGenerator get() { 41 return sInstance; 42 } 43 44 private long mLastAddress = 0x0L; 45 MacAddressGenerator()46 private MacAddressGenerator() { 47 } 48 generateMacAddress()49 public String generateMacAddress() { 50 byte[] bytes = generateMacAddressBytes(); 51 return convertByteMacAddress(bytes); 52 } 53 generateMacAddressBytes()54 public byte[] generateMacAddressBytes() { 55 long addr = mLastAddress++; 56 byte[] bytes = new byte[6]; 57 for (int i = 5; i >= 0; i--) { 58 bytes[i] = (byte) (addr & 0xFF); 59 addr = addr >> 8; 60 } 61 return bytes; 62 } 63 convertStringMacAddress(String address)64 public static byte[] convertStringMacAddress(String address) { 65 if (!BluetoothAdapter.checkBluetoothAddress(address)) { 66 throw new IllegalArgumentException("Not a valid bluetooth mac hex string: " + address); 67 } 68 byte[] bytes = new byte[6]; 69 String[] macValues = address.split(":"); 70 for (int i = 0; i < bytes.length; i++) { 71 bytes[i] = Integer.decode("0x" + macValues[i]).byteValue(); 72 } 73 return bytes; 74 } 75 convertByteMacAddress(byte[] address)76 public static String convertByteMacAddress(byte[] address) { 77 if (address == null || address.length != 6) { 78 throw new IllegalArgumentException("Bluetooth address must have 6 bytes"); 79 } 80 return String.format(Locale.US, "%02X:%02X:%02X:%02X:%02X:%02X", 81 address[0], address[1], address[2], address[3], address[4], address[5]); 82 } 83 } 84