1 /* 2 * Copyright (C) 2018 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 package libcore.net; 17 18 import android.system.GaiException; 19 import android.system.StructAddrinfo; 20 import java.net.Inet4Address; 21 import java.net.Inet6Address; 22 import java.net.InetAddress; 23 import libcore.io.Libcore; 24 25 import static android.system.OsConstants.AF_INET; 26 import static android.system.OsConstants.AI_NUMERICHOST; 27 28 /** 29 * Android specific utility methods for {@link InetAddress} instances. 30 * 31 * @hide 32 */ 33 @libcore.api.CorePlatformApi 34 public class InetAddressUtils { 35 36 private static final int NETID_UNSET = 0; 37 InetAddressUtils()38 private InetAddressUtils() { 39 } 40 41 /** 42 * Checks to see if the {@code address} is a numeric address (such as {@code "192.0.2.1"} or 43 * {@code "2001:db8::1:2"}). 44 * 45 * <p>A numeric address is either an IPv4 address containing exactly 4 decimal numbers or an 46 * IPv6 numeric address. IPv4 addresses that consist of either hexadecimal or octal digits or 47 * do not have exactly 4 numbers are not treated as numeric. 48 * 49 * <p>This method will never do a DNS lookup. 50 * 51 * @param address the address to parse. 52 * @return true if the supplied address is numeric, false otherwise. 53 */ 54 @libcore.api.CorePlatformApi isNumericAddress(String address)55 public static boolean isNumericAddress(String address) { 56 return parseNumericAddressNoThrow(address) != null; 57 } 58 59 /** 60 * Returns an InetAddress corresponding to the given numeric address (such 61 * as {@code "192.168.0.1"} or {@code "2001:4860:800d::68"}). 62 * 63 * <p>See {@link #isNumericAddress(String)} for a definition as to what constitutes a numeric 64 * address. 65 * 66 * <p>This method will never do a DNS lookup. 67 * 68 * @param address the address to parse, must be numeric. 69 * @return an {@link InetAddress} instance corresponding to the address. 70 * @throws IllegalArgumentException if {@code address} is not a numeric address. 71 */ 72 @libcore.api.CorePlatformApi parseNumericAddress(String address)73 public static InetAddress parseNumericAddress(String address) { 74 InetAddress result = parseNumericAddressNoThrow(address); 75 if (result == null) { 76 throw new IllegalArgumentException("Not a numeric address: " + address); 77 } 78 return result; 79 } 80 parseNumericAddressNoThrow(String address)81 public static InetAddress parseNumericAddressNoThrow(String address) { 82 StructAddrinfo hints = new StructAddrinfo(); 83 hints.ai_flags = AI_NUMERICHOST; 84 InetAddress[] addresses = null; 85 try { 86 addresses = Libcore.os.android_getaddrinfo(address, hints, NETID_UNSET); 87 } catch (GaiException ignored) { 88 } 89 if (addresses == null) { 90 return null; 91 } 92 return addresses[0]; 93 } 94 95 /** 96 * Like {@link #parseNumericAddressNoThrow(String)}}, but strips optional [] 97 * around a numeric IPv6 address. 98 */ parseNumericAddressNoThrowStripOptionalBrackets(String address)99 public static InetAddress parseNumericAddressNoThrowStripOptionalBrackets(String address) { 100 // Accept IPv6 addresses (only) in square brackets for compatibility. 101 if (address.startsWith("[") && address.endsWith("]") && address.indexOf(':') != -1) { 102 address = address.substring(1, address.length() - 1); 103 } 104 return InetAddressUtils.parseNumericAddressNoThrow(address); 105 } 106 } 107