1 /* 2 * Copyright (c) 2002, 2021, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package java.net; 26 import java.io.IOException; 27 import java.net.spi.InetAddressResolver.LookupPolicy; 28 29 import static java.net.spi.InetAddressResolver.LookupPolicy.IPV4; 30 31 /* 32 * Package private implementation of InetAddressImpl for IPv4. 33 * 34 * @since 1.4 35 */ 36 final class Inet4AddressImpl implements InetAddressImpl { 37 public native String getLocalHostName() throws UnknownHostException; 38 public InetAddress[] lookupAllHostAddr(String hostname, LookupPolicy lookupPolicy) 39 throws UnknownHostException { 40 if ((lookupPolicy.characteristics() & IPV4) == 0) { 41 throw new UnknownHostException(hostname); 42 } 43 return lookupAllHostAddr(hostname); 44 } 45 private native InetAddress[] lookupAllHostAddr(String hostname) throws UnknownHostException; 46 public native String getHostByAddr(byte[] addr) throws UnknownHostException; 47 private native boolean isReachable0(byte[] addr, int timeout, byte[] ifaddr, int ttl) throws IOException; 48 49 public synchronized InetAddress anyLocalAddress() { 50 if (anyLocalAddress == null) { 51 anyLocalAddress = new Inet4Address(); // {0x00,0x00,0x00,0x00} 52 anyLocalAddress.holder().hostName = "0.0.0.0"; 53 } 54 return anyLocalAddress; 55 } 56 57 public synchronized InetAddress loopbackAddress() { 58 if (loopbackAddress == null) { 59 byte[] loopback = {0x7f,0x00,0x00,0x01}; 60 loopbackAddress = new Inet4Address("localhost", loopback); 61 } 62 return loopbackAddress; 63 } 64 65 public boolean isReachable(InetAddress addr, int timeout, NetworkInterface netif, int ttl) throws IOException { 66 byte[] ifaddr = null; 67 if (netif != null) { 68 /* 69 * Let's make sure we use an address of the proper family 70 */ 71 java.util.Enumeration<InetAddress> it = netif.getInetAddresses(); 72 InetAddress inetaddr = null; 73 while (!(inetaddr instanceof Inet4Address) && 74 it.hasMoreElements()) 75 inetaddr = it.nextElement(); 76 if (inetaddr instanceof Inet4Address) 77 ifaddr = inetaddr.getAddress(); 78 } 79 return isReachable0(addr.getAddress(), timeout, ifaddr, ttl); 80 } 81 private InetAddress anyLocalAddress; 82 private InetAddress loopbackAddress; 83 } --- EOF ---