| /* InetAddress.java -- Class to model an Internet address |
| Copyright (C) 1998, 1999, 2002, 2004 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.net; |
| |
| import gnu.classpath.Configuration; |
| |
| import java.io.IOException; |
| import java.io.ObjectInputStream; |
| import java.io.ObjectOutputStream; |
| import java.io.ObjectStreamException; |
| import java.io.Serializable; |
| |
| /** |
| * This class models an Internet address. It does not have a public |
| * constructor. Instead, new instances of this objects are created |
| * using the static methods getLocalHost(), getByName(), and |
| * getAllByName(). |
| * |
| * <p>This class fulfills the function of the C style functions gethostname(), |
| * gethostbyname(), and gethostbyaddr(). It resolves Internet DNS names |
| * into their corresponding numeric addresses and vice versa.</p> |
| * |
| * @author Aaron M. Renn (arenn@urbanophile.com) |
| * @author Per Bothner |
| * |
| * @specnote This class is not final since JK 1.4 |
| */ |
| public class InetAddress implements Serializable |
| { |
| private static final long serialVersionUID = 3286316764910316507L; |
| |
| /** |
| * Dummy InetAddress, used to bind socket to any (all) network interfaces. |
| */ |
| static InetAddress ANY_IF; |
| |
| private static final byte[] loopbackAddress = { 127, 0, 0, 1 }; |
| |
| private static final InetAddress loopback |
| = new Inet4Address(loopbackAddress, "localhost"); |
| |
| private static InetAddress localhost = null; |
| |
| static |
| { |
| // load the shared library needed for name resolution |
| if (Configuration.INIT_LOAD_LIBRARY) |
| System.loadLibrary("javanet"); |
| |
| byte[] zeros = { 0, 0, 0, 0 }; |
| ANY_IF = new Inet4Address(zeros, "0.0.0.0"); |
| } |
| |
| /** |
| * The Serialized Form specifies that an int 'address' is saved/restored. |
| * This class uses a byte array internally so we'll just do the conversion |
| * at serialization time and leave the rest of the algorithm as is. |
| */ |
| private int address; |
| |
| /** |
| * An array of octets representing an IP address. |
| */ |
| transient byte[] addr; |
| |
| /** |
| * The name of the host for this address. |
| */ |
| String hostName; |
| |
| /** |
| * The field 'family' seems to be the AF_ value. |
| * FIXME: Much of the code in the other java.net classes does not make |
| * use of this family field. A better implementation would be to make |
| * use of getaddrinfo() and have other methods just check the family |
| * field rather than examining the length of the address each time. |
| */ |
| int family; |
| |
| /** |
| * Initializes this object's addr instance variable from the passed in |
| * int array. Note that this constructor is protected and is called |
| * only by static methods in this class. |
| * |
| * @param ipaddr The IP number of this address as an array of bytes |
| * @param hostname The hostname of this IP address. |
| */ |
| InetAddress(byte[] ipaddr, String hostname) |
| { |
| addr = (null == ipaddr) ? null : (byte[]) ipaddr.clone(); |
| hostName = hostname; |
| |
| if (ipaddr != null) |
| family = getFamily(ipaddr); |
| } |
| |
| /** |
| * Returns true if this address is a multicast address, false otherwise. |
| * An address is multicast if the high four bits are "1110". These are |
| * also known as "Class D" addresses. |
| * |
| * @return true if mulitcast, false if not |
| * |
| * @since 1.1 |
| */ |
| public boolean isMulticastAddress() |
| { |
| // Mask against high order bits of 1110 |
| if (addr.length == 4) |
| return (addr[0] & 0xF0) == 0xE0; |
| |
| // Mask against high order bits of 11111111 |
| if (addr.length == 16) |
| return addr [0] == (byte) 0xFF; |
| |
| return false; |
| } |
| |
| /** |
| * Utility routine to check if the InetAddress in a wildcard address |
| * |
| * @since 1.4 |
| */ |
| public boolean isAnyLocalAddress() |
| { |
| // This is the IPv4 implementation. |
| // Any class derived from InetAddress should override this. |
| return equals(ANY_IF); |
| } |
| |
| /** |
| * Utility routine to check if the InetAddress is a loopback address |
| * |
| * @since 1.4 |
| */ |
| public boolean isLoopbackAddress() |
| { |
| // This is the IPv4 implementation. |
| // Any class derived from InetAddress should override this. |
| return addr[0] == 0x7F; |
| } |
| |
| /** |
| * Utility routine to check if InetAddress is a link local address |
| * |
| * @since 1.4 |
| */ |
| public boolean isLinkLocalAddress() |
| { |
| // This is the IPv4 implementation. |
| // Any class derived from InetAddress should override this. |
| // XXX: This seems to not exist with IPv4 addresses |
| return false; |
| } |
| |
| /** |
| * Utility routine to check if InetAddress is a site local address |
| * |
| * @since 1.4 |
| */ |
| public boolean isSiteLocalAddress() |
| { |
| // This is the IPv4 implementation. |
| // Any class derived from InetAddress should override this. |
| // 10.0.0.0/8 |
| if (addr[0] == 0x0A) |
| return true; |
| |
| // XXX: Suns JDK 1.4.1 (on Linux) seems to have a bug here: |
| // it says 172.16.0.0 - 172.255.255.255 are site local addresses |
| // 172.16.0.0/12 |
| if (addr[0] == 0xAC && (addr[1] & 0xF0) == 0x01) |
| return true; |
| |
| // 192.168.0.0/16 |
| if (addr[0] == 0xC0 && addr[1] == 0xA8) |
| return true; |
| |
| // XXX: Do we need to check more addresses here ? |
| return false; |
| } |
| |
| /** |
| * Utility routine to check if InetAddress is a global multicast address |
| * |
| * @since 1.4 |
| */ |
| public boolean isMCGlobal() |
| { |
| // This is the IPv4 implementation. |
| // Any class derived from InetAddress should override this. |
| // XXX: This seems to not exist with IPv4 addresses |
| return false; |
| } |
| |
| /** |
| * Utility reoutine to check if InetAddress is a node local multicast address |
| * |
| * @since 1.4 |
| */ |
| public boolean isMCNodeLocal() |
| { |
| // This is the IPv4 implementation. |
| // Any class derived from InetAddress should override this. |
| // XXX: This seems to not exist with IPv4 addresses |
| return false; |
| } |
| |
| /** |
| * Utility reoutine to check if InetAddress is a link local multicast address |
| * |
| * @since 1.4 |
| */ |
| public boolean isMCLinkLocal() |
| { |
| // This is the IPv4 implementation. |
| // Any class derived from InetAddress should override this. |
| if (! isMulticastAddress()) |
| return false; |
| |
| return (addr[0] == 0xE0 && addr[1] == 0x00 && addr[2] == 0x00); |
| } |
| |
| /** |
| * Utility routine to check if InetAddress is a site local multicast address |
| * |
| * @since 1.4 |
| */ |
| public boolean isMCSiteLocal() |
| { |
| // This is the IPv4 implementation. |
| // Any class derived from InetAddress should override this. |
| // XXX: This seems to not exist with IPv4 addresses |
| return false; |
| } |
| |
| /** |
| * Utility reoutine to check if InetAddress is a organization local |
| * multicast address |
| * |
| * @since 1.4 |
| */ |
| public boolean isMCOrgLocal() |
| { |
| // This is the IPv4 implementation. |
| // Any class derived from InetAddress should override this. |
| // XXX: This seems to not exist with IPv4 addresses |
| return false; |
| } |
| |
| /** |
| * Returns the hostname for this address. This will return the IP address |
| * as a String if there is no hostname available for this address |
| * |
| * @return The hostname for this address |
| */ |
| public String getHostName() |
| { |
| if (hostName != null) |
| return hostName; |
| |
| // Lookup hostname and set field. |
| lookup (null, this, false); |
| |
| return hostName; |
| } |
| |
| /** |
| * Returns the canonical hostname represented by this InetAddress |
| * |
| * @since 1.4 |
| */ |
| public String getCanonicalHostName() |
| { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) |
| { |
| try |
| { |
| sm.checkConnect(hostName, -1); |
| } |
| catch (SecurityException e) |
| { |
| return getHostAddress(); |
| } |
| } |
| |
| // Try to find the FDQN now |
| InetAddress address; |
| byte[] ipaddr = getAddress(); |
| |
| if (ipaddr.length == 16) |
| address = new Inet6Address(getAddress(), null); |
| else |
| address = new Inet4Address(getAddress(), null); |
| |
| return address.getHostName(); |
| } |
| |
| /** |
| * Returns the IP address of this object as a byte array. |
| * |
| * @return IP address |
| */ |
| public byte[] getAddress() |
| { |
| // An experiment shows that JDK1.2 returns a different byte array each |
| // time. This makes sense, in terms of security. |
| return (byte[]) addr.clone(); |
| } |
| |
| /* Helper function due to a CNI limitation. */ |
| private static InetAddress[] allocArray (int count) |
| { |
| return new InetAddress [count]; |
| } |
| |
| /* Helper function due to a CNI limitation. */ |
| private static SecurityException checkConnect (String hostname) |
| { |
| SecurityManager s = System.getSecurityManager(); |
| |
| if (s == null) |
| return null; |
| |
| try |
| { |
| s.checkConnect (hostname, -1); |
| return null; |
| } |
| catch (SecurityException ex) |
| { |
| return ex; |
| } |
| } |
| |
| /** |
| * Returns the IP address of this object as a String. The address is in |
| * the dotted octet notation, for example, "127.0.0.1". |
| * |
| * @return The IP address of this object in String form |
| * |
| * @since 1.0.2 |
| */ |
| public String getHostAddress() |
| { |
| StringBuffer sb = new StringBuffer(40); |
| |
| int len = addr.length; |
| int i = 0; |
| |
| if (len == 16) |
| { // An IPv6 address. |
| for ( ; ; i += 2) |
| { |
| if (i >= 16) |
| return sb.toString(); |
| |
| int x = ((addr [i] & 0xFF) << 8) | (addr [i + 1] & 0xFF); |
| boolean empty = sb.length() == 0; |
| |
| if (empty) |
| { |
| if (i == 10 && x == 0xFFFF) |
| { // IPv4-mapped IPv6 address. |
| sb.append (":FFFF:"); |
| break; // Continue as IPv4 address; |
| } |
| else if (i == 12) |
| { // IPv4-compatible IPv6 address. |
| sb.append (':'); |
| break; // Continue as IPv4 address. |
| } |
| else if (i > 0) |
| sb.append ("::"); |
| } |
| else |
| sb.append (':'); |
| |
| if (x != 0 || i >= 14) |
| sb.append (Integer.toHexString (x).toUpperCase()); |
| } |
| } |
| |
| for ( ; ; ) |
| { |
| sb.append(addr[i] & 0xff); |
| i++; |
| |
| if (i == len) |
| break; |
| |
| sb.append('.'); |
| } |
| |
| return sb.toString(); |
| } |
| |
| /** |
| * Returns a hash value for this address. Useful for creating hash |
| * tables. Overrides Object.hashCode() |
| * |
| * @return A hash value for this address. |
| */ |
| public int hashCode() |
| { |
| // There hashing algorithm is not specified, but a simple experiment |
| // shows that it is equal to the address, as a 32-bit big-endian integer. |
| int hash = 0; |
| int len = addr.length; |
| int i = len > 4 ? len - 4 : 0; |
| |
| for (; i < len; i++) |
| hash = (hash << 8) | (addr[i] & 0xFF); |
| |
| return hash; |
| } |
| |
| /** |
| * Tests this address for equality against another InetAddress. The two |
| * addresses are considered equal if they contain the exact same octets. |
| * This implementation overrides Object.equals() |
| * |
| * @param obj The address to test for equality |
| * |
| * @return true if the passed in object's address is equal to this one's, |
| * false otherwise |
| */ |
| public boolean equals(Object obj) |
| { |
| if (! (obj instanceof InetAddress)) |
| return false; |
| |
| // "The Java Class Libraries" 2nd edition says "If a machine has |
| // multiple names instances of InetAddress for different name of |
| // that same machine are not equal. This is because they have |
| // different host names." This violates the description in the |
| // JDK 1.2 API documentation. A little experimentation |
| // shows that the latter is correct. |
| byte[] addr2 = ((InetAddress) obj).addr; |
| |
| if (addr.length != addr2.length) |
| return false; |
| |
| for (int i = 0; i < addr.length; i++) |
| if (addr[i] != addr2[i]) |
| return false; |
| |
| return true; |
| } |
| |
| /** |
| * Converts this address to a String. This string contains the IP in |
| * dotted decimal form. For example: "127.0.0.1" This method is equivalent |
| * to getHostAddress() and overrides Object.toString() |
| * |
| * @return This address in String form |
| */ |
| public String toString() |
| { |
| String addr = getHostAddress(); |
| String host = (hostName != null) ? hostName : addr; |
| return host + "/" + addr; |
| } |
| |
| /** |
| * Returns an InetAddress object given the raw IP address. |
| * |
| * The argument is in network byte order: the highest order byte of the |
| * address is in getAddress()[0]. |
| * |
| * @param addr The IP address to create the InetAddress object from |
| * |
| * @exception UnknownHostException If IP address has illegal length |
| * |
| * @since 1.4 |
| */ |
| public static InetAddress getByAddress(byte[] addr) |
| throws UnknownHostException |
| { |
| return getByAddress(null, addr); |
| } |
| |
| /** |
| * Creates an InetAddress based on the provided host name and IP address. |
| * No name service is checked for the validity of the address. |
| * |
| * @param host The hostname of the InetAddress object to create |
| * @param addr The IP address to create the InetAddress object from |
| * |
| * @exception UnknownHostException If IP address is of illegal length |
| * |
| * @since 1.4 |
| */ |
| public static InetAddress getByAddress(String host, byte[] addr) |
| throws UnknownHostException |
| { |
| if (addr.length == 4) |
| return new Inet4Address(addr, host); |
| |
| if (addr.length == 16) |
| return new Inet6Address(addr, host); |
| |
| throw new UnknownHostException("IP address has illegal length"); |
| } |
| |
| /** |
| * If host is a valid numeric IP address, return the numeric address. |
| * Otherwise, return null. |
| */ |
| private static native byte[] aton (String host); |
| |
| private static native InetAddress[] lookup (String hostname, |
| InetAddress addr, boolean all); |
| |
| private static native int getFamily (byte[] address); |
| |
| /** |
| * Returns an InetAddress object representing the IP address of the given |
| * hostname. This name can be either a hostname such as "www.urbanophile.com" |
| * or an IP address in dotted decimal format such as "127.0.0.1". If the |
| * hostname is null or "", the hostname of the local machine is supplied by |
| * default. This method is equivalent to returning the first element in |
| * the InetAddress array returned from GetAllByName. |
| * |
| * @param hostname The name of the desired host, or null for the local |
| * loopback address. |
| * |
| * @return The address of the host as an InetAddress object. |
| * |
| * @exception UnknownHostException If no IP address for the host could |
| * be found |
| * @exception SecurityException If a security manager exists and its |
| * checkConnect method doesn't allow the operation |
| */ |
| public static InetAddress getByName(String hostname) |
| throws UnknownHostException |
| { |
| // If null or the empty string is supplied, the loopback address |
| // is returned. Note that this is permitted without a security check. |
| if (hostname == null || hostname.length() == 0) |
| return loopback; |
| |
| SecurityManager s = System.getSecurityManager(); |
| if (s != null) |
| s.checkConnect(hostname, -1); |
| |
| // Assume that the host string is an IP address |
| byte[] address = aton(hostname); |
| if (address != null) |
| { |
| if (address.length == 4) |
| return new Inet4Address (address, null); |
| else if (address.length == 16) |
| { |
| if ((address [10] == 0xFF) && (address [11] == 0xFF)) |
| { |
| byte[] ip4addr = new byte [4]; |
| ip4addr [0] = address [12]; |
| ip4addr [1] = address [13]; |
| ip4addr [2] = address [14]; |
| ip4addr [3] = address [15]; |
| return new Inet4Address (ip4addr, null); |
| } |
| return new Inet6Address (address, null); |
| } |
| else |
| throw new UnknownHostException ("Address has invalid length"); |
| } |
| |
| // Try to resolve the host by DNS |
| InetAddress result = new InetAddress(null, null); |
| lookup (hostname, result, false); |
| return result; |
| } |
| |
| /** |
| * Returns an array of InetAddress objects representing all the host/ip |
| * addresses of a given host, given the host's name. This name can be |
| * either a hostname such as "www.urbanophile.com" or an IP address in |
| * dotted decimal format such as "127.0.0.1". If the value is null, the |
| * hostname of the local machine is supplied by default. |
| * |
| * @param hostname The name of the desired host, or null for the |
| * local loopback address. |
| * |
| * @return All addresses of the host as an array of InetAddress objects. |
| * |
| * @exception UnknownHostException If no IP address for the host could |
| * be found |
| * @exception SecurityException If a security manager exists and its |
| * checkConnect method doesn't allow the operation |
| */ |
| public static InetAddress[] getAllByName(String hostname) |
| throws UnknownHostException |
| { |
| // If null or the empty string is supplied, the loopback address |
| // is returned. Note that this is permitted without a security check. |
| if (hostname == null || hostname.length() == 0) |
| return new InetAddress[] {loopback}; |
| |
| SecurityManager s = System.getSecurityManager(); |
| if (s != null) |
| s.checkConnect(hostname, -1); |
| |
| // Check if hostname is an IP address |
| byte[] address = aton (hostname); |
| if (address != null) |
| { |
| InetAddress[] result = new InetAddress [1]; |
| result [0] = new InetAddress (address, null); |
| return result; |
| } |
| |
| // Try to resolve the hostname by DNS |
| return lookup (hostname, null, true); |
| } |
| |
| /** |
| * This native method looks up the hostname of the local machine |
| * we are on. If the actual hostname cannot be determined, then the |
| * value "localhost" will be used. This native method wrappers the |
| * "gethostname" function. |
| * |
| * @return The local hostname. |
| */ |
| private static native String getLocalHostname(); |
| |
| /** |
| * Returns an InetAddress object representing the address of the current |
| * host. |
| * |
| * @return The local host's address |
| * |
| * @exception UnknownHostException If no IP address for the host could |
| * be found |
| */ |
| public static InetAddress getLocalHost() throws UnknownHostException |
| { |
| SecurityManager s = System.getSecurityManager(); |
| |
| // Experimentation shows that JDK1.2 does cache the result. |
| // However, if there is a security manager, and the cached result |
| // is other than "localhost", we need to check again. |
| if (localhost == null |
| || (s != null && ! localhost.isLoopbackAddress())) |
| getLocalHost (s); |
| |
| return localhost; |
| } |
| |
| private static synchronized void getLocalHost (SecurityManager s) |
| throws UnknownHostException |
| { |
| // Check the localhost cache again, now that we've synchronized. |
| if (s == null && localhost != null) |
| return; |
| |
| String hostname = getLocalHostname(); |
| |
| if (s != null) |
| { |
| // "The Java Class Libraries" suggests that if the security |
| // manager disallows getting the local host name, then |
| // we use the loopback host. |
| // However, the JDK 1.2 API claims to throw SecurityException, |
| // which seems to suggest SecurityException is *not* caught. |
| // In this case, experimentation shows that former is correct. |
| try |
| { |
| // This is wrong, if the name returned from getLocalHostname() |
| // is not a fully qualified name. FIXME. |
| s.checkConnect (hostname, -1); |
| } |
| catch (SecurityException ex) |
| { |
| hostname = null; |
| } |
| } |
| |
| if (hostname != null && hostname.length() != 0) |
| { |
| try |
| { |
| localhost = new InetAddress (null, null); |
| lookup (hostname, localhost, false); |
| } |
| catch (Exception ex) |
| { |
| } |
| } |
| else |
| throw new UnknownHostException(); |
| |
| if (localhost == null) |
| localhost = new InetAddress (loopbackAddress, "localhost"); |
| } |
| |
| /** |
| * Needed for serialization |
| */ |
| private void readResolve() throws ObjectStreamException |
| { |
| // FIXME: implement this |
| } |
| |
| private void readObject(ObjectInputStream ois) |
| throws IOException, ClassNotFoundException |
| { |
| ois.defaultReadObject(); |
| addr = new byte[4]; |
| addr[3] = (byte) address; |
| |
| for (int i = 2; i >= 0; --i) |
| addr[i] = (byte) (address >>= 8); |
| |
| // Ignore family from serialized data. Since the saved address is 32 bits |
| // the deserialized object will have an IPv4 address i.e. AF_INET family. |
| // FIXME: An alternative is to call the aton method on the deserialized |
| // hostname to get a new address. The Serialized Form doc is silent |
| // on how these fields are used. |
| family = getFamily (addr); |
| } |
| |
| private void writeObject(ObjectOutputStream oos) throws IOException |
| { |
| // Build a 32 bit address from the last 4 bytes of a 4 byte IPv4 address |
| // or a 16 byte IPv6 address. |
| int len = addr.length; |
| int i = len - 4; |
| |
| for (; i < len; i++) |
| address = address << 8 | (((int) addr[i]) & 0xFF); |
| |
| oos.defaultWriteObject(); |
| } |
| } |