dhcp4java-1.00.src.zip_DHCP java_dhcp4ja_dhcp4java_dhcp4java-1.0

/* * This file is part of dhcp4java, a DHCP API for the Java language. * (c) 2006 Stephan Hadinger * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ package org.dhcp4java; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.IOException; import java.io.Serializable; import java.net.DatagramPacket; import java.net.Inet4Address; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.UnknownHostException; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.LinkedHashMap; import java.util.Map; import java.util.logging.Level; import java.util.logging.Logger; import static org.dhcp4java.DHCPConstants.*; /** * The basic class for manipulating DHCP packets. * * @author Stephan Hadinger * @version 1.00 * * <p>There are two basic ways to build a new DHCPPacket object. * <p>First one is to build an object from scratch using the constructor and setters. * If you need to set repeatedly the same set of parameters and options, * you can create a "master" object and clone it many times. * * <pre> * DHCPPacket discover = new DHCPPacket(); * discover.setOp(DHCPPacket.BOOTREQUEST); * discover.setHtype(DHCPPacket.HTYPE_ETHER); * discover.setHlen((byte) 6); * discover.setHops((byte) 0); * discover.setXid( (new Random()).nextInt() ); * ... * </pre> * Second is to decode a DHCP datagram received from the network. * In this case, the object is created through a factory. * * <p>Example: simple DHCP sniffer * <pre> * DatagramSocket socket = new DatagramSocket(67); * while (true) { * DatagramPacket pac = new DatagramPacket(new byte[1500], 1500); * socket.receive(pac); * DHCPPacket dhcp = DHCPPacket.getPacket(pac); * System.out.println(dhcp.toString()); * } * </pre> * In this second way, beware that a <tt>BadPacketExpcetion</tt> is thrown * if the datagram contains invalid DHCP data. * * * <p><b>Getters and Setters</b>: methods are provided with high-level data structures * wherever it is possible (String, InetAddress...). However there are also low-overhead * version (suffix <tt>Raw</tt>) dealing directly with <tt>byte[]</tt> for maximum performance. * They are useful in servers for copying parameters in a servers from a request to a response without * any type conversion. All parameters are copies, you may modify them as you like without * any side-effect on the <tt>DHCPPacket</tt> object. * * <h4>DHCP datagram format description:</h4> * <blockquote><table cellspacing=2> * <tr><th>Field</th><th>Octets</th><th>Description</th></tr> * <tr><td valign=top><tt>op</tt></td><td valign=top>1</td> * <td>Message op code / message type.<br> * use constants * <tt>BOOTREQUEST</tt>, * <tt>BOOTREPLY</tt></td></tr> * <tr><td valign=top><tt>htype</tt></td> * <td valign=top>1</td><td>Hardware address type, see ARP section in * "Assigned Numbers" RFC<br> * use constants * <tt>HTYPE_ETHER</tt>, * <tt>HTYPE_IEEE802</tt>, * <tt>HTYPE_FDDI</tt></td></tr> * <tr><td valign=top><tt>hlen</tt></td><td>1</td><td>Hardware address length * (e.g. '6' for ethernet).</td></tr> * <tr><td valign=top><tt>hops</tt></td><td valign=top>1</td><td>Client sets to zero, optionally used * by relay agents when booting via a relay agent.</td></tr> * <tr><td valign=top><tt>xid</tt></td><td valign=top>4</td> * <td>Transaction ID, a random number chosen by the * client, used by the client and server to associate * messages and responses between a client and a * server.</td></tr> * <tr><td valign=top><tt>secs</tt></td><td valign=top>2</td> * <td>Filled in by client, seconds elapsed since client * began address acquisition or renewal process.</td></tr> * <tr><td valign=top><tt>flags</tt></td><td valign=top>2</td> * <td>Flags (see below).</td></tr> * <tr><td valign=top><tt>ciaddr</tt></td><td valign=top>4</td> * <td>Client IP address; only filled in if client is in * BOUND, RENEW or REBINDING state and can respond * to ARP requests.</td></tr> * <tr><td valign=top><tt>yiaddr</tt></td><td valign=top>4</td> * <td>'your' (client) IP address.</td></tr> * <tr><td valign=top><tt>siaddr</tt></td><td valign=top>4</td> * <td>IP address of next server to use in bootstrap; * returned in DHCPOFFER, DHCPACK by server.</td></tr> * <tr><td valign=top><tt>giaddr</tt></td><td valign=top>4</td> * <td>Relay agent IP address, used in booting via a * relay agent.</td></tr> * <tr><td valign=top><tt>chaddr</tt></td><td valign=top>16</td> * <td>Client hardware address.</td></tr> * <tr><td valign=top><tt>sname</tt></td><td valign=top>64</td> * <td>Optional server host name, null terminated string.</td></tr> * <tr><td valign=top><tt>file</tt></td><td valign=top>128</td> * <td>Boot file name, null terminated string; "generic" * name or null in DHCPDISCOVER, fully qualified * directory-path name in DHCPOFFER.</td></tr> * <tr><td valign=top><tt>isDhcp</tt></td><td valign=top>4</td> * <td>Controls whether the packet is BOOTP or DHCP. * DHCP contains the "magic cookie" of 4 bytes. * 0x63 0x82 0x53 0x63.</td></tr> * <tr><td valign=top><tt>DHO_*code*</tt></td><td valign=top>*</td> * <td>Optional parameters field. See the options * documents for a list of defined options. See below.</td></tr> * <tr><td valign=top><tt>padding</tt></td><td valign=top>*</td> * <td>Optional padding at the end of the packet.</td></tr> * </table></blockquote> * * <h4>DHCP Option</h4> * * The following options are codes are supported: * <pre> * DHO_SUBNET_MASK(1) * DHO_TIME_OFFSET(2) * DHO_ROUTERS(3) * DHO_TIME_SERVERS(4) * DHO_NAME_SERVERS(5) * DHO_DOMAIN_NAME_SERVERS(6) * DHO_LOG_SERVERS(7) * DHO_COOKIE_SERVERS(8) * DHO_LPR_SERVERS(9) * DHO_IMPRESS_SERVERS(10) * DHO_RESOURCE_LOCATION_SERVERS(11) * DHO_HOST_NAME(12) * DHO_BOOT_SIZE(13) * DHO_MERIT_DUMP(14) * DHO_DOMAIN_NAME(15) * DHO_SWAP_SERVER(16) * DHO_ROOT_PATH(17) * DHO_EXTENSIONS_PATH(18) * DHO_IP_FORWARDING(19) * DHO_NON_LOCAL_SOURCE_ROUTING(20) * DHO_POLICY_FILTER(21) * DHO_MAX_DGRAM_REASSEMBLY(22) * DHO_DEFAULT_IP_TTL(23) * DHO_PATH_MTU_AGING_TIMEOUT(24) * DHO_PATH_MTU_PLATEAU_TABLE(25) * DHO_INTERFACE_MTU(26) * DHO_ALL_SUBNETS_LOCAL(27) * DHO_BROADCAST_ADDRESS(28) * DHO_PERFORM_MASK_DISCOVERY(29) * DHO_MASK_SUPPLIER(30) * DHO_ROUTER_DISCOVERY(31) * DHO_ROUTER_SOLICITATION_ADDRESS(32) * DHO_STATIC_ROUTES(33) * DHO_TRAILER_ENCAPSULATION(34) * DHO_ARP_CACHE_TIMEOUT(35) * DHO_IEEE802_3_ENCAPSULATION(36) * DHO_DEFAULT_TCP_TTL(37) * DHO_TCP_KEEPALIVE_INTERVAL(38) * DHO_TCP_KEEPALIVE_GARBAGE(39) * DHO_NIS_SERVERS(41) * DHO_NTP_SERVERS(42) * DHO_VENDOR_ENCAPSULATED_OPTIONS(43) * DHO_NETBIOS_NAME_SERVERS(44) * DHO_NETBIOS_DD_SERVER(45) * DHO_NETBIOS_NODE_TYPE(46)