实现DHCP客户端和服务端的源代码

/* * 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 server; import static org.dhcp4java.DHCPConstants.BOOTREPLY; import static org.dhcp4java.DHCPConstants.DHCPACK; import static org.dhcp4java.DHCPConstants.DHCPOFFER; import static org.dhcp4java.DHCPConstants.DHO_DHCP_LEASE_TIME; import static org.dhcp4java.DHCPConstants.DHO_DHCP_SERVER_IDENTIFIER; import static org.dhcp4java.DHCPConstants.DHO_ROUTERS; import static org.dhcp4java.DHCPConstants.DHO_SUBNET_MASK; import static org.dhcp4java.DHCPConstants.HTYPE_ETHER; import java.net.InetAddress; import java.net.UnknownHostException; import java.util.HashMap; import java.util.Properties; import java.util.logging.Level; import java.util.logging.Logger; import org.dhcp4java.DHCPCoreServer; import org.dhcp4java.DHCPOption; import org.dhcp4java.DHCPPacket; import org.dhcp4java.DHCPResponseFactory; import org.dhcp4java.DHCPServerInitException; import org.dhcp4java.DHCPServlet; /** * A sample DHCP servlet (under construction). * * @author Stephan Hadinger * @version 0.60 */ public class DHCPStaticServlet extends DHCPServlet { private static final Logger logger = Logger .getLogger("org.dhcp4java.examplesserver.dhcpstaticserver"); private HashMap<String, InetAddress> macIpMap = new HashMap<String, InetAddress>(); DHCPOption[] commonOptions; /* * (non-Javadoc) * * @see org.dhcp4java.DHCPServlet#init(java.util.Properties) */ @Override public void init(Properties props) { // we create a dummy packet to extract "common options" DHCPPacket temp = new DHCPPacket(); try { // parse all properties to extract static client definitions for (Object keyObject : props.keySet()) { String key = ((String) keyObject); if (key.startsWith("client.")) { String addrString = (String) props.get(keyObject); try { InetAddress addr = InetAddress.getByName(addrString); this.macIpMap.put(key.substring("client.".length()) .toLowerCase(), addr); } catch (UnknownHostException e) { logger.log(Level.SEVERE, "Could not parse InetAddress " + addrString, e); } } } temp.setOptionAsInetAddress(DHO_DHCP_SERVER_IDENTIFIER, "192.168.1.1"); temp.setOptionAsInt(DHO_DHCP_LEASE_TIME, 3600 * 24 * 7); /* 1 week */ temp.setOptionAsInetAddress(DHO_SUBNET_MASK, "255.255.255.0"); temp.setOptionAsInetAddress(DHO_ROUTERS, "192.168.1.1"); // store options in a instance array this.commonOptions = temp.getOptionsArray(); } catch (UnknownHostException e) { throw new RuntimeException(e); } } /** * @see org.dhcp4java.DHCPServlet#doDiscover(org.dhcp4java.DHCPPacket) */ @Override protected DHCPPacket doDiscover(DHCPPacket request) { InetAddress clientIp = this.calcAddrFromMac(request); if (clientIp == null) { return null; } DHCPPacket response = new DHCPPacket(); response.setOp(BOOTREPLY); response.setHtype(request.getHtype()); response.setHlen(request.getHlen()); response.setHops((byte) 0); response.setXid(request.getXid()); response.setSecs((short) 0); response.setYiaddr(clientIp); response.setSiaddr(server.getSockAddress().getAddress()); // server // identifier response.setFlags(request.getFlags()); response.setGiaddrRaw(request.getGiaddrRaw()); response.setChaddr(request.getChaddr()); response.setDHCPMessageType(DHCPOFFER); response.setOptions(this.commonOptions); response.setAddrPort(DHCPResponseFactory.getDefaultSocketAddress( request, response.getOp())); return response; } /** * @see org.dhcp4java.DHCPServlet#doRequest(org.dhcp4java.DHCPPacket) */ @Override protected DHCPPacket doRequest(DHCPPacket request) { InetAddress clientIp = this.calcAddrFromMac(request); if (clientIp == null) { return null; } DHCPPacket response = new DHCPPacket(); response.setOp(BOOTREPLY); response.setHtype(request.getHtype()); response.setHlen(request.getHlen()); response.setHops((byte) 0); response.setXid(request.getXid()); response.setSecs((short) 0); response.setCiaddrRaw(request.getCiaddrRaw()); response.setYiaddr(clientIp); response.setSiaddr(server.getSockAddress().getAddress()); // server // identifier response.setFlags(request.getFlags()); response.setGiaddrRaw(request.getGiaddrRaw()); response.setChaddr(request.getChaddr()); response.setDHCPMessageType(DHCPACK); response.setOptions(this.commonOptions); response.setAddrPort(DHCPResponseFactory.getDefaultSocketAddress( request, response.getOp())); return response; } /** * @see org.dhcp4java.DHCPServlet#doDecline(org.dhcp4java.DHCPPacket) */ @Override protected DHCPPacket doDecline(DHCPPacket request) { logger.warning("DHCPDECLINE received:" + request.toString()); return null; } /** * @see org.dhcp4java.DHCPServlet#doRelease(org.dhcp4java.DHCPPacket) */ @Override protected DHCPPacket doRelease(DHCPPacket request) { logger.info("DHCPRELEASE received:" + request.toString()); return null; } /** * Calculate address from packet and @MAC Address. * * <p> * Also checks if this client is accepted (Vendor, User...) * * @param request * @return address for client, or null if ignore */ private InetAddress calcAddrFromMac(DHCPPacket request) { // check @MAC address format if ((request.getHtype() != HTYPE_ETHER) && (request.getHlen() != 6)) { return null; } // look for map InetAddress clientIp = this.macIpMap.get(request.getChaddrAsHex() .toLowerCase()); if (clientIp == null) { return null; // not found } return clientIp; } /** * Server launcher. * * @param args * command line arguments - ignored */ public static void main(String[] args) { try { DHCPCoreServer server = DHCPCoreServer.initServer( new DHCPStaticServlet(), null); logger.setLevel(Level.ALL); new Thread(server).start(); } catch (DHCPServerInitException e) { logger.log(Level.SEVERE, "Server init", e); } } }