/*
* $Id$
*
* Copyright (C) 2003-2015 JNode.org
*
* 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.jnode.net.ipv4.dhcp;
import java.io.UnsupportedEncodingException;
import java.net.DatagramPacket;
import java.net.Inet4Address;
import java.util.HashMap;
import java.util.Map;
import org.jnode.net.SocketBuffer;
import org.jnode.net.ipv4.bootp.BOOTPHeader;
/**
* RFC 2131 and 2132.
*
* @author markhale
*/
public class DHCPMessage {
public static final int OPTIONS_SIZE = 312;
public static final int SIZE = BOOTPHeader.SIZE + OPTIONS_SIZE;
// RFC 2132
public static final int PAD_OPTION = 0;
/** 4 bytes */
public static final int SUBNET_MASK_OPTION = 1;
/** Signed 32-bit integer, seconds */
public static final int TIME_OFFSET_OPTION = 2;
/** IP address */
public static final int ROUTER_OPTION = 3;
/** IP address */
public static final int TIME_SERVER_OPTION = 4;
/** IP address */
public static final int NAME_SERVER_OPTION = 5;
/** IP address */
public static final int DNS_OPTION = 6;
/** IP address */
public static final int LOG_SERVER_OPTION = 7;
/** IP address */
public static final int COOKIE_SERVER_OPTION = 8;
/** IP address */
public static final int LPR_SERVER_OPTION = 9;
/** String */
public static final int HOST_NAME_OPTION = 12;
/** String */
public static final int DOMAIN_NAME_OPTION = 15;
/** Byte */
public static final int TTL_OPTION = 23;
/** IP address */
public static final int REQUESTED_IP_ADDRESS_OPTION = 50;
/** Unsigned 32-bit integer, seconds */
public static final int LEASE_TIME_OPTION = 51;
/** Byte, FILE_OVERLOAD, SNAME_OVERLOAD, BOTH_OVERLOAD */
public static final int OPTION_OVERLOAD_OPTION = 52;
public static final int FILE_OVERLOAD = 1;
public static final int SNAME_OVERLOAD = 2;
public static final int BOTH_OVERLOAD = 3;
/** Byte */
public static final int MESSAGE_TYPE_OPTION = 53;
/** IP address */
public static final int SERVER_IDENTIFIER_OPTION = 54;
/** String */
public static final int MESSAGE_OPTION = 56;
/** Unsigned 16-bit integer, minimum value is MIN_PACKET_SIZE */
public static final int MAX_PACKET_SIZE_OPTION = 57;
public static final int MIN_PACKET_SIZE = 576;
/** Unsigned 32-bit integer, seconds */
public static final int RENEWAL_TIME_OPTION = 58;
/** Unsigned 32-bit integer, seconds */
public static final int REBINDING_TIME_OPTION = 59;
public static final int CLIENT_IDENTIFIER_OPTION = 61;
public static final int TFTP_SERVER_OPTION = 66;
/** IP address */
public static final int SMTP_SERVER_OPTION = 69;
/** IP address */
public static final int POP3_SERVER_OPTION = 70;
/** IP address */
public static final int NNTP_SERVER_OPTION = 71;
/** IP address */
public static final int WWW_SERVER_OPTION = 72;
/** IP address */
public static final int FINGER_SERVER_OPTION = 73;
/** IP address */
public static final int IRC_SERVER_OPTION = 74;
/** String URL: JNode specific option */
public static final int PLUGIN_LOADER_OPTION = 130;
public static final int END_OPTION = 255;
// message types
public static final int DHCPDISCOVER = 1;
public static final int DHCPOFFER = 2;
public static final int DHCPREQUEST = 3;
public static final int DHCPDECLINE = 4;
public static final int DHCPACK = 5;
public static final int DHCPNAK = 6;
public static final int DHCPRELEASE = 7;
public static final int DHCPINFORM = 8;
private final BOOTPHeader header;
private int messageType;
private final Map<Integer, byte[]> options = new HashMap<Integer, byte[]>();
/**
* Create a new message
*/
private DHCPMessage(BOOTPHeader hdr) {
header = hdr;
}
public DHCPMessage(BOOTPHeader hdr, int msgType) {
this(hdr);
messageType = msgType;
}
public DHCPMessage(SocketBuffer skbuf) {
this(new BOOTPHeader(skbuf));
int i = BOOTPHeader.SIZE + 4;
int optionCode = skbuf.get(i);
while (optionCode != END_OPTION) {
if (optionCode == PAD_OPTION) {
i++;
} else {
int optionLength = skbuf.get(i + 1);
byte[] optionValue = new byte[optionLength];
skbuf.get(optionValue, 0, i + 2, optionLength);
setOption(optionCode, optionValue);
i += optionLength + 2;
}
optionCode = skbuf.get(i);
}
}
public DHCPMessage(DatagramPacket packet) {
this(new SocketBuffer(packet.getData(), packet.getOffset(), packet.getLength()));
}
public BOOTPHeader getHeader() {
return header;
}
public void setMessageType(int value) {
messageType = value;
}
public int getMessageType() {
return messageType;
}
/**
* Sets a DHCP option with an array of bytes.
*/
public void setOption(int code, byte[] value) {
if (code == MESSAGE_TYPE_OPTION) {
messageType = value[0];
} else {
options.put(code, value);
}
}
/**
* Sets a DHCP option with an unsigned 16-bit integer. Convenience method.
*/
public void setOption16(int code, int value) {
byte[] b = new byte[] {(byte) ((value >> 8) & 0xFF), (byte) (value & 0xFF)};
setOption(code, b);
}
/**
* Sets a DHCP option with a string. Convenience method.
*/
public void setOption(int code, String value) {
try {
setOption(code, value.getBytes("US-ASCII"));
} catch (UnsupportedEncodingException ex) {
throw new RuntimeException(ex);
}
}
/**
* Sets a DHCP option with an IP address. Convenience method.
*/
public void setOption(int code, Inet4Address value) {
setOption(code, value.getAddress());
}
/**
* Gets a DHCP option as an array of bytes.
*/
public byte[] getOption(int code) {
if (code == MESSAGE_TYPE_OPTION)
return new byte[] {(byte) messageType};
else
return (byte[]) options.get(code);
}
/**
* Gets this message as a DatagramPacket
*/
public DatagramPacket toDatagramPacket() {
final SocketBuffer skbuf = new SocketBuffer();
skbuf.insert(OPTIONS_SIZE);
// magic cookie
skbuf.set(0, 99);
skbuf.set(1, 130);
skbuf.set(2, 83);
skbuf.set(3, 99);
// options
skbuf.set(4, MESSAGE_TYPE_OPTION);
skbuf.set(5, 1);
skbuf.set(6, messageType);
int n = 7;
for (Map.Entry<Integer, byte[]> entry : options.entrySet()) {
final int optionCode = entry.getKey();
final byte optionValue[] = entry.getValue();
skbuf.set(n, optionCode);
skbuf.set(n + 1, optionValue.length);
skbuf.set(n + 2, optionValue, 0, optionValue.length);
n += optionValue.length + 2;
}
skbuf.set(n, END_OPTION);
header.prefixTo(skbuf);
final byte[] data = skbuf.toByteArray();
return new DatagramPacket(data, data.length);
}
}