path: root/dhcp.h

/*
 *  OpenVPN -- An application to securely tunnel IP networks
 *             over a single TCP/UDP port, with support for SSL/TLS-based
 *             session authentication and key exchange,
 *             packet encryption, packet authentication, and
 *             packet compression.
 *
 *  Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program 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 this program (see the file COPYING included with this
 *  distribution); if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef DHCP_H
#define DHCP_H

#include "common.h"
#include "buffer.h"
#include "proto.h"

#pragma pack(1)

/* DHCP Option types */
#define DHCP_PAD          0
#define DHCP_ROUTER       3
#define DHCP_MSG_TYPE    53  /* message type (u8) */
#define DHCP_END        255

/* DHCP Messages types */
#define DHCPDISCOVER 1
#define DHCPOFFER    2
#define DHCPREQUEST  3
#define DHCPDECLINE  4
#define DHCPACK      5
#define DHCPNAK      6
#define DHCPRELEASE  7
#define DHCPINFORM   8

/* DHCP UDP port numbers */
#define BOOTPS_PORT 67
#define BOOTPC_PORT 68

struct dhcp {
# define BOOTREQUEST 1
# define BOOTREPLY   2
  uint8_t op;          /* message op */

  uint8_t  htype;      /* hardware address type (e.g. '1' = 10Mb Ethernet) */
  uint8_t  hlen;       /* hardware address length (e.g. '6' for 10Mb Ethernet) */
  uint8_t  hops;       /* client sets to 0, may be used by relay agents */
  uint32_t xid;        /* transaction ID, chosen by client */
  uint16_t secs;       /* seconds since request process began, set by client */
  uint16_t flags;
  uint32_t ciaddr;     /* client IP address, client sets if known */
  uint32_t yiaddr;     /* 'your' IP address -- server's response to client */
  uint32_t siaddr;     /* server IP address */
  uint32_t giaddr;     /* relay agent IP address */
  uint8_t  chaddr[16]; /* client hardware address */
  uint8_t  sname[64];  /* optional server host name */
  uint8_t  file[128];  /* boot file name */
  uint32_t magic;      /* must be 0x63825363 (network order) */
};

struct dhcp_full {
  struct openvpn_iphdr ip;
  struct openvpn_udphdr udp;
  struct dhcp dhcp;
# define DHCP_OPTIONS_BUFFER_SIZE 256
  uint8_t options[DHCP_OPTIONS_BUFFER_SIZE];
};

#pragma pack()

in_addr_t dhcp_extract_router_msg (struct buffer *ipbuf);

#endif