/*
* TAP-Win32/TAP-Win64 -- A kernel driver to provide virtual tap
* device functionality on Windows.
*
* This code was inspired by the CIPE-Win32 driver by Damion K. Wilson.
*
* This source code is Copyright (C) 2002-2007 OpenVPN Solutions LLC,
* and is released under the GPL version 2 (see below), however due
* to the extra costs of supporting Windows Vista, OpenVPN Solutions
* LLC reserves the right to change the terms of the TAP-Win32/TAP-Win64
* license for versions 9.1 and higher prior to the official release of
* OpenVPN 2.1.
*
* 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
*/
#pragma pack(1)
//===================================================
// How many bad DHCPREQUESTs do we receive before we
// return a NAK?
//
// A bad DHCPREQUEST is defined to be one where the
// requestor doesn't know its IP address.
//===================================================
#define BAD_DHCPREQUEST_NAK_THRESHOLD 3
//==============================================
// Maximum number of DHCP options bytes supplied
//==============================================
#define DHCP_USER_SUPPLIED_OPTIONS_BUFFER_SIZE 256
#define DHCP_OPTIONS_BUFFER_SIZE 256
//===================================
// UDP port numbers of DHCP messages.
//===================================
#define BOOTPS_PORT 67
#define BOOTPC_PORT 68
//===========================
// The DHCP message structure
//===========================
typedef struct {
# define BOOTREQUEST 1
# define BOOTREPLY 2
UCHAR op; /* message op */
UCHAR htype; /* hardware address type (e.g. '1' = 10Mb Ethernet) */
UCHAR hlen; /* hardware address length (e.g. '6' for 10Mb Ethernet) */
UCHAR hops; /* client sets to 0, may be used by relay agents */
ULONG xid; /* transaction ID, chosen by client */
USHORT secs; /* seconds since request process began, set by client */
USHORT flags;
ULONG ciaddr; /* client IP address, client sets if known */
ULONG yiaddr; /* 'your' IP address -- server's response to client */
ULONG siaddr; /* server IP address */
ULONG giaddr; /* relay agent IP address */
UCHAR chaddr[16]; /* client hardware address */
UCHAR sname[64]; /* optional server host name */
UCHAR file[128]; /* boot file name */
ULONG magic; /* must be 0x63825363 (network order) */
} DHCP;
typedef struct {
ETH_HEADER eth;
IPHDR ip;
UDPHDR udp;
DHCP dhcp;
} DHCPPre;
typedef struct {
DHCPPre pre;
UCHAR options[DHCP_OPTIONS_BUFFER_SIZE];
} DHCPFull;
typedef struct {
unsigned int optlen;
BOOLEAN overflow;
DHCPFull msg;
} DHCPMsg;
//===================
// Macros for DHCPMSG
//===================
#define DHCPMSG_LEN_BASE(p) (sizeof (DHCPPre))
#define DHCPMSG_LEN_OPT(p) ((p)->optlen)
#define DHCPMSG_LEN_FULL(p) (DHCPMSG_LEN_BASE(p) + DHCPMSG_LEN_OPT(p))
#define DHCPMSG_BUF(p) ((UCHAR*) &(p)->msg)
#define DHCPMSG_OVERFLOW(p) ((p)->overflow)
//========================================
// structs to hold individual DHCP options
//========================================
typedef struct {
UCHAR type;
} DHCPOPT0;
typedef struct {
UCHAR type;
UCHAR len;
UCHAR data;
} DHCPOPT8;
typedef struct {
UCHAR type;
UCHAR len;
ULONG data;
} DHCPOPT32;
#pragma pack()
//==================
// DHCP Option types
//==================
#define DHCP_MSG_TYPE 53 /* message type (u8) */
#define DHCP_PARM_REQ 55 /* parameter request list: c1 (u8), ... */
#define DHCP_CLIENT_ID 61 /* client ID: type (u8), i1 (u8), ... */
#define DHCP_IP 50 /* requested IP addr (u32) */
#define DHCP_NETMASK 1 /* subnet mask (u32) */
#define DHCP_LEASE_TIME 51 /* lease time sec (u32) */
#define DHCP_RENEW_TIME 58 /* renewal time sec (u32) */
#define DHCP_REBIND_TIME 59 /* rebind time sec (u32) */
#define DHCP_SERVER_ID 54 /* server ID: IP addr (u32) */
#define DHCP_PAD 0
#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
#if DBG
VOID
DumpDHCP (const ETH_HEADER *eth,
const IPHDR *ip,
const UDPHDR *udp,
const DHCP *dhcp,
const int optlen);
#endif
