release/src/router/openvpn/tap-win32/dhcp.h

   1 /*
   2  *  TAP-Win32/TAP-Win64 -- A kernel driver to provide virtual tap
   3  *                         device functionality on Windows.
   4  *
   5  *  This code was inspired by the CIPE-Win32 driver by Damion K. Wilson.
   6  *
   7  *  This source code is Copyright (C) 2002-2009 OpenVPN Technologies, Inc.,
   8  *  and is released under the GPL version 2 (see below), however due
   9  *  to the extra costs of supporting Windows Vista, OpenVPN Solutions
  10  *  LLC reserves the right to change the terms of the TAP-Win32/TAP-Win64
  11  *  license for versions 9.1 and higher prior to the official release of
  12  *  OpenVPN 2.1.
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License version 2
  16  *  as published by the Free Software Foundation.
  17  *
  18  *  This program is distributed in the hope that it will be useful,
  19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  *  GNU General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License
  24  *  along with this program (see the file COPYING included with this
  25  *  distribution); if not, write to the Free Software Foundation, Inc.,
  26  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  27  */
  28
  29 #pragma pack(1)
  30
  31 //===================================================
  32 // How many bad DHCPREQUESTs do we receive before we
  33 // return a NAK?
  34 //
  35 // A bad DHCPREQUEST is defined to be one where the
  36 // requestor doesn't know its IP address.
  37 //===================================================
  38
  39 #define BAD_DHCPREQUEST_NAK_THRESHOLD 3
  40
  41 //==============================================
  42 // Maximum number of DHCP options bytes supplied
  43 //==============================================
  44
  45 #define DHCP_USER_SUPPLIED_OPTIONS_BUFFER_SIZE 256
  46 #define DHCP_OPTIONS_BUFFER_SIZE               256
  47
  48 //===================================
  49 // UDP port numbers of DHCP messages.
  50 //===================================
  51
  52 #define BOOTPS_PORT 67
  53 #define BOOTPC_PORT 68
  54
  55 //===========================
  56 // The DHCP message structure
  57 //===========================
  58
  59 typedef struct {
  60 # define BOOTREQUEST 1
  61 # define BOOTREPLY   2
  62   UCHAR op;          /* message op */
  63
  64   UCHAR  htype;      /* hardware address type (e.g. '1' = 10Mb Ethernet) */
  65   UCHAR  hlen;       /* hardware address length (e.g. '6' for 10Mb Ethernet) */
  66   UCHAR  hops;       /* client sets to 0, may be used by relay agents */
  67   ULONG  xid;        /* transaction ID, chosen by client */
  68   USHORT secs;       /* seconds since request process began, set by client */
  69   USHORT flags;
  70   ULONG  ciaddr;     /* client IP address, client sets if known */
  71   ULONG  yiaddr;     /* 'your' IP address -- server's response to client */
  72   ULONG  siaddr;     /* server IP address */
  73   ULONG  giaddr;     /* relay agent IP address */
  74   UCHAR  chaddr[16]; /* client hardware address */
  75   UCHAR  sname[64];  /* optional server host name */
  76   UCHAR  file[128];  /* boot file name */
  77   ULONG  magic;      /* must be 0x63825363 (network order) */
  78 } DHCP;
  79
  80 typedef struct {
  81   ETH_HEADER eth;
  82   IPHDR ip;
  83   UDPHDR udp;
  84   DHCP dhcp;
  85 } DHCPPre;
  86
  87 typedef struct {
  88   DHCPPre pre;
  89   UCHAR options[DHCP_OPTIONS_BUFFER_SIZE];
  90 } DHCPFull;
  91
  92 typedef struct {
  93   unsigned int optlen;
  94   BOOLEAN overflow;
  95   DHCPFull msg;
  96 } DHCPMsg;
  97
  98 //===================
  99 // Macros for DHCPMSG
 100 //===================
 101
 102 #define DHCPMSG_LEN_BASE(p) (sizeof (DHCPPre))
 103 #define DHCPMSG_LEN_OPT(p)  ((p)->optlen)
 104 #define DHCPMSG_LEN_FULL(p) (DHCPMSG_LEN_BASE(p) + DHCPMSG_LEN_OPT(p))
 105 #define DHCPMSG_BUF(p)      ((UCHAR*) &(p)->msg)
 106 #define DHCPMSG_OVERFLOW(p) ((p)->overflow)
 107
 108 //========================================
 109 // structs to hold individual DHCP options
 110 //========================================
 111
 112 typedef struct {
 113   UCHAR type;
 114 } DHCPOPT0;
 115
 116 typedef struct {
 117   UCHAR type;
 118   UCHAR len;
 119   UCHAR data;
 120 } DHCPOPT8;
 121
 122 typedef struct {
 123   UCHAR type;
 124   UCHAR len;
 125   ULONG data;
 126 } DHCPOPT32;
 127
 128 #pragma pack()
 129
 130 //==================
 131 // DHCP Option types
 132 //==================
 133
 134 #define DHCP_MSG_TYPE    53  /* message type (u8) */
 135 #define DHCP_PARM_REQ    55  /* parameter request list: c1 (u8), ... */
 136 #define DHCP_CLIENT_ID   61  /* client ID: type (u8), i1 (u8), ... */
 137 #define DHCP_IP          50  /* requested IP addr (u32) */
 138 #define DHCP_NETMASK      1  /* subnet mask (u32) */
 139 #define DHCP_LEASE_TIME  51  /* lease time sec (u32) */
 140 #define DHCP_RENEW_TIME  58  /* renewal time sec (u32) */
 141 #define DHCP_REBIND_TIME 59  /* rebind time sec (u32) */
 142 #define DHCP_SERVER_ID   54  /* server ID: IP addr (u32) */
 143 #define DHCP_PAD          0
 144 #define DHCP_END        255
 145
 146 //====================
 147 // DHCP Messages types
 148 //====================
 149
 150 #define DHCPDISCOVER 1
 151 #define DHCPOFFER    2
 152 #define DHCPREQUEST  3
 153 #define DHCPDECLINE  4
 154 #define DHCPACK      5
 155 #define DHCPNAK      6
 156 #define DHCPRELEASE  7
 157 #define DHCPINFORM   8
 158
 159 #if DBG
 160
 161 VOID
 162 DumpDHCP (const ETH_HEADER *eth,
 163           const IPHDR *ip,
 164           const UDPHDR *udp,
 165           const DHCP *dhcp,
 166           const int optlen);
 167
 168 #endif