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