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1.1.6

    1: /*
    2:  *  $Id: libnet_build_arp.c,v 1.1.1.2 2013/07/22 11:54:42 misho Exp $
    3:  *
    4:  *  libnet
    5:  *  libnet_build_arp.c - ARP packet assembler
    6:  *
    7:  *  Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>
    8:  *  All rights reserved.
    9:  *
   10:  * Redistribution and use in source and binary forms, with or without
   11:  * modification, are permitted provided that the following conditions
   12:  * are met:
   13:  * 1. Redistributions of source code must retain the above copyright
   14:  *    notice, this list of conditions and the following disclaimer.
   15:  * 2. Redistributions in binary form must reproduce the above copyright
   16:  *    notice, this list of conditions and the following disclaimer in the
   17:  *    documentation and/or other materials provided with the distribution.
   18:  *
   19:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   20:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   23:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29:  * SUCH DAMAGE.
   30:  *
   31:  */
   32: 
   33: #if (HAVE_CONFIG_H)
   34: #include "../include/config.h"
   35: #endif
   36: #if (!(_WIN32) || (__CYGWIN__)) 
   37: #include "../include/libnet.h"
   38: #else
   39: #include "../include/win32/libnet.h"
   40: #endif
   41: 
   42: 
   43: libnet_ptag_t
   44: libnet_build_arp(uint16_t hrd, uint16_t pro, uint8_t hln, uint8_t pln,
   45: uint16_t op, const uint8_t *sha, const uint8_t *spa, const uint8_t *tha, const uint8_t *tpa,
   46: const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
   47: {
   48:     uint32_t n, h;
   49:     libnet_pblock_t *p;
   50:     struct libnet_arp_hdr arp_hdr;
   51: 
   52:     if (l == NULL)
   53:     { 
   54:         return (-1); 
   55:     }
   56: 
   57:     n = LIBNET_ARP_H + (2 * hln) + (2 * pln) + payload_s;
   58:     h = 0;  /* ARP headers have no checksum */
   59: 
   60:     /*
   61:      *  Find the existing protocol block if a ptag is specified, or create
   62:      *  a new one.
   63:      */
   64:     p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_ARP_H);
   65:     if (p == NULL)
   66:     {
   67:         return (-1);
   68:     }
   69: 
   70:     memset(&arp_hdr, 0, sizeof(arp_hdr));
   71:     arp_hdr.ar_hrd = htons(hrd);       /* hardware address type */
   72:     arp_hdr.ar_pro = htons(pro);       /* protocol address type */
   73:     arp_hdr.ar_hln = hln;              /* hardware address length */
   74:     arp_hdr.ar_pln = pln;              /* protocol address length */
   75:     arp_hdr.ar_op  = htons(op);        /* opcode command */
   76: 
   77:     n = libnet_pblock_append(l, p, (uint8_t *)&arp_hdr, LIBNET_ARP_H);
   78:     if (n == -1)
   79:     {
   80:         /* err msg set in libnet_pblock_append() */
   81:         goto bad; 
   82:     }
   83:     n = libnet_pblock_append(l, p, sha, hln);
   84:     if (n == -1)
   85:     {
   86:         /* err msg set in libnet_pblock_append() */
   87:         goto bad;
   88:     }
   89:     n = libnet_pblock_append(l, p, spa, pln);
   90:     if (n == -1)
   91:     {
   92:         /* err msg set in libnet_pblock_append() */
   93:         goto bad;
   94:     }
   95:     n = libnet_pblock_append(l, p, tha, hln);
   96:     if (n == -1)
   97:     {
   98:         /* err msg set in libnet_pblock_append() */
   99:         goto bad;
  100:     } 
  101:     n = libnet_pblock_append(l, p, tpa, pln);
  102:     if (n == -1)
  103:     {
  104:         /* err msg set in libnet_pblock_append() */
  105:         goto bad;
  106:     }
  107: 
  108:     /* boilerplate payload sanity check / append macro */
  109:     LIBNET_DO_PAYLOAD(l, p);
  110: 
  111:     return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ARP_H));
  112: bad:
  113:     libnet_pblock_delete(l, p);
  114:     return (-1);
  115: }
  116: 
  117: libnet_ptag_t
  118: libnet_autobuild_arp(uint16_t op, const uint8_t *sha, const uint8_t *spa, const uint8_t *tha,
  119: uint8_t *tpa, libnet_t *l)
  120: {
  121:     u_short hrd;
  122:     
  123:     switch (l->link_type)
  124:     {
  125:         case 1: /* DLT_EN10MB */
  126:             hrd = ARPHRD_ETHER;
  127:             break;
  128:         case 6: /* DLT_IEEE802 */
  129:             hrd = ARPHRD_IEEE802; 
  130:             break;
  131:         default:
  132:             hrd = 0;
  133:             snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
  134:                     "%s(): unsupported link type\n", __func__);
  135:             return (-1);
  136:         /* add other link-layers */
  137:     }
  138:     
  139:     return (libnet_build_arp(
  140:         hrd,                                    /* hardware addr */
  141:         ETHERTYPE_IP,                           /* protocol addr */
  142:         6,                                      /* hardware addr size */
  143:         4,                                      /* protocol addr size */
  144:         op,                                     /* operation type */
  145:         sha,                                    /* sender hardware addr */
  146:         spa,                                    /* sender protocol addr */
  147:         tha,                                    /* target hardware addr */
  148:         tpa,                                    /* target protocol addr */
  149:         NULL,                                   /* payload */
  150:         0,                                      /* payload size */
  151:         l,                                      /* libnet context */
  152:         0));                                    /* libnet id */
  153: }
  154: 
  155: /* EOF */