Annotation of embedaddon/libnet/src/libnet_build_arp.c, revision 1.1.1.1

1.1       misho       1: /*
                      2:  *  $Id: libnet_build_arp.c,v 1.12 2004/03/01 20:26:12 mike 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(u_int16_t hrd, u_int16_t pro, u_int8_t hln, u_int8_t pln,
                     45: u_int16_t op, u_int8_t *sha, u_int8_t *spa, u_int8_t *tha, u_int8_t *tpa,
                     46: u_int8_t *payload, u_int32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
                     47: {
                     48:     u_int32_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, (u_int8_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:     if ((payload && !payload_s) || (!payload && payload_s))
                    109:     {
                    110:          snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
                    111:                  "%s(): payload inconsistency\n", __func__);
                    112:         goto bad;
                    113:     }
                    114: 
                    115:     if (payload && payload_s)
                    116:     {
                    117:         n = libnet_pblock_append(l, p, payload, payload_s);
                    118:         if (n == -1)
                    119:         {
                    120:             /* err msg set in libnet_pblock_append() */
                    121:             goto bad;
                    122:         }
                    123:     }
                    124: 
                    125:     return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ARP_H));
                    126: bad:
                    127:     libnet_pblock_delete(l, p);
                    128:     return (-1);
                    129: }
                    130: 
                    131: libnet_ptag_t
                    132: libnet_autobuild_arp(u_int16_t op, u_int8_t *sha, u_int8_t *spa, u_int8_t *tha,
                    133: u_int8_t *tpa, libnet_t *l)
                    134: {
                    135:     u_short hrd;
                    136:     
                    137:     switch (l->link_type)
                    138:     {
                    139:         case 1: /* DLT_EN10MB */
                    140:             hrd = ARPHRD_ETHER;
                    141:             break;
                    142:         case 6: /* DLT_IEEE802 */
                    143:             hrd = ARPHRD_IEEE802; 
                    144:             break;
                    145:         default:
                    146:             hrd = 0;
                    147:             snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
                    148:                     "%s(): unsupported link type\n", __func__);
                    149:             return (-1);
                    150:         /* add other link-layers */
                    151:     }
                    152:     
                    153:     return (libnet_build_arp(
                    154:         hrd,                                    /* hardware addr */
                    155:         ETHERTYPE_IP,                           /* protocol addr */
                    156:         6,                                      /* hardware addr size */
                    157:         4,                                      /* protocol addr size */
                    158:         op,                                     /* operation type */
                    159:         sha,                                    /* sender hardware addr */
                    160:         spa,                       /* sender protocol addr */
                    161:         tha,                                    /* target hardware addr */
                    162:         tpa,                       /* target protocol addr */
                    163:         NULL,                                   /* payload */
                    164:         0,                                      /* payload size */
                    165:         l,                                      /* libnet context */
                    166:         0));                                    /* libnet id */
                    167: }
                    168: 
                    169: /* EOF */

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