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libnet

    1: /*
    2:  *  $Id: libnet_build_ethernet.c,v 1.1.1.1 2012/02/21 22:14:23 misho Exp $
    3:  *
    4:  *  libnet
    5:  *  libnet_build_ethernet.c - ethernet 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: libnet_ptag_t
   43: libnet_build_ethernet(u_int8_t *dst, u_int8_t *src, u_int16_t type, u_int8_t *payload,
   44:             u_int32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
   45: {
   46:     u_int32_t n, h;
   47:     libnet_pblock_t *p;
   48:     struct libnet_ethernet_hdr eth_hdr;
   49: 
   50:     if (l == NULL)
   51:     { 
   52:         return (-1);
   53:     } 
   54: 
   55:     /* sanity check injection type if we're not in advanced mode */
   56:     if (l->injection_type != LIBNET_LINK &&
   57:             !(((l->injection_type) & LIBNET_ADV_MASK)))
   58:     {
   59:          snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
   60:             "%s(): called with non-link layer wire injection primitive",
   61:                     __func__);
   62:         p = NULL;
   63:         goto bad;
   64:     }
   65: 
   66:     n = LIBNET_ETH_H + payload_s;
   67:     h = 0;
   68:  
   69:     /*
   70:      *  Find the existing protocol block if a ptag is specified, or create
   71:      *  a new one.
   72:      */
   73:     p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_ETH_H);
   74:     if (p == NULL)
   75:     {
   76:         return (-1);
   77:     }
   78: 
   79: 	memset(&eth_hdr, 0, sizeof(eth_hdr));
   80: 	memcpy(eth_hdr.ether_dhost, dst, ETHER_ADDR_LEN);  /* destination address */
   81:     memcpy(eth_hdr.ether_shost, src, ETHER_ADDR_LEN);  /* source address */
   82:     eth_hdr.ether_type = htons(type);                  /* packet type */
   83: 
   84:     n = libnet_pblock_append(l, p, (u_int8_t *)&eth_hdr, LIBNET_ETH_H);
   85:     if (n == -1)
   86:     {
   87:         goto bad;
   88:     }
   89: 
   90:     if ((payload && !payload_s) || (!payload && payload_s))
   91:     {
   92:          snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
   93: 			     "%s(): payload inconsistency\n", __func__);
   94:         goto bad;
   95:     }
   96:  
   97:     if (payload && payload_s)
   98:     {
   99:         n = libnet_pblock_append(l, p, payload, payload_s);
  100:         if (n == -1)
  101:         {
  102:             goto bad;
  103:         }
  104:     }
  105:  
  106:     return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ETH_H));
  107: bad:
  108:     libnet_pblock_delete(l, p);
  109:     return (-1);
  110: }
  111: 
  112: 
  113: libnet_ptag_t
  114: libnet_autobuild_ethernet(u_int8_t *dst, u_int16_t type, libnet_t *l)
  115: {
  116:     u_int32_t n, h;
  117:     struct libnet_ether_addr *src;
  118:     libnet_pblock_t *p;
  119:     libnet_ptag_t ptag;
  120:     struct libnet_ethernet_hdr eth_hdr;
  121: 
  122:     if (l == NULL)
  123:     { 
  124:         return (-1);
  125:     } 
  126: 
  127:     /* sanity check injection type if we're not in advanced mode */
  128:     if (l->injection_type != LIBNET_LINK &&
  129:             !(((l->injection_type) & LIBNET_ADV_MASK)))
  130:     {
  131:          snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
  132:             "libnet_autobuild_ethernet() called with non-link layer wire"
  133:             " injection primitive");
  134:         p = NULL;
  135:         goto bad;
  136:     }
  137: 
  138:     n = LIBNET_ETH_H;
  139:     h = 0;
  140:     ptag = LIBNET_PTAG_INITIALIZER;
  141:     src = libnet_get_hwaddr(l);
  142:     if (src == NULL)
  143:     {
  144:         /* err msg set in libnet_get_hwaddr() */
  145:         return (-1);
  146:     }
  147: 
  148:     /*
  149:      *  Create a new pblock. 
  150:      */
  151:     p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_ETH_H);
  152:     if (p == NULL)
  153:     {
  154:         return (-1);
  155:     }
  156: 
  157: 	memset(&eth_hdr, 0, sizeof(eth_hdr));
  158: 	memcpy(eth_hdr.ether_dhost, dst, ETHER_ADDR_LEN);  /* destination address */
  159:     memcpy(eth_hdr.ether_shost, src, ETHER_ADDR_LEN);  /* source address */
  160:     eth_hdr.ether_type = htons(type);                  /* packet type */
  161: 
  162:     n = libnet_pblock_append(l, p, (u_int8_t *)&eth_hdr, LIBNET_ETH_H);
  163:     if (n == -1)
  164:     {
  165:         goto bad;
  166:     }
  167: 
  168:     return (libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ETH_H));
  169: bad:
  170:     libnet_pblock_delete(l, p);
  171:     return (-1); 
  172: }
  173: /* EOF */