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Version 1.2p1

    1: /*
    2:  *  $Id: libnet_build_ethernet.c,v 1.1.1.3 2023/09/27 11:11:38 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: #include "common.h"
   34: 
   35: libnet_ptag_t
   36: libnet_build_ethernet(const uint8_t *dst, const uint8_t *src, uint16_t type, 
   37: const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
   38: {
   39:     uint32_t n, h;
   40:     libnet_pblock_t *p;
   41:     struct libnet_ethernet_hdr eth_hdr;
   42: 
   43:     if (l == NULL)
   44:     { 
   45:         return (-1);
   46:     } 
   47: 
   48:     /* sanity check injection type if we're not in advanced mode */
   49:     if (l->injection_type != LIBNET_LINK &&
   50:             !(((l->injection_type) & LIBNET_ADV_MASK)))
   51:     {
   52:          snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
   53:             "%s(): called with non-link layer wire injection primitive",
   54:                     __func__);
   55:         p = NULL;
   56:         goto bad;
   57:     }
   58: 
   59:     n = LIBNET_ETH_H + payload_s;
   60:     h = 0;
   61:  
   62:     /*
   63:      *  Find the existing protocol block if a ptag is specified, or create
   64:      *  a new one.
   65:      */
   66:     p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_ETH_H);
   67:     if (p == NULL)
   68:     {
   69:         return (-1);
   70:     }
   71: 
   72:     memset(&eth_hdr, 0, sizeof(eth_hdr));
   73:     memcpy(eth_hdr.ether_dhost, dst, ETHER_ADDR_LEN);  /* destination address */
   74:     memcpy(eth_hdr.ether_shost, src, ETHER_ADDR_LEN);  /* source address */
   75:     eth_hdr.ether_type = htons(type);                  /* packet type */
   76: 
   77:     n = libnet_pblock_append(l, p, (uint8_t *)&eth_hdr, LIBNET_ETH_H);
   78:     if (n == -1)
   79:     {
   80:         goto bad;
   81:     }
   82: 
   83:     /* boilerplate payload sanity check / append macro */
   84:     LIBNET_DO_PAYLOAD(l, p);
   85:  
   86:     return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ETH_H));
   87: bad:
   88:     libnet_pblock_delete(l, p);
   89:     return (-1);
   90: }
   91: 
   92: 
   93: libnet_ptag_t
   94: libnet_autobuild_ethernet(const uint8_t *dst, uint16_t type, libnet_t *l)
   95: {
   96:     uint32_t n, h;
   97:     struct libnet_ether_addr *src;
   98:     libnet_pblock_t *p;
   99:     libnet_ptag_t ptag;
  100:     struct libnet_ethernet_hdr eth_hdr;
  101: 
  102:     if (l == NULL)
  103:     { 
  104:         return (-1);
  105:     } 
  106: 
  107:     /* sanity check injection type if we're not in advanced mode */
  108:     if (l->injection_type != LIBNET_LINK &&
  109:             !(((l->injection_type) & LIBNET_ADV_MASK)))
  110:     {
  111:          snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
  112:             "libnet_autobuild_ethernet() called with non-link layer wire"
  113:             " injection primitive");
  114:         p = NULL;
  115:         goto bad;
  116:     }
  117: 
  118:     n = LIBNET_ETH_H;
  119:     h = 0;
  120:     ptag = LIBNET_PTAG_INITIALIZER;
  121:     src = libnet_get_hwaddr(l);
  122:     if (src == NULL)
  123:     {
  124:         /* err msg set in libnet_get_hwaddr() */
  125:         return (-1);
  126:     }
  127: 
  128:     /*
  129:      *  Create a new pblock. 
  130:      */
  131:     p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_ETH_H);
  132:     if (p == NULL)
  133:     {
  134:         return (-1);
  135:     }
  136: 
  137:     memset(&eth_hdr, 0, sizeof(eth_hdr));
  138:     memcpy(eth_hdr.ether_dhost, dst, ETHER_ADDR_LEN);  /* destination address */
  139:     memcpy(eth_hdr.ether_shost, src, ETHER_ADDR_LEN);  /* source address */
  140:     eth_hdr.ether_type = htons(type);                  /* packet type */
  141: 
  142:     n = libnet_pblock_append(l, p, (uint8_t *)&eth_hdr, LIBNET_ETH_H);
  143:     if (n == -1)
  144:     {
  145:         goto bad;
  146:     }
  147: 
  148:     return (libnet_pblock_update(l, p, h, LIBNET_PBLOCK_ETH_H));
  149: bad:
  150:     libnet_pblock_delete(l, p);
  151:     return (-1); 
  152: }
  153: 
  154: /**
  155:  * Local Variables:
  156:  *  indent-tabs-mode: nil
  157:  *  c-file-style: "stroustrup"
  158:  * End:
  159:  */