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1.1.6

    1: /*
    2:  *  $Id: libnet_build_igmp.c,v 1.1.1.2 2013/07/22 11:54:42 misho Exp $
    3:  *
    4:  *  libnet
    5:  *  libnet_build_igmp.c - IGMP 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_igmp(uint8_t type, uint8_t reserved, uint16_t sum, uint32_t ip,
   44: const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)
   45: {
   46:     uint32_t n, h;
   47:     libnet_pblock_t *p;
   48:     struct libnet_igmp_hdr igmp_hdr;
   49: 
   50:     if (l == NULL)
   51:     { 
   52:         return (-1);
   53:     } 
   54: 
   55:     n = LIBNET_IGMP_H + payload_s;
   56:     h = LIBNET_IGMP_H;
   57: 
   58:     /*
   59:      *  Find the existing protocol block if a ptag is specified, or create
   60:      *  a new one.
   61:      */
   62:     p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_IGMP_H);
   63:     if (p == NULL)
   64:     {
   65:         return (-1);
   66:     }
   67: 
   68:     memset(&igmp_hdr, 0, sizeof(igmp_hdr));
   69:     igmp_hdr.igmp_type         = type;
   70:     igmp_hdr.igmp_code         = reserved;
   71:     igmp_hdr.igmp_sum          = (sum ? htons(sum) : 0);
   72:     igmp_hdr.igmp_group.s_addr = ip;
   73: 
   74:     n = libnet_pblock_append(l, p, (uint8_t *)&igmp_hdr, LIBNET_IGMP_H);
   75:     if (n == -1)
   76:     {
   77:         goto bad;
   78:     }
   79: 
   80:     /* boilerplate payload sanity check / append macro */
   81:     LIBNET_DO_PAYLOAD(l, p);
   82: 
   83:     if (sum == 0)
   84:     {
   85:         /*
   86:          *  If checksum is zero, by default libnet will compute a checksum
   87:          *  for the user.  The programmer can override this by calling
   88:          *  libnet_toggle_checksum(l, ptag, 1);
   89:          */
   90:         libnet_pblock_setflags(p, LIBNET_PBLOCK_DO_CHECKSUM);
   91:     }
   92: 
   93:     return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_IGMP_H));
   94: bad:
   95:     libnet_pblock_delete(l, p);
   96:     return (-1);
   97: }
   98: 
   99: /* EOF */