/*

 *  $Id: libnet_build_igmp.c,v 1.12 2004/04/13 17:32:28 mike Exp $

 *

 *  libnet

 *  libnet_build_igmp.c - IGMP packet assembler

 *

 *  Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>

 *  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 */

#if (HAVE_CONFIG_H)

#include "../include/config.h"

#endif

#if (!(_WIN32) || (__CYGWIN__)) 

#include "../include/libnet.h"

#else

#include "../include/win32/libnet.h"

#endif

libnet_ptag_t

libnet_build_igmp(uint8_t type, uint8_t reserved, uint16_t sum, uint32_t ip,

const uint8_t *payload, uint32_t payload_s, libnet_t *l, libnet_ptag_t ptag)

{

    uint32_t n, h;

    libnet_pblock_t *p;

    struct libnet_igmp_hdr igmp_hdr;

    if (l == NULL)

    { 

        return (-1);

    } 

    n = LIBNET_IGMP_H + payload_s;

    h = LIBNET_IGMP_H;

    /*

     *  Find the existing protocol block if a ptag is specified, or create

     *  a new one.

     */

    p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_IGMP_H);

    if (p == NULL)

    {

        return (-1);

    }

    memset(&igmp_hdr, 0, sizeof(igmp_hdr));

    igmp_hdr.igmp_type         = type;

    igmp_hdr.igmp_code         = reserved;

    igmp_hdr.igmp_sum          = (sum ? htons(sum) : 0);

    igmp_hdr.igmp_group.s_addr = ip;

    n = libnet_pblock_append(l, p, (uint8_t *)&igmp_hdr, LIBNET_IGMP_H);

    if (n == -1)

    {

        goto bad;

    }

    /* boilerplate payload sanity check / append macro */

    LIBNET_DO_PAYLOAD(l, p);

    if (sum == 0)

    {

        /*

         *  If checksum is zero, by default libnet will compute a checksum

         *  for the user.  The programmer can override this by calling

         *  libnet_toggle_checksum(l, ptag, 1);

         */

        libnet_pblock_setflags(p, LIBNET_PBLOCK_DO_CHECKSUM);

    }

    return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_IGMP_H));

bad:

    libnet_pblock_delete(l, p);

    return (-1);

}

/* EOF */