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Version 1.2p1

    1: /*
    2:  *  $Id: libnet_build_igmp.c,v 1.1.1.3 2023/09/27 11:11:38 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: #include "common.h"
   34: 
   35: libnet_ptag_t
   36: libnet_build_igmp(uint8_t type, uint8_t reserved, uint16_t sum, uint32_t ip,
   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_igmp_hdr igmp_hdr;
   42: 
   43:     if (l == NULL)
   44:     { 
   45:         return (-1);
   46:     } 
   47: 
   48:     n = LIBNET_IGMP_H + payload_s;
   49:     h = LIBNET_IGMP_H;
   50: 
   51:     /*
   52:      *  Find the existing protocol block if a ptag is specified, or create
   53:      *  a new one.
   54:      */
   55:     p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_IGMP_H);
   56:     if (p == NULL)
   57:     {
   58:         return (-1);
   59:     }
   60: 
   61:     memset(&igmp_hdr, 0, sizeof(igmp_hdr));
   62:     igmp_hdr.igmp_type         = type;
   63:     igmp_hdr.igmp_code         = reserved;
   64:     igmp_hdr.igmp_sum          = (sum ? htons(sum) : 0);
   65:     igmp_hdr.igmp_group.s_addr = ip;
   66: 
   67:     n = libnet_pblock_append(l, p, (uint8_t *)&igmp_hdr, LIBNET_IGMP_H);
   68:     if (n == -1)
   69:     {
   70:         goto bad;
   71:     }
   72: 
   73:     /* boilerplate payload sanity check / append macro */
   74:     LIBNET_DO_PAYLOAD(l, p);
   75: 
   76:     if (sum == 0)
   77:     {
   78:         /*
   79:          *  If checksum is zero, by default libnet will compute a checksum
   80:          *  for the user.  The programmer can override this by calling
   81:          *  libnet_toggle_checksum(l, ptag, 1);
   82:          */
   83:         libnet_pblock_setflags(p, LIBNET_PBLOCK_DO_CHECKSUM);
   84:     }
   85: 
   86:     return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_IGMP_H));
   87: bad:
   88:     libnet_pblock_delete(l, p);
   89:     return (-1);
   90: }
   91: 
   92: /**
   93:  * Local Variables:
   94:  *  indent-tabs-mode: nil
   95:  *  c-file-style: "stroustrup"
   96:  * End:
   97:  */