Return to libnet_build_mpls.c CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / libnet / src

Version 1.2p1

    1: /*
    2:  *  $Id: libnet_build_mpls.c,v 1.1.1.3 2023/09/27 11:11:38 misho Exp $
    3:  *
    4:  *  libnet
    5:  *  libnet_build_mpls.c - MPLS 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_mpls(uint32_t label, uint8_t experimental, uint8_t bos, 
   37: uint8_t ttl, const uint8_t *payload, uint32_t payload_s, libnet_t *l,
   38: libnet_ptag_t ptag)
   39: {
   40:     uint32_t n, h;
   41:     libnet_pblock_t *p;
   42:     struct libnet_mpls_hdr mpls_hdr;
   43: 
   44:     if (l == NULL)
   45:     { 
   46:         return (-1);
   47:     } 
   48: 
   49:     n = LIBNET_MPLS_H + payload_s;
   50:     h = 0;
   51: 
   52:     /*
   53:      *  Find the existing protocol block if a ptag is specified, or create
   54:      *  a new one.
   55:      */
   56:     p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_MPLS_H);
   57:     if (p == NULL)
   58:     {
   59:         return (-1);
   60:     }
   61: 
   62:     memset(&mpls_hdr, 0, sizeof(mpls_hdr));
   63:     mpls_hdr.mpls_les = htonl((((label & 0x000fffff) << 12) |
   64:                               ((experimental & 0x07) <<  9) |
   65:                               ((bos & 0x01)          <<  8) |
   66:                               ((ttl & 0xff))));
   67: 
   68:     n = libnet_pblock_append(l, p, (uint8_t *)&mpls_hdr, LIBNET_MPLS_H);
   69:     if (n == -1)
   70:     {
   71:         goto bad;
   72:     }
   73: 
   74:     /* boilerplate payload sanity check / append macro */
   75:     LIBNET_DO_PAYLOAD(l, p);
   76: 
   77:     /*
   78:      *  The link offset is actually 4 bytes further into the header than
   79:      *  before (the MPLS header adds this 4 bytes).  We need to update the
   80:      *  link offset pointer. XXX - should we set this here?
   81:      *  Probably not.  We should make pblock_coalesce check the pblock type
   82:      *  and adjust accordingly.
   83:      */
   84:     l->link_offset += 4;
   85: 
   86:     return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_MPLS_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:  */