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Annotation of embedaddon/libnet/src/libnet_build_mpls.c, revision 1.1.1.1

1.1       misho       1: /*
                      2:  *  $Id: libnet_build_mpls.c,v 1.9 2004/03/01 20:26:12 mike 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: #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_mpls(u_int32_t label, u_int8_t experimental, u_int8_t bos, 
                     44: u_int8_t ttl, u_int8_t *payload, u_int32_t payload_s, libnet_t *l,
                     45: libnet_ptag_t ptag)
                     46: {
                     47:     u_int32_t n, h;
                     48:     libnet_pblock_t *p;
                     49:     struct libnet_mpls_hdr mpls_hdr;
                     50: 
                     51:     if (l == NULL)
                     52:     { 
                     53:         return (-1);
                     54:     } 
                     55: 
                     56:     n = LIBNET_MPLS_H + payload_s;
                     57:     h = 0;
                     58: 
                     59:     /*
                     60:      *  Find the existing protocol block if a ptag is specified, or create
                     61:      *  a new one.
                     62:      */
                     63:     p = libnet_pblock_probe(l, ptag, n, LIBNET_PBLOCK_MPLS_H);
                     64:     if (p == NULL)
                     65:     {
                     66:         return (-1);
                     67:     }
                     68: 
                     69:     memset(&mpls_hdr, 0, sizeof(mpls_hdr));
                     70:     mpls_hdr.mpls_les = htonl((((label & 0x000fffff) << 12) |
                     71:                               ((experimental & 0x07) <<  9) |
                     72:                               ((bos & 0x01)          <<  8) |
                     73:                               ((ttl & 0xff))));
                     74: 
                     75:     n = libnet_pblock_append(l, p, (u_int8_t *)&mpls_hdr, LIBNET_MPLS_H);
                     76:     if (n == -1)
                     77:     {
                     78:         goto bad;
                     79:     }
                     80: 
                     81:     if ((payload && !payload_s) || (!payload && payload_s))
                     82:     {
                     83:          snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
                     84:                             "%s(): payload inconsistency\n", __func__);
                     85:         goto bad;
                     86:     }
                     87: 
                     88:     if (payload && payload_s)
                     89:     {
                     90:         n = libnet_pblock_append(l, p, payload, payload_s);
                     91:         if (n == -1)
                     92:         {
                     93:             goto bad;
                     94:         }
                     95:     }
                     96: 
                     97:     /*
                     98:      *  The link offset is actually 4 bytes further into the header than
                     99:      *  before (the MPLS header adds this 4 bytes).  We need to update the
                    100:      *  link offset pointer. XXX - should we set this here?
                    101:      *  Probably not.  We should make pblock_coalesce check the pblock type
                    102:      *  and adjust accordingly.
                    103:      */
                    104:     l->link_offset += 4;
                    105: 
                    106:     return (ptag ? ptag : libnet_pblock_update(l, p, h, LIBNET_PBLOCK_MPLS_H));
                    107: bad:
                    108:     libnet_pblock_delete(l, p);
                    109:     return (-1);
                    110: }
                    111: 
                    112: /* EOF */