source: rtems-libbsd/freebsd/contrib/tcpdump/print-mpls.c @ 084d4db

#include <machine/rtems-bsd-user-space.h>

/*
 * Copyright (C) 2001 WIDE Project.  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.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
 */

#ifndef lint
static const char rcsid[] _U_ =
    "@(#) $Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.14 2005-07-05 09:38:19 hannes Exp $ (LBL)";
#endif

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <tcpdump-stdinc.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "addrtoname.h"
#include "interface.h"
#include "extract.h"                    /* must come after interface.h */
#include "mpls.h"

static const char *mpls_labelname[] = {
/*0*/   "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL",
        "implicit NULL", "rsvd",
/*5*/   "rsvd", "rsvd", "rsvd", "rsvd", "rsvd",
/*10*/  "rsvd", "rsvd", "rsvd", "rsvd", "rsvd",
/*15*/  "rsvd",
};

enum mpls_packet_type {
        PT_UNKNOWN,
        PT_IPV4,
        PT_IPV6,
        PT_OSI
};

/*
 * RFC3032: MPLS label stack encoding
 */
void
mpls_print(const u_char *bp, u_int length)
{
        const u_char *p;
        u_int32_t label_entry;
        u_int16_t label_stack_depth = 0;
        enum mpls_packet_type pt = PT_UNKNOWN;

        p = bp;
        printf("MPLS");
        do {
                TCHECK2(*p, sizeof(label_entry));
                label_entry = EXTRACT_32BITS(p);
                printf("%s(label %u",
                       (label_stack_depth && vflag) ? "\n\t" : " ",
                       MPLS_LABEL(label_entry));
                label_stack_depth++;
                if (vflag &&
                    MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0]))
                        printf(" (%s)", mpls_labelname[MPLS_LABEL(label_entry)]);
                printf(", exp %u", MPLS_EXP(label_entry));
                if (MPLS_STACK(label_entry))
                        printf(", [S]");
                printf(", ttl %u)", MPLS_TTL(label_entry));

                p += sizeof(label_entry);
        } while (!MPLS_STACK(label_entry));

        /*
         * Try to figure out the packet type.
         */
        switch (MPLS_LABEL(label_entry)) {

        case 0: /* IPv4 explicit NULL label */
        case 3: /* IPv4 implicit NULL label */
                pt = PT_IPV4;
                break;

        case 2: /* IPv6 explicit NULL label */
                pt = PT_IPV6;
                break;

        default:
                /*
                 * Generally there's no indication of protocol in MPLS label
                 * encoding.
                 *
                 * However, draft-hsmit-isis-aal5mux-00.txt describes a
                 * technique for encapsulating IS-IS and IP traffic on the
                 * same ATM virtual circuit; you look at the first payload
                 * byte to determine the network layer protocol, based on
                 * the fact that
                 *
                 *      1) the first byte of an IP header is 0x45-0x4f
                 *         for IPv4 and 0x60-0x6f for IPv6;
                 *
                 *      2) the first byte of an OSI CLNP packet is 0x81,
                 *         the first byte of an OSI ES-IS packet is 0x82,
                 *         and the first byte of an OSI IS-IS packet is
                 *         0x83;
                 *
                 * so the network layer protocol can be inferred from the
                 * first byte of the packet, if the protocol is one of the
                 * ones listed above.
                 *
                 * Cisco sends control-plane traffic MPLS-encapsulated in
                 * this fashion.
                 */
                switch(*p) {

                case 0x45:
                case 0x46:
                case 0x47:
                case 0x48:
                case 0x49:
                case 0x4a:
                case 0x4b:
                case 0x4c:
                case 0x4d:
                case 0x4e:
                case 0x4f:
                        pt = PT_IPV4;
                        break;
                                
                case 0x60:
                case 0x61:
                case 0x62:
                case 0x63:
                case 0x64:
                case 0x65:
                case 0x66:
                case 0x67:
                case 0x68:
                case 0x69:
                case 0x6a:
                case 0x6b:
                case 0x6c:
                case 0x6d:
                case 0x6e:
                case 0x6f:
                        pt = PT_IPV6;
                        break;

                case 0x81:
                case 0x82:
                case 0x83:
                        pt = PT_OSI;
                        break;

                default:
                        /* ok bail out - we did not figure out what it is*/
                        break;
                }
        }

        /*
         * Print the payload.
         */
        if (pt == PT_UNKNOWN) {
                if (!suppress_default_print)
                        default_print(p, length - (p - bp));
                return;
        }
        if (vflag)
                printf("\n\t");
        else
                printf(" ");
        switch (pt) {

        case PT_IPV4:
                ip_print(gndo, p, length - (p - bp));
                break;

        case PT_IPV6:
#ifdef INET6
                ip6_print(gndo, p, length - (p - bp));
#else
                printf("IPv6, length: %u", length);
#endif
                break;

        case PT_OSI:
                isoclns_print(p, length - (p - bp), length - (p - bp));
                break;

        default:
                break;
        }
        return;

trunc:
        printf("[|MPLS]");
}


/*
 * Local Variables:
 * c-style: whitesmith
 * c-basic-offset: 8
 * End:
 */