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/*
* 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",
};
/*
* 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;
p = bp;
printf("MPLS");
do {
TCHECK2(*p, sizeof(label_entry));
label_entry = EXTRACT_32BITS(p);
printf("%s(label %u",
label_stack_depth ? "\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));
switch (MPLS_LABEL(label_entry)) {
case 0: /* IPv4 explicit NULL label */
case 3: /* IPv4 implicit NULL label */
if (vflag>0) {
printf("\n\t");
ip_print(gndo, p, length - (p - bp));
}
else printf(", IP, length: %u",length);
break;
#ifdef INET6
case 2: /* IPv6 explicit NULL label */
if (vflag>0) {
printf("\n\t");
ip6_print(p, length - (p - bp));
}
else printf(", IPv6, length: %u",length);
break;
#endif
default:
/*
* Generally there's no indication of protocol in MPLS label
* encoding, however draft-hsmit-isis-aal5mux-00.txt describes
* a technique that looks at the first payload byte if the BOS (bottom of stack)
* bit is set and tries to determine the network layer protocol
* 0x45-0x4f is IPv4
* 0x60-0x6f is IPv6
* 0x81-0x83 is OSI (CLNP,ES-IS,IS-IS)
* this technique is sometimes known as NULL encapsulation
* and decoding is particularly useful for control-plane traffic [BGP]
* which cisco by default sends MPLS encapsulated
*/
if (MPLS_STACK(label_entry)) { /* only do this if the stack bit is set */
switch(*p) {
case 0x45:
case 0x46:
case 0x47:
case 0x48:
case 0x49:
case 0x4a:
case 0x4b:
case 0x4c:
case 0x4d:
case 0x4e:
case 0x4f:
if (vflag>0) {
printf("\n\t");
ip_print(gndo, p, length - (p - bp));
}
else printf(", IP, length: %u",length);
break;
#ifdef INET6
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:
if (vflag>0) {
printf("\n\t");
ip6_print(p, length - (p - bp));
}
else printf(", IPv6, length: %u",length);
break;
#endif
case 0x81:
case 0x82:
case 0x83:
if (vflag>0) {
printf("\n\t");
isoclns_print(p, length - (p - bp), length - (p - bp));
}
else printf(", OSI, length: %u",length);
break;
default:
/* ok bail out - we did not figure out what it is*/
break;
}
}
return;
}
trunc:
printf("[|MPLS]");
}
/*
* Local Variables:
* c-style: whitesmith
* c-basic-offset: 8
* End:
*/
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