2 * Copyright (C) 2001 WIDE Project. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. Neither the name of the project nor the names of its contributors
13 * may be used to endorse or promote products derived from this software
14 * without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 static const char rcsid[] _U_ =
31 "@(#) $Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.14 2005-07-05 09:38:19 hannes Exp $ (LBL)";
38 #include <tcpdump-stdinc.h>
44 #include "addrtoname.h"
45 #include "interface.h"
46 #include "extract.h" /* must come after interface.h */
49 static const char *mpls_labelname[] = {
50 /*0*/ "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL",
51 "implicit NULL", "rsvd",
52 /*5*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd",
53 /*10*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd",
58 * RFC3032: MPLS label stack encoding
61 mpls_print(const u_char *bp, u_int length)
64 u_int32_t label_entry;
65 u_int16_t label_stack_depth = 0;
70 TCHECK2(*p, sizeof(label_entry));
71 label_entry = EXTRACT_32BITS(p);
73 label_stack_depth ? "\n\t" : " ",
74 MPLS_LABEL(label_entry));
77 MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0]))
78 printf(" (%s)", mpls_labelname[MPLS_LABEL(label_entry)]);
79 printf(", exp %u", MPLS_EXP(label_entry));
80 if (MPLS_STACK(label_entry))
82 printf(", ttl %u)", MPLS_TTL(label_entry));
84 p += sizeof(label_entry);
85 } while (!MPLS_STACK(label_entry));
87 switch (MPLS_LABEL(label_entry)) {
88 case 0: /* IPv4 explicit NULL label */
89 case 3: /* IPv4 implicit NULL label */
92 ip_print(gndo, p, length - (p - bp));
94 else printf(", IP, length: %u",length);
97 case 2: /* IPv6 explicit NULL label */
100 ip6_print(p, length - (p - bp));
102 else printf(", IPv6, length: %u",length);
107 * Generally there's no indication of protocol in MPLS label
108 * encoding, however draft-hsmit-isis-aal5mux-00.txt describes
109 * a technique that looks at the first payload byte if the BOS (bottom of stack)
110 * bit is set and tries to determine the network layer protocol
113 * 0x81-0x83 is OSI (CLNP,ES-IS,IS-IS)
114 * this technique is sometimes known as NULL encapsulation
115 * and decoding is particularly useful for control-plane traffic [BGP]
116 * which cisco by default sends MPLS encapsulated
119 if (MPLS_STACK(label_entry)) { /* only do this if the stack bit is set */
134 ip_print(gndo, p, length - (p - bp));
136 else printf(", IP, length: %u",length);
157 ip6_print(p, length - (p - bp));
159 else printf(", IPv6, length: %u",length);
167 isoclns_print(p, length - (p - bp), length - (p - bp));
169 else printf(", OSI, length: %u",length);
172 /* ok bail out - we did not figure out what it is*/
186 * c-style: whitesmith