1 /*
2 * Copyright (C) 2001 WIDE Project. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
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.
15 *
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
26 * SUCH DAMAGE.
27 */
28
29 #ifndef lint
30 static const char rcsid[] _U_ =
31 "@(#) $Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.13.2.1 2005/07/05 09:39:29 hannes Exp $ (LBL)";
32 #endif
33
34 #ifdef HAVE_CONFIG_H
35 #include "config.h"
36 #endif
37
38 #include <tcpdump-stdinc.h>
39
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43
44 #include "addrtoname.h"
45 #include "interface.h"
46 #include "extract.h" /* must come after interface.h */
47 #include "mpls.h"
48
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",
54 /*15*/ "rsvd",
55 };
56
57 /*
58 * RFC3032: MPLS label stack encoding
59 */
60 void
mpls_print(const u_char * bp,u_int length)61 mpls_print(const u_char *bp, u_int length)
62 {
63 const u_char *p;
64 u_int32_t label_entry;
65 u_int16_t label_stack_depth = 0;
66
67 p = bp;
68 printf("MPLS");
69 do {
70 TCHECK2(*p, sizeof(label_entry));
71 label_entry = EXTRACT_32BITS(p);
72 printf("%s(label %u",
73 label_stack_depth ? "\n\t" : " ",
74 MPLS_LABEL(label_entry));
75 label_stack_depth++;
76 if (vflag &&
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))
81 printf(", [S]");
82 printf(", ttl %u)", MPLS_TTL(label_entry));
83
84 p += sizeof(label_entry);
85 } while (!MPLS_STACK(label_entry));
86
87 switch (MPLS_LABEL(label_entry)) {
88 case 0: /* IPv4 explicit NULL label */
89 case 3: /* IPv4 implicit NULL label */
90 if (vflag>0) {
91 printf("\n\t");
92 ip_print(gndo, p, length - (p - bp));
93 }
94 else printf(", IP, length: %u",length);
95 break;
96 #ifdef INET6
97 case 2: /* IPv6 explicit NULL label */
98 if (vflag>0) {
99 printf("\n\t");
100 ip6_print(p, length - (p - bp));
101 }
102 else printf(", IPv6, length: %u",length);
103 break;
104 #endif
105 default:
106 /*
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
111 * 0x45-0x4f is IPv4
112 * 0x60-0x6f is IPv6
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
117 */
118
119 if (MPLS_STACK(label_entry)) { /* only do this if the stack bit is set */
120 switch(*p) {
121 case 0x45:
122 case 0x46:
123 case 0x47:
124 case 0x48:
125 case 0x49:
126 case 0x4a:
127 case 0x4b:
128 case 0x4c:
129 case 0x4d:
130 case 0x4e:
131 case 0x4f:
132 if (vflag>0) {
133 printf("\n\t");
134 ip_print(gndo, p, length - (p - bp));
135 }
136 else printf(", IP, length: %u",length);
137 break;
138 #ifdef INET6
139 case 0x60:
140 case 0x61:
141 case 0x62:
142 case 0x63:
143 case 0x64:
144 case 0x65:
145 case 0x66:
146 case 0x67:
147 case 0x68:
148 case 0x69:
149 case 0x6a:
150 case 0x6b:
151 case 0x6c:
152 case 0x6d:
153 case 0x6e:
154 case 0x6f:
155 if (vflag>0) {
156 printf("\n\t");
157 ip6_print(p, length - (p - bp));
158 }
159 else printf(", IPv6, length: %u",length);
160 break;
161 #endif
162 case 0x81:
163 case 0x82:
164 case 0x83:
165 if (vflag>0) {
166 printf("\n\t");
167 isoclns_print(p, length - (p - bp), length - (p - bp));
168 }
169 else printf(", OSI, length: %u",length);
170 break;
171 default:
172 /* ok bail out - we did not figure out what it is*/
173 break;
174 }
175 }
176 return;
177 }
178
179 trunc:
180 printf("[|MPLS]");
181 }
182
183
184 /*
185 * Local Variables:
186 * c-style: whitesmith
187 * c-basic-offset: 8
188 * End:
189 */
190