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 1.14 2005-07-05 09:38:19 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 enum mpls_packet_type {
58 PT_UNKNOWN,
59 PT_IPV4,
60 PT_IPV6,
61 PT_OSI
62 };
63
64 /*
65 * RFC3032: MPLS label stack encoding
66 */
67 void
mpls_print(const u_char * bp,u_int length)68 mpls_print(const u_char *bp, u_int length)
69 {
70 const u_char *p;
71 u_int32_t label_entry;
72 u_int16_t label_stack_depth = 0;
73 enum mpls_packet_type pt = PT_UNKNOWN;
74
75 p = bp;
76 printf("MPLS");
77 do {
78 TCHECK2(*p, sizeof(label_entry));
79 label_entry = EXTRACT_32BITS(p);
80 printf("%s(label %u",
81 (label_stack_depth && vflag) ? "\n\t" : " ",
82 MPLS_LABEL(label_entry));
83 label_stack_depth++;
84 if (vflag &&
85 MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0]))
86 printf(" (%s)", mpls_labelname[MPLS_LABEL(label_entry)]);
87 printf(", exp %u", MPLS_EXP(label_entry));
88 if (MPLS_STACK(label_entry))
89 printf(", [S]");
90 printf(", ttl %u)", MPLS_TTL(label_entry));
91
92 p += sizeof(label_entry);
93 } while (!MPLS_STACK(label_entry));
94
95 /*
96 * Try to figure out the packet type.
97 */
98 switch (MPLS_LABEL(label_entry)) {
99
100 case 0: /* IPv4 explicit NULL label */
101 case 3: /* IPv4 implicit NULL label */
102 pt = PT_IPV4;
103 break;
104
105 case 2: /* IPv6 explicit NULL label */
106 pt = PT_IPV6;
107 break;
108
109 default:
110 /*
111 * Generally there's no indication of protocol in MPLS label
112 * encoding.
113 *
114 * However, draft-hsmit-isis-aal5mux-00.txt describes a
115 * technique for encapsulating IS-IS and IP traffic on the
116 * same ATM virtual circuit; you look at the first payload
117 * byte to determine the network layer protocol, based on
118 * the fact that
119 *
120 * 1) the first byte of an IP header is 0x45-0x4f
121 * for IPv4 and 0x60-0x6f for IPv6;
122 *
123 * 2) the first byte of an OSI CLNP packet is 0x81,
124 * the first byte of an OSI ES-IS packet is 0x82,
125 * and the first byte of an OSI IS-IS packet is
126 * 0x83;
127 *
128 * so the network layer protocol can be inferred from the
129 * first byte of the packet, if the protocol is one of the
130 * ones listed above.
131 *
132 * Cisco sends control-plane traffic MPLS-encapsulated in
133 * this fashion.
134 */
135 switch(*p) {
136
137 case 0x45:
138 case 0x46:
139 case 0x47:
140 case 0x48:
141 case 0x49:
142 case 0x4a:
143 case 0x4b:
144 case 0x4c:
145 case 0x4d:
146 case 0x4e:
147 case 0x4f:
148 pt = PT_IPV4;
149 break;
150
151 case 0x60:
152 case 0x61:
153 case 0x62:
154 case 0x63:
155 case 0x64:
156 case 0x65:
157 case 0x66:
158 case 0x67:
159 case 0x68:
160 case 0x69:
161 case 0x6a:
162 case 0x6b:
163 case 0x6c:
164 case 0x6d:
165 case 0x6e:
166 case 0x6f:
167 pt = PT_IPV6;
168 break;
169
170 case 0x81:
171 case 0x82:
172 case 0x83:
173 pt = PT_OSI;
174 break;
175
176 default:
177 /* ok bail out - we did not figure out what it is*/
178 break;
179 }
180 }
181
182 /*
183 * Print the payload.
184 */
185 if (pt == PT_UNKNOWN) {
186 if (!suppress_default_print)
187 default_print(p, length - (p - bp));
188 return;
189 }
190 if (vflag)
191 printf("\n\t");
192 else
193 printf(" ");
194 switch (pt) {
195
196 case PT_IPV4:
197 ip_print(gndo, p, length - (p - bp));
198 break;
199
200 case PT_IPV6:
201 #ifdef INET6
202 ip6_print(gndo, p, length - (p - bp));
203 #else
204 printf("IPv6, length: %u", length);
205 #endif
206 break;
207
208 case PT_OSI:
209 isoclns_print(p, length - (p - bp), length - (p - bp));
210 break;
211
212 default:
213 break;
214 }
215 return;
216
217 trunc:
218 printf("[|MPLS]");
219 }
220
221
222 /*
223 * Local Variables:
224 * c-style: whitesmith
225 * c-basic-offset: 8
226 * End:
227 */
228