summaryrefslogtreecommitdiffstats
path: root/contrib/tcpdump/print-mpls.c
blob: 9d545677cc8cde27c71671c8181b7a754a408b93 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
/*
 * 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 1.13.2.1 2005/07/05 09:39:29 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:
 */
OpenPOWER on IntegriCloud