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
|
/* $OpenBSD: print-mpls.c,v 1.4 2018/07/06 07:00:49 dlg Exp $ */
/*
* Copyright (c) 2005 Jason L. Wright (jason@thought.net)
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/socket.h>
#include <sys/types.h>
#include <netmpls/mpls.h>
#include <stdio.h>
#include "interface.h"
#include "extract.h" /* must come after interface.h */
#define CW_SEQUENCE_MASK (0x0000ffffU)
int controlword_tryprint(const u_char **, u_int *);
void
mpls_print(const u_char *bp, u_int len)
{
u_int32_t tag, label, exp, bottom, ttl;
int has_cw;
do {
if (bp + sizeof(tag) > snapend)
goto trunc;
tag = EXTRACT_32BITS(bp);
bp += sizeof(tag);
len -= sizeof(tag);
label = (tag >> 12) & 0xfffff;
exp = (tag >> 9) & 0x7;
bottom = (tag >> 8) & 0x1;
ttl = (tag >> 0) & 0xff;
printf("MPLS(label %u, exp %u, ttl %u) ", label, exp, ttl);
/* XXX decode "Router Alert Label" */
} while (!bottom);
/* Handle pseudowire control word. */
has_cw = controlword_tryprint(&bp, &len);
/*
* guessing the underlying protocol is about all we can do if
* it's not explicitly defined.
*/
switch (label) {
case 0x00000: /* IPv4 Explicit NULL */
ip_print(bp, len);
break;
case 0x00001: /* Router Alert */
/* shouldn't happen at stack bottom */
printf("Route-Alert");
break;
case 0x00002: /* IPv6 Explicit NULL */
ip6_print(bp, len);
break;
case 0x00003: /* Implicit NULL */
/* shouldn't happen in the tag stack */
printf("Implicit-NULL");
break;
case 0x00004: /* reserved labels */
case 0x00005:
case 0x00006:
case 0x00007:
case 0x00008:
case 0x00009:
case 0x0000a:
case 0x0000b:
case 0x0000c:
case 0x0000d:
case 0x0000e:
case 0x0000f:
break;
default: /* dunno, guess? */
if (len == 0)
break;
if (bp >= snapend)
goto trunc;
switch (bp[0] & 0xf0) {
case 0x40:
ip_print(bp, len);
break;
case 0x60:
ip6_print(bp, len);
break;
}
}
if (has_cw)
ether_tryprint(bp, len, 0);
return;
trunc:
printf("[|mpls]");
}
/* Print control word if any and returns 1 on success. */
int
controlword_tryprint(const u_char **bp, u_int *lenp)
{
uint32_t cw, frag, seq;
if (*lenp < 4)
return (0);
cw = EXTRACT_32BITS(*bp);
if (cw & CW_ZERO_MASK)
return (0);
*bp += sizeof(cw);
*lenp += sizeof(cw);
frag = (cw & CW_FRAG_MASK) >> 16;
seq = cw & CW_SEQUENCE_MASK;
printf("CW(frag %u, sequence %u) ", frag, seq);
return (1);
}
|
