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
|
/* Copyright (c) 2015, bugyo
* 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*/
/* \summary: Network Service Header (NSH) printer */
/* specification: draft-ietf-sfc-nsh-01 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#include "netdissect.h"
#include "extract.h"
static const struct tok nsh_flags [] = {
{ 0x20, "O" },
{ 0x10, "C" },
{ 0, NULL }
};
#define NSH_BASE_HDR_LEN 4
#define NSH_SERVICE_PATH_HDR_LEN 4
#define NSH_HDR_WORD_SIZE 4U
void
nsh_print(netdissect_options *ndo, const u_char *bp, u_int len)
{
u_int n, vn;
uint8_t ver;
uint8_t flags;
u_int length;
uint8_t md_type;
uint8_t next_protocol;
uint32_t service_path_id;
uint8_t service_index;
uint32_t ctx;
uint16_t tlv_class;
uint8_t tlv_type;
uint8_t tlv_len;
u_int next_len;
ndo->ndo_protocol = "nsh";
/* print Base Header and Service Path Header */
if (len < NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN)
goto trunc;
ND_TCHECK_LEN(bp, NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN);
ver = (uint8_t)(GET_U_1(bp) >> 6);
flags = GET_U_1(bp);
bp += 1;
length = GET_U_1(bp);
bp += 1;
md_type = GET_U_1(bp);
bp += 1;
next_protocol = GET_U_1(bp);
bp += 1;
service_path_id = GET_BE_U_3(bp);
bp += 3;
service_index = GET_U_1(bp);
bp += 1;
ND_PRINT("NSH, ");
if (ndo->ndo_vflag > 1) {
ND_PRINT("ver %u, ", ver);
}
ND_PRINT("flags [%s], ", bittok2str_nosep(nsh_flags, "none", flags));
if (ndo->ndo_vflag > 2) {
ND_PRINT("length %u, ", length);
ND_PRINT("md type 0x%x, ", md_type);
}
if (ndo->ndo_vflag > 1) {
ND_PRINT("next-protocol 0x%x, ", next_protocol);
}
ND_PRINT("service-path-id 0x%06x, ", service_path_id);
ND_PRINT("service-index 0x%x", service_index);
/* Make sure we have all the headers */
if (len < length * NSH_HDR_WORD_SIZE)
goto trunc;
ND_TCHECK_LEN(bp, length * NSH_HDR_WORD_SIZE);
/*
* length includes the lengths of the Base and Service Path headers.
* That means it must be at least 2.
*/
if (length < 2)
goto trunc;
/*
* Print, or skip, the Context Headers.
* (length - 2) is the length of those headers.
*/
if (ndo->ndo_vflag > 2) {
if (md_type == 0x01) {
for (n = 0; n < length - 2; n++) {
ctx = GET_BE_U_4(bp);
bp += NSH_HDR_WORD_SIZE;
ND_PRINT("\n Context[%02u]: 0x%08x", n, ctx);
}
}
else if (md_type == 0x02) {
n = 0;
while (n < length - 2) {
tlv_class = GET_BE_U_2(bp);
bp += 2;
tlv_type = GET_U_1(bp);
bp += 1;
tlv_len = GET_U_1(bp);
bp += 1;
ND_PRINT("\n TLV Class %u, Type %u, Len %u",
tlv_class, tlv_type, tlv_len);
n += 1;
if (length - 2 < n + tlv_len) {
ND_PRINT(" ERROR: invalid-tlv-length");
return;
}
for (vn = 0; vn < tlv_len; vn++) {
ctx = GET_BE_U_4(bp);
bp += NSH_HDR_WORD_SIZE;
ND_PRINT("\n Value[%02u]: 0x%08x", vn, ctx);
}
n += tlv_len;
}
}
else {
ND_PRINT("ERROR: unknown-next-protocol");
return;
}
}
else {
bp += (length - 2) * NSH_HDR_WORD_SIZE;
}
ND_PRINT(ndo->ndo_vflag ? "\n " : ": ");
/* print Next Protocol */
next_len = len - length * NSH_HDR_WORD_SIZE;
switch (next_protocol) {
case 0x1:
ip_print(ndo, bp, next_len);
break;
case 0x2:
ip6_print(ndo, bp, next_len);
break;
case 0x3:
ether_print(ndo, bp, next_len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
break;
default:
ND_PRINT("ERROR: unknown-next-protocol");
return;
}
return;
trunc:
nd_print_trunc(ndo);
}
|
