1 /*
2 * Redistribution and use in source and binary forms, with or without
3 * modification, are permitted provided that: (1) source code
4 * distributions retain the above copyright notice and this paragraph
5 * in its entirety, and (2) distributions including binary code include
6 * the above copyright notice and this paragraph in its entirety in
7 * the documentation or other materials provided with the distribution.
8 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
9 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
10 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
11 * FOR A PARTICULAR PURPOSE.
12 *
13 * Original code by Hannes Gredler (hannes@juniper.net)
14 */
15
16 #define NETDISSECT_REWORKED
17 #ifdef HAVE_CONFIG_H
18 #include "config.h"
19 #endif
20
21 #include <tcpdump-stdinc.h>
22
23 #include "interface.h"
24 #include "extract.h"
25
26 #include "udp.h"
27
28 /*
29 * Control packet, BFDv0, draft-katz-ward-bfd-01.txt
30 *
31 * 0 1 2 3
32 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
33 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
34 * |Vers | Diag |H|D|P|F| Rsvd | Detect Mult | Length |
35 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
36 * | My Discriminator |
37 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
38 * | Your Discriminator |
39 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
40 * | Desired Min TX Interval |
41 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
42 * | Required Min RX Interval |
43 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 * | Required Min Echo RX Interval |
45 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 */
47
48 /*
49 * Control packet, BFDv1, draft-ietf-bfd-base-02.txt
50 *
51 * 0 1 2 3
52 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
53 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
54 * |Vers | Diag |Sta|P|F|C|A|D|R| Detect Mult | Length |
55 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
56 * | My Discriminator |
57 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
58 * | Your Discriminator |
59 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
60 * | Desired Min TX Interval |
61 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
62 * | Required Min RX Interval |
63 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
64 * | Required Min Echo RX Interval |
65 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
66 */
67
68 struct bfd_header_t {
69 uint8_t version_diag;
70 uint8_t flags;
71 uint8_t detect_time_multiplier;
72 uint8_t length;
73 uint8_t my_discriminator[4];
74 uint8_t your_discriminator[4];
75 uint8_t desired_min_tx_interval[4];
76 uint8_t required_min_rx_interval[4];
77 uint8_t required_min_echo_interval[4];
78 };
79
80 /*
81 * An optional Authentication Header may be present
82 *
83 * 0 1 2 3
84 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
85 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
86 * | Auth Type | Auth Len | Authentication Data... |
87 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
88 */
89
90 struct bfd_auth_header_t {
91 uint8_t auth_type;
92 uint8_t auth_len;
93 uint8_t auth_data;
94 };
95
96 static const struct tok bfd_v1_authentication_values[] = {
97 { 0, "Reserved" },
98 { 1, "Simple Password" },
99 { 2, "Keyed MD5" },
100 { 3, "Meticulous Keyed MD5" },
101 { 4, "Keyed SHA1" },
102 { 5, "Meticulous Keyed SHA1" },
103 { 0, NULL }
104 };
105
106 #define BFD_EXTRACT_VERSION(x) (((x)&0xe0)>>5)
107 #define BFD_EXTRACT_DIAG(x) ((x)&0x1f)
108
109 static const struct tok bfd_port_values[] = {
110 { BFD_CONTROL_PORT, "Control" },
111 { BFD_ECHO_PORT, "Echo" },
112 { 0, NULL }
113 };
114
115
116 static const struct tok bfd_diag_values[] = {
117 { 0, "No Diagnostic" },
118 { 1, "Control Detection Time Expired" },
119 { 2, "Echo Function Failed" },
120 { 3, "Neighbor Signaled Session Down" },
121 { 4, "Forwarding Plane Reset" },
122 { 5, "Path Down" },
123 { 6, "Concatenated Path Down" },
124 { 7, "Administratively Down" },
125 { 8, "Reverse Concatenated Path Down" },
126 { 0, NULL }
127 };
128
129 static const struct tok bfd_v0_flag_values[] = {
130 { 0x80, "I Hear You" },
131 { 0x40, "Demand" },
132 { 0x20, "Poll" },
133 { 0x10, "Final" },
134 { 0x08, "Reserved" },
135 { 0x04, "Reserved" },
136 { 0x02, "Reserved" },
137 { 0x01, "Reserved" },
138 { 0, NULL }
139 };
140
141 #define BFD_FLAG_AUTH 0x04
142
143 static const struct tok bfd_v1_flag_values[] = {
144 { 0x20, "Poll" },
145 { 0x10, "Final" },
146 { 0x08, "Control Plane Independent" },
147 { BFD_FLAG_AUTH, "Authentication Present" },
148 { 0x02, "Demand" },
149 { 0x01, "Reserved" },
150 { 0, NULL }
151 };
152
153 static const struct tok bfd_v1_state_values[] = {
154 { 0, "AdminDown" },
155 { 1, "Down" },
156 { 2, "Init" },
157 { 3, "Up" },
158 { 0, NULL }
159 };
160
161 void
bfd_print(netdissect_options * ndo,register const u_char * pptr,register u_int len,register u_int port)162 bfd_print(netdissect_options *ndo, register const u_char *pptr,
163 register u_int len, register u_int port)
164 {
165 const struct bfd_header_t *bfd_header;
166 const struct bfd_auth_header_t *bfd_auth_header;
167 uint8_t version = 0;
168
169 bfd_header = (const struct bfd_header_t *)pptr;
170 if (port == BFD_CONTROL_PORT) {
171 ND_TCHECK(*bfd_header);
172 version = BFD_EXTRACT_VERSION(bfd_header->version_diag);
173 } else if (port == BFD_ECHO_PORT) {
174 /* Echo is BFD v1 only */
175 version = 1;
176 }
177 switch ((port << 8) | version) {
178
179 /* BFDv0 */
180 case (BFD_CONTROL_PORT << 8):
181 if (ndo->ndo_vflag < 1)
182 {
183 ND_PRINT((ndo, "BFDv%u, %s, Flags: [%s], length: %u",
184 version,
185 tok2str(bfd_port_values, "unknown (%u)", port),
186 bittok2str(bfd_v0_flag_values, "none", bfd_header->flags),
187 len));
188 return;
189 }
190
191 ND_PRINT((ndo, "BFDv%u, length: %u\n\t%s, Flags: [%s], Diagnostic: %s (0x%02x)",
192 version,
193 len,
194 tok2str(bfd_port_values, "unknown (%u)", port),
195 bittok2str(bfd_v0_flag_values, "none", bfd_header->flags),
196 tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(bfd_header->version_diag)),
197 BFD_EXTRACT_DIAG(bfd_header->version_diag)));
198
199 ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u",
200 bfd_header->detect_time_multiplier,
201 bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000,
202 bfd_header->length));
203
204
205 ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator)));
206 ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator)));
207 ND_PRINT((ndo, "\n\t Desired min Tx Interval: %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000));
208 ND_PRINT((ndo, "\n\t Required min Rx Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000));
209 ND_PRINT((ndo, "\n\t Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000));
210 break;
211
212 /* BFDv1 */
213 case (BFD_CONTROL_PORT << 8 | 1):
214 if (ndo->ndo_vflag < 1)
215 {
216 ND_PRINT((ndo, "BFDv%u, %s, State %s, Flags: [%s], length: %u",
217 version,
218 tok2str(bfd_port_values, "unknown (%u)", port),
219 tok2str(bfd_v1_state_values, "unknown (%u)", (bfd_header->flags & 0xc0) >> 6),
220 bittok2str(bfd_v1_flag_values, "none", bfd_header->flags & 0x3f),
221 len));
222 return;
223 }
224
225 ND_PRINT((ndo, "BFDv%u, length: %u\n\t%s, State %s, Flags: [%s], Diagnostic: %s (0x%02x)",
226 version,
227 len,
228 tok2str(bfd_port_values, "unknown (%u)", port),
229 tok2str(bfd_v1_state_values, "unknown (%u)", (bfd_header->flags & 0xc0) >> 6),
230 bittok2str(bfd_v1_flag_values, "none", bfd_header->flags & 0x3f),
231 tok2str(bfd_diag_values,"unknown",BFD_EXTRACT_DIAG(bfd_header->version_diag)),
232 BFD_EXTRACT_DIAG(bfd_header->version_diag)));
233
234 ND_PRINT((ndo, "\n\tDetection Timer Multiplier: %u (%u ms Detection time), BFD Length: %u",
235 bfd_header->detect_time_multiplier,
236 bfd_header->detect_time_multiplier * EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000,
237 bfd_header->length));
238
239
240 ND_PRINT((ndo, "\n\tMy Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->my_discriminator)));
241 ND_PRINT((ndo, ", Your Discriminator: 0x%08x", EXTRACT_32BITS(bfd_header->your_discriminator)));
242 ND_PRINT((ndo, "\n\t Desired min Tx Interval: %4u ms", EXTRACT_32BITS(bfd_header->desired_min_tx_interval)/1000));
243 ND_PRINT((ndo, "\n\t Required min Rx Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_rx_interval)/1000));
244 ND_PRINT((ndo, "\n\t Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000));
245
246 if (bfd_header->flags & BFD_FLAG_AUTH) {
247 pptr += sizeof (const struct bfd_header_t);
248 bfd_auth_header = (const struct bfd_auth_header_t *)pptr;
249 ND_TCHECK2(*bfd_auth_header, sizeof(const struct bfd_auth_header_t));
250 ND_PRINT((ndo, "\n\t%s (%u) Authentication, length %u present",
251 tok2str(bfd_v1_authentication_values,"Unknown",bfd_auth_header->auth_type),
252 bfd_auth_header->auth_type,
253 bfd_auth_header->auth_len));
254 }
255 break;
256
257 /* BFDv0 */
258 case (BFD_ECHO_PORT << 8): /* not yet supported - fall through */
259 /* BFDv1 */
260 case (BFD_ECHO_PORT << 8 | 1):
261
262 default:
263 ND_PRINT((ndo, "BFD, %s, length: %u",
264 tok2str(bfd_port_values, "unknown (%u)", port),
265 len));
266 if (ndo->ndo_vflag >= 1) {
267 if(!print_unknown_data(ndo, pptr,"\n\t",len))
268 return;
269 }
270 break;
271 }
272 return;
273
274 trunc:
275 ND_PRINT((ndo, "[|BFD]"));
276 }
277 /*
278 * Local Variables:
279 * c-style: whitesmith
280 * c-basic-offset: 8
281 * End:
282 */
283