1 /*
2 * Copyright (c) 1998-2007 The TCPDUMP project
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that: (1) source code
6 * distributions retain the above copyright notice and this paragraph
7 * in its entirety, and (2) distributions including binary code include
8 * the above copyright notice and this paragraph in its entirety in
9 * the documentation or other materials provided with the distribution.
10 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
11 * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
12 * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
13 * FOR A PARTICULAR PURPOSE.
14 *
15 * Reference documentation:
16 * http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml
17 * http://www.cisco.com/warp/public/473/21.html
18 * http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
19 *
20 * Original code ode by Carles Kishimoto <carles.kishimoto@gmail.com>
21 */
22
23 /* \summary: Cisco VLAN Trunking Protocol (VTP) printer */
24
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28
29 #include <netdissect-stdinc.h>
30
31 #include "netdissect.h"
32 #include "addrtoname.h"
33 #include "extract.h"
34
35 #define VTP_HEADER_LEN 36
36 #define VTP_DOMAIN_NAME_LEN 32
37 #define VTP_MD5_DIGEST_LEN 16
38 #define VTP_UPDATE_TIMESTAMP_LEN 12
39 #define VTP_VLAN_INFO_OFFSET 12
40
41 #define VTP_SUMMARY_ADV 0x01
42 #define VTP_SUBSET_ADV 0x02
43 #define VTP_ADV_REQUEST 0x03
44 #define VTP_JOIN_MESSAGE 0x04
45
46 struct vtp_vlan_ {
47 uint8_t len;
48 uint8_t status;
49 uint8_t type;
50 uint8_t name_len;
51 uint16_t vlanid;
52 uint16_t mtu;
53 uint32_t index;
54 };
55
56 static const struct tok vtp_message_type_values[] = {
57 { VTP_SUMMARY_ADV, "Summary advertisement"},
58 { VTP_SUBSET_ADV, "Subset advertisement"},
59 { VTP_ADV_REQUEST, "Advertisement request"},
60 { VTP_JOIN_MESSAGE, "Join message"},
61 { 0, NULL }
62 };
63
64 static const struct tok vtp_header_values[] = {
65 { 0x01, "Followers"}, /* On Summary advertisement, 3rd byte is Followers */
66 { 0x02, "Seq number"}, /* On Subset advertisement, 3rd byte is Sequence number */
67 { 0x03, "Rsvd"}, /* On Adver. requests 3rd byte is Rsvd */
68 { 0x04, "Rsvd"}, /* On Adver. requests 3rd byte is Rsvd */
69 { 0, NULL }
70 };
71
72 static const struct tok vtp_vlan_type_values[] = {
73 { 0x01, "Ethernet"},
74 { 0x02, "FDDI"},
75 { 0x03, "TrCRF"},
76 { 0x04, "FDDI-net"},
77 { 0x05, "TrBRF"},
78 { 0, NULL }
79 };
80
81 static const struct tok vtp_vlan_status[] = {
82 { 0x00, "Operational"},
83 { 0x01, "Suspended"},
84 { 0, NULL }
85 };
86
87 #define VTP_VLAN_SOURCE_ROUTING_RING_NUMBER 0x01
88 #define VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER 0x02
89 #define VTP_VLAN_STP_TYPE 0x03
90 #define VTP_VLAN_PARENT_VLAN 0x04
91 #define VTP_VLAN_TRANS_BRIDGED_VLAN 0x05
92 #define VTP_VLAN_PRUNING 0x06
93 #define VTP_VLAN_BRIDGE_TYPE 0x07
94 #define VTP_VLAN_ARP_HOP_COUNT 0x08
95 #define VTP_VLAN_STE_HOP_COUNT 0x09
96 #define VTP_VLAN_BACKUP_CRF_MODE 0x0A
97
98 static const struct tok vtp_vlan_tlv_values[] = {
99 { VTP_VLAN_SOURCE_ROUTING_RING_NUMBER, "Source-Routing Ring Number TLV"},
100 { VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER, "Source-Routing Bridge Number TLV"},
101 { VTP_VLAN_STP_TYPE, "STP type TLV"},
102 { VTP_VLAN_PARENT_VLAN, "Parent VLAN TLV"},
103 { VTP_VLAN_TRANS_BRIDGED_VLAN, "Translationally bridged VLANs TLV"},
104 { VTP_VLAN_PRUNING, "Pruning TLV"},
105 { VTP_VLAN_BRIDGE_TYPE, "Bridge Type TLV"},
106 { VTP_VLAN_ARP_HOP_COUNT, "Max ARP Hop Count TLV"},
107 { VTP_VLAN_STE_HOP_COUNT, "Max STE Hop Count TLV"},
108 { VTP_VLAN_BACKUP_CRF_MODE, "Backup CRF Mode TLV"},
109 { 0, NULL }
110 };
111
112 static const struct tok vtp_stp_type_values[] = {
113 { 1, "SRT"},
114 { 2, "SRB"},
115 { 3, "Auto"},
116 { 0, NULL }
117 };
118
119 void
vtp_print(netdissect_options * ndo,const u_char * pptr,u_int length)120 vtp_print (netdissect_options *ndo,
121 const u_char *pptr, u_int length)
122 {
123 int type, len, tlv_len, tlv_value, mgmtd_len;
124 const u_char *tptr;
125 const struct vtp_vlan_ *vtp_vlan;
126
127 if (length < VTP_HEADER_LEN)
128 goto trunc;
129
130 tptr = pptr;
131
132 ND_TCHECK2(*tptr, VTP_HEADER_LEN);
133
134 type = *(tptr+1);
135 ND_PRINT((ndo, "VTPv%u, Message %s (0x%02x), length %u",
136 *tptr,
137 tok2str(vtp_message_type_values,"Unknown message type", type),
138 type,
139 length));
140
141 /* In non-verbose mode, just print version and message type */
142 if (ndo->ndo_vflag < 1) {
143 return;
144 }
145
146 /* verbose mode print all fields */
147 ND_PRINT((ndo, "\n\tDomain name: "));
148 mgmtd_len = *(tptr + 3);
149 if (mgmtd_len < 1 || mgmtd_len > 32) {
150 ND_PRINT((ndo, " [invalid MgmtD Len %d]", mgmtd_len));
151 return;
152 }
153 fn_printzp(ndo, tptr + 4, mgmtd_len, NULL);
154 ND_PRINT((ndo, ", %s: %u",
155 tok2str(vtp_header_values, "Unknown", type),
156 *(tptr+2)));
157
158 tptr += VTP_HEADER_LEN;
159
160 switch (type) {
161
162 case VTP_SUMMARY_ADV:
163
164 /*
165 * SUMMARY ADVERTISEMENT
166 *
167 * 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
168 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
169 * | Version | Code | Followers | MgmtD Len |
170 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
171 * | Management Domain Name (zero-padded to 32 bytes) |
172 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
173 * | Configuration revision number |
174 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
175 * | Updater Identity IP address |
176 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
177 * | Update Timestamp (12 bytes) |
178 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
179 * | MD5 digest (16 bytes) |
180 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
181 *
182 */
183
184 ND_TCHECK2(*tptr, 8);
185 ND_PRINT((ndo, "\n\t Config Rev %x, Updater %s",
186 EXTRACT_32BITS(tptr),
187 ipaddr_string(ndo, tptr+4)));
188 tptr += 8;
189 ND_TCHECK2(*tptr, VTP_UPDATE_TIMESTAMP_LEN);
190 ND_PRINT((ndo, ", Timestamp 0x%08x 0x%08x 0x%08x",
191 EXTRACT_32BITS(tptr),
192 EXTRACT_32BITS(tptr + 4),
193 EXTRACT_32BITS(tptr + 8)));
194 tptr += VTP_UPDATE_TIMESTAMP_LEN;
195 ND_TCHECK2(*tptr, VTP_MD5_DIGEST_LEN);
196 ND_PRINT((ndo, ", MD5 digest: %08x%08x%08x%08x",
197 EXTRACT_32BITS(tptr),
198 EXTRACT_32BITS(tptr + 4),
199 EXTRACT_32BITS(tptr + 8),
200 EXTRACT_32BITS(tptr + 12)));
201 tptr += VTP_MD5_DIGEST_LEN;
202 break;
203
204 case VTP_SUBSET_ADV:
205
206 /*
207 * SUBSET ADVERTISEMENT
208 *
209 * 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
210 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
211 * | Version | Code | Seq number | MgmtD Len |
212 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
213 * | Management Domain Name (zero-padded to 32 bytes) |
214 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
215 * | Configuration revision number |
216 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
217 * | VLAN info field 1 |
218 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
219 * | ................ |
220 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
221 * | VLAN info field N |
222 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
223 *
224 */
225
226 ND_PRINT((ndo, ", Config Rev %x", EXTRACT_32BITS(tptr)));
227
228 /*
229 * VLAN INFORMATION
230 * 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
231 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
232 * | V info len | Status | VLAN type | VLAN name len |
233 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
234 * | ISL vlan id | MTU size |
235 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
236 * | 802.10 index (SAID) |
237 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
238 * | VLAN name |
239 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
240 *
241 */
242
243 tptr += 4;
244 while (tptr < (pptr+length)) {
245
246 len = *tptr;
247 if (len == 0)
248 break;
249
250 ND_TCHECK2(*tptr, len);
251
252 vtp_vlan = (const struct vtp_vlan_*)tptr;
253 ND_TCHECK(*vtp_vlan);
254 ND_PRINT((ndo, "\n\tVLAN info status %s, type %s, VLAN-id %u, MTU %u, SAID 0x%08x, Name ",
255 tok2str(vtp_vlan_status,"Unknown",vtp_vlan->status),
256 tok2str(vtp_vlan_type_values,"Unknown",vtp_vlan->type),
257 EXTRACT_16BITS(&vtp_vlan->vlanid),
258 EXTRACT_16BITS(&vtp_vlan->mtu),
259 EXTRACT_32BITS(&vtp_vlan->index)));
260 fn_printzp(ndo, tptr + VTP_VLAN_INFO_OFFSET, vtp_vlan->name_len, NULL);
261
262 /*
263 * Vlan names are aligned to 32-bit boundaries.
264 */
265 len -= VTP_VLAN_INFO_OFFSET + 4*((vtp_vlan->name_len + 3)/4);
266 tptr += VTP_VLAN_INFO_OFFSET + 4*((vtp_vlan->name_len + 3)/4);
267
268 /* TLV information follows */
269
270 while (len > 0) {
271
272 /*
273 * Cisco specs says 2 bytes for type + 2 bytes for length, take only 1
274 * See: http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
275 */
276 type = *tptr;
277 tlv_len = *(tptr+1);
278
279 ND_PRINT((ndo, "\n\t\t%s (0x%04x) TLV",
280 tok2str(vtp_vlan_tlv_values, "Unknown", type),
281 type));
282
283 /*
284 * infinite loop check
285 */
286 if (type == 0 || tlv_len == 0) {
287 return;
288 }
289
290 ND_TCHECK2(*tptr, tlv_len * 2 +2);
291
292 tlv_value = EXTRACT_16BITS(tptr+2);
293
294 switch (type) {
295 case VTP_VLAN_STE_HOP_COUNT:
296 ND_PRINT((ndo, ", %u", tlv_value));
297 break;
298
299 case VTP_VLAN_PRUNING:
300 ND_PRINT((ndo, ", %s (%u)",
301 tlv_value == 1 ? "Enabled" : "Disabled",
302 tlv_value));
303 break;
304
305 case VTP_VLAN_STP_TYPE:
306 ND_PRINT((ndo, ", %s (%u)",
307 tok2str(vtp_stp_type_values, "Unknown", tlv_value),
308 tlv_value));
309 break;
310
311 case VTP_VLAN_BRIDGE_TYPE:
312 ND_PRINT((ndo, ", %s (%u)",
313 tlv_value == 1 ? "SRB" : "SRT",
314 tlv_value));
315 break;
316
317 case VTP_VLAN_BACKUP_CRF_MODE:
318 ND_PRINT((ndo, ", %s (%u)",
319 tlv_value == 1 ? "Backup" : "Not backup",
320 tlv_value));
321 break;
322
323 /*
324 * FIXME those are the defined TLVs that lack a decoder
325 * you are welcome to contribute code ;-)
326 */
327
328 case VTP_VLAN_SOURCE_ROUTING_RING_NUMBER:
329 case VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER:
330 case VTP_VLAN_PARENT_VLAN:
331 case VTP_VLAN_TRANS_BRIDGED_VLAN:
332 case VTP_VLAN_ARP_HOP_COUNT:
333 default:
334 print_unknown_data(ndo, tptr, "\n\t\t ", 2 + tlv_len*2);
335 break;
336 }
337 len -= 2 + tlv_len*2;
338 tptr += 2 + tlv_len*2;
339 }
340 }
341 break;
342
343 case VTP_ADV_REQUEST:
344
345 /*
346 * ADVERTISEMENT REQUEST
347 *
348 * 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
349 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
350 * | Version | Code | Reserved | MgmtD Len |
351 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
352 * | Management Domain Name (zero-padded to 32 bytes) |
353 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
354 * | Start value |
355 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
356 *
357 */
358
359 ND_TCHECK2(*tptr, 4);
360 ND_PRINT((ndo, "\n\tStart value: %u", EXTRACT_32BITS(tptr)));
361 break;
362
363 case VTP_JOIN_MESSAGE:
364
365 /* FIXME - Could not find message format */
366 break;
367
368 default:
369 break;
370 }
371
372 return;
373
374 trunc:
375 ND_PRINT((ndo, "[|vtp]"));
376 }
377
378 /*
379 * Local Variables:
380 * c-style: whitesmith
381 * c-basic-offset: 4
382 * End:
383 */
384