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