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[tcpdump] / print-cdp.c
1 /*
2 * Copyright (c) 1992, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 *
21 * Code by Gert Doering, SpaceNet GmbH, gert@space.net
22 *
23 * Reference documentation:
24 * http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
25 */
26
27 #define NETDISSECT_REWORKED
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include <tcpdump-stdinc.h>
33
34 #include <string.h>
35
36 #include "interface.h"
37 #include "addrtoname.h"
38 #include "extract.h" /* must come after interface.h */
39 #include "nlpid.h"
40
41 static const char tstr[] = "[|cdp]";
42
43 #define CDP_HEADER_LEN 4
44 #define CDP_HEADER_OFFSET 2
45
46 static const struct tok cdp_tlv_values[] = {
47 { 0x01, "Device-ID"},
48 { 0x02, "Address"},
49 { 0x03, "Port-ID"},
50 { 0x04, "Capability"},
51 { 0x05, "Version String"},
52 { 0x06, "Platform"},
53 { 0x07, "Prefixes"},
54 { 0x08, "Protocol-Hello option"},
55 { 0x09, "VTP Management Domain"},
56 { 0x0a, "Native VLAN ID"},
57 { 0x0b, "Duplex"},
58 { 0x0e, "ATA-186 VoIP VLAN request"},
59 { 0x0f, "ATA-186 VoIP VLAN assignment"},
60 { 0x10, "power consumption"},
61 { 0x11, "MTU"},
62 { 0x12, "AVVID trust bitmap"},
63 { 0x13, "AVVID untrusted ports CoS"},
64 { 0x14, "System Name"},
65 { 0x15, "System Object ID (not decoded)"},
66 { 0x16, "Management Addresses"},
67 { 0x17, "Physical Location"},
68 { 0, NULL}
69 };
70
71 static const struct tok cdp_capability_values[] = {
72 { 0x01, "Router" },
73 { 0x02, "Transparent Bridge" },
74 { 0x04, "Source Route Bridge" },
75 { 0x08, "L2 Switch" },
76 { 0x10, "L3 capable" },
77 { 0x20, "IGMP snooping" },
78 { 0x40, "L1 capable" },
79 { 0, NULL }
80 };
81
82 static int cdp_print_addr(netdissect_options *, const u_char *, int);
83 static int cdp_print_prefixes(netdissect_options *, const u_char *, int);
84 static unsigned long cdp_get_number(const u_char *, int);
85
86 void
87 cdp_print(netdissect_options *ndo,
88 const u_char *pptr, u_int length, u_int caplen)
89 {
90 int type, len, i, j;
91 const u_char *tptr;
92
93 if (caplen < CDP_HEADER_LEN) {
94 ND_PRINT((ndo, "%s", tstr));
95 return;
96 }
97
98 tptr = pptr; /* temporary pointer */
99
100 ND_TCHECK2(*tptr, CDP_HEADER_LEN);
101 ND_PRINT((ndo, "CDPv%u, ttl: %us", *tptr, *(tptr + 1)));
102 if (ndo->ndo_vflag)
103 ND_PRINT((ndo, ", checksum: 0x%04x (unverified), length %u", EXTRACT_16BITS(tptr+CDP_HEADER_OFFSET), length));
104 tptr += CDP_HEADER_LEN;
105
106 while (tptr < (pptr+length)) {
107 ND_TCHECK2(*tptr, CDP_HEADER_LEN); /* read out Type and Length */
108 type = EXTRACT_16BITS(tptr);
109 len = EXTRACT_16BITS(tptr+CDP_HEADER_OFFSET); /* object length includes the 4 bytes header length */
110 if (len < CDP_HEADER_LEN) {
111 if (ndo->ndo_vflag)
112 ND_PRINT((ndo, "\n\t%s (0x%02x), TLV length: %u byte%s (too short)",
113 tok2str(cdp_tlv_values,"unknown field type", type),
114 type,
115 len,
116 PLURAL_SUFFIX(len))); /* plural */
117 else
118 ND_PRINT((ndo, ", %s TLV length %u too short",
119 tok2str(cdp_tlv_values,"unknown field type", type),
120 len));
121 break;
122 }
123 tptr += CDP_HEADER_LEN;
124 len -= CDP_HEADER_LEN;
125
126 ND_TCHECK2(*tptr, len);
127
128 if (ndo->ndo_vflag || type == 1) { /* in non-verbose mode just print Device-ID */
129
130 if (ndo->ndo_vflag)
131 ND_PRINT((ndo, "\n\t%s (0x%02x), value length: %u byte%s: ",
132 tok2str(cdp_tlv_values,"unknown field type", type),
133 type,
134 len,
135 PLURAL_SUFFIX(len))); /* plural */
136
137 switch (type) {
138
139 case 0x01: /* Device-ID */
140 if (!ndo->ndo_vflag)
141 ND_PRINT((ndo, ", Device-ID "));
142 ND_PRINT((ndo, "'"));
143 fn_printn(ndo, tptr, len, NULL);
144 ND_PRINT((ndo, "'"));
145 break;
146 case 0x02: /* Address */
147 if (cdp_print_addr(ndo, tptr, len) < 0)
148 goto trunc;
149 break;
150 case 0x03: /* Port-ID */
151 ND_PRINT((ndo, "'"));
152 fn_printn(ndo, tptr, len, NULL);
153 ND_PRINT((ndo, "'"));
154 break;
155 case 0x04: /* Capabilities */
156 if (len < 4)
157 goto trunc;
158 ND_PRINT((ndo, "(0x%08x): %s",
159 EXTRACT_32BITS(tptr),
160 bittok2str(cdp_capability_values, "none", EXTRACT_32BITS(tptr))));
161 break;
162 case 0x05: /* Version */
163 ND_PRINT((ndo, "\n\t "));
164 for (i=0;i<len;i++) {
165 j = *(tptr+i);
166 ND_PRINT((ndo, "%c", j));
167 if (j == 0x0a) /* lets rework the version string to get a nice identation */
168 ND_PRINT((ndo, "\t "));
169 }
170 break;
171 case 0x06: /* Platform */
172 ND_PRINT((ndo, "'"));
173 fn_printn(ndo, tptr, len, NULL);
174 ND_PRINT((ndo, "'"));
175 break;
176 case 0x07: /* Prefixes */
177 if (cdp_print_prefixes(ndo, tptr, len) < 0)
178 goto trunc;
179 break;
180 case 0x08: /* Protocol Hello Option - not documented */
181 break;
182 case 0x09: /* VTP Mgmt Domain - CDPv2 */
183 ND_PRINT((ndo, "'"));
184 fn_printn(ndo, tptr, len, NULL);
185 ND_PRINT((ndo, "'"));
186 break;
187 case 0x0a: /* Native VLAN ID - CDPv2 */
188 if (len < 2)
189 goto trunc;
190 ND_PRINT((ndo, "%d", EXTRACT_16BITS(tptr)));
191 break;
192 case 0x0b: /* Duplex - CDPv2 */
193 if (len < 1)
194 goto trunc;
195 ND_PRINT((ndo, "%s", *(tptr) ? "full": "half"));
196 break;
197
198 /* http://www.cisco.com/univercd/cc/td/doc/product/voice/ata/atarn/186rn21m.htm
199 * plus more details from other sources
200 */
201 case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
202 if (len < 3)
203 goto trunc;
204 ND_PRINT((ndo, "app %d, vlan %d", *(tptr), EXTRACT_16BITS(tptr + 1)));
205 break;
206 case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
207 ND_PRINT((ndo, "%1.2fW", cdp_get_number(tptr, len) / 1000.0));
208 break;
209 case 0x11: /* MTU - not documented */
210 if (len < 4)
211 goto trunc;
212 ND_PRINT((ndo, "%u bytes", EXTRACT_32BITS(tptr)));
213 break;
214 case 0x12: /* AVVID trust bitmap - not documented */
215 if (len < 1)
216 goto trunc;
217 ND_PRINT((ndo, "0x%02x", *(tptr)));
218 break;
219 case 0x13: /* AVVID untrusted port CoS - not documented */
220 if (len < 1)
221 goto trunc;
222 ND_PRINT((ndo, "0x%02x", *(tptr)));
223 break;
224 case 0x14: /* System Name - not documented */
225 ND_PRINT((ndo, "'"));
226 fn_printn(ndo, tptr, len, NULL);
227 ND_PRINT((ndo, "'"));
228 break;
229 case 0x16: /* System Object ID - not documented */
230 if (cdp_print_addr(ndo, tptr, len) < 0)
231 goto trunc;
232 break;
233 case 0x17: /* Physical Location - not documented */
234 if (len < 1)
235 goto trunc;
236 ND_PRINT((ndo, "0x%02x", *(tptr)));
237 if (len > 1) {
238 ND_PRINT((ndo, "/"));
239 fn_printn(ndo, tptr + 1, len - 1, NULL);
240 }
241 break;
242 default:
243 print_unknown_data(ndo, tptr, "\n\t ", len);
244 break;
245 }
246 }
247 tptr = tptr+len;
248 }
249 if (ndo->ndo_vflag < 1)
250 ND_PRINT((ndo, ", length %u", caplen));
251
252 return;
253 trunc:
254 ND_PRINT((ndo, "%s", tstr));
255 }
256
257 /*
258 * Protocol type values.
259 *
260 * PT_NLPID means that the protocol type field contains an OSI NLPID.
261 *
262 * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2
263 * LLC header that specifies that the payload is for that protocol.
264 */
265 #define PT_NLPID 1 /* OSI NLPID */
266 #define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */
267
268 static int
269 cdp_print_addr(netdissect_options *ndo,
270 const u_char * p, int l)
271 {
272 int pt, pl, al, num;
273 const u_char *endp = p + l;
274 #ifdef INET6
275 static const u_char prot_ipv6[] = {
276 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
277 };
278 #endif
279
280 ND_TCHECK2(*p, 4);
281 if (p + 4 > endp)
282 goto trunc;
283 num = EXTRACT_32BITS(p);
284 p += 4;
285
286 while (p < endp && num >= 0) {
287 ND_TCHECK2(*p, 2);
288 if (p + 2 > endp)
289 goto trunc;
290 pt = p[0]; /* type of "protocol" field */
291 pl = p[1]; /* length of "protocol" field */
292 p += 2;
293
294 ND_TCHECK2(p[pl], 2);
295 if (p + pl + 2 > endp)
296 goto trunc;
297 al = EXTRACT_16BITS(&p[pl]); /* address length */
298
299 if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) {
300 /*
301 * IPv4: protocol type = NLPID, protocol length = 1
302 * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4),
303 * address length = 4
304 */
305 p += 3;
306
307 ND_TCHECK2(*p, 4);
308 if (p + 4 > endp)
309 goto trunc;
310 ND_PRINT((ndo, "IPv4 (%u) %s", num, ipaddr_string(ndo, p)));
311 p += 4;
312 }
313 #ifdef INET6
314 else if (pt == PT_IEEE_802_2 && pl == 8 &&
315 memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
316 /*
317 * IPv6: protocol type = IEEE 802.2 header,
318 * protocol length = 8 (size of LLC+SNAP header),
319 * protocol = LLC+SNAP header with the IPv6
320 * Ethertype, address length = 16
321 */
322 p += 10;
323 ND_TCHECK2(*p, al);
324 if (p + al > endp)
325 goto trunc;
326
327 ND_PRINT((ndo, "IPv6 (%u) %s", num, ip6addr_string(ndo, p)));
328 p += al;
329 }
330 #endif
331 else {
332 /*
333 * Generic case: just print raw data
334 */
335 ND_TCHECK2(*p, pl);
336 if (p + pl > endp)
337 goto trunc;
338 ND_PRINT((ndo, "pt=0x%02x, pl=%d, pb=", *(p - 2), pl));
339 while (pl-- > 0)
340 ND_PRINT((ndo, " %02x", *p++));
341 ND_TCHECK2(*p, 2);
342 if (p + 2 > endp)
343 goto trunc;
344 al = (*p << 8) + *(p + 1);
345 ND_PRINT((ndo, ", al=%d, a=", al));
346 p += 2;
347 ND_TCHECK2(*p, al);
348 if (p + al > endp)
349 goto trunc;
350 while (al-- > 0)
351 ND_PRINT((ndo, " %02x", *p++));
352 }
353 num--;
354 if (num)
355 ND_PRINT((ndo, " "));
356 }
357
358 return 0;
359
360 trunc:
361 return -1;
362 }
363
364
365 static int
366 cdp_print_prefixes(netdissect_options *ndo,
367 const u_char * p, int l)
368 {
369 if (l % 5)
370 goto trunc;
371
372 ND_PRINT((ndo, " IPv4 Prefixes (%d):", l / 5));
373
374 while (l > 0) {
375 ND_PRINT((ndo, " %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]));
376 l -= 5;
377 p += 5;
378 }
379
380 return 0;
381
382 trunc:
383 return -1;
384 }
385
386 /* read in a <n>-byte number, MSB first
387 * (of course this can handle max sizeof(long))
388 */
389 static unsigned long cdp_get_number(const u_char * p, int l)
390 {
391 unsigned long res=0;
392 while( l>0 )
393 {
394 res = (res<<8) + *p;
395 p++; l--;
396 }
397 return res;
398 }
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