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 #ifndef lint
28 static const char rcsid[] _U_ =
29 "@(#) $Header: /tcpdump/master/tcpdump/print-cdp.c,v 1.25 2004-10-07 14:53:11 hannes Exp $";
30 #endif
31
32 #ifdef HAVE_CONFIG_H
33 #include "config.h"
34 #endif
35
36 #include <tcpdump-stdinc.h>
37
38 #include <stdio.h>
39 #include <string.h>
40
41 #include "interface.h"
42 #include "addrtoname.h"
43 #include "extract.h" /* must come after interface.h */
44 #include "nlpid.h"
45
46 #define CDP_HEADER_LEN 4
47
48 static const struct tok cdp_tlv_values[] = {
49 { 0x01, "Device-ID"},
50 { 0x02, "Address"},
51 { 0x03, "Port-ID"},
52 { 0x04, "Capability"},
53 { 0x05, "Version String"},
54 { 0x06, "Platform"},
55 { 0x07, "Prefixes"},
56 { 0x08, "Protocol-Hello option"},
57 { 0x09, "VTP Management Domain"},
58 { 0x0a, "Native VLAN ID"},
59 { 0x0b, "Duplex"},
60 { 0x0e, "ATA-186 VoIP VLAN request"},
61 { 0x0f, "ATA-186 VoIP VLAN assignment"},
62 { 0x10, "power consumption"},
63 { 0x11, "MTU"},
64 { 0x12, "AVVID trust bitmap"},
65 { 0x13, "AVVID untrusted ports CoS"},
66 { 0x14, "System Name"},
67 { 0x15, "System Object ID (not decoded)"},
68 { 0x16, "Management Addresses"},
69 { 0x17, "Physical Location"},
70 { 0, NULL}
71 };
72
73 static const struct tok cdp_capability_values[] = {
74 { 0x01, "Router" },
75 { 0x02, "Transparent Bridge" },
76 { 0x04, "Source Route Bridge" },
77 { 0x08, "L2 Switch" },
78 { 0x10, "L3 capable" },
79 { 0x20, "IGMP snooping" },
80 { 0x40, "L1 capable" },
81 { 0, NULL }
82 };
83
84 static int cdp_print_addr(const u_char *, int);
85 static int cdp_print_prefixes(const u_char *, int);
86 static unsigned long cdp_get_number(const u_char *, int);
87
88 void
cdp_print(const u_char * pptr,u_int length,u_int caplen)89 cdp_print(const u_char *pptr, u_int length, u_int caplen)
90 {
91 int type, len, i, j;
92 const u_char *tptr;
93
94 if (caplen < CDP_HEADER_LEN) {
95 (void)printf("[|cdp]");
96 return;
97 }
98
99 tptr = pptr; /* temporary pointer */
100
101 if (!TTEST2(*tptr, CDP_HEADER_LEN))
102 goto trunc;
103 printf("CDPv%u, ttl: %us", *tptr, *(tptr+1));
104 if (vflag)
105 printf(", checksum: %u (unverified), length %u", EXTRACT_16BITS(tptr), length);
106 tptr += CDP_HEADER_LEN;
107
108 while (tptr < (pptr+length)) {
109
110 if (!TTEST2(*tptr, 4)) /* read out Type and Length */
111 goto trunc;
112 type = EXTRACT_16BITS(tptr);
113 len = EXTRACT_16BITS(tptr+2); /* object length includes the 4 bytes header length */
114 tptr += 4;
115 len -= 4;
116
117 if (!TTEST2(*tptr, len))
118 goto trunc;
119
120 if (vflag || type == 1) { /* in non-verbose mode just print Device-ID */
121
122 if (vflag)
123 printf("\n\t%s (0x%02x), length: %u byte%s: ",
124 tok2str(cdp_tlv_values,"unknown field type", type),
125 type,
126 len,
127 PLURAL_SUFFIX(len)); /* plural */
128
129 switch (type) {
130
131 case 0x01: /* Device-ID */
132 if (!vflag)
133 printf(", Device-ID ");
134 printf("'");
135 fn_printn(tptr, len, NULL);
136 printf("'");
137 break;
138 case 0x02: /* Address */
139 if (cdp_print_addr(tptr, len) < 0)
140 goto trunc;
141 break;
142 case 0x03: /* Port-ID */
143 printf("'");
144 fn_printn(tptr, len, NULL);
145 printf("'");
146 break;
147 case 0x04: /* Capabilities */
148 printf("(0x%08x): %s",
149 EXTRACT_32BITS(tptr),
150 bittok2str(cdp_capability_values, "none",EXTRACT_32BITS(tptr)));
151 break;
152 case 0x05: /* Version */
153 printf("\n\t ");
154 for (i=0;i<len;i++) {
155 j = *(tptr+i);
156 putchar(j);
157 if (j == 0x0a) /* lets rework the version string to get a nice identation */
158 printf("\t ");
159 }
160 break;
161 case 0x06: /* Platform */
162 printf("'");
163 fn_printn(tptr, len, NULL);
164 printf("'");
165 break;
166 case 0x07: /* Prefixes */
167 if (cdp_print_prefixes(tptr, len) < 0)
168 goto trunc;
169 break;
170 case 0x08: /* Protocol Hello Option - not documented */
171 break;
172 case 0x09: /* VTP Mgmt Domain - not documented */
173 printf("'");
174 fn_printn(tptr, len, NULL);
175 printf("'");
176 break;
177 case 0x0a: /* Native VLAN ID - not documented */
178 printf("%d",EXTRACT_16BITS(tptr));
179 break;
180 case 0x0b: /* Duplex - not documented */
181 printf("%s", *(tptr) ? "full": "half");
182 break;
183
184 /* http://www.cisco.com/univercd/cc/td/doc/product/voice/ata/atarn/186rn21m.htm
185 * plus more details from other sources
186 */
187 case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
188 printf("app %d, vlan %d",
189 *(tptr), EXTRACT_16BITS(tptr+1));
190 break;
191 case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
192 printf("%1.2fW",
193 cdp_get_number(tptr, len)/1000.0 );
194 break;
195 case 0x11: /* MTU - not documented */
196 printf("%u bytes", EXTRACT_32BITS(tptr));
197 break;
198 case 0x12: /* AVVID trust bitmap - not documented */
199 printf("0x%02x", *(tptr) );
200 break;
201 case 0x13: /* AVVID untrusted port CoS - not documented */
202 printf("0x%02x", *(tptr));
203 break;
204 case 0x14: /* System Name - not documented */
205 printf("'");
206 fn_printn(tptr, len, NULL);
207 printf("'");
208 break;
209 case 0x16: /* System Object ID - not documented */
210 if (cdp_print_addr(tptr, len) < 0)
211 goto trunc;
212 break;
213 case 0x17: /* Physical Location - not documented */
214 printf("0x%02x", *(tptr));
215 if (len > 1) {
216 printf("/");
217 fn_printn(tptr + 1, len - 1, NULL);
218 }
219 break;
220 default:
221 print_unknown_data(tptr,"\n\t ",len);
222 break;
223 }
224 }
225 /* avoid infinite loop */
226 if (len == 0)
227 break;
228 tptr = tptr+len;
229 }
230 if (vflag < 1)
231 printf(", length %u",caplen);
232
233 return;
234 trunc:
235 printf("[|cdp]");
236 }
237
238 /*
239 * Protocol type values.
240 *
241 * PT_NLPID means that the protocol type field contains an OSI NLPID.
242 *
243 * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2
244 * LLC header that specifies that the payload is for that protocol.
245 */
246 #define PT_NLPID 1 /* OSI NLPID */
247 #define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */
248
249 static int
cdp_print_addr(const u_char * p,int l)250 cdp_print_addr(const u_char * p, int l)
251 {
252 int pt, pl, al, num;
253 const u_char *endp = p + l;
254 #ifdef INET6
255 static u_char prot_ipv6[] = {
256 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
257 };
258 #endif
259
260 TCHECK2(*p, 2);
261 num = EXTRACT_32BITS(p);
262 p += 4;
263
264 while (p < endp && num >= 0) {
265 TCHECK2(*p, 2);
266 if (p + 2 > endp)
267 goto trunc;
268 pt = p[0]; /* type of "protocol" field */
269 pl = p[1]; /* length of "protocol" field */
270 p += 2;
271
272 TCHECK2(p[pl], 2);
273 if (p + pl + 2 > endp)
274 goto trunc;
275 al = EXTRACT_16BITS(&p[pl]); /* address length */
276
277 if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) {
278 /*
279 * IPv4: protocol type = NLPID, protocol length = 1
280 * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4),
281 * address length = 4
282 */
283 p += 3;
284
285 TCHECK2(*p, 4);
286 if (p + 4 > endp)
287 goto trunc;
288 printf("IPv4 (%u) %s",
289 num,
290 ipaddr_string(p));
291 p += 4;
292 }
293 #ifdef INET6
294 else if (pt == PT_IEEE_802_2 && pl == 8 &&
295 memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
296 /*
297 * IPv6: protocol type = IEEE 802.2 header,
298 * protocol length = 8 (size of LLC+SNAP header),
299 * protocol = LLC+SNAP header with the IPv6
300 * Ethertype, address length = 16
301 */
302 p += 10;
303 TCHECK2(*p, al);
304 if (p + al > endp)
305 goto trunc;
306
307 printf("IPv6 (%u) %s",
308 num,
309 ip6addr_string(p));
310 p += al;
311 }
312 #endif
313 else {
314 /*
315 * Generic case: just print raw data
316 */
317 TCHECK2(*p, pl);
318 if (p + pl > endp)
319 goto trunc;
320 printf("pt=0x%02x, pl=%d, pb=", *(p - 2), pl);
321 while (pl-- > 0)
322 printf(" %02x", *p++);
323 TCHECK2(*p, 2);
324 if (p + 2 > endp)
325 goto trunc;
326 al = (*p << 8) + *(p + 1);
327 printf(", al=%d, a=", al);
328 p += 2;
329 TCHECK2(*p, al);
330 if (p + al > endp)
331 goto trunc;
332 while (al-- > 0)
333 printf(" %02x", *p++);
334 }
335 num--;
336 if (num)
337 printf(" ");
338 }
339
340 return 0;
341
342 trunc:
343 return -1;
344 }
345
346
347 static int
cdp_print_prefixes(const u_char * p,int l)348 cdp_print_prefixes(const u_char * p, int l)
349 {
350 if (l % 5)
351 goto trunc;
352
353 printf(" IPv4 Prefixes (%d):", l / 5);
354
355 while (l > 0) {
356 printf(" %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]);
357 l -= 5;
358 p += 5;
359 }
360
361 return 0;
362
363 trunc:
364 return -1;
365 }
366
367 /* read in a <n>-byte number, MSB first
368 * (of course this can handle max sizeof(long))
369 */
cdp_get_number(const u_char * p,int l)370 static unsigned long cdp_get_number(const u_char * p, int l)
371 {
372 unsigned long res=0;
373 while( l>0 )
374 {
375 res = (res<<8) + *p;
376 p++; l--;
377 }
378 return res;
379 }
380