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 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 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 len>1 ? "s" : ""); /* plural */
128
129 switch (type) {
130
131 case 0x01: /* Device-ID */
132 if (!vflag)
133 printf(", Device-ID '%.*s'", len, tptr);
134 else
135 printf("'%.*s'", len, tptr);
136 break;
137 case 0x02: /* Address */
138 if (cdp_print_addr(tptr, len) < 0)
139 goto trunc;
140 break;
141 case 0x03: /* Port-ID */
142 printf("'%.*s'", len, tptr);
143 break;
144 case 0x04: /* Capabilities */
145 printf("(0x%08x): %s",
146 EXTRACT_32BITS(tptr),
147 bittok2str(cdp_capability_values, "none",EXTRACT_32BITS(tptr)));
148 break;
149 case 0x05: /* Version */
150 printf("\n\t ");
151 for (i=0;i<len;i++) {
152 j = *(tptr+i);
153 putchar(j);
154 if (j == 0x0a) /* lets rework the version string to get a nice identation */
155 printf("\t ");
156 }
157 break;
158 case 0x06: /* Platform */
159 printf("'%.*s'", len, tptr);
160 break;
161 case 0x07: /* Prefixes */
162 if (cdp_print_prefixes(tptr, len) < 0)
163 goto trunc;
164 break;
165 case 0x08: /* Protocol Hello Option - not documented */
166 break;
167 case 0x09: /* VTP Mgmt Domain - not documented */
168 printf("'%.*s'", len,tptr);
169 break;
170 case 0x0a: /* Native VLAN ID - not documented */
171 printf("%d",EXTRACT_16BITS(tptr));
172 break;
173 case 0x0b: /* Duplex - not documented */
174 printf("%s", *(tptr) ? "full": "half");
175 break;
176
177 /* http://www.cisco.com/univercd/cc/td/doc/product/voice/ata/atarn/186rn21m.htm
178 * plus more details from other sources
179 */
180 case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
181 printf("app %d, vlan %d",
182 *(tptr), EXTRACT_16BITS(tptr+1));
183 break;
184 case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
185 printf("%1.2fW",
186 cdp_get_number(tptr, len)/1000.0 );
187 break;
188 case 0x11: /* MTU - not documented */
189 printf("%u bytes", EXTRACT_32BITS(tptr));
190 break;
191 case 0x12: /* AVVID trust bitmap - not documented */
192 printf("0x%02x", *(tptr) );
193 break;
194 case 0x13: /* AVVID untrusted port CoS - not documented */
195 printf("0x%02x", *(tptr));
196 break;
197 case 0x14: /* System Name - not documented */
198 printf("'%.*s'", len, tptr);
199 break;
200 case 0x16: /* System Object ID - not documented */
201 if (cdp_print_addr(tptr, len) < 0)
202 goto trunc;
203 break;
204 case 0x17: /* Physical Location - not documented */
205 printf("0x%02x/%.*s", *(tptr), len - 1, tptr + 1 );
206 break;
207 default:
208 print_unknown_data(tptr,"\n\t ",len);
209 break;
210 }
211 }
212 /* avoid infinite loop */
213 if (len == 0)
214 break;
215 tptr = tptr+len;
216 }
217 if (vflag < 1)
218 printf(", length %u",caplen);
219
220 return;
221 trunc:
222 printf("[|cdp]");
223 }
224
225 /*
226 * Protocol type values.
227 *
228 * PT_NLPID means that the protocol type field contains an OSI NLPID.
229 *
230 * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2
231 * LLC header that specifies that the payload is for that protocol.
232 */
233 #define PT_NLPID 1 /* OSI NLPID */
234 #define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */
235
236 static int
cdp_print_addr(const u_char * p,int l)237 cdp_print_addr(const u_char * p, int l)
238 {
239 int pt, pl, al, num;
240 const u_char *endp = p + l;
241 #ifdef INET6
242 static u_char prot_ipv6[] = {
243 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
244 };
245 #endif
246
247 TCHECK2(*p, 2);
248 num = EXTRACT_32BITS(p);
249 p += 4;
250
251 while (p < endp && num >= 0) {
252 TCHECK2(*p, 2);
253 if (p + 2 > endp)
254 goto trunc;
255 pt = p[0]; /* type of "protocol" field */
256 pl = p[1]; /* length of "protocol" field */
257 p += 2;
258
259 TCHECK2(p[pl], 2);
260 if (p + pl + 2 > endp)
261 goto trunc;
262 al = EXTRACT_16BITS(&p[pl]); /* address length */
263
264 if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) {
265 /*
266 * IPv4: protocol type = NLPID, protocol length = 1
267 * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4),
268 * address length = 4
269 */
270 p += 3;
271
272 TCHECK2(*p, 4);
273 if (p + 4 > endp)
274 goto trunc;
275 printf("IPv4 (%u) %s",
276 num,
277 ipaddr_string(p));
278 p += 4;
279 }
280 #ifdef INET6
281 else if (pt == PT_IEEE_802_2 && pl == 8 &&
282 memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
283 /*
284 * IPv6: protocol type = IEEE 802.2 header,
285 * protocol length = 8 (size of LLC+SNAP header),
286 * protocol = LLC+SNAP header with the IPv6
287 * Ethertype, address length = 16
288 */
289 p += 10;
290 TCHECK2(*p, al);
291 if (p + al > endp)
292 goto trunc;
293
294 printf("IPv6 (%u) %s",
295 num,
296 ip6addr_string(p));
297 p += al;
298 }
299 #endif
300 else {
301 /*
302 * Generic case: just print raw data
303 */
304 TCHECK2(*p, pl);
305 if (p + pl > endp)
306 goto trunc;
307 printf("pt=0x%02x, pl=%d, pb=", *(p - 2), pl);
308 while (pl-- > 0)
309 printf(" %02x", *p++);
310 TCHECK2(*p, 2);
311 if (p + 2 > endp)
312 goto trunc;
313 al = (*p << 8) + *(p + 1);
314 printf(", al=%d, a=", al);
315 p += 2;
316 TCHECK2(*p, al);
317 if (p + al > endp)
318 goto trunc;
319 while (al-- > 0)
320 printf(" %02x", *p++);
321 }
322 num--;
323 if (num)
324 printf(" ");
325 }
326
327 return 0;
328
329 trunc:
330 return -1;
331 }
332
333
334 static int
cdp_print_prefixes(const u_char * p,int l)335 cdp_print_prefixes(const u_char * p, int l)
336 {
337 if (l % 5)
338 goto trunc;
339
340 printf(" IPv4 Prefixes (%d):", l / 5);
341
342 while (l > 0) {
343 printf(" %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]);
344 l -= 5;
345 p += 5;
346 }
347
348 return 0;
349
350 trunc:
351 return -1;
352 }
353
354 /* read in a <n>-byte number, MSB first
355 * (of course this can handle max sizeof(long))
356 */
cdp_get_number(const u_char * p,int l)357 static unsigned long cdp_get_number(const u_char * p, int l)
358 {
359 unsigned long res=0;
360 while( l>0 )
361 {
362 res = (res<<8) + *p;
363 p++; l--;
364 }
365 return res;
366 }
367