xref: /freebsd/contrib/tcpdump/print-cdp.c (revision bb15ca603fa442c72dde3f3cb8b46db6970e3950)
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
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 ");
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
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
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  */
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