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
28static 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
48static 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
73static 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
84static int cdp_print_addr(const u_char *, int);
85static int cdp_print_prefixes(const u_char *, int);
86static unsigned long cdp_get_number(const u_char *, int);
87
88void
89cdp_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;
234trunc:
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
249static int
250cdp_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
342trunc:
343	return -1;
344}
345
346
347static int
348cdp_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
363trunc:
364	return -1;
365}
366
367/* read in a <n>-byte number, MSB first
368 * (of course this can handle max sizeof(long))
369 */
370static 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