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 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 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                               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;
221trunc:
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
236static int
237cdp_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
329trunc:
330	return -1;
331}
332
333
334static int
335cdp_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
350trunc:
351	return -1;
352}
353
354/* read in a <n>-byte number, MSB first
355 * (of course this can handle max sizeof(long))
356 */
357static 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