print-dvmrp.c revision 98524 
1/*
2 * Copyright (c) 1995, 1996
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
22#ifndef lint
23static const char rcsid[] =
24    "@(#) $Header: /tcpdump/master/tcpdump/print-dvmrp.c,v 1.21 2001/05/10 05:30:20 fenner Exp $ (LBL)";
25#endif
26
27#ifdef HAVE_CONFIG_H
28#include "config.h"
29#endif
30
31#include <sys/param.h>
32#include <sys/time.h>
33#include <sys/socket.h>
34
35#include <netinet/in.h>
36
37#include <stdio.h>
38#include <string.h>
39#include <stdlib.h>
40#include <unistd.h>
41
42#include "interface.h"
43#include "extract.h"
44#include "addrtoname.h"
45
46/*
47 * DVMRP message types and flag values shamelessly stolen from
48 * mrouted/dvmrp.h.
49 */
50#define DVMRP_PROBE		1	/* for finding neighbors */
51#define DVMRP_REPORT		2	/* for reporting some or all routes */
52#define DVMRP_ASK_NEIGHBORS	3	/* sent by mapper, asking for a list */
53					/* of this router's neighbors */
54#define DVMRP_NEIGHBORS		4	/* response to such a request */
55#define DVMRP_ASK_NEIGHBORS2	5	/* as above, want new format reply */
56#define DVMRP_NEIGHBORS2	6
57#define DVMRP_PRUNE		7	/* prune message */
58#define DVMRP_GRAFT		8	/* graft message */
59#define DVMRP_GRAFT_ACK		9	/* graft acknowledgement */
60
61/*
62 * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
63 */
64#define DVMRP_NF_TUNNEL		0x01	/* neighbors reached via tunnel */
65#define DVMRP_NF_SRCRT		0x02	/* tunnel uses IP source routing */
66#define DVMRP_NF_DOWN		0x10	/* kernel state of interface */
67#define DVMRP_NF_DISABLED	0x20	/* administratively disabled */
68#define DVMRP_NF_QUERIER	0x40	/* I am the subnet's querier */
69
70static void print_probe(const u_char *, const u_char *, u_int);
71static void print_report(const u_char *, const u_char *, u_int);
72static void print_neighbors(const u_char *, const u_char *, u_int);
73static void print_neighbors2(const u_char *, const u_char *, u_int);
74static void print_prune(const u_char *, const u_char *, u_int);
75static void print_graft(const u_char *, const u_char *, u_int);
76static void print_graft_ack(const u_char *, const u_char *, u_int);
77
78static u_int32_t target_level;
79
80void
81dvmrp_print(register const u_char *bp, register u_int len)
82{
83	register const u_char *ep;
84	register u_char type;
85
86	ep = (const u_char *)snapend;
87	if (bp >= ep)
88		return;
89
90	type = bp[1];
91
92	/* Skip IGMP header */
93	bp += 8;
94	len -= 8;
95
96	switch (type) {
97
98	case DVMRP_PROBE:
99		printf(" Probe");
100		if (vflag)
101			print_probe(bp, ep, len);
102		break;
103
104	case DVMRP_REPORT:
105		printf(" Report");
106		if (vflag > 1)
107			print_report(bp, ep, len);
108		break;
109
110	case DVMRP_ASK_NEIGHBORS:
111		printf(" Ask-neighbors(old)");
112		break;
113
114	case DVMRP_NEIGHBORS:
115		printf(" Neighbors(old)");
116		print_neighbors(bp, ep, len);
117		break;
118
119	case DVMRP_ASK_NEIGHBORS2:
120		printf(" Ask-neighbors2");
121		break;
122
123	case DVMRP_NEIGHBORS2:
124		printf(" Neighbors2");
125		/*
126		 * extract version and capabilities from IGMP group
127		 * address field
128		 */
129		bp -= 4;
130		target_level = (bp[0] << 24) | (bp[1] << 16) |
131		    (bp[2] << 8) | bp[3];
132		bp += 4;
133		print_neighbors2(bp, ep, len);
134		break;
135
136	case DVMRP_PRUNE:
137		printf(" Prune");
138		print_prune(bp, ep, len);
139		break;
140
141	case DVMRP_GRAFT:
142		printf(" Graft");
143		print_graft(bp, ep, len);
144		break;
145
146	case DVMRP_GRAFT_ACK:
147		printf(" Graft-ACK");
148		print_graft_ack(bp, ep, len);
149		break;
150
151	default:
152		printf(" [type %d]", type);
153		break;
154	}
155}
156
157static void
158print_report(register const u_char *bp, register const u_char *ep,
159    register u_int len)
160{
161	register u_int32_t mask, origin;
162	register int metric, i, width, done;
163
164	while (len > 0) {
165		if (len < 3) {
166			printf(" [|]");
167			return;
168		}
169		mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
170		width = 1;
171		if (bp[0])
172			width = 2;
173		if (bp[1])
174			width = 3;
175		if (bp[2])
176			width = 4;
177
178		printf("\n\tMask %s", intoa(htonl(mask)));
179		bp += 3;
180		len -= 3;
181		do {
182			if (bp + width + 1 > ep) {
183				printf(" [|]");
184				return;
185			}
186			if (len < width + 1) {
187				printf("\n\t  [Truncated Report]");
188				return;
189			}
190			origin = 0;
191			for (i = 0; i < width; ++i)
192				origin = origin << 8 | *bp++;
193			for ( ; i < 4; ++i)
194				origin <<= 8;
195
196			metric = *bp++;
197			done = metric & 0x80;
198			metric &= 0x7f;
199			printf("\n\t  %s metric %d", intoa(htonl(origin)),
200				metric);
201			len -= width + 1;
202		} while (!done);
203	}
204}
205
206static void
207print_probe(register const u_char *bp, register const u_char *ep,
208    register u_int len)
209{
210	register u_int32_t genid;
211
212	TCHECK2(bp[0], 4);
213	if ((len < 4) || ((bp + 4) > ep)) {
214		/* { (ctags) */
215		printf(" [|}");
216		return;
217	}
218	genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
219	bp += 4;
220	len -= 4;
221	if (vflag > 1)
222		printf("\n\t");
223	else
224		printf(" ");
225	printf("genid %u", genid);
226	if (vflag < 2)
227		return;
228
229	while ((len > 0) && (bp < ep)) {
230		TCHECK2(bp[0], 4);
231		printf("\n\tneighbor %s", ipaddr_string(bp));
232		bp += 4; len -= 4;
233	}
234	return;
235trunc:
236	(void)printf("[|dvmrp]");
237}
238
239static void
240print_neighbors(register const u_char *bp, register const u_char *ep,
241    register u_int len)
242{
243	const u_char *laddr;
244	register u_char metric;
245	register u_char thresh;
246	register int ncount;
247
248	while (len > 0 && bp < ep) {
249		TCHECK2(bp[0], 7);
250		laddr = bp;
251		bp += 4;
252		metric = *bp++;
253		thresh = *bp++;
254		ncount = *bp++;
255		len -= 7;
256		while (--ncount >= 0) {
257			TCHECK2(bp[0], 4);
258			printf(" [%s ->", ipaddr_string(laddr));
259			printf(" %s, (%d/%d)]",
260				   ipaddr_string(bp), metric, thresh);
261			bp += 4;
262			len -= 4;
263		}
264	}
265	return;
266trunc:
267	(void)printf("[|dvmrp]");
268}
269
270static void
271print_neighbors2(register const u_char *bp, register const u_char *ep,
272    register u_int len)
273{
274	const u_char *laddr;
275	register u_char metric, thresh, flags;
276	register int ncount;
277
278	printf(" (v %d.%d):",
279	       (int)target_level & 0xff,
280	       (int)(target_level >> 8) & 0xff);
281
282	while (len > 0 && bp < ep) {
283		TCHECK2(bp[0], 8);
284		laddr = bp;
285		bp += 4;
286		metric = *bp++;
287		thresh = *bp++;
288		flags = *bp++;
289		ncount = *bp++;
290		len -= 8;
291		while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
292			printf(" [%s -> ", ipaddr_string(laddr));
293			printf("%s (%d/%d", ipaddr_string(bp),
294				     metric, thresh);
295			if (flags & DVMRP_NF_TUNNEL)
296				printf("/tunnel");
297			if (flags & DVMRP_NF_SRCRT)
298				printf("/srcrt");
299			if (flags & DVMRP_NF_QUERIER)
300				printf("/querier");
301			if (flags & DVMRP_NF_DISABLED)
302				printf("/disabled");
303			if (flags & DVMRP_NF_DOWN)
304				printf("/down");
305			printf(")]");
306			bp += 4;
307			len -= 4;
308		}
309		if (ncount != -1) {
310			printf(" [|]");
311			return;
312		}
313	}
314	return;
315trunc:
316	(void)printf("[|dvmrp]");
317}
318
319static void
320print_prune(register const u_char *bp, register const u_char *ep,
321    register u_int len)
322{
323	TCHECK2(bp[0], 12);
324	printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
325	bp += 8;
326	(void)printf(" timer ");
327	relts_print(EXTRACT_32BITS(bp));
328	return;
329trunc:
330	(void)printf("[|dvmrp]");
331}
332
333static void
334print_graft(register const u_char *bp, register const u_char *ep,
335    register u_int len)
336{
337	TCHECK2(bp[0], 8);
338	printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
339	return;
340trunc:
341	(void)printf("[|dvmrp]");
342}
343
344static void
345print_graft_ack(register const u_char *bp, register const u_char *ep,
346    register u_int len)
347{
348	TCHECK2(bp[0], 8);
349	printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
350	return;
351trunc:
352	(void)printf("[|dvmrp]");
353}
354