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/* \summary: Distance Vector Multicast Routing Protocol printer */
23
24#ifdef HAVE_CONFIG_H
25#include "config.h"
26#endif
27
28#include <netdissect-stdinc.h>
29
30#include "netdissect.h"
31#include "extract.h"
32#include "addrtoname.h"
33
34/*
35 * DVMRP message types and flag values shamelessly stolen from
36 * mrouted/dvmrp.h.
37 */
38#define DVMRP_PROBE		1	/* for finding neighbors */
39#define DVMRP_REPORT		2	/* for reporting some or all routes */
40#define DVMRP_ASK_NEIGHBORS	3	/* sent by mapper, asking for a list */
41					/* of this router's neighbors */
42#define DVMRP_NEIGHBORS		4	/* response to such a request */
43#define DVMRP_ASK_NEIGHBORS2	5	/* as above, want new format reply */
44#define DVMRP_NEIGHBORS2	6
45#define DVMRP_PRUNE		7	/* prune message */
46#define DVMRP_GRAFT		8	/* graft message */
47#define DVMRP_GRAFT_ACK		9	/* graft acknowledgement */
48
49/*
50 * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
51 */
52#define DVMRP_NF_TUNNEL		0x01	/* neighbors reached via tunnel */
53#define DVMRP_NF_SRCRT		0x02	/* tunnel uses IP source routing */
54#define DVMRP_NF_DOWN		0x10	/* kernel state of interface */
55#define DVMRP_NF_DISABLED	0x20	/* administratively disabled */
56#define DVMRP_NF_QUERIER	0x40	/* I am the subnet's querier */
57
58static int print_probe(netdissect_options *, const u_char *, const u_char *, u_int);
59static int print_report(netdissect_options *, const u_char *, const u_char *, u_int);
60static int print_neighbors(netdissect_options *, const u_char *, const u_char *, u_int);
61static int print_neighbors2(netdissect_options *, const u_char *, const u_char *, u_int);
62static int print_prune(netdissect_options *, const u_char *);
63static int print_graft(netdissect_options *, const u_char *);
64static int print_graft_ack(netdissect_options *, const u_char *);
65
66static uint32_t target_level;
67
68void
69dvmrp_print(netdissect_options *ndo,
70            register const u_char *bp, register u_int len)
71{
72	register const u_char *ep;
73	register u_char type;
74
75	ep = (const u_char *)ndo->ndo_snapend;
76	if (bp >= ep)
77		return;
78
79	ND_TCHECK(bp[1]);
80	type = bp[1];
81
82	/* Skip IGMP header */
83	bp += 8;
84	len -= 8;
85
86	switch (type) {
87
88	case DVMRP_PROBE:
89		ND_PRINT((ndo, " Probe"));
90		if (ndo->ndo_vflag) {
91			if (print_probe(ndo, bp, ep, len) < 0)
92				goto trunc;
93		}
94		break;
95
96	case DVMRP_REPORT:
97		ND_PRINT((ndo, " Report"));
98		if (ndo->ndo_vflag > 1) {
99			if (print_report(ndo, bp, ep, len) < 0)
100				goto trunc;
101		}
102		break;
103
104	case DVMRP_ASK_NEIGHBORS:
105		ND_PRINT((ndo, " Ask-neighbors(old)"));
106		break;
107
108	case DVMRP_NEIGHBORS:
109		ND_PRINT((ndo, " Neighbors(old)"));
110		if (print_neighbors(ndo, bp, ep, len) < 0)
111			goto trunc;
112		break;
113
114	case DVMRP_ASK_NEIGHBORS2:
115		ND_PRINT((ndo, " Ask-neighbors2"));
116		break;
117
118	case DVMRP_NEIGHBORS2:
119		ND_PRINT((ndo, " Neighbors2"));
120		/*
121		 * extract version and capabilities from IGMP group
122		 * address field
123		 */
124		bp -= 4;
125		ND_TCHECK2(bp[0], 4);
126		target_level = (bp[0] << 24) | (bp[1] << 16) |
127		    (bp[2] << 8) | bp[3];
128		bp += 4;
129		if (print_neighbors2(ndo, bp, ep, len) < 0)
130			goto trunc;
131		break;
132
133	case DVMRP_PRUNE:
134		ND_PRINT((ndo, " Prune"));
135		if (print_prune(ndo, bp) < 0)
136			goto trunc;
137		break;
138
139	case DVMRP_GRAFT:
140		ND_PRINT((ndo, " Graft"));
141		if (print_graft(ndo, bp) < 0)
142			goto trunc;
143		break;
144
145	case DVMRP_GRAFT_ACK:
146		ND_PRINT((ndo, " Graft-ACK"));
147		if (print_graft_ack(ndo, bp) < 0)
148			goto trunc;
149		break;
150
151	default:
152		ND_PRINT((ndo, " [type %d]", type));
153		break;
154	}
155	return;
156
157trunc:
158	ND_PRINT((ndo, "[|dvmrp]"));
159	return;
160}
161
162static int
163print_report(netdissect_options *ndo,
164             register const u_char *bp, register const u_char *ep,
165             register u_int len)
166{
167	register uint32_t mask, origin;
168	register int metric, done;
169	register u_int i, width;
170
171	while (len > 0) {
172		if (len < 3) {
173			ND_PRINT((ndo, " [|]"));
174			return (0);
175		}
176		ND_TCHECK2(bp[0], 3);
177		mask = (uint32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
178		width = 1;
179		if (bp[0])
180			width = 2;
181		if (bp[1])
182			width = 3;
183		if (bp[2])
184			width = 4;
185
186		ND_PRINT((ndo, "\n\tMask %s", intoa(htonl(mask))));
187		bp += 3;
188		len -= 3;
189		do {
190			if (bp + width + 1 > ep) {
191				ND_PRINT((ndo, " [|]"));
192				return (0);
193			}
194			if (len < width + 1) {
195				ND_PRINT((ndo, "\n\t  [Truncated Report]"));
196				return (0);
197			}
198			origin = 0;
199			for (i = 0; i < width; ++i) {
200				ND_TCHECK(*bp);
201				origin = origin << 8 | *bp++;
202			}
203			for ( ; i < 4; ++i)
204				origin <<= 8;
205
206			ND_TCHECK(*bp);
207			metric = *bp++;
208			done = metric & 0x80;
209			metric &= 0x7f;
210			ND_PRINT((ndo, "\n\t  %s metric %d", intoa(htonl(origin)),
211				metric));
212			len -= width + 1;
213		} while (!done);
214	}
215	return (0);
216trunc:
217	return (-1);
218}
219
220static int
221print_probe(netdissect_options *ndo,
222            register const u_char *bp, register const u_char *ep,
223            register u_int len)
224{
225	register uint32_t genid;
226
227	ND_TCHECK2(bp[0], 4);
228	if ((len < 4) || ((bp + 4) > ep)) {
229		/* { (ctags) */
230		ND_PRINT((ndo, " [|}"));
231		return (0);
232	}
233	genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
234	bp += 4;
235	len -= 4;
236	ND_PRINT((ndo, ndo->ndo_vflag > 1 ? "\n\t" : " "));
237	ND_PRINT((ndo, "genid %u", genid));
238	if (ndo->ndo_vflag < 2)
239		return (0);
240
241	while ((len > 0) && (bp < ep)) {
242		ND_TCHECK2(bp[0], 4);
243		ND_PRINT((ndo, "\n\tneighbor %s", ipaddr_string(ndo, bp)));
244		bp += 4; len -= 4;
245	}
246	return (0);
247trunc:
248	return (-1);
249}
250
251static int
252print_neighbors(netdissect_options *ndo,
253                register const u_char *bp, register const u_char *ep,
254                register u_int len)
255{
256	const u_char *laddr;
257	register u_char metric;
258	register u_char thresh;
259	register int ncount;
260
261	while (len > 0 && bp < ep) {
262		ND_TCHECK2(bp[0], 7);
263		laddr = bp;
264		bp += 4;
265		metric = *bp++;
266		thresh = *bp++;
267		ncount = *bp++;
268		len -= 7;
269		while (--ncount >= 0) {
270			ND_TCHECK2(bp[0], 4);
271			ND_PRINT((ndo, " [%s ->", ipaddr_string(ndo, laddr)));
272			ND_PRINT((ndo, " %s, (%d/%d)]",
273				   ipaddr_string(ndo, bp), metric, thresh));
274			bp += 4;
275			len -= 4;
276		}
277	}
278	return (0);
279trunc:
280	return (-1);
281}
282
283static int
284print_neighbors2(netdissect_options *ndo,
285                 register const u_char *bp, register const u_char *ep,
286                 register u_int len)
287{
288	const u_char *laddr;
289	register u_char metric, thresh, flags;
290	register int ncount;
291
292	ND_PRINT((ndo, " (v %d.%d):",
293	       (int)target_level & 0xff,
294	       (int)(target_level >> 8) & 0xff));
295
296	while (len > 0 && bp < ep) {
297		ND_TCHECK2(bp[0], 8);
298		laddr = bp;
299		bp += 4;
300		metric = *bp++;
301		thresh = *bp++;
302		flags = *bp++;
303		ncount = *bp++;
304		len -= 8;
305		while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
306			ND_PRINT((ndo, " [%s -> ", ipaddr_string(ndo, laddr)));
307			ND_PRINT((ndo, "%s (%d/%d", ipaddr_string(ndo, bp),
308				     metric, thresh));
309			if (flags & DVMRP_NF_TUNNEL)
310				ND_PRINT((ndo, "/tunnel"));
311			if (flags & DVMRP_NF_SRCRT)
312				ND_PRINT((ndo, "/srcrt"));
313			if (flags & DVMRP_NF_QUERIER)
314				ND_PRINT((ndo, "/querier"));
315			if (flags & DVMRP_NF_DISABLED)
316				ND_PRINT((ndo, "/disabled"));
317			if (flags & DVMRP_NF_DOWN)
318				ND_PRINT((ndo, "/down"));
319			ND_PRINT((ndo, ")]"));
320			bp += 4;
321			len -= 4;
322		}
323		if (ncount != -1) {
324			ND_PRINT((ndo, " [|]"));
325			return (0);
326		}
327	}
328	return (0);
329trunc:
330	return (-1);
331}
332
333static int
334print_prune(netdissect_options *ndo,
335            register const u_char *bp)
336{
337	ND_TCHECK2(bp[0], 12);
338	ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
339	bp += 8;
340	ND_PRINT((ndo, " timer "));
341	unsigned_relts_print(ndo, EXTRACT_32BITS(bp));
342	return (0);
343trunc:
344	return (-1);
345}
346
347static int
348print_graft(netdissect_options *ndo,
349            register const u_char *bp)
350{
351	ND_TCHECK2(bp[0], 8);
352	ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
353	return (0);
354trunc:
355	return (-1);
356}
357
358static int
359print_graft_ack(netdissect_options *ndo,
360                register const u_char *bp)
361{
362	ND_TCHECK2(bp[0], 8);
363	ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
364	return (0);
365trunc:
366	return (-1);
367}
368