print-igmp.c revision 1.8 
1/*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994, 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#include <sys/cdefs.h>
23#ifndef lint
24__RCSID("$NetBSD: print-igmp.c,v 1.8 2020/02/24 18:39:47 kamil Exp $");
25#endif
26
27/* \summary: Internet Group Management Protocol (IGMP) printer */
28
29#ifdef HAVE_CONFIG_H
30#include "config.h"
31#endif
32
33#include <netdissect-stdinc.h>
34
35#include "netdissect.h"
36#include "addrtoname.h"
37#include "extract.h"
38
39#ifndef IN_CLASSD
40#define IN_CLASSD(i) (((int32_t)(i) & 0xf0000000) == 0xe0000000)
41#endif
42
43static const char tstr[] = "[|igmp]";
44
45/* (following from ipmulti/mrouted/prune.h) */
46
47/*
48 * The packet format for a traceroute request.
49 */
50struct tr_query {
51    uint32_t  tr_src;          /* traceroute source */
52    uint32_t  tr_dst;          /* traceroute destination */
53    uint32_t  tr_raddr;        /* traceroute response address */
54    uint32_t  tr_rttlqid;      /* response ttl and qid */
55};
56
57#define TR_GETTTL(x)        (int)(((x) >> 24) & 0xff)
58#define TR_GETQID(x)        ((x) & 0x00ffffff)
59
60/*
61 * Traceroute response format.  A traceroute response has a tr_query at the
62 * beginning, followed by one tr_resp for each hop taken.
63 */
64struct tr_resp {
65    uint32_t tr_qarr;          /* query arrival time */
66    uint32_t tr_inaddr;        /* incoming interface address */
67    uint32_t tr_outaddr;       /* outgoing interface address */
68    uint32_t tr_rmtaddr;       /* parent address in source tree */
69    uint32_t tr_vifin;         /* input packet count on interface */
70    uint32_t tr_vifout;        /* output packet count on interface */
71    uint32_t tr_pktcnt;        /* total incoming packets for src-grp */
72    uint8_t  tr_rproto;      /* routing proto deployed on router */
73    uint8_t  tr_fttl;        /* ttl required to forward on outvif */
74    uint8_t  tr_smask;       /* subnet mask for src addr */
75    uint8_t  tr_rflags;      /* forwarding error codes */
76};
77
78/* defs within mtrace */
79#define TR_QUERY 1
80#define TR_RESP 2
81
82/* fields for tr_rflags (forwarding error codes) */
83#define TR_NO_ERR   0
84#define TR_WRONG_IF 1
85#define TR_PRUNED   2
86#define TR_OPRUNED  3
87#define TR_SCOPED   4
88#define TR_NO_RTE   5
89#define TR_NO_FWD   7
90#define TR_NO_SPACE 0x81
91#define TR_OLD_ROUTER   0x82
92
93/* fields for tr_rproto (routing protocol) */
94#define TR_PROTO_DVMRP  1
95#define TR_PROTO_MOSPF  2
96#define TR_PROTO_PIM    3
97#define TR_PROTO_CBT    4
98
99/* igmpv3 report types */
100static const struct tok igmpv3report2str[] = {
101	{ 1,	"is_in" },
102	{ 2,	"is_ex" },
103	{ 3,	"to_in" },
104	{ 4,	"to_ex" },
105	{ 5,	"allow" },
106	{ 6,	"block" },
107	{ 0,	NULL }
108};
109
110UNALIGNED_OK
111static void
112print_mtrace(netdissect_options *ndo,
113             register const u_char *bp, register u_int len)
114{
115    register const struct tr_query *tr = (const struct tr_query *)(bp + 8);
116
117    ND_TCHECK(*tr);
118    if (len < 8 + sizeof (struct tr_query)) {
119	ND_PRINT((ndo, " [invalid len %d]", len));
120	return;
121    }
122    ND_PRINT((ndo, "mtrace %u: %s to %s reply-to %s",
123        TR_GETQID(EXTRACT_32BITS(&tr->tr_rttlqid)),
124        ipaddr_string(ndo, &tr->tr_src), ipaddr_string(ndo, &tr->tr_dst),
125        ipaddr_string(ndo, &tr->tr_raddr)));
126    if (IN_CLASSD(EXTRACT_32BITS(&tr->tr_raddr)))
127        ND_PRINT((ndo, " with-ttl %d", TR_GETTTL(EXTRACT_32BITS(&tr->tr_rttlqid))));
128    return;
129trunc:
130    ND_PRINT((ndo, "%s", tstr));
131}
132
133static void
134print_mresp(netdissect_options *ndo,
135            register const u_char *bp, register u_int len)
136{
137    register const struct tr_query *tr = (const struct tr_query *)(bp + 8);
138
139    ND_TCHECK(*tr);
140    if (len < 8 + sizeof (struct tr_query)) {
141	ND_PRINT((ndo, " [invalid len %d]", len));
142	return;
143    }
144    ND_PRINT((ndo, "mresp %lu: %s to %s reply-to %s",
145        (u_long)TR_GETQID(EXTRACT_32BITS(&tr->tr_rttlqid)),
146        ipaddr_string(ndo, &tr->tr_src), ipaddr_string(ndo, &tr->tr_dst),
147        ipaddr_string(ndo, &tr->tr_raddr)));
148    if (IN_CLASSD(EXTRACT_32BITS(&tr->tr_raddr)))
149        ND_PRINT((ndo, " with-ttl %d", TR_GETTTL(EXTRACT_32BITS(&tr->tr_rttlqid))));
150    return;
151trunc:
152    ND_PRINT((ndo, "%s", tstr));
153}
154
155static void
156print_igmpv3_report(netdissect_options *ndo,
157                    register const u_char *bp, register u_int len)
158{
159    u_int group, nsrcs, ngroups;
160    register u_int i, j;
161
162    /* Minimum len is 16, and should be a multiple of 4 */
163    if (len < 16 || len & 0x03) {
164	ND_PRINT((ndo, " [invalid len %d]", len));
165	return;
166    }
167    ND_TCHECK2(bp[6], 2);
168    ngroups = EXTRACT_16BITS(&bp[6]);
169    ND_PRINT((ndo, ", %d group record(s)", ngroups));
170    if (ndo->ndo_vflag > 0) {
171	/* Print the group records */
172	group = 8;
173        for (i=0; i<ngroups; i++) {
174	    if (len < group+8) {
175		ND_PRINT((ndo, " [invalid number of groups]"));
176		return;
177	    }
178	    ND_TCHECK2(bp[group+4], 4);
179            ND_PRINT((ndo, " [gaddr %s", ipaddr_string(ndo, &bp[group+4])));
180	    ND_PRINT((ndo, " %s", tok2str(igmpv3report2str, " [v3-report-#%d]",
181								bp[group])));
182            nsrcs = EXTRACT_16BITS(&bp[group+2]);
183	    /* Check the number of sources and print them */
184	    if (len < group+8+(nsrcs<<2)) {
185		ND_PRINT((ndo, " [invalid number of sources %d]", nsrcs));
186		return;
187	    }
188            if (ndo->ndo_vflag == 1)
189                ND_PRINT((ndo, ", %d source(s)", nsrcs));
190            else {
191		/* Print the sources */
192                ND_PRINT((ndo, " {"));
193                for (j=0; j<nsrcs; j++) {
194		    ND_TCHECK2(bp[group+8+(j<<2)], 4);
195		    ND_PRINT((ndo, " %s", ipaddr_string(ndo, &bp[group+8+(j<<2)])));
196		}
197                ND_PRINT((ndo, " }"));
198            }
199	    /* Next group record */
200            group += 8 + (nsrcs << 2);
201	    ND_PRINT((ndo, "]"));
202        }
203    }
204    return;
205trunc:
206    ND_PRINT((ndo, "%s", tstr));
207}
208
209static void
210print_igmpv3_query(netdissect_options *ndo,
211                   register const u_char *bp, register u_int len)
212{
213    u_int mrc;
214    u_int mrt;
215    u_int nsrcs;
216    register u_int i;
217
218    ND_PRINT((ndo, " v3"));
219    /* Minimum len is 12, and should be a multiple of 4 */
220    if (len < 12 || len & 0x03) {
221	ND_PRINT((ndo, " [invalid len %d]", len));
222	return;
223    }
224    ND_TCHECK(bp[1]);
225    mrc = bp[1];
226    if (mrc < 128) {
227	mrt = mrc;
228    } else {
229        mrt = ((mrc & 0x0f) | 0x10) << (((mrc & 0x70) >> 4) + 3);
230    }
231    if (mrc != 100) {
232	ND_PRINT((ndo, " [max resp time "));
233        if (mrt < 600) {
234            ND_PRINT((ndo, "%.1fs", mrt * 0.1));
235        } else {
236            unsigned_relts_print(ndo, mrt / 10);
237        }
238	ND_PRINT((ndo, "]"));
239    }
240    ND_TCHECK2(bp[4], 4);
241    if (EXTRACT_32BITS(&bp[4]) == 0)
242	return;
243    ND_PRINT((ndo, " [gaddr %s", ipaddr_string(ndo, &bp[4])));
244    ND_TCHECK2(bp[10], 2);
245    nsrcs = EXTRACT_16BITS(&bp[10]);
246    if (nsrcs > 0) {
247	if (len < 12 + (nsrcs << 2))
248	    ND_PRINT((ndo, " [invalid number of sources]"));
249	else if (ndo->ndo_vflag > 1) {
250	    ND_PRINT((ndo, " {"));
251	    for (i=0; i<nsrcs; i++) {
252		ND_TCHECK2(bp[12+(i<<2)], 4);
253		ND_PRINT((ndo, " %s", ipaddr_string(ndo, &bp[12+(i<<2)])));
254	    }
255	    ND_PRINT((ndo, " }"));
256	} else
257	    ND_PRINT((ndo, ", %d source(s)", nsrcs));
258    }
259    ND_PRINT((ndo, "]"));
260    return;
261trunc:
262    ND_PRINT((ndo, "%s", tstr));
263}
264
265void
266igmp_print(netdissect_options *ndo,
267           register const u_char *bp, register u_int len)
268{
269    struct cksum_vec vec[1];
270
271    if (ndo->ndo_qflag) {
272        ND_PRINT((ndo, "igmp"));
273        return;
274    }
275
276    ND_TCHECK(bp[0]);
277    switch (bp[0]) {
278    case 0x11:
279        ND_PRINT((ndo, "igmp query"));
280	if (len >= 12)
281	    print_igmpv3_query(ndo, bp, len);
282	else {
283            ND_TCHECK(bp[1]);
284	    if (bp[1]) {
285		ND_PRINT((ndo, " v2"));
286		if (bp[1] != 100)
287		    ND_PRINT((ndo, " [max resp time %d]", bp[1]));
288	    } else
289		ND_PRINT((ndo, " v1"));
290            ND_TCHECK2(bp[4], 4);
291	    if (EXTRACT_32BITS(&bp[4]))
292                ND_PRINT((ndo, " [gaddr %s]", ipaddr_string(ndo, &bp[4])));
293            if (len != 8)
294                ND_PRINT((ndo, " [len %d]", len));
295	}
296        break;
297    case 0x12:
298        ND_TCHECK2(bp[4], 4);
299        ND_PRINT((ndo, "igmp v1 report %s", ipaddr_string(ndo, &bp[4])));
300        if (len != 8)
301            ND_PRINT((ndo, " [len %d]", len));
302        break;
303    case 0x16:
304        ND_TCHECK2(bp[4], 4);
305        ND_PRINT((ndo, "igmp v2 report %s", ipaddr_string(ndo, &bp[4])));
306        break;
307    case 0x22:
308        ND_PRINT((ndo, "igmp v3 report"));
309	print_igmpv3_report(ndo, bp, len);
310        break;
311    case 0x17:
312        ND_TCHECK2(bp[4], 4);
313        ND_PRINT((ndo, "igmp leave %s", ipaddr_string(ndo, &bp[4])));
314        break;
315    case 0x13:
316        ND_PRINT((ndo, "igmp dvmrp"));
317        if (len < 8)
318            ND_PRINT((ndo, " [len %d]", len));
319        else
320            dvmrp_print(ndo, bp, len);
321        break;
322    case 0x14:
323        ND_PRINT((ndo, "igmp pimv1"));
324        pimv1_print(ndo, bp, len);
325        break;
326    case 0x1e:
327        print_mresp(ndo, bp, len);
328        break;
329    case 0x1f:
330        print_mtrace(ndo, bp, len);
331        break;
332    default:
333        ND_PRINT((ndo, "igmp-%d", bp[0]));
334        break;
335    }
336
337    if (ndo->ndo_vflag && len >= 4 && ND_TTEST2(bp[0], len)) {
338        /* Check the IGMP checksum */
339        vec[0].ptr = bp;
340        vec[0].len = len;
341        if (in_cksum(vec, 1))
342            ND_PRINT((ndo, " bad igmp cksum %x!", EXTRACT_16BITS(&bp[2])));
343    }
344    return;
345trunc:
346    ND_PRINT((ndo, "%s", tstr));
347}
348