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