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