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
23 static const char rcsid[] _U_ =
24 "@(#) $Header: /tcpdump/master/tcpdump/print-dvmrp.c,v 1.27 2003/11/19 09:42:04 guy Exp $ (LBL)";
25 #endif
26
27 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30
31 #include <tcpdump-stdinc.h>
32
33 #include <stdio.h>
34 #include <string.h>
35 #include <stdlib.h>
36
37 #include "interface.h"
38 #include "extract.h"
39 #include "addrtoname.h"
40
41 /*
42 * DVMRP message types and flag values shamelessly stolen from
43 * mrouted/dvmrp.h.
44 */
45 #define DVMRP_PROBE 1 /* for finding neighbors */
46 #define DVMRP_REPORT 2 /* for reporting some or all routes */
47 #define DVMRP_ASK_NEIGHBORS 3 /* sent by mapper, asking for a list */
48 /* of this router's neighbors */
49 #define DVMRP_NEIGHBORS 4 /* response to such a request */
50 #define DVMRP_ASK_NEIGHBORS2 5 /* as above, want new format reply */
51 #define DVMRP_NEIGHBORS2 6
52 #define DVMRP_PRUNE 7 /* prune message */
53 #define DVMRP_GRAFT 8 /* graft message */
54 #define DVMRP_GRAFT_ACK 9 /* graft acknowledgement */
55
56 /*
57 * 'flags' byte values in DVMRP_NEIGHBORS2 reply.
58 */
59 #define DVMRP_NF_TUNNEL 0x01 /* neighbors reached via tunnel */
60 #define DVMRP_NF_SRCRT 0x02 /* tunnel uses IP source routing */
61 #define DVMRP_NF_DOWN 0x10 /* kernel state of interface */
62 #define DVMRP_NF_DISABLED 0x20 /* administratively disabled */
63 #define DVMRP_NF_QUERIER 0x40 /* I am the subnet's querier */
64
65 static int print_probe(const u_char *, const u_char *, u_int);
66 static int print_report(const u_char *, const u_char *, u_int);
67 static int print_neighbors(const u_char *, const u_char *, u_int);
68 static int print_neighbors2(const u_char *, const u_char *, u_int);
69 static int print_prune(const u_char *);
70 static int print_graft(const u_char *);
71 static int print_graft_ack(const u_char *);
72
73 static u_int32_t target_level;
74
75 void
dvmrp_print(register const u_char * bp,register u_int len)76 dvmrp_print(register const u_char *bp, register u_int len)
77 {
78 register const u_char *ep;
79 register u_char type;
80
81 ep = (const u_char *)snapend;
82 if (bp >= ep)
83 return;
84
85 TCHECK(bp[1]);
86 type = bp[1];
87
88 /* Skip IGMP header */
89 bp += 8;
90 len -= 8;
91
92 switch (type) {
93
94 case DVMRP_PROBE:
95 printf(" Probe");
96 if (vflag) {
97 if (print_probe(bp, ep, len) < 0)
98 goto trunc;
99 }
100 break;
101
102 case DVMRP_REPORT:
103 printf(" Report");
104 if (vflag > 1) {
105 if (print_report(bp, ep, len) < 0)
106 goto trunc;
107 }
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 if (print_neighbors(bp, ep, len) < 0)
117 goto trunc;
118 break;
119
120 case DVMRP_ASK_NEIGHBORS2:
121 printf(" Ask-neighbors2");
122 break;
123
124 case DVMRP_NEIGHBORS2:
125 printf(" Neighbors2");
126 /*
127 * extract version and capabilities from IGMP group
128 * address field
129 */
130 bp -= 4;
131 TCHECK2(bp[0], 4);
132 target_level = (bp[0] << 24) | (bp[1] << 16) |
133 (bp[2] << 8) | bp[3];
134 bp += 4;
135 if (print_neighbors2(bp, ep, len) < 0)
136 goto trunc;
137 break;
138
139 case DVMRP_PRUNE:
140 printf(" Prune");
141 if (print_prune(bp) < 0)
142 goto trunc;
143 break;
144
145 case DVMRP_GRAFT:
146 printf(" Graft");
147 if (print_graft(bp) < 0)
148 goto trunc;
149 break;
150
151 case DVMRP_GRAFT_ACK:
152 printf(" Graft-ACK");
153 if (print_graft_ack(bp) < 0)
154 goto trunc;
155 break;
156
157 default:
158 printf(" [type %d]", type);
159 break;
160 }
161 return;
162
163 trunc:
164 printf("[|dvmrp]");
165 return;
166 }
167
168 static int
print_report(register const u_char * bp,register const u_char * ep,register u_int len)169 print_report(register const u_char *bp, register const u_char *ep,
170 register u_int len)
171 {
172 register u_int32_t mask, origin;
173 register int metric, done;
174 register u_int i, width;
175
176 while (len > 0) {
177 if (len < 3) {
178 printf(" [|]");
179 return (0);
180 }
181 TCHECK2(bp[0], 3);
182 mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
183 width = 1;
184 if (bp[0])
185 width = 2;
186 if (bp[1])
187 width = 3;
188 if (bp[2])
189 width = 4;
190
191 printf("\n\tMask %s", intoa(htonl(mask)));
192 bp += 3;
193 len -= 3;
194 do {
195 if (bp + width + 1 > ep) {
196 printf(" [|]");
197 return (0);
198 }
199 if (len < width + 1) {
200 printf("\n\t [Truncated Report]");
201 return (0);
202 }
203 origin = 0;
204 for (i = 0; i < width; ++i) {
205 TCHECK(*bp);
206 origin = origin << 8 | *bp++;
207 }
208 for ( ; i < 4; ++i)
209 origin <<= 8;
210
211 TCHECK(*bp);
212 metric = *bp++;
213 done = metric & 0x80;
214 metric &= 0x7f;
215 printf("\n\t %s metric %d", intoa(htonl(origin)),
216 metric);
217 len -= width + 1;
218 } while (!done);
219 }
220 return (0);
221 trunc:
222 return (-1);
223 }
224
225 static int
print_probe(register const u_char * bp,register const u_char * ep,register u_int len)226 print_probe(register const u_char *bp, register const u_char *ep,
227 register u_int len)
228 {
229 register u_int32_t genid;
230
231 TCHECK2(bp[0], 4);
232 if ((len < 4) || ((bp + 4) > ep)) {
233 /* { (ctags) */
234 printf(" [|}");
235 return (0);
236 }
237 genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
238 bp += 4;
239 len -= 4;
240 if (vflag > 1)
241 printf("\n\t");
242 else
243 printf(" ");
244 printf("genid %u", genid);
245 if (vflag < 2)
246 return (0);
247
248 while ((len > 0) && (bp < ep)) {
249 TCHECK2(bp[0], 4);
250 printf("\n\tneighbor %s", ipaddr_string(bp));
251 bp += 4; len -= 4;
252 }
253 return (0);
254 trunc:
255 return (-1);
256 }
257
258 static int
print_neighbors(register const u_char * bp,register const u_char * ep,register u_int len)259 print_neighbors(register const u_char *bp, register const u_char *ep,
260 register u_int len)
261 {
262 const u_char *laddr;
263 register u_char metric;
264 register u_char thresh;
265 register int ncount;
266
267 while (len > 0 && bp < ep) {
268 TCHECK2(bp[0], 7);
269 laddr = bp;
270 bp += 4;
271 metric = *bp++;
272 thresh = *bp++;
273 ncount = *bp++;
274 len -= 7;
275 while (--ncount >= 0) {
276 TCHECK2(bp[0], 4);
277 printf(" [%s ->", ipaddr_string(laddr));
278 printf(" %s, (%d/%d)]",
279 ipaddr_string(bp), metric, thresh);
280 bp += 4;
281 len -= 4;
282 }
283 }
284 return (0);
285 trunc:
286 return (-1);
287 }
288
289 static int
print_neighbors2(register const u_char * bp,register const u_char * ep,register u_int len)290 print_neighbors2(register const u_char *bp, register const u_char *ep,
291 register u_int len)
292 {
293 const u_char *laddr;
294 register u_char metric, thresh, flags;
295 register int ncount;
296
297 printf(" (v %d.%d):",
298 (int)target_level & 0xff,
299 (int)(target_level >> 8) & 0xff);
300
301 while (len > 0 && bp < ep) {
302 TCHECK2(bp[0], 8);
303 laddr = bp;
304 bp += 4;
305 metric = *bp++;
306 thresh = *bp++;
307 flags = *bp++;
308 ncount = *bp++;
309 len -= 8;
310 while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
311 printf(" [%s -> ", ipaddr_string(laddr));
312 printf("%s (%d/%d", ipaddr_string(bp),
313 metric, thresh);
314 if (flags & DVMRP_NF_TUNNEL)
315 printf("/tunnel");
316 if (flags & DVMRP_NF_SRCRT)
317 printf("/srcrt");
318 if (flags & DVMRP_NF_QUERIER)
319 printf("/querier");
320 if (flags & DVMRP_NF_DISABLED)
321 printf("/disabled");
322 if (flags & DVMRP_NF_DOWN)
323 printf("/down");
324 printf(")]");
325 bp += 4;
326 len -= 4;
327 }
328 if (ncount != -1) {
329 printf(" [|]");
330 return (0);
331 }
332 }
333 return (0);
334 trunc:
335 return (-1);
336 }
337
338 static int
print_prune(register const u_char * bp)339 print_prune(register const u_char *bp)
340 {
341 TCHECK2(bp[0], 12);
342 printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
343 bp += 8;
344 (void)printf(" timer ");
345 relts_print(EXTRACT_32BITS(bp));
346 return (0);
347 trunc:
348 return (-1);
349 }
350
351 static int
print_graft(register const u_char * bp)352 print_graft(register const u_char *bp)
353 {
354 TCHECK2(bp[0], 8);
355 printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
356 return (0);
357 trunc:
358 return (-1);
359 }
360
361 static int
print_graft_ack(register const u_char * bp)362 print_graft_ack(register const u_char *bp)
363 {
364 TCHECK2(bp[0], 8);
365 printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
366 return (0);
367 trunc:
368 return (-1);
369 }
370