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
58 static int print_probe(netdissect_options *, const u_char *, const u_char *, u_int);
59 static int print_report(netdissect_options *, const u_char *, const u_char *, u_int);
60 static int print_neighbors(netdissect_options *, const u_char *, const u_char *, u_int);
61 static int print_neighbors2(netdissect_options *, const u_char *, const u_char *, u_int);
62 static int print_prune(netdissect_options *, const u_char *);
63 static int print_graft(netdissect_options *, const u_char *);
64 static int print_graft_ack(netdissect_options *, const u_char *);
65
66 static uint32_t target_level;
67
68 void
dvmrp_print(netdissect_options * ndo,register const u_char * bp,register u_int len)69 dvmrp_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
157 trunc:
158 ND_PRINT((ndo, "[|dvmrp]"));
159 return;
160 }
161
162 static int
print_report(netdissect_options * ndo,register const u_char * bp,register const u_char * ep,register u_int len)163 print_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);
216 trunc:
217 return (-1);
218 }
219
220 static int
print_probe(netdissect_options * ndo,register const u_char * bp,register const u_char * ep,register u_int len)221 print_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);
247 trunc:
248 return (-1);
249 }
250
251 static int
print_neighbors(netdissect_options * ndo,register const u_char * bp,register const u_char * ep,register u_int len)252 print_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);
279 trunc:
280 return (-1);
281 }
282
283 static int
print_neighbors2(netdissect_options * ndo,register const u_char * bp,register const u_char * ep,register u_int len)284 print_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);
329 trunc:
330 return (-1);
331 }
332
333 static int
print_prune(netdissect_options * ndo,register const u_char * bp)334 print_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);
343 trunc:
344 return (-1);
345 }
346
347 static int
print_graft(netdissect_options * ndo,register const u_char * bp)348 print_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);
354 trunc:
355 return (-1);
356 }
357
358 static int
print_graft_ack(netdissect_options * ndo,register const u_char * bp)359 print_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);
365 trunc:
366 return (-1);
367 }
368