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only call into ICMP_MPLS_EXT dissector for ICMP TIMXCEDD and UNREACH messages, do...
[tcpdump] / print-icmp.c
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 #ifndef lint
23 static const char rcsid[] _U_ =
24 "@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.78 2004-06-15 07:34:22 hannes 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
36 #include "interface.h"
37 #include "addrtoname.h"
38 #include "extract.h" /* must come after interface.h */
39
40 #include "ip.h"
41 #include "udp.h"
42 #include "ipproto.h"
43 #include "mpls.h"
44
45 /*
46 * Interface Control Message Protocol Definitions.
47 * Per RFC 792, September 1981.
48 */
49
50 /*
51 * Structure of an icmp header.
52 */
53 struct icmp {
54 u_int8_t icmp_type; /* type of message, see below */
55 u_int8_t icmp_code; /* type sub code */
56 u_int16_t icmp_cksum; /* ones complement cksum of struct */
57 union {
58 u_int8_t ih_pptr; /* ICMP_PARAMPROB */
59 struct in_addr ih_gwaddr; /* ICMP_REDIRECT */
60 struct ih_idseq {
61 u_int16_t icd_id;
62 u_int16_t icd_seq;
63 } ih_idseq;
64 u_int32_t ih_void;
65
66 /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
67 struct ih_pmtu {
68 u_int16_t ipm_void;
69 u_int16_t ipm_nextmtu;
70 } ih_pmtu;
71 } icmp_hun;
72 #define icmp_pptr icmp_hun.ih_pptr
73 #define icmp_gwaddr icmp_hun.ih_gwaddr
74 #define icmp_id icmp_hun.ih_idseq.icd_id
75 #define icmp_seq icmp_hun.ih_idseq.icd_seq
76 #define icmp_void icmp_hun.ih_void
77 #define icmp_pmvoid icmp_hun.ih_pmtu.ipm_void
78 #define icmp_nextmtu icmp_hun.ih_pmtu.ipm_nextmtu
79 union {
80 struct id_ts {
81 u_int32_t its_otime;
82 u_int32_t its_rtime;
83 u_int32_t its_ttime;
84 } id_ts;
85 struct id_ip {
86 struct ip idi_ip;
87 /* options and then 64 bits of data */
88 } id_ip;
89 struct mpls_ext {
90 u_int8_t legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
91 u_int8_t version_res[2];
92 u_int8_t checksum[2];
93 u_int8_t data[1];
94 } mpls_ext;
95 u_int32_t id_mask;
96 u_int8_t id_data[1];
97 } icmp_dun;
98 #define icmp_otime icmp_dun.id_ts.its_otime
99 #define icmp_rtime icmp_dun.id_ts.its_rtime
100 #define icmp_ttime icmp_dun.id_ts.its_ttime
101 #define icmp_ip icmp_dun.id_ip.idi_ip
102 #define icmp_mask icmp_dun.id_mask
103 #define icmp_data icmp_dun.id_data
104 #define icmp_mpls_ext_version icmp_dun.mpls_ext.version_res
105 #define icmp_mpls_ext_checksum icmp_dun.mpls_ext.checksum
106 #define icmp_mpls_ext_data icmp_dun.mpls_ext.data
107 };
108
109 #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
110 #define ICMP_MPLS_EXT_VERSION 2
111
112 /*
113 * Lower bounds on packet lengths for various types.
114 * For the error advice packets must first insure that the
115 * packet is large enought to contain the returned ip header.
116 * Only then can we do the check to see if 64 bits of packet
117 * data have been returned, since we need to check the returned
118 * ip header length.
119 */
120 #define ICMP_MINLEN 8 /* abs minimum */
121 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-icmp-mpls-02 */
122 #define ICMP_TSLEN (8 + 3 * sizeof (u_int32_t)) /* timestamp */
123 #define ICMP_MASKLEN 12 /* address mask */
124 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */
125 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
126 /* N.B.: must separately check that ip_hl >= 5 */
127
128 /*
129 * Definition of type and code field values.
130 */
131 #define ICMP_ECHOREPLY 0 /* echo reply */
132 #define ICMP_UNREACH 3 /* dest unreachable, codes: */
133 #define ICMP_UNREACH_NET 0 /* bad net */
134 #define ICMP_UNREACH_HOST 1 /* bad host */
135 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */
136 #define ICMP_UNREACH_PORT 3 /* bad port */
137 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */
138 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */
139 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */
140 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */
141 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */
142 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */
143 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */
144 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */
145 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */
146 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */
147 #define ICMP_REDIRECT 5 /* shorter route, codes: */
148 #define ICMP_REDIRECT_NET 0 /* for network */
149 #define ICMP_REDIRECT_HOST 1 /* for host */
150 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */
151 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */
152 #define ICMP_ECHO 8 /* echo service */
153 #define ICMP_ROUTERADVERT 9 /* router advertisement */
154 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */
155 #define ICMP_TIMXCEED 11 /* time exceeded, code: */
156 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */
157 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */
158 #define ICMP_PARAMPROB 12 /* ip header bad */
159 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */
160 #define ICMP_TSTAMP 13 /* timestamp request */
161 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */
162 #define ICMP_IREQ 15 /* information request */
163 #define ICMP_IREQREPLY 16 /* information reply */
164 #define ICMP_MASKREQ 17 /* address mask request */
165 #define ICMP_MASKREPLY 18 /* address mask reply */
166
167 #define ICMP_MAXTYPE 18
168
169 #define ICMP_INFOTYPE(type) \
170 ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
171 (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
172 (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
173 (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
174 (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
175 #define ICMP_MPLS_EXT_TYPE(type) \
176 ((type) == ICMP_UNREACH || (type) == ICMP_TIMXCEED)
177 /* rfc1700 */
178 #ifndef ICMP_UNREACH_NET_UNKNOWN
179 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */
180 #endif
181 #ifndef ICMP_UNREACH_HOST_UNKNOWN
182 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */
183 #endif
184 #ifndef ICMP_UNREACH_ISOLATED
185 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */
186 #endif
187 #ifndef ICMP_UNREACH_NET_PROHIB
188 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */
189 #endif
190 #ifndef ICMP_UNREACH_HOST_PROHIB
191 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */
192 #endif
193 #ifndef ICMP_UNREACH_TOSNET
194 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */
195 #endif
196 #ifndef ICMP_UNREACH_TOSHOST
197 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */
198 #endif
199
200 /* rfc1716 */
201 #ifndef ICMP_UNREACH_FILTER_PROHIB
202 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */
203 #endif
204 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
205 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */
206 #endif
207 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
208 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */
209 #endif
210
211 /* Most of the icmp types */
212 static struct tok icmp2str[] = {
213 { ICMP_ECHOREPLY, "echo reply" },
214 { ICMP_SOURCEQUENCH, "source quench" },
215 { ICMP_ECHO, "echo request" },
216 { ICMP_ROUTERSOLICIT, "router solicitation" },
217 { ICMP_TSTAMP, "time stamp request" },
218 { ICMP_TSTAMPREPLY, "time stamp reply" },
219 { ICMP_IREQ, "information request" },
220 { ICMP_IREQREPLY, "information reply" },
221 { ICMP_MASKREQ, "address mask request" },
222 { 0, NULL }
223 };
224
225 /* Formats for most of the ICMP_UNREACH codes */
226 static struct tok unreach2str[] = {
227 { ICMP_UNREACH_NET, "net %s unreachable" },
228 { ICMP_UNREACH_HOST, "host %s unreachable" },
229 { ICMP_UNREACH_SRCFAIL,
230 "%s unreachable - source route failed" },
231 { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" },
232 { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" },
233 { ICMP_UNREACH_ISOLATED,
234 "%s unreachable - source host isolated" },
235 { ICMP_UNREACH_NET_PROHIB,
236 "net %s unreachable - admin prohibited" },
237 { ICMP_UNREACH_HOST_PROHIB,
238 "host %s unreachable - admin prohibited" },
239 { ICMP_UNREACH_TOSNET,
240 "net %s unreachable - tos prohibited" },
241 { ICMP_UNREACH_TOSHOST,
242 "host %s unreachable - tos prohibited" },
243 { ICMP_UNREACH_FILTER_PROHIB,
244 "host %s unreachable - admin prohibited filter" },
245 { ICMP_UNREACH_HOST_PRECEDENCE,
246 "host %s unreachable - host precedence violation" },
247 { ICMP_UNREACH_PRECEDENCE_CUTOFF,
248 "host %s unreachable - precedence cutoff" },
249 { 0, NULL }
250 };
251
252 /* Formats for the ICMP_REDIRECT codes */
253 static struct tok type2str[] = {
254 { ICMP_REDIRECT_NET, "redirect %s to net %s" },
255 { ICMP_REDIRECT_HOST, "redirect %s to host %s" },
256 { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" },
257 { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" },
258 { 0, NULL }
259 };
260
261 /* rfc1191 */
262 struct mtu_discovery {
263 u_int16_t unused;
264 u_int16_t nexthopmtu;
265 };
266
267 /* rfc1256 */
268 struct ih_rdiscovery {
269 u_int8_t ird_addrnum;
270 u_int8_t ird_addrsiz;
271 u_int16_t ird_lifetime;
272 };
273
274 struct id_rdiscovery {
275 u_int32_t ird_addr;
276 u_int32_t ird_pref;
277 };
278
279 /* draft-bonica-icmp-mpls-02 */
280 struct icmp_mpls_ext_object_header_t {
281 u_int8_t length[2];
282 u_int8_t class_num;
283 u_int8_t ctype;
284 };
285
286 static const struct tok icmp_mpls_ext_obj_values[] = {
287 { 1, "MPLS Stack Entry" },
288 { 2, "Extended Payload" },
289 { 0, NULL}
290 };
291
292 void
293 icmp_print(const u_char *bp, u_int plen, const u_char *bp2, int fragmented)
294 {
295 char *cp;
296 const struct icmp *dp;
297 const struct ip *ip;
298 const char *str, *fmt;
299 const struct ip *oip;
300 const struct udphdr *ouh;
301 const u_int8_t *obj_tptr;
302 u_int32_t raw_label;
303 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
304 u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype;
305 char buf[MAXHOSTNAMELEN + 100];
306
307 dp = (struct icmp *)bp;
308 ip = (struct ip *)bp2;
309 str = buf;
310
311 TCHECK(dp->icmp_code);
312 switch (dp->icmp_type) {
313
314 case ICMP_ECHO:
315 case ICMP_ECHOREPLY:
316 TCHECK(dp->icmp_seq);
317 (void)snprintf(buf, sizeof(buf), "echo %s seq %u",
318 dp->icmp_type == ICMP_ECHO ?
319 "request" : "reply",
320 EXTRACT_16BITS(&dp->icmp_seq));
321 break;
322
323 case ICMP_UNREACH:
324 TCHECK(dp->icmp_ip.ip_dst);
325 switch (dp->icmp_code) {
326
327 case ICMP_UNREACH_PROTOCOL:
328 TCHECK(dp->icmp_ip.ip_p);
329 (void)snprintf(buf, sizeof(buf),
330 "%s protocol %d unreachable",
331 ipaddr_string(&dp->icmp_ip.ip_dst),
332 dp->icmp_ip.ip_p);
333 break;
334
335 case ICMP_UNREACH_PORT:
336 TCHECK(dp->icmp_ip.ip_p);
337 oip = &dp->icmp_ip;
338 hlen = IP_HL(oip) * 4;
339 ouh = (struct udphdr *)(((u_char *)oip) + hlen);
340 TCHECK(ouh->uh_dport);
341 dport = EXTRACT_16BITS(&ouh->uh_dport);
342 switch (oip->ip_p) {
343
344 case IPPROTO_TCP:
345 (void)snprintf(buf, sizeof(buf),
346 "%s tcp port %s unreachable",
347 ipaddr_string(&oip->ip_dst),
348 tcpport_string(dport));
349 break;
350
351 case IPPROTO_UDP:
352 (void)snprintf(buf, sizeof(buf),
353 "%s udp port %s unreachable",
354 ipaddr_string(&oip->ip_dst),
355 udpport_string(dport));
356 break;
357
358 default:
359 (void)snprintf(buf, sizeof(buf),
360 "%s protocol %d port %d unreachable",
361 ipaddr_string(&oip->ip_dst),
362 oip->ip_p, dport);
363 break;
364 }
365 break;
366
367 case ICMP_UNREACH_NEEDFRAG:
368 {
369 register const struct mtu_discovery *mp;
370 mp = (struct mtu_discovery *)&dp->icmp_void;
371 mtu = EXTRACT_16BITS(&mp->nexthopmtu);
372 if (mtu) {
373 (void)snprintf(buf, sizeof(buf),
374 "%s unreachable - need to frag (mtu %d)",
375 ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
376 } else {
377 (void)snprintf(buf, sizeof(buf),
378 "%s unreachable - need to frag",
379 ipaddr_string(&dp->icmp_ip.ip_dst));
380 }
381 }
382 break;
383
384 default:
385 fmt = tok2str(unreach2str, "#%d %%s unreachable",
386 dp->icmp_code);
387 (void)snprintf(buf, sizeof(buf), fmt,
388 ipaddr_string(&dp->icmp_ip.ip_dst));
389 break;
390 }
391 break;
392
393 case ICMP_REDIRECT:
394 TCHECK(dp->icmp_ip.ip_dst);
395 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
396 dp->icmp_code);
397 (void)snprintf(buf, sizeof(buf), fmt,
398 ipaddr_string(&dp->icmp_ip.ip_dst),
399 ipaddr_string(&dp->icmp_gwaddr));
400 break;
401
402 case ICMP_ROUTERADVERT:
403 {
404 register const struct ih_rdiscovery *ihp;
405 register const struct id_rdiscovery *idp;
406 u_int lifetime, num, size;
407
408 (void)snprintf(buf, sizeof(buf), "router advertisement");
409 cp = buf + strlen(buf);
410
411 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
412 TCHECK(*ihp);
413 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
414 cp = buf + strlen(buf);
415 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
416 if (lifetime < 60) {
417 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
418 lifetime);
419 } else if (lifetime < 60 * 60) {
420 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
421 lifetime / 60, lifetime % 60);
422 } else {
423 (void)snprintf(cp, sizeof(buf) - (cp - buf),
424 "%u:%02u:%02u",
425 lifetime / 3600,
426 (lifetime % 3600) / 60,
427 lifetime % 60);
428 }
429 cp = buf + strlen(buf);
430
431 num = ihp->ird_addrnum;
432 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
433 cp = buf + strlen(buf);
434
435 size = ihp->ird_addrsiz;
436 if (size != 2) {
437 (void)snprintf(cp, sizeof(buf) - (cp - buf),
438 " [size %d]", size);
439 break;
440 }
441 idp = (struct id_rdiscovery *)&dp->icmp_data;
442 while (num-- > 0) {
443 TCHECK(*idp);
444 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
445 ipaddr_string(&idp->ird_addr),
446 EXTRACT_32BITS(&idp->ird_pref));
447 cp = buf + strlen(buf);
448 ++idp;
449 }
450 }
451 break;
452
453 case ICMP_TIMXCEED:
454 TCHECK(dp->icmp_ip.ip_dst);
455 switch (dp->icmp_code) {
456
457 case ICMP_TIMXCEED_INTRANS:
458 str = "time exceeded in-transit";
459 break;
460
461 case ICMP_TIMXCEED_REASS:
462 str = "ip reassembly time exceeded";
463 break;
464
465 default:
466 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
467 dp->icmp_code);
468 break;
469 }
470 break;
471
472 case ICMP_PARAMPROB:
473 if (dp->icmp_code)
474 (void)snprintf(buf, sizeof(buf),
475 "parameter problem - code %d", dp->icmp_code);
476 else {
477 TCHECK(dp->icmp_pptr);
478 (void)snprintf(buf, sizeof(buf),
479 "parameter problem - octet %d", dp->icmp_pptr);
480 }
481 break;
482
483 case ICMP_MASKREPLY:
484 TCHECK(dp->icmp_mask);
485 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
486 EXTRACT_32BITS(&dp->icmp_mask));
487 break;
488
489 case ICMP_TSTAMP:
490 TCHECK(dp->icmp_seq);
491 (void)snprintf(buf, sizeof(buf),
492 "time stamp query id %u seq %u",
493 EXTRACT_16BITS(&dp->icmp_id),
494 EXTRACT_16BITS(&dp->icmp_seq));
495 break;
496
497 case ICMP_TSTAMPREPLY:
498 TCHECK(dp->icmp_ttime);
499 (void)snprintf(buf, sizeof(buf),
500 "time stamp reply id %u seq %u : org 0x%x recv 0x%x xmit 0x%x",
501 EXTRACT_16BITS(&dp->icmp_id),
502 EXTRACT_16BITS(&dp->icmp_seq),
503 EXTRACT_32BITS(&dp->icmp_otime),
504 EXTRACT_32BITS(&dp->icmp_rtime),
505 EXTRACT_32BITS(&dp->icmp_ttime));
506 break;
507
508 default:
509 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
510 break;
511 }
512 (void)printf("ICMP %s, length %u", str, plen);
513 if (vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
514 u_int16_t sum, icmp_sum;
515 if (TTEST2(*bp, plen)) {
516 sum = in_cksum((u_short*)dp, plen, 0);
517 if (sum != 0) {
518 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum);
519 (void)printf(" (wrong icmp cksum %x (->%x)!)",
520 icmp_sum,
521 in_cksum_shouldbe(icmp_sum, sum));
522 }
523 }
524 }
525 if (vflag >= 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
526 bp += 8;
527 (void)printf("\n\t");
528 ip = (struct ip *)bp;
529 snaplen = snapend - bp;
530 ip_print(bp, EXTRACT_16BITS(&ip->ip_len));
531 }
532
533 if (vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) {
534
535 /*
536 * Sanity checking of the header.
537 */
538 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(dp->icmp_mpls_ext_version)) != ICMP_MPLS_EXT_VERSION) {
539 printf("\n\tMPLS extension v%u packet not supported",
540 ICMP_MPLS_EXT_EXTRACT_VERSION(*(dp->icmp_mpls_ext_version)));
541 return;
542 }
543
544 hlen = plen - ICMP_EXTD_MINLEN;
545 printf("\n\tMPLS extension v%u, checksum 0x%04x (unverified), length %u", /* FIXME */
546 ICMP_MPLS_EXT_EXTRACT_VERSION(*(dp->icmp_mpls_ext_version)),
547 EXTRACT_16BITS(dp->icmp_mpls_ext_checksum),
548 hlen);
549 hlen -= 4; /* subtract common header size */
550
551 obj_tptr = (u_int8_t *)dp->icmp_mpls_ext_data;
552
553 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
554
555 icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr;
556 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length);
557 obj_class_num = icmp_mpls_ext_object_header->class_num;
558 obj_ctype = icmp_mpls_ext_object_header->ctype;
559 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
560
561 printf("\n\t %s Object (%u), Class-Type: %u, length %u",
562 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
563 obj_class_num,
564 obj_ctype,
565 obj_tlen);
566
567 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
568 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
569
570 switch (obj_class_num) {
571 case 1:
572 switch(obj_ctype) {
573 case 1:
574 raw_label = EXTRACT_32BITS(obj_tptr);
575 printf("\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label));
576 if (MPLS_STACK(raw_label))
577 printf(", [S]");
578 printf(", ttl %u", MPLS_TTL(raw_label));
579 break;
580 default:
581 print_unknown_data(obj_tptr, "\n\t ", obj_tlen);
582 }
583 break;
584
585 /*
586 * FIXME those are the defined objects that lack a decoder
587 * you are welcome to contribute code ;-)
588 */
589 case 2:
590 default:
591 print_unknown_data(obj_tptr, "\n\t ", obj_tlen);
592 break;
593 }
594 hlen -= obj_tlen;
595 obj_tptr += obj_tlen;
596 }
597 }
598
599 return;
600 trunc:
601 fputs("[|icmp]", stdout);
602 }
[mirror] the TCPdump network dissector