Move tcpdump-3.9/ to tcpdump/. No need for a versioned dir.
[dragonfly.git] / contrib / tcpdump / print-icmp.c
CommitLineData
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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
23static const char rcsid[] _U_ =
825e8fa1 24 "@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.81.2.6 2007/09/13 17:40:18 guy Exp $ (LBL)";
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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 */
53struct 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;
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65 } icmp_hun;
66#define icmp_pptr icmp_hun.ih_pptr
67#define icmp_gwaddr icmp_hun.ih_gwaddr
68#define icmp_id icmp_hun.ih_idseq.icd_id
69#define icmp_seq icmp_hun.ih_idseq.icd_seq
70#define icmp_void icmp_hun.ih_void
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71 union {
72 struct id_ts {
73 u_int32_t its_otime;
74 u_int32_t its_rtime;
75 u_int32_t its_ttime;
76 } id_ts;
77 struct id_ip {
78 struct ip idi_ip;
79 /* options and then 64 bits of data */
80 } id_ip;
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81 u_int32_t id_mask;
82 u_int8_t id_data[1];
83 } icmp_dun;
84#define icmp_otime icmp_dun.id_ts.its_otime
85#define icmp_rtime icmp_dun.id_ts.its_rtime
86#define icmp_ttime icmp_dun.id_ts.its_ttime
87#define icmp_ip icmp_dun.id_ip.idi_ip
88#define icmp_mask icmp_dun.id_mask
89#define icmp_data icmp_dun.id_data
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90};
91
92#define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
93#define ICMP_MPLS_EXT_VERSION 2
94
95/*
96 * Lower bounds on packet lengths for various types.
97 * For the error advice packets must first insure that the
98 * packet is large enought to contain the returned ip header.
99 * Only then can we do the check to see if 64 bits of packet
100 * data have been returned, since we need to check the returned
101 * ip header length.
102 */
103#define ICMP_MINLEN 8 /* abs minimum */
66170f0a 104#define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */
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105#define ICMP_TSLEN (8 + 3 * sizeof (u_int32_t)) /* timestamp */
106#define ICMP_MASKLEN 12 /* address mask */
107#define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */
108#define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
109 /* N.B.: must separately check that ip_hl >= 5 */
110
111/*
112 * Definition of type and code field values.
113 */
114#define ICMP_ECHOREPLY 0 /* echo reply */
115#define ICMP_UNREACH 3 /* dest unreachable, codes: */
116#define ICMP_UNREACH_NET 0 /* bad net */
117#define ICMP_UNREACH_HOST 1 /* bad host */
118#define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */
119#define ICMP_UNREACH_PORT 3 /* bad port */
120#define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */
121#define ICMP_UNREACH_SRCFAIL 5 /* src route failed */
122#define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */
123#define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */
124#define ICMP_UNREACH_ISOLATED 8 /* src host isolated */
125#define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */
126#define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */
127#define ICMP_UNREACH_TOSNET 11 /* bad tos for net */
128#define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */
129#define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */
130#define ICMP_REDIRECT 5 /* shorter route, codes: */
131#define ICMP_REDIRECT_NET 0 /* for network */
132#define ICMP_REDIRECT_HOST 1 /* for host */
133#define ICMP_REDIRECT_TOSNET 2 /* for tos and net */
134#define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */
135#define ICMP_ECHO 8 /* echo service */
136#define ICMP_ROUTERADVERT 9 /* router advertisement */
137#define ICMP_ROUTERSOLICIT 10 /* router solicitation */
138#define ICMP_TIMXCEED 11 /* time exceeded, code: */
139#define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */
140#define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */
141#define ICMP_PARAMPROB 12 /* ip header bad */
142#define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */
143#define ICMP_TSTAMP 13 /* timestamp request */
144#define ICMP_TSTAMPREPLY 14 /* timestamp reply */
145#define ICMP_IREQ 15 /* information request */
146#define ICMP_IREQREPLY 16 /* information reply */
147#define ICMP_MASKREQ 17 /* address mask request */
148#define ICMP_MASKREPLY 18 /* address mask reply */
149
150#define ICMP_MAXTYPE 18
151
152#define ICMP_INFOTYPE(type) \
153 ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
154 (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
155 (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
156 (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
157 (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
158#define ICMP_MPLS_EXT_TYPE(type) \
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159 ((type) == ICMP_UNREACH || \
160 (type) == ICMP_TIMXCEED || \
161 (type) == ICMP_PARAMPROB)
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162/* rfc1700 */
163#ifndef ICMP_UNREACH_NET_UNKNOWN
164#define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */
165#endif
166#ifndef ICMP_UNREACH_HOST_UNKNOWN
167#define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */
168#endif
169#ifndef ICMP_UNREACH_ISOLATED
170#define ICMP_UNREACH_ISOLATED 8 /* source host isolated */
171#endif
172#ifndef ICMP_UNREACH_NET_PROHIB
173#define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */
174#endif
175#ifndef ICMP_UNREACH_HOST_PROHIB
176#define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */
177#endif
178#ifndef ICMP_UNREACH_TOSNET
179#define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */
180#endif
181#ifndef ICMP_UNREACH_TOSHOST
182#define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */
183#endif
184
185/* rfc1716 */
186#ifndef ICMP_UNREACH_FILTER_PROHIB
187#define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */
188#endif
189#ifndef ICMP_UNREACH_HOST_PRECEDENCE
190#define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */
191#endif
192#ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
193#define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */
194#endif
195
196/* Most of the icmp types */
197static struct tok icmp2str[] = {
198 { ICMP_ECHOREPLY, "echo reply" },
199 { ICMP_SOURCEQUENCH, "source quench" },
200 { ICMP_ECHO, "echo request" },
201 { ICMP_ROUTERSOLICIT, "router solicitation" },
202 { ICMP_TSTAMP, "time stamp request" },
203 { ICMP_TSTAMPREPLY, "time stamp reply" },
204 { ICMP_IREQ, "information request" },
205 { ICMP_IREQREPLY, "information reply" },
206 { ICMP_MASKREQ, "address mask request" },
207 { 0, NULL }
208};
209
210/* Formats for most of the ICMP_UNREACH codes */
211static struct tok unreach2str[] = {
212 { ICMP_UNREACH_NET, "net %s unreachable" },
213 { ICMP_UNREACH_HOST, "host %s unreachable" },
214 { ICMP_UNREACH_SRCFAIL,
215 "%s unreachable - source route failed" },
216 { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" },
217 { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" },
218 { ICMP_UNREACH_ISOLATED,
219 "%s unreachable - source host isolated" },
220 { ICMP_UNREACH_NET_PROHIB,
221 "net %s unreachable - admin prohibited" },
222 { ICMP_UNREACH_HOST_PROHIB,
223 "host %s unreachable - admin prohibited" },
224 { ICMP_UNREACH_TOSNET,
225 "net %s unreachable - tos prohibited" },
226 { ICMP_UNREACH_TOSHOST,
227 "host %s unreachable - tos prohibited" },
228 { ICMP_UNREACH_FILTER_PROHIB,
229 "host %s unreachable - admin prohibited filter" },
230 { ICMP_UNREACH_HOST_PRECEDENCE,
231 "host %s unreachable - host precedence violation" },
232 { ICMP_UNREACH_PRECEDENCE_CUTOFF,
233 "host %s unreachable - precedence cutoff" },
234 { 0, NULL }
235};
236
237/* Formats for the ICMP_REDIRECT codes */
238static struct tok type2str[] = {
239 { ICMP_REDIRECT_NET, "redirect %s to net %s" },
240 { ICMP_REDIRECT_HOST, "redirect %s to host %s" },
241 { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" },
242 { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" },
243 { 0, NULL }
244};
245
246/* rfc1191 */
247struct mtu_discovery {
248 u_int16_t unused;
249 u_int16_t nexthopmtu;
250};
251
252/* rfc1256 */
253struct ih_rdiscovery {
254 u_int8_t ird_addrnum;
255 u_int8_t ird_addrsiz;
256 u_int16_t ird_lifetime;
257};
258
259struct id_rdiscovery {
260 u_int32_t ird_addr;
261 u_int32_t ird_pref;
262};
263
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264/*
265 * draft-bonica-internet-icmp-08
266 *
267 * The Destination Unreachable, Time Exceeded
268 * and Parameter Problem messages are slighly changed as per
269 * the above draft. A new Length field gets added to give
270 * the caller an idea about the length of the piggypacked
271 * IP packet before the MPLS extension header starts.
272 *
273 * The Length field represents length of the padded "original datagram"
274 * field measured in 32-bit words.
275 *
276 * 0 1 2 3
277 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
278 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
279 * | Type | Code | Checksum |
280 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
281 * | unused | Length | unused |
282 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
283 * | Internet Header + leading octets of original datagram |
284 * | |
285 * | // |
286 * | |
287 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
288 */
289
290struct icmp_ext_t {
291 u_int8_t icmp_type;
292 u_int8_t icmp_code;
293 u_int8_t icmp_checksum[2];
294 u_int8_t icmp_reserved;
295 u_int8_t icmp_length;
296 u_int8_t icmp_reserved2[2];
297 u_int8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
298 u_int8_t icmp_ext_version_res[2];
299 u_int8_t icmp_ext_checksum[2];
300 u_int8_t icmp_ext_data[1];
301};
302
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303struct icmp_mpls_ext_object_header_t {
304 u_int8_t length[2];
305 u_int8_t class_num;
306 u_int8_t ctype;
307};
308
309static const struct tok icmp_mpls_ext_obj_values[] = {
310 { 1, "MPLS Stack Entry" },
311 { 2, "Extended Payload" },
312 { 0, NULL}
313};
314
315/* prototypes */
316const char *icmp_tstamp_print(u_int);
317
318/* print the milliseconds since midnight UTC */
319const char *
320icmp_tstamp_print(u_int tstamp) {
321 u_int msec,sec,min,hrs;
322
323 static char buf[64];
324
325 msec = tstamp % 1000;
326 sec = tstamp / 1000;
327 min = sec / 60; sec -= min * 60;
328 hrs = min / 60; min -= hrs * 60;
329 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
330 return buf;
331}
332
333void
334icmp_print(const u_char *bp, u_int plen, const u_char *bp2, int fragmented)
335{
336 char *cp;
337 const struct icmp *dp;
66170f0a 338 const struct icmp_ext_t *ext_dp;
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339 const struct ip *ip;
340 const char *str, *fmt;
341 const struct ip *oip;
342 const struct udphdr *ouh;
343 const u_int8_t *obj_tptr;
344 u_int32_t raw_label;
66170f0a 345 const u_char *snapend_save;
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346 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
347 u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype;
348 char buf[MAXHOSTNAMELEN + 100];
349
350 dp = (struct icmp *)bp;
66170f0a 351 ext_dp = (struct icmp_ext_t *)bp;
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352 ip = (struct ip *)bp2;
353 str = buf;
354
355 TCHECK(dp->icmp_code);
356 switch (dp->icmp_type) {
357
358 case ICMP_ECHO:
359 case ICMP_ECHOREPLY:
360 TCHECK(dp->icmp_seq);
361 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
362 dp->icmp_type == ICMP_ECHO ?
363 "request" : "reply",
364 EXTRACT_16BITS(&dp->icmp_id),
365 EXTRACT_16BITS(&dp->icmp_seq));
366 break;
367
368 case ICMP_UNREACH:
369 TCHECK(dp->icmp_ip.ip_dst);
370 switch (dp->icmp_code) {
371
372 case ICMP_UNREACH_PROTOCOL:
373 TCHECK(dp->icmp_ip.ip_p);
374 (void)snprintf(buf, sizeof(buf),
375 "%s protocol %d unreachable",
376 ipaddr_string(&dp->icmp_ip.ip_dst),
377 dp->icmp_ip.ip_p);
378 break;
379
380 case ICMP_UNREACH_PORT:
381 TCHECK(dp->icmp_ip.ip_p);
382 oip = &dp->icmp_ip;
383 hlen = IP_HL(oip) * 4;
384 ouh = (struct udphdr *)(((u_char *)oip) + hlen);
385 TCHECK(ouh->uh_dport);
386 dport = EXTRACT_16BITS(&ouh->uh_dport);
387 switch (oip->ip_p) {
388
389 case IPPROTO_TCP:
390 (void)snprintf(buf, sizeof(buf),
391 "%s tcp port %s unreachable",
392 ipaddr_string(&oip->ip_dst),
393 tcpport_string(dport));
394 break;
395
396 case IPPROTO_UDP:
397 (void)snprintf(buf, sizeof(buf),
398 "%s udp port %s unreachable",
399 ipaddr_string(&oip->ip_dst),
400 udpport_string(dport));
401 break;
402
403 default:
404 (void)snprintf(buf, sizeof(buf),
405 "%s protocol %d port %d unreachable",
406 ipaddr_string(&oip->ip_dst),
407 oip->ip_p, dport);
408 break;
409 }
410 break;
411
412 case ICMP_UNREACH_NEEDFRAG:
413 {
414 register const struct mtu_discovery *mp;
415 mp = (struct mtu_discovery *)&dp->icmp_void;
416 mtu = EXTRACT_16BITS(&mp->nexthopmtu);
417 if (mtu) {
418 (void)snprintf(buf, sizeof(buf),
419 "%s unreachable - need to frag (mtu %d)",
420 ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
421 } else {
422 (void)snprintf(buf, sizeof(buf),
423 "%s unreachable - need to frag",
424 ipaddr_string(&dp->icmp_ip.ip_dst));
425 }
426 }
427 break;
428
429 default:
430 fmt = tok2str(unreach2str, "#%d %%s unreachable",
431 dp->icmp_code);
432 (void)snprintf(buf, sizeof(buf), fmt,
433 ipaddr_string(&dp->icmp_ip.ip_dst));
434 break;
435 }
436 break;
437
438 case ICMP_REDIRECT:
439 TCHECK(dp->icmp_ip.ip_dst);
440 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
441 dp->icmp_code);
442 (void)snprintf(buf, sizeof(buf), fmt,
443 ipaddr_string(&dp->icmp_ip.ip_dst),
444 ipaddr_string(&dp->icmp_gwaddr));
445 break;
446
447 case ICMP_ROUTERADVERT:
448 {
449 register const struct ih_rdiscovery *ihp;
450 register const struct id_rdiscovery *idp;
451 u_int lifetime, num, size;
452
453 (void)snprintf(buf, sizeof(buf), "router advertisement");
454 cp = buf + strlen(buf);
455
456 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
457 TCHECK(*ihp);
458 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
459 cp = buf + strlen(buf);
460 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
461 if (lifetime < 60) {
462 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
463 lifetime);
464 } else if (lifetime < 60 * 60) {
465 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
466 lifetime / 60, lifetime % 60);
467 } else {
468 (void)snprintf(cp, sizeof(buf) - (cp - buf),
469 "%u:%02u:%02u",
470 lifetime / 3600,
471 (lifetime % 3600) / 60,
472 lifetime % 60);
473 }
474 cp = buf + strlen(buf);
475
476 num = ihp->ird_addrnum;
477 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
478 cp = buf + strlen(buf);
479
480 size = ihp->ird_addrsiz;
481 if (size != 2) {
482 (void)snprintf(cp, sizeof(buf) - (cp - buf),
483 " [size %d]", size);
484 break;
485 }
486 idp = (struct id_rdiscovery *)&dp->icmp_data;
487 while (num-- > 0) {
488 TCHECK(*idp);
489 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
490 ipaddr_string(&idp->ird_addr),
491 EXTRACT_32BITS(&idp->ird_pref));
492 cp = buf + strlen(buf);
493 ++idp;
494 }
495 }
496 break;
497
498 case ICMP_TIMXCEED:
499 TCHECK(dp->icmp_ip.ip_dst);
500 switch (dp->icmp_code) {
501
502 case ICMP_TIMXCEED_INTRANS:
503 str = "time exceeded in-transit";
504 break;
505
506 case ICMP_TIMXCEED_REASS:
507 str = "ip reassembly time exceeded";
508 break;
509
510 default:
511 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
512 dp->icmp_code);
513 break;
514 }
515 break;
516
517 case ICMP_PARAMPROB:
518 if (dp->icmp_code)
519 (void)snprintf(buf, sizeof(buf),
520 "parameter problem - code %d", dp->icmp_code);
521 else {
522 TCHECK(dp->icmp_pptr);
523 (void)snprintf(buf, sizeof(buf),
524 "parameter problem - octet %d", dp->icmp_pptr);
525 }
526 break;
527
528 case ICMP_MASKREPLY:
529 TCHECK(dp->icmp_mask);
530 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
531 EXTRACT_32BITS(&dp->icmp_mask));
532 break;
533
534 case ICMP_TSTAMP:
535 TCHECK(dp->icmp_seq);
536 (void)snprintf(buf, sizeof(buf),
537 "time stamp query id %u seq %u",
538 EXTRACT_16BITS(&dp->icmp_id),
539 EXTRACT_16BITS(&dp->icmp_seq));
540 break;
541
542 case ICMP_TSTAMPREPLY:
543 TCHECK(dp->icmp_ttime);
544 (void)snprintf(buf, sizeof(buf),
545 "time stamp reply id %u seq %u: org %s",
546 EXTRACT_16BITS(&dp->icmp_id),
547 EXTRACT_16BITS(&dp->icmp_seq),
548 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime)));
549
550 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
551 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime)));
552 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
553 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime)));
554 break;
555
556 default:
557 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
558 break;
559 }
560 (void)printf("ICMP %s, length %u", str, plen);
561 if (vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
562 u_int16_t sum, icmp_sum;
563 if (TTEST2(*bp, plen)) {
564 sum = in_cksum((u_short*)dp, plen, 0);
565 if (sum != 0) {
566 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum);
567 (void)printf(" (wrong icmp cksum %x (->%x)!)",
568 icmp_sum,
569 in_cksum_shouldbe(icmp_sum, sum));
570 }
571 }
572 }
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573
574 /*
575 * print the remnants of the IP packet.
576 * save the snaplength as this may get overidden in the IP printer.
577 */
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578 if (vflag >= 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
579 bp += 8;
580 (void)printf("\n\t");
581 ip = (struct ip *)bp;
582 snaplen = snapend - bp;
66170f0a 583 snapend_save = snapend;
c8cf0f94 584 ip_print(gndo, bp, EXTRACT_16BITS(&ip->ip_len));
66170f0a 585 snapend = snapend_save;
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586 }
587
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588 /*
589 * Attempt to decode the MPLS extensions only for some ICMP types.
590 */
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591 if (vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) {
592
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593 TCHECK(*ext_dp);
594
595 /*
596 * Check first if the mpls extension header shows a non-zero length.
597 * If the length field is not set then silently verify the checksum
598 * to check if an extension header is present. This is expedient,
599 * however not all implementations set the length field proper.
600 */
601 if (!ext_dp->icmp_length &&
602 in_cksum((const u_short *)&ext_dp->icmp_ext_version_res,
603 plen - ICMP_EXTD_MINLEN, 0)) {
604 return;
605 }
606
607 printf("\n\tMPLS extension v%u",
608 ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)));
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609
610 /*
611 * Sanity checking of the header.
612 */
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613 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
614 ICMP_MPLS_EXT_VERSION) {
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615 printf(" packet not supported");
616 return;
617 }
618
619 hlen = plen - ICMP_EXTD_MINLEN;
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620 printf(", checksum 0x%04x (%scorrect), length %u",
621 EXTRACT_16BITS(ext_dp->icmp_ext_checksum),
622 in_cksum((const u_short *)&ext_dp->icmp_ext_version_res,
623 plen - ICMP_EXTD_MINLEN, 0) ? "in" : "",
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624 hlen);
625
626 hlen -= 4; /* subtract common header size */
66170f0a 627 obj_tptr = (u_int8_t *)ext_dp->icmp_ext_data;
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628
629 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
630
631 icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr;
632 TCHECK(*icmp_mpls_ext_object_header);
633 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length);
634 obj_class_num = icmp_mpls_ext_object_header->class_num;
635 obj_ctype = icmp_mpls_ext_object_header->ctype;
636 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
637
638 printf("\n\t %s Object (%u), Class-Type: %u, length %u",
639 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
640 obj_class_num,
641 obj_ctype,
642 obj_tlen);
643
644 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
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645
646 /* infinite loop protection */
647 if ((obj_class_num == 0) ||
648 (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) {
649 return;
650 }
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651 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
652
653 switch (obj_class_num) {
654 case 1:
655 switch(obj_ctype) {
656 case 1:
657 TCHECK2(*obj_tptr, 4);
658 raw_label = EXTRACT_32BITS(obj_tptr);
659 printf("\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label));
660 if (MPLS_STACK(raw_label))
661 printf(", [S]");
662 printf(", ttl %u", MPLS_TTL(raw_label));
663 break;
664 default:
665 print_unknown_data(obj_tptr, "\n\t ", obj_tlen);
666 }
667 break;
668
669 /*
670 * FIXME those are the defined objects that lack a decoder
671 * you are welcome to contribute code ;-)
672 */
673 case 2:
674 default:
675 print_unknown_data(obj_tptr, "\n\t ", obj_tlen);
676 break;
677 }
678 if (hlen < obj_tlen)
679 break;
680 hlen -= obj_tlen;
681 obj_tptr += obj_tlen;
682 }
683 }
684
685 return;
686trunc:
687 fputs("[|icmp]", stdout);
688}