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 #include <sys/cdefs.h>
23 #ifndef lint
24 __RCSID("$NetBSD: print-icmp.c,v 1.6 2015/03/31 21:59:35 christos Exp $");
25 #endif
26
27 #define NETDISSECT_REWORKED
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include <tcpdump-stdinc.h>
33
34 #include <stdio.h>
35 #include <string.h>
36
37 #include "interface.h"
38 #include "addrtoname.h"
39 #include "extract.h" /* must come after interface.h */
40
41 #include "ip.h"
42 #include "udp.h"
43 #include "ipproto.h"
44 #include "mpls.h"
45
46 /*
47 * Interface Control Message Protocol Definitions.
48 * Per RFC 792, September 1981.
49 */
50
51 /*
52 * Structure of an icmp header.
53 */
54 struct icmp {
55 uint8_t icmp_type; /* type of message, see below */
56 uint8_t icmp_code; /* type sub code */
57 uint16_t icmp_cksum; /* ones complement cksum of struct */
58 union {
59 uint8_t ih_pptr; /* ICMP_PARAMPROB */
60 struct in_addr ih_gwaddr; /* ICMP_REDIRECT */
61 struct ih_idseq {
62 uint16_t icd_id;
63 uint16_t icd_seq;
64 } ih_idseq;
65 uint32_t ih_void;
66 } icmp_hun;
67 #define icmp_pptr icmp_hun.ih_pptr
68 #define icmp_gwaddr icmp_hun.ih_gwaddr
69 #define icmp_id icmp_hun.ih_idseq.icd_id
70 #define icmp_seq icmp_hun.ih_idseq.icd_seq
71 #define icmp_void icmp_hun.ih_void
72 union {
73 struct id_ts {
74 uint32_t its_otime;
75 uint32_t its_rtime;
76 uint32_t its_ttime;
77 } id_ts;
78 struct id_ip {
79 struct ip idi_ip;
80 /* options and then 64 bits of data */
81 } id_ip;
82 uint32_t id_mask;
83 uint8_t id_data[1];
84 } icmp_dun;
85 #define icmp_otime icmp_dun.id_ts.its_otime
86 #define icmp_rtime icmp_dun.id_ts.its_rtime
87 #define icmp_ttime icmp_dun.id_ts.its_ttime
88 #define icmp_ip icmp_dun.id_ip.idi_ip
89 #define icmp_mask icmp_dun.id_mask
90 #define icmp_data icmp_dun.id_data
91 };
92
93 #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
94 #define ICMP_MPLS_EXT_VERSION 2
95
96 /*
97 * Lower bounds on packet lengths for various types.
98 * For the error advice packets must first insure that the
99 * packet is large enought to contain the returned ip header.
100 * Only then can we do the check to see if 64 bits of packet
101 * data have been returned, since we need to check the returned
102 * ip header length.
103 */
104 #define ICMP_MINLEN 8 /* abs minimum */
105 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */
106 #define ICMP_TSLEN (8 + 3 * sizeof (uint32_t)) /* timestamp */
107 #define ICMP_MASKLEN 12 /* address mask */
108 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */
109 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
110 /* N.B.: must separately check that ip_hl >= 5 */
111
112 /*
113 * Definition of type and code field values.
114 */
115 #define ICMP_ECHOREPLY 0 /* echo reply */
116 #define ICMP_UNREACH 3 /* dest unreachable, codes: */
117 #define ICMP_UNREACH_NET 0 /* bad net */
118 #define ICMP_UNREACH_HOST 1 /* bad host */
119 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */
120 #define ICMP_UNREACH_PORT 3 /* bad port */
121 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */
122 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */
123 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */
124 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */
125 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */
126 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */
127 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */
128 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */
129 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */
130 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */
131 #define ICMP_REDIRECT 5 /* shorter route, codes: */
132 #define ICMP_REDIRECT_NET 0 /* for network */
133 #define ICMP_REDIRECT_HOST 1 /* for host */
134 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */
135 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */
136 #define ICMP_ECHO 8 /* echo service */
137 #define ICMP_ROUTERADVERT 9 /* router advertisement */
138 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */
139 #define ICMP_TIMXCEED 11 /* time exceeded, code: */
140 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */
141 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */
142 #define ICMP_PARAMPROB 12 /* ip header bad */
143 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */
144 #define ICMP_TSTAMP 13 /* timestamp request */
145 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */
146 #define ICMP_IREQ 15 /* information request */
147 #define ICMP_IREQREPLY 16 /* information reply */
148 #define ICMP_MASKREQ 17 /* address mask request */
149 #define ICMP_MASKREPLY 18 /* address mask reply */
150
151 #define ICMP_MAXTYPE 18
152
153 #define ICMP_ERRTYPE(type) \
154 ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
155 (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
156 (type) == ICMP_PARAMPROB)
157 #define ICMP_MPLS_EXT_TYPE(type) \
158 ((type) == ICMP_UNREACH || \
159 (type) == ICMP_TIMXCEED || \
160 (type) == ICMP_PARAMPROB)
161 /* rfc1700 */
162 #ifndef ICMP_UNREACH_NET_UNKNOWN
163 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */
164 #endif
165 #ifndef ICMP_UNREACH_HOST_UNKNOWN
166 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */
167 #endif
168 #ifndef ICMP_UNREACH_ISOLATED
169 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */
170 #endif
171 #ifndef ICMP_UNREACH_NET_PROHIB
172 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */
173 #endif
174 #ifndef ICMP_UNREACH_HOST_PROHIB
175 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */
176 #endif
177 #ifndef ICMP_UNREACH_TOSNET
178 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */
179 #endif
180 #ifndef ICMP_UNREACH_TOSHOST
181 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */
182 #endif
183
184 /* rfc1716 */
185 #ifndef ICMP_UNREACH_FILTER_PROHIB
186 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */
187 #endif
188 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
189 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */
190 #endif
191 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
192 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */
193 #endif
194
195 /* Most of the icmp types */
196 static const struct tok icmp2str[] = {
197 { ICMP_ECHOREPLY, "echo reply" },
198 { ICMP_SOURCEQUENCH, "source quench" },
199 { ICMP_ECHO, "echo request" },
200 { ICMP_ROUTERSOLICIT, "router solicitation" },
201 { ICMP_TSTAMP, "time stamp request" },
202 { ICMP_TSTAMPREPLY, "time stamp reply" },
203 { ICMP_IREQ, "information request" },
204 { ICMP_IREQREPLY, "information reply" },
205 { ICMP_MASKREQ, "address mask request" },
206 { 0, NULL }
207 };
208
209 /* Formats for most of the ICMP_UNREACH codes */
210 static const struct tok unreach2str[] = {
211 { ICMP_UNREACH_NET, "net %s unreachable" },
212 { ICMP_UNREACH_HOST, "host %s unreachable" },
213 { ICMP_UNREACH_SRCFAIL,
214 "%s unreachable - source route failed" },
215 { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" },
216 { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" },
217 { ICMP_UNREACH_ISOLATED,
218 "%s unreachable - source host isolated" },
219 { ICMP_UNREACH_NET_PROHIB,
220 "net %s unreachable - admin prohibited" },
221 { ICMP_UNREACH_HOST_PROHIB,
222 "host %s unreachable - admin prohibited" },
223 { ICMP_UNREACH_TOSNET,
224 "net %s unreachable - tos prohibited" },
225 { ICMP_UNREACH_TOSHOST,
226 "host %s unreachable - tos prohibited" },
227 { ICMP_UNREACH_FILTER_PROHIB,
228 "host %s unreachable - admin prohibited filter" },
229 { ICMP_UNREACH_HOST_PRECEDENCE,
230 "host %s unreachable - host precedence violation" },
231 { ICMP_UNREACH_PRECEDENCE_CUTOFF,
232 "host %s unreachable - precedence cutoff" },
233 { 0, NULL }
234 };
235
236 /* Formats for the ICMP_REDIRECT codes */
237 static const struct tok type2str[] = {
238 { ICMP_REDIRECT_NET, "redirect %s to net %s" },
239 { ICMP_REDIRECT_HOST, "redirect %s to host %s" },
240 { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" },
241 { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" },
242 { 0, NULL }
243 };
244
245 /* rfc1191 */
246 struct mtu_discovery {
247 uint16_t unused;
248 uint16_t nexthopmtu;
249 };
250
251 /* rfc1256 */
252 struct ih_rdiscovery {
253 uint8_t ird_addrnum;
254 uint8_t ird_addrsiz;
255 uint16_t ird_lifetime;
256 };
257
258 struct id_rdiscovery {
259 uint32_t ird_addr;
260 uint32_t ird_pref;
261 };
262
263 /*
264 * draft-bonica-internet-icmp-08
265 *
266 * The Destination Unreachable, Time Exceeded
267 * and Parameter Problem messages are slighly changed as per
268 * the above draft. A new Length field gets added to give
269 * the caller an idea about the length of the piggypacked
270 * IP packet before the MPLS extension header starts.
271 *
272 * The Length field represents length of the padded "original datagram"
273 * field measured in 32-bit words.
274 *
275 * 0 1 2 3
276 * 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
277 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
278 * | Type | Code | Checksum |
279 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
280 * | unused | Length | unused |
281 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
282 * | Internet Header + leading octets of original datagram |
283 * | |
284 * | // |
285 * | |
286 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
287 */
288
289 struct icmp_ext_t {
290 uint8_t icmp_type;
291 uint8_t icmp_code;
292 uint8_t icmp_checksum[2];
293 uint8_t icmp_reserved;
294 uint8_t icmp_length;
295 uint8_t icmp_reserved2[2];
296 uint8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
297 uint8_t icmp_ext_version_res[2];
298 uint8_t icmp_ext_checksum[2];
299 uint8_t icmp_ext_data[1];
300 };
301
302 struct icmp_mpls_ext_object_header_t {
303 uint8_t length[2];
304 uint8_t class_num;
305 uint8_t ctype;
306 };
307
308 static const struct tok icmp_mpls_ext_obj_values[] = {
309 { 1, "MPLS Stack Entry" },
310 { 2, "Extended Payload" },
311 { 0, NULL}
312 };
313
314 /* prototypes */
315 const char *icmp_tstamp_print(u_int);
316
317 /* print the milliseconds since midnight UTC */
318 const char *
icmp_tstamp_print(u_int tstamp)319 icmp_tstamp_print(u_int tstamp)
320 {
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
333 void
icmp_print(netdissect_options * ndo,const u_char * bp,u_int plen,const u_char * bp2,int fragmented)334 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
335 int fragmented)
336 {
337 char *cp;
338 const struct icmp *dp;
339 const struct icmp_ext_t *ext_dp;
340 const struct ip *ip;
341 const char *str, *fmt;
342 const struct ip *oip;
343 const struct udphdr *ouh;
344 const uint8_t *obj_tptr;
345 uint32_t raw_label;
346 const u_char *snapend_save;
347 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
348 u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype;
349 char buf[MAXHOSTNAMELEN + 100];
350 struct cksum_vec vec[1];
351
352 dp = (struct icmp *)bp;
353 ext_dp = (struct icmp_ext_t *)bp;
354 ip = (struct ip *)bp2;
355 str = buf;
356
357 ND_TCHECK(dp->icmp_code);
358 switch (dp->icmp_type) {
359
360 case ICMP_ECHO:
361 case ICMP_ECHOREPLY:
362 ND_TCHECK(dp->icmp_seq);
363 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
364 dp->icmp_type == ICMP_ECHO ?
365 "request" : "reply",
366 EXTRACT_16BITS(&dp->icmp_id),
367 EXTRACT_16BITS(&dp->icmp_seq));
368 break;
369
370 case ICMP_UNREACH:
371 ND_TCHECK(dp->icmp_ip.ip_dst);
372 switch (dp->icmp_code) {
373
374 case ICMP_UNREACH_PROTOCOL:
375 ND_TCHECK(dp->icmp_ip.ip_p);
376 (void)snprintf(buf, sizeof(buf),
377 "%s protocol %d unreachable",
378 ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
379 dp->icmp_ip.ip_p);
380 break;
381
382 case ICMP_UNREACH_PORT:
383 ND_TCHECK(dp->icmp_ip.ip_p);
384 oip = &dp->icmp_ip;
385 hlen = IP_HL(oip) * 4;
386 ouh = (struct udphdr *)(((u_char *)oip) + hlen);
387 ND_TCHECK(ouh->uh_dport);
388 dport = EXTRACT_16BITS(&ouh->uh_dport);
389 switch (oip->ip_p) {
390
391 case IPPROTO_TCP:
392 (void)snprintf(buf, sizeof(buf),
393 "%s tcp port %s unreachable",
394 ipaddr_string(ndo, &oip->ip_dst),
395 tcpport_string(dport));
396 break;
397
398 case IPPROTO_UDP:
399 (void)snprintf(buf, sizeof(buf),
400 "%s udp port %s unreachable",
401 ipaddr_string(ndo, &oip->ip_dst),
402 udpport_string(dport));
403 break;
404
405 default:
406 (void)snprintf(buf, sizeof(buf),
407 "%s protocol %d port %d unreachable",
408 ipaddr_string(ndo, &oip->ip_dst),
409 oip->ip_p, dport);
410 break;
411 }
412 break;
413
414 case ICMP_UNREACH_NEEDFRAG:
415 {
416 register const struct mtu_discovery *mp;
417 mp = (struct mtu_discovery *)(u_char *)&dp->icmp_void;
418 mtu = EXTRACT_16BITS(&mp->nexthopmtu);
419 if (mtu) {
420 (void)snprintf(buf, sizeof(buf),
421 "%s unreachable - need to frag (mtu %d)",
422 ipaddr_string(ndo, &dp->icmp_ip.ip_dst), mtu);
423 } else {
424 (void)snprintf(buf, sizeof(buf),
425 "%s unreachable - need to frag",
426 ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
427 }
428 }
429 break;
430
431 default:
432 fmt = tok2str(unreach2str, "#%d %%s unreachable",
433 dp->icmp_code);
434 (void)snprintf(buf, sizeof(buf), fmt,
435 ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
436 break;
437 }
438 break;
439
440 case ICMP_REDIRECT:
441 ND_TCHECK(dp->icmp_ip.ip_dst);
442 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
443 dp->icmp_code);
444 (void)snprintf(buf, sizeof(buf), fmt,
445 ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
446 ipaddr_string(ndo, &dp->icmp_gwaddr));
447 break;
448
449 case ICMP_ROUTERADVERT:
450 {
451 register const struct ih_rdiscovery *ihp;
452 register const struct id_rdiscovery *idp;
453 u_int lifetime, num, size;
454
455 (void)snprintf(buf, sizeof(buf), "router advertisement");
456 cp = buf + strlen(buf);
457
458 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
459 ND_TCHECK(*ihp);
460 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
461 cp = buf + strlen(buf);
462 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
463 if (lifetime < 60) {
464 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
465 lifetime);
466 } else if (lifetime < 60 * 60) {
467 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
468 lifetime / 60, lifetime % 60);
469 } else {
470 (void)snprintf(cp, sizeof(buf) - (cp - buf),
471 "%u:%02u:%02u",
472 lifetime / 3600,
473 (lifetime % 3600) / 60,
474 lifetime % 60);
475 }
476 cp = buf + strlen(buf);
477
478 num = ihp->ird_addrnum;
479 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
480 cp = buf + strlen(buf);
481
482 size = ihp->ird_addrsiz;
483 if (size != 2) {
484 (void)snprintf(cp, sizeof(buf) - (cp - buf),
485 " [size %d]", size);
486 break;
487 }
488 idp = (struct id_rdiscovery *)&dp->icmp_data;
489 while (num-- > 0) {
490 ND_TCHECK(*idp);
491 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
492 ipaddr_string(ndo, &idp->ird_addr),
493 EXTRACT_32BITS(&idp->ird_pref));
494 cp = buf + strlen(buf);
495 ++idp;
496 }
497 }
498 break;
499
500 case ICMP_TIMXCEED:
501 ND_TCHECK(dp->icmp_ip.ip_dst);
502 switch (dp->icmp_code) {
503
504 case ICMP_TIMXCEED_INTRANS:
505 str = "time exceeded in-transit";
506 break;
507
508 case ICMP_TIMXCEED_REASS:
509 str = "ip reassembly time exceeded";
510 break;
511
512 default:
513 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
514 dp->icmp_code);
515 break;
516 }
517 break;
518
519 case ICMP_PARAMPROB:
520 if (dp->icmp_code)
521 (void)snprintf(buf, sizeof(buf),
522 "parameter problem - code %d", dp->icmp_code);
523 else {
524 ND_TCHECK(dp->icmp_pptr);
525 (void)snprintf(buf, sizeof(buf),
526 "parameter problem - octet %d", dp->icmp_pptr);
527 }
528 break;
529
530 case ICMP_MASKREPLY:
531 ND_TCHECK(dp->icmp_mask);
532 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
533 EXTRACT_32BITS(&dp->icmp_mask));
534 break;
535
536 case ICMP_TSTAMP:
537 ND_TCHECK(dp->icmp_seq);
538 (void)snprintf(buf, sizeof(buf),
539 "time stamp query id %u seq %u",
540 EXTRACT_16BITS(&dp->icmp_id),
541 EXTRACT_16BITS(&dp->icmp_seq));
542 break;
543
544 case ICMP_TSTAMPREPLY:
545 ND_TCHECK(dp->icmp_ttime);
546 (void)snprintf(buf, sizeof(buf),
547 "time stamp reply id %u seq %u: org %s",
548 EXTRACT_16BITS(&dp->icmp_id),
549 EXTRACT_16BITS(&dp->icmp_seq),
550 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime)));
551
552 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
553 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime)));
554 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
555 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime)));
556 break;
557
558 default:
559 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
560 break;
561 }
562 ND_PRINT((ndo, "ICMP %s, length %u", str, plen));
563 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
564 uint16_t sum, icmp_sum;
565 struct cksum_vec vec[1];
566 if (ND_TTEST2(*bp, plen)) {
567 vec[0].ptr = (const uint8_t *)(void *)dp;
568 vec[0].len = plen;
569 sum = in_cksum(vec, 1);
570 if (sum != 0) {
571 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum);
572 ND_PRINT((ndo, " (wrong icmp cksum %x (->%x)!)",
573 icmp_sum,
574 in_cksum_shouldbe(icmp_sum, sum)));
575 }
576 }
577 }
578
579 /*
580 * print the remnants of the IP packet.
581 * save the snaplength as this may get overidden in the IP printer.
582 */
583 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(dp->icmp_type)) {
584 bp += 8;
585 ND_PRINT((ndo, "\n\t"));
586 ip = (struct ip *)bp;
587 ndo->ndo_snaplen = ndo->ndo_snapend - bp;
588 snapend_save = ndo->ndo_snapend;
589 ip_print(ndo, bp, EXTRACT_16BITS(&ip->ip_len));
590 ndo->ndo_snapend = snapend_save;
591 }
592
593 /*
594 * Attempt to decode the MPLS extensions only for some ICMP types.
595 */
596 if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) {
597
598 ND_TCHECK(*ext_dp);
599
600 /*
601 * Check first if the mpls extension header shows a non-zero length.
602 * If the length field is not set then silently verify the checksum
603 * to check if an extension header is present. This is expedient,
604 * however not all implementations set the length field proper.
605 */
606 if (!ext_dp->icmp_length) {
607 vec[0].ptr = (const uint8_t *)(void *)&ext_dp->icmp_ext_version_res;
608 vec[0].len = plen - ICMP_EXTD_MINLEN;
609 if (in_cksum(vec, 1)) {
610 return;
611 }
612 }
613
614 ND_PRINT((ndo, "\n\tMPLS extension v%u",
615 ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))));
616
617 /*
618 * Sanity checking of the header.
619 */
620 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
621 ICMP_MPLS_EXT_VERSION) {
622 ND_PRINT((ndo, " packet not supported"));
623 return;
624 }
625
626 hlen = plen - ICMP_EXTD_MINLEN;
627 vec[0].ptr = (const uint8_t *)(void *)&ext_dp->icmp_ext_version_res;
628 vec[0].len = hlen;
629 ND_PRINT((ndo, ", checksum 0x%04x (%scorrect), length %u",
630 EXTRACT_16BITS(ext_dp->icmp_ext_checksum),
631 in_cksum(vec, 1) ? "in" : "",
632 hlen));
633
634 hlen -= 4; /* subtract common header size */
635 obj_tptr = (uint8_t *)ext_dp->icmp_ext_data;
636
637 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
638
639 icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr;
640 ND_TCHECK(*icmp_mpls_ext_object_header);
641 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length);
642 obj_class_num = icmp_mpls_ext_object_header->class_num;
643 obj_ctype = icmp_mpls_ext_object_header->ctype;
644 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
645
646 ND_PRINT((ndo, "\n\t %s Object (%u), Class-Type: %u, length %u",
647 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
648 obj_class_num,
649 obj_ctype,
650 obj_tlen));
651
652 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
653
654 /* infinite loop protection */
655 if ((obj_class_num == 0) ||
656 (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) {
657 return;
658 }
659 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
660
661 switch (obj_class_num) {
662 case 1:
663 switch(obj_ctype) {
664 case 1:
665 ND_TCHECK2(*obj_tptr, 4);
666 raw_label = EXTRACT_32BITS(obj_tptr);
667 ND_PRINT((ndo, "\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)));
668 if (MPLS_STACK(raw_label))
669 ND_PRINT((ndo, ", [S]"));
670 ND_PRINT((ndo, ", ttl %u", MPLS_TTL(raw_label)));
671 break;
672 default:
673 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
674 }
675 break;
676
677 /*
678 * FIXME those are the defined objects that lack a decoder
679 * you are welcome to contribute code ;-)
680 */
681 case 2:
682 default:
683 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
684 break;
685 }
686 if (hlen < obj_tlen)
687 break;
688 hlen -= obj_tlen;
689 obj_tptr += obj_tlen;
690 }
691 }
692
693 return;
694 trunc:
695 ND_PRINT((ndo, "[|icmp]"));
696 }
697 /*
698 * Local Variables:
699 * c-style: whitesmith
700 * c-basic-offset: 8
701 * End:
702 */
703