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Merge pull request #916 from stevekay/master
[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 /* \summary: Internet Control Message Protocol (ICMP) printer */
23
24 #ifdef HAVE_CONFIG_H
25 #include <config.h>
26 #endif
27
28 #include "netdissect-stdinc.h"
29
30 #include <stdio.h>
31 #include <string.h>
32
33 #include "netdissect.h"
34 #include "addrtoname.h"
35 #include "extract.h"
36
37 #include "ip.h"
38 #include "udp.h"
39 #include "ipproto.h"
40 #include "mpls.h"
41
42 /*
43 * Interface Control Message Protocol Definitions.
44 * Per RFC 792, September 1981.
45 */
46
47 /*
48 * Structure of an icmp header.
49 */
50 struct icmp {
51 nd_uint8_t icmp_type; /* type of message, see below */
52 nd_uint8_t icmp_code; /* type sub code */
53 nd_uint16_t icmp_cksum; /* ones complement cksum of struct */
54 union {
55 nd_uint8_t ih_pptr; /* ICMP_PARAMPROB */
56 nd_ipv4 ih_gwaddr; /* ICMP_REDIRECT */
57 struct ih_idseq {
58 nd_uint16_t icd_id;
59 nd_uint16_t icd_seq;
60 } ih_idseq;
61 nd_uint32_t ih_void;
62 } icmp_hun;
63 #define icmp_pptr icmp_hun.ih_pptr
64 #define icmp_gwaddr icmp_hun.ih_gwaddr
65 #define icmp_id icmp_hun.ih_idseq.icd_id
66 #define icmp_seq icmp_hun.ih_idseq.icd_seq
67 #define icmp_void icmp_hun.ih_void
68 union {
69 struct id_ts {
70 nd_uint32_t its_otime;
71 nd_uint32_t its_rtime;
72 nd_uint32_t its_ttime;
73 } id_ts;
74 struct id_ip {
75 struct ip idi_ip;
76 /* options and then 64 bits of data */
77 } id_ip;
78 nd_uint32_t id_mask;
79 nd_byte id_data[1];
80 } icmp_dun;
81 #define icmp_otime icmp_dun.id_ts.its_otime
82 #define icmp_rtime icmp_dun.id_ts.its_rtime
83 #define icmp_ttime icmp_dun.id_ts.its_ttime
84 #define icmp_ip icmp_dun.id_ip.idi_ip
85 #define icmp_mask icmp_dun.id_mask
86 #define icmp_data icmp_dun.id_data
87 };
88
89 #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
90 #define ICMP_MPLS_EXT_VERSION 2
91
92 /*
93 * Lower bounds on packet lengths for various types.
94 * For the error advice packets must first insure that the
95 * packet is large enough to contain the returned ip header.
96 * Only then can we do the check to see if 64 bits of packet
97 * data have been returned, since we need to check the returned
98 * ip header length.
99 */
100 #define ICMP_MINLEN 8 /* abs minimum */
101 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */
102 #define ICMP_TSLEN (8 + 3 * sizeof (uint32_t)) /* timestamp */
103 #define ICMP_MASKLEN 12 /* address mask */
104 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */
105 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
106 /* N.B.: must separately check that ip_hl >= 5 */
107
108 /*
109 * Definition of type and code field values.
110 */
111 #define ICMP_ECHOREPLY 0 /* echo reply */
112 #define ICMP_UNREACH 3 /* dest unreachable, codes: */
113 #define ICMP_UNREACH_NET 0 /* bad net */
114 #define ICMP_UNREACH_HOST 1 /* bad host */
115 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */
116 #define ICMP_UNREACH_PORT 3 /* bad port */
117 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */
118 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */
119 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */
120 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */
121 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */
122 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */
123 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */
124 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */
125 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */
126 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */
127 #define ICMP_REDIRECT 5 /* shorter route, codes: */
128 #define ICMP_REDIRECT_NET 0 /* for network */
129 #define ICMP_REDIRECT_HOST 1 /* for host */
130 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */
131 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */
132 #define ICMP_ECHO 8 /* echo service */
133 #define ICMP_ROUTERADVERT 9 /* router advertisement */
134 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */
135 #define ICMP_TIMXCEED 11 /* time exceeded, code: */
136 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */
137 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */
138 #define ICMP_PARAMPROB 12 /* ip header bad */
139 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */
140 #define ICMP_TSTAMP 13 /* timestamp request */
141 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */
142 #define ICMP_IREQ 15 /* information request */
143 #define ICMP_IREQREPLY 16 /* information reply */
144 #define ICMP_MASKREQ 17 /* address mask request */
145 #define ICMP_MASKREPLY 18 /* address mask reply */
146
147 #define ICMP_MAXTYPE 18
148
149 #define ICMP_ERRTYPE(type) \
150 ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
151 (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
152 (type) == ICMP_PARAMPROB)
153 #define ICMP_MPLS_EXT_TYPE(type) \
154 ((type) == ICMP_UNREACH || \
155 (type) == ICMP_TIMXCEED || \
156 (type) == ICMP_PARAMPROB)
157 /* rfc1700 */
158 #ifndef ICMP_UNREACH_NET_UNKNOWN
159 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */
160 #endif
161 #ifndef ICMP_UNREACH_HOST_UNKNOWN
162 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */
163 #endif
164 #ifndef ICMP_UNREACH_ISOLATED
165 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */
166 #endif
167 #ifndef ICMP_UNREACH_NET_PROHIB
168 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */
169 #endif
170 #ifndef ICMP_UNREACH_HOST_PROHIB
171 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */
172 #endif
173 #ifndef ICMP_UNREACH_TOSNET
174 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */
175 #endif
176 #ifndef ICMP_UNREACH_TOSHOST
177 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */
178 #endif
179
180 /* rfc1716 */
181 #ifndef ICMP_UNREACH_FILTER_PROHIB
182 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */
183 #endif
184 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
185 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */
186 #endif
187 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
188 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */
189 #endif
190
191 /* Most of the icmp types */
192 static const struct tok icmp2str[] = {
193 { ICMP_ECHOREPLY, "echo reply" },
194 { ICMP_SOURCEQUENCH, "source quench" },
195 { ICMP_ECHO, "echo request" },
196 { ICMP_ROUTERSOLICIT, "router solicitation" },
197 { ICMP_TSTAMP, "time stamp request" },
198 { ICMP_TSTAMPREPLY, "time stamp reply" },
199 { ICMP_IREQ, "information request" },
200 { ICMP_IREQREPLY, "information reply" },
201 { ICMP_MASKREQ, "address mask request" },
202 { 0, NULL }
203 };
204
205 /* rfc1191 */
206 struct mtu_discovery {
207 nd_uint16_t unused;
208 nd_uint16_t nexthopmtu;
209 };
210
211 /* rfc1256 */
212 struct ih_rdiscovery {
213 nd_uint8_t ird_addrnum;
214 nd_uint8_t ird_addrsiz;
215 nd_uint16_t ird_lifetime;
216 };
217
218 struct id_rdiscovery {
219 nd_uint32_t ird_addr;
220 nd_uint32_t ird_pref;
221 };
222
223 /*
224 * draft-bonica-internet-icmp-08
225 *
226 * The Destination Unreachable, Time Exceeded
227 * and Parameter Problem messages are slightly changed as per
228 * the above draft. A new Length field gets added to give
229 * the caller an idea about the length of the piggybacked
230 * IP packet before the MPLS extension header starts.
231 *
232 * The Length field represents length of the padded "original datagram"
233 * field measured in 32-bit words.
234 *
235 * 0 1 2 3
236 * 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
237 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
238 * | Type | Code | Checksum |
239 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
240 * | unused | Length | unused |
241 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
242 * | Internet Header + leading octets of original datagram |
243 * | |
244 * | // |
245 * | |
246 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
247 */
248
249 struct icmp_ext_t {
250 nd_uint8_t icmp_type;
251 nd_uint8_t icmp_code;
252 nd_uint16_t icmp_checksum;
253 nd_byte icmp_reserved;
254 nd_uint8_t icmp_length;
255 nd_byte icmp_reserved2[2];
256 nd_byte icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
257 nd_byte icmp_ext_version_res[2];
258 nd_uint16_t icmp_ext_checksum;
259 nd_byte icmp_ext_data[1];
260 };
261
262 struct icmp_mpls_ext_object_header_t {
263 nd_uint16_t length;
264 nd_uint8_t class_num;
265 nd_uint8_t ctype;
266 };
267
268 static const struct tok icmp_mpls_ext_obj_values[] = {
269 { 1, "MPLS Stack Entry" },
270 { 2, "Extended Payload" },
271 { 0, NULL}
272 };
273
274 /* prototypes */
275 const char *icmp_tstamp_print(u_int);
276
277 /* print the milliseconds since midnight UTC */
278 const char *
279 icmp_tstamp_print(u_int tstamp)
280 {
281 u_int msec,sec,min,hrs;
282
283 static char buf[64];
284
285 msec = tstamp % 1000;
286 sec = tstamp / 1000;
287 min = sec / 60; sec -= min * 60;
288 hrs = min / 60; min -= hrs * 60;
289 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
290 return buf;
291 }
292
293 void
294 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
295 int fragmented)
296 {
297 char *cp;
298 const struct icmp *dp;
299 uint8_t icmp_type, icmp_code;
300 const struct icmp_ext_t *ext_dp;
301 const struct ip *ip;
302 const char *str;
303 const struct ip *oip;
304 uint8_t ip_proto;
305 const struct udphdr *ouh;
306 const uint8_t *obj_tptr;
307 uint32_t raw_label;
308 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
309 u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype;
310 uint16_t dport;
311 char buf[MAXHOSTNAMELEN + 100];
312 struct cksum_vec vec[1];
313
314 ndo->ndo_protocol = "icmp";
315 dp = (const struct icmp *)bp;
316 ext_dp = (const struct icmp_ext_t *)bp;
317 ip = (const struct ip *)bp2;
318 str = buf;
319
320 icmp_type = GET_U_1(dp->icmp_type);
321 icmp_code = GET_U_1(dp->icmp_code);
322 switch (icmp_type) {
323
324 case ICMP_ECHO:
325 case ICMP_ECHOREPLY:
326 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
327 icmp_type == ICMP_ECHO ?
328 "request" : "reply",
329 GET_BE_U_2(dp->icmp_id),
330 GET_BE_U_2(dp->icmp_seq));
331 break;
332
333 case ICMP_UNREACH:
334 switch (icmp_code) {
335
336 case ICMP_UNREACH_NET:
337 (void)snprintf(buf, sizeof(buf),
338 "net %s unreachable",
339 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
340 break;
341
342 case ICMP_UNREACH_HOST:
343 (void)snprintf(buf, sizeof(buf),
344 "host %s unreachable",
345 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
346 break;
347
348 case ICMP_UNREACH_PROTOCOL:
349 (void)snprintf(buf, sizeof(buf),
350 "%s protocol %u unreachable",
351 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
352 GET_U_1(dp->icmp_ip.ip_p));
353 break;
354
355 case ICMP_UNREACH_PORT:
356 ND_TCHECK_1(dp->icmp_ip.ip_p);
357 oip = &dp->icmp_ip;
358 hlen = IP_HL(oip) * 4;
359 ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
360 dport = GET_BE_U_2(ouh->uh_dport);
361 ip_proto = GET_U_1(oip->ip_p);
362 switch (ip_proto) {
363
364 case IPPROTO_TCP:
365 (void)snprintf(buf, sizeof(buf),
366 "%s tcp port %s unreachable",
367 GET_IPADDR_STRING(oip->ip_dst),
368 tcpport_string(ndo, dport));
369 break;
370
371 case IPPROTO_UDP:
372 (void)snprintf(buf, sizeof(buf),
373 "%s udp port %s unreachable",
374 GET_IPADDR_STRING(oip->ip_dst),
375 udpport_string(ndo, dport));
376 break;
377
378 default:
379 (void)snprintf(buf, sizeof(buf),
380 "%s protocol %u port %u unreachable",
381 GET_IPADDR_STRING(oip->ip_dst),
382 ip_proto, dport);
383 break;
384 }
385 break;
386
387 case ICMP_UNREACH_NEEDFRAG:
388 {
389 const struct mtu_discovery *mp;
390 mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void;
391 mtu = GET_BE_U_2(mp->nexthopmtu);
392 if (mtu) {
393 (void)snprintf(buf, sizeof(buf),
394 "%s unreachable - need to frag (mtu %u)",
395 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), mtu);
396 } else {
397 (void)snprintf(buf, sizeof(buf),
398 "%s unreachable - need to frag",
399 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
400 }
401 }
402 break;
403
404 case ICMP_UNREACH_SRCFAIL:
405 (void)snprintf(buf, sizeof(buf),
406 "%s unreachable - source route failed",
407 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
408 break;
409
410 case ICMP_UNREACH_NET_UNKNOWN:
411 (void)snprintf(buf, sizeof(buf),
412 "net %s unreachable - unknown",
413 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
414 break;
415
416 case ICMP_UNREACH_HOST_UNKNOWN:
417 (void)snprintf(buf, sizeof(buf),
418 "host %s unreachable - unknown",
419 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
420 break;
421
422 case ICMP_UNREACH_ISOLATED:
423 (void)snprintf(buf, sizeof(buf),
424 "%s unreachable - source host isolated",
425 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
426 break;
427
428 case ICMP_UNREACH_NET_PROHIB:
429 (void)snprintf(buf, sizeof(buf),
430 "net %s unreachable - admin prohibited",
431 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
432 break;
433
434 case ICMP_UNREACH_HOST_PROHIB:
435 (void)snprintf(buf, sizeof(buf),
436 "host %s unreachable - admin prohibited",
437 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
438 break;
439
440 case ICMP_UNREACH_TOSNET:
441 (void)snprintf(buf, sizeof(buf),
442 "net %s unreachable - tos prohibited",
443 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
444 break;
445
446 case ICMP_UNREACH_TOSHOST:
447 (void)snprintf(buf, sizeof(buf),
448 "host %s unreachable - tos prohibited",
449 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
450 break;
451
452 case ICMP_UNREACH_FILTER_PROHIB:
453 (void)snprintf(buf, sizeof(buf),
454 "host %s unreachable - admin prohibited filter",
455 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
456 break;
457
458 case ICMP_UNREACH_HOST_PRECEDENCE:
459 (void)snprintf(buf, sizeof(buf),
460 "host %s unreachable - host precedence violation",
461 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
462 break;
463
464 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
465 (void)snprintf(buf, sizeof(buf),
466 "host %s unreachable - precedence cutoff",
467 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
468 break;
469
470 default:
471 (void)snprintf(buf, sizeof(buf),
472 "%s unreachable - #%u",
473 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
474 icmp_code);
475 break;
476 }
477 break;
478
479 case ICMP_REDIRECT:
480 switch (icmp_code) {
481
482 case ICMP_REDIRECT_NET:
483 (void)snprintf(buf, sizeof(buf),
484 "redirect %s to net %s",
485 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
486 GET_IPADDR_STRING(dp->icmp_gwaddr));
487 break;
488
489 case ICMP_REDIRECT_HOST:
490 (void)snprintf(buf, sizeof(buf),
491 "redirect %s to host %s",
492 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
493 GET_IPADDR_STRING(dp->icmp_gwaddr));
494 break;
495
496 case ICMP_REDIRECT_TOSNET:
497 (void)snprintf(buf, sizeof(buf),
498 "redirect-tos %s to net %s",
499 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
500 GET_IPADDR_STRING(dp->icmp_gwaddr));
501 break;
502
503 case ICMP_REDIRECT_TOSHOST:
504 (void)snprintf(buf, sizeof(buf),
505 "redirect-tos %s to host %s",
506 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
507 GET_IPADDR_STRING(dp->icmp_gwaddr));
508 break;
509
510 default:
511 (void)snprintf(buf, sizeof(buf),
512 "redirect-#%u %s to %s", icmp_code,
513 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
514 GET_IPADDR_STRING(dp->icmp_gwaddr));
515 break;
516 }
517 break;
518
519 case ICMP_ROUTERADVERT:
520 {
521 const struct ih_rdiscovery *ihp;
522 const struct id_rdiscovery *idp;
523 u_int lifetime, num, size;
524
525 (void)snprintf(buf, sizeof(buf), "router advertisement");
526 cp = buf + strlen(buf);
527
528 ihp = (const struct ih_rdiscovery *)&dp->icmp_void;
529 ND_TCHECK_SIZE(ihp);
530 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
531 cp = buf + strlen(buf);
532 lifetime = GET_BE_U_2(ihp->ird_lifetime);
533 if (lifetime < 60) {
534 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
535 lifetime);
536 } else if (lifetime < 60 * 60) {
537 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
538 lifetime / 60, lifetime % 60);
539 } else {
540 (void)snprintf(cp, sizeof(buf) - (cp - buf),
541 "%u:%02u:%02u",
542 lifetime / 3600,
543 (lifetime % 3600) / 60,
544 lifetime % 60);
545 }
546 cp = buf + strlen(buf);
547
548 num = GET_U_1(ihp->ird_addrnum);
549 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %u:", num);
550 cp = buf + strlen(buf);
551
552 size = GET_U_1(ihp->ird_addrsiz);
553 if (size != 2) {
554 (void)snprintf(cp, sizeof(buf) - (cp - buf),
555 " [size %u]", size);
556 break;
557 }
558 idp = (const struct id_rdiscovery *)&dp->icmp_data;
559 while (num > 0) {
560 ND_TCHECK_SIZE(idp);
561 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
562 GET_IPADDR_STRING(idp->ird_addr),
563 GET_BE_U_4(idp->ird_pref));
564 cp = buf + strlen(buf);
565 ++idp;
566 num--;
567 }
568 }
569 break;
570
571 case ICMP_TIMXCEED:
572 ND_TCHECK_4(dp->icmp_ip.ip_dst);
573 switch (icmp_code) {
574
575 case ICMP_TIMXCEED_INTRANS:
576 str = "time exceeded in-transit";
577 break;
578
579 case ICMP_TIMXCEED_REASS:
580 str = "ip reassembly time exceeded";
581 break;
582
583 default:
584 (void)snprintf(buf, sizeof(buf), "time exceeded-#%u",
585 icmp_code);
586 break;
587 }
588 break;
589
590 case ICMP_PARAMPROB:
591 if (icmp_code)
592 (void)snprintf(buf, sizeof(buf),
593 "parameter problem - code %u", icmp_code);
594 else {
595 (void)snprintf(buf, sizeof(buf),
596 "parameter problem - octet %u",
597 GET_U_1(dp->icmp_pptr));
598 }
599 break;
600
601 case ICMP_MASKREPLY:
602 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
603 GET_BE_U_4(dp->icmp_mask));
604 break;
605
606 case ICMP_TSTAMP:
607 (void)snprintf(buf, sizeof(buf),
608 "time stamp query id %u seq %u",
609 GET_BE_U_2(dp->icmp_id),
610 GET_BE_U_2(dp->icmp_seq));
611 break;
612
613 case ICMP_TSTAMPREPLY:
614 ND_TCHECK_4(dp->icmp_ttime);
615 (void)snprintf(buf, sizeof(buf),
616 "time stamp reply id %u seq %u: org %s",
617 GET_BE_U_2(dp->icmp_id),
618 GET_BE_U_2(dp->icmp_seq),
619 icmp_tstamp_print(GET_BE_U_4(dp->icmp_otime)));
620
621 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
622 icmp_tstamp_print(GET_BE_U_4(dp->icmp_rtime)));
623 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
624 icmp_tstamp_print(GET_BE_U_4(dp->icmp_ttime)));
625 break;
626
627 default:
628 str = tok2str(icmp2str, "type-#%u", icmp_type);
629 break;
630 }
631 ND_PRINT("ICMP %s, length %u", str, plen);
632 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
633 if (ND_TTEST_LEN(bp, plen)) {
634 uint16_t sum;
635
636 vec[0].ptr = (const uint8_t *)(const void *)dp;
637 vec[0].len = plen;
638 sum = in_cksum(vec, 1);
639 if (sum != 0) {
640 uint16_t icmp_sum = GET_BE_U_2(dp->icmp_cksum);
641 ND_PRINT(" (wrong icmp cksum %x (->%x)!)",
642 icmp_sum,
643 in_cksum_shouldbe(icmp_sum, sum));
644 }
645 }
646 }
647
648 /*
649 * print the remnants of the IP packet.
650 * save the snaplength as this may get overridden in the IP printer.
651 */
652 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) {
653 const u_char *snapend_save;
654
655 bp += 8;
656 ND_PRINT("\n\t");
657 ip = (const struct ip *)bp;
658 snapend_save = ndo->ndo_snapend;
659 /*
660 * Update the snapend because extensions (MPLS, ...) may be
661 * present after the IP packet. In this case the current
662 * (outer) packet's snapend is not what ip_print() needs to
663 * decode an IP packet nested in the middle of an ICMP payload.
664 *
665 * This prevents that, in ip_print(), for the nested IP packet,
666 * the remaining length < remaining caplen.
667 */
668 ndo->ndo_snapend = ND_MIN(bp + GET_BE_U_2(ip->ip_len),
669 ndo->ndo_snapend);
670 ip_print(ndo, bp, GET_BE_U_2(ip->ip_len));
671 ndo->ndo_snapend = snapend_save;
672 }
673
674 /* ndo_protocol reassignment after ip_print() call */
675 ndo->ndo_protocol = "icmp";
676
677 /*
678 * Attempt to decode the MPLS extensions only for some ICMP types.
679 */
680 if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(icmp_type)) {
681
682 ND_TCHECK_SIZE(ext_dp);
683
684 /*
685 * Check first if the mpls extension header shows a non-zero length.
686 * If the length field is not set then silently verify the checksum
687 * to check if an extension header is present. This is expedient,
688 * however not all implementations set the length field proper.
689 */
690 if (GET_U_1(ext_dp->icmp_length) == 0 &&
691 ND_TTEST_LEN(ext_dp->icmp_ext_version_res, plen - ICMP_EXTD_MINLEN)) {
692 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
693 vec[0].len = plen - ICMP_EXTD_MINLEN;
694 if (in_cksum(vec, 1)) {
695 return;
696 }
697 }
698
699 ND_PRINT("\n\tMPLS extension v%u",
700 ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)));
701
702 /*
703 * Sanity checking of the header.
704 */
705 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
706 ICMP_MPLS_EXT_VERSION) {
707 ND_PRINT(" packet not supported");
708 return;
709 }
710
711 hlen = plen - ICMP_EXTD_MINLEN;
712 if (ND_TTEST_LEN(ext_dp->icmp_ext_version_res, hlen)) {
713 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
714 vec[0].len = hlen;
715 ND_PRINT(", checksum 0x%04x (%scorrect), length %u",
716 GET_BE_U_2(ext_dp->icmp_ext_checksum),
717 in_cksum(vec, 1) ? "in" : "",
718 hlen);
719 }
720
721 hlen -= 4; /* subtract common header size */
722 obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data;
723
724 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
725
726 icmp_mpls_ext_object_header = (const struct icmp_mpls_ext_object_header_t *)obj_tptr;
727 ND_TCHECK_SIZE(icmp_mpls_ext_object_header);
728 obj_tlen = GET_BE_U_2(icmp_mpls_ext_object_header->length);
729 obj_class_num = GET_U_1(icmp_mpls_ext_object_header->class_num);
730 obj_ctype = GET_U_1(icmp_mpls_ext_object_header->ctype);
731 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
732
733 ND_PRINT("\n\t %s Object (%u), Class-Type: %u, length %u",
734 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
735 obj_class_num,
736 obj_ctype,
737 obj_tlen);
738
739 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
740
741 /* infinite loop protection */
742 if ((obj_class_num == 0) ||
743 (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) {
744 return;
745 }
746 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
747
748 switch (obj_class_num) {
749 case 1:
750 switch(obj_ctype) {
751 case 1:
752 raw_label = GET_BE_U_4(obj_tptr);
753 ND_PRINT("\n\t label %u, tc %u", MPLS_LABEL(raw_label), MPLS_TC(raw_label));
754 if (MPLS_STACK(raw_label))
755 ND_PRINT(", [S]");
756 ND_PRINT(", ttl %u", MPLS_TTL(raw_label));
757 break;
758 default:
759 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
760 }
761 break;
762
763 /*
764 * FIXME those are the defined objects that lack a decoder
765 * you are welcome to contribute code ;-)
766 */
767 case 2:
768 default:
769 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
770 break;
771 }
772 if (hlen < obj_tlen)
773 break;
774 hlen -= obj_tlen;
775 obj_tptr += obj_tlen;
776 }
777 }
778
779 return;
780 trunc:
781 nd_print_trunc(ndo);
782 }
[mirror] the TCPdump network dissector