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[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 #include <config.h>
25
26 #include "netdissect-stdinc.h"
27
28 #include <stdio.h>
29 #include <string.h>
30
31 #include "netdissect.h"
32 #include "addrtoname.h"
33 #include "extract.h"
34
35 #include "ip.h"
36 #include "udp.h"
37 #include "ipproto.h"
38 #include "mpls.h"
39
40 /*
41 * Interface Control Message Protocol Definitions.
42 * Per RFC 792, September 1981.
43 */
44
45 /*
46 * Structure of an icmp header.
47 */
48 struct icmp {
49 nd_uint8_t icmp_type; /* type of message, see below */
50 nd_uint8_t icmp_code; /* type sub code */
51 nd_uint16_t icmp_cksum; /* ones complement cksum of struct */
52 union {
53 nd_uint8_t ih_pptr; /* ICMP_PARAMPROB */
54 nd_ipv4 ih_gwaddr; /* ICMP_REDIRECT */
55 struct ih_idseq {
56 nd_uint16_t icd_id;
57 nd_uint16_t icd_seq;
58 } ih_idseq;
59 nd_uint32_t ih_void;
60 } icmp_hun;
61 #define icmp_pptr icmp_hun.ih_pptr
62 #define icmp_gwaddr icmp_hun.ih_gwaddr
63 #define icmp_id icmp_hun.ih_idseq.icd_id
64 #define icmp_seq icmp_hun.ih_idseq.icd_seq
65 #define icmp_void icmp_hun.ih_void
66 union {
67 struct id_ts {
68 nd_uint32_t its_otime;
69 nd_uint32_t its_rtime;
70 nd_uint32_t its_ttime;
71 } id_ts;
72 struct id_ip {
73 struct ip idi_ip;
74 /* options and then 64 bits of data */
75 } id_ip;
76 nd_uint32_t id_mask;
77 nd_byte id_data[1];
78 } icmp_dun;
79 #define icmp_otime icmp_dun.id_ts.its_otime
80 #define icmp_rtime icmp_dun.id_ts.its_rtime
81 #define icmp_ttime icmp_dun.id_ts.its_ttime
82 #define icmp_ip icmp_dun.id_ip.idi_ip
83 #define icmp_mask icmp_dun.id_mask
84 #define icmp_data icmp_dun.id_data
85 };
86
87 /*
88 * Lower bounds on packet lengths for various types.
89 * For the error advice packets must first insure that the
90 * packet is large enough to contain the returned ip header.
91 * Only then can we do the check to see if 64 bits of packet
92 * data have been returned, since we need to check the returned
93 * ip header length.
94 */
95 #define ICMP_MINLEN 8 /* abs minimum */
96 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */
97 #define ICMP_TSLEN (8 + 3 * sizeof (uint32_t)) /* timestamp */
98 #define ICMP_MASKLEN 12 /* address mask */
99 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */
100 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
101 /* N.B.: must separately check that ip_hl >= 5 */
102
103 /*
104 * Definition of type and code field values.
105 */
106 #define ICMP_ECHOREPLY 0 /* echo reply */
107 #define ICMP_UNREACH 3 /* dest unreachable, codes: */
108 #define ICMP_UNREACH_NET 0 /* bad net */
109 #define ICMP_UNREACH_HOST 1 /* bad host */
110 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */
111 #define ICMP_UNREACH_PORT 3 /* bad port */
112 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */
113 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */
114 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */
115 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */
116 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */
117 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */
118 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */
119 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */
120 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */
121 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */
122 #define ICMP_REDIRECT 5 /* shorter route, codes: */
123 #define ICMP_REDIRECT_NET 0 /* for network */
124 #define ICMP_REDIRECT_HOST 1 /* for host */
125 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */
126 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */
127 #define ICMP_ECHO 8 /* echo service */
128 #define ICMP_ROUTERADVERT 9 /* router advertisement */
129 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */
130 #define ICMP_TIMXCEED 11 /* time exceeded, code: */
131 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */
132 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */
133 #define ICMP_PARAMPROB 12 /* ip header bad */
134 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */
135 #define ICMP_TSTAMP 13 /* timestamp request */
136 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */
137 #define ICMP_IREQ 15 /* information request */
138 #define ICMP_IREQREPLY 16 /* information reply */
139 #define ICMP_MASKREQ 17 /* address mask request */
140 #define ICMP_MASKREPLY 18 /* address mask reply */
141
142 #define ICMP_MAXTYPE 18
143
144 #define ICMP_ERRTYPE(type) \
145 ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
146 (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
147 (type) == ICMP_PARAMPROB)
148 #define ICMP_MULTIPART_EXT_TYPE(type) \
149 ((type) == ICMP_UNREACH || \
150 (type) == ICMP_TIMXCEED || \
151 (type) == ICMP_PARAMPROB)
152 /* rfc1700 */
153 #ifndef ICMP_UNREACH_NET_UNKNOWN
154 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */
155 #endif
156 #ifndef ICMP_UNREACH_HOST_UNKNOWN
157 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */
158 #endif
159 #ifndef ICMP_UNREACH_ISOLATED
160 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */
161 #endif
162 #ifndef ICMP_UNREACH_NET_PROHIB
163 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */
164 #endif
165 #ifndef ICMP_UNREACH_HOST_PROHIB
166 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */
167 #endif
168 #ifndef ICMP_UNREACH_TOSNET
169 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */
170 #endif
171 #ifndef ICMP_UNREACH_TOSHOST
172 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */
173 #endif
174
175 /* rfc1716 */
176 #ifndef ICMP_UNREACH_FILTER_PROHIB
177 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */
178 #endif
179 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
180 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */
181 #endif
182 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
183 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */
184 #endif
185
186 /* Most of the icmp types */
187 static const struct tok icmp2str[] = {
188 { ICMP_ECHOREPLY, "echo reply" },
189 { ICMP_SOURCEQUENCH, "source quench" },
190 { ICMP_ECHO, "echo request" },
191 { ICMP_ROUTERSOLICIT, "router solicitation" },
192 { ICMP_TSTAMP, "time stamp request" },
193 { ICMP_TSTAMPREPLY, "time stamp reply" },
194 { ICMP_IREQ, "information request" },
195 { ICMP_IREQREPLY, "information reply" },
196 { ICMP_MASKREQ, "address mask request" },
197 { 0, NULL }
198 };
199
200 /* rfc1191 */
201 struct mtu_discovery {
202 nd_uint16_t unused;
203 nd_uint16_t nexthopmtu;
204 };
205
206 /* rfc1256 */
207 struct ih_rdiscovery {
208 nd_uint8_t ird_addrnum;
209 nd_uint8_t ird_addrsiz;
210 nd_uint16_t ird_lifetime;
211 };
212
213 struct id_rdiscovery {
214 nd_uint32_t ird_addr;
215 nd_uint32_t ird_pref;
216 };
217
218 /*
219 * RFC 4884 - Extended ICMP to Support Multi-Part Messages
220 *
221 * This is a general extension mechanism, based on the mechanism
222 * in draft-bonica-icmp-mpls-02 ICMP Extensions for MultiProtocol
223 * Label Switching.
224 *
225 * The Destination Unreachable, Time Exceeded
226 * and Parameter Problem messages are slightly changed as per
227 * the above RFC. A new Length field gets added to give
228 * the caller an idea about the length of the piggybacked
229 * IP packet before the extension header starts.
230 *
231 * The Length field represents length of the padded "original datagram"
232 * field measured in 32-bit words.
233 *
234 * 0 1 2 3
235 * 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
236 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
237 * | Type | Code | Checksum |
238 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
239 * | unused | Length | unused |
240 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
241 * | Internet Header + leading octets of original datagram |
242 * | |
243 * | // |
244 * | |
245 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
246 */
247
248 struct icmp_ext_t {
249 nd_uint8_t icmp_type;
250 nd_uint8_t icmp_code;
251 nd_uint16_t icmp_checksum;
252 nd_byte icmp_reserved;
253 nd_uint8_t icmp_length;
254 nd_byte icmp_reserved2[2];
255 nd_byte icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
256 nd_byte icmp_ext_version_res[2];
257 nd_uint16_t icmp_ext_checksum;
258 nd_byte icmp_ext_data[1];
259 };
260
261 /*
262 * Extract version from the first octet of icmp_ext_version_res.
263 */
264 #define ICMP_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
265
266 /*
267 * Current version.
268 */
269 #define ICMP_EXT_VERSION 2
270
271 /*
272 * Extension object class numbers.
273 *
274 * Class 1 dates back to draft-bonica-icmp-mpls-02.
275 */
276
277 /* rfc4950 */
278 #define MPLS_STACK_ENTRY_OBJECT_CLASS 1
279
280 struct icmp_multipart_ext_object_header_t {
281 nd_uint16_t length;
282 nd_uint8_t class_num;
283 nd_uint8_t ctype;
284 };
285
286 static const struct tok icmp_multipart_ext_obj_values[] = {
287 { 1, "MPLS Stack Entry" },
288 { 2, "Interface Identification" },
289 { 0, NULL}
290 };
291
292 /* prototypes */
293 const char *icmp_tstamp_print(u_int);
294
295 /* print the milliseconds since midnight UTC */
296 const char *
297 icmp_tstamp_print(u_int tstamp)
298 {
299 u_int msec,sec,min,hrs;
300
301 static char buf[64];
302
303 msec = tstamp % 1000;
304 sec = tstamp / 1000;
305 min = sec / 60; sec -= min * 60;
306 hrs = min / 60; min -= hrs * 60;
307 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
308 return buf;
309 }
310
311 void
312 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
313 int fragmented)
314 {
315 char *cp;
316 const struct icmp *dp;
317 uint8_t icmp_type, icmp_code;
318 const struct icmp_ext_t *ext_dp;
319 const struct ip *ip;
320 const char *str;
321 const struct ip *oip;
322 uint8_t ip_proto;
323 const struct udphdr *ouh;
324 const uint8_t *obj_tptr;
325 uint32_t raw_label;
326 const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header;
327 u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype;
328 uint16_t dport;
329 char buf[MAXHOSTNAMELEN + 100];
330 struct cksum_vec vec[1];
331
332 ndo->ndo_protocol = "icmp";
333 dp = (const struct icmp *)bp;
334 ext_dp = (const struct icmp_ext_t *)bp;
335 ip = (const struct ip *)bp2;
336 str = buf;
337
338 icmp_type = GET_U_1(dp->icmp_type);
339 icmp_code = GET_U_1(dp->icmp_code);
340 switch (icmp_type) {
341
342 case ICMP_ECHO:
343 case ICMP_ECHOREPLY:
344 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
345 icmp_type == ICMP_ECHO ?
346 "request" : "reply",
347 GET_BE_U_2(dp->icmp_id),
348 GET_BE_U_2(dp->icmp_seq));
349 break;
350
351 case ICMP_UNREACH:
352 switch (icmp_code) {
353
354 case ICMP_UNREACH_NET:
355 (void)snprintf(buf, sizeof(buf),
356 "net %s unreachable",
357 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
358 break;
359
360 case ICMP_UNREACH_HOST:
361 (void)snprintf(buf, sizeof(buf),
362 "host %s unreachable",
363 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
364 break;
365
366 case ICMP_UNREACH_PROTOCOL:
367 (void)snprintf(buf, sizeof(buf),
368 "%s protocol %u unreachable",
369 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
370 GET_U_1(dp->icmp_ip.ip_p));
371 break;
372
373 case ICMP_UNREACH_PORT:
374 ND_TCHECK_1(dp->icmp_ip.ip_p);
375 oip = &dp->icmp_ip;
376 hlen = IP_HL(oip) * 4;
377 ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
378 dport = GET_BE_U_2(ouh->uh_dport);
379 ip_proto = GET_U_1(oip->ip_p);
380 switch (ip_proto) {
381
382 case IPPROTO_TCP:
383 (void)snprintf(buf, sizeof(buf),
384 "%s tcp port %s unreachable",
385 GET_IPADDR_STRING(oip->ip_dst),
386 tcpport_string(ndo, dport));
387 break;
388
389 case IPPROTO_UDP:
390 (void)snprintf(buf, sizeof(buf),
391 "%s udp port %s unreachable",
392 GET_IPADDR_STRING(oip->ip_dst),
393 udpport_string(ndo, dport));
394 break;
395
396 default:
397 (void)snprintf(buf, sizeof(buf),
398 "%s protocol %u port %u unreachable",
399 GET_IPADDR_STRING(oip->ip_dst),
400 ip_proto, dport);
401 break;
402 }
403 break;
404
405 case ICMP_UNREACH_NEEDFRAG:
406 {
407 const struct mtu_discovery *mp;
408 mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void;
409 mtu = GET_BE_U_2(mp->nexthopmtu);
410 if (mtu) {
411 (void)snprintf(buf, sizeof(buf),
412 "%s unreachable - need to frag (mtu %u)",
413 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), mtu);
414 } else {
415 (void)snprintf(buf, sizeof(buf),
416 "%s unreachable - need to frag",
417 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
418 }
419 }
420 break;
421
422 case ICMP_UNREACH_SRCFAIL:
423 (void)snprintf(buf, sizeof(buf),
424 "%s unreachable - source route failed",
425 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
426 break;
427
428 case ICMP_UNREACH_NET_UNKNOWN:
429 (void)snprintf(buf, sizeof(buf),
430 "net %s unreachable - unknown",
431 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
432 break;
433
434 case ICMP_UNREACH_HOST_UNKNOWN:
435 (void)snprintf(buf, sizeof(buf),
436 "host %s unreachable - unknown",
437 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
438 break;
439
440 case ICMP_UNREACH_ISOLATED:
441 (void)snprintf(buf, sizeof(buf),
442 "%s unreachable - source host isolated",
443 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
444 break;
445
446 case ICMP_UNREACH_NET_PROHIB:
447 (void)snprintf(buf, sizeof(buf),
448 "net %s unreachable - admin prohibited",
449 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
450 break;
451
452 case ICMP_UNREACH_HOST_PROHIB:
453 (void)snprintf(buf, sizeof(buf),
454 "host %s unreachable - admin prohibited",
455 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
456 break;
457
458 case ICMP_UNREACH_TOSNET:
459 (void)snprintf(buf, sizeof(buf),
460 "net %s unreachable - tos prohibited",
461 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
462 break;
463
464 case ICMP_UNREACH_TOSHOST:
465 (void)snprintf(buf, sizeof(buf),
466 "host %s unreachable - tos prohibited",
467 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
468 break;
469
470 case ICMP_UNREACH_FILTER_PROHIB:
471 (void)snprintf(buf, sizeof(buf),
472 "host %s unreachable - admin prohibited filter",
473 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
474 break;
475
476 case ICMP_UNREACH_HOST_PRECEDENCE:
477 (void)snprintf(buf, sizeof(buf),
478 "host %s unreachable - host precedence violation",
479 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
480 break;
481
482 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
483 (void)snprintf(buf, sizeof(buf),
484 "host %s unreachable - precedence cutoff",
485 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
486 break;
487
488 default:
489 (void)snprintf(buf, sizeof(buf),
490 "%s unreachable - #%u",
491 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
492 icmp_code);
493 break;
494 }
495 break;
496
497 case ICMP_REDIRECT:
498 switch (icmp_code) {
499
500 case ICMP_REDIRECT_NET:
501 (void)snprintf(buf, sizeof(buf),
502 "redirect %s to net %s",
503 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
504 GET_IPADDR_STRING(dp->icmp_gwaddr));
505 break;
506
507 case ICMP_REDIRECT_HOST:
508 (void)snprintf(buf, sizeof(buf),
509 "redirect %s to host %s",
510 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
511 GET_IPADDR_STRING(dp->icmp_gwaddr));
512 break;
513
514 case ICMP_REDIRECT_TOSNET:
515 (void)snprintf(buf, sizeof(buf),
516 "redirect-tos %s to net %s",
517 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
518 GET_IPADDR_STRING(dp->icmp_gwaddr));
519 break;
520
521 case ICMP_REDIRECT_TOSHOST:
522 (void)snprintf(buf, sizeof(buf),
523 "redirect-tos %s to host %s",
524 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
525 GET_IPADDR_STRING(dp->icmp_gwaddr));
526 break;
527
528 default:
529 (void)snprintf(buf, sizeof(buf),
530 "redirect-#%u %s to %s", icmp_code,
531 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
532 GET_IPADDR_STRING(dp->icmp_gwaddr));
533 break;
534 }
535 break;
536
537 case ICMP_ROUTERADVERT:
538 {
539 const struct ih_rdiscovery *ihp;
540 const struct id_rdiscovery *idp;
541 u_int lifetime, num, size;
542
543 (void)snprintf(buf, sizeof(buf), "router advertisement");
544 cp = buf + strlen(buf);
545
546 ihp = (const struct ih_rdiscovery *)&dp->icmp_void;
547 ND_TCHECK_SIZE(ihp);
548 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
549 cp = buf + strlen(buf);
550 lifetime = GET_BE_U_2(ihp->ird_lifetime);
551 if (lifetime < 60) {
552 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
553 lifetime);
554 } else if (lifetime < 60 * 60) {
555 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
556 lifetime / 60, lifetime % 60);
557 } else {
558 (void)snprintf(cp, sizeof(buf) - (cp - buf),
559 "%u:%02u:%02u",
560 lifetime / 3600,
561 (lifetime % 3600) / 60,
562 lifetime % 60);
563 }
564 cp = buf + strlen(buf);
565
566 num = GET_U_1(ihp->ird_addrnum);
567 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %u:", num);
568 cp = buf + strlen(buf);
569
570 size = GET_U_1(ihp->ird_addrsiz);
571 if (size != 2) {
572 (void)snprintf(cp, sizeof(buf) - (cp - buf),
573 " [size %u]", size);
574 break;
575 }
576 idp = (const struct id_rdiscovery *)&dp->icmp_data;
577 while (num > 0) {
578 ND_TCHECK_SIZE(idp);
579 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
580 GET_IPADDR_STRING(idp->ird_addr),
581 GET_BE_U_4(idp->ird_pref));
582 cp = buf + strlen(buf);
583 ++idp;
584 num--;
585 }
586 }
587 break;
588
589 case ICMP_TIMXCEED:
590 ND_TCHECK_4(dp->icmp_ip.ip_dst);
591 switch (icmp_code) {
592
593 case ICMP_TIMXCEED_INTRANS:
594 str = "time exceeded in-transit";
595 break;
596
597 case ICMP_TIMXCEED_REASS:
598 str = "ip reassembly time exceeded";
599 break;
600
601 default:
602 (void)snprintf(buf, sizeof(buf), "time exceeded-#%u",
603 icmp_code);
604 break;
605 }
606 break;
607
608 case ICMP_PARAMPROB:
609 if (icmp_code)
610 (void)snprintf(buf, sizeof(buf),
611 "parameter problem - code %u", icmp_code);
612 else {
613 (void)snprintf(buf, sizeof(buf),
614 "parameter problem - octet %u",
615 GET_U_1(dp->icmp_pptr));
616 }
617 break;
618
619 case ICMP_MASKREPLY:
620 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
621 GET_BE_U_4(dp->icmp_mask));
622 break;
623
624 case ICMP_TSTAMP:
625 (void)snprintf(buf, sizeof(buf),
626 "time stamp query id %u seq %u",
627 GET_BE_U_2(dp->icmp_id),
628 GET_BE_U_2(dp->icmp_seq));
629 break;
630
631 case ICMP_TSTAMPREPLY:
632 ND_TCHECK_4(dp->icmp_ttime);
633 (void)snprintf(buf, sizeof(buf),
634 "time stamp reply id %u seq %u: org %s",
635 GET_BE_U_2(dp->icmp_id),
636 GET_BE_U_2(dp->icmp_seq),
637 icmp_tstamp_print(GET_BE_U_4(dp->icmp_otime)));
638
639 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
640 icmp_tstamp_print(GET_BE_U_4(dp->icmp_rtime)));
641 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
642 icmp_tstamp_print(GET_BE_U_4(dp->icmp_ttime)));
643 break;
644
645 default:
646 str = tok2str(icmp2str, "type-#%u", icmp_type);
647 break;
648 }
649 ND_PRINT("ICMP %s, length %u", str, plen);
650 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
651 if (ND_TTEST_LEN(bp, plen)) {
652 uint16_t sum;
653
654 vec[0].ptr = (const uint8_t *)(const void *)dp;
655 vec[0].len = plen;
656 sum = in_cksum(vec, 1);
657 if (sum != 0) {
658 uint16_t icmp_sum = GET_BE_U_2(dp->icmp_cksum);
659 ND_PRINT(" (wrong icmp cksum %x (->%x)!)",
660 icmp_sum,
661 in_cksum_shouldbe(icmp_sum, sum));
662 }
663 }
664 }
665
666 /*
667 * print the remnants of the IP packet.
668 * save the snaplength as this may get overridden in the IP printer.
669 */
670 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) {
671 const u_char *snapend_save;
672
673 bp += 8;
674 ND_PRINT("\n\t");
675 ip = (const struct ip *)bp;
676 snapend_save = ndo->ndo_snapend;
677 /*
678 * Update the snapend because extensions (MPLS, ...) may be
679 * present after the IP packet. In this case the current
680 * (outer) packet's snapend is not what ip_print() needs to
681 * decode an IP packet nested in the middle of an ICMP payload.
682 *
683 * This prevents that, in ip_print(), for the nested IP packet,
684 * the remaining length < remaining caplen.
685 */
686 ndo->ndo_snapend = ND_MIN(bp + GET_BE_U_2(ip->ip_len),
687 ndo->ndo_snapend);
688 ip_print(ndo, bp, GET_BE_U_2(ip->ip_len));
689 ndo->ndo_snapend = snapend_save;
690 }
691
692 /* ndo_protocol reassignment after ip_print() call */
693 ndo->ndo_protocol = "icmp";
694
695 /*
696 * Attempt to decode multi-part message extensions (rfc4884) only for some ICMP types.
697 */
698 if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MULTIPART_EXT_TYPE(icmp_type)) {
699
700 ND_TCHECK_SIZE(ext_dp);
701
702 /*
703 * Check first if the multi-part extension header shows a non-zero length.
704 * If the length field is not set then silently verify the checksum
705 * to check if an extension header is present. This is expedient,
706 * however not all implementations set the length field proper.
707 */
708 if (GET_U_1(ext_dp->icmp_length) == 0 &&
709 ND_TTEST_LEN(ext_dp->icmp_ext_version_res, plen - ICMP_EXTD_MINLEN)) {
710 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
711 vec[0].len = plen - ICMP_EXTD_MINLEN;
712 if (in_cksum(vec, 1)) {
713 return;
714 }
715 }
716
717 ND_PRINT("\n\tICMP Multi-Part extension v%u",
718 ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)));
719
720 /*
721 * Sanity checking of the header.
722 */
723 if (ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
724 ICMP_EXT_VERSION) {
725 ND_PRINT(" packet not supported");
726 return;
727 }
728
729 hlen = plen - ICMP_EXTD_MINLEN;
730 if (ND_TTEST_LEN(ext_dp->icmp_ext_version_res, hlen)) {
731 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
732 vec[0].len = hlen;
733 ND_PRINT(", checksum 0x%04x (%scorrect), length %u",
734 GET_BE_U_2(ext_dp->icmp_ext_checksum),
735 in_cksum(vec, 1) ? "in" : "",
736 hlen);
737 }
738
739 hlen -= 4; /* subtract common header size */
740 obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data;
741
742 while (hlen > sizeof(struct icmp_multipart_ext_object_header_t)) {
743
744 icmp_multipart_ext_object_header = (const struct icmp_multipart_ext_object_header_t *)obj_tptr;
745 ND_TCHECK_SIZE(icmp_multipart_ext_object_header);
746 obj_tlen = GET_BE_U_2(icmp_multipart_ext_object_header->length);
747 obj_class_num = GET_U_1(icmp_multipart_ext_object_header->class_num);
748 obj_ctype = GET_U_1(icmp_multipart_ext_object_header->ctype);
749 obj_tptr += sizeof(struct icmp_multipart_ext_object_header_t);
750
751 ND_PRINT("\n\t %s Object (%u), Class-Type: %u, length %u",
752 tok2str(icmp_multipart_ext_obj_values,"unknown",obj_class_num),
753 obj_class_num,
754 obj_ctype,
755 obj_tlen);
756
757 hlen-=sizeof(struct icmp_multipart_ext_object_header_t); /* length field includes tlv header */
758
759 /* infinite loop protection */
760 if ((obj_class_num == 0) ||
761 (obj_tlen < sizeof(struct icmp_multipart_ext_object_header_t))) {
762 return;
763 }
764 obj_tlen-=sizeof(struct icmp_multipart_ext_object_header_t);
765
766 switch (obj_class_num) {
767 case MPLS_STACK_ENTRY_OBJECT_CLASS:
768 switch(obj_ctype) {
769 case 1:
770 raw_label = GET_BE_U_4(obj_tptr);
771 ND_PRINT("\n\t label %u, tc %u", MPLS_LABEL(raw_label), MPLS_TC(raw_label));
772 if (MPLS_STACK(raw_label))
773 ND_PRINT(", [S]");
774 ND_PRINT(", ttl %u", MPLS_TTL(raw_label));
775 break;
776 default:
777 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
778 }
779 break;
780
781 default:
782 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
783 break;
784 }
785 if (hlen < obj_tlen)
786 break;
787 hlen -= obj_tlen;
788 obj_tptr += obj_tlen;
789 }
790 }
791
792 return;
793 trunc:
794 nd_print_trunc(ndo);
795 }
[mirror] the TCPdump network dissector