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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 #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 /*
90 * Lower bounds on packet lengths for various types.
91 * For the error advice packets must first insure that the
92 * packet is large enough to contain the returned ip header.
93 * Only then can we do the check to see if 64 bits of packet
94 * data have been returned, since we need to check the returned
95 * ip header length.
96 */
97 #define ICMP_MINLEN 8 /* abs minimum */
98 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */
99 #define ICMP_TSLEN (8 + 3 * sizeof (uint32_t)) /* timestamp */
100 #define ICMP_MASKLEN 12 /* address mask */
101 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */
102 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
103 /* N.B.: must separately check that ip_hl >= 5 */
104
105 /*
106 * Definition of type and code field values.
107 */
108 #define ICMP_ECHOREPLY 0 /* echo reply */
109 #define ICMP_UNREACH 3 /* dest unreachable, codes: */
110 #define ICMP_UNREACH_NET 0 /* bad net */
111 #define ICMP_UNREACH_HOST 1 /* bad host */
112 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */
113 #define ICMP_UNREACH_PORT 3 /* bad port */
114 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */
115 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */
116 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */
117 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */
118 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */
119 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */
120 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */
121 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */
122 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */
123 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */
124 #define ICMP_REDIRECT 5 /* shorter route, codes: */
125 #define ICMP_REDIRECT_NET 0 /* for network */
126 #define ICMP_REDIRECT_HOST 1 /* for host */
127 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */
128 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */
129 #define ICMP_ECHO 8 /* echo service */
130 #define ICMP_ROUTERADVERT 9 /* router advertisement */
131 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */
132 #define ICMP_TIMXCEED 11 /* time exceeded, code: */
133 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */
134 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */
135 #define ICMP_PARAMPROB 12 /* ip header bad */
136 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */
137 #define ICMP_TSTAMP 13 /* timestamp request */
138 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */
139 #define ICMP_IREQ 15 /* information request */
140 #define ICMP_IREQREPLY 16 /* information reply */
141 #define ICMP_MASKREQ 17 /* address mask request */
142 #define ICMP_MASKREPLY 18 /* address mask reply */
143
144 #define ICMP_MAXTYPE 18
145
146 #define ICMP_ERRTYPE(type) \
147 ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
148 (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
149 (type) == ICMP_PARAMPROB)
150 #define ICMP_MULTIPART_EXT_TYPE(type) \
151 ((type) == ICMP_UNREACH || \
152 (type) == ICMP_TIMXCEED || \
153 (type) == ICMP_PARAMPROB)
154 /* rfc1700 */
155 #ifndef ICMP_UNREACH_NET_UNKNOWN
156 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */
157 #endif
158 #ifndef ICMP_UNREACH_HOST_UNKNOWN
159 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */
160 #endif
161 #ifndef ICMP_UNREACH_ISOLATED
162 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */
163 #endif
164 #ifndef ICMP_UNREACH_NET_PROHIB
165 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */
166 #endif
167 #ifndef ICMP_UNREACH_HOST_PROHIB
168 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */
169 #endif
170 #ifndef ICMP_UNREACH_TOSNET
171 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */
172 #endif
173 #ifndef ICMP_UNREACH_TOSHOST
174 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */
175 #endif
176
177 /* rfc1716 */
178 #ifndef ICMP_UNREACH_FILTER_PROHIB
179 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */
180 #endif
181 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
182 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */
183 #endif
184 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
185 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */
186 #endif
187
188 /* Most of the icmp types */
189 static const struct tok icmp2str[] = {
190 { ICMP_ECHOREPLY, "echo reply" },
191 { ICMP_SOURCEQUENCH, "source quench" },
192 { ICMP_ECHO, "echo request" },
193 { ICMP_ROUTERSOLICIT, "router solicitation" },
194 { ICMP_TSTAMP, "time stamp request" },
195 { ICMP_TSTAMPREPLY, "time stamp reply" },
196 { ICMP_IREQ, "information request" },
197 { ICMP_IREQREPLY, "information reply" },
198 { ICMP_MASKREQ, "address mask request" },
199 { 0, NULL }
200 };
201
202 /* rfc1191 */
203 struct mtu_discovery {
204 nd_uint16_t unused;
205 nd_uint16_t nexthopmtu;
206 };
207
208 /* rfc1256 */
209 struct ih_rdiscovery {
210 nd_uint8_t ird_addrnum;
211 nd_uint8_t ird_addrsiz;
212 nd_uint16_t ird_lifetime;
213 };
214
215 struct id_rdiscovery {
216 nd_uint32_t ird_addr;
217 nd_uint32_t ird_pref;
218 };
219
220 /*
221 * RFC 4884 - Extended ICMP to Support Multi-Part Messages
222 *
223 * This is a general extension mechanism, based on the mechanism
224 * in draft-bonica-icmp-mpls-02 ICMP Extensions for MultiProtocol
225 * Label Switching.
226 *
227 * The Destination Unreachable, Time Exceeded
228 * and Parameter Problem messages are slightly changed as per
229 * the above RFC. A new Length field gets added to give
230 * the caller an idea about the length of the piggybacked
231 * IP packet before the extension header starts.
232 *
233 * The Length field represents length of the padded "original datagram"
234 * field measured in 32-bit words.
235 *
236 * 0 1 2 3
237 * 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
238 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
239 * | Type | Code | Checksum |
240 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
241 * | unused | Length | unused |
242 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
243 * | Internet Header + leading octets of original datagram |
244 * | |
245 * | // |
246 * | |
247 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
248 */
249
250 struct icmp_ext_t {
251 nd_uint8_t icmp_type;
252 nd_uint8_t icmp_code;
253 nd_uint16_t icmp_checksum;
254 nd_byte icmp_reserved;
255 nd_uint8_t icmp_length;
256 nd_byte icmp_reserved2[2];
257 nd_byte icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
258 nd_byte icmp_ext_version_res[2];
259 nd_uint16_t icmp_ext_checksum;
260 nd_byte icmp_ext_data[1];
261 };
262
263 /*
264 * Extract version from the first octet of icmp_ext_version_res.
265 */
266 #define ICMP_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
267
268 /*
269 * Current version.
270 */
271 #define ICMP_EXT_VERSION 2
272
273 /*
274 * Extension object class numbers.
275 *
276 * Class 1 dates back to draft-bonica-icmp-mpls-02.
277 */
278
279 /* rfc4950 */
280 #define MPLS_STACK_ENTRY_OBJECT_CLASS 1
281
282 struct icmp_multipart_ext_object_header_t {
283 nd_uint16_t length;
284 nd_uint8_t class_num;
285 nd_uint8_t ctype;
286 };
287
288 static const struct tok icmp_multipart_ext_obj_values[] = {
289 { 1, "MPLS Stack Entry" },
290 { 2, "Interface Identification" },
291 { 0, NULL}
292 };
293
294 /* prototypes */
295 const char *icmp_tstamp_print(u_int);
296
297 /* print the milliseconds since midnight UTC */
298 const char *
299 icmp_tstamp_print(u_int tstamp)
300 {
301 u_int msec,sec,min,hrs;
302
303 static char buf[64];
304
305 msec = tstamp % 1000;
306 sec = tstamp / 1000;
307 min = sec / 60; sec -= min * 60;
308 hrs = min / 60; min -= hrs * 60;
309 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
310 return buf;
311 }
312
313 void
314 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
315 int fragmented)
316 {
317 char *cp;
318 const struct icmp *dp;
319 uint8_t icmp_type, icmp_code;
320 const struct icmp_ext_t *ext_dp;
321 const struct ip *ip;
322 const char *str;
323 const struct ip *oip;
324 uint8_t ip_proto;
325 const struct udphdr *ouh;
326 const uint8_t *obj_tptr;
327 uint32_t raw_label;
328 const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header;
329 u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype;
330 uint16_t dport;
331 char buf[MAXHOSTNAMELEN + 100];
332 struct cksum_vec vec[1];
333
334 ndo->ndo_protocol = "icmp";
335 dp = (const struct icmp *)bp;
336 ext_dp = (const struct icmp_ext_t *)bp;
337 ip = (const struct ip *)bp2;
338 str = buf;
339
340 icmp_type = GET_U_1(dp->icmp_type);
341 icmp_code = GET_U_1(dp->icmp_code);
342 switch (icmp_type) {
343
344 case ICMP_ECHO:
345 case ICMP_ECHOREPLY:
346 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
347 icmp_type == ICMP_ECHO ?
348 "request" : "reply",
349 GET_BE_U_2(dp->icmp_id),
350 GET_BE_U_2(dp->icmp_seq));
351 break;
352
353 case ICMP_UNREACH:
354 switch (icmp_code) {
355
356 case ICMP_UNREACH_NET:
357 (void)snprintf(buf, sizeof(buf),
358 "net %s unreachable",
359 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
360 break;
361
362 case ICMP_UNREACH_HOST:
363 (void)snprintf(buf, sizeof(buf),
364 "host %s unreachable",
365 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
366 break;
367
368 case ICMP_UNREACH_PROTOCOL:
369 (void)snprintf(buf, sizeof(buf),
370 "%s protocol %u unreachable",
371 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
372 GET_U_1(dp->icmp_ip.ip_p));
373 break;
374
375 case ICMP_UNREACH_PORT:
376 ND_TCHECK_1(dp->icmp_ip.ip_p);
377 oip = &dp->icmp_ip;
378 hlen = IP_HL(oip) * 4;
379 ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
380 dport = GET_BE_U_2(ouh->uh_dport);
381 ip_proto = GET_U_1(oip->ip_p);
382 switch (ip_proto) {
383
384 case IPPROTO_TCP:
385 (void)snprintf(buf, sizeof(buf),
386 "%s tcp port %s unreachable",
387 GET_IPADDR_STRING(oip->ip_dst),
388 tcpport_string(ndo, dport));
389 break;
390
391 case IPPROTO_UDP:
392 (void)snprintf(buf, sizeof(buf),
393 "%s udp port %s unreachable",
394 GET_IPADDR_STRING(oip->ip_dst),
395 udpport_string(ndo, dport));
396 break;
397
398 default:
399 (void)snprintf(buf, sizeof(buf),
400 "%s protocol %u port %u unreachable",
401 GET_IPADDR_STRING(oip->ip_dst),
402 ip_proto, dport);
403 break;
404 }
405 break;
406
407 case ICMP_UNREACH_NEEDFRAG:
408 {
409 const struct mtu_discovery *mp;
410 mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void;
411 mtu = GET_BE_U_2(mp->nexthopmtu);
412 if (mtu) {
413 (void)snprintf(buf, sizeof(buf),
414 "%s unreachable - need to frag (mtu %u)",
415 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), mtu);
416 } else {
417 (void)snprintf(buf, sizeof(buf),
418 "%s unreachable - need to frag",
419 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
420 }
421 }
422 break;
423
424 case ICMP_UNREACH_SRCFAIL:
425 (void)snprintf(buf, sizeof(buf),
426 "%s unreachable - source route failed",
427 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
428 break;
429
430 case ICMP_UNREACH_NET_UNKNOWN:
431 (void)snprintf(buf, sizeof(buf),
432 "net %s unreachable - unknown",
433 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
434 break;
435
436 case ICMP_UNREACH_HOST_UNKNOWN:
437 (void)snprintf(buf, sizeof(buf),
438 "host %s unreachable - unknown",
439 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
440 break;
441
442 case ICMP_UNREACH_ISOLATED:
443 (void)snprintf(buf, sizeof(buf),
444 "%s unreachable - source host isolated",
445 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
446 break;
447
448 case ICMP_UNREACH_NET_PROHIB:
449 (void)snprintf(buf, sizeof(buf),
450 "net %s unreachable - admin prohibited",
451 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
452 break;
453
454 case ICMP_UNREACH_HOST_PROHIB:
455 (void)snprintf(buf, sizeof(buf),
456 "host %s unreachable - admin prohibited",
457 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
458 break;
459
460 case ICMP_UNREACH_TOSNET:
461 (void)snprintf(buf, sizeof(buf),
462 "net %s unreachable - tos prohibited",
463 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
464 break;
465
466 case ICMP_UNREACH_TOSHOST:
467 (void)snprintf(buf, sizeof(buf),
468 "host %s unreachable - tos prohibited",
469 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
470 break;
471
472 case ICMP_UNREACH_FILTER_PROHIB:
473 (void)snprintf(buf, sizeof(buf),
474 "host %s unreachable - admin prohibited filter",
475 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
476 break;
477
478 case ICMP_UNREACH_HOST_PRECEDENCE:
479 (void)snprintf(buf, sizeof(buf),
480 "host %s unreachable - host precedence violation",
481 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
482 break;
483
484 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
485 (void)snprintf(buf, sizeof(buf),
486 "host %s unreachable - precedence cutoff",
487 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
488 break;
489
490 default:
491 (void)snprintf(buf, sizeof(buf),
492 "%s unreachable - #%u",
493 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
494 icmp_code);
495 break;
496 }
497 break;
498
499 case ICMP_REDIRECT:
500 switch (icmp_code) {
501
502 case ICMP_REDIRECT_NET:
503 (void)snprintf(buf, sizeof(buf),
504 "redirect %s to net %s",
505 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
506 GET_IPADDR_STRING(dp->icmp_gwaddr));
507 break;
508
509 case ICMP_REDIRECT_HOST:
510 (void)snprintf(buf, sizeof(buf),
511 "redirect %s to host %s",
512 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
513 GET_IPADDR_STRING(dp->icmp_gwaddr));
514 break;
515
516 case ICMP_REDIRECT_TOSNET:
517 (void)snprintf(buf, sizeof(buf),
518 "redirect-tos %s to net %s",
519 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
520 GET_IPADDR_STRING(dp->icmp_gwaddr));
521 break;
522
523 case ICMP_REDIRECT_TOSHOST:
524 (void)snprintf(buf, sizeof(buf),
525 "redirect-tos %s to host %s",
526 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
527 GET_IPADDR_STRING(dp->icmp_gwaddr));
528 break;
529
530 default:
531 (void)snprintf(buf, sizeof(buf),
532 "redirect-#%u %s to %s", icmp_code,
533 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
534 GET_IPADDR_STRING(dp->icmp_gwaddr));
535 break;
536 }
537 break;
538
539 case ICMP_ROUTERADVERT:
540 {
541 const struct ih_rdiscovery *ihp;
542 const struct id_rdiscovery *idp;
543 u_int lifetime, num, size;
544
545 (void)snprintf(buf, sizeof(buf), "router advertisement");
546 cp = buf + strlen(buf);
547
548 ihp = (const struct ih_rdiscovery *)&dp->icmp_void;
549 ND_TCHECK_SIZE(ihp);
550 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
551 cp = buf + strlen(buf);
552 lifetime = GET_BE_U_2(ihp->ird_lifetime);
553 if (lifetime < 60) {
554 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
555 lifetime);
556 } else if (lifetime < 60 * 60) {
557 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
558 lifetime / 60, lifetime % 60);
559 } else {
560 (void)snprintf(cp, sizeof(buf) - (cp - buf),
561 "%u:%02u:%02u",
562 lifetime / 3600,
563 (lifetime % 3600) / 60,
564 lifetime % 60);
565 }
566 cp = buf + strlen(buf);
567
568 num = GET_U_1(ihp->ird_addrnum);
569 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %u:", num);
570 cp = buf + strlen(buf);
571
572 size = GET_U_1(ihp->ird_addrsiz);
573 if (size != 2) {
574 (void)snprintf(cp, sizeof(buf) - (cp - buf),
575 " [size %u]", size);
576 break;
577 }
578 idp = (const struct id_rdiscovery *)&dp->icmp_data;
579 while (num > 0) {
580 ND_TCHECK_SIZE(idp);
581 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
582 GET_IPADDR_STRING(idp->ird_addr),
583 GET_BE_U_4(idp->ird_pref));
584 cp = buf + strlen(buf);
585 ++idp;
586 num--;
587 }
588 }
589 break;
590
591 case ICMP_TIMXCEED:
592 ND_TCHECK_4(dp->icmp_ip.ip_dst);
593 switch (icmp_code) {
594
595 case ICMP_TIMXCEED_INTRANS:
596 str = "time exceeded in-transit";
597 break;
598
599 case ICMP_TIMXCEED_REASS:
600 str = "ip reassembly time exceeded";
601 break;
602
603 default:
604 (void)snprintf(buf, sizeof(buf), "time exceeded-#%u",
605 icmp_code);
606 break;
607 }
608 break;
609
610 case ICMP_PARAMPROB:
611 if (icmp_code)
612 (void)snprintf(buf, sizeof(buf),
613 "parameter problem - code %u", icmp_code);
614 else {
615 (void)snprintf(buf, sizeof(buf),
616 "parameter problem - octet %u",
617 GET_U_1(dp->icmp_pptr));
618 }
619 break;
620
621 case ICMP_MASKREPLY:
622 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
623 GET_BE_U_4(dp->icmp_mask));
624 break;
625
626 case ICMP_TSTAMP:
627 (void)snprintf(buf, sizeof(buf),
628 "time stamp query id %u seq %u",
629 GET_BE_U_2(dp->icmp_id),
630 GET_BE_U_2(dp->icmp_seq));
631 break;
632
633 case ICMP_TSTAMPREPLY:
634 ND_TCHECK_4(dp->icmp_ttime);
635 (void)snprintf(buf, sizeof(buf),
636 "time stamp reply id %u seq %u: org %s",
637 GET_BE_U_2(dp->icmp_id),
638 GET_BE_U_2(dp->icmp_seq),
639 icmp_tstamp_print(GET_BE_U_4(dp->icmp_otime)));
640
641 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
642 icmp_tstamp_print(GET_BE_U_4(dp->icmp_rtime)));
643 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
644 icmp_tstamp_print(GET_BE_U_4(dp->icmp_ttime)));
645 break;
646
647 default:
648 str = tok2str(icmp2str, "type-#%u", icmp_type);
649 break;
650 }
651 ND_PRINT("ICMP %s, length %u", str, plen);
652 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
653 if (ND_TTEST_LEN(bp, plen)) {
654 uint16_t sum;
655
656 vec[0].ptr = (const uint8_t *)(const void *)dp;
657 vec[0].len = plen;
658 sum = in_cksum(vec, 1);
659 if (sum != 0) {
660 uint16_t icmp_sum = GET_BE_U_2(dp->icmp_cksum);
661 ND_PRINT(" (wrong icmp cksum %x (->%x)!)",
662 icmp_sum,
663 in_cksum_shouldbe(icmp_sum, sum));
664 }
665 }
666 }
667
668 /*
669 * print the remnants of the IP packet.
670 * save the snaplength as this may get overridden in the IP printer.
671 */
672 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) {
673 const u_char *snapend_save;
674
675 bp += 8;
676 ND_PRINT("\n\t");
677 ip = (const struct ip *)bp;
678 snapend_save = ndo->ndo_snapend;
679 /*
680 * Update the snapend because extensions (MPLS, ...) may be
681 * present after the IP packet. In this case the current
682 * (outer) packet's snapend is not what ip_print() needs to
683 * decode an IP packet nested in the middle of an ICMP payload.
684 *
685 * This prevents that, in ip_print(), for the nested IP packet,
686 * the remaining length < remaining caplen.
687 */
688 ndo->ndo_snapend = ND_MIN(bp + GET_BE_U_2(ip->ip_len),
689 ndo->ndo_snapend);
690 ip_print(ndo, bp, GET_BE_U_2(ip->ip_len));
691 ndo->ndo_snapend = snapend_save;
692 }
693
694 /* ndo_protocol reassignment after ip_print() call */
695 ndo->ndo_protocol = "icmp";
696
697 /*
698 * Attempt to decode multi-part message extensions (rfc4884) only for some ICMP types.
699 */
700 if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MULTIPART_EXT_TYPE(icmp_type)) {
701
702 ND_TCHECK_SIZE(ext_dp);
703
704 /*
705 * Check first if the multi-part extension header shows a non-zero length.
706 * If the length field is not set then silently verify the checksum
707 * to check if an extension header is present. This is expedient,
708 * however not all implementations set the length field proper.
709 */
710 if (GET_U_1(ext_dp->icmp_length) == 0 &&
711 ND_TTEST_LEN(ext_dp->icmp_ext_version_res, plen - ICMP_EXTD_MINLEN)) {
712 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
713 vec[0].len = plen - ICMP_EXTD_MINLEN;
714 if (in_cksum(vec, 1)) {
715 return;
716 }
717 }
718
719 ND_PRINT("\n\tICMP Multi-Part extension v%u",
720 ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)));
721
722 /*
723 * Sanity checking of the header.
724 */
725 if (ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
726 ICMP_EXT_VERSION) {
727 ND_PRINT(" packet not supported");
728 return;
729 }
730
731 hlen = plen - ICMP_EXTD_MINLEN;
732 if (ND_TTEST_LEN(ext_dp->icmp_ext_version_res, hlen)) {
733 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
734 vec[0].len = hlen;
735 ND_PRINT(", checksum 0x%04x (%scorrect), length %u",
736 GET_BE_U_2(ext_dp->icmp_ext_checksum),
737 in_cksum(vec, 1) ? "in" : "",
738 hlen);
739 }
740
741 hlen -= 4; /* subtract common header size */
742 obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data;
743
744 while (hlen > sizeof(struct icmp_multipart_ext_object_header_t)) {
745
746 icmp_multipart_ext_object_header = (const struct icmp_multipart_ext_object_header_t *)obj_tptr;
747 ND_TCHECK_SIZE(icmp_multipart_ext_object_header);
748 obj_tlen = GET_BE_U_2(icmp_multipart_ext_object_header->length);
749 obj_class_num = GET_U_1(icmp_multipart_ext_object_header->class_num);
750 obj_ctype = GET_U_1(icmp_multipart_ext_object_header->ctype);
751 obj_tptr += sizeof(struct icmp_multipart_ext_object_header_t);
752
753 ND_PRINT("\n\t %s Object (%u), Class-Type: %u, length %u",
754 tok2str(icmp_multipart_ext_obj_values,"unknown",obj_class_num),
755 obj_class_num,
756 obj_ctype,
757 obj_tlen);
758
759 hlen-=sizeof(struct icmp_multipart_ext_object_header_t); /* length field includes tlv header */
760
761 /* infinite loop protection */
762 if ((obj_class_num == 0) ||
763 (obj_tlen < sizeof(struct icmp_multipart_ext_object_header_t))) {
764 return;
765 }
766 obj_tlen-=sizeof(struct icmp_multipart_ext_object_header_t);
767
768 switch (obj_class_num) {
769 case MPLS_STACK_ENTRY_OBJECT_CLASS:
770 switch(obj_ctype) {
771 case 1:
772 raw_label = GET_BE_U_4(obj_tptr);
773 ND_PRINT("\n\t label %u, tc %u", MPLS_LABEL(raw_label), MPLS_TC(raw_label));
774 if (MPLS_STACK(raw_label))
775 ND_PRINT(", [S]");
776 ND_PRINT(", ttl %u", MPLS_TTL(raw_label));
777 break;
778 default:
779 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
780 }
781 break;
782
783 default:
784 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
785 break;
786 }
787 if (hlen < obj_tlen)
788 break;
789 hlen -= obj_tlen;
790 obj_tptr += obj_tlen;
791 }
792 }
793
794 return;
795 trunc:
796 nd_print_trunc(ndo);
797 }
[mirror] the TCPdump network dissector