print-icmp.c revision 1.13 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 1.13 2023/08/17 20:19:40 christos Exp $");
25 #endif
26
27 /* \summary: Internet Control Message Protocol (ICMP) printer */
28
29 #ifdef HAVE_CONFIG_H
30 #include <config.h>
31 #endif
32
33 #include "netdissect-stdinc.h"
34
35 #include <stdio.h>
36 #include <string.h>
37
38 #include "netdissect.h"
39 #include "addrtoname.h"
40 #include "extract.h"
41
42 #include "ip.h"
43 #include "udp.h"
44 #include "ipproto.h"
45 #include "mpls.h"
46
47 /*
48 * Interface Control Message Protocol Definitions.
49 * Per RFC 792, September 1981.
50 */
51
52 /*
53 * Structure of an icmp header.
54 */
55 struct icmp {
56 nd_uint8_t icmp_type; /* type of message, see below */
57 nd_uint8_t icmp_code; /* type sub code */
58 nd_uint16_t icmp_cksum; /* ones complement cksum of struct */
59 union {
60 nd_uint8_t ih_pptr; /* ICMP_PARAMPROB */
61 nd_ipv4 ih_gwaddr; /* ICMP_REDIRECT */
62 struct ih_idseq {
63 nd_uint16_t icd_id;
64 nd_uint16_t icd_seq;
65 } ih_idseq;
66 nd_uint32_t ih_void;
67 } icmp_hun;
68 #define icmp_pptr icmp_hun.ih_pptr
69 #define icmp_gwaddr icmp_hun.ih_gwaddr
70 #define icmp_id icmp_hun.ih_idseq.icd_id
71 #define icmp_seq icmp_hun.ih_idseq.icd_seq
72 #define icmp_void icmp_hun.ih_void
73 union {
74 struct id_ts {
75 nd_uint32_t its_otime;
76 nd_uint32_t its_rtime;
77 nd_uint32_t its_ttime;
78 } id_ts;
79 struct id_ip {
80 struct ip idi_ip;
81 /* options and then 64 bits of data */
82 } id_ip;
83 nd_uint32_t id_mask;
84 nd_byte id_data[1];
85 } icmp_dun;
86 #define icmp_otime icmp_dun.id_ts.its_otime
87 #define icmp_rtime icmp_dun.id_ts.its_rtime
88 #define icmp_ttime icmp_dun.id_ts.its_ttime
89 #define icmp_ip icmp_dun.id_ip.idi_ip
90 #define icmp_mask icmp_dun.id_mask
91 #define icmp_data icmp_dun.id_data
92 } UNALIGNED;
93
94 /*
95 * Lower bounds on packet lengths for various types.
96 * For the error advice packets must first insure that the
97 * packet is large enough to contain the returned ip header.
98 * Only then can we do the check to see if 64 bits of packet
99 * data have been returned, since we need to check the returned
100 * ip header length.
101 */
102 #define ICMP_MINLEN 8 /* abs minimum */
103 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */
104 #define ICMP_TSLEN (8 + 3 * sizeof (uint32_t)) /* timestamp */
105 #define ICMP_MASKLEN 12 /* address mask */
106 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */
107 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
108 /* N.B.: must separately check that ip_hl >= 5 */
109
110 /*
111 * Definition of type and code field values.
112 */
113 #define ICMP_ECHOREPLY 0 /* echo reply */
114 #define ICMP_UNREACH 3 /* dest unreachable, codes: */
115 #define ICMP_UNREACH_NET 0 /* bad net */
116 #define ICMP_UNREACH_HOST 1 /* bad host */
117 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */
118 #define ICMP_UNREACH_PORT 3 /* bad port */
119 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */
120 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */
121 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */
122 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */
123 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */
124 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */
125 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */
126 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */
127 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */
128 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */
129 #define ICMP_REDIRECT 5 /* shorter route, codes: */
130 #define ICMP_REDIRECT_NET 0 /* for network */
131 #define ICMP_REDIRECT_HOST 1 /* for host */
132 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */
133 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */
134 #define ICMP_ECHO 8 /* echo service */
135 #define ICMP_ROUTERADVERT 9 /* router advertisement */
136 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */
137 #define ICMP_TIMXCEED 11 /* time exceeded, code: */
138 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */
139 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */
140 #define ICMP_PARAMPROB 12 /* ip header bad */
141 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */
142 #define ICMP_TSTAMP 13 /* timestamp request */
143 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */
144 #define ICMP_IREQ 15 /* information request */
145 #define ICMP_IREQREPLY 16 /* information reply */
146 #define ICMP_MASKREQ 17 /* address mask request */
147 #define ICMP_MASKREPLY 18 /* address mask reply */
148
149 #define ICMP_MAXTYPE 18
150
151 #define ICMP_ERRTYPE(type) \
152 ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
153 (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
154 (type) == ICMP_PARAMPROB)
155 #define ICMP_MULTIPART_EXT_TYPE(type) \
156 ((type) == ICMP_UNREACH || \
157 (type) == ICMP_TIMXCEED || \
158 (type) == ICMP_PARAMPROB)
159 /* rfc1700 */
160 #ifndef ICMP_UNREACH_NET_UNKNOWN
161 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */
162 #endif
163 #ifndef ICMP_UNREACH_HOST_UNKNOWN
164 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */
165 #endif
166 #ifndef ICMP_UNREACH_ISOLATED
167 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */
168 #endif
169 #ifndef ICMP_UNREACH_NET_PROHIB
170 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */
171 #endif
172 #ifndef ICMP_UNREACH_HOST_PROHIB
173 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */
174 #endif
175 #ifndef ICMP_UNREACH_TOSNET
176 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */
177 #endif
178 #ifndef ICMP_UNREACH_TOSHOST
179 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */
180 #endif
181
182 /* rfc1716 */
183 #ifndef ICMP_UNREACH_FILTER_PROHIB
184 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */
185 #endif
186 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
187 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */
188 #endif
189 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
190 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */
191 #endif
192
193 /* Most of the icmp types */
194 static const struct tok icmp2str[] = {
195 { ICMP_ECHOREPLY, "echo reply" },
196 { ICMP_SOURCEQUENCH, "source quench" },
197 { ICMP_ECHO, "echo request" },
198 { ICMP_ROUTERSOLICIT, "router solicitation" },
199 { ICMP_TSTAMP, "time stamp request" },
200 { ICMP_TSTAMPREPLY, "time stamp reply" },
201 { ICMP_IREQ, "information request" },
202 { ICMP_IREQREPLY, "information reply" },
203 { ICMP_MASKREQ, "address mask request" },
204 { 0, NULL }
205 };
206
207 /* rfc1191 */
208 struct mtu_discovery {
209 nd_uint16_t unused;
210 nd_uint16_t nexthopmtu;
211 };
212
213 /* rfc1256 */
214 struct ih_rdiscovery {
215 nd_uint8_t ird_addrnum;
216 nd_uint8_t ird_addrsiz;
217 nd_uint16_t ird_lifetime;
218 };
219
220 struct id_rdiscovery {
221 nd_uint32_t ird_addr;
222 nd_uint32_t ird_pref;
223 };
224
225 /*
226 * RFC 4884 - Extended ICMP to Support Multi-Part Messages
227 *
228 * This is a general extension mechanism, based on the mechanism
229 * in draft-bonica-icmp-mpls-02 ICMP Extensions for MultiProtocol
230 * Label Switching.
231 *
232 * The Destination Unreachable, Time Exceeded
233 * and Parameter Problem messages are slightly changed as per
234 * the above RFC. A new Length field gets added to give
235 * the caller an idea about the length of the piggybacked
236 * IP packet before the extension header starts.
237 *
238 * The Length field represents length of the padded "original datagram"
239 * field measured in 32-bit words.
240 *
241 * 0 1 2 3
242 * 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
243 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
244 * | Type | Code | Checksum |
245 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
246 * | unused | Length | unused |
247 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
248 * | Internet Header + leading octets of original datagram |
249 * | |
250 * | // |
251 * | |
252 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
253 */
254
255 struct icmp_ext_t {
256 nd_uint8_t icmp_type;
257 nd_uint8_t icmp_code;
258 nd_uint16_t icmp_checksum;
259 nd_byte icmp_reserved;
260 nd_uint8_t icmp_length;
261 nd_byte icmp_reserved2[2];
262 nd_byte icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
263 nd_byte icmp_ext_version_res[2];
264 nd_uint16_t icmp_ext_checksum;
265 nd_byte icmp_ext_data[1];
266 };
267
268 /*
269 * Extract version from the first octet of icmp_ext_version_res.
270 */
271 #define ICMP_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
272
273 /*
274 * Current version.
275 */
276 #define ICMP_EXT_VERSION 2
277
278 /*
279 * Extension object class numbers.
280 *
281 * Class 1 dates back to draft-bonica-icmp-mpls-02.
282 */
283
284 /* rfc4950 */
285 #define MPLS_STACK_ENTRY_OBJECT_CLASS 1
286
287 struct icmp_multipart_ext_object_header_t {
288 nd_uint16_t length;
289 nd_uint8_t class_num;
290 nd_uint8_t ctype;
291 };
292
293 static const struct tok icmp_multipart_ext_obj_values[] = {
294 { 1, "MPLS Stack Entry" },
295 { 2, "Interface Identification" },
296 { 0, NULL}
297 };
298
299 /* prototypes */
300 const char *icmp_tstamp_print(u_int);
301
302 /* print the milliseconds since midnight UTC */
303 const char *
304 icmp_tstamp_print(u_int tstamp)
305 {
306 u_int msec,sec,min,hrs;
307
308 static char buf[64];
309
310 msec = tstamp % 1000;
311 sec = tstamp / 1000;
312 min = sec / 60; sec -= min * 60;
313 hrs = min / 60; min -= hrs * 60;
314 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
315 return buf;
316 }
317
318 UNALIGNED_OK
319 void
320 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
321 int fragmented)
322 {
323 char *cp;
324 const struct icmp *dp;
325 uint8_t icmp_type, icmp_code;
326 const struct icmp_ext_t *ext_dp;
327 const struct ip *ip;
328 const char *str;
329 const struct ip *oip;
330 uint8_t ip_proto;
331 const struct udphdr *ouh;
332 const uint8_t *obj_tptr;
333 uint32_t raw_label;
334 const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header;
335 u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype;
336 uint16_t dport;
337 char buf[MAXHOSTNAMELEN + 100];
338 struct cksum_vec vec[1];
339
340 ndo->ndo_protocol = "icmp";
341 dp = (const struct icmp *)bp;
342 ext_dp = (const struct icmp_ext_t *)bp;
343 ip = (const struct ip *)bp2;
344 str = buf;
345
346 icmp_type = GET_U_1(dp->icmp_type);
347 icmp_code = GET_U_1(dp->icmp_code);
348 switch (icmp_type) {
349
350 case ICMP_ECHO:
351 case ICMP_ECHOREPLY:
352 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
353 icmp_type == ICMP_ECHO ?
354 "request" : "reply",
355 GET_BE_U_2(dp->icmp_id),
356 GET_BE_U_2(dp->icmp_seq));
357 break;
358
359 case ICMP_UNREACH:
360 switch (icmp_code) {
361
362 case ICMP_UNREACH_NET:
363 (void)snprintf(buf, sizeof(buf),
364 "net %s unreachable",
365 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
366 break;
367
368 case ICMP_UNREACH_HOST:
369 (void)snprintf(buf, sizeof(buf),
370 "host %s unreachable",
371 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
372 break;
373
374 case ICMP_UNREACH_PROTOCOL:
375 (void)snprintf(buf, sizeof(buf),
376 "%s protocol %u unreachable",
377 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
378 GET_U_1(dp->icmp_ip.ip_p));
379 break;
380
381 case ICMP_UNREACH_PORT:
382 ND_TCHECK_1(dp->icmp_ip.ip_p);
383 oip = &dp->icmp_ip;
384 hlen = IP_HL(oip) * 4;
385 ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
386 dport = GET_BE_U_2(ouh->uh_dport);
387 ip_proto = GET_U_1(oip->ip_p);
388 switch (ip_proto) {
389
390 case IPPROTO_TCP:
391 (void)snprintf(buf, sizeof(buf),
392 "%s tcp port %s unreachable",
393 GET_IPADDR_STRING(oip->ip_dst),
394 tcpport_string(ndo, dport));
395 break;
396
397 case IPPROTO_UDP:
398 (void)snprintf(buf, sizeof(buf),
399 "%s udp port %s unreachable",
400 GET_IPADDR_STRING(oip->ip_dst),
401 udpport_string(ndo, dport));
402 break;
403
404 default:
405 (void)snprintf(buf, sizeof(buf),
406 "%s protocol %u port %u unreachable",
407 GET_IPADDR_STRING(oip->ip_dst),
408 ip_proto, dport);
409 break;
410 }
411 break;
412
413 case ICMP_UNREACH_NEEDFRAG:
414 {
415 const struct mtu_discovery *mp;
416 mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void;
417 mtu = GET_BE_U_2(mp->nexthopmtu);
418 if (mtu) {
419 (void)snprintf(buf, sizeof(buf),
420 "%s unreachable - need to frag (mtu %u)",
421 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), mtu);
422 } else {
423 (void)snprintf(buf, sizeof(buf),
424 "%s unreachable - need to frag",
425 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
426 }
427 }
428 break;
429
430 case ICMP_UNREACH_SRCFAIL:
431 (void)snprintf(buf, sizeof(buf),
432 "%s unreachable - source route failed",
433 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
434 break;
435
436 case ICMP_UNREACH_NET_UNKNOWN:
437 (void)snprintf(buf, sizeof(buf),
438 "net %s unreachable - unknown",
439 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
440 break;
441
442 case ICMP_UNREACH_HOST_UNKNOWN:
443 (void)snprintf(buf, sizeof(buf),
444 "host %s unreachable - unknown",
445 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
446 break;
447
448 case ICMP_UNREACH_ISOLATED:
449 (void)snprintf(buf, sizeof(buf),
450 "%s unreachable - source host isolated",
451 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
452 break;
453
454 case ICMP_UNREACH_NET_PROHIB:
455 (void)snprintf(buf, sizeof(buf),
456 "net %s unreachable - admin prohibited",
457 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
458 break;
459
460 case ICMP_UNREACH_HOST_PROHIB:
461 (void)snprintf(buf, sizeof(buf),
462 "host %s unreachable - admin prohibited",
463 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
464 break;
465
466 case ICMP_UNREACH_TOSNET:
467 (void)snprintf(buf, sizeof(buf),
468 "net %s unreachable - tos prohibited",
469 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
470 break;
471
472 case ICMP_UNREACH_TOSHOST:
473 (void)snprintf(buf, sizeof(buf),
474 "host %s unreachable - tos prohibited",
475 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
476 break;
477
478 case ICMP_UNREACH_FILTER_PROHIB:
479 (void)snprintf(buf, sizeof(buf),
480 "host %s unreachable - admin prohibited filter",
481 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
482 break;
483
484 case ICMP_UNREACH_HOST_PRECEDENCE:
485 (void)snprintf(buf, sizeof(buf),
486 "host %s unreachable - host precedence violation",
487 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
488 break;
489
490 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
491 (void)snprintf(buf, sizeof(buf),
492 "host %s unreachable - precedence cutoff",
493 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
494 break;
495
496 default:
497 (void)snprintf(buf, sizeof(buf),
498 "%s unreachable - #%u",
499 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
500 icmp_code);
501 break;
502 }
503 break;
504
505 case ICMP_REDIRECT:
506 switch (icmp_code) {
507
508 case ICMP_REDIRECT_NET:
509 (void)snprintf(buf, sizeof(buf),
510 "redirect %s to net %s",
511 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
512 GET_IPADDR_STRING(dp->icmp_gwaddr));
513 break;
514
515 case ICMP_REDIRECT_HOST:
516 (void)snprintf(buf, sizeof(buf),
517 "redirect %s to host %s",
518 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
519 GET_IPADDR_STRING(dp->icmp_gwaddr));
520 break;
521
522 case ICMP_REDIRECT_TOSNET:
523 (void)snprintf(buf, sizeof(buf),
524 "redirect-tos %s to net %s",
525 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
526 GET_IPADDR_STRING(dp->icmp_gwaddr));
527 break;
528
529 case ICMP_REDIRECT_TOSHOST:
530 (void)snprintf(buf, sizeof(buf),
531 "redirect-tos %s to host %s",
532 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
533 GET_IPADDR_STRING(dp->icmp_gwaddr));
534 break;
535
536 default:
537 (void)snprintf(buf, sizeof(buf),
538 "redirect-#%u %s to %s", icmp_code,
539 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
540 GET_IPADDR_STRING(dp->icmp_gwaddr));
541 break;
542 }
543 break;
544
545 case ICMP_ROUTERADVERT:
546 {
547 const struct ih_rdiscovery *ihp;
548 const struct id_rdiscovery *idp;
549 u_int lifetime, num, size;
550
551 (void)snprintf(buf, sizeof(buf), "router advertisement");
552 cp = buf + strlen(buf);
553
554 ihp = (const struct ih_rdiscovery *)&dp->icmp_void;
555 ND_TCHECK_SIZE(ihp);
556 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
557 cp = buf + strlen(buf);
558 lifetime = GET_BE_U_2(ihp->ird_lifetime);
559 if (lifetime < 60) {
560 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
561 lifetime);
562 } else if (lifetime < 60 * 60) {
563 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
564 lifetime / 60, lifetime % 60);
565 } else {
566 (void)snprintf(cp, sizeof(buf) - (cp - buf),
567 "%u:%02u:%02u",
568 lifetime / 3600,
569 (lifetime % 3600) / 60,
570 lifetime % 60);
571 }
572 cp = buf + strlen(buf);
573
574 num = GET_U_1(ihp->ird_addrnum);
575 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %u:", num);
576 cp = buf + strlen(buf);
577
578 size = GET_U_1(ihp->ird_addrsiz);
579 if (size != 2) {
580 (void)snprintf(cp, sizeof(buf) - (cp - buf),
581 " [size %u]", size);
582 break;
583 }
584 idp = (const struct id_rdiscovery *)&dp->icmp_data;
585 while (num > 0) {
586 ND_TCHECK_SIZE(idp);
587 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
588 GET_IPADDR_STRING(idp->ird_addr),
589 GET_BE_U_4(idp->ird_pref));
590 cp = buf + strlen(buf);
591 ++idp;
592 num--;
593 }
594 }
595 break;
596
597 case ICMP_TIMXCEED:
598 ND_TCHECK_4(dp->icmp_ip.ip_dst);
599 switch (icmp_code) {
600
601 case ICMP_TIMXCEED_INTRANS:
602 str = "time exceeded in-transit";
603 break;
604
605 case ICMP_TIMXCEED_REASS:
606 str = "ip reassembly time exceeded";
607 break;
608
609 default:
610 (void)snprintf(buf, sizeof(buf), "time exceeded-#%u",
611 icmp_code);
612 break;
613 }
614 break;
615
616 case ICMP_PARAMPROB:
617 if (icmp_code)
618 (void)snprintf(buf, sizeof(buf),
619 "parameter problem - code %u", icmp_code);
620 else {
621 (void)snprintf(buf, sizeof(buf),
622 "parameter problem - octet %u",
623 GET_U_1(dp->icmp_pptr));
624 }
625 break;
626
627 case ICMP_MASKREPLY:
628 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
629 GET_BE_U_4(dp->icmp_mask));
630 break;
631
632 case ICMP_TSTAMP:
633 (void)snprintf(buf, sizeof(buf),
634 "time stamp query id %u seq %u",
635 GET_BE_U_2(dp->icmp_id),
636 GET_BE_U_2(dp->icmp_seq));
637 break;
638
639 case ICMP_TSTAMPREPLY:
640 ND_TCHECK_4(dp->icmp_ttime);
641 (void)snprintf(buf, sizeof(buf),
642 "time stamp reply id %u seq %u: org %s",
643 GET_BE_U_2(dp->icmp_id),
644 GET_BE_U_2(dp->icmp_seq),
645 icmp_tstamp_print(GET_BE_U_4(dp->icmp_otime)));
646
647 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
648 icmp_tstamp_print(GET_BE_U_4(dp->icmp_rtime)));
649 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
650 icmp_tstamp_print(GET_BE_U_4(dp->icmp_ttime)));
651 break;
652
653 default:
654 str = tok2str(icmp2str, "type-#%u", icmp_type);
655 break;
656 }
657 ND_PRINT("ICMP %s, length %u", str, plen);
658 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
659 if (ND_TTEST_LEN(bp, plen)) {
660 uint16_t sum;
661
662 vec[0].ptr = (const uint8_t *)(const void *)dp;
663 vec[0].len = plen;
664 sum = in_cksum(vec, 1);
665 if (sum != 0) {
666 uint16_t icmp_sum = GET_BE_U_2(dp->icmp_cksum);
667 ND_PRINT(" (wrong icmp cksum %x (->%x)!)",
668 icmp_sum,
669 in_cksum_shouldbe(icmp_sum, sum));
670 }
671 }
672 }
673
674 /*
675 * print the remnants of the IP packet.
676 * save the snaplength as this may get overridden in the IP printer.
677 */
678 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) {
679 const u_char *snapend_save;
680
681 bp += 8;
682 ND_PRINT("\n\t");
683 ip = (const struct ip *)bp;
684 snapend_save = ndo->ndo_snapend;
685 /*
686 * Update the snapend because extensions (MPLS, ...) may be
687 * present after the IP packet. In this case the current
688 * (outer) packet's snapend is not what ip_print() needs to
689 * decode an IP packet nested in the middle of an ICMP payload.
690 *
691 * This prevents that, in ip_print(), for the nested IP packet,
692 * the remaining length < remaining caplen.
693 */
694 ndo->ndo_snapend = ND_MIN(bp + GET_BE_U_2(ip->ip_len),
695 ndo->ndo_snapend);
696 ip_print(ndo, bp, GET_BE_U_2(ip->ip_len));
697 ndo->ndo_snapend = snapend_save;
698 }
699
700 /* ndo_protocol reassignment after ip_print() call */
701 ndo->ndo_protocol = "icmp";
702
703 /*
704 * Attempt to decode multi-part message extensions (rfc4884) only for some ICMP types.
705 */
706 if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MULTIPART_EXT_TYPE(icmp_type)) {
707
708 ND_TCHECK_SIZE(ext_dp);
709
710 /*
711 * Check first if the multi-part extension header shows a non-zero length.
712 * If the length field is not set then silently verify the checksum
713 * to check if an extension header is present. This is expedient,
714 * however not all implementations set the length field proper.
715 */
716 if (GET_U_1(ext_dp->icmp_length) == 0 &&
717 ND_TTEST_LEN(ext_dp->icmp_ext_version_res, plen - ICMP_EXTD_MINLEN)) {
718 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
719 vec[0].len = plen - ICMP_EXTD_MINLEN;
720 if (in_cksum(vec, 1)) {
721 return;
722 }
723 }
724
725 ND_PRINT("\n\tICMP Multi-Part extension v%u",
726 ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)));
727
728 /*
729 * Sanity checking of the header.
730 */
731 if (ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
732 ICMP_EXT_VERSION) {
733 ND_PRINT(" packet not supported");
734 return;
735 }
736
737 hlen = plen - ICMP_EXTD_MINLEN;
738 if (ND_TTEST_LEN(ext_dp->icmp_ext_version_res, hlen)) {
739 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
740 vec[0].len = hlen;
741 ND_PRINT(", checksum 0x%04x (%scorrect), length %u",
742 GET_BE_U_2(ext_dp->icmp_ext_checksum),
743 in_cksum(vec, 1) ? "in" : "",
744 hlen);
745 }
746
747 hlen -= 4; /* subtract common header size */
748 obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data;
749
750 while (hlen > sizeof(struct icmp_multipart_ext_object_header_t)) {
751
752 icmp_multipart_ext_object_header = (const struct icmp_multipart_ext_object_header_t *)obj_tptr;
753 ND_TCHECK_SIZE(icmp_multipart_ext_object_header);
754 obj_tlen = GET_BE_U_2(icmp_multipart_ext_object_header->length);
755 obj_class_num = GET_U_1(icmp_multipart_ext_object_header->class_num);
756 obj_ctype = GET_U_1(icmp_multipart_ext_object_header->ctype);
757 obj_tptr += sizeof(struct icmp_multipart_ext_object_header_t);
758
759 ND_PRINT("\n\t %s Object (%u), Class-Type: %u, length %u",
760 tok2str(icmp_multipart_ext_obj_values,"unknown",obj_class_num),
761 obj_class_num,
762 obj_ctype,
763 obj_tlen);
764
765 hlen-=sizeof(struct icmp_multipart_ext_object_header_t); /* length field includes tlv header */
766
767 /* infinite loop protection */
768 if ((obj_class_num == 0) ||
769 (obj_tlen < sizeof(struct icmp_multipart_ext_object_header_t))) {
770 return;
771 }
772 obj_tlen-=sizeof(struct icmp_multipart_ext_object_header_t);
773
774 switch (obj_class_num) {
775 case MPLS_STACK_ENTRY_OBJECT_CLASS:
776 switch(obj_ctype) {
777 case 1:
778 raw_label = GET_BE_U_4(obj_tptr);
779 ND_PRINT("\n\t label %u, tc %u", MPLS_LABEL(raw_label), MPLS_TC(raw_label));
780 if (MPLS_STACK(raw_label))
781 ND_PRINT(", [S]");
782 ND_PRINT(", ttl %u", MPLS_TTL(raw_label));
783 break;
784 default:
785 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
786 }
787 break;
788
789 default:
790 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
791 break;
792 }
793 if (hlen < obj_tlen)
794 break;
795 hlen -= obj_tlen;
796 obj_tptr += obj_tlen;
797 }
798 }
799
800 return;
801 trunc:
802 nd_print_trunc(ndo);
803 }
804