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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 #define ICMP_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_MULTIPART_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 /* rfc4950 */
192 #define MPLS_STACK_ENTRY_OBJECT_CLASS 1
193 /* rfc5837 */
194 #define INTERFACE_INFORMATION_OBJECT_CLASS 2
195
196 /* Most of the icmp types */
197 static const struct tok icmp2str[] = {
198 { ICMP_ECHOREPLY, "echo reply" },
199 { ICMP_SOURCEQUENCH, "source quench" },
200 { ICMP_ECHO, "echo request" },
201 { ICMP_ROUTERSOLICIT, "router solicitation" },
202 { ICMP_TSTAMP, "time stamp request" },
203 { ICMP_TSTAMPREPLY, "time stamp reply" },
204 { ICMP_IREQ, "information request" },
205 { ICMP_IREQREPLY, "information reply" },
206 { ICMP_MASKREQ, "address mask request" },
207 { 0, NULL }
208 };
209
210 /* rfc1191 */
211 struct mtu_discovery {
212 nd_uint16_t unused;
213 nd_uint16_t nexthopmtu;
214 };
215
216 /* rfc1256 */
217 struct ih_rdiscovery {
218 nd_uint8_t ird_addrnum;
219 nd_uint8_t ird_addrsiz;
220 nd_uint16_t ird_lifetime;
221 };
222
223 struct id_rdiscovery {
224 nd_uint32_t ird_addr;
225 nd_uint32_t ird_pref;
226 };
227
228 /*
229 * draft-bonica-internet-icmp-08
230 *
231 * The Destination Unreachable, Time Exceeded
232 * and Parameter Problem messages are slightly changed as per
233 * the above draft. A new Length field gets added to give
234 * the caller an idea about the length of the piggybacked
235 * IP packet before the MPLS extension header starts.
236 *
237 * The Length field represents length of the padded "original datagram"
238 * field measured in 32-bit words.
239 *
240 * 0 1 2 3
241 * 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
242 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
243 * | Type | Code | Checksum |
244 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
245 * | unused | Length | unused |
246 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
247 * | Internet Header + leading octets of original datagram |
248 * | |
249 * | // |
250 * | |
251 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
252 */
253
254 struct icmp_ext_t {
255 nd_uint8_t icmp_type;
256 nd_uint8_t icmp_code;
257 nd_uint16_t icmp_checksum;
258 nd_byte icmp_reserved;
259 nd_uint8_t icmp_length;
260 nd_byte icmp_reserved2[2];
261 nd_byte icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
262 nd_byte icmp_ext_version_res[2];
263 nd_uint16_t icmp_ext_checksum;
264 nd_byte icmp_ext_data[1];
265 };
266
267 struct icmp_multipart_ext_object_header_t {
268 nd_uint16_t length;
269 nd_uint8_t class_num;
270 nd_uint8_t ctype;
271 };
272
273 static const struct tok icmp_multipart_ext_obj_values[] = {
274 { 1, "MPLS Stack Entry" },
275 { 2, "Interface Identification" },
276 { 0, NULL}
277 };
278
279 /* prototypes */
280 const char *icmp_tstamp_print(u_int);
281
282 /* print the milliseconds since midnight UTC */
283 const char *
284 icmp_tstamp_print(u_int tstamp)
285 {
286 u_int msec,sec,min,hrs;
287
288 static char buf[64];
289
290 msec = tstamp % 1000;
291 sec = tstamp / 1000;
292 min = sec / 60; sec -= min * 60;
293 hrs = min / 60; min -= hrs * 60;
294 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
295 return buf;
296 }
297
298 void
299 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
300 int fragmented)
301 {
302 char *cp;
303 const struct icmp *dp;
304 uint8_t icmp_type, icmp_code;
305 const struct icmp_ext_t *ext_dp;
306 const struct ip *ip;
307 const char *str;
308 const struct ip *oip;
309 uint8_t ip_proto;
310 const struct udphdr *ouh;
311 const uint8_t *obj_tptr;
312 uint32_t raw_label;
313 const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header;
314 u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype;
315 uint16_t dport;
316 char buf[MAXHOSTNAMELEN + 100];
317 struct cksum_vec vec[1];
318
319 ndo->ndo_protocol = "icmp";
320 dp = (const struct icmp *)bp;
321 ext_dp = (const struct icmp_ext_t *)bp;
322 ip = (const struct ip *)bp2;
323 str = buf;
324
325 icmp_type = GET_U_1(dp->icmp_type);
326 icmp_code = GET_U_1(dp->icmp_code);
327 switch (icmp_type) {
328
329 case ICMP_ECHO:
330 case ICMP_ECHOREPLY:
331 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
332 icmp_type == ICMP_ECHO ?
333 "request" : "reply",
334 GET_BE_U_2(dp->icmp_id),
335 GET_BE_U_2(dp->icmp_seq));
336 break;
337
338 case ICMP_UNREACH:
339 switch (icmp_code) {
340
341 case ICMP_UNREACH_NET:
342 (void)snprintf(buf, sizeof(buf),
343 "net %s unreachable",
344 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
345 break;
346
347 case ICMP_UNREACH_HOST:
348 (void)snprintf(buf, sizeof(buf),
349 "host %s unreachable",
350 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
351 break;
352
353 case ICMP_UNREACH_PROTOCOL:
354 (void)snprintf(buf, sizeof(buf),
355 "%s protocol %u unreachable",
356 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
357 GET_U_1(dp->icmp_ip.ip_p));
358 break;
359
360 case ICMP_UNREACH_PORT:
361 ND_TCHECK_1(dp->icmp_ip.ip_p);
362 oip = &dp->icmp_ip;
363 hlen = IP_HL(oip) * 4;
364 ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
365 dport = GET_BE_U_2(ouh->uh_dport);
366 ip_proto = GET_U_1(oip->ip_p);
367 switch (ip_proto) {
368
369 case IPPROTO_TCP:
370 (void)snprintf(buf, sizeof(buf),
371 "%s tcp port %s unreachable",
372 GET_IPADDR_STRING(oip->ip_dst),
373 tcpport_string(ndo, dport));
374 break;
375
376 case IPPROTO_UDP:
377 (void)snprintf(buf, sizeof(buf),
378 "%s udp port %s unreachable",
379 GET_IPADDR_STRING(oip->ip_dst),
380 udpport_string(ndo, dport));
381 break;
382
383 default:
384 (void)snprintf(buf, sizeof(buf),
385 "%s protocol %u port %u unreachable",
386 GET_IPADDR_STRING(oip->ip_dst),
387 ip_proto, dport);
388 break;
389 }
390 break;
391
392 case ICMP_UNREACH_NEEDFRAG:
393 {
394 const struct mtu_discovery *mp;
395 mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void;
396 mtu = GET_BE_U_2(mp->nexthopmtu);
397 if (mtu) {
398 (void)snprintf(buf, sizeof(buf),
399 "%s unreachable - need to frag (mtu %u)",
400 GET_IPADDR_STRING(dp->icmp_ip.ip_dst), mtu);
401 } else {
402 (void)snprintf(buf, sizeof(buf),
403 "%s unreachable - need to frag",
404 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
405 }
406 }
407 break;
408
409 case ICMP_UNREACH_SRCFAIL:
410 (void)snprintf(buf, sizeof(buf),
411 "%s unreachable - source route failed",
412 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
413 break;
414
415 case ICMP_UNREACH_NET_UNKNOWN:
416 (void)snprintf(buf, sizeof(buf),
417 "net %s unreachable - unknown",
418 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
419 break;
420
421 case ICMP_UNREACH_HOST_UNKNOWN:
422 (void)snprintf(buf, sizeof(buf),
423 "host %s unreachable - unknown",
424 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
425 break;
426
427 case ICMP_UNREACH_ISOLATED:
428 (void)snprintf(buf, sizeof(buf),
429 "%s unreachable - source host isolated",
430 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
431 break;
432
433 case ICMP_UNREACH_NET_PROHIB:
434 (void)snprintf(buf, sizeof(buf),
435 "net %s unreachable - admin prohibited",
436 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
437 break;
438
439 case ICMP_UNREACH_HOST_PROHIB:
440 (void)snprintf(buf, sizeof(buf),
441 "host %s unreachable - admin prohibited",
442 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
443 break;
444
445 case ICMP_UNREACH_TOSNET:
446 (void)snprintf(buf, sizeof(buf),
447 "net %s unreachable - tos prohibited",
448 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
449 break;
450
451 case ICMP_UNREACH_TOSHOST:
452 (void)snprintf(buf, sizeof(buf),
453 "host %s unreachable - tos prohibited",
454 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
455 break;
456
457 case ICMP_UNREACH_FILTER_PROHIB:
458 (void)snprintf(buf, sizeof(buf),
459 "host %s unreachable - admin prohibited filter",
460 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
461 break;
462
463 case ICMP_UNREACH_HOST_PRECEDENCE:
464 (void)snprintf(buf, sizeof(buf),
465 "host %s unreachable - host precedence violation",
466 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
467 break;
468
469 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
470 (void)snprintf(buf, sizeof(buf),
471 "host %s unreachable - precedence cutoff",
472 GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
473 break;
474
475 default:
476 (void)snprintf(buf, sizeof(buf),
477 "%s unreachable - #%u",
478 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
479 icmp_code);
480 break;
481 }
482 break;
483
484 case ICMP_REDIRECT:
485 switch (icmp_code) {
486
487 case ICMP_REDIRECT_NET:
488 (void)snprintf(buf, sizeof(buf),
489 "redirect %s to net %s",
490 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
491 GET_IPADDR_STRING(dp->icmp_gwaddr));
492 break;
493
494 case ICMP_REDIRECT_HOST:
495 (void)snprintf(buf, sizeof(buf),
496 "redirect %s to host %s",
497 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
498 GET_IPADDR_STRING(dp->icmp_gwaddr));
499 break;
500
501 case ICMP_REDIRECT_TOSNET:
502 (void)snprintf(buf, sizeof(buf),
503 "redirect-tos %s to net %s",
504 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
505 GET_IPADDR_STRING(dp->icmp_gwaddr));
506 break;
507
508 case ICMP_REDIRECT_TOSHOST:
509 (void)snprintf(buf, sizeof(buf),
510 "redirect-tos %s to host %s",
511 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
512 GET_IPADDR_STRING(dp->icmp_gwaddr));
513 break;
514
515 default:
516 (void)snprintf(buf, sizeof(buf),
517 "redirect-#%u %s to %s", icmp_code,
518 GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
519 GET_IPADDR_STRING(dp->icmp_gwaddr));
520 break;
521 }
522 break;
523
524 case ICMP_ROUTERADVERT:
525 {
526 const struct ih_rdiscovery *ihp;
527 const struct id_rdiscovery *idp;
528 u_int lifetime, num, size;
529
530 (void)snprintf(buf, sizeof(buf), "router advertisement");
531 cp = buf + strlen(buf);
532
533 ihp = (const struct ih_rdiscovery *)&dp->icmp_void;
534 ND_TCHECK_SIZE(ihp);
535 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
536 cp = buf + strlen(buf);
537 lifetime = GET_BE_U_2(ihp->ird_lifetime);
538 if (lifetime < 60) {
539 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
540 lifetime);
541 } else if (lifetime < 60 * 60) {
542 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
543 lifetime / 60, lifetime % 60);
544 } else {
545 (void)snprintf(cp, sizeof(buf) - (cp - buf),
546 "%u:%02u:%02u",
547 lifetime / 3600,
548 (lifetime % 3600) / 60,
549 lifetime % 60);
550 }
551 cp = buf + strlen(buf);
552
553 num = GET_U_1(ihp->ird_addrnum);
554 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %u:", num);
555 cp = buf + strlen(buf);
556
557 size = GET_U_1(ihp->ird_addrsiz);
558 if (size != 2) {
559 (void)snprintf(cp, sizeof(buf) - (cp - buf),
560 " [size %u]", size);
561 break;
562 }
563 idp = (const struct id_rdiscovery *)&dp->icmp_data;
564 while (num > 0) {
565 ND_TCHECK_SIZE(idp);
566 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
567 GET_IPADDR_STRING(idp->ird_addr),
568 GET_BE_U_4(idp->ird_pref));
569 cp = buf + strlen(buf);
570 ++idp;
571 num--;
572 }
573 }
574 break;
575
576 case ICMP_TIMXCEED:
577 ND_TCHECK_4(dp->icmp_ip.ip_dst);
578 switch (icmp_code) {
579
580 case ICMP_TIMXCEED_INTRANS:
581 str = "time exceeded in-transit";
582 break;
583
584 case ICMP_TIMXCEED_REASS:
585 str = "ip reassembly time exceeded";
586 break;
587
588 default:
589 (void)snprintf(buf, sizeof(buf), "time exceeded-#%u",
590 icmp_code);
591 break;
592 }
593 break;
594
595 case ICMP_PARAMPROB:
596 if (icmp_code)
597 (void)snprintf(buf, sizeof(buf),
598 "parameter problem - code %u", icmp_code);
599 else {
600 (void)snprintf(buf, sizeof(buf),
601 "parameter problem - octet %u",
602 GET_U_1(dp->icmp_pptr));
603 }
604 break;
605
606 case ICMP_MASKREPLY:
607 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
608 GET_BE_U_4(dp->icmp_mask));
609 break;
610
611 case ICMP_TSTAMP:
612 (void)snprintf(buf, sizeof(buf),
613 "time stamp query id %u seq %u",
614 GET_BE_U_2(dp->icmp_id),
615 GET_BE_U_2(dp->icmp_seq));
616 break;
617
618 case ICMP_TSTAMPREPLY:
619 ND_TCHECK_4(dp->icmp_ttime);
620 (void)snprintf(buf, sizeof(buf),
621 "time stamp reply id %u seq %u: org %s",
622 GET_BE_U_2(dp->icmp_id),
623 GET_BE_U_2(dp->icmp_seq),
624 icmp_tstamp_print(GET_BE_U_4(dp->icmp_otime)));
625
626 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
627 icmp_tstamp_print(GET_BE_U_4(dp->icmp_rtime)));
628 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
629 icmp_tstamp_print(GET_BE_U_4(dp->icmp_ttime)));
630 break;
631
632 default:
633 str = tok2str(icmp2str, "type-#%u", icmp_type);
634 break;
635 }
636 ND_PRINT("ICMP %s, length %u", str, plen);
637 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
638 if (ND_TTEST_LEN(bp, plen)) {
639 uint16_t sum;
640
641 vec[0].ptr = (const uint8_t *)(const void *)dp;
642 vec[0].len = plen;
643 sum = in_cksum(vec, 1);
644 if (sum != 0) {
645 uint16_t icmp_sum = GET_BE_U_2(dp->icmp_cksum);
646 ND_PRINT(" (wrong icmp cksum %x (->%x)!)",
647 icmp_sum,
648 in_cksum_shouldbe(icmp_sum, sum));
649 }
650 }
651 }
652
653 /*
654 * print the remnants of the IP packet.
655 * save the snaplength as this may get overridden in the IP printer.
656 */
657 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) {
658 const u_char *snapend_save;
659
660 bp += 8;
661 ND_PRINT("\n\t");
662 ip = (const struct ip *)bp;
663 snapend_save = ndo->ndo_snapend;
664 /*
665 * Update the snapend because extensions (MPLS, ...) may be
666 * present after the IP packet. In this case the current
667 * (outer) packet's snapend is not what ip_print() needs to
668 * decode an IP packet nested in the middle of an ICMP payload.
669 *
670 * This prevents that, in ip_print(), for the nested IP packet,
671 * the remaining length < remaining caplen.
672 */
673 ndo->ndo_snapend = ND_MIN(bp + GET_BE_U_2(ip->ip_len),
674 ndo->ndo_snapend);
675 ip_print(ndo, bp, GET_BE_U_2(ip->ip_len));
676 ndo->ndo_snapend = snapend_save;
677 }
678
679 /* ndo_protocol reassignment after ip_print() call */
680 ndo->ndo_protocol = "icmp";
681
682 /*
683 * Attempt to decode multi-part message extensions (rfc4884) only for some ICMP types.
684 */
685 if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MULTIPART_EXT_TYPE(icmp_type)) {
686
687 ND_TCHECK_SIZE(ext_dp);
688
689 /*
690 * Check first if the multi-part extension header shows a non-zero length.
691 * If the length field is not set then silently verify the checksum
692 * to check if an extension header is present. This is expedient,
693 * however not all implementations set the length field proper.
694 */
695 if (GET_U_1(ext_dp->icmp_length) == 0 &&
696 ND_TTEST_LEN(ext_dp->icmp_ext_version_res, plen - ICMP_EXTD_MINLEN)) {
697 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
698 vec[0].len = plen - ICMP_EXTD_MINLEN;
699 if (in_cksum(vec, 1)) {
700 return;
701 }
702 }
703
704 ND_PRINT("\n\tICMP Multi-Part extension v%u",
705 ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)));
706
707 /*
708 * Sanity checking of the header.
709 */
710 if (ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
711 ICMP_MPLS_EXT_VERSION) {
712 ND_PRINT(" packet not supported");
713 return;
714 }
715
716 hlen = plen - ICMP_EXTD_MINLEN;
717 if (ND_TTEST_LEN(ext_dp->icmp_ext_version_res, hlen)) {
718 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
719 vec[0].len = hlen;
720 ND_PRINT(", checksum 0x%04x (%scorrect), length %u",
721 GET_BE_U_2(ext_dp->icmp_ext_checksum),
722 in_cksum(vec, 1) ? "in" : "",
723 hlen);
724 }
725
726 hlen -= 4; /* subtract common header size */
727 obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data;
728
729 while (hlen > sizeof(struct icmp_multipart_ext_object_header_t)) {
730
731 icmp_multipart_ext_object_header = (const struct icmp_multipart_ext_object_header_t *)obj_tptr;
732 ND_TCHECK_SIZE(icmp_multipart_ext_object_header);
733 obj_tlen = GET_BE_U_2(icmp_multipart_ext_object_header->length);
734 obj_class_num = GET_U_1(icmp_multipart_ext_object_header->class_num);
735 obj_ctype = GET_U_1(icmp_multipart_ext_object_header->ctype);
736 obj_tptr += sizeof(struct icmp_multipart_ext_object_header_t);
737
738 ND_PRINT("\n\t %s Object (%u), Class-Type: %u, length %u",
739 tok2str(icmp_multipart_ext_obj_values,"unknown",obj_class_num),
740 obj_class_num,
741 obj_ctype,
742 obj_tlen);
743
744 hlen-=sizeof(struct icmp_multipart_ext_object_header_t); /* length field includes tlv header */
745
746 /* infinite loop protection */
747 if ((obj_class_num == 0) ||
748 (obj_tlen < sizeof(struct icmp_multipart_ext_object_header_t))) {
749 return;
750 }
751 obj_tlen-=sizeof(struct icmp_multipart_ext_object_header_t);
752
753 switch (obj_class_num) {
754 case 1:
755 switch(obj_ctype) {
756 case 1:
757 raw_label = GET_BE_U_4(obj_tptr);
758 ND_PRINT("\n\t label %u, tc %u", MPLS_LABEL(raw_label), MPLS_TC(raw_label));
759 if (MPLS_STACK(raw_label))
760 ND_PRINT(", [S]");
761 ND_PRINT(", ttl %u", MPLS_TTL(raw_label));
762 break;
763 default:
764 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
765 }
766 break;
767
768 /*
769 * FIXME those are the defined objects that lack a decoder
770 * you are welcome to contribute code ;-)
771 */
772 case 2:
773 default:
774 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
775 break;
776 }
777 if (hlen < obj_tlen)
778 break;
779 hlen -= obj_tlen;
780 obj_tptr += obj_tlen;
781 }
782 }
783
784 return;
785 trunc:
786 nd_print_trunc(ndo);
787 }
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