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 * $FreeBSD$
22 */
23
24 #define NETDISSECT_REWORKED
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28
29 #include <tcpdump-stdinc.h>
30
31 #include <stdio.h>
32 #include <string.h>
33
34 #include "interface.h"
35 #include "addrtoname.h"
36 #include "extract.h" /* must come after interface.h */
37
38 #include "ip.h"
39 #include "udp.h"
40 #include "ipproto.h"
41 #include "mpls.h"
42
43 /*
44 * Interface Control Message Protocol Definitions.
45 * Per RFC 792, September 1981.
46 */
47
48 /*
49 * Structure of an icmp header.
50 */
51 struct icmp {
52 uint8_t icmp_type; /* type of message, see below */
53 uint8_t icmp_code; /* type sub code */
54 uint16_t icmp_cksum; /* ones complement cksum of struct */
55 union {
56 uint8_t ih_pptr; /* ICMP_PARAMPROB */
57 struct in_addr ih_gwaddr; /* ICMP_REDIRECT */
58 struct ih_idseq {
59 uint16_t icd_id;
60 uint16_t icd_seq;
61 } ih_idseq;
62 uint32_t ih_void;
63 } icmp_hun;
64 #define icmp_pptr icmp_hun.ih_pptr
65 #define icmp_gwaddr icmp_hun.ih_gwaddr
66 #define icmp_id icmp_hun.ih_idseq.icd_id
67 #define icmp_seq icmp_hun.ih_idseq.icd_seq
68 #define icmp_void icmp_hun.ih_void
69 union {
70 struct id_ts {
71 uint32_t its_otime;
72 uint32_t its_rtime;
73 uint32_t its_ttime;
74 } id_ts;
75 struct id_ip {
76 struct ip idi_ip;
77 /* options and then 64 bits of data */
78 } id_ip;
79 uint32_t id_mask;
80 uint8_t id_data[1];
81 } icmp_dun;
82 #define icmp_otime icmp_dun.id_ts.its_otime
83 #define icmp_rtime icmp_dun.id_ts.its_rtime
84 #define icmp_ttime icmp_dun.id_ts.its_ttime
85 #define icmp_ip icmp_dun.id_ip.idi_ip
86 #define icmp_mask icmp_dun.id_mask
87 #define icmp_data icmp_dun.id_data
88 };
89
90 #define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
91 #define ICMP_MPLS_EXT_VERSION 2
92
93 /*
94 * Lower bounds on packet lengths for various types.
95 * For the error advice packets must first insure that the
96 * packet is large enought to contain the returned ip header.
97 * Only then can we do the check to see if 64 bits of packet
98 * data have been returned, since we need to check the returned
99 * ip header length.
100 */
101 #define ICMP_MINLEN 8 /* abs minimum */
102 #define ICMP_EXTD_MINLEN (156 - sizeof (struct ip)) /* draft-bonica-internet-icmp-08 */
103 #define ICMP_TSLEN (8 + 3 * sizeof (uint32_t)) /* timestamp */
104 #define ICMP_MASKLEN 12 /* address mask */
105 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */
106 #define ICMP_ADVLEN(p) (8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
107 /* N.B.: must separately check that ip_hl >= 5 */
108
109 /*
110 * Definition of type and code field values.
111 */
112 #define ICMP_ECHOREPLY 0 /* echo reply */
113 #define ICMP_UNREACH 3 /* dest unreachable, codes: */
114 #define ICMP_UNREACH_NET 0 /* bad net */
115 #define ICMP_UNREACH_HOST 1 /* bad host */
116 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */
117 #define ICMP_UNREACH_PORT 3 /* bad port */
118 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */
119 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */
120 #define ICMP_UNREACH_NET_UNKNOWN 6 /* unknown net */
121 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* unknown host */
122 #define ICMP_UNREACH_ISOLATED 8 /* src host isolated */
123 #define ICMP_UNREACH_NET_PROHIB 9 /* prohibited access */
124 #define ICMP_UNREACH_HOST_PROHIB 10 /* ditto */
125 #define ICMP_UNREACH_TOSNET 11 /* bad tos for net */
126 #define ICMP_UNREACH_TOSHOST 12 /* bad tos for host */
127 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */
128 #define ICMP_REDIRECT 5 /* shorter route, codes: */
129 #define ICMP_REDIRECT_NET 0 /* for network */
130 #define ICMP_REDIRECT_HOST 1 /* for host */
131 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */
132 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */
133 #define ICMP_ECHO 8 /* echo service */
134 #define ICMP_ROUTERADVERT 9 /* router advertisement */
135 #define ICMP_ROUTERSOLICIT 10 /* router solicitation */
136 #define ICMP_TIMXCEED 11 /* time exceeded, code: */
137 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */
138 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */
139 #define ICMP_PARAMPROB 12 /* ip header bad */
140 #define ICMP_PARAMPROB_OPTABSENT 1 /* req. opt. absent */
141 #define ICMP_TSTAMP 13 /* timestamp request */
142 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */
143 #define ICMP_IREQ 15 /* information request */
144 #define ICMP_IREQREPLY 16 /* information reply */
145 #define ICMP_MASKREQ 17 /* address mask request */
146 #define ICMP_MASKREPLY 18 /* address mask reply */
147
148 #define ICMP_MAXTYPE 18
149
150 #define ICMP_ERRTYPE(type) \
151 ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
152 (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
153 (type) == ICMP_PARAMPROB)
154 #define ICMP_MPLS_EXT_TYPE(type) \
155 ((type) == ICMP_UNREACH || \
156 (type) == ICMP_TIMXCEED || \
157 (type) == ICMP_PARAMPROB)
158 /* rfc1700 */
159 #ifndef ICMP_UNREACH_NET_UNKNOWN
160 #define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */
161 #endif
162 #ifndef ICMP_UNREACH_HOST_UNKNOWN
163 #define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */
164 #endif
165 #ifndef ICMP_UNREACH_ISOLATED
166 #define ICMP_UNREACH_ISOLATED 8 /* source host isolated */
167 #endif
168 #ifndef ICMP_UNREACH_NET_PROHIB
169 #define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */
170 #endif
171 #ifndef ICMP_UNREACH_HOST_PROHIB
172 #define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */
173 #endif
174 #ifndef ICMP_UNREACH_TOSNET
175 #define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */
176 #endif
177 #ifndef ICMP_UNREACH_TOSHOST
178 #define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */
179 #endif
180
181 /* rfc1716 */
182 #ifndef ICMP_UNREACH_FILTER_PROHIB
183 #define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */
184 #endif
185 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
186 #define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */
187 #endif
188 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
189 #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */
190 #endif
191
192 /* Most of the icmp types */
193 static const struct tok icmp2str[] = {
194 { ICMP_ECHOREPLY, "echo reply" },
195 { ICMP_SOURCEQUENCH, "source quench" },
196 { ICMP_ECHO, "echo request" },
197 { ICMP_ROUTERSOLICIT, "router solicitation" },
198 { ICMP_TSTAMP, "time stamp request" },
199 { ICMP_TSTAMPREPLY, "time stamp reply" },
200 { ICMP_IREQ, "information request" },
201 { ICMP_IREQREPLY, "information reply" },
202 { ICMP_MASKREQ, "address mask request" },
203 { 0, NULL }
204 };
205
206 /* Formats for most of the ICMP_UNREACH codes */
207 static const struct tok unreach2str[] = {
208 { ICMP_UNREACH_NET, "net %s unreachable" },
209 { ICMP_UNREACH_HOST, "host %s unreachable" },
210 { ICMP_UNREACH_SRCFAIL,
211 "%s unreachable - source route failed" },
212 { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" },
213 { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" },
214 { ICMP_UNREACH_ISOLATED,
215 "%s unreachable - source host isolated" },
216 { ICMP_UNREACH_NET_PROHIB,
217 "net %s unreachable - admin prohibited" },
218 { ICMP_UNREACH_HOST_PROHIB,
219 "host %s unreachable - admin prohibited" },
220 { ICMP_UNREACH_TOSNET,
221 "net %s unreachable - tos prohibited" },
222 { ICMP_UNREACH_TOSHOST,
223 "host %s unreachable - tos prohibited" },
224 { ICMP_UNREACH_FILTER_PROHIB,
225 "host %s unreachable - admin prohibited filter" },
226 { ICMP_UNREACH_HOST_PRECEDENCE,
227 "host %s unreachable - host precedence violation" },
228 { ICMP_UNREACH_PRECEDENCE_CUTOFF,
229 "host %s unreachable - precedence cutoff" },
230 { 0, NULL }
231 };
232
233 /* Formats for the ICMP_REDIRECT codes */
234 static const struct tok type2str[] = {
235 { ICMP_REDIRECT_NET, "redirect %s to net %s" },
236 { ICMP_REDIRECT_HOST, "redirect %s to host %s" },
237 { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" },
238 { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" },
239 { 0, NULL }
240 };
241
242 /* rfc1191 */
243 struct mtu_discovery {
244 uint16_t unused;
245 uint16_t nexthopmtu;
246 };
247
248 /* rfc1256 */
249 struct ih_rdiscovery {
250 uint8_t ird_addrnum;
251 uint8_t ird_addrsiz;
252 uint16_t ird_lifetime;
253 };
254
255 struct id_rdiscovery {
256 uint32_t ird_addr;
257 uint32_t ird_pref;
258 };
259
260 /*
261 * draft-bonica-internet-icmp-08
262 *
263 * The Destination Unreachable, Time Exceeded
264 * and Parameter Problem messages are slighly changed as per
265 * the above draft. A new Length field gets added to give
266 * the caller an idea about the length of the piggypacked
267 * IP packet before the MPLS extension header starts.
268 *
269 * The Length field represents length of the padded "original datagram"
270 * field measured in 32-bit words.
271 *
272 * 0 1 2 3
273 * 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
274 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
275 * | Type | Code | Checksum |
276 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
277 * | unused | Length | unused |
278 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
279 * | Internet Header + leading octets of original datagram |
280 * | |
281 * | // |
282 * | |
283 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
284 */
285
286 struct icmp_ext_t {
287 uint8_t icmp_type;
288 uint8_t icmp_code;
289 uint8_t icmp_checksum[2];
290 uint8_t icmp_reserved;
291 uint8_t icmp_length;
292 uint8_t icmp_reserved2[2];
293 uint8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
294 uint8_t icmp_ext_version_res[2];
295 uint8_t icmp_ext_checksum[2];
296 uint8_t icmp_ext_data[1];
297 };
298
299 struct icmp_mpls_ext_object_header_t {
300 uint8_t length[2];
301 uint8_t class_num;
302 uint8_t ctype;
303 };
304
305 static const struct tok icmp_mpls_ext_obj_values[] = {
306 { 1, "MPLS Stack Entry" },
307 { 2, "Extended Payload" },
308 { 0, NULL}
309 };
310
311 /* prototypes */
312 const char *icmp_tstamp_print(u_int);
313
314 /* print the milliseconds since midnight UTC */
315 const char *
icmp_tstamp_print(u_int tstamp)316 icmp_tstamp_print(u_int tstamp)
317 {
318 u_int msec,sec,min,hrs;
319
320 static char buf[64];
321
322 msec = tstamp % 1000;
323 sec = tstamp / 1000;
324 min = sec / 60; sec -= min * 60;
325 hrs = min / 60; min -= hrs * 60;
326 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
327 return buf;
328 }
329
330 void
icmp_print(netdissect_options * ndo,const u_char * bp,u_int plen,const u_char * bp2,int fragmented)331 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
332 int fragmented)
333 {
334 char *cp;
335 const struct icmp *dp;
336 const struct icmp_ext_t *ext_dp;
337 const struct ip *ip;
338 const char *str, *fmt;
339 const struct ip *oip;
340 const struct udphdr *ouh;
341 const uint8_t *obj_tptr;
342 uint32_t raw_label;
343 const u_char *snapend_save;
344 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
345 u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype;
346 char buf[MAXHOSTNAMELEN + 100];
347 struct cksum_vec vec[1];
348
349 dp = (struct icmp *)bp;
350 ext_dp = (struct icmp_ext_t *)bp;
351 ip = (struct ip *)bp2;
352 str = buf;
353
354 ND_TCHECK(dp->icmp_code);
355 switch (dp->icmp_type) {
356
357 case ICMP_ECHO:
358 case ICMP_ECHOREPLY:
359 ND_TCHECK(dp->icmp_seq);
360 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
361 dp->icmp_type == ICMP_ECHO ?
362 "request" : "reply",
363 EXTRACT_16BITS(&dp->icmp_id),
364 EXTRACT_16BITS(&dp->icmp_seq));
365 break;
366
367 case ICMP_UNREACH:
368 ND_TCHECK(dp->icmp_ip.ip_dst);
369 switch (dp->icmp_code) {
370
371 case ICMP_UNREACH_PROTOCOL:
372 ND_TCHECK(dp->icmp_ip.ip_p);
373 (void)snprintf(buf, sizeof(buf),
374 "%s protocol %d unreachable",
375 ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
376 dp->icmp_ip.ip_p);
377 break;
378
379 case ICMP_UNREACH_PORT:
380 ND_TCHECK(dp->icmp_ip.ip_p);
381 oip = &dp->icmp_ip;
382 hlen = IP_HL(oip) * 4;
383 ouh = (struct udphdr *)(((u_char *)oip) + hlen);
384 ND_TCHECK(ouh->uh_dport);
385 dport = EXTRACT_16BITS(&ouh->uh_dport);
386 switch (oip->ip_p) {
387
388 case IPPROTO_TCP:
389 (void)snprintf(buf, sizeof(buf),
390 "%s tcp port %s unreachable",
391 ipaddr_string(ndo, &oip->ip_dst),
392 tcpport_string(dport));
393 break;
394
395 case IPPROTO_UDP:
396 (void)snprintf(buf, sizeof(buf),
397 "%s udp port %s unreachable",
398 ipaddr_string(ndo, &oip->ip_dst),
399 udpport_string(dport));
400 break;
401
402 default:
403 (void)snprintf(buf, sizeof(buf),
404 "%s protocol %d port %d unreachable",
405 ipaddr_string(ndo, &oip->ip_dst),
406 oip->ip_p, dport);
407 break;
408 }
409 break;
410
411 case ICMP_UNREACH_NEEDFRAG:
412 {
413 register const struct mtu_discovery *mp;
414 mp = (struct mtu_discovery *)(u_char *)&dp->icmp_void;
415 mtu = EXTRACT_16BITS(&mp->nexthopmtu);
416 if (mtu) {
417 (void)snprintf(buf, sizeof(buf),
418 "%s unreachable - need to frag (mtu %d)",
419 ipaddr_string(ndo, &dp->icmp_ip.ip_dst), mtu);
420 } else {
421 (void)snprintf(buf, sizeof(buf),
422 "%s unreachable - need to frag",
423 ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
424 }
425 }
426 break;
427
428 default:
429 fmt = tok2str(unreach2str, "#%d %%s unreachable",
430 dp->icmp_code);
431 (void)snprintf(buf, sizeof(buf), fmt,
432 ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
433 break;
434 }
435 break;
436
437 case ICMP_REDIRECT:
438 ND_TCHECK(dp->icmp_ip.ip_dst);
439 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
440 dp->icmp_code);
441 (void)snprintf(buf, sizeof(buf), fmt,
442 ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
443 ipaddr_string(ndo, &dp->icmp_gwaddr));
444 break;
445
446 case ICMP_ROUTERADVERT:
447 {
448 register const struct ih_rdiscovery *ihp;
449 register const struct id_rdiscovery *idp;
450 u_int lifetime, num, size;
451
452 (void)snprintf(buf, sizeof(buf), "router advertisement");
453 cp = buf + strlen(buf);
454
455 ihp = (struct ih_rdiscovery *)&dp->icmp_void;
456 ND_TCHECK(*ihp);
457 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
458 cp = buf + strlen(buf);
459 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
460 if (lifetime < 60) {
461 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
462 lifetime);
463 } else if (lifetime < 60 * 60) {
464 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
465 lifetime / 60, lifetime % 60);
466 } else {
467 (void)snprintf(cp, sizeof(buf) - (cp - buf),
468 "%u:%02u:%02u",
469 lifetime / 3600,
470 (lifetime % 3600) / 60,
471 lifetime % 60);
472 }
473 cp = buf + strlen(buf);
474
475 num = ihp->ird_addrnum;
476 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
477 cp = buf + strlen(buf);
478
479 size = ihp->ird_addrsiz;
480 if (size != 2) {
481 (void)snprintf(cp, sizeof(buf) - (cp - buf),
482 " [size %d]", size);
483 break;
484 }
485 idp = (struct id_rdiscovery *)&dp->icmp_data;
486 while (num-- > 0) {
487 ND_TCHECK(*idp);
488 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
489 ipaddr_string(ndo, &idp->ird_addr),
490 EXTRACT_32BITS(&idp->ird_pref));
491 cp = buf + strlen(buf);
492 ++idp;
493 }
494 }
495 break;
496
497 case ICMP_TIMXCEED:
498 ND_TCHECK(dp->icmp_ip.ip_dst);
499 switch (dp->icmp_code) {
500
501 case ICMP_TIMXCEED_INTRANS:
502 str = "time exceeded in-transit";
503 break;
504
505 case ICMP_TIMXCEED_REASS:
506 str = "ip reassembly time exceeded";
507 break;
508
509 default:
510 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
511 dp->icmp_code);
512 break;
513 }
514 break;
515
516 case ICMP_PARAMPROB:
517 if (dp->icmp_code)
518 (void)snprintf(buf, sizeof(buf),
519 "parameter problem - code %d", dp->icmp_code);
520 else {
521 ND_TCHECK(dp->icmp_pptr);
522 (void)snprintf(buf, sizeof(buf),
523 "parameter problem - octet %d", dp->icmp_pptr);
524 }
525 break;
526
527 case ICMP_MASKREPLY:
528 ND_TCHECK(dp->icmp_mask);
529 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
530 EXTRACT_32BITS(&dp->icmp_mask));
531 break;
532
533 case ICMP_TSTAMP:
534 ND_TCHECK(dp->icmp_seq);
535 (void)snprintf(buf, sizeof(buf),
536 "time stamp query id %u seq %u",
537 EXTRACT_16BITS(&dp->icmp_id),
538 EXTRACT_16BITS(&dp->icmp_seq));
539 break;
540
541 case ICMP_TSTAMPREPLY:
542 ND_TCHECK(dp->icmp_ttime);
543 (void)snprintf(buf, sizeof(buf),
544 "time stamp reply id %u seq %u: org %s",
545 EXTRACT_16BITS(&dp->icmp_id),
546 EXTRACT_16BITS(&dp->icmp_seq),
547 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime)));
548
549 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
550 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime)));
551 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
552 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime)));
553 break;
554
555 default:
556 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
557 break;
558 }
559 ND_PRINT((ndo, "ICMP %s, length %u", str, plen));
560 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
561 uint16_t sum, icmp_sum;
562 struct cksum_vec vec[1];
563 if (ND_TTEST2(*bp, plen)) {
564 vec[0].ptr = (const uint8_t *)(void *)dp;
565 vec[0].len = plen;
566 sum = in_cksum(vec, 1);
567 if (sum != 0) {
568 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum);
569 ND_PRINT((ndo, " (wrong icmp cksum %x (->%x)!)",
570 icmp_sum,
571 in_cksum_shouldbe(icmp_sum, sum)));
572 }
573 }
574 }
575
576 /*
577 * print the remnants of the IP packet.
578 * save the snaplength as this may get overidden in the IP printer.
579 */
580 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(dp->icmp_type)) {
581 bp += 8;
582 ND_PRINT((ndo, "\n\t"));
583 ip = (struct ip *)bp;
584 ndo->ndo_snaplen = ndo->ndo_snapend - bp;
585 snapend_save = ndo->ndo_snapend;
586 ip_print(ndo, bp, EXTRACT_16BITS(&ip->ip_len));
587 ndo->ndo_snapend = snapend_save;
588 }
589
590 /*
591 * Attempt to decode the MPLS extensions only for some ICMP types.
592 */
593 if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) {
594
595 ND_TCHECK(*ext_dp);
596
597 /*
598 * Check first if the mpls extension header shows a non-zero length.
599 * If the length field is not set then silently verify the checksum
600 * to check if an extension header is present. This is expedient,
601 * however not all implementations set the length field proper.
602 */
603 if (!ext_dp->icmp_length) {
604 vec[0].ptr = (const uint8_t *)(void *)&ext_dp->icmp_ext_version_res;
605 vec[0].len = plen - ICMP_EXTD_MINLEN;
606 if (in_cksum(vec, 1)) {
607 return;
608 }
609 }
610
611 ND_PRINT((ndo, "\n\tMPLS extension v%u",
612 ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))));
613
614 /*
615 * Sanity checking of the header.
616 */
617 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
618 ICMP_MPLS_EXT_VERSION) {
619 ND_PRINT((ndo, " packet not supported"));
620 return;
621 }
622
623 hlen = plen - ICMP_EXTD_MINLEN;
624 vec[0].ptr = (const uint8_t *)(void *)&ext_dp->icmp_ext_version_res;
625 vec[0].len = hlen;
626 ND_PRINT((ndo, ", checksum 0x%04x (%scorrect), length %u",
627 EXTRACT_16BITS(ext_dp->icmp_ext_checksum),
628 in_cksum(vec, 1) ? "in" : "",
629 hlen));
630
631 hlen -= 4; /* subtract common header size */
632 obj_tptr = (uint8_t *)ext_dp->icmp_ext_data;
633
634 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
635
636 icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr;
637 ND_TCHECK(*icmp_mpls_ext_object_header);
638 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length);
639 obj_class_num = icmp_mpls_ext_object_header->class_num;
640 obj_ctype = icmp_mpls_ext_object_header->ctype;
641 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
642
643 ND_PRINT((ndo, "\n\t %s Object (%u), Class-Type: %u, length %u",
644 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
645 obj_class_num,
646 obj_ctype,
647 obj_tlen));
648
649 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
650
651 /* infinite loop protection */
652 if ((obj_class_num == 0) ||
653 (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) {
654 return;
655 }
656 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
657
658 switch (obj_class_num) {
659 case 1:
660 switch(obj_ctype) {
661 case 1:
662 ND_TCHECK2(*obj_tptr, 4);
663 raw_label = EXTRACT_32BITS(obj_tptr);
664 ND_PRINT((ndo, "\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)));
665 if (MPLS_STACK(raw_label))
666 ND_PRINT((ndo, ", [S]"));
667 ND_PRINT((ndo, ", ttl %u", MPLS_TTL(raw_label)));
668 break;
669 default:
670 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
671 }
672 break;
673
674 /*
675 * FIXME those are the defined objects that lack a decoder
676 * you are welcome to contribute code ;-)
677 */
678 case 2:
679 default:
680 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
681 break;
682 }
683 if (hlen < obj_tlen)
684 break;
685 hlen -= obj_tlen;
686 obj_tptr += obj_tlen;
687 }
688 }
689
690 return;
691 trunc:
692 ND_PRINT((ndo, "[|icmp]"));
693 }
694 /*
695 * Local Variables:
696 * c-style: whitesmith
697 * c-basic-offset: 8
698 * End:
699 */
700