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 uint8_t icmp_type; /* type of message, see below */
52 uint8_t icmp_code; /* type sub code */
53 uint16_t icmp_cksum; /* ones complement cksum of struct */
54 union {
55 uint8_t ih_pptr; /* ICMP_PARAMPROB */
56 struct in_addr ih_gwaddr; /* ICMP_REDIRECT */
57 struct ih_idseq {
58 uint16_t icd_id;
59 uint16_t icd_seq;
60 } ih_idseq;
61 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 uint32_t its_otime;
71 uint32_t its_rtime;
72 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 uint32_t id_mask;
79 uint8_t 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_MPLS_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 enought 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_MPLS_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 /* Most of the icmp types */
192 static const struct tok icmp2str[] = {
193 { ICMP_ECHOREPLY, "echo reply" },
194 { ICMP_SOURCEQUENCH, "source quench" },
195 { ICMP_ECHO, "echo request" },
196 { ICMP_ROUTERSOLICIT, "router solicitation" },
197 { ICMP_TSTAMP, "time stamp request" },
198 { ICMP_TSTAMPREPLY, "time stamp reply" },
199 { ICMP_IREQ, "information request" },
200 { ICMP_IREQREPLY, "information reply" },
201 { ICMP_MASKREQ, "address mask request" },
202 { 0, NULL }
203 };
204
205 /* Formats for most of the ICMP_UNREACH codes */
206 static const struct tok unreach2str[] = {
207 { ICMP_UNREACH_NET, "net %s unreachable" },
208 { ICMP_UNREACH_HOST, "host %s unreachable" },
209 { ICMP_UNREACH_SRCFAIL,
210 "%s unreachable - source route failed" },
211 { ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" },
212 { ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" },
213 { ICMP_UNREACH_ISOLATED,
214 "%s unreachable - source host isolated" },
215 { ICMP_UNREACH_NET_PROHIB,
216 "net %s unreachable - admin prohibited" },
217 { ICMP_UNREACH_HOST_PROHIB,
218 "host %s unreachable - admin prohibited" },
219 { ICMP_UNREACH_TOSNET,
220 "net %s unreachable - tos prohibited" },
221 { ICMP_UNREACH_TOSHOST,
222 "host %s unreachable - tos prohibited" },
223 { ICMP_UNREACH_FILTER_PROHIB,
224 "host %s unreachable - admin prohibited filter" },
225 { ICMP_UNREACH_HOST_PRECEDENCE,
226 "host %s unreachable - host precedence violation" },
227 { ICMP_UNREACH_PRECEDENCE_CUTOFF,
228 "host %s unreachable - precedence cutoff" },
229 { 0, NULL }
230 };
231
232 /* Formats for the ICMP_REDIRECT codes */
233 static const struct tok type2str[] = {
234 { ICMP_REDIRECT_NET, "redirect %s to net %s" },
235 { ICMP_REDIRECT_HOST, "redirect %s to host %s" },
236 { ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" },
237 { ICMP_REDIRECT_TOSHOST, "redirect-tos %s to host %s" },
238 { 0, NULL }
239 };
240
241 /* rfc1191 */
242 struct mtu_discovery {
243 uint16_t unused;
244 uint16_t nexthopmtu;
245 };
246
247 /* rfc1256 */
248 struct ih_rdiscovery {
249 uint8_t ird_addrnum;
250 uint8_t ird_addrsiz;
251 uint16_t ird_lifetime;
252 };
253
254 struct id_rdiscovery {
255 uint32_t ird_addr;
256 uint32_t ird_pref;
257 };
258
259 /*
260 * draft-bonica-internet-icmp-08
261 *
262 * The Destination Unreachable, Time Exceeded
263 * and Parameter Problem messages are slighly changed as per
264 * the above draft. A new Length field gets added to give
265 * the caller an idea about the length of the piggypacked
266 * IP packet before the MPLS extension header starts.
267 *
268 * The Length field represents length of the padded "original datagram"
269 * field measured in 32-bit words.
270 *
271 * 0 1 2 3
272 * 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
273 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
274 * | Type | Code | Checksum |
275 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
276 * | unused | Length | unused |
277 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
278 * | Internet Header + leading octets of original datagram |
279 * | |
280 * | // |
281 * | |
282 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
283 */
284
285 struct icmp_ext_t {
286 uint8_t icmp_type;
287 uint8_t icmp_code;
288 uint8_t icmp_checksum[2];
289 uint8_t icmp_reserved;
290 uint8_t icmp_length;
291 uint8_t icmp_reserved2[2];
292 uint8_t icmp_ext_legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
293 uint8_t icmp_ext_version_res[2];
294 uint8_t icmp_ext_checksum[2];
295 uint8_t icmp_ext_data[1];
296 };
297
298 struct icmp_mpls_ext_object_header_t {
299 uint8_t length[2];
300 uint8_t class_num;
301 uint8_t ctype;
302 };
303
304 static const struct tok icmp_mpls_ext_obj_values[] = {
305 { 1, "MPLS Stack Entry" },
306 { 2, "Extended Payload" },
307 { 0, NULL}
308 };
309
310 /* prototypes */
311 const char *icmp_tstamp_print(u_int);
312
313 /* print the milliseconds since midnight UTC */
314 const char *
icmp_tstamp_print(u_int tstamp)315 icmp_tstamp_print(u_int tstamp)
316 {
317 u_int msec,sec,min,hrs;
318
319 static char buf[64];
320
321 msec = tstamp % 1000;
322 sec = tstamp / 1000;
323 min = sec / 60; sec -= min * 60;
324 hrs = min / 60; min -= hrs * 60;
325 snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
326 return buf;
327 }
328
329 void
icmp_print(netdissect_options * ndo,const u_char * bp,u_int plen,const u_char * bp2,int fragmented)330 icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2,
331 int fragmented)
332 {
333 char *cp;
334 const struct icmp *dp;
335 const struct icmp_ext_t *ext_dp;
336 const struct ip *ip;
337 const char *str, *fmt;
338 const struct ip *oip;
339 const struct udphdr *ouh;
340 const uint8_t *obj_tptr;
341 uint32_t raw_label;
342 const u_char *snapend_save;
343 const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
344 u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype;
345 char buf[MAXHOSTNAMELEN + 100];
346 struct cksum_vec vec[1];
347
348 dp = (const struct icmp *)bp;
349 ext_dp = (const struct icmp_ext_t *)bp;
350 ip = (const struct ip *)bp2;
351 str = buf;
352
353 ND_TCHECK(dp->icmp_code);
354 switch (dp->icmp_type) {
355
356 case ICMP_ECHO:
357 case ICMP_ECHOREPLY:
358 ND_TCHECK(dp->icmp_seq);
359 (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
360 dp->icmp_type == ICMP_ECHO ?
361 "request" : "reply",
362 EXTRACT_16BITS(&dp->icmp_id),
363 EXTRACT_16BITS(&dp->icmp_seq));
364 break;
365
366 case ICMP_UNREACH:
367 ND_TCHECK(dp->icmp_ip.ip_dst);
368 switch (dp->icmp_code) {
369
370 case ICMP_UNREACH_PROTOCOL:
371 ND_TCHECK(dp->icmp_ip.ip_p);
372 (void)snprintf(buf, sizeof(buf),
373 "%s protocol %d unreachable",
374 ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
375 dp->icmp_ip.ip_p);
376 break;
377
378 case ICMP_UNREACH_PORT:
379 ND_TCHECK(dp->icmp_ip.ip_p);
380 oip = &dp->icmp_ip;
381 hlen = IP_HL(oip) * 4;
382 ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
383 ND_TCHECK(ouh->uh_dport);
384 dport = EXTRACT_16BITS(&ouh->uh_dport);
385 switch (oip->ip_p) {
386
387 case IPPROTO_TCP:
388 (void)snprintf(buf, sizeof(buf),
389 "%s tcp port %s unreachable",
390 ipaddr_string(ndo, &oip->ip_dst),
391 tcpport_string(ndo, dport));
392 break;
393
394 case IPPROTO_UDP:
395 (void)snprintf(buf, sizeof(buf),
396 "%s udp port %s unreachable",
397 ipaddr_string(ndo, &oip->ip_dst),
398 udpport_string(ndo, dport));
399 break;
400
401 default:
402 (void)snprintf(buf, sizeof(buf),
403 "%s protocol %d port %d unreachable",
404 ipaddr_string(ndo, &oip->ip_dst),
405 oip->ip_p, dport);
406 break;
407 }
408 break;
409
410 case ICMP_UNREACH_NEEDFRAG:
411 {
412 register const struct mtu_discovery *mp;
413 mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void;
414 mtu = EXTRACT_16BITS(&mp->nexthopmtu);
415 if (mtu) {
416 (void)snprintf(buf, sizeof(buf),
417 "%s unreachable - need to frag (mtu %d)",
418 ipaddr_string(ndo, &dp->icmp_ip.ip_dst), mtu);
419 } else {
420 (void)snprintf(buf, sizeof(buf),
421 "%s unreachable - need to frag",
422 ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
423 }
424 }
425 break;
426
427 default:
428 fmt = tok2str(unreach2str, "#%d %%s unreachable",
429 dp->icmp_code);
430 (void)snprintf(buf, sizeof(buf), fmt,
431 ipaddr_string(ndo, &dp->icmp_ip.ip_dst));
432 break;
433 }
434 break;
435
436 case ICMP_REDIRECT:
437 ND_TCHECK(dp->icmp_ip.ip_dst);
438 fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
439 dp->icmp_code);
440 (void)snprintf(buf, sizeof(buf), fmt,
441 ipaddr_string(ndo, &dp->icmp_ip.ip_dst),
442 ipaddr_string(ndo, &dp->icmp_gwaddr));
443 break;
444
445 case ICMP_ROUTERADVERT:
446 {
447 register const struct ih_rdiscovery *ihp;
448 register const struct id_rdiscovery *idp;
449 u_int lifetime, num, size;
450
451 (void)snprintf(buf, sizeof(buf), "router advertisement");
452 cp = buf + strlen(buf);
453
454 ihp = (const struct ih_rdiscovery *)&dp->icmp_void;
455 ND_TCHECK(*ihp);
456 (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
457 cp = buf + strlen(buf);
458 lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
459 if (lifetime < 60) {
460 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
461 lifetime);
462 } else if (lifetime < 60 * 60) {
463 (void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
464 lifetime / 60, lifetime % 60);
465 } else {
466 (void)snprintf(cp, sizeof(buf) - (cp - buf),
467 "%u:%02u:%02u",
468 lifetime / 3600,
469 (lifetime % 3600) / 60,
470 lifetime % 60);
471 }
472 cp = buf + strlen(buf);
473
474 num = ihp->ird_addrnum;
475 (void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
476 cp = buf + strlen(buf);
477
478 size = ihp->ird_addrsiz;
479 if (size != 2) {
480 (void)snprintf(cp, sizeof(buf) - (cp - buf),
481 " [size %d]", size);
482 break;
483 }
484 idp = (const struct id_rdiscovery *)&dp->icmp_data;
485 while (num-- > 0) {
486 ND_TCHECK(*idp);
487 (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
488 ipaddr_string(ndo, &idp->ird_addr),
489 EXTRACT_32BITS(&idp->ird_pref));
490 cp = buf + strlen(buf);
491 ++idp;
492 }
493 }
494 break;
495
496 case ICMP_TIMXCEED:
497 ND_TCHECK(dp->icmp_ip.ip_dst);
498 switch (dp->icmp_code) {
499
500 case ICMP_TIMXCEED_INTRANS:
501 str = "time exceeded in-transit";
502 break;
503
504 case ICMP_TIMXCEED_REASS:
505 str = "ip reassembly time exceeded";
506 break;
507
508 default:
509 (void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
510 dp->icmp_code);
511 break;
512 }
513 break;
514
515 case ICMP_PARAMPROB:
516 if (dp->icmp_code)
517 (void)snprintf(buf, sizeof(buf),
518 "parameter problem - code %d", dp->icmp_code);
519 else {
520 ND_TCHECK(dp->icmp_pptr);
521 (void)snprintf(buf, sizeof(buf),
522 "parameter problem - octet %d", dp->icmp_pptr);
523 }
524 break;
525
526 case ICMP_MASKREPLY:
527 ND_TCHECK(dp->icmp_mask);
528 (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
529 EXTRACT_32BITS(&dp->icmp_mask));
530 break;
531
532 case ICMP_TSTAMP:
533 ND_TCHECK(dp->icmp_seq);
534 (void)snprintf(buf, sizeof(buf),
535 "time stamp query id %u seq %u",
536 EXTRACT_16BITS(&dp->icmp_id),
537 EXTRACT_16BITS(&dp->icmp_seq));
538 break;
539
540 case ICMP_TSTAMPREPLY:
541 ND_TCHECK(dp->icmp_ttime);
542 (void)snprintf(buf, sizeof(buf),
543 "time stamp reply id %u seq %u: org %s",
544 EXTRACT_16BITS(&dp->icmp_id),
545 EXTRACT_16BITS(&dp->icmp_seq),
546 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime)));
547
548 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
549 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime)));
550 (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
551 icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime)));
552 break;
553
554 default:
555 str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
556 break;
557 }
558 ND_PRINT((ndo, "ICMP %s, length %u", str, plen));
559 if (ndo->ndo_vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
560 uint16_t sum, icmp_sum;
561
562 if (ND_TTEST2(*bp, plen)) {
563 vec[0].ptr = (const uint8_t *)(const void *)dp;
564 vec[0].len = plen;
565 sum = in_cksum(vec, 1);
566 if (sum != 0) {
567 icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum);
568 ND_PRINT((ndo, " (wrong icmp cksum %x (->%x)!)",
569 icmp_sum,
570 in_cksum_shouldbe(icmp_sum, sum)));
571 }
572 }
573 }
574
575 /*
576 * print the remnants of the IP packet.
577 * save the snaplength as this may get overidden in the IP printer.
578 */
579 if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(dp->icmp_type)) {
580 bp += 8;
581 ND_PRINT((ndo, "\n\t"));
582 ip = (const struct ip *)bp;
583 ndo->ndo_snaplen = ndo->ndo_snapend - bp;
584 snapend_save = ndo->ndo_snapend;
585 ND_TCHECK_16BITS(&ip->ip_len);
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 ND_TTEST2(ext_dp->icmp_ext_version_res, plen - ICMP_EXTD_MINLEN)) {
605 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
606 vec[0].len = plen - ICMP_EXTD_MINLEN;
607 if (in_cksum(vec, 1)) {
608 return;
609 }
610 }
611
612 ND_PRINT((ndo, "\n\tMPLS extension v%u",
613 ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))));
614
615 /*
616 * Sanity checking of the header.
617 */
618 if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
619 ICMP_MPLS_EXT_VERSION) {
620 ND_PRINT((ndo, " packet not supported"));
621 return;
622 }
623
624 hlen = plen - ICMP_EXTD_MINLEN;
625 if (ND_TTEST2(ext_dp->icmp_ext_version_res, hlen)) {
626 vec[0].ptr = (const uint8_t *)(const void *)&ext_dp->icmp_ext_version_res;
627 vec[0].len = hlen;
628 ND_PRINT((ndo, ", checksum 0x%04x (%scorrect), length %u",
629 EXTRACT_16BITS(ext_dp->icmp_ext_checksum),
630 in_cksum(vec, 1) ? "in" : "",
631 hlen));
632 }
633
634 hlen -= 4; /* subtract common header size */
635 obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data;
636
637 while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
638
639 icmp_mpls_ext_object_header = (const struct icmp_mpls_ext_object_header_t *)obj_tptr;
640 ND_TCHECK(*icmp_mpls_ext_object_header);
641 obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length);
642 obj_class_num = icmp_mpls_ext_object_header->class_num;
643 obj_ctype = icmp_mpls_ext_object_header->ctype;
644 obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
645
646 ND_PRINT((ndo, "\n\t %s Object (%u), Class-Type: %u, length %u",
647 tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
648 obj_class_num,
649 obj_ctype,
650 obj_tlen));
651
652 hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
653
654 /* infinite loop protection */
655 if ((obj_class_num == 0) ||
656 (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) {
657 return;
658 }
659 obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
660
661 switch (obj_class_num) {
662 case 1:
663 switch(obj_ctype) {
664 case 1:
665 ND_TCHECK2(*obj_tptr, 4);
666 raw_label = EXTRACT_32BITS(obj_tptr);
667 ND_PRINT((ndo, "\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)));
668 if (MPLS_STACK(raw_label))
669 ND_PRINT((ndo, ", [S]"));
670 ND_PRINT((ndo, ", ttl %u", MPLS_TTL(raw_label)));
671 break;
672 default:
673 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
674 }
675 break;
676
677 /*
678 * FIXME those are the defined objects that lack a decoder
679 * you are welcome to contribute code ;-)
680 */
681 case 2:
682 default:
683 print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen);
684 break;
685 }
686 if (hlen < obj_tlen)
687 break;
688 hlen -= obj_tlen;
689 obj_tptr += obj_tlen;
690 }
691 }
692
693 return;
694 trunc:
695 ND_PRINT((ndo, "[|icmp]"));
696 }
697 /*
698 * Local Variables:
699 * c-style: whitesmith
700 * c-basic-offset: 8
701 * End:
702 */
703