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#ifndef lint
23static const char rcsid[] _U_ =
24    "@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.81.2.2 2005/07/01 16:13:37 hannes Exp $ (LBL)";
25#endif
26
27#ifdef HAVE_CONFIG_H
28#include "config.h"
29#endif
30
31#include <tcpdump-stdinc.h>
32
33#include <stdio.h>
34#include <string.h>
35
36#include "interface.h"
37#include "addrtoname.h"
38#include "extract.h"			/* must come after interface.h */
39
40#include "ip.h"
41#include "udp.h"
42#include "ipproto.h"
43#include "mpls.h"
44
45/*
46 * Interface Control Message Protocol Definitions.
47 * Per RFC 792, September 1981.
48 */
49
50/*
51 * Structure of an icmp header.
52 */
53struct icmp {
54	u_int8_t  icmp_type;		/* type of message, see below */
55	u_int8_t  icmp_code;		/* type sub code */
56	u_int16_t icmp_cksum;		/* ones complement cksum of struct */
57	union {
58		u_int8_t ih_pptr;			/* ICMP_PARAMPROB */
59		struct in_addr ih_gwaddr;	/* ICMP_REDIRECT */
60		struct ih_idseq {
61			u_int16_t icd_id;
62			u_int16_t icd_seq;
63		} ih_idseq;
64		u_int32_t ih_void;
65
66		/* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
67		struct ih_pmtu {
68			u_int16_t ipm_void;
69			u_int16_t ipm_nextmtu;
70		} ih_pmtu;
71	} icmp_hun;
72#define	icmp_pptr	icmp_hun.ih_pptr
73#define	icmp_gwaddr	icmp_hun.ih_gwaddr
74#define	icmp_id		icmp_hun.ih_idseq.icd_id
75#define	icmp_seq	icmp_hun.ih_idseq.icd_seq
76#define	icmp_void	icmp_hun.ih_void
77#define	icmp_pmvoid	icmp_hun.ih_pmtu.ipm_void
78#define	icmp_nextmtu	icmp_hun.ih_pmtu.ipm_nextmtu
79	union {
80		struct id_ts {
81			u_int32_t its_otime;
82			u_int32_t its_rtime;
83			u_int32_t its_ttime;
84		} id_ts;
85		struct id_ip  {
86			struct ip idi_ip;
87			/* options and then 64 bits of data */
88		} id_ip;
89                struct mpls_ext {
90                    u_int8_t legacy_header[128]; /* extension header starts 128 bytes after ICMP header */
91                    u_int8_t version_res[2];
92                    u_int8_t checksum[2];
93                    u_int8_t data[1];
94                } mpls_ext;
95		u_int32_t id_mask;
96		u_int8_t id_data[1];
97	} icmp_dun;
98#define	icmp_otime	icmp_dun.id_ts.its_otime
99#define	icmp_rtime	icmp_dun.id_ts.its_rtime
100#define	icmp_ttime	icmp_dun.id_ts.its_ttime
101#define	icmp_ip		icmp_dun.id_ip.idi_ip
102#define	icmp_mask	icmp_dun.id_mask
103#define	icmp_data	icmp_dun.id_data
104#define	icmp_mpls_ext_version	icmp_dun.mpls_ext.version_res
105#define	icmp_mpls_ext_checksum	icmp_dun.mpls_ext.checksum
106#define	icmp_mpls_ext_data	icmp_dun.mpls_ext.data
107};
108
109#define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
110#define ICMP_MPLS_EXT_VERSION 2
111
112/*
113 * Lower bounds on packet lengths for various types.
114 * For the error advice packets must first insure that the
115 * packet is large enought to contain the returned ip header.
116 * Only then can we do the check to see if 64 bits of packet
117 * data have been returned, since we need to check the returned
118 * ip header length.
119 */
120#define	ICMP_MINLEN	8				/* abs minimum */
121#define ICMP_EXTD_MINLEN (156 - sizeof (struct ip))     /* draft-bonica-icmp-mpls-02 */
122#define	ICMP_TSLEN	(8 + 3 * sizeof (u_int32_t))	/* timestamp */
123#define	ICMP_MASKLEN	12				/* address mask */
124#define	ICMP_ADVLENMIN	(8 + sizeof (struct ip) + 8)	/* min */
125#define	ICMP_ADVLEN(p)	(8 + (IP_HL(&(p)->icmp_ip) << 2) + 8)
126	/* N.B.: must separately check that ip_hl >= 5 */
127
128/*
129 * Definition of type and code field values.
130 */
131#define	ICMP_ECHOREPLY		0		/* echo reply */
132#define	ICMP_UNREACH		3		/* dest unreachable, codes: */
133#define		ICMP_UNREACH_NET	0		/* bad net */
134#define		ICMP_UNREACH_HOST	1		/* bad host */
135#define		ICMP_UNREACH_PROTOCOL	2		/* bad protocol */
136#define		ICMP_UNREACH_PORT	3		/* bad port */
137#define		ICMP_UNREACH_NEEDFRAG	4		/* IP_DF caused drop */
138#define		ICMP_UNREACH_SRCFAIL	5		/* src route failed */
139#define		ICMP_UNREACH_NET_UNKNOWN 6		/* unknown net */
140#define		ICMP_UNREACH_HOST_UNKNOWN 7		/* unknown host */
141#define		ICMP_UNREACH_ISOLATED	8		/* src host isolated */
142#define		ICMP_UNREACH_NET_PROHIB	9		/* prohibited access */
143#define		ICMP_UNREACH_HOST_PROHIB 10		/* ditto */
144#define		ICMP_UNREACH_TOSNET	11		/* bad tos for net */
145#define		ICMP_UNREACH_TOSHOST	12		/* bad tos for host */
146#define	ICMP_SOURCEQUENCH	4		/* packet lost, slow down */
147#define	ICMP_REDIRECT		5		/* shorter route, codes: */
148#define		ICMP_REDIRECT_NET	0		/* for network */
149#define		ICMP_REDIRECT_HOST	1		/* for host */
150#define		ICMP_REDIRECT_TOSNET	2		/* for tos and net */
151#define		ICMP_REDIRECT_TOSHOST	3		/* for tos and host */
152#define	ICMP_ECHO		8		/* echo service */
153#define	ICMP_ROUTERADVERT	9		/* router advertisement */
154#define	ICMP_ROUTERSOLICIT	10		/* router solicitation */
155#define	ICMP_TIMXCEED		11		/* time exceeded, code: */
156#define		ICMP_TIMXCEED_INTRANS	0		/* ttl==0 in transit */
157#define		ICMP_TIMXCEED_REASS	1		/* ttl==0 in reass */
158#define	ICMP_PARAMPROB		12		/* ip header bad */
159#define		ICMP_PARAMPROB_OPTABSENT 1		/* req. opt. absent */
160#define	ICMP_TSTAMP		13		/* timestamp request */
161#define	ICMP_TSTAMPREPLY	14		/* timestamp reply */
162#define	ICMP_IREQ		15		/* information request */
163#define	ICMP_IREQREPLY		16		/* information reply */
164#define	ICMP_MASKREQ		17		/* address mask request */
165#define	ICMP_MASKREPLY		18		/* address mask reply */
166
167#define	ICMP_MAXTYPE		18
168
169#define	ICMP_INFOTYPE(type) \
170	((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
171	(type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
172	(type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
173	(type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
174	(type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)
175#define	ICMP_MPLS_EXT_TYPE(type) \
176	((type) == ICMP_UNREACH || (type) == ICMP_TIMXCEED)
177/* rfc1700 */
178#ifndef ICMP_UNREACH_NET_UNKNOWN
179#define ICMP_UNREACH_NET_UNKNOWN	6	/* destination net unknown */
180#endif
181#ifndef ICMP_UNREACH_HOST_UNKNOWN
182#define ICMP_UNREACH_HOST_UNKNOWN	7	/* destination host unknown */
183#endif
184#ifndef ICMP_UNREACH_ISOLATED
185#define ICMP_UNREACH_ISOLATED		8	/* source host isolated */
186#endif
187#ifndef ICMP_UNREACH_NET_PROHIB
188#define ICMP_UNREACH_NET_PROHIB		9	/* admin prohibited net */
189#endif
190#ifndef ICMP_UNREACH_HOST_PROHIB
191#define ICMP_UNREACH_HOST_PROHIB	10	/* admin prohibited host */
192#endif
193#ifndef ICMP_UNREACH_TOSNET
194#define ICMP_UNREACH_TOSNET		11	/* tos prohibited net */
195#endif
196#ifndef ICMP_UNREACH_TOSHOST
197#define ICMP_UNREACH_TOSHOST		12	/* tos prohibited host */
198#endif
199
200/* rfc1716 */
201#ifndef ICMP_UNREACH_FILTER_PROHIB
202#define ICMP_UNREACH_FILTER_PROHIB	13	/* admin prohibited filter */
203#endif
204#ifndef ICMP_UNREACH_HOST_PRECEDENCE
205#define ICMP_UNREACH_HOST_PRECEDENCE	14	/* host precedence violation */
206#endif
207#ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
208#define ICMP_UNREACH_PRECEDENCE_CUTOFF	15	/* precedence cutoff */
209#endif
210
211/* Most of the icmp types */
212static struct tok icmp2str[] = {
213	{ ICMP_ECHOREPLY,		"echo reply" },
214	{ ICMP_SOURCEQUENCH,		"source quench" },
215	{ ICMP_ECHO,			"echo request" },
216	{ ICMP_ROUTERSOLICIT,		"router solicitation" },
217	{ ICMP_TSTAMP,			"time stamp request" },
218	{ ICMP_TSTAMPREPLY,		"time stamp reply" },
219	{ ICMP_IREQ,			"information request" },
220	{ ICMP_IREQREPLY,		"information reply" },
221	{ ICMP_MASKREQ,			"address mask request" },
222	{ 0,				NULL }
223};
224
225/* Formats for most of the ICMP_UNREACH codes */
226static struct tok unreach2str[] = {
227	{ ICMP_UNREACH_NET,		"net %s unreachable" },
228	{ ICMP_UNREACH_HOST,		"host %s unreachable" },
229	{ ICMP_UNREACH_SRCFAIL,
230	    "%s unreachable - source route failed" },
231	{ ICMP_UNREACH_NET_UNKNOWN,	"net %s unreachable - unknown" },
232	{ ICMP_UNREACH_HOST_UNKNOWN,	"host %s unreachable - unknown" },
233	{ ICMP_UNREACH_ISOLATED,
234	    "%s unreachable - source host isolated" },
235	{ ICMP_UNREACH_NET_PROHIB,
236	    "net %s unreachable - admin prohibited" },
237	{ ICMP_UNREACH_HOST_PROHIB,
238	    "host %s unreachable - admin prohibited" },
239	{ ICMP_UNREACH_TOSNET,
240	    "net %s unreachable - tos prohibited" },
241	{ ICMP_UNREACH_TOSHOST,
242	    "host %s unreachable - tos prohibited" },
243	{ ICMP_UNREACH_FILTER_PROHIB,
244	    "host %s unreachable - admin prohibited filter" },
245	{ ICMP_UNREACH_HOST_PRECEDENCE,
246	    "host %s unreachable - host precedence violation" },
247	{ ICMP_UNREACH_PRECEDENCE_CUTOFF,
248	    "host %s unreachable - precedence cutoff" },
249	{ 0,				NULL }
250};
251
252/* Formats for the ICMP_REDIRECT codes */
253static struct tok type2str[] = {
254	{ ICMP_REDIRECT_NET,		"redirect %s to net %s" },
255	{ ICMP_REDIRECT_HOST,		"redirect %s to host %s" },
256	{ ICMP_REDIRECT_TOSNET,		"redirect-tos %s to net %s" },
257	{ ICMP_REDIRECT_TOSHOST,	"redirect-tos %s to host %s" },
258	{ 0,				NULL }
259};
260
261/* rfc1191 */
262struct mtu_discovery {
263	u_int16_t unused;
264	u_int16_t nexthopmtu;
265};
266
267/* rfc1256 */
268struct ih_rdiscovery {
269	u_int8_t ird_addrnum;
270	u_int8_t ird_addrsiz;
271	u_int16_t ird_lifetime;
272};
273
274struct id_rdiscovery {
275	u_int32_t ird_addr;
276	u_int32_t ird_pref;
277};
278
279/* draft-bonica-icmp-mpls-02 */
280struct icmp_mpls_ext_object_header_t {
281    u_int8_t length[2];
282    u_int8_t class_num;
283    u_int8_t ctype;
284};
285
286static const struct tok icmp_mpls_ext_obj_values[] = {
287    { 1, "MPLS Stack Entry" },
288    { 2, "Extended Payload" },
289    { 0, NULL}
290};
291
292/* prototypes */
293const char *icmp_tstamp_print(u_int);
294
295/* print the milliseconds since midnight UTC */
296const char *
297icmp_tstamp_print(u_int tstamp) {
298    u_int msec,sec,min,hrs;
299
300    static char buf[64];
301
302    msec = tstamp % 1000;
303    sec = tstamp / 1000;
304    min = sec / 60; sec -= min * 60;
305    hrs = min / 60; min -= hrs * 60;
306    snprintf(buf, sizeof(buf), "%02u:%02u:%02u.%03u",hrs,min,sec,msec);
307    return buf;
308}
309
310void
311icmp_print(const u_char *bp, u_int plen, const u_char *bp2, int fragmented)
312{
313	char *cp;
314	const struct icmp *dp;
315	const struct ip *ip;
316	const char *str, *fmt;
317	const struct ip *oip;
318	const struct udphdr *ouh;
319        const u_int8_t *obj_tptr;
320        u_int32_t raw_label;
321	const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
322	u_int hlen, dport, mtu, obj_tlen, obj_class_num, obj_ctype;
323	char buf[MAXHOSTNAMELEN + 100];
324
325	dp = (struct icmp *)bp;
326	ip = (struct ip *)bp2;
327	str = buf;
328
329	TCHECK(dp->icmp_code);
330	switch (dp->icmp_type) {
331
332	case ICMP_ECHO:
333	case ICMP_ECHOREPLY:
334		TCHECK(dp->icmp_seq);
335		(void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
336                               dp->icmp_type == ICMP_ECHO ?
337                               "request" : "reply",
338                               EXTRACT_16BITS(&dp->icmp_id),
339                               EXTRACT_16BITS(&dp->icmp_seq));
340		break;
341
342	case ICMP_UNREACH:
343		TCHECK(dp->icmp_ip.ip_dst);
344		switch (dp->icmp_code) {
345
346		case ICMP_UNREACH_PROTOCOL:
347			TCHECK(dp->icmp_ip.ip_p);
348			(void)snprintf(buf, sizeof(buf),
349			    "%s protocol %d unreachable",
350			    ipaddr_string(&dp->icmp_ip.ip_dst),
351			    dp->icmp_ip.ip_p);
352			break;
353
354		case ICMP_UNREACH_PORT:
355			TCHECK(dp->icmp_ip.ip_p);
356			oip = &dp->icmp_ip;
357			hlen = IP_HL(oip) * 4;
358			ouh = (struct udphdr *)(((u_char *)oip) + hlen);
359			TCHECK(ouh->uh_dport);
360			dport = EXTRACT_16BITS(&ouh->uh_dport);
361			switch (oip->ip_p) {
362
363			case IPPROTO_TCP:
364				(void)snprintf(buf, sizeof(buf),
365					"%s tcp port %s unreachable",
366					ipaddr_string(&oip->ip_dst),
367					tcpport_string(dport));
368				break;
369
370			case IPPROTO_UDP:
371				(void)snprintf(buf, sizeof(buf),
372					"%s udp port %s unreachable",
373					ipaddr_string(&oip->ip_dst),
374					udpport_string(dport));
375				break;
376
377			default:
378				(void)snprintf(buf, sizeof(buf),
379					"%s protocol %d port %d unreachable",
380					ipaddr_string(&oip->ip_dst),
381					oip->ip_p, dport);
382				break;
383			}
384			break;
385
386		case ICMP_UNREACH_NEEDFRAG:
387		    {
388			register const struct mtu_discovery *mp;
389			mp = (struct mtu_discovery *)&dp->icmp_void;
390			mtu = EXTRACT_16BITS(&mp->nexthopmtu);
391			if (mtu) {
392				(void)snprintf(buf, sizeof(buf),
393				    "%s unreachable - need to frag (mtu %d)",
394				    ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
395			} else {
396				(void)snprintf(buf, sizeof(buf),
397				    "%s unreachable - need to frag",
398				    ipaddr_string(&dp->icmp_ip.ip_dst));
399			}
400		    }
401			break;
402
403		default:
404			fmt = tok2str(unreach2str, "#%d %%s unreachable",
405			    dp->icmp_code);
406			(void)snprintf(buf, sizeof(buf), fmt,
407			    ipaddr_string(&dp->icmp_ip.ip_dst));
408			break;
409		}
410		break;
411
412	case ICMP_REDIRECT:
413		TCHECK(dp->icmp_ip.ip_dst);
414		fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
415		    dp->icmp_code);
416		(void)snprintf(buf, sizeof(buf), fmt,
417		    ipaddr_string(&dp->icmp_ip.ip_dst),
418		    ipaddr_string(&dp->icmp_gwaddr));
419		break;
420
421	case ICMP_ROUTERADVERT:
422	    {
423		register const struct ih_rdiscovery *ihp;
424		register const struct id_rdiscovery *idp;
425		u_int lifetime, num, size;
426
427		(void)snprintf(buf, sizeof(buf), "router advertisement");
428		cp = buf + strlen(buf);
429
430		ihp = (struct ih_rdiscovery *)&dp->icmp_void;
431		TCHECK(*ihp);
432		(void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
433		cp = buf + strlen(buf);
434		lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
435		if (lifetime < 60) {
436			(void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
437			    lifetime);
438		} else if (lifetime < 60 * 60) {
439			(void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
440			    lifetime / 60, lifetime % 60);
441		} else {
442			(void)snprintf(cp, sizeof(buf) - (cp - buf),
443			    "%u:%02u:%02u",
444			    lifetime / 3600,
445			    (lifetime % 3600) / 60,
446			    lifetime % 60);
447		}
448		cp = buf + strlen(buf);
449
450		num = ihp->ird_addrnum;
451		(void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
452		cp = buf + strlen(buf);
453
454		size = ihp->ird_addrsiz;
455		if (size != 2) {
456			(void)snprintf(cp, sizeof(buf) - (cp - buf),
457			    " [size %d]", size);
458			break;
459		}
460		idp = (struct id_rdiscovery *)&dp->icmp_data;
461		while (num-- > 0) {
462			TCHECK(*idp);
463			(void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
464			    ipaddr_string(&idp->ird_addr),
465			    EXTRACT_32BITS(&idp->ird_pref));
466			cp = buf + strlen(buf);
467			++idp;
468		}
469	    }
470		break;
471
472	case ICMP_TIMXCEED:
473		TCHECK(dp->icmp_ip.ip_dst);
474		switch (dp->icmp_code) {
475
476		case ICMP_TIMXCEED_INTRANS:
477			str = "time exceeded in-transit";
478			break;
479
480		case ICMP_TIMXCEED_REASS:
481			str = "ip reassembly time exceeded";
482			break;
483
484		default:
485			(void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
486			    dp->icmp_code);
487			break;
488		}
489		break;
490
491	case ICMP_PARAMPROB:
492		if (dp->icmp_code)
493			(void)snprintf(buf, sizeof(buf),
494			    "parameter problem - code %d", dp->icmp_code);
495		else {
496			TCHECK(dp->icmp_pptr);
497			(void)snprintf(buf, sizeof(buf),
498			    "parameter problem - octet %d", dp->icmp_pptr);
499		}
500		break;
501
502	case ICMP_MASKREPLY:
503		TCHECK(dp->icmp_mask);
504		(void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
505		    EXTRACT_32BITS(&dp->icmp_mask));
506		break;
507
508	case ICMP_TSTAMP:
509		TCHECK(dp->icmp_seq);
510		(void)snprintf(buf, sizeof(buf),
511		    "time stamp query id %u seq %u",
512		    EXTRACT_16BITS(&dp->icmp_id),
513		    EXTRACT_16BITS(&dp->icmp_seq));
514		break;
515
516	case ICMP_TSTAMPREPLY:
517		TCHECK(dp->icmp_ttime);
518		(void)snprintf(buf, sizeof(buf),
519		    "time stamp reply id %u seq %u: org %s",
520                               EXTRACT_16BITS(&dp->icmp_id),
521                               EXTRACT_16BITS(&dp->icmp_seq),
522                               icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_otime)));
523
524                (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", recv %s",
525                         icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_rtime)));
526                (void)snprintf(buf+strlen(buf),sizeof(buf)-strlen(buf),", xmit %s",
527                         icmp_tstamp_print(EXTRACT_32BITS(&dp->icmp_ttime)));
528                break;
529
530	default:
531		str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
532		break;
533	}
534	(void)printf("ICMP %s, length %u", str, plen);
535	if (vflag && !fragmented) { /* don't attempt checksumming if this is a frag */
536		u_int16_t sum, icmp_sum;
537		if (TTEST2(*bp, plen)) {
538			sum = in_cksum((u_short*)dp, plen, 0);
539			if (sum != 0) {
540				icmp_sum = EXTRACT_16BITS(&dp->icmp_cksum);
541				(void)printf(" (wrong icmp cksum %x (->%x)!)",
542					     icmp_sum,
543					     in_cksum_shouldbe(icmp_sum, sum));
544			}
545		}
546	}
547	if (vflag >= 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
548		bp += 8;
549		(void)printf("\n\t");
550		ip = (struct ip *)bp;
551		snaplen = snapend - bp;
552		ip_print(gndo, bp, EXTRACT_16BITS(&ip->ip_len));
553	}
554
555        if (vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(dp->icmp_type)) {
556
557            TCHECK(*(dp->icmp_mpls_ext_version));
558            printf("\n\tMPLS extension v%u",ICMP_MPLS_EXT_EXTRACT_VERSION(*(dp->icmp_mpls_ext_version)));
559
560            /*
561             * Sanity checking of the header.
562             */
563            if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(dp->icmp_mpls_ext_version)) != ICMP_MPLS_EXT_VERSION) {
564                printf(" packet not supported");
565                return;
566            }
567
568            hlen = plen - ICMP_EXTD_MINLEN;
569            TCHECK2(*(dp->icmp_mpls_ext_checksum), 2);
570            printf(", checksum 0x%04x (unverified), length %u", /* FIXME */
571                   EXTRACT_16BITS(dp->icmp_mpls_ext_checksum),
572                   hlen);
573
574            hlen -= 4; /* subtract common header size */
575            obj_tptr = (u_int8_t *)dp->icmp_mpls_ext_data;
576
577            while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
578
579                icmp_mpls_ext_object_header = (struct icmp_mpls_ext_object_header_t *)obj_tptr;
580                TCHECK(*icmp_mpls_ext_object_header);
581                obj_tlen = EXTRACT_16BITS(icmp_mpls_ext_object_header->length);
582                obj_class_num = icmp_mpls_ext_object_header->class_num;
583                obj_ctype = icmp_mpls_ext_object_header->ctype;
584                obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
585
586                printf("\n\t  %s Object (%u), Class-Type: %u, length %u",
587                       tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
588                       obj_class_num,
589                       obj_ctype,
590                       obj_tlen);
591
592                hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
593                if (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))
594                    break;
595                obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
596
597                switch (obj_class_num) {
598                case 1:
599                    switch(obj_ctype) {
600                    case 1:
601                        TCHECK2(*obj_tptr, 4);
602                        raw_label = EXTRACT_32BITS(obj_tptr);
603                        printf("\n\t    label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label));
604                        if (MPLS_STACK(raw_label))
605                            printf(", [S]");
606                        printf(", ttl %u", MPLS_TTL(raw_label));
607                        break;
608                    default:
609                        print_unknown_data(obj_tptr, "\n\t    ", obj_tlen);
610                    }
611                    break;
612
613               /*
614                *  FIXME those are the defined objects that lack a decoder
615                *  you are welcome to contribute code ;-)
616                */
617                case 2:
618                default:
619                    print_unknown_data(obj_tptr, "\n\t    ", obj_tlen);
620                    break;
621                }
622                if (hlen < obj_tlen)
623                    break;
624                hlen -= obj_tlen;
625                obj_tptr += obj_tlen;
626            }
627        }
628
629	return;
630trunc:
631	fputs("[|icmp]", stdout);
632}
633