print-icmp.c - platform/external/tcpdump - Git at Google

 /*
  * Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994, 1995, 1996
  *	The Regents of the University of California.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that: (1) source code distributions
  * retain the above copyright notice and this paragraph in its entirety, (2)
  * distributions including binary code include the above copyright notice and
  * this paragraph in its entirety in the documentation or other materials
  * provided with the distribution, and (3) all advertising materials mentioning
  * features or use of this software display the following acknowledgement:
  * ``This product includes software developed by the University of California,
  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  * the University nor the names of its contributors may be used to endorse
  * or promote products derived from this software without specific prior
  * written permission.
  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */

 #ifndef lint
 static const char rcsid[] =
     "@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.48 2000-07-01 03:39:03 assar Exp $ (LBL)";
 #endif

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <sys/param.h>
 #include <sys/time.h>
 #include <sys/socket.h>

 struct mbuf;
 struct rtentry;
 #include <net/if.h>

 #include <netinet/in.h>
 #include <netinet/if_ether.h>
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
 #include <netinet/ip_icmp.h>
 #include <netinet/ip_var.h>
 #include <netinet/udp.h>
 #include <netinet/udp_var.h>
 #include <netinet/tcp.h>

 #include <stdio.h>
 #include <string.h>

 #include "interface.h"
 #include "addrtoname.h"
 #include "extract.h"			/* must come after interface.h */

 /* rfc1700 */
 #ifndef ICMP_UNREACH_NET_UNKNOWN
 #define ICMP_UNREACH_NET_UNKNOWN	6	/* destination net unknown */
 #endif
 #ifndef ICMP_UNREACH_HOST_UNKNOWN
 #define ICMP_UNREACH_HOST_UNKNOWN	7	/* destination host unknown */
 #endif
 #ifndef ICMP_UNREACH_ISOLATED
 #define ICMP_UNREACH_ISOLATED		8	/* source host isolated */
 #endif
 #ifndef ICMP_UNREACH_NET_PROHIB
 #define ICMP_UNREACH_NET_PROHIB		9	/* admin prohibited net */
 #endif
 #ifndef ICMP_UNREACH_HOST_PROHIB
 #define ICMP_UNREACH_HOST_PROHIB	10	/* admin prohibited host */
 #endif
 #ifndef ICMP_UNREACH_TOSNET
 #define ICMP_UNREACH_TOSNET		11	/* tos prohibited net */
 #endif
 #ifndef ICMP_UNREACH_TOSHOST
 #define ICMP_UNREACH_TOSHOST		12	/* tos prohibited host */
 #endif

 /* rfc1716 */
 #ifndef ICMP_UNREACH_FILTER_PROHIB
 #define ICMP_UNREACH_FILTER_PROHIB	13	/* admin prohibited filter */
 #endif
 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
 #define ICMP_UNREACH_HOST_PRECEDENCE	14	/* host precedence violation */
 #endif
 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
 #define ICMP_UNREACH_PRECEDENCE_CUTOFF	15	/* precedence cutoff */
 #endif

 /* rfc1256 */
 #ifndef ICMP_ROUTERADVERT
 #define ICMP_ROUTERADVERT		9	/* router advertisement */
 #endif
 #ifndef ICMP_ROUTERSOLICIT
 #define ICMP_ROUTERSOLICIT		10	/* router solicitation */
 #endif

 /* Most of the icmp types */
 static struct tok icmp2str[] = {
 	{ ICMP_ECHOREPLY,		"echo reply" },
 	{ ICMP_SOURCEQUENCH,		"source quench" },
 	{ ICMP_ECHO,			"echo request" },
 	{ ICMP_ROUTERSOLICIT,		"router solicitation" },
 	{ ICMP_TSTAMP,			"time stamp request" },
 	{ ICMP_TSTAMPREPLY,		"time stamp reply" },
 	{ ICMP_IREQ,			"information request" },
 	{ ICMP_IREQREPLY,		"information reply" },
 	{ ICMP_MASKREQ,			"address mask request" },
 	{ 0,				NULL }
 };

 /* Formats for most of the ICMP_UNREACH codes */
 static struct tok unreach2str[] = {
 	{ ICMP_UNREACH_NET,		"net %s unreachable" },
 	{ ICMP_UNREACH_HOST,		"host %s unreachable" },
 	{ ICMP_UNREACH_SRCFAIL,
 	    "%s unreachable - source route failed" },
 	{ ICMP_UNREACH_NET_UNKNOWN,	"net %s unreachable - unknown" },
 	{ ICMP_UNREACH_HOST_UNKNOWN,	"host %s unreachable - unknown" },
 	{ ICMP_UNREACH_ISOLATED,
 	    "%s unreachable - source host isolated" },
 	{ ICMP_UNREACH_NET_PROHIB,
 	    "net %s unreachable - admin prohibited" },
 	{ ICMP_UNREACH_HOST_PROHIB,
 	    "host %s unreachable - admin prohibited" },
 	{ ICMP_UNREACH_TOSNET,
 	    "net %s unreachable - tos prohibited" },
 	{ ICMP_UNREACH_TOSHOST,
 	    "host %s unreachable - tos prohibited" },
 	{ ICMP_UNREACH_FILTER_PROHIB,
 	    "host %s unreachable - admin prohibited filter" },
 	{ ICMP_UNREACH_HOST_PRECEDENCE,
 	    "host %s unreachable - host precedence violation" },
 	{ ICMP_UNREACH_PRECEDENCE_CUTOFF,
 	    "host %s unreachable - precedence cutoff" },
 	{ 0,				NULL }
 };

 /* Formats for the ICMP_REDIRECT codes */
 static struct tok type2str[] = {
 	{ ICMP_REDIRECT_NET,		"redirect %s to net %s" },
 	{ ICMP_REDIRECT_HOST,		"redirect %s to host %s" },
 	{ ICMP_REDIRECT_TOSNET,		"redirect-tos %s to net %s" },
 	{ ICMP_REDIRECT_TOSHOST,	"redirect-tos %s to net %s" },
 	{ 0,				NULL }
 };

 /* rfc1191 */
 struct mtu_discovery {
 	short unused;
 	short nexthopmtu;
 };

 /* rfc1256 */
 struct ih_rdiscovery {
 	u_char ird_addrnum;
 	u_char ird_addrsiz;
 	u_short ird_lifetime;
 };

 struct id_rdiscovery {
 	u_int32_t ird_addr;
 	u_int32_t ird_pref;
 };

 void
 icmp_print(register const u_char *bp, u_int plen, register const u_char *bp2)
 {
 	register char *cp;
 	register const struct icmp *dp;
 	register const struct ip *ip;
 	register const char *str, *fmt;
 	register const struct ip *oip;
 	register const struct udphdr *ouh;
 	register u_int hlen, dport, mtu;
 	char buf[256];

 	dp = (struct icmp *)bp;
 	ip = (struct ip *)bp2;
 	str = buf;

 #if 0
         (void)printf("%s > %s: ",
 		ipaddr_string(&ip->ip_src),
 		ipaddr_string(&ip->ip_dst));
 #endif

 	TCHECK(dp->icmp_code);
 	switch (dp->icmp_type) {

 	case ICMP_UNREACH:
 		TCHECK(dp->icmp_ip.ip_dst);
 		switch (dp->icmp_code) {

 		case ICMP_UNREACH_PROTOCOL:
 			TCHECK(dp->icmp_ip.ip_p);
 			(void)snprintf(buf, sizeof(buf),
 			    "%s protocol %d unreachable",
 			    ipaddr_string(&dp->icmp_ip.ip_dst),
 			    dp->icmp_ip.ip_p);
 			break;

 		case ICMP_UNREACH_PORT:
 			TCHECK(dp->icmp_ip.ip_p);
 			oip = &dp->icmp_ip;
 			hlen = oip->ip_hl * 4;
 			ouh = (struct udphdr *)(((u_char *)oip) + hlen);
 			dport = ntohs(ouh->uh_dport);
 			switch (oip->ip_p) {

 			case IPPROTO_TCP:
 				(void)snprintf(buf, sizeof(buf),
 					"%s tcp port %s unreachable",
 					ipaddr_string(&oip->ip_dst),
 					tcpport_string(dport));
 				break;

 			case IPPROTO_UDP:
 				(void)snprintf(buf, sizeof(buf),
 					"%s udp port %s unreachable",
 					ipaddr_string(&oip->ip_dst),
 					udpport_string(dport));
 				break;

 			default:
 				(void)snprintf(buf, sizeof(buf),
 					"%s protocol %d port %d unreachable",
 					ipaddr_string(&oip->ip_dst),
 					oip->ip_p, dport);
 				break;
 			}
 			break;

 		case ICMP_UNREACH_NEEDFRAG:
 		    {
 			register const struct mtu_discovery *mp;
 			mp = (struct mtu_discovery *)&dp->icmp_void;
                         mtu = EXTRACT_16BITS(&mp->nexthopmtu);
                         if (mtu) {
 				(void)snprintf(buf, sizeof(buf),
 				    "%s unreachable - need to frag (mtu %d)",
 				    ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
                         } else {
 				(void)snprintf(buf, sizeof(buf),
 				    "%s unreachable - need to frag",
 				    ipaddr_string(&dp->icmp_ip.ip_dst));
 			}
 		    }
 			break;

 		default:
 			fmt = tok2str(unreach2str, "#%d %%s unreachable",
 			    dp->icmp_code);
 			(void)snprintf(buf, sizeof(buf), fmt,
 			    ipaddr_string(&dp->icmp_ip.ip_dst));
 			break;
 		}
 		break;

 	case ICMP_REDIRECT:
 		TCHECK(dp->icmp_ip.ip_dst);
 		fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
 		    dp->icmp_code);
 		(void)snprintf(buf, sizeof(buf), fmt,
 		    ipaddr_string(&dp->icmp_ip.ip_dst),
 		    ipaddr_string(&dp->icmp_gwaddr));
 		break;

 	case ICMP_ROUTERADVERT:
 	    {
 		register const struct ih_rdiscovery *ihp;
 		register const struct id_rdiscovery *idp;
 		u_int lifetime, num, size;

 		(void)snprintf(buf, sizeof(buf), "router advertisement");
 		cp = buf + strlen(buf);

 		ihp = (struct ih_rdiscovery *)&dp->icmp_void;
 		TCHECK(*ihp);
 		(void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
 		cp = buf + strlen(buf);
 		lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
 		if (lifetime < 60) {
 			(void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
 			    lifetime);
 		} else if (lifetime < 60 * 60) {
 			(void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
 			    lifetime / 60, lifetime % 60);
 		} else {
 			(void)snprintf(cp, sizeof(buf) - (cp - buf),
 			    "%u:%02u:%02u",
 			    lifetime / 3600,
 			    (lifetime % 3600) / 60,
 			    lifetime % 60);
 		}
 		cp = buf + strlen(buf);

 		num = ihp->ird_addrnum;
 		(void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
 		cp = buf + strlen(buf);

 		size = ihp->ird_addrsiz;
 		if (size != 2) {
 			(void)snprintf(cp, sizeof(buf) - (cp - buf),
 			    " [size %d]", size);
 			break;
 		}
 		idp = (struct id_rdiscovery *)&dp->icmp_data;
 		while (num-- > 0) {
 			TCHECK(*idp);
 			(void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
 			    ipaddr_string(&idp->ird_addr),
 			    EXTRACT_32BITS(&idp->ird_pref));
 			cp = buf + strlen(buf);
 			++idp;
 		}
 	    }
 		break;

 	case ICMP_TIMXCEED:
 		TCHECK(dp->icmp_ip.ip_dst);
 		switch (dp->icmp_code) {

 		case ICMP_TIMXCEED_INTRANS:
 			str = "time exceeded in-transit";
 			break;

 		case ICMP_TIMXCEED_REASS:
 			str = "ip reassembly time exceeded";
 			break;

 		default:
 			(void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
 			    dp->icmp_code);
 			break;
 		}
 		break;

 	case ICMP_PARAMPROB:
 		if (dp->icmp_code)
 			(void)snprintf(buf, sizeof(buf),
 			    "parameter problem - code %d", dp->icmp_code);
 		else {
 			TCHECK(dp->icmp_pptr);
 			(void)snprintf(buf, sizeof(buf),
 			    "parameter problem - octet %d", dp->icmp_pptr);
 		}
 		break;

 	case ICMP_MASKREPLY:
 		TCHECK(dp->icmp_mask);
 		(void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
 		    (unsigned)ntohl(dp->icmp_mask));
 		break;

 	case ICMP_TSTAMP:
 		TCHECK(dp->icmp_seq);
 		(void)sprintf(buf, "time stamp query id %u seq %u",
 		    (unsigned)ntohs(dp->icmp_id),
 		    (unsigned)ntohs(dp->icmp_seq));
 		break;

 	case ICMP_TSTAMPREPLY:
 		TCHECK(dp->icmp_ttime);
 		(void)sprintf(buf, "time stamp reply id %u seq %u : org 0x%lx recv 0x%lx xmit 0x%lx",
 		    (unsigned)ntohs(dp->icmp_id),
 		    (unsigned)ntohs(dp->icmp_seq),
 		    (unsigned long)ntohl(dp->icmp_otime),
 		    (unsigned long)ntohl(dp->icmp_rtime),
 		    (unsigned long)ntohl(dp->icmp_ttime));
 		break;

 	default:
 		str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
 		break;
 	}
         (void)printf("icmp: %s", str);
 	if (vflag) {
 		if (TTEST2(*bp, plen)) {
 			if (in_cksum((u_short*)dp, plen, 0))
 				printf(" (wrong icmp csum)");
 		}
 	}
  	if (vflag > 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
  		bp += 8;
  		(void)printf(" for ");
  		ip = (struct ip *)bp;
  		snaplen = snapend - bp;
  		ip_print(bp, ntohs(ip->ip_len));
  	}
 	return;
 trunc:
 	fputs("[|icmp]", stdout);
 }
	/*
	* Copyright (c) 1988, 1989, 1990, 1991, 1993, 1994, 1995, 1996
	* The Regents of the University of California. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that: (1) source code distributions
	* retain the above copyright notice and this paragraph in its entirety, (2)
	* distributions including binary code include the above copyright notice and
	* this paragraph in its entirety in the documentation or other materials
	* provided with the distribution, and (3) all advertising materials mentioning
	* features or use of this software display the following acknowledgement:
	* ``This product includes software developed by the University of California,
	* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
	* the University nor the names of its contributors may be used to endorse
	* or promote products derived from this software without specific prior
	* written permission.
	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	*/

	#ifndef lint
	static const char rcsid[] =
	"@(#) $Header: /tcpdump/master/tcpdump/print-icmp.c,v 1.48 2000-07-01 03:39:03 assar Exp $ (LBL)";
	#endif

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include <sys/param.h>
	#include <sys/time.h>
	#include <sys/socket.h>

	struct mbuf;
	struct rtentry;
	#include <net/if.h>

	#include <netinet/in.h>
	#include <netinet/if_ether.h>
	#include <netinet/in_systm.h>
	#include <netinet/ip.h>
	#include <netinet/ip_icmp.h>
	#include <netinet/ip_var.h>
	#include <netinet/udp.h>
	#include <netinet/udp_var.h>
	#include <netinet/tcp.h>

	#include <stdio.h>
	#include <string.h>

	#include "interface.h"
	#include "addrtoname.h"
	#include "extract.h" /* must come after interface.h */

	/* rfc1700 */
	#ifndef ICMP_UNREACH_NET_UNKNOWN
	#define ICMP_UNREACH_NET_UNKNOWN 6 /* destination net unknown */
	#endif
	#ifndef ICMP_UNREACH_HOST_UNKNOWN
	#define ICMP_UNREACH_HOST_UNKNOWN 7 /* destination host unknown */
	#endif
	#ifndef ICMP_UNREACH_ISOLATED
	#define ICMP_UNREACH_ISOLATED 8 /* source host isolated */
	#endif
	#ifndef ICMP_UNREACH_NET_PROHIB
	#define ICMP_UNREACH_NET_PROHIB 9 /* admin prohibited net */
	#endif
	#ifndef ICMP_UNREACH_HOST_PROHIB
	#define ICMP_UNREACH_HOST_PROHIB 10 /* admin prohibited host */
	#endif
	#ifndef ICMP_UNREACH_TOSNET
	#define ICMP_UNREACH_TOSNET 11 /* tos prohibited net */
	#endif
	#ifndef ICMP_UNREACH_TOSHOST
	#define ICMP_UNREACH_TOSHOST 12 /* tos prohibited host */
	#endif

	/* rfc1716 */
	#ifndef ICMP_UNREACH_FILTER_PROHIB
	#define ICMP_UNREACH_FILTER_PROHIB 13 /* admin prohibited filter */
	#endif
	#ifndef ICMP_UNREACH_HOST_PRECEDENCE
	#define ICMP_UNREACH_HOST_PRECEDENCE 14 /* host precedence violation */
	#endif
	#ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
	#define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */
	#endif

	/* rfc1256 */
	#ifndef ICMP_ROUTERADVERT
	#define ICMP_ROUTERADVERT 9 /* router advertisement */
	#endif
	#ifndef ICMP_ROUTERSOLICIT
	#define ICMP_ROUTERSOLICIT 10 /* router solicitation */
	#endif

	/* Most of the icmp types */
	static struct tok icmp2str[] = {
	{ ICMP_ECHOREPLY, "echo reply" },
	{ ICMP_SOURCEQUENCH, "source quench" },
	{ ICMP_ECHO, "echo request" },
	{ ICMP_ROUTERSOLICIT, "router solicitation" },
	{ ICMP_TSTAMP, "time stamp request" },
	{ ICMP_TSTAMPREPLY, "time stamp reply" },
	{ ICMP_IREQ, "information request" },
	{ ICMP_IREQREPLY, "information reply" },
	{ ICMP_MASKREQ, "address mask request" },
	{ 0, NULL }
	};

	/* Formats for most of the ICMP_UNREACH codes */
	static struct tok unreach2str[] = {
	{ ICMP_UNREACH_NET, "net %s unreachable" },
	{ ICMP_UNREACH_HOST, "host %s unreachable" },
	{ ICMP_UNREACH_SRCFAIL,
	"%s unreachable - source route failed" },
	{ ICMP_UNREACH_NET_UNKNOWN, "net %s unreachable - unknown" },
	{ ICMP_UNREACH_HOST_UNKNOWN, "host %s unreachable - unknown" },
	{ ICMP_UNREACH_ISOLATED,
	"%s unreachable - source host isolated" },
	{ ICMP_UNREACH_NET_PROHIB,
	"net %s unreachable - admin prohibited" },
	{ ICMP_UNREACH_HOST_PROHIB,
	"host %s unreachable - admin prohibited" },
	{ ICMP_UNREACH_TOSNET,
	"net %s unreachable - tos prohibited" },
	{ ICMP_UNREACH_TOSHOST,
	"host %s unreachable - tos prohibited" },
	{ ICMP_UNREACH_FILTER_PROHIB,
	"host %s unreachable - admin prohibited filter" },
	{ ICMP_UNREACH_HOST_PRECEDENCE,
	"host %s unreachable - host precedence violation" },
	{ ICMP_UNREACH_PRECEDENCE_CUTOFF,
	"host %s unreachable - precedence cutoff" },
	{ 0, NULL }
	};

	/* Formats for the ICMP_REDIRECT codes */
	static struct tok type2str[] = {
	{ ICMP_REDIRECT_NET, "redirect %s to net %s" },
	{ ICMP_REDIRECT_HOST, "redirect %s to host %s" },
	{ ICMP_REDIRECT_TOSNET, "redirect-tos %s to net %s" },
	{ ICMP_REDIRECT_TOSHOST, "redirect-tos %s to net %s" },
	{ 0, NULL }
	};

	/* rfc1191 */
	struct mtu_discovery {
	short unused;
	short nexthopmtu;
	};

	/* rfc1256 */
	struct ih_rdiscovery {
	u_char ird_addrnum;
	u_char ird_addrsiz;
	u_short ird_lifetime;
	};

	struct id_rdiscovery {
	u_int32_t ird_addr;
	u_int32_t ird_pref;
	};

	void
	icmp_print(register const u_char bp, u_int plen, register const u_char bp2)
	{
	register char *cp;
	register const struct icmp *dp;
	register const struct ip *ip;
	register const char str, fmt;
	register const struct ip *oip;
	register const struct udphdr *ouh;
	register u_int hlen, dport, mtu;
	char buf[256];

	dp = (struct icmp *)bp;
	ip = (struct ip *)bp2;
	str = buf;

	#if 0
	(void)printf("%s > %s: ",
	ipaddr_string(&ip->ip_src),
	ipaddr_string(&ip->ip_dst));
	#endif

	TCHECK(dp->icmp_code);
	switch (dp->icmp_type) {

	case ICMP_UNREACH:
	TCHECK(dp->icmp_ip.ip_dst);
	switch (dp->icmp_code) {

	case ICMP_UNREACH_PROTOCOL:
	TCHECK(dp->icmp_ip.ip_p);
	(void)snprintf(buf, sizeof(buf),
	"%s protocol %d unreachable",
	ipaddr_string(&dp->icmp_ip.ip_dst),
	dp->icmp_ip.ip_p);
	break;

	case ICMP_UNREACH_PORT:
	TCHECK(dp->icmp_ip.ip_p);
	oip = &dp->icmp_ip;
	hlen = oip->ip_hl * 4;
	ouh = (struct udphdr )(((u_char )oip) + hlen);
	dport = ntohs(ouh->uh_dport);
	switch (oip->ip_p) {

	case IPPROTO_TCP:
	(void)snprintf(buf, sizeof(buf),
	"%s tcp port %s unreachable",
	ipaddr_string(&oip->ip_dst),
	tcpport_string(dport));
	break;

	case IPPROTO_UDP:
	(void)snprintf(buf, sizeof(buf),
	"%s udp port %s unreachable",
	ipaddr_string(&oip->ip_dst),
	udpport_string(dport));
	break;

	default:
	(void)snprintf(buf, sizeof(buf),
	"%s protocol %d port %d unreachable",
	ipaddr_string(&oip->ip_dst),
	oip->ip_p, dport);
	break;
	}
	break;

	case ICMP_UNREACH_NEEDFRAG:
	{
	register const struct mtu_discovery *mp;
	mp = (struct mtu_discovery *)&dp->icmp_void;
	mtu = EXTRACT_16BITS(&mp->nexthopmtu);
	if (mtu) {
	(void)snprintf(buf, sizeof(buf),
	"%s unreachable - need to frag (mtu %d)",
	ipaddr_string(&dp->icmp_ip.ip_dst), mtu);
	} else {
	(void)snprintf(buf, sizeof(buf),
	"%s unreachable - need to frag",
	ipaddr_string(&dp->icmp_ip.ip_dst));
	}
	}
	break;

	default:
	fmt = tok2str(unreach2str, "#%d %%s unreachable",
	dp->icmp_code);
	(void)snprintf(buf, sizeof(buf), fmt,
	ipaddr_string(&dp->icmp_ip.ip_dst));
	break;
	}
	break;

	case ICMP_REDIRECT:
	TCHECK(dp->icmp_ip.ip_dst);
	fmt = tok2str(type2str, "redirect-#%d %%s to net %%s",
	dp->icmp_code);
	(void)snprintf(buf, sizeof(buf), fmt,
	ipaddr_string(&dp->icmp_ip.ip_dst),
	ipaddr_string(&dp->icmp_gwaddr));
	break;

	case ICMP_ROUTERADVERT:
	{
	register const struct ih_rdiscovery *ihp;
	register const struct id_rdiscovery *idp;
	u_int lifetime, num, size;

	(void)snprintf(buf, sizeof(buf), "router advertisement");
	cp = buf + strlen(buf);

	ihp = (struct ih_rdiscovery *)&dp->icmp_void;
	TCHECK(*ihp);
	(void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf));
	cp = buf + strlen(buf);
	lifetime = EXTRACT_16BITS(&ihp->ird_lifetime);
	if (lifetime < 60) {
	(void)snprintf(cp, sizeof(buf) - (cp - buf), "%u",
	lifetime);
	} else if (lifetime < 60 * 60) {
	(void)snprintf(cp, sizeof(buf) - (cp - buf), "%u:%02u",
	lifetime / 60, lifetime % 60);
	} else {
	(void)snprintf(cp, sizeof(buf) - (cp - buf),
	"%u:%02u:%02u",
	lifetime / 3600,
	(lifetime % 3600) / 60,
	lifetime % 60);
	}
	cp = buf + strlen(buf);

	num = ihp->ird_addrnum;
	(void)snprintf(cp, sizeof(buf) - (cp - buf), " %d:", num);
	cp = buf + strlen(buf);

	size = ihp->ird_addrsiz;
	if (size != 2) {
	(void)snprintf(cp, sizeof(buf) - (cp - buf),
	" [size %d]", size);
	break;
	}
	idp = (struct id_rdiscovery *)&dp->icmp_data;
	while (num-- > 0) {
	TCHECK(*idp);
	(void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
	ipaddr_string(&idp->ird_addr),
	EXTRACT_32BITS(&idp->ird_pref));
	cp = buf + strlen(buf);
	++idp;
	}
	}
	break;

	case ICMP_TIMXCEED:
	TCHECK(dp->icmp_ip.ip_dst);
	switch (dp->icmp_code) {

	case ICMP_TIMXCEED_INTRANS:
	str = "time exceeded in-transit";
	break;

	case ICMP_TIMXCEED_REASS:
	str = "ip reassembly time exceeded";
	break;

	default:
	(void)snprintf(buf, sizeof(buf), "time exceeded-#%d",
	dp->icmp_code);
	break;
	}
	break;

	case ICMP_PARAMPROB:
	if (dp->icmp_code)
	(void)snprintf(buf, sizeof(buf),
	"parameter problem - code %d", dp->icmp_code);
	else {
	TCHECK(dp->icmp_pptr);
	(void)snprintf(buf, sizeof(buf),
	"parameter problem - octet %d", dp->icmp_pptr);
	}
	break;

	case ICMP_MASKREPLY:
	TCHECK(dp->icmp_mask);
	(void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
	(unsigned)ntohl(dp->icmp_mask));
	break;

	case ICMP_TSTAMP:
	TCHECK(dp->icmp_seq);
	(void)sprintf(buf, "time stamp query id %u seq %u",
	(unsigned)ntohs(dp->icmp_id),
	(unsigned)ntohs(dp->icmp_seq));
	break;

	case ICMP_TSTAMPREPLY:
	TCHECK(dp->icmp_ttime);
	(void)sprintf(buf, "time stamp reply id %u seq %u : org 0x%lx recv 0x%lx xmit 0x%lx",
	(unsigned)ntohs(dp->icmp_id),
	(unsigned)ntohs(dp->icmp_seq),
	(unsigned long)ntohl(dp->icmp_otime),
	(unsigned long)ntohl(dp->icmp_rtime),
	(unsigned long)ntohl(dp->icmp_ttime));
	break;

	default:
	str = tok2str(icmp2str, "type-#%d", dp->icmp_type);
	break;
	}
	(void)printf("icmp: %s", str);
	if (vflag) {
	if (TTEST2(*bp, plen)) {
	if (in_cksum((u_short*)dp, plen, 0))
	printf(" (wrong icmp csum)");
	}
	}
	if (vflag > 1 && !ICMP_INFOTYPE(dp->icmp_type)) {
	bp += 8;
	(void)printf(" for ");
	ip = (struct ip *)bp;
	snaplen = snapend - bp;
	ip_print(bp, ntohs(ip->ip_len));
	}
	return;
	trunc:
	fputs("[\|icmp]", stdout);
	}