/* $USAGI: traceroute6.c,v 1.11 2001/11/27 15:27:32 yoshfuji Exp $ */

/*
 *      Modified for NRL 4.4BSD IPv6 release.
 *      07/31/96 bgp
 *
 *      Search for "#ifdef NRL" to find the changes.
 */

/*
 *	Modified for Linux IPv6 by Pedro Roque <roque@di.fc.ul.pt>
 *	31/07/1996
 *
 *	As ICMP error messages for IPv6 now include more than 8 bytes
 *	UDP datagrams are now sent via an UDP socket instead of magic
 *	RAW socket tricks.
 *
 *	Original copyright and comments left intact. They might not
 *	match the code anymore.
 */

/*-
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Van Jacobson.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1990, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

/*
 * traceroute host  - trace the route ip packets follow going to "host".
 *
 * Attempt to trace the route an ip packet would follow to some
 * internet host.  We find out intermediate hops by launching probe
 * packets with a small ttl (time to live) then listening for an
 * icmp "time exceeded" reply from a gateway.  We start our probes
 * with a ttl of one and increase by one until we get an icmp "port
 * unreachable" (which means we got to "host") or hit a max (which
 * defaults to 30 hops & can be changed with the -m flag).  Three
 * probes (change with -q flag) are sent at each ttl setting and a
 * line is printed showing the ttl, address of the gateway and
 * round trip time of each probe.  If the probe answers come from
 * different gateways, the address of each responding system will
 * be printed.  If there is no response within a 5 sec. timeout
 * interval (changed with the -w flag), a "*" is printed for that
 * probe.
 *
 * Probe packets are UDP format.  We don't want the destination
 * host to process them so the destination port is set to an
 * unlikely value (if some clod on the destination is using that
 * value, it can be changed with the -p flag).
 *
 * A sample use might be:
 *
 *     [yak 71]% traceroute nis.nsf.net.
 *     traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
 *      1  helios.ee.lbl.gov (128.3.112.1)  19 ms  19 ms  0 ms
 *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
 *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
 *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  39 ms
 *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  39 ms  39 ms  39 ms
 *      6  128.32.197.4 (128.32.197.4)  40 ms  59 ms  59 ms
 *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  59 ms
 *      8  129.140.70.13 (129.140.70.13)  99 ms  99 ms  80 ms
 *      9  129.140.71.6 (129.140.71.6)  139 ms  239 ms  319 ms
 *     10  129.140.81.7 (129.140.81.7)  220 ms  199 ms  199 ms
 *     11  nic.merit.edu (35.1.1.48)  239 ms  239 ms  239 ms
 *
 * Note that lines 2 & 3 are the same.  This is due to a buggy
 * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
 * packets with a zero ttl.
 *
 * A more interesting example is:
 *
 *     [yak 72]% traceroute allspice.lcs.mit.edu.
 *     traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
 *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
 *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  19 ms  19 ms
 *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  19 ms
 *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  19 ms  39 ms  39 ms
 *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  20 ms  39 ms  39 ms
 *      6  128.32.197.4 (128.32.197.4)  59 ms  119 ms  39 ms
 *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  39 ms
 *      8  129.140.70.13 (129.140.70.13)  80 ms  79 ms  99 ms
 *      9  129.140.71.6 (129.140.71.6)  139 ms  139 ms  159 ms
 *     10  129.140.81.7 (129.140.81.7)  199 ms  180 ms  300 ms
 *     11  129.140.72.17 (129.140.72.17)  300 ms  239 ms  239 ms
 *     12  * * *
 *     13  128.121.54.72 (128.121.54.72)  259 ms  499 ms  279 ms
 *     14  * * *
 *     15  * * *
 *     16  * * *
 *     17  * * *
 *     18  ALLSPICE.LCS.MIT.EDU (18.26.0.115)  339 ms  279 ms  279 ms
 *
 * (I start to see why I'm having so much trouble with mail to
 * MIT.)  Note that the gateways 12, 14, 15, 16 & 17 hops away
 * either don't send ICMP "time exceeded" messages or send them
 * with a ttl too small to reach us.  14 - 17 are running the
 * MIT C Gateway code that doesn't send "time exceeded"s.  God
 * only knows what's going on with 12.
 *
 * The silent gateway 12 in the above may be the result of a bug in
 * the 4.[23]BSD network code (and its derivatives):  4.x (x <= 3)
 * sends an unreachable message using whatever ttl remains in the
 * original datagram.  Since, for gateways, the remaining ttl is
 * zero, the icmp "time exceeded" is guaranteed to not make it back
 * to us.  The behavior of this bug is slightly more interesting
 * when it appears on the destination system:
 *
 *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
 *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  39 ms
 *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  39 ms  19 ms
 *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  19 ms
 *      5  ccn-nerif35.Berkeley.EDU (128.32.168.35)  39 ms  39 ms  39 ms
 *      6  csgw.Berkeley.EDU (128.32.133.254)  39 ms  59 ms  39 ms
 *      7  * * *
 *      8  * * *
 *      9  * * *
 *     10  * * *
 *     11  * * *
 *     12  * * *
 *     13  rip.Berkeley.EDU (128.32.131.22)  59 ms !  39 ms !  39 ms !
 *
 * Notice that there are 12 "gateways" (13 is the final
 * destination) and exactly the last half of them are "missing".
 * What's really happening is that rip (a Sun-3 running Sun OS3.5)
 * is using the ttl from our arriving datagram as the ttl in its
 * icmp reply.  So, the reply will time out on the return path
 * (with no notice sent to anyone since icmp's aren't sent for
 * icmp's) until we probe with a ttl that's at least twice the path
 * length.  I.e., rip is really only 7 hops away.  A reply that
 * returns with a ttl of 1 is a clue this problem exists.
 * Traceroute prints a "!" after the time if the ttl is <= 1.
 * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
 * non-standard (HPUX) software, expect to see this problem
 * frequently and/or take care picking the target host of your
 * probes.
 *
 * Other possible annotations after the time are !H, !N, !P (got a host,
 * network or protocol unreachable, respectively), !S or !F (source
 * route failed or fragmentation needed -- neither of these should
 * ever occur and the associated gateway is busted if you see one).  If
 * almost all the probes result in some kind of unreachable, traceroute
 * will give up and exit.
 *
 * Notes
 * -----
 * This program must be run by root or be setuid.  (I suggest that
 * you *don't* make it setuid -- casual use could result in a lot
 * of unnecessary traffic on our poor, congested nets.)
 *
 * This program requires a kernel mod that does not appear in any
 * system available from Berkeley:  A raw ip socket using proto
 * IPPROTO_RAW must interpret the data sent as an ip datagram (as
 * opposed to data to be wrapped in a ip datagram).  See the README
 * file that came with the source to this program for a description
 * of the mods I made to /sys/netinet/raw_ip.c.  Your mileage may
 * vary.  But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
 * MODIFIED TO RUN THIS PROGRAM.
 *
 * The udp port usage may appear bizarre (well, ok, it is bizarre).
 * The problem is that an icmp message only contains 8 bytes of
 * data from the original datagram.  8 bytes is the size of a udp
 * header so, if we want to associate replies with the original
 * datagram, the necessary information must be encoded into the
 * udp header (the ip id could be used but there's no way to
 * interlock with the kernel's assignment of ip id's and, anyway,
 * it would have taken a lot more kernel hacking to allow this
 * code to set the ip id).  So, to allow two or more users to
 * use traceroute simultaneously, we use this task's pid as the
 * source port (the high bit is set to move the port number out
 * of the "likely" range).  To keep track of which probe is being
 * replied to (so times and/or hop counts don't get confused by a
 * reply that was delayed in transit), we increment the destination
 * port number before each probe.
 *
 * Don't use this as a coding example.  I was trying to find a
 * routing problem and this code sort-of popped out after 48 hours
 * without sleep.  I was amazed it ever compiled, much less ran.
 *
 * I stole the idea for this program from Steve Deering.  Since
 * the first release, I've learned that had I attended the right
 * IETF working group meetings, I also could have stolen it from Guy
 * Almes or Matt Mathis.  I don't know (or care) who came up with
 * the idea first.  I envy the originators' perspicacity and I'm
 * glad they didn't keep the idea a secret.
 *
 * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
 * enhancements to the original distribution.
 *
 * I've hacked up a round-trip-route version of this that works by
 * sending a loose-source-routed udp datagram through the destination
 * back to yourself.  Unfortunately, SO many gateways botch source
 * routing, the thing is almost worthless.  Maybe one day...
 *
 *  -- Van Jacobson (van@helios.ee.lbl.gov)
 *     Tue Dec 20 03:50:13 PST 1988
 */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <net/if.h>

#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/udp.h>

#include <netinet/ip6.h>
#include <netinet/icmp6.h>

#include <arpa/inet.h>

#include <netdb.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "SNAPSHOT.h"

#define	MAXPACKET	65535
#ifndef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN	64
#endif

#ifndef FD_SET
#define NFDBITS         (8*sizeof(fd_set))
#define FD_SETSIZE      NFDBITS
#define FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
#define FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
#define FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
#define FD_ZERO(p)      bzero((char *)(p), sizeof(*(p)))
#endif

#define Fprintf (void)fprintf
#define Printf (void)printf

u_char	packet[512];		/* last inbound (icmp) packet */

int	wait_for_reply(int, struct sockaddr_in6 *, socklen_t *, int);
int	packet_ok(u_char *buf, int cc, struct sockaddr_in6 *from, int seq,
		  struct timeval *);
void	send_probe(int seq, int ttl);
double	deltaT (struct timeval *, struct timeval *);
char	*pr_addr(struct sockaddr *addr, socklen_t addrlen);
void	print(unsigned char *buf, int cc, struct sockaddr_in6 *from, socklen_t fromlen);
void	tvsub (struct timeval *, struct timeval *);
void	usage(void);

int icmp_sock;			/* receive (icmp) socket file descriptor */
int sndsock;			/* send (udp) socket file descriptor */
struct timezone tz;		/* leftover */

struct sockaddr_in6 whereto;	/* Who to try to reach */
socklen_t wheretolen;

struct sockaddr_in6 saddr;
socklen_t saddrlen;
struct sockaddr_in6 firsthop;
char *source = NULL;
char *device = NULL;
char *hostname;

int nprobes = 3;
int max_ttl = 30;
pid_t ident;
u_short port = 32768+666;	/* start udp dest port # for probe packets */
int options;			/* socket options */
int verbose;
int waittime = 5;		/* time to wait for response (in seconds) */
int nflag;			/* print addresses numerically */


struct pkt_format
{
	u_int32_t ident;
	u_int32_t seq;
	struct timeval tv;
};

char *sendbuff;
int datalen = sizeof(struct pkt_format);



int main(int argc, char *argv[])
{
	extern char *optarg;
	extern int optind;
	struct sockaddr_in6 from, *to;
	socklen_t fromlen;
	int ch, i, on, probe, seq, tos, ttl;
	struct addrinfo hints, *res0;
	int gai;
	char servbuf[NI_MAXSERV];
	int socket_errno;

	icmp_sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
	socket_errno = errno;

	setuid(getuid());

	on = 1;
	seq = tos = 0;
	to = (struct sockaddr_in6 *)&whereto;
	while ((ch = getopt(argc, argv, "dm:np:q:rs:t:w:vi:g:V")) != EOF) {
		switch(ch) {
		case 'd':
			options |= SO_DEBUG;
			break;
		case 'm':
			max_ttl = atoi(optarg);
			if (max_ttl <= 1) {
				Fprintf(stderr,
				    "traceroute: max ttl must be >1.\n");
				exit(1);
			}
			break;
		case 'n':
			nflag++;
			break;
		case 'p':
			port = atoi(optarg);
			if (port < 1) {
				Fprintf(stderr,
				    "traceroute: port must be >0.\n");
				exit(1);
			}
			break;
		case 'q':
			nprobes = atoi(optarg);
			if (nprobes < 1) {
				Fprintf(stderr,
				    "traceroute: nprobes must be >0.\n");
				exit(1);
			}
			break;
		case 'r':
			options |= SO_DONTROUTE;
			break;
		case 's':
			/*
			 * set the ip source address of the outbound
			 * probe (e.g., on a multi-homed host).
			 */
			source = optarg;
			break;
		case 'i':
			device = optarg;
			break;
		case 'g':
			Fprintf(stderr, "Sorry, rthdr is not yet supported\n");
			break;
		case 'v':
			verbose++;
			break;
		case 'w':
			waittime = atoi(optarg);
			if (waittime <= 1) {
				Fprintf(stderr,
				    "traceroute: wait must be >1 sec.\n");
				exit(1);
			}
			break;
		case 'V':
			printf("traceroute6 utility, iputils-ss%s\n", SNAPSHOT);
			exit(0);
		default:
			usage();
		}
	}
	argc -= optind;
	argv += optind;

	if (argc < 1)
		usage();

	setlinebuf (stdout);

	hostname = *argv;

	(void) bzero((char *)&whereto, sizeof(struct sockaddr_in6));

	sprintf(servbuf, "%d", port);
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = PF_INET6;
	hints.ai_socktype = SOCK_DGRAM;
	gai = getaddrinfo(*argv, servbuf, &hints, &res0);
	if (gai)
	{
		(void)fprintf(stderr,
			"traceroute: %s; host=%s\n",
			gai_strerror(gai), *argv);
		exit(1);
	}
	if (!res0->ai_addr || res0->ai_addr->sa_family != AF_INET6)
	{
		(void)fprintf(stderr,
			"traceroute: getaddrinfo() failed for host %s\n",
			*argv);
		exit(1);
	}
	if (res0->ai_addrlen > sizeof(whereto))
	{
		(void)fprintf(stderr,
			"traceroute: getaddrinfo() failed for host %s; returned sockaddr_in6{} is too large\n",
			*argv);
		exit(1);
	}
	memmove(&whereto, res0->ai_addr, res0->ai_addrlen);
	wheretolen = res0->ai_addrlen;
	freeaddrinfo(res0);

	firsthop = *to;
	if (*++argv)
		datalen = atoi(*argv);

	if (datalen < 0 || datalen >= MAXPACKET - sizeof(struct pkt_format)) {
		Fprintf(stderr,
		    "traceroute: packet size must be 0 <= s < %u.\n",
		    MAXPACKET - sizeof(struct pkt_format));
		exit(1);
	}
	datalen += sizeof(struct pkt_format);

	ident = getpid();

	sendbuff = malloc(datalen);
	if (sendbuff == NULL) {
		fprintf(stderr, "malloc failed\n");
		exit(1);
	}

	if (icmp_sock < 0){
		errno = socket_errno;
		perror("traceroute6: icmp socket");
		exit(1);
	}

	if (options & SO_DEBUG)
		setsockopt(icmp_sock, SOL_SOCKET, SO_DEBUG,
			   (char *)&on, sizeof(on));
	if (options & SO_DONTROUTE)
		setsockopt(icmp_sock, SOL_SOCKET, SO_DONTROUTE,
			   (char *)&on, sizeof(on));

	if ((sndsock = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
		perror("traceroute: UDP socket");
		exit(5);
	}
#ifdef SO_SNDBUF
	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen,
		       sizeof(datalen)) < 0) {
		perror("traceroute: SO_SNDBUF");
		exit(6);
	}
#endif SO_SNDBUF

	if (options & SO_DEBUG)
		(void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
				  (char *)&on, sizeof(on));
	if (options & SO_DONTROUTE)
		(void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
				  (char *)&on, sizeof(on));

	if (source == NULL) {
		int probe_fd = socket(AF_INET6, SOCK_DGRAM, 0);

		if (probe_fd < 0) {
			perror("socket");
			exit(1);
		}
		if (device) {
			struct ifreq ifr;
			memset(&ifr, 0, sizeof(ifr));
			strncpy(ifr.ifr_name, device, IFNAMSIZ-1);
			if (setsockopt(probe_fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) == -1)
				perror("WARNING: interface is ignored");
		}
		firsthop.sin6_port = htons(1025);
		if (connect(probe_fd, (struct sockaddr*)&firsthop, sizeof(firsthop)) == -1) {
			perror("connect");
			exit(1);
		}
		saddrlen = sizeof(saddr);
		if (getsockname(probe_fd, (struct sockaddr*)&saddr, &saddrlen) == -1) {
			perror("getsockname");
			exit(1);
		}
		saddr.sin6_port = 0;
		close(probe_fd);
	} else {
		struct addrinfo hints, *res0;
		memset(&hints, 0, sizeof(hints));
		hints.ai_family = PF_INET6;
		hints.ai_flags = AI_NUMERICHOST;
		if (getaddrinfo(source, NULL, &hints, &res0)){
			Printf("traceroute: unknown addr %s\n", source);
			exit(1);
		}
		if (res0->ai_addrlen > sizeof(struct sockaddr_in6)){
			freeaddrinfo(res0);
			Printf("traceroute: returned sockaddr_in6{} is too large\n");
			exit(1);
		}
		memcpy(&saddr, res0->ai_addr, res0->ai_addrlen);
		saddrlen = res0->ai_addrlen;
		freeaddrinfo(res0);
	}

	if (device) {
		struct ifreq ifr;
		strncpy(ifr.ifr_name, device, IFNAMSIZ-1);
		if (setsockopt(sndsock, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) == -1)
			perror("WARNING: interface is ignored");
	}

	if (bind(sndsock, (struct sockaddr *)&saddr, saddrlen) < 0) {
		perror ("traceroute: bind sending socket");
		exit (1);
	}
	if (bind(icmp_sock, (struct sockaddr *)&saddr, saddrlen) < 0) {
		perror ("traceroute: bind icmp6 socket");
		exit (1);
	}

	Fprintf(stderr, "traceroute to %s (%s)", hostname,
		pr_addr((struct sockaddr *)to, wheretolen));

	Fprintf(stderr, " from %s",
		pr_addr((struct sockaddr *)&saddr, saddrlen));
	Fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, datalen);
	(void) fflush(stderr);

	for (ttl = 1; ttl <= max_ttl; ++ttl) {
		struct in6_addr lastaddr = {{{0,}}};
		int got_there = 0;
		int unreachable = 0;

		Printf("%2d ", ttl);
		for (probe = 0; probe < nprobes; ++probe) {
			int cc, reset_timer;
			struct timeval t1, t2;
			struct timezone tz;

			gettimeofday(&t1, &tz);
			send_probe(++seq, ttl);
			reset_timer = 1;

			while ((cc = wait_for_reply(icmp_sock, &from, &fromlen, reset_timer)) != 0) {
				gettimeofday(&t2, &tz);
				if ((i = packet_ok(packet, cc, &from, seq, &t1))) {
					reset_timer = 1;
					if (memcmp(&from.sin6_addr, &lastaddr, sizeof(struct in6_addr))) {
						print(packet, cc, &from, fromlen);
						memcpy(&lastaddr,
						       &from.sin6_addr,
						       sizeof(struct in6_addr));
					}
					Printf("  %g ms", deltaT(&t1, &t2));
					switch(i - 1) {
					case ICMP6_DST_UNREACH_NOPORT:
						++got_there;
						break;

					case ICMP6_DST_UNREACH_NOROUTE:
						++unreachable;
						Printf(" !N");
						break;
					case ICMP6_DST_UNREACH_ADDR:
						++unreachable;
						Printf(" !H");
						break;

					case ICMP6_DST_UNREACH_ADMIN:
						++unreachable;
						Printf(" !S");
						break;
					}
					break;
				} else
					reset_timer = 0;
			}
			if (cc == 0)
				Printf(" *");
			(void) fflush(stdout);
		}
		putchar('\n');
		if (got_there || unreachable >= nprobes-1)
			exit(0);
	}

	return 0;
}

int
wait_for_reply(sock, from, fromlen, reset_timer)
	int sock;
	struct sockaddr_in6 *from;
	socklen_t *fromlen;
	int reset_timer;
{
	fd_set fds;
	static struct timeval wait;
	int cc = 0;

	FD_ZERO(&fds);
	FD_SET(sock, &fds);
	if (reset_timer) {
		/*
		 * traceroute could hang if someone else has a ping
		 * running and our ICMP reply gets dropped but we don't
		 * realize it because we keep waking up to handle those
		 * other ICMP packets that keep coming in.  To fix this,
		 * "reset_timer" will only be true if the last packet that
		 * came in was for us or if this is the first time we're
		 * waiting for a reply since sending out a probe.  Note
		 * that this takes advantage of the select() feature on
		 * Linux where the remaining timeout is written to the
		 * struct timeval area.
		 */
		wait.tv_sec = waittime;
		wait.tv_usec = 0;
	}

	if (select(sock+1, &fds, (fd_set *)0, (fd_set *)0, &wait) > 0) {
		cc=recvfrom(icmp_sock, (char *)packet, sizeof(packet), 0,
			    (struct sockaddr *)from, fromlen);
	}

	return(cc);
}


void send_probe(int seq, int ttl)
{
	struct pkt_format *pkt = (struct pkt_format *) sendbuff;
	int i;

	pkt->ident = htonl(ident);
	pkt->seq = htonl(seq);
	gettimeofday(&pkt->tv, &tz);

	i = setsockopt(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(int));
	if (i < 0)
	{
		perror("setsockopt");
		exit(1);
	}

	do {
		i = sendto(sndsock, sendbuff, datalen, 0,
			   (struct sockaddr *)&whereto, wheretolen);
	} while (i<0 && errno == ECONNREFUSED);

	if (i < 0 || i != datalen)  {
		if (i<0)
			perror("sendto");
		Printf("traceroute: wrote %s %d chars, ret=%d\n", hostname,
			datalen, i);
		(void) fflush(stdout);
	}
}


double deltaT(struct timeval *t1p, struct timeval *t2p)
{
	register double dt;

	dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
	     (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
	return (dt);
}


/*
 * Convert an ICMP "type" field to a printable string.
 */
char * pr_type(unsigned char t)
{
	static char *ttab1[] = {
		"Error",
		"Destination Unreachable",
		"Packet Too Big",
		"Time Exceeded in Transit",
		"Parameter Problem"
	};

	static char *ttab2[] = {
		"Echo Reply",
		"Echo Request",
		"Membership Query",
		"Membership Report",
		"Membership Reduction",
	};

	if (t < 5)
	{
		return (ttab1[t]);
	}

	if (t >= 128 && t <= 132)
	{
		return (ttab2[t]);
	}

	return("OUT-OF-RANGE");
}


int packet_ok(u_char *buf, int cc, struct sockaddr_in6 *from, int seq,
	      struct timeval *tv)
{
	struct icmp6_hdr *icp;
	u_char type, code;

	icp = (struct icmp6_hdr *) buf;

	type = icp->icmp6_type;
	code = icp->icmp6_code;

	if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT) ||
	    type == ICMP6_DST_UNREACH)
	{
		struct ip6_hdr *hip;
		struct udphdr *up;


		hip = (struct ip6_hdr *) (icp + 1);
		if (hip->ip6_nxt == IPPROTO_UDP)
		{
			struct pkt_format *pkt;
			
			up = (struct udphdr *)(hip+1);
			pkt = (struct pkt_format *) (up + 1);

			if (ntohl(pkt->ident) == ident &&
			    ntohl(pkt->seq) == seq)
			{
				*tv = pkt->tv;
				return (type == ICMP6_TIME_EXCEEDED? -1 : code+1);
			}
		}

	}

	if (verbose) {
		struct ip6_hdr *hip;
		u_int32_t *lp;
		char pa1[64];
		char pa2[64];
		int i;
		hip = (struct ip6_hdr *) (icp + 1);
		lp = (u_int32_t *) (icp + 1);

		Printf("\n%d bytes from %s to %s", cc,
		       inet_ntop(AF_INET6, &hip->ip6_src, pa1, sizeof(pa1)),
		       inet_ntop(AF_INET6, &hip->ip6_dst, pa2, sizeof(pa2)));
		
		Printf(": icmp type %d (%s) code %d\n", type, pr_type(type),
		       icp->icmp6_code);

		for (i = sizeof(struct ip6_hdr); i < cc ; i += 4)
			Printf("%2d: x%8.8x\n", i, *lp++);
	}

	return(0);
}

char *pr_addr(struct sockaddr *addr, socklen_t addrlen){
	static char abuf[128];

	if (getnameinfo(addr, addrlen, 
			abuf, sizeof(abuf), NULL ,0,
			NI_NUMERICHOST))
		strcpy(abuf, "???");
	return abuf;
}

void print(unsigned char *buf, int cc, struct sockaddr_in6 *from, socklen_t fromlen)
{
	char addrbuf[NI_MAXHOST];
	if (getnameinfo((struct sockaddr*)from, fromlen,
			addrbuf, sizeof(addrbuf), NULL, 0, 
			nflag ? NI_NUMERICHOST : 0))
		strcpy(addrbuf, "???");
	Printf(" %s", addrbuf);
	if (!nflag){
		if (getnameinfo((struct sockaddr*)from, fromlen,
				addrbuf, sizeof(addrbuf), NULL, 0, 
				NI_NUMERICHOST))
			strcpy(addrbuf, "???");
		Printf(" (%s)", addrbuf);
	}
}


/*
 * Subtract 2 timeval structs:  out = out - in.
 * Out is assumed to be >= in.
 */
void
tvsub(out, in)
	register struct timeval *out, *in;
{
	if ((out->tv_usec -= in->tv_usec) < 0)   {
		out->tv_sec--;
		out->tv_usec += 1000000;
	}
	out->tv_sec -= in->tv_sec;
}

void usage(void)
{
	fprintf(stderr,
"Usage: traceroute6 [-dnrvV] [-m max_ttl] [-p port#] [-q nqueries]\n\t\
[-s src_addr] [-t tos] [-w wait] host [data size]\n");
	exit(1);
}
