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traceroute6.c revision 1.23
      1 /*	$NetBSD: traceroute6.c,v 1.23 2002/06/29 07:49:25 itojun Exp $	*/
      2 /*	$KAME: traceroute6.c,v 1.53 2002/06/09 02:45:52 itojun Exp $	*/
      3 
      4 /*
      5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of the project nor the names of its contributors
     17  *    may be used to endorse or promote products derived from this software
     18  *    without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
     21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
     24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     30  * SUCH DAMAGE.
     31  */
     32 
     33 /*-
     34  * Copyright (c) 1990, 1993
     35  *	The Regents of the University of California.  All rights reserved.
     36  *
     37  * This code is derived from software contributed to Berkeley by
     38  * Van Jacobson.
     39  *
     40  * Redistribution and use in source and binary forms, with or without
     41  * modification, are permitted provided that the following conditions
     42  * are met:
     43  * 1. Redistributions of source code must retain the above copyright
     44  *    notice, this list of conditions and the following disclaimer.
     45  * 2. Redistributions in binary form must reproduce the above copyright
     46  *    notice, this list of conditions and the following disclaimer in the
     47  *    documentation and/or other materials provided with the distribution.
     48  * 3. All advertising materials mentioning features or use of this software
     49  *    must display the following acknowledgement:
     50  *	This product includes software developed by the University of
     51  *	California, Berkeley and its contributors.
     52  * 4. Neither the name of the University nor the names of its contributors
     53  *    may be used to endorse or promote products derived from this software
     54  *    without specific prior written permission.
     55  *
     56  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     66  * SUCH DAMAGE.
     67  */
     68 
     69 #if 0
     70 #ifndef lint
     71 static char copyright[] =
     72 "@(#) Copyright (c) 1990, 1993\n\
     73 	The Regents of the University of California.  All rights reserved.\n";
     74 #endif /* not lint */
     75 
     76 #ifndef lint
     77 static char sccsid[] = "@(#)traceroute.c	8.1 (Berkeley) 6/6/93";
     78 #endif /* not lint */
     79 #else
     80 #include <sys/cdefs.h>
     81 #ifndef lint
     82 __RCSID("$NetBSD: traceroute6.c,v 1.23 2002/06/29 07:49:25 itojun Exp $");
     83 #endif
     84 #endif
     85 
     86 /*
     87  * traceroute host  - trace the route ip packets follow going to "host".
     88  *
     89  * Attempt to trace the route an ip packet would follow to some
     90  * internet host.  We find out intermediate hops by launching probe
     91  * packets with a small ttl (time to live) then listening for an
     92  * icmp "time exceeded" reply from a gateway.  We start our probes
     93  * with a ttl of one and increase by one until we get an icmp "port
     94  * unreachable" (which means we got to "host") or hit a max (which
     95  * defaults to 30 hops & can be changed with the -m flag).  Three
     96  * probes (change with -q flag) are sent at each ttl setting and a
     97  * line is printed showing the ttl, address of the gateway and
     98  * round trip time of each probe.  If the probe answers come from
     99  * different gateways, the address of each responding system will
    100  * be printed.  If there is no response within a 5 sec. timeout
    101  * interval (changed with the -w flag), a "*" is printed for that
    102  * probe.
    103  *
    104  * Probe packets are UDP format.  We don't want the destination
    105  * host to process them so the destination port is set to an
    106  * unlikely value (if some clod on the destination is using that
    107  * value, it can be changed with the -p flag).
    108  *
    109  * A sample use might be:
    110  *
    111  *     [yak 71]% traceroute nis.nsf.net.
    112  *     traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
    113  *      1  helios.ee.lbl.gov (128.3.112.1)  19 ms  19 ms  0 ms
    114  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
    115  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
    116  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  39 ms
    117  *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  39 ms  39 ms  39 ms
    118  *      6  128.32.197.4 (128.32.197.4)  40 ms  59 ms  59 ms
    119  *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  59 ms
    120  *      8  129.140.70.13 (129.140.70.13)  99 ms  99 ms  80 ms
    121  *      9  129.140.71.6 (129.140.71.6)  139 ms  239 ms  319 ms
    122  *     10  129.140.81.7 (129.140.81.7)  220 ms  199 ms  199 ms
    123  *     11  nic.merit.edu (35.1.1.48)  239 ms  239 ms  239 ms
    124  *
    125  * Note that lines 2 & 3 are the same.  This is due to a buggy
    126  * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
    127  * packets with a zero ttl.
    128  *
    129  * A more interesting example is:
    130  *
    131  *     [yak 72]% traceroute allspice.lcs.mit.edu.
    132  *     traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
    133  *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
    134  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  19 ms  19 ms
    135  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  19 ms
    136  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  19 ms  39 ms  39 ms
    137  *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  20 ms  39 ms  39 ms
    138  *      6  128.32.197.4 (128.32.197.4)  59 ms  119 ms  39 ms
    139  *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  39 ms
    140  *      8  129.140.70.13 (129.140.70.13)  80 ms  79 ms  99 ms
    141  *      9  129.140.71.6 (129.140.71.6)  139 ms  139 ms  159 ms
    142  *     10  129.140.81.7 (129.140.81.7)  199 ms  180 ms  300 ms
    143  *     11  129.140.72.17 (129.140.72.17)  300 ms  239 ms  239 ms
    144  *     12  * * *
    145  *     13  128.121.54.72 (128.121.54.72)  259 ms  499 ms  279 ms
    146  *     14  * * *
    147  *     15  * * *
    148  *     16  * * *
    149  *     17  * * *
    150  *     18  ALLSPICE.LCS.MIT.EDU (18.26.0.115)  339 ms  279 ms  279 ms
    151  *
    152  * (I start to see why I'm having so much trouble with mail to
    153  * MIT.)  Note that the gateways 12, 14, 15, 16 & 17 hops away
    154  * either don't send ICMP "time exceeded" messages or send them
    155  * with a ttl too small to reach us.  14 - 17 are running the
    156  * MIT C Gateway code that doesn't send "time exceeded"s.  God
    157  * only knows what's going on with 12.
    158  *
    159  * The silent gateway 12 in the above may be the result of a bug in
    160  * the 4.[23]BSD network code (and its derivatives):  4.x (x <= 3)
    161  * sends an unreachable message using whatever ttl remains in the
    162  * original datagram.  Since, for gateways, the remaining ttl is
    163  * zero, the icmp "time exceeded" is guaranteed to not make it back
    164  * to us.  The behavior of this bug is slightly more interesting
    165  * when it appears on the destination system:
    166  *
    167  *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
    168  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  39 ms
    169  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  39 ms  19 ms
    170  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  19 ms
    171  *      5  ccn-nerif35.Berkeley.EDU (128.32.168.35)  39 ms  39 ms  39 ms
    172  *      6  csgw.Berkeley.EDU (128.32.133.254)  39 ms  59 ms  39 ms
    173  *      7  * * *
    174  *      8  * * *
    175  *      9  * * *
    176  *     10  * * *
    177  *     11  * * *
    178  *     12  * * *
    179  *     13  rip.Berkeley.EDU (128.32.131.22)  59 ms !  39 ms !  39 ms !
    180  *
    181  * Notice that there are 12 "gateways" (13 is the final
    182  * destination) and exactly the last half of them are "missing".
    183  * What's really happening is that rip (a Sun-3 running Sun OS3.5)
    184  * is using the ttl from our arriving datagram as the ttl in its
    185  * icmp reply.  So, the reply will time out on the return path
    186  * (with no notice sent to anyone since icmp's aren't sent for
    187  * icmp's) until we probe with a ttl that's at least twice the path
    188  * length.  I.e., rip is really only 7 hops away.  A reply that
    189  * returns with a ttl of 1 is a clue this problem exists.
    190  * Traceroute prints a "!" after the time if the ttl is <= 1.
    191  * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
    192  * non-standard (HPUX) software, expect to see this problem
    193  * frequently and/or take care picking the target host of your
    194  * probes.
    195  *
    196  * Other possible annotations after the time are !H, !N, !P (got a host,
    197  * network or protocol unreachable, respectively), !S or !F (source
    198  * route failed or fragmentation needed -- neither of these should
    199  * ever occur and the associated gateway is busted if you see one).  If
    200  * almost all the probes result in some kind of unreachable, traceroute
    201  * will give up and exit.
    202  *
    203  * Notes
    204  * -----
    205  * This program must be run by root or be setuid.  (I suggest that
    206  * you *don't* make it setuid -- casual use could result in a lot
    207  * of unnecessary traffic on our poor, congested nets.)
    208  *
    209  * This program requires a kernel mod that does not appear in any
    210  * system available from Berkeley:  A raw ip socket using proto
    211  * IPPROTO_RAW must interpret the data sent as an ip datagram (as
    212  * opposed to data to be wrapped in a ip datagram).  See the README
    213  * file that came with the source to this program for a description
    214  * of the mods I made to /sys/netinet/raw_ip.c.  Your mileage may
    215  * vary.  But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
    216  * MODIFIED TO RUN THIS PROGRAM.
    217  *
    218  * The udp port usage may appear bizarre (well, ok, it is bizarre).
    219  * The problem is that an icmp message only contains 8 bytes of
    220  * data from the original datagram.  8 bytes is the size of a udp
    221  * header so, if we want to associate replies with the original
    222  * datagram, the necessary information must be encoded into the
    223  * udp header (the ip id could be used but there's no way to
    224  * interlock with the kernel's assignment of ip id's and, anyway,
    225  * it would have taken a lot more kernel hacking to allow this
    226  * code to set the ip id).  So, to allow two or more users to
    227  * use traceroute simultaneously, we use this task's pid as the
    228  * source port (the high bit is set to move the port number out
    229  * of the "likely" range).  To keep track of which probe is being
    230  * replied to (so times and/or hop counts don't get confused by a
    231  * reply that was delayed in transit), we increment the destination
    232  * port number before each probe.
    233  *
    234  * Don't use this as a coding example.  I was trying to find a
    235  * routing problem and this code sort-of popped out after 48 hours
    236  * without sleep.  I was amazed it ever compiled, much less ran.
    237  *
    238  * I stole the idea for this program from Steve Deering.  Since
    239  * the first release, I've learned that had I attended the right
    240  * IETF working group meetings, I also could have stolen it from Guy
    241  * Almes or Matt Mathis.  I don't know (or care) who came up with
    242  * the idea first.  I envy the originators' perspicacity and I'm
    243  * glad they didn't keep the idea a secret.
    244  *
    245  * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
    246  * enhancements to the original distribution.
    247  *
    248  * I've hacked up a round-trip-route version of this that works by
    249  * sending a loose-source-routed udp datagram through the destination
    250  * back to yourself.  Unfortunately, SO many gateways botch source
    251  * routing, the thing is almost worthless.  Maybe one day...
    252  *
    253  *  -- Van Jacobson (van (at) helios.ee.lbl.gov)
    254  *     Tue Dec 20 03:50:13 PST 1988
    255  */
    256 
    257 #include <sys/param.h>
    258 #include <sys/time.h>
    259 #include <sys/socket.h>
    260 #include <sys/uio.h>
    261 #include <sys/file.h>
    262 #include <sys/ioctl.h>
    263 #include <sys/sysctl.h>
    264 
    265 #include <netinet/in.h>
    266 
    267 #include <arpa/inet.h>
    268 
    269 #include <netdb.h>
    270 #include <stdio.h>
    271 #include <err.h>
    272 #ifdef HAVE_POLL
    273 #include <poll.h>
    274 #endif
    275 #include <errno.h>
    276 #include <stdlib.h>
    277 #include <string.h>
    278 #include <unistd.h>
    279 
    280 #include <netinet/ip6.h>
    281 #include <netinet/icmp6.h>
    282 #include <netinet/udp.h>
    283 
    284 #ifdef IPSEC
    285 #include <net/route.h>
    286 #include <netinet6/ipsec.h>
    287 #endif
    288 
    289 #define DUMMY_PORT 10010
    290 
    291 #define	MAXPACKET	65535	/* max ip packet size */
    292 
    293 #ifndef HAVE_GETIPNODEBYNAME
    294 #define getipnodebyname(x, y, z, u)	gethostbyname2((x), (y))
    295 #define freehostent(x)
    296 #endif
    297 
    298 /*
    299  * format of a (udp) probe packet.
    300  */
    301 struct opacket {
    302 	u_char seq;		/* sequence number of this packet */
    303 	u_char hops;		/* hop limit of the packet */
    304 	struct timeval tv;	/* time packet left */
    305 };
    306 
    307 u_char	packet[512];		/* last inbound (icmp) packet */
    308 struct opacket	*outpacket;	/* last output (udp) packet */
    309 
    310 int	main __P((int, char *[]));
    311 int	wait_for_reply __P((int, struct msghdr *));
    312 #ifdef IPSEC
    313 #ifdef IPSEC_POLICY_IPSEC
    314 int	setpolicy __P((int so, char *policy));
    315 #endif
    316 #endif
    317 void	send_probe __P((int, int));
    318 struct udphdr *get_udphdr __P((struct ip6_hdr *, u_char *));
    319 int	get_hoplim __P((struct msghdr *));
    320 double	deltaT __P((struct timeval *, struct timeval *));
    321 char	*pr_type __P((int));
    322 int	packet_ok __P((struct msghdr *, int, int));
    323 void	print __P((struct msghdr *, int));
    324 void	tvsub __P((struct timeval *, struct timeval *));
    325 const char *inetname __P((struct sockaddr *));
    326 void	usage __P((void));
    327 
    328 int rcvsock;			/* receive (icmp) socket file descriptor */
    329 int sndsock;			/* send (udp) socket file descriptor */
    330 struct timezone tz;		/* leftover */
    331 
    332 struct msghdr rcvmhdr;
    333 struct iovec rcviov[2];
    334 int rcvhlim;
    335 struct in6_pktinfo *rcvpktinfo;
    336 
    337 struct sockaddr_in6 Src, Dst, Rcv;
    338 int datalen;			/* How much data */
    339 /* XXX: 2064 = 127(max hops in type 0 rthdr) * sizeof(ip6_hdr) + 16(margin) */
    340 char rtbuf[2064];
    341 #ifdef USE_RFC2292BIS
    342 struct ip6_rthdr *rth;
    343 #endif
    344 struct cmsghdr *cmsg;
    345 
    346 char *source = 0;
    347 char *hostname;
    348 
    349 int nprobes = 3;
    350 int first_hop = 1;
    351 int max_hops = 30;
    352 u_int16_t srcport;
    353 u_int16_t port = 32768+666;	/* start udp dest port # for probe packets */
    354 int options;			/* socket options */
    355 int verbose;
    356 int waittime = 5;		/* time to wait for response (in seconds) */
    357 int nflag;			/* print addresses numerically */
    358 int lflag;			/* print both numerical address & hostname */
    359 
    360 int
    361 main(argc, argv)
    362 	int argc;
    363 	char *argv[];
    364 {
    365 	struct hostent *hp;
    366 	int error;
    367 	struct addrinfo hints, *res;
    368 	int ch, i, on, probe, seq, hops, rcvcmsglen;
    369 	static u_char *rcvcmsgbuf;
    370 	char hbuf[NI_MAXHOST], src0[NI_MAXHOST];
    371 	char *ep;
    372 	int mib[4] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_DEFHLIM };
    373 	size_t size = sizeof(max_hops);
    374 	u_long lport;
    375 
    376 	/*
    377 	 * Receive ICMP
    378 	 */
    379 	if ((rcvsock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
    380 		perror("socket(ICMPv6)");
    381 		exit(5);
    382 	}
    383 
    384 	/* revoke privs */
    385 	seteuid(getuid());
    386 	setuid(getuid());
    387 
    388 	(void) sysctl(mib, sizeof(mib)/sizeof(mib[0]), &max_hops, &size,
    389 	    NULL, 0);
    390 
    391 	/* set a minimum set of socket options */
    392 	on = 1;
    393 	/* specify to tell receiving interface */
    394 #ifdef IPV6_RECVPKTINFO
    395 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
    396 	    sizeof(on)) < 0)
    397 		err(1, "setsockopt(IPV6_RECVPKTINFO)");
    398 #else  /* old adv. API */
    399 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
    400 	    sizeof(on)) < 0)
    401 		err(1, "setsockopt(IPV6_PKTINFO)");
    402 #endif
    403 
    404 	/* specify to tell value of hoplimit field of received IP6 hdr */
    405 #ifdef IPV6_RECVHOPLIMIT
    406 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
    407 	    sizeof(on)) < 0)
    408 		err(1, "setsockopt(IPV6_RECVHOPLIMIT)");
    409 #else  /* old adv. API */
    410 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
    411 	    sizeof(on)) < 0)
    412 		err(1, "setsockopt(IPV6_HOPLIMIT)");
    413 #endif
    414 
    415 	seq = 0;
    416 
    417 	while ((ch = getopt(argc, argv, "df:g:lm:np:q:rs:w:v")) != -1)
    418 		switch (ch) {
    419 		case 'd':
    420 			options |= SO_DEBUG;
    421 			break;
    422 		case 'f':
    423 			ep = NULL;
    424 			first_hop = strtoul(optarg, &ep, 0);
    425 			if (!*argv || *ep) {
    426 				fprintf(stderr,
    427 				    "traceroute6: invalid min hoplimit.\n");
    428 				exit(1);
    429 			}
    430 			if (first_hop > max_hops) {
    431 				fprintf(stderr,
    432 				    "traceroute6: min hoplimit must be <= %d.\n",
    433 				    max_hops);
    434 				exit(1);
    435 			}
    436 			break;
    437 		case 'g':
    438 			hp = getipnodebyname(optarg, AF_INET6, 0, &h_errno);
    439 			if (hp == NULL) {
    440 				fprintf(stderr,
    441 				    "traceroute6: unknown host %s\n", optarg);
    442 				exit(1);
    443 			}
    444 #ifdef USE_RFC2292BIS
    445 			if (rth == NULL) {
    446 				/*
    447 				 * XXX: We can't detect the number of
    448 				 * intermediate nodes yet.
    449 				 */
    450 				if ((rth = inet6_rth_init((void *)rtbuf,
    451 				    sizeof(rtbuf), IPV6_RTHDR_TYPE_0,
    452 				    0)) == NULL) {
    453 					fprintf(stderr,
    454 					    "inet6_rth_init failed.\n");
    455 					exit(1);
    456 				}
    457 			}
    458 			if (inet6_rth_add((void *)rth,
    459 			    (struct in6_addr *)hp->h_addr)) {
    460 				fprintf(stderr,
    461 				    "inet6_rth_add failed for %s\n",
    462 				    optarg);
    463 				exit(1);
    464 			}
    465 #else  /* old advanced API */
    466 			if (cmsg == NULL)
    467 				cmsg = inet6_rthdr_init(rtbuf, IPV6_RTHDR_TYPE_0);
    468 			inet6_rthdr_add(cmsg, (struct in6_addr *)hp->h_addr,
    469 			    IPV6_RTHDR_LOOSE);
    470 #endif
    471 			freehostent(hp);
    472 			break;
    473 		case 'l':
    474 			lflag++;
    475 			break;
    476 		case 'm':
    477 			ep = NULL;
    478 			max_hops = strtoul(optarg, &ep, 0);
    479 			if (!*argv || *ep) {
    480 				fprintf(stderr,
    481 				    "traceroute6: invalid max hoplimit.\n");
    482 				exit(1);
    483 			}
    484 			if (max_hops < first_hop) {
    485 				fprintf(stderr,
    486 				    "traceroute6: max hoplimit must be >= %d.\n",
    487 				    first_hop);
    488 				exit(1);
    489 			}
    490 			break;
    491 		case 'n':
    492 			nflag++;
    493 			break;
    494 		case 'p':
    495 			ep = NULL;
    496 			lport = strtoul(optarg, &ep, 0);
    497 			if (!*argv || *ep) {
    498 				fprintf(stderr, "traceroute6: port.\n");
    499 				exit(1);
    500 			}
    501 			if (lport == 0 || lport != (lport & 0xffff)) {
    502 				fprintf(stderr,
    503 				    "traceroute6: port out of range.\n");
    504 				exit(1);
    505 			}
    506 			port = lport & 0xffff;
    507 			break;
    508 		case 'q':
    509 			ep = NULL;
    510 			nprobes = strtoul(optarg, &ep, 0);
    511 			if (!*argv || *ep) {
    512 				fprintf(stderr,
    513 				    "traceroute6: invalid nprobes.\n");
    514 				exit(1);
    515 			}
    516 			if (nprobes < 1) {
    517 				fprintf(stderr,
    518 				    "traceroute6: nprobes must be >0.\n");
    519 				exit(1);
    520 			}
    521 			break;
    522 		case 'r':
    523 			options |= SO_DONTROUTE;
    524 			break;
    525 		case 's':
    526 			/*
    527 			 * set the ip source address of the outbound
    528 			 * probe (e.g., on a multi-homed host).
    529 			 */
    530 			source = optarg;
    531 			break;
    532 		case 'v':
    533 			verbose++;
    534 			break;
    535 		case 'w':
    536 			ep = NULL;
    537 			waittime = strtoul(optarg, &ep, 0);
    538 			if (!*argv || *ep) {
    539 				fprintf(stderr,
    540 				    "traceroute6: invalid wait time.\n");
    541 				exit(1);
    542 			}
    543 			if (waittime <= 1) {
    544 				fprintf(stderr,
    545 				    "traceroute6: wait must be >1 sec.\n");
    546 				exit(1);
    547 			}
    548 			break;
    549 		default:
    550 			usage();
    551 		}
    552 	argc -= optind;
    553 	argv += optind;
    554 
    555 	if (argc < 1 || argc > 2)
    556 		usage();
    557 
    558 #if 1
    559 	setvbuf(stdout, NULL, _IOLBF, BUFSIZ);
    560 #else
    561 	setlinebuf (stdout);
    562 #endif
    563 
    564 	memset(&hints, 0, sizeof(hints));
    565 	hints.ai_family = PF_INET6;
    566 	hints.ai_socktype = SOCK_RAW;
    567 	hints.ai_protocol = IPPROTO_ICMPV6;
    568 	hints.ai_flags = AI_CANONNAME;
    569 	error = getaddrinfo(*argv, NULL, &hints, &res);
    570 	if (error) {
    571 		fprintf(stderr,
    572 		    "traceroute6: %s\n", gai_strerror(error));
    573 		exit(1);
    574 	}
    575 	if (res->ai_addrlen != sizeof(Dst)) {
    576 		fprintf(stderr,
    577 		    "traceroute6: size of sockaddr mismatch\n");
    578 		exit(1);
    579 	}
    580 	memcpy(&Dst, res->ai_addr, res->ai_addrlen);
    581 	hostname = res->ai_canonname ? strdup(res->ai_canonname) : *argv;
    582 	if (!hostname) {
    583 		fprintf(stderr, "traceroute6: not enough core\n");
    584 		exit(1);
    585 	}
    586 
    587 	if (*++argv) {
    588 		ep = NULL;
    589 		datalen = strtoul(*argv, &ep, 0);
    590 		if (!*argv || *ep) {
    591 			fprintf(stderr,
    592 			    "traceroute6: invalid packet length.\n");
    593 			exit(1);
    594 		}
    595 	}
    596 	if (datalen < 0 || datalen >= MAXPACKET - sizeof(struct opacket)) {
    597 		fprintf(stderr,
    598 		    "traceroute6: packet size must be 0 <= s < %ld.\n",
    599 		    (long)(MAXPACKET - sizeof(struct opacket)));
    600 		exit(1);
    601 	}
    602 	datalen += sizeof(struct opacket);
    603 	outpacket = (struct opacket *)malloc((unsigned)datalen);
    604 	if (! outpacket) {
    605 		perror("malloc");
    606 		exit(1);
    607 	}
    608 	(void) bzero((char *)outpacket, datalen);
    609 
    610 	/* initialize msghdr for receiving packets */
    611 	rcviov[0].iov_base = (caddr_t)packet;
    612 	rcviov[0].iov_len = sizeof(packet);
    613 	rcvmhdr.msg_name = (caddr_t)&Rcv;
    614 	rcvmhdr.msg_namelen = sizeof(Rcv);
    615 	rcvmhdr.msg_iov = rcviov;
    616 	rcvmhdr.msg_iovlen = 1;
    617 	rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo))
    618 		+ CMSG_SPACE(sizeof(int));
    619 	if ((rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) {
    620 		fprintf(stderr, "traceroute6: malloc failed\n");
    621 		exit(1);
    622 	}
    623 	rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
    624 	rcvmhdr.msg_controllen = rcvcmsglen;
    625 
    626 	if (options & SO_DEBUG)
    627 		(void) setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
    628 		    (char *)&on, sizeof(on));
    629 	if (options & SO_DONTROUTE)
    630 		(void) setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
    631 		    (char *)&on, sizeof(on));
    632 #ifdef IPSEC
    633 #ifdef IPSEC_POLICY_IPSEC
    634 	/*
    635 	 * do not raise error even if setsockopt fails, kernel may have ipsec
    636 	 * turned off.
    637 	 */
    638 	if (setpolicy(rcvsock, "in bypass") < 0)
    639 		errx(1, "%s", ipsec_strerror());
    640 	if (setpolicy(rcvsock, "out bypass") < 0)
    641 		errx(1, "%s", ipsec_strerror());
    642 #else
    643     {
    644 	int level = IPSEC_LEVEL_NONE;
    645 
    646 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_ESP_TRANS_LEVEL, &level,
    647 	    sizeof(level));
    648 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_ESP_NETWORK_LEVEL, &level,
    649 	    sizeof(level));
    650 #ifdef IP_AUTH_TRANS_LEVEL
    651 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_TRANS_LEVEL, &level,
    652 	    sizeof(level));
    653 #else
    654 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_LEVEL, &level,
    655 	    sizeof(level));
    656 #endif
    657 #ifdef IP_AUTH_NETWORK_LEVEL
    658 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_NETWORK_LEVEL, &level,
    659 	    sizeof(level));
    660 #endif
    661     }
    662 #endif /*IPSEC_POLICY_IPSEC*/
    663 #endif /*IPSEC*/
    664 
    665 	/*
    666 	 * Send UDP
    667 	 */
    668 	if ((sndsock = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
    669 		perror("socket(SOCK_DGRAM)");
    670 		exit(5);
    671 	}
    672 #ifdef SO_SNDBUF
    673 	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen,
    674 	    sizeof(datalen)) < 0) {
    675 		perror("setsockopt(SO_SNDBUF)");
    676 		exit(6);
    677 	}
    678 #endif /* SO_SNDBUF */
    679 	if (options & SO_DEBUG)
    680 		(void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
    681 		    (char *)&on, sizeof(on));
    682 	if (options & SO_DONTROUTE)
    683 		(void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
    684 		    (char *)&on, sizeof(on));
    685 #ifdef USE_RFC2292BIS
    686 	if (rth) {/* XXX: there is no library to finalize the header... */
    687 		rth->ip6r_len = rth->ip6r_segleft * 2;
    688 		if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_RTHDR,
    689 		    (void *)rth, (rth->ip6r_len + 1) << 3)) {
    690 			fprintf(stderr, "setsockopt(IPV6_RTHDR): %s\n",
    691 			    strerror(errno));
    692 			exit(1);
    693 		}
    694 	}
    695 #else  /* old advanced API */
    696 	if (cmsg != NULL) {
    697 		inet6_rthdr_lasthop(cmsg, IPV6_RTHDR_LOOSE);
    698 		if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_PKTOPTIONS,
    699 		    rtbuf, cmsg->cmsg_len) < 0) {
    700 			fprintf(stderr, "setsockopt(IPV6_PKTOPTIONS): %s\n",
    701 			    strerror(errno));
    702 			exit(1);
    703 		}
    704 	}
    705 #endif /* USE_RFC2292BIS */
    706 #ifdef IPSEC
    707 #ifdef IPSEC_POLICY_IPSEC
    708 	/*
    709 	 * do not raise error even if setsockopt fails, kernel may have ipsec
    710 	 * turned off.
    711 	 */
    712 	if (setpolicy(sndsock, "in bypass") < 0)
    713 		errx(1, "%s", ipsec_strerror());
    714 	if (setpolicy(sndsock, "out bypass") < 0)
    715 		errx(1, "%s", ipsec_strerror());
    716 #else
    717     {
    718 	int level = IPSEC_LEVEL_BYPASS;
    719 
    720 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_ESP_TRANS_LEVEL, &level,
    721 	    sizeof(level));
    722 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_ESP_NETWORK_LEVEL, &level,
    723 	    sizeof(level));
    724 #ifdef IP_AUTH_TRANS_LEVEL
    725 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_TRANS_LEVEL, &level,
    726 	    sizeof(level));
    727 #else
    728 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_LEVEL, &level,
    729 	    sizeof(level));
    730 #endif
    731 #ifdef IP_AUTH_NETWORK_LEVEL
    732 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_NETWORK_LEVEL, &level,
    733 	    sizeof(level));
    734 #endif
    735     }
    736 #endif /*IPSEC_POLICY_IPSEC*/
    737 #endif /*IPSEC*/
    738 
    739 	/*
    740 	 * Source selection
    741 	 */
    742 	bzero(&Src, sizeof(Src));
    743 	if (source) {
    744 		struct addrinfo hints, *res;
    745 		int error;
    746 
    747 		memset(&hints, 0, sizeof(hints));
    748 		hints.ai_family = AF_INET6;
    749 		hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
    750 		hints.ai_flags = AI_NUMERICHOST;
    751 		error = getaddrinfo(source, "0", &hints, &res);
    752 		if (error) {
    753 			printf("traceroute6: %s: %s\n", source,
    754 			    gai_strerror(error));
    755 			exit(1);
    756 		}
    757 		if (res->ai_addrlen > sizeof(Src)) {
    758 			printf("traceroute6: %s: %s\n", source,
    759 			    gai_strerror(error));
    760 			exit(1);
    761 		}
    762 		memcpy(&Src, res->ai_addr, res->ai_addrlen);
    763 		freeaddrinfo(res);
    764 	} else {
    765 		struct sockaddr_in6 Nxt;
    766 		int dummy, len;
    767 
    768 		Nxt = Dst;
    769 		Nxt.sin6_port = htons(DUMMY_PORT);
    770 		if (cmsg != NULL)
    771 			bcopy(inet6_rthdr_getaddr(cmsg, 1), &Nxt.sin6_addr,
    772 			    sizeof(Nxt.sin6_addr));
    773 		if ((dummy = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
    774 			perror("socket");
    775 			exit(1);
    776 		}
    777 		if (connect(dummy, (struct sockaddr *)&Nxt, Nxt.sin6_len) < 0) {
    778 			perror("connect");
    779 			exit(1);
    780 		}
    781 		len = sizeof(Src);
    782 		if (getsockname(dummy, (struct sockaddr *)&Src, &len) < 0) {
    783 			perror("getsockname");
    784 			exit(1);
    785 		}
    786 		if (getnameinfo((struct sockaddr *)&Src, Src.sin6_len,
    787 		    src0, sizeof(src0), NULL, 0, NI_NUMERICHOST)) {
    788 			fprintf(stderr, "getnameinfo failed for source\n");
    789 			exit(1);
    790 		}
    791 		source = src0;
    792 		close(dummy);
    793 	}
    794 
    795 	Src.sin6_port = htons(0);
    796 	if (bind(sndsock, (struct sockaddr *)&Src, Src.sin6_len) < 0) {
    797 		perror("bind");
    798 		exit(1);
    799 	}
    800 
    801 	{
    802 		int len;
    803 
    804 		len = sizeof(Src);
    805 		if (getsockname(sndsock, (struct sockaddr *)&Src, &len) < 0) {
    806 			perror("getsockname");
    807 			exit(1);
    808 		}
    809 		srcport = ntohs(Src.sin6_port);
    810 	}
    811 
    812 	/*
    813 	 * Message to users
    814 	 */
    815 	if (getnameinfo((struct sockaddr *)&Dst, Dst.sin6_len, hbuf,
    816 	    sizeof(hbuf), NULL, 0, NI_NUMERICHOST))
    817 		strlcpy(hbuf, "(invalid)", sizeof(hbuf));
    818 	fprintf(stderr, "traceroute6");
    819 	fprintf(stderr, " to %s (%s)", hostname, hbuf);
    820 	if (source)
    821 		fprintf(stderr, " from %s", source);
    822 	fprintf(stderr, ", %d hops max, %d byte packets\n",
    823 	    max_hops, datalen);
    824 	(void) fflush(stderr);
    825 
    826 	if (first_hop > 1)
    827 		printf("Skipping %d intermediate hops\n", first_hop - 1);
    828 
    829 	/*
    830 	 * Main loop
    831 	 */
    832 	for (hops = first_hop; hops <= max_hops; ++hops) {
    833 		struct in6_addr lastaddr;
    834 		int got_there = 0;
    835 		int unreachable = 0;
    836 
    837 		printf("%2d ", hops);
    838 		bzero(&lastaddr, sizeof(lastaddr));
    839 		for (probe = 0; probe < nprobes; ++probe) {
    840 			int cc;
    841 			struct timeval t1, t2;
    842 			struct timezone tz;
    843 
    844 			(void) gettimeofday(&t1, &tz);
    845 			send_probe(++seq, hops);
    846 			while ((cc = wait_for_reply(rcvsock, &rcvmhdr))) {
    847 				(void) gettimeofday(&t2, &tz);
    848 				if ((i = packet_ok(&rcvmhdr, cc, seq))) {
    849 					if (! IN6_ARE_ADDR_EQUAL(&Rcv.sin6_addr,
    850 					    &lastaddr)) {
    851 						print(&rcvmhdr, cc);
    852 						lastaddr = Rcv.sin6_addr;
    853 					}
    854 					printf("  %g ms", deltaT(&t1, &t2));
    855 					switch (i - 1) {
    856 					case ICMP6_DST_UNREACH_NOROUTE:
    857 						++unreachable;
    858 						printf(" !N");
    859 						break;
    860 					case ICMP6_DST_UNREACH_ADMIN:
    861 						++unreachable;
    862 						printf(" !P");
    863 						break;
    864 					case ICMP6_DST_UNREACH_NOTNEIGHBOR:
    865 						++unreachable;
    866 						printf(" !S");
    867 						break;
    868 					case ICMP6_DST_UNREACH_ADDR:
    869 						++unreachable;
    870 						printf(" !A");
    871 						break;
    872 					case ICMP6_DST_UNREACH_NOPORT:
    873 						if (rcvhlim >= 0 &&
    874 						    rcvhlim <= 1)
    875 							printf(" !");
    876 						++got_there;
    877 						break;
    878 					}
    879 					break;
    880 				}
    881 			}
    882 			if (cc == 0)
    883 				printf(" *");
    884 			(void) fflush(stdout);
    885 		}
    886 		putchar('\n');
    887 		if (got_there ||
    888 		    (unreachable > 0 && unreachable >= ((nprobes + 1) / 2))) {
    889 			exit(0);
    890 		}
    891 	}
    892 
    893 	exit(0);
    894 }
    895 
    896 int
    897 wait_for_reply(sock, mhdr)
    898 	int sock;
    899 	struct msghdr *mhdr;
    900 {
    901 #ifdef HAVE_POLL
    902 	struct pollfd pfd[1];
    903 	int cc = 0;
    904 
    905 	pfd[0].fd = sock;
    906 	pfd[0].events = POLLIN;
    907 	pfd[0].revents = 0;
    908 
    909 	if (poll(pfd, 1, waittime * 1000) > 0)
    910 		cc = recvmsg(rcvsock, mhdr, 0);
    911 
    912 	return(cc);
    913 #else
    914 	fd_set *fdsp;
    915 	struct timeval wait;
    916 	int cc = 0, fdsn;
    917 
    918 	fdsn = howmany(sock + 1, NFDBITS) * sizeof(fd_mask);
    919 	if ((fdsp = (fd_set *)malloc(fdsn)) == NULL)
    920 		err(1, "malloc");
    921 	memset(fdsp, 0, fdsn);
    922 	FD_SET(sock, fdsp);
    923 	wait.tv_sec = waittime; wait.tv_usec = 0;
    924 
    925 	if (select(sock+1, fdsp, (fd_set *)0, (fd_set *)0, &wait) > 0)
    926 		cc = recvmsg(rcvsock, mhdr, 0);
    927 
    928 	free(fdsp);
    929 	return(cc);
    930 #endif
    931 }
    932 
    933 #ifdef IPSEC
    934 #ifdef IPSEC_POLICY_IPSEC
    935 int
    936 setpolicy(so, policy)
    937 	int so;
    938 	char *policy;
    939 {
    940 	char *buf;
    941 
    942 	buf = ipsec_set_policy(policy, strlen(policy));
    943 	if (buf == NULL) {
    944 		warnx("%s", ipsec_strerror());
    945 		return -1;
    946 	}
    947 	(void)setsockopt(so, IPPROTO_IPV6, IPV6_IPSEC_POLICY,
    948 	    buf, ipsec_get_policylen(buf));
    949 
    950 	free(buf);
    951 
    952 	return 0;
    953 }
    954 #endif
    955 #endif
    956 
    957 void
    958 send_probe(seq, hops)
    959 	int seq, hops;
    960 {
    961 	struct opacket *op = outpacket;
    962 	int i;
    963 
    964 	if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
    965 	    (char *)&hops, sizeof(hops)) < 0) {
    966 		perror("setsockopt IPV6_UNICAST_HOPS");
    967 	}
    968 
    969 	Dst.sin6_port = htons(port + seq);
    970 
    971 	op->seq = seq;
    972 	op->hops = hops;
    973 	(void) gettimeofday(&op->tv, &tz);
    974 
    975 	i = sendto(sndsock, (char *)outpacket, datalen , 0,
    976 	    (struct sockaddr *)&Dst, Dst.sin6_len);
    977 	if (i < 0 || i != datalen)  {
    978 		if (i<0)
    979 			perror("sendto");
    980 		printf("traceroute6: wrote %s %d chars, ret=%d\n",
    981 		    hostname, datalen, i);
    982 		(void) fflush(stdout);
    983 	}
    984 }
    985 
    986 int
    987 get_hoplim(mhdr)
    988 	struct msghdr *mhdr;
    989 {
    990 	struct cmsghdr *cm;
    991 
    992 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
    993 	    cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
    994 		if (cm->cmsg_level == IPPROTO_IPV6 &&
    995 		    cm->cmsg_type == IPV6_HOPLIMIT &&
    996 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
    997 			return(*(int *)CMSG_DATA(cm));
    998 	}
    999 
   1000 	return(-1);
   1001 }
   1002 
   1003 double
   1004 deltaT(t1p, t2p)
   1005 	struct timeval *t1p, *t2p;
   1006 {
   1007 	register double dt;
   1008 
   1009 	dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
   1010 	    (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
   1011 	return (dt);
   1012 }
   1013 
   1014 /*
   1015  * Convert an ICMP "type" field to a printable string.
   1016  */
   1017 char *
   1018 pr_type(t0)
   1019 	int t0;
   1020 {
   1021 	u_char t = t0 & 0xff;
   1022 	char *cp;
   1023 
   1024 	switch (t) {
   1025 	case ICMP6_DST_UNREACH:
   1026 		cp = "Destination Unreachable";
   1027 		break;
   1028 	case ICMP6_PACKET_TOO_BIG:
   1029 		cp = "Packet Too Big";
   1030 		break;
   1031 	case ICMP6_TIME_EXCEEDED:
   1032 		cp = "Time Exceeded";
   1033 		break;
   1034 	case ICMP6_PARAM_PROB:
   1035 		cp = "Parameter Problem";
   1036 		break;
   1037 	case ICMP6_ECHO_REQUEST:
   1038 		cp = "Echo Request";
   1039 		break;
   1040 	case ICMP6_ECHO_REPLY:
   1041 		cp = "Echo Reply";
   1042 		break;
   1043 	case ICMP6_MEMBERSHIP_QUERY:
   1044 		cp = "Group Membership Query";
   1045 		break;
   1046 	case ICMP6_MEMBERSHIP_REPORT:
   1047 		cp = "Group Membership Report";
   1048 		break;
   1049 	case ICMP6_MEMBERSHIP_REDUCTION:
   1050 		cp = "Group Membership Reduction";
   1051 		break;
   1052 	case ND_ROUTER_SOLICIT:
   1053 		cp = "Router Solicitation";
   1054 		break;
   1055 	case ND_ROUTER_ADVERT:
   1056 		cp = "Router Advertisement";
   1057 		break;
   1058 	case ND_NEIGHBOR_SOLICIT:
   1059 		cp = "Neighbor Solicitation";
   1060 		break;
   1061 	case ND_NEIGHBOR_ADVERT:
   1062 		cp = "Neighbor Advertisement";
   1063 		break;
   1064 	case ND_REDIRECT:
   1065 		cp = "Redirect";
   1066 		break;
   1067 	default:
   1068 		cp = "Unknown";
   1069 		break;
   1070 	}
   1071 	return cp;
   1072 }
   1073 
   1074 int
   1075 packet_ok(mhdr, cc, seq)
   1076 	struct msghdr *mhdr;
   1077 	int cc;
   1078 	int seq;
   1079 {
   1080 	register struct icmp6_hdr *icp;
   1081 	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
   1082 	u_char type, code;
   1083 	char *buf = (char *)mhdr->msg_iov[0].iov_base;
   1084 	struct cmsghdr *cm;
   1085 	int *hlimp;
   1086 	char hbuf[NI_MAXHOST];
   1087 
   1088 #ifdef OLDRAWSOCKET
   1089 	int hlen;
   1090 	struct ip6_hdr *ip;
   1091 #endif
   1092 
   1093 #ifdef OLDRAWSOCKET
   1094 	ip = (struct ip6_hdr *) buf;
   1095 	hlen = sizeof(struct ip6_hdr);
   1096 	if (cc < hlen + sizeof(struct icmp6_hdr)) {
   1097 		if (verbose) {
   1098 			if (getnameinfo((struct sockaddr *)from, from->sin6_len,
   1099 			    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
   1100 				strlcpy(hbuf, "invalid", sizeof(hbuf));
   1101 			printf("packet too short (%d bytes) from %s\n", cc,
   1102 			    hbuf);
   1103 		}
   1104 		return (0);
   1105 	}
   1106 	cc -= hlen;
   1107 	icp = (struct icmp6_hdr *)(buf + hlen);
   1108 #else
   1109 	if (cc < sizeof(struct icmp6_hdr)) {
   1110 		if (verbose) {
   1111 			if (getnameinfo((struct sockaddr *)from, from->sin6_len,
   1112 			    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
   1113 				strlcpy(hbuf, "invalid", sizeof(hbuf));
   1114 			printf("data too short (%d bytes) from %s\n", cc, hbuf);
   1115 		}
   1116 		return(0);
   1117 	}
   1118 	icp = (struct icmp6_hdr *)buf;
   1119 #endif
   1120 	/* get optional information via advanced API */
   1121 	rcvpktinfo = NULL;
   1122 	hlimp = NULL;
   1123 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
   1124 	    cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
   1125 		if (cm->cmsg_level == IPPROTO_IPV6 &&
   1126 		    cm->cmsg_type == IPV6_PKTINFO &&
   1127 		    cm->cmsg_len ==
   1128 		    CMSG_LEN(sizeof(struct in6_pktinfo)))
   1129 			rcvpktinfo = (struct in6_pktinfo *)(CMSG_DATA(cm));
   1130 
   1131 		if (cm->cmsg_level == IPPROTO_IPV6 &&
   1132 		    cm->cmsg_type == IPV6_HOPLIMIT &&
   1133 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
   1134 			hlimp = (int *)CMSG_DATA(cm);
   1135 	}
   1136 	if (rcvpktinfo == NULL || hlimp == NULL) {
   1137 		warnx("failed to get received hop limit or packet info");
   1138 #if 0
   1139 		return(0);
   1140 #else
   1141 		rcvhlim = 0;	/*XXX*/
   1142 #endif
   1143 	}
   1144 	else
   1145 		rcvhlim = *hlimp;
   1146 
   1147 	type = icp->icmp6_type;
   1148 	code = icp->icmp6_code;
   1149 	if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
   1150 	 || type == ICMP6_DST_UNREACH) {
   1151 		struct ip6_hdr *hip;
   1152 		struct udphdr *up;
   1153 
   1154 		hip = (struct ip6_hdr *)(icp + 1);
   1155 		if ((up = get_udphdr(hip, (u_char *)(buf + cc))) == NULL) {
   1156 			if (verbose)
   1157 				warnx("failed to get upper layer header");
   1158 			return(0);
   1159 		}
   1160 		if (up->uh_sport == htons(srcport) &&
   1161 		    up->uh_dport == htons(port + seq))
   1162 			return (type == ICMP6_TIME_EXCEEDED ? -1 : code + 1);
   1163 	}
   1164 	if (verbose) {
   1165 		int i;
   1166 		u_int8_t *p;
   1167 		char sbuf[NI_MAXHOST+1], dbuf[INET6_ADDRSTRLEN];
   1168 
   1169 		if (getnameinfo((struct sockaddr *)from, from->sin6_len,
   1170 		    sbuf, sizeof(sbuf), NULL, 0, NI_NUMERICHOST) != 0)
   1171 			strlcpy(sbuf, "invalid", sizeof(sbuf));
   1172 		printf("\n%d bytes from %s to %s", cc, sbuf,
   1173 		    rcvpktinfo ? inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
   1174 		    dbuf, sizeof(dbuf)) : "?");
   1175 		printf(": icmp type %d (%s) code %d\n", type, pr_type(type),
   1176 		    icp->icmp6_code);
   1177 		p = (u_int8_t *)(icp + 1);
   1178 #define WIDTH	16
   1179 		for (i = 0; i < cc; i++) {
   1180 			if (i % WIDTH == 0)
   1181 				printf("%04x:", i);
   1182 			if (i % 4 == 0)
   1183 				printf(" ");
   1184 			printf("%02x", p[i]);
   1185 			if (i % WIDTH == WIDTH - 1)
   1186 				printf("\n");
   1187 		}
   1188 		if (cc % WIDTH != 0)
   1189 			printf("\n");
   1190 	}
   1191 	return(0);
   1192 }
   1193 
   1194 /*
   1195  * Increment pointer until find the UDP header.
   1196  */
   1197 struct udphdr *
   1198 get_udphdr(ip6, lim)
   1199 	struct ip6_hdr *ip6;
   1200 	u_char *lim;
   1201 {
   1202 	u_char *cp = (u_char *)ip6, nh;
   1203 	int hlen;
   1204 
   1205 	if (cp + sizeof(*ip6) >= lim)
   1206 		return(NULL);
   1207 
   1208 	nh = ip6->ip6_nxt;
   1209 	cp += sizeof(struct ip6_hdr);
   1210 
   1211 	while (lim - cp >= 8) {
   1212 		switch (nh) {
   1213 		case IPPROTO_ESP:
   1214 		case IPPROTO_TCP:
   1215 		case IPPROTO_ICMPV6:
   1216 			 return(NULL);
   1217 		case IPPROTO_UDP:
   1218 			 return((struct udphdr *)cp);
   1219 		case IPPROTO_FRAGMENT:
   1220 			 hlen = sizeof(struct ip6_frag);
   1221 			 nh = ((struct ip6_frag *)cp)->ip6f_nxt;
   1222 			 break;
   1223 		case IPPROTO_AH:
   1224 			 hlen = (((struct ip6_ext *)cp)->ip6e_len + 2) << 2;
   1225 			 nh = ((struct ip6_ext *)cp)->ip6e_nxt;
   1226 			 break;
   1227 		default:
   1228 			  hlen = (((struct ip6_ext *)cp)->ip6e_len + 1) << 3;
   1229 			  nh = ((struct ip6_ext *)cp)->ip6e_nxt;
   1230 			  break;
   1231 		}
   1232 
   1233 		cp += hlen;
   1234 	}
   1235 
   1236 	return(NULL);
   1237 }
   1238 
   1239 void
   1240 print(mhdr, cc)
   1241 	struct msghdr *mhdr;
   1242 	int cc;
   1243 {
   1244 	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
   1245 	char hbuf[NI_MAXHOST];
   1246 
   1247 	if (getnameinfo((struct sockaddr *)from, from->sin6_len,
   1248 	    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
   1249 		strlcpy(hbuf, "invalid", sizeof(hbuf));
   1250 	if (nflag)
   1251 		printf(" %s", hbuf);
   1252 	else if (lflag)
   1253 		printf(" %s (%s)", inetname((struct sockaddr *)from), hbuf);
   1254 	else
   1255 		printf(" %s", inetname((struct sockaddr *)from));
   1256 
   1257 	if (verbose) {
   1258 #ifdef OLDRAWSOCKET
   1259 		printf(" %d bytes to %s", cc,
   1260 		    rcvpktinfo ? inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
   1261 		    hbuf, sizeof(hbuf)) : "?");
   1262 #else
   1263 		printf(" %d bytes of data to %s", cc,
   1264 		    rcvpktinfo ?  inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
   1265 		    hbuf, sizeof(hbuf)) : "?");
   1266 #endif
   1267 	}
   1268 }
   1269 
   1270 /*
   1271  * Subtract 2 timeval structs:  out = out - in.
   1272  * Out is assumed to be >= in.
   1273  */
   1274 void
   1275 tvsub(out, in)
   1276 	register struct timeval *out, *in;
   1277 {
   1278 
   1279 	if ((out->tv_usec -= in->tv_usec) < 0)   {
   1280 		out->tv_sec--;
   1281 		out->tv_usec += 1000000;
   1282 	}
   1283 	out->tv_sec -= in->tv_sec;
   1284 }
   1285 
   1286 /*
   1287  * Construct an Internet address representation.
   1288  * If the nflag has been supplied, give
   1289  * numeric value, otherwise try for symbolic name.
   1290  */
   1291 const char *
   1292 inetname(sa)
   1293 	struct sockaddr *sa;
   1294 {
   1295 	register char *cp;
   1296 	static char line[NI_MAXHOST];
   1297 	static char domain[MAXHOSTNAMELEN + 1];
   1298 	static int first = 1;
   1299 
   1300 	if (first && !nflag) {
   1301 		first = 0;
   1302 		if (gethostname(domain, sizeof(domain)) == 0 &&
   1303 		    (cp = strchr(domain, '.')))
   1304 			(void) strlcpy(domain, cp + 1, sizeof(domain));
   1305 		else
   1306 			domain[0] = 0;
   1307 	}
   1308 	cp = NULL;
   1309 	if (!nflag) {
   1310 		if (getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
   1311 		    NI_NAMEREQD) == 0) {
   1312 			if ((cp = strchr(line, '.')) &&
   1313 			    !strcmp(cp + 1, domain))
   1314 				*cp = 0;
   1315 			cp = line;
   1316 		}
   1317 	}
   1318 	if (cp)
   1319 		return cp;
   1320 
   1321 	if (getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
   1322 	    NI_NUMERICHOST) != 0)
   1323 		strlcpy(line, "invalid", sizeof(line));
   1324 	return line;
   1325 }
   1326 
   1327 void
   1328 usage()
   1329 {
   1330 
   1331 	fprintf(stderr,
   1332 "usage: traceroute6 [-dlnrv] [-f firsthop] [-g gateway] [-m hoplimit] [-p port]\n"
   1333 "       [-q probes] [-s src] [-w waittime] target [datalen]\n");
   1334 	exit(1);
   1335 }
   1336