xref: /netbsd-src/usr.sbin/traceroute6/traceroute6.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: traceroute6.c,v 1.17 2001/05/07 14:00:23 kleink Exp $	*/
2 /*	$KAME: traceroute6.c,v 1.39 2000/12/22 15:11:05 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 1.17 2001/05/07 14:00:23 kleink 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@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 
264 #include <netinet/in.h>
265 
266 #include <arpa/inet.h>
267 
268 #include <netdb.h>
269 #include <stdio.h>
270 #include <err.h>
271 #ifdef HAVE_POLL
272 #include <poll.h>
273 #endif
274 #include <errno.h>
275 #include <stdlib.h>
276 #include <string.h>
277 #include <unistd.h>
278 
279 #include <netinet/ip6.h>
280 #include <netinet/icmp6.h>
281 #include <netinet/udp.h>
282 
283 #ifdef IPSEC
284 #include <net/route.h>
285 #include <netinet6/ipsec.h>
286 #endif
287 
288 #define DUMMY_PORT 10010
289 
290 #define	MAXPACKET	65535	/* max ip packet size */
291 
292 #ifndef FD_SET
293 #define NFDBITS         (8*sizeof(fd_set))
294 #define FD_SETSIZE      NFDBITS
295 #define FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
296 #define FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
297 #define FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
298 #define FD_ZERO(p)      bzero((char *)(p), sizeof(*(p)))
299 #endif
300 
301 #define Fprintf (void)fprintf
302 #define Sprintf (void)sprintf
303 #define Printf (void)printf
304 
305 #ifndef HAVE_GETIPNODEBYNAME
306 #define getipnodebyname(x, y, z, u)	gethostbyname2((x), (y))
307 #define freehostent(x)
308 #endif
309 
310 /*
311  * format of a (udp) probe packet.
312  */
313 struct opacket {
314 	u_char seq;		/* sequence number of this packet */
315 	u_char hops;		/* hop limit of the packet */
316 	struct timeval tv;	/* time packet left */
317 };
318 
319 u_char	packet[512];		/* last inbound (icmp) packet */
320 struct opacket	*outpacket;	/* last output (udp) packet */
321 
322 int	main __P((int, char *[]));
323 int	wait_for_reply __P((int, struct msghdr *));
324 #ifdef IPSEC
325 #ifdef IPSEC_POLICY_IPSEC
326 int	setpolicy __P((int so, char *policy));
327 #endif
328 #endif
329 void	send_probe __P((int, int));
330 struct udphdr *get_udphdr __P((struct ip6_hdr *, u_char *));
331 int	get_hoplim __P((struct msghdr *));
332 double	deltaT __P((struct timeval *, struct timeval *));
333 char	*pr_type __P((int));
334 int	packet_ok __P((struct msghdr *, int, int));
335 void	print __P((struct msghdr *, int));
336 void	tvsub __P((struct timeval *, struct timeval *));
337 const char *inetname __P((struct sockaddr *));
338 void	usage __P((void));
339 
340 int rcvsock;			/* receive (icmp) socket file descriptor */
341 int sndsock;			/* send (udp) socket file descriptor */
342 struct timezone tz;		/* leftover */
343 
344 struct msghdr rcvmhdr;
345 struct iovec rcviov[2];
346 int rcvhlim;
347 struct in6_pktinfo *rcvpktinfo;
348 
349 struct sockaddr_in6 Src, Dst, Rcv;
350 int datalen;			/* How much data */
351 /* XXX: 2064 = 127(max hops in type 0 rthdr) * sizeof(ip6_hdr) + 16(margin) */
352 char rtbuf[2064];
353 #ifdef USE_RFC2292BIS
354 struct ip6_rthdr *rth;
355 #endif
356 struct cmsghdr *cmsg;
357 
358 char *source = 0;
359 char *hostname;
360 
361 int nprobes = 3;
362 int first_hop = 1;
363 int max_hops = 30;
364 u_short ident;
365 u_short port = 32768+666;	/* start udp dest port # for probe packets */
366 int options;			/* socket options */
367 int verbose;
368 int waittime = 5;		/* time to wait for response (in seconds) */
369 int nflag;			/* print addresses numerically */
370 int lflag;			/* print both numerical address & hostname */
371 
372 #ifdef KAME_SCOPEID
373 const int niflag = NI_WITHSCOPEID;
374 #else
375 const int niflag = 0;
376 #endif
377 
378 int
379 main(argc, argv)
380 	int argc;
381 	char *argv[];
382 {
383 	struct hostent *hp;
384 	int error;
385 	struct addrinfo hints, *res;
386 	int ch, i, on, probe, seq, hops, rcvcmsglen;
387 	static u_char *rcvcmsgbuf;
388 	char hbuf[NI_MAXHOST], src0[NI_MAXHOST];
389 	char *ep;
390 
391 	/*
392 	 * Receive ICMP
393 	 */
394 	if ((rcvsock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
395 		perror("socket(ICMPv6)");
396 		exit(5);
397 	}
398 
399 	/* revoke privs */
400 	seteuid(getuid());
401 	setuid(getuid());
402 
403 	/* set a minimum set of socket options */
404 	on = 1;
405 	/* specify to tell receiving interface */
406 #ifdef IPV6_RECVPKTINFO
407 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
408 		       sizeof(on)) < 0)
409 		err(1, "setsockopt(IPV6_RECVPKTINFO)");
410 #else  /* old adv. API */
411 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
412 		       sizeof(on)) < 0)
413 		err(1, "setsockopt(IPV6_PKTINFO)");
414 #endif
415 
416 	/* specify to tell value of hoplimit field of received IP6 hdr */
417 #ifdef IPV6_RECVHOPLIMIT
418 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
419 		       sizeof(on)) < 0)
420 		err(1, "setsockopt(IPV6_RECVHOPLIMIT)");
421 #else  /* old adv. API */
422 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
423 		       sizeof(on)) < 0)
424 		err(1, "setsockopt(IPV6_HOPLIMIT)");
425 #endif
426 
427 	seq = 0;
428 
429 	while ((ch = getopt(argc, argv, "df:g:lm:np:q:rs:w:v")) != -1)
430 		switch(ch) {
431 		case 'd':
432 			options |= SO_DEBUG;
433 			break;
434 		case 'f':
435 			ep = NULL;
436 			first_hop = strtoul(optarg, &ep, 0);
437 			if (!*argv || *ep) {
438 				Fprintf(stderr,
439 				    "traceroute6: invalid min hoplimit.\n");
440 				exit(1);
441 			}
442 			if (first_hop > max_hops) {
443 				Fprintf(stderr,
444 				    "traceroute6: min hoplimit must be <= %d.\n", max_hops);
445 				exit(1);
446 			}
447 			break;
448 		case 'g':
449 			hp = getipnodebyname(optarg, AF_INET6, 0, &h_errno);
450 			if (hp == NULL) {
451 				Fprintf(stderr,
452 				    "traceroute6: unknown host %s\n", optarg);
453 				exit(1);
454 			}
455 #ifdef USE_RFC2292BIS
456 			if (rth == NULL) {
457 				/*
458 				 * XXX: We can't detect the number of
459 				 * intermediate nodes yet.
460 				 */
461 				if ((rth = inet6_rth_init((void *)rtbuf,
462 							 sizeof(rtbuf),
463 							 IPV6_RTHDR_TYPE_0,
464 							 0)) == NULL) {
465 					Fprintf(stderr,
466 						"inet6_rth_init failed.\n");
467 					exit(1);
468 				}
469 			}
470 			if (inet6_rth_add((void *)rth,
471 					  (struct in6_addr *)hp->h_addr)) {
472 				Fprintf(stderr,
473 					"inet6_rth_add failed for %s\n",
474 					optarg);
475 				exit(1);
476 			}
477 #else  /* old advanced API */
478 			if (cmsg == NULL)
479 				cmsg = inet6_rthdr_init(rtbuf, IPV6_RTHDR_TYPE_0);
480 			inet6_rthdr_add(cmsg, (struct in6_addr *)hp->h_addr, IPV6_RTHDR_LOOSE);
481 #endif
482 			freehostent(hp);
483 			break;
484 		case 'l':
485 			lflag++;
486 			break;
487 		case 'm':
488 			ep = NULL;
489 			max_hops = strtoul(optarg, &ep, 0);
490 			if (!*argv || *ep) {
491 				Fprintf(stderr,
492 				    "traceroute6: invalid max hoplimit.\n");
493 				exit(1);
494 			}
495 			if (max_hops < first_hop) {
496 				Fprintf(stderr,
497 				    "traceroute6: max hoplimit must be >= %d.\n", first_hop);
498 				exit(1);
499 			}
500 			break;
501 		case 'n':
502 			nflag++;
503 			break;
504 		case 'p':
505 			ep = NULL;
506 			port = strtoul(optarg, &ep, 0);
507 			if (!*argv || *ep) {
508 				Fprintf(stderr,
509 				    "traceroute6: port.\n");
510 				exit(1);
511 			}
512 			if (port < 1) {
513 				Fprintf(stderr,
514 				    "traceroute6: port must be >0.\n");
515 				exit(1);
516 			}
517 			break;
518 		case 'q':
519 			ep = NULL;
520 			nprobes = strtoul(optarg, &ep, 0);
521 			if (!*argv || *ep) {
522 				Fprintf(stderr,
523 				    "traceroute6: invalid nprobes.\n");
524 				exit(1);
525 			}
526 			if (nprobes < 1) {
527 				Fprintf(stderr,
528 				    "traceroute6: nprobes must be >0.\n");
529 				exit(1);
530 			}
531 			break;
532 		case 'r':
533 			options |= SO_DONTROUTE;
534 			break;
535 		case 's':
536 			/*
537 			 * set the ip source address of the outbound
538 			 * probe (e.g., on a multi-homed host).
539 			 */
540 			source = optarg;
541 			break;
542 		case 'v':
543 			verbose++;
544 			break;
545 		case 'w':
546 			ep = NULL;
547 			waittime = strtoul(optarg, &ep, 0);
548 			if (!*argv || *ep) {
549 				Fprintf(stderr,
550 				    "traceroute6: invalid wait time.\n");
551 				exit(1);
552 			}
553 			if (waittime <= 1) {
554 				Fprintf(stderr,
555 				    "traceroute6: wait must be >1 sec.\n");
556 				exit(1);
557 			}
558 			break;
559 		default:
560 			usage();
561 		}
562 	argc -= optind;
563 	argv += optind;
564 
565 	if (argc < 1 || argc > 2)
566 		usage();
567 
568 #if 1
569 	setvbuf(stdout, NULL, _IOLBF, BUFSIZ);
570 #else
571 	setlinebuf (stdout);
572 #endif
573 
574 	memset(&hints, 0, sizeof(hints));
575 	hints.ai_family = PF_INET6;
576 	hints.ai_socktype = SOCK_RAW;
577 	hints.ai_protocol = IPPROTO_ICMPV6;
578 	hints.ai_flags = AI_CANONNAME;
579 	error = getaddrinfo(*argv, NULL, &hints, &res);
580 	if (error) {
581 		(void)fprintf(stderr,
582 			      "traceroute6: %s\n", gai_strerror(error));
583 		exit(1);
584 	}
585 	if (res->ai_addrlen != sizeof(Dst)) {
586 		(void)fprintf(stderr,
587 			      "traceroute6: size of sockaddr mismatch\n");
588 		exit(1);
589 	}
590 	memcpy(&Dst, res->ai_addr, res->ai_addrlen);
591 	hostname = res->ai_canonname ? strdup(res->ai_canonname) : *argv;
592 	if (!hostname) {
593 		(void)fprintf(stderr, "traceroute6: not enhough core\n");
594 		exit(1);
595 	}
596 
597 	if (*++argv) {
598 		ep = NULL;
599 		datalen = strtoul(*argv, &ep, 0);
600 		if (!*argv || *ep) {
601 			Fprintf(stderr,
602 			    "traceroute6: invalid packet length.\n");
603 			exit(1);
604 		}
605 	}
606 	if (datalen < 0 || datalen >= MAXPACKET - sizeof(struct opacket)) {
607 		Fprintf(stderr,
608 		    "traceroute6: packet size must be 0 <= s < %ld.\n",
609 		    (long)(MAXPACKET - sizeof(struct opacket)));
610 		exit(1);
611 	}
612 	datalen += sizeof(struct opacket);
613 	outpacket = (struct opacket *)malloc((unsigned)datalen);
614 	if (! outpacket) {
615 		perror("malloc");
616 		exit(1);
617 	}
618 	(void) bzero((char *)outpacket, datalen);
619 
620 	/* initialize msghdr for receiving packets */
621 	rcviov[0].iov_base = (caddr_t)packet;
622 	rcviov[0].iov_len = sizeof(packet);
623 	rcvmhdr.msg_name = (caddr_t)&Rcv;
624 	rcvmhdr.msg_namelen = sizeof(Rcv);
625 	rcvmhdr.msg_iov = rcviov;
626 	rcvmhdr.msg_iovlen = 1;
627 	rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo))
628 		+ CMSG_SPACE(sizeof(int));
629 	if ((rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) {
630 		Fprintf(stderr, "traceroute6: malloc failed\n");
631 		exit(1);
632 	}
633 	rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
634 	rcvmhdr.msg_controllen = rcvcmsglen;
635 
636 	if (options & SO_DEBUG)
637 		(void) setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
638 				  (char *)&on, sizeof(on));
639 	if (options & SO_DONTROUTE)
640 		(void) setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
641 				  (char *)&on, sizeof(on));
642 #ifdef IPSEC
643 #ifdef IPSEC_POLICY_IPSEC
644 	/*
645 	 * do not raise error even if setsockopt fails, kernel may have ipsec
646 	 * turned off.
647 	 */
648 	if (setpolicy(rcvsock, "in bypass") < 0)
649 		errx(1, "%s", ipsec_strerror());
650 	if (setpolicy(rcvsock, "out bypass") < 0)
651 		errx(1, "%s", ipsec_strerror());
652 #else
653     {
654 	int level = IPSEC_LEVEL_NONE;
655 
656 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_ESP_TRANS_LEVEL, &level,
657 		sizeof(level));
658 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_ESP_NETWORK_LEVEL, &level,
659 		sizeof(level));
660 #ifdef IP_AUTH_TRANS_LEVEL
661 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_TRANS_LEVEL, &level,
662 		sizeof(level));
663 #else
664 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_LEVEL, &level,
665 		sizeof(level));
666 #endif
667 #ifdef IP_AUTH_NETWORK_LEVEL
668 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_NETWORK_LEVEL, &level,
669 		sizeof(level));
670 #endif
671     }
672 #endif /*IPSEC_POLICY_IPSEC*/
673 #endif /*IPSEC*/
674 
675 	/*
676 	 * Send UDP
677 	 */
678 	if ((sndsock = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
679 		perror("socket(SOCK_DGRAM)");
680 		exit(5);
681 	}
682 #ifdef SO_SNDBUF
683 	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&datalen,
684 		       sizeof(datalen)) < 0) {
685 		perror("setsockopt(SO_SNDBUF)");
686 		exit(6);
687 	}
688 #endif /* SO_SNDBUF */
689 	if (options & SO_DEBUG)
690 		(void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
691 				  (char *)&on, sizeof(on));
692 	if (options & SO_DONTROUTE)
693 		(void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
694 				  (char *)&on, sizeof(on));
695 #ifdef USE_RFC2292BIS
696 	if (rth) {/* XXX: there is no library to finalize the header... */
697 		rth->ip6r_len = rth->ip6r_segleft * 2;
698 		if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_RTHDR,
699 			       (void *)rth, (rth->ip6r_len + 1) << 3)) {
700 			Fprintf(stderr, "setsockopt(IPV6_RTHDR): %s\n",
701 				strerror(errno));
702 			exit(1);
703 		}
704 	}
705 #else  /* old advanced API */
706 	if (cmsg != NULL) {
707 		inet6_rthdr_lasthop(cmsg, IPV6_RTHDR_LOOSE);
708 		if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_PKTOPTIONS,
709 			       rtbuf, cmsg->cmsg_len) < 0) {
710 			Fprintf(stderr, "setsockopt(IPV6_PKTOPTIONS): %s\n",
711 				strerror(errno));
712 			exit(1);
713 		}
714 	}
715 #endif /* USE_RFC2292BIS */
716 #ifdef IPSEC
717 #ifdef IPSEC_POLICY_IPSEC
718 	/*
719 	 * do not raise error even if setsockopt fails, kernel may have ipsec
720 	 * turned off.
721 	 */
722 	if (setpolicy(sndsock, "in bypass") < 0)
723 		errx(1, "%s", ipsec_strerror());
724 	if (setpolicy(sndsock, "out bypass") < 0)
725 		errx(1, "%s", ipsec_strerror());
726 #else
727     {
728 	int level = IPSEC_LEVEL_BYPASS;
729 
730 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_ESP_TRANS_LEVEL, &level,
731 		sizeof(level));
732 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_ESP_NETWORK_LEVEL, &level,
733 		sizeof(level));
734 #ifdef IP_AUTH_TRANS_LEVEL
735 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_TRANS_LEVEL, &level,
736 		sizeof(level));
737 #else
738 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_LEVEL, &level,
739 		sizeof(level));
740 #endif
741 #ifdef IP_AUTH_NETWORK_LEVEL
742 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_NETWORK_LEVEL, &level,
743 		sizeof(level));
744 #endif
745     }
746 #endif /*IPSEC_POLICY_IPSEC*/
747 #endif /*IPSEC*/
748 
749 	/*
750 	 * Source selection
751 	 */
752 	bzero(&Src, sizeof(Src));
753 	if (source) {
754 		struct addrinfo hints, *res;
755 		int error;
756 
757 		memset(&hints, 0, sizeof(hints));
758 		hints.ai_family = AF_INET6;
759 		hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
760 		hints.ai_flags = AI_NUMERICHOST;
761 		error = getaddrinfo(source, "0", &hints, &res);
762 		if (error) {
763 			Printf("traceroute6: %s: %s\n", source,
764 			    gai_strerror(error));
765 			exit(1);
766 		}
767 		if (res->ai_addrlen > sizeof(Src)) {
768 			Printf("traceroute6: %s: %s\n", source,
769 			    gai_strerror(error));
770 			exit(1);
771 		}
772 		memcpy(&Src, res->ai_addr, res->ai_addrlen);
773 		freeaddrinfo(res);
774 	} else {
775 		struct sockaddr_in6 Nxt;
776 		int dummy, len;
777 
778 		Nxt = Dst;
779 		Nxt.sin6_port = htons(DUMMY_PORT);
780 		if (cmsg != NULL)
781 			bcopy(inet6_rthdr_getaddr(cmsg, 1), &Nxt.sin6_addr,
782 			      sizeof(Nxt.sin6_addr));
783 		if ((dummy = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
784 			perror("socket");
785 			exit(1);
786 		}
787 		if (connect(dummy, (struct sockaddr *)&Nxt, Nxt.sin6_len) < 0) {
788 			perror("connect");
789 			exit(1);
790 		}
791 		len = sizeof(Src);
792 		if (getsockname(dummy, (struct sockaddr *)&Src, &len) < 0) {
793 			perror("getsockname");
794 			exit(1);
795 		}
796 		if (getnameinfo((struct sockaddr *)&Src, Src.sin6_len,
797 				src0, sizeof(src0), NULL, 0,
798 				NI_NUMERICHOST | niflag)) {
799 			Fprintf(stderr, "getnameinfo failed for source\n");
800 			exit(1);
801 		}
802 		source = src0;
803 		close(dummy);
804 	}
805 
806 #if 1
807 	ident = (getpid() & 0xffff) | 0x8000;
808 #else
809 	ident = 0;	/*let the kernel pick one*/
810 #endif
811 	Src.sin6_port = htons(ident);
812 	if (bind(sndsock, (struct sockaddr *)&Src, Src.sin6_len) < 0) {
813 		perror("bind");
814 		exit(1);
815 	}
816 
817 	if (ident == 0) {
818 		int len;
819 
820 		len = sizeof(Src);
821 		if (getsockname(sndsock, (struct sockaddr *)&Src, &i) < 0) {
822 			perror("getsockname");
823 			exit(1);
824 		}
825 		ident = ntohs(Src.sin6_port);
826 	}
827 
828 	/*
829 	 * Message to users
830 	 */
831 	if (getnameinfo((struct sockaddr *)&Dst, Dst.sin6_len, hbuf,
832 			sizeof(hbuf), NULL, 0, NI_NUMERICHOST | niflag))
833 		strlcpy(hbuf, "(invalid)", sizeof(hbuf));
834 	Fprintf(stderr, "traceroute6");
835 	Fprintf(stderr, " to %s (%s)", hostname, hbuf);
836 	if (source)
837 		Fprintf(stderr, " from %s", source);
838 	Fprintf(stderr,
839 		", %d hops max, %d byte packets\n",
840 		max_hops, datalen);
841 	(void) fflush(stderr);
842 
843 	if (first_hop > 1)
844 		Printf("Skipping %d intermediate hops\n", first_hop - 1);
845 
846 	/*
847 	 * Main loop
848 	 */
849 	for (hops = first_hop; hops <= max_hops; ++hops) {
850 		struct in6_addr lastaddr;
851 		int got_there = 0;
852 		int unreachable = 0;
853 
854 		Printf("%2d ", hops);
855 		bzero(&lastaddr, sizeof(lastaddr));
856 		for (probe = 0; probe < nprobes; ++probe) {
857 			int cc;
858 			struct timeval t1, t2;
859 			struct timezone tz;
860 
861 			(void) gettimeofday(&t1, &tz);
862 			send_probe(++seq, hops);
863 			while ((cc = wait_for_reply(rcvsock, &rcvmhdr))) {
864 				(void) gettimeofday(&t2, &tz);
865 				if ((i = packet_ok(&rcvmhdr, cc, seq))) {
866 					if (! IN6_ARE_ADDR_EQUAL(&Rcv.sin6_addr,
867 							    &lastaddr)) {
868 						print(&rcvmhdr, cc);
869 						lastaddr = Rcv.sin6_addr;
870 					}
871 					Printf("  %g ms", deltaT(&t1, &t2));
872 					switch(i - 1) {
873 					case ICMP6_DST_UNREACH_NOROUTE:
874 						++unreachable;
875 						Printf(" !N");
876 						break;
877 					case ICMP6_DST_UNREACH_ADMIN:
878 						++unreachable;
879 						Printf(" !P");
880 						break;
881 					case ICMP6_DST_UNREACH_NOTNEIGHBOR:
882 						++unreachable;
883 						Printf(" !S");
884 						break;
885 					case ICMP6_DST_UNREACH_ADDR:
886 						++unreachable;
887 						Printf(" !A");
888 						break;
889 					case ICMP6_DST_UNREACH_NOPORT:
890 						if (rcvhlim >= 0 &&
891 						    rcvhlim <= 1)
892 							Printf(" !");
893 						++got_there;
894 						break;
895 					}
896 					break;
897 				}
898 			}
899 			if (cc == 0)
900 				Printf(" *");
901 			(void) fflush(stdout);
902 		}
903 		putchar('\n');
904 		if (got_there ||
905 		    (unreachable > 0 && unreachable >= ((nprobes + 1) / 2))) {
906 			exit(0);
907 		}
908 	}
909 
910 	exit(0);
911 }
912 
913 int
914 wait_for_reply(sock, mhdr)
915 	int sock;
916 	struct msghdr *mhdr;
917 {
918 #ifdef HAVE_POLL
919 	struct pollfd pfd[1];
920 	int cc = 0;
921 
922 	pfd[0].fd = sock;
923 	pfd[0].events = POLLIN;
924 	pfd[0].revents = 0;
925 
926 	if (poll(pfd, 1, waittime * 1000) > 0)
927 		cc = recvmsg(rcvsock, mhdr, 0);
928 
929 	return(cc);
930 #else
931 	fd_set *fdsp;
932 	struct timeval wait;
933 	int cc = 0, fdsn;
934 
935 	fdsn = howmany(sock + 1, NFDBITS) * sizeof(fd_mask);
936 	if ((fdsp = (fd_set *)malloc(fdsn)) == NULL)
937 		err(1, "malloc");
938 	memset(fdsp, 0, fdsn);
939 	FD_SET(sock, fdsp);
940 	wait.tv_sec = waittime; wait.tv_usec = 0;
941 
942 	if (select(sock+1, fdsp, (fd_set *)0, (fd_set *)0, &wait) > 0)
943 		cc = recvmsg(rcvsock, mhdr, 0);
944 
945 	free(fdsp);
946 	return(cc);
947 #endif
948 }
949 
950 #ifdef IPSEC
951 #ifdef IPSEC_POLICY_IPSEC
952 int
953 setpolicy(so, policy)
954 	int so;
955 	char *policy;
956 {
957 	char *buf;
958 
959 	buf = ipsec_set_policy(policy, strlen(policy));
960 	if (buf == NULL) {
961 		warnx("%s", ipsec_strerror());
962 		return -1;
963 	}
964 	(void)setsockopt(so, IPPROTO_IPV6, IPV6_IPSEC_POLICY,
965 		buf, ipsec_get_policylen(buf));
966 
967 	free(buf);
968 
969 	return 0;
970 }
971 #endif
972 #endif
973 
974 void
975 send_probe(seq, hops)
976 	int seq, hops;
977 {
978 	struct opacket *op = outpacket;
979 	int i;
980 
981 	if(setsockopt(sndsock, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
982 		      (char *)&hops, sizeof(hops)) < 0) {
983 		perror("setsockopt IPV6_UNICAST_HOPS");
984 	}
985 
986 	Dst.sin6_port = htons(port + seq);
987 
988 	op->seq = seq;
989 	op->hops = hops;
990 	(void) gettimeofday(&op->tv, &tz);
991 
992 	i = sendto(sndsock, (char *)outpacket, datalen , 0,
993 		   (struct sockaddr *)&Dst, Dst.sin6_len);
994 	if (i < 0 || i != datalen)  {
995 		if (i<0)
996 			perror("sendto");
997 		Printf("traceroute6: wrote %s %d chars, ret=%d\n", hostname,
998 		       datalen, i);
999 		(void) fflush(stdout);
1000 	}
1001 }
1002 
1003 int
1004 get_hoplim(mhdr)
1005 	struct msghdr *mhdr;
1006 {
1007 	struct cmsghdr *cm;
1008 
1009 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
1010 	     cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
1011 		if (cm->cmsg_level == IPPROTO_IPV6 &&
1012 		    cm->cmsg_type == IPV6_HOPLIMIT &&
1013 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
1014 			return(*(int *)CMSG_DATA(cm));
1015 	}
1016 
1017 	return(-1);
1018 }
1019 
1020 double
1021 deltaT(t1p, t2p)
1022 	struct timeval *t1p, *t2p;
1023 {
1024 	register double dt;
1025 
1026 	dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
1027 	     (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
1028 	return (dt);
1029 }
1030 
1031 
1032 /*
1033  * Convert an ICMP "type" field to a printable string.
1034  */
1035 char *
1036 pr_type(t0)
1037 	int t0;
1038 {
1039 	u_char t = t0 & 0xff;
1040 	char *cp;
1041 
1042 	switch (t) {
1043 	case ICMP6_DST_UNREACH:
1044 		cp = "Destination Unreachable";
1045 		break;
1046 	case ICMP6_PACKET_TOO_BIG:
1047 		cp = "Pakcet Too Big";
1048 		break;
1049 	case ICMP6_TIME_EXCEEDED:
1050 		cp = "Time Exceeded";
1051 		break;
1052 	case ICMP6_PARAM_PROB:
1053 		cp = "Parameter Problem";
1054 		break;
1055 	case ICMP6_ECHO_REQUEST:
1056 		cp = "Echo Request";
1057 		break;
1058 	case ICMP6_ECHO_REPLY:
1059 		cp = "Echo Reply";
1060 		break;
1061 	case ICMP6_MEMBERSHIP_QUERY:
1062 		cp = "Group Membership Query";
1063 		break;
1064 	case ICMP6_MEMBERSHIP_REPORT:
1065 		cp = "Group Membership Report";
1066 		break;
1067 	case ICMP6_MEMBERSHIP_REDUCTION:
1068 		cp = "Group Membership Reduction";
1069 		break;
1070 	case ND_ROUTER_SOLICIT:
1071 		cp = "Router Solicitation";
1072 		break;
1073 	case ND_ROUTER_ADVERT:
1074 		cp = "Router Advertisement";
1075 		break;
1076 	case ND_NEIGHBOR_SOLICIT:
1077 		cp = "Neighbor Solicitation";
1078 		break;
1079 	case ND_NEIGHBOR_ADVERT:
1080 		cp = "Neighbor Advertisement";
1081 		break;
1082 	case ND_REDIRECT:
1083 		cp = "Redirect";
1084 		break;
1085 	default:
1086 		cp = "Unknown";
1087 		break;
1088 	}
1089 	return cp;
1090 }
1091 
1092 
1093 int
1094 packet_ok(mhdr, cc, seq)
1095 	struct msghdr *mhdr;
1096 	int cc;
1097 	int seq;
1098 {
1099 	register struct icmp6_hdr *icp;
1100 	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
1101 	u_char type, code;
1102 	char *buf = (char *)mhdr->msg_iov[0].iov_base;
1103 	struct cmsghdr *cm;
1104 	int *hlimp;
1105 	char hbuf[NI_MAXHOST];
1106 
1107 #ifdef OLDRAWSOCKET
1108 	int hlen;
1109 	struct ip6_hdr *ip;
1110 #endif
1111 
1112 #ifdef OLDRAWSOCKET
1113 	ip = (struct ip6_hdr *) buf;
1114 	hlen = sizeof(struct ip6_hdr);
1115 	if (cc < hlen + sizeof(struct icmp6_hdr)) {
1116 		if (verbose) {
1117 			if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1118 			    hbuf, sizeof(hbuf), NULL, 0,
1119 			    NI_NUMERICHOST | niflag) != 0)
1120 				strlcpy(hbuf, "invalid", sizeof(hbuf));
1121 			Printf("packet too short (%d bytes) from %s\n", cc,
1122 			    hbuf);
1123 		}
1124 		return (0);
1125 	}
1126 	cc -= hlen;
1127 	icp = (struct icmp6_hdr *)(buf + hlen);
1128 #else
1129 	if (cc < sizeof(struct icmp6_hdr)) {
1130 		if (verbose) {
1131 			if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1132 			    hbuf, sizeof(hbuf), NULL, 0,
1133 			    NI_NUMERICHOST | niflag) != 0)
1134 				strlcpy(hbuf, "invalid", sizeof(hbuf));
1135 			Printf("data too short (%d bytes) from %s\n", cc, hbuf);
1136 		}
1137 		return(0);
1138 	}
1139 	icp = (struct icmp6_hdr *)buf;
1140 #endif
1141 	/* get optional information via advanced API */
1142 	rcvpktinfo = NULL;
1143 	hlimp = NULL;
1144 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
1145 	     cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
1146 		if (cm->cmsg_level == IPPROTO_IPV6 &&
1147 		    cm->cmsg_type == IPV6_PKTINFO &&
1148 		    cm->cmsg_len ==
1149 		    CMSG_LEN(sizeof(struct in6_pktinfo)))
1150 			rcvpktinfo = (struct in6_pktinfo *)(CMSG_DATA(cm));
1151 
1152 		if (cm->cmsg_level == IPPROTO_IPV6 &&
1153 		    cm->cmsg_type == IPV6_HOPLIMIT &&
1154 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
1155 			hlimp = (int *)CMSG_DATA(cm);
1156 	}
1157 	if (rcvpktinfo == NULL || hlimp == NULL) {
1158 		warnx("failed to get received hop limit or packet info");
1159 #if 0
1160 		return(0);
1161 #else
1162 		rcvhlim = 0;	/*XXX*/
1163 #endif
1164 	}
1165 	else
1166 		rcvhlim = *hlimp;
1167 
1168 	type = icp->icmp6_type;
1169 	code = icp->icmp6_code;
1170 	if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
1171 	 || type == ICMP6_DST_UNREACH) {
1172 		struct ip6_hdr *hip;
1173 		struct udphdr *up;
1174 
1175 		hip = (struct ip6_hdr *)(icp + 1);
1176 		if ((up = get_udphdr(hip, (u_char *)(buf + cc))) == NULL) {
1177 			if (verbose)
1178 				warnx("failed to get upper layer header");
1179 			return(0);
1180 		}
1181 		if (up->uh_sport == htons(ident) &&
1182 		    up->uh_dport == htons(port+seq))
1183 			return (type == ICMP6_TIME_EXCEEDED ? -1 : code + 1);
1184 	}
1185 	if (verbose) {
1186 		int i;
1187 		u_int8_t *p;
1188 		char sbuf[NI_MAXHOST+1], dbuf[INET6_ADDRSTRLEN];
1189 
1190 		if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1191 		    sbuf, sizeof(sbuf), NULL, 0, NI_NUMERICHOST | niflag) != 0)
1192 			strlcpy(sbuf, "invalid", sizeof(hbuf));
1193 		Printf("\n%d bytes from %s to %s", cc, sbuf,
1194 		    rcvpktinfo ? inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
1195 					dbuf, sizeof(dbuf))
1196 			       : "?");
1197 		Printf(": icmp type %d (%s) code %d\n", type, pr_type(type),
1198 		       icp->icmp6_code);
1199 		p = (u_int8_t *)(icp + 1);
1200 #define WIDTH	16
1201 		for (i = 0; i < cc; i++) {
1202 			if (i % WIDTH == 0)
1203 				Printf("%04x:", i);
1204 			if (i % 4 == 0)
1205 				Printf(" ");
1206 			Printf("%02x", p[i]);
1207 			if (i % WIDTH == WIDTH - 1)
1208 				Printf("\n");
1209 		}
1210 		if (cc % WIDTH != 0)
1211 			Printf("\n");
1212 	}
1213 	return(0);
1214 }
1215 
1216 /*
1217  * Increment pointer until find the UDP header.
1218  */
1219 struct udphdr *
1220 get_udphdr(ip6, lim)
1221 	struct ip6_hdr *ip6;
1222 	u_char *lim;
1223 {
1224 	u_char *cp = (u_char *)ip6, nh;
1225 	int hlen;
1226 
1227 	if (cp + sizeof(*ip6) >= lim)
1228 		return(NULL);
1229 
1230 	nh = ip6->ip6_nxt;
1231 	cp += sizeof(struct ip6_hdr);
1232 
1233 	while(lim - cp >= 8) {
1234 		switch(nh) {
1235 		 case IPPROTO_ESP:
1236 		 case IPPROTO_TCP:
1237 		 case IPPROTO_ICMPV6:
1238 			 return(NULL);
1239 		 case IPPROTO_UDP:
1240 			 return((struct udphdr *)cp);
1241 		 case IPPROTO_FRAGMENT:
1242 			 hlen = sizeof(struct ip6_frag);
1243 			 nh = ((struct ip6_frag *)cp)->ip6f_nxt;
1244 			 break;
1245 		 case IPPROTO_AH:
1246 			 hlen = (((struct ip6_ext *)cp)->ip6e_len + 2) << 2;
1247 			 nh = ((struct ip6_ext *)cp)->ip6e_nxt;
1248 			 break;
1249 		  default:
1250 			  hlen = (((struct ip6_ext *)cp)->ip6e_len + 1) << 3;
1251 			  nh = ((struct ip6_ext *)cp)->ip6e_nxt;
1252 			  break;
1253 		}
1254 
1255 		cp += hlen;
1256 	}
1257 
1258 	return(NULL);
1259 }
1260 
1261 void
1262 print(mhdr, cc)
1263 	struct msghdr *mhdr;
1264 	int cc;
1265 {
1266 	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
1267 	char hbuf[NI_MAXHOST];
1268 
1269 	if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1270 	    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST | niflag) != 0)
1271 		strlcpy(hbuf, "invalid", sizeof(hbuf));
1272 	if (nflag)
1273 		Printf(" %s", hbuf);
1274 	else if (lflag)
1275 		Printf(" %s (%s)", inetname((struct sockaddr *)from), hbuf);
1276 	else
1277 		Printf(" %s", inetname((struct sockaddr *)from));
1278 
1279 	if (verbose) {
1280 #ifdef OLDRAWSOCKET
1281 		Printf(" %d bytes to %s", cc,
1282 		    rcvpktinfo ? inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
1283 					hbuf, sizeof(hbuf))
1284 			       : "?");
1285 #else
1286 		Printf(" %d bytes of data to %s", cc,
1287 		    rcvpktinfo ?  inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
1288 					hbuf, sizeof(hbuf))
1289 			       : "?");
1290 #endif
1291 	}
1292 }
1293 
1294 /*
1295  * Subtract 2 timeval structs:  out = out - in.
1296  * Out is assumed to be >= in.
1297  */
1298 void
1299 tvsub(out, in)
1300 	register struct timeval *out, *in;
1301 {
1302 	if ((out->tv_usec -= in->tv_usec) < 0)   {
1303 		out->tv_sec--;
1304 		out->tv_usec += 1000000;
1305 	}
1306 	out->tv_sec -= in->tv_sec;
1307 }
1308 
1309 
1310 /*
1311  * Construct an Internet address representation.
1312  * If the nflag has been supplied, give
1313  * numeric value, otherwise try for symbolic name.
1314  */
1315 const char *
1316 inetname(sa)
1317 	struct sockaddr *sa;
1318 {
1319 	register char *cp;
1320 	static char line[NI_MAXHOST];
1321 	static char domain[MAXHOSTNAMELEN + 1];
1322 	static int first = 1;
1323 
1324 	if (first && !nflag) {
1325 		first = 0;
1326 		if (gethostname(domain, MAXHOSTNAMELEN) == 0 &&
1327 		    (cp = index(domain, '.')))
1328 			(void) strlcpy(domain, cp + 1, sizeof(domain));
1329 		else
1330 			domain[0] = 0;
1331 	}
1332 	cp = NULL;
1333 	if (!nflag) {
1334 		if (getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
1335 		    NI_NAMEREQD) == 0) {
1336 			if ((cp = index(line, '.')) &&
1337 			    !strcmp(cp + 1, domain))
1338 				*cp = 0;
1339 			cp = line;
1340 		}
1341 	}
1342 	if (cp)
1343 		return cp;
1344 
1345 	if (getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
1346 	    NI_NUMERICHOST | niflag) != 0)
1347 		strlcpy(line, "invalid", sizeof(line));
1348 	return line;
1349 }
1350 
1351 void
1352 usage()
1353 {
1354 	(void)fprintf(stderr,
1355 "usage: traceroute6 [-dlnrv] [-f firsthop] [-g gateway] [-m hoplimit] [-p port]\n"
1356 "       [-q probes] [-s src] [-w waittime] target [datalen]\n");
1357 	exit(1);
1358 }
1359