xref: /freebsd/usr.sbin/traceroute6/traceroute6.c (revision 7aa383846770374466b1dcb2cefd71bde9acf463)
1 /*	$KAME: traceroute6.c,v 1.68 2004/01/25 11:16:12 suz Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*-
33  * Copyright (c) 1990, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * This code is derived from software contributed to Berkeley by
37  * Van Jacobson.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. All advertising materials mentioning features or use of this software
48  *    must display the following acknowledgement:
49  *	This product includes software developed by the University of
50  *	California, Berkeley and its contributors.
51  * 4. Neither the name of the University nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  */
67 
68 #ifndef lint
69 static char copyright[] =
70 "@(#) Copyright (c) 1990, 1993\n\
71 	The Regents of the University of California.  All rights reserved.\n";
72 #endif /* not lint */
73 
74 #ifndef lint
75 #if 0
76 static char sccsid[] = "@(#)traceroute.c	8.1 (Berkeley) 6/6/93";
77 #endif
78 static const char rcsid[] =
79   "$FreeBSD$";
80 #endif /* not lint */
81 
82 /*
83  * traceroute host  - trace the route ip packets follow going to "host".
84  *
85  * Attempt to trace the route an ip packet would follow to some
86  * internet host.  We find out intermediate hops by launching probe
87  * packets with a small ttl (time to live) then listening for an
88  * icmp "time exceeded" reply from a gateway.  We start our probes
89  * with a ttl of one and increase by one until we get an icmp "port
90  * unreachable" (which means we got to "host") or hit a max (which
91  * defaults to 30 hops & can be changed with the -m flag).  Three
92  * probes (change with -q flag) are sent at each ttl setting and a
93  * line is printed showing the ttl, address of the gateway and
94  * round trip time of each probe.  If the probe answers come from
95  * different gateways, the address of each responding system will
96  * be printed.  If there is no response within a 5 sec. timeout
97  * interval (changed with the -w flag), a "*" is printed for that
98  * probe.
99  *
100  * Probe packets are UDP format.  We don't want the destination
101  * host to process them so the destination port is set to an
102  * unlikely value (if some clod on the destination is using that
103  * value, it can be changed with the -p flag).
104  *
105  * A sample use might be:
106  *
107  *     [yak 71]% traceroute nis.nsf.net.
108  *     traceroute to nis.nsf.net (35.1.1.48), 30 hops max, 56 byte packet
109  *      1  helios.ee.lbl.gov (128.3.112.1)  19 ms  19 ms  0 ms
110  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
111  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
112  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  39 ms
113  *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  39 ms  39 ms  39 ms
114  *      6  128.32.197.4 (128.32.197.4)  40 ms  59 ms  59 ms
115  *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  59 ms
116  *      8  129.140.70.13 (129.140.70.13)  99 ms  99 ms  80 ms
117  *      9  129.140.71.6 (129.140.71.6)  139 ms  239 ms  319 ms
118  *     10  129.140.81.7 (129.140.81.7)  220 ms  199 ms  199 ms
119  *     11  nic.merit.edu (35.1.1.48)  239 ms  239 ms  239 ms
120  *
121  * Note that lines 2 & 3 are the same.  This is due to a buggy
122  * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
123  * packets with a zero ttl.
124  *
125  * A more interesting example is:
126  *
127  *     [yak 72]% traceroute allspice.lcs.mit.edu.
128  *     traceroute to allspice.lcs.mit.edu (18.26.0.115), 30 hops max
129  *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
130  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  19 ms  19 ms
131  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  19 ms
132  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  19 ms  39 ms  39 ms
133  *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  20 ms  39 ms  39 ms
134  *      6  128.32.197.4 (128.32.197.4)  59 ms  119 ms  39 ms
135  *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  39 ms
136  *      8  129.140.70.13 (129.140.70.13)  80 ms  79 ms  99 ms
137  *      9  129.140.71.6 (129.140.71.6)  139 ms  139 ms  159 ms
138  *     10  129.140.81.7 (129.140.81.7)  199 ms  180 ms  300 ms
139  *     11  129.140.72.17 (129.140.72.17)  300 ms  239 ms  239 ms
140  *     12  * * *
141  *     13  128.121.54.72 (128.121.54.72)  259 ms  499 ms  279 ms
142  *     14  * * *
143  *     15  * * *
144  *     16  * * *
145  *     17  * * *
146  *     18  ALLSPICE.LCS.MIT.EDU (18.26.0.115)  339 ms  279 ms  279 ms
147  *
148  * (I start to see why I'm having so much trouble with mail to
149  * MIT.)  Note that the gateways 12, 14, 15, 16 & 17 hops away
150  * either don't send ICMP "time exceeded" messages or send them
151  * with a ttl too small to reach us.  14 - 17 are running the
152  * MIT C Gateway code that doesn't send "time exceeded"s.  God
153  * only knows what's going on with 12.
154  *
155  * The silent gateway 12 in the above may be the result of a bug in
156  * the 4.[23]BSD network code (and its derivatives):  4.x (x <= 3)
157  * sends an unreachable message using whatever ttl remains in the
158  * original datagram.  Since, for gateways, the remaining ttl is
159  * zero, the icmp "time exceeded" is guaranteed to not make it back
160  * to us.  The behavior of this bug is slightly more interesting
161  * when it appears on the destination system:
162  *
163  *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
164  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  39 ms
165  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  39 ms  19 ms
166  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  19 ms
167  *      5  ccn-nerif35.Berkeley.EDU (128.32.168.35)  39 ms  39 ms  39 ms
168  *      6  csgw.Berkeley.EDU (128.32.133.254)  39 ms  59 ms  39 ms
169  *      7  * * *
170  *      8  * * *
171  *      9  * * *
172  *     10  * * *
173  *     11  * * *
174  *     12  * * *
175  *     13  rip.Berkeley.EDU (128.32.131.22)  59 ms !  39 ms !  39 ms !
176  *
177  * Notice that there are 12 "gateways" (13 is the final
178  * destination) and exactly the last half of them are "missing".
179  * What's really happening is that rip (a Sun-3 running Sun OS3.5)
180  * is using the ttl from our arriving datagram as the ttl in its
181  * icmp reply.  So, the reply will time out on the return path
182  * (with no notice sent to anyone since icmp's aren't sent for
183  * icmp's) until we probe with a ttl that's at least twice the path
184  * length.  I.e., rip is really only 7 hops away.  A reply that
185  * returns with a ttl of 1 is a clue this problem exists.
186  * Traceroute prints a "!" after the time if the ttl is <= 1.
187  * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
188  * non-standard (HPUX) software, expect to see this problem
189  * frequently and/or take care picking the target host of your
190  * probes.
191  *
192  * Other possible annotations after the time are !H, !N, !P (got a host,
193  * network or protocol unreachable, respectively), !S or !F (source
194  * route failed or fragmentation needed -- neither of these should
195  * ever occur and the associated gateway is busted if you see one).  If
196  * almost all the probes result in some kind of unreachable, traceroute
197  * will give up and exit.
198  *
199  * Notes
200  * -----
201  * This program must be run by root or be setuid.  (I suggest that
202  * you *don't* make it setuid -- casual use could result in a lot
203  * of unnecessary traffic on our poor, congested nets.)
204  *
205  * This program requires a kernel mod that does not appear in any
206  * system available from Berkeley:  A raw ip socket using proto
207  * IPPROTO_RAW must interpret the data sent as an ip datagram (as
208  * opposed to data to be wrapped in an ip datagram).  See the README
209  * file that came with the source to this program for a description
210  * of the mods I made to /sys/netinet/raw_ip.c.  Your mileage may
211  * vary.  But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
212  * MODIFIED TO RUN THIS PROGRAM.
213  *
214  * The udp port usage may appear bizarre (well, ok, it is bizarre).
215  * The problem is that an icmp message only contains 8 bytes of
216  * data from the original datagram.  8 bytes is the size of a udp
217  * header so, if we want to associate replies with the original
218  * datagram, the necessary information must be encoded into the
219  * udp header (the ip id could be used but there's no way to
220  * interlock with the kernel's assignment of ip id's and, anyway,
221  * it would have taken a lot more kernel hacking to allow this
222  * code to set the ip id).  So, to allow two or more users to
223  * use traceroute simultaneously, we use this task's pid as the
224  * source port (the high bit is set to move the port number out
225  * of the "likely" range).  To keep track of which probe is being
226  * replied to (so times and/or hop counts don't get confused by a
227  * reply that was delayed in transit), we increment the destination
228  * port number before each probe.
229  *
230  * Don't use this as a coding example.  I was trying to find a
231  * routing problem and this code sort-of popped out after 48 hours
232  * without sleep.  I was amazed it ever compiled, much less ran.
233  *
234  * I stole the idea for this program from Steve Deering.  Since
235  * the first release, I've learned that had I attended the right
236  * IETF working group meetings, I also could have stolen it from Guy
237  * Almes or Matt Mathis.  I don't know (or care) who came up with
238  * the idea first.  I envy the originators' perspicacity and I'm
239  * glad they didn't keep the idea a secret.
240  *
241  * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
242  * enhancements to the original distribution.
243  *
244  * I've hacked up a round-trip-route version of this that works by
245  * sending a loose-source-routed udp datagram through the destination
246  * back to yourself.  Unfortunately, SO many gateways botch source
247  * routing, the thing is almost worthless.  Maybe one day...
248  *
249  *  -- Van Jacobson (van@helios.ee.lbl.gov)
250  *     Tue Dec 20 03:50:13 PST 1988
251  */
252 
253 #include <sys/param.h>
254 #include <sys/time.h>
255 #include <sys/socket.h>
256 #include <sys/uio.h>
257 #include <sys/file.h>
258 #include <sys/ioctl.h>
259 #include <sys/sysctl.h>
260 
261 #include <netinet/in.h>
262 
263 #include <arpa/inet.h>
264 
265 #include <netdb.h>
266 #include <stdio.h>
267 #include <err.h>
268 #ifdef HAVE_POLL
269 #include <poll.h>
270 #endif
271 #include <errno.h>
272 #include <stdlib.h>
273 #include <string.h>
274 #include <unistd.h>
275 
276 #include <netinet/ip6.h>
277 #include <netinet/icmp6.h>
278 #include <netinet/udp.h>
279 
280 #ifdef IPSEC
281 #include <net/route.h>
282 #include <netipsec/ipsec.h>
283 #endif
284 
285 #include "as.h"
286 
287 #define DUMMY_PORT 10010
288 
289 #define	MAXPACKET	65535	/* max ip packet size */
290 
291 #ifndef HAVE_GETIPNODEBYNAME
292 #define getipnodebyname(x, y, z, u)	gethostbyname2((x), (y))
293 #define freehostent(x)
294 #endif
295 
296 /*
297  * format of a (udp) probe packet.
298  */
299 struct tv32 {
300 	u_int32_t tv32_sec;
301 	u_int32_t tv32_usec;
302 };
303 
304 struct opacket {
305 	u_char seq;		/* sequence number of this packet */
306 	u_char hops;		/* hop limit of the packet */
307 	u_char pad[2];
308 	struct tv32 tv;		/* time packet left */
309 } __attribute__((__packed__));
310 
311 u_char	packet[512];		/* last inbound (icmp) packet */
312 struct opacket	*outpacket;	/* last output (udp) packet */
313 
314 int	main(int, char *[]);
315 int	wait_for_reply(int, struct msghdr *);
316 #ifdef IPSEC
317 #ifdef IPSEC_POLICY_IPSEC
318 int	setpolicy(int so, char *policy);
319 #endif
320 #endif
321 void	send_probe(int, u_long);
322 void	*get_uphdr(struct ip6_hdr *, u_char *);
323 int	get_hoplim(struct msghdr *);
324 double	deltaT(struct timeval *, struct timeval *);
325 char	*pr_type(int);
326 int	packet_ok(struct msghdr *, int, int);
327 void	print(struct msghdr *, int);
328 const char *inetname(struct sockaddr *);
329 void	usage(void);
330 
331 int rcvsock;			/* receive (icmp) socket file descriptor */
332 int sndsock;			/* send (udp) socket file descriptor */
333 
334 struct msghdr rcvmhdr;
335 struct iovec rcviov[2];
336 int rcvhlim;
337 struct in6_pktinfo *rcvpktinfo;
338 
339 struct sockaddr_in6 Src, Dst, Rcv;
340 u_long datalen;			/* How much data */
341 #define	ICMP6ECHOLEN	8
342 /* XXX: 2064 = 127(max hops in type 0 rthdr) * sizeof(ip6_hdr) + 16(margin) */
343 char rtbuf[2064];
344 #ifdef USE_RFC2292BIS
345 struct ip6_rthdr *rth;
346 #endif
347 struct cmsghdr *cmsg;
348 
349 char *source = 0;
350 char *hostname;
351 
352 u_long nprobes = 3;
353 u_long first_hop = 1;
354 u_long max_hops = 30;
355 u_int16_t srcport;
356 u_int16_t port = 32768+666;	/* start udp dest port # for probe packets */
357 u_int16_t ident;
358 int options;			/* socket options */
359 int verbose;
360 int waittime = 5;		/* time to wait for response (in seconds) */
361 int nflag;			/* print addresses numerically */
362 int useproto = IPPROTO_UDP;	/* protocol to use to send packet */
363 int lflag;			/* print both numerical address & hostname */
364 int as_path;			/* print as numbers for each hop */
365 char *as_server = NULL;
366 void *asn;
367 
368 int
369 main(argc, argv)
370 	int argc;
371 	char *argv[];
372 {
373 	int mib[4] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_DEFHLIM };
374 	char hbuf[NI_MAXHOST], src0[NI_MAXHOST], *ep;
375 	int ch, i, on = 1, seq, rcvcmsglen, error, minlen;
376 	struct addrinfo hints, *res;
377 	static u_char *rcvcmsgbuf;
378 	u_long probe, hops, lport;
379 	struct hostent *hp;
380 	size_t size;
381 	uid_t uid;
382 
383 	/*
384 	 * Receive ICMP
385 	 */
386 	if ((rcvsock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
387 		perror("socket(ICMPv6)");
388 		exit(5);
389 	}
390 
391 	size = sizeof(i);
392 	(void) sysctl(mib, sizeof(mib)/sizeof(mib[0]), &i, &size, NULL, 0);
393 	max_hops = i;
394 
395 	/* specify to tell receiving interface */
396 #ifdef IPV6_RECVPKTINFO
397 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
398 	    sizeof(on)) < 0)
399 		err(1, "setsockopt(IPV6_RECVPKTINFO)");
400 #else  /* old adv. API */
401 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
402 	    sizeof(on)) < 0)
403 		err(1, "setsockopt(IPV6_PKTINFO)");
404 #endif
405 
406 	/* specify to tell value of hoplimit field of received IP6 hdr */
407 #ifdef IPV6_RECVHOPLIMIT
408 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
409 	    sizeof(on)) < 0)
410 		err(1, "setsockopt(IPV6_RECVHOPLIMIT)");
411 #else  /* old adv. API */
412 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
413 	    sizeof(on)) < 0)
414 		err(1, "setsockopt(IPV6_HOPLIMIT)");
415 #endif
416 
417 	seq = 0;
418 
419 	while ((ch = getopt(argc, argv, "aA:df:g:Ilm:nNp:q:rs:Uvw:")) != -1)
420 		switch (ch) {
421 		case 'a':
422 			as_path = 1;
423 			break;
424 		case 'A':
425 			as_path = 1;
426 			as_server = optarg;
427 			break;
428 		case 'd':
429 			options |= SO_DEBUG;
430 			break;
431 		case 'f':
432 			ep = NULL;
433 			errno = 0;
434 			first_hop = strtoul(optarg, &ep, 0);
435 			if (errno || !*optarg || *ep || first_hop > 255) {
436 				fprintf(stderr,
437 				    "traceroute6: invalid min hoplimit.\n");
438 				exit(1);
439 			}
440 			break;
441 		case 'g':
442 			hp = getipnodebyname(optarg, AF_INET6, 0, &h_errno);
443 			if (hp == NULL) {
444 				fprintf(stderr,
445 				    "traceroute6: unknown host %s\n", optarg);
446 				exit(1);
447 			}
448 #ifdef USE_RFC2292BIS
449 			if (rth == NULL) {
450 				/*
451 				 * XXX: We can't detect the number of
452 				 * intermediate nodes yet.
453 				 */
454 				if ((rth = inet6_rth_init((void *)rtbuf,
455 				    sizeof(rtbuf), IPV6_RTHDR_TYPE_0,
456 				    0)) == NULL) {
457 					fprintf(stderr,
458 					    "inet6_rth_init failed.\n");
459 					exit(1);
460 				}
461 			}
462 			if (inet6_rth_add((void *)rth,
463 			    (struct in6_addr *)hp->h_addr)) {
464 				fprintf(stderr,
465 				    "inet6_rth_add failed for %s\n",
466 				    optarg);
467 				exit(1);
468 			}
469 #else  /* old advanced API */
470 			if (cmsg == NULL)
471 				cmsg = inet6_rthdr_init(rtbuf, IPV6_RTHDR_TYPE_0);
472 			inet6_rthdr_add(cmsg, (struct in6_addr *)hp->h_addr,
473 			    IPV6_RTHDR_LOOSE);
474 #endif
475 			freehostent(hp);
476 			break;
477 		case 'I':
478 			useproto = IPPROTO_ICMPV6;
479 			ident = htons(getpid() & 0xffff); /* same as ping6 */
480 			break;
481 		case 'l':
482 			lflag++;
483 			break;
484 		case 'm':
485 			ep = NULL;
486 			errno = 0;
487 			max_hops = strtoul(optarg, &ep, 0);
488 			if (errno || !*optarg || *ep || max_hops > 255) {
489 				fprintf(stderr,
490 				    "traceroute6: invalid max hoplimit.\n");
491 				exit(1);
492 			}
493 			break;
494 		case 'n':
495 			nflag++;
496 			break;
497 		case 'N':
498 			useproto = IPPROTO_NONE;
499 			break;
500 		case 'p':
501 			ep = NULL;
502 			errno = 0;
503 			lport = strtoul(optarg, &ep, 0);
504 			if (errno || !*optarg || *ep) {
505 				fprintf(stderr, "traceroute6: invalid port.\n");
506 				exit(1);
507 			}
508 			if (lport == 0 || lport != (lport & 0xffff)) {
509 				fprintf(stderr,
510 				    "traceroute6: port out of range.\n");
511 				exit(1);
512 			}
513 			port = lport & 0xffff;
514 			break;
515 		case 'q':
516 			ep = NULL;
517 			errno = 0;
518 			nprobes = strtoul(optarg, &ep, 0);
519 			if (errno || !*optarg || *ep) {
520 				fprintf(stderr,
521 				    "traceroute6: invalid nprobes.\n");
522 				exit(1);
523 			}
524 			if (nprobes < 1) {
525 				fprintf(stderr,
526 				    "traceroute6: nprobes must be >0.\n");
527 				exit(1);
528 			}
529 			break;
530 		case 'r':
531 			options |= SO_DONTROUTE;
532 			break;
533 		case 's':
534 			/*
535 			 * set the ip source address of the outbound
536 			 * probe (e.g., on a multi-homed host).
537 			 */
538 			source = optarg;
539 			break;
540 		case 'v':
541 			verbose++;
542 			break;
543 		case 'U':
544 			useproto = IPPROTO_UDP;
545 			break;
546 		case 'w':
547 			ep = NULL;
548 			errno = 0;
549 			waittime = strtoul(optarg, &ep, 0);
550 			if (errno || !*optarg || *ep) {
551 				fprintf(stderr,
552 				    "traceroute6: invalid wait time.\n");
553 				exit(1);
554 			}
555 			if (waittime < 1) {
556 				fprintf(stderr,
557 				    "traceroute6: wait must be >= 1 sec.\n");
558 				exit(1);
559 			}
560 			break;
561 		default:
562 			usage();
563 		}
564 	argc -= optind;
565 	argv += optind;
566 
567 	/*
568 	 * Open socket to send probe packets.
569 	 */
570 	switch (useproto) {
571 	case IPPROTO_ICMPV6:
572 		sndsock = rcvsock;
573 		break;
574 	case IPPROTO_UDP:
575 		if ((sndsock = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
576 			perror("socket(SOCK_DGRAM)");
577 			exit(5);
578 		}
579 		break;
580 	case IPPROTO_NONE:
581         	if ((sndsock = socket(AF_INET6, SOCK_RAW, IPPROTO_NONE)) < 0) {
582 			perror("socket(SOCK_RAW)");
583 			exit(5);
584 		}
585 		break;
586 	default:
587 		fprintf(stderr, "traceroute6: unknown probe protocol %d",
588 		    useproto);
589 		exit(5);
590 	}
591 	if (max_hops < first_hop) {
592 		fprintf(stderr,
593 		    "traceroute6: max hoplimit must be larger than first hoplimit.\n");
594 		exit(1);
595 	}
596 
597 	/* revoke privs */
598 	uid = getuid();
599 	if (setresuid(uid, uid, uid) == -1) {
600 		perror("setresuid");
601 		exit(1);
602 	}
603 
604 
605 	if (argc < 1 || argc > 2)
606 		usage();
607 
608 #if 1
609 	setvbuf(stdout, NULL, _IOLBF, BUFSIZ);
610 #else
611 	setlinebuf(stdout);
612 #endif
613 
614 	memset(&hints, 0, sizeof(hints));
615 	hints.ai_family = PF_INET6;
616 	hints.ai_socktype = SOCK_RAW;
617 	hints.ai_protocol = IPPROTO_ICMPV6;
618 	hints.ai_flags = AI_CANONNAME;
619 	error = getaddrinfo(*argv, NULL, &hints, &res);
620 	if (error) {
621 		fprintf(stderr,
622 		    "traceroute6: %s\n", gai_strerror(error));
623 		exit(1);
624 	}
625 	if (res->ai_addrlen != sizeof(Dst)) {
626 		fprintf(stderr,
627 		    "traceroute6: size of sockaddr mismatch\n");
628 		exit(1);
629 	}
630 	memcpy(&Dst, res->ai_addr, res->ai_addrlen);
631 	hostname = res->ai_canonname ? strdup(res->ai_canonname) : *argv;
632 	if (!hostname) {
633 		fprintf(stderr, "traceroute6: not enough core\n");
634 		exit(1);
635 	}
636 	if (res->ai_next) {
637 		if (getnameinfo(res->ai_addr, res->ai_addrlen, hbuf,
638 		    sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
639 			strlcpy(hbuf, "?", sizeof(hbuf));
640 		fprintf(stderr, "traceroute6: Warning: %s has multiple "
641 		    "addresses; using %s\n", hostname, hbuf);
642 	}
643 
644 	if (*++argv) {
645 		ep = NULL;
646 		errno = 0;
647 		datalen = strtoul(*argv, &ep, 0);
648 		if (errno || !*argv || *ep) {
649 			fprintf(stderr,
650 			    "traceroute6: invalid packet length.\n");
651 			exit(1);
652 		}
653 	}
654 	switch (useproto) {
655 	case IPPROTO_ICMPV6:
656 		minlen = ICMP6ECHOLEN + sizeof(struct tv32);
657 		break;
658 	case IPPROTO_UDP:
659 		minlen = sizeof(struct opacket);
660 		break;
661 	case IPPROTO_NONE:
662 		minlen = 0;
663 		datalen = 0;
664 		break;
665 	default:
666 		fprintf(stderr, "traceroute6: unknown probe protocol %d.\n",
667 		    useproto);
668 		exit(1);
669 	}
670 	if (datalen < minlen)
671 		datalen = minlen;
672 	else if (datalen >= MAXPACKET) {
673 		fprintf(stderr,
674 		    "traceroute6: packet size must be %d <= s < %ld.\n",
675 		    minlen, (long)MAXPACKET);
676 		exit(1);
677 	}
678 	outpacket = (struct opacket *)malloc((unsigned)datalen);
679 	if (!outpacket) {
680 		perror("malloc");
681 		exit(1);
682 	}
683 	(void) bzero((char *)outpacket, datalen);
684 
685 	/* initialize msghdr for receiving packets */
686 	rcviov[0].iov_base = (caddr_t)packet;
687 	rcviov[0].iov_len = sizeof(packet);
688 	rcvmhdr.msg_name = (caddr_t)&Rcv;
689 	rcvmhdr.msg_namelen = sizeof(Rcv);
690 	rcvmhdr.msg_iov = rcviov;
691 	rcvmhdr.msg_iovlen = 1;
692 	rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
693 	    CMSG_SPACE(sizeof(int));
694 	if ((rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) {
695 		fprintf(stderr, "traceroute6: malloc failed\n");
696 		exit(1);
697 	}
698 	rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
699 	rcvmhdr.msg_controllen = rcvcmsglen;
700 
701 	if (options & SO_DEBUG)
702 		(void) setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
703 		    (char *)&on, sizeof(on));
704 	if (options & SO_DONTROUTE)
705 		(void) setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
706 		    (char *)&on, sizeof(on));
707 #ifdef IPSEC
708 #ifdef IPSEC_POLICY_IPSEC
709 	/*
710 	 * do not raise error even if setsockopt fails, kernel may have ipsec
711 	 * turned off.
712 	 */
713 	if (setpolicy(rcvsock, "in bypass") < 0)
714 		errx(1, "%s", ipsec_strerror());
715 	if (setpolicy(rcvsock, "out bypass") < 0)
716 		errx(1, "%s", ipsec_strerror());
717 #else
718     {
719 	int level = IPSEC_LEVEL_NONE;
720 
721 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_ESP_TRANS_LEVEL, &level,
722 	    sizeof(level));
723 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_ESP_NETWORK_LEVEL, &level,
724 	    sizeof(level));
725 #ifdef IP_AUTH_TRANS_LEVEL
726 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_TRANS_LEVEL, &level,
727 	    sizeof(level));
728 #else
729 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_LEVEL, &level,
730 	    sizeof(level));
731 #endif
732 #ifdef IP_AUTH_NETWORK_LEVEL
733 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_NETWORK_LEVEL, &level,
734 	    sizeof(level));
735 #endif
736     }
737 #endif /*IPSEC_POLICY_IPSEC*/
738 #endif /*IPSEC*/
739 
740 #ifdef SO_SNDBUF
741 	i = datalen;
742 	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&i,
743 	    sizeof(i)) < 0 && useproto != IPPROTO_NONE) {
744 		perror("setsockopt(SO_SNDBUF)");
745 		exit(6);
746 	}
747 #endif /* SO_SNDBUF */
748 	if (options & SO_DEBUG)
749 		(void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
750 		    (char *)&on, sizeof(on));
751 	if (options & SO_DONTROUTE)
752 		(void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
753 		    (char *)&on, sizeof(on));
754 #ifdef USE_RFC2292BIS
755 	if (rth) {/* XXX: there is no library to finalize the header... */
756 		rth->ip6r_len = rth->ip6r_segleft * 2;
757 		if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_RTHDR,
758 		    (void *)rth, (rth->ip6r_len + 1) << 3)) {
759 			fprintf(stderr, "setsockopt(IPV6_RTHDR): %s\n",
760 			    strerror(errno));
761 			exit(1);
762 		}
763 	}
764 #else  /* old advanced API */
765 	if (cmsg != NULL) {
766 		inet6_rthdr_lasthop(cmsg, IPV6_RTHDR_LOOSE);
767 		if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_PKTOPTIONS,
768 		    rtbuf, cmsg->cmsg_len) < 0) {
769 			fprintf(stderr, "setsockopt(IPV6_PKTOPTIONS): %s\n",
770 			    strerror(errno));
771 			exit(1);
772 		}
773 	}
774 #endif /* USE_RFC2292BIS */
775 #ifdef IPSEC
776 #ifdef IPSEC_POLICY_IPSEC
777 	/*
778 	 * do not raise error even if setsockopt fails, kernel may have ipsec
779 	 * turned off.
780 	 */
781 	if (setpolicy(sndsock, "in bypass") < 0)
782 		errx(1, "%s", ipsec_strerror());
783 	if (setpolicy(sndsock, "out bypass") < 0)
784 		errx(1, "%s", ipsec_strerror());
785 #else
786     {
787 	int level = IPSEC_LEVEL_BYPASS;
788 
789 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_ESP_TRANS_LEVEL, &level,
790 	    sizeof(level));
791 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_ESP_NETWORK_LEVEL, &level,
792 	    sizeof(level));
793 #ifdef IP_AUTH_TRANS_LEVEL
794 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_TRANS_LEVEL, &level,
795 	    sizeof(level));
796 #else
797 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_LEVEL, &level,
798 	    sizeof(level));
799 #endif
800 #ifdef IP_AUTH_NETWORK_LEVEL
801 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_NETWORK_LEVEL, &level,
802 	    sizeof(level));
803 #endif
804     }
805 #endif /*IPSEC_POLICY_IPSEC*/
806 #endif /*IPSEC*/
807 
808 	/*
809 	 * Source selection
810 	 */
811 	bzero(&Src, sizeof(Src));
812 	if (source) {
813 		struct addrinfo hints, *res;
814 		int error;
815 
816 		memset(&hints, 0, sizeof(hints));
817 		hints.ai_family = AF_INET6;
818 		hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
819 		hints.ai_flags = AI_NUMERICHOST;
820 		error = getaddrinfo(source, "0", &hints, &res);
821 		if (error) {
822 			printf("traceroute6: %s: %s\n", source,
823 			    gai_strerror(error));
824 			exit(1);
825 		}
826 		if (res->ai_addrlen > sizeof(Src)) {
827 			printf("traceroute6: %s: %s\n", source,
828 			    gai_strerror(error));
829 			exit(1);
830 		}
831 		memcpy(&Src, res->ai_addr, res->ai_addrlen);
832 		freeaddrinfo(res);
833 	} else {
834 		struct sockaddr_in6 Nxt;
835 		int dummy;
836 		socklen_t len;
837 
838 		Nxt = Dst;
839 		Nxt.sin6_port = htons(DUMMY_PORT);
840 		if (cmsg != NULL)
841 			bcopy(inet6_rthdr_getaddr(cmsg, 1), &Nxt.sin6_addr,
842 			    sizeof(Nxt.sin6_addr));
843 		if ((dummy = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
844 			perror("socket");
845 			exit(1);
846 		}
847 		if (connect(dummy, (struct sockaddr *)&Nxt, Nxt.sin6_len) < 0) {
848 			perror("connect");
849 			exit(1);
850 		}
851 		len = sizeof(Src);
852 		if (getsockname(dummy, (struct sockaddr *)&Src, &len) < 0) {
853 			perror("getsockname");
854 			exit(1);
855 		}
856 		if (getnameinfo((struct sockaddr *)&Src, Src.sin6_len,
857 		    src0, sizeof(src0), NULL, 0, NI_NUMERICHOST)) {
858 			fprintf(stderr, "getnameinfo failed for source\n");
859 			exit(1);
860 		}
861 		source = src0;
862 		close(dummy);
863 	}
864 
865 	Src.sin6_port = htons(0);
866 	if (bind(sndsock, (struct sockaddr *)&Src, Src.sin6_len) < 0) {
867 		perror("bind");
868 		exit(1);
869 	}
870 
871 	{
872 		socklen_t len;
873 
874 		len = sizeof(Src);
875 		if (getsockname(sndsock, (struct sockaddr *)&Src, &len) < 0) {
876 			perror("getsockname");
877 			exit(1);
878 		}
879 		srcport = ntohs(Src.sin6_port);
880 	}
881 
882 	if (as_path) {
883 		asn = as_setup(as_server);
884 		if (asn == NULL) {
885 			fprintf(stderr,
886 			    "traceroute6: as_setup failed, AS# lookups"
887 			    " disabled\n");
888 			(void)fflush(stderr);
889 			as_path = 0;
890 		}
891 	}
892 
893 	/*
894 	 * Message to users
895 	 */
896 	if (getnameinfo((struct sockaddr *)&Dst, Dst.sin6_len, hbuf,
897 	    sizeof(hbuf), NULL, 0, NI_NUMERICHOST))
898 		strlcpy(hbuf, "(invalid)", sizeof(hbuf));
899 	fprintf(stderr, "traceroute6");
900 	fprintf(stderr, " to %s (%s)", hostname, hbuf);
901 	if (source)
902 		fprintf(stderr, " from %s", source);
903 	fprintf(stderr, ", %lu hops max, %lu byte packets\n",
904 	    max_hops, datalen);
905 	(void) fflush(stderr);
906 
907 	if (first_hop > 1)
908 		printf("Skipping %lu intermediate hops\n", first_hop - 1);
909 
910 	/*
911 	 * Main loop
912 	 */
913 	for (hops = first_hop; hops <= max_hops; ++hops) {
914 		struct in6_addr lastaddr;
915 		int got_there = 0;
916 		int unreachable = 0;
917 
918 		printf("%2lu ", hops);
919 		bzero(&lastaddr, sizeof(lastaddr));
920 		for (probe = 0; probe < nprobes; ++probe) {
921 			int cc;
922 			struct timeval t1, t2;
923 
924 			(void) gettimeofday(&t1, NULL);
925 			send_probe(++seq, hops);
926 			while ((cc = wait_for_reply(rcvsock, &rcvmhdr))) {
927 				(void) gettimeofday(&t2, NULL);
928 				if ((i = packet_ok(&rcvmhdr, cc, seq))) {
929 					if (!IN6_ARE_ADDR_EQUAL(&Rcv.sin6_addr,
930 					    &lastaddr)) {
931 						if (probe > 0)
932 							fputs("\n   ", stdout);
933 						print(&rcvmhdr, cc);
934 						lastaddr = Rcv.sin6_addr;
935 					}
936 					printf("  %.3f ms", deltaT(&t1, &t2));
937 					switch (i - 1) {
938 					case ICMP6_DST_UNREACH_NOROUTE:
939 						++unreachable;
940 						printf(" !N");
941 						break;
942 					case ICMP6_DST_UNREACH_ADMIN:
943 						++unreachable;
944 						printf(" !P");
945 						break;
946 					case ICMP6_DST_UNREACH_NOTNEIGHBOR:
947 						++unreachable;
948 						printf(" !S");
949 						break;
950 					case ICMP6_DST_UNREACH_ADDR:
951 						++unreachable;
952 						printf(" !A");
953 						break;
954 					case ICMP6_DST_UNREACH_NOPORT:
955 						if (rcvhlim >= 0 &&
956 						    rcvhlim <= 1)
957 							printf(" !");
958 						++got_there;
959 						break;
960 					}
961 					break;
962 				}
963 			}
964 			if (cc == 0)
965 				printf(" *");
966 			(void) fflush(stdout);
967 		}
968 		putchar('\n');
969 		if (got_there ||
970 		    (unreachable > 0 && unreachable >= ((nprobes + 1) / 2))) {
971 			exit(0);
972 		}
973 	}
974 	if (as_path)
975 		as_shutdown(asn);
976 
977 	exit(0);
978 }
979 
980 int
981 wait_for_reply(sock, mhdr)
982 	int sock;
983 	struct msghdr *mhdr;
984 {
985 #ifdef HAVE_POLL
986 	struct pollfd pfd[1];
987 	int cc = 0;
988 
989 	pfd[0].fd = sock;
990 	pfd[0].events = POLLIN;
991 	pfd[0].revents = 0;
992 
993 	if (poll(pfd, 1, waittime * 1000) > 0)
994 		cc = recvmsg(rcvsock, mhdr, 0);
995 
996 	return(cc);
997 #else
998 	fd_set *fdsp;
999 	struct timeval wait;
1000 	int cc = 0, fdsn;
1001 
1002 	fdsn = howmany(sock + 1, NFDBITS) * sizeof(fd_mask);
1003 	if ((fdsp = (fd_set *)malloc(fdsn)) == NULL)
1004 		err(1, "malloc");
1005 	memset(fdsp, 0, fdsn);
1006 	FD_SET(sock, fdsp);
1007 	wait.tv_sec = waittime; wait.tv_usec = 0;
1008 
1009 	if (select(sock+1, fdsp, (fd_set *)0, (fd_set *)0, &wait) > 0)
1010 		cc = recvmsg(rcvsock, mhdr, 0);
1011 
1012 	free(fdsp);
1013 	return(cc);
1014 #endif
1015 }
1016 
1017 #ifdef IPSEC
1018 #ifdef IPSEC_POLICY_IPSEC
1019 int
1020 setpolicy(so, policy)
1021 	int so;
1022 	char *policy;
1023 {
1024 	char *buf;
1025 
1026 	buf = ipsec_set_policy(policy, strlen(policy));
1027 	if (buf == NULL) {
1028 		warnx("%s", ipsec_strerror());
1029 		return -1;
1030 	}
1031 	(void)setsockopt(so, IPPROTO_IPV6, IPV6_IPSEC_POLICY,
1032 	    buf, ipsec_get_policylen(buf));
1033 
1034 	free(buf);
1035 
1036 	return 0;
1037 }
1038 #endif
1039 #endif
1040 
1041 void
1042 send_probe(seq, hops)
1043 	int seq;
1044 	u_long hops;
1045 {
1046 	struct icmp6_hdr *icp;
1047 	struct opacket *op;
1048 	struct timeval tv;
1049 	struct tv32 tv32;
1050 	int i;
1051 
1052 	i = hops;
1053 	if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
1054 	    (char *)&i, sizeof(i)) < 0) {
1055 		perror("setsockopt IPV6_UNICAST_HOPS");
1056 	}
1057 
1058 	Dst.sin6_port = htons(port + seq);
1059 	(void) gettimeofday(&tv, NULL);
1060 	tv32.tv32_sec = htonl(tv.tv_sec);
1061 	tv32.tv32_usec = htonl(tv.tv_usec);
1062 
1063 	switch (useproto) {
1064 	case IPPROTO_ICMPV6:
1065 		icp = (struct icmp6_hdr *)outpacket;
1066 
1067 		icp->icmp6_type = ICMP6_ECHO_REQUEST;
1068 		icp->icmp6_code = 0;
1069 		icp->icmp6_cksum = 0;
1070 		icp->icmp6_id = ident;
1071 		icp->icmp6_seq = htons(seq);
1072 		bcopy(&tv32, ((u_int8_t *)outpacket + ICMP6ECHOLEN),
1073 		    sizeof(tv32));
1074 		break;
1075 	case IPPROTO_UDP:
1076 		op = outpacket;
1077 
1078 		op->seq = seq;
1079 		op->hops = hops;
1080 		bcopy(&tv32, &op->tv, sizeof tv32);
1081 		break;
1082 	case IPPROTO_NONE:
1083 		/* No space for anything. No harm as seq/tv32 are decorative. */
1084 		break;
1085 	default:
1086 		fprintf(stderr, "Unknown probe protocol %d.\n", useproto);
1087 		exit(1);
1088 	}
1089 
1090 	i = sendto(sndsock, (char *)outpacket, datalen, 0,
1091 	    (struct sockaddr *)&Dst, Dst.sin6_len);
1092 	if (i < 0 || i != datalen)  {
1093 		if (i < 0)
1094 			perror("sendto");
1095 		printf("traceroute6: wrote %s %lu chars, ret=%d\n",
1096 		    hostname, datalen, i);
1097 		(void) fflush(stdout);
1098 	}
1099 }
1100 
1101 int
1102 get_hoplim(mhdr)
1103 	struct msghdr *mhdr;
1104 {
1105 	struct cmsghdr *cm;
1106 
1107 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
1108 	    cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
1109 		if (cm->cmsg_level == IPPROTO_IPV6 &&
1110 		    cm->cmsg_type == IPV6_HOPLIMIT &&
1111 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
1112 			return(*(int *)CMSG_DATA(cm));
1113 	}
1114 
1115 	return(-1);
1116 }
1117 
1118 double
1119 deltaT(t1p, t2p)
1120 	struct timeval *t1p, *t2p;
1121 {
1122 	double dt;
1123 
1124 	dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
1125 	    (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
1126 	return (dt);
1127 }
1128 
1129 /*
1130  * Convert an ICMP "type" field to a printable string.
1131  */
1132 char *
1133 pr_type(t0)
1134 	int t0;
1135 {
1136 	u_char t = t0 & 0xff;
1137 	char *cp;
1138 
1139 	switch (t) {
1140 	case ICMP6_DST_UNREACH:
1141 		cp = "Destination Unreachable";
1142 		break;
1143 	case ICMP6_PACKET_TOO_BIG:
1144 		cp = "Packet Too Big";
1145 		break;
1146 	case ICMP6_TIME_EXCEEDED:
1147 		cp = "Time Exceeded";
1148 		break;
1149 	case ICMP6_PARAM_PROB:
1150 		cp = "Parameter Problem";
1151 		break;
1152 	case ICMP6_ECHO_REQUEST:
1153 		cp = "Echo Request";
1154 		break;
1155 	case ICMP6_ECHO_REPLY:
1156 		cp = "Echo Reply";
1157 		break;
1158 	case ICMP6_MEMBERSHIP_QUERY:
1159 		cp = "Group Membership Query";
1160 		break;
1161 	case ICMP6_MEMBERSHIP_REPORT:
1162 		cp = "Group Membership Report";
1163 		break;
1164 	case ICMP6_MEMBERSHIP_REDUCTION:
1165 		cp = "Group Membership Reduction";
1166 		break;
1167 	case ND_ROUTER_SOLICIT:
1168 		cp = "Router Solicitation";
1169 		break;
1170 	case ND_ROUTER_ADVERT:
1171 		cp = "Router Advertisement";
1172 		break;
1173 	case ND_NEIGHBOR_SOLICIT:
1174 		cp = "Neighbor Solicitation";
1175 		break;
1176 	case ND_NEIGHBOR_ADVERT:
1177 		cp = "Neighbor Advertisement";
1178 		break;
1179 	case ND_REDIRECT:
1180 		cp = "Redirect";
1181 		break;
1182 	default:
1183 		cp = "Unknown";
1184 		break;
1185 	}
1186 	return cp;
1187 }
1188 
1189 int
1190 packet_ok(mhdr, cc, seq)
1191 	struct msghdr *mhdr;
1192 	int cc;
1193 	int seq;
1194 {
1195 	struct icmp6_hdr *icp;
1196 	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
1197 	u_char type, code;
1198 	char *buf = (char *)mhdr->msg_iov[0].iov_base;
1199 	struct cmsghdr *cm;
1200 	int *hlimp;
1201 	char hbuf[NI_MAXHOST];
1202 
1203 #ifdef OLDRAWSOCKET
1204 	int hlen;
1205 	struct ip6_hdr *ip;
1206 #endif
1207 
1208 #ifdef OLDRAWSOCKET
1209 	ip = (struct ip6_hdr *) buf;
1210 	hlen = sizeof(struct ip6_hdr);
1211 	if (cc < hlen + sizeof(struct icmp6_hdr)) {
1212 		if (verbose) {
1213 			if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1214 			    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
1215 				strlcpy(hbuf, "invalid", sizeof(hbuf));
1216 			printf("packet too short (%d bytes) from %s\n", cc,
1217 			    hbuf);
1218 		}
1219 		return (0);
1220 	}
1221 	cc -= hlen;
1222 	icp = (struct icmp6_hdr *)(buf + hlen);
1223 #else
1224 	if (cc < sizeof(struct icmp6_hdr)) {
1225 		if (verbose) {
1226 			if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1227 			    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
1228 				strlcpy(hbuf, "invalid", sizeof(hbuf));
1229 			printf("data too short (%d bytes) from %s\n", cc, hbuf);
1230 		}
1231 		return(0);
1232 	}
1233 	icp = (struct icmp6_hdr *)buf;
1234 #endif
1235 	/* get optional information via advanced API */
1236 	rcvpktinfo = NULL;
1237 	hlimp = NULL;
1238 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
1239 	    cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
1240 		if (cm->cmsg_level == IPPROTO_IPV6 &&
1241 		    cm->cmsg_type == IPV6_PKTINFO &&
1242 		    cm->cmsg_len ==
1243 		    CMSG_LEN(sizeof(struct in6_pktinfo)))
1244 			rcvpktinfo = (struct in6_pktinfo *)(CMSG_DATA(cm));
1245 
1246 		if (cm->cmsg_level == IPPROTO_IPV6 &&
1247 		    cm->cmsg_type == IPV6_HOPLIMIT &&
1248 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
1249 			hlimp = (int *)CMSG_DATA(cm);
1250 	}
1251 	if (rcvpktinfo == NULL || hlimp == NULL) {
1252 		warnx("failed to get received hop limit or packet info");
1253 #if 0
1254 		return(0);
1255 #else
1256 		rcvhlim = 0;	/*XXX*/
1257 #endif
1258 	}
1259 	else
1260 		rcvhlim = *hlimp;
1261 
1262 	type = icp->icmp6_type;
1263 	code = icp->icmp6_code;
1264 	if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
1265 	    || type == ICMP6_DST_UNREACH) {
1266 		struct ip6_hdr *hip;
1267 		void *up;
1268 
1269 		hip = (struct ip6_hdr *)(icp + 1);
1270 		if ((up = get_uphdr(hip, (u_char *)(buf + cc))) == NULL) {
1271 			if (verbose)
1272 				warnx("failed to get upper layer header");
1273 			return(0);
1274 		}
1275 		switch (useproto) {
1276 		case IPPROTO_ICMPV6:
1277 			if (((struct icmp6_hdr *)up)->icmp6_id == ident &&
1278 			    ((struct icmp6_hdr *)up)->icmp6_seq == htons(seq))
1279 				return (type == ICMP6_TIME_EXCEEDED ?
1280 				    -1 : code + 1);
1281 			break;
1282 		case IPPROTO_UDP:
1283 			if (((struct udphdr *)up)->uh_sport == htons(srcport) &&
1284 			    ((struct udphdr *)up)->uh_dport == htons(port + seq))
1285 				return (type == ICMP6_TIME_EXCEEDED ?
1286 				    -1 : code + 1);
1287 			break;
1288 		case IPPROTO_NONE:
1289 			return (type == ICMP6_TIME_EXCEEDED ?  -1 : code + 1);
1290 		default:
1291 			fprintf(stderr, "Unknown probe proto %d.\n", useproto);
1292 			break;
1293 		}
1294 	} else if (useproto == IPPROTO_ICMPV6 && type == ICMP6_ECHO_REPLY) {
1295 		if (icp->icmp6_id == ident &&
1296 		    icp->icmp6_seq == htons(seq))
1297 			return (ICMP6_DST_UNREACH_NOPORT + 1);
1298 	}
1299 	if (verbose) {
1300 		char sbuf[NI_MAXHOST+1], dbuf[INET6_ADDRSTRLEN];
1301 		u_int8_t *p;
1302 		int i;
1303 
1304 		if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1305 		    sbuf, sizeof(sbuf), NULL, 0, NI_NUMERICHOST) != 0)
1306 			strlcpy(sbuf, "invalid", sizeof(sbuf));
1307 		printf("\n%d bytes from %s to %s", cc, sbuf,
1308 		    rcvpktinfo ? inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
1309 		    dbuf, sizeof(dbuf)) : "?");
1310 		printf(": icmp type %d (%s) code %d\n", type, pr_type(type),
1311 		    icp->icmp6_code);
1312 		p = (u_int8_t *)(icp + 1);
1313 #define WIDTH	16
1314 		for (i = 0; i < cc; i++) {
1315 			if (i % WIDTH == 0)
1316 				printf("%04x:", i);
1317 			if (i % 4 == 0)
1318 				printf(" ");
1319 			printf("%02x", p[i]);
1320 			if (i % WIDTH == WIDTH - 1)
1321 				printf("\n");
1322 		}
1323 		if (cc % WIDTH != 0)
1324 			printf("\n");
1325 	}
1326 	return(0);
1327 }
1328 
1329 /*
1330  * Increment pointer until find the UDP or ICMP header.
1331  */
1332 void *
1333 get_uphdr(ip6, lim)
1334 	struct ip6_hdr *ip6;
1335 	u_char *lim;
1336 {
1337 	u_char *cp = (u_char *)ip6, nh;
1338 	int hlen;
1339 	static u_char none_hdr[1]; /* Fake pointer for IPPROTO_NONE. */
1340 
1341 	if (cp + sizeof(*ip6) > lim)
1342 		return(NULL);
1343 
1344 	nh = ip6->ip6_nxt;
1345 	cp += sizeof(struct ip6_hdr);
1346 
1347 	while (lim - cp >= (nh == IPPROTO_NONE ? 0 : 8)) {
1348 		switch (nh) {
1349 		case IPPROTO_ESP:
1350 		case IPPROTO_TCP:
1351 			return(NULL);
1352 		case IPPROTO_ICMPV6:
1353 			return(useproto == nh ? cp : NULL);
1354 		case IPPROTO_UDP:
1355 			return(useproto == nh ? cp : NULL);
1356 		case IPPROTO_NONE:
1357 			return(useproto == nh ? none_hdr : NULL);
1358 		case IPPROTO_FRAGMENT:
1359 			hlen = sizeof(struct ip6_frag);
1360 			nh = ((struct ip6_frag *)cp)->ip6f_nxt;
1361 			break;
1362 		case IPPROTO_AH:
1363 			hlen = (((struct ip6_ext *)cp)->ip6e_len + 2) << 2;
1364 			nh = ((struct ip6_ext *)cp)->ip6e_nxt;
1365 			break;
1366 		default:
1367 			hlen = (((struct ip6_ext *)cp)->ip6e_len + 1) << 3;
1368 			nh = ((struct ip6_ext *)cp)->ip6e_nxt;
1369 			break;
1370 		}
1371 
1372 		cp += hlen;
1373 	}
1374 
1375 	return(NULL);
1376 }
1377 
1378 void
1379 print(mhdr, cc)
1380 	struct msghdr *mhdr;
1381 	int cc;
1382 {
1383 	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
1384 	char hbuf[NI_MAXHOST];
1385 
1386 	if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1387 	    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
1388 		strlcpy(hbuf, "invalid", sizeof(hbuf));
1389 	if (as_path)
1390 		printf(" [AS%u]", as_lookup(asn, hbuf, AF_INET6));
1391 	if (nflag)
1392 		printf(" %s", hbuf);
1393 	else if (lflag)
1394 		printf(" %s (%s)", inetname((struct sockaddr *)from), hbuf);
1395 	else
1396 		printf(" %s", inetname((struct sockaddr *)from));
1397 
1398 	if (verbose) {
1399 #ifdef OLDRAWSOCKET
1400 		printf(" %d bytes to %s", cc,
1401 		    rcvpktinfo ? inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
1402 		    hbuf, sizeof(hbuf)) : "?");
1403 #else
1404 		printf(" %d bytes of data to %s", cc,
1405 		    rcvpktinfo ?  inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
1406 		    hbuf, sizeof(hbuf)) : "?");
1407 #endif
1408 	}
1409 }
1410 
1411 /*
1412  * Construct an Internet address representation.
1413  * If the nflag has been supplied, give
1414  * numeric value, otherwise try for symbolic name.
1415  */
1416 const char *
1417 inetname(sa)
1418 	struct sockaddr *sa;
1419 {
1420 	static char line[NI_MAXHOST], domain[MAXHOSTNAMELEN + 1];
1421 	static int first = 1;
1422 	char *cp;
1423 
1424 	if (first && !nflag) {
1425 		first = 0;
1426 		if (gethostname(domain, sizeof(domain)) == 0 &&
1427 		    (cp = strchr(domain, '.')))
1428 			(void) strlcpy(domain, cp + 1, sizeof(domain));
1429 		else
1430 			domain[0] = 0;
1431 	}
1432 	cp = NULL;
1433 	if (!nflag) {
1434 		if (getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
1435 		    NI_NAMEREQD) == 0) {
1436 			if ((cp = strchr(line, '.')) &&
1437 			    !strcmp(cp + 1, domain))
1438 				*cp = 0;
1439 			cp = line;
1440 		}
1441 	}
1442 	if (cp)
1443 		return cp;
1444 
1445 	if (getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
1446 	    NI_NUMERICHOST) != 0)
1447 		strlcpy(line, "invalid", sizeof(line));
1448 	return line;
1449 }
1450 
1451 void
1452 usage()
1453 {
1454 
1455 	fprintf(stderr,
1456 "usage: traceroute6 [-dIlnNrUv] [-f firsthop] [-g gateway] [-m hoplimit]\n"
1457 "       [-p port] [-q probes] [-s src] [-w waittime] target [datalen]\n");
1458 	exit(1);
1459 }
1460