xref: /minix/usr.sbin/traceroute6/traceroute6.c (revision fb9c64b2)
1 /*	$NetBSD: traceroute6.c,v 1.43 2012/12/10 18:11:33 christos Exp $	*/
2 /*	$KAME: traceroute6.c,v 1.67 2004/01/25 03:24:39 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. Neither the name of the University nor the names of its contributors
49  *    may be used to endorse or promote products derived from this software
50  *    without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62  * SUCH DAMAGE.
63  */
64 
65 #if 0
66 #ifndef lint
67 static char copyright[] =
68 "@(#) Copyright (c) 1990, 1993\n\
69 	The Regents of the University of California.  All rights reserved.\n";
70 #endif /* not lint */
71 
72 #ifndef lint
73 static char sccsid[] = "@(#)traceroute.c	8.1 (Berkeley) 6/6/93";
74 #endif /* not lint */
75 #else
76 #include <sys/cdefs.h>
77 #ifndef lint
78 __RCSID("$NetBSD: traceroute6.c,v 1.43 2012/12/10 18:11:33 christos Exp $");
79 #endif
80 #endif
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 a 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 } __packed;
310 
311 static u_char	packet[512];		/* last inbound (icmp) packet */
312 static struct opacket	*outpacket;	/* last output (udp) packet */
313 
314 static ssize_t	wait_for_reply(int, struct msghdr *);
315 #ifdef IPSEC
316 #ifdef IPSEC_POLICY_IPSEC
317 static int	setpolicy(int so, const char *policy);
318 #endif
319 #endif
320 static void send_probe(int, u_long);
321 static struct udphdr *get_udphdr(struct ip6_hdr *, u_char *);
322 #if 0
323 static int get_hoplim(struct msghdr *);
324 #endif
325 static double deltaT(struct timeval *, struct timeval *);
326 static const char *pr_type(int);
327 static int packet_ok(struct msghdr *, ssize_t, int);
328 static void print(struct msghdr *, int);
329 static const char *inetname(struct sockaddr *);
330 static void usage(void) __attribute__((__noreturn__));
331 
332 static int rcvsock;		/* receive (icmp) socket file descriptor */
333 static int sndsock;		/* send (udp) socket file descriptor */
334 
335 static struct msghdr rcvmhdr;
336 static struct iovec rcviov[2];
337 static int rcvhlim;
338 static struct in6_pktinfo *rcvpktinfo;
339 
340 static struct sockaddr_in6 Src, Dst, Rcv;
341 static u_long datalen;			/* How much data */
342 #define	ICMP6ECHOLEN	8
343 /* XXX: 2064 = 127(max hops in type 0 rthdr) * sizeof(ip6_hdr) + 16(margin) */
344 static char rtbuf[2064];
345 #ifdef USE_RFC3542
346 static struct ip6_rthdr *rth;
347 #endif
348 static struct cmsghdr *cmsg;
349 
350 static char *source;
351 static char *hostname;
352 
353 static u_long nprobes = 3;
354 static u_long first_hop = 1;
355 static u_long max_hops = 30;
356 static u_int16_t srcport;
357 static u_int16_t port = 32768+666;/* start udp dest port # for probe packets */
358 static u_int16_t ident;
359 static int options;		/* socket options */
360 static int verbose;
361 static int waittime = 5;	/* time to wait for response (in seconds) */
362 static int nflag;		/* print addresses numerically */
363 static int useicmp;
364 static int lflag;		/* print both numerical address & hostname */
365 static int as_path;		/* print as numbers for each hop */
366 static char *as_server = NULL;
367 static void *asn;
368 
369 int
370 main(int argc, char *argv[])
371 {
372 	int mib[4] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_DEFHLIM };
373 	char hbuf[NI_MAXHOST], src0[NI_MAXHOST], *ep;
374 	int ch, i, on = 1, seq, rcvcmsglen, error;
375 	u_long 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 
382 	/*
383 	 * Receive ICMP
384 	 */
385 	if ((rcvsock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0)
386 		err(5, "socket(ICMPv6)");
387 
388 	/* revoke privs */
389 	seteuid(getuid());
390 	setuid(getuid());
391 
392 	size = sizeof(i);
393 	(void) sysctl(mib, sizeof(mib)/sizeof(mib[0]), &i, &size, NULL, 0);
394 	max_hops = i;
395 
396 	/* specify to tell receiving interface */
397 #ifdef IPV6_RECVPKTINFO
398 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
399 	    sizeof(on)) < 0)
400 		err(1, "setsockopt(IPV6_RECVPKTINFO)");
401 #else  /* old adv. API */
402 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
403 	    sizeof(on)) < 0)
404 		err(1, "setsockopt(IPV6_PKTINFO)");
405 #endif
406 
407 	/* specify to tell value of hoplimit field of received IP6 hdr */
408 #ifdef IPV6_RECVHOPLIMIT
409 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
410 	    sizeof(on)) < 0)
411 		err(1, "setsockopt(IPV6_RECVHOPLIMIT)");
412 #else  /* old adv. API */
413 	if (setsockopt(rcvsock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
414 	    sizeof(on)) < 0)
415 		err(1, "setsockopt(IPV6_HOPLIMIT)");
416 #endif
417 
418 	seq = 0;
419 
420 	while ((ch = getopt(argc, argv, "aA:df:g:Ilm:np:q:rs:w:v")) != -1)
421 		switch (ch) {
422 		case 'a':
423 			as_path = 1;
424 			break;
425 		case 'A':
426 			as_path = 1;
427 			as_server = optarg;
428 			break;
429 		case 'd':
430 			options |= SO_DEBUG;
431 			break;
432 		case 'f':
433 			ep = NULL;
434 			errno = 0;
435 			first_hop = strtoul(optarg, &ep, 0);
436 			if (errno || !*optarg || *ep|| first_hop > 255)
437 				errx(1, "Invalid min hoplimit `%s'", optarg);
438 			break;
439 		case 'g':
440 			hp = getipnodebyname(optarg, AF_INET6, 0, &h_errno);
441 			if (hp == NULL)
442 				errx(1, "Unknown host `%s'", optarg);
443 #ifdef USE_RFC3542
444 			if (rth == NULL) {
445 				/*
446 				 * XXX: We can't detect the number of
447 				 * intermediate nodes yet.
448 				 */
449 				if ((rth = inet6_rth_init((void *)rtbuf,
450 				    sizeof(rtbuf), IPV6_RTHDR_TYPE_0,
451 				    0)) == NULL) {
452 					errx(1, "inet6_rth_init failed");
453 				}
454 			}
455 			if (inet6_rth_add((void *)rth,
456 			    (struct in6_addr *)hp->h_addr))
457 				errx(1, "inet6_rth_add failed for `%s'",
458 				    optarg);
459 #else  /* old advanced API */
460 			if (cmsg == NULL)
461 				cmsg = inet6_rthdr_init(rtbuf,
462 				    IPV6_RTHDR_TYPE_0);
463 			inet6_rthdr_add(cmsg, (struct in6_addr *)hp->h_addr,
464 			    IPV6_RTHDR_LOOSE);
465 #endif
466 			freehostent(hp);
467 			break;
468 		case 'I':
469 			useicmp++;
470 			/* same as ping6 */
471 			ident = htons(arc4random() & 0xffff);
472 			break;
473 		case 'l':
474 			lflag++;
475 			break;
476 		case 'm':
477 			ep = NULL;
478 			errno = 0;
479 			max_hops = strtoul(optarg, &ep, 0);
480 			if (errno || !*optarg || *ep || max_hops > 255)
481 				errx(1, "Invalid max hoplimit `%s'", optarg);
482 			break;
483 		case 'n':
484 			nflag++;
485 			break;
486 		case 'p':
487 			ep = NULL;
488 			errno = 0;
489 			lport = strtoul(optarg, &ep, 0);
490 			if (errno || !*optarg || *ep)
491 				errx(1, "Invalid port `%s'", optarg);
492 			if (lport == 0 || lport != (lport & 0xffff))
493 				errx(1, "Port `%s' out of range", optarg);
494 			port = lport & 0xffff;
495 			break;
496 		case 'q':
497 			ep = NULL;
498 			errno = 0;
499 			nprobes = strtoul(optarg, &ep, 0);
500 			if (errno || !*optarg || *ep)
501 				errx(1, "Invalid nprobes `%s'", optarg);
502 			if (nprobes < 1)
503 				errx(1, "nprobes `%s' must be > 0", optarg);
504 			break;
505 		case 'r':
506 			options |= SO_DONTROUTE;
507 			break;
508 		case 's':
509 			/*
510 			 * set the ip source address of the outbound
511 			 * probe (e.g., on a multi-homed host).
512 			 */
513 			source = optarg;
514 			break;
515 		case 'v':
516 			verbose++;
517 			break;
518 		case 'w':
519 			ep = NULL;
520 			errno = 0;
521 			waittime = strtoul(optarg, &ep, 0);
522 			if (errno || !*optarg || *ep)
523 				errx(1, "Invalid wait time `%s'", optarg);
524 			if (waittime <= 1)
525 				errx(1, "Wait `%s' must be > 1 sec", optarg);
526 			break;
527 		default:
528 			usage();
529 		}
530 	argc -= optind;
531 	argv += optind;
532 
533 	if (max_hops < first_hop)
534 		errx(1, "max hoplimit `%lu' must be larger than "
535 		    "first hoplimit `%lu'", max_hops, first_hop);
536 
537 	if (argc < 1 || argc > 2)
538 		usage();
539 
540 #if 1
541 	setvbuf(stdout, NULL, _IOLBF, BUFSIZ);
542 #else
543 	setlinebuf(stdout);
544 #endif
545 
546 	memset(&hints, 0, sizeof(hints));
547 	hints.ai_family = PF_INET6;
548 	hints.ai_socktype = SOCK_RAW;
549 	hints.ai_protocol = IPPROTO_ICMPV6;
550 	hints.ai_flags = AI_CANONNAME;
551 	error = getaddrinfo(*argv, NULL, &hints, &res);
552 	if (error)
553 		errx(1, "%s", gai_strerror(error));
554 	if (res->ai_addrlen != sizeof(Dst))
555 		errx(1, "size of sockaddr mismatch");
556 	memcpy(&Dst, res->ai_addr, res->ai_addrlen);
557 	hostname = res->ai_canonname ? strdup(res->ai_canonname) : *argv;
558 	if (!hostname)
559 		err(1, NULL);
560 	if (res->ai_next) {
561 		if (getnameinfo(res->ai_addr, res->ai_addrlen, hbuf,
562 		    sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
563 			strlcpy(hbuf, "?", sizeof(hbuf));
564 		warnx("`%s' has multiple addresses; using `%s'",
565 		    hostname, hbuf);
566 	}
567 
568 	if (*++argv) {
569 		ep = NULL;
570 		errno = 0;
571 		datalen = strtoul(*argv, &ep, 0);
572 		if (errno || !*argv || *ep)
573 			errx(1, "Invalid packet length `%s'", *argv);
574 	}
575 	if (useicmp)
576 		minlen = ICMP6ECHOLEN + sizeof(struct tv32);
577 	else
578 		minlen = sizeof(struct opacket);
579 	if (datalen < minlen)
580 		datalen = minlen;
581 	else if (datalen >= MAXPACKET)
582 		errx(1, "Packet size must be %lu <= s < %lu",
583 		    minlen, (u_long)MAXPACKET);
584 	outpacket = (struct opacket *)malloc((unsigned)datalen);
585 	if (!outpacket)
586 		err(1, NULL);
587 	memset(outpacket, 0, datalen);
588 
589 	/* initialize msghdr for receiving packets */
590 	rcviov[0].iov_base = (caddr_t)packet;
591 	rcviov[0].iov_len = sizeof(packet);
592 	rcvmhdr.msg_name = (caddr_t)&Rcv;
593 	rcvmhdr.msg_namelen = sizeof(Rcv);
594 	rcvmhdr.msg_iov = rcviov;
595 	rcvmhdr.msg_iovlen = 1;
596 	rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
597 	    CMSG_SPACE(sizeof(int));
598 	if ((rcvcmsgbuf = malloc(rcvcmsglen)) == NULL)
599 		err(1, NULL);
600 	rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
601 	rcvmhdr.msg_controllen = rcvcmsglen;
602 
603 	if (options & SO_DEBUG)
604 		(void) setsockopt(rcvsock, SOL_SOCKET, SO_DEBUG,
605 		    (char *)&on, sizeof(on));
606 	if (options & SO_DONTROUTE)
607 		(void) setsockopt(rcvsock, SOL_SOCKET, SO_DONTROUTE,
608 		    (char *)&on, sizeof(on));
609 #ifdef IPSEC
610 #ifdef IPSEC_POLICY_IPSEC
611 	/*
612 	 * do not raise error even if setsockopt fails, kernel may have ipsec
613 	 * turned off.
614 	 */
615 	if (setpolicy(rcvsock, "in bypass") < 0)
616 		errx(1, "%s", ipsec_strerror());
617 	if (setpolicy(rcvsock, "out bypass") < 0)
618 		errx(1, "%s", ipsec_strerror());
619 #else
620     {
621 	int level = IPSEC_LEVEL_NONE;
622 
623 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_ESP_TRANS_LEVEL, &level,
624 	    sizeof(level));
625 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_ESP_NETWORK_LEVEL, &level,
626 	    sizeof(level));
627 #ifdef IP_AUTH_TRANS_LEVEL
628 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_TRANS_LEVEL, &level,
629 	    sizeof(level));
630 #else
631 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_LEVEL, &level,
632 	    sizeof(level));
633 #endif
634 #ifdef IP_AUTH_NETWORK_LEVEL
635 	(void)setsockopt(rcvsock, IPPROTO_IPV6, IPV6_AUTH_NETWORK_LEVEL, &level,
636 	    sizeof(level));
637 #endif
638     }
639 #endif /*IPSEC_POLICY_IPSEC*/
640 #endif /*IPSEC*/
641 
642 	/*
643 	 * Send UDP or ICMP
644 	 */
645 	if (useicmp) {
646 		sndsock = rcvsock;
647 	} else {
648 		if ((sndsock = socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
649 			err(5, "socket(SOCK_DGRAM)");
650 	}
651 #ifdef SO_SNDBUF
652 	i = datalen;
653 	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&i,
654 	    sizeof(i)) < 0)
655 		err(6, "setsockopt(SO_SNDBUF)");
656 #endif /* SO_SNDBUF */
657 	if (options & SO_DEBUG)
658 		(void) setsockopt(sndsock, SOL_SOCKET, SO_DEBUG,
659 		    (char *)&on, sizeof(on));
660 	if (options & SO_DONTROUTE)
661 		(void) setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE,
662 		    (char *)&on, sizeof(on));
663 #ifdef USE_RFC3542
664 	if (rth) {/* XXX: there is no library to finalize the header... */
665 		rth->ip6r_len = rth->ip6r_segleft * 2;
666 		if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_RTHDR,
667 		    (void *)rth, (rth->ip6r_len + 1) << 3))
668 			err(1, "setsockopt(IPV6_RTHDR)");
669 	}
670 #else  /* old advanced API */
671 	if (cmsg != NULL) {
672 		inet6_rthdr_lasthop(cmsg, IPV6_RTHDR_LOOSE);
673 		if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_PKTOPTIONS,
674 		    rtbuf, cmsg->cmsg_len) < 0)
675 			err(1, "setsockopt(IPV6_PKTOPTIONS)");
676 	}
677 #endif /* USE_RFC3542 */
678 #ifdef IPSEC
679 #ifdef IPSEC_POLICY_IPSEC
680 	/*
681 	 * do not raise error even if setsockopt fails, kernel may have ipsec
682 	 * turned off.
683 	 */
684 	if (setpolicy(sndsock, "in bypass") < 0)
685 		errx(1, "%s", ipsec_strerror());
686 	if (setpolicy(sndsock, "out bypass") < 0)
687 		errx(1, "%s", ipsec_strerror());
688 #else
689     {
690 	int level = IPSEC_LEVEL_BYPASS;
691 
692 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_ESP_TRANS_LEVEL, &level,
693 	    sizeof(level));
694 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_ESP_NETWORK_LEVEL, &level,
695 	    sizeof(level));
696 #ifdef IP_AUTH_TRANS_LEVEL
697 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_TRANS_LEVEL, &level,
698 	    sizeof(level));
699 #else
700 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_LEVEL, &level,
701 	    sizeof(level));
702 #endif
703 #ifdef IP_AUTH_NETWORK_LEVEL
704 	(void)setsockopt(sndsock, IPPROTO_IPV6, IPV6_AUTH_NETWORK_LEVEL, &level,
705 	    sizeof(level));
706 #endif
707     }
708 #endif /*IPSEC_POLICY_IPSEC*/
709 #endif /*IPSEC*/
710 
711 	/*
712 	 * Source selection
713 	 */
714 	memset(&Src, 0, sizeof(Src));
715 	if (source) {
716 		struct addrinfo hints0, *res0;
717 		int error0;
718 
719 		memset(&hints0, 0, sizeof(hints0));
720 		hints0.ai_family = AF_INET6;
721 		hints0.ai_socktype = SOCK_DGRAM;	/*dummy*/
722 		hints0.ai_flags = AI_NUMERICHOST;
723 		error0 = getaddrinfo(source, "0", &hints0, &res0);
724 		if (error0)
725 			errx(1, "Cannot get address for `%s' (%s)", source,
726 			    gai_strerror(error0));
727 		if (res0->ai_addrlen > sizeof(Src))
728 			errx(1, "Bad incompatible address length");
729 		memcpy(&Src, res0->ai_addr, res0->ai_addrlen);
730 		freeaddrinfo(res0);
731 	} else {
732 		struct sockaddr_in6 Nxt;
733 		int dummy;
734 		socklen_t len;
735 
736 		Nxt = Dst;
737 		Nxt.sin6_port = htons(DUMMY_PORT);
738 		if (cmsg != NULL)
739 			memcpy( &Nxt.sin6_addr, inet6_rthdr_getaddr(cmsg, 1),
740 			    sizeof(Nxt.sin6_addr));
741 		if ((dummy = socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
742 			err(1, "socket");
743 		if (connect(dummy, (struct sockaddr *)&Nxt, Nxt.sin6_len) < 0)
744 			err(1, "connect");
745 		len = sizeof(Src);
746 		if (getsockname(dummy, (struct sockaddr *)&Src, &len) < 0)
747 			err(1, "getsockname");
748 		if ((error = getnameinfo((struct sockaddr *)&Src, Src.sin6_len,
749 		    src0, sizeof(src0), NULL, 0, NI_NUMERICHOST)))
750 			errx(1, "getnameinfo failed for source (%s)",
751 			    gai_strerror(error));
752 		source = src0;
753 		close(dummy);
754 	}
755 
756 	Src.sin6_port = htons(0);
757 	if (bind(sndsock, (struct sockaddr *)&Src, Src.sin6_len) < 0)
758 		err(1, "bind");
759 
760 	{
761 		socklen_t len;
762 
763 		len = sizeof(Src);
764 		if (getsockname(sndsock, (struct sockaddr *)&Src, &len) < 0)
765 			err(1, "bind");
766 		srcport = ntohs(Src.sin6_port);
767 	}
768 
769 	if (as_path) {
770 		asn = as_setup(as_server);
771 		if (asn == NULL) {
772 			warnx("as_setup failed, AS# lookups disabled");
773 			(void)fflush(stderr);
774 			as_path = 0;
775 		}
776 	 }
777 
778 	/*
779 	 * Message to users
780 	 */
781 	if (getnameinfo((struct sockaddr *)&Dst, Dst.sin6_len, hbuf,
782 	    sizeof(hbuf), NULL, 0, NI_NUMERICHOST))
783 		strlcpy(hbuf, "(invalid)", sizeof(hbuf));
784 	fprintf(stderr, "traceroute6");
785 	fprintf(stderr, " to %s (%s)", hostname, hbuf);
786 	if (source)
787 		fprintf(stderr, " from %s", source);
788 	fprintf(stderr, ", %lu hops max, %lu byte packets\n",
789 	    max_hops, datalen);
790 	(void) fflush(stderr);
791 
792 	if (first_hop > 1)
793 		printf("Skipping %lu intermediate hops\n", first_hop - 1);
794 
795 	/*
796 	 * Main loop
797 	 */
798 	for (hops = first_hop; hops <= max_hops; ++hops) {
799 		struct in6_addr lastaddr;
800 		int got_there = 0;
801 		u_long unreachable = 0;
802 
803 		printf("%2lu ", hops);
804 		memset(&lastaddr, 0, sizeof(lastaddr));
805 		for (probe = 0; probe < nprobes; ++probe) {
806 			int cc;
807 			struct timeval t1, t2;
808 
809 			(void) gettimeofday(&t1, NULL);
810 			if (!useicmp && htons((in_port_t)(port + seq + 1)) == 0)
811 				seq++;
812 			send_probe(++seq, hops);
813 			while ((cc = wait_for_reply(rcvsock, &rcvmhdr))) {
814 				(void) gettimeofday(&t2, NULL);
815 				if ((i = packet_ok(&rcvmhdr, cc, seq))) {
816 					if (!IN6_ARE_ADDR_EQUAL(&Rcv.sin6_addr,
817 					    &lastaddr)) {
818 						print(&rcvmhdr, cc);
819 						lastaddr = Rcv.sin6_addr;
820 					}
821 					printf("  %g ms", deltaT(&t1, &t2));
822 					switch (i - 1) {
823 					case ICMP6_DST_UNREACH_NOROUTE:
824 						++unreachable;
825 						printf(" !N");
826 						break;
827 					case ICMP6_DST_UNREACH_ADMIN:
828 						++unreachable;
829 						printf(" !X");
830 						break;
831 					case ICMP6_DST_UNREACH_NOTNEIGHBOR:
832 						++unreachable;
833 						printf(" !S");
834 						break;
835 					case ICMP6_DST_UNREACH_ADDR:
836 						++unreachable;
837 						printf(" !H");
838 						break;
839 					case ICMP6_DST_UNREACH_NOPORT:
840 						if (rcvhlim >= 0 &&
841 						    rcvhlim <= 1)
842 							printf(" !");
843 						++got_there;
844 						break;
845 					}
846 					break;
847 				}
848 			}
849 			if (cc == 0)
850 				printf(" *");
851 			(void) fflush(stdout);
852 		}
853 		putchar('\n');
854 		if (got_there ||
855 		    (unreachable > 0 && unreachable >= ((nprobes + 1) / 2))) {
856 			exit(0);
857 		}
858 	}
859 
860 	if (as_path)
861 		as_shutdown(asn);
862 
863 	exit(0);
864 }
865 
866 static ssize_t
867 wait_for_reply(int sock, struct msghdr *mhdr)
868 {
869 #ifdef HAVE_POLL
870 	struct pollfd pfd[1];
871 	ssize_t cc = 0;
872 
873 	pfd[0].fd = sock;
874 	pfd[0].events = POLLIN;
875 	pfd[0].revents = 0;
876 
877 	if (poll(pfd, 1, waittime * 1000) > 0)
878 		cc = recvmsg(rcvsock, mhdr, 0);
879 
880 	return cc;
881 #else
882 	fd_set *fdsp;
883 	struct timeval wait;
884 	ssize_t cc = 0;
885 	int fdsn;
886 
887 	fdsn = howmany(sock + 1, NFDBITS) * sizeof(fd_mask);
888 	if ((fdsp = (fd_set *)malloc(fdsn)) == NULL)
889 		err(1, "malloc");
890 	memset(fdsp, 0, fdsn);
891 	FD_SET(sock, fdsp);
892 	wait.tv_sec = waittime; wait.tv_usec = 0;
893 
894 	if (select(sock+1, fdsp, (fd_set *)0, (fd_set *)0, &wait) > 0)
895 		cc = recvmsg(rcvsock, mhdr, 0);
896 
897 	free(fdsp);
898 	return cc;
899 #endif
900 }
901 
902 #ifdef IPSEC
903 #ifdef IPSEC_POLICY_IPSEC
904 static int
905 setpolicy(int so, const char *policy)
906 {
907 	char *buf;
908 
909 	buf = ipsec_set_policy(policy, strlen(policy));
910 	if (buf == NULL) {
911 		warnx("%s", ipsec_strerror());
912 		return -1;
913 	}
914 	(void)setsockopt(so, IPPROTO_IPV6, IPV6_IPSEC_POLICY,
915 	    buf, ipsec_get_policylen(buf));
916 
917 	free(buf);
918 
919 	return 0;
920 }
921 #endif
922 #endif
923 
924 static void
925 send_probe(int seq, u_long hops)
926 {
927 	struct timeval tv;
928 	struct tv32 tv32;
929 	int i;
930 
931 	i = hops;
932 	if (setsockopt(sndsock, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
933 	    (char *)&i, sizeof(i)) < 0)
934 		warn("setsockopt IPV6_UNICAST_HOPS");
935 
936 	Dst.sin6_port = htons(port + seq);
937 	(void) gettimeofday(&tv, NULL);
938 	tv32.tv32_sec = htonl(tv.tv_sec);
939 	tv32.tv32_usec = htonl(tv.tv_usec);
940 
941 	if (useicmp) {
942 		struct icmp6_hdr *icp = (struct icmp6_hdr *)outpacket;
943 
944 		icp->icmp6_type = ICMP6_ECHO_REQUEST;
945 		icp->icmp6_code = 0;
946 		icp->icmp6_cksum = 0;
947 		icp->icmp6_id = ident;
948 		icp->icmp6_seq = htons(seq);
949 		memcpy(((u_int8_t *)outpacket + ICMP6ECHOLEN), &tv32,
950 		    sizeof(tv32));
951 	} else {
952 		struct opacket *op = outpacket;
953 
954 		op->seq = seq;
955 		op->hops = hops;
956 		memcpy(&op->tv, &tv32, sizeof tv32);
957 	}
958 
959 	i = sendto(sndsock, (char *)outpacket, datalen , 0,
960 	    (struct sockaddr *)&Dst, Dst.sin6_len);
961 	if (i < 0 || i != (int)datalen)  {
962 		if (i < 0)
963 			warnx("sendto");
964 		printf("traceroute6: wrote %s %lu chars, ret=%d\n",
965 		    hostname, datalen, i);
966 		(void) fflush(stdout);
967 	}
968 }
969 
970 #if 0
971 static int
972 get_hoplim(struct msghdr *mhdr)
973 {
974 	struct cmsghdr *cm;
975 
976 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
977 	    cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
978 		if (cm->cmsg_level == IPPROTO_IPV6 &&
979 		    cm->cmsg_type == IPV6_HOPLIMIT &&
980 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
981 			return *(int *)CMSG_DATA(cm);
982 	}
983 
984 	return -1;
985 }
986 #endif
987 
988 static double
989 deltaT(struct timeval *t1p, struct timeval *t2p)
990 {
991 	double dt;
992 
993 	dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
994 	    (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
995 	return dt;
996 }
997 
998 /*
999  * Convert an ICMP "type" field to a printable string.
1000  */
1001 static const char *
1002 pr_type(int t0)
1003 {
1004 	u_char t = t0 & 0xff;
1005 	const char *cp;
1006 
1007 	switch (t) {
1008 	case ICMP6_DST_UNREACH:
1009 		cp = "Destination Unreachable";
1010 		break;
1011 	case ICMP6_PACKET_TOO_BIG:
1012 		cp = "Packet Too Big";
1013 		break;
1014 	case ICMP6_TIME_EXCEEDED:
1015 		cp = "Time Exceeded";
1016 		break;
1017 	case ICMP6_PARAM_PROB:
1018 		cp = "Parameter Problem";
1019 		break;
1020 	case ICMP6_ECHO_REQUEST:
1021 		cp = "Echo Request";
1022 		break;
1023 	case ICMP6_ECHO_REPLY:
1024 		cp = "Echo Reply";
1025 		break;
1026 	case ICMP6_MEMBERSHIP_QUERY:
1027 		cp = "Group Membership Query";
1028 		break;
1029 	case ICMP6_MEMBERSHIP_REPORT:
1030 		cp = "Group Membership Report";
1031 		break;
1032 	case ICMP6_MEMBERSHIP_REDUCTION:
1033 		cp = "Group Membership Reduction";
1034 		break;
1035 	case ND_ROUTER_SOLICIT:
1036 		cp = "Router Solicitation";
1037 		break;
1038 	case ND_ROUTER_ADVERT:
1039 		cp = "Router Advertisement";
1040 		break;
1041 	case ND_NEIGHBOR_SOLICIT:
1042 		cp = "Neighbor Solicitation";
1043 		break;
1044 	case ND_NEIGHBOR_ADVERT:
1045 		cp = "Neighbor Advertisement";
1046 		break;
1047 	case ND_REDIRECT:
1048 		cp = "Redirect";
1049 		break;
1050 	default:
1051 		cp = "Unknown";
1052 		break;
1053 	}
1054 	return cp;
1055 }
1056 
1057 static int
1058 packet_ok(struct msghdr *mhdr, ssize_t cc, int seq)
1059 {
1060 	struct icmp6_hdr *icp;
1061 	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
1062 	u_char type, code;
1063 	char *buf = (char *)mhdr->msg_iov[0].iov_base;
1064 	struct cmsghdr *cm;
1065 	int *hlimp;
1066 	char hbuf[NI_MAXHOST];
1067 
1068 #ifdef OLDRAWSOCKET
1069 	int hlen;
1070 	struct ip6_hdr *ip;
1071 #endif
1072 
1073 #ifdef OLDRAWSOCKET
1074 	ip = (struct ip6_hdr *) buf;
1075 	hlen = sizeof(struct ip6_hdr);
1076 	if (cc < hlen + sizeof(struct icmp6_hdr)) {
1077 		if (verbose) {
1078 			if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1079 			    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
1080 				strlcpy(hbuf, "invalid", sizeof(hbuf));
1081 			printf("packet too short (%d bytes) from %s\n", cc,
1082 			    hbuf);
1083 		}
1084 		return 0;
1085 	}
1086 	cc -= hlen;
1087 	icp = (struct icmp6_hdr *)(buf + hlen);
1088 #else
1089 	if (cc < (ssize_t)sizeof(struct icmp6_hdr)) {
1090 		if (verbose) {
1091 			if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1092 			    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
1093 				strlcpy(hbuf, "invalid", sizeof(hbuf));
1094 			printf("data too short (%zd bytes) from %s\n", cc,
1095 			    hbuf);
1096 		}
1097 		return 0;
1098 	}
1099 	icp = (struct icmp6_hdr *)buf;
1100 #endif
1101 	/* get optional information via advanced API */
1102 	rcvpktinfo = NULL;
1103 	hlimp = NULL;
1104 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
1105 	    cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
1106 		if (cm->cmsg_level == IPPROTO_IPV6 &&
1107 		    cm->cmsg_type == IPV6_PKTINFO &&
1108 		    cm->cmsg_len ==
1109 		    CMSG_LEN(sizeof(struct in6_pktinfo)))
1110 			rcvpktinfo = (struct in6_pktinfo *)(CMSG_DATA(cm));
1111 
1112 		if (cm->cmsg_level == IPPROTO_IPV6 &&
1113 		    cm->cmsg_type == IPV6_HOPLIMIT &&
1114 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
1115 			hlimp = (int *)CMSG_DATA(cm);
1116 	}
1117 	if (rcvpktinfo == NULL || hlimp == NULL) {
1118 		warnx("failed to get received hop limit or packet info");
1119 #if 0
1120 		return 0;
1121 #else
1122 		rcvhlim = 0;	/*XXX*/
1123 #endif
1124 	}
1125 	else
1126 		rcvhlim = *hlimp;
1127 
1128 	type = icp->icmp6_type;
1129 	code = icp->icmp6_code;
1130 	if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
1131 	    || type == ICMP6_DST_UNREACH) {
1132 		struct ip6_hdr *hip;
1133 		struct udphdr *up;
1134 
1135 		hip = (struct ip6_hdr *)(icp + 1);
1136 		if ((up = get_udphdr(hip, (u_char *)(buf + cc))) == NULL) {
1137 			if (verbose)
1138 				warnx("failed to get upper layer header");
1139 			return 0;
1140 		}
1141 		if (useicmp &&
1142 		    ((struct icmp6_hdr *)up)->icmp6_id == ident &&
1143 		    ((struct icmp6_hdr *)up)->icmp6_seq == htons(seq))
1144 			return type == ICMP6_TIME_EXCEEDED ? -1 : code + 1;
1145 		else if (!useicmp &&
1146 		    up->uh_sport == htons(srcport) &&
1147 		    up->uh_dport == htons(port + seq))
1148 			return type == ICMP6_TIME_EXCEEDED ? -1 : code + 1;
1149 	} else if (useicmp && type == ICMP6_ECHO_REPLY) {
1150 		if (icp->icmp6_id == ident &&
1151 		    icp->icmp6_seq == htons(seq))
1152 			return ICMP6_DST_UNREACH_NOPORT + 1;
1153 	}
1154 	if (verbose) {
1155 		char sbuf[NI_MAXHOST+1], dbuf[INET6_ADDRSTRLEN];
1156 		u_int8_t *p;
1157 		ssize_t i;
1158 
1159 		if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1160 		    sbuf, sizeof(sbuf), NULL, 0, NI_NUMERICHOST) != 0)
1161 			strlcpy(sbuf, "invalid", sizeof(sbuf));
1162 		printf("\n%zd bytes from %s to %s", cc, sbuf,
1163 		    rcvpktinfo ? inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
1164 		    dbuf, sizeof(dbuf)) : "?");
1165 		printf(": icmp type %d (%s) code %d\n", type, pr_type(type),
1166 		    icp->icmp6_code);
1167 		p = (u_int8_t *)(icp + 1);
1168 #define WIDTH	16
1169 		for (i = 0; i < cc; i++) {
1170 			if (i % WIDTH == 0)
1171 				printf("%04zx:", i);
1172 			if (i % 4 == 0)
1173 				printf(" ");
1174 			printf("%02x", p[i]);
1175 			if (i % WIDTH == WIDTH - 1)
1176 				printf("\n");
1177 		}
1178 		if (cc % WIDTH != 0)
1179 			printf("\n");
1180 	}
1181 	return 0;
1182 }
1183 
1184 /*
1185  * Increment pointer until find the UDP or ICMP header.
1186  */
1187 static struct udphdr *
1188 get_udphdr(struct ip6_hdr *ip6, u_char *lim)
1189 {
1190 	u_char *cp = (u_char *)ip6, nh;
1191 	int hlen;
1192 
1193 	if (cp + sizeof(*ip6) >= lim)
1194 		return NULL;
1195 
1196 	nh = ip6->ip6_nxt;
1197 	cp += sizeof(struct ip6_hdr);
1198 
1199 	while (lim - cp >= 8) {
1200 		switch (nh) {
1201 		case IPPROTO_ESP:
1202 		case IPPROTO_TCP:
1203 			return NULL;
1204 		case IPPROTO_ICMPV6:
1205 			return useicmp ? (struct udphdr *)cp : NULL;
1206 		case IPPROTO_UDP:
1207 			return useicmp ? NULL : (struct udphdr *)cp;
1208 		case IPPROTO_FRAGMENT:
1209 			hlen = sizeof(struct ip6_frag);
1210 			nh = ((struct ip6_frag *)cp)->ip6f_nxt;
1211 			break;
1212 		case IPPROTO_AH:
1213 			hlen = (((struct ip6_ext *)cp)->ip6e_len + 2) << 2;
1214 			nh = ((struct ip6_ext *)cp)->ip6e_nxt;
1215 			break;
1216 		default:
1217 			hlen = (((struct ip6_ext *)cp)->ip6e_len + 1) << 3;
1218 			nh = ((struct ip6_ext *)cp)->ip6e_nxt;
1219 			break;
1220 		}
1221 
1222 		cp += hlen;
1223 	}
1224 
1225 	return NULL;
1226 }
1227 
1228 static void
1229 print(struct msghdr *mhdr, int cc)
1230 {
1231 	struct sockaddr_in6 *from = (struct sockaddr_in6 *)mhdr->msg_name;
1232 	char hbuf[NI_MAXHOST];
1233 
1234 	if (getnameinfo((struct sockaddr *)from, from->sin6_len,
1235 	    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
1236 		strlcpy(hbuf, "invalid", sizeof(hbuf));
1237 	if (as_path)
1238 		printf(" [AS%u]", as_lookup(asn, hbuf, AF_INET6));
1239 	if (nflag)
1240 		printf(" %s", hbuf);
1241 	else if (lflag)
1242 		printf(" %s (%s)", inetname((struct sockaddr *)from), hbuf);
1243 	else
1244 		printf(" %s", inetname((struct sockaddr *)from));
1245 
1246 	if (verbose) {
1247 #ifdef OLDRAWSOCKET
1248 		printf(" %d bytes to %s", cc,
1249 		    rcvpktinfo ? inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
1250 		    hbuf, sizeof(hbuf)) : "?");
1251 #else
1252 		printf(" %d bytes of data to %s", cc,
1253 		    rcvpktinfo ?  inet_ntop(AF_INET6, &rcvpktinfo->ipi6_addr,
1254 		    hbuf, sizeof(hbuf)) : "?");
1255 #endif
1256 	}
1257 }
1258 
1259 /*
1260  * Construct an Internet address representation.
1261  * If the nflag has been supplied, give
1262  * numeric value, otherwise try for symbolic name.
1263  */
1264 static const char *
1265 inetname(struct sockaddr *sa)
1266 {
1267 	static char line[NI_MAXHOST], domain[MAXHOSTNAMELEN + 1];
1268 	static int first = 1;
1269 	char *cp;
1270 
1271 	if (first && !nflag) {
1272 		first = 0;
1273 		if (gethostname(domain, sizeof(domain)) == 0 &&
1274 		    (cp = strchr(domain, '.')))
1275 			(void) strlcpy(domain, cp + 1, sizeof(domain));
1276 		else
1277 			domain[0] = 0;
1278 	}
1279 	cp = NULL;
1280 	if (!nflag) {
1281 		if (getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
1282 		    NI_NAMEREQD) == 0) {
1283 			if ((cp = strchr(line, '.')) &&
1284 			    !strcmp(cp + 1, domain))
1285 				*cp = 0;
1286 			cp = line;
1287 		}
1288 	}
1289 	if (cp)
1290 		return cp;
1291 
1292 	if (getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
1293 	    NI_NUMERICHOST) != 0)
1294 		strlcpy(line, "invalid", sizeof(line));
1295 	return line;
1296 }
1297 
1298 static void
1299 usage(void)
1300 {
1301 
1302 	fprintf(stderr,
1303 "Usage: %s [-adIlnrv] [-A as_server] [-f firsthop] [-g gateway]\n"
1304 "\t[-m hoplimit] [-p port] [-q probes] [-s src] [-w waittime] target [datalen]\n",
1305 	getprogname());
1306 	exit(1);
1307 }
1308