xref: /freebsd/usr.sbin/traceroute/traceroute.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
1 /*
2  * Copyright (c) 1988, 1989, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that: (1) source code distributions
7  * retain the above copyright notice and this paragraph in its entirety, (2)
8  * distributions including binary code include the above copyright notice and
9  * this paragraph in its entirety in the documentation or other materials
10  * provided with the distribution, and (3) all advertising materials mentioning
11  * features or use of this software display the following acknowledgement:
12  * ``This product includes software developed by the University of California,
13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14  * the University nor the names of its contributors may be used to endorse
15  * or promote products derived from this software without specific prior
16  * written permission.
17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20  */
21 
22 /*
23  * traceroute host  - trace the route ip packets follow going to "host".
24  *
25  * Attempt to trace the route an ip packet would follow to some
26  * internet host.  We find out intermediate hops by launching probe
27  * packets with a small ttl (time to live) then listening for an
28  * icmp "time exceeded" reply from a gateway.  We start our probes
29  * with a ttl of one and increase by one until we get an icmp "port
30  * unreachable" (which means we got to "host") or hit a max (which
31  * defaults to net.inet.ip.ttl hops & can be changed with the -m flag).
32  * Three probes (change with -q flag) are sent at each ttl setting and
33  * a line is printed showing the ttl, address of the gateway and
34  * round trip time of each probe.  If the probe answers come from
35  * different gateways, the address of each responding system will
36  * be printed.  If there is no response within a 5 sec. timeout
37  * interval (changed with the -w flag), a "*" is printed for that
38  * probe.
39  *
40  * Probe packets are UDP format.  We don't want the destination
41  * host to process them so the destination port is set to an
42  * unlikely value (if some clod on the destination is using that
43  * value, it can be changed with the -p flag).
44  *
45  * A sample use might be:
46  *
47  *     [yak 71]% traceroute nis.nsf.net.
48  *     traceroute to nis.nsf.net (35.1.1.48), 64 hops max, 40 byte packets
49  *      1  helios.ee.lbl.gov (128.3.112.1)  19 ms  19 ms  0 ms
50  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
51  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  39 ms  19 ms
52  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  39 ms
53  *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  39 ms  39 ms  39 ms
54  *      6  128.32.197.4 (128.32.197.4)  40 ms  59 ms  59 ms
55  *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  59 ms
56  *      8  129.140.70.13 (129.140.70.13)  99 ms  99 ms  80 ms
57  *      9  129.140.71.6 (129.140.71.6)  139 ms  239 ms  319 ms
58  *     10  129.140.81.7 (129.140.81.7)  220 ms  199 ms  199 ms
59  *     11  nic.merit.edu (35.1.1.48)  239 ms  239 ms  239 ms
60  *
61  * Note that lines 2 & 3 are the same.  This is due to a buggy
62  * kernel on the 2nd hop system -- lbl-csam.arpa -- that forwards
63  * packets with a zero ttl.
64  *
65  * A more interesting example is:
66  *
67  *     [yak 72]% traceroute allspice.lcs.mit.edu.
68  *     traceroute to allspice.lcs.mit.edu (18.26.0.115), 64 hops max, 40 byte packets
69  *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
70  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  19 ms  19 ms
71  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  19 ms
72  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  19 ms  39 ms  39 ms
73  *      5  ccn-nerif22.Berkeley.EDU (128.32.168.22)  20 ms  39 ms  39 ms
74  *      6  128.32.197.4 (128.32.197.4)  59 ms  119 ms  39 ms
75  *      7  131.119.2.5 (131.119.2.5)  59 ms  59 ms  39 ms
76  *      8  129.140.70.13 (129.140.70.13)  80 ms  79 ms  99 ms
77  *      9  129.140.71.6 (129.140.71.6)  139 ms  139 ms  159 ms
78  *     10  129.140.81.7 (129.140.81.7)  199 ms  180 ms  300 ms
79  *     11  129.140.72.17 (129.140.72.17)  300 ms  239 ms  239 ms
80  *     12  * * *
81  *     13  128.121.54.72 (128.121.54.72)  259 ms  499 ms  279 ms
82  *     14  * * *
83  *     15  * * *
84  *     16  * * *
85  *     17  * * *
86  *     18  ALLSPICE.LCS.MIT.EDU (18.26.0.115)  339 ms  279 ms  279 ms
87  *
88  * (I start to see why I'm having so much trouble with mail to
89  * MIT.)  Note that the gateways 12, 14, 15, 16 & 17 hops away
90  * either don't send ICMP "time exceeded" messages or send them
91  * with a ttl too small to reach us.  14 - 17 are running the
92  * MIT C Gateway code that doesn't send "time exceeded"s.  God
93  * only knows what's going on with 12.
94  *
95  * The silent gateway 12 in the above may be the result of a bug in
96  * the 4.[23]BSD network code (and its derivatives):  4.x (x <= 3)
97  * sends an unreachable message using whatever ttl remains in the
98  * original datagram.  Since, for gateways, the remaining ttl is
99  * zero, the icmp "time exceeded" is guaranteed to not make it back
100  * to us.  The behavior of this bug is slightly more interesting
101  * when it appears on the destination system:
102  *
103  *      1  helios.ee.lbl.gov (128.3.112.1)  0 ms  0 ms  0 ms
104  *      2  lilac-dmc.Berkeley.EDU (128.32.216.1)  39 ms  19 ms  39 ms
105  *      3  lilac-dmc.Berkeley.EDU (128.32.216.1)  19 ms  39 ms  19 ms
106  *      4  ccngw-ner-cc.Berkeley.EDU (128.32.136.23)  39 ms  40 ms  19 ms
107  *      5  ccn-nerif35.Berkeley.EDU (128.32.168.35)  39 ms  39 ms  39 ms
108  *      6  csgw.Berkeley.EDU (128.32.133.254)  39 ms  59 ms  39 ms
109  *      7  * * *
110  *      8  * * *
111  *      9  * * *
112  *     10  * * *
113  *     11  * * *
114  *     12  * * *
115  *     13  rip.Berkeley.EDU (128.32.131.22)  59 ms !  39 ms !  39 ms !
116  *
117  * Notice that there are 12 "gateways" (13 is the final
118  * destination) and exactly the last half of them are "missing".
119  * What's really happening is that rip (a Sun-3 running Sun OS3.5)
120  * is using the ttl from our arriving datagram as the ttl in its
121  * icmp reply.  So, the reply will time out on the return path
122  * (with no notice sent to anyone since icmp's aren't sent for
123  * icmp's) until we probe with a ttl that's at least twice the path
124  * length.  I.e., rip is really only 7 hops away.  A reply that
125  * returns with a ttl of 1 is a clue this problem exists.
126  * Traceroute prints a "!" after the time if the ttl is <= 1.
127  * Since vendors ship a lot of obsolete (DEC's Ultrix, Sun 3.x) or
128  * non-standard (HPUX) software, expect to see this problem
129  * frequently and/or take care picking the target host of your
130  * probes.
131  *
132  * Other possible annotations after the time are !H, !N, !P (got a host,
133  * network or protocol unreachable, respectively), !S or !F (source
134  * route failed or fragmentation needed -- neither of these should
135  * ever occur and the associated gateway is busted if you see one).  If
136  * almost all the probes result in some kind of unreachable, traceroute
137  * will give up and exit.
138  *
139  * Notes
140  * -----
141  * This program must be run by root or be setuid.  (I suggest that
142  * you *don't* make it setuid -- casual use could result in a lot
143  * of unnecessary traffic on our poor, congested nets.)
144  *
145  * This program requires a kernel mod that does not appear in any
146  * system available from Berkeley:  A raw ip socket using proto
147  * IPPROTO_RAW must interpret the data sent as an ip datagram (as
148  * opposed to data to be wrapped in an ip datagram).  See the README
149  * file that came with the source to this program for a description
150  * of the mods I made to /sys/netinet/raw_ip.c.  Your mileage may
151  * vary.  But, again, ANY 4.x (x < 4) BSD KERNEL WILL HAVE TO BE
152  * MODIFIED TO RUN THIS PROGRAM.
153  *
154  * The udp port usage may appear bizarre (well, ok, it is bizarre).
155  * The problem is that an icmp message only contains 8 bytes of
156  * data from the original datagram.  8 bytes is the size of a udp
157  * header so, if we want to associate replies with the original
158  * datagram, the necessary information must be encoded into the
159  * udp header (the ip id could be used but there's no way to
160  * interlock with the kernel's assignment of ip id's and, anyway,
161  * it would have taken a lot more kernel hacking to allow this
162  * code to set the ip id).  So, to allow two or more users to
163  * use traceroute simultaneously, we use this task's pid as the
164  * source port (the high bit is set to move the port number out
165  * of the "likely" range).  To keep track of which probe is being
166  * replied to (so times and/or hop counts don't get confused by a
167  * reply that was delayed in transit), we increment the destination
168  * port number before each probe.
169  *
170  * Don't use this as a coding example.  I was trying to find a
171  * routing problem and this code sort-of popped out after 48 hours
172  * without sleep.  I was amazed it ever compiled, much less ran.
173  *
174  * I stole the idea for this program from Steve Deering.  Since
175  * the first release, I've learned that had I attended the right
176  * IETF working group meetings, I also could have stolen it from Guy
177  * Almes or Matt Mathis.  I don't know (or care) who came up with
178  * the idea first.  I envy the originators' perspicacity and I'm
179  * glad they didn't keep the idea a secret.
180  *
181  * Tim Seaver, Ken Adelman and C. Philip Wood provided bug fixes and/or
182  * enhancements to the original distribution.
183  *
184  * I've hacked up a round-trip-route version of this that works by
185  * sending a loose-source-routed udp datagram through the destination
186  * back to yourself.  Unfortunately, SO many gateways botch source
187  * routing, the thing is almost worthless.  Maybe one day...
188  *
189  *  -- Van Jacobson (van@ee.lbl.gov)
190  *     Tue Dec 20 03:50:13 PST 1988
191  */
192 
193 #include <sys/param.h>
194 #include <sys/capsicum.h>
195 #include <sys/file.h>
196 #include <sys/ioctl.h>
197 #include <sys/select.h>
198 #include <sys/socket.h>
199 #include <sys/sysctl.h>
200 #include <sys/time.h>
201 
202 #include <netinet/in_systm.h>
203 #include <netinet/in.h>
204 #include <netinet/ip.h>
205 #include <netinet/ip_var.h>
206 #include <netinet/ip_icmp.h>
207 #include <netinet/sctp.h>
208 #include <netinet/sctp_header.h>
209 #include <netinet/udp.h>
210 #include <netinet/tcp.h>
211 #include <netinet/tcpip.h>
212 
213 #include <arpa/inet.h>
214 
215 #ifdef WITH_CASPER
216 #include <libcasper.h>
217 #include <casper/cap_dns.h>
218 #endif
219 
220 #ifdef	IPSEC
221 #include <net/route.h>
222 #include <netipsec/ipsec.h>	/* XXX */
223 #endif	/* IPSEC */
224 
225 #include <ctype.h>
226 #include <capsicum_helpers.h>
227 #include <err.h>
228 #include <errno.h>
229 #include <fcntl.h>
230 #include <malloc.h>
231 #include <memory.h>
232 #include <netdb.h>
233 #include <stdio.h>
234 #include <stdlib.h>
235 #include <string.h>
236 #include <unistd.h>
237 
238 /* rfc1716 */
239 #ifndef ICMP_UNREACH_FILTER_PROHIB
240 #define ICMP_UNREACH_FILTER_PROHIB	13	/* admin prohibited filter */
241 #endif
242 #ifndef ICMP_UNREACH_HOST_PRECEDENCE
243 #define ICMP_UNREACH_HOST_PRECEDENCE	14	/* host precedence violation */
244 #endif
245 #ifndef ICMP_UNREACH_PRECEDENCE_CUTOFF
246 #define ICMP_UNREACH_PRECEDENCE_CUTOFF	15	/* precedence cutoff */
247 #endif
248 
249 #include "findsaddr.h"
250 #include "ifaddrlist.h"
251 #include "as.h"
252 #include "traceroute.h"
253 
254 /* Maximum number of gateways (include room for one noop) */
255 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(u_int32_t)))
256 
257 #ifndef MAXHOSTNAMELEN
258 #define MAXHOSTNAMELEN	64
259 #endif
260 
261 #define Fprintf (void)fprintf
262 #define Printf (void)printf
263 
264 /* What a GRE packet header looks like */
265 struct grehdr {
266 	u_int16_t   flags;
267 	u_int16_t   proto;
268 	u_int16_t   length;	/* PPTP version of these fields */
269 	u_int16_t   callId;
270 };
271 #ifndef IPPROTO_GRE
272 #define IPPROTO_GRE	47
273 #endif
274 
275 /* For GRE, we prepare what looks like a PPTP packet */
276 #define GRE_PPTP_PROTO	0x880b
277 
278 /* Host name and address list */
279 struct hostinfo {
280 	char *name;
281 	int n;
282 	u_int32_t *addrs;
283 };
284 
285 /* Data section of the probe packet */
286 struct outdata {
287 	u_char seq;		/* sequence number of this packet */
288 	u_char ttl;		/* ttl packet left with */
289 	struct timeval tv;	/* time packet left */
290 };
291 
292 u_char	packet[512];		/* last inbound (icmp) packet */
293 
294 struct ip *outip;		/* last output ip packet */
295 u_char *outp;		/* last output inner protocol packet */
296 
297 struct ip *hip = NULL;		/* Quoted IP header */
298 int hiplen = 0;
299 
300 /* loose source route gateway list (including room for final destination) */
301 u_int32_t gwlist[NGATEWAYS + 1];
302 
303 int s;				/* receive (icmp) socket file descriptor */
304 int sndsock;			/* send (udp) socket file descriptor */
305 
306 struct sockaddr whereto;	/* Who to try to reach */
307 struct sockaddr wherefrom;	/* Who we are */
308 int packlen;			/* total length of packet */
309 int protlen;			/* length of protocol part of packet */
310 int minpacket;			/* min ip packet size */
311 int maxpacket = 32 * 1024;	/* max ip packet size */
312 int pmtu;			/* Path MTU Discovery (RFC1191) */
313 u_int pausemsecs;
314 
315 char *prog;
316 char *source;
317 char *hostname;
318 char *device;
319 static const char devnull[] = "/dev/null";
320 
321 int nprobes = -1;
322 int max_ttl;
323 int first_ttl = 1;
324 u_short ident;
325 u_short port;			/* protocol specific base "port" */
326 
327 int options;			/* socket options */
328 int verbose;
329 int waittime = 5;		/* time to wait for response (in seconds) */
330 int nflag;			/* print addresses numerically */
331 int as_path;			/* print as numbers for each hop */
332 char *as_server = NULL;
333 void *asn;
334 #ifdef CANT_HACK_IPCKSUM
335 int doipcksum = 0;		/* don't calculate ip checksums by default */
336 #else
337 int doipcksum = 1;		/* calculate ip checksums by default */
338 #endif
339 int optlen;			/* length of ip options */
340 int fixedPort = 0;		/* Use fixed destination port for TCP and UDP */
341 int printdiff = 0;		/* Print the difference between sent and quoted */
342 int ecnflag = 0;		/* ECN bleaching detection flag */
343 
344 extern int optind;
345 extern int opterr;
346 extern char *optarg;
347 
348 #ifdef WITH_CASPER
349 static cap_channel_t *capdns;
350 #endif
351 
352 /* Forwards */
353 double	deltaT(struct timeval *, struct timeval *);
354 void	freehostinfo(struct hostinfo *);
355 void	getaddr(u_int32_t *, char *);
356 struct	hostinfo *gethostinfo(char *);
357 u_short	in_cksum(u_short *, int);
358 u_int32_t sctp_crc32c(const void *, u_int32_t);
359 char	*inetname(struct in_addr);
360 int	main(int, char **);
361 u_short p_cksum(struct ip *, u_short *, int, int);
362 int	packet_ok(u_char *, int, struct sockaddr_in *, int);
363 char	*pr_type(u_char);
364 void	print(u_char *, int, struct sockaddr_in *);
365 #ifdef	IPSEC
366 int	setpolicy(int so, char *policy);
367 #endif
368 void	send_probe(int, int);
369 struct outproto *setproto(char *);
370 int	str2val(const char *, const char *, int, int);
371 void	tvsub(struct timeval *, struct timeval *);
372 void usage(void);
373 int	wait_for_reply(int, struct sockaddr_in *, const struct timeval *);
374 void pkt_compare(const u_char *, int, const u_char *, int);
375 
376 void	udp_prep(struct outdata *);
377 int	udp_check(const u_char *, int);
378 void	udplite_prep(struct outdata *);
379 int	udplite_check(const u_char *, int);
380 void	tcp_prep(struct outdata *);
381 int	tcp_check(const u_char *, int);
382 void	sctp_prep(struct outdata *);
383 int	sctp_check(const u_char *, int);
384 void	gre_prep(struct outdata *);
385 int	gre_check(const u_char *, int);
386 void	gen_prep(struct outdata *);
387 int	gen_check(const u_char *, int);
388 void	icmp_prep(struct outdata *);
389 int	icmp_check(const u_char *, int);
390 
391 /* Descriptor structure for each outgoing protocol we support */
392 struct outproto {
393 	char	*name;		/* name of protocol */
394 	const char *key;	/* An ascii key for the bytes of the header */
395 	u_char	num;		/* IP protocol number */
396 	u_short	hdrlen;		/* max size of protocol header */
397 	u_short	port;		/* default base protocol-specific "port" */
398 	void	(*prepare)(struct outdata *);
399 				/* finish preparing an outgoing packet */
400 	int	(*check)(const u_char *, int);
401 				/* check an incoming packet */
402 };
403 
404 /* List of supported protocols. The first one is the default. The last
405    one is the handler for generic protocols not explicitly listed. */
406 struct	outproto protos[] = {
407 	{
408 		"udp",
409 		"spt dpt len sum",
410 		IPPROTO_UDP,
411 		sizeof(struct udphdr),
412 		32768 + 666,
413 		udp_prep,
414 		udp_check
415 	},
416 	{
417 		"udplite",
418 		"spt dpt cov sum",
419 		IPPROTO_UDPLITE,
420 		sizeof(struct udphdr),
421 		32768 + 666,
422 		udplite_prep,
423 		udplite_check
424 	},
425 	{
426 		"tcp",
427 		"spt dpt seq     ack     xxflwin sum urp",
428 		IPPROTO_TCP,
429 		sizeof(struct tcphdr),
430 		32768 + 666,
431 		tcp_prep,
432 		tcp_check
433 	},
434 	{
435 		"sctp",
436 		"spt dpt vtag    crc     tyfllen tyfllen ",
437 		IPPROTO_SCTP,
438 		sizeof(struct sctphdr),
439 		32768 + 666,
440 		sctp_prep,
441 		sctp_check
442 	},
443 	{
444 		"gre",
445 		"flg pro len clid",
446 		IPPROTO_GRE,
447 		sizeof(struct grehdr),
448 		GRE_PPTP_PROTO,
449 		gre_prep,
450 		gre_check
451 	},
452 	{
453 		"icmp",
454 		"typ cod sum ",
455 		IPPROTO_ICMP,
456 		sizeof(struct icmp),
457 		0,
458 		icmp_prep,
459 		icmp_check
460 	},
461 	{
462 		NULL,
463 		"",
464 		0,
465 		2 * sizeof(u_short),
466 		0,
467 		gen_prep,
468 		gen_check
469 	},
470 };
471 struct	outproto *proto = &protos[0];
472 
473 const char *ip_hdr_key = "vhtslen id  off tlprsum srcip   dstip   opts";
474 
475 int
476 main(int argc, char **argv)
477 {
478 	register int op, code, n;
479 	register char *cp;
480 	register const char *err;
481 	register u_int32_t *ap;
482 	register struct sockaddr_in *from = (struct sockaddr_in *)&wherefrom;
483 	register struct sockaddr_in *to = (struct sockaddr_in *)&whereto;
484 	register struct hostinfo *hi;
485 	int on = 1;
486 	register struct protoent *pe;
487 	register int ttl, probe, i;
488 	register int seq = 0;
489 	int tos = 0, settos = 0;
490 	register int lsrr = 0;
491 	register u_short off = 0;
492 	struct ifaddrlist *al;
493 	char errbuf[132];
494 	int requestPort = -1;
495 	int sump = 0;
496 	int sockerrno;
497 #ifdef WITH_CASPER
498 	const char *types[] = { "NAME2ADDR", "ADDR2NAME" };
499 	int families[1];
500 	cap_channel_t *casper;
501 #endif
502 	cap_rights_t rights;
503 	bool cansandbox;
504 
505 	/* Insure the socket fds won't be 0, 1 or 2 */
506 	if (open(devnull, O_RDONLY) < 0 ||
507 	    open(devnull, O_RDONLY) < 0 ||
508 	    open(devnull, O_RDONLY) < 0) {
509 		Fprintf(stderr, "%s: open \"%s\": %s\n",
510 		    prog, devnull, strerror(errno));
511 		exit(1);
512 	}
513 	/*
514 	 * Do the setuid-required stuff first, then lose privileges ASAP.
515 	 * Do error checking for these two calls where they appeared in
516 	 * the original code.
517 	 */
518 	cp = "icmp";
519 	pe = getprotobyname(cp);
520 	if (pe) {
521 		if ((s = socket(AF_INET, SOCK_RAW, pe->p_proto)) < 0)
522 			sockerrno = errno;
523 		else if ((sndsock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0)
524 			sockerrno = errno;
525 	}
526 
527 	if (setuid(getuid()) != 0) {
528 		perror("setuid()");
529 		exit(1);
530 	}
531 
532 #ifdef WITH_CASPER
533 	casper = cap_init();
534 	if (casper == NULL)
535 		errx(1, "unable to create casper process");
536 	capdns = cap_service_open(casper, "system.dns");
537 	if (capdns == NULL)
538 		errx(1, "unable to open system.dns service");
539 	if (cap_dns_type_limit(capdns, types, 2) < 0)
540 		errx(1, "unable to limit access to system.dns service");
541 	families[0] = AF_INET;
542 	if (cap_dns_family_limit(capdns, families, 1) < 0)
543 		errx(1, "unable to limit access to system.dns service");
544 #endif /* WITH_CASPER */
545 
546 #ifdef IPCTL_DEFTTL
547 	{
548 		int mib[4] = { CTL_NET, PF_INET, IPPROTO_IP, IPCTL_DEFTTL };
549 		size_t sz = sizeof(max_ttl);
550 
551 		if (sysctl(mib, 4, &max_ttl, &sz, NULL, 0) == -1) {
552 			perror("sysctl(net.inet.ip.ttl)");
553 			exit(1);
554 		}
555 	}
556 #else /* !IPCTL_DEFTTL */
557 	max_ttl = 30;
558 #endif
559 
560 #ifdef WITH_CASPER
561 	cap_close(casper);
562 #endif
563 
564 	if (argv[0] == NULL)
565 		prog = "traceroute";
566 	else if ((cp = strrchr(argv[0], '/')) != NULL)
567 		prog = cp + 1;
568 	else
569 		prog = argv[0];
570 
571 	opterr = 0;
572 	while ((op = getopt(argc, argv, "aA:eEdDFInrSvxf:g:i:M:m:P:p:q:s:t:w:z:")) != EOF)
573 		switch (op) {
574 		case 'a':
575 			as_path = 1;
576 			break;
577 
578 		case 'A':
579 			as_path = 1;
580 			as_server = optarg;
581 			break;
582 
583 		case 'd':
584 			options |= SO_DEBUG;
585 			break;
586 
587 		case 'D':
588 			printdiff = 1;
589 			break;
590 
591 		case 'e':
592 			fixedPort = 1;
593 			break;
594 
595 		case 'E':
596 			ecnflag = 1;
597 			break;
598 
599 		case 'f':
600 		case 'M':	/* FreeBSD compat. */
601 			first_ttl = str2val(optarg, "first ttl", 1, 255);
602 			break;
603 
604 		case 'F':
605 			off = IP_DF;
606 			break;
607 
608 		case 'g':
609 			if (lsrr >= NGATEWAYS) {
610 				Fprintf(stderr,
611 				    "%s: No more than %d gateways\n",
612 				    prog, NGATEWAYS);
613 				exit(1);
614 			}
615 			getaddr(gwlist + lsrr, optarg);
616 			++lsrr;
617 			break;
618 
619 		case 'i':
620 			device = optarg;
621 			break;
622 
623 		case 'I':
624 			proto = setproto("icmp");
625 			break;
626 
627 		case 'm':
628 			max_ttl = str2val(optarg, "max ttl", 1, 255);
629 			break;
630 
631 		case 'n':
632 			++nflag;
633 			break;
634 
635 		case 'P':
636 			proto = setproto(optarg);
637 			break;
638 
639 		case 'p':
640 			requestPort = (u_short)str2val(optarg, "port",
641 			    1, (1 << 16) - 1);
642 			break;
643 
644 		case 'q':
645 			nprobes = str2val(optarg, "nprobes", 1, -1);
646 			break;
647 
648 		case 'r':
649 			options |= SO_DONTROUTE;
650 			break;
651 
652 		case 's':
653 			/*
654 			 * set the ip source address of the outbound
655 			 * probe (e.g., on a multi-homed host).
656 			 */
657 			source = optarg;
658 			break;
659 
660 		case 'S':
661 			sump = 1;
662 			break;
663 
664 		case 't':
665 			tos = str2val(optarg, "tos", 0, 255);
666 			++settos;
667 			break;
668 
669 		case 'v':
670 			++verbose;
671 			break;
672 
673 		case 'x':
674 			doipcksum = (doipcksum == 0);
675 			break;
676 
677 		case 'w':
678 			waittime = str2val(optarg, "wait time",
679 			    1, 24 * 60 * 60);
680 			break;
681 
682 		case 'z':
683 			pausemsecs = str2val(optarg, "pause msecs",
684 			    0, 60 * 60 * 1000);
685 			break;
686 
687 		default:
688 			usage();
689 		}
690 
691 	/* Set requested port, if any, else default for this protocol */
692 	port = (requestPort != -1) ? requestPort : proto->port;
693 
694 	if (nprobes == -1)
695 		nprobes = printdiff ? 1 : 3;
696 
697 	if (first_ttl > max_ttl) {
698 		Fprintf(stderr,
699 		    "%s: first ttl (%d) may not be greater than max ttl (%d)\n",
700 		    prog, first_ttl, max_ttl);
701 		exit(1);
702 	}
703 
704 	if (!doipcksum)
705 		Fprintf(stderr, "%s: Warning: ip checksums disabled\n", prog);
706 
707 	if (lsrr > 0)
708 		optlen = (lsrr + 1) * sizeof(gwlist[0]);
709 	minpacket = sizeof(*outip) + proto->hdrlen + optlen;
710 	if (minpacket > 40)
711 		packlen = minpacket;
712 	else
713 		packlen = 40;
714 
715 	/* Process destination and optional packet size */
716 	switch (argc - optind) {
717 
718 	case 2:
719 		packlen = str2val(argv[optind + 1],
720 		    "packet length", minpacket, maxpacket);
721 		/* Fall through */
722 
723 	case 1:
724 		hostname = argv[optind];
725 		hi = gethostinfo(hostname);
726 		setsin(to, hi->addrs[0]);
727 		if (hi->n > 1)
728 			Fprintf(stderr,
729 		    "%s: Warning: %s has multiple addresses; using %s\n",
730 				prog, hostname, inet_ntoa(to->sin_addr));
731 		hostname = hi->name;
732 		hi->name = NULL;
733 		freehostinfo(hi);
734 		break;
735 
736 	default:
737 		usage();
738 	}
739 
740 	setlinebuf(stdout);
741 
742 	protlen = packlen - sizeof(*outip) - optlen;
743 	if ((proto->num == IPPROTO_SCTP) && (packlen & 3)) {
744 		Fprintf(stderr, "%s: packet length must be a multiple of 4\n",
745 		    prog);
746 		exit(1);
747 	}
748 
749 	outip = (struct ip *)malloc((unsigned)packlen);
750 	if (outip == NULL) {
751 		Fprintf(stderr, "%s: malloc: %s\n", prog, strerror(errno));
752 		exit(1);
753 	}
754 	memset((char *)outip, 0, packlen);
755 
756 	outip->ip_v = IPVERSION;
757 	if (settos)
758 		outip->ip_tos = tos;
759 	if (ecnflag) {
760 		outip->ip_tos &= ~IPTOS_ECN_MASK;
761 		outip->ip_tos |= IPTOS_ECN_ECT1;
762 	}
763 	outip->ip_len = htons(packlen);
764 	outip->ip_off = htons(off);
765 	outip->ip_p = proto->num;
766 	outp = (u_char *)(outip + 1);
767 	if (lsrr > 0) {
768 		register u_char *optlist;
769 
770 		optlist = outp;
771 		outp += optlen;
772 
773 		/* final hop */
774 		gwlist[lsrr] = to->sin_addr.s_addr;
775 
776 		outip->ip_dst.s_addr = gwlist[0];
777 
778 		/* force 4 byte alignment */
779 		optlist[0] = IPOPT_NOP;
780 		/* loose source route option */
781 		optlist[1] = IPOPT_LSRR;
782 		i = lsrr * sizeof(gwlist[0]);
783 		optlist[2] = i + 3;
784 		/* Pointer to LSRR addresses */
785 		optlist[3] = IPOPT_MINOFF;
786 		memcpy(optlist + 4, gwlist + 1, i);
787 	} else
788 		outip->ip_dst = to->sin_addr;
789 
790 	outip->ip_hl = (outp - (u_char *)outip) >> 2;
791 	ident = (getpid() & 0xffff) | 0x8000;
792 
793 	if (pe == NULL) {
794 		Fprintf(stderr, "%s: unknown protocol %s\n", prog, cp);
795 		exit(1);
796 	}
797 	if (s < 0) {
798 		errno = sockerrno;
799 		Fprintf(stderr, "%s: icmp socket: %s\n", prog, strerror(errno));
800 		exit(1);
801 	}
802 	if (options & SO_DEBUG)
803 		(void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&on,
804 		    sizeof(on));
805 	if (options & SO_DONTROUTE)
806 		(void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
807 		    sizeof(on));
808 
809 #if	defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
810 	if (setpolicy(s, "in bypass") < 0)
811 		errx(1, "%s", ipsec_strerror());
812 
813 	if (setpolicy(s, "out bypass") < 0)
814 		errx(1, "%s", ipsec_strerror());
815 #endif	/* defined(IPSEC) && defined(IPSEC_POLICY_IPSEC) */
816 
817 	if (sndsock < 0) {
818 		errno = sockerrno;
819 		Fprintf(stderr, "%s: raw socket: %s\n", prog, strerror(errno));
820 		exit(1);
821 	}
822 
823 #ifdef SO_SNDBUF
824 	if (setsockopt(sndsock, SOL_SOCKET, SO_SNDBUF, (char *)&packlen,
825 	    sizeof(packlen)) < 0) {
826 		Fprintf(stderr, "%s: SO_SNDBUF: %s\n", prog, strerror(errno));
827 		exit(1);
828 	}
829 #endif
830 #ifdef IP_HDRINCL
831 	if (setsockopt(sndsock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
832 	    sizeof(on)) < 0) {
833 		Fprintf(stderr, "%s: IP_HDRINCL: %s\n", prog, strerror(errno));
834 		exit(1);
835 	}
836 #else
837 #ifdef IP_TOS
838 	if (settos && setsockopt(sndsock, IPPROTO_IP, IP_TOS,
839 	    (char *)&tos, sizeof(tos)) < 0) {
840 		Fprintf(stderr, "%s: setsockopt tos %d: %s\n",
841 		    prog, tos, strerror(errno));
842 		exit(1);
843 	}
844 #endif
845 #endif
846 	if (options & SO_DEBUG)
847 		(void)setsockopt(sndsock, SOL_SOCKET, SO_DEBUG, (char *)&on,
848 		    sizeof(on));
849 	if (options & SO_DONTROUTE)
850 		(void)setsockopt(sndsock, SOL_SOCKET, SO_DONTROUTE, (char *)&on,
851 		    sizeof(on));
852 
853 	/* Get the interface address list */
854 	n = ifaddrlist(&al, errbuf);
855 	if (n < 0) {
856 		Fprintf(stderr, "%s: ifaddrlist: %s\n", prog, errbuf);
857 		exit(1);
858 	}
859 	if (n == 0) {
860 		Fprintf(stderr,
861 		    "%s: Can't find any network interfaces\n", prog);
862 		exit(1);
863 	}
864 
865 	/* Look for a specific device */
866 	if (device != NULL) {
867 		for (i = n; i > 0; --i, ++al)
868 			if (strcmp(device, al->device) == 0)
869 				break;
870 		if (i <= 0) {
871 			Fprintf(stderr, "%s: Can't find interface %.32s\n",
872 			    prog, device);
873 			exit(1);
874 		}
875 	}
876 
877 	/* Determine our source address */
878 	if (source == NULL) {
879 		/*
880 		 * If a device was specified, use the interface address.
881 		 * Otherwise, try to determine our source address.
882 		 */
883 		if (device != NULL)
884 			setsin(from, al->addr);
885 		else if ((err = findsaddr(to, from)) != NULL) {
886 			Fprintf(stderr, "%s: findsaddr: %s\n",
887 			    prog, err);
888 			exit(1);
889 		}
890 	} else {
891 		hi = gethostinfo(source);
892 		source = hi->name;
893 		hi->name = NULL;
894 		/*
895 		 * If the device was specified make sure it
896 		 * corresponds to the source address specified.
897 		 * Otherwise, use the first address (and warn if
898 		 * there are more than one).
899 		 */
900 		if (device != NULL) {
901 			for (i = hi->n, ap = hi->addrs; i > 0; --i, ++ap)
902 				if (*ap == al->addr)
903 					break;
904 			if (i <= 0) {
905 				Fprintf(stderr,
906 				    "%s: %s is not on interface %.32s\n",
907 				    prog, source, device);
908 				exit(1);
909 			}
910 			setsin(from, *ap);
911 		} else {
912 			setsin(from, hi->addrs[0]);
913 			if (hi->n > 1)
914 				Fprintf(stderr,
915 			"%s: Warning: %s has multiple addresses; using %s\n",
916 				    prog, source, inet_ntoa(from->sin_addr));
917 		}
918 		freehostinfo(hi);
919 	}
920 
921 	outip->ip_src = from->sin_addr;
922 
923 	/* Check the source address (-s), if any, is valid */
924 	if (bind(sndsock, (struct sockaddr *)from, sizeof(*from)) < 0) {
925 		Fprintf(stderr, "%s: bind: %s\n",
926 		    prog, strerror(errno));
927 		exit(1);
928 	}
929 
930 	if (as_path) {
931 		asn = as_setup(as_server);
932 		if (asn == NULL) {
933 			Fprintf(stderr, "%s: as_setup failed, AS# lookups"
934 			    " disabled\n", prog);
935 			(void)fflush(stderr);
936 			as_path = 0;
937 		}
938 	}
939 
940 	if (connect(sndsock, (struct sockaddr *)&whereto,
941 	    sizeof(whereto)) != 0) {
942 		Fprintf(stderr, "%s: connect: %s\n", prog, strerror(errno));
943 		exit(1);
944 	}
945 
946 #ifdef WITH_CASPER
947 	cansandbox = true;
948 #else
949 	if (nflag)
950 		cansandbox = true;
951 	else
952 		cansandbox = false;
953 #endif
954 
955 	caph_cache_catpages();
956 
957 	/*
958 	 * Here we enter capability mode. Further down access to global
959 	 * namespaces (e.g filesystem) is restricted (see capsicum(4)).
960 	 * We must connect(2) our socket before this point.
961 	 */
962 	if (cansandbox && cap_enter() < 0) {
963 		if (errno != ENOSYS) {
964 			Fprintf(stderr, "%s: cap_enter: %s\n", prog,
965 			    strerror(errno));
966 			exit(1);
967 		} else {
968 			cansandbox = false;
969 		}
970 	}
971 
972 	cap_rights_init(&rights, CAP_SEND, CAP_SETSOCKOPT);
973 	if (cansandbox && cap_rights_limit(sndsock, &rights) < 0) {
974 		Fprintf(stderr, "%s: cap_rights_limit sndsock: %s\n", prog,
975 		    strerror(errno));
976 		exit(1);
977 	}
978 
979 	cap_rights_init(&rights, CAP_RECV, CAP_EVENT);
980 	if (cansandbox && cap_rights_limit(s, &rights) < 0) {
981 		Fprintf(stderr, "%s: cap_rights_limit s: %s\n", prog,
982 		    strerror(errno));
983 		exit(1);
984 	}
985 
986 #if	defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
987 	if (setpolicy(sndsock, "in bypass") < 0)
988 		errx(1, "%s", ipsec_strerror());
989 
990 	if (setpolicy(sndsock, "out bypass") < 0)
991 		errx(1, "%s", ipsec_strerror());
992 #endif	/* defined(IPSEC) && defined(IPSEC_POLICY_IPSEC) */
993 
994 	Fprintf(stderr, "%s to %s (%s)",
995 	    prog, hostname, inet_ntoa(to->sin_addr));
996 	if (source)
997 		Fprintf(stderr, " from %s", source);
998 	Fprintf(stderr, ", %d hops max, %d byte packets\n", max_ttl, packlen);
999 	(void)fflush(stderr);
1000 
1001 	for (ttl = first_ttl; ttl <= max_ttl; ++ttl) {
1002 		u_int32_t lastaddr = 0;
1003 		int gotlastaddr = 0;
1004 		int got_there = 0;
1005 		int unreachable = 0;
1006 		int sentfirst = 0;
1007 		int loss;
1008 
1009 		Printf("%2d ", ttl);
1010 		for (probe = 0, loss = 0; probe < nprobes; ++probe) {
1011 			register int cc;
1012 			struct timeval t1, t2;
1013 			register struct ip *ip;
1014 			struct outdata outdata;
1015 
1016 			if (sentfirst && pausemsecs > 0)
1017 				usleep(pausemsecs * 1000);
1018 			/* Prepare outgoing data */
1019 			outdata.seq = ++seq;
1020 			outdata.ttl = ttl;
1021 
1022 			/* Avoid alignment problems by copying bytewise: */
1023 			(void)gettimeofday(&t1, NULL);
1024 			memcpy(&outdata.tv, &t1, sizeof(outdata.tv));
1025 
1026 			/* Finalize and send packet */
1027 			(*proto->prepare)(&outdata);
1028 			send_probe(seq, ttl);
1029 			++sentfirst;
1030 
1031 			/* Wait for a reply */
1032 			while ((cc = wait_for_reply(s, from, &t1)) != 0) {
1033 				double T;
1034 				int precis;
1035 
1036 				(void)gettimeofday(&t2, NULL);
1037 				i = packet_ok(packet, cc, from, seq);
1038 				/* Skip short packet */
1039 				if (i == 0)
1040 					continue;
1041 				if (!gotlastaddr ||
1042 				    from->sin_addr.s_addr != lastaddr) {
1043 					if (gotlastaddr)
1044 						printf("\n   ");
1045 					print(packet, cc, from);
1046 					lastaddr = from->sin_addr.s_addr;
1047 					++gotlastaddr;
1048 				}
1049 				T = deltaT(&t1, &t2);
1050 #ifdef SANE_PRECISION
1051 				if (T >= 1000.0)
1052 					precis = 0;
1053 				else if (T >= 100.0)
1054 					precis = 1;
1055 				else if (T >= 10.0)
1056 					precis = 2;
1057 				else
1058 #endif
1059 					precis = 3;
1060 				Printf("  %.*f ms", precis, T);
1061 				if (ecnflag) {
1062 					u_char ecn = hip->ip_tos & IPTOS_ECN_MASK;
1063 					switch (ecn) {
1064 					case IPTOS_ECN_ECT1:
1065 						Printf(" (ecn=passed)");
1066 						break;
1067 					case IPTOS_ECN_NOTECT:
1068 						Printf(" (ecn=bleached)");
1069 						break;
1070 					case IPTOS_ECN_CE:
1071 						Printf(" (ecn=congested)");
1072 						break;
1073 					default:
1074 						Printf(" (ecn=mangled)");
1075 						break;
1076 					}
1077 				}
1078 				if (printdiff) {
1079 					Printf("\n");
1080 					Printf("%*.*s%s\n",
1081 					    -(outip->ip_hl << 3),
1082 					    outip->ip_hl << 3,
1083 					    ip_hdr_key,
1084 					    proto->key);
1085 					pkt_compare((void *)outip, packlen,
1086 					    (void *)hip, hiplen);
1087 				}
1088 				if (i == -2) {
1089 #ifndef ARCHAIC
1090 					ip = (struct ip *)packet;
1091 					if (ip->ip_ttl <= 1)
1092 						Printf(" !");
1093 #endif
1094 					++got_there;
1095 					break;
1096 				}
1097 				/* time exceeded in transit */
1098 				if (i == -1)
1099 					break;
1100 				code = i - 1;
1101 				switch (code) {
1102 
1103 				case ICMP_UNREACH_PORT:
1104 #ifndef ARCHAIC
1105 					ip = (struct ip *)packet;
1106 					if (ip->ip_ttl <= 1)
1107 						Printf(" !");
1108 #endif
1109 					++got_there;
1110 					break;
1111 
1112 				case ICMP_UNREACH_NET:
1113 					++unreachable;
1114 					Printf(" !N");
1115 					break;
1116 
1117 				case ICMP_UNREACH_HOST:
1118 					++unreachable;
1119 					Printf(" !H");
1120 					break;
1121 
1122 				case ICMP_UNREACH_PROTOCOL:
1123 					++got_there;
1124 					Printf(" !P");
1125 					break;
1126 
1127 				case ICMP_UNREACH_NEEDFRAG:
1128 					++unreachable;
1129 					Printf(" !F-%d", pmtu);
1130 					break;
1131 
1132 				case ICMP_UNREACH_SRCFAIL:
1133 					++unreachable;
1134 					Printf(" !S");
1135 					break;
1136 
1137 				case ICMP_UNREACH_NET_UNKNOWN:
1138 					++unreachable;
1139 					Printf(" !U");
1140 					break;
1141 
1142 				case ICMP_UNREACH_HOST_UNKNOWN:
1143 					++unreachable;
1144 					Printf(" !W");
1145 					break;
1146 
1147 				case ICMP_UNREACH_ISOLATED:
1148 					++unreachable;
1149 					Printf(" !I");
1150 					break;
1151 
1152 				case ICMP_UNREACH_NET_PROHIB:
1153 					++unreachable;
1154 					Printf(" !A");
1155 					break;
1156 
1157 				case ICMP_UNREACH_HOST_PROHIB:
1158 					++unreachable;
1159 					Printf(" !Z");
1160 					break;
1161 
1162 				case ICMP_UNREACH_TOSNET:
1163 					++unreachable;
1164 					Printf(" !Q");
1165 					break;
1166 
1167 				case ICMP_UNREACH_TOSHOST:
1168 					++unreachable;
1169 					Printf(" !T");
1170 					break;
1171 
1172 				case ICMP_UNREACH_FILTER_PROHIB:
1173 					++unreachable;
1174 					Printf(" !X");
1175 					break;
1176 
1177 				case ICMP_UNREACH_HOST_PRECEDENCE:
1178 					++unreachable;
1179 					Printf(" !V");
1180 					break;
1181 
1182 				case ICMP_UNREACH_PRECEDENCE_CUTOFF:
1183 					++unreachable;
1184 					Printf(" !C");
1185 					break;
1186 
1187 				default:
1188 					++unreachable;
1189 					Printf(" !<%d>", code);
1190 					break;
1191 				}
1192 				break;
1193 			}
1194 			if (cc == 0) {
1195 				loss++;
1196 				Printf(" *");
1197 			}
1198 			(void)fflush(stdout);
1199 		}
1200 		if (sump) {
1201 			Printf(" (%d%% loss)", (loss * 100) / nprobes);
1202 		}
1203 		putchar('\n');
1204 		if (got_there ||
1205 		    (unreachable > 0 && unreachable >= nprobes - 1))
1206 			break;
1207 	}
1208 	if (as_path)
1209 		as_shutdown(asn);
1210 	exit(0);
1211 }
1212 
1213 int
1214 wait_for_reply(register int sock, register struct sockaddr_in *fromp,
1215     register const struct timeval *tp)
1216 {
1217 	fd_set *fdsp;
1218 	size_t nfds;
1219 	struct timeval now, wait;
1220 	register int cc = 0;
1221 	register int error;
1222 	int fromlen = sizeof(*fromp);
1223 
1224 	nfds = howmany(sock + 1, NFDBITS);
1225 	if ((fdsp = malloc(nfds * sizeof(fd_mask))) == NULL)
1226 		err(1, "malloc");
1227 	memset(fdsp, 0, nfds * sizeof(fd_mask));
1228 	FD_SET(sock, fdsp);
1229 
1230 	wait.tv_sec = tp->tv_sec + waittime;
1231 	wait.tv_usec = tp->tv_usec;
1232 	(void)gettimeofday(&now, NULL);
1233 	tvsub(&wait, &now);
1234 	if (wait.tv_sec < 0) {
1235 		wait.tv_sec = 0;
1236 		wait.tv_usec = 1;
1237 	}
1238 
1239 	error = select(sock + 1, fdsp, NULL, NULL, &wait);
1240 	if (error == -1 && errno == EINVAL) {
1241 		Fprintf(stderr, "%s: botched select() args\n", prog);
1242 		exit(1);
1243 	}
1244 	if (error > 0)
1245 		cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
1246 			    (struct sockaddr *)fromp, &fromlen);
1247 
1248 	free(fdsp);
1249 	return (cc);
1250 }
1251 
1252 void
1253 send_probe(int seq, int ttl)
1254 {
1255 	register int cc;
1256 
1257 	outip->ip_ttl = ttl;
1258 	outip->ip_id = htons(ident + seq);
1259 
1260 	/* XXX undocumented debugging hack */
1261 	if (verbose > 1) {
1262 		register const u_short *sp;
1263 		register int nshorts, i;
1264 
1265 		sp = (u_short *)outip;
1266 		nshorts = (u_int)packlen / sizeof(u_short);
1267 		i = 0;
1268 		Printf("[ %d bytes", packlen);
1269 		while (--nshorts >= 0) {
1270 			if ((i++ % 8) == 0)
1271 				Printf("\n\t");
1272 			Printf(" %04x", ntohs(*sp++));
1273 		}
1274 		if (packlen & 1) {
1275 			if ((i % 8) == 0)
1276 				Printf("\n\t");
1277 			Printf(" %02x", *(u_char *)sp);
1278 		}
1279 		Printf("]\n");
1280 	}
1281 
1282 #if !defined(IP_HDRINCL) && defined(IP_TTL)
1283 	if (setsockopt(sndsock, IPPROTO_IP, IP_TTL,
1284 	    (char *)&ttl, sizeof(ttl)) < 0) {
1285 		Fprintf(stderr, "%s: setsockopt ttl %d: %s\n",
1286 		    prog, ttl, strerror(errno));
1287 		exit(1);
1288 	}
1289 #endif
1290 
1291 	cc = send(sndsock, (char *)outip, packlen, 0);
1292 	if (cc < 0 || cc != packlen)  {
1293 		if (cc < 0)
1294 			Fprintf(stderr, "%s: sendto: %s\n",
1295 			    prog, strerror(errno));
1296 		Printf("%s: wrote %s %d chars, ret=%d\n",
1297 		    prog, hostname, packlen, cc);
1298 		(void)fflush(stdout);
1299 	}
1300 }
1301 
1302 #if	defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
1303 int
1304 setpolicy(int so, char *policy)
1305 {
1306 	char *buf;
1307 
1308 	buf = ipsec_set_policy(policy, strlen(policy));
1309 	if (buf == NULL) {
1310 		warnx("%s", ipsec_strerror());
1311 		return (-1);
1312 	}
1313 	(void)setsockopt(so, IPPROTO_IP, IP_IPSEC_POLICY,
1314 		buf, ipsec_get_policylen(buf));
1315 
1316 	free(buf);
1317 
1318 	return (0);
1319 }
1320 #endif
1321 
1322 double
1323 deltaT(struct timeval *t1p, struct timeval *t2p)
1324 {
1325 	register double dt;
1326 
1327 	dt = (double)(t2p->tv_sec - t1p->tv_sec) * 1000.0 +
1328 	     (double)(t2p->tv_usec - t1p->tv_usec) / 1000.0;
1329 	return (dt);
1330 }
1331 
1332 /*
1333  * Convert an ICMP "type" field to a printable string.
1334  */
1335 char *
1336 pr_type(register u_char t)
1337 {
1338 	static char *ttab[] = {
1339 	"Echo Reply",	"ICMP 1",	"ICMP 2",	"Dest Unreachable",
1340 	"Source Quench", "Redirect",	"ICMP 6",	"ICMP 7",
1341 	"Echo",		"ICMP 9",	"ICMP 10",	"Time Exceeded",
1342 	"Param Problem", "Timestamp",	"Timestamp Reply", "Info Request",
1343 	"Info Reply"
1344 	};
1345 
1346 	if (t > 16)
1347 		return ("OUT-OF-RANGE");
1348 
1349 	return (ttab[t]);
1350 }
1351 
1352 int
1353 packet_ok(register u_char *buf, int cc, register struct sockaddr_in *from,
1354     register int seq)
1355 {
1356 	register struct icmp *icp;
1357 	register u_char type, code;
1358 	register int hlen;
1359 #ifndef ARCHAIC
1360 	register struct ip *ip;
1361 
1362 	ip = (struct ip *) buf;
1363 	hlen = ip->ip_hl << 2;
1364 	if (cc < hlen + ICMP_MINLEN) {
1365 		if (verbose)
1366 			Printf("packet too short (%d bytes) from %s\n", cc,
1367 				inet_ntoa(from->sin_addr));
1368 		return (0);
1369 	}
1370 	cc -= hlen;
1371 	icp = (struct icmp *)(buf + hlen);
1372 #else
1373 	icp = (struct icmp *)buf;
1374 #endif
1375 	type = icp->icmp_type;
1376 	code = icp->icmp_code;
1377 	/* Path MTU Discovery (RFC1191) */
1378 	if (code != ICMP_UNREACH_NEEDFRAG)
1379 		pmtu = 0;
1380 	else {
1381 		pmtu = ntohs(icp->icmp_nextmtu);
1382 	}
1383 	if (type == ICMP_ECHOREPLY
1384 	    && proto->num == IPPROTO_ICMP
1385 	    && (*proto->check)((u_char *)icp, (u_char)seq))
1386 		return (-2);
1387 	if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) ||
1388 	    type == ICMP_UNREACH) {
1389 		u_char *inner;
1390 
1391 		hip = &icp->icmp_ip;
1392 		hiplen = ((u_char *)icp + cc) - (u_char *)hip;
1393 		hlen = hip->ip_hl << 2;
1394 		inner = (u_char *)((u_char *)hip + hlen);
1395 		if (hlen + 16 <= cc
1396 		    && hip->ip_p == proto->num
1397 		    && (*proto->check)(inner, (u_char)seq))
1398 			return (type == ICMP_TIMXCEED ? -1 : code + 1);
1399 	}
1400 #ifndef ARCHAIC
1401 	if (verbose) {
1402 		register int i;
1403 		u_int32_t *lp = (u_int32_t *)&icp->icmp_ip;
1404 
1405 		Printf("\n%d bytes from %s to ", cc, inet_ntoa(from->sin_addr));
1406 		Printf("%s: icmp type %d (%s) code %d\n",
1407 		    inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
1408 		for (i = 4; i <= cc - ICMP_MINLEN; i += sizeof(*lp))
1409 			Printf("%2d: %8.8x\n", i, ntohl(*lp++));
1410 	}
1411 #endif
1412 	return (0);
1413 }
1414 
1415 void
1416 icmp_prep(struct outdata *outdata)
1417 {
1418 	struct icmp *const icmpheader = (struct icmp *) outp;
1419 
1420 	icmpheader->icmp_type = ICMP_ECHO;
1421 	icmpheader->icmp_id = htons(ident);
1422 	icmpheader->icmp_seq = htons(outdata->seq);
1423 	icmpheader->icmp_cksum = 0;
1424 	icmpheader->icmp_cksum = in_cksum((u_short *)icmpheader, protlen);
1425 	if (icmpheader->icmp_cksum == 0)
1426 		icmpheader->icmp_cksum = 0xffff;
1427 }
1428 
1429 int
1430 icmp_check(const u_char *data, int seq)
1431 {
1432 	struct icmp *const icmpheader = (struct icmp *) data;
1433 
1434 	return (icmpheader->icmp_id == htons(ident)
1435 	    && icmpheader->icmp_seq == htons(seq));
1436 }
1437 
1438 void
1439 udp_prep(struct outdata *outdata)
1440 {
1441 	struct udphdr *const outudp = (struct udphdr *) outp;
1442 
1443 	outudp->uh_sport = htons(ident + (fixedPort ? outdata->seq : 0));
1444 	outudp->uh_dport = htons(port + (fixedPort ? 0 : outdata->seq));
1445 	outudp->uh_ulen = htons((u_short)protlen);
1446 	outudp->uh_sum = 0;
1447 	if (doipcksum) {
1448 	    u_short sum = p_cksum(outip, (u_short *)outudp, protlen, protlen);
1449 	    outudp->uh_sum = (sum) ? sum : 0xffff;
1450 	}
1451 
1452 	return;
1453 }
1454 
1455 int
1456 udp_check(const u_char *data, int seq)
1457 {
1458 	struct udphdr *const udp = (struct udphdr *) data;
1459 
1460 	return (ntohs(udp->uh_sport) == ident + (fixedPort ? seq : 0) &&
1461 	    ntohs(udp->uh_dport) == port + (fixedPort ? 0 : seq));
1462 }
1463 
1464 void
1465 udplite_prep(struct outdata *outdata)
1466 {
1467 	struct udphdr *const outudp = (struct udphdr *) outp;
1468 
1469 	outudp->uh_sport = htons(ident + (fixedPort ? outdata->seq : 0));
1470 	outudp->uh_dport = htons(port + (fixedPort ? 0 : outdata->seq));
1471 	outudp->uh_ulen = htons(8);
1472 	outudp->uh_sum = 0;
1473 	if (doipcksum) {
1474 	    u_short sum = p_cksum(outip, (u_short *)outudp, protlen, 8);
1475 	    outudp->uh_sum = (sum) ? sum : 0xffff;
1476 	}
1477 
1478 	return;
1479 }
1480 
1481 int
1482 udplite_check(const u_char *data, int seq)
1483 {
1484 	struct udphdr *const udp = (struct udphdr *) data;
1485 
1486 	return (ntohs(udp->uh_sport) == ident + (fixedPort ? seq : 0) &&
1487 	    ntohs(udp->uh_dport) == port + (fixedPort ? 0 : seq));
1488 }
1489 
1490 void
1491 tcp_prep(struct outdata *outdata)
1492 {
1493 	struct tcphdr *const tcp = (struct tcphdr *) outp;
1494 
1495 	tcp->th_sport = htons(ident);
1496 	tcp->th_dport = htons(port + (fixedPort ? 0 : outdata->seq));
1497 	tcp->th_seq = (tcp->th_sport << 16) | tcp->th_dport;
1498 	tcp->th_ack = 0;
1499 	tcp->th_off = 5;
1500 	tcp->th_flags = TH_SYN;
1501 	tcp->th_sum = 0;
1502 
1503 	if (doipcksum)
1504 	    tcp->th_sum = p_cksum(outip, (u_short *)tcp, protlen, protlen);
1505 }
1506 
1507 int
1508 tcp_check(const u_char *data, int seq)
1509 {
1510 	struct tcphdr *const tcp = (struct tcphdr *) data;
1511 
1512 	return (ntohs(tcp->th_sport) == ident
1513 	    && ntohs(tcp->th_dport) == port + (fixedPort ? 0 : seq)
1514 	    && tcp->th_seq == (tcp_seq)((tcp->th_sport << 16) | tcp->th_dport));
1515 }
1516 
1517 void
1518 sctp_prep(struct outdata *outdata)
1519 {
1520 	struct sctphdr *const sctp = (struct sctphdr *) outp;
1521 	struct sctp_chunkhdr *chk;
1522 	struct sctp_init_chunk *init;
1523 	struct sctp_paramhdr *param;
1524 
1525 	sctp->src_port = htons(ident);
1526 	sctp->dest_port = htons(port + (fixedPort ? 0 : outdata->seq));
1527 	if (protlen >= (int)(sizeof(struct sctphdr) +
1528 	    sizeof(struct sctp_init_chunk))) {
1529 		sctp->v_tag = 0;
1530 	} else {
1531 		sctp->v_tag = (sctp->src_port << 16) | sctp->dest_port;
1532 	}
1533 	sctp->checksum = htonl(0);
1534 	if (protlen >= (int)(sizeof(struct sctphdr) +
1535 	    sizeof(struct sctp_init_chunk))) {
1536 		/*
1537 		 * Send a packet containing an INIT chunk. This works
1538 		 * better in case of firewalls on the path, but
1539 		 * results in a probe packet containing at least
1540 		 * 32 bytes of payload. For shorter payloads, use
1541 		 * SHUTDOWN-ACK chunks.
1542 		 */
1543 		init = (struct sctp_init_chunk *)(sctp + 1);
1544 		init->ch.chunk_type = SCTP_INITIATION;
1545 		init->ch.chunk_flags = 0;
1546 		init->ch.chunk_length = htons((u_int16_t)(protlen -
1547 		    sizeof(struct sctphdr)));
1548 		init->init.initiate_tag = (sctp->src_port << 16) |
1549 		    sctp->dest_port;
1550 		init->init.a_rwnd = htonl(1500);
1551 		init->init.num_outbound_streams = htons(1);
1552 		init->init.num_inbound_streams = htons(1);
1553 		init->init.initial_tsn = htonl(0);
1554 		if (protlen >= (int)(sizeof(struct sctphdr) +
1555 		    sizeof(struct sctp_init_chunk) +
1556 		    sizeof(struct sctp_paramhdr))) {
1557 			param = (struct sctp_paramhdr *)(init + 1);
1558 			param->param_type = htons(SCTP_PAD);
1559 			param->param_length =
1560 			    htons((u_int16_t)(protlen -
1561 			    sizeof(struct sctphdr) -
1562 			    sizeof(struct sctp_init_chunk)));
1563 		}
1564 	} else {
1565 		/*
1566 		 * Send a packet containing a SHUTDOWN-ACK chunk,
1567 		 * possibly followed by a PAD chunk.
1568 		 */
1569 		if (protlen >=
1570 		    (int)(sizeof(struct sctphdr) +
1571 		    sizeof(struct sctp_chunkhdr))) {
1572 			chk = (struct sctp_chunkhdr *)(sctp + 1);
1573 			chk->chunk_type = SCTP_SHUTDOWN_ACK;
1574 			chk->chunk_flags = 0;
1575 			chk->chunk_length = htons(4);
1576 		}
1577 		if (protlen >=
1578 		    (int)(sizeof(struct sctphdr) +
1579 		    2 * sizeof(struct sctp_chunkhdr))) {
1580 			chk = chk + 1;
1581 			chk->chunk_type = SCTP_PAD_CHUNK;
1582 			chk->chunk_flags = 0;
1583 			chk->chunk_length = htons(protlen -
1584 			    (sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr)));
1585 		}
1586 	}
1587 	if (doipcksum) {
1588 		sctp->checksum = sctp_crc32c(sctp, protlen);
1589 	}
1590 }
1591 
1592 int
1593 sctp_check(const u_char *data, int seq)
1594 {
1595 	struct sctphdr *const sctp = (struct sctphdr *) data;
1596 
1597 	if (ntohs(sctp->src_port) != ident ||
1598 	    ntohs(sctp->dest_port) != port + (fixedPort ? 0 : seq))
1599 		return (0);
1600 	if (protlen < (int)(sizeof(struct sctphdr) +
1601 	    sizeof(struct sctp_init_chunk))) {
1602 		return (sctp->v_tag ==
1603 		    (u_int32_t)((sctp->src_port << 16) | sctp->dest_port));
1604 	} else {
1605 		/*
1606 		 * Don't verify the initiate_tag, since it is not available,
1607 		 * most of the time.
1608 		 */
1609 		return (sctp->v_tag == 0);
1610 	}
1611 }
1612 
1613 void
1614 gre_prep(struct outdata *outdata)
1615 {
1616 	struct grehdr *const gre = (struct grehdr *) outp;
1617 
1618 	gre->flags = htons(0x2001);
1619 	gre->proto = htons(port);
1620 	gre->length = 0;
1621 	gre->callId = htons(ident + outdata->seq);
1622 }
1623 
1624 int
1625 gre_check(const u_char *data, int seq)
1626 {
1627 	struct grehdr *const gre = (struct grehdr *) data;
1628 
1629 	return (ntohs(gre->proto) == port
1630 	    && ntohs(gre->callId) == ident + seq);
1631 }
1632 
1633 void
1634 gen_prep(struct outdata *outdata)
1635 {
1636 	u_int16_t *const ptr = (u_int16_t *) outp;
1637 
1638 	ptr[0] = htons(ident);
1639 	ptr[1] = htons(port + outdata->seq);
1640 }
1641 
1642 int
1643 gen_check(const u_char *data, int seq)
1644 {
1645 	u_int16_t *const ptr = (u_int16_t *) data;
1646 
1647 	return (ntohs(ptr[0]) == ident
1648 	    && ntohs(ptr[1]) == port + seq);
1649 }
1650 
1651 void
1652 print(register u_char *buf, register int cc, register struct sockaddr_in *from)
1653 {
1654 	register struct ip *ip;
1655 	register int hlen;
1656 	char addr[INET_ADDRSTRLEN];
1657 
1658 	ip = (struct ip *) buf;
1659 	hlen = ip->ip_hl << 2;
1660 	cc -= hlen;
1661 
1662 	strlcpy(addr, inet_ntoa(from->sin_addr), sizeof(addr));
1663 
1664 	if (as_path)
1665 		Printf(" [AS%u]", as_lookup(asn, addr, AF_INET));
1666 
1667 	if (nflag)
1668 		Printf(" %s", addr);
1669 	else
1670 		Printf(" %s (%s)", inetname(from->sin_addr), addr);
1671 
1672 	if (verbose)
1673 		Printf(" %d bytes to %s", cc, inet_ntoa(ip->ip_dst));
1674 }
1675 
1676 /*
1677  * Checksum routine for UDP and TCP headers.
1678  */
1679 u_short
1680 p_cksum(struct ip *ip, u_short *data, int len, int cov)
1681 {
1682 	static struct ipovly ipo;
1683 	u_short sum[2];
1684 
1685 	ipo.ih_pr = ip->ip_p;
1686 	ipo.ih_len = htons(len);
1687 	ipo.ih_src = ip->ip_src;
1688 	ipo.ih_dst = ip->ip_dst;
1689 
1690 	sum[1] = in_cksum((u_short *)&ipo, sizeof(ipo)); /* pseudo ip hdr cksum */
1691 	sum[0] = in_cksum(data, cov);                    /* payload data cksum */
1692 
1693 	return (~in_cksum(sum, sizeof(sum)));
1694 }
1695 
1696 /*
1697  * Checksum routine for Internet Protocol family headers (C Version)
1698  */
1699 u_short
1700 in_cksum(register u_short *addr, register int len)
1701 {
1702 	register int nleft = len;
1703 	register u_short *w = addr;
1704 	register u_short answer;
1705 	register int sum = 0;
1706 
1707 	/*
1708 	 *  Our algorithm is simple, using a 32 bit accumulator (sum),
1709 	 *  we add sequential 16 bit words to it, and at the end, fold
1710 	 *  back all the carry bits from the top 16 bits into the lower
1711 	 *  16 bits.
1712 	 */
1713 	while (nleft > 1)  {
1714 		sum += *w++;
1715 		nleft -= 2;
1716 	}
1717 
1718 	/* mop up an odd byte, if necessary */
1719 	if (nleft == 1)
1720 		sum += *(u_char *)w;
1721 
1722 	/*
1723 	 * add back carry outs from top 16 bits to low 16 bits
1724 	 */
1725 	sum = (sum >> 16) + (sum & 0xffff);	/* add hi 16 to low 16 */
1726 	sum += (sum >> 16);			/* add carry */
1727 	answer = ~sum;				/* truncate to 16 bits */
1728 	return (answer);
1729 }
1730 
1731 /*
1732  * CRC32C routine for the Stream Control Transmission Protocol
1733  */
1734 
1735 #define CRC32C(c, d) (c = (c >> 8) ^ crc_c[(c ^ (d)) & 0xFF])
1736 
1737 static u_int32_t crc_c[256] = {
1738 	0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4,
1739 	0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB,
1740 	0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B,
1741 	0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24,
1742 	0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B,
1743 	0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384,
1744 	0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54,
1745 	0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B,
1746 	0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A,
1747 	0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35,
1748 	0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5,
1749 	0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA,
1750 	0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45,
1751 	0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A,
1752 	0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A,
1753 	0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595,
1754 	0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48,
1755 	0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957,
1756 	0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687,
1757 	0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198,
1758 	0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927,
1759 	0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38,
1760 	0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8,
1761 	0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7,
1762 	0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096,
1763 	0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789,
1764 	0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859,
1765 	0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46,
1766 	0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9,
1767 	0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6,
1768 	0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36,
1769 	0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829,
1770 	0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C,
1771 	0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93,
1772 	0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043,
1773 	0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C,
1774 	0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3,
1775 	0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC,
1776 	0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C,
1777 	0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033,
1778 	0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652,
1779 	0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D,
1780 	0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D,
1781 	0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982,
1782 	0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D,
1783 	0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622,
1784 	0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2,
1785 	0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED,
1786 	0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530,
1787 	0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F,
1788 	0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF,
1789 	0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0,
1790 	0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F,
1791 	0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540,
1792 	0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90,
1793 	0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F,
1794 	0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE,
1795 	0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1,
1796 	0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321,
1797 	0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E,
1798 	0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81,
1799 	0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E,
1800 	0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E,
1801 	0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351
1802 };
1803 
1804 u_int32_t
1805 sctp_crc32c(const void *packet, u_int32_t len)
1806 {
1807 	u_int32_t i, crc32c;
1808 	u_int8_t byte0, byte1, byte2, byte3;
1809 	const u_int8_t *buf = (const u_int8_t *)packet;
1810 
1811 	crc32c = ~0;
1812 	for (i = 0; i < len; i++)
1813 		CRC32C(crc32c, buf[i]);
1814 	crc32c = ~crc32c;
1815 	byte0  = crc32c & 0xff;
1816 	byte1  = (crc32c >> 8) & 0xff;
1817 	byte2  = (crc32c >> 16) & 0xff;
1818 	byte3  = (crc32c >> 24) & 0xff;
1819 	crc32c = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3);
1820 	return (htonl(crc32c));
1821 }
1822 
1823 /*
1824  * Subtract 2 timeval structs:  out = out - in.
1825  * Out is assumed to be within about LONG_MAX seconds of in.
1826  */
1827 void
1828 tvsub(register struct timeval *out, register struct timeval *in)
1829 {
1830 
1831 	if ((out->tv_usec -= in->tv_usec) < 0)   {
1832 		--out->tv_sec;
1833 		out->tv_usec += 1000000;
1834 	}
1835 	out->tv_sec -= in->tv_sec;
1836 }
1837 
1838 /*
1839  * Construct an Internet address representation.
1840  * If the nflag has been supplied, give
1841  * numeric value, otherwise try for symbolic name.
1842  */
1843 char *
1844 inetname(struct in_addr in)
1845 {
1846 	register char *cp;
1847 	register struct hostent *hp;
1848 	static int first = 1;
1849 	static char domain[MAXHOSTNAMELEN + 1], line[MAXHOSTNAMELEN + 1];
1850 
1851 	if (first && !nflag) {
1852 		first = 0;
1853 		if (gethostname(domain, sizeof(domain) - 1) < 0)
1854 			domain[0] = '\0';
1855 		else {
1856 			cp = strchr(domain, '.');
1857 			if (cp == NULL) {
1858 #ifdef WITH_CASPER
1859 				if (capdns != NULL)
1860 					hp = cap_gethostbyname(capdns, domain);
1861 				else
1862 #endif
1863 					hp = gethostbyname(domain);
1864 				if (hp != NULL)
1865 					cp = strchr(hp->h_name, '.');
1866 			}
1867 			if (cp == NULL)
1868 				domain[0] = '\0';
1869 			else {
1870 				++cp;
1871 				(void)strncpy(domain, cp, sizeof(domain) - 1);
1872 				domain[sizeof(domain) - 1] = '\0';
1873 			}
1874 		}
1875 	}
1876 	if (!nflag && in.s_addr != INADDR_ANY) {
1877 #ifdef WITH_CASPER
1878 		if (capdns != NULL)
1879 			hp = cap_gethostbyaddr(capdns, (char *)&in, sizeof(in),
1880 			    AF_INET);
1881 		else
1882 #endif
1883 			hp = gethostbyaddr((char *)&in, sizeof(in), AF_INET);
1884 		if (hp != NULL) {
1885 			if ((cp = strchr(hp->h_name, '.')) != NULL &&
1886 			    strcmp(cp + 1, domain) == 0)
1887 				*cp = '\0';
1888 			(void)strncpy(line, hp->h_name, sizeof(line) - 1);
1889 			line[sizeof(line) - 1] = '\0';
1890 			return (line);
1891 		}
1892 	}
1893 	return (inet_ntoa(in));
1894 }
1895 
1896 struct hostinfo *
1897 gethostinfo(register char *hostname)
1898 {
1899 	register int n;
1900 	register struct hostent *hp;
1901 	register struct hostinfo *hi;
1902 	register char **p;
1903 	register u_int32_t addr, *ap;
1904 
1905 	if (strlen(hostname) >= MAXHOSTNAMELEN) {
1906 		Fprintf(stderr, "%s: hostname \"%.32s...\" is too long\n",
1907 		    prog, hostname);
1908 		exit(1);
1909 	}
1910 	hi = calloc(1, sizeof(*hi));
1911 	if (hi == NULL) {
1912 		Fprintf(stderr, "%s: calloc %s\n", prog, strerror(errno));
1913 		exit(1);
1914 	}
1915 	addr = inet_addr(hostname);
1916 	if ((int32_t)addr != -1) {
1917 		hi->name = strdup(hostname);
1918 		hi->n = 1;
1919 		hi->addrs = calloc(1, sizeof(hi->addrs[0]));
1920 		if (hi->addrs == NULL) {
1921 			Fprintf(stderr, "%s: calloc %s\n",
1922 			    prog, strerror(errno));
1923 			exit(1);
1924 		}
1925 		hi->addrs[0] = addr;
1926 		return (hi);
1927 	}
1928 
1929 #ifdef WITH_CASPER
1930 	if (capdns != NULL)
1931 		hp = cap_gethostbyname(capdns, hostname);
1932 	else
1933 #endif
1934 		hp = gethostbyname(hostname);
1935 	if (hp == NULL) {
1936 		Fprintf(stderr, "%s: unknown host %s\n", prog, hostname);
1937 		exit(1);
1938 	}
1939 	if (hp->h_addrtype != AF_INET || hp->h_length != 4) {
1940 		Fprintf(stderr, "%s: bad host %s\n", prog, hostname);
1941 		exit(1);
1942 	}
1943 	hi->name = strdup(hp->h_name);
1944 	for (n = 0, p = hp->h_addr_list; *p != NULL; ++n, ++p)
1945 		continue;
1946 	hi->n = n;
1947 	hi->addrs = calloc(n, sizeof(hi->addrs[0]));
1948 	if (hi->addrs == NULL) {
1949 		Fprintf(stderr, "%s: calloc %s\n", prog, strerror(errno));
1950 		exit(1);
1951 	}
1952 	for (ap = hi->addrs, p = hp->h_addr_list; *p != NULL; ++ap, ++p)
1953 		memcpy(ap, *p, sizeof(*ap));
1954 	return (hi);
1955 }
1956 
1957 void
1958 freehostinfo(register struct hostinfo *hi)
1959 {
1960 	if (hi->name != NULL) {
1961 		free(hi->name);
1962 		hi->name = NULL;
1963 	}
1964 	free((char *)hi->addrs);
1965 	free((char *)hi);
1966 }
1967 
1968 void
1969 getaddr(register u_int32_t *ap, register char *hostname)
1970 {
1971 	register struct hostinfo *hi;
1972 
1973 	hi = gethostinfo(hostname);
1974 	*ap = hi->addrs[0];
1975 	freehostinfo(hi);
1976 }
1977 
1978 void
1979 setsin(register struct sockaddr_in *sin, register u_int32_t addr)
1980 {
1981 
1982 	memset(sin, 0, sizeof(*sin));
1983 	sin->sin_len = sizeof(*sin);
1984 	sin->sin_family = AF_INET;
1985 	sin->sin_addr.s_addr = addr;
1986 }
1987 
1988 /* String to value with optional min and max. Handles decimal and hex. */
1989 int
1990 str2val(register const char *str, register const char *what,
1991     register int mi, register int ma)
1992 {
1993 	register const char *cp;
1994 	register int val;
1995 	char *ep;
1996 
1997 	if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
1998 		cp = str + 2;
1999 		val = (int)strtol(cp, &ep, 16);
2000 	} else
2001 		val = (int)strtol(str, &ep, 10);
2002 	if (*ep != '\0') {
2003 		Fprintf(stderr, "%s: \"%s\" bad value for %s\n",
2004 		    prog, str, what);
2005 		exit(1);
2006 	}
2007 	if (val < mi && mi >= 0) {
2008 		if (mi == 0)
2009 			Fprintf(stderr, "%s: %s must be >= %d\n",
2010 			    prog, what, mi);
2011 		else
2012 			Fprintf(stderr, "%s: %s must be > %d\n",
2013 			    prog, what, mi - 1);
2014 		exit(1);
2015 	}
2016 	if (val > ma && ma >= 0) {
2017 		Fprintf(stderr, "%s: %s must be <= %d\n", prog, what, ma);
2018 		exit(1);
2019 	}
2020 	return (val);
2021 }
2022 
2023 struct outproto *
2024 setproto(char *pname)
2025 {
2026 	struct outproto *proto;
2027 	int i;
2028 
2029 	for (i = 0; protos[i].name != NULL; i++) {
2030 		if (strcasecmp(protos[i].name, pname) == 0) {
2031 			break;
2032 		}
2033 	}
2034 	proto = &protos[i];
2035 	if (proto->name == NULL) {	/* generic handler */
2036 		struct protoent *pe;
2037 		u_long pnum;
2038 
2039 		/* Determine the IP protocol number */
2040 		if ((pe = getprotobyname(pname)) != NULL)
2041 			pnum = pe->p_proto;
2042 		else
2043 			pnum = str2val(optarg, "proto number", 1, 255);
2044 		proto->num = pnum;
2045 	}
2046 	return (proto);
2047 }
2048 
2049 void
2050 pkt_compare(const u_char *a, int la, const u_char *b, int lb) {
2051 	int l;
2052 	int i;
2053 
2054 	for (i = 0; i < la; i++)
2055 		Printf("%02x", (unsigned int)a[i]);
2056 	Printf("\n");
2057 	l = (la <= lb) ? la : lb;
2058 	for (i = 0; i < l; i++)
2059 		if (a[i] == b[i])
2060 			Printf("__");
2061 		else
2062 			Printf("%02x", (unsigned int)b[i]);
2063 	for (; i < lb; i++)
2064 		Printf("%02x", (unsigned int)b[i]);
2065 	Printf("\n");
2066 }
2067 
2068 
2069 void
2070 usage(void)
2071 {
2072 	Fprintf(stderr,
2073 	    "Usage: %s [-adDeEFInrSvx] [-A as_server] [-f first_ttl] [-g gateway]\n"
2074 	    "\t[-i iface] [-m max_ttl] [-M first_ttl] [-p port] [-P proto]\n"
2075 	    "\t[-q nprobes] [-s src_addr] [-t tos] [-w waittime]\n"
2076 	    "\t[-z pausemsecs] host [packetlen]\n", prog);
2077 	exit(1);
2078 }
2079