xref: /freebsd/sbin/ping/ping.c (revision 535af610)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Mike Muuss.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #if 0
36 #ifndef lint
37 static const char copyright[] =
38 "@(#) Copyright (c) 1989, 1993\n\
39 	The Regents of the University of California.  All rights reserved.\n";
40 #endif /* not lint */
41 
42 #ifndef lint
43 static char sccsid[] = "@(#)ping.c	8.1 (Berkeley) 6/5/93";
44 #endif /* not lint */
45 #endif
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 /*
50  *			P I N G . C
51  *
52  * Using the Internet Control Message Protocol (ICMP) "ECHO" facility,
53  * measure round-trip-delays and packet loss across network paths.
54  *
55  * Author -
56  *	Mike Muuss
57  *	U. S. Army Ballistic Research Laboratory
58  *	December, 1983
59  *
60  * Status -
61  *	Public Domain.  Distribution Unlimited.
62  * Bugs -
63  *	More statistics could always be gathered.
64  *	This program has to run SUID to ROOT to access the ICMP socket.
65  */
66 
67 #include <sys/param.h>		/* NB: we rely on this for <sys/types.h> */
68 #include <sys/capsicum.h>
69 #include <sys/socket.h>
70 #include <sys/sysctl.h>
71 #include <sys/time.h>
72 #include <sys/uio.h>
73 
74 #include <netinet/in.h>
75 #include <netinet/in_systm.h>
76 #include <netinet/ip.h>
77 #include <netinet/ip_icmp.h>
78 #include <netinet/ip_var.h>
79 #include <arpa/inet.h>
80 
81 #include <libcasper.h>
82 #include <casper/cap_dns.h>
83 
84 #ifdef IPSEC
85 #include <netipsec/ipsec.h>
86 #endif /*IPSEC*/
87 
88 #include <capsicum_helpers.h>
89 #include <ctype.h>
90 #include <err.h>
91 #include <errno.h>
92 #include <math.h>
93 #include <netdb.h>
94 #include <stddef.h>
95 #include <signal.h>
96 #include <stdio.h>
97 #include <stdlib.h>
98 #include <string.h>
99 #include <sysexits.h>
100 #include <time.h>
101 #include <unistd.h>
102 
103 #include "main.h"
104 #include "ping.h"
105 #include "utils.h"
106 
107 #define	INADDR_LEN	((int)sizeof(in_addr_t))
108 #define	TIMEVAL_LEN	((int)sizeof(struct tv32))
109 #define	MASK_LEN	(ICMP_MASKLEN - ICMP_MINLEN)
110 #define	TS_LEN		(ICMP_TSLEN - ICMP_MINLEN)
111 #define	DEFDATALEN	56		/* default data length */
112 #define	FLOOD_BACKOFF	20000		/* usecs to back off if F_FLOOD mode */
113 					/* runs out of buffer space */
114 #define	MAXIPLEN	(sizeof(struct ip) + MAX_IPOPTLEN)
115 #define	MAXICMPLEN	(ICMP_ADVLENMIN + MAX_IPOPTLEN)
116 #define	MAXWAIT		10000		/* max ms to wait for response */
117 #define	MAXALARM	(60 * 60)	/* max seconds for alarm timeout */
118 #define	MAXTOS		255
119 
120 #define	A(bit)		rcvd_tbl[(bit)>>3]	/* identify byte in array */
121 #define	B(bit)		(1 << ((bit) & 0x07))	/* identify bit in byte */
122 #define	SET(bit)	(A(bit) |= B(bit))
123 #define	CLR(bit)	(A(bit) &= (~B(bit)))
124 #define	TST(bit)	(A(bit) & B(bit))
125 
126 struct tv32 {
127 	int32_t tv32_sec;
128 	int32_t tv32_nsec;
129 };
130 
131 /* various options */
132 static int options;
133 #define	F_FLOOD		0x0001
134 #define	F_INTERVAL	0x0002
135 #define	F_NUMERIC	0x0004
136 #define	F_PINGFILLED	0x0008
137 #define	F_QUIET		0x0010
138 #define	F_RROUTE	0x0020
139 #define	F_SO_DEBUG	0x0040
140 #define	F_SO_DONTROUTE	0x0080
141 #define	F_VERBOSE	0x0100
142 #define	F_QUIET2	0x0200
143 #define	F_NOLOOP	0x0400
144 #define	F_MTTL		0x0800
145 #define	F_MIF		0x1000
146 #define	F_AUDIBLE	0x2000
147 #ifdef IPSEC
148 #ifdef IPSEC_POLICY_IPSEC
149 #define F_POLICY	0x4000
150 #endif /*IPSEC_POLICY_IPSEC*/
151 #endif /*IPSEC*/
152 #define	F_TTL		0x8000
153 #define	F_MISSED	0x10000
154 #define	F_ONCE		0x20000
155 #define	F_HDRINCL	0x40000
156 #define	F_MASK		0x80000
157 #define	F_TIME		0x100000
158 #define	F_SWEEP		0x200000
159 #define	F_WAITTIME	0x400000
160 #define	F_IP_VLAN_PCP	0x800000
161 #define	F_DOT		0x1000000
162 
163 /*
164  * MAX_DUP_CHK is the number of bits in received table, i.e. the maximum
165  * number of received sequence numbers we can keep track of.  Change 128
166  * to 8192 for complete accuracy...
167  */
168 #define	MAX_DUP_CHK	(8 * 128)
169 static int mx_dup_ck = MAX_DUP_CHK;
170 static char rcvd_tbl[MAX_DUP_CHK / 8];
171 
172 static struct sockaddr_in whereto;	/* who to ping */
173 static int datalen = DEFDATALEN;
174 static int maxpayload;
175 static int ssend;		/* send socket file descriptor */
176 static int srecv;		/* receive socket file descriptor */
177 static u_char outpackhdr[IP_MAXPACKET], *outpack;
178 static char BBELL = '\a';	/* characters written for MISSED and AUDIBLE */
179 static char BSPACE = '\b';	/* characters written for flood */
180 static const char *DOT = ".";
181 static size_t DOTlen = 1;
182 static size_t DOTidx = 0;
183 static char *hostname;
184 static char *shostname;
185 static int ident;		/* process id to identify our packets */
186 static int uid;			/* cached uid for micro-optimization */
187 static u_char icmp_type = ICMP_ECHO;
188 static u_char icmp_type_rsp = ICMP_ECHOREPLY;
189 static int phdr_len = 0;
190 static int send_len;
191 
192 /* counters */
193 static long nmissedmax;		/* max value of ntransmitted - nreceived - 1 */
194 static long npackets;		/* max packets to transmit */
195 static long nreceived;		/* # of packets we got back */
196 static long nrepeats;		/* number of duplicates */
197 static long ntransmitted;	/* sequence # for outbound packets = #sent */
198 static long snpackets;			/* max packets to transmit in one sweep */
199 static long sntransmitted;	/* # of packets we sent in this sweep */
200 static int sweepmax;		/* max value of payload in sweep */
201 static int sweepmin = 0;	/* start value of payload in sweep */
202 static int sweepincr = 1;	/* payload increment in sweep */
203 static int interval = 1000;	/* interval between packets, ms */
204 static int waittime = MAXWAIT;	/* timeout for each packet */
205 static long nrcvtimeout = 0;	/* # of packets we got back after waittime */
206 
207 /* timing */
208 static int timing;		/* flag to do timing */
209 static double tmin = 999999999.0;	/* minimum round trip time */
210 static double tmax = 0.0;	/* maximum round trip time */
211 static double tsum = 0.0;	/* sum of all times, for doing average */
212 static double tsumsq = 0.0;	/* sum of all times squared, for std. dev. */
213 
214 /* nonzero if we've been told to finish up */
215 static volatile sig_atomic_t finish_up;
216 static volatile sig_atomic_t siginfo_p;
217 
218 static cap_channel_t *capdns;
219 
220 static void fill(char *, char *);
221 static cap_channel_t *capdns_setup(void);
222 static void check_status(void);
223 static void finish(void) __dead2;
224 static void pinger(void);
225 static char *pr_addr(struct in_addr);
226 static char *pr_ntime(n_time);
227 static void pr_icmph(struct icmp *, struct ip *, const u_char *const);
228 static void pr_iph(struct ip *, const u_char *);
229 static void pr_pack(char *, ssize_t, struct sockaddr_in *, struct timespec *);
230 static void status(int);
231 static void stopit(int);
232 
233 int
234 ping(int argc, char *const *argv)
235 {
236 	struct sockaddr_in from, sock_in;
237 	struct in_addr ifaddr;
238 	struct timespec last, intvl;
239 	struct iovec iov;
240 	struct msghdr msg;
241 	struct sigaction si_sa;
242 	size_t sz;
243 	u_char *datap, packet[IP_MAXPACKET] __aligned(4);
244 	const char *errstr;
245 	char *ep, *source, *target, *payload;
246 	struct hostent *hp;
247 #ifdef IPSEC_POLICY_IPSEC
248 	char *policy_in, *policy_out;
249 #endif
250 	struct sockaddr_in *to;
251 	double t;
252 	u_long alarmtimeout;
253 	long long ltmp;
254 	int almost_done, ch, df, hold, i, icmp_len, mib[4], preload;
255 	int ssend_errno, srecv_errno, tos, ttl, pcp;
256 	char ctrl[CMSG_SPACE(sizeof(struct timespec))];
257 	char hnamebuf[MAXHOSTNAMELEN], snamebuf[MAXHOSTNAMELEN];
258 #ifdef IP_OPTIONS
259 	char rspace[MAX_IPOPTLEN];	/* record route space */
260 #endif
261 	unsigned char loop, mttl;
262 
263 	payload = source = NULL;
264 #ifdef IPSEC_POLICY_IPSEC
265 	policy_in = policy_out = NULL;
266 #endif
267 	cap_rights_t rights;
268 
269 	options |= F_NUMERIC;
270 
271 	/*
272 	 * Do the stuff that we need root priv's for *first*, and
273 	 * then drop our setuid bit.  Save error reporting for
274 	 * after arg parsing.
275 	 *
276 	 * Historicaly ping was using one socket 's' for sending and for
277 	 * receiving. After capsicum(4) related changes we use two
278 	 * sockets. It was done for special ping use case - when user
279 	 * issue ping on multicast or broadcast address replies come
280 	 * from different addresses, not from the address we
281 	 * connect(2)'ed to, and send socket do not receive those
282 	 * packets.
283 	 */
284 	ssend = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
285 	ssend_errno = errno;
286 	srecv = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
287 	srecv_errno = errno;
288 
289 	if (setuid(getuid()) != 0)
290 		err(EX_NOPERM, "setuid() failed");
291 	uid = getuid();
292 
293 	if (ssend < 0) {
294 		errno = ssend_errno;
295 		err(EX_OSERR, "ssend socket");
296 	}
297 
298 	if (srecv < 0) {
299 		errno = srecv_errno;
300 		err(EX_OSERR, "srecv socket");
301 	}
302 
303 	alarmtimeout = df = preload = tos = pcp = 0;
304 
305 	outpack = outpackhdr + sizeof(struct ip);
306 	while ((ch = getopt(argc, argv, PING4OPTS)) != -1) {
307 		switch(ch) {
308 		case '.':
309 			options |= F_DOT;
310 			if (optarg != NULL) {
311 				DOT = optarg;
312 				DOTlen = strlen(optarg);
313 			}
314 			break;
315 		case '4':
316 			/* This option is processed in main(). */
317 			break;
318 		case 'A':
319 			options |= F_MISSED;
320 			break;
321 		case 'a':
322 			options |= F_AUDIBLE;
323 			break;
324 		case 'C':
325 			options |= F_IP_VLAN_PCP;
326 			ltmp = strtonum(optarg, -1, 7, &errstr);
327 			if (errstr != NULL)
328 				errx(EX_USAGE, "invalid PCP: `%s'", optarg);
329 			pcp = ltmp;
330 			break;
331 		case 'c':
332 			ltmp = strtonum(optarg, 1, LONG_MAX, &errstr);
333 			if (errstr != NULL)
334 				errx(EX_USAGE,
335 				    "invalid count of packets to transmit: `%s'",
336 				    optarg);
337 			npackets = (long)ltmp;
338 			break;
339 		case 'D':
340 			options |= F_HDRINCL;
341 			df = 1;
342 			break;
343 		case 'd':
344 			options |= F_SO_DEBUG;
345 			break;
346 		case 'f':
347 			if (uid) {
348 				errno = EPERM;
349 				err(EX_NOPERM, "-f flag");
350 			}
351 			options |= F_FLOOD;
352 			options |= F_DOT;
353 			setbuf(stdout, (char *)NULL);
354 			break;
355 		case 'G': /* Maximum packet size for ping sweep */
356 			ltmp = strtonum(optarg, 1, INT_MAX, &errstr);
357 			if (errstr != NULL) {
358 				errx(EX_USAGE, "invalid packet size: `%s'",
359 				    optarg);
360 			}
361 			sweepmax = (int)ltmp;
362 			if (uid != 0 && sweepmax > DEFDATALEN) {
363 				errc(EX_NOPERM, EPERM,
364 				    "packet size too large: %d > %u",
365 				    sweepmax, DEFDATALEN);
366 			}
367 			options |= F_SWEEP;
368 			break;
369 		case 'g': /* Minimum packet size for ping sweep */
370 			ltmp = strtonum(optarg, 1, INT_MAX, &errstr);
371 			if (errstr != NULL) {
372 				errx(EX_USAGE, "invalid packet size: `%s'",
373 				    optarg);
374 			}
375 			sweepmin = (int)ltmp;
376 			if (uid != 0 && sweepmin > DEFDATALEN) {
377 				errc(EX_NOPERM, EPERM,
378 				    "packet size too large: %d > %u",
379 				    sweepmin, DEFDATALEN);
380 			}
381 			options |= F_SWEEP;
382 			break;
383 		case 'H':
384 			options &= ~F_NUMERIC;
385 			break;
386 		case 'h': /* Packet size increment for ping sweep */
387 			ltmp = strtonum(optarg, 1, INT_MAX, &errstr);
388 			if (errstr != NULL) {
389 				errx(EX_USAGE, "invalid packet size: `%s'",
390 				    optarg);
391 			}
392 			sweepincr = (int)ltmp;
393 			if (uid != 0 && sweepincr > DEFDATALEN) {
394 				errc(EX_NOPERM, EPERM,
395 				    "packet size too large: %d > %u",
396 				    sweepincr, DEFDATALEN);
397 			}
398 			options |= F_SWEEP;
399 			break;
400 		case 'I':		/* multicast interface */
401 			if (inet_aton(optarg, &ifaddr) == 0)
402 				errx(EX_USAGE,
403 				    "invalid multicast interface: `%s'",
404 				    optarg);
405 			options |= F_MIF;
406 			break;
407 		case 'i':		/* wait between sending packets */
408 			t = strtod(optarg, &ep) * 1000.0;
409 			if (*ep || ep == optarg || t > (double)INT_MAX)
410 				errx(EX_USAGE, "invalid timing interval: `%s'",
411 				    optarg);
412 			options |= F_INTERVAL;
413 			interval = (int)t;
414 			if (uid && interval < 1000) {
415 				errno = EPERM;
416 				err(EX_NOPERM, "-i interval too short");
417 			}
418 			break;
419 		case 'L':
420 			options |= F_NOLOOP;
421 			loop = 0;
422 			break;
423 		case 'l':
424 			ltmp = strtonum(optarg, 0, INT_MAX, &errstr);
425 			if (errstr != NULL)
426 				errx(EX_USAGE,
427 				    "invalid preload value: `%s'", optarg);
428 			if (uid) {
429 				errno = EPERM;
430 				err(EX_NOPERM, "-l flag");
431 			}
432 			preload = (int)ltmp;
433 			break;
434 		case 'M':
435 			switch(optarg[0]) {
436 			case 'M':
437 			case 'm':
438 				options |= F_MASK;
439 				break;
440 			case 'T':
441 			case 't':
442 				options |= F_TIME;
443 				break;
444 			default:
445 				errx(EX_USAGE, "invalid message: `%c'", optarg[0]);
446 				break;
447 			}
448 			break;
449 		case 'm':		/* TTL */
450 			ltmp = strtonum(optarg, 0, MAXTTL, &errstr);
451 			if (errstr != NULL)
452 				errx(EX_USAGE, "invalid TTL: `%s'", optarg);
453 			ttl = (int)ltmp;
454 			options |= F_TTL;
455 			break;
456 		case 'n':
457 			options |= F_NUMERIC;
458 			break;
459 		case 'o':
460 			options |= F_ONCE;
461 			break;
462 #ifdef IPSEC
463 #ifdef IPSEC_POLICY_IPSEC
464 		case 'P':
465 			options |= F_POLICY;
466 			if (!strncmp("in", optarg, 2))
467 				policy_in = strdup(optarg);
468 			else if (!strncmp("out", optarg, 3))
469 				policy_out = strdup(optarg);
470 			else
471 				errx(1, "invalid security policy");
472 			break;
473 #endif /*IPSEC_POLICY_IPSEC*/
474 #endif /*IPSEC*/
475 		case 'p':		/* fill buffer with user pattern */
476 			options |= F_PINGFILLED;
477 			payload = optarg;
478 			break;
479 		case 'Q':
480 			options |= F_QUIET2;
481 			break;
482 		case 'q':
483 			options |= F_QUIET;
484 			break;
485 		case 'R':
486 			options |= F_RROUTE;
487 			break;
488 		case 'r':
489 			options |= F_SO_DONTROUTE;
490 			break;
491 		case 'S':
492 			source = optarg;
493 			break;
494 		case 's':		/* size of packet to send */
495 			ltmp = strtonum(optarg, 0, INT_MAX, &errstr);
496 			if (errstr != NULL)
497 				errx(EX_USAGE, "invalid packet size: `%s'",
498 				    optarg);
499 			datalen = (int)ltmp;
500 			if (uid != 0 && datalen > DEFDATALEN) {
501 				errno = EPERM;
502 				err(EX_NOPERM,
503 				    "packet size too large: %d > %u",
504 				    datalen, DEFDATALEN);
505 			}
506 			break;
507 		case 'T':		/* multicast TTL */
508 			ltmp = strtonum(optarg, 0, MAXTTL, &errstr);
509 			if (errstr != NULL)
510 				errx(EX_USAGE, "invalid multicast TTL: `%s'",
511 				    optarg);
512 			mttl = (unsigned char)ltmp;
513 			options |= F_MTTL;
514 			break;
515 		case 't':
516 			alarmtimeout = strtoul(optarg, &ep, 0);
517 			if ((alarmtimeout < 1) || (alarmtimeout == ULONG_MAX))
518 				errx(EX_USAGE, "invalid timeout: `%s'",
519 				    optarg);
520 			if (alarmtimeout > MAXALARM)
521 				errx(EX_USAGE, "invalid timeout: `%s' > %d",
522 				    optarg, MAXALARM);
523 			{
524 				struct itimerval itv;
525 
526 				timerclear(&itv.it_interval);
527 				timerclear(&itv.it_value);
528 				itv.it_value.tv_sec = (time_t)alarmtimeout;
529 				if (setitimer(ITIMER_REAL, &itv, NULL) != 0)
530 					err(1, "setitimer");
531 			}
532 			break;
533 		case 'v':
534 			options |= F_VERBOSE;
535 			break;
536 		case 'W':		/* wait ms for answer */
537 			t = strtod(optarg, &ep);
538 			if (*ep || ep == optarg || t > (double)INT_MAX)
539 				errx(EX_USAGE, "invalid timing interval: `%s'",
540 				    optarg);
541 			options |= F_WAITTIME;
542 			waittime = (int)t;
543 			break;
544 		case 'z':
545 			options |= F_HDRINCL;
546 			ltmp = strtol(optarg, &ep, 0);
547 			if (*ep || ep == optarg || ltmp > MAXTOS || ltmp < 0)
548 				errx(EX_USAGE, "invalid TOS: `%s'", optarg);
549 			tos = ltmp;
550 			break;
551 		default:
552 			usage();
553 		}
554 	}
555 
556 	if (argc - optind != 1)
557 		usage();
558 	target = argv[optind];
559 
560 	switch (options & (F_MASK|F_TIME)) {
561 	case 0: break;
562 	case F_MASK:
563 		icmp_type = ICMP_MASKREQ;
564 		icmp_type_rsp = ICMP_MASKREPLY;
565 		phdr_len = MASK_LEN;
566 		if (!(options & F_QUIET))
567 			(void)printf("ICMP_MASKREQ\n");
568 		break;
569 	case F_TIME:
570 		icmp_type = ICMP_TSTAMP;
571 		icmp_type_rsp = ICMP_TSTAMPREPLY;
572 		phdr_len = TS_LEN;
573 		if (!(options & F_QUIET))
574 			(void)printf("ICMP_TSTAMP\n");
575 		break;
576 	default:
577 		errx(EX_USAGE, "ICMP_TSTAMP and ICMP_MASKREQ are exclusive.");
578 		break;
579 	}
580 	icmp_len = sizeof(struct ip) + ICMP_MINLEN + phdr_len;
581 	if (options & F_RROUTE)
582 		icmp_len += MAX_IPOPTLEN;
583 	maxpayload = IP_MAXPACKET - icmp_len;
584 	if (datalen > maxpayload)
585 		errx(EX_USAGE, "packet size too large: %d > %d", datalen,
586 		    maxpayload);
587 	send_len = icmp_len + datalen;
588 	datap = &outpack[ICMP_MINLEN + phdr_len + TIMEVAL_LEN];
589 	if (options & F_PINGFILLED) {
590 		fill((char *)datap, payload);
591 	}
592 	capdns = capdns_setup();
593 	if (source) {
594 		bzero((char *)&sock_in, sizeof(sock_in));
595 		sock_in.sin_family = AF_INET;
596 		if (inet_aton(source, &sock_in.sin_addr) != 0) {
597 			shostname = source;
598 		} else {
599 			hp = cap_gethostbyname2(capdns, source, AF_INET);
600 			if (!hp)
601 				errx(EX_NOHOST, "cannot resolve %s: %s",
602 				    source, hstrerror(h_errno));
603 
604 			sock_in.sin_len = sizeof sock_in;
605 			if ((unsigned)hp->h_length > sizeof(sock_in.sin_addr) ||
606 			    hp->h_length < 0)
607 				errx(1, "gethostbyname2: illegal address");
608 			memcpy(&sock_in.sin_addr, hp->h_addr_list[0],
609 			    sizeof(sock_in.sin_addr));
610 			(void)strncpy(snamebuf, hp->h_name,
611 			    sizeof(snamebuf) - 1);
612 			snamebuf[sizeof(snamebuf) - 1] = '\0';
613 			shostname = snamebuf;
614 		}
615 		if (bind(ssend, (struct sockaddr *)&sock_in, sizeof sock_in) ==
616 		    -1)
617 			err(1, "bind");
618 	}
619 
620 	bzero(&whereto, sizeof(whereto));
621 	to = &whereto;
622 	to->sin_family = AF_INET;
623 	to->sin_len = sizeof *to;
624 	if (inet_aton(target, &to->sin_addr) != 0) {
625 		hostname = target;
626 	} else {
627 		hp = cap_gethostbyname2(capdns, target, AF_INET);
628 		if (!hp)
629 			errx(EX_NOHOST, "cannot resolve %s: %s",
630 			    target, hstrerror(h_errno));
631 
632 		if ((unsigned)hp->h_length > sizeof(to->sin_addr))
633 			errx(1, "gethostbyname2 returned an illegal address");
634 		memcpy(&to->sin_addr, hp->h_addr_list[0], sizeof to->sin_addr);
635 		(void)strncpy(hnamebuf, hp->h_name, sizeof(hnamebuf) - 1);
636 		hnamebuf[sizeof(hnamebuf) - 1] = '\0';
637 		hostname = hnamebuf;
638 	}
639 
640 	/* From now on we will use only reverse DNS lookups. */
641 #ifdef WITH_CASPER
642 	if (capdns != NULL) {
643 		const char *types[1];
644 
645 		types[0] = "ADDR2NAME";
646 		if (cap_dns_type_limit(capdns, types, 1) < 0)
647 			err(1, "unable to limit access to system.dns service");
648 	}
649 #endif
650 	if (connect(ssend, (struct sockaddr *)&whereto, sizeof(whereto)) != 0)
651 		err(1, "connect");
652 
653 	if (options & F_FLOOD && options & F_INTERVAL)
654 		errx(EX_USAGE, "-f and -i: incompatible options");
655 
656 	if (options & F_FLOOD && IN_MULTICAST(ntohl(to->sin_addr.s_addr)))
657 		errx(EX_USAGE,
658 		    "-f flag cannot be used with multicast destination");
659 	if (options & (F_MIF | F_NOLOOP | F_MTTL)
660 	    && !IN_MULTICAST(ntohl(to->sin_addr.s_addr)))
661 		errx(EX_USAGE,
662 		    "-I, -L, -T flags cannot be used with unicast destination");
663 
664 	if (datalen >= TIMEVAL_LEN)	/* can we time transfer */
665 		timing = 1;
666 
667 	if ((options & (F_PINGFILLED | F_SWEEP)) == 0)
668 		for (i = TIMEVAL_LEN; i < datalen; ++i)
669 			*datap++ = i;
670 
671 	ident = getpid() & 0xFFFF;
672 
673 	hold = 1;
674 	if (options & F_SO_DEBUG) {
675 		(void)setsockopt(ssend, SOL_SOCKET, SO_DEBUG, (char *)&hold,
676 		    sizeof(hold));
677 		(void)setsockopt(srecv, SOL_SOCKET, SO_DEBUG, (char *)&hold,
678 		    sizeof(hold));
679 	}
680 	if (options & F_SO_DONTROUTE)
681 		(void)setsockopt(ssend, SOL_SOCKET, SO_DONTROUTE, (char *)&hold,
682 		    sizeof(hold));
683 	if (options & F_IP_VLAN_PCP) {
684 		(void)setsockopt(ssend, IPPROTO_IP, IP_VLAN_PCP, (char *)&pcp,
685 		    sizeof(pcp));
686 	}
687 #ifdef IPSEC
688 #ifdef IPSEC_POLICY_IPSEC
689 	if (options & F_POLICY) {
690 		char *buf;
691 		if (policy_in != NULL) {
692 			buf = ipsec_set_policy(policy_in, strlen(policy_in));
693 			if (buf == NULL)
694 				errx(EX_CONFIG, "%s", ipsec_strerror());
695 			if (setsockopt(srecv, IPPROTO_IP, IP_IPSEC_POLICY,
696 					buf, ipsec_get_policylen(buf)) < 0)
697 				err(EX_CONFIG,
698 				    "ipsec policy cannot be configured");
699 			free(buf);
700 		}
701 
702 		if (policy_out != NULL) {
703 			buf = ipsec_set_policy(policy_out, strlen(policy_out));
704 			if (buf == NULL)
705 				errx(EX_CONFIG, "%s", ipsec_strerror());
706 			if (setsockopt(ssend, IPPROTO_IP, IP_IPSEC_POLICY,
707 					buf, ipsec_get_policylen(buf)) < 0)
708 				err(EX_CONFIG,
709 				    "ipsec policy cannot be configured");
710 			free(buf);
711 		}
712 	}
713 #endif /*IPSEC_POLICY_IPSEC*/
714 #endif /*IPSEC*/
715 
716 	if (options & F_HDRINCL) {
717 		struct ip ip;
718 
719 		memcpy(&ip, outpackhdr, sizeof(ip));
720 		if (!(options & (F_TTL | F_MTTL))) {
721 			mib[0] = CTL_NET;
722 			mib[1] = PF_INET;
723 			mib[2] = IPPROTO_IP;
724 			mib[3] = IPCTL_DEFTTL;
725 			sz = sizeof(ttl);
726 			if (sysctl(mib, 4, &ttl, &sz, NULL, 0) == -1)
727 				err(1, "sysctl(net.inet.ip.ttl)");
728 		}
729 		setsockopt(ssend, IPPROTO_IP, IP_HDRINCL, &hold, sizeof(hold));
730 		ip.ip_v = IPVERSION;
731 		ip.ip_hl = sizeof(struct ip) >> 2;
732 		ip.ip_tos = tos;
733 		ip.ip_id = 0;
734 		ip.ip_off = htons(df ? IP_DF : 0);
735 		ip.ip_ttl = ttl;
736 		ip.ip_p = IPPROTO_ICMP;
737 		ip.ip_src.s_addr = source ? sock_in.sin_addr.s_addr : INADDR_ANY;
738 		ip.ip_dst = to->sin_addr;
739 		memcpy(outpackhdr, &ip, sizeof(ip));
740         }
741 
742 	/*
743 	 * Here we enter capability mode. Further down access to global
744 	 * namespaces (e.g filesystem) is restricted (see capsicum(4)).
745 	 * We must connect(2) our socket before this point.
746 	 */
747 	caph_cache_catpages();
748 	if (caph_enter_casper() < 0)
749 		err(1, "caph_enter_casper");
750 
751 	cap_rights_init(&rights, CAP_RECV, CAP_EVENT, CAP_SETSOCKOPT);
752 	if (caph_rights_limit(srecv, &rights) < 0)
753 		err(1, "cap_rights_limit srecv");
754 	cap_rights_init(&rights, CAP_SEND, CAP_SETSOCKOPT);
755 	if (caph_rights_limit(ssend, &rights) < 0)
756 		err(1, "cap_rights_limit ssend");
757 
758 	/* record route option */
759 	if (options & F_RROUTE) {
760 #ifdef IP_OPTIONS
761 		bzero(rspace, sizeof(rspace));
762 		rspace[IPOPT_OPTVAL] = IPOPT_RR;
763 		rspace[IPOPT_OLEN] = sizeof(rspace) - 1;
764 		rspace[IPOPT_OFFSET] = IPOPT_MINOFF;
765 		rspace[sizeof(rspace) - 1] = IPOPT_EOL;
766 		if (setsockopt(ssend, IPPROTO_IP, IP_OPTIONS, rspace,
767 		    sizeof(rspace)) < 0)
768 			err(EX_OSERR, "setsockopt IP_OPTIONS");
769 #else
770 		errx(EX_UNAVAILABLE,
771 		    "record route not available in this implementation");
772 #endif /* IP_OPTIONS */
773 	}
774 
775 	if (options & F_TTL) {
776 		if (setsockopt(ssend, IPPROTO_IP, IP_TTL, &ttl,
777 		    sizeof(ttl)) < 0) {
778 			err(EX_OSERR, "setsockopt IP_TTL");
779 		}
780 	}
781 	if (options & F_NOLOOP) {
782 		if (setsockopt(ssend, IPPROTO_IP, IP_MULTICAST_LOOP, &loop,
783 		    sizeof(loop)) < 0) {
784 			err(EX_OSERR, "setsockopt IP_MULTICAST_LOOP");
785 		}
786 	}
787 	if (options & F_MTTL) {
788 		if (setsockopt(ssend, IPPROTO_IP, IP_MULTICAST_TTL, &mttl,
789 		    sizeof(mttl)) < 0) {
790 			err(EX_OSERR, "setsockopt IP_MULTICAST_TTL");
791 		}
792 	}
793 	if (options & F_MIF) {
794 		if (setsockopt(ssend, IPPROTO_IP, IP_MULTICAST_IF, &ifaddr,
795 		    sizeof(ifaddr)) < 0) {
796 			err(EX_OSERR, "setsockopt IP_MULTICAST_IF");
797 		}
798 	}
799 #ifdef SO_TIMESTAMP
800 	{
801 		int on = 1;
802 		int ts_clock = SO_TS_MONOTONIC;
803 		if (setsockopt(srecv, SOL_SOCKET, SO_TIMESTAMP, &on,
804 		    sizeof(on)) < 0)
805 			err(EX_OSERR, "setsockopt SO_TIMESTAMP");
806 		if (setsockopt(srecv, SOL_SOCKET, SO_TS_CLOCK, &ts_clock,
807 		    sizeof(ts_clock)) < 0)
808 			err(EX_OSERR, "setsockopt SO_TS_CLOCK");
809 	}
810 #endif
811 	if (sweepmax) {
812 		if (sweepmin > sweepmax)
813 			errx(EX_USAGE,
814 	    "Maximum packet size must be no less than the minimum packet size");
815 
816 		if (sweepmax > maxpayload - TIMEVAL_LEN)
817 			errx(EX_USAGE, "Invalid sweep maximum");
818 
819 		if (datalen != DEFDATALEN)
820 			errx(EX_USAGE,
821 		    "Packet size and ping sweep are mutually exclusive");
822 
823 		if (npackets > 0) {
824 			snpackets = npackets;
825 			npackets = 0;
826 		} else
827 			snpackets = 1;
828 		datalen = sweepmin;
829 		send_len = icmp_len + sweepmin;
830 	}
831 	if (options & F_SWEEP && !sweepmax)
832 		errx(EX_USAGE, "Maximum sweep size must be specified");
833 
834 	/*
835 	 * When pinging the broadcast address, you can get a lot of answers.
836 	 * Doing something so evil is useful if you are trying to stress the
837 	 * ethernet, or just want to fill the arp cache to get some stuff for
838 	 * /etc/ethers.  But beware: RFC 1122 allows hosts to ignore broadcast
839 	 * or multicast pings if they wish.
840 	 */
841 
842 	/*
843 	 * XXX receive buffer needs undetermined space for mbuf overhead
844 	 * as well.
845 	 */
846 	hold = IP_MAXPACKET + 128;
847 	(void)setsockopt(srecv, SOL_SOCKET, SO_RCVBUF, (char *)&hold,
848 	    sizeof(hold));
849 	/* CAP_SETSOCKOPT removed */
850 	cap_rights_init(&rights, CAP_RECV, CAP_EVENT);
851 	if (caph_rights_limit(srecv, &rights) < 0)
852 		err(1, "cap_rights_limit srecv setsockopt");
853 	if (uid == 0)
854 		(void)setsockopt(ssend, SOL_SOCKET, SO_SNDBUF, (char *)&hold,
855 		    sizeof(hold));
856 	/* CAP_SETSOCKOPT removed */
857 	cap_rights_init(&rights, CAP_SEND);
858 	if (caph_rights_limit(ssend, &rights) < 0)
859 		err(1, "cap_rights_limit ssend setsockopt");
860 
861 	if (to->sin_family == AF_INET) {
862 		(void)printf("PING %s (%s)", hostname,
863 		    inet_ntoa(to->sin_addr));
864 		if (source)
865 			(void)printf(" from %s", shostname);
866 		if (sweepmax)
867 			(void)printf(": (%d ... %d) data bytes\n",
868 			    sweepmin, sweepmax);
869 		else
870 			(void)printf(": %d data bytes\n", datalen);
871 
872 	} else {
873 		if (sweepmax)
874 			(void)printf("PING %s: (%d ... %d) data bytes\n",
875 			    hostname, sweepmin, sweepmax);
876 		else
877 			(void)printf("PING %s: %d data bytes\n", hostname, datalen);
878 	}
879 
880 	/*
881 	 * Use sigaction() instead of signal() to get unambiguous semantics,
882 	 * in particular with SA_RESTART not set.
883 	 */
884 
885 	sigemptyset(&si_sa.sa_mask);
886 	si_sa.sa_flags = 0;
887 
888 	si_sa.sa_handler = stopit;
889 	if (sigaction(SIGINT, &si_sa, 0) == -1) {
890 		err(EX_OSERR, "sigaction SIGINT");
891 	}
892 
893 	si_sa.sa_handler = status;
894 	if (sigaction(SIGINFO, &si_sa, 0) == -1) {
895 		err(EX_OSERR, "sigaction");
896 	}
897 
898         if (alarmtimeout > 0) {
899 		si_sa.sa_handler = stopit;
900 		if (sigaction(SIGALRM, &si_sa, 0) == -1)
901 			err(EX_OSERR, "sigaction SIGALRM");
902         }
903 
904 	bzero(&msg, sizeof(msg));
905 	msg.msg_name = (caddr_t)&from;
906 	msg.msg_iov = &iov;
907 	msg.msg_iovlen = 1;
908 #ifdef SO_TIMESTAMP
909 	msg.msg_control = (caddr_t)ctrl;
910 	msg.msg_controllen = sizeof(ctrl);
911 #endif
912 	iov.iov_base = packet;
913 	iov.iov_len = IP_MAXPACKET;
914 
915 	if (preload == 0)
916 		pinger();		/* send the first ping */
917 	else {
918 		if (npackets != 0 && preload > npackets)
919 			preload = npackets;
920 		while (preload--)	/* fire off them quickies */
921 			pinger();
922 	}
923 	(void)clock_gettime(CLOCK_MONOTONIC, &last);
924 
925 	if (options & F_FLOOD) {
926 		intvl.tv_sec = 0;
927 		intvl.tv_nsec = 10000000;
928 	} else {
929 		intvl.tv_sec = interval / 1000;
930 		intvl.tv_nsec = interval % 1000 * 1000000;
931 	}
932 
933 	almost_done = 0;
934 	while (!finish_up) {
935 		struct timespec now, timeout;
936 		fd_set rfds;
937 		int n;
938 		ssize_t cc;
939 
940 		check_status();
941 		if ((unsigned)srecv >= FD_SETSIZE)
942 			errx(EX_OSERR, "descriptor too large");
943 		FD_ZERO(&rfds);
944 		FD_SET(srecv, &rfds);
945 		(void)clock_gettime(CLOCK_MONOTONIC, &now);
946 		timespecadd(&last, &intvl, &timeout);
947 		timespecsub(&timeout, &now, &timeout);
948 		if (timeout.tv_sec < 0)
949 			timespecclear(&timeout);
950 		n = pselect(srecv + 1, &rfds, NULL, NULL, &timeout, NULL);
951 		if (n < 0)
952 			continue;	/* Must be EINTR. */
953 		if (n == 1) {
954 			struct timespec *tv = NULL;
955 #ifdef SO_TIMESTAMP
956 			struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
957 #endif
958 			msg.msg_namelen = sizeof(from);
959 			if ((cc = recvmsg(srecv, &msg, 0)) < 0) {
960 				if (errno == EINTR)
961 					continue;
962 				warn("recvmsg");
963 				continue;
964 			}
965 			/* If we have a 0 byte read from recvfrom continue */
966 			if (cc == 0)
967 				continue;
968 #ifdef SO_TIMESTAMP
969 			if (cmsg != NULL &&
970 			    cmsg->cmsg_level == SOL_SOCKET &&
971 			    cmsg->cmsg_type == SCM_TIMESTAMP &&
972 			    cmsg->cmsg_len == CMSG_LEN(sizeof *tv)) {
973 				/* Copy to avoid alignment problems: */
974 				memcpy(&now, CMSG_DATA(cmsg), sizeof(now));
975 				tv = &now;
976 			}
977 #endif
978 			if (tv == NULL) {
979 				(void)clock_gettime(CLOCK_MONOTONIC, &now);
980 				tv = &now;
981 			}
982 			pr_pack((char *)packet, cc, &from, tv);
983 			if ((options & F_ONCE && nreceived) ||
984 			    (npackets && nreceived >= npackets))
985 				break;
986 		}
987 		if (n == 0 || options & F_FLOOD) {
988 			if (sweepmax && sntransmitted == snpackets) {
989 				if (datalen + sweepincr > sweepmax)
990 					break;
991 				for (i = 0; i < sweepincr; i++)
992 					*datap++ = i;
993 				datalen += sweepincr;
994 				send_len = icmp_len + datalen;
995 				sntransmitted = 0;
996 			}
997 			if (!npackets || ntransmitted < npackets)
998 				pinger();
999 			else {
1000 				if (almost_done)
1001 					break;
1002 				almost_done = 1;
1003 				intvl.tv_nsec = 0;
1004 				if (nreceived) {
1005 					intvl.tv_sec = 2 * tmax / 1000;
1006 					if (!intvl.tv_sec)
1007 						intvl.tv_sec = 1;
1008 				} else {
1009 					intvl.tv_sec = waittime / 1000;
1010 					intvl.tv_nsec = waittime % 1000 * 1000000;
1011 				}
1012 			}
1013 			(void)clock_gettime(CLOCK_MONOTONIC, &last);
1014 			if (ntransmitted - nreceived - 1 > nmissedmax) {
1015 				nmissedmax = ntransmitted - nreceived - 1;
1016 				if (options & F_MISSED)
1017 					(void)write(STDOUT_FILENO, &BBELL, 1);
1018 			}
1019 		}
1020 	}
1021 	finish();
1022 	/* NOTREACHED */
1023 	exit(0);	/* Make the compiler happy */
1024 }
1025 
1026 /*
1027  * stopit --
1028  *	Set the global bit that causes the main loop to quit.
1029  * Do NOT call finish() from here, since finish() does far too much
1030  * to be called from a signal handler.
1031  */
1032 void
1033 stopit(int sig __unused)
1034 {
1035 
1036 	/*
1037 	 * When doing reverse DNS lookups, the finish_up flag might not
1038 	 * be noticed for a while.  Just exit if we get a second SIGINT.
1039 	 */
1040 	if (!(options & F_NUMERIC) && finish_up)
1041 		_exit(nreceived ? 0 : 2);
1042 	finish_up = 1;
1043 }
1044 
1045 /*
1046  * pinger --
1047  *	Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
1048  * will be added on by the kernel.  The ID field is our UNIX process ID,
1049  * and the sequence number is an ascending integer.  The first TIMEVAL_LEN
1050  * bytes of the data portion are used to hold a UNIX "timespec" struct in
1051  * host byte-order, to compute the round-trip time.
1052  */
1053 static void
1054 pinger(void)
1055 {
1056 	struct timespec now;
1057 	struct tv32 tv32;
1058 	struct icmp icp;
1059 	int cc, i;
1060 	u_char *packet;
1061 
1062 	packet = outpack;
1063 	memcpy(&icp, outpack, ICMP_MINLEN + phdr_len);
1064 	icp.icmp_type = icmp_type;
1065 	icp.icmp_code = 0;
1066 	icp.icmp_cksum = 0;
1067 	icp.icmp_seq = htons(ntransmitted);
1068 	icp.icmp_id = ident;			/* ID */
1069 
1070 	CLR(ntransmitted % mx_dup_ck);
1071 
1072 	if ((options & F_TIME) || timing) {
1073 		(void)clock_gettime(CLOCK_MONOTONIC, &now);
1074 		/*
1075 		 * Truncate seconds down to 32 bits in order
1076 		 * to fit the timestamp within 8 bytes of the
1077 		 * packet. We're only concerned with
1078 		 * durations, not absolute times.
1079 		 */
1080 		tv32.tv32_sec = (uint32_t)htonl(now.tv_sec);
1081 		tv32.tv32_nsec = (uint32_t)htonl(now.tv_nsec);
1082 		if (options & F_TIME)
1083 			icp.icmp_otime = htonl((now.tv_sec % (24*60*60))
1084 				* 1000 + now.tv_nsec / 1000000);
1085 		if (timing)
1086 			bcopy((void *)&tv32,
1087 			    (void *)&outpack[ICMP_MINLEN + phdr_len],
1088 			    sizeof(tv32));
1089 	}
1090 
1091 	memcpy(outpack, &icp, ICMP_MINLEN + phdr_len);
1092 
1093 	cc = ICMP_MINLEN + phdr_len + datalen;
1094 
1095 	/* compute ICMP checksum here */
1096 	icp.icmp_cksum = in_cksum(outpack, cc);
1097 	/* Update icmp_cksum in the raw packet data buffer. */
1098 	memcpy(outpack + offsetof(struct icmp, icmp_cksum), &icp.icmp_cksum,
1099 	    sizeof(icp.icmp_cksum));
1100 
1101 	if (options & F_HDRINCL) {
1102 		struct ip ip;
1103 
1104 		cc += sizeof(struct ip);
1105 		ip.ip_len = htons(cc);
1106 		/* Update ip_len in the raw packet data buffer. */
1107 		memcpy(outpackhdr + offsetof(struct ip, ip_len), &ip.ip_len,
1108 		    sizeof(ip.ip_len));
1109 		ip.ip_sum = in_cksum(outpackhdr, cc);
1110 		/* Update ip_sum in the raw packet data buffer. */
1111 		memcpy(outpackhdr + offsetof(struct ip, ip_sum), &ip.ip_sum,
1112 		    sizeof(ip.ip_sum));
1113 		packet = outpackhdr;
1114 	}
1115 	i = send(ssend, (char *)packet, cc, 0);
1116 	if (i < 0 || i != cc)  {
1117 		if (i < 0) {
1118 			if (options & F_FLOOD && errno == ENOBUFS) {
1119 				usleep(FLOOD_BACKOFF);
1120 				return;
1121 			}
1122 			warn("sendto");
1123 		} else {
1124 			warn("%s: partial write: %d of %d bytes",
1125 			     hostname, i, cc);
1126 		}
1127 	}
1128 	ntransmitted++;
1129 	sntransmitted++;
1130 	if (!(options & F_QUIET) && options & F_DOT)
1131 		(void)write(STDOUT_FILENO, &DOT[DOTidx++ % DOTlen], 1);
1132 }
1133 
1134 /*
1135  * pr_pack --
1136  *	Print out the packet, if it came from us.  This logic is necessary
1137  * because ALL readers of the ICMP socket get a copy of ALL ICMP packets
1138  * which arrive ('tis only fair).  This permits multiple copies of this
1139  * program to be run without having intermingled output (or statistics!).
1140  */
1141 static void
1142 pr_pack(char *buf, ssize_t cc, struct sockaddr_in *from, struct timespec *tv)
1143 {
1144 	struct in_addr ina;
1145 	u_char *cp, *dp, l;
1146 	struct icmp icp;
1147 	struct ip ip;
1148 	const u_char *icmp_data_raw;
1149 	ssize_t icmp_data_raw_len;
1150 	double triptime;
1151 	int dupflag, i, j, recv_len;
1152 	int8_t hlen;
1153 	uint16_t seq;
1154 	static int old_rrlen;
1155 	static char old_rr[MAX_IPOPTLEN];
1156 	struct ip oip;
1157 	u_char oip_header_len;
1158 	struct icmp oicmp;
1159 	const u_char *oicmp_raw;
1160 
1161 	/*
1162 	 * Get size of IP header of the received packet.
1163 	 * The header length is contained in the lower four bits of the first
1164 	 * byte and represents the number of 4 byte octets the header takes up.
1165 	 *
1166 	 * The IHL minimum value is 5 (20 bytes) and its maximum value is 15
1167 	 * (60 bytes).
1168 	 */
1169 	memcpy(&l, buf, sizeof(l));
1170 	hlen = (l & 0x0f) << 2;
1171 
1172 	/* Reject IP packets with a short header */
1173 	if (hlen < (int8_t) sizeof(struct ip)) {
1174 		if (options & F_VERBOSE)
1175 			warn("IHL too short (%d bytes) from %s", hlen,
1176 			     inet_ntoa(from->sin_addr));
1177 		return;
1178 	}
1179 
1180 	memcpy(&ip, buf, sizeof(struct ip));
1181 
1182 	/* Check packet has enough data to carry a valid ICMP header */
1183 	recv_len = cc;
1184 	if (cc < hlen + ICMP_MINLEN) {
1185 		if (options & F_VERBOSE)
1186 			warn("packet too short (%zd bytes) from %s", cc,
1187 			     inet_ntoa(from->sin_addr));
1188 		return;
1189 	}
1190 
1191 	icmp_data_raw_len = cc - (hlen + offsetof(struct icmp, icmp_data));
1192 	icmp_data_raw = buf + hlen + offsetof(struct icmp, icmp_data);
1193 
1194 	/* Now the ICMP part */
1195 	cc -= hlen;
1196 	memcpy(&icp, buf + hlen, MIN((ssize_t)sizeof(icp), cc));
1197 	if (icp.icmp_type == icmp_type_rsp) {
1198 		if (icp.icmp_id != ident)
1199 			return;			/* 'Twas not our ECHO */
1200 		++nreceived;
1201 		triptime = 0.0;
1202 		if (timing) {
1203 			struct timespec tv1;
1204 			struct tv32 tv32;
1205 			const u_char *tp;
1206 
1207 			tp = icmp_data_raw + phdr_len;
1208 
1209 			if ((size_t)(cc - ICMP_MINLEN - phdr_len) >=
1210 			    sizeof(tv1)) {
1211 				/* Copy to avoid alignment problems: */
1212 				memcpy(&tv32, tp, sizeof(tv32));
1213 				tv1.tv_sec = ntohl(tv32.tv32_sec);
1214 				tv1.tv_nsec = ntohl(tv32.tv32_nsec);
1215 				timespecsub(tv, &tv1, tv);
1216 				triptime = ((double)tv->tv_sec) * 1000.0 +
1217 				    ((double)tv->tv_nsec) / 1000000.0;
1218 				if (triptime < 0) {
1219 					warnx("time of day goes back (%.3f ms),"
1220 					    " clamping time to 0",
1221 					    triptime);
1222 					triptime = 0;
1223 				}
1224 				tsum += triptime;
1225 				tsumsq += triptime * triptime;
1226 				if (triptime < tmin)
1227 					tmin = triptime;
1228 				if (triptime > tmax)
1229 					tmax = triptime;
1230 			} else
1231 				timing = 0;
1232 		}
1233 
1234 		seq = ntohs(icp.icmp_seq);
1235 
1236 		if (TST(seq % mx_dup_ck)) {
1237 			++nrepeats;
1238 			--nreceived;
1239 			dupflag = 1;
1240 		} else {
1241 			SET(seq % mx_dup_ck);
1242 			dupflag = 0;
1243 		}
1244 
1245 		if (options & F_QUIET)
1246 			return;
1247 
1248 		if (options & F_WAITTIME && triptime > waittime) {
1249 			++nrcvtimeout;
1250 			return;
1251 		}
1252 
1253 		if (options & F_DOT)
1254 			(void)write(STDOUT_FILENO, &BSPACE, 1);
1255 		else {
1256 			(void)printf("%zd bytes from %s: icmp_seq=%u", cc,
1257 			    pr_addr(from->sin_addr), seq);
1258 			(void)printf(" ttl=%d", ip.ip_ttl);
1259 			if (timing)
1260 				(void)printf(" time=%.3f ms", triptime);
1261 			if (dupflag)
1262 				(void)printf(" (DUP!)");
1263 			if (options & F_AUDIBLE)
1264 				(void)write(STDOUT_FILENO, &BBELL, 1);
1265 			if (options & F_MASK) {
1266 				/* Just prentend this cast isn't ugly */
1267 				(void)printf(" mask=%s",
1268 					inet_ntoa(*(struct in_addr *)&(icp.icmp_mask)));
1269 			}
1270 			if (options & F_TIME) {
1271 				(void)printf(" tso=%s", pr_ntime(icp.icmp_otime));
1272 				(void)printf(" tsr=%s", pr_ntime(icp.icmp_rtime));
1273 				(void)printf(" tst=%s", pr_ntime(icp.icmp_ttime));
1274 			}
1275 			if (recv_len != send_len) {
1276                         	(void)printf(
1277 				     "\nwrong total length %d instead of %d",
1278 				     recv_len, send_len);
1279 			}
1280 			/* check the data */
1281 			cp = (u_char*)(buf + hlen + offsetof(struct icmp,
1282 				icmp_data) + phdr_len);
1283 			dp = &outpack[ICMP_MINLEN + phdr_len];
1284 			cc -= ICMP_MINLEN + phdr_len;
1285 			i = 0;
1286 			if (timing) {   /* don't check variable timestamp */
1287 				cp += TIMEVAL_LEN;
1288 				dp += TIMEVAL_LEN;
1289 				cc -= TIMEVAL_LEN;
1290 				i += TIMEVAL_LEN;
1291 			}
1292 			for (; i < datalen && cc > 0; ++i, ++cp, ++dp, --cc) {
1293 				if (*cp != *dp) {
1294 	(void)printf("\nwrong data byte #%d should be 0x%x but was 0x%x",
1295 	    i, *dp, *cp);
1296 					(void)printf("\ncp:");
1297 					cp = (u_char*)(buf + hlen +
1298 					    offsetof(struct icmp, icmp_data));
1299 					for (i = 0; i < datalen; ++i, ++cp) {
1300 						if ((i % 16) == 8)
1301 							(void)printf("\n\t");
1302 						(void)printf("%2x ", *cp);
1303 					}
1304 					(void)printf("\ndp:");
1305 					cp = &outpack[ICMP_MINLEN];
1306 					for (i = 0; i < datalen; ++i, ++cp) {
1307 						if ((i % 16) == 8)
1308 							(void)printf("\n\t");
1309 						(void)printf("%2x ", *cp);
1310 					}
1311 					break;
1312 				}
1313 			}
1314 		}
1315 	} else {
1316 		/*
1317 		 * We've got something other than an ECHOREPLY.
1318 		 * See if it's a reply to something that we sent.
1319 		 * We can compare IP destination, protocol,
1320 		 * and ICMP type and ID.
1321 		 *
1322 		 * Only print all the error messages if we are running
1323 		 * as root to avoid leaking information not normally
1324 		 * available to those not running as root.
1325 		 */
1326 
1327 		/*
1328 		 * If we don't have enough bytes for a quoted IP header and an
1329 		 * ICMP header then stop.
1330 		 */
1331 		if (icmp_data_raw_len <
1332 				(ssize_t)(sizeof(struct ip) + sizeof(struct icmp))) {
1333 			if (options & F_VERBOSE)
1334 				warnx("quoted data too short (%zd bytes) from %s",
1335 					icmp_data_raw_len, inet_ntoa(from->sin_addr));
1336 			return;
1337 		}
1338 
1339 		memcpy(&oip_header_len, icmp_data_raw, sizeof(oip_header_len));
1340 		oip_header_len = (oip_header_len & 0x0f) << 2;
1341 
1342 		/* Reject IP packets with a short header */
1343 		if (oip_header_len < sizeof(struct ip)) {
1344 			if (options & F_VERBOSE)
1345 				warnx("inner IHL too short (%d bytes) from %s",
1346 					oip_header_len, inet_ntoa(from->sin_addr));
1347 			return;
1348 		}
1349 
1350 		/*
1351 		 * Check against the actual IHL length, to protect against
1352 		 * quoated packets carrying IP options.
1353 		 */
1354 		if (icmp_data_raw_len <
1355 				(ssize_t)(oip_header_len + sizeof(struct icmp))) {
1356 			if (options & F_VERBOSE)
1357 				warnx("inner packet too short (%zd bytes) from %s",
1358 				     icmp_data_raw_len, inet_ntoa(from->sin_addr));
1359 			return;
1360 		}
1361 
1362 		memcpy(&oip, icmp_data_raw, sizeof(struct ip));
1363 		oicmp_raw = icmp_data_raw + oip_header_len;
1364 		memcpy(&oicmp, oicmp_raw, sizeof(struct icmp));
1365 
1366 		if (((options & F_VERBOSE) && uid == 0) ||
1367 		    (!(options & F_QUIET2) &&
1368 		     (oip.ip_dst.s_addr == whereto.sin_addr.s_addr) &&
1369 		     (oip.ip_p == IPPROTO_ICMP) &&
1370 		     (oicmp.icmp_type == ICMP_ECHO) &&
1371 		     (oicmp.icmp_id == ident))) {
1372 		    (void)printf("%zd bytes from %s: ", cc,
1373 			pr_addr(from->sin_addr));
1374 		    pr_icmph(&icp, &oip, icmp_data_raw);
1375 		} else
1376 		    return;
1377 	}
1378 
1379 	/* Display any IP options */
1380 	cp = (u_char *)buf + sizeof(struct ip);
1381 
1382 	for (; hlen > (int)sizeof(struct ip); --hlen, ++cp)
1383 		switch (*cp) {
1384 		case IPOPT_EOL:
1385 			hlen = 0;
1386 			break;
1387 		case IPOPT_LSRR:
1388 		case IPOPT_SSRR:
1389 			(void)printf(*cp == IPOPT_LSRR ?
1390 			    "\nLSRR: " : "\nSSRR: ");
1391 			j = cp[IPOPT_OLEN] - IPOPT_MINOFF + 1;
1392 			hlen -= 2;
1393 			cp += 2;
1394 			if (j >= INADDR_LEN &&
1395 			    j <= hlen - (int)sizeof(struct ip)) {
1396 				for (;;) {
1397 					bcopy(++cp, &ina.s_addr, INADDR_LEN);
1398 					if (ina.s_addr == 0)
1399 						(void)printf("\t0.0.0.0");
1400 					else
1401 						(void)printf("\t%s",
1402 						     pr_addr(ina));
1403 					hlen -= INADDR_LEN;
1404 					cp += INADDR_LEN - 1;
1405 					j -= INADDR_LEN;
1406 					if (j < INADDR_LEN)
1407 						break;
1408 					(void)putchar('\n');
1409 				}
1410 			} else
1411 				(void)printf("\t(truncated route)\n");
1412 			break;
1413 		case IPOPT_RR:
1414 			j = cp[IPOPT_OLEN];		/* get length */
1415 			i = cp[IPOPT_OFFSET];		/* and pointer */
1416 			hlen -= 2;
1417 			cp += 2;
1418 			if (i > j)
1419 				i = j;
1420 			i = i - IPOPT_MINOFF + 1;
1421 			if (i < 0 || i > (hlen - (int)sizeof(struct ip))) {
1422 				old_rrlen = 0;
1423 				continue;
1424 			}
1425 			if (i == old_rrlen
1426 			    && !bcmp((char *)cp, old_rr, i)
1427 			    && !(options & F_DOT)) {
1428 				(void)printf("\t(same route)");
1429 				hlen -= i;
1430 				cp += i;
1431 				break;
1432 			}
1433 			old_rrlen = i;
1434 			bcopy((char *)cp, old_rr, i);
1435 			(void)printf("\nRR: ");
1436 			if (i >= INADDR_LEN &&
1437 			    i <= hlen - (int)sizeof(struct ip)) {
1438 				for (;;) {
1439 					bcopy(++cp, &ina.s_addr, INADDR_LEN);
1440 					if (ina.s_addr == 0)
1441 						(void)printf("\t0.0.0.0");
1442 					else
1443 						(void)printf("\t%s",
1444 						     pr_addr(ina));
1445 					hlen -= INADDR_LEN;
1446 					cp += INADDR_LEN - 1;
1447 					i -= INADDR_LEN;
1448 					if (i < INADDR_LEN)
1449 						break;
1450 					(void)putchar('\n');
1451 				}
1452 			} else
1453 				(void)printf("\t(truncated route)");
1454 			break;
1455 		case IPOPT_NOP:
1456 			(void)printf("\nNOP");
1457 			break;
1458 		default:
1459 			(void)printf("\nunknown option %x", *cp);
1460 			break;
1461 		}
1462 	if (!(options & F_DOT)) {
1463 		(void)putchar('\n');
1464 		(void)fflush(stdout);
1465 	}
1466 }
1467 
1468 /*
1469  * status --
1470  *	Print out statistics when SIGINFO is received.
1471  */
1472 
1473 static void
1474 status(int sig __unused)
1475 {
1476 
1477 	siginfo_p = 1;
1478 }
1479 
1480 static void
1481 check_status(void)
1482 {
1483 
1484 	if (siginfo_p) {
1485 		siginfo_p = 0;
1486 		(void)fprintf(stderr, "\r%ld/%ld packets received (%.1f%%)",
1487 		    nreceived, ntransmitted,
1488 		    ntransmitted ? nreceived * 100.0 / ntransmitted : 0.0);
1489 		if (nreceived && timing)
1490 			(void)fprintf(stderr, " %.3f min / %.3f avg / %.3f max",
1491 			    tmin, tsum / (nreceived + nrepeats), tmax);
1492 		(void)fprintf(stderr, "\n");
1493 	}
1494 }
1495 
1496 /*
1497  * finish --
1498  *	Print out statistics, and give up.
1499  */
1500 static void
1501 finish(void)
1502 {
1503 
1504 	(void)signal(SIGINT, SIG_IGN);
1505 	(void)signal(SIGALRM, SIG_IGN);
1506 	(void)putchar('\n');
1507 	(void)fflush(stdout);
1508 	(void)printf("--- %s ping statistics ---\n", hostname);
1509 	(void)printf("%ld packets transmitted, ", ntransmitted);
1510 	(void)printf("%ld packets received, ", nreceived);
1511 	if (nrepeats)
1512 		(void)printf("+%ld duplicates, ", nrepeats);
1513 	if (ntransmitted) {
1514 		if (nreceived > ntransmitted)
1515 			(void)printf("-- somebody's printing up packets!");
1516 		else
1517 			(void)printf("%.1f%% packet loss",
1518 			    ((ntransmitted - nreceived) * 100.0) /
1519 			    ntransmitted);
1520 	}
1521 	if (nrcvtimeout)
1522 		(void)printf(", %ld packets out of wait time", nrcvtimeout);
1523 	(void)putchar('\n');
1524 	if (nreceived && timing) {
1525 		double n = nreceived + nrepeats;
1526 		double avg = tsum / n;
1527 		double vari = tsumsq / n - avg * avg;
1528 		(void)printf(
1529 		    "round-trip min/avg/max/stddev = %.3f/%.3f/%.3f/%.3f ms\n",
1530 		    tmin, avg, tmax, sqrt(vari));
1531 	}
1532 
1533 	if (nreceived)
1534 		exit(0);
1535 	else
1536 		exit(2);
1537 }
1538 
1539 /*
1540  * pr_icmph --
1541  *	Print a descriptive string about an ICMP header.
1542  */
1543 static void
1544 pr_icmph(struct icmp *icp, struct ip *oip, const u_char *const oicmp_raw)
1545 {
1546 
1547 	switch(icp->icmp_type) {
1548 	case ICMP_ECHOREPLY:
1549 		(void)printf("Echo Reply\n");
1550 		/* XXX ID + Seq + Data */
1551 		break;
1552 	case ICMP_UNREACH:
1553 		switch(icp->icmp_code) {
1554 		case ICMP_UNREACH_NET:
1555 			(void)printf("Destination Net Unreachable\n");
1556 			break;
1557 		case ICMP_UNREACH_HOST:
1558 			(void)printf("Destination Host Unreachable\n");
1559 			break;
1560 		case ICMP_UNREACH_PROTOCOL:
1561 			(void)printf("Destination Protocol Unreachable\n");
1562 			break;
1563 		case ICMP_UNREACH_PORT:
1564 			(void)printf("Destination Port Unreachable\n");
1565 			break;
1566 		case ICMP_UNREACH_NEEDFRAG:
1567 			(void)printf("frag needed and DF set (MTU %d)\n",
1568 					ntohs(icp->icmp_nextmtu));
1569 			break;
1570 		case ICMP_UNREACH_SRCFAIL:
1571 			(void)printf("Source Route Failed\n");
1572 			break;
1573 		case ICMP_UNREACH_FILTER_PROHIB:
1574 			(void)printf("Communication prohibited by filter\n");
1575 			break;
1576 		default:
1577 			(void)printf("Dest Unreachable, Bad Code: %d\n",
1578 			    icp->icmp_code);
1579 			break;
1580 		}
1581 		/* Print returned IP header information */
1582 		pr_iph(oip, oicmp_raw);
1583 		break;
1584 	case ICMP_SOURCEQUENCH:
1585 		(void)printf("Source Quench\n");
1586 		pr_iph(oip, oicmp_raw);
1587 		break;
1588 	case ICMP_REDIRECT:
1589 		switch(icp->icmp_code) {
1590 		case ICMP_REDIRECT_NET:
1591 			(void)printf("Redirect Network");
1592 			break;
1593 		case ICMP_REDIRECT_HOST:
1594 			(void)printf("Redirect Host");
1595 			break;
1596 		case ICMP_REDIRECT_TOSNET:
1597 			(void)printf("Redirect Type of Service and Network");
1598 			break;
1599 		case ICMP_REDIRECT_TOSHOST:
1600 			(void)printf("Redirect Type of Service and Host");
1601 			break;
1602 		default:
1603 			(void)printf("Redirect, Bad Code: %d", icp->icmp_code);
1604 			break;
1605 		}
1606 		(void)printf("(New addr: %s)\n", inet_ntoa(icp->icmp_gwaddr));
1607 		pr_iph(oip, oicmp_raw);
1608 		break;
1609 	case ICMP_ECHO:
1610 		(void)printf("Echo Request\n");
1611 		/* XXX ID + Seq + Data */
1612 		break;
1613 	case ICMP_TIMXCEED:
1614 		switch(icp->icmp_code) {
1615 		case ICMP_TIMXCEED_INTRANS:
1616 			(void)printf("Time to live exceeded\n");
1617 			break;
1618 		case ICMP_TIMXCEED_REASS:
1619 			(void)printf("Frag reassembly time exceeded\n");
1620 			break;
1621 		default:
1622 			(void)printf("Time exceeded, Bad Code: %d\n",
1623 			    icp->icmp_code);
1624 			break;
1625 		}
1626 		pr_iph(oip, oicmp_raw);
1627 		break;
1628 	case ICMP_PARAMPROB:
1629 		(void)printf("Parameter problem: pointer = 0x%02x\n",
1630 		    icp->icmp_hun.ih_pptr);
1631 		pr_iph(oip, oicmp_raw);
1632 		break;
1633 	case ICMP_TSTAMP:
1634 		(void)printf("Timestamp\n");
1635 		/* XXX ID + Seq + 3 timestamps */
1636 		break;
1637 	case ICMP_TSTAMPREPLY:
1638 		(void)printf("Timestamp Reply\n");
1639 		/* XXX ID + Seq + 3 timestamps */
1640 		break;
1641 	case ICMP_IREQ:
1642 		(void)printf("Information Request\n");
1643 		/* XXX ID + Seq */
1644 		break;
1645 	case ICMP_IREQREPLY:
1646 		(void)printf("Information Reply\n");
1647 		/* XXX ID + Seq */
1648 		break;
1649 	case ICMP_MASKREQ:
1650 		(void)printf("Address Mask Request\n");
1651 		break;
1652 	case ICMP_MASKREPLY:
1653 		(void)printf("Address Mask Reply\n");
1654 		break;
1655 	case ICMP_ROUTERADVERT:
1656 		(void)printf("Router Advertisement\n");
1657 		break;
1658 	case ICMP_ROUTERSOLICIT:
1659 		(void)printf("Router Solicitation\n");
1660 		break;
1661 	default:
1662 		(void)printf("Bad ICMP type: %d\n", icp->icmp_type);
1663 	}
1664 }
1665 
1666 /*
1667  * pr_iph --
1668  *	Print an IP header with options.
1669  */
1670 static void
1671 pr_iph(struct ip *ip, const u_char *cp)
1672 {
1673 	struct in_addr ina;
1674 	int hlen;
1675 
1676 	hlen = ip->ip_hl << 2;
1677 	cp = cp + sizeof(struct ip);		/* point to options */
1678 
1679 	(void)printf("Vr HL TOS  Len   ID Flg  off TTL Pro  cks      Src      Dst\n");
1680 	(void)printf(" %1x  %1x  %02x %04x %04x",
1681 	    ip->ip_v, ip->ip_hl, ip->ip_tos, ntohs(ip->ip_len),
1682 	    ntohs(ip->ip_id));
1683 	(void)printf("   %1x %04x",
1684 	    (ntohs(ip->ip_off) & 0xe000) >> 13,
1685 	    ntohs(ip->ip_off) & 0x1fff);
1686 	(void)printf("  %02x  %02x %04x", ip->ip_ttl, ip->ip_p,
1687 							    ntohs(ip->ip_sum));
1688 	memcpy(&ina, &ip->ip_src.s_addr, sizeof ina);
1689 	(void)printf(" %s ", inet_ntoa(ina));
1690 	memcpy(&ina, &ip->ip_dst.s_addr, sizeof ina);
1691 	(void)printf(" %s ", inet_ntoa(ina));
1692 	/* dump any option bytes */
1693 	while (hlen-- > (int)sizeof(struct ip)) {
1694 		(void)printf("%02x", *cp++);
1695 	}
1696 	(void)putchar('\n');
1697 }
1698 
1699 /*
1700  * pr_addr --
1701  *	Return an ascii host address as a dotted quad and optionally with
1702  * a hostname.
1703  */
1704 static char *
1705 pr_addr(struct in_addr ina)
1706 {
1707 	struct hostent *hp;
1708 	static char buf[16 + 3 + MAXHOSTNAMELEN];
1709 
1710 	if (options & F_NUMERIC)
1711 		return inet_ntoa(ina);
1712 
1713 	hp = cap_gethostbyaddr(capdns, (char *)&ina, sizeof(ina), AF_INET);
1714 
1715 	if (hp == NULL)
1716 		return inet_ntoa(ina);
1717 
1718 	(void)snprintf(buf, sizeof(buf), "%s (%s)", hp->h_name,
1719 	    inet_ntoa(ina));
1720 	return(buf);
1721 }
1722 
1723 static char *
1724 pr_ntime(n_time timestamp)
1725 {
1726 	static char buf[11];
1727 	int hour, min, sec;
1728 
1729 	sec = ntohl(timestamp) / 1000;
1730 	hour = sec / 60 / 60;
1731 	min = (sec % (60 * 60)) / 60;
1732 	sec = (sec % (60 * 60)) % 60;
1733 
1734 	(void)snprintf(buf, sizeof(buf), "%02d:%02d:%02d", hour, min, sec);
1735 
1736 	return (buf);
1737 }
1738 
1739 static void
1740 fill(char *bp, char *patp)
1741 {
1742 	char *cp;
1743 	int pat[16];
1744 	u_int ii, jj, kk;
1745 
1746 	for (cp = patp; *cp; cp++) {
1747 		if (!isxdigit(*cp))
1748 			errx(EX_USAGE,
1749 			    "patterns must be specified as hex digits");
1750 
1751 	}
1752 	ii = sscanf(patp,
1753 	    "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x",
1754 	    &pat[0], &pat[1], &pat[2], &pat[3], &pat[4], &pat[5], &pat[6],
1755 	    &pat[7], &pat[8], &pat[9], &pat[10], &pat[11], &pat[12],
1756 	    &pat[13], &pat[14], &pat[15]);
1757 
1758 	if (ii > 0)
1759 		for (kk = 0; kk <= maxpayload - (TIMEVAL_LEN + ii); kk += ii)
1760 			for (jj = 0; jj < ii; ++jj)
1761 				bp[jj + kk] = pat[jj];
1762 	if (!(options & F_QUIET)) {
1763 		(void)printf("PATTERN: 0x");
1764 		for (jj = 0; jj < ii; ++jj)
1765 			(void)printf("%02x", bp[jj] & 0xFF);
1766 		(void)printf("\n");
1767 	}
1768 }
1769 
1770 static cap_channel_t *
1771 capdns_setup(void)
1772 {
1773 	cap_channel_t *capcas, *capdnsloc;
1774 #ifdef WITH_CASPER
1775 	const char *types[2];
1776 	int families[1];
1777 #endif
1778 	capcas = cap_init();
1779 	if (capcas == NULL)
1780 		err(1, "unable to create casper process");
1781 	capdnsloc = cap_service_open(capcas, "system.dns");
1782 	/* Casper capability no longer needed. */
1783 	cap_close(capcas);
1784 	if (capdnsloc == NULL)
1785 		err(1, "unable to open system.dns service");
1786 #ifdef WITH_CASPER
1787 	types[0] = "NAME2ADDR";
1788 	types[1] = "ADDR2NAME";
1789 	if (cap_dns_type_limit(capdnsloc, types, 2) < 0)
1790 		err(1, "unable to limit access to system.dns service");
1791 	families[0] = AF_INET;
1792 	if (cap_dns_family_limit(capdnsloc, families, 1) < 0)
1793 		err(1, "unable to limit access to system.dns service");
1794 #endif
1795 	return (capdnsloc);
1796 }
1797