xref: /freebsd/sbin/ping/ping.c (revision 952d112864d8008aa87278a30a539d888a8493cd)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Mike Muuss.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static const char copyright[] =
39 "@(#) Copyright (c) 1989, 1993\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 /*
45 static char sccsid[] = "@(#)ping.c	8.1 (Berkeley) 6/5/93";
46 */
47 static const char rcsid[] =
48 	"$Id: ping.c,v 1.20 1997/03/03 09:50:21 imp Exp $";
49 #endif /* not lint */
50 
51 /*
52  *			P I N G . C
53  *
54  * Using the InterNet Control Message Protocol (ICMP) "ECHO" facility,
55  * measure round-trip-delays and packet loss across network paths.
56  *
57  * Author -
58  *	Mike Muuss
59  *	U. S. Army Ballistic Research Laboratory
60  *	December, 1983
61  *
62  * Status -
63  *	Public Domain.  Distribution Unlimited.
64  * Bugs -
65  *	More statistics could always be gathered.
66  *	This program has to run SUID to ROOT to access the ICMP socket.
67  */
68 
69 #include <sys/param.h>		/* NB: we rely on this for <sys/types.h> */
70 
71 #include <ctype.h>
72 #include <err.h>
73 #include <errno.h>
74 #include <netdb.h>
75 #include <signal.h>
76 #include <stdio.h>
77 #include <stdlib.h>
78 #include <string.h>
79 #include <sysexits.h>
80 #include <termios.h>
81 #include <unistd.h>
82 
83 #include <sys/socket.h>
84 #include <sys/file.h>
85 #include <sys/time.h>
86 
87 #include <netinet/in.h>
88 #include <netinet/in_systm.h>
89 #include <netinet/ip.h>
90 #include <netinet/ip_icmp.h>
91 #include <netinet/ip_var.h>
92 #include <arpa/inet.h>
93 
94 #define	DEFDATALEN	(64 - 8)	/* default data length */
95 #define	MAXIPLEN	60
96 #define	MAXICMPLEN	76
97 #define	MAXPACKET	(65536 - 60 - 8)/* max packet size */
98 #define	MAXWAIT		10		/* max seconds to wait for response */
99 #define	NROUTES		9		/* number of record route slots */
100 
101 #define	A(bit)		rcvd_tbl[(bit)>>3]	/* identify byte in array */
102 #define	B(bit)		(1 << ((bit) & 0x07))	/* identify bit in byte */
103 #define	SET(bit)	(A(bit) |= B(bit))
104 #define	CLR(bit)	(A(bit) &= (~B(bit)))
105 #define	TST(bit)	(A(bit) & B(bit))
106 
107 /* various options */
108 int options;
109 #define	F_FLOOD		0x0001
110 #define	F_INTERVAL	0x0002
111 #define	F_NUMERIC	0x0004
112 #define	F_PINGFILLED	0x0008
113 #define	F_QUIET		0x0010
114 #define	F_RROUTE	0x0020
115 #define	F_SO_DEBUG	0x0040
116 #define	F_SO_DONTROUTE	0x0080
117 #define	F_VERBOSE	0x0100
118 #define	F_QUIET2	0x0200
119 #define	F_NOLOOP	0x0400
120 #define	F_MTTL		0x0800
121 #define	F_MIF		0x1000
122 #define	F_AUDIBLE	0x2000
123 
124 /*
125  * MAX_DUP_CHK is the number of bits in received table, i.e. the maximum
126  * number of received sequence numbers we can keep track of.  Change 128
127  * to 8192 for complete accuracy...
128  */
129 #define	MAX_DUP_CHK	(8 * 128)
130 int mx_dup_ck = MAX_DUP_CHK;
131 char rcvd_tbl[MAX_DUP_CHK / 8];
132 
133 struct sockaddr whereto;	/* who to ping */
134 int datalen = DEFDATALEN;
135 int s;				/* socket file descriptor */
136 u_char outpack[MAXPACKET];
137 char BSPACE = '\b';		/* characters written for flood */
138 char DOT = '.';
139 char *hostname;
140 int ident;			/* process id to identify our packets */
141 int uid;			/* cached uid for micro-optimization */
142 
143 /* counters */
144 long npackets;			/* max packets to transmit */
145 long nreceived;			/* # of packets we got back */
146 long nrepeats;			/* number of duplicates */
147 long ntransmitted;		/* sequence # for outbound packets = #sent */
148 int interval = 1;		/* interval between packets */
149 
150 /* timing */
151 int timing;			/* flag to do timing */
152 double tmin = 999999999.0;	/* minimum round trip time */
153 double tmax = 0.0;		/* maximum round trip time */
154 double tsum = 0.0;		/* sum of all times, for doing average */
155 
156 int reset_kerninfo;
157 sig_atomic_t siginfo_p;
158 
159 static void fill(char *, char *);
160 static u_short in_cksum(u_short *, int);
161 static void catcher(int sig);
162 static void check_status(void);
163 static void finish(int) __dead2;
164 static void pinger(void);
165 static char *pr_addr(struct in_addr);
166 static void pr_icmph(struct icmp *);
167 static void pr_iph(struct ip *);
168 static void pr_pack(char *, int, struct sockaddr_in *);
169 static void pr_retip(struct ip *);
170 static void status(int);
171 static void tvsub(struct timeval *, struct timeval *);
172 static void usage(const char *) __dead2;
173 
174 int
175 main(argc, argv)
176 	int argc;
177 	char *const *argv;
178 {
179 	struct timeval timeout;
180 	struct hostent *hp;
181 	struct sockaddr_in *to;
182 	struct termios ts;
183 	register int i;
184 	int ch, fdmask, hold, packlen, preload, sockerrno;
185 	struct in_addr ifaddr;
186 	unsigned char ttl, loop;
187 	u_char *datap, *packet;
188 	char *target, hnamebuf[MAXHOSTNAMELEN];
189 	char *ep;
190 	u_long ultmp;
191 #ifdef IP_OPTIONS
192 	char rspace[3 + 4 * NROUTES + 1];	/* record route space */
193 #endif
194 	struct sigaction si_sa;
195 
196 	/*
197 	 * Do the stuff that we need root priv's for *first*, and
198 	 * then drop our setuid bit.  Save error reporting for
199 	 * after arg parsing.
200 	 */
201 	s = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
202 	sockerrno = errno;
203 
204 	setuid(getuid());
205 	uid = getuid();
206 
207 	preload = 0;
208 
209 	datap = &outpack[8 + sizeof(struct timeval)];
210 	while ((ch = getopt(argc, argv, "I:LQRT:c:adfi:l:np:qrs:v")) != -1) {
211 		switch(ch) {
212 		case 'a':
213 			options |= F_AUDIBLE;
214 			break;
215 		case 'c':
216 			ultmp = strtoul(optarg, &ep, 0);
217 			if (*ep || ep == optarg || ultmp > LONG_MAX || !ultmp)
218 				errx(EX_USAGE,
219 				    "invalid count of packets to transmit: `%s'",
220 				    optarg);
221 			npackets = ultmp;
222 			break;
223 		case 'd':
224 			options |= F_SO_DEBUG;
225 			break;
226 		case 'f':
227 			if (getuid()) {
228 				errno = EPERM;
229 				err(EX_NOPERM, "-f flag");
230 			}
231 			options |= F_FLOOD;
232 			setbuf(stdout, (char *)NULL);
233 			break;
234 		case 'i':		/* wait between sending packets */
235 			ultmp = strtoul(optarg, &ep, 0);
236 			if (*ep || ep == optarg || ultmp > INT_MAX)
237 				errx(EX_USAGE,
238 				     "invalid timing interval: `%s'", optarg);
239 			options |= F_INTERVAL;
240 			interval = ultmp;
241 			break;
242 		case 'I':		/* multicast interface */
243 			if (inet_aton(optarg, &ifaddr) == 0)
244 				errx(EX_USAGE,
245 				     "invalid multicast interface: `%s'",
246 				     optarg);
247 			options |= F_MIF;
248 			break;
249 		case 'l':
250 			ultmp = strtoul(optarg, &ep, 0);
251 			if (*ep || ep == optarg || ultmp > INT_MAX)
252 				errx(EX_USAGE,
253 				     "invalid preload value: `%s'", optarg);
254 			if (getuid()) {
255 				errno = EPERM;
256 				err(EX_NOPERM, "-l flag");
257 			}
258 			options |= F_FLOOD;
259 			preload = ultmp;
260 			break;
261 		case 'L':
262 			options |= F_NOLOOP;
263 			loop = 0;
264 			break;
265 		case 'n':
266 			options |= F_NUMERIC;
267 			break;
268 		case 'p':		/* fill buffer with user pattern */
269 			options |= F_PINGFILLED;
270 			fill((char *)datap, optarg);
271 				break;
272 		case 'Q':
273 			options |= F_QUIET2;
274 			break;
275 		case 'q':
276 			options |= F_QUIET;
277 			break;
278 		case 'R':
279 			options |= F_RROUTE;
280 			break;
281 		case 'r':
282 			options |= F_SO_DONTROUTE;
283 			break;
284 		case 's':		/* size of packet to send */
285 			ultmp = strtoul(optarg, &ep, 0);
286 			if (ultmp > MAXPACKET)
287 				errx(EX_USAGE, "packet size too large: %lu",
288 				     ultmp);
289 			if (*ep || ep == optarg || !ultmp)
290 				errx(EX_USAGE, "invalid packet size: `%s'",
291 				     optarg);
292 			datalen = ultmp;
293 			break;
294 		case 'T':		/* multicast TTL */
295 			ultmp = strtoul(optarg, &ep, 0);
296 			if (*ep || ep == optarg || ultmp > 255)
297 				errx(EX_USAGE, "invalid multicast TTL: `%s'",
298 				     optarg);
299 			ttl = ultmp;
300 			options |= F_MTTL;
301 			break;
302 		case 'v':
303 			options |= F_VERBOSE;
304 			break;
305 		default:
306 
307 			usage(argv[0]);
308 		}
309 	}
310 
311 	if (argc - optind != 1)
312 		usage(argv[0]);
313 	target = argv[optind];
314 
315 	bzero((char *)&whereto, sizeof(struct sockaddr));
316 	to = (struct sockaddr_in *)&whereto;
317 	to->sin_family = AF_INET;
318 	if (inet_aton(target, &to->sin_addr) != 0) {
319 		hostname = target;
320 	} else {
321 		hp = gethostbyname2(target, AF_INET);
322 		if (!hp)
323 			errx(EX_NOHOST, "cannot resolve %s: %s",
324 			     target, hstrerror(h_errno));
325 
326 		to->sin_len = sizeof *to;
327 		if (hp->h_length > sizeof(to->sin_addr))
328 			errx(1,"gethostbyname2 returned an illegal address");
329 		memcpy(&to->sin_addr, hp->h_addr_list[0], sizeof to->sin_addr);
330 		(void)strncpy(hnamebuf, hp->h_name, sizeof(hnamebuf) - 1);
331 		hnamebuf[(sizeof hnamebuf) - 1] = '\0';
332 		hostname = hnamebuf;
333 	}
334 
335 	if (options & F_FLOOD && options & F_INTERVAL)
336 		errx(EX_USAGE, "-f and -i: incompatible options");
337 
338 	if (options & F_FLOOD && IN_MULTICAST(ntohl(to->sin_addr.s_addr)))
339 		errx(EX_USAGE,
340 		     "-f flag cannot be used with multicast destination");
341 	if (options & (F_MIF | F_NOLOOP | F_MTTL)
342 	    && !IN_MULTICAST(ntohl(to->sin_addr.s_addr)))
343 		errx(EX_USAGE,
344 		     "-I, -L, -T flags cannot be used with unicast destination");
345 
346 	if (datalen >= sizeof(struct timeval))	/* can we time transfer */
347 		timing = 1;
348 	packlen = datalen + MAXIPLEN + MAXICMPLEN;
349 	if (!(packet = (u_char *)malloc((size_t)packlen)))
350 		err(EX_UNAVAILABLE, "malloc");
351 
352 	if (!(options & F_PINGFILLED))
353 		for (i = 8; i < datalen; ++i)
354 			*datap++ = i;
355 
356 	ident = getpid() & 0xFFFF;
357 
358 	if (s < 0) {
359 		errno = sockerrno;
360 		err(EX_OSERR, "socket");
361 	}
362 	hold = 1;
363 	if (options & F_SO_DEBUG)
364 		(void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&hold,
365 		    sizeof(hold));
366 	if (options & F_SO_DONTROUTE)
367 		(void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&hold,
368 		    sizeof(hold));
369 
370 	/* record route option */
371 	if (options & F_RROUTE) {
372 #ifdef IP_OPTIONS
373 		rspace[IPOPT_OPTVAL] = IPOPT_RR;
374 		rspace[IPOPT_OLEN] = sizeof(rspace)-1;
375 		rspace[IPOPT_OFFSET] = IPOPT_MINOFF;
376 		if (setsockopt(s, IPPROTO_IP, IP_OPTIONS, rspace,
377 		    sizeof(rspace)) < 0)
378 			err(EX_OSERR, "setsockopt IP_OPTIONS");
379 #else
380 		errx(EX_UNAVAILABLE,
381 		  "record route not available in this implementation");
382 #endif /* IP_OPTIONS */
383 	}
384 
385 	if (options & F_NOLOOP) {
386 		if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_LOOP, &loop,
387 		    sizeof(loop)) < 0) {
388 			err(EX_OSERR, "setsockopt IP_MULTICAST_LOOP");
389 		}
390 	}
391 	if (options & F_MTTL) {
392 		if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &ttl,
393 		    sizeof(ttl)) < 0) {
394 			err(EX_OSERR, "setsockopt IP_MULTICAST_TTL");
395 		}
396 	}
397 	if (options & F_MIF) {
398 		if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, &ifaddr,
399 		    sizeof(ifaddr)) < 0) {
400 			err(EX_OSERR, "setsockopt IP_MULTICAST_IF");
401 		}
402 	}
403 
404 	/*
405 	 * When pinging the broadcast address, you can get a lot of answers.
406 	 * Doing something so evil is useful if you are trying to stress the
407 	 * ethernet, or just want to fill the arp cache to get some stuff for
408 	 * /etc/ethers.  But beware: RFC 1122 allows hosts to ignore broadcast
409 	 * or multicast pings if they wish.
410 	 */
411 	hold = 48 * 1024;
412 	(void)setsockopt(s, SOL_SOCKET, SO_RCVBUF, (char *)&hold,
413 	    sizeof(hold));
414 
415 	if (to->sin_family == AF_INET)
416 		(void)printf("PING %s (%s): %d data bytes\n", hostname,
417 		    inet_ntoa(to->sin_addr),
418 		    datalen);
419 	else
420 		(void)printf("PING %s: %d data bytes\n", hostname, datalen);
421 
422 	(void)signal(SIGINT, finish);
423 	(void)signal(SIGALRM, catcher);
424 
425 	/*
426 	 * Use sigaction instead of signal() to get unambiguous semantics
427 	 * for SIGINFO, in particular with SA_RESTART not set.
428 	 */
429 	si_sa.sa_handler = status;
430 	sigemptyset(&si_sa.sa_mask);
431 	si_sa.sa_flags = 0;
432 	if (sigaction(SIGINFO, &si_sa, 0) == -1) {
433 		err(EX_OSERR, "sigaction");
434 	}
435 
436 	if (tcgetattr(STDOUT_FILENO, &ts) != -1) {
437 		reset_kerninfo = !(ts.c_lflag & NOKERNINFO);
438 		ts.c_lflag |= NOKERNINFO;
439 		tcsetattr(STDOUT_FILENO, TCSANOW, &ts);
440 	}
441 
442 	while (preload--)		/* fire off them quickies */
443 		pinger();
444 
445 	if ((options & F_FLOOD) == 0)
446 		catcher(0);		/* start things going */
447 
448 	for (;;) {
449 		struct sockaddr_in from;
450 		register int cc;
451 		int fromlen;
452 
453 		check_status();
454 		if (options & F_FLOOD) {
455 			pinger();
456 			timeout.tv_sec = 0;
457 			timeout.tv_usec = 10000;
458 			fdmask = 1 << s;
459 			if (select(s + 1, (fd_set *)&fdmask, (fd_set *)NULL,
460 			    (fd_set *)NULL, &timeout) < 1)
461 				continue;
462 		}
463 		fromlen = sizeof(from);
464 		if ((cc = recvfrom(s, (char *)packet, packlen, 0,
465 		    (struct sockaddr *)&from, &fromlen)) < 0) {
466 			if (errno == EINTR)
467 				continue;
468 			perror("ping: recvfrom");
469 			continue;
470 		}
471 		pr_pack((char *)packet, cc, &from);
472 		if (npackets && nreceived >= npackets)
473 			break;
474 	}
475 	finish(0);
476 	/* NOTREACHED */
477 	exit(0);	/* Make the compiler happy */
478 }
479 
480 /*
481  * catcher --
482  *	This routine causes another PING to be transmitted, and then
483  * schedules another SIGALRM for 1 second from now.
484  *
485  * bug --
486  *	Our sense of time will slowly skew (i.e., packets will not be
487  * launched exactly at 1-second intervals).  This does not affect the
488  * quality of the delay and loss statistics.
489  */
490 static void
491 catcher(int sig)
492 {
493 	int waittime;
494 
495 	pinger();
496 	(void)signal(SIGALRM, catcher);
497 	if (!npackets || ntransmitted < npackets)
498 		alarm((u_int)interval);
499 	else {
500 		if (nreceived) {
501 			waittime = 2 * tmax / 1000;
502 			if (!waittime)
503 				waittime = 1;
504 		} else
505 			waittime = MAXWAIT;
506 		(void)signal(SIGALRM, finish);
507 		(void)alarm((u_int)waittime);
508 	}
509 }
510 
511 /*
512  * pinger --
513  *	Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
514  * will be added on by the kernel.  The ID field is our UNIX process ID,
515  * and the sequence number is an ascending integer.  The first 8 bytes
516  * of the data portion are used to hold a UNIX "timeval" struct in host
517  * byte-order, to compute the round-trip time.
518  */
519 static void
520 pinger(void)
521 {
522 	register struct icmp *icp;
523 	register int cc;
524 	int i;
525 
526 	icp = (struct icmp *)outpack;
527 	icp->icmp_type = ICMP_ECHO;
528 	icp->icmp_code = 0;
529 	icp->icmp_cksum = 0;
530 	icp->icmp_seq = ntransmitted++;
531 	icp->icmp_id = ident;			/* ID */
532 
533 	CLR(icp->icmp_seq % mx_dup_ck);
534 
535 	if (timing)
536 		(void)gettimeofday((struct timeval *)&outpack[8],
537 		    (struct timezone *)NULL);
538 
539 	cc = datalen + 8;			/* skips ICMP portion */
540 
541 	/* compute ICMP checksum here */
542 	icp->icmp_cksum = in_cksum((u_short *)icp, cc);
543 
544 	i = sendto(s, (char *)outpack, cc, 0, &whereto,
545 	    sizeof(struct sockaddr));
546 
547 	if (i < 0 || i != cc)  {
548 		if (i < 0) {
549 			warn("sendto");
550 		} else {
551 			warn("%s: partial write: %d of %d bytes",
552 			     hostname, cc, i);
553 		}
554 	}
555 	if (!(options & F_QUIET) && options & F_FLOOD)
556 		(void)write(STDOUT_FILENO, &DOT, 1);
557 }
558 
559 /*
560  * pr_pack --
561  *	Print out the packet, if it came from us.  This logic is necessary
562  * because ALL readers of the ICMP socket get a copy of ALL ICMP packets
563  * which arrive ('tis only fair).  This permits multiple copies of this
564  * program to be run without having intermingled output (or statistics!).
565  */
566 static void
567 pr_pack(buf, cc, from)
568 	char *buf;
569 	int cc;
570 	struct sockaddr_in *from;
571 {
572 	register struct icmp *icp;
573 	register u_long l;
574 	register int i, j;
575 	register u_char *cp,*dp;
576 	static int old_rrlen;
577 	static char old_rr[MAX_IPOPTLEN];
578 	struct ip *ip;
579 	struct timeval tv, *tp;
580 	double triptime;
581 	int hlen, dupflag;
582 
583 	(void)gettimeofday(&tv, (struct timezone *)NULL);
584 
585 	/* Check the IP header */
586 	ip = (struct ip *)buf;
587 	hlen = ip->ip_hl << 2;
588 	if (cc < hlen + ICMP_MINLEN) {
589 		if (options & F_VERBOSE)
590 			warn("packet too short (%d bytes) from %s", cc,
591 			     inet_ntoa(from->sin_addr));
592 		return;
593 	}
594 
595 	/* Now the ICMP part */
596 	cc -= hlen;
597 	icp = (struct icmp *)(buf + hlen);
598 	if (icp->icmp_type == ICMP_ECHOREPLY) {
599 		if (icp->icmp_id != ident)
600 			return;			/* 'Twas not our ECHO */
601 		++nreceived;
602 		if (timing) {
603 #ifndef icmp_data
604 			tp = (struct timeval *)&icp->icmp_ip;
605 #else
606 			tp = (struct timeval *)icp->icmp_data;
607 #endif
608 			tvsub(&tv, tp);
609 			triptime = ((double)tv.tv_sec) * 1000.0 +
610 			    ((double)tv.tv_usec) / 1000.0;
611 			tsum += triptime;
612 			if (triptime < tmin)
613 				tmin = triptime;
614 			if (triptime > tmax)
615 				tmax = triptime;
616 		}
617 
618 		if (TST(icp->icmp_seq % mx_dup_ck)) {
619 			++nrepeats;
620 			--nreceived;
621 			dupflag = 1;
622 		} else {
623 			SET(icp->icmp_seq % mx_dup_ck);
624 			dupflag = 0;
625 		}
626 
627 		if (options & F_QUIET)
628 			return;
629 
630 		if (options & F_FLOOD)
631 			(void)write(STDOUT_FILENO, &BSPACE, 1);
632 		else {
633 			(void)printf("%d bytes from %s: icmp_seq=%u", cc,
634 			   inet_ntoa(*(struct in_addr *)&from->sin_addr.s_addr),
635 			   icp->icmp_seq);
636 			(void)printf(" ttl=%d", ip->ip_ttl);
637 			if (timing)
638 				(void)printf(" time=%.3f ms", triptime);
639 			if (dupflag)
640 				(void)printf(" (DUP!)");
641 			if (options & F_AUDIBLE)
642 				(void)printf("\a");
643 			/* check the data */
644 			cp = (u_char*)&icp->icmp_data[8];
645 			dp = &outpack[8 + sizeof(struct timeval)];
646 			for (i = 8; i < datalen; ++i, ++cp, ++dp) {
647 				if (*cp != *dp) {
648 	(void)printf("\nwrong data byte #%d should be 0x%x but was 0x%x",
649 	    i, *dp, *cp);
650 					cp = (u_char*)&icp->icmp_data[0];
651 					for (i = 8; i < datalen; ++i, ++cp) {
652 						if ((i % 32) == 8)
653 							(void)printf("\n\t");
654 						(void)printf("%x ", *cp);
655 					}
656 					break;
657 				}
658 			}
659 		}
660 	} else {
661 		/*
662 		 * We've got something other than an ECHOREPLY.
663 		 * See if it's a reply to something that we sent.
664 		 * We can compare IP destination, protocol,
665 		 * and ICMP type and ID.
666 		 *
667 		 * Only print all the error messages if we are running
668 		 * as root to avoid leaking information not normally
669 		 * available to those not running as root.
670 		 */
671 #ifndef icmp_data
672 		struct ip *oip = &icp->icmp_ip;
673 #else
674 		struct ip *oip = (struct ip *)icp->icmp_data;
675 #endif
676 		struct icmp *oicmp = (struct icmp *)(oip + 1);
677 
678 		if (((options & F_VERBOSE) && uid == 0) ||
679 		    (!(options & F_QUIET2) &&
680 		     (oip->ip_dst.s_addr ==
681 			 ((struct sockaddr_in *)&whereto)->sin_addr.s_addr) &&
682 		     (oip->ip_p == IPPROTO_ICMP) &&
683 		     (oicmp->icmp_type == ICMP_ECHO) &&
684 		     (oicmp->icmp_id == ident))) {
685 		    (void)printf("%d bytes from %s: ", cc,
686 			pr_addr(from->sin_addr));
687 		    pr_icmph(icp);
688 		} else
689 		    return;
690 	}
691 
692 	/* Display any IP options */
693 	cp = (u_char *)buf + sizeof(struct ip);
694 
695 	for (; hlen > (int)sizeof(struct ip); --hlen, ++cp)
696 		switch (*cp) {
697 		case IPOPT_EOL:
698 			hlen = 0;
699 			break;
700 		case IPOPT_LSRR:
701 			(void)printf("\nLSRR: ");
702 			hlen -= 2;
703 			j = *++cp;
704 			++cp;
705 			if (j > IPOPT_MINOFF)
706 				for (;;) {
707 					l = *++cp;
708 					l = (l<<8) + *++cp;
709 					l = (l<<8) + *++cp;
710 					l = (l<<8) + *++cp;
711 					if (l == 0) {
712 						printf("\t0.0.0.0");
713 					} else {
714 						struct in_addr ina;
715 						ina.s_addr = ntohl(l);
716 						printf("\t%s", pr_addr(ina));
717 					}
718 				hlen -= 4;
719 				j -= 4;
720 				if (j <= IPOPT_MINOFF)
721 					break;
722 				(void)putchar('\n');
723 			}
724 			break;
725 		case IPOPT_RR:
726 			j = *++cp;		/* get length */
727 			i = *++cp;		/* and pointer */
728 			hlen -= 2;
729 			if (i > j)
730 				i = j;
731 			i -= IPOPT_MINOFF;
732 			if (i <= 0)
733 				continue;
734 			if (i == old_rrlen
735 			    && cp == (u_char *)buf + sizeof(struct ip) + 2
736 			    && !bcmp((char *)cp, old_rr, i)
737 			    && !(options & F_FLOOD)) {
738 				(void)printf("\t(same route)");
739 				i = ((i + 3) / 4) * 4;
740 				hlen -= i;
741 				cp += i;
742 				break;
743 			}
744 			old_rrlen = i;
745 			bcopy((char *)cp, old_rr, i);
746 			(void)printf("\nRR: ");
747 			for (;;) {
748 				l = *++cp;
749 				l = (l<<8) + *++cp;
750 				l = (l<<8) + *++cp;
751 				l = (l<<8) + *++cp;
752 				if (l == 0) {
753 					printf("\t0.0.0.0");
754 				} else {
755 					struct in_addr ina;
756 					ina.s_addr = ntohl(l);
757 					printf("\t%s", pr_addr(ina));
758 				}
759 				hlen -= 4;
760 				i -= 4;
761 				if (i <= 0)
762 					break;
763 				(void)putchar('\n');
764 			}
765 			break;
766 		case IPOPT_NOP:
767 			(void)printf("\nNOP");
768 			break;
769 		default:
770 			(void)printf("\nunknown option %x", *cp);
771 			break;
772 		}
773 	if (!(options & F_FLOOD)) {
774 		(void)putchar('\n');
775 		(void)fflush(stdout);
776 	}
777 }
778 
779 /*
780  * in_cksum --
781  *	Checksum routine for Internet Protocol family headers (C Version)
782  */
783 u_short
784 in_cksum(addr, len)
785 	u_short *addr;
786 	int len;
787 {
788 	register int nleft = len;
789 	register u_short *w = addr;
790 	register int sum = 0;
791 	u_short answer = 0;
792 
793 	/*
794 	 * Our algorithm is simple, using a 32 bit accumulator (sum), we add
795 	 * sequential 16 bit words to it, and at the end, fold back all the
796 	 * carry bits from the top 16 bits into the lower 16 bits.
797 	 */
798 	while (nleft > 1)  {
799 		sum += *w++;
800 		nleft -= 2;
801 	}
802 
803 	/* mop up an odd byte, if necessary */
804 	if (nleft == 1) {
805 		*(u_char *)(&answer) = *(u_char *)w ;
806 		sum += answer;
807 	}
808 
809 	/* add back carry outs from top 16 bits to low 16 bits */
810 	sum = (sum >> 16) + (sum & 0xffff);	/* add hi 16 to low 16 */
811 	sum += (sum >> 16);			/* add carry */
812 	answer = ~sum;				/* truncate to 16 bits */
813 	return(answer);
814 }
815 
816 /*
817  * tvsub --
818  *	Subtract 2 timeval structs:  out = out - in.  Out is assumed to
819  * be >= in.
820  */
821 static void
822 tvsub(out, in)
823 	register struct timeval *out, *in;
824 {
825 	if ((out->tv_usec -= in->tv_usec) < 0) {
826 		--out->tv_sec;
827 		out->tv_usec += 1000000;
828 	}
829 	out->tv_sec -= in->tv_sec;
830 }
831 
832 /*
833  * status --
834  *	Print out statistics when SIGINFO is received.
835  */
836 
837 static void
838 status(sig)
839 	int sig;
840 {
841 	siginfo_p = 1;
842 }
843 
844 static void
845 check_status()
846 {
847 	if (siginfo_p) {
848 		siginfo_p = 0;
849 		(void)fprintf(stderr,
850 	"\r%ld/%ld packets received (%.0f%%) %.3f min / %.3f avg / %.3f max\n",
851 		    nreceived, ntransmitted,
852 		    ntransmitted ? nreceived * 100.0 / ntransmitted : 0.0,
853 		    nreceived ? tmin : 0.0,
854 		    nreceived + nrepeats ? tsum / (nreceived + nrepeats) : tsum,
855 		    tmax);
856 	}
857 }
858 
859 /*
860  * finish --
861  *	Print out statistics, and give up.
862  */
863 static void
864 finish(int sig)
865 {
866 	struct termios ts;
867 
868 	(void)signal(SIGINT, SIG_IGN);
869 	(void)putchar('\n');
870 	(void)fflush(stdout);
871 	(void)printf("--- %s ping statistics ---\n", hostname);
872 	(void)printf("%ld packets transmitted, ", ntransmitted);
873 	(void)printf("%ld packets received, ", nreceived);
874 	if (nrepeats)
875 		(void)printf("+%ld duplicates, ", nrepeats);
876 	if (ntransmitted)
877 		if (nreceived > ntransmitted)
878 			(void)printf("-- somebody's printing up packets!");
879 		else
880 			(void)printf("%d%% packet loss",
881 			    (int) (((ntransmitted - nreceived) * 100) /
882 			    ntransmitted));
883 	(void)putchar('\n');
884 	if (nreceived && timing)
885 		(void)printf("round-trip min/avg/max = %.3f/%.3f/%.3f ms\n",
886 		    tmin, tsum / (nreceived + nrepeats), tmax);
887 	if (reset_kerninfo && tcgetattr(STDOUT_FILENO, &ts) != -1) {
888 		ts.c_lflag &= ~NOKERNINFO;
889 		tcsetattr(STDOUT_FILENO, TCSANOW, &ts);
890 	}
891 
892 	if (nreceived)
893 		exit(0);
894 	else
895 		exit(2);
896 }
897 
898 #ifdef notdef
899 static char *ttab[] = {
900 	"Echo Reply",		/* ip + seq + udata */
901 	"Dest Unreachable",	/* net, host, proto, port, frag, sr + IP */
902 	"Source Quench",	/* IP */
903 	"Redirect",		/* redirect type, gateway, + IP  */
904 	"Echo",
905 	"Time Exceeded",	/* transit, frag reassem + IP */
906 	"Parameter Problem",	/* pointer + IP */
907 	"Timestamp",		/* id + seq + three timestamps */
908 	"Timestamp Reply",	/* " */
909 	"Info Request",		/* id + sq */
910 	"Info Reply"		/* " */
911 };
912 #endif
913 
914 /*
915  * pr_icmph --
916  *	Print a descriptive string about an ICMP header.
917  */
918 static void
919 pr_icmph(icp)
920 	struct icmp *icp;
921 {
922 	switch(icp->icmp_type) {
923 	case ICMP_ECHOREPLY:
924 		(void)printf("Echo Reply\n");
925 		/* XXX ID + Seq + Data */
926 		break;
927 	case ICMP_UNREACH:
928 		switch(icp->icmp_code) {
929 		case ICMP_UNREACH_NET:
930 			(void)printf("Destination Net Unreachable\n");
931 			break;
932 		case ICMP_UNREACH_HOST:
933 			(void)printf("Destination Host Unreachable\n");
934 			break;
935 		case ICMP_UNREACH_PROTOCOL:
936 			(void)printf("Destination Protocol Unreachable\n");
937 			break;
938 		case ICMP_UNREACH_PORT:
939 			(void)printf("Destination Port Unreachable\n");
940 			break;
941 		case ICMP_UNREACH_NEEDFRAG:
942 			(void)printf("frag needed and DF set (MTU %d)\n",
943 					icp->icmp_nextmtu);
944 			break;
945 		case ICMP_UNREACH_SRCFAIL:
946 			(void)printf("Source Route Failed\n");
947 			break;
948 		case ICMP_UNREACH_FILTER_PROHIB:
949 			(void)printf("Communication prohibited by filter\n");
950 			break;
951 		default:
952 			(void)printf("Dest Unreachable, Bad Code: %d\n",
953 			    icp->icmp_code);
954 			break;
955 		}
956 		/* Print returned IP header information */
957 #ifndef icmp_data
958 		pr_retip(&icp->icmp_ip);
959 #else
960 		pr_retip((struct ip *)icp->icmp_data);
961 #endif
962 		break;
963 	case ICMP_SOURCEQUENCH:
964 		(void)printf("Source Quench\n");
965 #ifndef icmp_data
966 		pr_retip(&icp->icmp_ip);
967 #else
968 		pr_retip((struct ip *)icp->icmp_data);
969 #endif
970 		break;
971 	case ICMP_REDIRECT:
972 		switch(icp->icmp_code) {
973 		case ICMP_REDIRECT_NET:
974 			(void)printf("Redirect Network");
975 			break;
976 		case ICMP_REDIRECT_HOST:
977 			(void)printf("Redirect Host");
978 			break;
979 		case ICMP_REDIRECT_TOSNET:
980 			(void)printf("Redirect Type of Service and Network");
981 			break;
982 		case ICMP_REDIRECT_TOSHOST:
983 			(void)printf("Redirect Type of Service and Host");
984 			break;
985 		default:
986 			(void)printf("Redirect, Bad Code: %d", icp->icmp_code);
987 			break;
988 		}
989 		(void)printf("(New addr: 0x%08lx)\n", icp->icmp_gwaddr.s_addr);
990 #ifndef icmp_data
991 		pr_retip(&icp->icmp_ip);
992 #else
993 		pr_retip((struct ip *)icp->icmp_data);
994 #endif
995 		break;
996 	case ICMP_ECHO:
997 		(void)printf("Echo Request\n");
998 		/* XXX ID + Seq + Data */
999 		break;
1000 	case ICMP_TIMXCEED:
1001 		switch(icp->icmp_code) {
1002 		case ICMP_TIMXCEED_INTRANS:
1003 			(void)printf("Time to live exceeded\n");
1004 			break;
1005 		case ICMP_TIMXCEED_REASS:
1006 			(void)printf("Frag reassembly time exceeded\n");
1007 			break;
1008 		default:
1009 			(void)printf("Time exceeded, Bad Code: %d\n",
1010 			    icp->icmp_code);
1011 			break;
1012 		}
1013 #ifndef icmp_data
1014 		pr_retip(&icp->icmp_ip);
1015 #else
1016 		pr_retip((struct ip *)icp->icmp_data);
1017 #endif
1018 		break;
1019 	case ICMP_PARAMPROB:
1020 		(void)printf("Parameter problem: pointer = 0x%02x\n",
1021 		    icp->icmp_hun.ih_pptr);
1022 #ifndef icmp_data
1023 		pr_retip(&icp->icmp_ip);
1024 #else
1025 		pr_retip((struct ip *)icp->icmp_data);
1026 #endif
1027 		break;
1028 	case ICMP_TSTAMP:
1029 		(void)printf("Timestamp\n");
1030 		/* XXX ID + Seq + 3 timestamps */
1031 		break;
1032 	case ICMP_TSTAMPREPLY:
1033 		(void)printf("Timestamp Reply\n");
1034 		/* XXX ID + Seq + 3 timestamps */
1035 		break;
1036 	case ICMP_IREQ:
1037 		(void)printf("Information Request\n");
1038 		/* XXX ID + Seq */
1039 		break;
1040 	case ICMP_IREQREPLY:
1041 		(void)printf("Information Reply\n");
1042 		/* XXX ID + Seq */
1043 		break;
1044 	case ICMP_MASKREQ:
1045 		(void)printf("Address Mask Request\n");
1046 		break;
1047 	case ICMP_MASKREPLY:
1048 		(void)printf("Address Mask Reply\n");
1049 		break;
1050 	case ICMP_ROUTERADVERT:
1051 		(void)printf("Router Advertisement\n");
1052 		break;
1053 	case ICMP_ROUTERSOLICIT:
1054 		(void)printf("Router Solicitation\n");
1055 		break;
1056 	default:
1057 		(void)printf("Bad ICMP type: %d\n", icp->icmp_type);
1058 	}
1059 }
1060 
1061 /*
1062  * pr_iph --
1063  *	Print an IP header with options.
1064  */
1065 static void
1066 pr_iph(ip)
1067 	struct ip *ip;
1068 {
1069 	int hlen;
1070 	u_char *cp;
1071 
1072 	hlen = ip->ip_hl << 2;
1073 	cp = (u_char *)ip + 20;		/* point to options */
1074 
1075 	(void)printf("Vr HL TOS  Len   ID Flg  off TTL Pro  cks      Src      Dst\n");
1076 	(void)printf(" %1x  %1x  %02x %04x %04x",
1077 	    ip->ip_v, ip->ip_hl, ip->ip_tos, ntohs(ip->ip_len),
1078 	    ntohs(ip->ip_id));
1079 	(void)printf("   %1lx %04lx", (ntohl(ip->ip_off) & 0xe000) >> 13,
1080 	    ntohl(ip->ip_off) & 0x1fff);
1081 	(void)printf("  %02x  %02x %04x", ip->ip_ttl, ip->ip_p,
1082 							    ntohs(ip->ip_sum));
1083 	(void)printf(" %s ", inet_ntoa(*(struct in_addr *)&ip->ip_src.s_addr));
1084 	(void)printf(" %s ", inet_ntoa(*(struct in_addr *)&ip->ip_dst.s_addr));
1085 	/* dump any option bytes */
1086 	while (hlen-- > 20) {
1087 		(void)printf("%02x", *cp++);
1088 	}
1089 	(void)putchar('\n');
1090 }
1091 
1092 /*
1093  * pr_addr --
1094  *	Return an ascii host address as a dotted quad and optionally with
1095  * a hostname.
1096  */
1097 static char *
1098 pr_addr(ina)
1099 	struct in_addr ina;
1100 {
1101 	struct hostent *hp;
1102 	static char buf[16 + 3 + MAXHOSTNAMELEN];
1103 
1104 	if ((options & F_NUMERIC) ||
1105 	    !(hp = gethostbyaddr((char *)&ina, 4, AF_INET)))
1106 		return inet_ntoa(ina);
1107 	else
1108 		(void)snprintf(buf, sizeof(buf), "%s (%s)", hp->h_name,
1109 		    inet_ntoa(ina));
1110 	return(buf);
1111 }
1112 
1113 /*
1114  * pr_retip --
1115  *	Dump some info on a returned (via ICMP) IP packet.
1116  */
1117 static void
1118 pr_retip(ip)
1119 	struct ip *ip;
1120 {
1121 	int hlen;
1122 	u_char *cp;
1123 
1124 	pr_iph(ip);
1125 	hlen = ip->ip_hl << 2;
1126 	cp = (u_char *)ip + hlen;
1127 
1128 	if (ip->ip_p == 6)
1129 		(void)printf("TCP: from port %u, to port %u (decimal)\n",
1130 		    (*cp * 256 + *(cp + 1)), (*(cp + 2) * 256 + *(cp + 3)));
1131 	else if (ip->ip_p == 17)
1132 		(void)printf("UDP: from port %u, to port %u (decimal)\n",
1133 			(*cp * 256 + *(cp + 1)), (*(cp + 2) * 256 + *(cp + 3)));
1134 }
1135 
1136 static void
1137 fill(bp, patp)
1138 	char *bp, *patp;
1139 {
1140 	register int ii, jj, kk;
1141 	int pat[16];
1142 	char *cp;
1143 
1144 	for (cp = patp; *cp; cp++) {
1145 		if (!isxdigit(*cp))
1146 			errx(EX_USAGE,
1147 			     "patterns must be specified as hex digits");
1148 
1149 	}
1150 	ii = sscanf(patp,
1151 	    "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x",
1152 	    &pat[0], &pat[1], &pat[2], &pat[3], &pat[4], &pat[5], &pat[6],
1153 	    &pat[7], &pat[8], &pat[9], &pat[10], &pat[11], &pat[12],
1154 	    &pat[13], &pat[14], &pat[15]);
1155 
1156 	if (ii > 0)
1157 		for (kk = 0;
1158 		    kk <= MAXPACKET - (8 + sizeof(struct timeval) + ii);
1159 		    kk += ii)
1160 			for (jj = 0; jj < ii; ++jj)
1161 				bp[jj + kk] = pat[jj];
1162 	if (!(options & F_QUIET)) {
1163 		(void)printf("PATTERN: 0x");
1164 		for (jj = 0; jj < ii; ++jj)
1165 			(void)printf("%02x", bp[jj] & 0xFF);
1166 		(void)printf("\n");
1167 	}
1168 }
1169 
1170 static void
1171 usage(argv0)
1172 	const char *argv0;
1173 {
1174 	if (strrchr(argv0,'/'))
1175 		argv0 = strrchr(argv0,'/') + 1;
1176 	fprintf(stderr,
1177 		"usage: %s [-QRadfnqrv] [-c count] [-i wait] [-l preload] "
1178 		"[-p pattern]\n       [-s packetsize] "
1179 		"[host | [-L] [-I iface] [-T ttl] mcast-group]\n",
1180 		argv0);
1181 	exit(EX_USAGE);
1182 }
1183