xref: /src/sbin/ping/ping.c

/*	$NetBSD: ping.c,v 1.118 2021/06/11 18:47:56 rillig Exp $	*/

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Muuss.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 *			P I N G . C
 *
 * Using the InterNet Control Message Protocol (ICMP) "ECHO" facility,
 * measure round-trip-delays and packet loss across network paths.
 *
 * Author -
 *	Mike Muuss
 *	U. S. Army Ballistic Research Laboratory
 *	December, 1983
 * Modified at Uc Berkeley
 * Record Route and verbose headers - Phil Dykstra, BRL, March 1988.
 * Multicast options (ttl, if, loop) - Steve Deering, Stanford, August 1988.
 * ttl, duplicate detection - Cliff Frost, UCB, April 1989
 * Pad pattern - Cliff Frost (from Tom Ferrin, UCSF), April 1989
 *
 * Status -
 *	Public Domain.  Distribution Unlimited.
 *
 * Bugs -
 *	More statistics could always be gathered.
 *	This program has to run SUID to ROOT to access the ICMP socket.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: ping.c,v 1.118 2021/06/11 18:47:56 rillig Exp $");
#endif

#include <stdio.h>
#include <stddef.h>
#include <errno.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <termios.h>
#include <stdlib.h>
#include <unistd.h>
#include <poll.h>
#include <limits.h>
#include <math.h>
#include <string.h>
#include <err.h>

#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_var.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <netdb.h>

#ifdef IPSEC
#include <netipsec/ipsec.h>
#endif /*IPSEC*/

#include "prog_ops.h"

#define FLOOD_INTVL	0.01		/* default flood output interval */
#define	MAXPACKET	(IP_MAXPACKET-60-8)	/* max packet size */

#define F_VERBOSE	0x0001
#define F_QUIET		0x0002		/* minimize all output */
#define F_SEMI_QUIET	0x0004		/* ignore our ICMP errors */
#define F_FLOOD		0x0008		/* flood-ping */
#define	F_RECORD_ROUTE	0x0010		/* record route */
#define F_SOURCE_ROUTE	0x0020		/* loose source route */
#define F_PING_FILLED	0x0040		/* is buffer filled with user data? */
#define F_PING_RANDOM	0x0080		/* use random data */
#define	F_NUMERIC	0x0100		/* do not do gethostbyaddr() calls */
#define F_TIMING	0x0200		/* room for a timestamp */
#define F_DF		0x0400		/* set IP DF bit */
#define F_SOURCE_ADDR	0x0800		/* set source IP address/interface */
#define F_ONCE		0x1000		/* exit(0) after receiving 1 reply */
#define F_MCAST		0x2000		/* multicast target */
#define F_MCAST_NOLOOP	0x4000		/* no multicast loopback */
#define F_AUDIBLE	0x8000		/* audible output */
#define F_TIMING64	0x10000		/* 64 bit time, nanoseconds */
#ifdef IPSEC
#ifdef IPSEC_POLICY_IPSEC
#define F_POLICY	0x20000
#else
#define	F_AUTHHDR	0x20000
#define	F_ENCRYPT	0x40000
#endif /*IPSEC_POLICY_IPSEC*/
#endif /*IPSEC*/


/* MAX_DUP_CHK is the number of bits in received table, the
 *	maximum number of received sequence numbers we can track to check
 *	for duplicates.
 */
#define MAX_DUP_CHK     (8 * 2048)
static u_char	rcvd_tbl[MAX_DUP_CHK/8];
static int     nrepeats = 0;
#define A(seq)	rcvd_tbl[(seq/8)%sizeof(rcvd_tbl)]  /* byte in array */
#define B(seq)	(1 << (seq & 0x07))	/* bit in byte */
#define SET(seq) (A(seq) |= B(seq))
#define CLR(seq) (A(seq) &= (~B(seq)))
#define TST(seq) (A(seq) & B(seq))

struct tv32 {
	int32_t tv32_sec;
	int32_t tv32_usec;
};


static u_char	*packet;
static int	packlen;
static int	pingflags = 0, options;
static int	pongflags = 0;
static char	*fill_pat;

static int s;					/* Socket file descriptor */
static int sloop;				/* Socket file descriptor/loopback */

#define PHDR_LEN sizeof(struct tv32)		/* size of timestamp header */
#define PHDR64_LEN sizeof(struct timespec)	/* size of timestamp header */
static struct sockaddr_in whereto, send_addr;	/* Who to ping */
static struct sockaddr_in src_addr;		/* from where */
static struct sockaddr_in loc_addr;		/* 127.1 */
static int datalen;				/* How much data */
static int phdrlen;

static sigset_t blockmask, enablemask;		/* signal masks */

#ifndef __NetBSD__
static char *progname;
#define	getprogname()		(progname)
#define	setprogname(name)	((void)(progname = (name)))
#endif

static char hostname[MAXHOSTNAMELEN];

static struct {
	struct ip	o_ip;
	char		o_opt[MAX_IPOPTLEN];
	union {
		u_char	    u_buf[MAXPACKET+offsetof(struct icmp, icmp_data)];
		struct icmp u_icmp;
	} o_u;
} out_pack;
#define	opack_icmp	out_pack.o_u.u_icmp
static struct ip *opack_ip;

static uint8_t optspace[MAX_IPOPTLEN];		/* record route space */
static int optlen;

static int npackets;				/* total packets to send */
static int preload;				/* number of packets to "preload" */
static int ntransmitted;			/* output sequence # = #sent */
static int ident;				/* 16 random bits to identify our packets */

static int nreceived;				/* # of packets we got back */

static double interval;			/* interval between packets */
static struct timespec interval_tv;
static double tmin = 999999999.0;
static double tmax = 0.0;
static double tsum = 0.0;			/* sum of all times */
static double tsumsq = 0.0;
static double maxwait = 0.0;

static int bufspace = IP_MAXPACKET;

static struct timespec now, clear_cache, last_tx, next_tx, first_tx;
static struct timespec last_rx, first_rx;
static int lastrcvd = 1;			/* last ping sent has been received */

static struct timespec jiggle_time;
static int jiggle_cnt, total_jiggled, jiggle_direction = -1;

__dead static void doit(void);
static void prefinish(int);
static void prtsig(int);
__dead static void finish(int);
static void blocksignals(void);
static void enablesignals(void);
static void summary(int);
static void pinger(void);
static void fill(void);
static void rnd_fill(void);
static double diffsec(struct timespec *, struct timespec *);
#if 0
static void timespecadd(struct timespec *, struct timespec *);
#endif
static void sec_to_timespec(const double, struct timespec *);
static double timespec_to_sec(const struct timespec *);
static void pr_pack(u_char *, int, struct sockaddr_in *);
static u_int16_t in_cksum(u_int16_t *, u_int);
static void pr_saddr(u_char *);
static char *pr_addr(struct in_addr *);
static void pr_iph(struct icmp *, int);
static void pr_retip(struct icmp *, int);
static int pr_icmph(struct icmp *, struct sockaddr_in *, int);
static void jiggle(int), jiggle_flush(int);
static void gethost(const char *, const char *,
		    struct sockaddr_in *, char *, int);
__dead static void usage(void);

int
main(int argc, char *argv[])
{
	int c, i, on = 1, hostind = 0;
	long l;
	int len = -1, compat = 0;
	u_char ttl = 0;
	u_long tos = 0;
	char *p;
#ifdef IPSEC
#ifdef IPSEC_POLICY_IPSEC
	char *policy_in = NULL;
	char *policy_out = NULL;
#endif
#endif
#ifdef SIGINFO
	struct sigaction sa;
#endif

	if (prog_init && prog_init() == -1)
		err(EXIT_FAILURE, "init failed");

	if ((s = prog_socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0)
		err(EXIT_FAILURE, "Cannot create socket");
	if ((sloop = prog_socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0)
		err(EXIT_FAILURE, "Cannot create socket");

	/*
	 * sloop is never read on.  This prevents packets from
	 * queueing in its recv buffer.
	 */
	if (prog_shutdown(sloop, SHUT_RD) == -1)
		warn("Cannot shutdown for read");

	if (prog_setuid(prog_getuid()) == -1)
		err(EXIT_FAILURE, "setuid");

	setprogname(argv[0]);

#ifndef IPSEC
#define IPSECOPT
#else
#ifdef IPSEC_POLICY_IPSEC
#define IPSECOPT	"E:"
#else
#define IPSECOPT	"AE"
#endif /*IPSEC_POLICY_IPSEC*/
#endif
	while ((c = getopt(argc, argv,
			   "ac:CdDfg:h:i:I:l:Lnop:PqQrRs:t:T:vw:" IPSECOPT)) != -1) {
#undef IPSECOPT
		switch (c) {
		case 'a':
			pingflags |= F_AUDIBLE;
			break;
		case 'C':
			compat = 1;
			break;
		case 'c':
			l = strtol(optarg, &p, 0);
			if (*p != '\0' || l <= 0)
				errx(EXIT_FAILURE,
				    "Bad/invalid number of packets: %s",
				    optarg);
#if INT_MAX < LONG_MAX
			if (l > INT_MAX)
				errx(EXIT_FAILURE,
				    "Too many packets to count: %ld", l);
#endif
			npackets = l;
			break;
		case 'D':
			pingflags |= F_DF;
			break;
		case 'd':
			options |= SO_DEBUG;
			break;
		case 'f':
			pingflags |= F_FLOOD;
			break;
		case 'h':
			hostind = optind-1;
			break;
		case 'i':		/* wait between sending packets */
			interval = strtod(optarg, &p);
			if (*p != '\0' || interval <= 0)
				errx(EXIT_FAILURE, "Bad/invalid interval: %s",
				    optarg);
			/*
			 * In order to avoid overflowing the microseconds
			 * argument of poll() the interval must be less than
			 * INT_MAX/1000. Limit it to one second less than
			 * that to be safe.
			 */
			if (interval >= INT_MAX/1000.0 - 1.0)
				errx(EXIT_FAILURE,
				    "Timing interval %g too large", interval);
			break;
		case 'l':
			l = strtol(optarg, &p, 0);
			if (*p != '\0' || l < 0)
				errx(EXIT_FAILURE, "Bad/invalid preload value: "
				    "%s", optarg);
#if INT_MAX < LONG_MAX
			if (l > INT_MAX)
				errx(EXIT_FAILURE,
				    "Too many preload packets: %ld", l);
#endif
			preload = l;
			break;
		case 'n':
			pingflags |= F_NUMERIC;
			break;
		case 'o':
			pingflags |= F_ONCE;
			break;
		case 'p':		/* fill buffer with user pattern */
			if (pingflags & F_PING_RANDOM)
				errx(EXIT_FAILURE,
				    "Only one of -P and -p allowed");
			pingflags |= F_PING_FILLED;
			fill_pat = optarg;
			break;
		case 'P':
			if (pingflags & F_PING_FILLED)
				errx(EXIT_FAILURE,
				    "Only one of -P and -p allowed");
			pingflags |= F_PING_RANDOM;
			break;
		case 'q':
			pingflags |= F_QUIET;
			break;
		case 'Q':
			pingflags |= F_SEMI_QUIET;
			break;
		case 'r':
			options |= SO_DONTROUTE;
			break;
		case 's':		/* size of packet to send */
			l = strtol(optarg, &p, 0);
			if (*p != '\0' || l < 0)
				errx(EXIT_FAILURE,
				    "Bad/invalid packet size: %s", optarg);
			if (l > MAXPACKET)
				errx(EXIT_FAILURE, "packet size is too large");
			len = (int)l;
			break;
		case 'v':
			pingflags |= F_VERBOSE;
			break;
		case 'R':
			pingflags |= F_RECORD_ROUTE;
			break;
		case 'L':
			pingflags |= F_MCAST_NOLOOP;
			break;
		case 't':
			tos = strtoul(optarg, &p, 0);
			if (*p != '\0' ||  tos > 0xFF)
				errx(EXIT_FAILURE, "bad tos value: %s", optarg);
			break;
		case 'T':
			l = strtol(optarg, &p, 0);
			if (*p != '\0' || l > 255 || l <= 0)
				errx(EXIT_FAILURE, "ttl out of range: %s",
				    optarg);
			ttl = (u_char)l;    /* cannot check >255 otherwise */
			break;
		case 'I':
			pingflags |= F_SOURCE_ADDR;
			gethost("-I", optarg, &src_addr, 0, 0);
			break;
		case 'g':
			pingflags |= F_SOURCE_ROUTE;
			gethost("-g", optarg, &send_addr, 0, 0);
			break;
		case 'w':
			maxwait = strtod(optarg, &p);
			if (*p != '\0' || maxwait <= 0)
				errx(EXIT_FAILURE, "Bad/invalid maxwait time: "
				    "%s", optarg);
			break;
#ifdef IPSEC
#ifdef IPSEC_POLICY_IPSEC
		case 'E':
			pingflags |= F_POLICY;
			if (!strncmp("in", optarg, 2)) {
				policy_in = strdup(optarg);
				if (!policy_in)
					err(EXIT_FAILURE, "strdup");
			} else if (!strncmp("out", optarg, 3)) {
				policy_out = strdup(optarg);
				if (!policy_out)
					err(EXIT_FAILURE, "strdup");
			} else
				errx(EXIT_FAILURE, "invalid security policy: "
				    "%s", optarg);
			break;
#else
		case 'A':
			pingflags |= F_AUTHHDR;
			break;
		case 'E':
			pingflags |= F_ENCRYPT;
			break;
#endif /*IPSEC_POLICY_IPSEC*/
#endif /*IPSEC*/
		default:
			usage();
			break;
		}
	}

	if (interval == 0)
		interval = (pingflags & F_FLOOD) ? FLOOD_INTVL : 1.0;
	if (pingflags & F_FLOOD && prog_getuid())
		errx(EXIT_FAILURE, "Must be superuser to use -f");
	if (interval < 1.0 && prog_getuid())
		errx(EXIT_FAILURE, "Must be superuser to use < 1 sec "
		    "ping interval");
	if (preload > 0 && prog_getuid())
		errx(EXIT_FAILURE, "Must be superuser to use -l");

	sec_to_timespec(interval, &interval_tv);
	if (interval_tv.tv_sec == 0 && interval_tv.tv_nsec == 0) {
		errx(EXIT_FAILURE, "Packet interval must be at least 1 ns");
	}

	if ((pingflags & (F_AUDIBLE|F_FLOOD)) == (F_AUDIBLE|F_FLOOD))
		warnx("Sorry, no audible output for flood pings");

	if (npackets != 0) {
		npackets += preload;
	} else {
		npackets = INT_MAX;
	}

	if (hostind == 0) {
		if (optind != argc-1)
			usage();
		else
			hostind = optind;
	}
	else if (hostind >= argc - 1)
		usage();

	gethost("", argv[hostind], &whereto, hostname, sizeof(hostname));
	if (IN_MULTICAST(ntohl(whereto.sin_addr.s_addr)))
		pingflags |= F_MCAST;
	if (!(pingflags & F_SOURCE_ROUTE))
		(void) memcpy(&send_addr, &whereto, sizeof(send_addr));

	loc_addr.sin_family = AF_INET;
	loc_addr.sin_len = sizeof(struct sockaddr_in);
	loc_addr.sin_addr.s_addr = htonl((127 << 24) + 1);

	if (len != -1)
		datalen = len;
	else
		datalen = 64 - PHDR_LEN;
	if (!compat && datalen >= (int)PHDR64_LEN) { /* can we time them? */
		pingflags |= F_TIMING64;
		phdrlen = PHDR64_LEN;
	} else if (datalen >= (int)PHDR_LEN) {	/* can we time them? */
		pingflags |= F_TIMING;
		phdrlen = PHDR_LEN;
	} else
		phdrlen = 0;

	packlen = datalen + 60 + 76;	/* MAXIP + MAXICMP */
	if ((packet = malloc(packlen)) == NULL)
		err(EXIT_FAILURE, "Can't allocate %d bytes", packlen);

	if (pingflags & F_PING_FILLED) {
		fill();
	} else if (pingflags & F_PING_RANDOM) {
		rnd_fill();
	} else {
		for (i = phdrlen; i < datalen; i++)
			opack_icmp.icmp_data[i] = i;
	}

	ident = arc4random() & 0xFFFF;

	if (options & SO_DEBUG) {
		if (prog_setsockopt(s, SOL_SOCKET, SO_DEBUG,
			       (char *)&on, sizeof(on)) == -1)
			warn("Can't turn on socket debugging");
	}
	if (options & SO_DONTROUTE) {
		if (prog_setsockopt(s, SOL_SOCKET, SO_DONTROUTE,
			       (char *)&on, sizeof(on)) == -1)
			warn("SO_DONTROUTE");
	}

	if (options & SO_DEBUG) {
		if (prog_setsockopt(sloop, SOL_SOCKET, SO_DEBUG,
			       (char *)&on, sizeof(on)) == -1)
			warn("Can't turn on socket debugging");
	}
	if (options & SO_DONTROUTE) {
		if (prog_setsockopt(sloop, SOL_SOCKET, SO_DONTROUTE,
			       (char *)&on, sizeof(on)) == -1)
			warn("SO_DONTROUTE");
	}

	if (pingflags & F_SOURCE_ROUTE) {
		optspace[IPOPT_OPTVAL] = IPOPT_LSRR;
		optspace[IPOPT_OLEN] = optlen = 7;
		optspace[IPOPT_OFFSET] = IPOPT_MINOFF;
		(void)memcpy(&optspace[IPOPT_MINOFF-1], &whereto.sin_addr,
			     sizeof(whereto.sin_addr));
		optspace[optlen++] = IPOPT_NOP;
	}
	if (pingflags & F_RECORD_ROUTE) {
		optspace[optlen+IPOPT_OPTVAL] = IPOPT_RR;
		optspace[optlen+IPOPT_OLEN] = (MAX_IPOPTLEN -1-optlen);
		optspace[optlen+IPOPT_OFFSET] = IPOPT_MINOFF;
		optlen = MAX_IPOPTLEN;
	}
	/* this leaves opack_ip 0(mod 4) aligned */
	opack_ip = (struct ip *)((char *)&out_pack.o_ip
				 + sizeof(out_pack.o_opt)
				 - optlen);
	(void) memcpy(opack_ip + 1, optspace, optlen);

	if (prog_setsockopt(s, IPPROTO_IP, IP_HDRINCL,
	    (char *) &on, sizeof(on)) < 0)
		err(EXIT_FAILURE, "Can't set special IP header");

	opack_ip->ip_v = IPVERSION;
	opack_ip->ip_hl = (sizeof(struct ip)+optlen) >> 2;
	opack_ip->ip_tos = tos;
	opack_ip->ip_off = (pingflags & F_DF) ? IP_DF : 0;
	opack_ip->ip_ttl = ttl ? ttl : MAXTTL;
	opack_ip->ip_p = IPPROTO_ICMP;
	opack_ip->ip_src = src_addr.sin_addr;
	opack_ip->ip_dst = send_addr.sin_addr;

	if (pingflags & F_MCAST) {
		if (pingflags & F_MCAST_NOLOOP) {
			u_char loop = 0;
			if (prog_setsockopt(s, IPPROTO_IP,
			    IP_MULTICAST_LOOP,
			    (char *) &loop, 1) < 0)
				err(EXIT_FAILURE, "Can't disable multicast loopback");
		}

		if (ttl != 0
		    && prog_setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
		    (char *) &ttl, 1) < 0)
			err(EXIT_FAILURE, "Can't set multicast time-to-live");

		if ((pingflags & F_SOURCE_ADDR)
		    && prog_setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
				  (char *) &src_addr.sin_addr,
				  sizeof(src_addr.sin_addr)) < 0)
			err(EXIT_FAILURE, "Can't set multicast source interface");

	} else if (pingflags & F_SOURCE_ADDR) {
		if (prog_setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
			       (char *) &src_addr.sin_addr,
			       sizeof(src_addr.sin_addr)) < 0)
			err(EXIT_FAILURE, "Can't set source interface/address");
	}
#ifdef IPSEC
#ifdef IPSEC_POLICY_IPSEC
    {
	char *buf;
	if (pingflags & F_POLICY) {
		if (policy_in != NULL) {
			buf = ipsec_set_policy(policy_in, strlen(policy_in));
			if (buf == NULL)
				errx(EXIT_FAILURE, "%s", ipsec_strerror());
			if (prog_setsockopt(s, IPPROTO_IP, IP_IPSEC_POLICY,
					buf, ipsec_get_policylen(buf)) < 0) {
				err(EXIT_FAILURE, "ipsec policy cannot be "
				    "configured");
			}
			free(buf);
		}
		if (policy_out != NULL) {
			buf = ipsec_set_policy(policy_out, strlen(policy_out));
			if (buf == NULL)
				errx(EXIT_FAILURE, "%s", ipsec_strerror());
			if (prog_setsockopt(s, IPPROTO_IP, IP_IPSEC_POLICY,
					buf, ipsec_get_policylen(buf)) < 0) {
				err(EXIT_FAILURE, "ipsec policy cannot be "
				    "configured");
			}
			free(buf);
		}
	}
	buf = ipsec_set_policy("out bypass", strlen("out bypass"));
	if (buf == NULL)
		errx(EXIT_FAILURE, "%s", ipsec_strerror());
	if (prog_setsockopt(sloop, IPPROTO_IP, IP_IPSEC_POLICY,
			buf, ipsec_get_policylen(buf)) < 0) {
#if 0
		warnx("ipsec is not configured");
#else
		/* ignore it, should be okay */
#endif
	}
	free(buf);
    }
#else
    {
	int optval;
	if (pingflags & F_AUTHHDR) {
		optval = IPSEC_LEVEL_REQUIRE;
#ifdef IP_AUTH_TRANS_LEVEL
		(void)prog_setsockopt(s, IPPROTO_IP, IP_AUTH_TRANS_LEVEL,
			(char *)&optval, sizeof(optval));
#else
		(void)prog_setsockopt(s, IPPROTO_IP, IP_AUTH_LEVEL,
			(char *)&optval, sizeof(optval));
#endif
	}
	if (pingflags & F_ENCRYPT) {
		optval = IPSEC_LEVEL_REQUIRE;
		(void)prog_setsockopt(s, IPPROTO_IP, IP_ESP_TRANS_LEVEL,
			(char *)&optval, sizeof(optval));
	}
	optval = IPSEC_LEVEL_BYPASS;
#ifdef IP_AUTH_TRANS_LEVEL
	(void)prog_setsockopt(sloop, IPPROTO_IP, IP_AUTH_TRANS_LEVEL,
		(char *)&optval, sizeof(optval));
#else
	(void)prog_setsockopt(sloop, IPPROTO_IP, IP_AUTH_LEVEL,
		(char *)&optval, sizeof(optval));
#endif
	(void)prog_setsockopt(sloop, IPPROTO_IP, IP_ESP_TRANS_LEVEL,
		(char *)&optval, sizeof(optval));
    }
#endif /*IPSEC_POLICY_IPSEC*/
#endif /*IPSEC*/

	(void)printf("PING %s (%s): %d data bytes\n", hostname,
		     inet_ntoa(whereto.sin_addr), datalen);

	/* When pinging the broadcast address, you can get a lot
	 * of answers.  Doing something so evil is useful if you
	 * are trying to stress the ethernet, or just want to
	 * fill the arp cache to get some stuff for /etc/ethers.
	 */
	while (0 > prog_setsockopt(s, SOL_SOCKET, SO_RCVBUF,
			      (char*)&bufspace, sizeof(bufspace))) {
		if ((bufspace -= 4096) <= 0)
			err(EXIT_FAILURE, "Cannot set the receive buffer size");
	}

	/* make it possible to send giant probes, but do not worry now
	 * if it fails, since we probably won't send giant probes.
	 */
	(void)prog_setsockopt(s, SOL_SOCKET, SO_SNDBUF,
			 (char*)&bufspace, sizeof(bufspace));

	(void)signal(SIGINT, prefinish);

	/*
	 * Set up two signal masks:
	 *    - blockmask blocks the signals we catch
	 *    - enablemask does not
	 */

	sigemptyset(&enablemask);
	sigemptyset(&blockmask);
	sigaddset(&blockmask, SIGINT);
#ifdef SIGINFO
	sigaddset(&blockmask, SIGINFO);
#else
	sigaddset(&blockmask, SIGQUIT);
#endif

#ifdef SIGINFO
	sa.sa_handler = prtsig;
	sa.sa_flags = SA_NOKERNINFO;
	sigemptyset(&sa.sa_mask);
	(void)sigaction(SIGINFO, &sa, NULL);
#else
	(void)signal(SIGQUIT, prtsig);
#endif
	(void)signal(SIGCONT, prtsig);

	blocksignals();

	/* fire off them quickies */
	for (i = 0; i < preload; i++) {
		clock_gettime(CLOCK_MONOTONIC, &now);
		pinger();
	}

	doit();
	return 0;
}

static void
doit(void)
{
	int cc;
	struct sockaddr_in from;
	socklen_t fromlen;
	double sec, last, d_last;
	struct pollfd fdmaskp[1];

	(void)clock_gettime(CLOCK_MONOTONIC, &clear_cache);
	if (maxwait != 0) {
		last = timespec_to_sec(&clear_cache) + maxwait;
		d_last = 0;
	} else {
		last = 0;
		d_last = 365*24*60*60;
	}

	do {
		clock_gettime(CLOCK_MONOTONIC, &now);

		if (last != 0)
			d_last = last - timespec_to_sec(&now);

		if (ntransmitted < npackets && d_last > 0) {
			/* send if within 100 usec or late for next packet */
			sec = diffsec(&next_tx, &now);
			if (sec <= 0.0001 ||
			    (lastrcvd && (pingflags & F_FLOOD))) {
				pinger();
				sec = diffsec(&next_tx, &now);
			}
			if (sec < 0.0)
				sec = 0.0;
			if (d_last < sec)
				sec = d_last;

		} else {
			/* For the last response, wait twice as long as the
			 * worst case seen, or 10 times as long as the
			 * maximum interpacket interval, whichever is longer.
			 */
			sec = MAX(2 * tmax, 10 * interval) -
			    diffsec(&now, &last_tx);
			if (d_last < sec)
				sec = d_last;
			if (sec <= 0)
				break;
		}


		fdmaskp[0].fd = s;
		fdmaskp[0].events = POLLIN;

		enablesignals();
		cc = prog_poll(fdmaskp, 1, (int)(sec * 1000));
		blocksignals();

		if (cc <= 0) {
			if (cc < 0) {
				if (errno == EINTR)
					continue;
				jiggle_flush(1);
				err(EXIT_FAILURE, "poll");
			}
			continue;
		}

		fromlen  = sizeof(from);
		cc = prog_recvfrom(s, (char *) packet, packlen,
			      0, (struct sockaddr *)&from,
			      &fromlen);
		if (cc < 0) {
			if (errno != EINTR) {
				jiggle_flush(1);
				warn("recvfrom");
				(void)fflush(stderr);
			}
			continue;
		}
		clock_gettime(CLOCK_MONOTONIC, &now);
		pr_pack(packet, cc, &from);

	} while (nreceived < npackets
		 && (nreceived == 0 || !(pingflags & F_ONCE)));

	finish(0);
}


static void
jiggle_flush(int nl)			/* new line if there are dots */
{
	int serrno = errno;

	if (jiggle_cnt > 0) {
		total_jiggled += jiggle_cnt;
		jiggle_direction = 1;
		do {
			(void)putchar('.');
		} while (--jiggle_cnt > 0);

	} else if (jiggle_cnt < 0) {
		total_jiggled -= jiggle_cnt;
		jiggle_direction = -1;
		do {
			(void)putchar('\b');
		} while (++jiggle_cnt < 0);
	}

	if (nl) {
		if (total_jiggled != 0)
			(void)putchar('\n');
		total_jiggled = 0;
		jiggle_direction = -1;
	}

	(void)fflush(stdout);
	(void)fflush(stderr);
	jiggle_time = now;
	errno = serrno;
}


/* jiggle the cursor for flood-ping
 */
static void
jiggle(int delta)
{
	double dt;

	if (pingflags & F_QUIET)
		return;

	/* do not back up into messages */
	if (total_jiggled+jiggle_cnt+delta < 0)
		return;

	jiggle_cnt += delta;

	/* flush the FLOOD dots when things are quiet
	 * or occassionally to make the cursor jiggle.
	 */
	dt = diffsec(&last_tx, &jiggle_time);
	if (dt > 0.2 || (dt >= 0.15 && delta*jiggle_direction < 0))
		jiggle_flush(0);
}


/*
 * Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
 * will be added on by the kernel.  The ID field is random,
 * and the sequence number is an ascending integer.  The first phdrlen bytes
 * of the data portion are used to hold a UNIX "timeval" struct in VAX
 * byte-order, to compute the round-trip time, or a UNIX "timespec" in native
 * format.
 */
static void
pinger(void)
{
	struct tv32 tv32;
	int i, cc, sw;
	double waittime;
	long numskip;

	opack_icmp.icmp_code = 0;
	opack_icmp.icmp_seq = htons((u_int16_t)(ntransmitted));

	/* clear the cached route in the kernel after an ICMP
	 * response such as a Redirect is seen to stop causing
	 * more such packets.  Also clear the cached route
	 * periodically in case of routing changes that make
	 * black holes come and go.
	 */
	if (clear_cache.tv_sec != now.tv_sec) {
		opack_icmp.icmp_type = ICMP_ECHOREPLY;
		opack_icmp.icmp_id = ~ident;
		opack_icmp.icmp_cksum = 0;
		opack_icmp.icmp_cksum = in_cksum((u_int16_t *)&opack_icmp,
		    ICMP_MINLEN);
		sw = 0;
		if (prog_setsockopt(sloop, IPPROTO_IP, IP_HDRINCL,
			       (char *)&sw, sizeof(sw)) < 0)
			err(EXIT_FAILURE, "Can't turn off special IP header");
		if (prog_sendto(sloop, (char *) &opack_icmp,
			   ICMP_MINLEN, MSG_DONTROUTE,
			   (struct sockaddr *)&loc_addr,
			   sizeof(struct sockaddr_in)) < 0) {
			/*
			 * XXX: we only report this as a warning in verbose
			 * mode because people get confused when they see
			 * this error when they are running in single user
			 * mode and they have not configured lo0
			 */
			if (pingflags & F_VERBOSE)
				warn("failed to clear cached route");
		}
		sw = 1;
		if (prog_setsockopt(sloop, IPPROTO_IP, IP_HDRINCL,
			       (char *)&sw, sizeof(sw)) < 0)
			err(EXIT_FAILURE, "Can't set special IP header");

		(void)clock_gettime(CLOCK_MONOTONIC, &clear_cache);
	}

	opack_icmp.icmp_type = ICMP_ECHO;
	opack_icmp.icmp_id = ident;

	if (pingflags & F_TIMING) {
		tv32.tv32_sec = (uint32_t)htonl(now.tv_sec);
		tv32.tv32_usec = htonl(now.tv_nsec / 1000);
		(void) memcpy(&opack_icmp.icmp_data[0], &tv32, sizeof(tv32));
	} else if (pingflags & F_TIMING64)
		(void) memcpy(&opack_icmp.icmp_data[0], &now, sizeof(now));

	cc = MAX(datalen, ICMP_MINLEN) + PHDR_LEN;
	opack_icmp.icmp_cksum = 0;
	opack_icmp.icmp_cksum = in_cksum((u_int16_t *)&opack_icmp, cc);

	cc += opack_ip->ip_hl<<2;
	opack_ip->ip_len = cc;
	i = prog_sendto(s, (char *) opack_ip, cc, 0,
		   (struct sockaddr *)&send_addr, sizeof(struct sockaddr_in));
	if (i != cc) {
		jiggle_flush(1);
		if (i < 0)
			warn("sendto");
		else
			warnx("wrote %s %d chars, ret=%d", hostname, cc, i);
		(void)fflush(stderr);
	}
	lastrcvd = 0;

	CLR(ntransmitted);
	ntransmitted++;

	last_tx = now;
	if (next_tx.tv_sec == 0) {
		first_tx = now;
		next_tx = now;
	}

	/* Transmit regularly, at always the same microsecond in the
	 * second when going at one packet per second.
	 * If we are at most 100 ms behind, send extras to get caught up.
	 * Otherwise, skip packets we were too slow to send.
	 */
	waittime = diffsec(&next_tx, &now);
	if (waittime < -1.0) {
		/* very behind - forget about being precise */
		next_tx.tv_sec += (int)(-waittime);
	} else if (waittime < -0.1) {
		/* behind - skip a few */
		if (interval_tv.tv_sec == 0) {
			numskip = (long)(-waittime / interval_tv.tv_nsec);
			next_tx.tv_nsec += numskip * interval_tv.tv_nsec;
			/*
			 * We can add at most one second's worth, but allow
			 * for tv_nsec reaching 2 billion just in case FP
			 * issues strike.
			 */
			while (next_tx.tv_nsec >= 1000000000) {
				next_tx.tv_sec++;
				next_tx.tv_nsec -= 1000000000;
			}
		} else {
			do {
				timespecadd(&next_tx, &interval_tv, &next_tx);
			} while (diffsec(&next_tx, &now) < -0.1);
		}

	} else if (waittime <= interval) {
		timespecadd(&next_tx, &interval_tv, &next_tx);
	}

	if (pingflags & F_FLOOD)
		jiggle(1);

	/* While the packet is going out, ready buffer for the next
	 * packet. Use a fast but not very good random number generator.
	 */
	if (pingflags & F_PING_RANDOM)
		rnd_fill();
}


static void
pr_pack_sub(int cc,
	    char *addr,
	    int seqno,
	    int dupflag,
	    int ttl,
	    double triptime)
{
	jiggle_flush(1);

	if (pingflags & F_FLOOD)
		return;

	(void)printf("%d bytes from %s: icmp_seq=%u", cc, addr, seqno);
	if (dupflag)
		(void)printf(" DUP!");
	(void)printf(" ttl=%d", ttl);
	if (pingflags & (F_TIMING|F_TIMING64)) {
		const unsigned int prec = (pingflags & F_TIMING64) != 0 ? 6 : 3;

		(void)printf(" time=%.*f ms", prec, triptime*1000.0);
	}

	/*
	 * Send beep to stderr, since that's more likely than stdout
	 * to go to a terminal..
	 */
	if (pingflags & F_AUDIBLE && !dupflag)
		(void)fprintf(stderr,"\a");
}


/*
 * Print out the packet, if it came from us.  This logic is necessary
 * because ALL readers of the ICMP socket get a copy of ALL ICMP packets
 * which arrive ('tis only fair).  This permits multiple copies of this
 * program to be run without having intermingled output (or statistics!).
 */
static void
pr_pack(u_char *buf,
	int tot_len,
	struct sockaddr_in *from)
{
	struct ip *ip;
	struct icmp *icp;
	int i, j, net_len;
	u_char *cp;
	static int old_rrlen;
	static char old_rr[MAX_IPOPTLEN];
	int hlen, dupflag = 0, dumped;
	double triptime = 0.0;
#define PR_PACK_SUB() {if (!dumped) {			\
	dumped = 1;					\
	pr_pack_sub(net_len, inet_ntoa(from->sin_addr),	\
		    ntohs((u_int16_t)icp->icmp_seq),	\
		    dupflag, ip->ip_ttl, triptime);}}

	/* Check the IP header */
	ip = (struct ip *) buf;
	hlen = ip->ip_hl << 2;
	if (tot_len < hlen + ICMP_MINLEN) {
		if (pingflags & F_VERBOSE) {
			jiggle_flush(1);
			(void)printf("packet too short (%d bytes) from %s\n",
				     tot_len, inet_ntoa(from->sin_addr));
		}
		return;
	}

	/* Now the ICMP part */
	dumped = 0;
	net_len = tot_len - hlen;
	icp = (struct icmp *)(buf + hlen);
	if (icp->icmp_type == ICMP_ECHOREPLY
	    && icp->icmp_id == ident) {

		if (icp->icmp_seq == htons((u_int16_t)(ntransmitted-1)))
			lastrcvd = 1;
		last_rx = now;
		if (first_rx.tv_sec == 0)
			first_rx = last_rx;
		nreceived++;
		if (pingflags & (F_TIMING|F_TIMING64)) {
			struct timespec tv;

			if (pingflags & F_TIMING) {
				struct tv32 tv32;

				(void)memcpy(&tv32, icp->icmp_data, sizeof(tv32));
				tv.tv_sec = (uint32_t)ntohl(tv32.tv32_sec);
				tv.tv_nsec = ntohl(tv32.tv32_usec) * 1000;
			} else if (pingflags & F_TIMING64)
				(void)memcpy(&tv, icp->icmp_data, sizeof(tv));
			else
				memset(&tv, 0, sizeof(tv));	/* XXX: gcc */

			triptime = diffsec(&last_rx, &tv);
			tsum += triptime;
			tsumsq += triptime * triptime;
			if (triptime < tmin)
				tmin = triptime;
			if (triptime > tmax)
				tmax = triptime;
		}

		if (TST(ntohs((u_int16_t)icp->icmp_seq))) {
			nrepeats++, nreceived--;
			dupflag=1;
		} else {
			SET(ntohs((u_int16_t)icp->icmp_seq));
		}

		if (tot_len != opack_ip->ip_len) {
			PR_PACK_SUB();
			switch (opack_ip->ip_len - tot_len) {
			case MAX_IPOPTLEN:
				if ((pongflags & F_RECORD_ROUTE) != 0)
					break;
				if ((pingflags & F_RECORD_ROUTE) == 0)
					goto out;
				pongflags |= F_RECORD_ROUTE;
				(void)printf("\nremote host does not "
				    "support record route");
				break;
			case 8:
				if ((pongflags & F_SOURCE_ROUTE) != 0)
					break;
				if ((pingflags & F_SOURCE_ROUTE) == 0)
					goto out;
				pongflags |= F_SOURCE_ROUTE;
				(void)printf("\nremote host does not "
				    "support source route");
				break;
			default:
			out:
				(void)printf("\nwrong total length %d "
				    "instead of %d", tot_len, opack_ip->ip_len);
				break;
			}
		}

		if (!dupflag) {
			static u_int16_t last_seqno = 0xffff;
			u_int16_t seqno = ntohs((u_int16_t)icp->icmp_seq);
			u_int16_t gap = seqno - (last_seqno + 1);
			if (gap > 0 && gap < 0x8000 &&
			    (pingflags & F_VERBOSE)) {
				(void)printf("[*** sequence gap of %u "
				    "packets from %u ... %u ***]\n", gap,
				    (u_int16_t) (last_seqno + 1),
				    (u_int16_t) (seqno - 1));
				if (pingflags & F_QUIET)
					summary(0);
			}

			if (gap < 0x8000)
				last_seqno = seqno;
		}

		if (pingflags & F_QUIET)
			return;

		if (!(pingflags & F_FLOOD))
			PR_PACK_SUB();

		/* check the data */
		if ((size_t)(tot_len - hlen) >
		    offsetof(struct icmp, icmp_data) + datalen
		    && !(pingflags & F_PING_RANDOM)
		    && memcmp(icp->icmp_data + phdrlen,
			    opack_icmp.icmp_data + phdrlen,
			    datalen - phdrlen)) {
			for (i = phdrlen; i < datalen; i++) {
				if (icp->icmp_data[i] !=
				    opack_icmp.icmp_data[i])
					break;
			}
			PR_PACK_SUB();
			(void)printf("\nwrong data byte #%d should have been"
				     " %#x but was %#x", i - phdrlen,
				     (u_char)opack_icmp.icmp_data[i],
				     (u_char)icp->icmp_data[i]);
			for (i = phdrlen; i < datalen; i++) {
				if ((i % 16) == 0)
					(void)printf("\n\t");
				(void)printf("%2x ",(u_char)icp->icmp_data[i]);
			}
		}

	} else {
		if (!pr_icmph(icp, from, net_len))
			return;
		dumped = 2;
	}

	/* Display any IP options */
	cp = buf + sizeof(struct ip);
	while (hlen > (int)sizeof(struct ip)) {
		switch (*cp) {
		case IPOPT_EOL:
			hlen = 0;
			break;
		case IPOPT_LSRR:
			hlen -= 2;
			j = *++cp;
			++cp;
			j -= IPOPT_MINOFF;
			if (j <= 0)
				continue;
			if (dumped <= 1) {
				j = ((j+3)/4)*4;
				hlen -= j;
				cp += j;
				break;
			}
			PR_PACK_SUB();
			(void)printf("\nLSRR: ");
			for (;;) {
				pr_saddr(cp);
				cp += 4;
				hlen -= 4;
				j -= 4;
				if (j <= 0)
					break;
				(void)putchar('\n');
			}
			break;
		case IPOPT_RR:
			j = *++cp;	/* get length */
			i = *++cp;	/* and pointer */
			hlen -= 2;
			if (i > j)
				i = j;
			i -= IPOPT_MINOFF;
			if (i <= 0)
				continue;
			if (dumped <= 1) {
				if (i == old_rrlen
				    && !memcmp(cp, old_rr, i)) {
					if (dumped)
					    (void)printf("\t(same route)");
					j = ((i+3)/4)*4;
					hlen -= j;
					cp += j;
					break;
				}
				old_rrlen = i;
				(void) memcpy(old_rr, cp, i);
			}
			if (!dumped) {
				jiggle_flush(1);
				(void)printf("RR: ");
				dumped = 1;
			} else {
				(void)printf("\nRR: ");
			}
			for (;;) {
				pr_saddr(cp);
				cp += 4;
				hlen -= 4;
				i -= 4;
				if (i <= 0)
					break;
				(void)putchar('\n');
			}
			break;
		case IPOPT_NOP:
			if (dumped <= 1)
				break;
			PR_PACK_SUB();
			(void)printf("\nNOP");
			break;
		default:
			PR_PACK_SUB();
			(void)printf("\nunknown option 0x%x", *cp);
			break;
		}
		hlen--;
		cp++;
	}

	if (dumped) {
		(void)putchar('\n');
		(void)fflush(stdout);
	} else {
		jiggle(-1);
	}
}


/* Compute the IP checksum
 *	This assumes the packet is less than 32K long.
 */
static u_int16_t
in_cksum(u_int16_t *p, u_int len)
{
	u_int32_t sum = 0;
	int nwords = len >> 1;

	while (nwords-- != 0)
		sum += *p++;

	if (len & 1) {
		union {
			u_int16_t w;
			u_int8_t c[2];
		} u;
		u.c[0] = *(u_char *)p;
		u.c[1] = 0;
		sum += u.w;
	}

	/* end-around-carry */
	sum = (sum >> 16) + (sum & 0xffff);
	sum += (sum >> 16);
	return (~sum);
}


/*
 * compute the difference of two timespecs in seconds
 */
static double
diffsec(struct timespec *timenow,
	struct timespec *then)
{
	if (timenow->tv_sec == 0)
		return -1;
	return (timenow->tv_sec - then->tv_sec)
	    * 1.0 + (timenow->tv_nsec - then->tv_nsec) / 1000000000.0;
}


#if 0
static void
timespecadd(struct timespec *t1,
	   struct timespec *t2)
{

	t1->tv_sec += t2->tv_sec;
	if ((t1->tv_nsec += t2->tv_nsec) >= 1000000000) {
		t1->tv_sec++;
		t1->tv_nsec -= 1000000000;
	}
}
#endif


static void
sec_to_timespec(const double sec, struct timespec *tp)
{
	tp->tv_sec = sec;
	tp->tv_nsec = (sec - tp->tv_sec) * 1000000000.0;
}


static double
timespec_to_sec(const struct timespec *tp)
{
	return tp->tv_sec + tp->tv_nsec / 1000000000.0;
}


/*
 * Print statistics.
 * Heavily buffered STDIO is used here, so that all the statistics
 * will be written with 1 sys-write call.  This is nice when more
 * than one copy of the program is running on a terminal;  it prevents
 * the statistics output from becomming intermingled.
 */
static void
summary(int header)
{
	jiggle_flush(1);

	if (header)
		(void)printf("\n----%s PING Statistics----\n", hostname);
	(void)printf("%d packets transmitted, ", ntransmitted);
	(void)printf("%d packets received, ", nreceived);
	if (nrepeats)
		(void)printf("+%d duplicates, ", nrepeats);
	if (ntransmitted) {
		if (nreceived > ntransmitted)
			(void)printf("-- somebody's duplicating packets!");
		else
			(void)printf("%.1f%% packet loss",
				     (((ntransmitted-nreceived)*100.0) /
					    ntransmitted));
	}
	(void)printf("\n");
	if (nreceived && (pingflags & (F_TIMING|F_TIMING64))) {
		double n = nreceived + nrepeats;
		double avg = (tsum / n);
		double variance = 0.0;
		const unsigned int prec = (pingflags & F_TIMING64) != 0 ? 6 : 3;
		if (n>1)
			variance = (tsumsq - n*avg*avg) /(n-1);

		(void)printf("round-trip min/avg/max/stddev = "
			"%.*f/%.*f/%.*f/%.*f ms\n",
			prec, tmin * 1000.0,
			prec, avg * 1000.0,
			prec, tmax * 1000.0,
			prec, sqrt(variance) * 1000.0);
		if (pingflags & F_FLOOD) {
			double r = diffsec(&last_rx, &first_rx);
			double t = diffsec(&last_tx, &first_tx);
			if (r == 0)
				r = 0.0001;
			if (t == 0)
				t = 0.0001;
			(void)printf("  %.1f packets/sec sent, "
				     " %.1f packets/sec received\n",
				     ntransmitted/t, nreceived/r);
		}
	}
}


/*
 * Print statistics when SIGINFO is received.
 */
/* ARGSUSED */
static void
prtsig(int dummy)
{

	summary(0);
#ifndef SIGINFO
	(void)signal(SIGQUIT, prtsig);
#endif
}


/*
 * On the first SIGINT, allow any outstanding packets to dribble in
 */
static void
prefinish(int sig)
{
	if (lastrcvd			/* quit now if caught up */
	    || nreceived == 0)		/* or if remote is dead */
		finish(0);

	(void)signal(sig, finish);	/* do this only the 1st time */

	if (npackets > ntransmitted)	/* let the normal limit work */
		npackets = ntransmitted;
}

/*
 * Print statistics and give up.
 */
/* ARGSUSED */
static void
finish(int dummy)
{
#ifdef SIGINFO
	(void)signal(SIGINFO, SIG_DFL);
#else
	(void)signal(SIGQUIT, SIG_DFL);
#endif

	summary(1);
	exit(nreceived > 0 ? 0 : 2);
}

static void
blocksignals(void)
{
	if (sigprocmask(SIG_SETMASK, &blockmask, NULL) == -1) {
		err(EXIT_FAILURE, "blocksignals: sigprocmask");
	}
}

static void
enablesignals(void)
{
	if (sigprocmask(SIG_SETMASK, &enablemask, NULL) == -1) {
		err(EXIT_FAILURE, "enablesignals: sigprocmask");
	}
}


static int				/* 0=do not print it */
ck_pr_icmph(struct icmp *icp,
	    struct sockaddr_in *from,
	    int cc,
	    int override)		/* 1=override VERBOSE if interesting */
{
	int	hlen;
	struct ip ipb, *ip = &ipb;
	struct icmp icp2b, *icp2 = &icp2b;
	int res;

	if (pingflags & F_VERBOSE) {
		res = 1;
		jiggle_flush(1);
	} else {
		res = 0;
	}

	(void) memcpy(ip, icp->icmp_data, sizeof(*ip));
	hlen = ip->ip_hl << 2;
	if (ip->ip_p == IPPROTO_ICMP
	    && hlen + 6 <= cc) {
		(void) memcpy(icp2, &icp->icmp_data[hlen], sizeof(*icp2));
		if (icp2->icmp_id == ident) {
			/* remember to clear route cached in kernel
			 * if this non-Echo-Reply ICMP message was for one
			 * of our packets.
			 */
			clear_cache.tv_sec = 0;

			if (!res && override
			    && (pingflags & (F_QUIET|F_SEMI_QUIET)) == 0) {
				jiggle_flush(1);
				(void)printf("%d bytes from %s: ",
					     cc, pr_addr(&from->sin_addr));
				res = 1;
			}
		}
	}

	return res;
}


/*
 *  Print a descriptive string about an ICMP header other than an echo reply.
 */
static int				/* 0=printed nothing */
pr_icmph(struct icmp *icp,
	 struct sockaddr_in *from,
	 int cc)
{
	switch (icp->icmp_type ) {
	case ICMP_UNREACH:
		if (!ck_pr_icmph(icp, from, cc, 1))
			return 0;
		switch (icp->icmp_code) {
		case ICMP_UNREACH_NET:
			(void)printf("Destination Net Unreachable");
			break;
		case ICMP_UNREACH_HOST:
			(void)printf("Destination Host Unreachable");
			break;
		case ICMP_UNREACH_PROTOCOL:
			(void)printf("Destination Protocol Unreachable");
			break;
		case ICMP_UNREACH_PORT:
			(void)printf("Destination Port Unreachable");
			break;
		case ICMP_UNREACH_NEEDFRAG:
			(void)printf("frag needed and DF set.  Next MTU=%d",
			       ntohs(icp->icmp_nextmtu));
			break;
		case ICMP_UNREACH_SRCFAIL:
			(void)printf("Source Route Failed");
			break;
		case ICMP_UNREACH_NET_UNKNOWN:
			(void)printf("Unreachable unknown net");
			break;
		case ICMP_UNREACH_HOST_UNKNOWN:
			(void)printf("Unreachable unknown host");
			break;
		case ICMP_UNREACH_ISOLATED:
			(void)printf("Unreachable host isolated");
			break;
		case ICMP_UNREACH_NET_PROHIB:
			(void)printf("Net prohibited access");
			break;
		case ICMP_UNREACH_HOST_PROHIB:
			(void)printf("Host prohibited access");
			break;
		case ICMP_UNREACH_TOSNET:
			(void)printf("Bad TOS for net");
			break;
		case ICMP_UNREACH_TOSHOST:
			(void)printf("Bad TOS for host");
			break;
		case 13:
			(void)printf("Communication prohibited");
			break;
		case 14:
			(void)printf("Host precedence violation");
			break;
		case 15:
			(void)printf("Precedence cutoff");
			break;
		default:
			(void)printf("Bad Destination Unreachable Code: %d",
				     icp->icmp_code);
			break;
		}
		/* Print returned IP header information */
		pr_retip(icp, cc);
		break;

	case ICMP_SOURCEQUENCH:
		if (!ck_pr_icmph(icp, from, cc, 1))
			return 0;
		(void)printf("Source Quench");
		pr_retip(icp, cc);
		break;

	case ICMP_REDIRECT:
		if (!ck_pr_icmph(icp, from, cc, 1))
			return 0;
		switch (icp->icmp_code) {
		case ICMP_REDIRECT_NET:
			(void)printf("Redirect Network");
			break;
		case ICMP_REDIRECT_HOST:
			(void)printf("Redirect Host");
			break;
		case ICMP_REDIRECT_TOSNET:
			(void)printf("Redirect Type of Service and Network");
			break;
		case ICMP_REDIRECT_TOSHOST:
			(void)printf("Redirect Type of Service and Host");
			break;
		default:
			(void)printf("Redirect--Bad Code: %d", icp->icmp_code);
			break;
		}
		(void)printf(" New router addr: %s",
			     pr_addr(&icp->icmp_hun.ih_gwaddr));
		pr_retip(icp, cc);
		break;

	case ICMP_ECHO:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Echo Request: ID=%d seq=%d",
			     ntohs(icp->icmp_id), ntohs(icp->icmp_seq));
		break;

	case ICMP_ECHOREPLY:
		/* displaying other's pings is too noisey */
#if 0
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Echo Reply: ID=%d seq=%d",
			     ntohs(icp->icmp_id), ntohs(icp->icmp_seq));
		break;
#else
		return 0;
#endif

	case ICMP_ROUTERADVERT:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Router Discovery Advert");
		break;

	case ICMP_ROUTERSOLICIT:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Router Discovery Solicit");
		break;

	case ICMP_TIMXCEED:
		if (!ck_pr_icmph(icp, from, cc, 1))
			return 0;
		switch (icp->icmp_code ) {
		case ICMP_TIMXCEED_INTRANS:
			(void)printf("Time To Live exceeded");
			break;
		case ICMP_TIMXCEED_REASS:
			(void)printf("Frag reassembly time exceeded");
			break;
		default:
			(void)printf("Time exceeded, Bad Code: %d",
				     icp->icmp_code);
			break;
		}
		pr_retip(icp, cc);
		break;

	case ICMP_PARAMPROB:
		if (!ck_pr_icmph(icp, from, cc, 1))
			return 0;
		(void)printf("Parameter problem: pointer = 0x%02x",
			     icp->icmp_hun.ih_pptr);
		pr_retip(icp, cc);
		break;

	case ICMP_TSTAMP:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Timestamp");
		break;

	case ICMP_TSTAMPREPLY:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Timestamp Reply");
		break;

	case ICMP_IREQ:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Information Request");
		break;

	case ICMP_IREQREPLY:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Information Reply");
		break;

	case ICMP_MASKREQ:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Address Mask Request");
		break;

	case ICMP_MASKREPLY:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Address Mask Reply");
		break;

	default:
		if (!ck_pr_icmph(icp, from, cc, 0))
			return 0;
		(void)printf("Bad ICMP type: %d", icp->icmp_type);
		if (pingflags & F_VERBOSE)
			pr_iph(icp, cc);
	}

	return 1;
}


/*
 *  Print an IP header with options.
 */
static void
pr_iph(struct icmp *icp,
       int cc)
{
	int	hlen;
	u_char	*cp;
	struct ip __aligned(4) ipb;
	struct ip *ip = &ipb;

	(void) memcpy(ip, icp->icmp_data, sizeof(*ip));

	hlen = ip->ip_hl << 2;
	cp = (u_char *) &icp->icmp_data[20];	/* point to options */

	(void)printf("\n Vr HL TOS  Len   ID Flg  off TTL Pro  cks      Src	     Dst\n");
	(void)printf("  %1x  %1x  %02x %04x %04x",
		     ip->ip_v, ip->ip_hl, ip->ip_tos, ip->ip_len, ip->ip_id);
	(void)printf("   %1x %04x",
		     ((ip->ip_off)&0xe000)>>13, (ip->ip_off)&0x1fff);
	(void)printf("  %02x  %02x %04x",
		     ip->ip_ttl, ip->ip_p, ip->ip_sum);
	(void)printf(" %15s ",
		     inet_ntoa(*(struct in_addr *)&ip->ip_src.s_addr));
	(void)printf(" %s ", inet_ntoa(*(struct in_addr *)&ip->ip_dst.s_addr));
	/* dump any option bytes */
	while (hlen-- > 20 && cp < (u_char*)icp+cc) {
		(void)printf("%02x", *cp++);
	}
}

/*
 * Print an ASCII host address starting from a string of bytes.
 */
static void
pr_saddr(u_char *cp)
{
	n_long l;
	struct in_addr addr;

	l = (u_char)*++cp;
	l = (l<<8) + (u_char)*++cp;
	l = (l<<8) + (u_char)*++cp;
	l = (l<<8) + (u_char)*++cp;
	addr.s_addr = htonl(l);
	(void)printf("\t%s", (l == 0) ? "0.0.0.0" : pr_addr(&addr));
}


/*
 *  Return an ASCII host address
 *  as a dotted quad and optionally with a hostname
 */
static char *
pr_addr(struct in_addr *addr)		/* in network order */
{
	struct	hostent	*hp;
	static	char buf[MAXHOSTNAMELEN+4+16+1];

	if ((pingflags & F_NUMERIC)
	    || !(hp = gethostbyaddr((char *)addr, sizeof(*addr), AF_INET))) {
		(void)snprintf(buf, sizeof(buf), "%s", inet_ntoa(*addr));
	} else {
		(void)snprintf(buf, sizeof(buf), "%s (%s)", hp->h_name,
		    inet_ntoa(*addr));
	}

	return buf;
}

/*
 *  Dump some info on a returned (via ICMP) IP packet.
 */
static void
pr_retip(struct icmp *icp,
	 int cc)
{
	int	hlen;
	u_char	*cp;
	struct ip ipb, *ip = &ipb;

	(void) memcpy(ip, icp->icmp_data, sizeof(*ip));

	if (pingflags & F_VERBOSE)
		pr_iph(icp, cc);

	hlen = ip->ip_hl << 2;
	cp = (u_char *) &icp->icmp_data[hlen];

	if (ip->ip_p == IPPROTO_TCP) {
		if (pingflags & F_VERBOSE)
			(void)printf("\n  TCP: from port %u, to port %u",
				     (*cp*256+*(cp+1)), (*(cp+2)*256+*(cp+3)));
	} else if (ip->ip_p == IPPROTO_UDP) {
		if (pingflags & F_VERBOSE)
			(void)printf("\n  UDP: from port %u, to port %u",
				     (*cp*256+*(cp+1)), (*(cp+2)*256+*(cp+3)));
	} else if (ip->ip_p == IPPROTO_ICMP) {
		struct icmp icp2;
		(void) memcpy(&icp2, cp, sizeof(icp2));
		if (icp2.icmp_type == ICMP_ECHO) {
			if (pingflags & F_VERBOSE)
				(void)printf("\n  ID=%u icmp_seq=%u",
					     ntohs((u_int16_t)icp2.icmp_id),
					     ntohs((u_int16_t)icp2.icmp_seq));
			else
				(void)printf(" for icmp_seq=%u",
					     ntohs((u_int16_t)icp2.icmp_seq));
		}
	}
}

static void
fill(void)
{
	int i, j, k;
	char *cp;
	int pat[16];

	for (cp = fill_pat; *cp != '\0'; cp++) {
		if (!isxdigit((unsigned char)*cp))
			break;
	}
	if (cp == fill_pat || *cp != '\0' || (cp-fill_pat) > 16*2) {
		(void)fflush(stdout);
		errx(EXIT_FAILURE, "\"-p %s\": patterns must be specified with"
		     " 1-32 hex digits\n",
		     fill_pat);
	}

	i = sscanf(fill_pat,
		   "%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x%2x",
		    &pat[0], &pat[1], &pat[2], &pat[3],
		    &pat[4], &pat[5], &pat[6], &pat[7],
		    &pat[8], &pat[9], &pat[10], &pat[11],
		    &pat[12], &pat[13], &pat[14], &pat[15]);

	for (k = phdrlen, j = 0; k < datalen; k++) {
		opack_icmp.icmp_data[k] = pat[j];
		if (++j >= i)
			j = 0;
	}

	if (!(pingflags & F_QUIET)) {
		(void)printf("PATTERN: 0x");
		for (j=0; j<i; j++)
			(void)printf("%02x",
				     (u_char)opack_icmp.icmp_data[phdrlen + j]);
		(void)printf("\n");
	}

}


static void
rnd_fill(void)
{
	static u_int32_t rnd;
	int i;

	for (i = phdrlen; i < datalen; i++) {
		rnd = (3141592621U * rnd + 663896637U);
		opack_icmp.icmp_data[i] = rnd>>24;
	}
}


static void
gethost(const char *arg,
	const char *name,
	struct sockaddr_in *sa,
	char *realname,
	int realname_len)
{
	struct hostent *hp;

	(void)memset(sa, 0, sizeof(*sa));
	sa->sin_family = AF_INET;
	sa->sin_len = sizeof(struct sockaddr_in);

	/* If it is an IP address, try to convert it to a name to
	 * have something nice to display.
	 */
	if (inet_aton(name, &sa->sin_addr) != 0) {
		if (realname) {
			if (pingflags & F_NUMERIC)
				hp = 0;
			else
				hp = gethostbyaddr((char *)&sa->sin_addr,
				    sizeof(sa->sin_addr), AF_INET);
			(void)strlcpy(realname, hp ? hp->h_name : name,
			    realname_len);
		}
		return;
	}

	hp = gethostbyname(name);
	if (!hp)
		errx(EXIT_FAILURE, "Cannot resolve \"%s\" (%s)",
		    name, hstrerror(h_errno));

	if (hp->h_addrtype != AF_INET)
		errx(EXIT_FAILURE, "%s only supported with IP", arg);

	(void)memcpy(&sa->sin_addr, hp->h_addr, sizeof(sa->sin_addr));

	if (realname)
		(void)strlcpy(realname, hp->h_name, realname_len);
}


static void
usage(void)
{
#ifdef IPSEC
#ifdef IPSEC_POLICY_IPSEC
#define IPSECOPT	"\n     [-E policy] "
#else
#define IPSECOPT	"\n     [-AE] "
#endif /*IPSEC_POLICY_IPSEC*/
#else
#define IPSECOPT	""
#endif /*IPSEC*/

	(void)fprintf(stderr, "usage: \n"
	    "%s [-aCDdfLnoPQqRrv] [-c count] [-g gateway] [-h host]"
	    " [-I addr] [-i interval]\n"
	    "     [-l preload] [-p pattern] [-s size] [-T ttl] [-t tos]"
	    " [-w maxwait] " IPSECOPT "host\n",
	    getprogname());
	exit(1);
}