/*
 * 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.
 *
 * @(#) Copyright (c) 1989, 1993 The Regents of the University of California.  All rights reserved.
 * @(#)ping.c   8.1 (Berkeley) 6/5/93
 * $FreeBSD: src/sbin/ping/ping.c,v 1.111 2007/05/21 14:38:45 cognet Exp $
 */

/*
 *                      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 <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 MAXPAYLOAD      (IP_MAXPACKET - MAXIPLEN - ICMP_MINLEN)
#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 {
        int32_t tv32_sec;
        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
#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;

/* 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 */
long interval = 1000000;        /* interval between packets, usec */
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;

int
main(int argc, char **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] __aligned(4);
        char *ep, *source, *target, *payload;
        struct hostent *hp;
        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;

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

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

        alarmtimeout = df = preload = tos = 0;

        outpack = outpackhdr + sizeof(struct ip);
        while ((ch = getopt(argc, argv, "Aac:DdfG:g:h:I:i:Ll:M:m:nop:QqRrS:s:T:t:vW:z:")) != -1) {
                switch(ch) {
                case 'A':
                        options |= F_MISSED;
                        break;
                case 'a':
                        options |= F_AUDIBLE;
                        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, 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);
                        if (uid != 0 && ultmp > DEFDATALEN) {
                                errno = EPERM;
                                err(EX_NOPERM,
                                    "packet size too large: %lu > %u",
                                    ultmp, DEFDATALEN);
                        }
                        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);
                        if (uid != 0 && ultmp > DEFDATALEN) {
                                errno = EPERM;
                                err(EX_NOPERM,
                                    "packet size too large: %lu > %u",
                                    ultmp, DEFDATALEN);
                        }
                        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);
                        if (uid != 0 && ultmp > DEFDATALEN) {
                                errno = EPERM;
                                err(EX_NOPERM,
                                    "packet size too large: %lu > %u",
                                    ultmp, DEFDATALEN);
                        }
                        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) * 1000000.0; /* sec -> usec */
                        if (*ep || ep == optarg ||
                            t > (double)LONG_MAX || t <= 0)
                                errx(EX_USAGE, "invalid timing interval: `%s'",
                                    optarg);
                        options |= F_INTERVAL;
                        interval = (long)t;
                        if (uid != 0 && interval < 2000 /* 2 ms */) {
                                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 != 0) {
                                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;
                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);
                        if (ultmp > MAXPAYLOAD)
                                errx(EX_USAGE,
                                    "packet size too large: %lu > %lu",
                                    ultmp, MAXPAYLOAD);
                        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((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 || t <= 0)
                                errx(EX_USAGE, "invalid wait timeout: `%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 (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))
                        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))
                        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));
                        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);
                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 (options & F_SO_DEBUG)
                setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&hold,
                    sizeof(hold));
        if (options & F_SO_DONTROUTE)
                setsockopt(s, SOL_SOCKET, SO_DONTROUTE, (char *)&hold,
                    sizeof(hold));
        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 ? htons(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;
        setsockopt(s, SOL_SOCKET, SO_RCVBUF, (char *)&hold,
            sizeof(hold));
        if (uid == 0)
                setsockopt(s, SOL_SOCKET, SO_SNDBUF, (char *)&hold,
                    sizeof(hold));

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

        } else {
                if (sweepmax)
                        printf("PING %s: (%d ... %d) data bytes\n",
                            hostname, sweepmin, sweepmax);
                else
                        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 = &from;
        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;
#ifdef SO_TIMESTAMP
        msg.msg_control = ctrl;
#endif
        iov.iov_base = (char *)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();
        }
        gettimeofday(&last, NULL);

        if (options & F_FLOOD) {
                intvl.tv_sec = 0;
                intvl.tv_usec = 10000;
        } else {
                intvl.tv_sec = interval / 1000000;
                intvl.tv_usec = interval % 1000000;
        }

        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);
                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) {
                                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;
                                }
                        }
                        gettimeofday(&last, NULL);
                        if (ntransmitted - nreceived - 1 > nmissedmax) {
                                nmissedmax = ntransmitted - nreceived - 1;
                                if (options & F_MISSED)
                                        write(STDOUT_FILENO, &BBELL, 1);
                        }
                }
        }
        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(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) {
                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 = htons(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)
                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(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 >= (int)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)
                        write(STDOUT_FILENO, &BSPACE, 1);
                else {
                        printf("%d bytes from %s: icmp_seq=%u", cc,
                           inet_ntoa(*(struct in_addr *)&from->sin_addr.s_addr),
                           seq);
                        printf(" ttl=%d", ip->ip_ttl);
                        if (timing)
                                printf(" time=%.3f ms", triptime);
                        if (dupflag)
                                printf(" (DUP!)");
                        if (options & F_AUDIBLE)
                                write(STDOUT_FILENO, &BBELL, 1);
                        if (options & F_MASK) {
                                /* Just prentend this cast isn't ugly */
                                printf(" mask=%s",
                                        pr_addr(*(struct in_addr *)&(icp->icmp_mask)));
                        }
                        if (options & F_TIME) {
                                printf(" tso=%s", pr_ntime(icp->icmp_otime));
                                printf(" tsr=%s", pr_ntime(icp->icmp_rtime));
                                printf(" tst=%s", pr_ntime(icp->icmp_ttime));
                        }
                        if (recv_len != send_len) {
                                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) {
        printf("\nwrong data byte #%d should be 0x%x but was 0x%x",
            i, *dp, *cp);
                                        printf("\ncp:");
                                        cp = (u_char*)&icp->icmp_data[0];
                                        for (i = 0; i < datalen; ++i, ++cp) {
                                                if ((i % 16) == 8)
                                                        printf("\n\t");
                                                printf("%2x ", *cp);
                                        }
                                        printf("\ndp:");
                                        cp = &outpack[ICMP_MINLEN];
                                        for (i = 0; i < datalen; ++i, ++cp) {
                                                if ((i % 16) == 8)
                                                        printf("\n\t");
                                                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))) {
                    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:
                        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)
                                                printf("\t0.0.0.0");
                                        else
                                                printf("\t%s", pr_addr(ina));
                                        hlen -= INADDR_LEN;
                                        cp += INADDR_LEN - 1;
                                        j -= INADDR_LEN;
                                        if (j < INADDR_LEN)
                                                break;
                                        putchar('\n');
                                }
                        } else
                                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)) {
                                printf("\t(same route)");
                                hlen -= i;
                                cp += i;
                                break;
                        }
                        old_rrlen = i;
                        bcopy((char *)cp, old_rr, i);
                        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)
                                                printf("\t0.0.0.0");
                                        else
                                                printf("\t%s", pr_addr(ina));
                                        hlen -= INADDR_LEN;
                                        cp += INADDR_LEN - 1;
                                        i -= INADDR_LEN;
                                        if (i < INADDR_LEN)
                                                break;
                                        putchar('\n');
                                }
                        } else
                                printf("\t(truncated route)");
                        break;
                case IPOPT_NOP:
                        printf("\nNOP");
                        break;
                default:
                        printf("\nunknown option %x", *cp);
                        break;
                }
        if (!(options & F_FLOOD)) {
                putchar('\n');
                fflush(stdout);
        }
}

/*
 * in_cksum --
 *      Checksum routine for Internet Protocol family headers (C Version)
 */
u_short
in_cksum(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(struct timeval *out, struct timeval *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(int sig __unused)
{

        siginfo_p = 1;
}

static void
check_status(void)
{

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

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

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

        switch(icp->icmp_type) {
        case ICMP_ECHOREPLY:
                printf("Echo Reply\n");
                /* XXX ID + Seq + Data */
                break;
        case ICMP_UNREACH:
                switch(icp->icmp_code) {
                case ICMP_UNREACH_NET:
                        printf("Destination Net Unreachable\n");
                        break;
                case ICMP_UNREACH_HOST:
                        printf("Destination Host Unreachable\n");
                        break;
                case ICMP_UNREACH_PROTOCOL:
                        printf("Destination Protocol Unreachable\n");
                        break;
                case ICMP_UNREACH_PORT:
                        printf("Destination Port Unreachable\n");
                        break;
                case ICMP_UNREACH_NEEDFRAG:
                        printf("frag needed and DF set (MTU %d)\n",
                                        ntohs(icp->icmp_nextmtu));
                        break;
                case ICMP_UNREACH_SRCFAIL:
                        printf("Source Route Failed\n");
                        break;
                case ICMP_UNREACH_FILTER_PROHIB:
                        printf("Communication prohibited by filter\n");
                        break;
                default:
                        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:
                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:
                        printf("Redirect Network");
                        break;
                case ICMP_REDIRECT_HOST:
                        printf("Redirect Host");
                        break;
                case ICMP_REDIRECT_TOSNET:
                        printf("Redirect Type of Service and Network");
                        break;
                case ICMP_REDIRECT_TOSHOST:
                        printf("Redirect Type of Service and Host");
                        break;
                default:
                        printf("Redirect, Bad Code: %d", icp->icmp_code);
                        break;
                }
                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:
                printf("Echo Request\n");
                /* XXX ID + Seq + Data */
                break;
        case ICMP_TIMXCEED:
                switch(icp->icmp_code) {
                case ICMP_TIMXCEED_INTRANS:
                        printf("Time to live exceeded\n");
                        break;
                case ICMP_TIMXCEED_REASS:
                        printf("Frag reassembly time exceeded\n");
                        break;
                default:
                        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:
                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:
                printf("Timestamp\n");
                /* XXX ID + Seq + 3 timestamps */
                break;
        case ICMP_TSTAMPREPLY:
                printf("Timestamp Reply\n");
                /* XXX ID + Seq + 3 timestamps */
                break;
        case ICMP_IREQ:
                printf("Information Request\n");
                /* XXX ID + Seq */
                break;
        case ICMP_IREQREPLY:
                printf("Information Reply\n");
                /* XXX ID + Seq */
                break;
        case ICMP_MASKREQ:
                printf("Address Mask Request\n");
                break;
        case ICMP_MASKREPLY:
                printf("Address Mask Reply\n");
                break;
        case ICMP_ROUTERADVERT:
                printf("Router Advertisement\n");
                break;
        case ICMP_ROUTERSOLICIT:
                printf("Router Solicitation\n");
                break;
        default:
                printf("Bad ICMP type: %d\n", icp->icmp_type);
        }
}

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

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

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

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

        if ((options & F_NUMERIC) ||
            !(hp = gethostbyaddr(&ina, 4, AF_INET)))
                return inet_ntoa(ina);
        else
                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(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)
                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)
                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;

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

        return (buf);
}

static void
fill(char *bp, char *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)) {
                printf("PATTERN: 0x");
                for (jj = 0; jj < ii; ++jj)
                        printf("%02x", bp[jj] & 0xFF);
                printf("\n");
        }
}

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] [-c count] [-G sweepmaxsize] [-g sweepminsize]",
"            [-h sweepincrsize] [-i wait] [-l preload] [-M mask | time] [-m ttl]",
"            [-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] [-p pattern] [-S src_addr]",
"            [-s packetsize] [-T ttl] [-t timeout] [-W waittime]",
"            [-z tos] mcast-group");
        exit(EX_USAGE);
}