root/sbin/ping6/ping6.c
/*      $NetBSD: ping6.c,v 1.108 2025/07/11 22:19:53 andvar Exp $       */
/*      $KAME: ping6.c,v 1.164 2002/11/16 14:05:37 itojun Exp $ */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * 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 project 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 PROJECT 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 PROJECT 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.
 */

/*      BSDI    ping.c,v 2.3 1996/01/21 17:56:50 jch Exp        */

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

#if 0
#ifndef lint
static 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 */
#else
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: ping6.c,v 1.108 2025/07/11 22:19:53 andvar Exp $");
#endif
#endif

/*
 * 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.
 */
/*
 * NOTE:
 * USE_SIN6_SCOPE_ID assumes that sin6_scope_id has the same semantics
 * as IPV6_PKTINFO.  Some people object it (sin6_scope_id specifies *link*
 * while IPV6_PKTINFO specifies *interface*.  Link is defined as collection of
 * network attached to 1 or more interfaces)
 */

#include <sys/param.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <netdb.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <math.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <poll.h>

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

#include <md5.h>

#include "prog_ops.h"

struct tv32 {
        u_int32_t tv32_sec;
        u_int32_t tv32_usec;
};

#define MAXPACKETLEN    131072
#define IP6LEN          40
#define ICMP6ECHOLEN    8       /* icmp echo header len excluding time */
#define ICMP6ECHOTMLEN sizeof(struct tv32)
#define ICMP6_NIQLEN    (ICMP6ECHOLEN + 8)
/* FQDN case, 64 bits of nonce + 32 bits ttl */
#define ICMP6_NIRLEN    (ICMP6ECHOLEN + 12)
#define EXTRA           256     /* for AH and various other headers. weird. */
#define DEFDATALEN      ICMP6ECHOTMLEN
#define MAXDATALEN      MAXPACKETLEN - IP6LEN - ICMP6ECHOLEN
#define NROUTES         9               /* number of record route slots */

#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))

#define F_FLOOD         0x0001
#define F_INTERVAL      0x0002
#define F_PINGFILLED    0x0008
#define F_QUIET         0x0010
#define F_SO_DEBUG      0x0040
#define F_VERBOSE       0x0100
#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
#define F_POLICY        0x0400
#endif
#define F_NODEADDR      0x0800
#define F_FQDN          0x1000
#define F_INTERFACE     0x2000
#define F_SRCADDR       0x4000
#define F_HOSTNAME      0x10000
#define F_FQDNOLD       0x20000
#define F_NIGROUP       0x40000
#define F_SUPTYPES      0x80000
#define F_ONCE          0x200000
#define F_NOUSERDATA    (F_NODEADDR | F_FQDN | F_FQDNOLD | F_SUPTYPES)
static u_int options;

#define DUMMY_PORT      10101

/*
 * 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 * 8192)
static int mx_dup_ck = MAX_DUP_CHK;
static char rcvd_tbl[MAX_DUP_CHK / 8];

static struct addrinfo *res;
static struct sockaddr_in6 dst; /* who to ping6 */
static struct sockaddr_in6 src; /* src addr of this packet */
static socklen_t srclen;
static int datalen = DEFDATALEN;
static int s;                           /* socket file descriptor */
static u_char outpack[MAXPACKETLEN] __aligned(sizeof(u_long));
static char BSPACE = '\b';              /* characters written for flood */
static char DOT = '.';
static char *hostname;
static int ident;                       /* 16 random bits to identify our packets */
static u_int8_t nonce[8];               /* nonce field for node information */
static int hoplimit = -1;               /* hoplimit */

/* counters */
static long npackets;                   /* max packets to transmit */
static long nreceived;                  /* # of packets we got back */
static long nrepeats;                   /* number of duplicates */
static long ntransmitted;               /* sequence # for outbound packets = #sent */
static struct timespec interval = {1, 0}; /* interval between packets */

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

/* timing */
static int timing;                      /* flag to do timing */
static double tmin = 999999999.0;       /* minimum round trip time */
static double tmax = 0.0;               /* maximum round trip time */
static double tsum = 0.0;               /* sum of all times, for doing average */
static double tsumsq = 0.0;             /* sum of all times squared, for std. dev. */
static double maxwait = 0.0;            /* maxwait for reply in ms */
static double deadline = 0.0;           /* max running time in seconds */

/* for node addresses */
static u_short naflags;

/* for ancillary data(advanced API) */
static struct msghdr smsghdr;
static struct iovec smsgiov;
static char *scmsg = 0;

static volatile sig_atomic_t seenint;
#ifdef SIGINFO
static volatile sig_atomic_t seeninfo;
#endif

__dead static void      doit(u_char *, u_int);
static void      fill(char *, char *);
static int       get_hoplim(struct msghdr *);
static int       get_pathmtu(struct msghdr *);
static struct in6_pktinfo *get_rcvpktinfo(struct msghdr *);
static void      onsignal(int);
__dead static void       onsigexit(int);
static size_t    pingerlen(void);
static void      pinger(void);
static const char *pr_addr(struct sockaddr *, int);
static void      pr_icmph(struct icmp6_hdr *, u_char *);
static void      pr_iph(struct ip6_hdr *);
static void      pr_suptypes(struct icmp6_nodeinfo *, size_t);
static void      pr_nodeaddr(struct icmp6_nodeinfo *, int);
static int       myechoreply(const struct icmp6_hdr *);
static int       mynireply(const struct icmp6_nodeinfo *);
static char *dnsdecode(const u_char **, const u_char *, const u_char *,
        char *, size_t);
static void      pr_pack(u_char *, int, struct msghdr *);
static void      pr_exthdrs(struct msghdr *);
static void      pr_ip6opt(void *);
static void      pr_rthdr(void *);
static int       pr_bitrange(u_int32_t, int, int);
static void      pr_retip(struct ip6_hdr *, u_char *);
static void      summary(void);
static void      tvsub(struct timeval *, struct timeval *);
#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
static int       setpolicy(int, char *);
#endif
static char     *nigroup(char *);
static double   timespec_to_sec(const struct timespec *tp);
static double   diffsec(struct timespec *, struct timespec *);
__dead static void       usage(void);

int
main(int argc, char *argv[])
{
        struct addrinfo hints;
        u_int i, packlen;
        long l;
        int ch, hold, preload, optval, ret_ga;
        u_char *datap, *packet;
        char *e, *target, *ifname = NULL, *gateway = NULL;
        int ip6optlen = 0;
        struct cmsghdr *scmsgp = NULL;
        u_long lsockbufsize;
        int sockbufsize = 0;
        int usepktinfo = 0;
        struct in6_pktinfo *pktinfo = NULL;
        struct ip6_rthdr *rthdr = NULL;
#ifdef IPSEC_POLICY_IPSEC
        char *policy_in = NULL;
        char *policy_out = NULL;
#endif
        double intval;
        int mflag = 0;

        /* just to be sure */
        memset(&smsghdr, 0, sizeof(smsghdr));
        memset(&smsgiov, 0, sizeof(smsgiov));

        preload = 0;
        datap = &outpack[ICMP6ECHOLEN + ICMP6ECHOTMLEN];

#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
#define ADDOPTS "P:"
#else
#define ADDOPTS
#endif

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

        while ((ch = getopt(argc, argv,
            "a:b:c:dfHg:h:I:i:l:mnNop:qS:s:tvwWx:X:" ADDOPTS)) != -1) {
#undef ADDOPTS
                switch (ch) {
                case 'a':
                {
                        char *cp;

                        options &= ~F_NOUSERDATA;
                        options |= F_NODEADDR;
                        for (cp = optarg; *cp != '\0'; cp++) {
                                switch (*cp) {
                                case 'a':
                                        naflags |= NI_NODEADDR_FLAG_ALL;
                                        break;
                                case 'c':
                                case 'C':
                                        naflags |= NI_NODEADDR_FLAG_COMPAT;
                                        break;
                                case 'l':
                                case 'L':
                                        naflags |= NI_NODEADDR_FLAG_LINKLOCAL;
                                        break;
                                case 's':
                                case 'S':
                                        naflags |= NI_NODEADDR_FLAG_SITELOCAL;
                                        break;
                                case 'g':
                                case 'G':
                                        naflags |= NI_NODEADDR_FLAG_GLOBAL;
                                        break;
                                case 'A': /* experimental. not in the spec */
#ifdef NI_NODEADDR_FLAG_ANYCAST
                                        naflags |= NI_NODEADDR_FLAG_ANYCAST;
                                        break;
#else
                                        errx(1,
"-a A is not supported on the platform");
                                        /*NOTREACHED*/
#endif
                                default:
                                        usage();
                                        /*NOTREACHED*/
                                }
                        }
                        break;
                }
                case 'b':
                        errno = 0;
                        e = NULL;
                        lsockbufsize = strtoul(optarg, &e, 10);
                        sockbufsize = lsockbufsize;
                        if (errno || !*optarg || *e ||
                            (u_long)sockbufsize != lsockbufsize)
                                errx(1, "invalid socket buffer size");
                        break;
                case 'c':
                        l = strtol(optarg, &e, 10);
                        if (l <= 0 || *optarg == '\0' || *e != '\0')
                                errx(1,
                                    "illegal number of packets -- %s", optarg);
#if INT_MAX < LONG_MAX
                        if (l > INT_MAX)
                                errx(EXIT_FAILURE,
                                    "Too many packets to count: %ld", l);
#endif
                        npackets = l;
                        break;
                case 'd':
                        options |= F_SO_DEBUG;
                        break;
                case 'f':
                        if (prog_getuid()) {
                                errno = EPERM;
                                errx(1, "Must be superuser to flood ping");
                        }
                        options |= F_FLOOD;
                        setbuf(stdout, NULL);
                        interval.tv_sec = 0;
                        interval.tv_nsec = 10 * 1000 * 1000; /* 10 ms */
                        break;
                case 'g':
                        gateway = optarg;
                        break;
                case 'H':
                        options |= F_HOSTNAME;
                        break;
                case 'h':               /* hoplimit */
                        hoplimit = strtol(optarg, &e, 10);
                        if (*optarg == '\0' || *e != '\0')
                                errx(1, "illegal hoplimit %s", optarg);
                        if (255 < hoplimit || hoplimit < -1)
                                errx(1,
                                    "illegal hoplimit -- %s", optarg);
                        break;
                case 'I':
                        ifname = optarg;
                        options |= F_INTERFACE;
#ifndef USE_SIN6_SCOPE_ID
                        usepktinfo++;
#endif
                        break;
                case 'i':               /* wait between sending packets */
                        intval = strtod(optarg, &e);
                        if (*optarg == '\0' || *e != '\0')
                                errx(1, "illegal timing interval %s", optarg);
                        if (intval < 1 && prog_getuid()) {
                                errx(1, "%s: only root may use interval < 1s",
                                    strerror(EPERM));
                        }
                        if (intval > INT_MAX/1000.0 - 1.0) {
                                errx(1, "Interval %s too large", optarg);
                        }
                        interval.tv_sec = (time_t)intval;
                        interval.tv_nsec =
                            (long)((intval - interval.tv_sec) * 1000000000);
                        if (interval.tv_sec < 0 || interval.tv_nsec < 0)
                                errx(1, "illegal timing interval %s", optarg);
                        /* less than 1/hz does not make sense */
                        if (interval.tv_sec == 0 &&
                            interval.tv_nsec < 10000000) {
                                warnx("Interval too small; raised to 0.01");
                                interval.tv_nsec = 10000000;
                        }
                        options |= F_INTERVAL;
                        break;
                case 'l':
                        if (prog_getuid()) {
                                errno = EPERM;
                                errx(1, "Must be superuser to preload");
                        }
                        l = strtol(optarg, &e, 10);
                        if (l < 0 || *optarg == '\0' || *e != '\0')
                                errx(1, "illegal preload value -- %s", optarg);
#if INT_MAX < LONG_MAX
                        if (l > INT_MAX)
                                errx(EXIT_FAILURE,
                                    "Too many preload packets: %ld", l);
#endif
                        preload = l;
                        break;
                case 'm':
                        mflag++;
                        break;
                case 'n':
                        options &= ~F_HOSTNAME;
                        break;
                case 'N':
                        options |= F_NIGROUP;
                        break;
                case 'o':
                        options |= F_ONCE;
                        break;
                case 'p':               /* fill buffer with user pattern */
                        options |= F_PINGFILLED;
                        fill((char *)datap, optarg);
                                break;
                case 'q':
                        options |= F_QUIET;
                        break;
                case 'S':
                        memset(&hints, 0, sizeof(struct addrinfo));
                        hints.ai_flags = AI_NUMERICHOST; /* allow hostname? */
                        hints.ai_family = AF_INET6;
                        hints.ai_socktype = SOCK_RAW;
                        hints.ai_protocol = IPPROTO_ICMPV6;

                        ret_ga = getaddrinfo(optarg, NULL, &hints, &res);
                        if (ret_ga) {
                                errx(1, "invalid source address: %s",
                                     gai_strerror(ret_ga));
                        }
                        /*
                         * res->ai_family must be AF_INET6 and res->ai_addrlen
                         * must be sizeof(src).
                         */
                        memcpy(&src, res->ai_addr, res->ai_addrlen);
                        srclen = res->ai_addrlen;
                        freeaddrinfo(res);
                        options |= F_SRCADDR;
                        break;
                case 's':               /* size of packet to send */
                        datalen = strtol(optarg, &e, 10);
                        if (datalen < 0 || *optarg == '\0' || *e != '\0')
                                errx(1, "illegal datalen value -- %s", optarg);
                        if (datalen > MAXDATALEN) {
                                errx(1,
                                    "datalen value too large, maximum is %d",
                                    MAXDATALEN);
                        }
                        break;
                case 't':
                        options &= ~F_NOUSERDATA;
                        options |= F_SUPTYPES;
                        break;
                case 'v':
                        options |= F_VERBOSE;
                        break;
                case 'w':
                        options &= ~F_NOUSERDATA;
                        options |= F_FQDN;
                        break;
                case 'W':
                        options &= ~F_NOUSERDATA;
                        options |= F_FQDNOLD;
                        break;
                case 'x':
                        maxwait = strtod(optarg, &e);
                        if (*e != '\0' || maxwait <= 0)
                                errx(EXIT_FAILURE, "Bad/invalid maxwait time: "
                                    "%s", optarg);
                        break;
                case 'X':
                        deadline = strtod(optarg, &e);
                        if (*e != '\0' || deadline <= 0)
                                errx(EXIT_FAILURE, "Bad/invalid deadline time: "
                                    "%s", optarg);
                        break;

#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
                case 'P':
                        options |= F_POLICY;
                        if (!strncmp("in", optarg, 2)) {
                                if ((policy_in = strdup(optarg)) == NULL)
                                        errx(1, "strdup");
                        } else if (!strncmp("out", optarg, 3)) {
                                if ((policy_out = strdup(optarg)) == NULL)
                                        errx(1, "strdup");
                        } else
                                errx(1, "invalid security policy");
                        break;
#endif
                default:
                        usage();
                        /*NOTREACHED*/
                }
        }

        argc -= optind;
        argv += optind;

        if (argc != 1) {
                usage();
                /*NOTREACHED*/
        }

        if (options & F_NIGROUP) {
                target = nigroup(argv[argc - 1]);
                if (target == NULL) {
                        usage();
                        /*NOTREACHED*/
                }
        } else
                target = argv[argc - 1];

        if ((options & F_PINGFILLED) != 0 && datalen <= (int)ICMP6ECHOTMLEN) {
                warnx("-p: No fill space; increase packet size with -s");
        }

        /* getaddrinfo */
        memset(&hints, 0, sizeof(struct addrinfo));
        hints.ai_flags = AI_CANONNAME;
        hints.ai_family = AF_INET6;
        hints.ai_socktype = SOCK_RAW;
        hints.ai_protocol = IPPROTO_ICMPV6;

        ret_ga = getaddrinfo(target, NULL, &hints, &res);
        if (ret_ga)
                errx(1, "%s", gai_strerror(ret_ga));
        if (res->ai_canonname)
                hostname = res->ai_canonname;
        else
                hostname = target;

        if (!res->ai_addr)
                errx(1, "getaddrinfo failed");

        memcpy(&dst, res->ai_addr, res->ai_addrlen);

        if ((s = prog_socket(res->ai_family, res->ai_socktype,
            res->ai_protocol)) < 0)
                err(1, "socket");

        /* set the source address if specified. */
        if ((options & F_SRCADDR) &&
            prog_bind(s, (struct sockaddr *)&src, srclen) != 0) {
                err(1, "bind");
        }

        /* set the gateway (next hop) if specified */
        if (gateway) {
                struct addrinfo ghints, *gres;
                int error;

                memset(&ghints, 0, sizeof(ghints));
                ghints.ai_family = AF_INET6;
                ghints.ai_socktype = SOCK_RAW;
                ghints.ai_protocol = IPPROTO_ICMPV6;

                error = getaddrinfo(gateway, NULL, &hints, &gres);
                if (error) {
                        errx(1, "getaddrinfo for the gateway %s: %s",
                             gateway, gai_strerror(error));
                }
                if (gres->ai_next && (options & F_VERBOSE))
                        warnx("gateway resolves to multiple addresses");

                if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_NEXTHOP,
                               gres->ai_addr, gres->ai_addrlen)) {
                        err(1, "setsockopt(IPV6_NEXTHOP)");
                }

                freeaddrinfo(gres);
        }

        /*
         * let the kernel pass extension headers of incoming packets,
         * for privileged socket options
         */
        if ((options & F_VERBOSE) != 0) {
                int opton = 1;

                if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_RECVHOPOPTS, &opton,
                    sizeof(opton)))
                        err(1, "setsockopt(IPV6_RECVHOPOPTS)");

                if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_RECVDSTOPTS, &opton,
                    sizeof(opton)))
                        err(1, "setsockopt(IPV6_RECVDSTOPTS)");

#ifdef IPV6_RECVRTHDRDSTOPTS
                if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_RECVRTHDRDSTOPTS, &opton,
                    sizeof(opton)))
                        err(1, "setsockopt(IPV6_RECVRTHDRDSTOPTS)");
#endif
        }

        /* revoke root privilege */
        prog_seteuid(prog_getuid());
        prog_setuid(prog_getuid());

        if ((options & F_FLOOD) && (options & F_INTERVAL))
                errx(1, "-f and -i incompatible options");

        if ((options & F_NOUSERDATA) == 0) {
                if (datalen >= (int)sizeof(struct tv32)) {
                        /* we can time transfer */
                        timing = 1;
                } else
                        timing = 0;
                /* in F_VERBOSE case, we may get non-echoreply packets*/
                if (options & F_VERBOSE)
                        packlen = 2048 + IP6LEN + ICMP6ECHOLEN + EXTRA;
                else
                        packlen = datalen + IP6LEN + ICMP6ECHOLEN + EXTRA;
        } else {
                /* suppress timing for node information query */
                timing = 0;
                datalen = 2048;
                packlen = 2048 + IP6LEN + ICMP6ECHOLEN + EXTRA;
        }

        if (!(packet = (u_char *)malloc(packlen)))
                err(1, "Unable to allocate packet");
        if (!(options & F_PINGFILLED))
                for (i = ICMP6ECHOLEN; i < packlen; ++i)
                        *datap++ = i;

        ident = arc4random() & 0xFFFF;
        memset(nonce, 0, sizeof(nonce));
        for (i = 0; i < sizeof(nonce); i += sizeof(u_int32_t)) {
                uint32_t r = arc4random();
                memcpy(&nonce[i], &r, sizeof(r));
        }

        hold = 1;

        if (options & F_SO_DEBUG)
                (void)prog_setsockopt(s, SOL_SOCKET, SO_DEBUG, (char *)&hold,
                    sizeof(hold));
        optval = IPV6_DEFHLIM;
        if (IN6_IS_ADDR_MULTICAST(&dst.sin6_addr))
                if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
                    &optval, sizeof(optval)) == -1)
                        err(1, "IPV6_MULTICAST_HOPS");

        if (mflag != 1) {
                optval = mflag > 1 ? 0 : 1;

                if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_USE_MIN_MTU,
                    &optval, sizeof(optval)) == -1)
                        err(1, "setsockopt(IPV6_USE_MIN_MTU)");
        } else {
                optval = 1;
                if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_RECVPATHMTU,
                    &optval, sizeof(optval)) == -1)
                        err(1, "setsockopt(IPV6_RECVPATHMTU)");
        }

#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
        if (options & F_POLICY) {
                if (setpolicy(s, policy_in) < 0)
                        errx(1, "%s", ipsec_strerror());
                if (setpolicy(s, policy_out) < 0)
                        errx(1, "%s", ipsec_strerror());
        }
#endif

#ifdef ICMP6_FILTER
    {
        struct icmp6_filter filt;
        if (!(options & F_VERBOSE)) {
                ICMP6_FILTER_SETBLOCKALL(&filt);
                if ((options & F_FQDN) || (options & F_FQDNOLD) ||
                    (options & F_NODEADDR) || (options & F_SUPTYPES))
                        ICMP6_FILTER_SETPASS(ICMP6_NI_REPLY, &filt);
                else
                        ICMP6_FILTER_SETPASS(ICMP6_ECHO_REPLY, &filt);
        } else {
                ICMP6_FILTER_SETPASSALL(&filt);
        }
        if (prog_setsockopt(s, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
            sizeof(filt)) < 0)
                err(1, "setsockopt(ICMP6_FILTER)");
    }
#endif /*ICMP6_FILTER*/

        /* let the kernel pass extension headers of incoming packets */
        if ((options & F_VERBOSE) != 0) {
                int opton = 1;

                if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_RECVRTHDR, &opton,
                    sizeof(opton)))
                        err(1, "setsockopt(IPV6_RECVRTHDR)");
        }

/*
        optval = 1;
        if (IN6_IS_ADDR_MULTICAST(&dst.sin6_addr))
                if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
                    &optval, sizeof(optval)) == -1)
                        err(1, "IPV6_MULTICAST_LOOP");
*/

        /* Specify the outgoing interface and/or the source address */
        if (usepktinfo)
                ip6optlen += CMSG_SPACE(sizeof(struct in6_pktinfo));

        if (hoplimit != -1)
                ip6optlen += CMSG_SPACE(sizeof(int));

        /* set IP6 packet options */
        if (ip6optlen) {
                if ((scmsg = (char *)malloc(ip6optlen)) == 0)
                        errx(1, "can't allocate enough memory");
                smsghdr.msg_control = (caddr_t)scmsg;
                smsghdr.msg_controllen = ip6optlen;
                scmsgp = (struct cmsghdr *)scmsg;
        }
        if (usepktinfo) {
                pktinfo = (struct in6_pktinfo *)(CMSG_DATA(scmsgp));
                memset(pktinfo, 0, sizeof(*pktinfo));
                scmsgp->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
                scmsgp->cmsg_level = IPPROTO_IPV6;
                scmsgp->cmsg_type = IPV6_PKTINFO;
                scmsgp = CMSG_NXTHDR(&smsghdr, scmsgp);
        }

        /* set the outgoing interface */
        if (ifname) {
#ifndef USE_SIN6_SCOPE_ID
                /* pktinfo must have already been allocated */
                if ((pktinfo->ipi6_ifindex = if_nametoindex(ifname)) == 0)
                        errx(1, "%s: invalid interface name", ifname);
#else
                if ((dst.sin6_scope_id = if_nametoindex(ifname)) == 0)
                        errx(1, "%s: invalid interface name", ifname);
#endif
        }
        if (hoplimit != -1) {
                scmsgp->cmsg_len = CMSG_LEN(sizeof(int));
                scmsgp->cmsg_level = IPPROTO_IPV6;
                scmsgp->cmsg_type = IPV6_HOPLIMIT;
                *(int *)(CMSG_DATA(scmsgp)) = hoplimit;

                scmsgp = CMSG_NXTHDR(&smsghdr, scmsgp);
        }

        if (!(options & F_SRCADDR)) {
                /*
                 * get the source address. XXX since we revoked the root
                 * privilege, we cannot use a raw socket for this.
                 */
                int dummy;
                socklen_t len = sizeof(src);

                if ((dummy = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
                        err(1, "UDP socket");

                src.sin6_family = AF_INET6;
                src.sin6_addr = dst.sin6_addr;
                src.sin6_port = ntohs(DUMMY_PORT);
                src.sin6_scope_id = dst.sin6_scope_id;

                if (pktinfo &&
                    prog_setsockopt(dummy, IPPROTO_IPV6, IPV6_PKTINFO,
                    (void *)pktinfo, sizeof(*pktinfo)))
                        err(1, "UDP setsockopt(IPV6_PKTINFO)");

                if (hoplimit != -1 &&
                    prog_setsockopt(dummy, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
                    (void *)&hoplimit, sizeof(hoplimit)))
                        err(1, "UDP setsockopt(IPV6_UNICAST_HOPS)");

                if (hoplimit != -1 &&
                    prog_setsockopt(dummy, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
                    (void *)&hoplimit, sizeof(hoplimit)))
                        err(1, "UDP setsockopt(IPV6_MULTICAST_HOPS)");

                if (rthdr &&
                    prog_setsockopt(dummy, IPPROTO_IPV6, IPV6_RTHDR,
                    (void *)rthdr, (rthdr->ip6r_len + 1) << 3))
                        err(1, "UDP setsockopt(IPV6_RTHDR)");

                if (prog_connect(dummy, (struct sockaddr *)&src, len) < 0)
                        err(1, "UDP connect");

                if (prog_getsockname(dummy, (struct sockaddr *)&src, &len) < 0)
                        err(1, "getsockname");

                prog_close(dummy);
        }

        if (sockbufsize) {
                if (datalen > sockbufsize)
                        warnx("you need -b to increase socket buffer size");
                if (prog_setsockopt(s, SOL_SOCKET, SO_SNDBUF, &sockbufsize,
                    sizeof(sockbufsize)) < 0)
                        err(1, "setsockopt(SO_SNDBUF)");
                if (prog_setsockopt(s, SOL_SOCKET, SO_RCVBUF, &sockbufsize,
                    sizeof(sockbufsize)) < 0)
                        err(1, "setsockopt(SO_RCVBUF)");
        } else {
                if (datalen > 8 * 1024) /*XXX*/
                        warnx("you need -b to increase socket buffer size");
                /*
                 * 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.
                 */
                hold = 48 * 1024;
                prog_setsockopt(s, SOL_SOCKET, SO_RCVBUF, (char *)&hold,
                    sizeof(hold));
        }

        optval = 1;
#ifndef USE_SIN6_SCOPE_ID
        if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, &optval,
            sizeof(optval)) < 0)
                warn("setsockopt(IPV6_RECVPKTINFO)"); /* XXX err? */
#endif

        if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &optval,
            sizeof(optval)) < 0)
                warn("setsockopt(IPV6_RECVHOPLIMIT)"); /* XXX err? */

        printf("PING6(%lu=40+8+%lu bytes) ", (unsigned long)(40 + pingerlen()),
            (unsigned long)(pingerlen() - 8));
        printf("%s --> ", pr_addr((struct sockaddr *)&src, sizeof(src)));
        printf("%s\n", pr_addr((struct sockaddr *)&dst, sizeof(dst)));

        while (preload--)               /* Fire off them quickies. */
                pinger();

        (void)signal(SIGINT, onsignal);
#ifdef SIGINFO
        (void)signal(SIGINFO, onsignal);
#endif

        seenint = 0;
#ifdef SIGINFO
        seeninfo = 0;
#endif

        doit(packet, packlen);
        /*NOTREACHED*/
        return 0;
}

static void
doit(u_char *packet, u_int packlen)
{
        int cc;
        struct pollfd fdmaskp[1];
        struct sockaddr_in6 from;
        double sec, last, d_last;
        long orig_npackets = npackets;

        if (npackets == 0)
                npackets = LONG_MAX;

        clock_gettime(CLOCK_MONOTONIC, &now);
        if (deadline > 0) {
                last = timespec_to_sec(&now) + deadline;
                d_last = 0;
        } else {
                last = 0;
                d_last = 365*24*60*60;
        }

        for (;;) {
                struct msghdr m;
                u_long buf[1024 / sizeof(u_long)];
                struct iovec iov[2];

                clock_gettime(CLOCK_MONOTONIC, &now);

                if (seenint) {
                        onsigexit(SIGINT);
                        seenint = 0;
                        continue;
                }
#ifdef SIGINFO
                if (seeninfo) {
                        summary();
                        seeninfo = 0;
                        continue;
                }
#endif
                if (last != 0)
                        d_last = last - timespec_to_sec(&now);

                if (ntransmitted < npackets && d_last > 0) {
                        /* send if within 100 usec or late for next packet */
                        sec = diffsec(&next_tx, &now);
                        if ((sec <= 0.0001 && (options & F_FLOOD) == 0) ||
                            (lastrcvd && (options & F_FLOOD))) {
                                pinger();
                                sec = diffsec(&next_tx, &now);
                        }
                        if (sec < 0.0)
                                sec = 0.0;
                        if (d_last < sec)
                                sec = d_last;
                } else {
                        /* For the last response, wait twice as long as the
                         * worst case seen, or 10 times as long as the
                         * maximum interpacket interval, whichever is longer.
                         */
                        sec = MAX(2 * tmax, 10 * interval.tv_sec) -
                            diffsec(&now, &last_tx);
                        if (d_last < sec)
                                sec = d_last;
                        if (sec <= 0)
                                break;
                }

                fdmaskp[0].fd = s;
                fdmaskp[0].events = POLLIN;
                cc = prog_poll(fdmaskp, 1, (int)(sec * 1000));
                if (cc < 0) {
                        if (errno != EINTR) {
                                warn("poll");
                                sleep(1);
                        }
                        continue;
                } else if (cc == 0)
                        continue;

                m.msg_name = (caddr_t)&from;
                m.msg_namelen = sizeof(from);
                memset(&iov, 0, sizeof(iov));
                iov[0].iov_base = (caddr_t)packet;
                iov[0].iov_len = packlen;
                m.msg_iov = iov;
                m.msg_iovlen = 1;
                m.msg_control = (caddr_t)buf;
                m.msg_controllen = sizeof(buf);

                cc = prog_recvmsg(s, &m, 0);
                if (cc < 0) {
                        if (errno != EINTR) {
                                warn("recvmsg");
                                sleep(1);
                        }
                        continue;
                } else if (cc == 0) {
                        int mtu;

                        /*
                         * receive control messages only. Process the
                         * exceptions (currently the only possibility is
                         * a path MTU notification.)
                         */
                        if ((mtu = get_pathmtu(&m)) > 0) {
                                if ((options & F_VERBOSE) != 0) {
                                        printf("new path MTU (%d) is "
                                            "notified\n", mtu);
                                }
                        }
                        continue;
                } else {
                        /*
                         * an ICMPv6 message (probably an echoreply) arrived.
                         */
                        pr_pack(packet, cc, &m);
                }
                if (npackets && nreceived >= npackets)
                        break;
                if (nreceived != 0 && (options & F_ONCE))
                        break;
        }

        summary();

        if (orig_npackets)
                exit(nreceived != orig_npackets);
        else
                exit(nreceived == 0);
}

static void
onsignal(int sig)
{

        switch (sig) {
        case SIGINT:
                seenint++;
                break;
#ifdef SIGINFO
        case SIGINFO:
                seeninfo++;
                break;
#endif
        }
}

/*
 * pinger --
 *      Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
 * will be added on by the kernel.  The ID field is random,
 * and the sequence number is an ascending integer.  The first 8 bytes
 * of the data portion are used to hold a UNIX "timeval" struct in VAX
 * byte-order, to compute the round-trip time.
 */
static size_t
pingerlen(void)
{
        size_t l;

        if (options & F_FQDN)
                l = ICMP6_NIQLEN + sizeof(dst.sin6_addr);
        else if (options & F_FQDNOLD)
                l = ICMP6_NIQLEN;
        else if (options & F_NODEADDR)
                l = ICMP6_NIQLEN + sizeof(dst.sin6_addr);
        else if (options & F_SUPTYPES)
                l = ICMP6_NIQLEN;
        else
                l = ICMP6ECHOLEN + datalen;

        return l;
}

static void
pinger(void)
{
        struct icmp6_hdr *icp;
        struct iovec iov[2];
        int i, cc;
        struct icmp6_nodeinfo *nip;
        uint16_t seq;

        if (npackets && ntransmitted >= npackets)
                return; /* no more transmission */

        icp = (struct icmp6_hdr *)outpack;
        nip = (struct icmp6_nodeinfo *)outpack;
        memset(icp, 0, sizeof(*icp));
        icp->icmp6_cksum = 0;
        seq = ntransmitted++;
        lastrcvd = 0;
        CLR(seq % mx_dup_ck);
        seq = ntohs(seq);

        if (options & F_FQDN) {
                icp->icmp6_code = ICMP6_NI_SUBJ_IPV6;
                nip->ni_qtype = htons(NI_QTYPE_FQDN);
                nip->ni_flags = htons(0);

                memcpy(&outpack[ICMP6_NIQLEN], &dst.sin6_addr,
                    sizeof(dst.sin6_addr));
                cc = ICMP6_NIQLEN + sizeof(dst.sin6_addr);
        } else if (options & F_FQDNOLD) {
                /* packet format in 03 draft - no Subject data on queries */
                icp->icmp6_code = 0;    /* code field is always 0 */
                nip->ni_qtype = htons(NI_QTYPE_FQDN);
                nip->ni_flags = htons(0);

                cc = ICMP6_NIQLEN;
        } else if (options & F_NODEADDR) {
                icp->icmp6_code = ICMP6_NI_SUBJ_IPV6;
                nip->ni_qtype = htons(NI_QTYPE_NODEADDR);
                nip->ni_flags = naflags;

                memcpy(&outpack[ICMP6_NIQLEN], &dst.sin6_addr,
                    sizeof(dst.sin6_addr));
                cc = ICMP6_NIQLEN + sizeof(dst.sin6_addr);
        } else if (options & F_SUPTYPES) {
                icp->icmp6_code = ICMP6_NI_SUBJ_FQDN;   /*empty*/
                nip->ni_qtype = htons(NI_QTYPE_SUPTYPES);
                /* we support compressed bitmap */
                nip->ni_flags = NI_SUPTYPE_FLAG_COMPRESS;

                cc = ICMP6_NIQLEN;
        } else
                cc = 0; /* XXX: gcc */

        if (options & (F_FQDN|F_FQDNOLD|F_NODEADDR|F_SUPTYPES)) {
                icp->icmp6_type = ICMP6_NI_QUERY;
                memcpy(nip->icmp6_ni_nonce, nonce,
                    sizeof(nip->icmp6_ni_nonce));
                memcpy(nip->icmp6_ni_nonce, &seq, sizeof(seq));
                datalen = 0;
        } else {
                icp->icmp6_type = ICMP6_ECHO_REQUEST;
                icp->icmp6_code = 0;
                icp->icmp6_id = htons(ident);
                icp->icmp6_seq = seq;
                if (timing) {
                        struct timeval tv;
                        struct tv32 *tv32;
                        (void)gettimeofday(&tv, NULL);
                        tv32 = (struct tv32 *)&outpack[ICMP6ECHOLEN];
                        tv32->tv32_sec = htonl(tv.tv_sec);
                        tv32->tv32_usec = htonl(tv.tv_usec);
                }
                cc = ICMP6ECHOLEN + datalen;
        }

#ifdef DIAGNOSTIC
        if (pingerlen() != cc)
                errx(1, "internal error; length mismatch");
#endif

        smsghdr.msg_name = (caddr_t)&dst;
        smsghdr.msg_namelen = sizeof(dst);
        memset(&iov, 0, sizeof(iov));
        iov[0].iov_base = (caddr_t)outpack;
        iov[0].iov_len = cc;
        smsghdr.msg_iov = iov;
        smsghdr.msg_iovlen = 1;

        i = prog_sendmsg(s, &smsghdr, 0);

        if (i < 0 || i != cc)  {
                if (i < 0)
                        warn("sendmsg");
                printf("ping6: wrote %s %d chars, ret=%d\n",
                    hostname, cc, i);
        }
        if (!(options & F_QUIET) && options & F_FLOOD)
                (void)write(STDOUT_FILENO, &DOT, 1);

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

        /* Transmit regularly, at always the same microsecond in the
         * second when going at one packet per second.
         * If we are at most 100 ms behind, send extras to get caught up.
         * Otherwise, skip packets we were too slow to send.
         */
        if (diffsec(&next_tx, &now) <= interval.tv_sec) {
                do {
                        timespecadd(&next_tx, &interval, &next_tx);
                } while (diffsec(&next_tx, &now) < -0.1);
        }
}

static int
myechoreply(const struct icmp6_hdr *icp)
{
        if (ntohs(icp->icmp6_id) == ident)
                return 1;
        else
                return 0;
}

static int
mynireply(const struct icmp6_nodeinfo *nip)
{
        if (memcmp(nip->icmp6_ni_nonce + sizeof(u_int16_t),
            nonce + sizeof(u_int16_t),
            sizeof(nonce) - sizeof(u_int16_t)) == 0)
                return 1;
        else
                return 0;
}

static char *
dnsdecode(const u_char **sp, const u_char *ep, const u_char *base, char *buf,
          size_t bufsiz)
{
        int i;
        const u_char *cp;
        char cresult[MAXDNAME + 1];
        const u_char *comp;
        int l;

        i = 0;          /* XXXGCC -Wuninitialized [sun2] */

        cp = *sp;
        *buf = '\0';

        if (cp >= ep)
                return NULL;
        while (cp < ep) {
                i = *cp;
                if (i == 0 || cp != *sp) {
                        if (strlcat((char *)buf, ".", bufsiz) >= bufsiz)
                                return NULL;    /*result overrun*/
                }
                if (i == 0)
                        break;
                cp++;

                if ((i & 0xc0) == 0xc0 && cp - base > (i & 0x3f)) {
                        /* DNS compression */
                        if (!base)
                                return NULL;

                        comp = base + (i & 0x3f);
                        if (dnsdecode(&comp, cp, base, cresult,
                            sizeof(cresult)) == NULL)
                                return NULL;
                        if (strlcat(buf, cresult, bufsiz) >= bufsiz)
                                return NULL;    /*result overrun*/
                        break;
                } else if ((i & 0x3f) == i) {
                        if (i > ep - cp)
                                return NULL;    /*source overrun*/
                        while (i-- > 0 && cp < ep) {
                                l = snprintf(cresult, sizeof(cresult),
                                    isprint(*cp) ? "%c" : "\\%03o", *cp & 0xff);
                                if (l >= (int)sizeof(cresult) || l < 0)
                                        return NULL;
                                if (strlcat(buf, cresult, bufsiz) >= bufsiz)
                                        return NULL;    /*result overrun*/
                                cp++;
                        }
                } else
                        return NULL;    /*invalid label*/
        }
        if (i != 0)
                return NULL;    /*not terminated*/
        cp++;
        *sp = cp;
        return buf;
}

/*
 * 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(u_char *buf, int cc, struct msghdr *mhdr)
{
#define safeputc(c)     printf((isprint((c)) ? "%c" : "\\%03o"), c)
        struct icmp6_hdr *icp;
        struct icmp6_nodeinfo *ni;
        int i;
        int hoplim;
        struct sockaddr *from;
        int fromlen;
        u_char *cp = NULL, *dp, *end = buf + cc;
        struct in6_pktinfo *pktinfo = NULL;
        struct timeval tv, tp;
        struct tv32 *tpp;
        double triptime = 0;
        int dupflag;
        size_t off;
        int oldfqdn;
        u_int16_t seq;
        char dnsname[MAXDNAME + 1];

        (void)gettimeofday(&tv, NULL);

        if (!mhdr || !mhdr->msg_name ||
            mhdr->msg_namelen != sizeof(struct sockaddr_in6) ||
            ((struct sockaddr *)mhdr->msg_name)->sa_family != AF_INET6) {
                if (options & F_VERBOSE)
                        warnx("invalid peername");
                return;
        }
        from = (struct sockaddr *)mhdr->msg_name;
        fromlen = mhdr->msg_namelen;
        if (cc < (int)sizeof(struct icmp6_hdr)) {
                if (options & F_VERBOSE)
                        warnx("packet too short (%d bytes) from %s", cc,
                            pr_addr(from, fromlen));
                return;
        }
        icp = (struct icmp6_hdr *)buf;
        ni = (struct icmp6_nodeinfo *)buf;
        off = 0;

        if ((hoplim = get_hoplim(mhdr)) == -1) {
                warnx("failed to get receiving hop limit");
                return;
        }
        if ((pktinfo = get_rcvpktinfo(mhdr)) == NULL) {
                warnx("failed to get receiving packet information");
                return;
        }

        if (icp->icmp6_type == ICMP6_ECHO_REPLY && myechoreply(icp)) {
                seq = ntohs(icp->icmp6_seq);
                ++nreceived;
                lastrcvd = 1;
                if (timing) {
                        tpp = (struct tv32 *)(icp + 1);
                        tp.tv_sec = ntohl(tpp->tv32_sec);
                        tp.tv_usec = ntohl(tpp->tv32_usec);
                        tvsub(&tv, &tp);
                        triptime = ((double)tv.tv_sec) * 1000.0 +
                            ((double)tv.tv_usec) / 1000.0;
                        if (maxwait > 0 && triptime > maxwait) {
                                nreceived--;
                                return; /* DISCARD */
                        }
                        tsum += triptime;
                        tsumsq += triptime * triptime;
                        if (triptime < tmin)
                                tmin = triptime;
                        if (triptime > tmax)
                                tmax = triptime;
                }

                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_FLOOD)
                        (void)write(STDOUT_FILENO, &BSPACE, 1);
                else {
                        printf("%d bytes from %s, icmp_seq=%u", cc,
                            pr_addr(from, fromlen), seq);
                        printf(" hlim=%d", hoplim);
                        if ((options & F_VERBOSE) != 0) {
                                struct sockaddr_in6 dstsa;

                                memset(&dstsa, 0, sizeof(dstsa));
                                dstsa.sin6_family = AF_INET6;
#ifdef SIN6_LEN
                                dstsa.sin6_len = sizeof(dstsa);
#endif
                                dstsa.sin6_scope_id = pktinfo->ipi6_ifindex;
                                dstsa.sin6_addr = pktinfo->ipi6_addr;
                                printf(" dst=%s",
                                    pr_addr((struct sockaddr *)&dstsa,
                                    sizeof(dstsa)));
                        }
                        if (timing)
                                printf(" time=%.3f ms", triptime);
                        if (dupflag)
                                printf("(DUP!)");
                        /* check the data */
                        cp = buf + off + ICMP6ECHOLEN + ICMP6ECHOTMLEN;
                        dp = outpack + ICMP6ECHOLEN + ICMP6ECHOTMLEN;
                        for (i = 8; cp < end; ++i, ++cp, ++dp) {
                                if (*cp != *dp) {
                                        printf("\nwrong data byte #%d should be 0x%x but was 0x%x", i, *dp, *cp);
                                        break;
                                }
                        }
                }
        } else if (icp->icmp6_type == ICMP6_NI_REPLY && mynireply(ni)) {
                memcpy(&seq, ni->icmp6_ni_nonce, sizeof(seq));
                seq = ntohs(seq);
                ++nreceived;
                if (TST(seq % mx_dup_ck)) {
                        ++nrepeats;
                        --nreceived;
                        dupflag = 1;
                } else {
                        SET(seq % mx_dup_ck);
                        dupflag = 0;
                }

                if (options & F_QUIET)
                        return;

                printf("%d bytes from %s: ", cc, pr_addr(from, fromlen));

                switch (ntohs(ni->ni_code)) {
                case ICMP6_NI_SUCCESS:
                        break;
                case ICMP6_NI_REFUSED:
                        printf("refused, type 0x%x", ntohs(ni->ni_type));
                        goto fqdnend;
                case ICMP6_NI_UNKNOWN:
                        printf("unknown, type 0x%x", ntohs(ni->ni_type));
                        goto fqdnend;
                default:
                        printf("unknown code 0x%x, type 0x%x",
                            ntohs(ni->ni_code), ntohs(ni->ni_type));
                        goto fqdnend;
                }

                switch (ntohs(ni->ni_qtype)) {
                case NI_QTYPE_NOOP:
                        printf("NodeInfo NOOP");
                        break;
                case NI_QTYPE_SUPTYPES:
                        pr_suptypes(ni, end - (u_char *)ni);
                        break;
                case NI_QTYPE_NODEADDR:
                        pr_nodeaddr(ni, end - (u_char *)ni);
                        break;
                case NI_QTYPE_FQDN:
                default:        /* XXX: for backward compatibility */
                        cp = (u_char *)ni + ICMP6_NIRLEN;
                        if (buf[off + ICMP6_NIRLEN] ==
                            cc - off - ICMP6_NIRLEN - 1)
                                oldfqdn = 1;
                        else
                                oldfqdn = 0;
                        if (oldfqdn) {
                                cp++;   /* skip length */
                                while (cp < end) {
                                        safeputc(*cp & 0xff);
                                        cp++;
                                }
                        } else {
                                i = 0;
                                while (cp < end) {
                                        if (dnsdecode((void *)&cp, end,
                                            (const u_char *)(ni + 1), dnsname,
                                            sizeof(dnsname)) == NULL) {
                                                printf("???");
                                                break;
                                        }
                                        /*
                                         * name-lookup special handling for
                                         * truncated name
                                         */
                                        if (cp + 1 <= end && !*cp &&
                                            strlen(dnsname) > 0) {
                                                dnsname[strlen(dnsname) - 1] = '\0';
                                                cp++;
                                        }
                                        printf("%s%s", i > 0 ? "," : "",
                                            dnsname);
                                }
                        }
                        if (options & F_VERBOSE) {
                                int32_t ttl;
                                int comma = 0;

                                printf(" (");   /*)*/

                                switch (ni->ni_code) {
                                case ICMP6_NI_REFUSED:
                                        printf("refused");
                                        comma++;
                                        break;
                                case ICMP6_NI_UNKNOWN:
                                        printf("unknown qtype");
                                        comma++;
                                        break;
                                }

                                if ((end - (u_char *)ni) < ICMP6_NIRLEN) {
                                        /* case of refusion, unknown */
                                        /*(*/
                                        putchar(')');
                                        goto fqdnend;
                                }
                                ttl = (int32_t)ntohl(*(u_long *)&buf[off+ICMP6ECHOLEN+8]);
                                if (comma)
                                        printf(",");
                                if (!(ni->ni_flags & NI_FQDN_FLAG_VALIDTTL)) {
                                        printf("TTL=%d:meaningless",
                                            (int)ttl);
                                } else {
                                        if (ttl < 0) {
                                                printf("TTL=%d:invalid",
                                                   ttl);
                                        } else
                                                printf("TTL=%d", ttl);
                                }
                                comma++;

                                if (oldfqdn) {
                                        if (comma)
                                                printf(",");
                                        printf("03 draft");
                                        comma++;
                                } else {
                                        cp = (u_char *)ni + ICMP6_NIRLEN;
                                        if (cp == end) {
                                                if (comma)
                                                        printf(",");
                                                printf("no name");
                                                comma++;
                                        }
                                }

                                if (buf[off + ICMP6_NIRLEN] !=
                                    cc - off - ICMP6_NIRLEN - 1 && oldfqdn) {
                                        if (comma)
                                                printf(",");
                                        printf("invalid namelen:%d/%lu",
                                            buf[off + ICMP6_NIRLEN],
                                            (u_long)cc - off - ICMP6_NIRLEN - 1);
                                        comma++;
                                }
                                /*(*/
                                putchar(')');
                        }
                fqdnend:
                        ;
                }
        } else {
                /* We've got something other than an ECHOREPLY */
                if (!(options & F_VERBOSE))
                        return;
                printf("%d bytes from %s: ", cc, pr_addr(from, fromlen));
                pr_icmph(icp, end);
        }

        if (!(options & F_FLOOD)) {
                (void)putchar('\n');
                if (options & F_VERBOSE)
                        pr_exthdrs(mhdr);
                (void)fflush(stdout);
        }
#undef safeputc
}

static void
pr_exthdrs(struct msghdr *mhdr)
{
        struct cmsghdr *cm;

        for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
             cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
                if (cm->cmsg_level != IPPROTO_IPV6)
                        continue;

                switch (cm->cmsg_type) {
                case IPV6_HOPOPTS:
                        printf("  HbH Options: ");
                        pr_ip6opt(CMSG_DATA(cm));
                        break;
                case IPV6_DSTOPTS:
#ifdef IPV6_RTHDRDSTOPTS
                case IPV6_RTHDRDSTOPTS:
#endif
                        printf("  Dst Options: ");
                        pr_ip6opt(CMSG_DATA(cm));
                        break;
                case IPV6_RTHDR:
                        printf("  Routing: ");
                        pr_rthdr(CMSG_DATA(cm));
                        break;
                }
        }
}

static void
pr_ip6opt(void *extbuf)
{
        struct ip6_hbh *ext;
        int currentlen;
        u_int8_t type;
        size_t extlen;
        socklen_t len;
        void *databuf;
        size_t offset;
        u_int16_t value2;
        u_int32_t value4;

        ext = (struct ip6_hbh *)extbuf;
        extlen = (ext->ip6h_len + 1) * 8;
        printf("nxt %u, len %u (%lu bytes)\n", ext->ip6h_nxt,
            (unsigned int)ext->ip6h_len, (unsigned long)extlen);

        currentlen = 0;
        while (1) {
                currentlen = inet6_opt_next(extbuf, extlen, currentlen,
                    &type, &len, &databuf);
                if (currentlen == -1)
                        break;
                switch (type) {
                /*
                 * Note that inet6_opt_next automatically skips any padding
                 * optins.
                 */
                case IP6OPT_JUMBO:
                        offset = 0;
                        offset = inet6_opt_get_val(databuf, offset,
                            &value4, sizeof(value4));
                        printf("    Jumbo Payload Opt: Length %u\n",
                            (u_int32_t)ntohl(value4));
                        break;
                case IP6OPT_ROUTER_ALERT:
                        offset = 0;
                        offset = inet6_opt_get_val(databuf, offset,
                                                   &value2, sizeof(value2));
                        printf("    Router Alert Opt: Type %u\n",
                            ntohs(value2));
                        break;
                default:
                        printf("    Received Opt %u len %lu\n",
                            type, (unsigned long)len);
                        break;
                }
        }
        return;
}

static void
pr_rthdr(void *extbuf)
{
        struct in6_addr *in6;
        char ntopbuf[INET6_ADDRSTRLEN];
        struct ip6_rthdr *rh = (struct ip6_rthdr *)extbuf;
        int i, segments;

        /* print fixed part of the header */
        printf("nxt %u, len %u (%d bytes), type %u, ", rh->ip6r_nxt,
            rh->ip6r_len, (rh->ip6r_len + 1) << 3, rh->ip6r_type);
        if ((segments = inet6_rth_segments(extbuf)) >= 0)
                printf("%d segments, ", segments);
        else
                printf("segments unknown, ");
        printf("%d left\n", rh->ip6r_segleft);

        for (i = 0; i < segments; i++) {
                in6 = inet6_rth_getaddr(extbuf, i);
                if (in6 == NULL)
                        printf("   [%d]<NULL>\n", i);
                else {
                        if (!inet_ntop(AF_INET6, in6, ntopbuf,
                            sizeof(ntopbuf)))
                                strlcpy(ntopbuf, "?", sizeof(ntopbuf));
                        printf("   [%d]%s\n", i, ntopbuf);
                }
        }

        return;

}

static int
pr_bitrange(u_int32_t v, int soff, int ii)
{
        int off;
        int i;

        off = 0;
        while (off < 32) {
                /* shift till we have 0x01 */
                if ((v & 0x01) == 0) {
                        if (ii > 1)
                                printf("-%u", soff + off - 1);
                        ii = 0;
                        switch (v & 0x0f) {
                        case 0x00:
                                v >>= 4;
                                off += 4;
                                continue;
                        case 0x08:
                                v >>= 3;
                                off += 3;
                                continue;
                        case 0x04: case 0x0c:
                                v >>= 2;
                                off += 2;
                                continue;
                        default:
                                v >>= 1;
                                off += 1;
                                continue;
                        }
                }

                /* we have 0x01 with us */
                for (i = 0; i < 32 - off; i++) {
                        if ((v & (0x01 << i)) == 0)
                                break;
                }
                if (!ii)
                        printf(" %u", soff + off);
                ii += i;
                v >>= i; off += i;
        }
        return ii;
}

static void
pr_suptypes(struct icmp6_nodeinfo *ni /* ni->qtype must be SUPTYPES */,
            size_t nilen)
{
        size_t clen;
        u_int32_t v;
        const u_char *cp, *end;
        u_int16_t cur;
        struct cbit {
                u_int16_t words;        /*32bit count*/
                u_int16_t skip;
        } cbit;
#define MAXQTYPES       (1 << 16)
        size_t off;
        int b;

        cp = (u_char *)(ni + 1);
        end = ((u_char *)ni) + nilen;
        cur = 0;
        b = 0;

        printf("NodeInfo Supported Qtypes");
        if (options & F_VERBOSE) {
                if (ni->ni_flags & NI_SUPTYPE_FLAG_COMPRESS)
                        printf(", compressed bitmap");
                else
                        printf(", raw bitmap");
        }

        while (cp < end) {
                size_t skip = 0;
                clen = (size_t)(end - cp);
                if ((ni->ni_flags & NI_SUPTYPE_FLAG_COMPRESS) == 0) {
                        if (clen == 0 || clen > MAXQTYPES / 8 ||
                            clen % sizeof(v)) {
                                printf("???");
                                return;
                        }
                } else {
                        if (clen < sizeof(cbit) || clen % sizeof(v))
                                return;
                        memcpy(&cbit, cp, sizeof(cbit));
                        if (sizeof(cbit) + ntohs(cbit.words) * sizeof(v) >
                            clen)
                                return;
                        cp += sizeof(cbit);
                        clen = ntohs(cbit.words) * sizeof(v);
                        skip = (size_t)ntohs(cbit.skip) * 32;
                        if (cur + clen * 8 + skip > MAXQTYPES)
                                return;
                }

                for (off = 0; off < clen; off += sizeof(v)) {
                        memcpy(&v, cp + off, sizeof(v));
                        v = (u_int32_t)ntohl(v);
                        b = pr_bitrange(v, (int)(cur + off * 8), b);
                }
                /* flush the remaining bits */
                b = pr_bitrange(0, (int)(cur + off * 8), b);

                cp += clen;
                cur += clen * 8 + skip;
        }
}

static void
pr_nodeaddr(struct icmp6_nodeinfo *ni, /* ni->qtype must be NODEADDR */
            int nilen)
{
        u_char *cp = (u_char *)(ni + 1);
        char ntop_buf[INET6_ADDRSTRLEN];
        int withttl = 0;

        nilen -= sizeof(struct icmp6_nodeinfo);

        if (options & F_VERBOSE) {
                switch (ni->ni_code) {
                case ICMP6_NI_REFUSED:
                        printf("refused");
                        break;
                case ICMP6_NI_UNKNOWN:
                        printf("unknown qtype");
                        break;
                }
                if (ni->ni_flags & NI_NODEADDR_FLAG_TRUNCATE)
                        printf(" truncated");
        }
        putchar('\n');
        if (nilen <= 0)
                printf("  no address\n");

        /*
         * In icmp-name-lookups 05 and later, TTL of each returned address
         * is contained in the response. We try to detect the version
         * by the length of the data, but note that the detection algorithm
         * is incomplete. We assume the latest draft by default.
         */
        if (nilen % (sizeof(u_int32_t) + sizeof(struct in6_addr)) == 0)
                withttl = 1;
        while (nilen > 0) {
                u_int32_t ttl = 0;

                if (withttl) {
                        /* XXX: alignment? */
                        ttl = (u_int32_t)ntohl(*(u_int32_t *)cp);
                        cp += sizeof(u_int32_t);
                        nilen -= sizeof(u_int32_t);
                }

                if (inet_ntop(AF_INET6, cp, ntop_buf, sizeof(ntop_buf)) ==
                    NULL)
                        strlcpy(ntop_buf, "?", sizeof(ntop_buf));
                printf("  %s", ntop_buf);
                if (withttl) {
                        if (ttl == 0xffffffff) {
                                /*
                                 * XXX: can this convention be applied to all
                                 * type of TTL (i.e. non-ND TTL)?
                                 */
                                printf("(TTL=infty)");
                        }
                        else
                                printf("(TTL=%u)", ttl);
                }
                putchar('\n');

                nilen -= sizeof(struct in6_addr);
                cp += sizeof(struct in6_addr);
        }
}

static int
get_hoplim(struct msghdr *mhdr)
{
        struct cmsghdr *cm;

        for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
             cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
                if (cm->cmsg_len == 0)
                        return(-1);

                if (cm->cmsg_level == IPPROTO_IPV6 &&
                    cm->cmsg_type == IPV6_HOPLIMIT &&
                    cm->cmsg_len == CMSG_LEN(sizeof(int)))
                        return(*(int *)CMSG_DATA(cm));
        }

        return(-1);
}

static struct in6_pktinfo *
get_rcvpktinfo(struct msghdr *mhdr)
{
        struct cmsghdr *cm;

        for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
             cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
                if (cm->cmsg_len == 0)
                        return(NULL);

                if (cm->cmsg_level == IPPROTO_IPV6 &&
                    cm->cmsg_type == IPV6_PKTINFO &&
                    cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo)))
                        return((struct in6_pktinfo *)CMSG_DATA(cm));
        }

        return(NULL);
}

static int
get_pathmtu(struct msghdr *mhdr)
{
#ifdef IPV6_RECVPATHMTU
        struct cmsghdr *cm;
        struct ip6_mtuinfo *mtuctl = NULL;

        for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(mhdr); cm;
             cm = (struct cmsghdr *)CMSG_NXTHDR(mhdr, cm)) {
                if (cm->cmsg_len == 0)
                        return(0);

                if (cm->cmsg_level == IPPROTO_IPV6 &&
                    cm->cmsg_type == IPV6_PATHMTU &&
                    cm->cmsg_len == CMSG_LEN(sizeof(struct ip6_mtuinfo))) {
                        mtuctl = (struct ip6_mtuinfo *)CMSG_DATA(cm);

                        /*
                         * If the notified destination is different from
                         * the one we are pinging, just ignore the info.
                         * We check the scope ID only when both notified value
                         * and our own value have non-0 values, because we may
                         * have used the default scope zone ID for sending,
                         * in which case the scope ID value is 0.
                         */
                        if (!IN6_ARE_ADDR_EQUAL(&mtuctl->ip6m_addr.sin6_addr,
                                                &dst.sin6_addr) ||
                            (mtuctl->ip6m_addr.sin6_scope_id &&
                             dst.sin6_scope_id &&
                             mtuctl->ip6m_addr.sin6_scope_id !=
                             dst.sin6_scope_id)) {
                                if ((options & F_VERBOSE) != 0) {
                                        printf("path MTU for %s is notified. "
                                               "(ignored)\n",
                                           pr_addr((struct sockaddr *)&mtuctl->ip6m_addr,
                                           sizeof(mtuctl->ip6m_addr)));
                                }
                                return(0);
                        }

                        /*
                         * Ignore an invalid MTU. XXX: can we just believe
                         * the kernel check?
                         */
                        if (mtuctl->ip6m_mtu < IPV6_MMTU)
                                return(0);

                        /* notification for our destination. return the MTU. */
                        return((int)mtuctl->ip6m_mtu);
                }
        }
#endif
        return(0);
}

/*
 * 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;
}

/*
 * onsigexit --
 */
static void
onsigexit(int sig)
{
        summary();

        if (sig == SIGINT) {
                (void)signal(SIGINT, SIG_DFL);
                (void)kill(getpid(), SIGINT);
        }

        exit(1);
}

/*
 * summary --
 *      Print out statistics.
 */
static void
summary(void)
{

        printf("\n--- %s ping6 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 duplicating packets!");
                else
                        printf("%.1f%% packet loss",
                            ((((double)ntransmitted - nreceived) * 100.0) /
                            ntransmitted));
        }
        (void)putchar('\n');
        if (nreceived && timing) {
                /* Only display average to microseconds */
                double num = nreceived + nrepeats;
                double dev, avg;
                if (num > 1) {
                        avg = tsum / num;
                        dev = sqrt((tsumsq - num * avg * avg) / (num - 1));
                } else {
                        avg = tsum;
                        dev = 0.0;
                }
                printf(
                    "round-trip min/avg/max/std-dev = %.3f/%.3f/%.3f/%.3f ms\n",
                    tmin, avg, tmax, dev);
                (void)fflush(stdout);
        }
        (void)fflush(stdout);
}

/*subject type*/
static const char *niqcode[] = {
        "IPv6 address",
        "DNS label",    /*or empty*/
        "IPv4 address",
};

/*result code*/
static const char *nircode[] = {
        "Success", "Refused", "Unknown",
};


/*
 * pr_icmph --
 *      Print a descriptive string about an ICMP header.
 */
static void
pr_icmph(struct icmp6_hdr *icp, u_char *end)
{
        char ntop_buf[INET6_ADDRSTRLEN];
        struct nd_redirect *red;
        struct icmp6_nodeinfo *ni;
        char dnsname[MAXDNAME + 1];
        const u_char *cp;
        size_t l;

        switch (icp->icmp6_type) {
        case ICMP6_DST_UNREACH:
                switch (icp->icmp6_code) {
                case ICMP6_DST_UNREACH_NOROUTE:
                        printf("No Route to Destination\n");
                        break;
                case ICMP6_DST_UNREACH_ADMIN:
                        printf("Destination Administratively "
                            "Unreachable\n");
                        break;
                case ICMP6_DST_UNREACH_BEYONDSCOPE:
                        printf("Destination Unreachable Beyond Scope\n");
                        break;
                case ICMP6_DST_UNREACH_ADDR:
                        printf("Destination Host Unreachable\n");
                        break;
                case ICMP6_DST_UNREACH_NOPORT:
                        printf("Destination Port Unreachable\n");
                        break;
                default:
                        printf("Destination Unreachable, Bad Code: %d\n",
                            icp->icmp6_code);
                        break;
                }
                /* Print returned IP header information */
                pr_retip((struct ip6_hdr *)(icp + 1), end);
                break;
        case ICMP6_PACKET_TOO_BIG:
                printf("Packet too big mtu = %d\n",
                    (int)ntohl(icp->icmp6_mtu));
                pr_retip((struct ip6_hdr *)(icp + 1), end);
                break;
        case ICMP6_TIME_EXCEEDED:
                switch (icp->icmp6_code) {
                case ICMP6_TIME_EXCEED_TRANSIT:
                        printf("Time to live exceeded\n");
                        break;
                case ICMP6_TIME_EXCEED_REASSEMBLY:
                        printf("Frag reassembly time exceeded\n");
                        break;
                default:
                        printf("Time exceeded, Bad Code: %d\n",
                            icp->icmp6_code);
                        break;
                }
                pr_retip((struct ip6_hdr *)(icp + 1), end);
                break;
        case ICMP6_PARAM_PROB:
                printf("Parameter problem: ");
                switch (icp->icmp6_code) {
                case ICMP6_PARAMPROB_HEADER:
                        printf("Erroneous Header ");
                        break;
                case ICMP6_PARAMPROB_NEXTHEADER:
                        printf("Unknown Nextheader ");
                        break;
                case ICMP6_PARAMPROB_OPTION:
                        printf("Unrecognized Option ");
                        break;
                case ICMP6_PARAMPROB_FRAGMENT:
                        printf("First Fragment Has Incomplete Chain ");
                        break;
                default:
                        printf("Bad code(%d) ", icp->icmp6_code);
                        break;
                }
                printf("pointer = 0x%02x\n",
                    (u_int32_t)ntohl(icp->icmp6_pptr));
                pr_retip((struct ip6_hdr *)(icp + 1), end);
                break;
        case ICMP6_ECHO_REQUEST:
                printf("Echo Request");
                /* XXX ID + Seq + Data */
                break;
        case ICMP6_ECHO_REPLY:
                printf("Echo Reply");
                /* XXX ID + Seq + Data */
                break;
        case ICMP6_MEMBERSHIP_QUERY:
                printf("Listener Query");
                break;
        case ICMP6_MEMBERSHIP_REPORT:
                printf("Listener Report");
                break;
        case ICMP6_MEMBERSHIP_REDUCTION:
                printf("Listener Done");
                break;
        case ND_ROUTER_SOLICIT:
                printf("Router Solicitation");
                break;
        case ND_ROUTER_ADVERT:
                printf("Router Advertisement");
                break;
        case ND_NEIGHBOR_SOLICIT:
                printf("Neighbor Solicitation");
                break;
        case ND_NEIGHBOR_ADVERT:
                printf("Neighbor Advertisement");
                break;
        case ND_REDIRECT:
                red = (struct nd_redirect *)icp;
                printf("Redirect\n");
                if (!inet_ntop(AF_INET6, &red->nd_rd_dst, ntop_buf,
                    sizeof(ntop_buf)))
                        strlcpy(ntop_buf, "?", sizeof(ntop_buf));
                printf("Destination: %s", ntop_buf);
                if (!inet_ntop(AF_INET6, &red->nd_rd_target, ntop_buf,
                    sizeof(ntop_buf)))
                        strlcpy(ntop_buf, "?", sizeof(ntop_buf));
                printf(" New Target: %s", ntop_buf);
                break;
        case ICMP6_NI_QUERY:
                printf("Node Information Query");
                /* XXX ID + Seq + Data */
                ni = (struct icmp6_nodeinfo *)icp;
                l = end - (u_char *)(ni + 1);
                printf(", ");
                switch (ntohs(ni->ni_qtype)) {
                case NI_QTYPE_NOOP:
                        printf("NOOP");
                        break;
                case NI_QTYPE_SUPTYPES:
                        printf("Supported qtypes");
                        break;
                case NI_QTYPE_FQDN:
                        printf("DNS name");
                        break;
                case NI_QTYPE_NODEADDR:
                        printf("nodeaddr");
                        break;
                case NI_QTYPE_IPV4ADDR:
                        printf("IPv4 nodeaddr");
                        break;
                default:
                        printf("unknown qtype");
                        break;
                }
                if (options & F_VERBOSE) {
                        switch (ni->ni_code) {
                        case ICMP6_NI_SUBJ_IPV6:
                                if (l == sizeof(struct in6_addr) &&
                                    inet_ntop(AF_INET6, ni + 1, ntop_buf,
                                    sizeof(ntop_buf)) != NULL) {
                                        printf(", subject=%s(%s)",
                                            niqcode[ni->ni_code], ntop_buf);
                                } else {
#if 1
                                        /* backward compat to -W */
                                        printf(", oldfqdn");
#else
                                        printf(", invalid");
#endif
                                }
                                break;
                        case ICMP6_NI_SUBJ_FQDN:
                                if (end == (u_char *)(ni + 1)) {
                                        printf(", no subject");
                                        break;
                                }
                                printf(", subject=%s", niqcode[ni->ni_code]);
                                cp = (const u_char *)(ni + 1);
                                if (dnsdecode(&cp, end, NULL, dnsname,
                                    sizeof(dnsname)) != NULL)
                                        printf("(%s)", dnsname);
                                else
                                        printf("(invalid)");
                                break;
                        case ICMP6_NI_SUBJ_IPV4:
                                if (l == sizeof(struct in_addr) &&
                                    inet_ntop(AF_INET, ni + 1, ntop_buf,
                                    sizeof(ntop_buf)) != NULL) {
                                        printf(", subject=%s(%s)",
                                            niqcode[ni->ni_code], ntop_buf);
                                } else
                                        printf(", invalid");
                                break;
                        default:
                                printf(", invalid");
                                break;
                        }
                }
                break;
        case ICMP6_NI_REPLY:
                printf("Node Information Reply");
                /* XXX ID + Seq + Data */
                ni = (struct icmp6_nodeinfo *)icp;
                printf(", ");
                switch (ntohs(ni->ni_qtype)) {
                case NI_QTYPE_NOOP:
                        printf("NOOP");
                        break;
                case NI_QTYPE_SUPTYPES:
                        printf("Supported qtypes");
                        break;
                case NI_QTYPE_FQDN:
                        printf("DNS name");
                        break;
                case NI_QTYPE_NODEADDR:
                        printf("nodeaddr");
                        break;
                case NI_QTYPE_IPV4ADDR:
                        printf("IPv4 nodeaddr");
                        break;
                default:
                        printf("unknown qtype");
                        break;
                }
                if (options & F_VERBOSE) {
                        if (ni->ni_code >= sizeof(nircode) / sizeof(nircode[0]))
                                printf(", invalid");
                        else
                                printf(", %s", nircode[ni->ni_code]);
                }
                break;
        default:
                printf("Bad ICMP type: %d", icp->icmp6_type);
        }
}

/*
 * pr_iph --
 *      Print an IP6 header.
 */
static void
pr_iph(struct ip6_hdr *ip6)
{
        u_int32_t flow = ip6->ip6_flow & IPV6_FLOWLABEL_MASK;
        u_int8_t tc;
        char ntop_buf[INET6_ADDRSTRLEN];

        tc = *(&ip6->ip6_vfc + 1); /* XXX */
        tc = (tc >> 4) & 0x0f;
        tc |= (ip6->ip6_vfc << 4);

        printf("Vr TC  Flow Plen Nxt Hlim\n");
        printf(" %1x %02x %05x %04x  %02x   %02x\n",
            (ip6->ip6_vfc & IPV6_VERSION_MASK) >> 4, tc, (u_int32_t)ntohl(flow),
            ntohs(ip6->ip6_plen), ip6->ip6_nxt, ip6->ip6_hlim);
        if (!inet_ntop(AF_INET6, &ip6->ip6_src, ntop_buf, sizeof(ntop_buf)))
                strlcpy(ntop_buf, "?", sizeof(ntop_buf));
        printf("%s->", ntop_buf);
        if (!inet_ntop(AF_INET6, &ip6->ip6_dst, ntop_buf, sizeof(ntop_buf)))
                strlcpy(ntop_buf, "?", sizeof(ntop_buf));
        printf("%s\n", ntop_buf);
}

/*
 * pr_addr --
 *      Return an ascii host address as a dotted quad and optionally with
 * a hostname.
 */
static const char *
pr_addr(struct sockaddr *addr, int addrlen)
{
        static char buf[NI_MAXHOST];
        int flag = 0;

        if ((options & F_HOSTNAME) == 0)
                flag |= NI_NUMERICHOST;

        if (getnameinfo(addr, addrlen, buf, sizeof(buf), NULL, 0, flag) == 0)
                return (buf);
        else
                return "?";
}

/*
 * pr_retip --
 *      Dump some info on a returned (via ICMPv6) IPv6 packet.
 */
static void
pr_retip(struct ip6_hdr *ip6, u_char *end)
{
        u_char *cp = (u_char *)ip6, nh;
        int hlen;

        if (end - (u_char *)ip6 < (intptr_t)sizeof(*ip6)) {
                printf("IP6");
                goto trunc;
        }
        pr_iph(ip6);
        hlen = sizeof(*ip6);

        nh = ip6->ip6_nxt;
        cp += hlen;
        while (end - cp >= 8) {
                switch (nh) {
                case IPPROTO_HOPOPTS:
                        printf("HBH ");
                        hlen = (((struct ip6_hbh *)cp)->ip6h_len+1) << 3;
                        nh = ((struct ip6_hbh *)cp)->ip6h_nxt;
                        break;
                case IPPROTO_DSTOPTS:
                        printf("DSTOPT ");
                        hlen = (((struct ip6_dest *)cp)->ip6d_len+1) << 3;
                        nh = ((struct ip6_dest *)cp)->ip6d_nxt;
                        break;
                case IPPROTO_FRAGMENT:
                        printf("FRAG ");
                        hlen = sizeof(struct ip6_frag);
                        nh = ((struct ip6_frag *)cp)->ip6f_nxt;
                        break;
                case IPPROTO_ROUTING:
                        printf("RTHDR ");
                        hlen = (((struct ip6_rthdr *)cp)->ip6r_len+1) << 3;
                        nh = ((struct ip6_rthdr *)cp)->ip6r_nxt;
                        break;
#ifdef IPSEC
                case IPPROTO_AH:
                        printf("AH ");
                        hlen = (((struct ip6_ext *)cp)->ip6e_len+2) << 2;
                        nh = ((struct ip6_ext *)cp)->ip6e_nxt;
                        break;
#endif
                case IPPROTO_ICMPV6:
                        printf("ICMP6: type = %d, code = %d\n",
                            *cp, *(cp + 1));
                        return;
                case IPPROTO_ESP:
                        printf("ESP\n");
                        return;
                case IPPROTO_TCP:
                        printf("TCP: from port %u, to port %u (decimal)\n",
                            (*cp * 256 + *(cp + 1)),
                            (*(cp + 2) * 256 + *(cp + 3)));
                        return;
                case IPPROTO_UDP:
                        printf("UDP: from port %u, to port %u (decimal)\n",
                            (*cp * 256 + *(cp + 1)),
                            (*(cp + 2) * 256 + *(cp + 3)));
                        return;
                default:
                        printf("Unknown Header(%d)\n", nh);
                        return;
                }

                if ((cp += hlen) >= end)
                        goto trunc;
        }
        if (end - cp < 8)
                goto trunc;

        putchar('\n');
        return;

  trunc:
        printf("...\n");
        return;
}

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

        for (cp = patp; *cp; cp++)
                if (!isxdigit((unsigned char)*cp))
                        errx(1, "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]);

/* xxx */
        if (ii > 0)
                for (kk = 0;
                    kk <= (int)(MAXDATALEN - (8 + sizeof(struct tv32) + 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");
        }
}

#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
static int
setpolicy(int so, char *policy)
{
        char *buf;

        if (policy == NULL)
                return 0;       /* ignore */

        buf = ipsec_set_policy(policy, strlen(policy));
        if (buf == NULL)
                errx(1, "%s", ipsec_strerror());
        if (prog_setsockopt(s, IPPROTO_IPV6, IPV6_IPSEC_POLICY, buf,
            ipsec_get_policylen(buf)) < 0)
                warnx("Unable to set IPsec policy");
        free(buf);

        return 0;
}
#endif

static char *
nigroup(char *name)
{
        char *p;
        char *q;
        MD5_CTX ctxt;
        u_int8_t digest[16];
        u_int8_t c;
        size_t l;
        char hbuf[NI_MAXHOST];
        struct in6_addr in6;

        p = strchr(name, '.');
        if (!p)
                p = name + strlen(name);
        l = p - name;
        if (l > 63 || l > sizeof(hbuf) - 1)
                return NULL;    /*label too long*/
        strncpy(hbuf, name, l);
        hbuf[(int)l] = '\0';

        for (q = name; *q; q++) {
                if (isupper(*(unsigned char *)q))
                        *q = tolower(*(unsigned char *)q);
        }

        /* generate 8 bytes of pseudo-random value. */
        memset(&ctxt, 0, sizeof(ctxt));
        MD5Init(&ctxt);
        c = l & 0xff;
        MD5Update(&ctxt, &c, sizeof(c));
        MD5Update(&ctxt, (unsigned char *)name, l);
        MD5Final(digest, &ctxt);

        if (inet_pton(AF_INET6, "ff02::2:0000:0000", &in6) != 1)
                return NULL;    /*XXX*/
        bcopy(digest, &in6.s6_addr[12], 4);

        if (inet_ntop(AF_INET6, &in6, hbuf, sizeof(hbuf)) == NULL)
                return NULL;

        return strdup(hbuf);
}

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

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

static void
usage(void)
{
        fprintf(stderr,
            "usage: ping6 [-dfHmNnqtvWw] [-a addrtype] [-b bufsize]\n"
            "\t[-c count] [-g gateway] [-h hoplimit] [-I interface]\n"
            "\t[-i wait] [-l preload]"
#if defined(IPSEC) && defined(IPSEC_POLICY_IPSEC)
            " [-P policy]"
#endif
            "\n"
            "\t[-p pattern] [-S sourceaddr] [-s packetsize] [-X deadline]\n"
            "\t[-x maxwait] host\n");
        exit(1);
}