/*      $NetBSD: ndp.c,v 1.60 2023/08/18 13:07:38 tnn Exp $     */
/*      $KAME: ndp.c,v 1.121 2005/07/13 11:30:13 keiichi Exp $  */

/*
 * Copyright (C) 1995, 1996, 1997, 1998, and 1999 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.
 */
/*
 * Copyright (c) 1984, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Sun Microsystems, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (c) 1997
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
 * Based on:
 * "@(#) Copyright (c) 1984, 1993\n\
 *      The Regents of the University of California.  All rights reserved.\n";
 *
 * "@(#)arp.c   8.2 (Berkeley) 1/2/94";
 */

/*
 * ndp - display, set, delete and flush neighbor cache
 */


#include <sys/param.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/time.h>

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

#include <netinet/in.h>

#include <netinet/icmp6.h>
#include <netinet6/in6_var.h>
#include <netinet6/nd6.h>

#include <arpa/inet.h>

#include <netdb.h>
#include <errno.h>
#include <nlist.h>
#include <stdio.h>
#include <string.h>
#include <paths.h>
#include <err.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>

#include "prog_ops.h"

static pid_t pid;
static int nflag;
static int tflag;
static int32_t thiszone;        /* time difference with gmt */
static int my_s = -1;
static unsigned int repeat = 0;


static char host_buf[NI_MAXHOST];               /* getnameinfo() */
static char ifix_buf[IFNAMSIZ];         /* if_indextoname() */

static void getsocket(void);
static int set(int, char **);
static void get(char *);
static int delete(struct rt_msghdr *, char *);
static void delete_one(char *);
static void do_foreach(struct in6_addr *, char *, int);
static struct in6_nbrinfo *getnbrinfo(struct in6_addr *, unsigned int, int);
static char *ether_str(struct sockaddr_dl *);
static int ndp_ether_aton(char *, u_char *);
__dead static void usage(void);
static int rtmsg(int, struct rt_msghdr *);
static void ifinfo(char *, int, char **);
static const char *sec2str(time_t);
static char *ether_str(struct sockaddr_dl *);
static void ts_print(const struct timeval *);
static int32_t gmt2local(time_t t);

#define NDP_F_CLEAR     1
#define NDP_F_DELETE    2

static int mode = 0;
static char *arg = NULL;

int
main(int argc, char **argv)
{
        int ch;

        while ((ch = getopt(argc, argv, "acd:f:i:nstA:")) != -1)
                switch (ch) {
                case 'a':
                case 'c':
                case 's':
                case 'd':
                case 'f':
                case 'i' :
                        if (mode) {
                                usage();
                                /*NOTREACHED*/
                        }
                        mode = ch;
                        arg = optarg;
                        break;
                case 'n':
                        nflag = 1;
                        break;
                case 't':
                        tflag = 1;
                        break;
                case 'A':
                        if (mode) {
                                usage();
                                /*NOTREACHED*/
                        }
                        mode = 'a';
                        repeat = atoi(optarg);
                        break;
                default:
                        usage();
                }

        argc -= optind;
        argv += optind;

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

        pid = prog_getpid();
        thiszone = gmt2local(0L);

        switch (mode) {
        case 'a':
        case 'c':
                if (argc != 0) {
                        usage();
                        /*NOTREACHED*/
                }
                do_foreach(0, NULL, mode == 'c' ? NDP_F_CLEAR : 0);
                break;
        case 'd':
                if (argc != 0) {
                        usage();
                        /*NOTREACHED*/
                }
                delete_one(arg);
                break;
        case 'i':
                ifinfo(arg, argc, argv);
                break;
        case 's':
                if (argc < 2 || argc > 4)
                        usage();
                return(set(argc, argv) ? 1 : 0);
        case 0:
                if (argc != 1) {
                        usage();
                        /*NOTREACHED*/
                }
                get(argv[0]);
                break;
        }
        return(0);
}

static void
makeaddr(struct sockaddr_in6 *mysin, const void *resp)
{
        const struct sockaddr_in6 *res = resp;
        mysin->sin6_addr = res->sin6_addr;
        mysin->sin6_scope_id = res->sin6_scope_id;
        inet6_putscopeid(mysin, INET6_IS_ADDR_LINKLOCAL);
}

static void
getsocket(void)
{
        if (my_s < 0) {
                my_s = prog_socket(PF_ROUTE, SOCK_RAW, 0);
                if (my_s < 0)
                        err(1, "socket");
        }
}

#ifdef notdef
static struct sockaddr_in6 so_mask = {
        .sin6_len = sizeof(so_mask),
        .sin6_family = AF_INET6
};
#endif
static struct sockaddr_in6 blank_sin = {
        .sin6_len = sizeof(blank_sin),
        .sin6_family = AF_INET6
};
static struct sockaddr_in6 sin_m;
static struct sockaddr_dl blank_sdl = {
        .sdl_len = sizeof(blank_sdl),
        .sdl_family = AF_LINK,
};
static struct sockaddr_dl sdl_m;
static int expire_time, flags, found_entry;
static struct {
        struct  rt_msghdr m_rtm;
        char    m_space[512];
} m_rtmsg;

/*
 * Set an individual neighbor cache entry
 */
static int
set(int argc, char **argv)
{
        register struct sockaddr_in6 *mysin = &sin_m;
        register struct sockaddr_dl *sdl;
        register struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
        struct addrinfo hints, *res;
        int gai_error;
        u_char *ea;
        char *host = argv[0], *eaddr = argv[1];

        getsocket();
        argc -= 2;
        argv += 2;
        sdl_m = blank_sdl;
        sin_m = blank_sin;

        (void)memset(&hints, 0, sizeof(hints));
        hints.ai_family = AF_INET6;
        gai_error = getaddrinfo(host, NULL, &hints, &res);
        if (gai_error) {
                warnx("%s: %s", host, gai_strerror(gai_error));
                return 1;
        }
        makeaddr(mysin, res->ai_addr);
        freeaddrinfo(res);
        ea = (u_char *)LLADDR(&sdl_m);
        if (ndp_ether_aton(eaddr, ea) == 0)
                sdl_m.sdl_alen = 6;
        flags = expire_time = 0;
        while (argc-- > 0) {
                if (strncmp(argv[0], "temp", 4) == 0) {
                        struct timeval tim;

                        (void)gettimeofday(&tim, 0);
                        expire_time = tim.tv_sec + 20 * 60;
                } else if (strncmp(argv[0], "proxy", 5) == 0)
                        flags |= RTF_ANNOUNCE;
                argv++;
        }
        if (rtmsg(RTM_GET, NULL) < 0) {
                errx(1, "RTM_GET(%s) failed", host);
                /* NOTREACHED */
        }
        mysin = (struct sockaddr_in6 *)(void *)(rtm + 1);
        sdl = (struct sockaddr_dl *)(void *)(RT_ROUNDUP(mysin->sin6_len) + (char *)(void *)mysin);
        if (IN6_ARE_ADDR_EQUAL(&mysin->sin6_addr, &sin_m.sin6_addr)) {
                if (sdl->sdl_family == AF_LINK &&
                    !(rtm->rtm_flags & RTF_GATEWAY)) {
                        switch (sdl->sdl_type) {
                        case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
                        case IFT_ISO88024: case IFT_ISO88025:
                                goto overwrite;
                        }
                }
                /*
                 * IPv4 arp command retries with sin_other = SIN_PROXY here.
                 */
                (void)fprintf(stderr, "set: cannot configure a new entry\n");
                return 1;
        }

overwrite:
        if (sdl->sdl_family != AF_LINK) {
                warnx("cannot intuit interface index and type for %s", host);
                return (1);
        }
        sdl_m.sdl_type = sdl->sdl_type;
        sdl_m.sdl_index = sdl->sdl_index;
        return (rtmsg(RTM_ADD, NULL));
}

/*
 * Display an individual neighbor cache entry
 */
static void
get(char *host)
{
        struct sockaddr_in6 *mysin = &sin_m;
        struct addrinfo hints, *res;
        int gai_error;

        sin_m = blank_sin;
        (void)memset(&hints, 0, sizeof(hints));
        hints.ai_family = AF_INET6;
        gai_error = getaddrinfo(host, NULL, &hints, &res);
        if (gai_error) {
                warnx("%s: %s", host, gai_strerror(gai_error));
                return;
        }
        makeaddr(mysin, res->ai_addr);
        freeaddrinfo(res);
        do_foreach(&mysin->sin6_addr, host, 0);
        if (found_entry == 0) {
                (void)getnameinfo((struct sockaddr *)(void *)mysin,
                    (socklen_t)mysin->sin6_len,
                    host_buf, sizeof(host_buf), NULL ,0,
                    (nflag ? NI_NUMERICHOST : 0));
                errx(1, "%s (%s) -- no entry", host, host_buf);
        }
}

static void
delete_one(char *host)
{
        struct sockaddr_in6 *mysin = &sin_m;
        struct addrinfo hints, *res;
        int gai_error;

        sin_m = blank_sin;
        (void)memset(&hints, 0, sizeof(hints));
        hints.ai_family = AF_INET6;
        gai_error = getaddrinfo(host, NULL, &hints, &res);
        if (gai_error) {
                warnx("%s: %s", host, gai_strerror(gai_error));
                return;
        }
        makeaddr(mysin, res->ai_addr);
        freeaddrinfo(res);
        do_foreach(&mysin->sin6_addr, host, NDP_F_DELETE);
}

/*
 * Delete a neighbor cache entry
 */
static int
delete(struct rt_msghdr *rtm, char *host)
{
        char delete_host_buf[NI_MAXHOST];
        struct sockaddr_in6 *mysin = &sin_m;
        struct sockaddr_dl *sdl;

        getsocket();
        mysin = (struct sockaddr_in6 *)(void *)(rtm + 1);
        sdl = (struct sockaddr_dl *)(void *)(RT_ROUNDUP(mysin->sin6_len) +
            (char *)(void *)mysin);

        if (sdl->sdl_family != AF_LINK) {
                (void)printf("cannot locate %s\n", host);
                return (1);
        }
        if (rtmsg(RTM_DELETE, rtm) == 0) {
                struct sockaddr_in6 s6 = *mysin; /* XXX: for safety */

                s6.sin6_scope_id = 0;
                inet6_putscopeid(&s6, INET6_IS_ADDR_LINKLOCAL);
                (void)getnameinfo((struct sockaddr *)(void *)&s6,
                    (socklen_t)s6.sin6_len, delete_host_buf,
                    sizeof(delete_host_buf), NULL, 0,
                    (nflag ? NI_NUMERICHOST : 0));
                (void)printf("%s (%s) deleted\n", host, delete_host_buf);
        }

        return 0;
}

#define W_ADDR  (8 * 4 + 7)
#define W_LL    17
#define W_IF    6

/*
 * Iterate on neighbor caches and do
 * - dump all caches,
 * - clear all caches (NDP_F_CLEAR) or
 * - remove matched caches (NDP_F_DELETE)
 */
static void
do_foreach(struct in6_addr *addr, char *host, int _flags)
{
        int mib[6];
        size_t needed;
        char *lim, *buf, *next;
        struct rt_msghdr *rtm;
        struct sockaddr_in6 *mysin;
        struct sockaddr_dl *sdl;
        struct in6_nbrinfo *nbi;
        struct timeval tim;
        int addrwidth;
        int llwidth;
        int ifwidth;
        char flgbuf[8], *fl;
        const char *ifname;
        int cflag = _flags == NDP_F_CLEAR;
        int dflag = _flags == NDP_F_DELETE;

        /* Print header */
        if (!tflag && !cflag)
                (void)printf("%-*.*s %-*.*s %*.*s %-9.9s %1s %2s\n",
                    W_ADDR, W_ADDR, "Neighbor", W_LL, W_LL, "Linklayer Address",
                    W_IF, W_IF, "Netif", "Expire", "S", "Fl");

again:;
        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;
        mib[3] = AF_INET6;
        mib[4] = NET_RT_FLAGS;
        mib[5] = RTF_LLDATA;
        if (prog_sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
                err(1, "sysctl(PF_ROUTE estimate)");
        if (needed > 0) {
                if ((buf = malloc(needed)) == NULL)
                        err(1, "malloc");
                if (prog_sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
                        free(buf);
                        if (errno == ENOBUFS)
                                goto again;
                        err(1, "sysctl(PF_ROUTE, NET_RT_FLAGS)");
                }
                lim = buf + needed;
        } else
                buf = lim = NULL;

        for (next = buf; next && next < lim; next += rtm->rtm_msglen) {
                int isrouter = 0, prbs = 0;

                rtm = (struct rt_msghdr *)(void *)next;
                mysin = (struct sockaddr_in6 *)(void *)(rtm + 1);
                sdl = (struct sockaddr_dl *)(void *)((char *)(void *)mysin + RT_ROUNDUP(mysin->sin6_len));

                /*
                 * Some OSes can produce a route that has the LINK flag but
                 * has a non-AF_LINK gateway (e.g. fe80::xx%lo0 on FreeBSD
                 * and BSD/OS, where xx is not the interface identifier on
                 * lo0).  Such routes entry would annoy getnbrinfo() below,
                 * so we skip them.
                 * XXX: such routes should have the GATEWAY flag, not the
                 * LINK flag.  However, there is rotten routing software
                 * that advertises all routes that have the GATEWAY flag.
                 * Thus, KAME kernel intentionally does not set the LINK flag.
                 * What is to be fixed is not ndp, but such routing software
                 * (and the kernel workaround)...
                 */
                if (sdl->sdl_family != AF_LINK)
                        continue;

                if (!(rtm->rtm_flags & RTF_HOST))
                        continue;

                if (addr) {
                        if (!IN6_ARE_ADDR_EQUAL(addr, &mysin->sin6_addr))
                                continue;
                        found_entry = 1;
                } else if (IN6_IS_ADDR_MULTICAST(&mysin->sin6_addr))
                        continue;
                if (dflag) {
                        (void)delete(rtm, host_buf);
                        continue;
                }
                if (IN6_IS_ADDR_LINKLOCAL(&mysin->sin6_addr) ||
                    IN6_IS_ADDR_MC_LINKLOCAL(&mysin->sin6_addr)) {
                        uint16_t scopeid = mysin->sin6_scope_id;
                        inet6_getscopeid(mysin, INET6_IS_ADDR_LINKLOCAL|
                            INET6_IS_ADDR_MC_LINKLOCAL);
                        if (scopeid == 0)
                                mysin->sin6_scope_id = sdl->sdl_index;
                }
                (void)getnameinfo((struct sockaddr *)(void *)mysin,
                    (socklen_t)mysin->sin6_len,
                    host_buf, sizeof(host_buf), NULL, 0,
                    (nflag ? NI_NUMERICHOST : 0));
                if (cflag) {
                        /* Restore scopeid */
                        if (IN6_IS_ADDR_LINKLOCAL(&mysin->sin6_addr) ||
                            IN6_IS_ADDR_MC_LINKLOCAL(&mysin->sin6_addr))
                                inet6_putscopeid(mysin, INET6_IS_ADDR_LINKLOCAL|
                                    INET6_IS_ADDR_MC_LINKLOCAL);
                        if ((rtm->rtm_flags & RTF_STATIC) == 0)
                                (void)delete(rtm, host_buf);
                        continue;
                }
                (void)gettimeofday(&tim, 0);
                if (tflag)
                        ts_print(&tim);

                addrwidth = strlen(host_buf);
                if (addrwidth < W_ADDR)
                        addrwidth = W_ADDR;
                llwidth = strlen(ether_str(sdl));
                if (W_ADDR + W_LL - addrwidth > llwidth)
                        llwidth = W_ADDR + W_LL - addrwidth;
                ifname = if_indextoname((unsigned int)sdl->sdl_index, ifix_buf);
                if (!ifname)
                        ifname = "?";
                ifwidth = strlen(ifname);
                if (W_ADDR + W_LL + W_IF - addrwidth - llwidth > ifwidth)
                        ifwidth = W_ADDR + W_LL + W_IF - addrwidth - llwidth;

                (void)printf("%-*.*s %-*.*s %*.*s", addrwidth, addrwidth,
                    host_buf, llwidth, llwidth, ether_str(sdl), ifwidth,
                    ifwidth, ifname);

                /* Print neighbor discovery specific informations */
                nbi = getnbrinfo(&mysin->sin6_addr,
                    (unsigned int)sdl->sdl_index, 1);
                if (nbi) {
                        if (nbi->expire > tim.tv_sec) {
                                (void)printf(" %-9.9s",
                                    sec2str(nbi->expire - tim.tv_sec));
                        } else if (nbi->expire == 0)
                                (void)printf(" %-9.9s", "permanent");
                        else
                                (void)printf(" %-9.9s", "expired");

                        switch (nbi->state) {
                        case ND_LLINFO_NOSTATE:
                                 (void)printf(" N");
                                 break;
                        case ND_LLINFO_WAITDELETE:
                                 (void)printf(" W");
                                 break;
                        case ND_LLINFO_INCOMPLETE:
                                 (void)printf(" I");
                                 break;
                        case ND_LLINFO_REACHABLE:
                                 (void)printf(" R");
                                 break;
                        case ND_LLINFO_STALE:
                                 (void)printf(" S");
                                 break;
                        case ND_LLINFO_DELAY:
                                 (void)printf(" D");
                                 break;
                        case ND_LLINFO_PROBE:
                                 (void)printf(" P");
                                 break;
                        case ND_LLINFO_UNREACHABLE:
                                 (void)printf(" U");
                                 break;
                        default:
                                 (void)printf(" ?");
                                 break;
                        }

                        isrouter = nbi->isrouter;
                        prbs = nbi->asked;
                } else {
                        warnx("failed to get neighbor information");
                        (void)printf("  ");
                }

                /*
                 * other flags. R: router, P: proxy, W: ??
                 */
                fl = flgbuf;
                if (isrouter)
                        *fl++ = 'R';
                if (rtm->rtm_flags & RTF_ANNOUNCE)
                        *fl++ = 'p';
                *fl++ = '\0';
                (void)printf(" %s", flgbuf);

                if (prbs)
                        (void)printf(" %d", prbs);

                (void)printf("\n");
        }
        if (buf != NULL)
                free(buf);

        if (repeat) {
                (void)printf("\n");
                (void)fflush(stdout);
                (void)sleep(repeat);
                goto again;
        }
}

static struct in6_nbrinfo *
getnbrinfo(struct in6_addr *addr, unsigned int ifindex, int warning)
{
        static struct in6_nbrinfo nbi;
        int s;

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

        (void)memset(&nbi, 0, sizeof(nbi));
        (void)if_indextoname(ifindex, nbi.ifname);
        nbi.addr = *addr;
        if (prog_ioctl(s, SIOCGNBRINFO_IN6, &nbi) < 0) {
                if (warning)
                        warn("ioctl(SIOCGNBRINFO_IN6)");
                (void)prog_close(s);
                return(NULL);
        }

        (void)prog_close(s);
        return(&nbi);
}

static char *
ether_str(struct sockaddr_dl *sdl)
{
        static char hbuf[NI_MAXHOST];

        if (sdl->sdl_alen) {
                if (getnameinfo((struct sockaddr *)(void *)sdl,
                    (socklen_t)sdl->sdl_len,
                    hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0)
                        (void)snprintf(hbuf, sizeof(hbuf), "<invalid>");
        } else
                (void)snprintf(hbuf, sizeof(hbuf), "(incomplete)");

        return(hbuf);
}

static int
ndp_ether_aton(char *a, u_char *n)
{
        int i, o[6];

        i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o[0], &o[1], &o[2],
            &o[3], &o[4], &o[5]);
        if (i != 6) {
                warnx("invalid Ethernet address '%s'", a);
                return (1);
        }
        for (i = 0; i < 6; i++)
                n[i] = o[i];
        return (0);
}

static void
usage(void)
{
        const char *pn = getprogname();

        (void)fprintf(stderr, "Usage: %s [-nt] hostname\n", pn);
        (void)fprintf(stderr,
            "       %s [-nt] -a | -c\n", pn);
        (void)fprintf(stderr, "       %s [-nt] -A wait\n", pn);
        (void)fprintf(stderr, "       %s [-nt] -d hostname\n", pn);
        (void)fprintf(stderr, "       %s [-nt] -f filename\n", pn);
        (void)fprintf(stderr, "       %s [-nt] -i interface [flags...]\n", pn);
        (void)fprintf(stderr,
            "       %s [-nt] -s nodename etheraddr [temp] [proxy]\n", pn);
        exit(1);
}

static int
rtmsg(int cmd, struct rt_msghdr *_rtm)
{
        static int seq;
        register struct rt_msghdr *rtm = _rtm;
        register char *cp = m_rtmsg.m_space;
        register int l;

        errno = 0;
        if (rtm != NULL) {
                memcpy(&m_rtmsg, rtm, rtm->rtm_msglen);
                rtm = &m_rtmsg.m_rtm;
                goto doit;
        }
        (void)memset(&m_rtmsg, 0, sizeof(m_rtmsg));
        rtm = &m_rtmsg.m_rtm;
        rtm->rtm_flags = flags;
        rtm->rtm_version = RTM_VERSION;

        switch (cmd) {
        default:
                errx(1, "internal wrong cmd");
                /*NOTREACHED*/
        case RTM_ADD:
                rtm->rtm_addrs |= RTA_GATEWAY;
                if (expire_time) {
                        rtm->rtm_rmx.rmx_expire = expire_time;
                        rtm->rtm_inits = RTV_EXPIRE;
                }
                rtm->rtm_flags |= (RTF_HOST | RTF_STATIC | RTF_LLDATA);
#ifdef notdef   /* we don't support ipv6addr/128 type proxying. */
                if (rtm->rtm_flags & RTF_ANNOUNCE) {
                        rtm->rtm_flags &= ~RTF_HOST;
                        rtm->rtm_addrs |= RTA_NETMASK;
                }
#endif
                rtm->rtm_addrs |= RTA_DST;
                break;
        case RTM_GET:
                rtm->rtm_flags |= RTF_LLDATA;
                rtm->rtm_addrs |= RTA_DST | RTA_GATEWAY;
        }
#define NEXTADDR(w, s) \
        if (rtm->rtm_addrs & (w)) { \
                (void)memcpy(cp, &s, sizeof(s)); \
                RT_ADVANCE(cp, (struct sockaddr *)(void *)&s); \
        }

        NEXTADDR(RTA_DST, sin_m);
        NEXTADDR(RTA_GATEWAY, sdl_m);
#ifdef notdef   /* we don't support ipv6addr/128 type proxying. */
        (void)memset(&so_mask.sin6_addr, 0xff, sizeof(so_mask.sin6_addr));
        NEXTADDR(RTA_NETMASK, so_mask);
#endif

        rtm->rtm_msglen = cp - (char *)(void *)&m_rtmsg;
doit:
        l = rtm->rtm_msglen;
        rtm->rtm_seq = ++seq;
        rtm->rtm_type = cmd;
        if (prog_write(my_s, &m_rtmsg, (size_t)l) == -1) {
                if (errno != ESRCH || cmd != RTM_DELETE)
                        err(1, "writing to routing socket");
        }
        do {
                l = prog_read(my_s, &m_rtmsg, sizeof(m_rtmsg));
        } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid));
        if (l < 0)
                warn("read from routing socket");
        return (0);
}

static void
ifinfo(char *ifname, int argc, char **argv)
{
        struct in6_ndireq nd;
        int i, s;
        u_int32_t newflags;
        bool valset = false, flagset = false;

        if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
                err(1, "socket");
        (void)memset(&nd, 0, sizeof(nd));
        (void)strlcpy(nd.ifname, ifname, sizeof(nd.ifname));
        if (prog_ioctl(s, SIOCGIFINFO_IN6, &nd) < 0)
                err(1, "ioctl(SIOCGIFINFO_IN6)");
#define ND nd.ndi
        newflags = ND.flags;
        for (i = 0; i < argc; i++) {
                int clear = 0;
                char *cp = argv[i];

                if (*cp == '-') {
                        clear = 1;
                        cp++;
                }

#define SETFLAG(s, f) \
        do {\
                if (strcmp(cp, (s)) == 0) {\
                        if (clear)\
                                newflags &= ~(f);\
                        else\
                                newflags |= (f);\
                        flagset = true; \
                }\
        } while (0)
/*
 * XXX: this macro is not 100% correct, in that it matches "nud" against
 *      "nudbogus".  But we just let it go since this is minor.
 */
#define SETVALUE(f, v) \
        do { \
                char *valptr; \
                unsigned long newval; \
                v = 0; /* unspecified */ \
                if (strncmp(cp, f, strlen(f)) == 0) { \
                        valptr = strchr(cp, '='); \
                        if (valptr == NULL) \
                                err(1, "syntax error in %s field", (f)); \
                        errno = 0; \
                        newval = strtoul(++valptr, NULL, 0); \
                        if (errno) \
                                err(1, "syntax error in %s's value", (f)); \
                        v = newval; \
                        valset = true; \
                } \
        } while (0)

#ifdef ND6_IFF_IFDISABLED
                SETFLAG("disabled", ND6_IFF_IFDISABLED);
#endif
                SETFLAG("nud", ND6_IFF_PERFORMNUD);
#ifdef ND6_IFF_ACCEPT_RTADV
                SETFLAG("accept_rtadv", ND6_IFF_ACCEPT_RTADV);
#endif
#ifdef ND6_IFF_OVERRIDE_RTADV
                SETFLAG("override_rtadv", ND6_IFF_OVERRIDE_RTADV);
#endif
#ifdef ND6_IFF_AUTO_LINKLOCAL
                SETFLAG("auto_linklocal", ND6_IFF_AUTO_LINKLOCAL);
#endif
#ifdef ND6_IFF_PREFER_SOURCE
                SETFLAG("prefer_source", ND6_IFF_PREFER_SOURCE);
#endif
#ifdef ND6_IFF_DONT_SET_IFROUTE
                SETFLAG("dont_set_ifroute", ND6_IFF_DONT_SET_IFROUTE);
#endif
                SETVALUE("basereachable", ND.basereachable);
                SETVALUE("retrans", ND.retrans);
                SETVALUE("curhlim", ND.chlim);

                ND.flags = newflags;
#ifdef SIOCSIFINFO_IN6
                if (valset && prog_ioctl(s, SIOCSIFINFO_IN6, &nd) < 0)
                        err(1, "ioctl(SIOCSIFINFO_IN6)");
#endif
                if (flagset && prog_ioctl(s, SIOCSIFINFO_FLAGS, &nd) < 0)
                        err(1, "ioctl(SIOCSIFINFO_FLAGS)");
#undef SETFLAG
#undef SETVALUE
        }

        if (prog_ioctl(s, SIOCGIFINFO_IN6, &nd) < 0)
                err(1, "ioctl(SIOCGIFINFO_IN6)");
        (void)printf("curhlim=%d", ND.chlim);
        (void)printf(", basereachable=%ds%dms",
            ND.basereachable / 1000, ND.basereachable % 1000);
        (void)printf(", retrans=%ds%dms", ND.retrans / 1000, ND.retrans % 1000);
        if (ND.flags) {
                (void)printf("\nFlags: ");
                if ((ND.flags & ND6_IFF_PERFORMNUD))
                        (void)printf("nud ");
#ifdef ND6_IFF_IFDISABLED
                if ((ND.flags & ND6_IFF_IFDISABLED))
                        (void)printf("disabled ");
#endif
#ifdef ND6_IFF_AUTO_LINKLOCAL
                if ((ND.flags & ND6_IFF_AUTO_LINKLOCAL))
                        (void)printf("auto_linklocal ");
#endif
#ifdef ND6_IFF_PREFER_SOURCE
                if ((ND.flags & ND6_IFF_PREFER_SOURCE))
                        (void)printf("prefer_source ");
#endif
        }
        (void)putc('\n', stdout);
#undef ND

        (void)prog_close(s);
}

static const char *
sec2str(time_t total)
{
        static char result[256];
        int days, hours, mins, secs;
        int first = 1;
        char *p = result;
        char *ep = &result[sizeof(result)];
        int n;

        days = total / 3600 / 24;
        hours = (total / 3600) % 24;
        mins = (total / 60) % 60;
        secs = total % 60;

        if (days) {
                first = 0;
                n = snprintf(p, (size_t)(ep - p), "%dd", days);
                if (n < 0 || n >= ep - p)
                        return "?";
                p += n;
        }
        if (!first || hours) {
                first = 0;
                n = snprintf(p, (size_t)(ep - p), "%dh", hours);
                if (n < 0 || n >= ep - p)
                        return "?";
                p += n;
        }
        if (!first || mins) {
                first = 0;
                n = snprintf(p, (size_t)(ep - p), "%dm", mins);
                if (n < 0 || n >= ep - p)
                        return "?";
                p += n;
        }
        (void)snprintf(p, (size_t)(ep - p), "%ds", secs);

        return(result);
}

/*
 * Print the timestamp
 * from tcpdump/util.c
 */
static void
ts_print(const struct timeval *tvp)
{
        int s;

        /* Default */
        s = (tvp->tv_sec + thiszone) % 86400;
        (void)printf("%02d:%02d:%02d.%06u ",
            s / 3600, (s % 3600) / 60, s % 60, (u_int32_t)tvp->tv_usec);
}

/*
 * Returns the difference between gmt and local time in seconds.
 * Use gmtime() and localtime() to keep things simple.
 */
static int32_t
gmt2local(time_t t)
{
        int dt, dir;
        struct tm *gmt, *loc;
        struct tm sgmt;

        if (t == 0)
                t = time(NULL);
        gmt = &sgmt;
        *gmt = *gmtime(&t);
        loc = localtime(&t);
        dt = (loc->tm_hour - gmt->tm_hour) * 60 * 60 +
            (loc->tm_min - gmt->tm_min) * 60;

        /*
         * If the year or julian day is different, we span 00:00 GMT
         * and must add or subtract a day. Check the year first to
         * avoid problems when the julian day wraps.
         */
        dir = loc->tm_year - gmt->tm_year;
        if (dir == 0)
                dir = loc->tm_yday - gmt->tm_yday;
        dt += dir * 24 * 60 * 60;

        return (dt);
}