root/usr.sbin/ndp/ndp.c
/*      $OpenBSD: ndp.c,v 1.109 2023/04/05 13:56:41 bluhm Exp $ */
/*      $KAME: ndp.c,v 1.101 2002/07/17 08:46:33 itojun 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.
 */

/*
 * 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/ioctl.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/queue.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 <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <err.h>

/* packing rule for routing socket */
#define ROUNDUP(a) \
        ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))

static pid_t pid;
static int nflag;
static int tflag;
static int rtsock = -1;
static int repeat = 0;

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

int file(char *);
void getsocket(void);
int parse_host(const char *, struct sockaddr_in6 *);
int set(int, char **);
void get(const char *);
int delete(const char *);
void dump(struct sockaddr_in6 *, int);
static struct in6_nbrinfo *getnbrinfo(struct in6_addr *, int, int);
static char *ether_str(struct sockaddr_dl *);
int ndp_ether_aton(const char *, u_char *);
void usage(void);
int rtmsg(int);
int rtget(struct sockaddr_in6 **, struct sockaddr_dl **);
void ifinfo(const char *);
static char *sec2str(time_t);
static int rdomain;

int
main(int argc, char *argv[])
{
        int              ch, mode = 0, error = 0;
        char            *arg = NULL;
        const char      *errstr;

        pid = getpid();
        rdomain = getrtable();
        while ((ch = getopt(argc, argv, "acd:f:i:nstA:V:")) != -1) {
                switch (ch) {
                case 'a':
                case 'c':
                case 'p':
                case 'r':
                case 'P':
                case 's':
                        if (mode) {
                                usage();
                        }
                        mode = ch;
                        arg = NULL;
                        break;
                case 'd':
                case 'f':
                case 'i' :
                        if (mode) {
                                usage();
                        }
                        mode = ch;
                        arg = optarg;
                        break;
                case 'n':
                        nflag = 1;
                        break;
                case 't':
                        tflag = 1;
                        break;
                case 'A':
                        if (mode) {
                                usage();
                        }
                        mode = 'a';
                        repeat = strtonum(optarg, 1, INT_MAX, &errstr);
                        if (errstr) {
                                usage();
                        }
                        break;
                case 'V':
                        rdomain = strtonum(optarg, 0, RT_TABLEID_MAX, &errstr);
                        if (errstr != NULL) {
                                warn("bad rdomain: %s", errstr);
                                usage();
                        }
                        break;
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        switch (mode) {
        case 'a':
        case 'c':
                if (argc != 0) {
                        usage();
                }
                dump(NULL, mode == 'c');
                break;
        case 'd':
                if (argc != 0) {
                        usage();
                }
                error = delete(arg);
                break;
        case 'f':
                if (argc != 0)
                        usage();
                file(arg);
                break;
        case 'i':
                if (argc != 0)
                        usage();
                ifinfo(arg);
                break;
        case 's':
                if (argc < 2 || argc > 4)
                        usage();
                exit(set(argc, argv) ? 1 : 0);
        case 0:
                if (argc != 1) {
                        usage();
                }
                get(argv[0]);
                break;
        }
        return (error);
}

/*
 * Process a file to set standard ndp entries
 */
int
file(char *name)
{
        FILE *fp;
        int i, retval;
        char line[100], arg[5][50], *args[5];

        if ((fp = fopen(name, "r")) == NULL) {
                err(1, "cannot open %s", name);
        }
        args[0] = &arg[0][0];
        args[1] = &arg[1][0];
        args[2] = &arg[2][0];
        args[3] = &arg[3][0];
        args[4] = &arg[4][0];
        retval = 0;
        while (fgets(line, sizeof(line), fp) != NULL) {
                i = sscanf(line, "%49s %49s %49s %49s %49s",
                    arg[0], arg[1], arg[2], arg[3], arg[4]);
                if (i < 2) {
                        warnx("bad line: %s", line);
                        retval = 1;
                        continue;
                }
                if (set(i, args))
                        retval = 1;
        }
        fclose(fp);
        return (retval);
}

void
getsocket(void)
{
        socklen_t len = sizeof(rdomain);

        if (rtsock >= 0)
                return;
        rtsock = socket(AF_ROUTE, SOCK_RAW, 0);
        if (rtsock == -1)
                err(1, "routing socket");
        if (setsockopt(rtsock, AF_ROUTE, ROUTE_TABLEFILTER, &rdomain, len) == -1)
                err(1, "ROUTE_TABLEFILTER");

        if (pledge("stdio dns", NULL) == -1)
                err(1, "pledge");
}

int
parse_host(const char *host, struct sockaddr_in6 *sin6)
{
        struct addrinfo hints, *res;
        int gai_error;

        bzero(&hints, sizeof(hints));
        hints.ai_family = AF_INET6;
        if (nflag)
                hints.ai_flags = AI_NUMERICHOST;

        gai_error = getaddrinfo(host, NULL, &hints, &res);
        if (gai_error) {
                warnx("%s: %s", host, gai_strerror(gai_error));
                return 1;
        }
        *sin6 = *(struct sockaddr_in6 *)res->ai_addr;
        freeaddrinfo(res);
        return 0;
}

struct  sockaddr_in6 so_mask = {sizeof(so_mask), AF_INET6 };
struct  sockaddr_in6 blank_sin = {sizeof(blank_sin), AF_INET6 }, sin_m;
struct  sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
struct  sockaddr_dl ifp_m = { sizeof(ifp_m), AF_LINK };
time_t  expire_time;
int     flags, found_entry;
struct  {
        struct  rt_msghdr m_rtm;
        char    m_space[512];
}       m_rtmsg;

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

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

        if (parse_host(host, sin))
                return 1;
        ea = (u_char *)LLADDR(&sdl_m);
        if (ndp_ether_aton(eaddr, ea) == 0)
                sdl_m.sdl_alen = 6;
        expire_time = 0;
        flags = 0;
        while (argc-- > 0) {
                if (strncmp(argv[0], "temp", 4) == 0) {
                        struct timeval now;

                        gettimeofday(&now, 0);
                        expire_time = now.tv_sec + 20 * 60;
                } else if (strncmp(argv[0], "proxy", 5) == 0)
                        flags |= RTF_ANNOUNCE;
                argv++;
        }

        if (rtget(&sin, &sdl)) {
                errx(1, "RTM_GET(%s) failed", host);
        }

        if (IN6_ARE_ADDR_EQUAL(&sin->sin6_addr, &sin_m.sin6_addr) &&
            sin->sin6_scope_id == sin_m.sin6_scope_id) {
                if (sdl->sdl_family == AF_LINK &&
                    (rtm->rtm_flags & RTF_LLINFO) &&
                    !(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.
                 */
                warnx("set: cannot configure a new entry");
                return 1;
        }

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

/*
 * Display an individual neighbor cache entry
 */
void
get(const char *host)
{
        struct sockaddr_in6 *sin = &sin_m;

        sin_m = blank_sin;
        if (parse_host(host, sin))
                return;

        dump(sin, 0);
        if (found_entry == 0) {
                getnameinfo((struct sockaddr *)sin, sin->sin6_len, host_buf,
                    sizeof(host_buf), NULL ,0,
                    (nflag ? NI_NUMERICHOST : 0));
                printf("%s (%s) -- no entry\n", host, host_buf);
                exit(1);
        }
}

/*
 * Delete a neighbor cache entry
 */
int
delete(const char *host)
{
        struct sockaddr_in6 *sin;
        struct rt_msghdr *rtm;
        struct sockaddr_dl *sdl;

        sin = &sin_m;
        rtm = &m_rtmsg.m_rtm;

        getsocket();
        sin_m = blank_sin;              /* struct copy */
        if (parse_host(host, sin))
                return 1;
        if (rtget(&sin, &sdl)) {
                warn("%s", host);
                return 1;
        }
        if (IN6_ARE_ADDR_EQUAL(&sin->sin6_addr, &sin_m.sin6_addr) &&
            sin->sin6_scope_id == sin_m.sin6_scope_id) {
                if (sdl->sdl_family == AF_LINK && rtm->rtm_flags & RTF_LLINFO) {
                        if (rtm->rtm_flags & RTF_LOCAL)
                                return 0;
                        if ((rtm->rtm_flags & RTF_GATEWAY) == 0)
                                goto delete;
                }
        }

        /*
         * IPv4 arp command retries with sin_other = SIN_PROXY here.
         */
        warnx("delete: cannot locate %s", host);
        return 1;

delete:
        if (sdl->sdl_family != AF_LINK) {
                printf("cannot locate %s\n", host);
                return 1;
        }
        if (rtmsg(RTM_DELETE))
                return 1;
        getnameinfo((struct sockaddr *)sin, sin->sin6_len, host_buf,
            sizeof(host_buf), NULL, 0, (nflag ? NI_NUMERICHOST : 0));
        printf("%s (%s) deleted\n", host, host_buf);
        return 0;
}

/*
 * strlen("2001:0db8:3333:4444:5555:6666:7777:8888") == 39
 */
#define W_ADDR  39
#define W_LL    17
#define W_IF    7

/*
 * Dump the entire neighbor cache
 */
void
dump(struct sockaddr_in6 *addr, int cflag)
{
        int mib[7];
        size_t needed;
        char *lim, *buf = NULL, *next;
        struct rt_msghdr *rtm;
        struct sockaddr_in6 *sin;
        struct sockaddr_dl *sdl;
        struct in6_nbrinfo *nbi;
        struct timeval now;
        int addrwidth;
        int llwidth;
        int ifwidth;
        char *ifname;

        /* Print header */
        if (!tflag && !cflag)
                printf("%-*.*s %-*.*s %*.*s %-9.9s %1s %5s\n",
                    W_ADDR, W_ADDR, "Neighbor", W_LL, W_LL, "Linklayer Address",
                    W_IF, W_IF, "Netif", "Expire", "S", "Flags");

again:;
        lim = NULL;
        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;
        mib[3] = AF_INET6;
        mib[4] = NET_RT_FLAGS;
        mib[5] = RTF_LLINFO;
        mib[6] = rdomain;
        while (1) {
                if (sysctl(mib, 7, NULL, &needed, NULL, 0) == -1)
                        err(1, "sysctl(PF_ROUTE estimate)");
                if (needed == 0)
                        break;
                if ((buf = realloc(buf, needed)) == NULL)
                        err(1, "realloc");
                if (sysctl(mib, 7, buf, &needed, NULL, 0) == -1) {
                        if (errno == ENOMEM)
                                continue;
                        err(1, "sysctl(PF_ROUTE, NET_RT_FLAGS)");
                }
                lim = buf + needed;
                break;
        }

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

                rtm = (struct rt_msghdr *)next;
                if (rtm->rtm_version != RTM_VERSION)
                        continue;
                sin = (struct sockaddr_in6 *)(next + rtm->rtm_hdrlen);
#ifdef __KAME__
                {
                        struct in6_addr *in6 = &sin->sin6_addr;
                        if ((IN6_IS_ADDR_LINKLOCAL(in6) ||
                            IN6_IS_ADDR_MC_LINKLOCAL(in6) ||
                            IN6_IS_ADDR_MC_INTFACELOCAL(in6)) &&
                            sin->sin6_scope_id == 0) {
                                sin->sin6_scope_id = (u_int32_t)
                                    ntohs(*(u_short *)&in6->s6_addr[2]);
                                *(u_short *)&in6->s6_addr[2] = 0;
                        }
                }
#endif
                sdl = (struct sockaddr_dl *)((char *)sin + ROUNDUP(sin->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->sin6_addr,
                            &sin->sin6_addr) || addr->sin6_scope_id !=
                            sin->sin6_scope_id)
                                continue;
                        found_entry = 1;
                } else if (IN6_IS_ADDR_MULTICAST(&sin->sin6_addr))
                        continue;
                getnameinfo((struct sockaddr *)sin, sin->sin6_len, host_buf,
                    sizeof(host_buf), NULL, 0, (nflag ? NI_NUMERICHOST : 0));
                if (cflag) {
                        if (rtm->rtm_flags & RTF_CLONED)
                                delete(host_buf);
                        continue;
                }
                gettimeofday(&now, 0);
                if (tflag) {
                        char buf[sizeof("00:00:00")];
                        struct tm *tm;

                        tm = localtime(&now.tv_sec);
                        if (tm != NULL) {
                                strftime(buf, sizeof(buf), "%H:%M:%S", tm);
                                printf("%s.%06ld ", buf, now.tv_usec);
                        }
                }

                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(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;

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

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

                        switch (nbi->state) {
                        case ND6_LLINFO_NOSTATE:
                                 printf(" N");
                                 break;
                        case ND6_LLINFO_INCOMPLETE:
                                 printf(" I");
                                 break;
                        case ND6_LLINFO_REACHABLE:
                                 printf(" R");
                                 break;
                        case ND6_LLINFO_STALE:
                                 printf(" S");
                                 break;
                        case ND6_LLINFO_DELAY:
                                 printf(" D");
                                 break;
                        case ND6_LLINFO_PROBE:
                                 printf(" P");
                                 break;
                        default:
                                 printf(" ?");
                                 break;
                        }

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

                printf(" %s%s%s",
                    (rtm->rtm_flags & RTF_LOCAL) ? "l" : "",
                    isrouter ? "R" : "",
                    (rtm->rtm_flags & RTF_ANNOUNCE) ? "p" : "");

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

                printf("\n");
        }

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

        free(buf);
}

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

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

        bzero(&nbi, sizeof(nbi));
        if_indextoname(ifindex, nbi.ifname);
        nbi.addr = *addr;
        if (ioctl(s, SIOCGNBRINFO_IN6, (caddr_t)&nbi) == -1) {
                if (warning)
                        warn("ioctl(SIOCGNBRINFO_IN6)");
                close(s);
                return(NULL);
        }

        close(s);
        return(&nbi);
}

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

        if (sdl->sdl_alen) {
                cp = (u_char *)LLADDR(sdl);
                snprintf(hbuf, sizeof(hbuf), "%02x:%02x:%02x:%02x:%02x:%02x",
                    cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]);
        } else
                snprintf(hbuf, sizeof(hbuf), "(incomplete)");

        return(hbuf);
}

int
ndp_ether_aton(const 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);
}

void
usage(void)
{
        printf("usage: ndp [-acnt] ");
        printf("[-A wait] [-d hostname] [-f filename] [-i interface]\n");
        printf("\t[-s nodename ether_addr [temp] [proxy]] ");
        printf("[-V rdomain] [hostname]\n");
        exit(1);
}

int
rtmsg(int cmd)
{
        static int seq;
        int rlen;
        struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
        char *cp = m_rtmsg.m_space;
        int l;

        errno = 0;
        if (cmd == RTM_DELETE)
                goto doit;
        bzero((char *)&m_rtmsg, sizeof(m_rtmsg));
        rtm->rtm_flags = flags;
        rtm->rtm_version = RTM_VERSION;
        rtm->rtm_tableid = rdomain;

        switch (cmd) {
        default:
                errx(1, "internal wrong cmd");
        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);
#if 0   /* 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
                /* FALLTHROUGH */
        case RTM_GET:
                rtm->rtm_addrs |= (RTA_DST | RTA_IFP);
        }

#define NEXTADDR(w, s)                                                  \
        if (rtm->rtm_addrs & (w)) {                                     \
                memcpy(cp, &(s), sizeof(s));                            \
                ADVANCE(cp, (struct sockaddr *)&(s));                   \
        }

#ifdef __KAME__
        {
                struct sockaddr_in6 sin6 = sin_m;
                struct in6_addr *in6 = &sin6.sin6_addr;
                if (IN6_IS_ADDR_LINKLOCAL(in6) ||
                    IN6_IS_ADDR_MC_LINKLOCAL(in6) ||
                    IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
                        *(u_int16_t *)& in6->s6_addr[2] =
                            htons(sin6.sin6_scope_id);
                        sin6.sin6_scope_id = 0;
                }
                NEXTADDR(RTA_DST, sin6);
        }
#else
        NEXTADDR(RTA_DST, sin_m);
#endif
        NEXTADDR(RTA_GATEWAY, sdl_m);
#if 0   /* we don't support ipv6addr/128 type proxying. */
        memset(&so_mask.sin6_addr, 0xff, sizeof(so_mask.sin6_addr));
        NEXTADDR(RTA_NETMASK, so_mask);
#endif
        NEXTADDR(RTA_IFP, ifp_m);

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

int
rtget(struct sockaddr_in6 **sinp, struct sockaddr_dl **sdlp)
{
        struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
        struct sockaddr_in6 *sin = NULL;
        struct sockaddr_dl *sdl = NULL;
        struct sockaddr *sa;
        char *cp;
        unsigned int i;

        if (rtmsg(RTM_GET) < 0)
                return (1);

        if (rtm->rtm_addrs) {
                cp = ((char *)rtm + rtm->rtm_hdrlen);
                for (i = 1; i; i <<= 1) {
                        if (i & rtm->rtm_addrs) {
                                sa = (struct sockaddr *)cp;
                                switch (i) {
                                case RTA_DST:
                                        sin = (struct sockaddr_in6 *)sa;
                                        break;
                                case RTA_IFP:
                                        sdl = (struct sockaddr_dl *)sa;
                                        break;
                                default:
                                        break;
                                }
                                ADVANCE(cp, sa);
                        }
                }
        }

        if (sin == NULL || sdl == NULL)
                return (1);

#ifdef __KAME__
        {
                static struct sockaddr_in6 ksin;
                struct in6_addr *in6;

                /* do not damage the route message, we need it for delete */
                ksin = *sin;
                sin = &ksin;
                in6 = &sin->sin6_addr;

                if ((IN6_IS_ADDR_LINKLOCAL(in6) ||
                    IN6_IS_ADDR_MC_LINKLOCAL(in6) ||
                    IN6_IS_ADDR_MC_INTFACELOCAL(in6)) &&
                    sin->sin6_scope_id == 0) {
                        sin->sin6_scope_id = (u_int32_t)ntohs(*(u_short *)
                            &in6->s6_addr[2]);
                        *(u_short *)&in6->s6_addr[2] = 0;
                }
        }
#endif
        *sinp = sin;
        *sdlp = sdl;

        return (0);
}

void
ifinfo(const char *ifname)
{
        struct in6_ndireq nd;
        int s;

        if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) == -1) {
                err(1, "socket");
        }
        bzero(&nd, sizeof(nd));
        strlcpy(nd.ifname, ifname, sizeof(nd.ifname));
        if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) == -1)
                err(1, "ioctl(SIOCGIFINFO_IN6)");

        printf("reachable=%ds\n", nd.ndi.reachable);

        close(s);
}

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

        return(result);
}