root/sbin/route/route.c
/*      $NetBSD: route.c,v 1.169 2022/04/10 09:50:45 andvar Exp $       */

/*
 * Copyright (c) 1983, 1989, 1991, 1993
 *      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 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.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1983, 1989, 1991, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)route.c     8.6 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: route.c,v 1.169 2022/04/10 09:50:45 andvar Exp $");
#endif
#endif /* not lint */

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

#include <net/if.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <net80211/ieee80211_netbsd.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netatalk/at.h>
#include <netmpls/mpls.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <paths.h>
#include <err.h>
#include <util.h>

#include "keywords.h"
#include "extern.h"
#include "prog_ops.h"
#include "rtutil.h"

union sockunion {
        struct  sockaddr sa;
        struct  sockaddr_in sin;
#ifdef INET6
        struct  sockaddr_in6 sin6;
#endif
        struct  sockaddr_at sat;
        struct  sockaddr_dl sdl;
#ifndef SMALL
        struct  sockaddr_mpls smpls;
#endif /* SMALL */
        struct  sockaddr_storage sstorage;
};

typedef union sockunion *sup;

struct sou {
        union sockunion *so_dst, *so_gate, *so_mask, *so_genmask, *so_ifa,
                *so_ifp, *so_mpls;
};

static const char *route_strerror(int);
static void set_metric(const char *, int);
static int newroute(int, char *const *);
static void inet_makenetandmask(u_int32_t, struct sockaddr_in *, struct sou *);
#ifdef INET6
static int inet6_makenetandmask(const struct sockaddr_in6 *, struct sou *);
#endif
static int getaddr(int, const char *, struct hostent **, struct sou *);
static int flushroutes(int, char *const [], int);
static char *netmask_string(const struct sockaddr *, int, int);
static int prefixlen(const char *, struct sou *);
#ifndef SMALL
static void interfaces(void);
static void monitor(int, char * const *);
static int print_getmsg(struct rt_msghdr *, int, struct sou *);
static const char *linkstate(struct if_msghdr *);
static sup readtag(sup, const char *);
static void addtag(sup, const char *, int);
#endif /* SMALL */
static int rtmsg(int, int, struct sou *);
static void mask_addr(struct sou *);
static void print_rtmsg(struct rt_msghdr *, int);
static void pmsg_common(struct rt_msghdr *);
static void pmsg_addrs(const char *, int);
static void bprintf(FILE *, int, const char *);
static void sodump(sup, const char *);
static void sockaddr(const char *, struct sockaddr *);

int     pid, rtm_addrs;
int     sock;
int     forcehost, forcenet, doflush, af;
int     iflag, Lflag, nflag, qflag, tflag, Sflag, Tflag;
int     verbose, aflen = sizeof(struct sockaddr_in), rtag;
int     locking, lockrest, debugonly, shortoutput;
struct  rt_metrics rt_metrics;
int     rtm_inits;
short ns_nullh[] = {0,0,0};
short ns_bh[] = {-1,-1,-1};

static const char opts[] = "dfLnqSsTtv";

void
usage(const char *cp)
{

        if (cp)
                warnx("botched keyword: %s", cp);
        (void)fprintf(stderr,
            "Usage: %s [-%s] cmd [[-<qualifiers>] args]\n", getprogname(), opts);
        exit(1);
        /* NOTREACHED */
}

#define PRIETHER        "02x:%02x:%02x:%02x:%02x:%02x"
#define PRIETHER_ARGS(__enaddr) (__enaddr)[0], (__enaddr)[1], (__enaddr)[2], \
                                (__enaddr)[3], (__enaddr)[4], (__enaddr)[5]

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

        if (argc < 2)
                usage(NULL);

        while ((ch = getopt(argc, argv, opts)) != -1)
                switch (ch) {
                case 'd':
                        debugonly = 1;
                        break;
                case 'f':
                        doflush = 1;
                        break;
                case 'L':
                        Lflag = RT_LFLAG;
                        break;
                case 'n':
                        nflag = RT_NFLAG;
                        break;
                case 'q':
                        qflag = 1;
                        break;
                case 'S':
                        Sflag = 1;
                        break;
                case 's':
                        shortoutput = 1;
                        break;
                case 'T':
                        Tflag = RT_TFLAG;
                        break;
                case 't':
                        tflag = 1;
                        break;
                case 'v':
                        verbose = RT_VFLAG;
                        break;
                case '?':
                default:
                        usage(NULL);
                        /*NOTREACHED*/
                }
        argc -= optind;
        argv += optind;

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

        pid = prog_getpid();
        if (tflag)
                sock = prog_open("/dev/null", O_WRONLY, 0);
        else {
                int on = 1;

                sock = prog_socket(PF_ROUTE, SOCK_RAW, 0);
                if (prog_setsockopt(sock, SOL_SOCKET, SO_RERROR,
                    &on, sizeof(on)) == -1)
                        warn("SO_RERROR");
        }
        if (sock < 0)
                err(EXIT_FAILURE, "socket");

        if (*argv == NULL) {
                if (doflush)
                        ch = K_FLUSH;
                else
                        goto no_cmd;
        } else
                ch = keyword(*argv);

        switch (ch) {
#ifndef SMALL
        case K_GET:
#endif /* SMALL */
        case K_CHANGE:
        case K_ADD:
        case K_DELETE:
                if (doflush)
                        (void)flushroutes(1, argv, 0);
                return newroute(argc, argv);

        case K_SHOW:
                show(argc, argv, Lflag|nflag|Tflag|verbose);
                return 0;

#ifndef SMALL
        case K_MONITOR:
                monitor(argc, argv);
                return 0;

#endif /* SMALL */
        case K_FLUSH:
                return flushroutes(argc, argv, 0);

        case K_FLUSHALL:
                return flushroutes(argc, argv, 1);
        no_cmd:
        default:
                usage(*argv);
                /*NOTREACHED*/
        }
}

static char *
netmask_string(const struct sockaddr *mask, int len, int family)
{
        static char smask[INET6_ADDRSTRLEN];
        struct sockaddr_in nsin;
        struct sockaddr_in6 nsin6;

        if (len >= 0)
                snprintf(smask, sizeof(smask), "%d", len);
        else {
                switch (family) {
                case AF_INET:
                        memset(&nsin, 0, sizeof(nsin));
                        memcpy(&nsin, mask, mask->sa_len);
                        snprintf(smask, sizeof(smask), "%s",
                            inet_ntoa(nsin.sin_addr));
                        break;
                case AF_INET6:
                        memset(&nsin6, 0, sizeof(nsin6));
                        memcpy(&nsin6, mask, mask->sa_len);
                        inet_ntop(family, &nsin6.sin6_addr, smask,
                            sizeof(smask));
                        break;
                default:
                        snprintf(smask, sizeof(smask), "%s", any_ntoa(mask));
                }
        }

        return smask;
}
/*
 * Purge all entries in the routing tables not
 * associated with network interfaces.
 */
static int
flushroutes(int argc, char * const argv[], int doall)
{
        struct sockaddr *sa;
        size_t needed;
        int flags, mib[6], rlen, seqno;
        char *buf, *next, *lim;
        const char *afname;
        struct rt_msghdr *rtm;

        flags = 0;
        af = AF_UNSPEC;
        /* Don't want to read back our messages */
        prog_shutdown(sock, SHUT_RD);
        parse_show_opts(argc, argv, &af, &flags, &afname, false);
        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;             /* protocol */
        mib[3] = 0;             /* wildcard address family */
        mib[4] = NET_RT_DUMP;
        mib[5] = 0;             /* no flags */
        if (prog_sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
                err(EXIT_FAILURE, "route-sysctl-estimate");
        buf = lim = NULL;
        if (needed) {
                if ((buf = malloc(needed)) == NULL)
                        err(EXIT_FAILURE, "malloc");
                if (prog_sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
                        err(EXIT_FAILURE, "actual retrieval of routing table");
                lim = buf + needed;
        }
        if (verbose) {
                (void)printf("Examining routing table from sysctl\n");
                if (af != AF_UNSPEC)
                        printf("(address family %s)\n", afname);
        }
        if (needed == 0)
                return 0;
        seqno = 0;              /* ??? */
        for (next = buf; next < lim; next += rtm->rtm_msglen) {
                rtm = (struct rt_msghdr *)next;
                sa = (struct sockaddr *)(rtm + 1);
                if (verbose)
                        print_rtmsg(rtm, rtm->rtm_msglen);
                if ((rtm->rtm_flags & flags) != flags)
                        continue;
                if (!(rtm->rtm_flags & (RTF_GATEWAY | RTF_STATIC)) && !doall)
                        continue;
                if (af != AF_UNSPEC && sa->sa_family != af)
                        continue;
                if (debugonly)
                        continue;
                rtm->rtm_type = RTM_DELETE;
                rtm->rtm_seq = seqno;
                do {
                        rlen = prog_write(sock, next, rtm->rtm_msglen);
                } while (rlen == -1 && errno == ENOBUFS);
                if (rlen == -1) {
                        warnx("writing to routing socket: %s",
                            route_strerror(errno));
                        return 1;
                }
                if (rlen < (int)rtm->rtm_msglen) {
                        warnx("write to routing socket, got %d for rlen", rlen);
                        return 1;
                }
                seqno++;
                if (qflag)
                        continue;
                if (verbose)
                        print_rtmsg(rtm, rlen);
                else {
                        (void)printf("%-20.20s ", netname(sa, NULL, nflag));
                        sa = (struct sockaddr *)(RT_ROUNDUP(sa->sa_len) +
                            (char *)sa);
                        (void)printf("%-20.20s ", routename(sa, nflag));
                        (void)printf("done\n");
                }
        }
        free(buf);
        return 0;
}

static const char *
route_strerror(int error)
{

        switch (error) {
        case ESRCH:
                return "not in table";
        case EBUSY:
                return "entry in use";
        case ENOBUFS:
                return "routing table overflow";
        default:
                return strerror(error);
        }
}

static void
set_metric(const char *value, int key)
{
        int flag = 0;
        uint64_t noval, *valp = &noval;

        switch (key) {
#define caseof(x, y, z) \
        case x: valp = (uint64_t *)&rt_metrics.z; flag = y; break
        caseof(K_MTU, RTV_MTU, rmx_mtu);
        caseof(K_HOPCOUNT, RTV_HOPCOUNT, rmx_hopcount);
        caseof(K_EXPIRE, RTV_EXPIRE, rmx_expire);
        caseof(K_RECVPIPE, RTV_RPIPE, rmx_recvpipe);
        caseof(K_SENDPIPE, RTV_SPIPE, rmx_sendpipe);
        caseof(K_SSTHRESH, RTV_SSTHRESH, rmx_ssthresh);
        caseof(K_RTT, RTV_RTT, rmx_rtt);
        caseof(K_RTTVAR, RTV_RTTVAR, rmx_rttvar);
        }
        rtm_inits |= flag;
        if (lockrest || locking)
                rt_metrics.rmx_locks |= flag;
        if (locking)
                locking = 0;
        *valp = strtoul(value, NULL, 0);
}

static int
newroute(int argc, char *const *argv)
{
        const char *cmd, *dest = "", *gateway = "";
        int ishost = 0, ret, attempts, oerrno, flags = RTF_STATIC;
        int key;
        struct hostent *hp = 0;
        struct sou sou, *soup = &sou;

        sou.so_dst = calloc(1, sizeof(union sockunion));
        sou.so_gate = calloc(1, sizeof(union sockunion));
        sou.so_mask = calloc(1, sizeof(union sockunion));
        sou.so_genmask = calloc(1, sizeof(union sockunion));
        sou.so_ifa = calloc(1, sizeof(union sockunion));
        sou.so_ifp = calloc(1, sizeof(union sockunion));
        sou.so_mpls = calloc(1, sizeof(union sockunion));

        if (sou.so_dst == NULL || sou.so_gate == NULL || sou.so_mask == NULL ||
            sou.so_genmask == NULL || sou.so_ifa == NULL || sou.so_ifp == NULL ||
            sou.so_mpls == NULL)
                errx(EXIT_FAILURE, "Cannot allocate memory");

        cmd = argv[0];
        af = AF_UNSPEC;
        if (*cmd != 'g') {
                /* Don't want to read back our messages */
                prog_shutdown(sock, SHUT_RD);
        }
        while (--argc > 0) {
                if (**(++argv)== '-') {
                        switch (key = keyword(1 + *argv)) {

                        case K_SA:
                                af = PF_ROUTE;
                                aflen = sizeof(union sockunion);
                                break;

#ifndef SMALL
                        case K_ATALK:
                                af = AF_APPLETALK;
                                aflen = sizeof(struct sockaddr_at);
                                break;
#endif

                        case K_INET:
                                af = AF_INET;
                                aflen = sizeof(struct sockaddr_in);
                                break;

#ifdef INET6
                        case K_INET6:
                                af = AF_INET6;
                                aflen = sizeof(struct sockaddr_in6);
                                break;
#endif

                        case K_LINK:
                                af = AF_LINK;
                                aflen = sizeof(struct sockaddr_dl);
                                break;

#ifndef SMALL
                        case K_MPLS:
                                af = AF_MPLS;
                                aflen = sizeof(struct sockaddr_mpls);
                                break;
                        case K_TAG:
                                if (!--argc)
                                        usage(1+*argv);
                                af = AF_MPLS;
                                aflen = sizeof(struct sockaddr_mpls);
                                (void)getaddr(RTA_TAG, *++argv, 0, soup);
                                break;
#endif /* SMALL */

                        case K_IFACE:
                        case K_INTERFACE:
                                iflag++;
                                break;
                        case K_NOSTATIC:
                                flags &= ~RTF_STATIC;
                                break;
                        case K_LOCK:
                                locking = 1;
                                break;
                        case K_LOCKREST:
                                lockrest = 1;
                                break;
                        case K_HOST:
                                forcehost++;
                                break;
                        case K_REJECT:
                                flags |= RTF_REJECT;
                                break;
                        case K_NOREJECT:
                                flags &= ~RTF_REJECT;
                                break;
                        case K_BLACKHOLE:
                                flags |= RTF_BLACKHOLE;
                                break;
                        case K_NOBLACKHOLE:
                                flags &= ~RTF_BLACKHOLE;
                                break;
                        case K_PROTO1:
                                flags |= RTF_PROTO1;
                                break;
                        case K_PROTO2:
                                flags |= RTF_PROTO2;
                                break;
                        case K_PROXY:
                                flags |= RTF_ANNOUNCE;
                                break;
                        case K_CONNECTED:
                                flags |= RTF_CONNECTED;
                                break;
                        case K_NOCONNECTED:
                                flags &= ~RTF_CONNECTED;
                                break;
                        case K_STATIC:
                                flags |= RTF_STATIC;
                                break;
                        case K_IFA:
                                if (!--argc)
                                        usage(1+*argv);
                                (void)getaddr(RTA_IFA, *++argv, 0, soup);
                                break;
                        case K_IFP:
                                if (!--argc)
                                        usage(1+*argv);
                                (void)getaddr(RTA_IFP, *++argv, 0, soup);
                                break;
                        case K_GENMASK:
                                if (!--argc)
                                        usage(1+*argv);
                                (void)getaddr(RTA_GENMASK, *++argv, 0, soup);
                                break;
                        case K_GATEWAY:
                                if (!--argc)
                                        usage(1+*argv);
                                (void)getaddr(RTA_GATEWAY, *++argv, 0, soup);
                                break;
                        case K_DST:
                                if (!--argc)
                                        usage(1+*argv);
                                ishost = getaddr(RTA_DST, *++argv, &hp, soup);
                                dest = *argv;
                                break;
                        case K_NETMASK:
                                if (!--argc)
                                        usage(1+*argv);
                                (void)getaddr(RTA_NETMASK, *++argv, 0, soup);
                                /* FALLTHROUGH */
                        case K_NET:
                                forcenet++;
                                break;
                        case K_PREFIXLEN:
                                if (!--argc)
                                        usage(1+*argv);
                                ishost = prefixlen(*++argv, soup);
                                break;
                        case K_MTU:
                        case K_HOPCOUNT:
                        case K_EXPIRE:
                        case K_RECVPIPE:
                        case K_SENDPIPE:
                        case K_SSTHRESH:
                        case K_RTT:
                        case K_RTTVAR:
                                if (!--argc)
                                        usage(1+*argv);
                                set_metric(*++argv, key);
                                break;
                        default:
                                usage(1+*argv);
                        }
                } else {
                        if ((rtm_addrs & RTA_DST) == 0) {
                                dest = *argv;
                                ishost = getaddr(RTA_DST, *argv, &hp, soup);
                        } else if ((rtm_addrs & RTA_GATEWAY) == 0) {
                                gateway = *argv;
                                (void)getaddr(RTA_GATEWAY, *argv, &hp, soup);
                        } else {
                                ret = atoi(*argv);

                                if (ret == 0) {
                                    if (strcmp(*argv, "0") == 0) {
                                        if (!qflag)  {
                                            warnx("%s, %s",
                                                "old usage of trailing 0",
                                                "assuming route to if");
                                        }
                                    } else
                                        usage(NULL);
                                    iflag = 1;
                                    continue;
                                } else if (ret > 0 && ret < 10) {
                                    if (!qflag) {
                                        warnx("%s, %s",
                                            "old usage of trailing digit",
                                            "assuming route via gateway");
                                    }
                                    iflag = 0;
                                    continue;
                                }
                                (void)getaddr(RTA_NETMASK, *argv, 0, soup);
                        }
                }
        }
        if ((rtm_addrs & RTA_DST) == 0)
                errx(EXIT_FAILURE, "missing destination specification");
        if (*cmd == 'a' && (rtm_addrs & RTA_GATEWAY) == 0)
                errx(EXIT_FAILURE, "missing gateway specification");
        if (forcehost && forcenet)
                errx(EXIT_FAILURE, "-host and -net conflict");
        else if (forcehost)
                ishost = 1;
        else if (forcenet)
                ishost = 0;
        flags |= RTF_UP;
        if (ishost)
                flags |= RTF_HOST;
        if (iflag == 0)
                flags |= RTF_GATEWAY;
        for (attempts = 1; ; attempts++) {
                errno = 0;
                if ((ret = rtmsg(*cmd, flags, soup)) == 0)
                        break;
                if (errno != ENETUNREACH && errno != ESRCH)
                        break;
                if (af == AF_INET && *gateway && hp && hp->h_addr_list[1]) {
                        hp->h_addr_list++;
                        memmove(&soup->so_gate->sin.sin_addr, hp->h_addr_list[0],
                            hp->h_length);
                } else
                        break;
        }
        if (*cmd == 'g' || qflag)
                goto out;

        oerrno = errno;
        (void)printf("%s %s %s", cmd, ishost? "host" : "net", dest);
        if (*gateway) {
                (void)printf(": gateway %s", gateway);
                if (attempts > 1 && ret == 0 && af == AF_INET)
                    (void)printf(" (%s)",
                        inet_ntoa(soup->so_gate->sin.sin_addr));
        }
        if (ret == 0)
                (void)printf("\n");
        else
                (void)printf(": %s\n", route_strerror(oerrno));
out:
        free(sou.so_dst);
        free(sou.so_gate);
        free(sou.so_mask);
        free(sou.so_genmask);
        free(sou.so_ifa);
        free(sou.so_ifp);
        free(sou.so_mpls);

        return ret != 0;
}

static void
inet_makenetandmask(const u_int32_t net, struct sockaddr_in * const isin,
    struct sou *soup)
{
        struct sockaddr_in *sin;
        u_int32_t addr, mask = 0;
        char *cp;

        rtm_addrs |= RTA_NETMASK;
        if (net == 0)
                mask = addr = 0;
        else if (net < 128) {
                addr = net << IN_CLASSA_NSHIFT;
                mask = IN_CLASSA_NET;
        } else if (net < 192) {
                addr = net << IN_CLASSA_NSHIFT;
                mask = IN_CLASSB_NET;
        } else if (net < 224) {
                addr = net << IN_CLASSA_NSHIFT;
                mask = IN_CLASSC_NET;
        } else if (net < 256) {
                addr = net << IN_CLASSA_NSHIFT;
                mask = IN_CLASSD_NET;
        } else if (net < 49152) { /* 192 * 256 */
                addr = net << IN_CLASSB_NSHIFT;
                mask = IN_CLASSB_NET;
        } else if (net < 57344) { /* 224 * 256 */
                addr = net << IN_CLASSB_NSHIFT;
                mask = IN_CLASSC_NET;
        } else if (net < 65536) {
                addr = net << IN_CLASSB_NSHIFT;
                mask = IN_CLASSB_NET;
        } else if (net < 14680064L) { /* 224 * 65536 */
                addr = net << IN_CLASSC_NSHIFT;
                mask = IN_CLASSC_NET;
        } else if (net < 16777216L) { 
                addr = net << IN_CLASSC_NSHIFT;
                mask = IN_CLASSD_NET;
        } else {
                addr = net;
                if ((addr & IN_CLASSA_HOST) == 0)
                        mask =  IN_CLASSA_NET;
                else if ((addr & IN_CLASSB_HOST) == 0)
                        mask =  IN_CLASSB_NET;
                else if ((addr & IN_CLASSC_HOST) == 0)
                        mask =  IN_CLASSC_NET;
                else
                        mask = -1;
        }
        isin->sin_addr.s_addr = htonl(addr);
        sin = &soup->so_mask->sin;
        sin->sin_addr.s_addr = htonl(mask);
        sin->sin_len = 0;
        sin->sin_family = 0;
        cp = (char *)(&sin->sin_addr + 1);
        while (*--cp == 0 && cp > (char *)sin)
                ;
        sin->sin_len = 1 + cp - (char *)sin;
        sin->sin_family = AF_INET;
}

#ifdef INET6
/*
 * XXX the function may need more improvement...
 */
static int
inet6_makenetandmask(const struct sockaddr_in6 * const sin6, struct sou *soup)
{
        const char *plen;
        struct in6_addr in6;

        plen = NULL;
        if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr) &&
            sin6->sin6_scope_id == 0) {
                plen = "0";
        } else if ((sin6->sin6_addr.s6_addr[0] & 0xe0) == 0x20) {
                /* aggregatable global unicast - RFC2374 */
                memset(&in6, 0, sizeof(in6));
                if (!memcmp(&sin6->sin6_addr.s6_addr[8], &in6.s6_addr[8], 8))
                        plen = "64";
        }

        if (!plen || strcmp(plen, "128") == 0)
                return 1;
        else {
                rtm_addrs |= RTA_NETMASK;
                (void)prefixlen(plen, soup);
                return 0;
        }
}
#endif

/*
 * Interpret an argument as a network address of some kind,
 * returning 1 if a host address, 0 if a network address.
 */
static int
getaddr(int which, const char *s, struct hostent **hpp, struct sou *soup)
{
        sup su;
        struct hostent *hp;
        struct netent *np;
        u_int32_t val;
        char *t;
        int afamily;  /* local copy of af so we can change it */

        if (af == AF_UNSPEC) {
                af = AF_INET;
                aflen = sizeof(struct sockaddr_in);
        }
        afamily = af;
        rtm_addrs |= which;
        switch (which) {
        case RTA_DST:
                su = soup->so_dst;
                break;
        case RTA_GATEWAY:
                su = soup->so_gate;
                break;
        case RTA_NETMASK:
                su = soup->so_mask;
                break;
        case RTA_GENMASK:
                su = soup->so_genmask;
                break;
        case RTA_IFP:
                su = soup->so_ifp;
                afamily = AF_LINK;
                break;
        case RTA_IFA:
                su = soup->so_ifa;
                su->sa.sa_family = af;
                break;
#ifndef SMALL
        case RTA_TAG:
                su = soup->so_mpls;
                afamily = AF_MPLS;
                break;
#endif
        default:
                su = NULL;
                usage("Internal Error");
                /*NOTREACHED*/
        }
        su->sa.sa_len = aflen;
        su->sa.sa_family = afamily; /* cases that don't want it have left already */
        if (strcmp(s, "default") == 0) {
                switch (which) {
                case RTA_DST:
                        forcenet++;
                        (void)getaddr(RTA_NETMASK, s, 0, soup);
                        break;
                case RTA_NETMASK:
                case RTA_GENMASK:
                        su->sa.sa_len = 0;
                }
                return 0;
        }
        switch (afamily) {
#ifdef INET6
        case AF_INET6:
            {
                struct addrinfo hints, *res;
                char *slash = 0;

                if (which == RTA_DST && (slash = (strrchr(s, '/'))) != 0)
                        *slash = '\0';
                memset(&hints, 0, sizeof(hints));
                hints.ai_family = afamily;      /*AF_INET6*/
                hints.ai_flags = AI_NUMERICHOST;
                hints.ai_socktype = SOCK_DGRAM;         /*dummy*/
                if (getaddrinfo(s, "0", &hints, &res) != 0) {
                        hints.ai_flags = 0;
                        if (slash) {
                                *slash = '/';
                                slash = 0;
                        }
                        if (getaddrinfo(s, "0", &hints, &res) != 0)
                                errx(EXIT_FAILURE, "%s: bad value", s);
                }
                if (slash)
                        *slash = '/';
                if (sizeof(su->sin6) != res->ai_addrlen)
                        errx(EXIT_FAILURE, "%s: bad value", s);
                if (res->ai_next) {
                        errx(EXIT_FAILURE,
                            "%s: address resolved to multiple values", s);
                }
                memcpy(&su->sin6, res->ai_addr, sizeof(su->sin6));
                freeaddrinfo(res);
                inet6_putscopeid(&su->sin6, INET6_IS_ADDR_LINKLOCAL|
                    INET6_IS_ADDR_MC_LINKLOCAL);
                if (hints.ai_flags == AI_NUMERICHOST) {
                        if (slash)
                                return prefixlen(slash + 1, soup);
                        if (which == RTA_DST)
                                return inet6_makenetandmask(&su->sin6, soup);
                        return 0;
                } else
                        return 1;
            }
#endif

        case PF_ROUTE:
                su->sa.sa_len = sizeof(*su);
                sockaddr(s, &su->sa);
                return 1;

#ifndef SMALL
        case AF_APPLETALK:
                t = strchr (s, '.');
                if (!t) {
badataddr:
                        errx(EXIT_FAILURE, "bad address: %s", s);
                }
                val = atoi (s);
                if (val > 65535)
                        goto badataddr;
                su->sat.sat_addr.s_net = val;
                val = atoi (t);
                if (val > 256)
                        goto badataddr;
                su->sat.sat_addr.s_node = val;
                rtm_addrs |= RTA_NETMASK;
                return(forcehost || su->sat.sat_addr.s_node != 0);
        case AF_MPLS:
                if (which == RTA_DST)
                        soup->so_dst = readtag(su, s);
                else if (which == RTA_TAG)
                        soup->so_mpls = readtag(su, s);
                else
                        errx(EXIT_FAILURE, "MPLS can be used only as "
                            "DST or TAG");
                return 1;
#endif

        case AF_LINK:
                link_addr(s, &su->sdl);
                return 1;

        case AF_INET:
        default:
                break;
        }

        if (hpp == NULL)
                hpp = &hp;
        *hpp = NULL;

        if ((t = strchr(s, '/')) != NULL && which == RTA_DST) {
                *t = '\0';
                if (forcenet == 0) {
                        if ((val = inet_addr(s)) != INADDR_NONE) {
                                inet_makenetandmask(htonl(val), &su->sin, soup);
                                return prefixlen(&t[1], soup);
                        }
                } else {
                        if ((val = inet_network(s)) != INADDR_NONE) {
                                inet_makenetandmask(val, &su->sin, soup);
                                return prefixlen(&t[1], soup);
                        }
                }
                *t = '/';
        }
        if (inet_aton(s, &su->sin.sin_addr) &&
            (which != RTA_DST || forcenet == 0)) {
                val = su->sin.sin_addr.s_addr;
                if (inet_lnaof(su->sin.sin_addr) != INADDR_ANY)
                        return 1;
                else {
                        val = ntohl(val);
                        goto netdone;
                }
        }
        if ((val = inet_network(s)) != INADDR_NONE ||
            ((np = getnetbyname(s)) != NULL && (val = np->n_net) != 0)) {
netdone:
                if (which == RTA_DST)
                        inet_makenetandmask(val, &su->sin, soup);
                return 0;
        }
        hp = gethostbyname(s);
        if (hp) {
                *hpp = hp;
                su->sin.sin_family = hp->h_addrtype;
                memmove(&su->sin.sin_addr, hp->h_addr, hp->h_length);
                return 1;
        }
        errx(EXIT_FAILURE, "%s: bad value", s);
        /*NOTREACHED*/
}

#ifndef SMALL
static sup
readtag(sup su, const char *s)
{
        char *p, *n, *norig;
        int mplssize = 0;
        sup retsu = su;

        n = strdup(s);
        if (n == NULL)
                errx(EXIT_FAILURE, "%s: Cannot allocate memory", s);
        norig = n;
        for (uint i = 0; i < strlen(n); i++)
                if(n[i] == ',')
                        mplssize++;

#define MPLS_NEW_SIZE (sizeof(struct sockaddr_mpls) + \
    mplssize * sizeof(union mpls_shim))

        if (mplssize != 0 && sizeof(union sockunion) < MPLS_NEW_SIZE) {
                free(su);
                retsu = malloc(MPLS_NEW_SIZE);
                retsu->smpls.smpls_family = AF_MPLS;
        }
        retsu->smpls.smpls_len = MPLS_NEW_SIZE;
        mplssize = 0;
        while ((p = strchr(n, ',')) != NULL) {
                p[0] = '\0';
                addtag(retsu, n, mplssize);
                n = p + 1;
                mplssize++;
        }
        addtag(retsu, n, mplssize);

        free(norig);
        return retsu;
}

static void
addtag(sup su, const char *s, int where)
{
        union mpls_shim *ms = &su->smpls.smpls_addr;

        if (atoi(s) < 0 || atoi(s) >= (1 << 20))
                errx(EXIT_FAILURE, "%s: Bad tag", s);
        ms[where].s_addr = 0;
        ms[where].shim.label = atoi(s);
        ms[where].s_addr = htonl(ms[where].s_addr);
}
#endif  /* SMALL */

int
prefixlen(const char *s, struct sou *soup)
{
        int max, len = atoi(s);
#ifdef INET6
        int q, r;
#endif

        switch (af) {
        case AF_INET:
                max = sizeof(struct in_addr) * 8;
                break;
#ifdef INET6
        case AF_INET6:
                max = sizeof(struct in6_addr) * 8;
                break;
#endif
        default:
                errx(EXIT_FAILURE, "prefixlen is not supported with af %d", af);
                /*NOTREACHED*/
        }

        rtm_addrs |= RTA_NETMASK;       
        if (len < -1 || len > max)
                errx(EXIT_FAILURE, "%s: bad value", s);
        
#ifdef INET6
        q = len >> 3;
        r = len & 7;
#endif
        switch (af) {
        case AF_INET:
                memset(soup->so_mask, 0, sizeof(*soup->so_mask));
                soup->so_mask->sin.sin_family = AF_INET;
                soup->so_mask->sin.sin_len = sizeof(struct sockaddr_in);
                soup->so_mask->sin.sin_addr.s_addr = (len == 0 ? 0
                                : htonl(0xffffffff << (32 - len)));
                break;
#ifdef INET6
        case AF_INET6:
                soup->so_mask->sin6.sin6_family = AF_INET6;
                soup->so_mask->sin6.sin6_len = sizeof(struct sockaddr_in6);
                memset(&soup->so_mask->sin6.sin6_addr, 0,
                        sizeof(soup->so_mask->sin6.sin6_addr));
                if (q > 0)
                        memset(&soup->so_mask->sin6.sin6_addr, 0xff, q);
                if (r > 0)
                        *((u_char *)&soup->so_mask->sin6.sin6_addr + q) =
                            (0xff00 >> r) & 0xff;
                break;
#endif
        }
        return len == max;
}

#ifndef SMALL
static void
interfaces(void)
{
        size_t needed;
        int mib[6];
        char *buf, *lim, *next;
        struct rt_msghdr *rtm;

        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;             /* protocol */
        mib[3] = 0;             /* wildcard address family */
        mib[4] = NET_RT_IFLIST;
        mib[5] = 0;             /* no flags */
        if (prog_sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
                err(EXIT_FAILURE, "route-sysctl-estimate");
        if (needed) {
                if ((buf = malloc(needed)) == NULL)
                        err(EXIT_FAILURE, "malloc");
                if (prog_sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
                        err(EXIT_FAILURE,
                            "actual retrieval of interface table");
                }
                lim = buf + needed;
                for (next = buf; next < lim; next += rtm->rtm_msglen) {
                        rtm = (struct rt_msghdr *)next;
                        print_rtmsg(rtm, rtm->rtm_msglen);
                }
                free(buf);
        }
}

static void
monitor(int argc, char * const *argv)
{
        int i, n;
        union {
                char msg[2048];
                struct rt_msghdr hdr;
        } u;
        int count = 0;

        /* usage: route monitor [-c <count>] */

        /* eat "monitor" */
        argc -= 1;
        argv += 1;

        /* parse [-c <count>] */
        if (argc > 0) {
                if (argc != 2)
                        usage(argv[0]);
                if (strcmp(argv[0], "-c") != 0)
                        usage(argv[0]);

                count = atoi(argv[1]);
        }

        verbose = 1;
        if (debugonly) {
                interfaces();
                exit(0);
        }
        for(i = 0; count == 0 || i < count; i++) {
                time_t now;
                n = prog_read(sock, &u, sizeof(u));
                if (n == -1) {
                        warn("read");
                        continue;
                }
                now = time(NULL);
                (void)printf("got message of size %d on %s", n, ctime(&now));
                print_rtmsg(&u.hdr, n);
        }
}

#endif /* SMALL */


struct {
        struct  rt_msghdr m_rtm;
        char    m_space[512];
} m_rtmsg;

static int
rtmsg(int cmd, int flags, struct sou *soup)
{
        static int seq;
        int rlen;
        char *cp = m_rtmsg.m_space;
        int l;

#define NEXTADDR(w, u) \
        if (rtm_addrs & (w)) {\
            l = RT_ROUNDUP(u->sa.sa_len); memmove(cp, u, l); cp += l;\
            if (verbose && ! shortoutput) sodump(u,#u);\
        }

        errno = 0;
        memset(&m_rtmsg, 0, sizeof(m_rtmsg));
        if (cmd == 'a')
                cmd = RTM_ADD;
        else if (cmd == 'c')
                cmd = RTM_CHANGE;
        else if (cmd == 'g') {
#ifdef  SMALL
                return -1;
#else   /* SMALL */
                cmd = RTM_GET;
                if (soup->so_ifp->sa.sa_family == AF_UNSPEC) {
                        soup->so_ifp->sa.sa_family = AF_LINK;
                        soup->so_ifp->sa.sa_len = sizeof(struct sockaddr_dl);
                        rtm_addrs |= RTA_IFP;
                }
#endif  /* SMALL */
        } else
                cmd = RTM_DELETE;
#define rtm m_rtmsg.m_rtm
        rtm.rtm_type = cmd;
        rtm.rtm_flags = flags;
        rtm.rtm_version = RTM_VERSION;
        rtm.rtm_seq = ++seq;
        rtm.rtm_addrs = rtm_addrs;
        rtm.rtm_rmx = rt_metrics;
        rtm.rtm_inits = rtm_inits;

        if (rtm_addrs & RTA_NETMASK)
                mask_addr(soup);
        NEXTADDR(RTA_DST, soup->so_dst);
        NEXTADDR(RTA_GATEWAY, soup->so_gate);
        NEXTADDR(RTA_NETMASK, soup->so_mask);
        NEXTADDR(RTA_GENMASK, soup->so_genmask);
        NEXTADDR(RTA_IFP, soup->so_ifp);
        NEXTADDR(RTA_IFA, soup->so_ifa);
#ifndef SMALL
        NEXTADDR(RTA_TAG, soup->so_mpls);
#endif
        rtm.rtm_msglen = l = cp - (char *)&m_rtmsg;
        if (verbose && ! shortoutput) {
                if (rtm_addrs)
                        putchar('\n');
                print_rtmsg(&rtm, l);
        }
        if (debugonly)
                return 0;
        do {
                rlen = prog_write(sock, (char *)&m_rtmsg, l);
        } while (rlen == -1 && errno == ENOBUFS);
        if (rlen == -1) {
                warnx("writing to routing socket: %s", route_strerror(errno));
                return -1;
        }
        if (rlen < l) {
                warnx("write to routing socket, got %d for rlen", rlen);
                return 1;
        }
#ifndef SMALL
        if (cmd == RTM_GET) {
                do {
                        l = prog_read(sock,
                            (char *)&m_rtmsg, sizeof(m_rtmsg));
                } while (l > 0 && (rtm.rtm_seq != seq || rtm.rtm_pid != pid));
                if (l < 0)
                        err(EXIT_FAILURE, "read from routing socket");
                else
                        return print_getmsg(&rtm, l, soup);
        }
#endif  /* SMALL */
#undef rtm
        return 0;
}

static void
mask_addr(struct sou *soup)
{
        int olen = soup->so_mask->sa.sa_len;
        char *cp1 = olen + (char *)soup->so_mask, *cp2;

        for (soup->so_mask->sa.sa_len = 0; cp1 > (char *)soup->so_mask; )
                if (*--cp1 != 0) {
                        soup->so_mask->sa.sa_len = 1 + cp1 - (char *)soup->so_mask;
                        break;
                }
        if ((rtm_addrs & RTA_DST) == 0)
                return;
        switch (soup->so_dst->sa.sa_family) {
        case AF_INET:
#ifdef INET6
        case AF_INET6:
#endif
#ifndef SMALL
        case AF_APPLETALK:
#endif /* SMALL */
        case 0:
                return;
        }
        cp1 = soup->so_mask->sa.sa_len + 1 + (char *)soup->so_dst;
        cp2 = soup->so_dst->sa.sa_len + 1 + (char *)soup->so_dst;
        while (cp2 > cp1)
                *--cp2 = 0;
        cp2 = soup->so_mask->sa.sa_len + 1 + (char *)soup->so_mask;
        while (cp1 > soup->so_dst->sa.sa_data)
                *--cp1 &= *--cp2;
}

const char * const msgtypes[] = {
        [RTM_ADD] = "RTM_ADD: Add Route",
        [RTM_DELETE] = "RTM_DELETE: Delete Route",
        [RTM_CHANGE] = "RTM_CHANGE: Change Metrics, Flags or Gateway",
        [RTM_GET] = "RTM_GET: Report Metrics",
        [RTM_LOSING] = "RTM_LOSING: Kernel Suspects Partitioning",
        [RTM_REDIRECT] = "RTM_REDIRECT: Told to use different route",
        [RTM_MISS] = "RTM_MISS: Lookup failed on this address",
        [RTM_LOCK] = "RTM_LOCK: fix specified metrics",
        [RTM_OLDADD] = "RTM_OLDADD: caused by SIOCADDRT",
        [RTM_OLDDEL] = "RTM_OLDDEL: caused by SIOCDELRT",
        [RTM_NEWADDR] = "RTM_NEWADDR: address being added to iface",
        [RTM_DELADDR] = "RTM_DELADDR: address being removed from iface",
        [RTM_OOIFINFO] = "RTM_OOIFINFO: iface status change (pre-1.5)",
        [RTM_OIFINFO] = "RTM_OIFINFO: iface status change (pre-64bit time)",
        [RTM_IFANNOUNCE] = "RTM_IFANNOUNCE: iface arrival/departure",
        [RTM_IEEE80211] = "RTM_IEEE80211: IEEE80211 wireless event",
        [RTM_IFINFO] = "RTM_IFINFO: iface status change",
        [RTM_CHGADDR] = "RTM_CHGADDR: address being changed on iface",
};

const char unknownflags[] = "\020";
const char metricnames[] = RTVBITS;
const char routeflags[] = RTFBITS;
const char ifnetflags[] = IFFBITS;
const char in_ifflags[] = IN_IFFBITS;
const char in6_ifflags[] = IN6_IFFBITS;
const char addrnames[] = RTABITS;


#ifndef SMALL
static const char *
linkstate(struct if_msghdr *ifm)
{
        static char buf[64];

        switch (ifm->ifm_data.ifi_link_state) {
        case LINK_STATE_UNKNOWN:
                return "carrier: unknown";
        case LINK_STATE_DOWN:
                return "carrier: no carrier";
        case LINK_STATE_UP:
                return "carrier: active";
        default:
                (void)snprintf(buf, sizeof(buf), "carrier: 0x%x",
                    ifm->ifm_data.ifi_link_state);
                return buf;
        }
}
#endif /* SMALL */

static void
print_rtmsg(struct rt_msghdr *rtm, int msglen)
{
        struct if_msghdr *ifm;
        struct ifa_msghdr *ifam;
        struct if_announcemsghdr *ifan;
        union {
                struct ieee80211_join_event join;
                struct ieee80211_leave_event leave;
                struct ieee80211_replay_event replay;
                struct ieee80211_michael_event michael;
        } ev;
        size_t evlen = 0;

        if (verbose == 0)
                return;
        if (rtm->rtm_version != RTM_VERSION) {
                (void)printf("routing message version %d not understood\n",
                    rtm->rtm_version);
                return;
        }
        if (msgtypes[rtm->rtm_type])
                (void)printf("%s: ", msgtypes[rtm->rtm_type]);
        else
                (void)printf("#%d: ", rtm->rtm_type);
        (void)printf("len %d, ", rtm->rtm_msglen);
        switch (rtm->rtm_type) {
        case RTM_IFINFO:
                ifm = (struct if_msghdr *)rtm;
                (void)printf("if# %d, %s, flags: ", ifm->ifm_index,
#ifdef SMALL
                    ""
#else
                    linkstate(ifm)
#endif /* SMALL */
                    );
                bprintf(stdout, ifm->ifm_flags, ifnetflags);
                pmsg_addrs((char *)(ifm + 1), ifm->ifm_addrs);
                break;
        case RTM_NEWADDR:
        case RTM_DELADDR:
        case RTM_CHGADDR:
                ifam = (struct ifa_msghdr *)rtm;
                (void)printf("pid %d, metric %d, addrflags: ",
                    ifam->ifam_pid, ifam->ifam_metric);
                struct sockaddr *sa = (struct sockaddr *)(ifam + 1);
                const char *bits;
                switch (sa->sa_family) {
                case AF_INET:
                        bits = in_ifflags;
                        break;
                case AF_INET6:
                        bits = in6_ifflags;
                        break;
                default:
                        bits = unknownflags;
                        break;
                }
                bprintf(stdout, ifam->ifam_addrflags, bits);
                pmsg_addrs((char *)(ifam + 1), ifam->ifam_addrs);
                break;
        case RTM_IEEE80211:
                ifan = (struct if_announcemsghdr *)rtm;
                (void)printf("if# %d, what: ", ifan->ifan_index);
                switch (ifan->ifan_what) {
                case RTM_IEEE80211_ASSOC:
                        printf("associate");
                        break;
                case RTM_IEEE80211_REASSOC:
                        printf("re-associate");
                        break;
                case RTM_IEEE80211_DISASSOC:
                        printf("disassociate");
                        break;
                case RTM_IEEE80211_SCAN:
                        printf("scan complete");
                        break;
                case RTM_IEEE80211_JOIN:
                        evlen = sizeof(ev.join);
                        printf("join");
                        break;
                case RTM_IEEE80211_LEAVE:
                        evlen = sizeof(ev.leave);
                        printf("leave");
                        break;
                case RTM_IEEE80211_MICHAEL:
                        evlen = sizeof(ev.michael);
                        printf("michael");
                        break;
                case RTM_IEEE80211_REPLAY:
                        evlen = sizeof(ev.replay);
                        printf("replay");
                        break;
                default:
                        evlen = 0;
                        printf("#%d", ifan->ifan_what);
                        break;
                }
                if (sizeof(*ifan) + evlen > ifan->ifan_msglen) {
                        printf(" (truncated)\n");
                        break;
                }
                (void)memcpy(&ev, (ifan + 1), evlen);
                switch (ifan->ifan_what) {
                case RTM_IEEE80211_JOIN:
                case RTM_IEEE80211_LEAVE:
                        printf(" mac %" PRIETHER,
                            PRIETHER_ARGS(ev.join.iev_addr));
                        break;
                case RTM_IEEE80211_REPLAY:
                case RTM_IEEE80211_MICHAEL:
                        printf(" src %" PRIETHER " dst %" PRIETHER
                               " cipher %" PRIu8 " keyix %" PRIu8,
                               PRIETHER_ARGS(ev.replay.iev_src),
                               PRIETHER_ARGS(ev.replay.iev_dst),
                               ev.replay.iev_cipher,
                               ev.replay.iev_keyix);
                        if (ifan->ifan_what == RTM_IEEE80211_REPLAY) {
                                printf(" key rsc %#" PRIx64
                                       " frame rsc %#" PRIx64,
                                       ev.replay.iev_keyrsc, ev.replay.iev_rsc);
                        }
                        break;
                default:
                        break;
                }
                printf("\n");
                break;
        case RTM_IFANNOUNCE:
                ifan = (struct if_announcemsghdr *)rtm;
                (void)printf("if# %d, what: ", ifan->ifan_index);
                switch (ifan->ifan_what) {
                case IFAN_ARRIVAL:
                        printf("arrival");
                        break;
                case IFAN_DEPARTURE:
                        printf("departure");
                        break;
                default:
                        printf("#%d", ifan->ifan_what);
                        break;
                }
                printf("\n");
                break;
        case RTM_ADD:           /* FALLTHROUGH */
        case RTM_CHANGE:        /* FALLTHROUGH */
        case RTM_DELETE:        /* FALLTHROUGH */
        case RTM_GET:           /* FALLTHROUGH */
        case RTM_LOSING:        /* FALLTHROUGH */
        case RTM_MISS:
                (void)printf("pid %d, seq %d, errno %d, flags: ",
                        rtm->rtm_pid, rtm->rtm_seq, rtm->rtm_errno);
                bprintf(stdout, rtm->rtm_flags, routeflags);
                pmsg_common(rtm);
                break;
        }
}

#ifndef SMALL
static int
print_getmsg(struct rt_msghdr *rtm, int msglen, struct sou *soup)
{
        struct sockaddr *dst = NULL, *gate = NULL, *mask = NULL, *ifa = NULL, *mpls = NULL;
        struct sockaddr_dl *ifp = NULL;
        struct sockaddr *sa;
        char *cp;
        unsigned int i;

        if (! shortoutput) {
                (void)printf("   route to: %s\n",
                    routename(&soup->so_dst->sa, nflag));
        }
        if (rtm->rtm_version != RTM_VERSION) {
                warnx("routing message version %d not understood",
                    rtm->rtm_version);
                return 1;
        }
        if (rtm->rtm_msglen > msglen) {
                warnx("message length mismatch, in packet %d, returned %d",
                    rtm->rtm_msglen, msglen);
        }
        if (rtm->rtm_errno)  {
                warnx("RTM_GET: %s (errno %d)",
                    strerror(rtm->rtm_errno), rtm->rtm_errno);
                return 1;
        }
        cp = ((char *)(rtm + 1));
        if (rtm->rtm_addrs)
                for (i = 1; i; i <<= 1)
                        if (i & rtm->rtm_addrs) {
                                sa = (struct sockaddr *)cp;
                                switch (i) {
                                case RTA_DST:
                                        dst = sa;
                                        break;
                                case RTA_GATEWAY:
                                        gate = sa;
                                        break;
                                case RTA_NETMASK:
                                        mask = sa;
                                        break;
                                case RTA_IFP:
                                        if (sa->sa_family == AF_LINK &&
                                           ((struct sockaddr_dl *)sa)->sdl_nlen)
                                                ifp = (struct sockaddr_dl *)sa;
                                        break;
                                case RTA_IFA:
                                        ifa = sa;
                                        break;
                                case RTA_TAG:
                                        mpls = sa;
                                        break;
                                }
                                RT_ADVANCE(cp, sa);
                        }
        if (dst && mask)
                mask->sa_family = dst->sa_family;       /* XXX */
        if (dst && ! shortoutput)
                (void)printf("destination: %s\n",
                    routename(dst, nflag));
        if (mask && ! shortoutput) {
                int savenflag = nflag;

                nflag = RT_NFLAG;
                (void)printf("       mask: %s\n",
                    routename(mask, nflag));
                nflag = savenflag;
        }
        if (gate && rtm->rtm_flags & RTF_GATEWAY) {
                const char *name;

                name = routename(gate, nflag);
                if (shortoutput) {
                        if (*name == '\0')
                                return 1;
                        (void)printf("%s\n", name);
                } else
                        (void)printf("    gateway: %s\n", name);
        }
        if (mpls) {
                const char *name;
                name = routename(mpls, nflag);
                if(shortoutput) {
                        if (*name == '\0')
                                return 1;
                        printf("%s\n", name);
                } else
                        printf("        Tag: %s\n", name);
        }
                
        if (ifa && ! shortoutput)
                (void)printf(" local addr: %s\n",
                    routename(ifa, nflag));
        if (ifp && ! shortoutput)
                (void)printf("  interface: %.*s\n",
                    ifp->sdl_nlen, ifp->sdl_data);
        if (! shortoutput) {
                (void)printf("      flags: ");
                bprintf(stdout, rtm->rtm_flags, routeflags);
        }

#define lock(f) ((rtm->rtm_rmx.rmx_locks & __CONCAT(RTV_,f)) ? 'L' : ' ')
#define msec(u) (((u) + 500) / 1000)            /* usec to msec */

        if (! shortoutput) {
                (void)printf("\n%s\n", "\
 recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire");
                printf("%8"PRId64"%c ", rtm->rtm_rmx.rmx_recvpipe, lock(RPIPE));
                printf("%8"PRId64"%c ", rtm->rtm_rmx.rmx_sendpipe, lock(SPIPE));
                printf("%8"PRId64"%c ", rtm->rtm_rmx.rmx_ssthresh, lock(SSTHRESH));
                printf("%8"PRId64"%c ", msec(rtm->rtm_rmx.rmx_rtt), lock(RTT));
                printf("%8"PRId64"%c ", msec(rtm->rtm_rmx.rmx_rttvar), lock(RTTVAR));
                printf("%8"PRId64"%c ", rtm->rtm_rmx.rmx_hopcount, lock(HOPCOUNT));
                printf("%8"PRId64"%c ", rtm->rtm_rmx.rmx_mtu, lock(MTU));
                if (rtm->rtm_rmx.rmx_expire)
                        rtm->rtm_rmx.rmx_expire -= time(0);
                printf("%8"PRId64"%c\n", rtm->rtm_rmx.rmx_expire, lock(EXPIRE));
        }
#undef lock
#undef msec
#define RTA_IGN (RTA_DST|RTA_GATEWAY|RTA_NETMASK|RTA_IFP|RTA_IFA|RTA_BRD)

        if (shortoutput)
                return (rtm->rtm_addrs & RTF_GATEWAY) == 0;
        else if (verbose)
                pmsg_common(rtm);
        else if (rtm->rtm_addrs &~ RTA_IGN) {
                (void)printf("sockaddrs: ");
                bprintf(stdout, rtm->rtm_addrs, addrnames);
                putchar('\n');
        }
        return 0;
#undef  RTA_IGN
}
#endif  /* SMALL */

void
pmsg_common(struct rt_msghdr *rtm)
{
        (void)printf("\nlocks: ");
        bprintf(stdout, rtm->rtm_rmx.rmx_locks, metricnames);
        (void)printf(" inits: ");
        bprintf(stdout, rtm->rtm_inits, metricnames);
        pmsg_addrs((char *)(rtm + 1), rtm->rtm_addrs);
}

static void
extract_addrs(const char *cp, int addrs, const struct sockaddr *sa[], int *nmfp)
{
        int i, nmf = -1;

        for (i = 0; i < RTAX_MAX; i++) {
                if ((1 << i) & addrs) {
                        sa[i] = (const struct sockaddr *)cp;
                        if ((i == RTAX_DST || i == RTAX_IFA) &&
                            nmf == -1)
                                nmf = sa[i]->sa_family;
                        RT_ADVANCE(cp, sa[i]);
                } else
                        sa[i] = NULL;
        }

        if (nmfp != NULL)
                *nmfp = nmf;
}

static void
pmsg_addrs(const char *cp, int addrs)
{
        const struct sockaddr *sa[RTAX_MAX];
        int i, nmf;

        if (addrs != 0) {
                (void)printf("\nsockaddrs: ");
                bprintf(stdout, addrs, addrnames);
                (void)putchar('\n');
                extract_addrs(cp, addrs, sa, &nmf);
                for (i = 0; i < RTAX_MAX; i++) {
                        if (sa[i] == NULL)
                                continue;

                        if (i == RTAX_NETMASK && sa[i]->sa_len)
                                (void)printf(" %s",
                                    netmask_string(sa[i], -1, nmf));
                        else
                                (void)printf(" %s",
                                    routename(sa[i], nflag));
                }
        }
        (void)putchar('\n');
        (void)fflush(stdout);
}

static void
bprintf(FILE *fp, int b, const char *f)
{
        char buf[1024];

        snprintb(buf, sizeof(buf), f, b);
        fputs(buf, fp);
}

int
keyword(const char *cp)
{
        struct keytab *kt = keywords;

        while (kt->kt_cp && strcmp(kt->kt_cp, cp))
                kt++;
        return kt->kt_i;
}

static void
sodump(sup su, const char *which)
{
#ifdef INET6
        char ntop_buf[NI_MAXHOST];
#endif

        switch (su->sa.sa_family) {
        case AF_INET:
                (void)printf("%s: inet %s; ",
                    which, inet_ntoa(su->sin.sin_addr));
                break;
#ifndef SMALL
        case AF_APPLETALK:
                (void)printf("%s: atalk %d.%d; ",
                    which, su->sat.sat_addr.s_net, su->sat.sat_addr.s_node);
                break;
#endif
        case AF_LINK:
                (void)printf("%s: link %s; ",
                    which, link_ntoa(&su->sdl));
                break;
#ifdef INET6
        case AF_INET6:
                (void)printf("%s: inet6 %s; ",
                    which, inet_ntop(AF_INET6, &su->sin6.sin6_addr,
                                     ntop_buf, sizeof(ntop_buf)));
                break;
#endif
#ifndef SMALL
        case AF_MPLS:
            {
                union mpls_shim ms;
                const union mpls_shim *pms;
                int psize = sizeof(struct sockaddr_mpls);

                ms.s_addr = ntohl(su->smpls.smpls_addr.s_addr);
                printf("%s: mpls %u; ",
                    which, ms.shim.label);

                pms = &su->smpls.smpls_addr;
                while(psize < su->smpls.smpls_len) {
                        pms++;
                        ms.s_addr = ntohl(pms->s_addr);
                        printf("%u; ", ms.shim.label);
                        psize += sizeof(ms);
                }
                break;
            }
#endif /* SMALL */
        default:
                (void)printf("%s: (%d) %s; ",
                    which, su->sa.sa_family, any_ntoa(&su->sa));
        }
        (void)fflush(stdout);
}

/* States*/
#define VIRGIN  0
#define GOTONE  1
#define GOTTWO  2
/* Inputs */
#define DIGIT   (4*0)
#define END     (4*1)
#define DELIM   (4*2)

static void
sockaddr(const char *addr, struct sockaddr *sa)
{
        char *cp = (char *)sa;
        int size = sa->sa_len;
        char *cplim = cp + size;
        int byte = 0, state = VIRGIN, new = 0;

        (void)memset(cp, 0, size);
        cp++;
        do {
                if ((*addr >= '0') && (*addr <= '9')) {
                        new = *addr - '0';
                } else if ((*addr >= 'a') && (*addr <= 'f')) {
                        new = *addr - 'a' + 10;
                } else if ((*addr >= 'A') && (*addr <= 'F')) {
                        new = *addr - 'A' + 10;
                } else if (*addr == 0)
                        state |= END;
                else
                        state |= DELIM;
                addr++;
                switch (state /* | INPUT */) {
                case GOTTWO | DIGIT:
                        *cp++ = byte; /*FALLTHROUGH*/
                case VIRGIN | DIGIT:
                        state = GOTONE; byte = new; continue;
                case GOTONE | DIGIT:
                        state = GOTTWO; byte = new + (byte << 4); continue;
                default: /* | DELIM */
                        state = VIRGIN; *cp++ = byte; byte = 0; continue;
                case GOTONE | END:
                case GOTTWO | END:
                        *cp++ = byte; /* FALLTHROUGH */
                case VIRGIN | END:
                        break;
                }
                break;
        } while (cp < cplim);
        sa->sa_len = cp - (char *)sa;
}