XNSrouted/tables.c

/*
 * Copyright (c) 1985 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static char sccsid[] = "@(#)tables.c    5.7 (Berkeley) 9/20/88";
#endif /* not lint */

/*
 * Routing Table Management Daemon
 */
#include "defs.h"
#include <sys/ioctl.h>
#include <errno.h>

#ifndef DEBUG
#define DEBUG   0
#endif

extern  char *xns_ntoa();

int     install = !DEBUG;               /* if 1 call kernel */
int     delete = 1;
/*
 * Lookup dst in the tables for an exact match.
 */
struct rt_entry *
rtlookup(dst)
        struct sockaddr *dst;
{
        register struct rt_entry *rt;
        register struct rthash *rh;
        register u_int hash;
        struct afhash h;
        int doinghost = 1;

        if (dst->sa_family >= AF_MAX)
                return (0);
        (*afswitch[dst->sa_family].af_hash)(dst, &h);
        hash = h.afh_hosthash;
        rh = &hosthash[hash & ROUTEHASHMASK];
again:
        for (rt = rh->rt_forw; rt != (struct rt_entry *)rh; rt = rt->rt_forw) {
                if (rt->rt_hash != hash)
                        continue;
                if (equal(&rt->rt_dst, dst))
                        return (rt);
        }
        if (doinghost) {
                doinghost = 0;
                hash = h.afh_nethash;
                rh = &nethash[hash & ROUTEHASHMASK];
                goto again;
        }
        return (0);
}

/*
 * Find a route to dst as the kernel would.
 */
struct rt_entry *
rtfind(dst)
        struct sockaddr *dst;
{
        register struct rt_entry *rt;
        register struct rthash *rh;
        register u_int hash;
        struct afhash h;
        int af = dst->sa_family;
        int doinghost = 1, (*match)();

        if (af >= AF_MAX)
                return (0);
        (*afswitch[af].af_hash)(dst, &h);
        hash = h.afh_hosthash;
        rh = &hosthash[hash & ROUTEHASHMASK];

again:
        for (rt = rh->rt_forw; rt != (struct rt_entry *)rh; rt = rt->rt_forw) {
                if (rt->rt_hash != hash)
                        continue;
                if (doinghost) {
                        if (equal(&rt->rt_dst, dst))
                                return (rt);
                } else {
                        if (rt->rt_dst.sa_family == af &&
                            (*match)(&rt->rt_dst, dst))
                                return (rt);
                }
        }
        if (doinghost) {
                doinghost = 0;
                hash = h.afh_nethash;
                rh = &nethash[hash & ROUTEHASHMASK];
                match = afswitch[af].af_netmatch;
                goto again;
        }
        return (0);
}

rtadd(dst, gate, metric, state)
        struct sockaddr *dst, *gate;
        int metric, state;
{
        struct afhash h;
        register struct rt_entry *rt;
        struct rthash *rh;
        int af = dst->sa_family, flags;
        u_int hash;

        if (af >= AF_MAX)
                return;
        (*afswitch[af].af_hash)(dst, &h);
        flags = (*afswitch[af].af_ishost)(dst) ? RTF_HOST : 0;
        if (flags & RTF_HOST) {
                hash = h.afh_hosthash;
                rh = &hosthash[hash & ROUTEHASHMASK];
        } else {
                hash = h.afh_nethash;
                rh = &nethash[hash & ROUTEHASHMASK];
        }
        rt = (struct rt_entry *)malloc(sizeof (*rt));
        if (rt == 0)
                return;
        rt->rt_hash = hash;
        rt->rt_dst = *dst;
        rt->rt_router = *gate;
        rt->rt_metric = metric;
        rt->rt_timer = 0;
        rt->rt_flags = RTF_UP | flags;
        rt->rt_state = state | RTS_CHANGED;
        rt->rt_ifp = if_ifwithnet(&rt->rt_router);
        if (metric)
                rt->rt_flags |= RTF_GATEWAY;
        insque(rt, rh);
        TRACE_ACTION(ADD, rt);
        /*
         * If the ioctl fails because the gateway is unreachable
         * from this host, discard the entry.  This should only
         * occur because of an incorrect entry in /etc/gateways.
         */
        if (install && ioctl(s, SIOCADDRT, (char *)&rt->rt_rt) < 0) {
                if (errno != EEXIST)
                        perror("SIOCADDRT");
                if (errno == ENETUNREACH) {
                        TRACE_ACTION(DELETE, rt);
                        remque(rt);
                        free((char *)rt);
                }
        }
}

rtchange(rt, gate, metric)
        struct rt_entry *rt;
        struct sockaddr *gate;
        short metric;
{
        int doioctl = 0, metricchanged = 0;
        struct rtentry oldroute;

        if (!equal(&rt->rt_router, gate))
                doioctl++;
        if (metric != rt->rt_metric)
                metricchanged++;
        if (doioctl || metricchanged) {
                TRACE_ACTION(CHANGE FROM, rt);
                if (doioctl) {
                        oldroute = rt->rt_rt;
                        rt->rt_router = *gate;
                }
                rt->rt_metric = metric;
                if ((rt->rt_state & RTS_INTERFACE) && metric) {
                        rt->rt_state &= ~RTS_INTERFACE;
                        syslog(LOG_ERR,
                                "changing route from interface %s (timed out)",
                                rt->rt_ifp->int_name);
                }
                if (metric)
                        rt->rt_flags |= RTF_GATEWAY;
                else
                        rt->rt_flags &= ~RTF_GATEWAY;
                rt->rt_state |= RTS_CHANGED;
                TRACE_ACTION(CHANGE TO, rt);
        }
        if (doioctl && install) {
                if (ioctl(s, SIOCADDRT, (char *)&rt->rt_rt) < 0)
                  syslog(LOG_ERR, "SIOCADDRT dst %s, gw %s: %m",
                   xns_ntoa(&((struct sockaddr_ns *)&rt->rt_dst)->sns_addr),
                   xns_ntoa(&((struct sockaddr_ns *)&rt->rt_router)->sns_addr));
                if (delete && ioctl(s, SIOCDELRT, (char *)&oldroute) < 0)
                        perror("SIOCDELRT");
        }
}

rtdelete(rt)
        struct rt_entry *rt;
{

        if (rt->rt_state & RTS_INTERFACE) {
                syslog(LOG_ERR, "deleting route to interface %s (timed out)",
                        rt->rt_ifp->int_name);
        }
        TRACE_ACTION(DELETE, rt);
        if (install && ioctl(s, SIOCDELRT, (char *)&rt->rt_rt))
                perror("SIOCDELRT");
        remque(rt);
        free((char *)rt);
}

rtinit()
{
        register struct rthash *rh;

        for (rh = nethash; rh < &nethash[ROUTEHASHSIZ]; rh++)
                rh->rt_forw = rh->rt_back = (struct rt_entry *)rh;
        for (rh = hosthash; rh < &hosthash[ROUTEHASHSIZ]; rh++)
                rh->rt_forw = rh->rt_back = (struct rt_entry *)rh;
}