usr/src/sbin/XNSrouted/output.c

/*
 * Copyright (c) 1985 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 * Includes material written at Cornell University by Bill Nesheim,
 * by permission of the author.
 */

#ifndef lint
static char sccsid[] = "@(#)output.c    5.4 (Berkeley) %G%";
#endif

/*
 * Routing Table Management Daemon
 */
#include "defs.h"

/*
 * Apply the function "f" to all non-passive
 * interfaces.  If the interface supports the
 * use of broadcasting use it, otherwise address
 * the output to the known router.
 */
toall(f)
        int (*f)();
{
        register struct interface *ifp;
        register struct sockaddr *dst;
        register int flags;
        extern struct interface *ifnet;

        for (ifp = ifnet; ifp; ifp = ifp->int_next) {
                if (ifp->int_flags & IFF_PASSIVE)
                        continue;
                dst = ifp->int_flags & IFF_BROADCAST ? &ifp->int_broadaddr :
                      ifp->int_flags & IFF_POINTOPOINT ? &ifp->int_dstaddr :
                      &ifp->int_addr;
                flags = ifp->int_flags & IFF_INTERFACE ? MSG_DONTROUTE : 0;
                (*f)(dst, flags, ifp);
        }
}

/*
 * Output a preformed packet.
 */
/*ARGSUSED*/
sendmsg(dst, flags, ifp)
        struct sockaddr *dst;
        int flags;
        struct interface *ifp;
{

        (*afswitch[dst->sa_family].af_output)
                (flags, dst, sizeof (struct rip));
        TRACE_OUTPUT(ifp, dst, sizeof (struct rip));
}

/*
 * Supply dst with the contents of the routing tables.
 * If this won't fit in one packet, chop it up into several.
 */
supply(dst, flags, ifp)
        struct sockaddr *dst;
        int flags;
        struct interface *ifp;
{
        register struct rt_entry *rt;
        register struct rthash *rh;
        register struct netinfo *nn;
        register struct netinfo *n = msg->rip_nets;
        struct rthash *base = hosthash;
        struct sockaddr_ns *sns =  (struct sockaddr_ns *) dst;
        int (*output)() = afswitch[dst->sa_family].af_output;
        int doinghost = 1, size, metric;
        long net;

        msg->rip_cmd = ntohs(RIPCMD_RESPONSE);
again:
        for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++)
        for (rt = rh->rt_forw; rt != (struct rt_entry *)rh; rt = rt->rt_forw) {
                size = (char *)n - (char *)msg;
                if (size > MAXPACKETSIZE - sizeof (struct netinfo)) {
                        (*output)(flags, dst, size);
                        TRACE_OUTPUT(ifp, dst, size);
                        n = msg->rip_nets;
                }
                sns = (struct sockaddr_ns *)&rt->rt_dst;
                if ((rt->rt_flags & (RTF_HOST|RTF_GATEWAY)) == RTF_HOST)
                        sns = (struct sockaddr_ns *)&rt->rt_router;
                metric = min(rt->rt_metric + 1, HOPCNT_INFINITY);
                net = ns_netof(sns->sns_addr);
                /*
                 * Make sure that we don't put out a two net entries
                 * for a pt to pt link (one for the G route, one for the if)
                 * This is a kludge, and won't work if there are lots of nets.
                 */
                for (nn = msg->rip_nets; nn < n; nn++) {
                        if(net == xnnet(nn->rip_dst[0])) {
                                if(metric < ntohs(nn->rip_metric))
                                        nn->rip_metric = htons(metric);
                                goto next;
                        }
                }
                xnnet(n->rip_dst[0]) = net;
                n->rip_metric = htons(metric);
                n++;
        next:;
        }
        if (doinghost) {
                doinghost = 0;
                base = nethash;
                goto again;
        }
        if (n != msg->rip_nets) {
                size = (char *)n - (char *)msg;
                (*output)(flags, dst, size);
                TRACE_OUTPUT(ifp, dst, size);
        }
}