BSD 4_3_Tahoe release

[unix-history] / usr / src / etc / routed / output.c

/*
* Copyright (c) 1983, 1988 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and that due credit is given
* to the University of California at 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'' without express or implied warranty.
*/

#ifndef lint
static char sccsid[] = "@(#)output.c    5.10 (Berkeley) 5/31/88";
#endif /* not lint */

/*
* 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)(s, 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;
       register struct interface *ifp;
{
       register struct rt_entry *rt;
       register struct netinfo *n = msg->rip_nets;
       register struct rthash *rh;
       struct rthash *base = hosthash;
       int doinghost = 1, size;
       int (*output)() = afswitch[dst->sa_family].af_output;
       int (*sendroute)() = afswitch[dst->sa_family].af_sendroute;
       int npackets = 0;

       msg->rip_cmd = RIPCMD_RESPONSE;
       msg->rip_vers = RIPVERSION;
       bzero(msg->rip_res1, sizeof(msg->rip_res1));
again:
       for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++)
       for (rt = rh->rt_forw; rt != (struct rt_entry *)rh; rt = rt->rt_forw) {
               /*
                * Don't resend the information on the network
                * from which it was received (unless sending
                * in response to a query).
                */
               if (ifp && rt->rt_ifp == ifp &&
                   (rt->rt_state & RTS_INTERFACE) == 0)
                       continue;
               if (rt->rt_state & RTS_EXTERNAL)
                       continue;
               /*
                * Limit the spread of subnet information
                * to those who are interested.
                */
               if (doinghost == 0 && rt->rt_state & RTS_SUBNET) {
                       if (rt->rt_dst.sa_family != dst->sa_family)
                               continue;
                       if ((*sendroute)(rt, dst) == 0)
                               continue;
               }
               size = (char *)n - packet;
               if (size > MAXPACKETSIZE - sizeof (struct netinfo)) {
                       (*output)(s, flags, dst, size);
                       TRACE_OUTPUT(ifp, dst, size);
                       /*
                        * If only sending to ourselves,
                        * one packet is enough to monitor interface.
                        */
                       if ((ifp->int_flags &
                          (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0)
                               return;
                       n = msg->rip_nets;
                       npackets++;
               }
               n->rip_dst = rt->rt_dst;
               n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
               n->rip_metric = htonl(rt->rt_metric);
               n++;
       }
       if (doinghost) {
               doinghost = 0;
               base = nethash;
               goto again;
       }
       if (n != msg->rip_nets || npackets == 0) {
               size = (char *)n - packet;
               (*output)(s, flags, dst, size);
               TRACE_OUTPUT(ifp, dst, size);
       }
}