FreeBSD-5.3/usr.sbin/IPXrouted/input.c
/*
* Copyright (c) 1985, 1993
* The Regents of the University of California. All rights reserved.
*
* Copyright (c) 1995 John Hay. All rights reserved.
*
* This file includes significant work done at Cornell University by
* Bill Nesheim. That work included by permission.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* $FreeBSD: src/usr.sbin/IPXrouted/input.c,v 1.9 2003/11/15 17:10:56 trhodes Exp $
*/
#ifndef lint
static const char sccsid[] = "@(#)input.c 8.1 (Berkeley) 6/5/93";
#endif /* not lint */
/*
* IPX Routing Table Management Daemon
*/
#include "defs.h"
struct sockaddr *
ipx_nettosa(net)
union ipx_net net;
{
static struct sockaddr_ipx sxn;
bzero(&sxn, sizeof (struct sockaddr_ipx));
sxn.sipx_family = AF_IPX;
sxn.sipx_len = sizeof (sxn);
sxn.sipx_addr.x_net = net;
return( (struct sockaddr *)&sxn);
}
/*
* Process a newly received packet.
*/
void
rip_input(from, size)
struct sockaddr *from;
int size;
{
int newsize;
int rtchanged = 0;
struct rt_entry *rt;
struct netinfo *n;
struct interface *ifp = 0;
struct afswitch *afp;
struct sockaddr_ipx *ipxp;
ifp = if_ifwithnet(from);
ipxp = (struct sockaddr_ipx *)from;
if (ifp == 0) {
if(ftrace) {
fprintf(ftrace, "Received bogus packet from %s\n",
ipxdp_ntoa(&ipxp->sipx_addr));
}
return;
}
TRACE_INPUT(ifp, from, size);
if (from->sa_family >= AF_MAX)
return;
afp = &afswitch[from->sa_family];
size -= sizeof (u_short) /* command */;
n = msg->rip_nets;
switch (ntohs(msg->rip_cmd)) {
case RIPCMD_REQUEST:
if (ipx_hosteq(satoipx_addr(ifp->int_addr), ipxp->sipx_addr))
return;
newsize = 0;
while (size > 0) {
if (size < sizeof (struct netinfo))
break;
size -= sizeof (struct netinfo);
/*
* A single entry with rip_dst == DSTNETS_ALL and
* metric ``infinity'' means ``all routes''.
*
* XXX According to the IPX RIP spec the metric
* and tick fields can be anything. So maybe we
* should not check the metric???
*/
if (ipx_neteqnn(n->rip_dst, ipx_anynet) &&
ntohs(n->rip_metric) == HOPCNT_INFINITY &&
size == 0) {
supply(from, 0, ifp, 0);
return;
}
/*
* request for specific nets
*/
rt = rtlookup(ipx_nettosa(n->rip_dst));
if (ftrace) {
fprintf(ftrace,
"specific request for %s",
ipxdp_nettoa(n->rip_dst));
fprintf(ftrace,
" yields route %lx\n",
(u_long)rt);
}
/*
* XXX We break out on the first net that isn't
* found. The specs is a bit vague here. I'm not
* sure what we should do.
*/
if (rt == 0)
return;
/* XXX
* According to the spec we should not include
* information about networks for which the number
* of hops is 16.
*/
if (rt->rt_metric == (HOPCNT_INFINITY-1))
return;
n->rip_metric = htons( rt == 0 ? HOPCNT_INFINITY :
min(rt->rt_metric+1, HOPCNT_INFINITY));
n->rip_ticks = htons(rt->rt_ticks+1);
/*
* We use split horizon with a twist. If the requested
* net is the directly connected net we supply an
* answer. This is so that the host can learn about
* the routers on its net.
*/
{
register struct rt_entry *trt = rt;
while (trt) {
if ((trt->rt_ifp == ifp) &&
!ipx_neteqnn(n->rip_dst,
satoipx_addr(ifp->int_addr).x_net))
return;
trt = trt->rt_clone;
}
n++;
newsize += sizeof (struct netinfo);
}
}
if (newsize > 0) {
msg->rip_cmd = htons(RIPCMD_RESPONSE);
newsize += sizeof (u_short);
/* should check for if with dstaddr(from) first */
(*afp->af_output)(ripsock, 0, from, newsize);
TRACE_OUTPUT(ifp, from, newsize);
if (ftrace) {
/* XXX This should not happen anymore. */
if(ifp == 0)
fprintf(ftrace, "--- ifp = 0\n");
else
fprintf(ftrace,
"request arrived on interface %s\n",
ifp->int_name);
}
}
return;
case RIPCMD_RESPONSE:
/* verify message came from a router */
if ((*afp->af_portmatch)(from) == 0)
return;
(*afp->af_canon)(from);
/* are we talking to ourselves? */
if ((ifp = if_ifwithaddr(from)) != 0) {
rt = rtfind(from);
if (rt == 0 || (rt->rt_state & RTS_INTERFACE) == 0) {
addrouteforif(ifp);
rtchanged = 1;
} else
rt->rt_timer = 0;
return;
}
/* Update timer for interface on which the packet arrived.
* If from other end of a point-to-point link that isn't
* in the routing tables, (re-)add the route.
*/
if ((rt = rtfind(from)) && (rt->rt_state & RTS_INTERFACE)) {
if(ftrace) fprintf(ftrace, "Got route\n");
rt->rt_timer = 0;
} else if ((ifp = if_ifwithdstaddr(from)) != 0) {
if(ftrace) fprintf(ftrace, "Got partner\n");
addrouteforif(ifp);
rtchanged = 1;
}
for (; size > 0; size -= sizeof (struct netinfo), n++) {
struct sockaddr *sa;
if (size < sizeof (struct netinfo))
break;
if ((unsigned) ntohs(n->rip_metric) > HOPCNT_INFINITY)
continue;
rt = rtfind(sa = ipx_nettosa(n->rip_dst));
if (rt == 0) {
if (ntohs(n->rip_metric) == HOPCNT_INFINITY)
continue;
rtadd(sa, from, ntohs(n->rip_metric),
ntohs(n->rip_ticks), 0);
rtchanged = 1;
continue;
}
/*
* A clone is a different route to the same net
* with exactly the same cost (ticks and metric).
* They must all be recorded because those interfaces
* must be handled in the same way as the first route
* to that net. ie When using the split horizon
* algorithm we must look at these interfaces also.
*
* Update if from gateway and different,
* from anywhere and less ticks or
* if same ticks and shorter,
* or getting stale and equivalent.
*/
if (!equal(from, &rt->rt_router) &&
ntohs(n->rip_ticks) == rt->rt_ticks &&
ntohs(n->rip_metric) == rt->rt_metric &&
ntohs(n->rip_metric) != HOPCNT_INFINITY) {
register struct rt_entry *trt = rt->rt_clone;
while (trt) {
if (equal(from, &trt->rt_router)) {
trt->rt_timer = 0;
break;
}
trt = trt->rt_clone;
}
if (trt == NULL) {
rtadd_clone(rt, sa, from,
ntohs(n->rip_metric),
ntohs(n->rip_ticks), 0);
}
continue;
}
if ((equal(from, &rt->rt_router) &&
((ntohs(n->rip_ticks) != rt->rt_ticks) ||
(ntohs(n->rip_metric) != rt->rt_metric))) ||
(ntohs(n->rip_ticks) < rt->rt_ticks) ||
((ntohs(n->rip_ticks) == rt->rt_ticks) &&
(ntohs(n->rip_metric) < rt->rt_metric)) ||
(rt->rt_timer > (EXPIRE_TIME*2/3) &&
rt->rt_metric == ntohs(n->rip_metric) &&
ntohs(n->rip_metric) != HOPCNT_INFINITY)) {
rtchange(rt, from, ntohs(n->rip_metric),
ntohs(n->rip_ticks));
if (ntohs(n->rip_metric) == HOPCNT_INFINITY)
rt->rt_timer = EXPIRE_TIME;
else
rt->rt_timer = 0;
rtchanged = 1;
} else if (equal(from, &rt->rt_router) &&
(ntohs(n->rip_ticks) == rt->rt_ticks) &&
(ntohs(n->rip_metric) == rt->rt_metric) &&
(ntohs(n->rip_metric) != HOPCNT_INFINITY)) {
rt->rt_timer = 0;
}
}
if (rtchanged) {
register struct rthash *rh;
register struct rt_entry *rt;
toall(supply, NULL, 1);
for (rh = nethash; rh < &nethash[ROUTEHASHSIZ]; rh++)
for (rt = rh->rt_forw;
rt != (struct rt_entry *)rh;
rt = rt->rt_forw)
rt->rt_state &= ~RTS_CHANGED;
}
return;
}
}