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add Berkeley specific headers
[unix-history] / usr / src / sbin / routed / input.c
/*
* Copyright (c) 1983 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[] = "@(#)input.c 5.15 (Berkeley) %G%";
#endif /* not lint */
/*
* Routing Table Management Daemon
*/
#include "defs.h"
#include <sys/syslog.h>
/*
* Process a newly received packet.
*/
rip_input(from, size)
struct sockaddr *from;
int size;
{
register struct rt_entry *rt;
register struct netinfo *n;
register struct interface *ifp;
struct interface *if_ifwithdstaddr();
int newsize;
register struct afswitch *afp;
static struct sockaddr badfrom;
ifp = 0;
TRACE_INPUT(ifp, from, size);
if (from->sa_family >= af_max ||
(afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
syslog(LOG_INFO,
"\"from\" address in unsupported address family (%d), cmd %d\n",
from->sa_family, msg->rip_cmd);
return;
}
switch (msg->rip_cmd) {
case RIPCMD_REQUEST:
newsize = 0;
size -= 4 * sizeof (char);
n = msg->rip_nets;
while (size > 0) {
if (size < sizeof (struct netinfo))
break;
size -= sizeof (struct netinfo);
if (msg->rip_vers > 0) {
n->rip_dst.sa_family =
ntohs(n->rip_dst.sa_family);
n->rip_metric = ntohl(n->rip_metric);
}
/*
* A single entry with sa_family == AF_UNSPEC and
* metric ``infinity'' means ``all routes''.
* We respond to routers only if we are acting
* as a supplier, or to anyone other than a router
* (eg, query).
*/
if (n->rip_dst.sa_family == AF_UNSPEC &&
n->rip_metric == HOPCNT_INFINITY && size == 0) {
if (supplier || (*afp->af_portmatch)(from) == 0)
supply(from, 0, 0);
return;
}
if (n->rip_dst.sa_family < af_max &&
afswitch[n->rip_dst.sa_family].af_hash)
rt = rtlookup(&n->rip_dst);
else
rt = 0;
n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
min(rt->rt_metric + 1, HOPCNT_INFINITY);
if (msg->rip_vers > 0) {
n->rip_dst.sa_family =
htons(n->rip_dst.sa_family);
n->rip_metric = htonl(n->rip_metric);
}
n++, newsize += sizeof (struct netinfo);
}
if (newsize > 0) {
msg->rip_cmd = RIPCMD_RESPONSE;
newsize += sizeof (int);
(*afp->af_output)(s, 0, from, newsize);
}
return;
case RIPCMD_TRACEON:
case RIPCMD_TRACEOFF:
/* verify message came from a privileged port */
if ((*afp->af_portcheck)(from) == 0)
return;
if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
(IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
ifp->int_flags & IFF_PASSIVE) {
syslog(LOG_ERR, "trace command from unknown router, %s",
(*afswitch[from->sa_family].af_format)(from));
return;
}
packet[size] = '\0';
if (msg->rip_cmd == RIPCMD_TRACEON)
traceon(msg->rip_tracefile);
else
traceoff();
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? */
ifp = if_ifwithaddr(from);
if (ifp) {
rt = rtfind(from);
if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) &&
rt->rt_metric >= ifp->int_metric)
addrouteforif(ifp);
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 | RTS_REMOTE)))
rt->rt_timer = 0;
else if ((ifp = if_ifwithdstaddr(from)) &&
(rt == 0 || rt->rt_metric >= ifp->int_metric))
addrouteforif(ifp);
/*
* "Authenticate" router from which message originated.
* We accept routing packets from routers directly connected
* via broadcast or point-to-point networks,
* and from those listed in /etc/gateways.
*/
if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
(IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
ifp->int_flags & IFF_PASSIVE) {
if (bcmp((char *)from, (char *)&badfrom,
sizeof(badfrom)) != 0) {
syslog(LOG_ERR,
"packet from unknown router, %s",
(*afswitch[from->sa_family].af_format)(from));
badfrom = *from;
}
return;
}
size -= 4 * sizeof (char);
n = msg->rip_nets;
for (; size > 0; size -= sizeof (struct netinfo), n++) {
if (size < sizeof (struct netinfo))
break;
if (msg->rip_vers > 0) {
n->rip_dst.sa_family =
ntohs(n->rip_dst.sa_family);
n->rip_metric = ntohl(n->rip_metric);
}
if (n->rip_dst.sa_family >= af_max ||
(afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
(int (*)())0) {
syslog(LOG_INFO,
"route in unsupported address family (%d), from %s (af %d)\n",
n->rip_dst.sa_family,
(*afswitch[from->sa_family].af_format)(from),
from->sa_family);
continue;
}
if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
syslog(LOG_DEBUG,
"bad host in route from %s (af %d)\n",
(*afswitch[from->sa_family].af_format)(from),
from->sa_family);
continue;
}
/*
* Adjust metric according to incoming interface.
*/
if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
n->rip_metric += ifp->int_metric;
if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
n->rip_metric = HOPCNT_INFINITY;
rt = rtlookup(&n->rip_dst);
if (rt == 0 ||
(rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) ==
(RTS_INTERNAL|RTS_INTERFACE)) {
/*
* If we're hearing a logical network route
* back from a peer to which we sent it,
* ignore it.
*/
if (rt && rt->rt_state & RTS_SUBNET &&
(*afp->af_sendroute)(rt, from))
continue;
/*
* Look for an equivalent route that includes
* this one before adding this route.
*/
rt = rtfind(&n->rip_dst);
if (rt && equal(from, &rt->rt_router))
continue;
if (n->rip_metric < HOPCNT_INFINITY)
rtadd(&n->rip_dst, from, n->rip_metric, 0);
continue;
}
/*
* Update if from gateway and different,
* shorter, or getting stale and equivalent.
*/
if (equal(from, &rt->rt_router)) {
if (n->rip_metric != rt->rt_metric) {
rtchange(rt, from, n->rip_metric);
if (rt->rt_metric >= HOPCNT_INFINITY)
rt->rt_timer =
GARBAGE_TIME - EXPIRE_TIME;
} else if (rt->rt_metric < HOPCNT_INFINITY)
rt->rt_timer = 0;
} else if ((unsigned) n->rip_metric < rt->rt_metric ||
(rt->rt_timer > (EXPIRE_TIME/2) &&
rt->rt_metric == n->rip_metric &&
(unsigned) n->rip_metric < HOPCNT_INFINITY)) {
rtchange(rt, from, n->rip_metric);
rt->rt_timer = 0;
}
}
return;
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.