Ultrix-3.1/sys/net/route.c
/**********************************************************************
* Copyright (c) Digital Equipment Corporation 1984, 1985, 1986. *
* All Rights Reserved. *
* Reference "/usr/src/COPYRIGHT" for applicable restrictions. *
**********************************************************************/
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
* SCCSID: @(#)route.c 3.0 4/21/86
* Based on: @(#)route.c 6.10 (Berkeley) 6/8/85
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/dir.h>
#include <sys/user.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <net/if.h>
#include <netinet/in_systm.h>
#include <net/af.h>
#include <net/route.h>
int rttrash; /* routes not in table but not freed */
struct sockaddr wildcard; /* zero valued cookie for wildcard searches */
int rthashsize = RTHASHSIZ; /* for netstat, etc. */
/*
* Packet routing routines.
*/
rtalloc(ro)
register struct route *ro;
{
register struct rtentry *rt;
#ifndef pdp11
register struct mbuf *m;
register u_long hash;
#else pdp11
register unsigned int hash;
#endif pdp11
struct sockaddr *dst = &ro->ro_dst;
int (*match)(), doinghost, s;
struct afhash h;
u_int af = dst->sa_family;
#ifndef pdp11
struct mbuf **table;
#else pdp11
struct rtentry **table;
#endif pdp11
if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP))
return; /* XXX */
if (af >= AF_MAX)
return;
(*afswitch[af].af_hash)(dst, &h);
match = afswitch[af].af_netmatch;
hash = h.afh_hosthash, table = rthost, doinghost = 1;
s = splnet();
again:
#ifndef pdp11
for (m = table[RTHASHMOD(hash)]; m; m = m->m_next)
#else pdp11
for (rt = table[RTHASHMOD(hash)]; rt; rt = rt->rt_next)
#endif pdp11
{
#ifndef pdp11
rt = mtod(m, struct rtentry *);
#endif pdp11
if (rt->rt_hash != hash)
continue;
if ((rt->rt_flags & RTF_UP) == 0 ||
(rt->rt_ifp->if_flags & IFF_UP) == 0)
continue;
if (doinghost) {
if (bcmp((caddr_t)&rt->rt_dst, (caddr_t)dst,
sizeof (*dst)))
continue;
} else {
if (rt->rt_dst.sa_family != af ||
!(*match)(&rt->rt_dst, dst))
continue;
}
rt->rt_refcnt++;
splx(s);
if (dst == &wildcard)
rtstat.rts_wildcard++;
ro->ro_rt = rt;
return;
}
if (doinghost) {
doinghost = 0;
hash = h.afh_nethash, table = rtnet;
goto again;
}
/*
* Check for wildcard gateway, by convention network 0.
*/
if (dst != &wildcard) {
dst = &wildcard, hash = 0;
goto again;
}
splx(s);
rtstat.rts_unreach++;
}
rtfree(rt)
register struct rtentry *rt;
{
if (rt == 0)
panic("rtfree");
rt->rt_refcnt--;
if (rt->rt_refcnt == 0 && (rt->rt_flags&RTF_UP) == 0) {
rttrash--;
#ifndef pdp11
(void) m_free(dtom(rt));
#else pdp11
MSFREE(rt);
#endif pdp11
}
}
/*
* Force a routing table entry to the specified
* destination to go through the given gateway.
* Normally called as a result of a routing redirect
* message from the network layer.
*
* N.B.: must be called at splnet or higher
*
* Should notify all parties with a reference to
* the route that it's changed (so, for instance,
* current round trip time estimates could be flushed),
* but we have no back pointers at the moment.
*/
rtredirect(dst, gateway, flags)
struct sockaddr *dst, *gateway;
int flags;
{
struct route ro;
register struct rtentry *rt;
/* verify the gateway is directly reachable */
if (ifa_ifwithnet(gateway) == 0) {
rtstat.rts_badredirect++;
return;
}
ro.ro_dst = *dst;
ro.ro_rt = 0;
rtalloc(&ro);
rt = ro.ro_rt;
/*
* Create a new entry if we just got back a wildcard entry
* or the the lookup failed. This is necessary for hosts
* which use routing redirects generated by smart gateways
* to dynamically build the routing tables.
*/
if (rt &&
(*afswitch[dst->sa_family].af_netmatch)(&wildcard, &rt->rt_dst)) {
rtfree(rt);
rt = 0;
}
if (rt == 0) {
rtinit(dst, gateway, (flags & RTF_HOST) | RTF_GATEWAY);
rtstat.rts_dynamic++;
return;
}
/*
* Don't listen to the redirect if it's
* for a route to an interface.
*/
if (rt->rt_flags & RTF_GATEWAY) {
if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) {
/*
* Changing from route to net => route to host.
* Create new route, rather than smashing route to net.
*/
rtinit(dst, gateway, flags);
} else {
/*
* Smash the current notion of the gateway to
* this destination. This is probably not right,
* as it's conceivable a flurry of redirects could
* cause the gateway value to fluctuate wildly during
* dynamic routing reconfiguration.
*/
rt->rt_gateway = *gateway;
}
rtstat.rts_newgateway++;
}
rtfree(rt);
}
/*
* Routing table ioctl interface.
*/
rtioctl(cmd, data)
int cmd;
caddr_t data;
{
#ifdef pdp11
struct rtentry foo;
if (copyin(data, (caddr_t)&foo, sizeof(struct rtentry)) == -1)
return(EFAULT);
#endif pdp11
if (cmd != SIOCADDRT && cmd != SIOCDELRT)
return (EINVAL);
if (!suser())
return (u.u_error);
#ifndef pdp11
return (rtrequest(cmd, (struct rtentry *)data));
#else pdp11
return (rtrequest(cmd, &foo));
#endif pdp11
}
/*
* Carry out a request to change the routing table. Called by
* interfaces at boot time to make their ``local routes'' known,
* for ioctl's, and as the result of routing redirects.
*/
static
rtrequest(req, entry)
int req;
register struct rtentry *entry;
{
#ifndef pdp11
register struct mbuf *m, **mprev;
#else pdp11
register struct rtentry *m, **mprev;
#endif pdp11
register struct rtentry *rt;
struct afhash h;
int s, error = 0, (*match)();
u_int af;
u_long hash;
struct ifaddr *ifa;
af = entry->rt_dst.sa_family;
if (af >= AF_MAX)
return (EAFNOSUPPORT);
(*afswitch[af].af_hash)(&entry->rt_dst, &h);
if (entry->rt_flags & RTF_HOST) {
hash = h.afh_hosthash;
mprev = &rthost[RTHASHMOD(hash)];
} else {
hash = h.afh_nethash;
mprev = &rtnet[RTHASHMOD(hash)];
}
match = afswitch[af].af_netmatch;
s = splimp();
#ifndef pdp11
for (; m = *mprev; mprev = &m->m_next)
#else pdp11
for (; m = *mprev; mprev = &m->rt_next)
#endif pdp11
{
#ifndef pdp11
rt = mtod(m, struct rtentry *);
#else pdp11
rt = m;
#endif pdp11
if (rt->rt_hash != hash)
continue;
if (entry->rt_flags & RTF_HOST) {
#define equal(a1, a2) \
(bcmp((caddr_t)(a1), (caddr_t)(a2), sizeof (struct sockaddr)) == 0)
if (!equal(&rt->rt_dst, &entry->rt_dst))
continue;
} else {
if (rt->rt_dst.sa_family != entry->rt_dst.sa_family ||
(*match)(&rt->rt_dst, &entry->rt_dst) == 0)
continue;
}
if (equal(&rt->rt_gateway, &entry->rt_gateway))
break;
}
switch (req) {
case SIOCDELRT:
if (m == 0) {
error = ESRCH;
goto bad;
}
#ifndef pdp11
*mprev = m->m_next;
#else pdp11
*mprev = m->rt_next;
#endif pdp11
if (rt->rt_refcnt > 0) {
rt->rt_flags &= ~RTF_UP;
rttrash++;
#ifndef pdp11
m->m_next = 0;
#else pdp11
m->rt_next = 0;
#endif pdp11
} else
#ifndef pdp11
(void) m_free(m);
#else pdp11
MSFREE(m);
#endif pdp11
break;
case SIOCADDRT:
if (m) {
error = EEXIST;
goto bad;
}
ifa = ifa_ifwithaddr(&entry->rt_gateway);
if (ifa == 0) {
ifa = ifa_ifwithnet(&entry->rt_gateway);
if (ifa == 0) {
error = ENETUNREACH;
goto bad;
}
}
#ifndef pdp11
m = m_get(M_DONTWAIT, MT_RTABLE);
if (m == 0) {
error = ENOBUFS;
goto bad;
}
*mprev = m;
m->m_off = MMINOFF;
m->m_len = sizeof (struct rtentry);
rt = mtod(m, struct rtentry *);
#else pdp11
MSGET(rt, struct rtentry, MT_RTABLE, 0, M_DONTWAIT);
if (rt == NULL) {
error = ENOBUFS;
goto bad;
}
*mprev = rt;
rt->rt_next = NULL;
#endif pdp11
rt->rt_hash = hash;
rt->rt_dst = entry->rt_dst;
rt->rt_gateway = entry->rt_gateway;
rt->rt_flags =
RTF_UP | (entry->rt_flags & (RTF_HOST|RTF_GATEWAY));
rt->rt_refcnt = 0;
rt->rt_use = 0;
rt->rt_ifp = ifa->ifa_ifp;
break;
}
bad:
splx(s);
return (error);
}
/*
* Set up a routing table entry, normally
* for an interface.
*/
rtinit(dst, gateway, flags)
struct sockaddr *dst, *gateway;
int flags;
{
struct rtentry route;
int cmd;
if (flags == -1) {
cmd = (int)SIOCDELRT;
flags = 0;
} else {
cmd = (int)SIOCADDRT;
}
bzero((caddr_t)&route, sizeof (route));
route.rt_dst = *dst;
route.rt_gateway = *gateway;
route.rt_flags = flags;
(void) rtrequest(cmd, &route);
}