X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/f6311fb6ab21020b5f64fc0f4582a0fcf4f4c9a6..5b519e941140a2be657d68865fade9f5aa577b79:/usr/src/sys/net/route.c

diff --git a/usr/src/sys/net/route.c b/usr/src/sys/net/route.c
index 9692aeb384..7198fa901e 100644
--- a/usr/src/sys/net/route.c
+++ b/usr/src/sys/net/route.c
@@ -1,177 +1,323 @@
-/*	route.c	4.4	82/03/30	*/
-
-#include "../h/param.h"
-#include "../h/systm.h"
-#include "../h/mbuf.h"
-#include "../h/protosw.h"
-#include "../h/socket.h"
-#include "../h/ioctl.h"
-#include "../net/in.h"
-#include "../net/in_systm.h"
-#include "../net/if.h"
-#include "../net/af.h"
-#include "../net/route.h"
-#include <errno.h>
+/*
+ * Copyright (c) 1980, 1986 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.
+ *
+ *	@(#)route.c	7.3 (Berkeley) %G%
+ */
+
+#include "param.h"
+#include "systm.h"
+#include "mbuf.h"
+#include "protosw.h"
+#include "socket.h"
+#include "dir.h"
+#include "user.h"
+#include "ioctl.h"
+#include "errno.h"
+
+#include "if.h"
+#include "af.h"
+#include "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, *rtmin;
+	register struct rtentry *rt;
 	register struct mbuf *m;
-	register int hash;
-	struct afhash h;
+	register u_long hash;
 	struct sockaddr *dst = &ro->ro_dst;
-	int af = dst->sa_family, doinghost;
+	int (*match)(), doinghost, s;
+	struct afhash h;
+	u_int af = dst->sa_family;
+	struct mbuf **table;
 
-COUNT(RTALLOC);
-	if (ro->ro_rt && ro->ro_rt->rt_ifp)			/* XXX */
+	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);
-	hash = h.afh_hosthash;
-	rtmin = 0, doinghost = 1;
+	match = afswitch[af].af_netmatch;
+	hash = h.afh_hosthash, table = rthost, doinghost = 1;
+	s = splnet();
 again:
-	m = routehash[hash % RTHASHSIZ];
-	for (; m; m = m->m_next) {
+	for (m = table[RTHASHMOD(hash)]; m; m = m->m_next) {
 		rt = mtod(m, struct rtentry *);
-		if (rt->rt_hash[doinghost] != hash)
+		if (rt->rt_hash != hash)
+			continue;
+		if ((rt->rt_flags & RTF_UP) == 0 ||
+		    (rt->rt_ifp->if_flags & IFF_UP) == 0)
 			continue;
 		if (doinghost) {
-#define	equal(a1, a2) \
-	(bcmp((caddr_t)(a1), (caddr_t)(a2), sizeof(struct sockaddr)) == 0)
-			if (!equal(&rt->rt_dst, dst))
+			if (bcmp((caddr_t)&rt->rt_dst, (caddr_t)dst,
+			    sizeof (*dst)))
 				continue;
 		} else {
-			if (rt->rt_dst.sa_family != af)
-				continue;
-			if ((*afswitch[af].af_netmatch)(&rt->rt_dst, dst) == 0)
+			if (rt->rt_dst.sa_family != af ||
+			    !(*match)(&rt->rt_dst, dst))
 				continue;
 		}
-		if (rtmin == 0 || rt->rt_use < rtmin->rt_use)
-			rtmin = rt;
-	}
-	if (rtmin) {
-		ro->ro_rt = rt;
 		rt->rt_refcnt++;
+		splx(s);
+		if (dst == &wildcard)
+			rtstat.rts_wildcard++;
+		ro->ro_rt = rt;
 		return;
 	}
 	if (doinghost) {
 		doinghost = 0;
-		hash = h.afh_nethash;
+		hash = h.afh_nethash, table = rtnet;
 		goto again;
 	}
-	ro->ro_rt = 0;
-	return;
+	/*
+	 * 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;
 {
 
-COUNT(FREEROUTE);
 	if (rt == 0)
-		panic("freeroute");
+		panic("rtfree");
 	rt->rt_refcnt--;
-	/* on refcnt == 0 reclaim? notify someone? */
+	if (rt->rt_refcnt == 0 && (rt->rt_flags&RTF_UP) == 0) {
+		rttrash--;
+		(void) m_free(dtom(rt));
+	}
+}
+
+/*
+ * 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
+ *
+ */
+rtredirect(dst, gateway, flags, src)
+	struct sockaddr *dst, *gateway, *src;
+	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;
+#define	equal(a1, a2) \
+	(bcmp((caddr_t)(a1), (caddr_t)(a2), sizeof(struct sockaddr)) == 0)
+	/*
+	 * If the redirect isn't from our current router for this dst,
+	 * it's either old or wrong.  If it redirects us to ourselves,
+	 * we have a routing loop, perhaps as a result of an interface
+	 * going down recently.
+	 */
+	if ((rt && !equal(src, &rt->rt_gateway)) || ifa_ifwithaddr(gateway)) {
+		rtstat.rts_badredirect++;
+		if (rt)
+			rtfree(rt);
+		return;
+	}
+	/*
+	 * 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, (int)SIOCADDRT,
+		    (flags & RTF_HOST) | RTF_GATEWAY | RTF_DYNAMIC);
+		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, (int)SIOCADDRT,
+			    flags | RTF_DYNAMIC);
+			rtstat.rts_dynamic++;
+		} else {
+			/*
+			 * Smash the current notion of the gateway to
+			 * this destination.
+			 */
+			rt->rt_gateway = *gateway;
+			rt->rt_flags |= RTF_MODIFIED;
+			rtstat.rts_newgateway++;
+		}
+	} else
+		rtstat.rts_badredirect++;
+	rtfree(rt);
+}
+
+/*
+ * Routing table ioctl interface.
+ */
+rtioctl(cmd, data)
+	int cmd;
+	caddr_t data;
+{
+
+	if (cmd != SIOCADDRT && cmd != SIOCDELRT)
+		return (EINVAL);
+	if (!suser())
+		return (u.u_error);
+	return (rtrequest(cmd, (struct rtentry *)data));
 }
 
 /*
  * Carry out a request to change the routing table.  Called by
- * interfaces at boot time to make their ``local routes'' known
- * and for ioctl's.
+ * interfaces at boot time to make their ``local routes'' known,
+ * for ioctl's, and as the result of routing redirects.
  */
-rtrequest(req, new)
+rtrequest(req, entry)
 	int req;
-	register struct rtentry *new;
+	register struct rtentry *entry;
 {
-	register struct rtentry *rt;
 	register struct mbuf *m, **mprev;
-	register int hash;
-	struct sockaddr *sa = &new->rt_dst;
+	struct mbuf **mfirst;
+	register struct rtentry *rt;
 	struct afhash h;
-	int af = sa->sa_family, doinghost, s, error = 0;
+	int s, error = 0, (*match)();
+	u_int af;
+	u_long hash;
+	struct ifaddr *ifa;
+	struct ifaddr *ifa_ifwithdstaddr();
 
-COUNT(RTREQUEST);
-	(*afswitch[af].af_hash)(sa, &h);
-	hash = h.afh_hosthash;
-	doinghost = 1;
+	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();
-again:
-	mprev = &routehash[hash % RTHASHSIZ];
-	for (; m = *mprev; mprev = &m->m_next) {
+	for (mfirst = mprev; m = *mprev; mprev = &m->m_next) {
 		rt = mtod(m, struct rtentry *);
-		if (rt->rt_hash[doinghost] != hash)
+		if (rt->rt_hash != hash)
 			continue;
-		if (doinghost) {
-			if (!equal(&rt->rt_dst, &new->rt_dst))
+		if (entry->rt_flags & RTF_HOST) {
+			if (!equal(&rt->rt_dst, &entry->rt_dst))
 				continue;
 		} else {
-			if (rt->rt_dst.sa_family != af)
-				continue;
-			if ((*afswitch[af].af_netmatch)(&rt->rt_dst, sa) == 0)
+			if (rt->rt_dst.sa_family != entry->rt_dst.sa_family ||
+			    (*match)(&rt->rt_dst, &entry->rt_dst) == 0)
 				continue;
 		}
-		/* require full match on deletions */
-		if (req == SIOCDELRT &&
-		    !equal(&rt->rt_gateway, &new->rt_gateway))
-			continue;
-		/* don't keep multiple identical entries */
-		if (req == SIOCADDRT &&
-		    equal(&rt->rt_gateway, &new->rt_gateway)) {
-			error = EEXIST;
-			goto bad;
-		}
-		break;
-	}
-	if (m == 0 && doinghost) {
-		doinghost = 0;
-		hash = h.afh_nethash;
-		goto again;
-	}
-	if (m == 0 && req != SIOCADDRT) {
-		error = ESRCH;
-		goto bad;
+		if (equal(&rt->rt_gateway, &entry->rt_gateway))
+			break;
 	}
 	switch (req) {
 
 	case SIOCDELRT:
-		rt->rt_flags &= ~RTF_UP;
-		if (rt->rt_refcnt > 0)	/* should we notify protocols? */
-			error = EBUSY;
-		else
-			*mprev = m_free(m);
-		break;
-
-	case SIOCCHGRT:
-		rt->rt_flags = new->rt_flags;
-		if (rt->rt_refcnt > 0)
-			error = EBUSY;
-		else if (!equal(&rt->rt_gateway, &new->rt_gateway))
-			goto newneighbor;
+		if (m == 0) {
+			error = ESRCH;
+			goto bad;
+		}
+		*mprev = m->m_next;
+		if (rt->rt_refcnt > 0) {
+			rt->rt_flags &= ~RTF_UP;
+			rttrash++;
+			m->m_next = 0;
+		} else
+			(void) m_free(m);
 		break;
 
 	case SIOCADDRT:
-		m = m_get(M_DONTWAIT);
+		if (m) {
+			error = EEXIST;
+			goto bad;
+		}
+		if ((entry->rt_flags & RTF_GATEWAY) == 0) {
+			/*
+			 * If we are adding a route to an interface,
+			 * and the interface is a pt to pt link
+			 * we should search for the destination
+			 * as our clue to the interface.  Otherwise
+			 * we can use the local address.
+			 */
+			ifa = 0;
+			if (entry->rt_flags & RTF_HOST) 
+				ifa = ifa_ifwithdstaddr(&entry->rt_dst);
+			if (ifa == 0)
+				ifa = ifa_ifwithaddr(&entry->rt_gateway);
+		} else {
+			/*
+			 * If we are adding a route to a remote net
+			 * or host, the gateway may still be on the
+			 * other end of a pt to pt link.
+			 */
+			ifa = ifa_ifwithdstaddr(&entry->rt_gateway);
+		}
+		if (ifa == 0) {
+			ifa = ifa_ifwithnet(&entry->rt_gateway);
+			if (ifa == 0) {
+				error = ENETUNREACH;
+				goto bad;
+			}
+		}
+		m = m_get(M_DONTWAIT, MT_RTABLE);
 		if (m == 0) {
 			error = ENOBUFS;
-			break;
+			goto bad;
 		}
+		m->m_next = *mfirst;
+		*mfirst = m;
 		m->m_off = MMINOFF;
 		m->m_len = sizeof (struct rtentry);
-		*mprev = m;
 		rt = mtod(m, struct rtentry *);
-		*rt = *new;
-		rt->rt_hash[0] = h.afh_nethash;
-		rt->rt_hash[1] = h.afh_hosthash;
-newneighbor:
-		rt->rt_ifp = if_ifwithnet(&new->rt_gateway);
-		if (rt->rt_ifp == 0)
-			rt->rt_flags &= ~RTF_UP;
-		rt->rt_use = 0;
+		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|RTF_DYNAMIC));
 		rt->rt_refcnt = 0;
+		rt->rt_use = 0;
+		rt->rt_ifp = ifa->ifa_ifp;
 		break;
 	}
 bad:
@@ -183,19 +329,15 @@ bad:
  * Set up a routing table entry, normally
  * for an interface.
  */
-rtinit(dst, gateway, flags)
+rtinit(dst, gateway, cmd, flags)
 	struct sockaddr *dst, *gateway;
-	int flags;
+	int cmd, flags;
 {
 	struct rtentry route;
-	struct route ro;
 
+	bzero((caddr_t)&route, sizeof (route));
 	route.rt_dst = *dst;
 	route.rt_gateway = *gateway;
 	route.rt_flags = flags;
-	route.rt_use = 0;
-	(void) rtrequest(SIOCADDRT, &route);
-	ro.ro_rt = 0;
-	ro.ro_dst = *dst;
-	rtalloc(&ro);
+	(void) rtrequest(cmd, &route);
 }