Convert the two dimensional array to be malloced and introduce

an accessor function to get the correct rnh pointer back. Update netstat to get the correct pointer using kvm_read() as well. This not only fixes the ABI problem depending on the kernel option but also permits the tunable to overwrite the kernel option at boot time up to MAXFIBS, enlarging the number of FIBs without having to recompile. So people could just use GENERIC now. Reviewed by: julian, rwatson, zec X-MFC: not possible
svn path=/head/; revision=193232
2024-09-21 09:13:37 +00:00 · 2009-06-01 15:49:42 +00:00 · 2009-06-01 15:49:42 +00:00 · c2c2a7c11e · 2020-12-20 02:59:44 +00:00
parent b01c90a31a
commit c2c2a7c11e
13 changed files with 123 additions and 69 deletions
--- a/6
+++ b/6
@ -22,6 +22,12 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 8.x IS SLOW:
 	to maximize performance.  (To disable malloc debugging, run
 	ln -s aj /etc/malloc.conf.)

+20090601:
+	The way we are storing and accessing `routeing table' entries
+	has changed. Programs reading the FIB, like netstat, need to
+	be re-compiled.
+	Bump __FreeBSD_version to 800097.
+
 20090530:
 	Remove the tunable/sysctl debug.mpsafevfs as its initial purpose
 	is no more valid.
--- a/sys/net/if.c
+++ b/sys/net/if.c
@ -1001,7 +1001,8 @@ if_detach_internal(struct ifnet *ifp, int vmove)
 	 */
 	for (i = 1; i <= AF_MAX; i++) {
 		for (j = 0; j < rt_numfibs; j++) {
-			if ((rnh = V_rt_tables[j][i]) == NULL)
+			rnh = rt_tables_get_rnh(j, i);
+			if (rnh == NULL)
 				continue;
 			RADIX_NODE_HEAD_LOCK(rnh);
 			(void) rnh->rnh_walktree(rnh, if_rtdel, ifp);
--- a/sys/net/route.c
+++ b/sys/net/route.c
@ -91,15 +91,7 @@ TUNABLE_INT("net.add_addr_allfibs", &rt_add_addr_allfibs);

 #ifdef VIMAGE_GLOBALS
 static struct rtstat rtstat;
-
-/* by default only the first 'row' of tables will be accessed. */
-/* 
- * XXXMRT When we fix netstat, and do this differnetly,
- * we can allocate this dynamically. As long as we are keeping
- * things backwards compaitble we need to allocate this 
- * statically.
- */
-struct radix_node_head *rt_tables[RT_MAXFIBS][AF_MAX+1];
+struct radix_node_head *rt_tables;

 static int	rttrash;		/* routes not in table but not freed */
 #endif
@ -158,6 +150,32 @@ sysctl_my_fibnum(SYSCTL_HANDLER_ARGS)
 SYSCTL_PROC(_net, OID_AUTO, my_fibnum, CTLTYPE_INT|CTLFLAG_RD,
            NULL, 0, &sysctl_my_fibnum, "I", "default FIB of caller");

+static __inline struct radix_node_head **
+rt_tables_get_rnh_ptr(int table, int fam)
+{
+	INIT_VNET_NET(curvnet);
+	struct radix_node_head **rnh;
+
+	KASSERT(table >= 0 && table < rt_numfibs, ("%s: table out of bounds.",
+	    __func__));
+	KASSERT(fam >= 0 && fam < (AF_MAX+1), ("%s: fam out of bounds.",
+	    __func__));
+
+	/* rnh is [fib=0][af=0]. */
+	rnh = (struct radix_node_head **)V_rt_tables;
+	/* Get the offset to the requested table and fam. */
+	rnh += table * (AF_MAX+1) + fam;
+
+	return (rnh);
+}
+
+struct radix_node_head *
+rt_tables_get_rnh(int table, int fam)
+{
+
+	return (*rt_tables_get_rnh_ptr(table, fam));
+}
+
 static void
 route_init(void)
 {
@ -179,10 +197,14 @@ route_init(void)
 static int vnet_route_iattach(const void *unused __unused)
 {
 	INIT_VNET_NET(curvnet);
-	int table;
 	struct domain *dom;
+	struct radix_node_head **rnh;
+	int table;
 	int fam;

+	V_rt_tables = malloc(rt_numfibs * (AF_MAX+1) *
+	    sizeof(struct radix_node_head *), M_RTABLE, M_WAITOK|M_ZERO);
+
 	V_rtzone = uma_zcreate("rtentry", sizeof(struct rtentry), NULL, NULL,
 	    NULL, NULL, UMA_ALIGN_PTR, 0);
 	for (dom = domains; dom; dom = dom->dom_next) {
@ -198,8 +220,10 @@ static int vnet_route_iattach(const void *unused __unused)
 					 * (only for AF_INET and AF_INET6
 					 * which don't need it anyhow)
 					 */
-					dom->dom_rtattach(
-				    	    (void **)&V_rt_tables[table][fam],
+					rnh = rt_tables_get_rnh_ptr(table, fam);
+					if (rnh == NULL)
+						panic("%s: rnh NULL", __func__);
+					dom->dom_rtattach((void **)rnh,
 				    	    dom->dom_rtoffset);
 				} else {
 					break;
@ -300,7 +324,7 @@ rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags,
 	KASSERT((fibnum < rt_numfibs), ("rtalloc1_fib: bad fibnum"));
 	if (dst->sa_family != AF_INET)	/* Only INET supports > 1 fib now */
 		fibnum = 0;
-	rnh = V_rt_tables[fibnum][dst->sa_family];
+	rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
 	newrt = NULL;
 	/*
 	 * Look up the address in the table for that Address Family
@ -362,7 +386,7 @@ rtfree(struct rtentry *rt)
 	struct radix_node_head *rnh;

 	KASSERT(rt != NULL,("%s: NULL rt", __func__));
-	rnh = V_rt_tables[rt->rt_fibnum][rt_key(rt)->sa_family];
+	rnh = rt_tables_get_rnh(rt->rt_fibnum, rt_key(rt)->sa_family);
 	KASSERT(rnh != NULL,("%s: NULL rnh", __func__));

 	RT_LOCK_ASSERT(rt);
@ -463,8 +487,13 @@ rtredirect_fib(struct sockaddr *dst,
 	short *stat = NULL;
 	struct rt_addrinfo info;
 	struct ifaddr *ifa;
-	struct radix_node_head *rnh =
-	    V_rt_tables[fibnum][dst->sa_family];
+	struct radix_node_head *rnh;
+
+	rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
+	if (rnh == NULL) {
+		error = EAFNOSUPPORT;
+		goto out;
+	}

 	/* verify the gateway is directly reachable */
 	if ((ifa = ifa_ifwithnet(gateway)) == NULL) {
@ -774,7 +803,7 @@ rtexpunge(struct rtentry *rt)
 	/*
 	 * Find the correct routing tree to use for this Address Family
 	 */
-	rnh = V_rt_tables[rt->rt_fibnum][rt_key(rt)->sa_family];
+	rnh = rt_tables_get_rnh(rt->rt_fibnum, rt_key(rt)->sa_family);
 	RT_LOCK_ASSERT(rt);
 	if (rnh == NULL)
 		return (EAFNOSUPPORT);
@ -942,7 +971,7 @@ rtrequest1_fib(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt,
 	/*
 	 * Find the correct routing tree to use for this Address Family
 	 */
-	rnh = V_rt_tables[fibnum][dst->sa_family];
+	rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
 	if (rnh == NULL)
 		return (EAFNOSUPPORT);
 	needlock = ((flags & RTF_RNH_LOCKED) == 0);
@ -1134,9 +1163,9 @@ rt_setgate(struct rtentry *rt, struct sockaddr *dst, struct sockaddr *gate)
 	/* XXX dst may be overwritten, can we move this to below */
 	int dlen = SA_SIZE(dst), glen = SA_SIZE(gate);
 #ifdef INVARIANTS
-	INIT_VNET_NET(curvnet);
-	struct radix_node_head *rnh =
-	    V_rt_tables[rt->rt_fibnum][dst->sa_family];
+	struct radix_node_head *rnh;
+
+	rnh = rt_tables_get_rnh(rt->rt_fibnum, dst->sa_family);
 #endif

 	RT_LOCK_ASSERT(rt);
@ -1203,7 +1232,6 @@ rt_maskedcopy(struct sockaddr *src, struct sockaddr *dst, struct sockaddr *netma
 static inline  int
 rtinit1(struct ifaddr *ifa, int cmd, int flags, int fibnum)
 {
-	INIT_VNET_NET(curvnet);
 	struct sockaddr *dst;
 	struct sockaddr *netmask;
 	struct rtentry *rt = NULL;
@ -1273,7 +1301,8 @@ rtinit1(struct ifaddr *ifa, int cmd, int flags, int fibnum)
 			 * Look up an rtentry that is in the routing tree and
 			 * contains the correct info.
 			 */
-			if ((rnh = V_rt_tables[fibnum][dst->sa_family]) == NULL)
+			rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
+			if (rnh == NULL)
 				/* this table doesn't exist but others might */
 				continue;
 			RADIX_NODE_HEAD_LOCK(rnh);
--- a/sys/net/route.h
+++ b/sys/net/route.h
@ -373,7 +373,8 @@ struct rt_addrinfo {
 	}							\
 } while (0)

-extern struct radix_node_head *rt_tables[][AF_MAX+1];
+extern struct radix_node_head *rt_tables;
+struct radix_node_head *rt_tables_get_rnh(int, int);

 struct ifmultiaddr;

--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@ -460,7 +460,6 @@ static int
 route_output(struct mbuf *m, struct socket *so)
 {
 #define	sa_equal(a1, a2) (bcmp((a1), (a2), (a1)->sa_len) == 0)
-	INIT_VNET_NET(so->so_vnet);
 	struct rt_msghdr *rtm = NULL;
 	struct rtentry *rt = NULL;
 	struct radix_node_head *rnh;
@ -561,7 +560,8 @@ route_output(struct mbuf *m, struct socket *so)
 	case RTM_GET:
 	case RTM_CHANGE:
 	case RTM_LOCK:
-		rnh = V_rt_tables[so->so_fibnum][info.rti_info[RTAX_DST]->sa_family];
+		rnh = rt_tables_get_rnh(so->so_fibnum,
+		    info.rti_info[RTAX_DST]->sa_family);
 		if (rnh == NULL)
 			senderr(EAFNOSUPPORT);
 		RADIX_NODE_HEAD_RLOCK(rnh);
@ -1418,10 +1418,9 @@ sysctl_ifmalist(int af, struct walkarg *w)
 static int
 sysctl_rtsock(SYSCTL_HANDLER_ARGS)
 {
-	INIT_VNET_NET(curvnet);
 	int	*name = (int *)arg1;
 	u_int	namelen = arg2;
-	struct radix_node_head *rnh;
+	struct radix_node_head *rnh = NULL; /* silence compiler. */
 	int	i, lim, error = EINVAL;
 	u_char	af;
 	struct	walkarg w;
@ -1469,7 +1468,8 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS)
 		 * take care of routing entries
 		 */
 		for (error = 0; error == 0 && i <= lim; i++)
-			if ((rnh = V_rt_tables[req->td->td_proc->p_fibnum][i]) != NULL) {
+			rnh = rt_tables_get_rnh(req->td->td_proc->p_fibnum, i);
+			if (rnh != NULL) {
 				RADIX_NODE_HEAD_LOCK(rnh); 
 			    	error = rnh->rnh_walktree(rnh,
 				    sysctl_dumpentry, &w);
--- a/sys/net/vnet.h
+++ b/sys/net/vnet.h
@ -45,7 +45,7 @@ struct vnet_net {
 	struct knlist		_ifklist;

 	struct rtstat		_rtstat;
-	struct radix_node_head *_rt_tables[RT_MAXFIBS][AF_MAX+1];
+	struct radix_node_head *_rt_tables;
 	int			_rttrash;
 	uma_zone_t		_rtzone;

--- a/sys/netinet/in_rmx.c
+++ b/sys/netinet/in_rmx.c
@ -251,14 +251,14 @@ static void
 in_rtqtimo(void *rock)
 {
 	CURVNET_SET((struct vnet *) rock);
-	INIT_VNET_NET(curvnet);
 	INIT_VNET_INET(curvnet);
 	int fibnum;
 	void *newrock;
 	struct timeval atv;

 	for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
-		if ((newrock = V_rt_tables[fibnum][AF_INET]) != NULL)
+		newrock = rt_tables_get_rnh(fibnum, AF_INET);
+		if (newrock != NULL)
 			in_rtqtimo_one(newrock);
 	}
 	atv.tv_usec = 0;
@ -324,10 +324,9 @@ in_rtqdrain(void)
 	VNET_LIST_RLOCK();
 	VNET_FOREACH(vnet_iter) {
 		CURVNET_SET(vnet_iter);
-		INIT_VNET_NET(vnet_iter);

 		for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) {
-			rnh = V_rt_tables[fibnum][AF_INET];
+			rnh = rt_tables_get_rnh(fibnum, AF_INET);
 			arg.found = arg.killed = 0;
 			arg.rnh = rnh;
 			arg.nextstop = 0;
@ -423,7 +422,6 @@ in_ifadownkill(struct radix_node *rn, void *xap)
 int
 in_ifadown(struct ifaddr *ifa, int delete)
 {
-	INIT_VNET_NET(curvnet);
 	struct in_ifadown_arg arg;
 	struct radix_node_head *rnh;
 	int	fibnum;
@ -432,7 +430,7 @@ in_ifadown(struct ifaddr *ifa, int delete)
 		return 1;

 	for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) {
-		rnh = V_rt_tables[fibnum][AF_INET];
+		rnh = rt_tables_get_rnh(fibnum, AF_INET);
 		arg.ifa = ifa;
 		arg.del = delete;
 		RADIX_NODE_HEAD_LOCK(rnh);
--- a/sys/netinet6/in6_ifattach.c
+++ b/sys/netinet6/in6_ifattach.c
@ -777,11 +777,11 @@ in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
 void
 in6_ifdetach(struct ifnet *ifp)
 {
-	INIT_VNET_NET(ifp->if_vnet);
 	INIT_VNET_INET(ifp->if_vnet);
 	INIT_VNET_INET6(ifp->if_vnet);
 	struct in6_ifaddr *ia, *oia;
 	struct ifaddr *ifa, *next;
+	struct radix_node_head *rnh;
 	struct rtentry *rt;
 	short rtflags;
 	struct sockaddr_in6 sin6;
@ -874,15 +874,16 @@ in6_ifdetach(struct ifnet *ifp)
 		/* XXX: should not fail */
 		return;
 	/* XXX grab lock first to avoid LOR */
-	if (V_rt_tables[0][AF_INET6] != NULL) {
-		RADIX_NODE_HEAD_LOCK(V_rt_tables[0][AF_INET6]);
+	rnh = rt_tables_get_rnh(0, AF_INET6);
+	if (rnh != NULL) {
+		RADIX_NODE_HEAD_LOCK(rnh);
 		rt = rtalloc1((struct sockaddr *)&sin6, 0, RTF_RNH_LOCKED);
 		if (rt) {
 			if (rt->rt_ifp == ifp)
 				rtexpunge(rt);
 			RTFREE_LOCKED(rt);
 		}
-		RADIX_NODE_HEAD_UNLOCK(V_rt_tables[0][AF_INET6]);
+		RADIX_NODE_HEAD_UNLOCK(rnh);
 	}
 }

--- a/sys/netinet6/in6_rmx.c
+++ b/sys/netinet6/in6_rmx.c
@ -289,13 +289,17 @@ static void
 in6_rtqtimo(void *rock)
 {
 	CURVNET_SET_QUIET((struct vnet *) rock);
-	INIT_VNET_NET(curvnet);
 	INIT_VNET_INET6(curvnet);
-	struct radix_node_head *rnh = V_rt_tables[0][AF_INET6];
+	struct radix_node_head *rnh;
 	struct rtqk_arg arg;
 	struct timeval atv;
 	static time_t last_adjusted_timeout = 0;

+	rnh = rt_tables_get_rnh(0, AF_INET6);
+	if (rnh == NULL) {
+		CURVNET_RESTORE();
+		return;
+	}
 	arg.found = arg.killed = 0;
 	arg.rnh = rnh;
 	arg.nextstop = time_uptime + V_rtq_timeout6;
@ -377,12 +381,16 @@ static void
 in6_mtutimo(void *rock)
 {
 	CURVNET_SET_QUIET((struct vnet *) rock);
-	INIT_VNET_NET(curvnet);
 	INIT_VNET_INET6(curvnet);
-	struct radix_node_head *rnh = V_rt_tables[0][AF_INET6];
+	struct radix_node_head *rnh;
 	struct mtuex_arg arg;
 	struct timeval atv;

+	rnh = rt_tables_get_rnh(0, AF_INET6);
+	if (rnh == NULL) {
+		CURVNET_RESTORE();
+		return;
+	}
 	arg.rnh = rnh;
 	arg.nextstop = time_uptime + MTUTIMO_DEFAULT;
 	RADIX_NODE_HEAD_LOCK(rnh);
@ -405,9 +413,12 @@ void
 in6_rtqdrain(void)
 {
 	INIT_VNET_NET(curvnet);
-	struct radix_node_head *rnh = V_rt_tables[0][AF_INET6];
+	struct radix_node_head *rnh;
 	struct rtqk_arg arg;

+	rnh = rt_tables_get_rnh(0, AF_INET6);
+	if (rnh == NULL)
+		panic("%s: rnh == NULL", __func__);
 	arg.found = arg.killed = 0;
 	arg.rnh = rnh;
 	arg.nextstop = 0;
@ -429,9 +440,6 @@ in6_rtqdrain(void)
 int
 in6_inithead(void **head, int off)
 {
-#ifdef INVARIANTS
-	INIT_VNET_NET(curvnet);
-#endif
 	INIT_VNET_INET6(curvnet);
 	struct radix_node_head *rnh;

@ -447,7 +455,7 @@ in6_inithead(void **head, int off)
 	V_rtq_timeout6 = RTQ_TIMEOUT;

 	rnh = *head;
-	KASSERT(rnh == V_rt_tables[0][AF_INET6], ("rnh?"));
+	KASSERT(rnh == rt_tables_get_rnh(0, AF_INET6), ("rnh?"));
 	rnh->rnh_addaddr = in6_addroute;
 	rnh->rnh_matchaddr = in6_matroute;
 	callout_init(&V_rtq_timer6, CALLOUT_MPSAFE);
--- a/sys/netinet6/nd6_rtr.c
+++ b/sys/netinet6/nd6_rtr.c
@ -1549,7 +1549,6 @@ pfxlist_onlink_check()
 int
 nd6_prefix_onlink(struct nd_prefix *pr)
 {
-	INIT_VNET_NET(curvnet);
 	INIT_VNET_INET6(curvnet);
 	struct ifaddr *ifa;
 	struct ifnet *ifp = pr->ndpr_ifp;
@ -1632,7 +1631,8 @@ nd6_prefix_onlink(struct nd_prefix *pr)
 	    ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt);
 	if (error == 0) {
 		if (rt != NULL) /* this should be non NULL, though */ {
-			rnh = V_rt_tables[rt->rt_fibnum][AF_INET6];
+			rnh = rt_tables_get_rnh(rt->rt_fibnum, AF_INET6);
+			/* XXX what if rhn == NULL? */
 			RADIX_NODE_HEAD_LOCK(rnh);
 			RT_LOCK(rt);
 			if (!rt_setgate(rt, rt_key(rt), (struct sockaddr *)&null_sdl)) {
@ -2058,8 +2058,7 @@ in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
 void
 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
 {
-	INIT_VNET_NET(curvnet);
-	struct radix_node_head *rnh = V_rt_tables[0][AF_INET6];
+	struct radix_node_head *rnh;
 	int s = splnet();

 	/* We'll care only link-local addresses */
@ -2068,6 +2067,10 @@ rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
 		return;
 	}

+	rnh = rt_tables_get_rnh(0, AF_INET6);
+	if (rnh == NULL)
+		return;
+
 	RADIX_NODE_HEAD_LOCK(rnh);
 	rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
 	RADIX_NODE_HEAD_UNLOCK(rnh);
--- a/sys/nfsclient/bootp_subr.c
+++ b/sys/nfsclient/bootp_subr.c
@ -361,11 +361,15 @@ void
 bootpboot_p_rtlist(void)
 {
 	INIT_VNET_NET(curvnet);
+	struct radix_node_head *rnh;

 	printf("Routing table:\n");
-	RADIX_NODE_HEAD_RLOCK(V_rt_tables[0][AF_INET]);	/* could sleep XXX */
-	bootpboot_p_tree(V_rt_tables[0][AF_INET]->rnh_treetop);
-	RADIX_NODE_HEAD_RUNLOCK(V_rt_tables[0][AF_INET]);
+	rnh = rt_tables_get_rnh(0, AF_INET);
+	if (rnh == NULL)
+		return;
+	RADIX_NODE_HEAD_RLOCK(rnh);	/* could sleep XXX */
+	bootpboot_p_tree(rnh->rnh_treetop);
+	RADIX_NODE_HEAD_RUNLOCK(rnh);
 }

 void
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@ -57,7 +57,7 @@
 *		is created, otherwise 1.
 */
 #undef __FreeBSD_version
-#define __FreeBSD_version 800096	/* Master, propagated to newvers */
+#define __FreeBSD_version 800097	/* Master, propagated to newvers */

 #ifndef LOCORE
 #include <sys/types.h>
--- a/usr.bin/netstat/route.c
+++ b/usr.bin/netstat/route.c
@ -122,12 +122,7 @@ int	do_rtent = 0;
 struct	rtentry rtentry;
 struct	radix_node rnode;
 struct	radix_mask rmask;
-struct  rtline  {
-	struct	radix_node_head *tables[AF_MAX+1]; /*xxx*/
-};
-struct	rtline *rt_tables;
-
-struct	radix_node_head *rt_tables_line[1][AF_MAX+1]; /*xxx*/
+struct	radix_node_head **rt_tables;

 int	NewTree = 0;

@ -155,7 +150,7 @@ static void domask(char *, in_addr_t, u_long);
 void
 routepr(u_long rtree)
 {
-	struct radix_node_head *rnh, head;
+	struct radix_node_head **rnhp, *rnh, head;
 	size_t intsize;
 	int i;
 	int numfibs;
@ -165,7 +160,8 @@ routepr(u_long rtree)
 		fibnum = 0;
 	if (sysctlbyname("net.fibs", &numfibs, &intsize, NULL, 0) == -1)
 		numfibs = 1;
-	rt_tables = calloc(numfibs, sizeof(struct rtline));
+	rt_tables = calloc(numfibs * (AF_MAX+1),
+	    sizeof(struct radix_node_head *));
 	if (rt_tables == NULL)
 		err(EX_OSERR, "memory allocation failed");
 	/*
@ -186,8 +182,8 @@ routepr(u_long rtree)
 			return;
 		}

-		if (kread((u_long)(rtree), (char *)(rt_tables),
-		    (numfibs * sizeof(struct rtline))) != 0)
+		if (kread((u_long)(rtree), (char *)(rt_tables), (numfibs *
+		    (AF_MAX+1) * sizeof(struct radix_node_head *))) != 0)
 			return;
 		for (i = 0; i <= AF_MAX; i++) {
 			int tmpfib;
@ -195,8 +191,15 @@ routepr(u_long rtree)
 				tmpfib = 0;
 			else
 				tmpfib = fibnum;
-			if ((rnh = rt_tables[tmpfib].tables[i]) == 0)
+			rnhp = (struct radix_node_head **)*rt_tables;
+			/* Calculate the in-kernel address. */
+			rnhp += tmpfib * (AF_MAX+1) + i;
+			/* Read the in kernel rhn pointer. */
+			if (kget(rnhp, rnh) != 0)
 				continue;
+			if (rnh == NULL)
+				continue;
+			/* Read the rnh data. */
 			if (kget(rnh, head) != 0)
 				continue;
 			if (i == AF_UNSPEC) {