X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/91447636331957f3d9b5ca5b508f07c526b0074d..refs/heads/master:/bsd/net/radix.c

diff --git a/bsd/net/radix.c b/bsd/net/radix.c
index bbc3572b1..a9745cb42 100644
--- a/bsd/net/radix.c
+++ b/bsd/net/radix.c
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
- * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
- * 
- * @APPLE_LICENSE_HEADER_END@
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * Copyright (c) 1988, 1989, 1993
@@ -60,14 +66,10 @@
  */
 #ifndef _RADIX_H_
 #include <sys/param.h>
-#ifdef	KERNEL
 #include <sys/systm.h>
 #include <sys/malloc.h>
-#define	M_DONTWAIT M_NOWAIT
+#define M_DONTWAIT M_NOWAIT
 #include <sys/domain.h>
-#else
-#include <stdlib.h>
-#endif
 #include <sys/syslog.h>
 #include <net/radix.h>
 #include <sys/socket.h>
@@ -75,17 +77,17 @@
 #include <kern/locks.h>
 #endif
 
-static int	rn_walktree_from(struct radix_node_head *h, void *a,
-				      void *m, walktree_f_t *f, void *w);
+static int      rn_walktree_from(struct radix_node_head *h, void *a,
+    void *m, walktree_f_t *f, void *w);
 static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
 static struct radix_node
-	 *rn_insert(void *, struct radix_node_head *, int *,
-			struct radix_node [2]),
-	 *rn_newpair(void *, int, struct radix_node[2]),
-	 *rn_search(void *, struct radix_node *),
-	 *rn_search_m(void *, struct radix_node *, void *);
+*rn_insert(void *, struct radix_node_head *, int *,
+    struct radix_node[2]),
+*rn_newpair(void *, int, struct radix_node[2]),
+*rn_search(void *, struct radix_node *),
+*rn_search_m(void *, struct radix_node *, void *);
 
-static int	max_keylen;
+static int      max_keylen;
 static struct radix_mask *rn_mkfreelist;
 static struct radix_node_head *mask_rnhead;
 static char *addmask_key;
@@ -93,21 +95,19 @@ static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
 static char *rn_zeros, *rn_ones;
 
 
-extern lck_grp_t	*domain_proto_mtx_grp;
-extern lck_attr_t	*domain_proto_mtx_attr;
-lck_mtx_t *rn_mutex;
-
 #define rn_masktop (mask_rnhead->rnh_treetop)
 #undef Bcmp
 #define Bcmp(a, b, l) \
-	(l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l))
+	(l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (uint32_t)l))
 
-static int	rn_lexobetter(void *m_arg, void *n_arg);
+static int      rn_lexobetter(void *m_arg, void *n_arg);
 static struct radix_mask *
-		rn_new_radix_mask(struct radix_node *tt,
-				       struct radix_mask *next);
-static int	rn_satsifies_leaf(char *trial, struct radix_node *leaf,
-				       int skip);
+rn_new_radix_mask(struct radix_node *tt,
+    struct radix_mask *next);
+static int rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip,
+    rn_matchf_t *f, void *w);
+
+#define RN_MATCHF(rn, f, arg)   (f == NULL || (*f)((rn), arg))
 
 /*
  * The data structure for the keys is a radix tree with one way
@@ -144,132 +144,159 @@ static int	rn_satsifies_leaf(char *trial, struct radix_node *leaf,
  */
 
 static struct radix_node *
-rn_search(v_arg, head)
-	void *v_arg;
-	struct radix_node *head;
+rn_search(void *v_arg, struct radix_node *head)
 {
-	register struct radix_node *x;
-	register caddr_t v;
+	struct radix_node *x;
+	caddr_t v;
 
 	for (x = head, v = v_arg; x->rn_bit >= 0;) {
-		if (x->rn_bmask & v[x->rn_offset])
+		if (x->rn_bmask & v[x->rn_offset]) {
 			x = x->rn_right;
-		else
+		} else {
 			x = x->rn_left;
+		}
 	}
-	return (x);
+	return x;
 }
 
 static struct radix_node *
-rn_search_m(v_arg, head, m_arg)
-	struct radix_node *head;
-	void *v_arg, *m_arg;
+rn_search_m(void *v_arg, struct radix_node *head, void *m_arg)
 {
-	register struct radix_node *x;
-	register caddr_t v = v_arg, m = m_arg;
+	struct radix_node *x;
+	caddr_t v = v_arg, m = m_arg;
 
 	for (x = head; x->rn_bit >= 0;) {
 		if ((x->rn_bmask & m[x->rn_offset]) &&
-		    (x->rn_bmask & v[x->rn_offset]))
+		    (x->rn_bmask & v[x->rn_offset])) {
 			x = x->rn_right;
-		else
+		} else {
 			x = x->rn_left;
+		}
 	}
 	return x;
 }
 
 int
-rn_refines(m_arg, n_arg)
-	void *m_arg, *n_arg;
+rn_refines(void *m_arg, void *n_arg)
 {
-	register caddr_t m = m_arg, n = n_arg;
-	register caddr_t lim, lim2 = lim = n + *(u_char *)n;
+	caddr_t m = m_arg, n = n_arg;
+	caddr_t lim, lim2 = lim = n + *(u_char *)n;
 	int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
 	int masks_are_equal = 1;
 
-	if (longer > 0)
+	if (longer > 0) {
 		lim -= longer;
+	}
 	while (n < lim) {
-		if (*n & ~(*m))
+		if (*n & ~(*m)) {
 			return 0;
-		if (*n++ != *m++)
+		}
+		if (*n++ != *m++) {
 			masks_are_equal = 0;
+		}
 	}
-	while (n < lim2)
-		if (*n++)
+	while (n < lim2) {
+		if (*n++) {
 			return 0;
-	if (masks_are_equal && (longer < 0))
-		for (lim2 = m - longer; m < lim2; )
-			if (*m++)
+		}
+	}
+	if (masks_are_equal && (longer < 0)) {
+		for (lim2 = m - longer; m < lim2;) {
+			if (*m++) {
 				return 1;
-	return (!masks_are_equal);
+			}
+		}
+	}
+	return !masks_are_equal;
 }
 
 struct radix_node *
-rn_lookup(v_arg, m_arg, head)
-	void *v_arg, *m_arg;
-	struct radix_node_head *head;
+rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head)
 {
-	register struct radix_node *x;
-	caddr_t netmask = 0;
+	return rn_lookup_args(v_arg, m_arg, head, NULL, NULL);
+}
+
+struct radix_node *
+rn_lookup_args(void *v_arg, void *m_arg, struct radix_node_head *head,
+    rn_matchf_t *f, void *w)
+{
+	struct radix_node *x;
+	caddr_t netmask = NULL;
 
 	if (m_arg) {
 		x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset);
-		if (x == 0)
-			return (0);
+		if (x == 0) {
+			return NULL;
+		}
 		netmask = x->rn_key;
 	}
-	x = rn_match(v_arg, head);
+	x = rn_match_args(v_arg, head, f, w);
 	if (x && netmask) {
-		while (x && x->rn_mask != netmask)
+		while (x && x->rn_mask != netmask) {
 			x = x->rn_dupedkey;
+		}
 	}
 	return x;
 }
 
+/*
+ * Returns true if address 'trial' has no bits differing from the
+ * leaf's key when compared under the leaf's mask.  In other words,
+ * returns true when 'trial' matches leaf.  If a leaf-matching
+ * routine is passed in, it is also used to find a match on the
+ * conditions defined by the caller of rn_match.
+ */
 static int
-rn_satsifies_leaf(trial, leaf, skip)
-	char *trial;
-	register struct radix_node *leaf;
-	int skip;
+rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip,
+    rn_matchf_t *f, void *w)
 {
-	register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
+	char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
 	char *cplim;
 	int length = min(*(u_char *)cp, *(u_char *)cp2);
 
-	if (cp3 == 0)
+	if (cp3 == 0) {
 		cp3 = rn_ones;
-	else
+	} else {
 		length = min(length, *(u_char *)cp3);
+	}
 	cplim = cp + length; cp3 += skip; cp2 += skip;
-	for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
-		if ((*cp ^ *cp2) & *cp3)
+	for (cp += skip; cp < cplim; cp++, cp2++, cp3++) {
+		if ((*cp ^ *cp2) & *cp3) {
 			return 0;
-	return 1;
+		}
+	}
+
+	return RN_MATCHF(leaf, f, w);
 }
 
 struct radix_node *
-rn_match(v_arg, head)
-	void *v_arg;
-	struct radix_node_head *head;
+rn_match(void *v_arg, struct radix_node_head *head)
+{
+	return rn_match_args(v_arg, head, NULL, NULL);
+}
+
+struct radix_node *
+rn_match_args(void *v_arg, struct radix_node_head *head,
+    rn_matchf_t *f, void *w)
 {
 	caddr_t v = v_arg;
-	register struct radix_node *t = head->rnh_treetop, *x;
-	register caddr_t cp = v, cp2;
+	struct radix_node *t = head->rnh_treetop, *x;
+	caddr_t cp = v, cp2;
 	caddr_t cplim;
 	struct radix_node *saved_t, *top = t;
 	int off = t->rn_offset, vlen = *(u_char *)cp, matched_off;
-	register int test, b, rn_bit;
+	int test, b, rn_bit;
 
 	/*
 	 * Open code rn_search(v, top) to avoid overhead of extra
 	 * subroutine call.
 	 */
-	for (; t->rn_bit >= 0; ) {
-		if (t->rn_bmask & cp[t->rn_offset])
+	for (; t->rn_bit >= 0;) {
+		if (t->rn_bmask & cp[t->rn_offset]) {
 			t = t->rn_right;
-		else
+		} else {
 			t = t->rn_left;
+		}
 	}
 	/*
 	 * See if we match exactly as a host destination
@@ -282,12 +309,15 @@ rn_match(v_arg, head)
 	 * with a long one.  This wins big for class B&C netmasks which
 	 * are probably the most common case...
 	 */
-	if (t->rn_mask)
+	if (t->rn_mask) {
 		vlen = *(u_char *)t->rn_mask;
+	}
 	cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
-	for (; cp < cplim; cp++, cp2++)
-		if (*cp != *cp2)
+	for (; cp < cplim; cp++, cp2++) {
+		if (*cp != *cp2) {
 			goto on1;
+		}
+	}
 	/*
 	 * This extra grot is in case we are explicitly asked
 	 * to look up the default.  Ugh!
@@ -295,36 +325,57 @@ rn_match(v_arg, head)
 	 * Never return the root node itself, it seems to cause a
 	 * lot of confusion.
 	 */
-	if (t->rn_flags & RNF_ROOT)
+	if (t->rn_flags & RNF_ROOT) {
 		t = t->rn_dupedkey;
-	return t;
+	}
+	if (t == NULL || RN_MATCHF(t, f, w)) {
+		return t;
+	} else {
+		/*
+		 * Although we found an exact match on the key,
+		 * f() is looking for some other criteria as well.
+		 * Continue looking as if the exact match failed.
+		 */
+		if (t->rn_parent->rn_flags & RNF_ROOT) {
+			/* Hit the top; have to give up */
+			return NULL;
+		}
+		b = 0;
+		goto keeplooking;
+	}
 on1:
 	test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
-	for (b = 7; (test >>= 1) > 0;)
+	for (b = 7; (test >>= 1) > 0;) {
 		b--;
+	}
+keeplooking:
 	matched_off = cp - v;
 	b += matched_off << 3;
 	rn_bit = -1 - b;
 	/*
 	 * If there is a host route in a duped-key chain, it will be first.
 	 */
-	if ((saved_t = t)->rn_mask == 0)
+	if ((saved_t = t)->rn_mask == 0) {
 		t = t->rn_dupedkey;
-	for (; t; t = t->rn_dupedkey)
+	}
+	for (; t; t = t->rn_dupedkey) {
 		/*
 		 * Even if we don't match exactly as a host,
 		 * we may match if the leaf we wound up at is
 		 * a route to a net.
 		 */
 		if (t->rn_flags & RNF_NORMAL) {
-			if (rn_bit <= t->rn_bit)
-				return t;
-		} else if (rn_satsifies_leaf(v, t, matched_off))
+			if ((rn_bit <= t->rn_bit) && RN_MATCHF(t, f, w)) {
 				return t;
+			}
+		} else if (rn_satisfies_leaf(v, t, matched_off, f, w)) {
+			return t;
+		}
+	}
 	t = saved_t;
 	/* start searching up the tree */
 	do {
-		register struct radix_mask *m;
+		struct radix_mask *m;
 		t = t->rn_parent;
 		m = t->rn_mklist;
 		/*
@@ -335,36 +386,37 @@ on1:
 		 */
 		while (m) {
 			if (m->rm_flags & RNF_NORMAL) {
-				if (rn_bit <= m->rm_bit)
-					return (m->rm_leaf);
+				if ((rn_bit <= m->rm_bit) &&
+				    RN_MATCHF(m->rm_leaf, f, w)) {
+					return m->rm_leaf;
+				}
 			} else {
 				off = min(t->rn_offset, matched_off);
 				x = rn_search_m(v, t, m->rm_mask);
-				while (x && x->rn_mask != m->rm_mask)
+				while (x && x->rn_mask != m->rm_mask) {
 					x = x->rn_dupedkey;
-				if (x && rn_satsifies_leaf(v, x, off))
+				}
+				if (x && rn_satisfies_leaf(v, x, off, f, w)) {
 					return x;
+				}
 			}
 			m = m->rm_mklist;
 		}
 	} while (t != top);
-	return 0;
+	return NULL;
 }
 
 #ifdef RN_DEBUG
-int	rn_nodenum;
-struct	radix_node *rn_clist;
-int	rn_saveinfo;
-int	rn_debug =  1;
+int     rn_nodenum;
+struct  radix_node *rn_clist;
+int     rn_saveinfo;
+int     rn_debug =  1;
 #endif
 
 static struct radix_node *
-rn_newpair(v, b, nodes)
-	void *v;
-	int b;
-	struct radix_node nodes[2];
+rn_newpair(void *v, int b, struct radix_node nodes[2])
 {
-	register struct radix_node *tt = nodes, *t = tt + 1;
+	struct radix_node *tt = nodes, *t = tt + 1;
 	t->rn_bit = b;
 	t->rn_bmask = 0x80 >> (b & 7);
 	t->rn_left = tt;
@@ -373,7 +425,7 @@ rn_newpair(v, b, nodes)
 	tt->rn_key = (caddr_t)v;
 	tt->rn_parent = t;
 	tt->rn_flags = t->rn_flags = RNF_ACTIVE;
-	tt->rn_mklist = t->rn_mklist = 0;
+	tt->rn_mklist = t->rn_mklist = NULL;
 #ifdef RN_DEBUG
 	tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
 	tt->rn_twin = t;
@@ -384,195 +436,214 @@ rn_newpair(v, b, nodes)
 }
 
 static struct radix_node *
-rn_insert(v_arg, head, dupentry, nodes)
-	void *v_arg;
-	struct radix_node_head *head;
-	int *dupentry;
-	struct radix_node nodes[2];
+rn_insert(void *v_arg, struct radix_node_head *head, int *dupentry,
+    struct radix_node nodes[2])
 {
 	caddr_t v = v_arg;
 	struct radix_node *top = head->rnh_treetop;
 	int head_off = top->rn_offset, vlen = (int)*((u_char *)v);
-	register struct radix_node *t = rn_search(v_arg, top);
-	register caddr_t cp = v + head_off;
-	register int b;
+	struct radix_node *t = rn_search(v_arg, top);
+	caddr_t cp = v + head_off;
+	int b;
 	struct radix_node *tt;
-    	/*
+	/*
 	 * Find first bit at which v and t->rn_key differ
 	 */
-    {
-	register caddr_t cp2 = t->rn_key + head_off;
-	register int cmp_res;
-	caddr_t cplim = v + vlen;
+	{
+		caddr_t cp2 = t->rn_key + head_off;
+		int cmp_res;
+		caddr_t cplim = v + vlen;
 
-	while (cp < cplim)
-		if (*cp2++ != *cp++)
-			goto on1;
-	*dupentry = 1;
-	return t;
+		while (cp < cplim) {
+			if (*cp2++ != *cp++) {
+				goto on1;
+			}
+		}
+		*dupentry = 1;
+		return t;
 on1:
-	*dupentry = 0;
-	cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
-	for (b = (cp - v) << 3; cmp_res; b--)
-		cmp_res >>= 1;
-    }
-    {
-	register struct radix_node *p, *x = top;
-	cp = v;
-	do {
-		p = x;
-		if (cp[x->rn_offset] & x->rn_bmask)
-			x = x->rn_right;
-		else
-			x = x->rn_left;
-	} while (b > (unsigned) x->rn_bit);
-				/* x->rn_bit < b && x->rn_bit >= 0 */
+		*dupentry = 0;
+		cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
+		for (b = (cp - v) << 3; cmp_res; b--) {
+			cmp_res >>= 1;
+		}
+	}
+	{
+		struct radix_node *p, *x = top;
+		cp = v;
+		do {
+			p = x;
+			if (cp[x->rn_offset] & x->rn_bmask) {
+				x = x->rn_right;
+			} else {
+				x = x->rn_left;
+			}
+		} while (b > (unsigned) x->rn_bit);
+		/* x->rn_bit < b && x->rn_bit >= 0 */
 #ifdef RN_DEBUG
-	if (rn_debug)
-		log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
+		if (rn_debug) {
+			log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
+		}
 #endif
-	t = rn_newpair(v_arg, b, nodes); 
-	tt = t->rn_left;
-	if ((cp[p->rn_offset] & p->rn_bmask) == 0)
-		p->rn_left = t;
-	else
-		p->rn_right = t;
-	x->rn_parent = t;
-	t->rn_parent = p; /* frees x, p as temp vars below */
-	if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
-		t->rn_right = x;
-	} else {
-		t->rn_right = tt;
-		t->rn_left = x;
-	}
+		t = rn_newpair(v_arg, b, nodes);
+		tt = t->rn_left;
+		if ((cp[p->rn_offset] & p->rn_bmask) == 0) {
+			p->rn_left = t;
+		} else {
+			p->rn_right = t;
+		}
+		x->rn_parent = t;
+		t->rn_parent = p; /* frees x, p as temp vars below */
+		if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
+			t->rn_right = x;
+		} else {
+			t->rn_right = tt;
+			t->rn_left = x;
+		}
 #ifdef RN_DEBUG
-	if (rn_debug)
-		log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
+		if (rn_debug) {
+			log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
+		}
 #endif
-    }
-	return (tt);
+	}
+	return tt;
 }
 
 struct radix_node *
-rn_addmask(n_arg, search, skip)
-	int search, skip;
-	void *n_arg;
+rn_addmask(void *n_arg, int search, int skip)
 {
 	caddr_t netmask = (caddr_t)n_arg;
-	register struct radix_node *x;
-	register caddr_t cp, cplim;
-	register int b = 0, mlen, j;
+	struct radix_node *x;
+	caddr_t cp, cplim;
+	int b = 0, mlen, j;
 	int maskduplicated, m0, isnormal;
 	struct radix_node *saved_x;
 	static int last_zeroed = 0;
 
-	if ((mlen = *(u_char *)netmask) > max_keylen)
+	if ((mlen = *(u_char *)netmask) > max_keylen) {
 		mlen = max_keylen;
-	if (skip == 0)
+	}
+	if (skip == 0) {
 		skip = 1;
-	if (mlen <= skip)
-		return (mask_rnhead->rnh_nodes);
-	if (skip > 1)
+	}
+	if (mlen <= skip) {
+		return mask_rnhead->rnh_nodes;
+	}
+	if (skip > 1) {
 		Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
-	if ((m0 = mlen) > skip)
+	}
+	if ((m0 = mlen) > skip) {
 		Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
+	}
 	/*
 	 * Trim trailing zeroes.
 	 */
-	for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
+	for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) {
 		cp--;
+	}
 	mlen = cp - addmask_key;
 	if (mlen <= skip) {
-		if (m0 >= last_zeroed)
+		if (m0 >= last_zeroed) {
 			last_zeroed = mlen;
-		return (mask_rnhead->rnh_nodes);
+		}
+		return mask_rnhead->rnh_nodes;
 	}
-	if (m0 < last_zeroed)
+	if (m0 < last_zeroed) {
 		Bzero(addmask_key + m0, last_zeroed - m0);
+	}
 	*addmask_key = last_zeroed = mlen;
 	x = rn_search(addmask_key, rn_masktop);
-	if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
-		x = 0;
-	if (x || search)
-		return (x);
-	R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
-	if ((saved_x = x) == 0)
-		return (0);
-	Bzero(x, max_keylen + 2 * sizeof (*x));
+	if (Bcmp(addmask_key, x->rn_key, mlen) != 0) {
+		x = NULL;
+	}
+	if (x || search) {
+		return x;
+	}
+	R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof(*x));
+	if ((saved_x = x) == 0) {
+		return NULL;
+	}
+	Bzero(x, max_keylen + 2 * sizeof(*x));
 	netmask = cp = (caddr_t)(x + 2);
 	Bcopy(addmask_key, cp, mlen);
 	x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
 	if (maskduplicated) {
 		log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
 		R_Free(saved_x);
-		return (x);
+		return x;
 	}
+	mask_rnhead->rnh_cnt++;
 	/*
 	 * Calculate index of mask, and check for normalcy.
 	 */
 	cplim = netmask + mlen; isnormal = 1;
-	for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
+	for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) {
 		cp++;
+	}
 	if (cp != cplim) {
-		for (j = 0x80; (j & *cp) != 0; j >>= 1)
+		for (j = 0x80; (j & *cp) != 0; j >>= 1) {
 			b++;
-		if (*cp != normal_chars[b] || cp != (cplim - 1))
+		}
+		if (*cp != normal_chars[b] || cp != (cplim - 1)) {
 			isnormal = 0;
+		}
 	}
 	b += (cp - netmask) << 3;
 	x->rn_bit = -1 - b;
-	if (isnormal)
+	if (isnormal) {
 		x->rn_flags |= RNF_NORMAL;
-	return (x);
+	}
+	return x;
 }
 
-static int	/* XXX: arbitrary ordering for non-contiguous masks */
-rn_lexobetter(m_arg, n_arg)
-	void *m_arg, *n_arg;
+static int
+/* XXX: arbitrary ordering for non-contiguous masks */
+rn_lexobetter(void *m_arg, void *n_arg)
 {
-	register u_char *mp = m_arg, *np = n_arg, *lim;
+	u_char *mp = m_arg, *np = n_arg, *lim;
 
-	if (*mp > *np)
+	if (*mp > *np) {
 		return 1;  /* not really, but need to check longer one first */
-	if (*mp == *np)
-		for (lim = mp + *mp; mp < lim;)
-			if (*mp++ > *np++)
+	}
+	if (*mp == *np) {
+		for (lim = mp + *mp; mp < lim;) {
+			if (*mp++ > *np++) {
 				return 1;
+			}
+		}
+	}
 	return 0;
 }
 
 static struct radix_mask *
-rn_new_radix_mask(tt, next)
-	register struct radix_node *tt;
-	register struct radix_mask *next;
+rn_new_radix_mask(struct radix_node *tt, struct radix_mask *next)
 {
-	register struct radix_mask *m;
+	struct radix_mask *m;
 
 	MKGet(m);
 	if (m == 0) {
 		log(LOG_ERR, "Mask for route not entered\n");
-		return (0);
+		return NULL;
 	}
 	Bzero(m, sizeof *m);
 	m->rm_bit = tt->rn_bit;
 	m->rm_flags = tt->rn_flags;
-	if (tt->rn_flags & RNF_NORMAL)
+	if (tt->rn_flags & RNF_NORMAL) {
 		m->rm_leaf = tt;
-	else
+	} else {
 		m->rm_mask = tt->rn_mask;
+	}
 	m->rm_mklist = next;
 	tt->rn_mklist = m;
 	return m;
 }
 
 struct radix_node *
-rn_addroute(v_arg, n_arg, head, treenodes)
-	void *v_arg, *n_arg;
-	struct radix_node_head *head;
-	struct radix_node treenodes[2];
+rn_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
+    struct radix_node treenodes[2])
 {
 	caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
-	register struct radix_node *t, *x = 0, *tt;
+	struct radix_node *t, *x = NULL, *tt;
 	struct radix_node *saved_tt, *top = head->rnh_treetop;
 	short b = 0, b_leaf = 0;
 	int keyduplicated;
@@ -586,9 +657,10 @@ rn_addroute(v_arg, n_arg, head, treenodes)
 	 * the mask to speed avoiding duplicate references at
 	 * nodes and possibly save time in calculating indices.
 	 */
-	if (netmask)  {
-		if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0)
-			return (0);
+	if (netmask) {
+		if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0) {
+			return NULL;
+		}
 		b_leaf = x->rn_bit;
 		b = -1 - x->rn_bit;
 		netmask = x->rn_key;
@@ -599,14 +671,16 @@ rn_addroute(v_arg, n_arg, head, treenodes)
 	saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
 	if (keyduplicated) {
 		for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
-			if (tt->rn_mask == netmask)
-				return (0);
+			if (tt->rn_mask == netmask) {
+				return NULL;
+			}
 			if (netmask == 0 ||
 			    (tt->rn_mask &&
-			     ((b_leaf < tt->rn_bit) /* index(netmask) > node */
-			      || rn_refines(netmask, tt->rn_mask)
-			      || rn_lexobetter(netmask, tt->rn_mask))))
+			    ((b_leaf < tt->rn_bit)  /* index(netmask) > node */
+			    || rn_refines(netmask, tt->rn_mask)
+			    || rn_lexobetter(netmask, tt->rn_mask)))) {
 				break;
+			}
 		}
 		/*
 		 * If the mask is not duplicated, we wouldn't
@@ -619,32 +693,35 @@ rn_addroute(v_arg, n_arg, head, treenodes)
 		 * the head of the list.
 		 */
 		if (tt == saved_tt) {
-			struct	radix_node *xx = x;
+			struct  radix_node *xx = x;
 			/* link in at head of list */
 			(tt = treenodes)->rn_dupedkey = t;
 			tt->rn_flags = t->rn_flags;
 			tt->rn_parent = x = t->rn_parent;
-			t->rn_parent = tt;	 		/* parent */
-			if (x->rn_left == t)
+			t->rn_parent = tt;                      /* parent */
+			if (x->rn_left == t) {
 				x->rn_left = tt;
-			else
+			} else {
 				x->rn_right = tt;
+			}
 			saved_tt = tt; x = xx;
 		} else {
 			(tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
 			t->rn_dupedkey = tt;
-			tt->rn_parent = t;			/* parent */
-			if (tt->rn_dupedkey)			/* parent */
+			tt->rn_parent = t;                      /* parent */
+			if (tt->rn_dupedkey) {                  /* parent */
 				tt->rn_dupedkey->rn_parent = tt; /* parent */
+			}
 		}
 #ifdef RN_DEBUG
-		t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
+		t = tt + 1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
 		tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
 #endif
 		tt->rn_key = (caddr_t) v;
 		tt->rn_bit = -1;
 		tt->rn_flags = RNF_ACTIVE;
 	}
+	head->rnh_cnt++;
 	/*
 	 * Put mask in tree.
 	 */
@@ -654,34 +731,41 @@ rn_addroute(v_arg, n_arg, head, treenodes)
 		tt->rn_flags |= x->rn_flags & RNF_NORMAL;
 	}
 	t = saved_tt->rn_parent;
-	if (keyduplicated)
+	if (keyduplicated) {
 		goto on2;
+	}
 	b_leaf = -1 - t->rn_bit;
-	if (t->rn_right == saved_tt)
+	if (t->rn_right == saved_tt) {
 		x = t->rn_left;
-	else
+	} else {
 		x = t->rn_right;
+	}
 	/* Promote general routes from below */
 	if (x->rn_bit < 0) {
-	    for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
-		if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) {
-			*mp = m = rn_new_radix_mask(x, 0);
-			if (m)
-				mp = &m->rm_mklist;
+		for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) {
+			if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) {
+				*mp = m = rn_new_radix_mask(x, NULL);
+				if (m) {
+					mp = &m->rm_mklist;
+				}
+			}
 		}
 	} else if (x->rn_mklist) {
 		/*
 		 * Skip over masks whose index is > that of new node
 		 */
-		for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
-			if (m->rm_bit >= b_leaf)
+		for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
+			if (m->rm_bit >= b_leaf) {
 				break;
-		t->rn_mklist = m; *mp = 0;
+			}
+		}
+		t->rn_mklist = m; *mp = NULL;
 	}
 on2:
 	/* Add new route to highest possible ancestor's list */
-	if ((netmask == 0) || (b > t->rn_bit ))
+	if ((netmask == 0) || (b > t->rn_bit)) {
 		return tt; /* can't lift at all */
+	}
 	b_leaf = tt->rn_bit;
 	do {
 		x = t;
@@ -694,38 +778,40 @@ on2:
 	 * double loop on deletion.
 	 */
 	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
-		if (m->rm_bit < b_leaf)
+		if (m->rm_bit < b_leaf) {
 			continue;
-		if (m->rm_bit > b_leaf)
+		}
+		if (m->rm_bit > b_leaf) {
 			break;
+		}
 		if (m->rm_flags & RNF_NORMAL) {
 			mmask = m->rm_leaf->rn_mask;
 			if (tt->rn_flags & RNF_NORMAL) {
-			    log(LOG_ERR,
-			        "Non-unique normal route, mask not entered");
+				log(LOG_ERR,
+				    "Non-unique normal route, mask not entered");
 				return tt;
 			}
-		} else
+		} else {
 			mmask = m->rm_mask;
+		}
 		if (mmask == netmask) {
 			m->rm_refs++;
 			tt->rn_mklist = m;
 			return tt;
 		}
 		if (rn_refines(netmask, mmask)
-		    || rn_lexobetter(netmask, mmask))
+		    || rn_lexobetter(netmask, mmask)) {
 			break;
+		}
 	}
 	*mp = rn_new_radix_mask(tt, *mp);
 	return tt;
 }
 
 struct radix_node *
-rn_delete(v_arg, netmask_arg, head)
-	void *v_arg, *netmask_arg;
-	struct radix_node_head *head;
+rn_delete(void *v_arg, void *netmask_arg, struct radix_node_head *head)
 {
-	register struct radix_node *t, *p, *x, *tt;
+	struct radix_node *t, *p, *x, *tt;
 	struct radix_mask *m, *saved_m, **mp;
 	struct radix_node *dupedkey, *saved_tt, *top;
 	caddr_t v, netmask;
@@ -740,63 +826,77 @@ rn_delete(v_arg, netmask_arg, head)
 	saved_tt = tt;
 	top = x;
 	if (tt == 0 ||
-	    Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
-		return (0);
+	    Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) {
+		return NULL;
+	}
 	/*
 	 * Delete our route from mask lists.
 	 */
 	if (netmask) {
-		if ((x = rn_addmask(netmask, 1, head_off)) == 0)
-			return (0);
+		if ((x = rn_addmask(netmask, 1, head_off)) == 0) {
+			return NULL;
+		}
 		netmask = x->rn_key;
-		while (tt->rn_mask != netmask)
-			if ((tt = tt->rn_dupedkey) == 0)
-				return (0);
+		while (tt->rn_mask != netmask) {
+			if ((tt = tt->rn_dupedkey) == 0) {
+				return NULL;
+			}
+		}
 	}
-	if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
+	if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) {
 		goto on1;
+	}
 	if (tt->rn_flags & RNF_NORMAL) {
 		if (m->rm_leaf != tt || m->rm_refs > 0) {
 			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
-			return 0;  /* dangling ref could cause disaster */
+			return NULL;  /* dangling ref could cause disaster */
 		}
 	} else {
 		if (m->rm_mask != tt->rn_mask) {
 			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
 			goto on1;
 		}
-		if (--m->rm_refs >= 0)
+		if (--m->rm_refs >= 0) {
 			goto on1;
+		}
 	}
 	b = -1 - tt->rn_bit;
 	t = saved_tt->rn_parent;
-	if (b > t->rn_bit)
+	if (b > t->rn_bit) {
 		goto on1; /* Wasn't lifted at all */
+	}
 	do {
 		x = t;
 		t = t->rn_parent;
 	} while (b <= t->rn_bit && x != top);
-	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
+	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
 		if (m == saved_m) {
 			*mp = m->rm_mklist;
 			MKFree(m);
 			break;
 		}
+	}
 	if (m == 0) {
 		log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
-		if (tt->rn_flags & RNF_NORMAL)
-			return (0); /* Dangling ref to us */
+		if (tt->rn_flags & RNF_NORMAL) {
+			return NULL; /* Dangling ref to us */
+		}
 	}
 on1:
 	/*
 	 * Eliminate us from tree
 	 */
-	if (tt->rn_flags & RNF_ROOT)
-		return (0);
+	if (tt->rn_flags & RNF_ROOT) {
+		return NULL;
+	}
+	head->rnh_cnt--;
 #ifdef RN_DEBUG
 	/* Get us out of the creation list */
-	for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
-	if (t) t->rn_ybro = tt->rn_ybro;
+	for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {
+	}
+	if (t) {
+		t->rn_ybro = tt->rn_ybro;
+	}
 #endif
 	t = tt->rn_parent;
 	dupedkey = saved_tt->rn_dupedkey;
@@ -808,23 +908,28 @@ on1:
 		if (tt == saved_tt) {
 			/* remove from head of chain */
 			x = dupedkey; x->rn_parent = t;
-			if (t->rn_left == tt)
+			if (t->rn_left == tt) {
 				t->rn_left = x;
-			else
+			} else {
 				t->rn_right = x;
+			}
 		} else {
 			/* find node in front of tt on the chain */
-			for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
+			for (x = p = saved_tt; p && p->rn_dupedkey != tt;) {
 				p = p->rn_dupedkey;
+			}
 			if (p) {
 				p->rn_dupedkey = tt->rn_dupedkey;
-				if (tt->rn_dupedkey)		/* parent */
+				if (tt->rn_dupedkey) {          /* parent */
 					tt->rn_dupedkey->rn_parent = p;
-								/* parent */
-			} else log(LOG_ERR, "rn_delete: couldn't find us\n");
+				}
+				/* parent */
+			} else {
+				log(LOG_ERR, "rn_delete: couldn't find us\n");
+			}
 		}
 		t = tt + 1;
-		if  (t->rn_flags & RNF_ACTIVE) {
+		if (t->rn_flags & RNF_ACTIVE) {
 #ifndef RN_DEBUG
 			*++x = *t;
 			p = t->rn_parent;
@@ -834,49 +939,57 @@ on1:
 			t->rn_info = b;
 			p = t->rn_parent;
 #endif
-			if (p->rn_left == t)
+			if (p->rn_left == t) {
 				p->rn_left = x;
-			else
+			} else {
 				p->rn_right = x;
+			}
 			x->rn_left->rn_parent = x;
 			x->rn_right->rn_parent = x;
 		}
 		goto out;
 	}
-	if (t->rn_left == tt)
+	if (t->rn_left == tt) {
 		x = t->rn_right;
-	else
+	} else {
 		x = t->rn_left;
+	}
 	p = t->rn_parent;
-	if (p->rn_right == t)
+	if (p->rn_right == t) {
 		p->rn_right = x;
-	else
+	} else {
 		p->rn_left = x;
+	}
 	x->rn_parent = p;
 	/*
 	 * Demote routes attached to us.
 	 */
 	if (t->rn_mklist) {
 		if (x->rn_bit >= 0) {
-			for (mp = &x->rn_mklist; (m = *mp);)
+			for (mp = &x->rn_mklist; (m = *mp);) {
 				mp = &m->rm_mklist;
+			}
 			*mp = t->rn_mklist;
 		} else {
 			/* If there are any key,mask pairs in a sibling
-			   duped-key chain, some subset will appear sorted
-			   in the same order attached to our mklist */
-			for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
+			 *  duped-key chain, some subset will appear sorted
+			 *  in the same order attached to our mklist */
+			for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) {
 				if (m == x->rn_mklist) {
 					struct radix_mask *mm = m->rm_mklist;
-					x->rn_mklist = 0;
-					if (--(m->rm_refs) < 0)
+					x->rn_mklist = NULL;
+					if (--(m->rm_refs) < 0) {
 						MKFree(m);
+					}
 					m = mm;
 				}
-			if (m)
-				log(LOG_ERR,
-				    "rn_delete: Orphaned Mask %p at %p\n",
-				    (void *)m, (void *)x);
+			}
+			if (m) {
+				log(LOG_ERR, "rn_delete: Orphaned Mask "
+				    "0x%llx at 0x%llx\n",
+				    (uint64_t)VM_KERNEL_ADDRPERM(m),
+				    (uint64_t)VM_KERNEL_ADDRPERM(x));
+			}
 		}
 	}
 	/*
@@ -894,15 +1007,16 @@ on1:
 		t->rn_left->rn_parent = t;
 		t->rn_right->rn_parent = t;
 		p = x->rn_parent;
-		if (p->rn_left == x)
+		if (p->rn_left == x) {
 			p->rn_left = t;
-		else
+		} else {
 			p->rn_right = t;
+		}
 	}
 out:
 	tt->rn_flags &= ~RNF_ACTIVE;
 	tt[1].rn_flags &= ~RNF_ACTIVE;
-	return (tt);
+	return tt;
 }
 
 /*
@@ -910,38 +1024,49 @@ out:
  * exit.
  */
 static int
-rn_walktree_from(h, a, m, f, w)
-	struct radix_node_head *h;
-	void *a, *m;
-	walktree_f_t *f;
-	void *w;
+rn_walktree_from(struct radix_node_head *h, void *a, void *m, walktree_f_t *f,
+    void *w)
 {
 	int error;
 	struct radix_node *base, *next;
 	u_char *xa = (u_char *)a;
 	u_char *xm = (u_char *)m;
-	register struct radix_node *rn, *last = 0 /* shut up gcc */;
-	int stopping = 0;
+	struct radix_node *rn, *last;
+	int stopping;
 	int lastb;
+	int rnh_cnt;
+
+	/*
+	 * This gets complicated because we may delete the node while
+	 * applying the function f to it; we cannot simply use the next
+	 * leaf as the successor node in advance, because that leaf may
+	 * be removed as well during deletion when it is a clone of the
+	 * current node.  When that happens, we would end up referring
+	 * to an already-freed radix node as the successor node.  To get
+	 * around this issue, if we detect that the radix tree has changed
+	 * in dimension (smaller than before), we simply restart the walk
+	 * from the top of tree.
+	 */
+restart:
+	last = NULL;
+	stopping = 0;
+	rnh_cnt = h->rnh_cnt;
 
 	/*
 	 * rn_search_m is sort-of-open-coded here.
 	 */
-	/* printf("about to search\n"); */
-	for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
+	for (rn = h->rnh_treetop; rn->rn_bit >= 0;) {
 		last = rn;
-		/* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n",
-		       rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */
 		if (!(rn->rn_bmask & xm[rn->rn_offset])) {
 			break;
 		}
+
 		if (rn->rn_bmask & xa[rn->rn_offset]) {
 			rn = rn->rn_right;
 		} else {
 			rn = rn->rn_left;
 		}
 	}
-	/* printf("done searching\n"); */
 
 	/*
 	 * Two cases: either we stepped off the end of our mask,
@@ -952,119 +1077,157 @@ rn_walktree_from(h, a, m, f, w)
 	rn = last;
 	lastb = rn->rn_bit;
 
-	/* printf("rn %p, lastb %d\n", rn, lastb);*/
-
-	/*
-	 * This gets complicated because we may delete the node
-	 * while applying the function f to it, so we need to calculate
-	 * the successor node in advance.
-	 */
-	while (rn->rn_bit >= 0)
+	/* First time through node, go left */
+	while (rn->rn_bit >= 0) {
 		rn = rn->rn_left;
+	}
 
 	while (!stopping) {
-		/* printf("node %p (%d)\n", rn, rn->rn_bit); */
 		base = rn;
 		/* If at right child go back up, otherwise, go right */
 		while (rn->rn_parent->rn_right == rn
-		       && !(rn->rn_flags & RNF_ROOT)) {
+		    && !(rn->rn_flags & RNF_ROOT)) {
 			rn = rn->rn_parent;
 
 			/* if went up beyond last, stop */
-			if (rn->rn_bit < lastb) {
+			if (rn->rn_bit <= lastb) {
 				stopping = 1;
-				/* printf("up too far\n"); */
+				/*
+				 * XXX we should jump to the 'Process leaves'
+				 * part, because the values of 'rn' and 'next'
+				 * we compute will not be used. Not a big deal
+				 * because this loop will terminate, but it is
+				 * inefficient and hard to understand!
+				 */
 			}
 		}
 
-		/* Find the next *leaf* since next node might vanish, too */
-		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
+		/*
+		 * The following code (bug fix) inherited from FreeBSD is
+		 * currently disabled, because our implementation uses the
+		 * RTF_PRCLONING scheme that has been abandoned in current
+		 * FreeBSD release.  The scheme involves setting such a flag
+		 * for the default route entry, and therefore all off-link
+		 * destinations would become clones of that entry.  Enabling
+		 * the following code would be problematic at this point,
+		 * because the removal of default route would cause only
+		 * the left-half of the tree to be traversed, leaving the
+		 * right-half untouched.  If there are clones of the entry
+		 * that reside in that right-half, they would not be deleted
+		 * and would linger around until they expire or explicitly
+		 * deleted, which is a very bad thing.
+		 *
+		 * This code should be uncommented only after we get rid
+		 * of the RTF_PRCLONING scheme.
+		 */
+#if 0
+		/*
+		 * At the top of the tree, no need to traverse the right
+		 * half, prevent the traversal of the entire tree in the
+		 * case of default route.
+		 */
+		if (rn->rn_parent->rn_flags & RNF_ROOT) {
+			stopping = 1;
+		}
+#endif
+
+		/* Find the next *leaf* to start from */
+		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) {
 			rn = rn->rn_left;
+		}
 		next = rn;
 		/* Process leaves */
 		while ((rn = base) != 0) {
 			base = rn->rn_dupedkey;
-			/* printf("leaf %p\n", rn); */
 			if (!(rn->rn_flags & RNF_ROOT)
-			    && (error = (*f)(rn, w)))
-				return (error);
+			    && (error = (*f)(rn, w))) {
+				return error;
+			}
+		}
+		/* If one or more nodes got deleted, restart from top */
+		if (h->rnh_cnt < rnh_cnt) {
+			goto restart;
 		}
 		rn = next;
-
 		if (rn->rn_flags & RNF_ROOT) {
-			/* printf("root, stopping"); */
 			stopping = 1;
 		}
-
 	}
 	return 0;
 }
 
 static int
-rn_walktree(h, f, w)
-	struct radix_node_head *h;
-	walktree_f_t *f;
-	void *w;
+rn_walktree(struct radix_node_head *h, walktree_f_t *f, void *w)
 {
 	int error;
 	struct radix_node *base, *next;
-	register struct radix_node *rn = h->rnh_treetop;
+	struct radix_node *rn;
+	int rnh_cnt;
+
 	/*
-	 * This gets complicated because we may delete the node
-	 * while applying the function f to it, so we need to calculate
-	 * the successor node in advance.
+	 * This gets complicated because we may delete the node while
+	 * applying the function f to it; we cannot simply use the next
+	 * leaf as the successor node in advance, because that leaf may
+	 * be removed as well during deletion when it is a clone of the
+	 * current node.  When that happens, we would end up referring
+	 * to an already-freed radix node as the successor node.  To get
+	 * around this issue, if we detect that the radix tree has changed
+	 * in dimension (smaller than before), we simply restart the walk
+	 * from the top of tree.
 	 */
+restart:
+	rn = h->rnh_treetop;
+	rnh_cnt = h->rnh_cnt;
+
 	/* First time through node, go left */
-	while (rn->rn_bit >= 0) 
-		if (rn)
-			rn = rn->rn_left;
-		else return(0);
+	while (rn->rn_bit >= 0) {
+		rn = rn->rn_left;
+	}
 	for (;;) {
 		base = rn;
 		/* If at right child go back up, otherwise, go right */
-		while (rn != NULL && rn->rn_parent != NULL && rn->rn_parent->rn_right == rn
-		       && (rn->rn_flags & RNF_ROOT) == 0)
+		while (rn->rn_parent->rn_right == rn &&
+		    (rn->rn_flags & RNF_ROOT) == 0) {
 			rn = rn->rn_parent;
-		/* Find the next *leaf* since next node might vanish, too */
-		if (rn == NULL || rn->rn_parent == NULL || rn->rn_parent->rn_right == NULL)
-			return (0);
+		}
+		/* Find the next *leaf* to start from */
 		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) {
-			if (rn == NULL || rn->rn_parent == NULL || rn->rn_parent->rn_right == NULL || rn->rn_left == NULL)
-				return(0);
 			rn = rn->rn_left;
 		}
 		next = rn;
 		/* Process leaves */
-		while ((rn = base)) {
-			if (rn == NULL)
-				return(0);
+		while ((rn = base) != NULL) {
 			base = rn->rn_dupedkey;
 			if (!(rn->rn_flags & RNF_ROOT)
-			    && (error = (*f)(rn, w)))
-				return (error);
+			    && (error = (*f)(rn, w))) {
+				return error;
+			}
+		}
+		/* If one or more nodes got deleted, restart from top */
+		if (h->rnh_cnt < rnh_cnt) {
+			goto restart;
 		}
 		rn = next;
-		if (rn == NULL)
-			return (0);
-		if (rn->rn_flags & RNF_ROOT)
-			return (0);
+		if (rn->rn_flags & RNF_ROOT) {
+			return 0;
+		}
 	}
 	/* NOTREACHED */
 }
 
 int
-rn_inithead(head, off)
-	void **head;
-	int off;
+rn_inithead(void **head, int off)
 {
-	register struct radix_node_head *rnh;
-	register struct radix_node *t, *tt, *ttt;
-	if (*head)
-		return (1);
-	R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh));
-	if (rnh == 0)
-		return (0);
-	Bzero(rnh, sizeof (*rnh));
+	struct radix_node_head *rnh;
+	struct radix_node *t, *tt, *ttt;
+	if (*head) {
+		return 1;
+	}
+	R_Malloc(rnh, struct radix_node_head *, sizeof(*rnh));
+	if (rnh == 0) {
+		return 0;
+	}
+	Bzero(rnh, sizeof(*rnh));
 	*head = rnh;
 	t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
 	ttt = rnh->rnh_nodes + 2;
@@ -1078,75 +1241,44 @@ rn_inithead(head, off)
 	rnh->rnh_addaddr = rn_addroute;
 	rnh->rnh_deladdr = rn_delete;
 	rnh->rnh_matchaddr = rn_match;
+	rnh->rnh_matchaddr_args = rn_match_args;
 	rnh->rnh_lookup = rn_lookup;
+	rnh->rnh_lookup_args = rn_lookup_args;
 	rnh->rnh_walktree = rn_walktree;
 	rnh->rnh_walktree_from = rn_walktree_from;
 	rnh->rnh_treetop = t;
-	return (1);
+	rnh->rnh_cnt = 3;
+	return 1;
 }
 
 void
-rn_init()
+rn_init(void)
 {
 	char *cp, *cplim;
-#ifdef KERNEL
 	struct domain *dom;
 
 	/* lock already held when rn_init is called */
-	for (dom = domains; dom; dom = dom->dom_next)
-		if (dom->dom_maxrtkey > max_keylen)
+	TAILQ_FOREACH(dom, &domains, dom_entry) {
+		if (dom->dom_maxrtkey > max_keylen) {
 			max_keylen = dom->dom_maxrtkey;
-#endif
+		}
+	}
 	if (max_keylen == 0) {
 		log(LOG_ERR,
 		    "rn_init: radix functions require max_keylen be set\n");
 		return;
 	}
 	R_Malloc(rn_zeros, char *, 3 * max_keylen);
-	if (rn_zeros == NULL)
+	if (rn_zeros == NULL) {
 		panic("rn_init");
+	}
 	Bzero(rn_zeros, 3 * max_keylen);
 	rn_ones = cp = rn_zeros + max_keylen;
 	addmask_key = cplim = rn_ones + max_keylen;
-	while (cp < cplim)
+	while (cp < cplim) {
 		*cp++ = -1;
-	if (rn_inithead((void **)&mask_rnhead, 0) == 0)
+	}
+	if (rn_inithead((void **)&mask_rnhead, 0) == 0) {
 		panic("rn_init 2");
-
-	rn_mutex = lck_mtx_alloc_init(domain_proto_mtx_grp, domain_proto_mtx_attr);
-}
-int
-rn_lock(so, refcount, lr)
-	struct socket *so;
-	int refcount;
-	int lr;
-{
-//	printf("rn_lock: (global) so=%x ref=%d lr=%x\n", so, so->so_usecount, lr);
-	lck_mtx_assert(rn_mutex, LCK_MTX_ASSERT_NOTOWNED);
-	lck_mtx_lock(rn_mutex);
-	if (refcount)
-		so->so_usecount++;
-	return (0);
-}
-
-int
-rn_unlock(so, refcount, lr)
-	struct socket *so;
-	int refcount;
-	int lr;
-{
-//	printf("rn_unlock: (global) so=%x ref=%d lr=%x\n", so, so->so_usecount, lr);
-	if (refcount)
-		so->so_usecount--;
-	lck_mtx_assert(rn_mutex, LCK_MTX_ASSERT_OWNED);
-	lck_mtx_unlock(rn_mutex);
-	return (0);
-}
-lck_mtx_t *
-rn_getlock(so, locktype)
-	struct socket *so;
-	int locktype;
-{
-//	printf("rn_getlock: (global) so=%x\n", so);
-	return (rn_mutex);
+	}
 }