X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/ff6e181ae92fc6f1e89841290f461d1f2f9badd9..2dced7af2b695f87fe26496a3e73c219b7880cbc:/bsd/net/radix.c

diff --git a/bsd/net/radix.c b/bsd/net/radix.c
index 17a431a91..fdc7058b3 100644
--- a/bsd/net/radix.c
+++ b/bsd/net/radix.c
@@ -1,15 +1,20 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *
- * @APPLE_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. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- * 
+ * 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,
@@ -17,8 +22,8 @@
  * 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_LICENSE_HEADER_END@
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * Copyright (c) 1988, 1989, 1993
@@ -61,14 +66,10 @@
  */
 #ifndef _RADIX_H_
 #include <sys/param.h>
-#ifdef	KERNEL
 #include <sys/systm.h>
 #include <sys/malloc.h>
 #define	M_DONTWAIT M_NOWAIT
 #include <sys/domain.h>
-#else
-#include <stdlib.h>
-#endif
 #include <sys/syslog.h>
 #include <net/radix.h>
 #include <sys/socket.h>
@@ -96,19 +97,20 @@ 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 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);
+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
@@ -145,12 +147,10 @@ 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])
@@ -162,12 +162,10 @@ rn_search(v_arg, head)
 }
 
 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]) &&
@@ -180,11 +178,10 @@ rn_search_m(v_arg, head, m_arg)
 }
 
 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;
 
@@ -207,20 +204,25 @@ rn_refines(m_arg, n_arg)
 }
 
 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)
+{
+	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)
 {
-	register struct radix_node *x;
-	caddr_t netmask = 0;
+	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);
+			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)
 			x = x->rn_dupedkey;
@@ -228,13 +230,18 @@ rn_lookup(v_arg, m_arg, head)
 	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);
 
@@ -246,21 +253,27 @@ rn_satsifies_leaf(trial, leaf, skip)
 	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(void *v_arg, struct radix_node_head *head)
+{
+	return (rn_match_args(v_arg, head, NULL, NULL));
 }
 
 struct radix_node *
-rn_match(v_arg, head)
-	void *v_arg;
-	struct radix_node_head *head;
+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
@@ -298,11 +311,26 @@ rn_match(v_arg, head)
 	 */
 	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;)
 		b--;
+keeplooking:
 	matched_off = cp - v;
 	b += matched_off << 3;
 	rn_bit = -1 - b;
@@ -311,21 +339,23 @@ on1:
 	 */
 	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))
-				return t;
+			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;
 		/*
@@ -336,20 +366,21 @@ on1:
 		 */
 		while (m) {
 			if (m->rm_flags & RNF_NORMAL) {
-				if (rn_bit <= m->rm_bit)
+				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)
 					x = x->rn_dupedkey;
-				if (x && rn_satsifies_leaf(v, x, off))
-					return x;
+				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
@@ -360,12 +391,9 @@ 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;
@@ -374,7 +402,7 @@ 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;
@@ -385,25 +413,22 @@ 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 cp2 = t->rn_key + head_off;
+	int cmp_res;
 	caddr_t cplim = v + vlen;
 
 	while (cp < cplim)
@@ -418,7 +443,7 @@ on1:
 		cmp_res >>= 1;
     }
     {
-	register struct radix_node *p, *x = top;
+	struct radix_node *p, *x = top;
 	cp = v;
 	do {
 		p = x;
@@ -455,14 +480,12 @@ on1:
 }
 
 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;
@@ -493,12 +516,12 @@ rn_addmask(n_arg, search, skip)
 	*addmask_key = last_zeroed = mlen;
 	x = rn_search(addmask_key, rn_masktop);
 	if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
-		x = 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 (0);
+		return (NULL);
 	Bzero(x, max_keylen + 2 * sizeof (*x));
 	netmask = cp = (caddr_t)(x + 2);
 	Bcopy(addmask_key, cp, mlen);
@@ -508,6 +531,7 @@ rn_addmask(n_arg, search, skip)
 		R_Free(saved_x);
 		return (x);
 	}
+	mask_rnhead->rnh_cnt++;
 	/*
 	 * Calculate index of mask, and check for normalcy.
 	 */
@@ -528,10 +552,9 @@ rn_addmask(n_arg, search, skip)
 }
 
 static int	/* XXX: arbitrary ordering for non-contiguous masks */
-rn_lexobetter(m_arg, n_arg)
-	void *m_arg, *n_arg;
+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)
 		return 1;  /* not really, but need to check longer one first */
@@ -543,16 +566,14 @@ rn_lexobetter(m_arg, n_arg)
 }
 
 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;
@@ -567,13 +588,11 @@ rn_new_radix_mask(tt, next)
 }
 
 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;
@@ -589,7 +608,7 @@ rn_addroute(v_arg, n_arg, head, treenodes)
 	 */
 	if (netmask)  {
 		if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0)
-			return (0);
+			return (NULL);
 		b_leaf = x->rn_bit;
 		b = -1 - x->rn_bit;
 		netmask = x->rn_key;
@@ -601,7 +620,7 @@ rn_addroute(v_arg, n_arg, head, treenodes)
 	if (keyduplicated) {
 		for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
 			if (tt->rn_mask == netmask)
-				return (0);
+				return (NULL);
 			if (netmask == 0 ||
 			    (tt->rn_mask &&
 			     ((b_leaf < tt->rn_bit) /* index(netmask) > node */
@@ -646,6 +665,7 @@ rn_addroute(v_arg, n_arg, head, treenodes)
 		tt->rn_bit = -1;
 		tt->rn_flags = RNF_ACTIVE;
 	}
+	head->rnh_cnt++;
 	/*
 	 * Put mask in tree.
 	 */
@@ -666,7 +686,7 @@ rn_addroute(v_arg, n_arg, head, treenodes)
 	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);
+			*mp = m = rn_new_radix_mask(x, NULL);
 			if (m)
 				mp = &m->rm_mklist;
 		}
@@ -677,7 +697,7 @@ rn_addroute(v_arg, n_arg, head, treenodes)
 		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 */
@@ -722,11 +742,9 @@ on2:
 }
 
 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;
@@ -742,24 +760,24 @@ rn_delete(v_arg, netmask_arg, head)
 	top = x;
 	if (tt == 0 ||
 	    Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
-		return (0);
+		return (NULL);
 	/*
 	 * Delete our route from mask lists.
 	 */
 	if (netmask) {
 		if ((x = rn_addmask(netmask, 1, head_off)) == 0)
-			return (0);
+			return (NULL);
 		netmask = x->rn_key;
 		while (tt->rn_mask != netmask)
 			if ((tt = tt->rn_dupedkey) == 0)
-				return (0);
+				return (NULL);
 	}
 	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) {
@@ -786,14 +804,15 @@ rn_delete(v_arg, netmask_arg, head)
 	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 */
+			return (NULL); /* Dangling ref to us */
 	}
 on1:
 	/*
 	 * Eliminate us from tree
 	 */
 	if (tt->rn_flags & RNF_ROOT)
-		return (0);
+		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) {}
@@ -869,15 +888,16 @@ on1:
 			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;
+					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);
+				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));
 		}
 	}
 	/*
@@ -911,38 +931,47 @@ 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; ) {
 		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])) {
+		if (!(rn->rn_bmask & xm[rn->rn_offset]))
 			break;
-		}
-		if (rn->rn_bmask & xa[rn->rn_offset]) {
+
+		if (rn->rn_bmask & xa[rn->rn_offset])
 			rn = rn->rn_right;
-		} else {
+		else
 			rn = rn->rn_left;
-		}
 	}
-	/* printf("done searching\n"); */
 
 	/*
 	 * Two cases: either we stepped off the end of our mask,
@@ -953,18 +982,11 @@ 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.
-	 */
+	/* 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
@@ -972,81 +994,114 @@ rn_walktree_from(h, a, m, f, w)
 			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 */
+		/*
+		 * 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);
 		}
+		/* 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"); */
+		if (rn->rn_flags & RNF_ROOT)
 			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);
-		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);
+		/* 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)) {
-			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);
 		}
+		/* 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);
 	}
@@ -1054,12 +1109,10 @@ rn_walktree(h, f, w)
 }
 
 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;
+	struct radix_node_head *rnh;
+	struct radix_node *t, *tt, *ttt;
 	if (*head)
 		return (1);
 	R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh));
@@ -1079,25 +1132,27 @@ 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;
+	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)
+	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");
@@ -1113,41 +1168,4 @@ rn_init()
 		*cp++ = -1;
 	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);
 }