1/*
2 * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Copyright (c) 1988, 1989, 1993
30 *	The Regents of the University of California.  All rights reserved.
31 *
32 * Redistribution and use in source and binary forms, with or without
33 * modification, are permitted provided that the following conditions
34 * are met:
35 * 1. Redistributions of source code must retain the above copyright
36 *    notice, this list of conditions and the following disclaimer.
37 * 2. Redistributions in binary form must reproduce the above copyright
38 *    notice, this list of conditions and the following disclaimer in the
39 *    documentation and/or other materials provided with the distribution.
40 * 3. All advertising materials mentioning features or use of this software
41 *    must display the following acknowledgement:
42 *	This product includes software developed by the University of
43 *	California, Berkeley and its contributors.
44 * 4. Neither the name of the University nor the names of its contributors
45 *    may be used to endorse or promote products derived from this software
46 *    without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 *	@(#)radix.c	8.4 (Berkeley) 11/2/94
61 * $FreeBSD: src/sys/net/radix.c,v 1.20.2.2 2001/03/06 00:56:50 obrien Exp $
62 */
63
64/*
65 * Routines to build and maintain radix trees for routing lookups.
66 */
67#ifndef _RADIX_H_
68#include <sys/param.h>
69#include <sys/systm.h>
70#include <sys/malloc.h>
71#define	M_DONTWAIT M_NOWAIT
72#include <sys/domain.h>
73#include <sys/syslog.h>
74#include <net/radix.h>
75#include <sys/socket.h>
76#include <sys/socketvar.h>
77#include <kern/locks.h>
78#endif
79
80static int	rn_walktree_from(struct radix_node_head *h, void *a,
81				      void *m, walktree_f_t *f, void *w);
82static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
83static struct radix_node
84	 *rn_insert(void *, struct radix_node_head *, int *,
85			struct radix_node [2]),
86	 *rn_newpair(void *, int, struct radix_node[2]),
87	 *rn_search(void *, struct radix_node *),
88	 *rn_search_m(void *, struct radix_node *, void *);
89
90static int	max_keylen;
91static struct radix_mask *rn_mkfreelist;
92static struct radix_node_head *mask_rnhead;
93static char *addmask_key;
94static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
95static char *rn_zeros, *rn_ones;
96
97
98extern lck_grp_t	*domain_proto_mtx_grp;
99extern lck_attr_t	*domain_proto_mtx_attr;
100
101#define rn_masktop (mask_rnhead->rnh_treetop)
102#undef Bcmp
103#define Bcmp(a, b, l) \
104	(l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (uint32_t)l))
105
106static int	rn_lexobetter(void *m_arg, void *n_arg);
107static struct radix_mask *
108		rn_new_radix_mask(struct radix_node *tt,
109				       struct radix_mask *next);
110static int rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip,
111    rn_matchf_t *f, void *w);
112
113#define	RN_MATCHF(rn, f, arg)	(f == NULL || (*f)((rn), arg))
114
115/*
116 * The data structure for the keys is a radix tree with one way
117 * branching removed.  The index rn_bit at an internal node n represents a bit
118 * position to be tested.  The tree is arranged so that all descendants
119 * of a node n have keys whose bits all agree up to position rn_bit - 1.
120 * (We say the index of n is rn_bit.)
121 *
122 * There is at least one descendant which has a one bit at position rn_bit,
123 * and at least one with a zero there.
124 *
125 * A route is determined by a pair of key and mask.  We require that the
126 * bit-wise logical and of the key and mask to be the key.
127 * We define the index of a route to associated with the mask to be
128 * the first bit number in the mask where 0 occurs (with bit number 0
129 * representing the highest order bit).
130 *
131 * We say a mask is normal if every bit is 0, past the index of the mask.
132 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
133 * and m is a normal mask, then the route applies to every descendant of n.
134 * If the index(m) < rn_bit, this implies the trailing last few bits of k
135 * before bit b are all 0, (and hence consequently true of every descendant
136 * of n), so the route applies to all descendants of the node as well.
137 *
138 * Similar logic shows that a non-normal mask m such that
139 * index(m) <= index(n) could potentially apply to many children of n.
140 * Thus, for each non-host route, we attach its mask to a list at an internal
141 * node as high in the tree as we can go.
142 *
143 * The present version of the code makes use of normal routes in short-
144 * circuiting an explict mask and compare operation when testing whether
145 * a key satisfies a normal route, and also in remembering the unique leaf
146 * that governs a subtree.
147 */
148
149static struct radix_node *
150rn_search(void *v_arg, struct radix_node *head)
151{
152	struct radix_node *x;
153	caddr_t v;
154
155	for (x = head, v = v_arg; x->rn_bit >= 0;) {
156		if (x->rn_bmask & v[x->rn_offset])
157			x = x->rn_right;
158		else
159			x = x->rn_left;
160	}
161	return (x);
162}
163
164static struct radix_node *
165rn_search_m(void *v_arg, struct radix_node *head, void *m_arg)
166{
167	struct radix_node *x;
168	caddr_t v = v_arg, m = m_arg;
169
170	for (x = head; x->rn_bit >= 0;) {
171		if ((x->rn_bmask & m[x->rn_offset]) &&
172		    (x->rn_bmask & v[x->rn_offset]))
173			x = x->rn_right;
174		else
175			x = x->rn_left;
176	}
177	return x;
178}
179
180int
181rn_refines(void *m_arg, void *n_arg)
182{
183	caddr_t m = m_arg, n = n_arg;
184	caddr_t lim, lim2 = lim = n + *(u_char *)n;
185	int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
186	int masks_are_equal = 1;
187
188	if (longer > 0)
189		lim -= longer;
190	while (n < lim) {
191		if (*n & ~(*m))
192			return 0;
193		if (*n++ != *m++)
194			masks_are_equal = 0;
195	}
196	while (n < lim2)
197		if (*n++)
198			return 0;
199	if (masks_are_equal && (longer < 0))
200		for (lim2 = m - longer; m < lim2; )
201			if (*m++)
202				return 1;
203	return (!masks_are_equal);
204}
205
206struct radix_node *
207rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head)
208{
209	return (rn_lookup_args(v_arg, m_arg, head, NULL, NULL));
210}
211
212struct radix_node *
213rn_lookup_args(void *v_arg, void *m_arg, struct radix_node_head *head,
214    rn_matchf_t *f, void *w)
215{
216	struct radix_node *x;
217	caddr_t netmask = NULL;
218
219	if (m_arg) {
220		x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset);
221		if (x == 0)
222			return (NULL);
223		netmask = x->rn_key;
224	}
225	x = rn_match_args(v_arg, head, f, w);
226	if (x && netmask) {
227		while (x && x->rn_mask != netmask)
228			x = x->rn_dupedkey;
229	}
230	return x;
231}
232
233/*
234 * Returns true if address 'trial' has no bits differing from the
235 * leaf's key when compared under the leaf's mask.  In other words,
236 * returns true when 'trial' matches leaf.  If a leaf-matching
237 * routine is passed in, it is also used to find a match on the
238 * conditions defined by the caller of rn_match.
239 */
240static int
241rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip,
242    rn_matchf_t *f, void *w)
243{
244	char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
245	char *cplim;
246	int length = min(*(u_char *)cp, *(u_char *)cp2);
247
248	if (cp3 == 0)
249		cp3 = rn_ones;
250	else
251		length = min(length, *(u_char *)cp3);
252	cplim = cp + length; cp3 += skip; cp2 += skip;
253	for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
254		if ((*cp ^ *cp2) & *cp3)
255			return 0;
256
257	return (RN_MATCHF(leaf, f, w));
258}
259
260struct radix_node *
261rn_match(void *v_arg, struct radix_node_head *head)
262{
263	return (rn_match_args(v_arg, head, NULL, NULL));
264}
265
266struct radix_node *
267rn_match_args(void *v_arg, struct radix_node_head *head,
268    rn_matchf_t *f, void *w)
269{
270	caddr_t v = v_arg;
271	struct radix_node *t = head->rnh_treetop, *x;
272	caddr_t cp = v, cp2;
273	caddr_t cplim;
274	struct radix_node *saved_t, *top = t;
275	int off = t->rn_offset, vlen = *(u_char *)cp, matched_off;
276	int test, b, rn_bit;
277
278	/*
279	 * Open code rn_search(v, top) to avoid overhead of extra
280	 * subroutine call.
281	 */
282	for (; t->rn_bit >= 0; ) {
283		if (t->rn_bmask & cp[t->rn_offset])
284			t = t->rn_right;
285		else
286			t = t->rn_left;
287	}
288	/*
289	 * See if we match exactly as a host destination
290	 * or at least learn how many bits match, for normal mask finesse.
291	 *
292	 * It doesn't hurt us to limit how many bytes to check
293	 * to the length of the mask, since if it matches we had a genuine
294	 * match and the leaf we have is the most specific one anyway;
295	 * if it didn't match with a shorter length it would fail
296	 * with a long one.  This wins big for class B&C netmasks which
297	 * are probably the most common case...
298	 */
299	if (t->rn_mask)
300		vlen = *(u_char *)t->rn_mask;
301	cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
302	for (; cp < cplim; cp++, cp2++)
303		if (*cp != *cp2)
304			goto on1;
305	/*
306	 * This extra grot is in case we are explicitly asked
307	 * to look up the default.  Ugh!
308	 *
309	 * Never return the root node itself, it seems to cause a
310	 * lot of confusion.
311	 */
312	if (t->rn_flags & RNF_ROOT)
313		t = t->rn_dupedkey;
314	if (t == NULL || RN_MATCHF(t, f, w)) {
315		return (t);
316	} else {
317		/*
318		 * Although we found an exact match on the key,
319		 * f() is looking for some other criteria as well.
320		 * Continue looking as if the exact match failed.
321		 */
322		if (t->rn_parent->rn_flags & RNF_ROOT) {
323			/* Hit the top; have to give up */
324			return (NULL);
325		}
326		b = 0;
327		goto keeplooking;
328	}
329on1:
330	test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
331	for (b = 7; (test >>= 1) > 0;)
332		b--;
333keeplooking:
334	matched_off = cp - v;
335	b += matched_off << 3;
336	rn_bit = -1 - b;
337	/*
338	 * If there is a host route in a duped-key chain, it will be first.
339	 */
340	if ((saved_t = t)->rn_mask == 0)
341		t = t->rn_dupedkey;
342	for (; t; t = t->rn_dupedkey) {
343		/*
344		 * Even if we don't match exactly as a host,
345		 * we may match if the leaf we wound up at is
346		 * a route to a net.
347		 */
348		if (t->rn_flags & RNF_NORMAL) {
349			if ((rn_bit <= t->rn_bit) && RN_MATCHF(t, f, w))
350				return (t);
351		} else if (rn_satisfies_leaf(v, t, matched_off, f, w)) {
352			return (t);
353		}
354	}
355	t = saved_t;
356	/* start searching up the tree */
357	do {
358		struct radix_mask *m;
359		t = t->rn_parent;
360		m = t->rn_mklist;
361		/*
362		 * If non-contiguous masks ever become important
363		 * we can restore the masking and open coding of
364		 * the search and satisfaction test and put the
365		 * calculation of "off" back before the "do".
366		 */
367		while (m) {
368			if (m->rm_flags & RNF_NORMAL) {
369				if ((rn_bit <= m->rm_bit) &&
370				    RN_MATCHF(m->rm_leaf, f, w))
371					return (m->rm_leaf);
372			} else {
373				off = min(t->rn_offset, matched_off);
374				x = rn_search_m(v, t, m->rm_mask);
375				while (x && x->rn_mask != m->rm_mask)
376					x = x->rn_dupedkey;
377				if (x && rn_satisfies_leaf(v, x, off, f, w))
378					return (x);
379			}
380			m = m->rm_mklist;
381		}
382	} while (t != top);
383	return (NULL);
384}
385
386#ifdef RN_DEBUG
387int	rn_nodenum;
388struct	radix_node *rn_clist;
389int	rn_saveinfo;
390int	rn_debug =  1;
391#endif
392
393static struct radix_node *
394rn_newpair(void *v, int b, struct radix_node nodes[2])
395{
396	struct radix_node *tt = nodes, *t = tt + 1;
397	t->rn_bit = b;
398	t->rn_bmask = 0x80 >> (b & 7);
399	t->rn_left = tt;
400	t->rn_offset = b >> 3;
401	tt->rn_bit = -1;
402	tt->rn_key = (caddr_t)v;
403	tt->rn_parent = t;
404	tt->rn_flags = t->rn_flags = RNF_ACTIVE;
405	tt->rn_mklist = t->rn_mklist = NULL;
406#ifdef RN_DEBUG
407	tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
408	tt->rn_twin = t;
409	tt->rn_ybro = rn_clist;
410	rn_clist = tt;
411#endif
412	return t;
413}
414
415static struct radix_node *
416rn_insert(void *v_arg, struct radix_node_head *head, int *dupentry,
417	  struct radix_node nodes[2])
418{
419	caddr_t v = v_arg;
420	struct radix_node *top = head->rnh_treetop;
421	int head_off = top->rn_offset, vlen = (int)*((u_char *)v);
422	struct radix_node *t = rn_search(v_arg, top);
423	caddr_t cp = v + head_off;
424	int b;
425	struct radix_node *tt;
426    	/*
427	 * Find first bit at which v and t->rn_key differ
428	 */
429    {
430	caddr_t cp2 = t->rn_key + head_off;
431	int cmp_res;
432	caddr_t cplim = v + vlen;
433
434	while (cp < cplim)
435		if (*cp2++ != *cp++)
436			goto on1;
437	*dupentry = 1;
438	return t;
439on1:
440	*dupentry = 0;
441	cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
442	for (b = (cp - v) << 3; cmp_res; b--)
443		cmp_res >>= 1;
444    }
445    {
446	struct radix_node *p, *x = top;
447	cp = v;
448	do {
449		p = x;
450		if (cp[x->rn_offset] & x->rn_bmask)
451			x = x->rn_right;
452		else
453			x = x->rn_left;
454	} while (b > (unsigned) x->rn_bit);
455				/* x->rn_bit < b && x->rn_bit >= 0 */
456#ifdef RN_DEBUG
457	if (rn_debug)
458		log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
459#endif
460	t = rn_newpair(v_arg, b, nodes);
461	tt = t->rn_left;
462	if ((cp[p->rn_offset] & p->rn_bmask) == 0)
463		p->rn_left = t;
464	else
465		p->rn_right = t;
466	x->rn_parent = t;
467	t->rn_parent = p; /* frees x, p as temp vars below */
468	if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
469		t->rn_right = x;
470	} else {
471		t->rn_right = tt;
472		t->rn_left = x;
473	}
474#ifdef RN_DEBUG
475	if (rn_debug)
476		log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
477#endif
478    }
479	return (tt);
480}
481
482struct radix_node *
483rn_addmask(void *n_arg, int search, int skip)
484{
485	caddr_t netmask = (caddr_t)n_arg;
486	struct radix_node *x;
487	caddr_t cp, cplim;
488	int b = 0, mlen, j;
489	int maskduplicated, m0, isnormal;
490	struct radix_node *saved_x;
491	static int last_zeroed = 0;
492
493	if ((mlen = *(u_char *)netmask) > max_keylen)
494		mlen = max_keylen;
495	if (skip == 0)
496		skip = 1;
497	if (mlen <= skip)
498		return (mask_rnhead->rnh_nodes);
499	if (skip > 1)
500		Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
501	if ((m0 = mlen) > skip)
502		Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
503	/*
504	 * Trim trailing zeroes.
505	 */
506	for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
507		cp--;
508	mlen = cp - addmask_key;
509	if (mlen <= skip) {
510		if (m0 >= last_zeroed)
511			last_zeroed = mlen;
512		return (mask_rnhead->rnh_nodes);
513	}
514	if (m0 < last_zeroed)
515		Bzero(addmask_key + m0, last_zeroed - m0);
516	*addmask_key = last_zeroed = mlen;
517	x = rn_search(addmask_key, rn_masktop);
518	if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
519		x = NULL;
520	if (x || search)
521		return (x);
522	R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
523	if ((saved_x = x) == 0)
524		return (NULL);
525	Bzero(x, max_keylen + 2 * sizeof (*x));
526	netmask = cp = (caddr_t)(x + 2);
527	Bcopy(addmask_key, cp, mlen);
528	x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
529	if (maskduplicated) {
530		log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
531		R_Free(saved_x);
532		return (x);
533	}
534	mask_rnhead->rnh_cnt++;
535	/*
536	 * Calculate index of mask, and check for normalcy.
537	 */
538	cplim = netmask + mlen; isnormal = 1;
539	for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
540		cp++;
541	if (cp != cplim) {
542		for (j = 0x80; (j & *cp) != 0; j >>= 1)
543			b++;
544		if (*cp != normal_chars[b] || cp != (cplim - 1))
545			isnormal = 0;
546	}
547	b += (cp - netmask) << 3;
548	x->rn_bit = -1 - b;
549	if (isnormal)
550		x->rn_flags |= RNF_NORMAL;
551	return (x);
552}
553
554static int	/* XXX: arbitrary ordering for non-contiguous masks */
555rn_lexobetter(void *m_arg, void *n_arg)
556{
557	u_char *mp = m_arg, *np = n_arg, *lim;
558
559	if (*mp > *np)
560		return 1;  /* not really, but need to check longer one first */
561	if (*mp == *np)
562		for (lim = mp + *mp; mp < lim;)
563			if (*mp++ > *np++)
564				return 1;
565	return 0;
566}
567
568static struct radix_mask *
569rn_new_radix_mask(struct radix_node *tt, struct radix_mask *next)
570{
571	struct radix_mask *m;
572
573	MKGet(m);
574	if (m == 0) {
575		log(LOG_ERR, "Mask for route not entered\n");
576		return (NULL);
577	}
578	Bzero(m, sizeof *m);
579	m->rm_bit = tt->rn_bit;
580	m->rm_flags = tt->rn_flags;
581	if (tt->rn_flags & RNF_NORMAL)
582		m->rm_leaf = tt;
583	else
584		m->rm_mask = tt->rn_mask;
585	m->rm_mklist = next;
586	tt->rn_mklist = m;
587	return m;
588}
589
590struct radix_node *
591rn_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
592	    struct radix_node treenodes[2])
593{
594	caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
595	struct radix_node *t, *x = NULL, *tt;
596	struct radix_node *saved_tt, *top = head->rnh_treetop;
597	short b = 0, b_leaf = 0;
598	int keyduplicated;
599	caddr_t mmask;
600	struct radix_mask *m, **mp;
601
602	/*
603	 * In dealing with non-contiguous masks, there may be
604	 * many different routes which have the same mask.
605	 * We will find it useful to have a unique pointer to
606	 * the mask to speed avoiding duplicate references at
607	 * nodes and possibly save time in calculating indices.
608	 */
609	if (netmask)  {
610		if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0)
611			return (NULL);
612		b_leaf = x->rn_bit;
613		b = -1 - x->rn_bit;
614		netmask = x->rn_key;
615	}
616	/*
617	 * Deal with duplicated keys: attach node to previous instance
618	 */
619	saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
620	if (keyduplicated) {
621		for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
622			if (tt->rn_mask == netmask)
623				return (NULL);
624			if (netmask == 0 ||
625			    (tt->rn_mask &&
626			     ((b_leaf < tt->rn_bit) /* index(netmask) > node */
627			      || rn_refines(netmask, tt->rn_mask)
628			      || rn_lexobetter(netmask, tt->rn_mask))))
629				break;
630		}
631		/*
632		 * If the mask is not duplicated, we wouldn't
633		 * find it among possible duplicate key entries
634		 * anyway, so the above test doesn't hurt.
635		 *
636		 * We sort the masks for a duplicated key the same way as
637		 * in a masklist -- most specific to least specific.
638		 * This may require the unfortunate nuisance of relocating
639		 * the head of the list.
640		 */
641		if (tt == saved_tt) {
642			struct	radix_node *xx = x;
643			/* link in at head of list */
644			(tt = treenodes)->rn_dupedkey = t;
645			tt->rn_flags = t->rn_flags;
646			tt->rn_parent = x = t->rn_parent;
647			t->rn_parent = tt;	 		/* parent */
648			if (x->rn_left == t)
649				x->rn_left = tt;
650			else
651				x->rn_right = tt;
652			saved_tt = tt; x = xx;
653		} else {
654			(tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
655			t->rn_dupedkey = tt;
656			tt->rn_parent = t;			/* parent */
657			if (tt->rn_dupedkey)			/* parent */
658				tt->rn_dupedkey->rn_parent = tt; /* parent */
659		}
660#ifdef RN_DEBUG
661		t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
662		tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
663#endif
664		tt->rn_key = (caddr_t) v;
665		tt->rn_bit = -1;
666		tt->rn_flags = RNF_ACTIVE;
667	}
668	head->rnh_cnt++;
669	/*
670	 * Put mask in tree.
671	 */
672	if (netmask) {
673		tt->rn_mask = netmask;
674		tt->rn_bit = x->rn_bit;
675		tt->rn_flags |= x->rn_flags & RNF_NORMAL;
676	}
677	t = saved_tt->rn_parent;
678	if (keyduplicated)
679		goto on2;
680	b_leaf = -1 - t->rn_bit;
681	if (t->rn_right == saved_tt)
682		x = t->rn_left;
683	else
684		x = t->rn_right;
685	/* Promote general routes from below */
686	if (x->rn_bit < 0) {
687	    for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
688		if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) {
689			*mp = m = rn_new_radix_mask(x, NULL);
690			if (m)
691				mp = &m->rm_mklist;
692		}
693	} else if (x->rn_mklist) {
694		/*
695		 * Skip over masks whose index is > that of new node
696		 */
697		for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
698			if (m->rm_bit >= b_leaf)
699				break;
700		t->rn_mklist = m; *mp = NULL;
701	}
702on2:
703	/* Add new route to highest possible ancestor's list */
704	if ((netmask == 0) || (b > t->rn_bit ))
705		return tt; /* can't lift at all */
706	b_leaf = tt->rn_bit;
707	do {
708		x = t;
709		t = t->rn_parent;
710	} while (b <= t->rn_bit && x != top);
711	/*
712	 * Search through routes associated with node to
713	 * insert new route according to index.
714	 * Need same criteria as when sorting dupedkeys to avoid
715	 * double loop on deletion.
716	 */
717	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
718		if (m->rm_bit < b_leaf)
719			continue;
720		if (m->rm_bit > b_leaf)
721			break;
722		if (m->rm_flags & RNF_NORMAL) {
723			mmask = m->rm_leaf->rn_mask;
724			if (tt->rn_flags & RNF_NORMAL) {
725			    log(LOG_ERR,
726			        "Non-unique normal route, mask not entered");
727				return tt;
728			}
729		} else
730			mmask = m->rm_mask;
731		if (mmask == netmask) {
732			m->rm_refs++;
733			tt->rn_mklist = m;
734			return tt;
735		}
736		if (rn_refines(netmask, mmask)
737		    || rn_lexobetter(netmask, mmask))
738			break;
739	}
740	*mp = rn_new_radix_mask(tt, *mp);
741	return tt;
742}
743
744struct radix_node *
745rn_delete(void *v_arg, void *netmask_arg, struct radix_node_head *head)
746{
747	struct radix_node *t, *p, *x, *tt;
748	struct radix_mask *m, *saved_m, **mp;
749	struct radix_node *dupedkey, *saved_tt, *top;
750	caddr_t v, netmask;
751	int b, head_off, vlen;
752
753	v = v_arg;
754	netmask = netmask_arg;
755	x = head->rnh_treetop;
756	tt = rn_search(v, x);
757	head_off = x->rn_offset;
758	vlen =  *(u_char *)v;
759	saved_tt = tt;
760	top = x;
761	if (tt == 0 ||
762	    Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
763		return (NULL);
764	/*
765	 * Delete our route from mask lists.
766	 */
767	if (netmask) {
768		if ((x = rn_addmask(netmask, 1, head_off)) == 0)
769			return (NULL);
770		netmask = x->rn_key;
771		while (tt->rn_mask != netmask)
772			if ((tt = tt->rn_dupedkey) == 0)
773				return (NULL);
774	}
775	if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
776		goto on1;
777	if (tt->rn_flags & RNF_NORMAL) {
778		if (m->rm_leaf != tt || m->rm_refs > 0) {
779			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
780			return NULL;  /* dangling ref could cause disaster */
781		}
782	} else {
783		if (m->rm_mask != tt->rn_mask) {
784			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
785			goto on1;
786		}
787		if (--m->rm_refs >= 0)
788			goto on1;
789	}
790	b = -1 - tt->rn_bit;
791	t = saved_tt->rn_parent;
792	if (b > t->rn_bit)
793		goto on1; /* Wasn't lifted at all */
794	do {
795		x = t;
796		t = t->rn_parent;
797	} while (b <= t->rn_bit && x != top);
798	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
799		if (m == saved_m) {
800			*mp = m->rm_mklist;
801			MKFree(m);
802			break;
803		}
804	if (m == 0) {
805		log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
806		if (tt->rn_flags & RNF_NORMAL)
807			return (NULL); /* Dangling ref to us */
808	}
809on1:
810	/*
811	 * Eliminate us from tree
812	 */
813	if (tt->rn_flags & RNF_ROOT)
814		return (NULL);
815	head->rnh_cnt--;
816#ifdef RN_DEBUG
817	/* Get us out of the creation list */
818	for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
819	if (t) t->rn_ybro = tt->rn_ybro;
820#endif
821	t = tt->rn_parent;
822	dupedkey = saved_tt->rn_dupedkey;
823	if (dupedkey) {
824		/*
825		 * at this point, tt is the deletion target and saved_tt
826		 * is the head of the dupekey chain
827		 */
828		if (tt == saved_tt) {
829			/* remove from head of chain */
830			x = dupedkey; x->rn_parent = t;
831			if (t->rn_left == tt)
832				t->rn_left = x;
833			else
834				t->rn_right = x;
835		} else {
836			/* find node in front of tt on the chain */
837			for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
838				p = p->rn_dupedkey;
839			if (p) {
840				p->rn_dupedkey = tt->rn_dupedkey;
841				if (tt->rn_dupedkey)		/* parent */
842					tt->rn_dupedkey->rn_parent = p;
843								/* parent */
844			} else log(LOG_ERR, "rn_delete: couldn't find us\n");
845		}
846		t = tt + 1;
847		if  (t->rn_flags & RNF_ACTIVE) {
848#ifndef RN_DEBUG
849			*++x = *t;
850			p = t->rn_parent;
851#else
852			b = t->rn_info;
853			*++x = *t;
854			t->rn_info = b;
855			p = t->rn_parent;
856#endif
857			if (p->rn_left == t)
858				p->rn_left = x;
859			else
860				p->rn_right = x;
861			x->rn_left->rn_parent = x;
862			x->rn_right->rn_parent = x;
863		}
864		goto out;
865	}
866	if (t->rn_left == tt)
867		x = t->rn_right;
868	else
869		x = t->rn_left;
870	p = t->rn_parent;
871	if (p->rn_right == t)
872		p->rn_right = x;
873	else
874		p->rn_left = x;
875	x->rn_parent = p;
876	/*
877	 * Demote routes attached to us.
878	 */
879	if (t->rn_mklist) {
880		if (x->rn_bit >= 0) {
881			for (mp = &x->rn_mklist; (m = *mp);)
882				mp = &m->rm_mklist;
883			*mp = t->rn_mklist;
884		} else {
885			/* If there are any key,mask pairs in a sibling
886			   duped-key chain, some subset will appear sorted
887			   in the same order attached to our mklist */
888			for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
889				if (m == x->rn_mklist) {
890					struct radix_mask *mm = m->rm_mklist;
891					x->rn_mklist = NULL;
892					if (--(m->rm_refs) < 0)
893						MKFree(m);
894					m = mm;
895				}
896			if (m)
897				log(LOG_ERR, "rn_delete: Orphaned Mask "
898				    "0x%llx at 0x%llx\n",
899				    (uint64_t)VM_KERNEL_ADDRPERM(m),
900				    (uint64_t)VM_KERNEL_ADDRPERM(x));
901		}
902	}
903	/*
904	 * We may be holding an active internal node in the tree.
905	 */
906	x = tt + 1;
907	if (t != x) {
908#ifndef RN_DEBUG
909		*t = *x;
910#else
911		b = t->rn_info;
912		*t = *x;
913		t->rn_info = b;
914#endif
915		t->rn_left->rn_parent = t;
916		t->rn_right->rn_parent = t;
917		p = x->rn_parent;
918		if (p->rn_left == x)
919			p->rn_left = t;
920		else
921			p->rn_right = t;
922	}
923out:
924	tt->rn_flags &= ~RNF_ACTIVE;
925	tt[1].rn_flags &= ~RNF_ACTIVE;
926	return (tt);
927}
928
929/*
930 * This is the same as rn_walktree() except for the parameters and the
931 * exit.
932 */
933static int
934rn_walktree_from(struct radix_node_head *h, void *a, void *m, walktree_f_t *f,
935    void *w)
936{
937	int error;
938	struct radix_node *base, *next;
939	u_char *xa = (u_char *)a;
940	u_char *xm = (u_char *)m;
941	struct radix_node *rn, *last;
942	int stopping;
943	int lastb;
944	int rnh_cnt;
945
946	/*
947	 * This gets complicated because we may delete the node while
948	 * applying the function f to it; we cannot simply use the next
949	 * leaf as the successor node in advance, because that leaf may
950	 * be removed as well during deletion when it is a clone of the
951	 * current node.  When that happens, we would end up referring
952	 * to an already-freed radix node as the successor node.  To get
953	 * around this issue, if we detect that the radix tree has changed
954	 * in dimension (smaller than before), we simply restart the walk
955	 * from the top of tree.
956	 */
957restart:
958	last = NULL;
959	stopping = 0;
960	rnh_cnt = h->rnh_cnt;
961
962	/*
963	 * rn_search_m is sort-of-open-coded here.
964	 */
965	for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
966		last = rn;
967		if (!(rn->rn_bmask & xm[rn->rn_offset]))
968			break;
969
970		if (rn->rn_bmask & xa[rn->rn_offset])
971			rn = rn->rn_right;
972		else
973			rn = rn->rn_left;
974	}
975
976	/*
977	 * Two cases: either we stepped off the end of our mask,
978	 * in which case last == rn, or we reached a leaf, in which
979	 * case we want to start from the last node we looked at.
980	 * Either way, last is the node we want to start from.
981	 */
982	rn = last;
983	lastb = rn->rn_bit;
984
985	/* First time through node, go left */
986	while (rn->rn_bit >= 0)
987		rn = rn->rn_left;
988
989	while (!stopping) {
990		base = rn;
991		/* If at right child go back up, otherwise, go right */
992		while (rn->rn_parent->rn_right == rn
993		       && !(rn->rn_flags & RNF_ROOT)) {
994			rn = rn->rn_parent;
995
996			/* if went up beyond last, stop */
997			if (rn->rn_bit <= lastb) {
998				stopping = 1;
999				/*
1000				 * XXX we should jump to the 'Process leaves'
1001				 * part, because the values of 'rn' and 'next'
1002				 * we compute will not be used. Not a big deal
1003				 * because this loop will terminate, but it is
1004				 * inefficient and hard to understand!
1005				 */
1006			}
1007		}
1008
1009		/*
1010		 * The following code (bug fix) inherited from FreeBSD is
1011		 * currently disabled, because our implementation uses the
1012		 * RTF_PRCLONING scheme that has been abandoned in current
1013		 * FreeBSD release.  The scheme involves setting such a flag
1014		 * for the default route entry, and therefore all off-link
1015		 * destinations would become clones of that entry.  Enabling
1016		 * the following code would be problematic at this point,
1017		 * because the removal of default route would cause only
1018		 * the left-half of the tree to be traversed, leaving the
1019		 * right-half untouched.  If there are clones of the entry
1020		 * that reside in that right-half, they would not be deleted
1021		 * and would linger around until they expire or explicitly
1022		 * deleted, which is a very bad thing.
1023		 *
1024		 * This code should be uncommented only after we get rid
1025		 * of the RTF_PRCLONING scheme.
1026		 */
1027#if 0
1028		/*
1029		 * At the top of the tree, no need to traverse the right
1030		 * half, prevent the traversal of the entire tree in the
1031		 * case of default route.
1032		 */
1033		if (rn->rn_parent->rn_flags & RNF_ROOT)
1034			stopping = 1;
1035#endif
1036
1037		/* Find the next *leaf* to start from */
1038		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1039			rn = rn->rn_left;
1040		next = rn;
1041		/* Process leaves */
1042		while ((rn = base) != 0) {
1043			base = rn->rn_dupedkey;
1044			if (!(rn->rn_flags & RNF_ROOT)
1045			    && (error = (*f)(rn, w)))
1046				return (error);
1047		}
1048		/* If one or more nodes got deleted, restart from top */
1049		if (h->rnh_cnt < rnh_cnt)
1050			goto restart;
1051		rn = next;
1052		if (rn->rn_flags & RNF_ROOT)
1053			stopping = 1;
1054	}
1055	return 0;
1056}
1057
1058static int
1059rn_walktree(struct radix_node_head *h, walktree_f_t *f, void *w)
1060{
1061	int error;
1062	struct radix_node *base, *next;
1063	struct radix_node *rn;
1064	int rnh_cnt;
1065
1066	/*
1067	 * This gets complicated because we may delete the node while
1068	 * applying the function f to it; we cannot simply use the next
1069	 * leaf as the successor node in advance, because that leaf may
1070	 * be removed as well during deletion when it is a clone of the
1071	 * current node.  When that happens, we would end up referring
1072	 * to an already-freed radix node as the successor node.  To get
1073	 * around this issue, if we detect that the radix tree has changed
1074	 * in dimension (smaller than before), we simply restart the walk
1075	 * from the top of tree.
1076	 */
1077restart:
1078	rn = h->rnh_treetop;
1079	rnh_cnt = h->rnh_cnt;
1080
1081	/* First time through node, go left */
1082	while (rn->rn_bit >= 0)
1083		rn = rn->rn_left;
1084	for (;;) {
1085		base = rn;
1086		/* If at right child go back up, otherwise, go right */
1087		while (rn->rn_parent->rn_right == rn &&
1088		    (rn->rn_flags & RNF_ROOT) == 0)
1089			rn = rn->rn_parent;
1090		/* Find the next *leaf* to start from */
1091		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1092			rn = rn->rn_left;
1093		next = rn;
1094		/* Process leaves */
1095		while ((rn = base) != NULL) {
1096			base = rn->rn_dupedkey;
1097			if (!(rn->rn_flags & RNF_ROOT)
1098			    && (error = (*f)(rn, w)))
1099				return (error);
1100		}
1101		/* If one or more nodes got deleted, restart from top */
1102		if (h->rnh_cnt < rnh_cnt)
1103			goto restart;
1104		rn = next;
1105		if (rn->rn_flags & RNF_ROOT)
1106			return (0);
1107	}
1108	/* NOTREACHED */
1109}
1110
1111int
1112rn_inithead(void **head, int off)
1113{
1114	struct radix_node_head *rnh;
1115	struct radix_node *t, *tt, *ttt;
1116	if (*head)
1117		return (1);
1118	R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh));
1119	if (rnh == 0)
1120		return (0);
1121	Bzero(rnh, sizeof (*rnh));
1122	*head = rnh;
1123	t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
1124	ttt = rnh->rnh_nodes + 2;
1125	t->rn_right = ttt;
1126	t->rn_parent = t;
1127	tt = t->rn_left;
1128	tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
1129	tt->rn_bit = -1 - off;
1130	*ttt = *tt;
1131	ttt->rn_key = rn_ones;
1132	rnh->rnh_addaddr = rn_addroute;
1133	rnh->rnh_deladdr = rn_delete;
1134	rnh->rnh_matchaddr = rn_match;
1135	rnh->rnh_matchaddr_args = rn_match_args;
1136	rnh->rnh_lookup = rn_lookup;
1137	rnh->rnh_lookup_args = rn_lookup_args;
1138	rnh->rnh_walktree = rn_walktree;
1139	rnh->rnh_walktree_from = rn_walktree_from;
1140	rnh->rnh_treetop = t;
1141	rnh->rnh_cnt = 3;
1142	return (1);
1143}
1144
1145void
1146rn_init(void)
1147{
1148	char *cp, *cplim;
1149	struct domain *dom;
1150
1151	/* lock already held when rn_init is called */
1152	TAILQ_FOREACH(dom, &domains, dom_entry) {
1153		if (dom->dom_maxrtkey > max_keylen)
1154			max_keylen = dom->dom_maxrtkey;
1155	}
1156	if (max_keylen == 0) {
1157		log(LOG_ERR,
1158		    "rn_init: radix functions require max_keylen be set\n");
1159		return;
1160	}
1161	R_Malloc(rn_zeros, char *, 3 * max_keylen);
1162	if (rn_zeros == NULL)
1163		panic("rn_init");
1164	Bzero(rn_zeros, 3 * max_keylen);
1165	rn_ones = cp = rn_zeros + max_keylen;
1166	addmask_key = cplim = rn_ones + max_keylen;
1167	while (cp < cplim)
1168		*cp++ = -1;
1169	if (rn_inithead((void **)&mask_rnhead, 0) == 0)
1170		panic("rn_init 2");
1171}
1172