xref: /illumos-gate/usr/src/cmd/cmd-inet/usr.sbin/in.routed/radix.c (revision 2a8bcb4efb45d99ac41c94a75c396b362c414f7f)
1 /*
2  * Copyright 2001-2003 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  *
5  * Copyright (c) 1988, 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgment:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)radix.c	8.4 (Berkeley) 11/2/94
37  *
38  * $FreeBSD: src/sbin/routed/radix.c,v 1.6 2000/08/11 08:24:38 sheldonh Exp $
39  */
40 
41 /*
42  * Routines to build and maintain radix trees for routing lookups.
43  */
44 
45 #include "defs.h"
46 
47 static const size_t max_keylen = sizeof (struct sockaddr_in);
48 static struct radix_mask *rn_mkfreelist;
49 static struct radix_node_head *mask_rnhead;
50 static uint8_t *rn_zeros, *rn_ones, *addmask_key;
51 
52 #define	rn_masktop (mask_rnhead->rnh_treetop)
53 
54 static boolean_t rn_satisfies_leaf(uint8_t *, struct radix_node *, int);
55 
56 static boolean_t rn_refines(void *, void *);
57 
58 static struct radix_node
59 	 *rn_addmask(void *, uint_t, uint_t),
60 	 *rn_addroute(void *, void *, struct radix_node_head *,
61 	    struct radix_node [2]),
62 	 *rn_delete(void *, void *, struct radix_node_head *),
63 	 *rn_insert(void *, struct radix_node_head *, boolean_t *,
64 	    struct radix_node [2]),
65 	 *rn_match(void *, struct radix_node_head *),
66 	 *rn_newpair(void *, uint_t, struct radix_node[2]),
67 	 *rn_search(void *, struct radix_node *),
68 	 *rn_search_m(void *, struct radix_node *, void *);
69 
70 static struct radix_node *rn_lookup(void *, void *, struct radix_node_head *);
71 
72 #ifdef DEBUG
73 #define	DBGMSG(x)	msglog x
74 #else
75 #define	DBGMSG(x)	(void) 0
76 #endif
77 
78 /*
79  * The data structure for the keys is a radix tree with one way
80  * branching removed.  The index rn_b at an internal node n represents a bit
81  * position to be tested.  The tree is arranged so that all descendants
82  * of a node n have keys whose bits all agree up to position rn_b - 1.
83  * (We say the index of n is rn_b.)
84  *
85  * There is at least one descendant which has a one bit at position rn_b,
86  * and at least one with a zero there.
87  *
88  * A route is determined by a pair of key and mask.  We require that the
89  * bit-wise logical and of the key and mask to be the key.
90  * We define the index of a route to associated with the mask to be
91  * the first bit number in the mask where 0 occurs (with bit number 0
92  * representing the highest order bit).
93  *
94  * We say a mask is normal if every bit is 0, past the index of the mask.
95  * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b,
96  * and m is a normal mask, then the route applies to every descendant of n.
97  * If the index(m) < rn_b, this implies the trailing last few bits of k
98  * before bit b are all 0, (and hence consequently true of every descendant
99  * of n), so the route applies to all descendants of the node as well.
100  *
101  * Similar logic shows that a non-normal mask m such that
102  * index(m) <= index(n) could potentially apply to many children of n.
103  * Thus, for each non-host route, we attach its mask to a list at an internal
104  * node as high in the tree as we can go.
105  *
106  * The present version of the code makes use of normal routes in short-
107  * circuiting an explict mask and compare operation when testing whether
108  * a key satisfies a normal route, and also in remembering the unique leaf
109  * that governs a subtree.
110  */
111 
112 static struct radix_node *
rn_search(void * v_arg,struct radix_node * head)113 rn_search(void *v_arg, struct radix_node *head)
114 {
115 	struct radix_node *x;
116 	uint8_t *v;
117 
118 	for (x = head, v = v_arg; x->rn_b >= 0; ) {
119 		if (x->rn_bmask & v[x->rn_off])
120 			x = x->rn_r;
121 		else
122 			x = x->rn_l;
123 	}
124 	return (x);
125 }
126 
127 static struct radix_node *
rn_search_m(void * v_arg,struct radix_node * head,void * m_arg)128 rn_search_m(void *v_arg, struct radix_node *head, void *m_arg)
129 {
130 	struct radix_node *x;
131 	uint8_t *v = v_arg, *m = m_arg;
132 
133 	for (x = head; x->rn_b >= 0; ) {
134 		if (x->rn_bmask & m[x->rn_off] & v[x->rn_off])
135 			x = x->rn_r;
136 		else
137 			x = x->rn_l;
138 	}
139 	return (x);
140 }
141 
142 /*
143  * Returns true if there are no bits set in n_arg that are zero in
144  * m_arg and the masks aren't equal.  In other words, it returns true
145  * when m_arg is a finer-granularity netmask -- it represents a subset
146  * of the destinations implied by n_arg.
147  */
148 static boolean_t
rn_refines(void * m_arg,void * n_arg)149 rn_refines(void* m_arg, void *n_arg)
150 {
151 	uint8_t *m = m_arg, *n = n_arg;
152 	uint8_t *lim;
153 	boolean_t masks_are_equal = _B_TRUE;
154 
155 	lim = n + sizeof (struct sockaddr);
156 
157 	while (n < lim) {
158 		if (*n & ~(*m))
159 			return (_B_FALSE);
160 		if (*n++ != *m++)
161 			masks_are_equal = _B_FALSE;
162 	}
163 	return (!masks_are_equal);
164 }
165 
166 static struct radix_node *
rn_lookup(void * v_arg,void * m_arg,struct radix_node_head * head)167 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head)
168 {
169 	struct radix_node *x;
170 	uint8_t *netmask = NULL;
171 
172 	if (m_arg) {
173 		if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) ==
174 		    NULL) {
175 			DBGMSG(("rn_lookup: failed to add mask"));
176 			return (NULL);
177 		}
178 		netmask = x->rn_key;
179 	}
180 	x = rn_match(v_arg, head);
181 	if (x && netmask) {
182 		while (x && x->rn_mask != netmask)
183 			x = x->rn_dupedkey;
184 	}
185 	return (x);
186 }
187 
188 /*
189  * Returns true if address 'trial' has no bits differing from the
190  * leaf's key when compared under the leaf's mask.  In other words,
191  * returns true when 'trial' matches leaf.
192  */
193 static boolean_t
rn_satisfies_leaf(uint8_t * trial,struct radix_node * leaf,int skip)194 rn_satisfies_leaf(uint8_t *trial,
195     struct radix_node *leaf,
196     int skip)
197 {
198 	uint8_t *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
199 	uint8_t *cplim;
200 	size_t length;
201 
202 	length = sizeof (struct sockaddr);
203 
204 	if (cp3 == NULL)
205 		cp3 = rn_ones;
206 	cplim = cp + length;
207 	cp3 += skip;
208 	cp2 += skip;
209 	for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
210 		if ((*cp ^ *cp2) & *cp3)
211 			return (_B_FALSE);
212 	return (_B_TRUE);
213 }
214 
215 static struct radix_node *
rn_match(void * v_arg,struct radix_node_head * head)216 rn_match(void *v_arg, struct radix_node_head *head)
217 {
218 	uint8_t *v = v_arg;
219 	struct radix_node *t = head->rnh_treetop, *x;
220 	uint8_t *cp = v, *cp2;
221 	uint8_t *cplim;
222 	struct radix_node *saved_t, *top = t;
223 	uint_t off = t->rn_off, vlen, matched_off;
224 	int test, b, rn_b;
225 
226 	vlen = sizeof (struct sockaddr);
227 
228 	/*
229 	 * Open code rn_search(v, top) to avoid overhead of extra
230 	 * subroutine call.
231 	 */
232 	for (; t->rn_b >= 0; ) {
233 		if (t->rn_bmask & cp[t->rn_off])
234 			t = t->rn_r;
235 		else
236 			t = t->rn_l;
237 	}
238 
239 	cp += off;
240 	cp2 = t->rn_key + off;
241 	cplim = v + vlen;
242 	for (; cp < cplim; cp++, cp2++)
243 		if (*cp != *cp2)
244 			goto found_difference_with_key;
245 	/*
246 	 * This extra grot is in case we are explicitly asked
247 	 * to look up the default.  Ugh!
248 	 * Or 255.255.255.255
249 	 *
250 	 * In this case, we have a complete match of the key.  Unless
251 	 * the node is one of the roots, we are finished.
252 	 * If it is the zeros root, then take what we have, prefering
253 	 * any real data.
254 	 * If it is the ones root, then pretend the target key was followed
255 	 * by a byte of zeros.
256 	 */
257 	if (!(t->rn_flags & RNF_ROOT))
258 		return (t);		/* not a root */
259 	if (t->rn_dupedkey) {
260 		t = t->rn_dupedkey;
261 		return (t);		/* have some real data */
262 	}
263 	if (*(cp-1) == 0)
264 		return (t);		/* not the ones root */
265 	b = 0;				/* fake a zero after 255.255.255.255 */
266 	goto calculated_differing_bit;
267 found_difference_with_key:
268 	test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
269 	for (b = 7; (test >>= 1) > 0; )
270 		b--;
271 calculated_differing_bit:
272 	matched_off = cp - v;
273 	b += matched_off << 3;
274 	rn_b = -1 - b;
275 	/*
276 	 * If there is a host route in a duped-key chain, it will be first.
277 	 */
278 	if ((saved_t = t)->rn_mask == NULL)
279 		t = t->rn_dupedkey;
280 	for (; t; t = t->rn_dupedkey) {
281 		/*
282 		 * Even if we don't match exactly as a host,
283 		 * we may match if the leaf we wound up at is
284 		 * a route to a net.
285 		 */
286 		if (t->rn_flags & RNF_NORMAL) {
287 			if (rn_b <= t->rn_b)
288 				return (t);
289 		} else if (rn_satisfies_leaf(v, t, matched_off)) {
290 			return (t);
291 		}
292 	}
293 	t = saved_t;
294 	/* start searching up the tree */
295 	do {
296 		struct radix_mask *m;
297 		t = t->rn_p;
298 		if ((m = t->rn_mklist) != NULL) {
299 			/*
300 			 * If non-contiguous masks ever become important
301 			 * we can restore the masking and open coding of
302 			 * the search and satisfaction test and put the
303 			 * calculation of "off" back before the "do".
304 			 */
305 			do {
306 				if (m->rm_flags & RNF_NORMAL) {
307 					if (rn_b <= m->rm_b)
308 						return (m->rm_leaf);
309 				} else {
310 					off = MIN(t->rn_off, matched_off);
311 					x = rn_search_m(v, t, m->rm_mask);
312 					while (x != NULL &&
313 					    x->rn_mask != m->rm_mask)
314 						x = x->rn_dupedkey;
315 					if (x != NULL &&
316 					    rn_satisfies_leaf(v, x, off))
317 						return (x);
318 				}
319 			} while ((m = m->rm_mklist) != NULL);
320 		}
321 	} while (t != top);
322 	return (NULL);
323 }
324 
325 #ifdef RN_DEBUG
326 int	rn_nodenum;
327 struct	radix_node *rn_clist;
328 int	rn_saveinfo;
329 boolean_t	rn_debug =  1;
330 #endif
331 
332 static struct radix_node *
rn_newpair(void * v,uint_t b,struct radix_node nodes[2])333 rn_newpair(void *v, uint_t b, struct radix_node nodes[2])
334 {
335 	struct radix_node *tt = nodes, *t = tt + 1;
336 
337 	t->rn_b = b;
338 	t->rn_bmask = 0x80 >> (b & 7);
339 	t->rn_l = tt;
340 	t->rn_off = b >> 3;
341 	tt->rn_b = -1;
342 	tt->rn_key = v;
343 	tt->rn_p = t;
344 	tt->rn_flags = t->rn_flags = RNF_ACTIVE;
345 #ifdef RN_DEBUG
346 	tt->rn_info = rn_nodenum++;
347 	t->rn_info = rn_nodenum++;
348 	tt->rn_twin = t;
349 	tt->rn_ybro = rn_clist;
350 	rn_clist = tt;
351 #endif
352 	return (t);
353 }
354 
355 static struct radix_node *
rn_insert(void * v_arg,struct radix_node_head * head,boolean_t * dupentry,struct radix_node nodes[2])356 rn_insert(void* v_arg, struct radix_node_head *head, boolean_t *dupentry,
357     struct radix_node nodes[2])
358 {
359 	uint8_t *v = v_arg;
360 	struct radix_node *top = head->rnh_treetop;
361 	uint_t head_off = top->rn_off, vlen;
362 	struct radix_node *t = rn_search(v_arg, top);
363 	uint8_t *cp = v + head_off, b;
364 	struct radix_node *tt;
365 
366 	vlen = sizeof (struct sockaddr);
367 
368 	/*
369 	 * Find first bit at which v and t->rn_key differ
370 	 */
371 	{
372 		uint8_t *cp2 = t->rn_key + head_off;
373 		uint8_t cmp_res;
374 		uint8_t *cplim = v + vlen;
375 
376 		while (cp < cplim)
377 			if (*cp2++ != *cp++)
378 				goto found_differing_byte;
379 		/* handle adding 255.255.255.255 */
380 		if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) {
381 			*dupentry = _B_TRUE;
382 			return (t);
383 		}
384 found_differing_byte:
385 		*dupentry = _B_FALSE;
386 		cmp_res = cp[-1] ^ cp2[-1];
387 		for (b = (cp - v) << 3; cmp_res != 0; b--)
388 			cmp_res >>= 1;
389 	}
390 	{
391 		struct radix_node *p, *x = top;
392 		cp = v;
393 		do {
394 			p = x;
395 			if (cp[x->rn_off] & x->rn_bmask)
396 				x = x->rn_r;
397 			else
398 				x = x->rn_l;
399 		} while (b > (unsigned)x->rn_b);
400 #ifdef RN_DEBUG
401 		if (rn_debug) {
402 			msglog("rn_insert: Going In:");
403 			traverse(p);
404 		}
405 #endif
406 		t = rn_newpair(v_arg, b, nodes);
407 		tt = t->rn_l;
408 		if (!(cp[p->rn_off] & p->rn_bmask))
409 			p->rn_l = t;
410 		else
411 			p->rn_r = t;
412 		x->rn_p = t; /* frees x, p as temp vars below */
413 		t->rn_p = p;
414 		if (!(cp[t->rn_off] & t->rn_bmask)) {
415 			t->rn_r = x;
416 		} else {
417 			t->rn_r = tt;
418 			t->rn_l = x;
419 		}
420 #ifdef RN_DEBUG
421 		if (rn_debug) {
422 			msglog("rn_insert: Coming Out:");
423 			traverse(p);
424 		}
425 #endif
426 	}
427 	return (tt);
428 }
429 
430 static struct radix_node *
rn_addmask(void * n_arg,uint_t search,uint_t skip)431 rn_addmask(void *n_arg, uint_t search, uint_t skip)
432 {
433 	uint8_t *netmask = n_arg;
434 	struct radix_node *x;
435 	uint8_t *cp, *cplim;
436 	int b = 0, mlen, j, m0;
437 	boolean_t maskduplicated;
438 	struct radix_node *saved_x;
439 	static int last_zeroed = 0;
440 
441 	mlen = sizeof (struct sockaddr);
442 	if (skip == 0)
443 		skip = 1;
444 	if (mlen <= skip)
445 		return (mask_rnhead->rnh_nodes);
446 	if (skip > 1)
447 		(void) memmove(addmask_key + 1, rn_ones + 1, skip - 1);
448 	if ((m0 = mlen) > skip)
449 		(void) memmove(addmask_key + skip, netmask + skip, mlen - skip);
450 	/*
451 	 * Trim trailing zeroes.
452 	 */
453 	for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0; )
454 		cp--;
455 	mlen = cp - addmask_key;
456 	if (mlen <= skip) {
457 		if (m0 >= last_zeroed)
458 			last_zeroed = mlen;
459 		return (mask_rnhead->rnh_nodes);
460 	}
461 	if (m0 < last_zeroed)
462 		(void) memset(addmask_key + m0, 0, last_zeroed - m0);
463 	*addmask_key = last_zeroed = mlen;
464 	x = rn_search(addmask_key, rn_masktop);
465 	if (memcmp(addmask_key, x->rn_key, mlen) != 0)
466 		x = NULL;
467 	if (x != NULL || search != 0)
468 		return (x);
469 	x = rtmalloc(max_keylen + 2*sizeof (*x), "rn_addmask");
470 	saved_x = x;
471 	(void) memset(x, 0, max_keylen + 2 * sizeof (*x));
472 	netmask = cp = (uint8_t *)(x + 2);
473 	(void) memmove(cp, addmask_key, mlen);
474 	x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
475 	if (maskduplicated) {
476 #ifdef DEBUG
477 		logbad(1, "rn_addmask: mask impossibly already in tree");
478 #else
479 		msglog("rn_addmask: mask impossibly already in tree");
480 #endif
481 		free(saved_x);
482 		return (x);
483 	}
484 	/*
485 	 * Calculate index of mask, and check for normalcy.
486 	 */
487 	cplim = netmask + mlen;
488 	x->rn_flags |= RNF_NORMAL;
489 	for (cp = netmask + skip; (cp < cplim) && *cp == 0xff; )
490 		cp++;
491 	if (cp != cplim) {
492 		for (j = 0x80; (j & *cp) != 0; j >>= 1)
493 			b++;
494 		if (*cp != (0xFF & ~(0xFF >> b)) || cp != (cplim - 1))
495 			x->rn_flags &= ~RNF_NORMAL;
496 	}
497 	b += (cp - netmask) << 3;
498 	x->rn_b = -1 - b;
499 	return (x);
500 }
501 
502 static boolean_t /* Note: arbitrary ordering for non-contiguous masks */
rn_lexobetter(void * m_arg,void * n_arg)503 rn_lexobetter(void *m_arg, void *n_arg)
504 {
505 	uint8_t *mp = m_arg, *np = n_arg, *lim;
506 
507 	lim = mp + sizeof (struct sockaddr);
508 	while (mp < lim)
509 		if (*mp++ > *np++)
510 			return (_B_TRUE);
511 	return (_B_FALSE);
512 }
513 
514 static struct radix_mask *
rn_new_radix_mask(struct radix_node * tt,struct radix_mask * next)515 rn_new_radix_mask(struct radix_node *tt,
516     struct radix_mask *next)
517 {
518 	struct radix_mask *m;
519 
520 	MKGet(m);
521 	if (m == NULL) {
522 #ifdef DEBUG
523 		logbad(1, "Mask for route not entered");
524 #else
525 		msglog("Mask for route not entered");
526 #endif
527 		return (NULL);
528 	}
529 	(void) memset(m, 0, sizeof (*m));
530 	m->rm_b = tt->rn_b;
531 	m->rm_flags = tt->rn_flags;
532 	if (tt->rn_flags & RNF_NORMAL)
533 		m->rm_leaf = tt;
534 	else
535 		m->rm_mask = tt->rn_mask;
536 	m->rm_mklist = next;
537 	tt->rn_mklist = m;
538 	return (m);
539 }
540 
541 static struct radix_node *
rn_addroute(void * v_arg,void * n_arg,struct radix_node_head * head,struct radix_node treenodes[2])542 rn_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
543     struct radix_node treenodes[2])
544 {
545 	uint8_t *v = v_arg, *netmask = n_arg;
546 	struct radix_node *t, *x = 0, *tt;
547 	struct radix_node *saved_tt, *top = head->rnh_treetop;
548 	short b = 0, b_leaf = 0;
549 	boolean_t keyduplicated;
550 	uint8_t *mmask;
551 	struct radix_mask *m, **mp;
552 
553 	/*
554 	 * In dealing with non-contiguous masks, there may be
555 	 * many different routes which have the same mask.
556 	 * We will find it useful to have a unique pointer to
557 	 * the mask to speed avoiding duplicate references at
558 	 * nodes and possibly save time in calculating indices.
559 	 */
560 	if (netmask)  {
561 		if ((x = rn_addmask(netmask, 0, top->rn_off)) == NULL) {
562 			DBGMSG(("rn_addroute: addmask failed"));
563 			return (NULL);
564 		}
565 		b_leaf = x->rn_b;
566 		b = -1 - x->rn_b;
567 		netmask = x->rn_key;
568 	}
569 	/*
570 	 * Deal with duplicated keys: attach node to previous instance
571 	 */
572 	saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
573 	if (keyduplicated) {
574 		for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
575 			if (tt->rn_mask == netmask) {
576 				DBGMSG(("rn_addroute: duplicated route and "
577 				    "mask"));
578 				return (NULL);
579 			}
580 			if (netmask == NULL ||
581 			    (tt->rn_mask &&
582 				((b_leaf < tt->rn_b) ||
583 				    rn_refines(netmask, tt->rn_mask) ||
584 				    rn_lexobetter(netmask, tt->rn_mask))))
585 				break;
586 		}
587 		/*
588 		 * If the mask is not duplicated, we wouldn't
589 		 * find it among possible duplicate key entries
590 		 * anyway, so the above test doesn't hurt.
591 		 *
592 		 * We sort the masks for a duplicated key the same way as
593 		 * in a masklist -- most specific to least specific.
594 		 * This may require the unfortunate nuisance of relocating
595 		 * the head of the list.
596 		 */
597 		if (tt == saved_tt) {
598 			struct	radix_node *xx = x;
599 			/* link in at head of list */
600 			(tt = treenodes)->rn_dupedkey = t;
601 			tt->rn_flags = t->rn_flags;
602 			tt->rn_p = x = t->rn_p;
603 			if (x->rn_l == t)
604 				x->rn_l = tt;
605 			else
606 				x->rn_r = tt;
607 			saved_tt = tt;
608 			x = xx;
609 		} else {
610 			(tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
611 			t->rn_dupedkey = tt;
612 		}
613 #ifdef RN_DEBUG
614 		t = tt + 1;
615 		tt->rn_info = rn_nodenum++;
616 		t->rn_info = rn_nodenum++;
617 		tt->rn_twin = t;
618 		tt->rn_ybro = rn_clist;
619 		rn_clist = tt;
620 #endif
621 		tt->rn_key = v;
622 		tt->rn_b = -1;
623 		tt->rn_flags = RNF_ACTIVE;
624 	}
625 	/*
626 	 * Put mask in tree.
627 	 */
628 	if (netmask) {
629 		tt->rn_mask = netmask;
630 		tt->rn_b = x->rn_b;
631 		tt->rn_flags |= x->rn_flags & RNF_NORMAL;
632 	}
633 	t = saved_tt->rn_p;
634 	if (keyduplicated)
635 		goto key_already_in_tree;
636 	b_leaf = -1 - t->rn_b;
637 	if (t->rn_r == saved_tt)
638 		x = t->rn_l;
639 	else
640 		x = t->rn_r;
641 	/* Promote general routes from below */
642 	if (x->rn_b < 0) {
643 		for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
644 			if (x->rn_mask != NULL && (x->rn_b >= b_leaf) &&
645 			    x->rn_mklist == NULL) {
646 				if ((*mp = m = rn_new_radix_mask(x, 0)) != NULL)
647 					mp = &m->rm_mklist;
648 			}
649 	} else if (x->rn_mklist) {
650 		/*
651 		 * Skip over masks whose index is > that of new node
652 		 */
653 		for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist)
654 			if (m->rm_b >= b_leaf)
655 				break;
656 		t->rn_mklist = m;
657 		*mp = 0;
658 	}
659 key_already_in_tree:
660 	/* Add new route to highest possible ancestor's list */
661 	if ((netmask == NULL) || (b > t->rn_b)) {
662 		return (tt); /* can't lift at all */
663 	}
664 	b_leaf = tt->rn_b;
665 	do {
666 		x = t;
667 		t = t->rn_p;
668 	} while (b <= t->rn_b && x != top);
669 	/*
670 	 * Search through routes associated with node to
671 	 * insert new route according to index.
672 	 * Need same criteria as when sorting dupedkeys to avoid
673 	 * double loop on deletion.
674 	 */
675 	for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist) {
676 		if (m->rm_b < b_leaf)
677 			continue;
678 		if (m->rm_b > b_leaf)
679 			break;
680 		if (m->rm_flags & RNF_NORMAL) {
681 			mmask = m->rm_leaf->rn_mask;
682 			if (tt->rn_flags & RNF_NORMAL) {
683 #ifdef DEBUG
684 				logbad(1, "Non-unique normal route, mask "
685 				    "not entered");
686 #else
687 				msglog("Non-unique normal route, mask "
688 				    "not entered");
689 #endif
690 				return (tt);
691 			}
692 		} else
693 			mmask = m->rm_mask;
694 		if (mmask == netmask) {
695 			m->rm_refs++;
696 			tt->rn_mklist = m;
697 			return (tt);
698 		}
699 		if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
700 			break;
701 	}
702 	*mp = rn_new_radix_mask(tt, *mp);
703 	return (tt);
704 }
705 
706 static struct radix_node *
rn_delete(void * v_arg,void * netmask_arg,struct radix_node_head * head)707 rn_delete(void *v_arg, void *netmask_arg, struct radix_node_head *head)
708 {
709 	struct radix_node *t, *p, *x, *tt;
710 	struct radix_mask *m, *saved_m, **mp;
711 	struct radix_node *dupedkey, *saved_tt, *top;
712 	uint8_t *v, *netmask;
713 	int b;
714 	uint_t head_off, vlen;
715 
716 	v = v_arg;
717 	netmask = netmask_arg;
718 	x = head->rnh_treetop;
719 	tt = rn_search(v, x);
720 	head_off = x->rn_off;
721 	vlen = sizeof (struct sockaddr);
722 	saved_tt = tt;
723 	top = x;
724 	if (tt == NULL ||
725 	    memcmp(v + head_off, tt->rn_key + head_off, vlen - head_off) != 0) {
726 		DBGMSG(("rn_delete: unable to locate route to delete"));
727 		return (NULL);
728 	}
729 	/*
730 	 * Delete our route from mask lists.
731 	 */
732 	if (netmask) {
733 		if ((x = rn_addmask(netmask, 1, head_off)) == NULL) {
734 			DBGMSG(("rn_delete: cannot add mask"));
735 			return (NULL);
736 		}
737 		netmask = x->rn_key;
738 		while (tt->rn_mask != netmask)
739 			if ((tt = tt->rn_dupedkey) == NULL) {
740 				DBGMSG(("rn_delete: cannot locate mask"));
741 				return (NULL);
742 			}
743 	}
744 	if (tt->rn_mask == NULL || (saved_m = m = tt->rn_mklist) == NULL)
745 		goto annotation_removed;
746 	if (tt->rn_flags & RNF_NORMAL) {
747 		if (m->rm_leaf != tt || m->rm_refs > 0) {
748 #ifdef DEBUG
749 			logbad(1, "rn_delete: inconsistent annotation");
750 #else
751 			msglog("rn_delete: inconsistent annotation");
752 #endif
753 			return (NULL);  /* dangling ref could cause disaster */
754 		}
755 	} else {
756 		if (m->rm_mask != tt->rn_mask) {
757 #ifdef DEBUG
758 			logbad(1, "rn_delete: inconsistent annotation");
759 #else
760 			msglog("rn_delete: inconsistent annotation");
761 #endif
762 			goto annotation_removed;
763 		}
764 		if (--m->rm_refs >= 0)
765 			goto annotation_removed;
766 	}
767 	b = -1 - tt->rn_b;
768 	t = saved_tt->rn_p;
769 	if (b > t->rn_b)
770 		goto annotation_removed; /* Wasn't lifted at all */
771 	do {
772 		x = t;
773 		t = t->rn_p;
774 	} while (b <= t->rn_b && x != top);
775 	for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist)
776 		if (m == saved_m) {
777 			*mp = m->rm_mklist;
778 			MKFree(m);
779 			break;
780 		}
781 	if (m == NULL) {
782 #ifdef DEBUG
783 		logbad(1, "rn_delete: couldn't find our annotation");
784 #else
785 		msglog("rn_delete: couldn't find our annotation");
786 #endif
787 		if (tt->rn_flags & RNF_NORMAL)
788 			return (NULL); /* Dangling ref to us */
789 	}
790 annotation_removed:
791 	/*
792 	 * Eliminate us from tree
793 	 */
794 	if (tt->rn_flags & RNF_ROOT) {
795 		DBGMSG(("rn_delete: cannot delete root"));
796 		return (NULL);
797 	}
798 #ifdef RN_DEBUG
799 	/* Get us out of the creation list */
800 	for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
801 	if (t != NULL)
802 		t->rn_ybro = tt->rn_ybro;
803 #endif
804 	t = tt->rn_p;
805 	if ((dupedkey = saved_tt->rn_dupedkey) != NULL) {
806 		if (tt == saved_tt) {
807 			x = dupedkey;
808 			x->rn_p = t;
809 			if (t->rn_l == tt)
810 				t->rn_l = x;
811 			else
812 				t->rn_r = x;
813 		} else {
814 			for (x = p = saved_tt; p && p->rn_dupedkey != tt; )
815 				p = p->rn_dupedkey;
816 			if (p != NULL) {
817 				p->rn_dupedkey = tt->rn_dupedkey;
818 			} else {
819 #ifdef DEBUG
820 				logbad(1, "rn_delete: couldn't find us");
821 #else
822 				msglog("rn_delete: couldn't find us");
823 #endif
824 			}
825 		}
826 		t = tt + 1;
827 		if (t->rn_flags & RNF_ACTIVE) {
828 #ifndef RN_DEBUG
829 			*++x = *t;
830 			p = t->rn_p;
831 #else
832 			b = t->rn_info;
833 			*++x = *t;
834 			t->rn_info = b;
835 			p = t->rn_p;
836 #endif
837 			if (p->rn_l == t)
838 				p->rn_l = x;
839 			else
840 				p->rn_r = x;
841 			x->rn_l->rn_p = x;
842 			x->rn_r->rn_p = x;
843 		}
844 		goto out;
845 	}
846 	if (t->rn_l == tt)
847 		x = t->rn_r;
848 	else
849 		x = t->rn_l;
850 	p = t->rn_p;
851 	if (p->rn_r == t)
852 		p->rn_r = x;
853 	else
854 		p->rn_l = x;
855 	x->rn_p = p;
856 	/*
857 	 * Demote routes attached to us.
858 	 */
859 	if (t->rn_mklist) {
860 		if (x->rn_b >= 0) {
861 			for (mp = &x->rn_mklist; (m = *mp) != NULL; )
862 				mp = &m->rm_mklist;
863 			*mp = t->rn_mklist;
864 		} else {
865 			/*
866 			 * If there are any key,mask pairs in a sibling
867 			 * duped-key chain, some subset will appear sorted
868 			 * in the same order attached to our mklist
869 			 */
870 			for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
871 				if (m == x->rn_mklist) {
872 					struct radix_mask *mm = m->rm_mklist;
873 					x->rn_mklist = 0;
874 					if (--(m->rm_refs) < 0)
875 						MKFree(m);
876 					m = mm;
877 				}
878 			if (m != NULL) {
879 #ifdef DEBUG
880 				logbad(1, "rn_delete: Orphaned Mask %p at %p\n",
881 				    m, x);
882 #else
883 				msglog("rn_delete: Orphaned Mask %p at %p\n", m,
884 				    x);
885 #endif
886 			}
887 		}
888 	}
889 	/*
890 	 * We may be holding an active internal node in the tree.
891 	 */
892 	x = tt + 1;
893 	if (t != x) {
894 #ifndef RN_DEBUG
895 		*t = *x;
896 #else
897 		b = t->rn_info;
898 		*t = *x;
899 		t->rn_info = b;
900 #endif
901 		t->rn_l->rn_p = t;
902 		t->rn_r->rn_p = t;
903 		p = x->rn_p;
904 		if (p->rn_l == x)
905 			p->rn_l = t;
906 		else
907 			p->rn_r = t;
908 	}
909 out:
910 	tt->rn_flags &= ~RNF_ACTIVE;
911 	tt[1].rn_flags &= ~RNF_ACTIVE;
912 	return (tt);
913 }
914 
915 int
rn_walktree(struct radix_node_head * h,int (* f)(struct radix_node *,void *),void * w)916 rn_walktree(struct radix_node_head *h,
917     int (*f)(struct radix_node *, void *),
918     void *w)
919 {
920 	int error;
921 	struct radix_node *base, *next;
922 	struct radix_node *rn = h->rnh_treetop;
923 	/*
924 	 * This gets complicated because we may delete the node
925 	 * while applying the function f to it, so we need to calculate
926 	 * the successor node in advance.
927 	 */
928 	/* First time through node, go left */
929 	while (rn->rn_b >= 0)
930 		rn = rn->rn_l;
931 	do {
932 		base = rn;
933 		/* If at right child go back up, otherwise, go right */
934 		while (rn->rn_p->rn_r == rn && !(rn->rn_flags & RNF_ROOT))
935 			rn = rn->rn_p;
936 		/* Find the next *leaf* since next node might vanish, too */
937 		for (rn = rn->rn_p->rn_r; rn->rn_b >= 0; )
938 			rn = rn->rn_l;
939 		next = rn;
940 		/* Process leaves */
941 		while ((rn = base) != NULL) {
942 			base = rn->rn_dupedkey;
943 			if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
944 				return (error);
945 		}
946 		rn = next;
947 	} while (!(rn->rn_flags & RNF_ROOT));
948 	return (0);
949 }
950 
951 int
rn_inithead(void ** head,uint_t off)952 rn_inithead(void **head, uint_t off)
953 {
954 	struct radix_node_head *rnh;
955 	struct radix_node *t, *tt, *ttt;
956 	if (*head)
957 		return (1);
958 	rnh = rtmalloc(sizeof (*rnh), "rn_inithead");
959 	(void) memset(rnh, 0, sizeof (*rnh));
960 	*head = rnh;
961 	t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
962 	ttt = rnh->rnh_nodes + 2;
963 	t->rn_r = ttt;
964 	t->rn_p = t;
965 	tt = t->rn_l;
966 	tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
967 	tt->rn_b = -1 - off;
968 	*ttt = *tt;
969 	ttt->rn_key = rn_ones;
970 	rnh->rnh_addaddr = rn_addroute;
971 	rnh->rnh_deladdr = rn_delete;
972 	rnh->rnh_matchaddr = rn_match;
973 	rnh->rnh_lookup = rn_lookup;
974 	rnh->rnh_walktree = rn_walktree;
975 	rnh->rnh_treetop = t;
976 	return (1);
977 }
978 
979 void
rn_init(void)980 rn_init(void)
981 {
982 	uint8_t *cp, *cplim;
983 
984 	if (max_keylen == 0) {
985 		logbad(1, "radix functions require max_keylen be set");
986 		return;
987 	}
988 	rn_zeros = rtmalloc(3 * max_keylen, "rn_init");
989 	(void) memset(rn_zeros, 0, 3 * max_keylen);
990 	rn_ones = cp = rn_zeros + max_keylen;
991 	addmask_key = cplim = rn_ones + max_keylen;
992 	while (cp < cplim)
993 		*cp++ = 0xFF;
994 	if (rn_inithead((void **)&mask_rnhead, 0) == 0) {
995 		logbad(0, "rn_init: could not initialize radix tree");
996 	}
997 }
998