xref: /dragonfly/sys/net/radix.c (revision db299a73)
1 /*
2  * Copyright (c) 1988, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)radix.c	8.4 (Berkeley) 11/2/94
30  * $FreeBSD: src/sys/net/radix.c,v 1.20.2.3 2002/04/28 05:40:25 suz Exp $
31  */
32 
33 /*
34  * Routines to build and maintain radix trees for routing lookups.
35  */
36 #include <sys/param.h>
37 #ifdef	_KERNEL
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/domain.h>
41 #include <sys/globaldata.h>
42 #include <sys/thread.h>
43 #else
44 #include <stdlib.h>
45 #endif
46 #include <sys/syslog.h>
47 #include <net/radix.h>
48 
49 /*
50  * The arguments to the radix functions are really counted byte arrays with
51  * the length in the first byte.  struct sockaddr's fit this type structurally.
52  */
53 #define clen(c)	(*(u_char *)(c))
54 
55 static int rn_walktree_from(struct radix_node_head *h, char *a, char *m,
56 			    walktree_f_t *f, void *w);
57 static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
58 
59 static struct radix_node
60     *rn_insert(char *, struct radix_node_head *, boolean_t *,
61 	       struct radix_node [2]),
62     *rn_newpair(char *, int, struct radix_node[2]),
63     *rn_search(const char *, struct radix_node *),
64     *rn_search_m(const char *, struct radix_node *, const char *);
65 
66 static struct radix_mask *rn_mkfreelist[MAXCPU];
67 static struct radix_node_head *mask_rnheads[MAXCPU];
68 
69 static char rn_zeros[RN_MAXKEYLEN];
70 static char rn_ones[RN_MAXKEYLEN] = RN_MAXKEYONES;
71 
72 static boolean_t rn_lexobetter(char *m, char *n);
73 static struct radix_mask *
74     rn_new_radix_mask(struct radix_node *tt, struct radix_mask *nextmask);
75 static boolean_t
76     rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip);
77 
78 static __inline struct radix_mask *
79 MKGet(struct radix_mask **l)
80 {
81 	struct radix_mask *m;
82 
83 	if (*l != NULL) {
84 		m = *l;
85 		*l = m->rm_next;
86 	} else {
87 		R_Malloc(m, struct radix_mask *, sizeof *m);
88 	}
89 	return m;
90 }
91 
92 static __inline void
93 MKFree(struct radix_mask **l, struct radix_mask *m)
94 {
95 	m->rm_next = *l;
96 	*l = m;
97 }
98 
99 /*
100  * The data structure for the keys is a radix tree with one way
101  * branching removed.  The index rn_bit at an internal node n represents a bit
102  * position to be tested.  The tree is arranged so that all descendants
103  * of a node n have keys whose bits all agree up to position rn_bit - 1.
104  * (We say the index of n is rn_bit.)
105  *
106  * There is at least one descendant which has a one bit at position rn_bit,
107  * and at least one with a zero there.
108  *
109  * A route is determined by a pair of key and mask.  We require that the
110  * bit-wise logical and of the key and mask to be the key.
111  * We define the index of a route to associated with the mask to be
112  * the first bit number in the mask where 0 occurs (with bit number 0
113  * representing the highest order bit).
114  *
115  * We say a mask is normal if every bit is 0, past the index of the mask.
116  * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
117  * and m is a normal mask, then the route applies to every descendant of n.
118  * If the index(m) < rn_bit, this implies the trailing last few bits of k
119  * before bit b are all 0, (and hence consequently true of every descendant
120  * of n), so the route applies to all descendants of the node as well.
121  *
122  * Similar logic shows that a non-normal mask m such that
123  * index(m) <= index(n) could potentially apply to many children of n.
124  * Thus, for each non-host route, we attach its mask to a list at an internal
125  * node as high in the tree as we can go.
126  *
127  * The present version of the code makes use of normal routes in short-
128  * circuiting an explict mask and compare operation when testing whether
129  * a key satisfies a normal route, and also in remembering the unique leaf
130  * that governs a subtree.
131  */
132 
133 static struct radix_node *
134 rn_search(const char *v, struct radix_node *head)
135 {
136 	struct radix_node *x;
137 
138 	x = head;
139 	while (x->rn_bit >= 0) {
140 		if (x->rn_bmask & v[x->rn_offset])
141 			x = x->rn_right;
142 		else
143 			x = x->rn_left;
144 	}
145 	return (x);
146 }
147 
148 static struct radix_node *
149 rn_search_m(const char *v, struct radix_node *head, const char *m)
150 {
151 	struct radix_node *x;
152 
153 	for (x = head; x->rn_bit >= 0;) {
154 		if ((x->rn_bmask & m[x->rn_offset]) &&
155 		    (x->rn_bmask & v[x->rn_offset]))
156 			x = x->rn_right;
157 		else
158 			x = x->rn_left;
159 	}
160 	return x;
161 }
162 
163 boolean_t
164 rn_refines(char *m, char *n)
165 {
166 	char *lim, *lim2;
167 	int longer = clen(n++) - clen(m++);
168 	boolean_t masks_are_equal = TRUE;
169 
170 	lim2 = lim = n + clen(n);
171 	if (longer > 0)
172 		lim -= longer;
173 	while (n < lim) {
174 		if (*n & ~(*m))
175 			return FALSE;
176 		if (*n++ != *m++)
177 			masks_are_equal = FALSE;
178 	}
179 	while (n < lim2)
180 		if (*n++)
181 			return FALSE;
182 	if (masks_are_equal && (longer < 0))
183 		for (lim2 = m - longer; m < lim2; )
184 			if (*m++)
185 				return TRUE;
186 	return (!masks_are_equal);
187 }
188 
189 struct radix_node *
190 rn_lookup(char *key, char *mask, struct radix_node_head *head)
191 {
192 	struct radix_node *x;
193 	char *netmask = NULL;
194 
195 	if (mask != NULL) {
196 		x = rn_addmask(mask, TRUE, head->rnh_treetop->rn_offset,
197 			       head->rnh_maskhead);
198 		if (x == NULL)
199 			return (NULL);
200 		netmask = x->rn_key;
201 	}
202 	x = rn_match(key, head);
203 	if (x != NULL && netmask != NULL) {
204 		while (x != NULL && x->rn_mask != netmask)
205 			x = x->rn_dupedkey;
206 	}
207 	return x;
208 }
209 
210 static boolean_t
211 rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip)
212 {
213 	char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
214 	char *cplim;
215 	int length = min(clen(cp), clen(cp2));
216 
217 	if (cp3 == NULL)
218 		cp3 = rn_ones;
219 	else
220 		length = min(length, clen(cp3));
221 	cplim = cp + length;
222 	cp3 += skip;
223 	cp2 += skip;
224 	for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
225 		if ((*cp ^ *cp2) & *cp3)
226 			return FALSE;
227 	return TRUE;
228 }
229 
230 struct radix_node *
231 rn_match(char *key, struct radix_node_head *head)
232 {
233 	struct radix_node *t, *x;
234 	char *cp = key, *cp2;
235 	char *cplim;
236 	struct radix_node *saved_t, *top = head->rnh_treetop;
237 	int off = top->rn_offset, klen, matched_off;
238 	int test, b, rn_bit;
239 
240 	t = rn_search(key, top);
241 	/*
242 	 * See if we match exactly as a host destination
243 	 * or at least learn how many bits match, for normal mask finesse.
244 	 *
245 	 * It doesn't hurt us to limit how many bytes to check
246 	 * to the length of the mask, since if it matches we had a genuine
247 	 * match and the leaf we have is the most specific one anyway;
248 	 * if it didn't match with a shorter length it would fail
249 	 * with a long one.  This wins big for class B&C netmasks which
250 	 * are probably the most common case...
251 	 */
252 	if (t->rn_mask != NULL)
253 		klen = clen(t->rn_mask);
254 	else
255 		klen = clen(key);
256 	cp += off; cp2 = t->rn_key + off; cplim = key + klen;
257 	for (; cp < cplim; cp++, cp2++)
258 		if (*cp != *cp2)
259 			goto on1;
260 	/*
261 	 * This extra grot is in case we are explicitly asked
262 	 * to look up the default.  Ugh!
263 	 *
264 	 * Never return the root node itself, it seems to cause a
265 	 * lot of confusion.
266 	 */
267 	if (t->rn_flags & RNF_ROOT)
268 		t = t->rn_dupedkey;
269 	return t;
270 on1:
271 	test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
272 	for (b = 7; (test >>= 1) > 0;)
273 		b--;
274 	matched_off = cp - key;
275 	b += matched_off << 3;
276 	rn_bit = -1 - b;
277 	/*
278 	 * If there is a host route in a duped-key chain, it will be first.
279 	 */
280 	if ((saved_t = t)->rn_mask == NULL)
281 		t = t->rn_dupedkey;
282 	for (; t; t = t->rn_dupedkey) {
283 		/*
284 		 * Even if we don't match exactly as a host,
285 		 * we may match if the leaf we wound up at is
286 		 * a route to a net.
287 		 */
288 		if (t->rn_flags & RNF_NORMAL) {
289 			if (rn_bit <= t->rn_bit)
290 				return t;
291 		} else if (rn_satisfies_leaf(key, t, matched_off))
292 				return t;
293 	}
294 	t = saved_t;
295 	/* start searching up the tree */
296 	do {
297 		struct radix_mask *m;
298 
299 		t = t->rn_parent;
300 		/*
301 		 * If non-contiguous masks ever become important
302 		 * we can restore the masking and open coding of
303 		 * the search and satisfaction test and put the
304 		 * calculation of "off" back before the "do".
305 		 */
306 		m = t->rn_mklist;
307 		while (m != NULL) {
308 			if (m->rm_flags & RNF_NORMAL) {
309 				if (rn_bit <= m->rm_bit)
310 					return (m->rm_leaf);
311 			} else {
312 				off = min(t->rn_offset, matched_off);
313 				x = rn_search_m(key, t, m->rm_mask);
314 				while (x != NULL && x->rn_mask != m->rm_mask)
315 					x = x->rn_dupedkey;
316 				if (x && rn_satisfies_leaf(key, x, off))
317 					return x;
318 			}
319 			m = m->rm_next;
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 =  TRUE;
330 #endif
331 
332 static struct radix_node *
333 rn_newpair(char *key, int indexbit, struct radix_node nodes[2])
334 {
335 	struct radix_node *leaf = &nodes[0], *interior = &nodes[1];
336 
337 	interior->rn_bit = indexbit;
338 	interior->rn_bmask = 0x80 >> (indexbit & 0x7);
339 	interior->rn_offset = indexbit >> 3;
340 	interior->rn_left = leaf;
341 	interior->rn_mklist = NULL;
342 
343 	leaf->rn_bit = -1;
344 	leaf->rn_key = key;
345 	leaf->rn_parent = interior;
346 	leaf->rn_flags = interior->rn_flags = RNF_ACTIVE;
347 	leaf->rn_mklist = NULL;
348 
349 #ifdef RN_DEBUG
350 	leaf->rn_info = rn_nodenum++;
351 	interior->rn_info = rn_nodenum++;
352 	leaf->rn_twin = interior;
353 	leaf->rn_ybro = rn_clist;
354 	rn_clist = leaf;
355 #endif
356 	return interior;
357 }
358 
359 static struct radix_node *
360 rn_insert(char *key, struct radix_node_head *head, boolean_t *dupentry,
361 	  struct radix_node nodes[2])
362 {
363 	struct radix_node *top = head->rnh_treetop;
364 	int head_off = top->rn_offset, klen = clen(key);
365 	struct radix_node *t = rn_search(key, top);
366 	char *cp = key + head_off;
367 	int b;
368 	struct radix_node *tt;
369 
370 	/*
371 	 * Find first bit at which the key and t->rn_key differ
372 	 */
373     {
374 	char *cp2 = t->rn_key + head_off;
375 	int cmp_res;
376 	char *cplim = key + klen;
377 
378 	while (cp < cplim)
379 		if (*cp2++ != *cp++)
380 			goto on1;
381 	*dupentry = TRUE;
382 	return t;
383 on1:
384 	*dupentry = FALSE;
385 	cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
386 	for (b = (cp - key) << 3; cmp_res; b--)
387 		cmp_res >>= 1;
388     }
389     {
390 	struct radix_node *p, *x = top;
391 
392 	cp = key;
393 	do {
394 		p = x;
395 		if (cp[x->rn_offset] & x->rn_bmask)
396 			x = x->rn_right;
397 		else
398 			x = x->rn_left;
399 	} while (b > (unsigned) x->rn_bit);
400 				/* x->rn_bit < b && x->rn_bit >= 0 */
401 #ifdef RN_DEBUG
402 	if (rn_debug)
403 		log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
404 #endif
405 	t = rn_newpair(key, b, nodes);
406 	tt = t->rn_left;
407 	if ((cp[p->rn_offset] & p->rn_bmask) == 0)
408 		p->rn_left = t;
409 	else
410 		p->rn_right = t;
411 	x->rn_parent = t;
412 	t->rn_parent = p; /* frees x, p as temp vars below */
413 	if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
414 		t->rn_right = x;
415 	} else {
416 		t->rn_right = tt;
417 		t->rn_left = x;
418 	}
419 #ifdef RN_DEBUG
420 	if (rn_debug)
421 		log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
422 #endif
423     }
424 	return (tt);
425 }
426 
427 struct radix_node *
428 rn_addmask(char *netmask, boolean_t search, int skip,
429 	   struct radix_node_head *mask_rnh)
430 {
431 	struct radix_node *x, *saved_x;
432 	char *cp, *cplim;
433 	int b = 0, mlen, m0, j;
434 	boolean_t maskduplicated, isnormal;
435 	char *addmask_key;
436 
437 	if ((mlen = clen(netmask)) > RN_MAXKEYLEN)
438 		mlen = RN_MAXKEYLEN;
439 	if (skip == 0)
440 		skip = 1;
441 	if (mlen <= skip)
442 		return (mask_rnh->rnh_nodes);
443 	R_Malloc(addmask_key, char *, RN_MAXKEYLEN);
444 	if (addmask_key == NULL)
445 		return NULL;
446 	if (skip > 1)
447 		bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
448 	if ((m0 = mlen) > skip)
449 		bcopy(netmask + skip, addmask_key + 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 >= mask_rnh->rnh_last_zeroed)
458 			mask_rnh->rnh_last_zeroed = mlen;
459 		Free(addmask_key);
460 		return (mask_rnh->rnh_nodes);
461 	}
462 	if (m0 < mask_rnh->rnh_last_zeroed)
463 		bzero(addmask_key + m0, mask_rnh->rnh_last_zeroed - m0);
464 	*addmask_key = mask_rnh->rnh_last_zeroed = mlen;
465 	x = rn_search(addmask_key, mask_rnh->rnh_treetop);
466 	if (x->rn_key == NULL) {
467 		kprintf("WARNING: radix_node->rn_key is NULL rn=%p\n", x);
468 		print_backtrace(-1);
469 		x = NULL;
470 	} else if (bcmp(addmask_key, x->rn_key, mlen) != 0) {
471 		x = NULL;
472 	}
473 	if (x != NULL || search)
474 		goto out;
475 	R_Malloc(x, struct radix_node *, RN_MAXKEYLEN + 2 * (sizeof *x));
476 	if ((saved_x = x) == NULL)
477 		goto out;
478 	bzero(x, RN_MAXKEYLEN + 2 * (sizeof *x));
479 	netmask = cp = (char *)(x + 2);
480 	bcopy(addmask_key, cp, mlen);
481 	x = rn_insert(cp, mask_rnh, &maskduplicated, x);
482 	if (maskduplicated) {
483 		log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
484 		Free(saved_x);
485 		goto out;
486 	}
487 	/*
488 	 * Calculate index of mask, and check for normalcy.
489 	 */
490 	isnormal = TRUE;
491 	cplim = netmask + mlen;
492 	for (cp = netmask + skip; cp < cplim && clen(cp) == 0xff;)
493 		cp++;
494 	if (cp != cplim) {
495 		static const char normal_chars[] = {
496 			0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1
497 		};
498 
499 		for (j = 0x80; (j & *cp) != 0; j >>= 1)
500 			b++;
501 		if (*cp != normal_chars[b] || cp != (cplim - 1))
502 			isnormal = FALSE;
503 	}
504 	b += (cp - netmask) << 3;
505 	x->rn_bit = -1 - b;
506 	if (isnormal)
507 		x->rn_flags |= RNF_NORMAL;
508 out:
509 	Free(addmask_key);
510 	return (x);
511 }
512 
513 /* XXX: arbitrary ordering for non-contiguous masks */
514 static boolean_t
515 rn_lexobetter(char *mp, char *np)
516 {
517 	char *lim;
518 
519 	if ((unsigned) *mp > (unsigned) *np)
520 		return TRUE;/* not really, but need to check longer one first */
521 	if (*mp == *np)
522 		for (lim = mp + clen(mp); mp < lim;)
523 			if (*mp++ > *np++)
524 				return TRUE;
525 	return FALSE;
526 }
527 
528 static struct radix_mask *
529 rn_new_radix_mask(struct radix_node *tt, struct radix_mask *nextmask)
530 {
531 	struct radix_mask *m;
532 
533 	m = MKGet(&rn_mkfreelist[mycpuid]);
534 	if (m == NULL) {
535 		log(LOG_ERR, "Mask for route not entered\n");
536 		return (NULL);
537 	}
538 	bzero(m, sizeof *m);
539 	m->rm_bit = tt->rn_bit;
540 	m->rm_flags = tt->rn_flags;
541 	if (tt->rn_flags & RNF_NORMAL)
542 		m->rm_leaf = tt;
543 	else
544 		m->rm_mask = tt->rn_mask;
545 	m->rm_next = nextmask;
546 	tt->rn_mklist = m;
547 	return m;
548 }
549 
550 struct radix_node *
551 rn_addroute(char *key, char *netmask, struct radix_node_head *head,
552 	    struct radix_node treenodes[2])
553 {
554 	struct radix_node *t, *x = NULL, *tt;
555 	struct radix_node *saved_tt, *top = head->rnh_treetop;
556 	short b = 0, b_leaf = 0;
557 	boolean_t keyduplicated;
558 	char *mmask;
559 	struct radix_mask *m, **mp;
560 
561 	/*
562 	 * In dealing with non-contiguous masks, there may be
563 	 * many different routes which have the same mask.
564 	 * We will find it useful to have a unique pointer to
565 	 * the mask to speed avoiding duplicate references at
566 	 * nodes and possibly save time in calculating indices.
567 	 */
568 	if (netmask != NULL)  {
569 		if ((x = rn_addmask(netmask, FALSE, top->rn_offset,
570 				    head->rnh_maskhead)) == NULL)
571 			return (NULL);
572 		b_leaf = x->rn_bit;
573 		b = -1 - x->rn_bit;
574 		netmask = x->rn_key;
575 	}
576 	/*
577 	 * Deal with duplicated keys: attach node to previous instance
578 	 */
579 	saved_tt = tt = rn_insert(key, head, &keyduplicated, treenodes);
580 	if (keyduplicated) {
581 		for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
582 			if (tt->rn_mask == netmask)
583 				return (NULL);
584 			if (netmask == NULL ||
585 			    (tt->rn_mask &&
586 			     ((b_leaf < tt->rn_bit) /* index(netmask) > node */
587 			      || rn_refines(netmask, tt->rn_mask)
588 			      || rn_lexobetter(netmask, tt->rn_mask))))
589 				break;
590 		}
591 		/*
592 		 * If the mask is not duplicated, we wouldn't
593 		 * find it among possible duplicate key entries
594 		 * anyway, so the above test doesn't hurt.
595 		 *
596 		 * We sort the masks for a duplicated key the same way as
597 		 * in a masklist -- most specific to least specific.
598 		 * This may require the unfortunate nuisance of relocating
599 		 * the head of the list.
600 		 */
601 		if (tt == saved_tt) {
602 			struct	radix_node *xx = x;
603 			/* link in at head of list */
604 			(tt = treenodes)->rn_dupedkey = t;
605 			tt->rn_flags = t->rn_flags;
606 			tt->rn_parent = x = t->rn_parent;
607 			t->rn_parent = tt;			/* parent */
608 			if (x->rn_left == t)
609 				x->rn_left = tt;
610 			else
611 				x->rn_right = tt;
612 			saved_tt = tt; x = xx;
613 		} else {
614 			(tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
615 			t->rn_dupedkey = tt;
616 			tt->rn_parent = t;			/* parent */
617 			if (tt->rn_dupedkey != NULL)		/* parent */
618 				tt->rn_dupedkey->rn_parent = tt; /* parent */
619 		}
620 #ifdef RN_DEBUG
621 		t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
622 		tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
623 #endif
624 		tt->rn_key = key;
625 		tt->rn_bit = -1;
626 		tt->rn_flags = RNF_ACTIVE;
627 	}
628 	/*
629 	 * Put mask in tree.
630 	 */
631 	if (netmask != NULL) {
632 		tt->rn_mask = netmask;
633 		tt->rn_bit = x->rn_bit;
634 		tt->rn_flags |= x->rn_flags & RNF_NORMAL;
635 	}
636 	t = saved_tt->rn_parent;
637 	if (keyduplicated)
638 		goto on2;
639 	b_leaf = -1 - t->rn_bit;
640 	if (t->rn_right == saved_tt)
641 		x = t->rn_left;
642 	else
643 		x = t->rn_right;
644 	/* Promote general routes from below */
645 	if (x->rn_bit < 0) {
646 		mp = &t->rn_mklist;
647 		while (x != NULL) {
648 			if (x->rn_mask != NULL &&
649 			    x->rn_bit >= b_leaf &&
650 			    x->rn_mklist == NULL) {
651 				*mp = m = rn_new_radix_mask(x, NULL);
652 				if (m != NULL)
653 					mp = &m->rm_next;
654 			}
655 			x = x->rn_dupedkey;
656 		}
657 	} else if (x->rn_mklist != NULL) {
658 		/*
659 		 * Skip over masks whose index is > that of new node
660 		 */
661 		for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_next)
662 			if (m->rm_bit >= b_leaf)
663 				break;
664 		t->rn_mklist = m;
665 		*mp = NULL;
666 	}
667 on2:
668 	/* Add new route to highest possible ancestor's list */
669 	if ((netmask == NULL) || (b > t->rn_bit ))
670 		return tt; /* can't lift at all */
671 	b_leaf = tt->rn_bit;
672 	do {
673 		x = t;
674 		t = t->rn_parent;
675 	} while (b <= t->rn_bit && x != top);
676 	/*
677 	 * Search through routes associated with node to
678 	 * insert new route according to index.
679 	 * Need same criteria as when sorting dupedkeys to avoid
680 	 * double loop on deletion.
681 	 */
682 	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_next) {
683 		if (m->rm_bit < b_leaf)
684 			continue;
685 		if (m->rm_bit > b_leaf)
686 			break;
687 		if (m->rm_flags & RNF_NORMAL) {
688 			mmask = m->rm_leaf->rn_mask;
689 			if (tt->rn_flags & RNF_NORMAL) {
690 			    log(LOG_ERR,
691 			        "Non-unique normal route, mask not entered\n");
692 				return tt;
693 			}
694 		} else
695 			mmask = m->rm_mask;
696 		if (mmask == netmask) {
697 			m->rm_refs++;
698 			tt->rn_mklist = m;
699 			return tt;
700 		}
701 		if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
702 			break;
703 	}
704 	*mp = rn_new_radix_mask(tt, *mp);
705 	return tt;
706 }
707 
708 struct radix_node *
709 rn_delete(char *key, char *netmask, struct radix_node_head *head)
710 {
711 	struct radix_node *t, *p, *x, *tt;
712 	struct radix_mask *m, *saved_m, **mp;
713 	struct radix_node *dupedkey, *saved_tt, *top;
714 	int b, head_off, klen;
715 	int cpu = mycpuid;
716 
717 	x = head->rnh_treetop;
718 	tt = rn_search(key, x);
719 	head_off = x->rn_offset;
720 	klen =  clen(key);
721 	saved_tt = tt;
722 	top = x;
723 	if (tt == NULL ||
724 	    bcmp(key + head_off, tt->rn_key + head_off, klen - head_off))
725 		return (NULL);
726 	/*
727 	 * Delete our route from mask lists.
728 	 */
729 	if (netmask != NULL) {
730 		if ((x = rn_addmask(netmask, TRUE, head_off,
731 				    head->rnh_maskhead)) == NULL)
732 			return (NULL);
733 		netmask = x->rn_key;
734 		while (tt->rn_mask != netmask)
735 			if ((tt = tt->rn_dupedkey) == NULL)
736 				return (NULL);
737 	}
738 	if (tt->rn_mask == NULL || (saved_m = m = tt->rn_mklist) == NULL)
739 		goto on1;
740 	if (tt->rn_flags & RNF_NORMAL) {
741 		if (m->rm_leaf != tt || m->rm_refs > 0) {
742 			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
743 			return (NULL);  /* dangling ref could cause disaster */
744 		}
745 	} else {
746 		if (m->rm_mask != tt->rn_mask) {
747 			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
748 			goto on1;
749 		}
750 		if (--m->rm_refs >= 0)
751 			goto on1;
752 	}
753 	b = -1 - tt->rn_bit;
754 	t = saved_tt->rn_parent;
755 	if (b > t->rn_bit)
756 		goto on1; /* Wasn't lifted at all */
757 	do {
758 		x = t;
759 		t = t->rn_parent;
760 	} while (b <= t->rn_bit && x != top);
761 	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_next)
762 		if (m == saved_m) {
763 			*mp = m->rm_next;
764 			MKFree(&rn_mkfreelist[cpu], m);
765 			break;
766 		}
767 	if (m == NULL) {
768 		log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
769 		if (tt->rn_flags & RNF_NORMAL)
770 			return (NULL); /* Dangling ref to us */
771 	}
772 on1:
773 	/*
774 	 * Eliminate us from tree
775 	 */
776 	if (tt->rn_flags & RNF_ROOT)
777 		return (NULL);
778 #ifdef RN_DEBUG
779 	/* Get us out of the creation list */
780 	for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
781 	if (t) t->rn_ybro = tt->rn_ybro;
782 #endif
783 	t = tt->rn_parent;
784 	dupedkey = saved_tt->rn_dupedkey;
785 	if (dupedkey != NULL) {
786 		/*
787 		 * at this point, tt is the deletion target and saved_tt
788 		 * is the head of the dupekey chain
789 		 */
790 		if (tt == saved_tt) {
791 			/* remove from head of chain */
792 			x = dupedkey; x->rn_parent = t;
793 			if (t->rn_left == tt)
794 				t->rn_left = x;
795 			else
796 				t->rn_right = x;
797 		} else {
798 			/* find node in front of tt on the chain */
799 			for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
800 				p = p->rn_dupedkey;
801 			if (p) {
802 				p->rn_dupedkey = tt->rn_dupedkey;
803 				if (tt->rn_dupedkey)		/* parent */
804 					tt->rn_dupedkey->rn_parent = p;
805 								/* parent */
806 			} else log(LOG_ERR, "rn_delete: couldn't find us\n");
807 		}
808 		t = tt + 1;
809 		if  (t->rn_flags & RNF_ACTIVE) {
810 #ifndef RN_DEBUG
811 			*++x = *t;
812 			p = t->rn_parent;
813 #else
814 			b = t->rn_info;
815 			*++x = *t;
816 			t->rn_info = b;
817 			p = t->rn_parent;
818 #endif
819 			if (p->rn_left == t)
820 				p->rn_left = x;
821 			else
822 				p->rn_right = x;
823 			x->rn_left->rn_parent = x;
824 			x->rn_right->rn_parent = x;
825 		}
826 		goto out;
827 	}
828 	if (t->rn_left == tt)
829 		x = t->rn_right;
830 	else
831 		x = t->rn_left;
832 	p = t->rn_parent;
833 	if (p->rn_right == t)
834 		p->rn_right = x;
835 	else
836 		p->rn_left = x;
837 	x->rn_parent = p;
838 	/*
839 	 * Demote routes attached to us.
840 	 */
841 	if (t->rn_mklist != NULL) {
842 		if (x->rn_bit >= 0) {
843 			for (mp = &x->rn_mklist; (m = *mp);)
844 				mp = &m->rm_next;
845 			*mp = t->rn_mklist;
846 		} else {
847 			/*
848 			 * If there are any (key, mask) pairs in a sibling
849 			 * duped-key chain, some subset will appear sorted
850 			 * in the same order attached to our mklist.
851 			 */
852 			for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
853 				if (m == x->rn_mklist) {
854 					struct radix_mask *mm = m->rm_next;
855 
856 					x->rn_mklist = NULL;
857 					if (--(m->rm_refs) < 0)
858 						MKFree(&rn_mkfreelist[cpu], m);
859 					m = mm;
860 				}
861 			if (m)
862 				log(LOG_ERR,
863 				    "rn_delete: Orphaned Mask %p at %p\n",
864 				    (void *)m, (void *)x);
865 		}
866 	}
867 	/*
868 	 * We may be holding an active internal node in the tree.
869 	 */
870 	x = tt + 1;
871 	if (t != x) {
872 #ifndef RN_DEBUG
873 		*t = *x;
874 #else
875 		b = t->rn_info;
876 		*t = *x;
877 		t->rn_info = b;
878 #endif
879 		t->rn_left->rn_parent = t;
880 		t->rn_right->rn_parent = t;
881 		p = x->rn_parent;
882 		if (p->rn_left == x)
883 			p->rn_left = t;
884 		else
885 			p->rn_right = t;
886 	}
887 out:
888 	tt->rn_flags &= ~RNF_ACTIVE;
889 	tt[1].rn_flags &= ~RNF_ACTIVE;
890 	return (tt);
891 }
892 
893 /*
894  * This is the same as rn_walktree() except for the parameters and the
895  * exit.
896  */
897 static int
898 rn_walktree_from(struct radix_node_head *h, char *xa, char *xm,
899 		 walktree_f_t *f, void *w)
900 {
901 	struct radix_node *base, *next;
902 	struct radix_node *rn, *last = NULL /* shut up gcc */;
903 	boolean_t stopping = FALSE;
904 	int lastb, error;
905 
906 	/*
907 	 * rn_search_m is sort-of-open-coded here.
908 	 */
909 	/* kprintf("about to search\n"); */
910 	for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
911 		last = rn;
912 		/* kprintf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n",
913 		       rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */
914 		if (!(rn->rn_bmask & xm[rn->rn_offset])) {
915 			break;
916 		}
917 		if (rn->rn_bmask & xa[rn->rn_offset]) {
918 			rn = rn->rn_right;
919 		} else {
920 			rn = rn->rn_left;
921 		}
922 	}
923 	/* kprintf("done searching\n"); */
924 
925 	/*
926 	 * Two cases: either we stepped off the end of our mask,
927 	 * in which case last == rn, or we reached a leaf, in which
928 	 * case we want to start from the last node we looked at.
929 	 * Either way, last is the node we want to start from.
930 	 */
931 	rn = last;
932 	lastb = rn->rn_bit;
933 
934 	/* kprintf("rn %p, lastb %d\n", rn, lastb);*/
935 
936 	/*
937 	 * This gets complicated because we may delete the node
938 	 * while applying the function f to it, so we need to calculate
939 	 * the successor node in advance.
940 	 */
941 	while (rn->rn_bit >= 0)
942 		rn = rn->rn_left;
943 
944 	while (!stopping) {
945 		/* kprintf("node %p (%d)\n", rn, rn->rn_bit); */
946 		base = rn;
947 		/* If at right child go back up, otherwise, go right */
948 		while (rn->rn_parent->rn_right == rn &&
949 		    !(rn->rn_flags & RNF_ROOT)) {
950 			rn = rn->rn_parent;
951 
952 			/* if went up beyond last, stop */
953 			if (rn->rn_bit < lastb) {
954 				stopping = TRUE;
955 				/* kprintf("up too far\n"); */
956 			}
957 		}
958 
959 		/* Find the next *leaf* since next node might vanish, too */
960 		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
961 			rn = rn->rn_left;
962 		next = rn;
963 		/* Process leaves */
964 		while ((rn = base) != NULL) {
965 			base = rn->rn_dupedkey;
966 			/* kprintf("leaf %p\n", rn); */
967 			if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
968 				return (error);
969 		}
970 		rn = next;
971 
972 		if (rn->rn_flags & RNF_ROOT) {
973 			/* kprintf("root, stopping"); */
974 			stopping = TRUE;
975 		}
976 
977 	}
978 	return 0;
979 }
980 
981 static int
982 rn_walktree(struct radix_node_head *h, walktree_f_t *f, void *w)
983 {
984 	struct radix_node *base, *next;
985 	struct radix_node *rn = h->rnh_treetop;
986 	int error;
987 
988 	/*
989 	 * This gets complicated because we may delete the node
990 	 * while applying the function f to it, so we need to calculate
991 	 * the successor node in advance.
992 	 */
993 	/* First time through node, go left */
994 	while (rn->rn_bit >= 0)
995 		rn = rn->rn_left;
996 	for (;;) {
997 		base = rn;
998 		/* If at right child go back up, otherwise, go right */
999 		while (rn->rn_parent->rn_right == rn &&
1000 		    !(rn->rn_flags & RNF_ROOT))
1001 			rn = rn->rn_parent;
1002 		/* Find the next *leaf* since next node might vanish, too */
1003 		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1004 			rn = rn->rn_left;
1005 		next = rn;
1006 		/* Process leaves */
1007 		while ((rn = base)) {
1008 			base = rn->rn_dupedkey;
1009 			if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
1010 				return (error);
1011 		}
1012 		rn = next;
1013 		if (rn->rn_flags & RNF_ROOT)
1014 			return (0);
1015 	}
1016 	/* NOTREACHED */
1017 }
1018 
1019 int
1020 rn_inithead(void **head, struct radix_node_head *maskhead, int off)
1021 {
1022 	struct radix_node_head *rnh;
1023 	struct radix_node *root, *left, *right;
1024 
1025 	if (*head != NULL)	/* already initialized */
1026 		return (1);
1027 
1028 	R_Malloc(rnh, struct radix_node_head *, sizeof *rnh);
1029 	if (rnh == NULL)
1030 		return (0);
1031 	bzero(rnh, sizeof *rnh);
1032 	*head = rnh;
1033 
1034 	root = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
1035 	right = &rnh->rnh_nodes[2];
1036 	root->rn_parent = root;
1037 	root->rn_flags = RNF_ROOT | RNF_ACTIVE;
1038 	root->rn_right = right;
1039 
1040 	left = root->rn_left;
1041 	left->rn_bit = -1 - off;
1042 	left->rn_flags = RNF_ROOT | RNF_ACTIVE;
1043 
1044 	*right = *left;
1045 	right->rn_key = rn_ones;
1046 
1047 	rnh->rnh_treetop = root;
1048 	rnh->rnh_maskhead = maskhead;
1049 
1050 	rnh->rnh_addaddr = rn_addroute;
1051 	rnh->rnh_deladdr = rn_delete;
1052 	rnh->rnh_matchaddr = rn_match;
1053 	rnh->rnh_lookup = rn_lookup;
1054 	rnh->rnh_walktree = rn_walktree;
1055 	rnh->rnh_walktree_from = rn_walktree_from;
1056 
1057 	return (1);
1058 }
1059 
1060 void
1061 rn_init(void)
1062 {
1063 	int cpu;
1064 #ifdef _KERNEL
1065 	struct domain *dom;
1066 
1067 	SLIST_FOREACH(dom, &domains, dom_next) {
1068 		if (dom->dom_maxrtkey > RN_MAXKEYLEN) {
1069 			panic("domain %s maxkey too big %d/%d",
1070 			      dom->dom_name, dom->dom_maxrtkey, RN_MAXKEYLEN);
1071 		}
1072 	}
1073 #endif
1074 	for (cpu = 0; cpu < ncpus; ++cpu) {
1075 		if (rn_inithead((void **)&mask_rnheads[cpu], NULL, 0) == 0)
1076 			panic("rn_init 2");
1077 	}
1078 }
1079 
1080 struct radix_node_head *
1081 rn_cpumaskhead(int cpu)
1082 {
1083 	KKASSERT(mask_rnheads[cpu] != NULL);
1084 	return mask_rnheads[cpu];
1085 }
1086