xref: /dragonfly/sys/net/radix.c (revision 65cc0652)
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 
48 #include <net/radix.h>
49 #include <net/netmsg2.h>
50 #include <net/netisr2.h>
51 
52 /*
53  * The arguments to the radix functions are really counted byte arrays with
54  * the length in the first byte.  struct sockaddr's fit this type structurally.
55  */
56 #define clen(c)	(*(u_char *)(c))
57 
58 static int rn_walktree_from(struct radix_node_head *h, char *a, char *m,
59 			    walktree_f_t *f, void *w);
60 static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
61 static int rn_walktree_at(struct radix_node_head *h, const char *a,
62 			    const char *m, walktree_f_t *f, void *w);
63 
64 static struct radix_node
65     *rn_insert(char *, struct radix_node_head *, boolean_t *,
66 	       struct radix_node [2]),
67     *rn_newpair(char *, int, struct radix_node[2]),
68     *rn_search(const char *, struct radix_node *),
69     *rn_search_m(const char *, struct radix_node *, const char *);
70 
71 static struct radix_mask *rn_mkfreelist[MAXCPU];
72 static struct radix_node_head *mask_rnheads[MAXCPU];
73 
74 static char rn_zeros[RN_MAXKEYLEN];
75 static char rn_ones[RN_MAXKEYLEN] = RN_MAXKEYONES;
76 
77 static boolean_t rn_lexobetter(char *m, char *n);
78 static struct radix_mask *
79     rn_new_radix_mask(struct radix_node *tt, struct radix_mask *nextmask);
80 static boolean_t
81     rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip);
82 
83 static __inline struct radix_mask *
84 MKGet(struct radix_mask **l)
85 {
86 	struct radix_mask *m;
87 
88 	if (*l != NULL) {
89 		m = *l;
90 		*l = m->rm_next;
91 	} else {
92 		R_Malloc(m, struct radix_mask *, sizeof *m);
93 	}
94 	return m;
95 }
96 
97 static __inline void
98 MKFree(struct radix_mask **l, struct radix_mask *m)
99 {
100 	m->rm_next = *l;
101 	*l = m;
102 }
103 
104 /*
105  * The data structure for the keys is a radix tree with one way
106  * branching removed.  The index rn_bit at an internal node n represents a bit
107  * position to be tested.  The tree is arranged so that all descendants
108  * of a node n have keys whose bits all agree up to position rn_bit - 1.
109  * (We say the index of n is rn_bit.)
110  *
111  * There is at least one descendant which has a one bit at position rn_bit,
112  * and at least one with a zero there.
113  *
114  * A route is determined by a pair of key and mask.  We require that the
115  * bit-wise logical and of the key and mask to be the key.
116  * We define the index of a route to associated with the mask to be
117  * the first bit number in the mask where 0 occurs (with bit number 0
118  * representing the highest order bit).
119  *
120  * We say a mask is normal if every bit is 0, past the index of the mask.
121  * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
122  * and m is a normal mask, then the route applies to every descendant of n.
123  * If the index(m) < rn_bit, this implies the trailing last few bits of k
124  * before bit b are all 0, (and hence consequently true of every descendant
125  * of n), so the route applies to all descendants of the node as well.
126  *
127  * Similar logic shows that a non-normal mask m such that
128  * index(m) <= index(n) could potentially apply to many children of n.
129  * Thus, for each non-host route, we attach its mask to a list at an internal
130  * node as high in the tree as we can go.
131  *
132  * The present version of the code makes use of normal routes in short-
133  * circuiting an explict mask and compare operation when testing whether
134  * a key satisfies a normal route, and also in remembering the unique leaf
135  * that governs a subtree.
136  */
137 
138 static struct radix_node *
139 rn_search(const char *v, struct radix_node *head)
140 {
141 	struct radix_node *x;
142 
143 	x = head;
144 	while (x->rn_bit >= 0) {
145 		if (x->rn_bmask & v[x->rn_offset])
146 			x = x->rn_right;
147 		else
148 			x = x->rn_left;
149 	}
150 	return (x);
151 }
152 
153 static struct radix_node *
154 rn_search_m(const char *v, struct radix_node *head, const char *m)
155 {
156 	struct radix_node *x;
157 
158 	for (x = head; x->rn_bit >= 0;) {
159 		if ((x->rn_bmask & m[x->rn_offset]) &&
160 		    (x->rn_bmask & v[x->rn_offset]))
161 			x = x->rn_right;
162 		else
163 			x = x->rn_left;
164 	}
165 	return x;
166 }
167 
168 boolean_t
169 rn_refines(char *m, char *n)
170 {
171 	char *lim, *lim2;
172 	int longer = clen(n++) - clen(m++);
173 	boolean_t masks_are_equal = TRUE;
174 
175 	lim2 = lim = n + clen(n);
176 	if (longer > 0)
177 		lim -= longer;
178 	while (n < lim) {
179 		if (*n & ~(*m))
180 			return FALSE;
181 		if (*n++ != *m++)
182 			masks_are_equal = FALSE;
183 	}
184 	while (n < lim2)
185 		if (*n++)
186 			return FALSE;
187 	if (masks_are_equal && (longer < 0))
188 		for (lim2 = m - longer; m < lim2; )
189 			if (*m++)
190 				return TRUE;
191 	return (!masks_are_equal);
192 }
193 
194 struct radix_node *
195 rn_lookup(char *key, char *mask, struct radix_node_head *head)
196 {
197 	struct radix_node *x;
198 	char *netmask = NULL;
199 
200 	if (mask != NULL) {
201 		x = rn_addmask(mask, TRUE, head->rnh_treetop->rn_offset,
202 			       head->rnh_maskhead);
203 		if (x == NULL)
204 			return (NULL);
205 		netmask = x->rn_key;
206 	}
207 	x = rn_match(key, head);
208 	if (x != NULL && netmask != NULL) {
209 		while (x != NULL && x->rn_mask != netmask)
210 			x = x->rn_dupedkey;
211 	}
212 	return x;
213 }
214 
215 static boolean_t
216 rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip)
217 {
218 	char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
219 	char *cplim;
220 	int length = min(clen(cp), clen(cp2));
221 
222 	if (cp3 == NULL)
223 		cp3 = rn_ones;
224 	else
225 		length = min(length, clen(cp3));
226 	cplim = cp + length;
227 	cp3 += skip;
228 	cp2 += skip;
229 	for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
230 		if ((*cp ^ *cp2) & *cp3)
231 			return FALSE;
232 	return TRUE;
233 }
234 
235 struct radix_node *
236 rn_match(char *key, struct radix_node_head *head)
237 {
238 	struct radix_node *t, *x;
239 	char *cp = key, *cp2;
240 	char *cplim;
241 	struct radix_node *saved_t, *top = head->rnh_treetop;
242 	int off = top->rn_offset, klen, matched_off;
243 	int test, b, rn_bit;
244 
245 	t = rn_search(key, top);
246 	/*
247 	 * See if we match exactly as a host destination
248 	 * or at least learn how many bits match, for normal mask finesse.
249 	 *
250 	 * It doesn't hurt us to limit how many bytes to check
251 	 * to the length of the mask, since if it matches we had a genuine
252 	 * match and the leaf we have is the most specific one anyway;
253 	 * if it didn't match with a shorter length it would fail
254 	 * with a long one.  This wins big for class B&C netmasks which
255 	 * are probably the most common case...
256 	 */
257 	if (t->rn_mask != NULL)
258 		klen = clen(t->rn_mask);
259 	else
260 		klen = clen(key);
261 	cp += off; cp2 = t->rn_key + off; cplim = key + klen;
262 	for (; cp < cplim; cp++, cp2++)
263 		if (*cp != *cp2)
264 			goto on1;
265 	/*
266 	 * This extra grot is in case we are explicitly asked
267 	 * to look up the default.  Ugh!
268 	 *
269 	 * Never return the root node itself, it seems to cause a
270 	 * lot of confusion.
271 	 */
272 	if (t->rn_flags & RNF_ROOT)
273 		t = t->rn_dupedkey;
274 	return t;
275 on1:
276 	test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
277 	for (b = 7; (test >>= 1) > 0;)
278 		b--;
279 	matched_off = cp - key;
280 	b += matched_off << 3;
281 	rn_bit = -1 - b;
282 	/*
283 	 * If there is a host route in a duped-key chain, it will be first.
284 	 */
285 	if ((saved_t = t)->rn_mask == NULL)
286 		t = t->rn_dupedkey;
287 	for (; t; t = t->rn_dupedkey) {
288 		/*
289 		 * Even if we don't match exactly as a host,
290 		 * we may match if the leaf we wound up at is
291 		 * a route to a net.
292 		 */
293 		if (t->rn_flags & RNF_NORMAL) {
294 			if (rn_bit <= t->rn_bit)
295 				return t;
296 		} else if (rn_satisfies_leaf(key, t, matched_off))
297 				return t;
298 	}
299 	t = saved_t;
300 	/* start searching up the tree */
301 	do {
302 		struct radix_mask *m;
303 
304 		t = t->rn_parent;
305 		/*
306 		 * If non-contiguous masks ever become important
307 		 * we can restore the masking and open coding of
308 		 * the search and satisfaction test and put the
309 		 * calculation of "off" back before the "do".
310 		 */
311 		m = t->rn_mklist;
312 		while (m != NULL) {
313 			if (m->rm_flags & RNF_NORMAL) {
314 				if (rn_bit <= m->rm_bit)
315 					return (m->rm_leaf);
316 			} else {
317 				off = min(t->rn_offset, matched_off);
318 				x = rn_search_m(key, t, m->rm_mask);
319 				while (x != NULL && x->rn_mask != m->rm_mask)
320 					x = x->rn_dupedkey;
321 				if (x && rn_satisfies_leaf(key, x, off))
322 					return x;
323 			}
324 			m = m->rm_next;
325 		}
326 	} while (t != top);
327 	return NULL;
328 }
329 
330 #ifdef RN_DEBUG
331 int rn_nodenum;
332 struct radix_node *rn_clist;
333 int rn_saveinfo;
334 boolean_t rn_debug =  TRUE;
335 #endif
336 
337 static struct radix_node *
338 rn_newpair(char *key, int indexbit, struct radix_node nodes[2])
339 {
340 	struct radix_node *leaf = &nodes[0], *interior = &nodes[1];
341 
342 	interior->rn_bit = indexbit;
343 	interior->rn_bmask = 0x80 >> (indexbit & 0x7);
344 	interior->rn_offset = indexbit >> 3;
345 	interior->rn_left = leaf;
346 	interior->rn_mklist = NULL;
347 
348 	leaf->rn_bit = -1;
349 	leaf->rn_key = key;
350 	leaf->rn_parent = interior;
351 	leaf->rn_flags = interior->rn_flags = RNF_ACTIVE;
352 	leaf->rn_mklist = NULL;
353 
354 #ifdef RN_DEBUG
355 	leaf->rn_info = rn_nodenum++;
356 	interior->rn_info = rn_nodenum++;
357 	leaf->rn_twin = interior;
358 	leaf->rn_ybro = rn_clist;
359 	rn_clist = leaf;
360 #endif
361 	return interior;
362 }
363 
364 static struct radix_node *
365 rn_insert(char *key, struct radix_node_head *head, boolean_t *dupentry,
366 	  struct radix_node nodes[2])
367 {
368 	struct radix_node *top = head->rnh_treetop;
369 	int head_off = top->rn_offset, klen = clen(key);
370 	struct radix_node *t = rn_search(key, top);
371 	char *cp = key + head_off;
372 	int b;
373 	struct radix_node *tt;
374 
375 	/*
376 	 * Find first bit at which the key and t->rn_key differ
377 	 */
378     {
379 	char *cp2 = t->rn_key + head_off;
380 	int cmp_res;
381 	char *cplim = key + klen;
382 
383 	while (cp < cplim)
384 		if (*cp2++ != *cp++)
385 			goto on1;
386 	*dupentry = TRUE;
387 	return t;
388 on1:
389 	*dupentry = FALSE;
390 	cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
391 	for (b = (cp - key) << 3; cmp_res; b--)
392 		cmp_res >>= 1;
393     }
394     {
395 	struct radix_node *p, *x = top;
396 
397 	cp = key;
398 	do {
399 		p = x;
400 		if (cp[x->rn_offset] & x->rn_bmask)
401 			x = x->rn_right;
402 		else
403 			x = x->rn_left;
404 	} while (b > (unsigned) x->rn_bit);
405 				/* x->rn_bit < b && x->rn_bit >= 0 */
406 #ifdef RN_DEBUG
407 	if (rn_debug)
408 		log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
409 #endif
410 	t = rn_newpair(key, b, nodes);
411 	tt = t->rn_left;
412 	if ((cp[p->rn_offset] & p->rn_bmask) == 0)
413 		p->rn_left = t;
414 	else
415 		p->rn_right = t;
416 	x->rn_parent = t;
417 	t->rn_parent = p; /* frees x, p as temp vars below */
418 	if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
419 		t->rn_right = x;
420 	} else {
421 		t->rn_right = tt;
422 		t->rn_left = x;
423 	}
424 #ifdef RN_DEBUG
425 	if (rn_debug)
426 		log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
427 #endif
428     }
429 	return (tt);
430 }
431 
432 struct radix_node *
433 rn_addmask(char *netmask, boolean_t search, int skip,
434 	   struct radix_node_head *mask_rnh)
435 {
436 	struct radix_node *x, *saved_x;
437 	char *cp, *cplim;
438 	int b = 0, mlen, m0, j;
439 	boolean_t maskduplicated, isnormal;
440 	char *addmask_key;
441 
442 	if ((mlen = clen(netmask)) > RN_MAXKEYLEN)
443 		mlen = RN_MAXKEYLEN;
444 	if (skip == 0)
445 		skip = 1;
446 	if (mlen <= skip)
447 		return (mask_rnh->rnh_nodes);
448 	R_Malloc(addmask_key, char *, RN_MAXKEYLEN);
449 	if (addmask_key == NULL)
450 		return NULL;
451 	if (skip > 1)
452 		bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
453 	if ((m0 = mlen) > skip)
454 		bcopy(netmask + skip, addmask_key + skip, mlen - skip);
455 	/*
456 	 * Trim trailing zeroes.
457 	 */
458 	for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
459 		cp--;
460 	mlen = cp - addmask_key;
461 	if (mlen <= skip) {
462 		if (m0 >= mask_rnh->rnh_last_zeroed)
463 			mask_rnh->rnh_last_zeroed = mlen;
464 		Free(addmask_key);
465 		return (mask_rnh->rnh_nodes);
466 	}
467 	if (m0 < mask_rnh->rnh_last_zeroed)
468 		bzero(addmask_key + m0, mask_rnh->rnh_last_zeroed - m0);
469 	*addmask_key = mask_rnh->rnh_last_zeroed = mlen;
470 	x = rn_search(addmask_key, mask_rnh->rnh_treetop);
471 	if (x->rn_key == NULL) {
472 		kprintf("WARNING: radix_node->rn_key is NULL rn=%p\n", x);
473 		print_backtrace(-1);
474 		x = NULL;
475 	} else if (bcmp(addmask_key, x->rn_key, mlen) != 0) {
476 		x = NULL;
477 	}
478 	if (x != NULL || search)
479 		goto out;
480 	R_Malloc(x, struct radix_node *, RN_MAXKEYLEN + 2 * (sizeof *x));
481 	if ((saved_x = x) == NULL)
482 		goto out;
483 	bzero(x, RN_MAXKEYLEN + 2 * (sizeof *x));
484 	netmask = cp = (char *)(x + 2);
485 	bcopy(addmask_key, cp, mlen);
486 	x = rn_insert(cp, mask_rnh, &maskduplicated, x);
487 	if (maskduplicated) {
488 		log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
489 		Free(saved_x);
490 		goto out;
491 	}
492 	/*
493 	 * Calculate index of mask, and check for normalcy.
494 	 */
495 	isnormal = TRUE;
496 	cplim = netmask + mlen;
497 	for (cp = netmask + skip; cp < cplim && clen(cp) == 0xff;)
498 		cp++;
499 	if (cp != cplim) {
500 		static const char normal_chars[] = {
501 			0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1
502 		};
503 
504 		for (j = 0x80; (j & *cp) != 0; j >>= 1)
505 			b++;
506 		if (*cp != normal_chars[b] || cp != (cplim - 1))
507 			isnormal = FALSE;
508 	}
509 	b += (cp - netmask) << 3;
510 	x->rn_bit = -1 - b;
511 	if (isnormal)
512 		x->rn_flags |= RNF_NORMAL;
513 out:
514 	Free(addmask_key);
515 	return (x);
516 }
517 
518 /* XXX: arbitrary ordering for non-contiguous masks */
519 static boolean_t
520 rn_lexobetter(char *mp, char *np)
521 {
522 	char *lim;
523 
524 	if ((unsigned) *mp > (unsigned) *np)
525 		return TRUE;/* not really, but need to check longer one first */
526 	if (*mp == *np)
527 		for (lim = mp + clen(mp); mp < lim;)
528 			if (*mp++ > *np++)
529 				return TRUE;
530 	return FALSE;
531 }
532 
533 static struct radix_mask *
534 rn_new_radix_mask(struct radix_node *tt, struct radix_mask *nextmask)
535 {
536 	struct radix_mask *m;
537 
538 	m = MKGet(&rn_mkfreelist[mycpuid]);
539 	if (m == NULL) {
540 		log(LOG_ERR, "Mask for route not entered\n");
541 		return (NULL);
542 	}
543 	bzero(m, sizeof *m);
544 	m->rm_bit = tt->rn_bit;
545 	m->rm_flags = tt->rn_flags;
546 	if (tt->rn_flags & RNF_NORMAL)
547 		m->rm_leaf = tt;
548 	else
549 		m->rm_mask = tt->rn_mask;
550 	m->rm_next = nextmask;
551 	tt->rn_mklist = m;
552 	return m;
553 }
554 
555 struct radix_node *
556 rn_addroute(char *key, char *netmask, struct radix_node_head *head,
557 	    struct radix_node treenodes[2])
558 {
559 	struct radix_node *t, *x = NULL, *tt;
560 	struct radix_node *saved_tt, *top = head->rnh_treetop;
561 	short b = 0, b_leaf = 0;
562 	boolean_t keyduplicated;
563 	char *mmask;
564 	struct radix_mask *m, **mp;
565 
566 	/*
567 	 * In dealing with non-contiguous masks, there may be
568 	 * many different routes which have the same mask.
569 	 * We will find it useful to have a unique pointer to
570 	 * the mask to speed avoiding duplicate references at
571 	 * nodes and possibly save time in calculating indices.
572 	 */
573 	if (netmask != NULL)  {
574 		if ((x = rn_addmask(netmask, FALSE, top->rn_offset,
575 				    head->rnh_maskhead)) == NULL)
576 			return (NULL);
577 		b_leaf = x->rn_bit;
578 		b = -1 - x->rn_bit;
579 		netmask = x->rn_key;
580 	}
581 	/*
582 	 * Deal with duplicated keys: attach node to previous instance
583 	 */
584 	saved_tt = tt = rn_insert(key, head, &keyduplicated, treenodes);
585 	if (keyduplicated) {
586 		for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
587 			if (tt->rn_mask == netmask)
588 				return (NULL);
589 			if (netmask == NULL ||
590 			    (tt->rn_mask &&
591 			     ((b_leaf < tt->rn_bit) /* index(netmask) > node */
592 			      || rn_refines(netmask, tt->rn_mask)
593 			      || rn_lexobetter(netmask, tt->rn_mask))))
594 				break;
595 		}
596 		/*
597 		 * If the mask is not duplicated, we wouldn't
598 		 * find it among possible duplicate key entries
599 		 * anyway, so the above test doesn't hurt.
600 		 *
601 		 * We sort the masks for a duplicated key the same way as
602 		 * in a masklist -- most specific to least specific.
603 		 * This may require the unfortunate nuisance of relocating
604 		 * the head of the list.
605 		 */
606 		if (tt == saved_tt) {
607 			struct	radix_node *xx = x;
608 			/* link in at head of list */
609 			(tt = treenodes)->rn_dupedkey = t;
610 			tt->rn_flags = t->rn_flags;
611 			tt->rn_parent = x = t->rn_parent;
612 			t->rn_parent = tt;			/* parent */
613 			if (x->rn_left == t)
614 				x->rn_left = tt;
615 			else
616 				x->rn_right = tt;
617 			saved_tt = tt; x = xx;
618 		} else {
619 			(tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
620 			t->rn_dupedkey = tt;
621 			tt->rn_parent = t;			/* parent */
622 			if (tt->rn_dupedkey != NULL)		/* parent */
623 				tt->rn_dupedkey->rn_parent = tt; /* parent */
624 		}
625 #ifdef RN_DEBUG
626 		t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
627 		tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
628 #endif
629 		tt->rn_key = key;
630 		tt->rn_bit = -1;
631 		tt->rn_flags = RNF_ACTIVE;
632 	}
633 	/*
634 	 * Put mask in tree.
635 	 */
636 	if (netmask != NULL) {
637 		tt->rn_mask = netmask;
638 		tt->rn_bit = x->rn_bit;
639 		tt->rn_flags |= x->rn_flags & RNF_NORMAL;
640 	}
641 	t = saved_tt->rn_parent;
642 	if (keyduplicated)
643 		goto on2;
644 	b_leaf = -1 - t->rn_bit;
645 	if (t->rn_right == saved_tt)
646 		x = t->rn_left;
647 	else
648 		x = t->rn_right;
649 	/* Promote general routes from below */
650 	if (x->rn_bit < 0) {
651 		mp = &t->rn_mklist;
652 		while (x != NULL) {
653 			if (x->rn_mask != NULL &&
654 			    x->rn_bit >= b_leaf &&
655 			    x->rn_mklist == NULL) {
656 				*mp = m = rn_new_radix_mask(x, NULL);
657 				if (m != NULL)
658 					mp = &m->rm_next;
659 			}
660 			x = x->rn_dupedkey;
661 		}
662 	} else if (x->rn_mklist != NULL) {
663 		/*
664 		 * Skip over masks whose index is > that of new node
665 		 */
666 		for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_next)
667 			if (m->rm_bit >= b_leaf)
668 				break;
669 		t->rn_mklist = m;
670 		*mp = NULL;
671 	}
672 on2:
673 	/* Add new route to highest possible ancestor's list */
674 	if ((netmask == NULL) || (b > t->rn_bit ))
675 		return tt; /* can't lift at all */
676 	b_leaf = tt->rn_bit;
677 	do {
678 		x = t;
679 		t = t->rn_parent;
680 	} while (b <= t->rn_bit && x != top);
681 	/*
682 	 * Search through routes associated with node to
683 	 * insert new route according to index.
684 	 * Need same criteria as when sorting dupedkeys to avoid
685 	 * double loop on deletion.
686 	 */
687 	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_next) {
688 		if (m->rm_bit < b_leaf)
689 			continue;
690 		if (m->rm_bit > b_leaf)
691 			break;
692 		if (m->rm_flags & RNF_NORMAL) {
693 			mmask = m->rm_leaf->rn_mask;
694 			if (tt->rn_flags & RNF_NORMAL) {
695 			    log(LOG_ERR,
696 			        "Non-unique normal route, mask not entered\n");
697 				return tt;
698 			}
699 		} else
700 			mmask = m->rm_mask;
701 		if (mmask == netmask) {
702 			m->rm_refs++;
703 			tt->rn_mklist = m;
704 			return tt;
705 		}
706 		if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
707 			break;
708 	}
709 	*mp = rn_new_radix_mask(tt, *mp);
710 	return tt;
711 }
712 
713 struct radix_node *
714 rn_delete(char *key, char *netmask, struct radix_node_head *head)
715 {
716 	struct radix_node *t, *p, *x, *tt;
717 	struct radix_mask *m, *saved_m, **mp;
718 	struct radix_node *dupedkey, *saved_tt, *top;
719 	int b, head_off, klen;
720 	int cpu = mycpuid;
721 
722 	x = head->rnh_treetop;
723 	tt = rn_search(key, x);
724 	head_off = x->rn_offset;
725 	klen =  clen(key);
726 	saved_tt = tt;
727 	top = x;
728 	if (tt == NULL ||
729 	    bcmp(key + head_off, tt->rn_key + head_off, klen - head_off))
730 		return (NULL);
731 	/*
732 	 * Delete our route from mask lists.
733 	 */
734 	if (netmask != NULL) {
735 		if ((x = rn_addmask(netmask, TRUE, head_off,
736 				    head->rnh_maskhead)) == NULL)
737 			return (NULL);
738 		netmask = x->rn_key;
739 		while (tt->rn_mask != netmask)
740 			if ((tt = tt->rn_dupedkey) == NULL)
741 				return (NULL);
742 	}
743 	if (tt->rn_mask == NULL || (saved_m = m = tt->rn_mklist) == NULL)
744 		goto on1;
745 	if (tt->rn_flags & RNF_NORMAL) {
746 		if (m->rm_leaf != tt || m->rm_refs > 0) {
747 			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
748 			return (NULL);  /* dangling ref could cause disaster */
749 		}
750 	} else {
751 		if (m->rm_mask != tt->rn_mask) {
752 			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
753 			goto on1;
754 		}
755 		if (--m->rm_refs >= 0)
756 			goto on1;
757 	}
758 	b = -1 - tt->rn_bit;
759 	t = saved_tt->rn_parent;
760 	if (b > t->rn_bit)
761 		goto on1; /* Wasn't lifted at all */
762 	do {
763 		x = t;
764 		t = t->rn_parent;
765 	} while (b <= t->rn_bit && x != top);
766 	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_next)
767 		if (m == saved_m) {
768 			*mp = m->rm_next;
769 			MKFree(&rn_mkfreelist[cpu], m);
770 			break;
771 		}
772 	if (m == NULL) {
773 		log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
774 		if (tt->rn_flags & RNF_NORMAL)
775 			return (NULL); /* Dangling ref to us */
776 	}
777 on1:
778 	/*
779 	 * Eliminate us from tree
780 	 */
781 	if (tt->rn_flags & RNF_ROOT)
782 		return (NULL);
783 #ifdef RN_DEBUG
784 	/* Get us out of the creation list */
785 	for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
786 	if (t) t->rn_ybro = tt->rn_ybro;
787 #endif
788 	t = tt->rn_parent;
789 	dupedkey = saved_tt->rn_dupedkey;
790 	if (dupedkey != NULL) {
791 		/*
792 		 * at this point, tt is the deletion target and saved_tt
793 		 * is the head of the dupekey chain
794 		 */
795 		if (tt == saved_tt) {
796 			/* remove from head of chain */
797 			x = dupedkey; x->rn_parent = t;
798 			if (t->rn_left == tt)
799 				t->rn_left = x;
800 			else
801 				t->rn_right = x;
802 		} else {
803 			/* find node in front of tt on the chain */
804 			for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
805 				p = p->rn_dupedkey;
806 			if (p) {
807 				p->rn_dupedkey = tt->rn_dupedkey;
808 				if (tt->rn_dupedkey)		/* parent */
809 					tt->rn_dupedkey->rn_parent = p;
810 								/* parent */
811 			} else log(LOG_ERR, "rn_delete: couldn't find us\n");
812 		}
813 		t = tt + 1;
814 		if  (t->rn_flags & RNF_ACTIVE) {
815 #ifndef RN_DEBUG
816 			*++x = *t;
817 			p = t->rn_parent;
818 #else
819 			b = t->rn_info;
820 			*++x = *t;
821 			t->rn_info = b;
822 			p = t->rn_parent;
823 #endif
824 			if (p->rn_left == t)
825 				p->rn_left = x;
826 			else
827 				p->rn_right = x;
828 			x->rn_left->rn_parent = x;
829 			x->rn_right->rn_parent = x;
830 		}
831 		goto out;
832 	}
833 	if (t->rn_left == tt)
834 		x = t->rn_right;
835 	else
836 		x = t->rn_left;
837 	p = t->rn_parent;
838 	if (p->rn_right == t)
839 		p->rn_right = x;
840 	else
841 		p->rn_left = x;
842 	x->rn_parent = p;
843 	/*
844 	 * Demote routes attached to us.
845 	 */
846 	if (t->rn_mklist != NULL) {
847 		if (x->rn_bit >= 0) {
848 			for (mp = &x->rn_mklist; (m = *mp);)
849 				mp = &m->rm_next;
850 			*mp = t->rn_mklist;
851 		} else {
852 			/*
853 			 * If there are any (key, mask) pairs in a sibling
854 			 * duped-key chain, some subset will appear sorted
855 			 * in the same order attached to our mklist.
856 			 */
857 			for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
858 				if (m == x->rn_mklist) {
859 					struct radix_mask *mm = m->rm_next;
860 
861 					x->rn_mklist = NULL;
862 					if (--(m->rm_refs) < 0)
863 						MKFree(&rn_mkfreelist[cpu], m);
864 					m = mm;
865 				}
866 			if (m)
867 				log(LOG_ERR,
868 				    "rn_delete: Orphaned Mask %p at %p\n",
869 				    (void *)m, (void *)x);
870 		}
871 	}
872 	/*
873 	 * We may be holding an active internal node in the tree.
874 	 */
875 	x = tt + 1;
876 	if (t != x) {
877 #ifndef RN_DEBUG
878 		*t = *x;
879 #else
880 		b = t->rn_info;
881 		*t = *x;
882 		t->rn_info = b;
883 #endif
884 		t->rn_left->rn_parent = t;
885 		t->rn_right->rn_parent = t;
886 		p = x->rn_parent;
887 		if (p->rn_left == x)
888 			p->rn_left = t;
889 		else
890 			p->rn_right = t;
891 	}
892 out:
893 	tt->rn_flags &= ~RNF_ACTIVE;
894 	tt[1].rn_flags &= ~RNF_ACTIVE;
895 	return (tt);
896 }
897 
898 /*
899  * This is the same as rn_walktree() except for the parameters and the
900  * exit.
901  */
902 static int
903 rn_walktree_from(struct radix_node_head *h, char *xa, char *xm,
904 		 walktree_f_t *f, void *w)
905 {
906 	struct radix_node *base, *next;
907 	struct radix_node *rn, *last = NULL /* shut up gcc */;
908 	boolean_t stopping = FALSE;
909 	int lastb, error;
910 
911 	/*
912 	 * rn_search_m is sort-of-open-coded here.
913 	 */
914 	/* kprintf("about to search\n"); */
915 	for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
916 		last = rn;
917 		/* kprintf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n",
918 		       rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */
919 		if (!(rn->rn_bmask & xm[rn->rn_offset])) {
920 			break;
921 		}
922 		if (rn->rn_bmask & xa[rn->rn_offset]) {
923 			rn = rn->rn_right;
924 		} else {
925 			rn = rn->rn_left;
926 		}
927 	}
928 	/* kprintf("done searching\n"); */
929 
930 	/*
931 	 * Two cases: either we stepped off the end of our mask,
932 	 * in which case last == rn, or we reached a leaf, in which
933 	 * case we want to start from the last node we looked at.
934 	 * Either way, last is the node we want to start from.
935 	 */
936 	rn = last;
937 	lastb = rn->rn_bit;
938 
939 	/* kprintf("rn %p, lastb %d\n", rn, lastb);*/
940 
941 	/*
942 	 * This gets complicated because we may delete the node
943 	 * while applying the function f to it, so we need to calculate
944 	 * the successor node in advance.
945 	 */
946 	while (rn->rn_bit >= 0)
947 		rn = rn->rn_left;
948 
949 	while (!stopping) {
950 		/* kprintf("node %p (%d)\n", rn, rn->rn_bit); */
951 		base = rn;
952 		/* If at right child go back up, otherwise, go right */
953 		while (rn->rn_parent->rn_right == rn &&
954 		    !(rn->rn_flags & RNF_ROOT)) {
955 			rn = rn->rn_parent;
956 
957 			/* if went up beyond last, stop */
958 			if (rn->rn_bit < lastb) {
959 				stopping = TRUE;
960 				/* kprintf("up too far\n"); */
961 			}
962 		}
963 
964 		/* Find the next *leaf* since next node might vanish, too */
965 		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
966 			rn = rn->rn_left;
967 		next = rn;
968 		/* Process leaves */
969 		while ((rn = base) != NULL) {
970 			base = rn->rn_dupedkey;
971 			/* kprintf("leaf %p\n", rn); */
972 			if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
973 				return (error);
974 		}
975 		rn = next;
976 
977 		if (rn->rn_flags & RNF_ROOT) {
978 			/* kprintf("root, stopping"); */
979 			stopping = TRUE;
980 		}
981 
982 	}
983 	return 0;
984 }
985 
986 static int
987 rn_walktree_at(struct radix_node_head *h, const char *a, const char *m,
988     walktree_f_t *f, void *w)
989 {
990 	struct radix_node *base, *next;
991 	struct radix_node *rn = h->rnh_treetop;
992 	int error;
993 
994 	/*
995 	 * This gets complicated because we may delete the node
996 	 * while applying the function f to it, so we need to calculate
997 	 * the successor node in advance.
998 	 */
999 	if (a == NULL) {
1000 		/* First time through node, go left */
1001 		while (rn->rn_bit >= 0)
1002 			rn = rn->rn_left;
1003 	} else {
1004 		if (m != NULL)
1005 			rn = rn_search_m(a, rn, m);
1006 		else
1007 			rn = rn_search(a, rn);
1008 	}
1009 	for (;;) {
1010 		base = rn;
1011 		/* If at right child go back up, otherwise, go right */
1012 		while (rn->rn_parent->rn_right == rn &&
1013 		    !(rn->rn_flags & RNF_ROOT))
1014 			rn = rn->rn_parent;
1015 		/* Find the next *leaf* since next node might vanish, too */
1016 		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1017 			rn = rn->rn_left;
1018 		next = rn;
1019 		/* Process leaves */
1020 		while ((rn = base)) {
1021 			base = rn->rn_dupedkey;
1022 			if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
1023 				return (error);
1024 		}
1025 		rn = next;
1026 		if (rn->rn_flags & RNF_ROOT)
1027 			return (0);
1028 	}
1029 	/* NOTREACHED */
1030 }
1031 
1032 static int
1033 rn_walktree(struct radix_node_head *h, walktree_f_t *f, void *w)
1034 {
1035 	return rn_walktree_at(h, NULL, NULL, f, w);
1036 }
1037 
1038 int
1039 rn_inithead(void **head, struct radix_node_head *maskhead, int off)
1040 {
1041 	struct radix_node_head *rnh;
1042 	struct radix_node *root, *left, *right;
1043 
1044 	if (*head != NULL)	/* already initialized */
1045 		return (1);
1046 
1047 	R_Malloc(rnh, struct radix_node_head *, sizeof *rnh);
1048 	if (rnh == NULL)
1049 		return (0);
1050 	bzero(rnh, sizeof *rnh);
1051 	*head = rnh;
1052 
1053 	root = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
1054 	right = &rnh->rnh_nodes[2];
1055 	root->rn_parent = root;
1056 	root->rn_flags = RNF_ROOT | RNF_ACTIVE;
1057 	root->rn_right = right;
1058 
1059 	left = root->rn_left;
1060 	left->rn_bit = -1 - off;
1061 	left->rn_flags = RNF_ROOT | RNF_ACTIVE;
1062 
1063 	*right = *left;
1064 	right->rn_key = rn_ones;
1065 
1066 	rnh->rnh_treetop = root;
1067 	rnh->rnh_maskhead = maskhead;
1068 
1069 	rnh->rnh_addaddr = rn_addroute;
1070 	rnh->rnh_deladdr = rn_delete;
1071 	rnh->rnh_matchaddr = rn_match;
1072 	rnh->rnh_lookup = rn_lookup;
1073 	rnh->rnh_walktree = rn_walktree;
1074 	rnh->rnh_walktree_from = rn_walktree_from;
1075 	rnh->rnh_walktree_at = rn_walktree_at;
1076 
1077 	return (1);
1078 }
1079 
1080 static void
1081 rn_init_handler(netmsg_t msg)
1082 {
1083 	int cpu = mycpuid;
1084 
1085 	ASSERT_NETISR_NCPUS(cpu);
1086 	if (rn_inithead((void **)&mask_rnheads[cpu], NULL, 0) == 0)
1087 		panic("rn_init 2");
1088 
1089 	netisr_forwardmsg(&msg->base, cpu + 1);
1090 }
1091 
1092 void
1093 rn_init(void)
1094 {
1095 	struct netmsg_base msg;
1096 #ifdef _KERNEL
1097 	struct domain *dom;
1098 
1099 	SLIST_FOREACH(dom, &domains, dom_next) {
1100 		if (dom->dom_maxrtkey > RN_MAXKEYLEN) {
1101 			panic("domain %s maxkey too big %d/%d",
1102 			      dom->dom_name, dom->dom_maxrtkey, RN_MAXKEYLEN);
1103 		}
1104 	}
1105 #endif
1106 	netmsg_init(&msg, NULL, &curthread->td_msgport, 0, rn_init_handler);
1107 	netisr_domsg_global(&msg);
1108 }
1109 
1110 struct radix_node_head *
1111 rn_cpumaskhead(int cpu)
1112 {
1113 
1114 	ASSERT_NETISR_NCPUS(cpu);
1115 	KKASSERT(mask_rnheads[cpu] != NULL);
1116 	return mask_rnheads[cpu];
1117 }
1118