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