FreeBSD/Linux Kernel Cross Reference
sys/net/radix.c
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. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)radix.c 8.5 (Berkeley) 5/19/95
34 * $FreeBSD: releng/5.1/sys/net/radix.c 110527 2003-02-08 01:44:09Z hsu $
35 */
36
37 /*
38 * Routines to build and maintain radix trees for routing lookups.
39 */
40 #ifndef _RADIX_H_
41 #include <sys/param.h>
42 #ifdef _KERNEL
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/systm.h>
46 #include <sys/malloc.h>
47 #include <sys/domain.h>
48 #else
49 #include <stdlib.h>
50 #endif
51 #include <sys/syslog.h>
52 #include <net/radix.h>
53 #endif
54
55 static int rn_walktree_from(struct radix_node_head *h, void *a, void *m,
56 walktree_f_t *f, void *w);
57 static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
58 static struct radix_node
59 *rn_insert(void *, struct radix_node_head *, int *,
60 struct radix_node [2]),
61 *rn_newpair(void *, int, struct radix_node[2]),
62 *rn_search(void *, struct radix_node *),
63 *rn_search_m(void *, struct radix_node *, void *);
64
65 static int max_keylen;
66 static struct radix_mask *rn_mkfreelist;
67 static struct radix_node_head *mask_rnhead;
68 static char *addmask_key;
69 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
70 static char *rn_zeros, *rn_ones;
71
72 #define rn_masktop (mask_rnhead->rnh_treetop)
73 #undef Bcmp
74 #define Bcmp(a, b, l) \
75 ((l) == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)(l)))
76
77 static int rn_lexobetter(void *m_arg, void *n_arg);
78 static struct radix_mask *
79 rn_new_radix_mask(struct radix_node *tt,
80 struct radix_mask *next);
81 static int rn_satisfies_leaf(char *trial, struct radix_node *leaf,
82 int skip);
83
84 /*
85 * The data structure for the keys is a radix tree with one way
86 * branching removed. The index rn_bit at an internal node n represents a bit
87 * position to be tested. The tree is arranged so that all descendants
88 * of a node n have keys whose bits all agree up to position rn_bit - 1.
89 * (We say the index of n is rn_bit.)
90 *
91 * There is at least one descendant which has a one bit at position rn_bit,
92 * and at least one with a zero there.
93 *
94 * A route is determined by a pair of key and mask. We require that the
95 * bit-wise logical and of the key and mask to be the key.
96 * We define the index of a route to associated with the mask to be
97 * the first bit number in the mask where 0 occurs (with bit number 0
98 * representing the highest order bit).
99 *
100 * We say a mask is normal if every bit is 0, past the index of the mask.
101 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
102 * and m is a normal mask, then the route applies to every descendant of n.
103 * If the index(m) < rn_bit, this implies the trailing last few bits of k
104 * before bit b are all 0, (and hence consequently true of every descendant
105 * of n), so the route applies to all descendants of the node as well.
106 *
107 * Similar logic shows that a non-normal mask m such that
108 * index(m) <= index(n) could potentially apply to many children of n.
109 * Thus, for each non-host route, we attach its mask to a list at an internal
110 * node as high in the tree as we can go.
111 *
112 * The present version of the code makes use of normal routes in short-
113 * circuiting an explict mask and compare operation when testing whether
114 * a key satisfies a normal route, and also in remembering the unique leaf
115 * that governs a subtree.
116 */
117
118 static struct radix_node *
119 rn_search(v_arg, head)
120 void *v_arg;
121 struct radix_node *head;
122 {
123 register struct radix_node *x;
124 register caddr_t v;
125
126 for (x = head, v = v_arg; x->rn_bit >= 0;) {
127 if (x->rn_bmask & v[x->rn_offset])
128 x = x->rn_right;
129 else
130 x = x->rn_left;
131 }
132 return (x);
133 }
134
135 static struct radix_node *
136 rn_search_m(v_arg, head, m_arg)
137 struct radix_node *head;
138 void *v_arg, *m_arg;
139 {
140 register struct radix_node *x;
141 register caddr_t v = v_arg, m = m_arg;
142
143 for (x = head; x->rn_bit >= 0;) {
144 if ((x->rn_bmask & m[x->rn_offset]) &&
145 (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 int
154 rn_refines(m_arg, n_arg)
155 void *m_arg, *n_arg;
156 {
157 register caddr_t m = m_arg, n = n_arg;
158 register caddr_t lim, lim2 = lim = n + *(u_char *)n;
159 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
160 int masks_are_equal = 1;
161
162 if (longer > 0)
163 lim -= longer;
164 while (n < lim) {
165 if (*n & ~(*m))
166 return 0;
167 if (*n++ != *m++)
168 masks_are_equal = 0;
169 }
170 while (n < lim2)
171 if (*n++)
172 return 0;
173 if (masks_are_equal && (longer < 0))
174 for (lim2 = m - longer; m < lim2; )
175 if (*m++)
176 return 1;
177 return (!masks_are_equal);
178 }
179
180 struct radix_node *
181 rn_lookup(v_arg, m_arg, head)
182 void *v_arg, *m_arg;
183 struct radix_node_head *head;
184 {
185 register struct radix_node *x;
186 caddr_t netmask = 0;
187
188 if (m_arg) {
189 x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset);
190 if (x == 0)
191 return (0);
192 netmask = x->rn_key;
193 }
194 x = rn_match(v_arg, head);
195 if (x && netmask) {
196 while (x && x->rn_mask != netmask)
197 x = x->rn_dupedkey;
198 }
199 return x;
200 }
201
202 static int
203 rn_satisfies_leaf(trial, leaf, skip)
204 char *trial;
205 register struct radix_node *leaf;
206 int skip;
207 {
208 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
209 char *cplim;
210 int length = min(*(u_char *)cp, *(u_char *)cp2);
211
212 if (cp3 == 0)
213 cp3 = rn_ones;
214 else
215 length = min(length, *(u_char *)cp3);
216 cplim = cp + length; cp3 += skip; cp2 += skip;
217 for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
218 if ((*cp ^ *cp2) & *cp3)
219 return 0;
220 return 1;
221 }
222
223 struct radix_node *
224 rn_match(v_arg, head)
225 void *v_arg;
226 struct radix_node_head *head;
227 {
228 caddr_t v = v_arg;
229 register struct radix_node *t = head->rnh_treetop, *x;
230 register caddr_t cp = v, cp2;
231 caddr_t cplim;
232 struct radix_node *saved_t, *top = t;
233 int off = t->rn_offset, vlen = *(u_char *)cp, matched_off;
234 register int test, b, rn_bit;
235
236 /*
237 * Open code rn_search(v, top) to avoid overhead of extra
238 * subroutine call.
239 */
240 for (; t->rn_bit >= 0; ) {
241 if (t->rn_bmask & cp[t->rn_offset])
242 t = t->rn_right;
243 else
244 t = t->rn_left;
245 }
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)
258 vlen = *(u_char *)t->rn_mask;
259 cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
260 for (; cp < cplim; cp++, cp2++)
261 if (*cp != *cp2)
262 goto on1;
263 /*
264 * This extra grot is in case we are explicitly asked
265 * to look up the default. Ugh!
266 *
267 * Never return the root node itself, it seems to cause a
268 * lot of confusion.
269 */
270 if (t->rn_flags & RNF_ROOT)
271 t = t->rn_dupedkey;
272 return t;
273 on1:
274 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
275 for (b = 7; (test >>= 1) > 0;)
276 b--;
277 matched_off = cp - v;
278 b += matched_off << 3;
279 rn_bit = -1 - b;
280 /*
281 * If there is a host route in a duped-key chain, it will be first.
282 */
283 if ((saved_t = t)->rn_mask == 0)
284 t = t->rn_dupedkey;
285 for (; t; t = t->rn_dupedkey)
286 /*
287 * Even if we don't match exactly as a host,
288 * we may match if the leaf we wound up at is
289 * a route to a net.
290 */
291 if (t->rn_flags & RNF_NORMAL) {
292 if (rn_bit <= t->rn_bit)
293 return t;
294 } else if (rn_satisfies_leaf(v, t, matched_off))
295 return t;
296 t = saved_t;
297 /* start searching up the tree */
298 do {
299 register struct radix_mask *m;
300 t = t->rn_parent;
301 m = t->rn_mklist;
302 /*
303 * If non-contiguous masks ever become important
304 * we can restore the masking and open coding of
305 * the search and satisfaction test and put the
306 * calculation of "off" back before the "do".
307 */
308 while (m) {
309 if (m->rm_flags & RNF_NORMAL) {
310 if (rn_bit <= m->rm_bit)
311 return (m->rm_leaf);
312 } else {
313 off = min(t->rn_offset, matched_off);
314 x = rn_search_m(v, t, m->rm_mask);
315 while (x && x->rn_mask != m->rm_mask)
316 x = x->rn_dupedkey;
317 if (x && rn_satisfies_leaf(v, x, off))
318 return x;
319 }
320 m = m->rm_mklist;
321 }
322 } while (t != top);
323 return 0;
324 }
325
326 #ifdef RN_DEBUG
327 int rn_nodenum;
328 struct radix_node *rn_clist;
329 int rn_saveinfo;
330 int rn_debug = 1;
331 #endif
332
333 static struct radix_node *
334 rn_newpair(v, b, nodes)
335 void *v;
336 int b;
337 struct radix_node nodes[2];
338 {
339 register struct radix_node *tt = nodes, *t = tt + 1;
340 t->rn_bit = b;
341 t->rn_bmask = 0x80 >> (b & 7);
342 t->rn_left = tt;
343 t->rn_offset = b >> 3;
344 tt->rn_bit = -1;
345 tt->rn_key = (caddr_t)v;
346 tt->rn_parent = t;
347 tt->rn_flags = t->rn_flags = RNF_ACTIVE;
348 tt->rn_mklist = t->rn_mklist = 0;
349 #ifdef RN_DEBUG
350 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
351 tt->rn_twin = t;
352 tt->rn_ybro = rn_clist;
353 rn_clist = tt;
354 #endif
355 return t;
356 }
357
358 static struct radix_node *
359 rn_insert(v_arg, head, dupentry, nodes)
360 void *v_arg;
361 struct radix_node_head *head;
362 int *dupentry;
363 struct radix_node nodes[2];
364 {
365 caddr_t v = v_arg;
366 struct radix_node *top = head->rnh_treetop;
367 int head_off = top->rn_offset, vlen = (int)*((u_char *)v);
368 register struct radix_node *t = rn_search(v_arg, top);
369 register caddr_t cp = v + head_off;
370 register int b;
371 struct radix_node *tt;
372 /*
373 * Find first bit at which v and t->rn_key differ
374 */
375 {
376 register caddr_t cp2 = t->rn_key + head_off;
377 register int cmp_res;
378 caddr_t cplim = v + vlen;
379
380 while (cp < cplim)
381 if (*cp2++ != *cp++)
382 goto on1;
383 *dupentry = 1;
384 return t;
385 on1:
386 *dupentry = 0;
387 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
388 for (b = (cp - v) << 3; cmp_res; b--)
389 cmp_res >>= 1;
390 }
391 {
392 register struct radix_node *p, *x = top;
393 cp = v;
394 do {
395 p = x;
396 if (cp[x->rn_offset] & x->rn_bmask)
397 x = x->rn_right;
398 else
399 x = x->rn_left;
400 } while (b > (unsigned) x->rn_bit);
401 /* x->rn_bit < b && x->rn_bit >= 0 */
402 #ifdef RN_DEBUG
403 if (rn_debug)
404 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
405 #endif
406 t = rn_newpair(v_arg, b, nodes);
407 tt = t->rn_left;
408 if ((cp[p->rn_offset] & p->rn_bmask) == 0)
409 p->rn_left = t;
410 else
411 p->rn_right = t;
412 x->rn_parent = t;
413 t->rn_parent = p; /* frees x, p as temp vars below */
414 if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
415 t->rn_right = x;
416 } else {
417 t->rn_right = tt;
418 t->rn_left = x;
419 }
420 #ifdef RN_DEBUG
421 if (rn_debug)
422 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
423 #endif
424 }
425 return (tt);
426 }
427
428 struct radix_node *
429 rn_addmask(n_arg, search, skip)
430 int search, skip;
431 void *n_arg;
432 {
433 caddr_t netmask = (caddr_t)n_arg;
434 register struct radix_node *x;
435 register caddr_t cp, cplim;
436 register int b = 0, mlen, j;
437 int maskduplicated, m0, isnormal;
438 struct radix_node *saved_x;
439 static int last_zeroed = 0;
440
441 if ((mlen = *(u_char *)netmask) > max_keylen)
442 mlen = max_keylen;
443 if (skip == 0)
444 skip = 1;
445 if (mlen <= skip)
446 return (mask_rnhead->rnh_nodes);
447 if (skip > 1)
448 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
449 if ((m0 = mlen) > skip)
450 Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
451 /*
452 * Trim trailing zeroes.
453 */
454 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
455 cp--;
456 mlen = cp - addmask_key;
457 if (mlen <= skip) {
458 if (m0 >= last_zeroed)
459 last_zeroed = mlen;
460 return (mask_rnhead->rnh_nodes);
461 }
462 if (m0 < last_zeroed)
463 Bzero(addmask_key + m0, last_zeroed - m0);
464 *addmask_key = last_zeroed = mlen;
465 x = rn_search(addmask_key, rn_masktop);
466 if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
467 x = 0;
468 if (x || search)
469 return (x);
470 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
471 if ((saved_x = x) == 0)
472 return (0);
473 Bzero(x, max_keylen + 2 * sizeof (*x));
474 netmask = cp = (caddr_t)(x + 2);
475 Bcopy(addmask_key, cp, mlen);
476 x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
477 if (maskduplicated) {
478 log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
479 Free(saved_x);
480 return (x);
481 }
482 /*
483 * Calculate index of mask, and check for normalcy.
484 */
485 cplim = netmask + mlen; isnormal = 1;
486 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
487 cp++;
488 if (cp != cplim) {
489 for (j = 0x80; (j & *cp) != 0; j >>= 1)
490 b++;
491 if (*cp != normal_chars[b] || cp != (cplim - 1))
492 isnormal = 0;
493 }
494 b += (cp - netmask) << 3;
495 x->rn_bit = -1 - b;
496 if (isnormal)
497 x->rn_flags |= RNF_NORMAL;
498 return (x);
499 }
500
501 static int /* XXX: arbitrary ordering for non-contiguous masks */
502 rn_lexobetter(m_arg, n_arg)
503 void *m_arg, *n_arg;
504 {
505 register u_char *mp = m_arg, *np = n_arg, *lim;
506
507 if (*mp > *np)
508 return 1; /* not really, but need to check longer one first */
509 if (*mp == *np)
510 for (lim = mp + *mp; mp < lim;)
511 if (*mp++ > *np++)
512 return 1;
513 return 0;
514 }
515
516 static struct radix_mask *
517 rn_new_radix_mask(tt, next)
518 register struct radix_node *tt;
519 register struct radix_mask *next;
520 {
521 register struct radix_mask *m;
522
523 MKGet(m);
524 if (m == 0) {
525 log(LOG_ERR, "Mask for route not entered\n");
526 return (0);
527 }
528 Bzero(m, sizeof *m);
529 m->rm_bit = tt->rn_bit;
530 m->rm_flags = tt->rn_flags;
531 if (tt->rn_flags & RNF_NORMAL)
532 m->rm_leaf = tt;
533 else
534 m->rm_mask = tt->rn_mask;
535 m->rm_mklist = next;
536 tt->rn_mklist = m;
537 return m;
538 }
539
540 struct radix_node *
541 rn_addroute(v_arg, n_arg, head, treenodes)
542 void *v_arg, *n_arg;
543 struct radix_node_head *head;
544 struct radix_node treenodes[2];
545 {
546 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
547 register struct radix_node *t, *x = 0, *tt;
548 struct radix_node *saved_tt, *top = head->rnh_treetop;
549 short b = 0, b_leaf = 0;
550 int keyduplicated;
551 caddr_t mmask;
552 struct radix_mask *m, **mp;
553
554 /*
555 * In dealing with non-contiguous masks, there may be
556 * many different routes which have the same mask.
557 * We will find it useful to have a unique pointer to
558 * the mask to speed avoiding duplicate references at
559 * nodes and possibly save time in calculating indices.
560 */
561 if (netmask) {
562 if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0)
563 return (0);
564 b_leaf = x->rn_bit;
565 b = -1 - x->rn_bit;
566 netmask = x->rn_key;
567 }
568 /*
569 * Deal with duplicated keys: attach node to previous instance
570 */
571 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
572 if (keyduplicated) {
573 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
574 if (tt->rn_mask == netmask)
575 return (0);
576 if (netmask == 0 ||
577 (tt->rn_mask &&
578 ((b_leaf < tt->rn_bit) /* index(netmask) > node */
579 || rn_refines(netmask, tt->rn_mask)
580 || rn_lexobetter(netmask, tt->rn_mask))))
581 break;
582 }
583 /*
584 * If the mask is not duplicated, we wouldn't
585 * find it among possible duplicate key entries
586 * anyway, so the above test doesn't hurt.
587 *
588 * We sort the masks for a duplicated key the same way as
589 * in a masklist -- most specific to least specific.
590 * This may require the unfortunate nuisance of relocating
591 * the head of the list.
592 *
593 * We also reverse, or doubly link the list through the
594 * parent pointer.
595 */
596 if (tt == saved_tt) {
597 struct radix_node *xx = x;
598 /* link in at head of list */
599 (tt = treenodes)->rn_dupedkey = t;
600 tt->rn_flags = t->rn_flags;
601 tt->rn_parent = x = t->rn_parent;
602 t->rn_parent = tt; /* parent */
603 if (x->rn_left == t)
604 x->rn_left = tt;
605 else
606 x->rn_right = tt;
607 saved_tt = tt; x = xx;
608 } else {
609 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
610 t->rn_dupedkey = tt;
611 tt->rn_parent = t; /* parent */
612 if (tt->rn_dupedkey) /* parent */
613 tt->rn_dupedkey->rn_parent = tt; /* parent */
614 }
615 #ifdef RN_DEBUG
616 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
617 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
618 #endif
619 tt->rn_key = (caddr_t) v;
620 tt->rn_bit = -1;
621 tt->rn_flags = RNF_ACTIVE;
622 }
623 /*
624 * Put mask in tree.
625 */
626 if (netmask) {
627 tt->rn_mask = netmask;
628 tt->rn_bit = x->rn_bit;
629 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
630 }
631 t = saved_tt->rn_parent;
632 if (keyduplicated)
633 goto on2;
634 b_leaf = -1 - t->rn_bit;
635 if (t->rn_right == saved_tt)
636 x = t->rn_left;
637 else
638 x = t->rn_right;
639 /* Promote general routes from below */
640 if (x->rn_bit < 0) {
641 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
642 if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) {
643 *mp = m = rn_new_radix_mask(x, 0);
644 if (m)
645 mp = &m->rm_mklist;
646 }
647 } else if (x->rn_mklist) {
648 /*
649 * Skip over masks whose index is > that of new node
650 */
651 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
652 if (m->rm_bit >= b_leaf)
653 break;
654 t->rn_mklist = m; *mp = 0;
655 }
656 on2:
657 /* Add new route to highest possible ancestor's list */
658 if ((netmask == 0) || (b > t->rn_bit ))
659 return tt; /* can't lift at all */
660 b_leaf = tt->rn_bit;
661 do {
662 x = t;
663 t = t->rn_parent;
664 } while (b <= t->rn_bit && x != top);
665 /*
666 * Search through routes associated with node to
667 * insert new route according to index.
668 * Need same criteria as when sorting dupedkeys to avoid
669 * double loop on deletion.
670 */
671 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
672 if (m->rm_bit < b_leaf)
673 continue;
674 if (m->rm_bit > b_leaf)
675 break;
676 if (m->rm_flags & RNF_NORMAL) {
677 mmask = m->rm_leaf->rn_mask;
678 if (tt->rn_flags & RNF_NORMAL) {
679 log(LOG_ERR,
680 "Non-unique normal route, mask not entered\n");
681 return tt;
682 }
683 } else
684 mmask = m->rm_mask;
685 if (mmask == netmask) {
686 m->rm_refs++;
687 tt->rn_mklist = m;
688 return tt;
689 }
690 if (rn_refines(netmask, mmask)
691 || rn_lexobetter(netmask, mmask))
692 break;
693 }
694 *mp = rn_new_radix_mask(tt, *mp);
695 return tt;
696 }
697
698 struct radix_node *
699 rn_delete(v_arg, netmask_arg, head)
700 void *v_arg, *netmask_arg;
701 struct radix_node_head *head;
702 {
703 register struct radix_node *t, *p, *x, *tt;
704 struct radix_mask *m, *saved_m, **mp;
705 struct radix_node *dupedkey, *saved_tt, *top;
706 caddr_t v, netmask;
707 int b, head_off, vlen;
708
709 v = v_arg;
710 netmask = netmask_arg;
711 x = head->rnh_treetop;
712 tt = rn_search(v, x);
713 head_off = x->rn_offset;
714 vlen = *(u_char *)v;
715 saved_tt = tt;
716 top = x;
717 if (tt == 0 ||
718 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
719 return (0);
720 /*
721 * Delete our route from mask lists.
722 */
723 if (netmask) {
724 if ((x = rn_addmask(netmask, 1, head_off)) == 0)
725 return (0);
726 netmask = x->rn_key;
727 while (tt->rn_mask != netmask)
728 if ((tt = tt->rn_dupedkey) == 0)
729 return (0);
730 }
731 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
732 goto on1;
733 if (tt->rn_flags & RNF_NORMAL) {
734 if (m->rm_leaf != tt || m->rm_refs > 0) {
735 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
736 return 0; /* dangling ref could cause disaster */
737 }
738 } else {
739 if (m->rm_mask != tt->rn_mask) {
740 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
741 goto on1;
742 }
743 if (--m->rm_refs >= 0)
744 goto on1;
745 }
746 b = -1 - tt->rn_bit;
747 t = saved_tt->rn_parent;
748 if (b > t->rn_bit)
749 goto on1; /* Wasn't lifted at all */
750 do {
751 x = t;
752 t = t->rn_parent;
753 } while (b <= t->rn_bit && x != top);
754 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
755 if (m == saved_m) {
756 *mp = m->rm_mklist;
757 MKFree(m);
758 break;
759 }
760 if (m == 0) {
761 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
762 if (tt->rn_flags & RNF_NORMAL)
763 return (0); /* Dangling ref to us */
764 }
765 on1:
766 /*
767 * Eliminate us from tree
768 */
769 if (tt->rn_flags & RNF_ROOT)
770 return (0);
771 #ifdef RN_DEBUG
772 /* Get us out of the creation list */
773 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
774 if (t) t->rn_ybro = tt->rn_ybro;
775 #endif
776 t = tt->rn_parent;
777 dupedkey = saved_tt->rn_dupedkey;
778 if (dupedkey) {
779 /*
780 * Here, tt is the deletion target and
781 * saved_tt is the head of the dupekey chain.
782 */
783 if (tt == saved_tt) {
784 /* remove from head of chain */
785 x = dupedkey; x->rn_parent = t;
786 if (t->rn_left == tt)
787 t->rn_left = x;
788 else
789 t->rn_right = x;
790 } else {
791 /* find node in front of tt on the chain */
792 for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
793 p = p->rn_dupedkey;
794 if (p) {
795 p->rn_dupedkey = tt->rn_dupedkey;
796 if (tt->rn_dupedkey) /* parent */
797 tt->rn_dupedkey->rn_parent = p;
798 /* parent */
799 } else log(LOG_ERR, "rn_delete: couldn't find us\n");
800 }
801 t = tt + 1;
802 if (t->rn_flags & RNF_ACTIVE) {
803 #ifndef RN_DEBUG
804 *++x = *t;
805 p = t->rn_parent;
806 #else
807 b = t->rn_info;
808 *++x = *t;
809 t->rn_info = b;
810 p = t->rn_parent;
811 #endif
812 if (p->rn_left == t)
813 p->rn_left = x;
814 else
815 p->rn_right = x;
816 x->rn_left->rn_parent = x;
817 x->rn_right->rn_parent = x;
818 }
819 goto out;
820 }
821 if (t->rn_left == tt)
822 x = t->rn_right;
823 else
824 x = t->rn_left;
825 p = t->rn_parent;
826 if (p->rn_right == t)
827 p->rn_right = x;
828 else
829 p->rn_left = x;
830 x->rn_parent = p;
831 /*
832 * Demote routes attached to us.
833 */
834 if (t->rn_mklist) {
835 if (x->rn_bit >= 0) {
836 for (mp = &x->rn_mklist; (m = *mp);)
837 mp = &m->rm_mklist;
838 *mp = t->rn_mklist;
839 } else {
840 /* If there are any key,mask pairs in a sibling
841 duped-key chain, some subset will appear sorted
842 in the same order attached to our mklist */
843 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
844 if (m == x->rn_mklist) {
845 struct radix_mask *mm = m->rm_mklist;
846 x->rn_mklist = 0;
847 if (--(m->rm_refs) < 0)
848 MKFree(m);
849 m = mm;
850 }
851 if (m)
852 log(LOG_ERR,
853 "rn_delete: Orphaned Mask %p at %p\n",
854 (void *)m, (void *)x);
855 }
856 }
857 /*
858 * We may be holding an active internal node in the tree.
859 */
860 x = tt + 1;
861 if (t != x) {
862 #ifndef RN_DEBUG
863 *t = *x;
864 #else
865 b = t->rn_info;
866 *t = *x;
867 t->rn_info = b;
868 #endif
869 t->rn_left->rn_parent = t;
870 t->rn_right->rn_parent = t;
871 p = x->rn_parent;
872 if (p->rn_left == x)
873 p->rn_left = t;
874 else
875 p->rn_right = t;
876 }
877 out:
878 tt->rn_flags &= ~RNF_ACTIVE;
879 tt[1].rn_flags &= ~RNF_ACTIVE;
880 return (tt);
881 }
882
883 /*
884 * This is the same as rn_walktree() except for the parameters and the
885 * exit.
886 */
887 static int
888 rn_walktree_from(h, a, m, f, w)
889 struct radix_node_head *h;
890 void *a, *m;
891 walktree_f_t *f;
892 void *w;
893 {
894 int error;
895 struct radix_node *base, *next;
896 u_char *xa = (u_char *)a;
897 u_char *xm = (u_char *)m;
898 register struct radix_node *rn, *last = 0 /* shut up gcc */;
899 int stopping = 0;
900 int lastb;
901
902 /*
903 * rn_search_m is sort-of-open-coded here.
904 */
905 /* printf("about to search\n"); */
906 for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
907 last = rn;
908 /* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n",
909 rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */
910 if (!(rn->rn_bmask & xm[rn->rn_offset])) {
911 break;
912 }
913 if (rn->rn_bmask & xa[rn->rn_offset]) {
914 rn = rn->rn_right;
915 } else {
916 rn = rn->rn_left;
917 }
918 }
919 /* printf("done searching\n"); */
920
921 /*
922 * Two cases: either we stepped off the end of our mask,
923 * in which case last == rn, or we reached a leaf, in which
924 * case we want to start from the last node we looked at.
925 * Either way, last is the node we want to start from.
926 */
927 rn = last;
928 lastb = rn->rn_bit;
929
930 /* printf("rn %p, lastb %d\n", rn, lastb);*/
931
932 /*
933 * This gets complicated because we may delete the node
934 * while applying the function f to it, so we need to calculate
935 * the successor node in advance.
936 */
937 while (rn->rn_bit >= 0)
938 rn = rn->rn_left;
939
940 while (!stopping) {
941 /* printf("node %p (%d)\n", rn, rn->rn_bit); */
942 base = rn;
943 /* If at right child go back up, otherwise, go right */
944 while (rn->rn_parent->rn_right == rn
945 && !(rn->rn_flags & RNF_ROOT)) {
946 rn = rn->rn_parent;
947
948 /* if went up beyond last, stop */
949 if (rn->rn_bit < lastb) {
950 stopping = 1;
951 /* printf("up too far\n"); */
952 }
953 }
954
955 /* Find the next *leaf* since next node might vanish, too */
956 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
957 rn = rn->rn_left;
958 next = rn;
959 /* Process leaves */
960 while ((rn = base) != 0) {
961 base = rn->rn_dupedkey;
962 /* printf("leaf %p\n", rn); */
963 if (!(rn->rn_flags & RNF_ROOT)
964 && (error = (*f)(rn, w)))
965 return (error);
966 }
967 rn = next;
968
969 if (rn->rn_flags & RNF_ROOT) {
970 /* printf("root, stopping"); */
971 stopping = 1;
972 }
973
974 }
975 return 0;
976 }
977
978 static int
979 rn_walktree(h, f, w)
980 struct radix_node_head *h;
981 walktree_f_t *f;
982 void *w;
983 {
984 int error;
985 struct radix_node *base, *next;
986 register struct radix_node *rn = h->rnh_treetop;
987 /*
988 * This gets complicated because we may delete the node
989 * while applying the function f to it, so we need to calculate
990 * the successor node in advance.
991 */
992 /* First time through node, go left */
993 while (rn->rn_bit >= 0)
994 rn = rn->rn_left;
995 for (;;) {
996 base = rn;
997 /* If at right child go back up, otherwise, go right */
998 while (rn->rn_parent->rn_right == rn
999 && (rn->rn_flags & RNF_ROOT) == 0)
1000 rn = rn->rn_parent;
1001 /* Find the next *leaf* since next node might vanish, too */
1002 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1003 rn = rn->rn_left;
1004 next = rn;
1005 /* Process leaves */
1006 while ((rn = base)) {
1007 base = rn->rn_dupedkey;
1008 if (!(rn->rn_flags & RNF_ROOT)
1009 && (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(head, off)
1021 void **head;
1022 int off;
1023 {
1024 register struct radix_node_head *rnh;
1025 register struct radix_node *t, *tt, *ttt;
1026 if (*head)
1027 return (1);
1028 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh));
1029 if (rnh == 0)
1030 return (0);
1031 Bzero(rnh, sizeof (*rnh));
1032 #ifdef _KERNEL
1033 RADIX_NODE_HEAD_LOCK_INIT(rnh);
1034 #endif
1035 *head = rnh;
1036 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
1037 ttt = rnh->rnh_nodes + 2;
1038 t->rn_right = ttt;
1039 t->rn_parent = t;
1040 tt = t->rn_left;
1041 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
1042 tt->rn_bit = -1 - off;
1043 *ttt = *tt;
1044 ttt->rn_key = rn_ones;
1045 rnh->rnh_addaddr = rn_addroute;
1046 rnh->rnh_deladdr = rn_delete;
1047 rnh->rnh_matchaddr = rn_match;
1048 rnh->rnh_lookup = rn_lookup;
1049 rnh->rnh_walktree = rn_walktree;
1050 rnh->rnh_walktree_from = rn_walktree_from;
1051 rnh->rnh_treetop = t;
1052 return (1);
1053 }
1054
1055 void
1056 rn_init()
1057 {
1058 char *cp, *cplim;
1059 #ifdef _KERNEL
1060 struct domain *dom;
1061
1062 for (dom = domains; dom; dom = dom->dom_next)
1063 if (dom->dom_maxrtkey > max_keylen)
1064 max_keylen = dom->dom_maxrtkey;
1065 #endif
1066 if (max_keylen == 0) {
1067 log(LOG_ERR,
1068 "rn_init: radix functions require max_keylen be set\n");
1069 return;
1070 }
1071 R_Malloc(rn_zeros, char *, 3 * max_keylen);
1072 if (rn_zeros == NULL)
1073 panic("rn_init");
1074 Bzero(rn_zeros, 3 * max_keylen);
1075 rn_ones = cp = rn_zeros + max_keylen;
1076 addmask_key = cplim = rn_ones + max_keylen;
1077 while (cp < cplim)
1078 *cp++ = -1;
1079 if (rn_inithead((void **)&mask_rnhead, 0) == 0)
1080 panic("rn_init 2");
1081 }
Cache object: 31982a76c170797a034a1c670f6db845
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