FreeBSD/Linux Kernel Cross Reference
sys/net/radix.c
1 /* $NetBSD: radix.c,v 1.31 2006/02/25 00:58:35 wiz Exp $ */
2
3 /*
4 * Copyright (c) 1988, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)radix.c 8.6 (Berkeley) 10/17/95
32 */
33
34 /*
35 * Routines to build and maintain radix trees for routing lookups.
36 */
37
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: radix.c,v 1.31 2006/02/25 00:58:35 wiz Exp $");
40
41 #ifndef _NET_RADIX_H_
42 #include <sys/param.h>
43 #ifdef _KERNEL
44 #include "opt_inet.h"
45
46 #include <sys/systm.h>
47 #include <sys/malloc.h>
48 #define M_DONTWAIT M_NOWAIT
49 #include <sys/domain.h>
50 #include <netinet/ip_encap.h>
51 #else
52 #include <stdlib.h>
53 #endif
54 #include <sys/syslog.h>
55 #include <net/radix.h>
56 #endif
57
58 int max_keylen;
59 struct radix_mask *rn_mkfreelist;
60 struct radix_node_head *mask_rnhead;
61 static char *addmask_key;
62 static const char normal_chars[] =
63 {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
64 static char *rn_zeros, *rn_ones;
65
66 #define rn_masktop (mask_rnhead->rnh_treetop)
67
68 static int rn_satisfies_leaf(const char *, struct radix_node *, int);
69 static int rn_lexobetter(const void *, const void *);
70 static struct radix_mask *rn_new_radix_mask(struct radix_node *,
71 struct radix_mask *);
72
73 /*
74 * The data structure for the keys is a radix tree with one way
75 * branching removed. The index rn_b at an internal node n represents a bit
76 * position to be tested. The tree is arranged so that all descendants
77 * of a node n have keys whose bits all agree up to position rn_b - 1.
78 * (We say the index of n is rn_b.)
79 *
80 * There is at least one descendant which has a one bit at position rn_b,
81 * and at least one with a zero there.
82 *
83 * A route is determined by a pair of key and mask. We require that the
84 * bit-wise logical and of the key and mask to be the key.
85 * We define the index of a route to associated with the mask to be
86 * the first bit number in the mask where 0 occurs (with bit number 0
87 * representing the highest order bit).
88 *
89 * We say a mask is normal if every bit is 0, past the index of the mask.
90 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b,
91 * and m is a normal mask, then the route applies to every descendant of n.
92 * If the index(m) < rn_b, this implies the trailing last few bits of k
93 * before bit b are all 0, (and hence consequently true of every descendant
94 * of n), so the route applies to all descendants of the node as well.
95 *
96 * Similar logic shows that a non-normal mask m such that
97 * index(m) <= index(n) could potentially apply to many children of n.
98 * Thus, for each non-host route, we attach its mask to a list at an internal
99 * node as high in the tree as we can go.
100 *
101 * The present version of the code makes use of normal routes in short-
102 * circuiting an explicit mask and compare operation when testing whether
103 * a key satisfies a normal route, and also in remembering the unique leaf
104 * that governs a subtree.
105 */
106
107 struct radix_node *
108 rn_search(
109 const void *v_arg,
110 struct radix_node *head)
111 {
112 const u_char * const v = v_arg;
113 struct radix_node *x;
114
115 for (x = head; x->rn_b >= 0;) {
116 if (x->rn_bmask & v[x->rn_off])
117 x = x->rn_r;
118 else
119 x = x->rn_l;
120 }
121 return (x);
122 }
123
124 struct radix_node *
125 rn_search_m(
126 const void *v_arg,
127 struct radix_node *head,
128 const void *m_arg)
129 {
130 struct radix_node *x;
131 const u_char * const v = v_arg;
132 const u_char * const m = m_arg;
133
134 for (x = head; x->rn_b >= 0;) {
135 if ((x->rn_bmask & m[x->rn_off]) &&
136 (x->rn_bmask & v[x->rn_off]))
137 x = x->rn_r;
138 else
139 x = x->rn_l;
140 }
141 return x;
142 }
143
144 int
145 rn_refines(
146 const void *m_arg,
147 const void *n_arg)
148 {
149 const char *m = m_arg;
150 const char *n = n_arg;
151 const char *lim = n + *(const u_char *)n;
152 const char *lim2 = lim;
153 int longer = (*(const u_char *)n++) - (int)(*(const u_char *)m++);
154 int masks_are_equal = 1;
155
156 if (longer > 0)
157 lim -= longer;
158 while (n < lim) {
159 if (*n & ~(*m))
160 return 0;
161 if (*n++ != *m++)
162 masks_are_equal = 0;
163 }
164 while (n < lim2)
165 if (*n++)
166 return 0;
167 if (masks_are_equal && (longer < 0))
168 for (lim2 = m - longer; m < lim2; )
169 if (*m++)
170 return 1;
171 return (!masks_are_equal);
172 }
173
174 struct radix_node *
175 rn_lookup(
176 const void *v_arg,
177 const void *m_arg,
178 struct radix_node_head *head)
179 {
180 struct radix_node *x;
181 const char *netmask = NULL;
182
183 if (m_arg) {
184 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0)
185 return (0);
186 netmask = x->rn_key;
187 }
188 x = rn_match(v_arg, head);
189 if (x && netmask) {
190 while (x && x->rn_mask != netmask)
191 x = x->rn_dupedkey;
192 }
193 return x;
194 }
195
196 static int
197 rn_satisfies_leaf(
198 const char *trial,
199 struct radix_node *leaf,
200 int skip)
201 {
202 const char *cp = trial;
203 const char *cp2 = leaf->rn_key;
204 const char *cp3 = leaf->rn_mask;
205 const char *cplim;
206 int length = min(*(const u_char *)cp, *(const u_char *)cp2);
207
208 if (cp3 == 0)
209 cp3 = rn_ones;
210 else
211 length = min(length, *(const u_char *)cp3);
212 cplim = cp + length; cp3 += skip; cp2 += skip;
213 for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
214 if ((*cp ^ *cp2) & *cp3)
215 return 0;
216 return 1;
217 }
218
219 struct radix_node *
220 rn_match(
221 const void *v_arg,
222 struct radix_node_head *head)
223 {
224 const char * const v = v_arg;
225 struct radix_node *t = head->rnh_treetop;
226 struct radix_node *top = t;
227 struct radix_node *x;
228 struct radix_node *saved_t;
229 const char *cp = v;
230 const char *cp2;
231 const char *cplim;
232 int off = t->rn_off;
233 int vlen = *(const u_char *)cp;
234 int matched_off;
235 int test, b, rn_b;
236
237 /*
238 * Open code rn_search(v, top) to avoid overhead of extra
239 * subroutine call.
240 */
241 for (; t->rn_b >= 0; ) {
242 if (t->rn_bmask & cp[t->rn_off])
243 t = t->rn_r;
244 else
245 t = t->rn_l;
246 }
247 /*
248 * See if we match exactly as a host destination
249 * or at least learn how many bits match, for normal mask finesse.
250 *
251 * It doesn't hurt us to limit how many bytes to check
252 * to the length of the mask, since if it matches we had a genuine
253 * match and the leaf we have is the most specific one anyway;
254 * if it didn't match with a shorter length it would fail
255 * with a long one. This wins big for class B&C netmasks which
256 * are probably the most common case...
257 */
258 if (t->rn_mask)
259 vlen = *(const u_char *)t->rn_mask;
260 cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
261 for (; cp < cplim; cp++, cp2++)
262 if (*cp != *cp2)
263 goto on1;
264 /*
265 * This extra grot is in case we are explicitly asked
266 * to look up the default. Ugh!
267 */
268 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey)
269 t = t->rn_dupedkey;
270 return t;
271 on1:
272 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
273 for (b = 7; (test >>= 1) > 0;)
274 b--;
275 matched_off = cp - v;
276 b += matched_off << 3;
277 rn_b = -1 - b;
278 /*
279 * If there is a host route in a duped-key chain, it will be first.
280 */
281 if ((saved_t = t)->rn_mask == 0)
282 t = t->rn_dupedkey;
283 for (; t; t = t->rn_dupedkey)
284 /*
285 * Even if we don't match exactly as a host,
286 * we may match if the leaf we wound up at is
287 * a route to a net.
288 */
289 if (t->rn_flags & RNF_NORMAL) {
290 if (rn_b <= t->rn_b)
291 return t;
292 } else if (rn_satisfies_leaf(v, t, matched_off))
293 return t;
294 t = saved_t;
295 /* start searching up the tree */
296 do {
297 struct radix_mask *m;
298 t = t->rn_p;
299 m = t->rn_mklist;
300 if (m) {
301 /*
302 * If non-contiguous masks ever become important
303 * we can restore the masking and open coding of
304 * the search and satisfaction test and put the
305 * calculation of "off" back before the "do".
306 */
307 do {
308 if (m->rm_flags & RNF_NORMAL) {
309 if (rn_b <= m->rm_b)
310 return (m->rm_leaf);
311 } else {
312 off = min(t->rn_off, matched_off);
313 x = rn_search_m(v, t, m->rm_mask);
314 while (x && x->rn_mask != m->rm_mask)
315 x = x->rn_dupedkey;
316 if (x && rn_satisfies_leaf(v, x, off))
317 return x;
318 }
319 m = m->rm_mklist;
320 } while (m);
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 struct radix_node *
334 rn_newpair(
335 const void *v,
336 int b,
337 struct radix_node nodes[2])
338 {
339 struct radix_node *tt = nodes;
340 struct radix_node *t = tt + 1;
341 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7);
342 t->rn_l = tt; t->rn_off = b >> 3;
343 tt->rn_b = -1; tt->rn_key = v; tt->rn_p = t;
344 tt->rn_flags = t->rn_flags = RNF_ACTIVE;
345 #ifdef RN_DEBUG
346 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
347 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
348 #endif
349 return t;
350 }
351
352 struct radix_node *
353 rn_insert(
354 const void *v_arg,
355 struct radix_node_head *head,
356 int *dupentry,
357 struct radix_node nodes[2])
358 {
359 struct radix_node *top = head->rnh_treetop;
360 struct radix_node *t = rn_search(v_arg, top);
361 struct radix_node *tt;
362 const char *v = v_arg;
363 int head_off = top->rn_off;
364 int vlen = *((const u_char *)v);
365 const char *cp = v + head_off;
366 int b;
367 /*
368 * Find first bit at which v and t->rn_key differ
369 */
370 {
371 const char *cp2 = t->rn_key + head_off;
372 const char *cplim = v + vlen;
373 int cmp_res;
374
375 while (cp < cplim)
376 if (*cp2++ != *cp++)
377 goto on1;
378 *dupentry = 1;
379 return t;
380 on1:
381 *dupentry = 0;
382 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
383 for (b = (cp - v) << 3; cmp_res; b--)
384 cmp_res >>= 1;
385 }
386 {
387 struct radix_node *p, *x = top;
388 cp = v;
389 do {
390 p = x;
391 if (cp[x->rn_off] & x->rn_bmask)
392 x = x->rn_r;
393 else x = x->rn_l;
394 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */
395 #ifdef RN_DEBUG
396 if (rn_debug)
397 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
398 #endif
399 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l;
400 if ((cp[p->rn_off] & p->rn_bmask) == 0)
401 p->rn_l = t;
402 else
403 p->rn_r = t;
404 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */
405 if ((cp[t->rn_off] & t->rn_bmask) == 0) {
406 t->rn_r = x;
407 } else {
408 t->rn_r = tt; t->rn_l = x;
409 }
410 #ifdef RN_DEBUG
411 if (rn_debug)
412 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
413 #endif
414 }
415 return (tt);
416 }
417
418 struct radix_node *
419 rn_addmask(
420 const void *n_arg,
421 int search,
422 int skip)
423 {
424 const char *netmask = n_arg;
425 const char *cp;
426 const char *cplim;
427 struct radix_node *x;
428 struct radix_node *saved_x;
429 int b = 0, mlen, j;
430 int maskduplicated, m0, isnormal;
431 static int last_zeroed = 0;
432
433 if ((mlen = *(const u_char *)netmask) > max_keylen)
434 mlen = max_keylen;
435 if (skip == 0)
436 skip = 1;
437 if (mlen <= skip)
438 return (mask_rnhead->rnh_nodes);
439 if (skip > 1)
440 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
441 if ((m0 = mlen) > skip)
442 Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
443 /*
444 * Trim trailing zeroes.
445 */
446 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
447 cp--;
448 mlen = cp - addmask_key;
449 if (mlen <= skip) {
450 if (m0 >= last_zeroed)
451 last_zeroed = mlen;
452 return (mask_rnhead->rnh_nodes);
453 }
454 if (m0 < last_zeroed)
455 Bzero(addmask_key + m0, last_zeroed - m0);
456 *addmask_key = last_zeroed = mlen;
457 x = rn_search(addmask_key, rn_masktop);
458 if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
459 x = 0;
460 if (x || search)
461 return (x);
462 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
463 if ((saved_x = x) == 0)
464 return (0);
465 Bzero(x, max_keylen + 2 * sizeof (*x));
466 cp = netmask = (caddr_t)(x + 2);
467 Bcopy(addmask_key, (caddr_t)(x + 2), mlen);
468 x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
469 if (maskduplicated) {
470 log(LOG_ERR, "rn_addmask: mask impossibly already in tree\n");
471 Free(saved_x);
472 return (x);
473 }
474 /*
475 * Calculate index of mask, and check for normalcy.
476 */
477 cplim = netmask + mlen; isnormal = 1;
478 for (cp = netmask + skip; (cp < cplim) && *(const u_char *)cp == 0xff;)
479 cp++;
480 if (cp != cplim) {
481 for (j = 0x80; (j & *cp) != 0; j >>= 1)
482 b++;
483 if (*cp != normal_chars[b] || cp != (cplim - 1))
484 isnormal = 0;
485 }
486 b += (cp - netmask) << 3;
487 x->rn_b = -1 - b;
488 if (isnormal)
489 x->rn_flags |= RNF_NORMAL;
490 return (x);
491 }
492
493 static int /* XXX: arbitrary ordering for non-contiguous masks */
494 rn_lexobetter(
495 const void *m_arg,
496 const void *n_arg)
497 {
498 const u_char *mp = m_arg;
499 const u_char *np = n_arg;
500 const u_char *lim;
501
502 if (*mp > *np)
503 return 1; /* not really, but need to check longer one first */
504 if (*mp == *np)
505 for (lim = mp + *mp; mp < lim;)
506 if (*mp++ > *np++)
507 return 1;
508 return 0;
509 }
510
511 static struct radix_mask *
512 rn_new_radix_mask(
513 struct radix_node *tt,
514 struct radix_mask *next)
515 {
516 struct radix_mask *m;
517
518 MKGet(m);
519 if (m == 0) {
520 log(LOG_ERR, "Mask for route not entered\n");
521 return (0);
522 }
523 Bzero(m, sizeof *m);
524 m->rm_b = tt->rn_b;
525 m->rm_flags = tt->rn_flags;
526 if (tt->rn_flags & RNF_NORMAL)
527 m->rm_leaf = tt;
528 else
529 m->rm_mask = tt->rn_mask;
530 m->rm_mklist = next;
531 tt->rn_mklist = m;
532 return m;
533 }
534
535 struct radix_node *
536 rn_addroute(
537 const void *v_arg,
538 const void *n_arg,
539 struct radix_node_head *head,
540 struct radix_node treenodes[2])
541 {
542 const char *v = v_arg;
543 const char *netmask = n_arg;
544 struct radix_node *t;
545 struct radix_node *x = 0;
546 struct radix_node *tt;
547 struct radix_node *saved_tt;
548 struct radix_node *top = head->rnh_treetop;
549 short b = 0, b_leaf = 0;
550 int keyduplicated;
551 const char *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_off)) == 0)
563 return (0);
564 b_leaf = x->rn_b;
565 b = -1 - x->rn_b;
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_b) || /* 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_p = x = t->rn_p;
602 t->rn_p = tt;
603 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt;
604 saved_tt = tt; x = xx;
605 } else {
606 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
607 t->rn_dupedkey = tt;
608 tt->rn_p = t;
609 if (tt->rn_dupedkey)
610 tt->rn_dupedkey->rn_p = tt;
611 }
612 #ifdef RN_DEBUG
613 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
614 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
615 #endif
616 tt->rn_key = __UNCONST(v); /*XXXUNCONST*/
617 tt->rn_b = -1;
618 tt->rn_flags = RNF_ACTIVE;
619 }
620 /*
621 * Put mask in tree.
622 */
623 if (netmask) {
624 tt->rn_mask = netmask;
625 tt->rn_b = x->rn_b;
626 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
627 }
628 t = saved_tt->rn_p;
629 if (keyduplicated)
630 goto on2;
631 b_leaf = -1 - t->rn_b;
632 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r;
633 /* Promote general routes from below */
634 if (x->rn_b < 0) {
635 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
636 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) {
637 *mp = m = rn_new_radix_mask(x, 0);
638 if (m)
639 mp = &m->rm_mklist;
640 }
641 } else if (x->rn_mklist) {
642 /*
643 * Skip over masks whose index is > that of new node
644 */
645 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
646 if (m->rm_b >= b_leaf)
647 break;
648 t->rn_mklist = m; *mp = 0;
649 }
650 on2:
651 /* Add new route to highest possible ancestor's list */
652 if ((netmask == 0) || (b > t->rn_b ))
653 return tt; /* can't lift at all */
654 b_leaf = tt->rn_b;
655 do {
656 x = t;
657 t = t->rn_p;
658 } while (b <= t->rn_b && x != top);
659 /*
660 * Search through routes associated with node to
661 * insert new route according to index.
662 * Need same criteria as when sorting dupedkeys to avoid
663 * double loop on deletion.
664 */
665 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
666 if (m->rm_b < b_leaf)
667 continue;
668 if (m->rm_b > b_leaf)
669 break;
670 if (m->rm_flags & RNF_NORMAL) {
671 mmask = m->rm_leaf->rn_mask;
672 if (tt->rn_flags & RNF_NORMAL) {
673 log(LOG_ERR, "Non-unique normal route,"
674 " mask not entered\n");
675 return tt;
676 }
677 } else
678 mmask = m->rm_mask;
679 if (mmask == netmask) {
680 m->rm_refs++;
681 tt->rn_mklist = m;
682 return tt;
683 }
684 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
685 break;
686 }
687 *mp = rn_new_radix_mask(tt, *mp);
688 return tt;
689 }
690
691 struct radix_node *
692 rn_delete(
693 const void *v_arg,
694 const void *netmask_arg,
695 struct radix_node_head *head)
696 {
697 struct radix_node *t;
698 struct radix_node *p;
699 struct radix_node *x;
700 struct radix_node *tt;
701 struct radix_node *dupedkey;
702 struct radix_node *saved_tt;
703 struct radix_node *top;
704 struct radix_mask *m;
705 struct radix_mask *saved_m;
706 struct radix_mask **mp;
707 const char *v = v_arg;
708 const char *netmask = netmask_arg;
709 int b, head_off, vlen;
710
711 x = head->rnh_treetop;
712 tt = rn_search(v, x);
713 head_off = x->rn_off;
714 vlen = *(const 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_b;
747 t = saved_tt->rn_p;
748 if (b > t->rn_b)
749 goto on1; /* Wasn't lifted at all */
750 do {
751 x = t;
752 t = t->rn_p;
753 } while (b <= t->rn_b && 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_p;
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 dupedkey chain.
782 */
783 if (tt == saved_tt) {
784 x = dupedkey; x->rn_p = t;
785 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x;
786 } else {
787 /* find node in front of tt on the chain */
788 for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
789 p = p->rn_dupedkey;
790 if (p) {
791 p->rn_dupedkey = tt->rn_dupedkey;
792 if (tt->rn_dupedkey)
793 tt->rn_dupedkey->rn_p = p;
794 } else log(LOG_ERR, "rn_delete: couldn't find us\n");
795 }
796 t = tt + 1;
797 if (t->rn_flags & RNF_ACTIVE) {
798 #ifndef RN_DEBUG
799 *++x = *t; p = t->rn_p;
800 #else
801 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p;
802 #endif
803 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x;
804 x->rn_l->rn_p = x; x->rn_r->rn_p = x;
805 }
806 goto out;
807 }
808 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l;
809 p = t->rn_p;
810 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x;
811 x->rn_p = p;
812 /*
813 * Demote routes attached to us.
814 */
815 if (t->rn_mklist) {
816 if (x->rn_b >= 0) {
817 for (mp = &x->rn_mklist; (m = *mp);)
818 mp = &m->rm_mklist;
819 *mp = t->rn_mklist;
820 } else {
821 /* If there are any key,mask pairs in a sibling
822 duped-key chain, some subset will appear sorted
823 in the same order attached to our mklist */
824 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
825 if (m == x->rn_mklist) {
826 struct radix_mask *mm = m->rm_mklist;
827 x->rn_mklist = 0;
828 if (--(m->rm_refs) < 0)
829 MKFree(m);
830 m = mm;
831 }
832 if (m)
833 log(LOG_ERR, "%s %p at %p\n",
834 "rn_delete: Orphaned Mask", m, x);
835 }
836 }
837 /*
838 * We may be holding an active internal node in the tree.
839 */
840 x = tt + 1;
841 if (t != x) {
842 #ifndef RN_DEBUG
843 *t = *x;
844 #else
845 b = t->rn_info; *t = *x; t->rn_info = b;
846 #endif
847 t->rn_l->rn_p = t; t->rn_r->rn_p = t;
848 p = x->rn_p;
849 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t;
850 }
851 out:
852 tt->rn_flags &= ~RNF_ACTIVE;
853 tt[1].rn_flags &= ~RNF_ACTIVE;
854 return (tt);
855 }
856
857 int
858 rn_walktree(
859 struct radix_node_head *h,
860 int (*f)(struct radix_node *, void *),
861 void *w)
862 {
863 int error;
864 struct radix_node *base;
865 struct radix_node *next;
866 struct radix_node *rn = h->rnh_treetop;
867 /*
868 * This gets complicated because we may delete the node
869 * while applying the function f to it, so we need to calculate
870 * the successor node in advance.
871 */
872 /* First time through node, go left */
873 while (rn->rn_b >= 0)
874 rn = rn->rn_l;
875 for (;;) {
876 base = rn;
877 /* If at right child go back up, otherwise, go right */
878 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0)
879 rn = rn->rn_p;
880 /* Find the next *leaf* since next node might vanish, too */
881 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;)
882 rn = rn->rn_l;
883 next = rn;
884 /* Process leaves */
885 while ((rn = base) != NULL) {
886 base = rn->rn_dupedkey;
887 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
888 return (error);
889 }
890 rn = next;
891 if (rn->rn_flags & RNF_ROOT)
892 return (0);
893 }
894 /* NOTREACHED */
895 }
896
897 int
898 rn_inithead(head, off)
899 void **head;
900 int off;
901 {
902 struct radix_node_head *rnh;
903
904 if (*head)
905 return (1);
906 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh));
907 if (rnh == 0)
908 return (0);
909 *head = rnh;
910 return rn_inithead0(rnh, off);
911 }
912
913 int
914 rn_inithead0(rnh, off)
915 struct radix_node_head *rnh;
916 int off;
917 {
918 struct radix_node *t;
919 struct radix_node *tt;
920 struct radix_node *ttt;
921
922 Bzero(rnh, sizeof (*rnh));
923 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
924 ttt = rnh->rnh_nodes + 2;
925 t->rn_r = ttt;
926 t->rn_p = t;
927 tt = t->rn_l;
928 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
929 tt->rn_b = -1 - off;
930 *ttt = *tt;
931 ttt->rn_key = rn_ones;
932 rnh->rnh_addaddr = rn_addroute;
933 rnh->rnh_deladdr = rn_delete;
934 rnh->rnh_matchaddr = rn_match;
935 rnh->rnh_lookup = rn_lookup;
936 rnh->rnh_walktree = rn_walktree;
937 rnh->rnh_treetop = t;
938 return (1);
939 }
940
941 void
942 rn_init()
943 {
944 char *cp, *cplim;
945 #ifdef _KERNEL
946 static int initialized;
947 __link_set_decl(domains, struct domain);
948 struct domain *const *dpp;
949
950 if (initialized)
951 return;
952 initialized = 1;
953
954 __link_set_foreach(dpp, domains) {
955 if ((*dpp)->dom_maxrtkey > max_keylen)
956 max_keylen = (*dpp)->dom_maxrtkey;
957 }
958 #ifdef INET
959 encap_setkeylen();
960 #endif
961 #endif
962 if (max_keylen == 0) {
963 log(LOG_ERR,
964 "rn_init: radix functions require max_keylen be set\n");
965 return;
966 }
967 R_Malloc(rn_zeros, char *, 3 * max_keylen);
968 if (rn_zeros == NULL)
969 panic("rn_init");
970 Bzero(rn_zeros, 3 * max_keylen);
971 rn_ones = cp = rn_zeros + max_keylen;
972 addmask_key = cplim = rn_ones + max_keylen;
973 while (cp < cplim)
974 *cp++ = -1;
975 if (rn_inithead((void *)&mask_rnhead, 0) == 0)
976 panic("rn_init 2");
977 }
Cache object: ac10db8a6725799294c658426ef73370
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