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 * 4. 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 8.5 (Berkeley) 5/19/95
30 * $FreeBSD$
31 */
32
33 /*
34 * Routines to build and maintain radix trees for routing lookups.
35 */
36 #ifndef _RADIX_H_
37 #include <sys/param.h>
38 #ifdef _KERNEL
39 #include <sys/lock.h>
40 #include <sys/mutex.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/domain.h>
44 #else
45 #include <stdlib.h>
46 #endif
47 #include <sys/syslog.h>
48 #include <net/radix.h>
49 #endif
50
51 static int rn_walktree_from(struct radix_node_head *h, void *a, void *m,
52 walktree_f_t *f, void *w);
53 static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
54 static struct radix_node
55 *rn_insert(void *, struct radix_node_head *, int *,
56 struct radix_node [2]),
57 *rn_newpair(void *, int, struct radix_node[2]),
58 *rn_search(void *, struct radix_node *),
59 *rn_search_m(void *, struct radix_node *, void *);
60
61 static int max_keylen;
62 static struct radix_mask *rn_mkfreelist;
63 static struct radix_node_head *mask_rnhead;
64 /*
65 * Work area -- the following point to 3 buffers of size max_keylen,
66 * allocated in this order in a block of memory malloc'ed by rn_init.
67 */
68 static char *rn_zeros, *rn_ones, *addmask_key;
69
70 #define MKGet(m) { \
71 if (rn_mkfreelist) { \
72 m = rn_mkfreelist; \
73 rn_mkfreelist = (m)->rm_mklist; \
74 } else \
75 R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask)); }
76
77 #define MKFree(m) { (m)->rm_mklist = rn_mkfreelist; rn_mkfreelist = (m);}
78
79 #define rn_masktop (mask_rnhead->rnh_treetop)
80
81 static int rn_lexobetter(void *m_arg, void *n_arg);
82 static struct radix_mask *
83 rn_new_radix_mask(struct radix_node *tt,
84 struct radix_mask *next);
85 static int rn_satisfies_leaf(char *trial, struct radix_node *leaf,
86 int skip);
87
88 /*
89 * The data structure for the keys is a radix tree with one way
90 * branching removed. The index rn_bit at an internal node n represents a bit
91 * position to be tested. The tree is arranged so that all descendants
92 * of a node n have keys whose bits all agree up to position rn_bit - 1.
93 * (We say the index of n is rn_bit.)
94 *
95 * There is at least one descendant which has a one bit at position rn_bit,
96 * and at least one with a zero there.
97 *
98 * A route is determined by a pair of key and mask. We require that the
99 * bit-wise logical and of the key and mask to be the key.
100 * We define the index of a route to associated with the mask to be
101 * the first bit number in the mask where 0 occurs (with bit number 0
102 * representing the highest order bit).
103 *
104 * We say a mask is normal if every bit is 0, past the index of the mask.
105 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
106 * and m is a normal mask, then the route applies to every descendant of n.
107 * If the index(m) < rn_bit, this implies the trailing last few bits of k
108 * before bit b are all 0, (and hence consequently true of every descendant
109 * of n), so the route applies to all descendants of the node as well.
110 *
111 * Similar logic shows that a non-normal mask m such that
112 * index(m) <= index(n) could potentially apply to many children of n.
113 * Thus, for each non-host route, we attach its mask to a list at an internal
114 * node as high in the tree as we can go.
115 *
116 * The present version of the code makes use of normal routes in short-
117 * circuiting an explict mask and compare operation when testing whether
118 * a key satisfies a normal route, and also in remembering the unique leaf
119 * that governs a subtree.
120 */
121
122 /*
123 * Most of the functions in this code assume that the key/mask arguments
124 * are sockaddr-like structures, where the first byte is an u_char
125 * indicating the size of the entire structure.
126 *
127 * To make the assumption more explicit, we use the LEN() macro to access
128 * this field. It is safe to pass an expression with side effects
129 * to LEN() as the argument is evaluated only once.
130 */
131 #define LEN(x) (*(const u_char *)(x))
132
133 /*
134 * XXX THIS NEEDS TO BE FIXED
135 * In the code, pointers to keys and masks are passed as either
136 * 'void *' (because callers use to pass pointers of various kinds), or
137 * 'caddr_t' (which is fine for pointer arithmetics, but not very
138 * clean when you dereference it to access data). Furthermore, caddr_t
139 * is really 'char *', while the natural type to operate on keys and
140 * masks would be 'u_char'. This mismatch require a lot of casts and
141 * intermediate variables to adapt types that clutter the code.
142 */
143
144 /*
145 * Search a node in the tree matching the key.
146 */
147 static struct radix_node *
148 rn_search(v_arg, head)
149 void *v_arg;
150 struct radix_node *head;
151 {
152 register struct radix_node *x;
153 register caddr_t v;
154
155 for (x = head, v = v_arg; x->rn_bit >= 0;) {
156 if (x->rn_bmask & v[x->rn_offset])
157 x = x->rn_right;
158 else
159 x = x->rn_left;
160 }
161 return (x);
162 }
163
164 /*
165 * Same as above, but with an additional mask.
166 * XXX note this function is used only once.
167 */
168 static struct radix_node *
169 rn_search_m(v_arg, head, m_arg)
170 struct radix_node *head;
171 void *v_arg, *m_arg;
172 {
173 register struct radix_node *x;
174 register caddr_t v = v_arg, m = m_arg;
175
176 for (x = head; x->rn_bit >= 0;) {
177 if ((x->rn_bmask & m[x->rn_offset]) &&
178 (x->rn_bmask & v[x->rn_offset]))
179 x = x->rn_right;
180 else
181 x = x->rn_left;
182 }
183 return x;
184 }
185
186 int
187 rn_refines(m_arg, n_arg)
188 void *m_arg, *n_arg;
189 {
190 register caddr_t m = m_arg, n = n_arg;
191 register caddr_t lim, lim2 = lim = n + LEN(n);
192 int longer = LEN(n++) - (int)LEN(m++);
193 int masks_are_equal = 1;
194
195 if (longer > 0)
196 lim -= longer;
197 while (n < lim) {
198 if (*n & ~(*m))
199 return 0;
200 if (*n++ != *m++)
201 masks_are_equal = 0;
202 }
203 while (n < lim2)
204 if (*n++)
205 return 0;
206 if (masks_are_equal && (longer < 0))
207 for (lim2 = m - longer; m < lim2; )
208 if (*m++)
209 return 1;
210 return (!masks_are_equal);
211 }
212
213 struct radix_node *
214 rn_lookup(v_arg, m_arg, head)
215 void *v_arg, *m_arg;
216 struct radix_node_head *head;
217 {
218 register struct radix_node *x;
219 caddr_t netmask = 0;
220
221 if (m_arg) {
222 x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset);
223 if (x == 0)
224 return (0);
225 netmask = x->rn_key;
226 }
227 x = rn_match(v_arg, head);
228 if (x && netmask) {
229 while (x && x->rn_mask != netmask)
230 x = x->rn_dupedkey;
231 }
232 return x;
233 }
234
235 static int
236 rn_satisfies_leaf(trial, leaf, skip)
237 char *trial;
238 register struct radix_node *leaf;
239 int skip;
240 {
241 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
242 char *cplim;
243 int length = min(LEN(cp), LEN(cp2));
244
245 if (cp3 == 0)
246 cp3 = rn_ones;
247 else
248 length = min(length, *(u_char *)cp3);
249 cplim = cp + length; cp3 += skip; cp2 += skip;
250 for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
251 if ((*cp ^ *cp2) & *cp3)
252 return 0;
253 return 1;
254 }
255
256 struct radix_node *
257 rn_match(v_arg, head)
258 void *v_arg;
259 struct radix_node_head *head;
260 {
261 caddr_t v = v_arg;
262 register struct radix_node *t = head->rnh_treetop, *x;
263 register caddr_t cp = v, cp2;
264 caddr_t cplim;
265 struct radix_node *saved_t, *top = t;
266 int off = t->rn_offset, vlen = LEN(cp), matched_off;
267 register int test, b, rn_bit;
268
269 /*
270 * Open code rn_search(v, top) to avoid overhead of extra
271 * subroutine call.
272 */
273 for (; t->rn_bit >= 0; ) {
274 if (t->rn_bmask & cp[t->rn_offset])
275 t = t->rn_right;
276 else
277 t = t->rn_left;
278 }
279 /*
280 * See if we match exactly as a host destination
281 * or at least learn how many bits match, for normal mask finesse.
282 *
283 * It doesn't hurt us to limit how many bytes to check
284 * to the length of the mask, since if it matches we had a genuine
285 * match and the leaf we have is the most specific one anyway;
286 * if it didn't match with a shorter length it would fail
287 * with a long one. This wins big for class B&C netmasks which
288 * are probably the most common case...
289 */
290 if (t->rn_mask)
291 vlen = *(u_char *)t->rn_mask;
292 cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
293 for (; cp < cplim; cp++, cp2++)
294 if (*cp != *cp2)
295 goto on1;
296 /*
297 * This extra grot is in case we are explicitly asked
298 * to look up the default. Ugh!
299 *
300 * Never return the root node itself, it seems to cause a
301 * lot of confusion.
302 */
303 if (t->rn_flags & RNF_ROOT)
304 t = t->rn_dupedkey;
305 return t;
306 on1:
307 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
308 for (b = 7; (test >>= 1) > 0;)
309 b--;
310 matched_off = cp - v;
311 b += matched_off << 3;
312 rn_bit = -1 - b;
313 /*
314 * If there is a host route in a duped-key chain, it will be first.
315 */
316 if ((saved_t = t)->rn_mask == 0)
317 t = t->rn_dupedkey;
318 for (; t; t = t->rn_dupedkey)
319 /*
320 * Even if we don't match exactly as a host,
321 * we may match if the leaf we wound up at is
322 * a route to a net.
323 */
324 if (t->rn_flags & RNF_NORMAL) {
325 if (rn_bit <= t->rn_bit)
326 return t;
327 } else if (rn_satisfies_leaf(v, t, matched_off))
328 return t;
329 t = saved_t;
330 /* start searching up the tree */
331 do {
332 register struct radix_mask *m;
333 t = t->rn_parent;
334 m = t->rn_mklist;
335 /*
336 * If non-contiguous masks ever become important
337 * we can restore the masking and open coding of
338 * the search and satisfaction test and put the
339 * calculation of "off" back before the "do".
340 */
341 while (m) {
342 if (m->rm_flags & RNF_NORMAL) {
343 if (rn_bit <= m->rm_bit)
344 return (m->rm_leaf);
345 } else {
346 off = min(t->rn_offset, matched_off);
347 x = rn_search_m(v, t, m->rm_mask);
348 while (x && x->rn_mask != m->rm_mask)
349 x = x->rn_dupedkey;
350 if (x && rn_satisfies_leaf(v, x, off))
351 return x;
352 }
353 m = m->rm_mklist;
354 }
355 } while (t != top);
356 return 0;
357 }
358
359 #ifdef RN_DEBUG
360 int rn_nodenum;
361 struct radix_node *rn_clist;
362 int rn_saveinfo;
363 int rn_debug = 1;
364 #endif
365
366 /*
367 * Whenever we add a new leaf to the tree, we also add a parent node,
368 * so we allocate them as an array of two elements: the first one must be
369 * the leaf (see RNTORT() in route.c), the second one is the parent.
370 * This routine initializes the relevant fields of the nodes, so that
371 * the leaf is the left child of the parent node, and both nodes have
372 * (almost) all all fields filled as appropriate.
373 * (XXX some fields are left unset, see the '#if 0' section).
374 * The function returns a pointer to the parent node.
375 */
376
377 static struct radix_node *
378 rn_newpair(v, b, nodes)
379 void *v;
380 int b;
381 struct radix_node nodes[2];
382 {
383 register struct radix_node *tt = nodes, *t = tt + 1;
384 t->rn_bit = b;
385 t->rn_bmask = 0x80 >> (b & 7);
386 t->rn_left = tt;
387 t->rn_offset = b >> 3;
388
389 #if 0 /* XXX perhaps we should fill these fields as well. */
390 t->rn_parent = t->rn_right = NULL;
391
392 tt->rn_mask = NULL;
393 tt->rn_dupedkey = NULL;
394 tt->rn_bmask = 0;
395 #endif
396 tt->rn_bit = -1;
397 tt->rn_key = (caddr_t)v;
398 tt->rn_parent = t;
399 tt->rn_flags = t->rn_flags = RNF_ACTIVE;
400 tt->rn_mklist = t->rn_mklist = 0;
401 #ifdef RN_DEBUG
402 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
403 tt->rn_twin = t;
404 tt->rn_ybro = rn_clist;
405 rn_clist = tt;
406 #endif
407 return t;
408 }
409
410 static struct radix_node *
411 rn_insert(v_arg, head, dupentry, nodes)
412 void *v_arg;
413 struct radix_node_head *head;
414 int *dupentry;
415 struct radix_node nodes[2];
416 {
417 caddr_t v = v_arg;
418 struct radix_node *top = head->rnh_treetop;
419 int head_off = top->rn_offset, vlen = (int)LEN(v);
420 register struct radix_node *t = rn_search(v_arg, top);
421 register caddr_t cp = v + head_off;
422 register int b;
423 struct radix_node *tt;
424 /*
425 * Find first bit at which v and t->rn_key differ
426 */
427 {
428 register caddr_t cp2 = t->rn_key + head_off;
429 register int cmp_res;
430 caddr_t cplim = v + vlen;
431
432 while (cp < cplim)
433 if (*cp2++ != *cp++)
434 goto on1;
435 *dupentry = 1;
436 return t;
437 on1:
438 *dupentry = 0;
439 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
440 for (b = (cp - v) << 3; cmp_res; b--)
441 cmp_res >>= 1;
442 }
443 {
444 register struct radix_node *p, *x = top;
445 cp = v;
446 do {
447 p = x;
448 if (cp[x->rn_offset] & x->rn_bmask)
449 x = x->rn_right;
450 else
451 x = x->rn_left;
452 } while (b > (unsigned) x->rn_bit);
453 /* x->rn_bit < b && x->rn_bit >= 0 */
454 #ifdef RN_DEBUG
455 if (rn_debug)
456 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
457 #endif
458 t = rn_newpair(v_arg, b, nodes);
459 tt = t->rn_left;
460 if ((cp[p->rn_offset] & p->rn_bmask) == 0)
461 p->rn_left = t;
462 else
463 p->rn_right = t;
464 x->rn_parent = t;
465 t->rn_parent = p; /* frees x, p as temp vars below */
466 if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
467 t->rn_right = x;
468 } else {
469 t->rn_right = tt;
470 t->rn_left = x;
471 }
472 #ifdef RN_DEBUG
473 if (rn_debug)
474 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
475 #endif
476 }
477 return (tt);
478 }
479
480 struct radix_node *
481 rn_addmask(n_arg, search, skip)
482 int search, skip;
483 void *n_arg;
484 {
485 caddr_t netmask = (caddr_t)n_arg;
486 register struct radix_node *x;
487 register caddr_t cp, cplim;
488 register int b = 0, mlen, j;
489 int maskduplicated, m0, isnormal;
490 struct radix_node *saved_x;
491 static int last_zeroed = 0;
492
493 if ((mlen = LEN(netmask)) > max_keylen)
494 mlen = max_keylen;
495 if (skip == 0)
496 skip = 1;
497 if (mlen <= skip)
498 return (mask_rnhead->rnh_nodes);
499 if (skip > 1)
500 bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
501 if ((m0 = mlen) > skip)
502 bcopy(netmask + skip, addmask_key + skip, mlen - skip);
503 /*
504 * Trim trailing zeroes.
505 */
506 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
507 cp--;
508 mlen = cp - addmask_key;
509 if (mlen <= skip) {
510 if (m0 >= last_zeroed)
511 last_zeroed = mlen;
512 return (mask_rnhead->rnh_nodes);
513 }
514 if (m0 < last_zeroed)
515 bzero(addmask_key + m0, last_zeroed - m0);
516 *addmask_key = last_zeroed = mlen;
517 x = rn_search(addmask_key, rn_masktop);
518 if (bcmp(addmask_key, x->rn_key, mlen) != 0)
519 x = 0;
520 if (x || search)
521 return (x);
522 R_Zalloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
523 if ((saved_x = x) == 0)
524 return (0);
525 netmask = cp = (caddr_t)(x + 2);
526 bcopy(addmask_key, cp, mlen);
527 x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
528 if (maskduplicated) {
529 log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
530 Free(saved_x);
531 return (x);
532 }
533 /*
534 * Calculate index of mask, and check for normalcy.
535 * First find the first byte with a 0 bit, then if there are
536 * more bits left (remember we already trimmed the trailing 0's),
537 * the pattern must be one of those in normal_chars[], or we have
538 * a non-contiguous mask.
539 */
540 cplim = netmask + mlen;
541 isnormal = 1;
542 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
543 cp++;
544 if (cp != cplim) {
545 static char normal_chars[] = {
546 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
547
548 for (j = 0x80; (j & *cp) != 0; j >>= 1)
549 b++;
550 if (*cp != normal_chars[b] || cp != (cplim - 1))
551 isnormal = 0;
552 }
553 b += (cp - netmask) << 3;
554 x->rn_bit = -1 - b;
555 if (isnormal)
556 x->rn_flags |= RNF_NORMAL;
557 return (x);
558 }
559
560 static int /* XXX: arbitrary ordering for non-contiguous masks */
561 rn_lexobetter(m_arg, n_arg)
562 void *m_arg, *n_arg;
563 {
564 register u_char *mp = m_arg, *np = n_arg, *lim;
565
566 if (LEN(mp) > LEN(np))
567 return 1; /* not really, but need to check longer one first */
568 if (LEN(mp) == LEN(np))
569 for (lim = mp + LEN(mp); mp < lim;)
570 if (*mp++ > *np++)
571 return 1;
572 return 0;
573 }
574
575 static struct radix_mask *
576 rn_new_radix_mask(tt, next)
577 register struct radix_node *tt;
578 register struct radix_mask *next;
579 {
580 register struct radix_mask *m;
581
582 MKGet(m);
583 if (m == 0) {
584 log(LOG_ERR, "Mask for route not entered\n");
585 return (0);
586 }
587 bzero(m, sizeof *m);
588 m->rm_bit = tt->rn_bit;
589 m->rm_flags = tt->rn_flags;
590 if (tt->rn_flags & RNF_NORMAL)
591 m->rm_leaf = tt;
592 else
593 m->rm_mask = tt->rn_mask;
594 m->rm_mklist = next;
595 tt->rn_mklist = m;
596 return m;
597 }
598
599 struct radix_node *
600 rn_addroute(v_arg, n_arg, head, treenodes)
601 void *v_arg, *n_arg;
602 struct radix_node_head *head;
603 struct radix_node treenodes[2];
604 {
605 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
606 register struct radix_node *t, *x = 0, *tt;
607 struct radix_node *saved_tt, *top = head->rnh_treetop;
608 short b = 0, b_leaf = 0;
609 int keyduplicated;
610 caddr_t mmask;
611 struct radix_mask *m, **mp;
612
613 /*
614 * In dealing with non-contiguous masks, there may be
615 * many different routes which have the same mask.
616 * We will find it useful to have a unique pointer to
617 * the mask to speed avoiding duplicate references at
618 * nodes and possibly save time in calculating indices.
619 */
620 if (netmask) {
621 if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0)
622 return (0);
623 b_leaf = x->rn_bit;
624 b = -1 - x->rn_bit;
625 netmask = x->rn_key;
626 }
627 /*
628 * Deal with duplicated keys: attach node to previous instance
629 */
630 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
631 if (keyduplicated) {
632 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
633 if (tt->rn_mask == netmask)
634 return (0);
635 if (netmask == 0 ||
636 (tt->rn_mask &&
637 ((b_leaf < tt->rn_bit) /* index(netmask) > node */
638 || rn_refines(netmask, tt->rn_mask)
639 || rn_lexobetter(netmask, tt->rn_mask))))
640 break;
641 }
642 /*
643 * If the mask is not duplicated, we wouldn't
644 * find it among possible duplicate key entries
645 * anyway, so the above test doesn't hurt.
646 *
647 * We sort the masks for a duplicated key the same way as
648 * in a masklist -- most specific to least specific.
649 * This may require the unfortunate nuisance of relocating
650 * the head of the list.
651 *
652 * We also reverse, or doubly link the list through the
653 * parent pointer.
654 */
655 if (tt == saved_tt) {
656 struct radix_node *xx = x;
657 /* link in at head of list */
658 (tt = treenodes)->rn_dupedkey = t;
659 tt->rn_flags = t->rn_flags;
660 tt->rn_parent = x = t->rn_parent;
661 t->rn_parent = tt; /* parent */
662 if (x->rn_left == t)
663 x->rn_left = tt;
664 else
665 x->rn_right = tt;
666 saved_tt = tt; x = xx;
667 } else {
668 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
669 t->rn_dupedkey = tt;
670 tt->rn_parent = t; /* parent */
671 if (tt->rn_dupedkey) /* parent */
672 tt->rn_dupedkey->rn_parent = tt; /* parent */
673 }
674 #ifdef RN_DEBUG
675 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
676 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
677 #endif
678 tt->rn_key = (caddr_t) v;
679 tt->rn_bit = -1;
680 tt->rn_flags = RNF_ACTIVE;
681 }
682 /*
683 * Put mask in tree.
684 */
685 if (netmask) {
686 tt->rn_mask = netmask;
687 tt->rn_bit = x->rn_bit;
688 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
689 }
690 t = saved_tt->rn_parent;
691 if (keyduplicated)
692 goto on2;
693 b_leaf = -1 - t->rn_bit;
694 if (t->rn_right == saved_tt)
695 x = t->rn_left;
696 else
697 x = t->rn_right;
698 /* Promote general routes from below */
699 if (x->rn_bit < 0) {
700 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
701 if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) {
702 *mp = m = rn_new_radix_mask(x, 0);
703 if (m)
704 mp = &m->rm_mklist;
705 }
706 } else if (x->rn_mklist) {
707 /*
708 * Skip over masks whose index is > that of new node
709 */
710 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
711 if (m->rm_bit >= b_leaf)
712 break;
713 t->rn_mklist = m; *mp = 0;
714 }
715 on2:
716 /* Add new route to highest possible ancestor's list */
717 if ((netmask == 0) || (b > t->rn_bit ))
718 return tt; /* can't lift at all */
719 b_leaf = tt->rn_bit;
720 do {
721 x = t;
722 t = t->rn_parent;
723 } while (b <= t->rn_bit && x != top);
724 /*
725 * Search through routes associated with node to
726 * insert new route according to index.
727 * Need same criteria as when sorting dupedkeys to avoid
728 * double loop on deletion.
729 */
730 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
731 if (m->rm_bit < b_leaf)
732 continue;
733 if (m->rm_bit > b_leaf)
734 break;
735 if (m->rm_flags & RNF_NORMAL) {
736 mmask = m->rm_leaf->rn_mask;
737 if (tt->rn_flags & RNF_NORMAL) {
738 log(LOG_ERR,
739 "Non-unique normal route, mask not entered\n");
740 return tt;
741 }
742 } else
743 mmask = m->rm_mask;
744 if (mmask == netmask) {
745 m->rm_refs++;
746 tt->rn_mklist = m;
747 return tt;
748 }
749 if (rn_refines(netmask, mmask)
750 || rn_lexobetter(netmask, mmask))
751 break;
752 }
753 *mp = rn_new_radix_mask(tt, *mp);
754 return tt;
755 }
756
757 struct radix_node *
758 rn_delete(v_arg, netmask_arg, head)
759 void *v_arg, *netmask_arg;
760 struct radix_node_head *head;
761 {
762 register struct radix_node *t, *p, *x, *tt;
763 struct radix_mask *m, *saved_m, **mp;
764 struct radix_node *dupedkey, *saved_tt, *top;
765 caddr_t v, netmask;
766 int b, head_off, vlen;
767
768 v = v_arg;
769 netmask = netmask_arg;
770 x = head->rnh_treetop;
771 tt = rn_search(v, x);
772 head_off = x->rn_offset;
773 vlen = LEN(v);
774 saved_tt = tt;
775 top = x;
776 if (tt == 0 ||
777 bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
778 return (0);
779 /*
780 * Delete our route from mask lists.
781 */
782 if (netmask) {
783 if ((x = rn_addmask(netmask, 1, head_off)) == 0)
784 return (0);
785 netmask = x->rn_key;
786 while (tt->rn_mask != netmask)
787 if ((tt = tt->rn_dupedkey) == 0)
788 return (0);
789 }
790 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
791 goto on1;
792 if (tt->rn_flags & RNF_NORMAL) {
793 if (m->rm_leaf != tt || m->rm_refs > 0) {
794 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
795 return 0; /* dangling ref could cause disaster */
796 }
797 } else {
798 if (m->rm_mask != tt->rn_mask) {
799 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
800 goto on1;
801 }
802 if (--m->rm_refs >= 0)
803 goto on1;
804 }
805 b = -1 - tt->rn_bit;
806 t = saved_tt->rn_parent;
807 if (b > t->rn_bit)
808 goto on1; /* Wasn't lifted at all */
809 do {
810 x = t;
811 t = t->rn_parent;
812 } while (b <= t->rn_bit && x != top);
813 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
814 if (m == saved_m) {
815 *mp = m->rm_mklist;
816 MKFree(m);
817 break;
818 }
819 if (m == 0) {
820 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
821 if (tt->rn_flags & RNF_NORMAL)
822 return (0); /* Dangling ref to us */
823 }
824 on1:
825 /*
826 * Eliminate us from tree
827 */
828 if (tt->rn_flags & RNF_ROOT)
829 return (0);
830 #ifdef RN_DEBUG
831 /* Get us out of the creation list */
832 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
833 if (t) t->rn_ybro = tt->rn_ybro;
834 #endif
835 t = tt->rn_parent;
836 dupedkey = saved_tt->rn_dupedkey;
837 if (dupedkey) {
838 /*
839 * Here, tt is the deletion target and
840 * saved_tt is the head of the dupekey chain.
841 */
842 if (tt == saved_tt) {
843 /* remove from head of chain */
844 x = dupedkey; x->rn_parent = t;
845 if (t->rn_left == tt)
846 t->rn_left = x;
847 else
848 t->rn_right = x;
849 } else {
850 /* find node in front of tt on the chain */
851 for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
852 p = p->rn_dupedkey;
853 if (p) {
854 p->rn_dupedkey = tt->rn_dupedkey;
855 if (tt->rn_dupedkey) /* parent */
856 tt->rn_dupedkey->rn_parent = p;
857 /* parent */
858 } else log(LOG_ERR, "rn_delete: couldn't find us\n");
859 }
860 t = tt + 1;
861 if (t->rn_flags & RNF_ACTIVE) {
862 #ifndef RN_DEBUG
863 *++x = *t;
864 p = t->rn_parent;
865 #else
866 b = t->rn_info;
867 *++x = *t;
868 t->rn_info = b;
869 p = t->rn_parent;
870 #endif
871 if (p->rn_left == t)
872 p->rn_left = x;
873 else
874 p->rn_right = x;
875 x->rn_left->rn_parent = x;
876 x->rn_right->rn_parent = x;
877 }
878 goto out;
879 }
880 if (t->rn_left == tt)
881 x = t->rn_right;
882 else
883 x = t->rn_left;
884 p = t->rn_parent;
885 if (p->rn_right == t)
886 p->rn_right = x;
887 else
888 p->rn_left = x;
889 x->rn_parent = p;
890 /*
891 * Demote routes attached to us.
892 */
893 if (t->rn_mklist) {
894 if (x->rn_bit >= 0) {
895 for (mp = &x->rn_mklist; (m = *mp);)
896 mp = &m->rm_mklist;
897 *mp = t->rn_mklist;
898 } else {
899 /* If there are any key,mask pairs in a sibling
900 duped-key chain, some subset will appear sorted
901 in the same order attached to our mklist */
902 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
903 if (m == x->rn_mklist) {
904 struct radix_mask *mm = m->rm_mklist;
905 x->rn_mklist = 0;
906 if (--(m->rm_refs) < 0)
907 MKFree(m);
908 m = mm;
909 }
910 if (m)
911 log(LOG_ERR,
912 "rn_delete: Orphaned Mask %p at %p\n",
913 (void *)m, (void *)x);
914 }
915 }
916 /*
917 * We may be holding an active internal node in the tree.
918 */
919 x = tt + 1;
920 if (t != x) {
921 #ifndef RN_DEBUG
922 *t = *x;
923 #else
924 b = t->rn_info;
925 *t = *x;
926 t->rn_info = b;
927 #endif
928 t->rn_left->rn_parent = t;
929 t->rn_right->rn_parent = t;
930 p = x->rn_parent;
931 if (p->rn_left == x)
932 p->rn_left = t;
933 else
934 p->rn_right = t;
935 }
936 out:
937 tt->rn_flags &= ~RNF_ACTIVE;
938 tt[1].rn_flags &= ~RNF_ACTIVE;
939 return (tt);
940 }
941
942 /*
943 * This is the same as rn_walktree() except for the parameters and the
944 * exit.
945 */
946 static int
947 rn_walktree_from(h, a, m, f, w)
948 struct radix_node_head *h;
949 void *a, *m;
950 walktree_f_t *f;
951 void *w;
952 {
953 int error;
954 struct radix_node *base, *next;
955 u_char *xa = (u_char *)a;
956 u_char *xm = (u_char *)m;
957 register struct radix_node *rn, *last = 0 /* shut up gcc */;
958 int stopping = 0;
959 int lastb;
960
961 /*
962 * rn_search_m is sort-of-open-coded here. We cannot use the
963 * function because we need to keep track of the last node seen.
964 */
965 /* printf("about to search\n"); */
966 for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
967 last = rn;
968 /* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n",
969 rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */
970 if (!(rn->rn_bmask & xm[rn->rn_offset])) {
971 break;
972 }
973 if (rn->rn_bmask & xa[rn->rn_offset]) {
974 rn = rn->rn_right;
975 } else {
976 rn = rn->rn_left;
977 }
978 }
979 /* printf("done searching\n"); */
980
981 /*
982 * Two cases: either we stepped off the end of our mask,
983 * in which case last == rn, or we reached a leaf, in which
984 * case we want to start from the last node we looked at.
985 * Either way, last is the node we want to start from.
986 */
987 rn = last;
988 lastb = rn->rn_bit;
989
990 /* printf("rn %p, lastb %d\n", rn, lastb);*/
991
992 /*
993 * This gets complicated because we may delete the node
994 * while applying the function f to it, so we need to calculate
995 * the successor node in advance.
996 */
997 while (rn->rn_bit >= 0)
998 rn = rn->rn_left;
999
1000 while (!stopping) {
1001 /* printf("node %p (%d)\n", rn, rn->rn_bit); */
1002 base = rn;
1003 /* If at right child go back up, otherwise, go right */
1004 while (rn->rn_parent->rn_right == rn
1005 && !(rn->rn_flags & RNF_ROOT)) {
1006 rn = rn->rn_parent;
1007
1008 /* if went up beyond last, stop */
1009 if (rn->rn_bit <= lastb) {
1010 stopping = 1;
1011 /* printf("up too far\n"); */
1012 /*
1013 * XXX we should jump to the 'Process leaves'
1014 * part, because the values of 'rn' and 'next'
1015 * we compute will not be used. Not a big deal
1016 * because this loop will terminate, but it is
1017 * inefficient and hard to understand!
1018 */
1019 }
1020 }
1021
1022 /*
1023 * At the top of the tree, no need to traverse the right
1024 * half, prevent the traversal of the entire tree in the
1025 * case of default route.
1026 */
1027 if (rn->rn_parent->rn_flags & RNF_ROOT)
1028 stopping = 1;
1029
1030 /* Find the next *leaf* since next node might vanish, too */
1031 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1032 rn = rn->rn_left;
1033 next = rn;
1034 /* Process leaves */
1035 while ((rn = base) != 0) {
1036 base = rn->rn_dupedkey;
1037 /* printf("leaf %p\n", rn); */
1038 if (!(rn->rn_flags & RNF_ROOT)
1039 && (error = (*f)(rn, w)))
1040 return (error);
1041 }
1042 rn = next;
1043
1044 if (rn->rn_flags & RNF_ROOT) {
1045 /* printf("root, stopping"); */
1046 stopping = 1;
1047 }
1048
1049 }
1050 return 0;
1051 }
1052
1053 static int
1054 rn_walktree(h, f, w)
1055 struct radix_node_head *h;
1056 walktree_f_t *f;
1057 void *w;
1058 {
1059 int error;
1060 struct radix_node *base, *next;
1061 register struct radix_node *rn = h->rnh_treetop;
1062 /*
1063 * This gets complicated because we may delete the node
1064 * while applying the function f to it, so we need to calculate
1065 * the successor node in advance.
1066 */
1067 /* First time through node, go left */
1068 while (rn->rn_bit >= 0)
1069 rn = rn->rn_left;
1070 for (;;) {
1071 base = rn;
1072 /* If at right child go back up, otherwise, go right */
1073 while (rn->rn_parent->rn_right == rn
1074 && (rn->rn_flags & RNF_ROOT) == 0)
1075 rn = rn->rn_parent;
1076 /* Find the next *leaf* since next node might vanish, too */
1077 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1078 rn = rn->rn_left;
1079 next = rn;
1080 /* Process leaves */
1081 while ((rn = base)) {
1082 base = rn->rn_dupedkey;
1083 if (!(rn->rn_flags & RNF_ROOT)
1084 && (error = (*f)(rn, w)))
1085 return (error);
1086 }
1087 rn = next;
1088 if (rn->rn_flags & RNF_ROOT)
1089 return (0);
1090 }
1091 /* NOTREACHED */
1092 }
1093
1094 /*
1095 * Allocate and initialize an empty tree. This has 3 nodes, which are
1096 * part of the radix_node_head (in the order <left,root,right>) and are
1097 * marked RNF_ROOT so they cannot be freed.
1098 * The leaves have all-zero and all-one keys, with significant
1099 * bits starting at 'off'.
1100 * Return 1 on success, 0 on error.
1101 */
1102 int
1103 rn_inithead(head, off)
1104 void **head;
1105 int off;
1106 {
1107 register struct radix_node_head *rnh;
1108 register struct radix_node *t, *tt, *ttt;
1109 if (*head)
1110 return (1);
1111 R_Zalloc(rnh, struct radix_node_head *, sizeof (*rnh));
1112 if (rnh == 0)
1113 return (0);
1114 #ifdef _KERNEL
1115 RADIX_NODE_HEAD_LOCK_INIT(rnh);
1116 #endif
1117 *head = rnh;
1118 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
1119 ttt = rnh->rnh_nodes + 2;
1120 t->rn_right = ttt;
1121 t->rn_parent = t;
1122 tt = t->rn_left; /* ... which in turn is rnh->rnh_nodes */
1123 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
1124 tt->rn_bit = -1 - off;
1125 *ttt = *tt;
1126 ttt->rn_key = rn_ones;
1127 rnh->rnh_addaddr = rn_addroute;
1128 rnh->rnh_deladdr = rn_delete;
1129 rnh->rnh_matchaddr = rn_match;
1130 rnh->rnh_lookup = rn_lookup;
1131 rnh->rnh_walktree = rn_walktree;
1132 rnh->rnh_walktree_from = rn_walktree_from;
1133 rnh->rnh_treetop = t;
1134 return (1);
1135 }
1136
1137 void
1138 rn_init()
1139 {
1140 char *cp, *cplim;
1141 #ifdef _KERNEL
1142 struct domain *dom;
1143
1144 for (dom = domains; dom; dom = dom->dom_next)
1145 if (dom->dom_maxrtkey > max_keylen)
1146 max_keylen = dom->dom_maxrtkey;
1147 #endif
1148 if (max_keylen == 0) {
1149 log(LOG_ERR,
1150 "rn_init: radix functions require max_keylen be set\n");
1151 return;
1152 }
1153 R_Malloc(rn_zeros, char *, 3 * max_keylen);
1154 if (rn_zeros == NULL)
1155 panic("rn_init");
1156 bzero(rn_zeros, 3 * max_keylen);
1157 rn_ones = cp = rn_zeros + max_keylen;
1158 addmask_key = cplim = rn_ones + max_keylen;
1159 while (cp < cplim)
1160 *cp++ = -1;
1161 if (rn_inithead((void **)(void *)&mask_rnhead, 0) == 0)
1162 panic("rn_init 2");
1163 }
Cache object: 48bf24aada8a19ea388708c75cd572c6
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