1 /* $NetBSD: radix.c,v 1.14 2021/12/05 07:15:03 msaitoh 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. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgment:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)radix.c 8.4 (Berkeley) 11/2/94
36 */
37
38 /*
39 * Routines to build and maintain radix trees for routing lookups.
40 */
41
42 #include "defs.h"
43
44 #ifdef __NetBSD__
45 __RCSID("$NetBSD: radix.c,v 1.14 2021/12/05 07:15:03 msaitoh Exp $");
46 #elif defined(__FreeBSD__)
47 __RCSID("$FreeBSD$");
48 #else
49 __RCSID("Revision: 2.23 ");
50 #ident "Revision: 2.23 "
51 #endif
52
53 #define log(x, msg) syslog(x, msg)
54 #define panic(s) {log(LOG_ERR,s); exit(1);}
55 #define min(a,b) (((a)<(b))?(a):(b))
56
57 int max_keylen;
58 struct radix_mask *rn_mkfreelist;
59 struct radix_node_head *mask_rnhead;
60 static char *addmask_key;
61 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
62 static char *rn_zeros, *rn_ones;
63
64 #define rn_masktop (mask_rnhead->rnh_treetop)
65 #undef Bcmp
66 #define Bcmp(a, b, l) (l == 0 ? 0 \
67 : memcmp((caddr_t)(a), (caddr_t)(b), (size_t)l))
68
69 static int rn_satisfies_leaf(char *, struct radix_node *, int);
70
71 /*
72 * The data structure for the keys is a radix tree with one way
73 * branching removed. The index rn_b at an internal node n represents a bit
74 * position to be tested. The tree is arranged so that all descendants
75 * of a node n have keys whose bits all agree up to position rn_b - 1.
76 * (We say the index of n is rn_b.)
77 *
78 * There is at least one descendant which has a one bit at position rn_b,
79 * and at least one with a zero there.
80 *
81 * A route is determined by a pair of key and mask. We require that the
82 * bit-wise logical and of the key and mask to be the key.
83 * We define the index of a route to associated with the mask to be
84 * the first bit number in the mask where 0 occurs (with bit number 0
85 * representing the highest order bit).
86 *
87 * We say a mask is normal if every bit is 0, past the index of the mask.
88 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b,
89 * and m is a normal mask, then the route applies to every descendant of n.
90 * If the index(m) < rn_b, this implies the trailing last few bits of k
91 * before bit b are all 0, (and hence consequently true of every descendant
92 * of n), so the route applies to all descendants of the node as well.
93 *
94 * Similar logic shows that a non-normal mask m such that
95 * index(m) <= index(n) could potentially apply to many children of n.
96 * Thus, for each non-host route, we attach its mask to a list at an internal
97 * node as high in the tree as we can go.
98 *
99 * The present version of the code makes use of normal routes in short-
100 * circuiting an explicit mask and compare operation when testing whether
101 * a key satisfies a normal route, and also in remembering the unique leaf
102 * that governs a subtree.
103 */
104
105 struct radix_node *
rn_search(void * v_arg,struct radix_node * head)106 rn_search(void *v_arg,
107 struct radix_node *head)
108 {
109 struct radix_node *x;
110 caddr_t v;
111
112 for (x = head, v = v_arg; x->rn_b >= 0;) {
113 if (x->rn_bmask & v[x->rn_off])
114 x = x->rn_r;
115 else
116 x = x->rn_l;
117 }
118 return (x);
119 }
120
121 struct radix_node *
rn_search_m(void * v_arg,struct radix_node * head,void * m_arg)122 rn_search_m(void *v_arg,
123 struct radix_node *head,
124 void *m_arg)
125 {
126 struct radix_node *x;
127 caddr_t v = v_arg, m = m_arg;
128
129 for (x = head; x->rn_b >= 0;) {
130 if ((x->rn_bmask & m[x->rn_off]) &&
131 (x->rn_bmask & v[x->rn_off]))
132 x = x->rn_r;
133 else
134 x = x->rn_l;
135 }
136 return x;
137 }
138
139 int
rn_refines(void * m_arg,void * n_arg)140 rn_refines(void* m_arg, void *n_arg)
141 {
142 caddr_t m = m_arg, n = n_arg;
143 caddr_t lim, lim2 = lim = n + *(u_char *)n;
144 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
145 int masks_are_equal = 1;
146
147 if (longer > 0)
148 lim -= longer;
149 while (n < lim) {
150 if (*n & ~(*m))
151 return 0;
152 if (*n++ != *m++)
153 masks_are_equal = 0;
154 }
155 while (n < lim2)
156 if (*n++)
157 return 0;
158 if (masks_are_equal && (longer < 0))
159 for (lim2 = m - longer; m < lim2; )
160 if (*m++)
161 return 1;
162 return (!masks_are_equal);
163 }
164
165 struct radix_node *
rn_lookup(void * v_arg,void * m_arg,struct radix_node_head * head)166 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head)
167 {
168 struct radix_node *x;
169 caddr_t netmask = 0;
170
171 if (m_arg) {
172 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0)
173 return (0);
174 netmask = x->rn_key;
175 }
176 x = rn_match(v_arg, head);
177 if (x && netmask) {
178 while (x && x->rn_mask != netmask)
179 x = x->rn_dupedkey;
180 }
181 return x;
182 }
183
184 static int
rn_satisfies_leaf(char * trial,struct radix_node * leaf,int skip)185 rn_satisfies_leaf(char *trial,
186 struct radix_node *leaf,
187 int skip)
188 {
189 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
190 char *cplim;
191 int length = min(*(u_char *)cp, *(u_char *)cp2);
192
193 if (cp3 == 0)
194 cp3 = rn_ones;
195 else
196 length = min(length, *(u_char *)cp3);
197 cplim = cp + length; cp3 += skip; cp2 += skip;
198 for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
199 if ((*cp ^ *cp2) & *cp3)
200 return 0;
201 return 1;
202 }
203
204 struct radix_node *
rn_match(void * v_arg,struct radix_node_head * head)205 rn_match(void *v_arg,
206 struct radix_node_head *head)
207 {
208 caddr_t v = v_arg;
209 struct radix_node *t = head->rnh_treetop, *x;
210 caddr_t cp = v, cp2;
211 caddr_t cplim;
212 struct radix_node *saved_t, *top = t;
213 int off = t->rn_off, vlen = *(u_char *)cp, matched_off;
214 int test, b, rn_b;
215
216 /*
217 * Open code rn_search(v, top) to avoid overhead of extra
218 * subroutine call.
219 */
220 for (; t->rn_b >= 0; ) {
221 if (t->rn_bmask & cp[t->rn_off])
222 t = t->rn_r;
223 else
224 t = t->rn_l;
225 }
226 /*
227 * See if we match exactly as a host destination
228 * or at least learn how many bits match, for normal mask finesse.
229 *
230 * It doesn't hurt us to limit how many bytes to check
231 * to the length of the mask, since if it matches we had a genuine
232 * match and the leaf we have is the most specific one anyway;
233 * if it didn't match with a shorter length it would fail
234 * with a long one. This wins big for class B&C netmasks which
235 * are probably the most common case...
236 */
237 if (t->rn_mask)
238 vlen = *(u_char *)t->rn_mask;
239 cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
240 for (; cp < cplim; cp++, cp2++)
241 if (*cp != *cp2)
242 goto on1;
243 /*
244 * This extra grot is in case we are explicitly asked
245 * to look up the default. Ugh!
246 * Or 255.255.255.255
247 *
248 * In this case, we have a complete match of the key. Unless
249 * the node is one of the roots, we are finished.
250 * If it is the zeros root, then take what we have, preferring
251 * any real data.
252 * If it is the ones root, then pretend the target key was followed
253 * by a byte of zeros.
254 */
255 if (!(t->rn_flags & RNF_ROOT))
256 return t; /* not a root */
257 if (t->rn_dupedkey) {
258 t = t->rn_dupedkey;
259 return t; /* have some real data */
260 }
261 if (*(cp-1) == 0)
262 return t; /* not the ones root */
263 b = 0; /* fake a zero after 255.255.255.255 */
264 goto on2;
265 on1:
266 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
267 for (b = 7; (test >>= 1) > 0;)
268 b--;
269 on2:
270 matched_off = cp - v;
271 b += matched_off << 3;
272 rn_b = -1 - b;
273 /*
274 * If there is a host route in a duped-key chain, it will be first.
275 */
276 if ((saved_t = t)->rn_mask == 0)
277 t = t->rn_dupedkey;
278 for (; t; t = t->rn_dupedkey) {
279 /*
280 * Even if we don't match exactly as a host,
281 * we may match if the leaf we wound up at is
282 * a route to a net.
283 */
284 if (t->rn_flags & RNF_NORMAL) {
285 if (rn_b <= t->rn_b)
286 return t;
287 } else if (rn_satisfies_leaf(v, t, matched_off)) {
288 return t;
289 }
290 }
291 t = saved_t;
292 /* start searching up the tree */
293 do {
294 struct radix_mask *m;
295 t = t->rn_p;
296 if ((m = t->rn_mklist)) {
297 /*
298 * If non-contiguous masks ever become important
299 * we can restore the masking and open coding of
300 * the search and satisfaction test and put the
301 * calculation of "off" back before the "do".
302 */
303 do {
304 if (m->rm_flags & RNF_NORMAL) {
305 if (rn_b <= m->rm_b)
306 return (m->rm_leaf);
307 } else {
308 off = min(t->rn_off, matched_off);
309 x = rn_search_m(v, t, m->rm_mask);
310 while (x && x->rn_mask != m->rm_mask)
311 x = x->rn_dupedkey;
312 if (x && rn_satisfies_leaf(v, x, off))
313 return x;
314 }
315 } while ((m = m->rm_mklist));
316 }
317 } while (t != top);
318 return 0;
319 }
320
321 #ifdef RN_DEBUG
322 int rn_nodenum;
323 struct radix_node *rn_clist;
324 int rn_saveinfo;
325 int rn_debug = 1;
326 #endif
327
328 struct radix_node *
rn_newpair(void * v,int b,struct radix_node nodes[2])329 rn_newpair(void *v, int b, struct radix_node nodes[2])
330 {
331 struct radix_node *tt = nodes, *t = tt + 1;
332 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7);
333 t->rn_l = tt; t->rn_off = b >> 3;
334 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t;
335 tt->rn_flags = t->rn_flags = RNF_ACTIVE;
336 #ifdef RN_DEBUG
337 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
338 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
339 #endif
340 return t;
341 }
342
343 struct radix_node *
rn_insert(void * v_arg,struct radix_node_head * head,int * dupentry,struct radix_node nodes[2])344 rn_insert(void* v_arg,
345 struct radix_node_head *head,
346 int *dupentry,
347 struct radix_node nodes[2])
348 {
349 caddr_t v = v_arg;
350 struct radix_node *top = head->rnh_treetop;
351 int head_off = top->rn_off, vlen = (int)*((u_char *)v);
352 struct radix_node *t = rn_search(v_arg, top);
353 caddr_t cp = v + head_off;
354 int b;
355 struct radix_node *tt;
356
357 /*
358 * Find first bit at which v and t->rn_key differ
359 */
360 {
361 caddr_t cp2 = t->rn_key + head_off;
362 int cmp_res;
363 caddr_t cplim = v + vlen;
364
365 while (cp < cplim)
366 if (*cp2++ != *cp++)
367 goto on1;
368 /* handle adding 255.255.255.255 */
369 if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) {
370 *dupentry = 1;
371 return t;
372 }
373 on1:
374 *dupentry = 0;
375 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
376 for (b = (cp - v) << 3; cmp_res; b--)
377 cmp_res >>= 1;
378 }
379 {
380 struct radix_node *p, *x = top;
381 cp = v;
382 do {
383 p = x;
384 if (cp[x->rn_off] & x->rn_bmask)
385 x = x->rn_r;
386 else x = x->rn_l;
387 } while ((unsigned)b > (unsigned)x->rn_b);
388 #ifdef RN_DEBUG
389 if (rn_debug)
390 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
391 #endif
392 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l;
393 if ((cp[p->rn_off] & p->rn_bmask) == 0)
394 p->rn_l = t;
395 else
396 p->rn_r = t;
397 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */
398 if ((cp[t->rn_off] & t->rn_bmask) == 0) {
399 t->rn_r = x;
400 } else {
401 t->rn_r = tt; t->rn_l = x;
402 }
403 #ifdef RN_DEBUG
404 if (rn_debug)
405 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
406 #endif
407 }
408 return (tt);
409 }
410
411 struct radix_node *
rn_addmask(void * n_arg,int search,int skip)412 rn_addmask(void *n_arg, int search, int skip)
413 {
414 caddr_t netmask = (caddr_t)n_arg;
415 struct radix_node *x;
416 caddr_t cp, cplim;
417 int b = 0, mlen, j;
418 int maskduplicated, m0, isnormal;
419 struct radix_node *saved_x;
420 static int last_zeroed = 0;
421
422 if ((mlen = *(u_char *)netmask) > max_keylen)
423 mlen = max_keylen;
424 if (skip == 0)
425 skip = 1;
426 if (mlen <= skip)
427 return (mask_rnhead->rnh_nodes);
428 if (skip > 1)
429 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
430 if ((m0 = mlen) > skip)
431 Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
432 /*
433 * Trim trailing zeroes.
434 */
435 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
436 cp--;
437 mlen = cp - addmask_key;
438 if (mlen <= skip) {
439 if (m0 >= last_zeroed)
440 last_zeroed = mlen;
441 return (mask_rnhead->rnh_nodes);
442 }
443 if (m0 < last_zeroed)
444 Bzero(addmask_key + m0, last_zeroed - m0);
445 *addmask_key = last_zeroed = mlen;
446 x = rn_search(addmask_key, rn_masktop);
447 if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
448 x = 0;
449 if (x || search)
450 return (x);
451 x = (struct radix_node *)rtmalloc(max_keylen + 2*sizeof(*x),
452 "rn_addmask");
453 saved_x = x;
454 Bzero(x, max_keylen + 2 * sizeof (*x));
455 netmask = cp = (caddr_t)(x + 2);
456 Bcopy(addmask_key, cp, mlen);
457 x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
458 if (maskduplicated) {
459 log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
460 Free(saved_x);
461 return (x);
462 }
463 /*
464 * Calculate index of mask, and check for normalcy.
465 */
466 cplim = netmask + mlen; isnormal = 1;
467 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
468 cp++;
469 if (cp != cplim) {
470 for (j = 0x80; (j & *cp) != 0; j >>= 1)
471 b++;
472 if (*cp != normal_chars[b] || cp != (cplim - 1))
473 isnormal = 0;
474 }
475 b += (cp - netmask) << 3;
476 x->rn_b = -1 - b;
477 if (isnormal)
478 x->rn_flags |= RNF_NORMAL;
479 return (x);
480 }
481
482 static int /* XXX: arbitrary ordering for non-contiguous masks */
rn_lexobetter(void * m_arg,void * n_arg)483 rn_lexobetter(void *m_arg, void *n_arg)
484 {
485 u_char *mp = m_arg, *np = n_arg, *lim;
486
487 if (*mp > *np)
488 return 1; /* not really, but need to check longer one first */
489 if (*mp == *np)
490 for (lim = mp + *mp; mp < lim;)
491 if (*mp++ > *np++)
492 return 1;
493 return 0;
494 }
495
496 static struct radix_mask *
rn_new_radix_mask(struct radix_node * tt,struct radix_mask * next)497 rn_new_radix_mask(struct radix_node *tt,
498 struct radix_mask *next)
499 {
500 struct radix_mask *m;
501
502 MKGet(m);
503 if (m == 0) {
504 log(LOG_ERR, "Mask for route not entered\n");
505 return (0);
506 }
507 Bzero(m, sizeof *m);
508 m->rm_b = tt->rn_b;
509 m->rm_flags = tt->rn_flags;
510 if (tt->rn_flags & RNF_NORMAL)
511 m->rm_leaf = tt;
512 else
513 m->rm_mask = tt->rn_mask;
514 m->rm_mklist = next;
515 tt->rn_mklist = m;
516 return m;
517 }
518
519 struct radix_node *
rn_addroute(void * v_arg,void * n_arg,struct radix_node_head * head,struct radix_node treenodes[2])520 rn_addroute(void *v_arg,
521 void *n_arg,
522 struct radix_node_head *head,
523 struct radix_node treenodes[2])
524 {
525 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
526 struct radix_node *t, *x = 0, *tt;
527 struct radix_node *saved_tt, *top = head->rnh_treetop;
528 short b = 0, b_leaf = 0;
529 int keyduplicated;
530 caddr_t mmask;
531 struct radix_mask *m, **mp;
532
533 /*
534 * In dealing with non-contiguous masks, there may be
535 * many different routes which have the same mask.
536 * We will find it useful to have a unique pointer to
537 * the mask to speed avoiding duplicate references at
538 * nodes and possibly save time in calculating indices.
539 */
540 if (netmask) {
541 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0)
542 return (0);
543 b_leaf = x->rn_b;
544 b = -1 - x->rn_b;
545 netmask = x->rn_key;
546 }
547 /*
548 * Deal with duplicated keys: attach node to previous instance
549 */
550 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
551 if (keyduplicated) {
552 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
553 if (tt->rn_mask == netmask)
554 return (0);
555 if (netmask == 0 ||
556 (tt->rn_mask &&
557 ((b_leaf < tt->rn_b) || /* index(netmask) > node */
558 rn_refines(netmask, tt->rn_mask) ||
559 rn_lexobetter(netmask, tt->rn_mask))))
560 break;
561 }
562 /*
563 * If the mask is not duplicated, we wouldn't
564 * find it among possible duplicate key entries
565 * anyway, so the above test doesn't hurt.
566 *
567 * We sort the masks for a duplicated key the same way as
568 * in a masklist -- most specific to least specific.
569 * This may require the unfortunate nuisance of relocating
570 * the head of the list.
571 */
572 if (tt == saved_tt) {
573 struct radix_node *xx = x;
574 /* link in at head of list */
575 (tt = treenodes)->rn_dupedkey = t;
576 tt->rn_flags = t->rn_flags;
577 tt->rn_p = x = t->rn_p;
578 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt;
579 saved_tt = tt; x = xx;
580 } else {
581 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
582 t->rn_dupedkey = tt;
583 }
584 #ifdef RN_DEBUG
585 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
586 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
587 #endif
588 tt->rn_key = (caddr_t) v;
589 tt->rn_b = -1;
590 tt->rn_flags = RNF_ACTIVE;
591 }
592 /*
593 * Put mask in tree.
594 */
595 if (netmask) {
596 tt->rn_mask = netmask;
597 tt->rn_b = x->rn_b;
598 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
599 }
600 t = saved_tt->rn_p;
601 if (keyduplicated)
602 goto on2;
603 b_leaf = -1 - t->rn_b;
604 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r;
605 /* Promote general routes from below */
606 if (x->rn_b < 0) {
607 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
608 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) {
609 if ((*mp = m = rn_new_radix_mask(x, 0)))
610 mp = &m->rm_mklist;
611 }
612 } else if (x->rn_mklist) {
613 /*
614 * Skip over masks whose index is > that of new node
615 */
616 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
617 if (m->rm_b >= b_leaf)
618 break;
619 t->rn_mklist = m; *mp = 0;
620 }
621 on2:
622 /* Add new route to highest possible ancestor's list */
623 if ((netmask == 0) || (b > t->rn_b ))
624 return tt; /* can't lift at all */
625 b_leaf = tt->rn_b;
626 do {
627 x = t;
628 t = t->rn_p;
629 } while (b <= t->rn_b && x != top);
630 /*
631 * Search through routes associated with node to
632 * insert new route according to index.
633 * Need same criteria as when sorting dupedkeys to avoid
634 * double loop on deletion.
635 */
636 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
637 if (m->rm_b < b_leaf)
638 continue;
639 if (m->rm_b > b_leaf)
640 break;
641 if (m->rm_flags & RNF_NORMAL) {
642 mmask = m->rm_leaf->rn_mask;
643 if (tt->rn_flags & RNF_NORMAL) {
644 log(LOG_ERR,
645 "Non-unique normal route, mask not entered");
646 return tt;
647 }
648 } else
649 mmask = m->rm_mask;
650 if (mmask == netmask) {
651 m->rm_refs++;
652 tt->rn_mklist = m;
653 return tt;
654 }
655 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
656 break;
657 }
658 *mp = rn_new_radix_mask(tt, *mp);
659 return tt;
660 }
661
662 struct radix_node *
rn_delete(void * v_arg,void * netmask_arg,struct radix_node_head * head)663 rn_delete(void *v_arg,
664 void *netmask_arg,
665 struct radix_node_head *head)
666 {
667 struct radix_node *t, *p, *x, *tt;
668 struct radix_mask *m, *saved_m, **mp;
669 struct radix_node *dupedkey, *saved_tt, *top;
670 caddr_t v, netmask;
671 int b, head_off, vlen;
672
673 v = v_arg;
674 netmask = netmask_arg;
675 x = head->rnh_treetop;
676 tt = rn_search(v, x);
677 head_off = x->rn_off;
678 vlen = *(u_char *)v;
679 saved_tt = tt;
680 top = x;
681 if (tt == 0 ||
682 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
683 return (0);
684 /*
685 * Delete our route from mask lists.
686 */
687 if (netmask) {
688 if ((x = rn_addmask(netmask, 1, head_off)) == 0)
689 return (0);
690 netmask = x->rn_key;
691 while (tt->rn_mask != netmask)
692 if ((tt = tt->rn_dupedkey) == 0)
693 return (0);
694 }
695 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
696 goto on1;
697 if (tt->rn_flags & RNF_NORMAL) {
698 if (m->rm_leaf != tt || m->rm_refs > 0) {
699 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
700 return 0; /* dangling ref could cause disaster */
701 }
702 } else {
703 if (m->rm_mask != tt->rn_mask) {
704 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
705 goto on1;
706 }
707 if (--m->rm_refs >= 0)
708 goto on1;
709 }
710 b = -1 - tt->rn_b;
711 t = saved_tt->rn_p;
712 if (b > t->rn_b)
713 goto on1; /* Wasn't lifted at all */
714 do {
715 x = t;
716 t = t->rn_p;
717 } while (b <= t->rn_b && x != top);
718 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
719 if (m == saved_m) {
720 *mp = m->rm_mklist;
721 MKFree(m);
722 break;
723 }
724 if (m == 0) {
725 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
726 if (tt->rn_flags & RNF_NORMAL)
727 return (0); /* Dangling ref to us */
728 }
729 on1:
730 /*
731 * Eliminate us from tree
732 */
733 if (tt->rn_flags & RNF_ROOT)
734 return (0);
735 #ifdef RN_DEBUG
736 /* Get us out of the creation list */
737 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
738 if (t) t->rn_ybro = tt->rn_ybro;
739 #endif
740 t = tt->rn_p;
741 if ((dupedkey = saved_tt->rn_dupedkey)) {
742 if (tt == saved_tt) {
743 x = dupedkey; x->rn_p = t;
744 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x;
745 } else {
746 for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
747 p = p->rn_dupedkey;
748 if (p) p->rn_dupedkey = tt->rn_dupedkey;
749 else log(LOG_ERR, "rn_delete: couldn't find us\n");
750 }
751 t = tt + 1;
752 if (t->rn_flags & RNF_ACTIVE) {
753 #ifndef RN_DEBUG
754 *++x = *t; p = t->rn_p;
755 #else
756 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p;
757 #endif
758 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x;
759 x->rn_l->rn_p = x; x->rn_r->rn_p = x;
760 }
761 goto out;
762 }
763 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l;
764 p = t->rn_p;
765 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x;
766 x->rn_p = p;
767 /*
768 * Demote routes attached to us.
769 */
770 if (t->rn_mklist) {
771 if (x->rn_b >= 0) {
772 for (mp = &x->rn_mklist; (m = *mp);)
773 mp = &m->rm_mklist;
774 *mp = t->rn_mklist;
775 } else {
776 /* If there are any key,mask pairs in a sibling
777 duped-key chain, some subset will appear sorted
778 in the same order attached to our mklist */
779 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
780 if (m == x->rn_mklist) {
781 struct radix_mask *mm = m->rm_mklist;
782 x->rn_mklist = 0;
783 if (--(m->rm_refs) < 0)
784 MKFree(m);
785 m = mm;
786 }
787 if (m)
788 syslog(LOG_ERR, "%s 0x%lx at 0x%lx\n",
789 "rn_delete: Orphaned Mask",
790 (unsigned long)m,
791 (unsigned long)x);
792 }
793 }
794 /*
795 * We may be holding an active internal node in the tree.
796 */
797 x = tt + 1;
798 if (t != x) {
799 #ifndef RN_DEBUG
800 *t = *x;
801 #else
802 b = t->rn_info; *t = *x; t->rn_info = b;
803 #endif
804 t->rn_l->rn_p = t; t->rn_r->rn_p = t;
805 p = x->rn_p;
806 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t;
807 }
808 out:
809 tt->rn_flags &= ~RNF_ACTIVE;
810 tt[1].rn_flags &= ~RNF_ACTIVE;
811 return (tt);
812 }
813
814 int
rn_walktree(struct radix_node_head * h,int (* f)(struct radix_node *,struct walkarg *),struct walkarg * w)815 rn_walktree(struct radix_node_head *h,
816 int (*f)(struct radix_node *, struct walkarg *),
817 struct walkarg *w)
818 {
819 int error;
820 struct radix_node *base, *next;
821 struct radix_node *rn = h->rnh_treetop;
822 /*
823 * This gets complicated because we may delete the node
824 * while applying the function f to it, so we need to calculate
825 * the successor node in advance.
826 */
827 /* First time through node, go left */
828 while (rn->rn_b >= 0)
829 rn = rn->rn_l;
830 for (;;) {
831 base = rn;
832 /* If at right child go back up, otherwise, go right */
833 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0)
834 rn = rn->rn_p;
835 /* Find the next *leaf* since next node might vanish, too */
836 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;)
837 rn = rn->rn_l;
838 next = rn;
839 /* Process leaves */
840 while ((rn = base)) {
841 base = rn->rn_dupedkey;
842 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
843 return (error);
844 }
845 rn = next;
846 if (rn->rn_flags & RNF_ROOT)
847 return (0);
848 }
849 /* NOTREACHED */
850 }
851
852 int
rn_inithead(void ** head,int off)853 rn_inithead(void **head, int off)
854 {
855 struct radix_node_head *rnh;
856 struct radix_node *t, *tt, *ttt;
857 if (*head)
858 return (1);
859 rnh = (struct radix_node_head *)rtmalloc(sizeof(*rnh), "rn_inithead");
860 Bzero(rnh, sizeof (*rnh));
861 *head = rnh;
862 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
863 ttt = rnh->rnh_nodes + 2;
864 t->rn_r = ttt;
865 t->rn_p = t;
866 tt = t->rn_l;
867 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
868 tt->rn_b = -1 - off;
869 *ttt = *tt;
870 ttt->rn_key = rn_ones;
871 rnh->rnh_addaddr = rn_addroute;
872 rnh->rnh_deladdr = rn_delete;
873 rnh->rnh_matchaddr = rn_match;
874 rnh->rnh_lookup = rn_lookup;
875 rnh->rnh_walktree = rn_walktree;
876 rnh->rnh_treetop = t;
877 return (1);
878 }
879
880 void
rn_init(void)881 rn_init(void)
882 {
883 char *cp, *cplim;
884 if (max_keylen == 0) {
885 printf("rn_init: radix functions require max_keylen be set\n");
886 return;
887 }
888 rn_zeros = (char *)rtmalloc(3 * max_keylen, "rn_init");
889 Bzero(rn_zeros, 3 * max_keylen);
890 rn_ones = cp = rn_zeros + max_keylen;
891 addmask_key = cplim = rn_ones + max_keylen;
892 while (cp < cplim)
893 *cp++ = -1;
894 if (rn_inithead((void *)&mask_rnhead, 0) == 0)
895 panic("rn_init 2");
896 }
897
898