1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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
32 /*
33 * Routines to build and maintain radix trees for routing lookups.
34 */
35
36 #include "defs.h"
37 #define log(x, msg) syslog(x, msg)
38 #define panic(s) {log(LOG_ERR,s); exit(1);}
39 #define min(a,b) (((a)<(b))?(a):(b))
40
41 int max_keylen;
42 static struct radix_mask *rn_mkfreelist;
43 static struct radix_node_head *mask_rnhead;
44 static char *addmask_key;
45 static const uint8_t normal_chars[] =
46 { 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
47 static char *rn_zeros, *rn_ones;
48
49 #define rn_masktop (mask_rnhead->rnh_treetop)
50 #define Bcmp(a, b, l) (l == 0 ? 0 \
51 : memcmp((caddr_t)(a), (caddr_t)(b), (size_t)l))
52
53 static int rn_satisfies_leaf(char *, struct radix_node *, int);
54 static struct radix_node *rn_addmask(void *n_arg, int search, int skip);
55 static struct radix_node *rn_addroute(void *v_arg, void *n_arg,
56 struct radix_node_head *head, struct radix_node treenodes[2]);
57 static struct radix_node *rn_match(void *v_arg, struct radix_node_head *head);
58
59 /*
60 * The data structure for the keys is a radix tree with one way
61 * branching removed. The index rn_b at an internal node n represents a bit
62 * position to be tested. The tree is arranged so that all descendants
63 * of a node n have keys whose bits all agree up to position rn_b - 1.
64 * (We say the index of n is rn_b.)
65 *
66 * There is at least one descendant which has a one bit at position rn_b,
67 * and at least one with a zero there.
68 *
69 * A route is determined by a pair of key and mask. We require that the
70 * bit-wise logical and of the key and mask to be the key.
71 * We define the index of a route to associated with the mask to be
72 * the first bit number in the mask where 0 occurs (with bit number 0
73 * representing the highest order bit).
74 *
75 * We say a mask is normal if every bit is 0, past the index of the mask.
76 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b,
77 * and m is a normal mask, then the route applies to every descendant of n.
78 * If the index(m) < rn_b, this implies the trailing last few bits of k
79 * before bit b are all 0, (and hence consequently true of every descendant
80 * of n), so the route applies to all descendants of the node as well.
81 *
82 * Similar logic shows that a non-normal mask m such that
83 * index(m) <= index(n) could potentially apply to many children of n.
84 * Thus, for each non-host route, we attach its mask to a list at an internal
85 * node as high in the tree as we can go.
86 *
87 * The present version of the code makes use of normal routes in short-
88 * circuiting an explicit mask and compare operation when testing whether
89 * a key satisfies a normal route, and also in remembering the unique leaf
90 * that governs a subtree.
91 */
92
93 static struct radix_node *
rn_search(void * v_arg,struct radix_node * head)94 rn_search(void *v_arg,
95 struct radix_node *head)
96 {
97 struct radix_node *x;
98 caddr_t v;
99
100 for (x = head, v = v_arg; x->rn_b >= 0;) {
101 if (x->rn_bmask & v[x->rn_off])
102 x = x->rn_r;
103 else
104 x = x->rn_l;
105 }
106 return (x);
107 }
108
109 static struct radix_node *
rn_search_m(void * v_arg,struct radix_node * head,void * m_arg)110 rn_search_m(void *v_arg,
111 struct radix_node *head,
112 void *m_arg)
113 {
114 struct radix_node *x;
115 caddr_t v = v_arg, m = m_arg;
116
117 for (x = head; x->rn_b >= 0;) {
118 if ((x->rn_bmask & m[x->rn_off]) &&
119 (x->rn_bmask & v[x->rn_off]))
120 x = x->rn_r;
121 else
122 x = x->rn_l;
123 }
124 return x;
125 }
126
127 static int
rn_refines(void * m_arg,void * n_arg)128 rn_refines(void* m_arg, void *n_arg)
129 {
130 caddr_t m = m_arg, n = n_arg;
131 caddr_t lim, lim2 = lim = n + *(u_char *)n;
132 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
133 int masks_are_equal = 1;
134
135 if (longer > 0)
136 lim -= longer;
137 while (n < lim) {
138 if (*n & ~(*m))
139 return 0;
140 if (*n++ != *m++)
141 masks_are_equal = 0;
142 }
143 while (n < lim2)
144 if (*n++)
145 return 0;
146 if (masks_are_equal && (longer < 0))
147 for (lim2 = m - longer; m < lim2; )
148 if (*m++)
149 return 1;
150 return (!masks_are_equal);
151 }
152
153 static struct radix_node *
rn_lookup(void * v_arg,void * m_arg,struct radix_node_head * head)154 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head)
155 {
156 struct radix_node *x;
157 caddr_t netmask = 0;
158
159 if (m_arg) {
160 if ((x = rn_addmask(m_arg, 1,
161 head->rnh_treetop->rn_off)) == NULL)
162 return (0);
163 netmask = x->rn_key;
164 }
165 x = rn_match(v_arg, head);
166 if (x && netmask) {
167 while (x && x->rn_mask != netmask)
168 x = x->rn_dupedkey;
169 }
170 return x;
171 }
172
173 static int
rn_satisfies_leaf(char * trial,struct radix_node * leaf,int skip)174 rn_satisfies_leaf(char *trial,
175 struct radix_node *leaf,
176 int skip)
177 {
178 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
179 char *cplim;
180 int length = min(*(u_char *)cp, *(u_char *)cp2);
181
182 if (cp3 == NULL)
183 cp3 = rn_ones;
184 else
185 length = min(length, *(u_char *)cp3);
186 cplim = cp + length; cp3 += skip; cp2 += skip;
187 for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
188 if ((*cp ^ *cp2) & *cp3)
189 return 0;
190 return 1;
191 }
192
193 static struct radix_node *
rn_match(void * v_arg,struct radix_node_head * head)194 rn_match(void *v_arg,
195 struct radix_node_head *head)
196 {
197 caddr_t v = v_arg;
198 struct radix_node *t = head->rnh_treetop, *x;
199 caddr_t cp = v, cp2;
200 caddr_t cplim;
201 struct radix_node *saved_t, *top = t;
202 int off = t->rn_off, vlen = *(u_char *)cp, matched_off;
203 int test, b, rn_b;
204
205 /*
206 * Open code rn_search(v, top) to avoid overhead of extra
207 * subroutine call.
208 */
209 for (; t->rn_b >= 0; ) {
210 if (t->rn_bmask & cp[t->rn_off])
211 t = t->rn_r;
212 else
213 t = t->rn_l;
214 }
215 /*
216 * See if we match exactly as a host destination
217 * or at least learn how many bits match, for normal mask finesse.
218 *
219 * It doesn't hurt us to limit how many bytes to check
220 * to the length of the mask, since if it matches we had a genuine
221 * match and the leaf we have is the most specific one anyway;
222 * if it didn't match with a shorter length it would fail
223 * with a long one. This wins big for class B&C netmasks which
224 * are probably the most common case...
225 */
226 if (t->rn_mask)
227 vlen = *(u_char *)t->rn_mask;
228 cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
229 for (; cp < cplim; cp++, cp2++)
230 if (*cp != *cp2)
231 goto on1;
232 /*
233 * This extra grot is in case we are explicitly asked
234 * to look up the default. Ugh!
235 * Or 255.255.255.255
236 *
237 * In this case, we have a complete match of the key. Unless
238 * the node is one of the roots, we are finished.
239 * If it is the zeros root, then take what we have, preferring
240 * any real data.
241 * If it is the ones root, then pretend the target key was followed
242 * by a byte of zeros.
243 */
244 if (!(t->rn_flags & RNF_ROOT))
245 return t; /* not a root */
246 if (t->rn_dupedkey) {
247 t = t->rn_dupedkey;
248 return t; /* have some real data */
249 }
250 if (*(cp-1) == 0)
251 return t; /* not the ones root */
252 b = 0; /* fake a zero after 255.255.255.255 */
253 goto on2;
254 on1:
255 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
256 for (b = 7; (test >>= 1) > 0;)
257 b--;
258 on2:
259 matched_off = cp - v;
260 b += matched_off << 3;
261 rn_b = -1 - b;
262 /*
263 * If there is a host route in a duped-key chain, it will be first.
264 */
265 if ((saved_t = t)->rn_mask == 0)
266 t = t->rn_dupedkey;
267 for (; t; t = t->rn_dupedkey) {
268 /*
269 * Even if we don't match exactly as a host,
270 * we may match if the leaf we wound up at is
271 * a route to a net.
272 */
273 if (t->rn_flags & RNF_NORMAL) {
274 if (rn_b <= t->rn_b)
275 return t;
276 } else if (rn_satisfies_leaf(v, t, matched_off)) {
277 return t;
278 }
279 }
280 t = saved_t;
281 /* start searching up the tree */
282 do {
283 struct radix_mask *m;
284 t = t->rn_p;
285 if ((m = t->rn_mklist)) {
286 /*
287 * If non-contiguous masks ever become important
288 * we can restore the masking and open coding of
289 * the search and satisfaction test and put the
290 * calculation of "off" back before the "do".
291 */
292 do {
293 if (m->rm_flags & RNF_NORMAL) {
294 if (rn_b <= m->rm_b)
295 return (m->rm_leaf);
296 } else {
297 off = min(t->rn_off, matched_off);
298 x = rn_search_m(v, t, m->rm_mask);
299 while (x && x->rn_mask != m->rm_mask)
300 x = x->rn_dupedkey;
301 if (x && rn_satisfies_leaf(v, x, off))
302 return x;
303 }
304 } while ((m = m->rm_mklist));
305 }
306 } while (t != top);
307 return 0;
308 }
309
310 #ifdef RN_DEBUG
311 int rn_nodenum;
312 struct radix_node *rn_clist;
313 int rn_saveinfo;
314 int rn_debug = 1;
315 #endif
316
317 static struct radix_node *
rn_newpair(void * v,int b,struct radix_node nodes[2])318 rn_newpair(void *v, int b, struct radix_node nodes[2])
319 {
320 struct radix_node *tt = nodes, *t = tt + 1;
321 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7);
322 t->rn_l = tt; t->rn_off = b >> 3;
323 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t;
324 tt->rn_flags = t->rn_flags = RNF_ACTIVE;
325 #ifdef RN_DEBUG
326 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
327 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
328 #endif
329 return t;
330 }
331
332 static struct radix_node *
rn_insert(void * v_arg,struct radix_node_head * head,int * dupentry,struct radix_node nodes[2])333 rn_insert(void* v_arg,
334 struct radix_node_head *head,
335 int *dupentry,
336 struct radix_node nodes[2])
337 {
338 caddr_t v = v_arg;
339 struct radix_node *top = head->rnh_treetop;
340 int head_off = top->rn_off, vlen = (int)*((u_char *)v);
341 struct radix_node *t = rn_search(v_arg, top);
342 caddr_t cp = v + head_off;
343 int b;
344 struct radix_node *tt;
345
346 /*
347 * Find first bit at which v and t->rn_key differ
348 */
349 {
350 caddr_t cp2 = t->rn_key + head_off;
351 int cmp_res;
352 caddr_t cplim = v + vlen;
353
354 while (cp < cplim)
355 if (*cp2++ != *cp++)
356 goto on1;
357 /* handle adding 255.255.255.255 */
358 if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) {
359 *dupentry = 1;
360 return t;
361 }
362 on1:
363 *dupentry = 0;
364 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
365 for (b = (cp - v) << 3; cmp_res; b--)
366 cmp_res >>= 1;
367 }
368 {
369 struct radix_node *p, *x = top;
370 cp = v;
371 do {
372 p = x;
373 if (cp[x->rn_off] & x->rn_bmask)
374 x = x->rn_r;
375 else x = x->rn_l;
376 } while ((unsigned)b > (unsigned)x->rn_b);
377 #ifdef RN_DEBUG
378 if (rn_debug)
379 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
380 #endif
381 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l;
382 if ((cp[p->rn_off] & p->rn_bmask) == 0)
383 p->rn_l = t;
384 else
385 p->rn_r = t;
386 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */
387 if ((cp[t->rn_off] & t->rn_bmask) == 0) {
388 t->rn_r = x;
389 } else {
390 t->rn_r = tt; t->rn_l = x;
391 }
392 #ifdef RN_DEBUG
393 if (rn_debug)
394 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
395 #endif
396 }
397 return (tt);
398 }
399
400 static struct radix_node *
rn_addmask(void * n_arg,int search,int skip)401 rn_addmask(void *n_arg, int search, int skip)
402 {
403 caddr_t netmask = (caddr_t)n_arg;
404 struct radix_node *x;
405 caddr_t cp, cplim;
406 int b = 0, mlen, j;
407 int maskduplicated, m0, isnormal;
408 struct radix_node *saved_x;
409 static int last_zeroed = 0;
410
411 if ((mlen = *(u_char *)netmask) > max_keylen)
412 mlen = max_keylen;
413 if (skip == 0)
414 skip = 1;
415 if (mlen <= skip)
416 return (mask_rnhead->rnh_nodes);
417 if (skip > 1)
418 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
419 if ((m0 = mlen) > skip)
420 Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
421 /*
422 * Trim trailing zeroes.
423 */
424 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
425 cp--;
426 mlen = cp - addmask_key;
427 if (mlen <= skip) {
428 if (m0 >= last_zeroed)
429 last_zeroed = mlen;
430 return (mask_rnhead->rnh_nodes);
431 }
432 if (m0 < last_zeroed)
433 Bzero(addmask_key + m0, last_zeroed - m0);
434 *addmask_key = last_zeroed = mlen;
435 x = rn_search(addmask_key, rn_masktop);
436 if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
437 x = NULL;
438 if (x || search)
439 return (x);
440 x = (struct radix_node *)rtmalloc(max_keylen + 2*sizeof(*x),
441 "rn_addmask");
442 saved_x = x;
443 Bzero(x, max_keylen + 2 * sizeof (*x));
444 netmask = cp = (caddr_t)(x + 2);
445 Bcopy(addmask_key, cp, mlen);
446 x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
447 if (maskduplicated) {
448 log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
449 Free(saved_x);
450 return (x);
451 }
452 /*
453 * Calculate index of mask, and check for normalcy.
454 */
455 cplim = netmask + mlen; isnormal = 1;
456 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
457 cp++;
458 if (cp != cplim) {
459 for (j = 0x80; (j & *cp) != 0; j >>= 1)
460 b++;
461 if (*cp != normal_chars[b] || cp != (cplim - 1))
462 isnormal = 0;
463 }
464 b += (cp - netmask) << 3;
465 x->rn_b = -1 - b;
466 if (isnormal)
467 x->rn_flags |= RNF_NORMAL;
468 return (x);
469 }
470
471 static int /* XXX: arbitrary ordering for non-contiguous masks */
rn_lexobetter(void * m_arg,void * n_arg)472 rn_lexobetter(void *m_arg, void *n_arg)
473 {
474 u_char *mp = m_arg, *np = n_arg, *lim;
475
476 if (*mp > *np)
477 return 1; /* not really, but need to check longer one first */
478 if (*mp == *np)
479 for (lim = mp + *mp; mp < lim;)
480 if (*mp++ > *np++)
481 return 1;
482 return 0;
483 }
484
485 static struct radix_mask *
rn_new_radix_mask(struct radix_node * tt,struct radix_mask * next)486 rn_new_radix_mask(struct radix_node *tt,
487 struct radix_mask *next)
488 {
489 struct radix_mask *m;
490
491 MKGet(m);
492 if (m == NULL) {
493 log(LOG_ERR, "Mask for route not entered\n");
494 return (0);
495 }
496 Bzero(m, sizeof *m);
497 m->rm_b = tt->rn_b;
498 m->rm_flags = tt->rn_flags;
499 if (tt->rn_flags & RNF_NORMAL)
500 m->rm_leaf = tt;
501 else
502 m->rm_mask = tt->rn_mask;
503 m->rm_mklist = next;
504 tt->rn_mklist = m;
505 return m;
506 }
507
508 static struct radix_node *
rn_addroute(void * v_arg,void * n_arg,struct radix_node_head * head,struct radix_node treenodes[2])509 rn_addroute(void *v_arg,
510 void *n_arg,
511 struct radix_node_head *head,
512 struct radix_node treenodes[2])
513 {
514 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
515 struct radix_node *t, *x = NULL, *tt;
516 struct radix_node *saved_tt, *top = head->rnh_treetop;
517 short b = 0, b_leaf = 0;
518 int keyduplicated;
519 caddr_t mmask;
520 struct radix_mask *m, **mp;
521
522 /*
523 * In dealing with non-contiguous masks, there may be
524 * many different routes which have the same mask.
525 * We will find it useful to have a unique pointer to
526 * the mask to speed avoiding duplicate references at
527 * nodes and possibly save time in calculating indices.
528 */
529 if (netmask) {
530 if ((x = rn_addmask(netmask, 0, top->rn_off)) == NULL)
531 return (0);
532 b_leaf = x->rn_b;
533 b = -1 - x->rn_b;
534 netmask = x->rn_key;
535 }
536 /*
537 * Deal with duplicated keys: attach node to previous instance
538 */
539 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
540 if (keyduplicated) {
541 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
542 if (tt->rn_mask == netmask)
543 return (0);
544 if (netmask == 0 ||
545 (tt->rn_mask &&
546 ((b_leaf < tt->rn_b) || /* index(netmask) > node */
547 rn_refines(netmask, tt->rn_mask) ||
548 rn_lexobetter(netmask, tt->rn_mask))))
549 break;
550 }
551 /*
552 * If the mask is not duplicated, we wouldn't
553 * find it among possible duplicate key entries
554 * anyway, so the above test doesn't hurt.
555 *
556 * We sort the masks for a duplicated key the same way as
557 * in a masklist -- most specific to least specific.
558 * This may require the unfortunate nuisance of relocating
559 * the head of the list.
560 */
561 if (tt == saved_tt) {
562 struct radix_node *xx = x;
563 /* link in at head of list */
564 (tt = treenodes)->rn_dupedkey = t;
565 tt->rn_flags = t->rn_flags;
566 tt->rn_p = x = t->rn_p;
567 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt;
568 saved_tt = tt; x = xx;
569 } else {
570 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
571 t->rn_dupedkey = tt;
572 }
573 #ifdef RN_DEBUG
574 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
575 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
576 #endif
577 tt->rn_key = (caddr_t) v;
578 tt->rn_b = -1;
579 tt->rn_flags = RNF_ACTIVE;
580 }
581 /*
582 * Put mask in tree.
583 */
584 if (netmask) {
585 tt->rn_mask = netmask;
586 tt->rn_b = x->rn_b;
587 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
588 }
589 t = saved_tt->rn_p;
590 if (keyduplicated)
591 goto on2;
592 b_leaf = -1 - t->rn_b;
593 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r;
594 /* Promote general routes from below */
595 if (x->rn_b < 0) {
596 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
597 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) {
598 if ((*mp = m = rn_new_radix_mask(x, 0)))
599 mp = &m->rm_mklist;
600 }
601 } else if (x->rn_mklist) {
602 /*
603 * Skip over masks whose index is > that of new node
604 */
605 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
606 if (m->rm_b >= b_leaf)
607 break;
608 t->rn_mklist = m; *mp = NULL;
609 }
610 on2:
611 /* Add new route to highest possible ancestor's list */
612 if ((netmask == 0) || (b > t->rn_b ))
613 return tt; /* can't lift at all */
614 b_leaf = tt->rn_b;
615 do {
616 x = t;
617 t = t->rn_p;
618 } while (b <= t->rn_b && x != top);
619 /*
620 * Search through routes associated with node to
621 * insert new route according to index.
622 * Need same criteria as when sorting dupedkeys to avoid
623 * double loop on deletion.
624 */
625 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
626 if (m->rm_b < b_leaf)
627 continue;
628 if (m->rm_b > b_leaf)
629 break;
630 if (m->rm_flags & RNF_NORMAL) {
631 mmask = m->rm_leaf->rn_mask;
632 if (tt->rn_flags & RNF_NORMAL) {
633 log(LOG_ERR,
634 "Non-unique normal route, mask not entered");
635 return tt;
636 }
637 } else
638 mmask = m->rm_mask;
639 if (mmask == netmask) {
640 m->rm_refs++;
641 tt->rn_mklist = m;
642 return tt;
643 }
644 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
645 break;
646 }
647 *mp = rn_new_radix_mask(tt, *mp);
648 return tt;
649 }
650
651 static struct radix_node *
rn_delete(void * v_arg,void * netmask_arg,struct radix_node_head * head)652 rn_delete(void *v_arg,
653 void *netmask_arg,
654 struct radix_node_head *head)
655 {
656 struct radix_node *t, *p, *x, *tt;
657 struct radix_mask *m, *saved_m, **mp;
658 struct radix_node *dupedkey, *saved_tt, *top;
659 caddr_t v, netmask;
660 int b, head_off, vlen;
661
662 v = v_arg;
663 netmask = netmask_arg;
664 x = head->rnh_treetop;
665 tt = rn_search(v, x);
666 head_off = x->rn_off;
667 vlen = *(u_char *)v;
668 saved_tt = tt;
669 top = x;
670 if (tt == NULL ||
671 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
672 return (0);
673 /*
674 * Delete our route from mask lists.
675 */
676 if (netmask) {
677 if ((x = rn_addmask(netmask, 1, head_off)) == NULL)
678 return (0);
679 netmask = x->rn_key;
680 while (tt->rn_mask != netmask)
681 if ((tt = tt->rn_dupedkey) == NULL)
682 return (0);
683 }
684 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == NULL)
685 goto on1;
686 if (tt->rn_flags & RNF_NORMAL) {
687 if (m->rm_leaf != tt || m->rm_refs > 0) {
688 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
689 return 0; /* dangling ref could cause disaster */
690 }
691 } else {
692 if (m->rm_mask != tt->rn_mask) {
693 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
694 goto on1;
695 }
696 if (--m->rm_refs >= 0)
697 goto on1;
698 }
699 b = -1 - tt->rn_b;
700 t = saved_tt->rn_p;
701 if (b > t->rn_b)
702 goto on1; /* Wasn't lifted at all */
703 do {
704 x = t;
705 t = t->rn_p;
706 } while (b <= t->rn_b && x != top);
707 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
708 if (m == saved_m) {
709 *mp = m->rm_mklist;
710 MKFree(m);
711 break;
712 }
713 if (m == NULL) {
714 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
715 if (tt->rn_flags & RNF_NORMAL)
716 return (0); /* Dangling ref to us */
717 }
718 on1:
719 /*
720 * Eliminate us from tree
721 */
722 if (tt->rn_flags & RNF_ROOT)
723 return (0);
724 #ifdef RN_DEBUG
725 /* Get us out of the creation list */
726 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
727 if (t) t->rn_ybro = tt->rn_ybro;
728 #endif
729 t = tt->rn_p;
730 if ((dupedkey = saved_tt->rn_dupedkey)) {
731 if (tt == saved_tt) {
732 x = dupedkey; x->rn_p = t;
733 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x;
734 } else {
735 for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
736 p = p->rn_dupedkey;
737 if (p) p->rn_dupedkey = tt->rn_dupedkey;
738 else log(LOG_ERR, "rn_delete: couldn't find us\n");
739 }
740 t = tt + 1;
741 if (t->rn_flags & RNF_ACTIVE) {
742 #ifndef RN_DEBUG
743 *++x = *t; p = t->rn_p;
744 #else
745 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p;
746 #endif
747 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x;
748 x->rn_l->rn_p = x; x->rn_r->rn_p = x;
749 }
750 goto out;
751 }
752 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l;
753 p = t->rn_p;
754 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x;
755 x->rn_p = p;
756 /*
757 * Demote routes attached to us.
758 */
759 if (t->rn_mklist) {
760 if (x->rn_b >= 0) {
761 for (mp = &x->rn_mklist; (m = *mp);)
762 mp = &m->rm_mklist;
763 *mp = t->rn_mklist;
764 } else {
765 /* If there are any key,mask pairs in a sibling
766 duped-key chain, some subset will appear sorted
767 in the same order attached to our mklist */
768 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
769 if (m == x->rn_mklist) {
770 struct radix_mask *mm = m->rm_mklist;
771 x->rn_mklist = 0;
772 if (--(m->rm_refs) < 0)
773 MKFree(m);
774 m = mm;
775 }
776 if (m)
777 syslog(LOG_ERR, "%s 0x%lx at 0x%lx\n",
778 "rn_delete: Orphaned Mask",
779 (unsigned long)m,
780 (unsigned long)x);
781 }
782 }
783 /*
784 * We may be holding an active internal node in the tree.
785 */
786 x = tt + 1;
787 if (t != x) {
788 #ifndef RN_DEBUG
789 *t = *x;
790 #else
791 b = t->rn_info; *t = *x; t->rn_info = b;
792 #endif
793 t->rn_l->rn_p = t; t->rn_r->rn_p = t;
794 p = x->rn_p;
795 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t;
796 }
797 out:
798 tt->rn_flags &= ~RNF_ACTIVE;
799 tt[1].rn_flags &= ~RNF_ACTIVE;
800 return (tt);
801 }
802
803 int
rn_walktree(struct radix_node_head * h,int (* f)(struct radix_node *,struct walkarg *),struct walkarg * w)804 rn_walktree(struct radix_node_head *h,
805 int (*f)(struct radix_node *, struct walkarg *),
806 struct walkarg *w)
807 {
808 int error;
809 struct radix_node *base, *next;
810 struct radix_node *rn = h->rnh_treetop;
811 /*
812 * This gets complicated because we may delete the node
813 * while applying the function f to it, so we need to calculate
814 * the successor node in advance.
815 */
816 /* First time through node, go left */
817 while (rn->rn_b >= 0)
818 rn = rn->rn_l;
819 for (;;) {
820 base = rn;
821 /* If at right child go back up, otherwise, go right */
822 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0)
823 rn = rn->rn_p;
824 /* Find the next *leaf* since next node might vanish, too */
825 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;)
826 rn = rn->rn_l;
827 next = rn;
828 /* Process leaves */
829 while ((rn = base)) {
830 base = rn->rn_dupedkey;
831 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
832 return (error);
833 }
834 rn = next;
835 if (rn->rn_flags & RNF_ROOT)
836 return (0);
837 }
838 /* NOTREACHED */
839 }
840
841 int
rn_inithead(struct radix_node_head ** head,int off)842 rn_inithead(struct radix_node_head **head, int off)
843 {
844 struct radix_node_head *rnh;
845 struct radix_node *t, *tt, *ttt;
846 if (*head)
847 return (1);
848 rnh = (struct radix_node_head *)rtmalloc(sizeof(*rnh), "rn_inithead");
849 Bzero(rnh, sizeof (*rnh));
850 *head = rnh;
851 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
852 ttt = rnh->rnh_nodes + 2;
853 t->rn_r = ttt;
854 t->rn_p = t;
855 tt = t->rn_l;
856 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
857 tt->rn_b = -1 - off;
858 *ttt = *tt;
859 ttt->rn_key = rn_ones;
860 rnh->rnh_addaddr = rn_addroute;
861 rnh->rnh_deladdr = rn_delete;
862 rnh->rnh_matchaddr = rn_match;
863 rnh->rnh_lookup = rn_lookup;
864 rnh->rnh_walktree = rn_walktree;
865 rnh->rnh_treetop = t;
866 return (1);
867 }
868
869 void
rn_init(void)870 rn_init(void)
871 {
872 char *cp, *cplim;
873 if (max_keylen == 0) {
874 printf("rn_init: radix functions require max_keylen be set\n");
875 return;
876 }
877 rn_zeros = (char *)rtmalloc(3 * max_keylen, "rn_init");
878 Bzero(rn_zeros, 3 * max_keylen);
879 rn_ones = cp = rn_zeros + max_keylen;
880 addmask_key = cplim = rn_ones + max_keylen;
881 while (cp < cplim)
882 *cp++ = -1;
883 if (rn_inithead(&mask_rnhead, 0) == 0)
884 panic("rn_init 2");
885 }
886
887