1 /*
2 * Copyright (c) 1988, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 *
7 * @(#)radix.c 8.5 (Berkeley) 05/19/95
8 */
9
10 /*
11 * Routines to build and maintain radix trees for routing lookups.
12 */
13 #ifndef _RADIX_H_
14 #include <sys/param.h>
15 #ifdef KERNEL
16 #include <sys/systm.h>
17 #include <sys/malloc.h>
18 #define M_DONTWAIT M_NOWAIT
19 #include <sys/domain.h>
20 #else
21 #include <stdlib.h>
22 #endif
23 #include <sys/syslog.h>
24 #include <net/radix.h>
25 #endif
26
27 int max_keylen;
28 struct radix_mask *rn_mkfreelist;
29 struct radix_node_head *mask_rnhead;
30 static char *addmask_key;
31 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
32 static char *rn_zeros, *rn_ones;
33
34 #define rn_masktop (mask_rnhead->rnh_treetop)
35 #undef Bcmp
36 #define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l))
37 /*
38 * The data structure for the keys is a radix tree with one way
39 * branching removed. The index rn_b at an internal node n represents a bit
40 * position to be tested. The tree is arranged so that all descendants
41 * of a node n have keys whose bits all agree up to position rn_b - 1.
42 * (We say the index of n is rn_b.)
43 *
44 * There is at least one descendant which has a one bit at position rn_b,
45 * and at least one with a zero there.
46 *
47 * A route is determined by a pair of key and mask. We require that the
48 * bit-wise logical and of the key and mask to be the key.
49 * We define the index of a route to associated with the mask to be
50 * the first bit number in the mask where 0 occurs (with bit number 0
51 * representing the highest order bit).
52 *
53 * We say a mask is normal if every bit is 0, past the index of the mask.
54 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b,
55 * and m is a normal mask, then the route applies to every descendant of n.
56 * If the index(m) < rn_b, this implies the trailing last few bits of k
57 * before bit b are all 0, (and hence consequently true of every descendant
58 * of n), so the route applies to all descendants of the node as well.
59 *
60 * Similar logic shows that a non-normal mask m such that
61 * index(m) <= index(n) could potentially apply to many children of n.
62 * Thus, for each non-host route, we attach its mask to a list at an internal
63 * node as high in the tree as we can go.
64 *
65 * The present version of the code makes use of normal routes in short-
66 * circuiting an explict mask and compare operation when testing whether
67 * a key satisfies a normal route, and also in remembering the unique leaf
68 * that governs a subtree.
69 */
70
71 struct radix_node *
rn_search(v_arg,head)72 rn_search(v_arg, head)
73 void *v_arg;
74 struct radix_node *head;
75 {
76 register struct radix_node *x;
77 register caddr_t v;
78
79 for (x = head, v = v_arg; x->rn_b >= 0;) {
80 if (x->rn_bmask & v[x->rn_off])
81 x = x->rn_r;
82 else
83 x = x->rn_l;
84 }
85 return (x);
86 };
87
88 struct radix_node *
rn_search_m(v_arg,head,m_arg)89 rn_search_m(v_arg, head, m_arg)
90 struct radix_node *head;
91 void *v_arg, *m_arg;
92 {
93 register struct radix_node *x;
94 register caddr_t v = v_arg, m = m_arg;
95
96 for (x = head; x->rn_b >= 0;) {
97 if ((x->rn_bmask & m[x->rn_off]) &&
98 (x->rn_bmask & v[x->rn_off]))
99 x = x->rn_r;
100 else
101 x = x->rn_l;
102 }
103 return x;
104 };
105
106 int
rn_refines(m_arg,n_arg)107 rn_refines(m_arg, n_arg)
108 void *m_arg, *n_arg;
109 {
110 register caddr_t m = m_arg, n = n_arg;
111 register caddr_t lim, lim2 = lim = n + *(u_char *)n;
112 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
113 int masks_are_equal = 1;
114
115 if (longer > 0)
116 lim -= longer;
117 while (n < lim) {
118 if (*n & ~(*m))
119 return 0;
120 if (*n++ != *m++)
121 masks_are_equal = 0;
122 }
123 while (n < lim2)
124 if (*n++)
125 return 0;
126 if (masks_are_equal && (longer < 0))
127 for (lim2 = m - longer; m < lim2; )
128 if (*m++)
129 return 1;
130 return (!masks_are_equal);
131 }
132
133 struct radix_node *
rn_lookup(v_arg,m_arg,head)134 rn_lookup(v_arg, m_arg, head)
135 void *v_arg, *m_arg;
136 struct radix_node_head *head;
137 {
138 register struct radix_node *x;
139 caddr_t netmask = 0;
140
141 if (m_arg) {
142 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0)
143 return (0);
144 netmask = x->rn_key;
145 }
146 x = rn_match(v_arg, head);
147 if (x && netmask) {
148 while (x && x->rn_mask != netmask)
149 x = x->rn_dupedkey;
150 }
151 return x;
152 }
153
154 static int
rn_satsifies_leaf(trial,leaf,skip)155 rn_satsifies_leaf(trial, leaf, skip)
156 char *trial;
157 register struct radix_node *leaf;
158 int skip;
159 {
160 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
161 char *cplim;
162 int length = min(*(u_char *)cp, *(u_char *)cp2);
163
164 if (cp3 == 0)
165 cp3 = rn_ones;
166 else
167 length = min(length, *(u_char *)cp3);
168 cplim = cp + length; cp3 += skip; cp2 += skip;
169 for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
170 if ((*cp ^ *cp2) & *cp3)
171 return 0;
172 return 1;
173 }
174
175 struct radix_node *
rn_match(v_arg,head)176 rn_match(v_arg, head)
177 void *v_arg;
178 struct radix_node_head *head;
179 {
180 caddr_t v = v_arg;
181 register struct radix_node *t = head->rnh_treetop, *x;
182 register caddr_t cp = v, cp2;
183 caddr_t cplim;
184 struct radix_node *saved_t, *top = t;
185 int off = t->rn_off, vlen = *(u_char *)cp, matched_off;
186 register int test, b, rn_b;
187
188 /*
189 * Open code rn_search(v, top) to avoid overhead of extra
190 * subroutine call.
191 */
192 for (; t->rn_b >= 0; ) {
193 if (t->rn_bmask & cp[t->rn_off])
194 t = t->rn_r;
195 else
196 t = t->rn_l;
197 }
198 /*
199 * See if we match exactly as a host destination
200 * or at least learn how many bits match, for normal mask finesse.
201 *
202 * It doesn't hurt us to limit how many bytes to check
203 * to the length of the mask, since if it matches we had a genuine
204 * match and the leaf we have is the most specific one anyway;
205 * if it didn't match with a shorter length it would fail
206 * with a long one. This wins big for class B&C netmasks which
207 * are probably the most common case...
208 */
209 if (t->rn_mask)
210 vlen = *(u_char *)t->rn_mask;
211 cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
212 for (; cp < cplim; cp++, cp2++)
213 if (*cp != *cp2)
214 goto on1;
215 /*
216 * This extra grot is in case we are explicitly asked
217 * to look up the default. Ugh!
218 */
219 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey)
220 t = t->rn_dupedkey;
221 return t;
222 on1:
223 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
224 for (b = 7; (test >>= 1) > 0;)
225 b--;
226 matched_off = cp - v;
227 b += matched_off << 3;
228 rn_b = -1 - b;
229 /*
230 * If there is a host route in a duped-key chain, it will be first.
231 */
232 if ((saved_t = t)->rn_mask == 0)
233 t = t->rn_dupedkey;
234 for (; t; t = t->rn_dupedkey)
235 /*
236 * Even if we don't match exactly as a host,
237 * we may match if the leaf we wound up at is
238 * a route to a net.
239 */
240 if (t->rn_flags & RNF_NORMAL) {
241 if (rn_b <= t->rn_b)
242 return t;
243 } else if (rn_satsifies_leaf(v, t, matched_off))
244 return t;
245 t = saved_t;
246 /* start searching up the tree */
247 do {
248 register struct radix_mask *m;
249 t = t->rn_p;
250 m = t->rn_mklist;
251 if (m) {
252 /*
253 * If non-contiguous masks ever become important
254 * we can restore the masking and open coding of
255 * the search and satisfaction test and put the
256 * calculation of "off" back before the "do".
257 */
258 do {
259 if (m->rm_flags & RNF_NORMAL) {
260 if (rn_b <= m->rm_b)
261 return (m->rm_leaf);
262 } else {
263 off = min(t->rn_off, matched_off);
264 x = rn_search_m(v, t, m->rm_mask);
265 while (x && x->rn_mask != m->rm_mask)
266 x = x->rn_dupedkey;
267 if (x && rn_satsifies_leaf(v, x, off))
268 return x;
269 }
270 m = m->rm_mklist;
271 } while (m);
272 }
273 } while (t != top);
274 return 0;
275 };
276
277 #ifdef RN_DEBUG
278 int rn_nodenum;
279 struct radix_node *rn_clist;
280 int rn_saveinfo;
281 int rn_debug = 1;
282 #endif
283
284 struct radix_node *
rn_newpair(v,b,nodes)285 rn_newpair(v, b, nodes)
286 void *v;
287 int b;
288 struct radix_node nodes[2];
289 {
290 register struct radix_node *tt = nodes, *t = tt + 1;
291 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7);
292 t->rn_l = tt; t->rn_off = b >> 3;
293 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t;
294 tt->rn_flags = t->rn_flags = RNF_ACTIVE;
295 #ifdef RN_DEBUG
296 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
297 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
298 #endif
299 return t;
300 }
301
302 struct radix_node *
rn_insert(v_arg,head,dupentry,nodes)303 rn_insert(v_arg, head, dupentry, nodes)
304 void *v_arg;
305 struct radix_node_head *head;
306 int *dupentry;
307 struct radix_node nodes[2];
308 {
309 caddr_t v = v_arg;
310 struct radix_node *top = head->rnh_treetop;
311 int head_off = top->rn_off, vlen = (int)*((u_char *)v);
312 register struct radix_node *t = rn_search(v_arg, top);
313 register caddr_t cp = v + head_off;
314 register int b;
315 struct radix_node *tt;
316 /*
317 * Find first bit at which v and t->rn_key differ
318 */
319 {
320 register caddr_t cp2 = t->rn_key + head_off;
321 register int cmp_res;
322 caddr_t cplim = v + vlen;
323
324 while (cp < cplim)
325 if (*cp2++ != *cp++)
326 goto on1;
327 *dupentry = 1;
328 return t;
329 on1:
330 *dupentry = 0;
331 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
332 for (b = (cp - v) << 3; cmp_res; b--)
333 cmp_res >>= 1;
334 }
335 {
336 register struct radix_node *p, *x = top;
337 cp = v;
338 do {
339 p = x;
340 if (cp[x->rn_off] & x->rn_bmask)
341 x = x->rn_r;
342 else x = x->rn_l;
343 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */
344 #ifdef RN_DEBUG
345 if (rn_debug)
346 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
347 #endif
348 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l;
349 if ((cp[p->rn_off] & p->rn_bmask) == 0)
350 p->rn_l = t;
351 else
352 p->rn_r = t;
353 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */
354 if ((cp[t->rn_off] & t->rn_bmask) == 0) {
355 t->rn_r = x;
356 } else {
357 t->rn_r = tt; t->rn_l = x;
358 }
359 #ifdef RN_DEBUG
360 if (rn_debug)
361 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
362 #endif
363 }
364 return (tt);
365 }
366
367 struct radix_node *
rn_addmask(n_arg,search,skip)368 rn_addmask(n_arg, search, skip)
369 int search, skip;
370 void *n_arg;
371 {
372 caddr_t netmask = (caddr_t)n_arg;
373 register struct radix_node *x;
374 register caddr_t cp, cplim;
375 register int b = 0, mlen, j;
376 int maskduplicated, m0, isnormal;
377 struct radix_node *saved_x;
378 static int last_zeroed = 0;
379
380 if ((mlen = *(u_char *)netmask) > max_keylen)
381 mlen = max_keylen;
382 if (skip == 0)
383 skip = 1;
384 if (mlen <= skip)
385 return (mask_rnhead->rnh_nodes);
386 if (skip > 1)
387 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
388 if ((m0 = mlen) > skip)
389 Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
390 /*
391 * Trim trailing zeroes.
392 */
393 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
394 cp--;
395 mlen = cp - addmask_key;
396 if (mlen <= skip) {
397 if (m0 >= last_zeroed)
398 last_zeroed = mlen;
399 return (mask_rnhead->rnh_nodes);
400 }
401 if (m0 < last_zeroed)
402 Bzero(addmask_key + m0, last_zeroed - m0);
403 *addmask_key = last_zeroed = mlen;
404 x = rn_search(addmask_key, rn_masktop);
405 if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
406 x = 0;
407 if (x || search)
408 return (x);
409 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
410 if ((saved_x = x) == 0)
411 return (0);
412 Bzero(x, max_keylen + 2 * sizeof (*x));
413 netmask = cp = (caddr_t)(x + 2);
414 Bcopy(addmask_key, cp, mlen);
415 x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
416 if (maskduplicated) {
417 log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
418 Free(saved_x);
419 return (x);
420 }
421 /*
422 * Calculate index of mask, and check for normalcy.
423 */
424 cplim = netmask + mlen; isnormal = 1;
425 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
426 cp++;
427 if (cp != cplim) {
428 for (j = 0x80; (j & *cp) != 0; j >>= 1)
429 b++;
430 if (*cp != normal_chars[b] || cp != (cplim - 1))
431 isnormal = 0;
432 }
433 b += (cp - netmask) << 3;
434 x->rn_b = -1 - b;
435 if (isnormal)
436 x->rn_flags |= RNF_NORMAL;
437 return (x);
438 }
439
440 static int /* XXX: arbitrary ordering for non-contiguous masks */
rn_lexobetter(m_arg,n_arg)441 rn_lexobetter(m_arg, n_arg)
442 void *m_arg, *n_arg;
443 {
444 register u_char *mp = m_arg, *np = n_arg, *lim;
445
446 if (*mp > *np)
447 return 1; /* not really, but need to check longer one first */
448 if (*mp == *np)
449 for (lim = mp + *mp; mp < lim;)
450 if (*mp++ > *np++)
451 return 1;
452 return 0;
453 }
454
455 static struct radix_mask *
rn_new_radix_mask(tt,next)456 rn_new_radix_mask(tt, next)
457 register struct radix_node *tt;
458 register struct radix_mask *next;
459 {
460 register struct radix_mask *m;
461
462 MKGet(m);
463 if (m == 0) {
464 log(LOG_ERR, "Mask for route not entered\n");
465 return (0);
466 }
467 Bzero(m, sizeof *m);
468 m->rm_b = tt->rn_b;
469 m->rm_flags = tt->rn_flags;
470 if (tt->rn_flags & RNF_NORMAL)
471 m->rm_leaf = tt;
472 else
473 m->rm_mask = tt->rn_mask;
474 m->rm_mklist = next;
475 tt->rn_mklist = m;
476 return m;
477 }
478
479 struct radix_node *
rn_addroute(v_arg,n_arg,head,treenodes)480 rn_addroute(v_arg, n_arg, head, treenodes)
481 void *v_arg, *n_arg;
482 struct radix_node_head *head;
483 struct radix_node treenodes[2];
484 {
485 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
486 register struct radix_node *t, *x = 0, *tt;
487 struct radix_node *saved_tt, *top = head->rnh_treetop;
488 short b = 0, b_leaf = 0;
489 int keyduplicated;
490 caddr_t mmask;
491 struct radix_mask *m, **mp;
492
493 /*
494 * In dealing with non-contiguous masks, there may be
495 * many different routes which have the same mask.
496 * We will find it useful to have a unique pointer to
497 * the mask to speed avoiding duplicate references at
498 * nodes and possibly save time in calculating indices.
499 */
500 if (netmask) {
501 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0)
502 return (0);
503 b_leaf = x->rn_b;
504 b = -1 - x->rn_b;
505 netmask = x->rn_key;
506 }
507 /*
508 * Deal with duplicated keys: attach node to previous instance
509 */
510 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
511 if (keyduplicated) {
512 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
513 if (tt->rn_mask == netmask)
514 return (0);
515 if (netmask == 0 ||
516 (tt->rn_mask &&
517 ((b_leaf < tt->rn_b) || /* index(netmask) > node */
518 rn_refines(netmask, tt->rn_mask) ||
519 rn_lexobetter(netmask, tt->rn_mask))))
520 break;
521 }
522 /*
523 * If the mask is not duplicated, we wouldn't
524 * find it among possible duplicate key entries
525 * anyway, so the above test doesn't hurt.
526 *
527 * We sort the masks for a duplicated key the same way as
528 * in a masklist -- most specific to least specific.
529 * This may require the unfortunate nuisance of relocating
530 * the head of the list.
531 *
532 * We also reverse, or doubly link the list through the
533 * parent pointer.
534 */
535 if (tt == saved_tt) {
536 struct radix_node *xx = x;
537 /* link in at head of list */
538 (tt = treenodes)->rn_dupedkey = t;
539 tt->rn_flags = t->rn_flags;
540 tt->rn_p = x = t->rn_p;
541 t->rn_p = tt;
542 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt;
543 saved_tt = tt; x = xx;
544 } else {
545 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
546 t->rn_dupedkey = tt;
547 tt->rn_p = t;
548 if (tt->rn_dupedkey)
549 tt->rn_dupedkey->rn_p = tt;
550 }
551 #ifdef RN_DEBUG
552 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
553 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
554 #endif
555 tt->rn_key = (caddr_t) v;
556 tt->rn_b = -1;
557 tt->rn_flags = RNF_ACTIVE;
558 }
559 /*
560 * Put mask in tree.
561 */
562 if (netmask) {
563 tt->rn_mask = netmask;
564 tt->rn_b = x->rn_b;
565 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
566 }
567 t = saved_tt->rn_p;
568 if (keyduplicated)
569 goto on2;
570 b_leaf = -1 - t->rn_b;
571 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r;
572 /* Promote general routes from below */
573 if (x->rn_b < 0) {
574 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
575 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) {
576 *mp = m = rn_new_radix_mask(x, 0);
577 if (m)
578 mp = &m->rm_mklist;
579 }
580 } else if (x->rn_mklist) {
581 /*
582 * Skip over masks whose index is > that of new node
583 */
584 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
585 if (m->rm_b >= b_leaf)
586 break;
587 t->rn_mklist = m; *mp = 0;
588 }
589 on2:
590 /* Add new route to highest possible ancestor's list */
591 if ((netmask == 0) || (b > t->rn_b ))
592 return tt; /* can't lift at all */
593 b_leaf = tt->rn_b;
594 do {
595 x = t;
596 t = t->rn_p;
597 } while (b <= t->rn_b && x != top);
598 /*
599 * Search through routes associated with node to
600 * insert new route according to index.
601 * Need same criteria as when sorting dupedkeys to avoid
602 * double loop on deletion.
603 */
604 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
605 if (m->rm_b < b_leaf)
606 continue;
607 if (m->rm_b > b_leaf)
608 break;
609 if (m->rm_flags & RNF_NORMAL) {
610 mmask = m->rm_leaf->rn_mask;
611 if (tt->rn_flags & RNF_NORMAL) {
612 log(LOG_ERR,
613 "Non-unique normal route, mask not entered");
614 return tt;
615 }
616 } else
617 mmask = m->rm_mask;
618 if (mmask == netmask) {
619 m->rm_refs++;
620 tt->rn_mklist = m;
621 return tt;
622 }
623 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
624 break;
625 }
626 *mp = rn_new_radix_mask(tt, *mp);
627 return tt;
628 }
629
630 struct radix_node *
rn_delete(v_arg,netmask_arg,head)631 rn_delete(v_arg, netmask_arg, head)
632 void *v_arg, *netmask_arg;
633 struct radix_node_head *head;
634 {
635 register struct radix_node *t, *p, *x, *tt;
636 struct radix_mask *m, *saved_m, **mp;
637 struct radix_node *dupedkey, *saved_tt, *top;
638 caddr_t v, netmask;
639 int b, head_off, vlen;
640
641 v = v_arg;
642 netmask = netmask_arg;
643 x = head->rnh_treetop;
644 tt = rn_search(v, x);
645 head_off = x->rn_off;
646 vlen = *(u_char *)v;
647 saved_tt = tt;
648 top = x;
649 if (tt == 0 ||
650 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
651 return (0);
652 /*
653 * Delete our route from mask lists.
654 */
655 if (netmask) {
656 if ((x = rn_addmask(netmask, 1, head_off)) == 0)
657 return (0);
658 netmask = x->rn_key;
659 while (tt->rn_mask != netmask)
660 if ((tt = tt->rn_dupedkey) == 0)
661 return (0);
662 }
663 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
664 goto on1;
665 if (tt->rn_flags & RNF_NORMAL) {
666 if (m->rm_leaf != tt || m->rm_refs > 0) {
667 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
668 return 0; /* dangling ref could cause disaster */
669 }
670 } else {
671 if (m->rm_mask != tt->rn_mask) {
672 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
673 goto on1;
674 }
675 if (--m->rm_refs >= 0)
676 goto on1;
677 }
678 b = -1 - tt->rn_b;
679 t = saved_tt->rn_p;
680 if (b > t->rn_b)
681 goto on1; /* Wasn't lifted at all */
682 do {
683 x = t;
684 t = t->rn_p;
685 } while (b <= t->rn_b && x != top);
686 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
687 if (m == saved_m) {
688 *mp = m->rm_mklist;
689 MKFree(m);
690 break;
691 }
692 if (m == 0) {
693 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
694 if (tt->rn_flags & RNF_NORMAL)
695 return (0); /* Dangling ref to us */
696 }
697 on1:
698 /*
699 * Eliminate us from tree
700 */
701 if (tt->rn_flags & RNF_ROOT)
702 return (0);
703 #ifdef RN_DEBUG
704 /* Get us out of the creation list */
705 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
706 if (t) t->rn_ybro = tt->rn_ybro;
707 #endif
708 t = tt->rn_p;
709 dupedkey = saved_tt->rn_dupedkey;
710 if (dupedkey) {
711 /*
712 * Here, tt is the deletion target, and
713 * saved_tt is the head of the dupedkey chain.
714 */
715 if (tt == saved_tt) {
716 x = dupedkey; x->rn_p = t;
717 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x;
718 } else {
719 /* find node in front of tt on the chain */
720 for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
721 p = p->rn_dupedkey;
722 if (p) {
723 p->rn_dupedkey = tt->rn_dupedkey;
724 if (tt->rn_dupedkey)
725 tt->rn_dupedkey->rn_p = p;
726 } else log(LOG_ERR, "rn_delete: couldn't find us\n");
727 }
728 t = tt + 1;
729 if (t->rn_flags & RNF_ACTIVE) {
730 #ifndef RN_DEBUG
731 *++x = *t; p = t->rn_p;
732 #else
733 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p;
734 #endif
735 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x;
736 x->rn_l->rn_p = x; x->rn_r->rn_p = x;
737 }
738 goto out;
739 }
740 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l;
741 p = t->rn_p;
742 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x;
743 x->rn_p = p;
744 /*
745 * Demote routes attached to us.
746 */
747 if (t->rn_mklist) {
748 if (x->rn_b >= 0) {
749 for (mp = &x->rn_mklist; (m = *mp);)
750 mp = &m->rm_mklist;
751 *mp = t->rn_mklist;
752 } else {
753 /* If there are any key,mask pairs in a sibling
754 duped-key chain, some subset will appear sorted
755 in the same order attached to our mklist */
756 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
757 if (m == x->rn_mklist) {
758 struct radix_mask *mm = m->rm_mklist;
759 x->rn_mklist = 0;
760 if (--(m->rm_refs) < 0)
761 MKFree(m);
762 m = mm;
763 }
764 if (m)
765 log(LOG_ERR, "%s %x at %x\n",
766 "rn_delete: Orphaned Mask", m, x);
767 }
768 }
769 /*
770 * We may be holding an active internal node in the tree.
771 */
772 x = tt + 1;
773 if (t != x) {
774 #ifndef RN_DEBUG
775 *t = *x;
776 #else
777 b = t->rn_info; *t = *x; t->rn_info = b;
778 #endif
779 t->rn_l->rn_p = t; t->rn_r->rn_p = t;
780 p = x->rn_p;
781 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t;
782 }
783 out:
784 tt->rn_flags &= ~RNF_ACTIVE;
785 tt[1].rn_flags &= ~RNF_ACTIVE;
786 return (tt);
787 }
788
789 int
rn_walktree(h,f,w)790 rn_walktree(h, f, w)
791 struct radix_node_head *h;
792 register int (*f)();
793 void *w;
794 {
795 int error;
796 struct radix_node *base, *next;
797 register struct radix_node *rn = h->rnh_treetop;
798 /*
799 * This gets complicated because we may delete the node
800 * while applying the function f to it, so we need to calculate
801 * the successor node in advance.
802 */
803 /* First time through node, go left */
804 while (rn->rn_b >= 0)
805 rn = rn->rn_l;
806 for (;;) {
807 base = rn;
808 /* If at right child go back up, otherwise, go right */
809 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0)
810 rn = rn->rn_p;
811 /* Find the next *leaf* since next node might vanish, too */
812 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;)
813 rn = rn->rn_l;
814 next = rn;
815 /* Process leaves */
816 while (rn = base) {
817 base = rn->rn_dupedkey;
818 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
819 return (error);
820 }
821 rn = next;
822 if (rn->rn_flags & RNF_ROOT)
823 return (0);
824 }
825 /* NOTREACHED */
826 }
827
828 int
rn_inithead(head,off)829 rn_inithead(head, off)
830 void **head;
831 int off;
832 {
833 register struct radix_node_head *rnh;
834 register struct radix_node *t, *tt, *ttt;
835 if (*head)
836 return (1);
837 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh));
838 if (rnh == 0)
839 return (0);
840 Bzero(rnh, sizeof (*rnh));
841 *head = rnh;
842 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
843 ttt = rnh->rnh_nodes + 2;
844 t->rn_r = ttt;
845 t->rn_p = t;
846 tt = t->rn_l;
847 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
848 tt->rn_b = -1 - off;
849 *ttt = *tt;
850 ttt->rn_key = rn_ones;
851 rnh->rnh_addaddr = rn_addroute;
852 rnh->rnh_deladdr = rn_delete;
853 rnh->rnh_matchaddr = rn_match;
854 rnh->rnh_lookup = rn_lookup;
855 rnh->rnh_walktree = rn_walktree;
856 rnh->rnh_treetop = t;
857 return (1);
858 }
859
860 void
rn_init()861 rn_init()
862 {
863 char *cp, *cplim;
864 #ifdef KERNEL
865 struct domain *dom;
866
867 for (dom = domains; dom; dom = dom->dom_next)
868 if (dom->dom_maxrtkey > max_keylen)
869 max_keylen = dom->dom_maxrtkey;
870 #endif
871 if (max_keylen == 0) {
872 log(LOG_ERR,
873 "rn_init: radix functions require max_keylen be set\n");
874 return;
875 }
876 R_Malloc(rn_zeros, char *, 3 * max_keylen);
877 if (rn_zeros == NULL)
878 panic("rn_init");
879 Bzero(rn_zeros, 3 * max_keylen);
880 rn_ones = cp = rn_zeros + max_keylen;
881 addmask_key = cplim = rn_ones + max_keylen;
882 while (cp < cplim)
883 *cp++ = -1;
884 if (rn_inithead((void **)&mask_rnhead, 0) == 0)
885 panic("rn_init 2");
886 }
887