1/*
2 * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Copyright (c) 1988, 1989, 1993
30 * The Regents of the University of California. All rights reserved.
31 *
32 * Redistribution and use in source and binary forms, with or without
33 * modification, are permitted provided that the following conditions
34 * are met:
35 * 1. Redistributions of source code must retain the above copyright
36 * notice, this list of conditions and the following disclaimer.
37 * 2. Redistributions in binary form must reproduce the above copyright
38 * notice, this list of conditions and the following disclaimer in the
39 * documentation and/or other materials provided with the distribution.
40 * 3. All advertising materials mentioning features or use of this software
41 * must display the following acknowledgement:
42 * This product includes software developed by the University of
43 * California, Berkeley and its contributors.
44 * 4. Neither the name of the University nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 * @(#)radix.c 8.4 (Berkeley) 11/2/94
61 * $FreeBSD: src/sys/net/radix.c,v 1.20.2.2 2001/03/06 00:56:50 obrien Exp $
62 */
63
64/*
65 * Routines to build and maintain radix trees for routing lookups.
66 */
67#ifndef _RADIX_H_
68#include <sys/param.h>
69#include <sys/systm.h>
70#include <sys/malloc.h>
71#define M_DONTWAIT M_NOWAIT
72#include <sys/domain.h>
73#include <sys/syslog.h>
74#include <net/radix.h>
75#include <sys/socket.h>
76#include <sys/socketvar.h>
77#include <kern/locks.h>
78#endif
79
80static int rn_walktree_from(struct radix_node_head *h, void *a,
81 void *m, walktree_f_t *f, void *w);
82static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
83static struct radix_node
84 *rn_insert(void *, struct radix_node_head *, int *,
85 struct radix_node [2]),
86 *rn_newpair(void *, int, struct radix_node[2]),
87 *rn_search(void *, struct radix_node *),
88 *rn_search_m(void *, struct radix_node *, void *);
89
90static int max_keylen;
91static struct radix_mask *rn_mkfreelist;
92static struct radix_node_head *mask_rnhead;
93static char *addmask_key;
94static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
95static char *rn_zeros, *rn_ones;
96
97
98extern lck_grp_t *domain_proto_mtx_grp;
99extern lck_attr_t *domain_proto_mtx_attr;
100
101#define rn_masktop (mask_rnhead->rnh_treetop)
102#undef Bcmp
103#define Bcmp(a, b, l) \
104 (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (uint32_t)l))
105
106static int rn_lexobetter(void *m_arg, void *n_arg);
107static struct radix_mask *
108 rn_new_radix_mask(struct radix_node *tt,
109 struct radix_mask *next);
110static int rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip,
111 rn_matchf_t *f, void *w);
112
113#define RN_MATCHF(rn, f, arg) (f == NULL || (*f)((rn), arg))
114
115/*
116 * The data structure for the keys is a radix tree with one way
117 * branching removed. The index rn_bit at an internal node n represents a bit
118 * position to be tested. The tree is arranged so that all descendants
119 * of a node n have keys whose bits all agree up to position rn_bit - 1.
120 * (We say the index of n is rn_bit.)
121 *
122 * There is at least one descendant which has a one bit at position rn_bit,
123 * and at least one with a zero there.
124 *
125 * A route is determined by a pair of key and mask. We require that the
126 * bit-wise logical and of the key and mask to be the key.
127 * We define the index of a route to associated with the mask to be
128 * the first bit number in the mask where 0 occurs (with bit number 0
129 * representing the highest order bit).
130 *
131 * We say a mask is normal if every bit is 0, past the index of the mask.
132 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
133 * and m is a normal mask, then the route applies to every descendant of n.
134 * If the index(m) < rn_bit, this implies the trailing last few bits of k
135 * before bit b are all 0, (and hence consequently true of every descendant
136 * of n), so the route applies to all descendants of the node as well.
137 *
138 * Similar logic shows that a non-normal mask m such that
139 * index(m) <= index(n) could potentially apply to many children of n.
140 * Thus, for each non-host route, we attach its mask to a list at an internal
141 * node as high in the tree as we can go.
142 *
143 * The present version of the code makes use of normal routes in short-
144 * circuiting an explict mask and compare operation when testing whether
145 * a key satisfies a normal route, and also in remembering the unique leaf
146 * that governs a subtree.
147 */
148
149static struct radix_node *
150rn_search(void *v_arg, struct radix_node *head)
151{
152 struct radix_node *x;
153 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
164static struct radix_node *
165rn_search_m(void *v_arg, struct radix_node *head, void *m_arg)
166{
167 struct radix_node *x;
168 caddr_t v = v_arg, m = m_arg;
169
170 for (x = head; x->rn_bit >= 0;) {
171 if ((x->rn_bmask & m[x->rn_offset]) &&
172 (x->rn_bmask & v[x->rn_offset]))
173 x = x->rn_right;
174 else
175 x = x->rn_left;
176 }
177 return x;
178}
179
180int
181rn_refines(void *m_arg, void *n_arg)
182{
183 caddr_t m = m_arg, n = n_arg;
184 caddr_t lim, lim2 = lim = n + *(u_char *)n;
185 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
186 int masks_are_equal = 1;
187
188 if (longer > 0)
189 lim -= longer;
190 while (n < lim) {
191 if (*n & ~(*m))
192 return 0;
193 if (*n++ != *m++)
194 masks_are_equal = 0;
195 }
196 while (n < lim2)
197 if (*n++)
198 return 0;
199 if (masks_are_equal && (longer < 0))
200 for (lim2 = m - longer; m < lim2; )
201 if (*m++)
202 return 1;
203 return (!masks_are_equal);
204}
205
206struct radix_node *
207rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head)
208{
209 return (rn_lookup_args(v_arg, m_arg, head, NULL, NULL));
210}
211
212struct radix_node *
213rn_lookup_args(void *v_arg, void *m_arg, struct radix_node_head *head,
214 rn_matchf_t *f, void *w)
215{
216 struct radix_node *x;
217 caddr_t netmask = NULL;
218
219 if (m_arg) {
220 x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset);
221 if (x == 0)
222 return (NULL);
223 netmask = x->rn_key;
224 }
225 x = rn_match_args(v_arg, head, f, w);
226 if (x && netmask) {
227 while (x && x->rn_mask != netmask)
228 x = x->rn_dupedkey;
229 }
230 return x;
231}
232
233/*
234 * Returns true if address 'trial' has no bits differing from the
235 * leaf's key when compared under the leaf's mask. In other words,
236 * returns true when 'trial' matches leaf. If a leaf-matching
237 * routine is passed in, it is also used to find a match on the
238 * conditions defined by the caller of rn_match.
239 */
240static int
241rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip,
242 rn_matchf_t *f, void *w)
243{
244 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
245 char *cplim;
246 int length = min(*(u_char *)cp, *(u_char *)cp2);
247
248 if (cp3 == 0)
249 cp3 = rn_ones;
250 else
251 length = min(length, *(u_char *)cp3);
252 cplim = cp + length; cp3 += skip; cp2 += skip;
253 for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
254 if ((*cp ^ *cp2) & *cp3)
255 return 0;
256
257 return (RN_MATCHF(leaf, f, w));
258}
259
260struct radix_node *
261rn_match(void *v_arg, struct radix_node_head *head)
262{
263 return (rn_match_args(v_arg, head, NULL, NULL));
264}
265
266struct radix_node *
267rn_match_args(void *v_arg, struct radix_node_head *head,
268 rn_matchf_t *f, void *w)
269{
270 caddr_t v = v_arg;
271 struct radix_node *t = head->rnh_treetop, *x;
272 caddr_t cp = v, cp2;
273 caddr_t cplim;
274 struct radix_node *saved_t, *top = t;
275 int off = t->rn_offset, vlen = *(u_char *)cp, matched_off;
276 int test, b, rn_bit;
277
278 /*
279 * Open code rn_search(v, top) to avoid overhead of extra
280 * subroutine call.
281 */
282 for (; t->rn_bit >= 0; ) {
283 if (t->rn_bmask & cp[t->rn_offset])
284 t = t->rn_right;
285 else
286 t = t->rn_left;
287 }
288 /*
289 * See if we match exactly as a host destination
290 * or at least learn how many bits match, for normal mask finesse.
291 *
292 * It doesn't hurt us to limit how many bytes to check
293 * to the length of the mask, since if it matches we had a genuine
294 * match and the leaf we have is the most specific one anyway;
295 * if it didn't match with a shorter length it would fail
296 * with a long one. This wins big for class B&C netmasks which
297 * are probably the most common case...
298 */
299 if (t->rn_mask)
300 vlen = *(u_char *)t->rn_mask;
301 cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
302 for (; cp < cplim; cp++, cp2++)
303 if (*cp != *cp2)
304 goto on1;
305 /*
306 * This extra grot is in case we are explicitly asked
307 * to look up the default. Ugh!
308 *
309 * Never return the root node itself, it seems to cause a
310 * lot of confusion.
311 */
312 if (t->rn_flags & RNF_ROOT)
313 t = t->rn_dupedkey;
314 if (t == NULL || RN_MATCHF(t, f, w)) {
315 return (t);
316 } else {
317 /*
318 * Although we found an exact match on the key,
319 * f() is looking for some other criteria as well.
320 * Continue looking as if the exact match failed.
321 */
322 if (t->rn_parent->rn_flags & RNF_ROOT) {
323 /* Hit the top; have to give up */
324 return (NULL);
325 }
326 b = 0;
327 goto keeplooking;
328 }
329on1:
330 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
331 for (b = 7; (test >>= 1) > 0;)
332 b--;
333keeplooking:
334 matched_off = cp - v;
335 b += matched_off << 3;
336 rn_bit = -1 - b;
337 /*
338 * If there is a host route in a duped-key chain, it will be first.
339 */
340 if ((saved_t = t)->rn_mask == 0)
341 t = t->rn_dupedkey;
342 for (; t; t = t->rn_dupedkey) {
343 /*
344 * Even if we don't match exactly as a host,
345 * we may match if the leaf we wound up at is
346 * a route to a net.
347 */
348 if (t->rn_flags & RNF_NORMAL) {
349 if ((rn_bit <= t->rn_bit) && RN_MATCHF(t, f, w))
350 return (t);
351 } else if (rn_satisfies_leaf(v, t, matched_off, f, w)) {
352 return (t);
353 }
354 }
355 t = saved_t;
356 /* start searching up the tree */
357 do {
358 struct radix_mask *m;
359 t = t->rn_parent;
360 m = t->rn_mklist;
361 /*
362 * If non-contiguous masks ever become important
363 * we can restore the masking and open coding of
364 * the search and satisfaction test and put the
365 * calculation of "off" back before the "do".
366 */
367 while (m) {
368 if (m->rm_flags & RNF_NORMAL) {
369 if ((rn_bit <= m->rm_bit) &&
370 RN_MATCHF(m->rm_leaf, f, w))
371 return (m->rm_leaf);
372 } else {
373 off = min(t->rn_offset, matched_off);
374 x = rn_search_m(v, t, m->rm_mask);
375 while (x && x->rn_mask != m->rm_mask)
376 x = x->rn_dupedkey;
377 if (x && rn_satisfies_leaf(v, x, off, f, w))
378 return (x);
379 }
380 m = m->rm_mklist;
381 }
382 } while (t != top);
383 return (NULL);
384}
385
386#ifdef RN_DEBUG
387int rn_nodenum;
388struct radix_node *rn_clist;
389int rn_saveinfo;
390int rn_debug = 1;
391#endif
392
393static struct radix_node *
394rn_newpair(void *v, int b, struct radix_node nodes[2])
395{
396 struct radix_node *tt = nodes, *t = tt + 1;
397 t->rn_bit = b;
398 t->rn_bmask = 0x80 >> (b & 7);
399 t->rn_left = tt;
400 t->rn_offset = b >> 3;
401 tt->rn_bit = -1;
402 tt->rn_key = (caddr_t)v;
403 tt->rn_parent = t;
404 tt->rn_flags = t->rn_flags = RNF_ACTIVE;
405 tt->rn_mklist = t->rn_mklist = NULL;
406#ifdef RN_DEBUG
407 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
408 tt->rn_twin = t;
409 tt->rn_ybro = rn_clist;
410 rn_clist = tt;
411#endif
412 return t;
413}
414
415static struct radix_node *
416rn_insert(void *v_arg, struct radix_node_head *head, int *dupentry,
417 struct radix_node nodes[2])
418{
419 caddr_t v = v_arg;
420 struct radix_node *top = head->rnh_treetop;
421 int head_off = top->rn_offset, vlen = (int)*((u_char *)v);
422 struct radix_node *t = rn_search(v_arg, top);
423 caddr_t cp = v + head_off;
424 int b;
425 struct radix_node *tt;
426 /*
427 * Find first bit at which v and t->rn_key differ
428 */
429 {
430 caddr_t cp2 = t->rn_key + head_off;
431 int cmp_res;
432 caddr_t cplim = v + vlen;
433
434 while (cp < cplim)
435 if (*cp2++ != *cp++)
436 goto on1;
437 *dupentry = 1;
438 return t;
439on1:
440 *dupentry = 0;
441 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
442 for (b = (cp - v) << 3; cmp_res; b--)
443 cmp_res >>= 1;
444 }
445 {
446 struct radix_node *p, *x = top;
447 cp = v;
448 do {
449 p = x;
450 if (cp[x->rn_offset] & x->rn_bmask)
451 x = x->rn_right;
452 else
453 x = x->rn_left;
454 } while (b > (unsigned) x->rn_bit);
455 /* x->rn_bit < b && x->rn_bit >= 0 */
456#ifdef RN_DEBUG
457 if (rn_debug)
458 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
459#endif
460 t = rn_newpair(v_arg, b, nodes);
461 tt = t->rn_left;
462 if ((cp[p->rn_offset] & p->rn_bmask) == 0)
463 p->rn_left = t;
464 else
465 p->rn_right = t;
466 x->rn_parent = t;
467 t->rn_parent = p; /* frees x, p as temp vars below */
468 if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
469 t->rn_right = x;
470 } else {
471 t->rn_right = tt;
472 t->rn_left = x;
473 }
474#ifdef RN_DEBUG
475 if (rn_debug)
476 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
477#endif
478 }
479 return (tt);
480}
481
482struct radix_node *
483rn_addmask(void *n_arg, int search, int skip)
484{
485 caddr_t netmask = (caddr_t)n_arg;
486 struct radix_node *x;
487 caddr_t cp, cplim;
488 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 = *(u_char *)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 = NULL;
520 if (x || search)
521 return (x);
522 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
523 if ((saved_x = x) == 0)
524 return (NULL);
525 Bzero(x, max_keylen + 2 * sizeof (*x));
526 netmask = cp = (caddr_t)(x + 2);
527 Bcopy(addmask_key, cp, mlen);
528 x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
529 if (maskduplicated) {
530 log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
531 R_Free(saved_x);
532 return (x);
533 }
534 mask_rnhead->rnh_cnt++;
535 /*
536 * Calculate index of mask, and check for normalcy.
537 */
538 cplim = netmask + mlen; isnormal = 1;
539 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
540 cp++;
541 if (cp != cplim) {
542 for (j = 0x80; (j & *cp) != 0; j >>= 1)
543 b++;
544 if (*cp != normal_chars[b] || cp != (cplim - 1))
545 isnormal = 0;
546 }
547 b += (cp - netmask) << 3;
548 x->rn_bit = -1 - b;
549 if (isnormal)
550 x->rn_flags |= RNF_NORMAL;
551 return (x);
552}
553
554static int /* XXX: arbitrary ordering for non-contiguous masks */
555rn_lexobetter(void *m_arg, void *n_arg)
556{
557 u_char *mp = m_arg, *np = n_arg, *lim;
558
559 if (*mp > *np)
560 return 1; /* not really, but need to check longer one first */
561 if (*mp == *np)
562 for (lim = mp + *mp; mp < lim;)
563 if (*mp++ > *np++)
564 return 1;
565 return 0;
566}
567
568static struct radix_mask *
569rn_new_radix_mask(struct radix_node *tt, struct radix_mask *next)
570{
571 struct radix_mask *m;
572
573 MKGet(m);
574 if (m == 0) {
575 log(LOG_ERR, "Mask for route not entered\n");
576 return (NULL);
577 }
578 Bzero(m, sizeof *m);
579 m->rm_bit = tt->rn_bit;
580 m->rm_flags = tt->rn_flags;
581 if (tt->rn_flags & RNF_NORMAL)
582 m->rm_leaf = tt;
583 else
584 m->rm_mask = tt->rn_mask;
585 m->rm_mklist = next;
586 tt->rn_mklist = m;
587 return m;
588}
589
590struct radix_node *
591rn_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
592 struct radix_node treenodes[2])
593{
594 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
595 struct radix_node *t, *x = NULL, *tt;
596 struct radix_node *saved_tt, *top = head->rnh_treetop;
597 short b = 0, b_leaf = 0;
598 int keyduplicated;
599 caddr_t mmask;
600 struct radix_mask *m, **mp;
601
602 /*
603 * In dealing with non-contiguous masks, there may be
604 * many different routes which have the same mask.
605 * We will find it useful to have a unique pointer to
606 * the mask to speed avoiding duplicate references at
607 * nodes and possibly save time in calculating indices.
608 */
609 if (netmask) {
610 if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0)
611 return (NULL);
612 b_leaf = x->rn_bit;
613 b = -1 - x->rn_bit;
614 netmask = x->rn_key;
615 }
616 /*
617 * Deal with duplicated keys: attach node to previous instance
618 */
619 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
620 if (keyduplicated) {
621 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
622 if (tt->rn_mask == netmask)
623 return (NULL);
624 if (netmask == 0 ||
625 (tt->rn_mask &&
626 ((b_leaf < tt->rn_bit) /* index(netmask) > node */
627 || rn_refines(netmask, tt->rn_mask)
628 || rn_lexobetter(netmask, tt->rn_mask))))
629 break;
630 }
631 /*
632 * If the mask is not duplicated, we wouldn't
633 * find it among possible duplicate key entries
634 * anyway, so the above test doesn't hurt.
635 *
636 * We sort the masks for a duplicated key the same way as
637 * in a masklist -- most specific to least specific.
638 * This may require the unfortunate nuisance of relocating
639 * the head of the list.
640 */
641 if (tt == saved_tt) {
642 struct radix_node *xx = x;
643 /* link in at head of list */
644 (tt = treenodes)->rn_dupedkey = t;
645 tt->rn_flags = t->rn_flags;
646 tt->rn_parent = x = t->rn_parent;
647 t->rn_parent = tt; /* parent */
648 if (x->rn_left == t)
649 x->rn_left = tt;
650 else
651 x->rn_right = tt;
652 saved_tt = tt; x = xx;
653 } else {
654 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
655 t->rn_dupedkey = tt;
656 tt->rn_parent = t; /* parent */
657 if (tt->rn_dupedkey) /* parent */
658 tt->rn_dupedkey->rn_parent = tt; /* parent */
659 }
660#ifdef RN_DEBUG
661 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
662 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
663#endif
664 tt->rn_key = (caddr_t) v;
665 tt->rn_bit = -1;
666 tt->rn_flags = RNF_ACTIVE;
667 }
668 head->rnh_cnt++;
669 /*
670 * Put mask in tree.
671 */
672 if (netmask) {
673 tt->rn_mask = netmask;
674 tt->rn_bit = x->rn_bit;
675 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
676 }
677 t = saved_tt->rn_parent;
678 if (keyduplicated)
679 goto on2;
680 b_leaf = -1 - t->rn_bit;
681 if (t->rn_right == saved_tt)
682 x = t->rn_left;
683 else
684 x = t->rn_right;
685 /* Promote general routes from below */
686 if (x->rn_bit < 0) {
687 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
688 if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) {
689 *mp = m = rn_new_radix_mask(x, NULL);
690 if (m)
691 mp = &m->rm_mklist;
692 }
693 } else if (x->rn_mklist) {
694 /*
695 * Skip over masks whose index is > that of new node
696 */
697 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
698 if (m->rm_bit >= b_leaf)
699 break;
700 t->rn_mklist = m; *mp = NULL;
701 }
702on2:
703 /* Add new route to highest possible ancestor's list */
704 if ((netmask == 0) || (b > t->rn_bit ))
705 return tt; /* can't lift at all */
706 b_leaf = tt->rn_bit;
707 do {
708 x = t;
709 t = t->rn_parent;
710 } while (b <= t->rn_bit && x != top);
711 /*
712 * Search through routes associated with node to
713 * insert new route according to index.
714 * Need same criteria as when sorting dupedkeys to avoid
715 * double loop on deletion.
716 */
717 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
718 if (m->rm_bit < b_leaf)
719 continue;
720 if (m->rm_bit > b_leaf)
721 break;
722 if (m->rm_flags & RNF_NORMAL) {
723 mmask = m->rm_leaf->rn_mask;
724 if (tt->rn_flags & RNF_NORMAL) {
725 log(LOG_ERR,
726 "Non-unique normal route, mask not entered");
727 return tt;
728 }
729 } else
730 mmask = m->rm_mask;
731 if (mmask == netmask) {
732 m->rm_refs++;
733 tt->rn_mklist = m;
734 return tt;
735 }
736 if (rn_refines(netmask, mmask)
737 || rn_lexobetter(netmask, mmask))
738 break;
739 }
740 *mp = rn_new_radix_mask(tt, *mp);
741 return tt;
742}
743
744struct radix_node *
745rn_delete(void *v_arg, void *netmask_arg, struct radix_node_head *head)
746{
747 struct radix_node *t, *p, *x, *tt;
748 struct radix_mask *m, *saved_m, **mp;
749 struct radix_node *dupedkey, *saved_tt, *top;
750 caddr_t v, netmask;
751 int b, head_off, vlen;
752
753 v = v_arg;
754 netmask = netmask_arg;
755 x = head->rnh_treetop;
756 tt = rn_search(v, x);
757 head_off = x->rn_offset;
758 vlen = *(u_char *)v;
759 saved_tt = tt;
760 top = x;
761 if (tt == 0 ||
762 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
763 return (NULL);
764 /*
765 * Delete our route from mask lists.
766 */
767 if (netmask) {
768 if ((x = rn_addmask(netmask, 1, head_off)) == 0)
769 return (NULL);
770 netmask = x->rn_key;
771 while (tt->rn_mask != netmask)
772 if ((tt = tt->rn_dupedkey) == 0)
773 return (NULL);
774 }
775 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
776 goto on1;
777 if (tt->rn_flags & RNF_NORMAL) {
778 if (m->rm_leaf != tt || m->rm_refs > 0) {
779 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
780 return NULL; /* dangling ref could cause disaster */
781 }
782 } else {
783 if (m->rm_mask != tt->rn_mask) {
784 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
785 goto on1;
786 }
787 if (--m->rm_refs >= 0)
788 goto on1;
789 }
790 b = -1 - tt->rn_bit;
791 t = saved_tt->rn_parent;
792 if (b > t->rn_bit)
793 goto on1; /* Wasn't lifted at all */
794 do {
795 x = t;
796 t = t->rn_parent;
797 } while (b <= t->rn_bit && x != top);
798 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
799 if (m == saved_m) {
800 *mp = m->rm_mklist;
801 MKFree(m);
802 break;
803 }
804 if (m == 0) {
805 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
806 if (tt->rn_flags & RNF_NORMAL)
807 return (NULL); /* Dangling ref to us */
808 }
809on1:
810 /*
811 * Eliminate us from tree
812 */
813 if (tt->rn_flags & RNF_ROOT)
814 return (NULL);
815 head->rnh_cnt--;
816#ifdef RN_DEBUG
817 /* Get us out of the creation list */
818 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
819 if (t) t->rn_ybro = tt->rn_ybro;
820#endif
821 t = tt->rn_parent;
822 dupedkey = saved_tt->rn_dupedkey;
823 if (dupedkey) {
824 /*
825 * at this point, tt is the deletion target and saved_tt
826 * is the head of the dupekey chain
827 */
828 if (tt == saved_tt) {
829 /* remove from head of chain */
830 x = dupedkey; x->rn_parent = t;
831 if (t->rn_left == tt)
832 t->rn_left = x;
833 else
834 t->rn_right = x;
835 } else {
836 /* find node in front of tt on the chain */
837 for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
838 p = p->rn_dupedkey;
839 if (p) {
840 p->rn_dupedkey = tt->rn_dupedkey;
841 if (tt->rn_dupedkey) /* parent */
842 tt->rn_dupedkey->rn_parent = p;
843 /* parent */
844 } else log(LOG_ERR, "rn_delete: couldn't find us\n");
845 }
846 t = tt + 1;
847 if (t->rn_flags & RNF_ACTIVE) {
848#ifndef RN_DEBUG
849 *++x = *t;
850 p = t->rn_parent;
851#else
852 b = t->rn_info;
853 *++x = *t;
854 t->rn_info = b;
855 p = t->rn_parent;
856#endif
857 if (p->rn_left == t)
858 p->rn_left = x;
859 else
860 p->rn_right = x;
861 x->rn_left->rn_parent = x;
862 x->rn_right->rn_parent = x;
863 }
864 goto out;
865 }
866 if (t->rn_left == tt)
867 x = t->rn_right;
868 else
869 x = t->rn_left;
870 p = t->rn_parent;
871 if (p->rn_right == t)
872 p->rn_right = x;
873 else
874 p->rn_left = x;
875 x->rn_parent = p;
876 /*
877 * Demote routes attached to us.
878 */
879 if (t->rn_mklist) {
880 if (x->rn_bit >= 0) {
881 for (mp = &x->rn_mklist; (m = *mp);)
882 mp = &m->rm_mklist;
883 *mp = t->rn_mklist;
884 } else {
885 /* If there are any key,mask pairs in a sibling
886 duped-key chain, some subset will appear sorted
887 in the same order attached to our mklist */
888 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
889 if (m == x->rn_mklist) {
890 struct radix_mask *mm = m->rm_mklist;
891 x->rn_mklist = NULL;
892 if (--(m->rm_refs) < 0)
893 MKFree(m);
894 m = mm;
895 }
896 if (m)
897 log(LOG_ERR, "rn_delete: Orphaned Mask "
898 "0x%llx at 0x%llx\n",
899 (uint64_t)VM_KERNEL_ADDRPERM(m),
900 (uint64_t)VM_KERNEL_ADDRPERM(x));
901 }
902 }
903 /*
904 * We may be holding an active internal node in the tree.
905 */
906 x = tt + 1;
907 if (t != x) {
908#ifndef RN_DEBUG
909 *t = *x;
910#else
911 b = t->rn_info;
912 *t = *x;
913 t->rn_info = b;
914#endif
915 t->rn_left->rn_parent = t;
916 t->rn_right->rn_parent = t;
917 p = x->rn_parent;
918 if (p->rn_left == x)
919 p->rn_left = t;
920 else
921 p->rn_right = t;
922 }
923out:
924 tt->rn_flags &= ~RNF_ACTIVE;
925 tt[1].rn_flags &= ~RNF_ACTIVE;
926 return (tt);
927}
928
929/*
930 * This is the same as rn_walktree() except for the parameters and the
931 * exit.
932 */
933static int
934rn_walktree_from(struct radix_node_head *h, void *a, void *m, walktree_f_t *f,
935 void *w)
936{
937 int error;
938 struct radix_node *base, *next;
939 u_char *xa = (u_char *)a;
940 u_char *xm = (u_char *)m;
941 struct radix_node *rn, *last;
942 int stopping;
943 int lastb;
944 int rnh_cnt;
945
946 /*
947 * This gets complicated because we may delete the node while
948 * applying the function f to it; we cannot simply use the next
949 * leaf as the successor node in advance, because that leaf may
950 * be removed as well during deletion when it is a clone of the
951 * current node. When that happens, we would end up referring
952 * to an already-freed radix node as the successor node. To get
953 * around this issue, if we detect that the radix tree has changed
954 * in dimension (smaller than before), we simply restart the walk
955 * from the top of tree.
956 */
957restart:
958 last = NULL;
959 stopping = 0;
960 rnh_cnt = h->rnh_cnt;
961
962 /*
963 * rn_search_m is sort-of-open-coded here.
964 */
965 for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
966 last = rn;
967 if (!(rn->rn_bmask & xm[rn->rn_offset]))
968 break;
969
970 if (rn->rn_bmask & xa[rn->rn_offset])
971 rn = rn->rn_right;
972 else
973 rn = rn->rn_left;
974 }
975
976 /*
977 * Two cases: either we stepped off the end of our mask,
978 * in which case last == rn, or we reached a leaf, in which
979 * case we want to start from the last node we looked at.
980 * Either way, last is the node we want to start from.
981 */
982 rn = last;
983 lastb = rn->rn_bit;
984
985 /* First time through node, go left */
986 while (rn->rn_bit >= 0)
987 rn = rn->rn_left;
988
989 while (!stopping) {
990 base = rn;
991 /* If at right child go back up, otherwise, go right */
992 while (rn->rn_parent->rn_right == rn
993 && !(rn->rn_flags & RNF_ROOT)) {
994 rn = rn->rn_parent;
995
996 /* if went up beyond last, stop */
997 if (rn->rn_bit <= lastb) {
998 stopping = 1;
999 /*
1000 * XXX we should jump to the 'Process leaves'
1001 * part, because the values of 'rn' and 'next'
1002 * we compute will not be used. Not a big deal
1003 * because this loop will terminate, but it is
1004 * inefficient and hard to understand!
1005 */
1006 }
1007 }
1008
1009 /*
1010 * The following code (bug fix) inherited from FreeBSD is
1011 * currently disabled, because our implementation uses the
1012 * RTF_PRCLONING scheme that has been abandoned in current
1013 * FreeBSD release. The scheme involves setting such a flag
1014 * for the default route entry, and therefore all off-link
1015 * destinations would become clones of that entry. Enabling
1016 * the following code would be problematic at this point,
1017 * because the removal of default route would cause only
1018 * the left-half of the tree to be traversed, leaving the
1019 * right-half untouched. If there are clones of the entry
1020 * that reside in that right-half, they would not be deleted
1021 * and would linger around until they expire or explicitly
1022 * deleted, which is a very bad thing.
1023 *
1024 * This code should be uncommented only after we get rid
1025 * of the RTF_PRCLONING scheme.
1026 */
1027#if 0
1028 /*
1029 * At the top of the tree, no need to traverse the right
1030 * half, prevent the traversal of the entire tree in the
1031 * case of default route.
1032 */
1033 if (rn->rn_parent->rn_flags & RNF_ROOT)
1034 stopping = 1;
1035#endif
1036
1037 /* Find the next *leaf* to start from */
1038 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1039 rn = rn->rn_left;
1040 next = rn;
1041 /* Process leaves */
1042 while ((rn = base) != 0) {
1043 base = rn->rn_dupedkey;
1044 if (!(rn->rn_flags & RNF_ROOT)
1045 && (error = (*f)(rn, w)))
1046 return (error);
1047 }
1048 /* If one or more nodes got deleted, restart from top */
1049 if (h->rnh_cnt < rnh_cnt)
1050 goto restart;
1051 rn = next;
1052 if (rn->rn_flags & RNF_ROOT)
1053 stopping = 1;
1054 }
1055 return 0;
1056}
1057
1058static int
1059rn_walktree(struct radix_node_head *h, walktree_f_t *f, void *w)
1060{
1061 int error;
1062 struct radix_node *base, *next;
1063 struct radix_node *rn;
1064 int rnh_cnt;
1065
1066 /*
1067 * This gets complicated because we may delete the node while
1068 * applying the function f to it; we cannot simply use the next
1069 * leaf as the successor node in advance, because that leaf may
1070 * be removed as well during deletion when it is a clone of the
1071 * current node. When that happens, we would end up referring
1072 * to an already-freed radix node as the successor node. To get
1073 * around this issue, if we detect that the radix tree has changed
1074 * in dimension (smaller than before), we simply restart the walk
1075 * from the top of tree.
1076 */
1077restart:
1078 rn = h->rnh_treetop;
1079 rnh_cnt = h->rnh_cnt;
1080
1081 /* First time through node, go left */
1082 while (rn->rn_bit >= 0)
1083 rn = rn->rn_left;
1084 for (;;) {
1085 base = rn;
1086 /* If at right child go back up, otherwise, go right */
1087 while (rn->rn_parent->rn_right == rn &&
1088 (rn->rn_flags & RNF_ROOT) == 0)
1089 rn = rn->rn_parent;
1090 /* Find the next *leaf* to start from */
1091 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1092 rn = rn->rn_left;
1093 next = rn;
1094 /* Process leaves */
1095 while ((rn = base) != NULL) {
1096 base = rn->rn_dupedkey;
1097 if (!(rn->rn_flags & RNF_ROOT)
1098 && (error = (*f)(rn, w)))
1099 return (error);
1100 }
1101 /* If one or more nodes got deleted, restart from top */
1102 if (h->rnh_cnt < rnh_cnt)
1103 goto restart;
1104 rn = next;
1105 if (rn->rn_flags & RNF_ROOT)
1106 return (0);
1107 }
1108 /* NOTREACHED */
1109}
1110
1111int
1112rn_inithead(void **head, int off)
1113{
1114 struct radix_node_head *rnh;
1115 struct radix_node *t, *tt, *ttt;
1116 if (*head)
1117 return (1);
1118 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh));
1119 if (rnh == 0)
1120 return (0);
1121 Bzero(rnh, sizeof (*rnh));
1122 *head = rnh;
1123 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
1124 ttt = rnh->rnh_nodes + 2;
1125 t->rn_right = ttt;
1126 t->rn_parent = t;
1127 tt = t->rn_left;
1128 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
1129 tt->rn_bit = -1 - off;
1130 *ttt = *tt;
1131 ttt->rn_key = rn_ones;
1132 rnh->rnh_addaddr = rn_addroute;
1133 rnh->rnh_deladdr = rn_delete;
1134 rnh->rnh_matchaddr = rn_match;
1135 rnh->rnh_matchaddr_args = rn_match_args;
1136 rnh->rnh_lookup = rn_lookup;
1137 rnh->rnh_lookup_args = rn_lookup_args;
1138 rnh->rnh_walktree = rn_walktree;
1139 rnh->rnh_walktree_from = rn_walktree_from;
1140 rnh->rnh_treetop = t;
1141 rnh->rnh_cnt = 3;
1142 return (1);
1143}
1144
1145void
1146rn_init(void)
1147{
1148 char *cp, *cplim;
1149 struct domain *dom;
1150
1151 /* lock already held when rn_init is called */
1152 TAILQ_FOREACH(dom, &domains, dom_entry) {
1153 if (dom->dom_maxrtkey > max_keylen)
1154 max_keylen = dom->dom_maxrtkey;
1155 }
1156 if (max_keylen == 0) {
1157 log(LOG_ERR,
1158 "rn_init: radix functions require max_keylen be set\n");
1159 return;
1160 }
1161 R_Malloc(rn_zeros, char *, 3 * max_keylen);
1162 if (rn_zeros == NULL)
1163 panic("rn_init");
1164 Bzero(rn_zeros, 3 * max_keylen);
1165 rn_ones = cp = rn_zeros + max_keylen;
1166 addmask_key = cplim = rn_ones + max_keylen;
1167 while (cp < cplim)
1168 *cp++ = -1;
1169 if (rn_inithead((void **)&mask_rnhead, 0) == 0)
1170 panic("rn_init 2");
1171}
1172