1/* $NetBSD: radix.c,v 1.46 2016/11/15 01:50:06 ozaki-r 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. 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 * @(#)radix.c 8.6 (Berkeley) 10/17/95
32 */
33
34/*
35 * Routines to build and maintain radix trees for routing lookups.
36 */
37
38#include <sys/cdefs.h>
39__KERNEL_RCSID(0, "$NetBSD: radix.c,v 1.46 2016/11/15 01:50:06 ozaki-r Exp $");
40
41#ifndef _NET_RADIX_H_
42#include <sys/param.h>
43#include <sys/queue.h>
44#include <sys/kmem.h>
45#ifdef _KERNEL
46#ifdef _KERNEL_OPT
47#include "opt_inet.h"
48#endif
49
50#include <sys/systm.h>
51#include <sys/malloc.h>
52#define M_DONTWAIT M_NOWAIT
53#include <sys/domain.h>
54#else
55#include <stdlib.h>
56#endif
57#include <sys/syslog.h>
58#include <net/radix.h>
59#endif
60
61typedef void (*rn_printer_t)(void *, const char *fmt, ...);
62
63int max_keylen;
64struct radix_mask *rn_mkfreelist;
65struct radix_node_head *mask_rnhead;
66static char *addmask_key;
67static const char normal_chars[] =
68 {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
69static char *rn_zeros, *rn_ones;
70
71#define rn_masktop (mask_rnhead->rnh_treetop)
72
73static int rn_satisfies_leaf(const char *, struct radix_node *, int);
74static int rn_lexobetter(const void *, const void *);
75static struct radix_mask *rn_new_radix_mask(struct radix_node *,
76 struct radix_mask *);
77static struct radix_node *rn_walknext(struct radix_node *, rn_printer_t,
78 void *);
79static struct radix_node *rn_walkfirst(struct radix_node *, rn_printer_t,
80 void *);
81static void rn_nodeprint(struct radix_node *, rn_printer_t, void *,
82 const char *);
83
84#define SUBTREE_OPEN "[ "
85#define SUBTREE_CLOSE " ]"
86
87#ifdef RN_DEBUG
88static void rn_treeprint(struct radix_node_head *, rn_printer_t, void *);
89#endif /* RN_DEBUG */
90
91/*
92 * The data structure for the keys is a radix tree with one way
93 * branching removed. The index rn_b at an internal node n represents a bit
94 * position to be tested. The tree is arranged so that all descendants
95 * of a node n have keys whose bits all agree up to position rn_b - 1.
96 * (We say the index of n is rn_b.)
97 *
98 * There is at least one descendant which has a one bit at position rn_b,
99 * and at least one with a zero there.
100 *
101 * A route is determined by a pair of key and mask. We require that the
102 * bit-wise logical and of the key and mask to be the key.
103 * We define the index of a route to associated with the mask to be
104 * the first bit number in the mask where 0 occurs (with bit number 0
105 * representing the highest order bit).
106 *
107 * We say a mask is normal if every bit is 0, past the index of the mask.
108 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b,
109 * and m is a normal mask, then the route applies to every descendant of n.
110 * If the index(m) < rn_b, this implies the trailing last few bits of k
111 * before bit b are all 0, (and hence consequently true of every descendant
112 * of n), so the route applies to all descendants of the node as well.
113 *
114 * Similar logic shows that a non-normal mask m such that
115 * index(m) <= index(n) could potentially apply to many children of n.
116 * Thus, for each non-host route, we attach its mask to a list at an internal
117 * node as high in the tree as we can go.
118 *
119 * The present version of the code makes use of normal routes in short-
120 * circuiting an explicit mask and compare operation when testing whether
121 * a key satisfies a normal route, and also in remembering the unique leaf
122 * that governs a subtree.
123 */
124
125struct radix_node *
126rn_search(
127 const void *v_arg,
128 struct radix_node *head)
129{
130 const u_char * const v = v_arg;
131 struct radix_node *x;
132
133 for (x = head; x->rn_b >= 0;) {
134 if (x->rn_bmask & v[x->rn_off])
135 x = x->rn_r;
136 else
137 x = x->rn_l;
138 }
139 return x;
140}
141
142struct radix_node *
143rn_search_m(
144 const void *v_arg,
145 struct radix_node *head,
146 const void *m_arg)
147{
148 struct radix_node *x;
149 const u_char * const v = v_arg;
150 const u_char * const m = m_arg;
151
152 for (x = head; x->rn_b >= 0;) {
153 if ((x->rn_bmask & m[x->rn_off]) &&
154 (x->rn_bmask & v[x->rn_off]))
155 x = x->rn_r;
156 else
157 x = x->rn_l;
158 }
159 return x;
160}
161
162int
163rn_refines(
164 const void *m_arg,
165 const void *n_arg)
166{
167 const char *m = m_arg;
168 const char *n = n_arg;
169 const char *lim = n + *(const u_char *)n;
170 const char *lim2 = lim;
171 int longer = (*(const u_char *)n++) - (int)(*(const u_char *)m++);
172 int masks_are_equal = 1;
173
174 if (longer > 0)
175 lim -= longer;
176 while (n < lim) {
177 if (*n & ~(*m))
178 return 0;
179 if (*n++ != *m++)
180 masks_are_equal = 0;
181 }
182 while (n < lim2)
183 if (*n++)
184 return 0;
185 if (masks_are_equal && (longer < 0))
186 for (lim2 = m - longer; m < lim2; )
187 if (*m++)
188 return 1;
189 return !masks_are_equal;
190}
191
192struct radix_node *
193rn_lookup(
194 const void *v_arg,
195 const void *m_arg,
196 struct radix_node_head *head)
197{
198 struct radix_node *x;
199 const char *netmask = NULL;
200
201 if (m_arg) {
202 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0)
203 return NULL;
204 netmask = x->rn_key;
205 }
206 x = rn_match(v_arg, head);
207 if (x != NULL && netmask != NULL) {
208 while (x != NULL && x->rn_mask != netmask)
209 x = x->rn_dupedkey;
210 }
211 return x;
212}
213
214static int
215rn_satisfies_leaf(
216 const char *trial,
217 struct radix_node *leaf,
218 int skip)
219{
220 const char *cp = trial;
221 const char *cp2 = leaf->rn_key;
222 const char *cp3 = leaf->rn_mask;
223 const char *cplim;
224 int length = min(*(const u_char *)cp, *(const u_char *)cp2);
225
226 if (cp3 == 0)
227 cp3 = rn_ones;
228 else
229 length = min(length, *(const u_char *)cp3);
230 cplim = cp + length; cp3 += skip; cp2 += skip;
231 for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
232 if ((*cp ^ *cp2) & *cp3)
233 return 0;
234 return 1;
235}
236
237struct radix_node *
238rn_match(
239 const void *v_arg,
240 struct radix_node_head *head)
241{
242 const char * const v = v_arg;
243 struct radix_node *t = head->rnh_treetop;
244 struct radix_node *top = t;
245 struct radix_node *x;
246 struct radix_node *saved_t;
247 const char *cp = v;
248 const char *cp2;
249 const char *cplim;
250 int off = t->rn_off;
251 int vlen = *(const u_char *)cp;
252 int matched_off;
253 int test, b, rn_b;
254
255 /*
256 * Open code rn_search(v, top) to avoid overhead of extra
257 * subroutine call.
258 */
259 for (; t->rn_b >= 0; ) {
260 if (t->rn_bmask & cp[t->rn_off])
261 t = t->rn_r;
262 else
263 t = t->rn_l;
264 }
265 /*
266 * See if we match exactly as a host destination
267 * or at least learn how many bits match, for normal mask finesse.
268 *
269 * It doesn't hurt us to limit how many bytes to check
270 * to the length of the mask, since if it matches we had a genuine
271 * match and the leaf we have is the most specific one anyway;
272 * if it didn't match with a shorter length it would fail
273 * with a long one. This wins big for class B&C netmasks which
274 * are probably the most common case...
275 */
276 if (t->rn_mask)
277 vlen = *(const u_char *)t->rn_mask;
278 cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
279 for (; cp < cplim; cp++, cp2++)
280 if (*cp != *cp2)
281 goto on1;
282 /*
283 * This extra grot is in case we are explicitly asked
284 * to look up the default. Ugh!
285 */
286 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey)
287 t = t->rn_dupedkey;
288 return t;
289on1:
290 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
291 for (b = 7; (test >>= 1) > 0;)
292 b--;
293 matched_off = cp - v;
294 b += matched_off << 3;
295 rn_b = -1 - b;
296 /*
297 * If there is a host route in a duped-key chain, it will be first.
298 */
299 if ((saved_t = t)->rn_mask == 0)
300 t = t->rn_dupedkey;
301 for (; t; t = t->rn_dupedkey)
302 /*
303 * Even if we don't match exactly as a host,
304 * we may match if the leaf we wound up at is
305 * a route to a net.
306 */
307 if (t->rn_flags & RNF_NORMAL) {
308 if (rn_b <= t->rn_b)
309 return t;
310 } else if (rn_satisfies_leaf(v, t, matched_off))
311 return t;
312 t = saved_t;
313 /* start searching up the tree */
314 do {
315 struct radix_mask *m;
316 t = t->rn_p;
317 m = t->rn_mklist;
318 if (m) {
319 /*
320 * If non-contiguous masks ever become important
321 * we can restore the masking and open coding of
322 * the search and satisfaction test and put the
323 * calculation of "off" back before the "do".
324 */
325 do {
326 if (m->rm_flags & RNF_NORMAL) {
327 if (rn_b <= m->rm_b)
328 return m->rm_leaf;
329 } else {
330 off = min(t->rn_off, matched_off);
331 x = rn_search_m(v, t, m->rm_mask);
332 while (x && x->rn_mask != m->rm_mask)
333 x = x->rn_dupedkey;
334 if (x && rn_satisfies_leaf(v, x, off))
335 return x;
336 }
337 m = m->rm_mklist;
338 } while (m);
339 }
340 } while (t != top);
341 return NULL;
342}
343
344static void
345rn_nodeprint(struct radix_node *rn, rn_printer_t printer, void *arg,
346 const char *delim)
347{
348 (*printer)(arg, "%s(%s%p: p<%p> l<%p> r<%p>)",
349 delim, ((void *)rn == arg) ? "*" : "", rn, rn->rn_p,
350 rn->rn_l, rn->rn_r);
351}
352
353#ifdef RN_DEBUG
354int rn_debug = 1;
355
356static void
357rn_dbg_print(void *arg, const char *fmt, ...)
358{
359 va_list ap;
360
361 va_start(ap, fmt);
362 vlog(LOG_DEBUG, fmt, ap);
363 va_end(ap);
364}
365
366static void
367rn_treeprint(struct radix_node_head *h, rn_printer_t printer, void *arg)
368{
369 struct radix_node *dup, *rn;
370 const char *delim;
371
372 if (printer == NULL)
373 return;
374
375 rn = rn_walkfirst(h->rnh_treetop, printer, arg);
376 for (;;) {
377 /* Process leaves */
378 delim = "";
379 for (dup = rn; dup != NULL; dup = dup->rn_dupedkey) {
380 if ((dup->rn_flags & RNF_ROOT) != 0)
381 continue;
382 rn_nodeprint(dup, printer, arg, delim);
383 delim = ", ";
384 }
385 rn = rn_walknext(rn, printer, arg);
386 if (rn->rn_flags & RNF_ROOT)
387 return;
388 }
389 /* NOTREACHED */
390}
391
392#define traverse(__head, __rn) rn_treeprint((__head), rn_dbg_print, (__rn))
393#endif /* RN_DEBUG */
394
395struct radix_node *
396rn_newpair(
397 const void *v,
398 int b,
399 struct radix_node nodes[2])
400{
401 struct radix_node *tt = nodes;
402 struct radix_node *t = tt + 1;
403 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7);
404 t->rn_l = tt; t->rn_off = b >> 3;
405 tt->rn_b = -1; tt->rn_key = v; tt->rn_p = t;
406 tt->rn_flags = t->rn_flags = RNF_ACTIVE;
407 return t;
408}
409
410struct radix_node *
411rn_insert(
412 const void *v_arg,
413 struct radix_node_head *head,
414 int *dupentry,
415 struct radix_node nodes[2])
416{
417 struct radix_node *top = head->rnh_treetop;
418 struct radix_node *t = rn_search(v_arg, top);
419 struct radix_node *tt;
420 const char *v = v_arg;
421 int head_off = top->rn_off;
422 int vlen = *((const u_char *)v);
423 const char *cp = v + head_off;
424 int b;
425 /*
426 * Find first bit at which v and t->rn_key differ
427 */
428 {
429 const char *cp2 = t->rn_key + head_off;
430 const char *cplim = v + vlen;
431 int cmp_res;
432
433 while (cp < cplim)
434 if (*cp2++ != *cp++)
435 goto on1;
436 *dupentry = 1;
437 return t;
438on1:
439 *dupentry = 0;
440 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
441 for (b = (cp - v) << 3; cmp_res; b--)
442 cmp_res >>= 1;
443 }
444 {
445 struct radix_node *p, *x = top;
446 cp = v;
447 do {
448 p = x;
449 if (cp[x->rn_off] & x->rn_bmask)
450 x = x->rn_r;
451 else x = x->rn_l;
452 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */
453#ifdef RN_DEBUG
454 if (rn_debug)
455 log(LOG_DEBUG, "%s: Going In:\n", __func__), traverse(head, p);
456#endif
457 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l;
458 if ((cp[p->rn_off] & p->rn_bmask) == 0)
459 p->rn_l = t;
460 else
461 p->rn_r = t;
462 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */
463 if ((cp[t->rn_off] & t->rn_bmask) == 0) {
464 t->rn_r = x;
465 } else {
466 t->rn_r = tt; t->rn_l = x;
467 }
468#ifdef RN_DEBUG
469 if (rn_debug) {
470 log(LOG_DEBUG, "%s: Coming Out:\n", __func__),
471 traverse(head, p);
472 }
473#endif /* RN_DEBUG */
474 }
475 return tt;
476}
477
478struct radix_node *
479rn_addmask(
480 const void *n_arg,
481 int search,
482 int skip)
483{
484 const char *netmask = n_arg;
485 const char *cp;
486 const char *cplim;
487 struct radix_node *x;
488 struct radix_node *saved_x;
489 int b = 0, mlen, j;
490 int maskduplicated, m0, isnormal;
491 static int last_zeroed = 0;
492
493 if ((mlen = *(const 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 memmove(addmask_key + 1, rn_ones + 1, skip - 1);
501 if ((m0 = mlen) > skip)
502 memmove(addmask_key + skip, netmask + 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 memset(addmask_key + m0, 0, last_zeroed - m0);
516 *addmask_key = last_zeroed = mlen;
517 x = rn_search(addmask_key, rn_masktop);
518 if (memcmp(addmask_key, x->rn_key, mlen) != 0)
519 x = 0;
520 if (x || search)
521 return x;
522 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
523 if ((saved_x = x) == NULL)
524 return NULL;
525 memset(x, 0, max_keylen + 2 * sizeof (*x));
526 cp = netmask = (void *)(x + 2);
527 memmove(x + 2, addmask_key, mlen);
528 x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
529 if (maskduplicated) {
530 log(LOG_ERR, "rn_addmask: mask impossibly already in tree\n");
531 Free(saved_x);
532 return x;
533 }
534 /*
535 * Calculate index of mask, and check for normalcy.
536 */
537 cplim = netmask + mlen; isnormal = 1;
538 for (cp = netmask + skip; (cp < cplim) && *(const u_char *)cp == 0xff;)
539 cp++;
540 if (cp != cplim) {
541 for (j = 0x80; (j & *cp) != 0; j >>= 1)
542 b++;
543 if (*cp != normal_chars[b] || cp != (cplim - 1))
544 isnormal = 0;
545 }
546 b += (cp - netmask) << 3;
547 x->rn_b = -1 - b;
548 if (isnormal)
549 x->rn_flags |= RNF_NORMAL;
550 return x;
551}
552
553static int /* XXX: arbitrary ordering for non-contiguous masks */
554rn_lexobetter(
555 const void *m_arg,
556 const void *n_arg)
557{
558 const u_char *mp = m_arg;
559 const u_char *np = n_arg;
560 const u_char *lim;
561
562 if (*mp > *np)
563 return 1; /* not really, but need to check longer one first */
564 if (*mp == *np)
565 for (lim = mp + *mp; mp < lim;)
566 if (*mp++ > *np++)
567 return 1;
568 return 0;
569}
570
571static struct radix_mask *
572rn_new_radix_mask(
573 struct radix_node *tt,
574 struct radix_mask *next)
575{
576 struct radix_mask *m;
577
578 MKGet(m);
579 if (m == NULL) {
580 log(LOG_ERR, "Mask for route not entered\n");
581 return NULL;
582 }
583 memset(m, 0, sizeof(*m));
584 m->rm_b = tt->rn_b;
585 m->rm_flags = tt->rn_flags;
586 if (tt->rn_flags & RNF_NORMAL)
587 m->rm_leaf = tt;
588 else
589 m->rm_mask = tt->rn_mask;
590 m->rm_mklist = next;
591 tt->rn_mklist = m;
592 return m;
593}
594
595struct radix_node *
596rn_addroute(
597 const void *v_arg,
598 const void *n_arg,
599 struct radix_node_head *head,
600 struct radix_node treenodes[2])
601{
602 const char *v = v_arg, *netmask = n_arg;
603 struct radix_node *t, *x = NULL, *tt;
604 struct radix_node *saved_tt, *top = head->rnh_treetop;
605 short b = 0, b_leaf = 0;
606 int keyduplicated;
607 const char *mmask;
608 struct radix_mask *m, **mp;
609
610 /*
611 * In dealing with non-contiguous masks, there may be
612 * many different routes which have the same mask.
613 * We will find it useful to have a unique pointer to
614 * the mask to speed avoiding duplicate references at
615 * nodes and possibly save time in calculating indices.
616 */
617 if (netmask != NULL) {
618 if ((x = rn_addmask(netmask, 0, top->rn_off)) == NULL)
619 return NULL;
620 b_leaf = x->rn_b;
621 b = -1 - x->rn_b;
622 netmask = x->rn_key;
623 }
624 /*
625 * Deal with duplicated keys: attach node to previous instance
626 */
627 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
628 if (keyduplicated) {
629 for (t = tt; tt != NULL; t = tt, tt = tt->rn_dupedkey) {
630 if (tt->rn_mask == netmask)
631 return NULL;
632 if (netmask == NULL ||
633 (tt->rn_mask != NULL &&
634 (b_leaf < tt->rn_b || /* index(netmask) > node */
635 rn_refines(netmask, tt->rn_mask) ||
636 rn_lexobetter(netmask, tt->rn_mask))))
637 break;
638 }
639 /*
640 * If the mask is not duplicated, we wouldn't
641 * find it among possible duplicate key entries
642 * anyway, so the above test doesn't hurt.
643 *
644 * We sort the masks for a duplicated key the same way as
645 * in a masklist -- most specific to least specific.
646 * This may require the unfortunate nuisance of relocating
647 * the head of the list.
648 *
649 * We also reverse, or doubly link the list through the
650 * parent pointer.
651 */
652 if (tt == saved_tt) {
653 struct radix_node *xx = x;
654 /* link in at head of list */
655 (tt = treenodes)->rn_dupedkey = t;
656 tt->rn_flags = t->rn_flags;
657 tt->rn_p = x = t->rn_p;
658 t->rn_p = tt;
659 if (x->rn_l == t)
660 x->rn_l = tt;
661 else
662 x->rn_r = tt;
663 saved_tt = tt;
664 x = xx;
665 } else {
666 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
667 t->rn_dupedkey = tt;
668 tt->rn_p = t;
669 if (tt->rn_dupedkey)
670 tt->rn_dupedkey->rn_p = tt;
671 }
672 tt->rn_key = v;
673 tt->rn_b = -1;
674 tt->rn_flags = RNF_ACTIVE;
675 }
676 /*
677 * Put mask in tree.
678 */
679 if (netmask != NULL) {
680 tt->rn_mask = netmask;
681 tt->rn_b = x->rn_b;
682 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
683 }
684 t = saved_tt->rn_p;
685 if (keyduplicated)
686 goto on2;
687 b_leaf = -1 - t->rn_b;
688 if (t->rn_r == saved_tt)
689 x = t->rn_l;
690 else
691 x = t->rn_r;
692 /* Promote general routes from below */
693 if (x->rn_b < 0) {
694 for (mp = &t->rn_mklist; x != NULL; x = x->rn_dupedkey) {
695 if (x->rn_mask != NULL && x->rn_b >= b_leaf &&
696 x->rn_mklist == NULL) {
697 *mp = m = rn_new_radix_mask(x, NULL);
698 if (m != NULL)
699 mp = &m->rm_mklist;
700 }
701 }
702 } else if (x->rn_mklist != NULL) {
703 /*
704 * Skip over masks whose index is > that of new node
705 */
706 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist)
707 if (m->rm_b >= b_leaf)
708 break;
709 t->rn_mklist = m;
710 *mp = NULL;
711 }
712on2:
713 /* Add new route to highest possible ancestor's list */
714 if (netmask == NULL || b > t->rn_b)
715 return tt; /* can't lift at all */
716 b_leaf = tt->rn_b;
717 do {
718 x = t;
719 t = t->rn_p;
720 } while (b <= t->rn_b && x != top);
721 /*
722 * Search through routes associated with node to
723 * insert new route according to index.
724 * Need same criteria as when sorting dupedkeys to avoid
725 * double loop on deletion.
726 */
727 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist) {
728 if (m->rm_b < b_leaf)
729 continue;
730 if (m->rm_b > b_leaf)
731 break;
732 if (m->rm_flags & RNF_NORMAL) {
733 mmask = m->rm_leaf->rn_mask;
734 if (tt->rn_flags & RNF_NORMAL) {
735 log(LOG_ERR, "Non-unique normal route,"
736 " mask not entered\n");
737 return tt;
738 }
739 } else
740 mmask = m->rm_mask;
741 if (mmask == netmask) {
742 m->rm_refs++;
743 tt->rn_mklist = m;
744 return tt;
745 }
746 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
747 break;
748 }
749 *mp = rn_new_radix_mask(tt, *mp);
750 return tt;
751}
752
753struct radix_node *
754rn_delete1(
755 const void *v_arg,
756 const void *netmask_arg,
757 struct radix_node_head *head,
758 struct radix_node *rn)
759{
760 struct radix_node *t, *p, *x, *tt;
761 struct radix_mask *m, *saved_m, **mp;
762 struct radix_node *dupedkey, *saved_tt, *top;
763 const char *v, *netmask;
764 int b, head_off, vlen;
765
766 v = v_arg;
767 netmask = netmask_arg;
768 x = head->rnh_treetop;
769 tt = rn_search(v, x);
770 head_off = x->rn_off;
771 vlen = *(const u_char *)v;
772 saved_tt = tt;
773 top = x;
774 if (tt == NULL ||
775 memcmp(v + head_off, tt->rn_key + head_off, vlen - head_off) != 0)
776 return NULL;
777 /*
778 * Delete our route from mask lists.
779 */
780 if (netmask != NULL) {
781 if ((x = rn_addmask(netmask, 1, head_off)) == NULL)
782 return NULL;
783 netmask = x->rn_key;
784 while (tt->rn_mask != netmask)
785 if ((tt = tt->rn_dupedkey) == NULL)
786 return NULL;
787 }
788 if (tt->rn_mask == NULL || (saved_m = m = tt->rn_mklist) == NULL)
789 goto on1;
790 if (tt->rn_flags & RNF_NORMAL) {
791 if (m->rm_leaf != tt || m->rm_refs > 0) {
792 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
793 return NULL; /* dangling ref could cause disaster */
794 }
795 } else {
796 if (m->rm_mask != tt->rn_mask) {
797 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
798 goto on1;
799 }
800 if (--m->rm_refs >= 0)
801 goto on1;
802 }
803 b = -1 - tt->rn_b;
804 t = saved_tt->rn_p;
805 if (b > t->rn_b)
806 goto on1; /* Wasn't lifted at all */
807 do {
808 x = t;
809 t = t->rn_p;
810 } while (b <= t->rn_b && x != top);
811 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist) {
812 if (m == saved_m) {
813 *mp = m->rm_mklist;
814 MKFree(m);
815 break;
816 }
817 }
818 if (m == NULL) {
819 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
820 if (tt->rn_flags & RNF_NORMAL)
821 return NULL; /* Dangling ref to us */
822 }
823on1:
824 /*
825 * Eliminate us from tree
826 */
827 if (tt->rn_flags & RNF_ROOT)
828 return NULL;
829#ifdef RN_DEBUG
830 if (rn_debug)
831 log(LOG_DEBUG, "%s: Going In:\n", __func__), traverse(head, tt);
832#endif
833 t = tt->rn_p;
834 dupedkey = saved_tt->rn_dupedkey;
835 if (dupedkey != NULL) {
836 /*
837 * Here, tt is the deletion target, and
838 * saved_tt is the head of the dupedkey chain.
839 */
840 if (tt == saved_tt) {
841 x = dupedkey;
842 x->rn_p = t;
843 if (t->rn_l == tt)
844 t->rn_l = x;
845 else
846 t->rn_r = x;
847 } else {
848 /* find node in front of tt on the chain */
849 for (x = p = saved_tt;
850 p != NULL && p->rn_dupedkey != tt;)
851 p = p->rn_dupedkey;
852 if (p != NULL) {
853 p->rn_dupedkey = tt->rn_dupedkey;
854 if (tt->rn_dupedkey != NULL)
855 tt->rn_dupedkey->rn_p = p;
856 } else
857 log(LOG_ERR, "rn_delete: couldn't find us\n");
858 }
859 t = tt + 1;
860 if (t->rn_flags & RNF_ACTIVE) {
861 *++x = *t;
862 p = t->rn_p;
863 if (p->rn_l == t)
864 p->rn_l = x;
865 else
866 p->rn_r = x;
867 x->rn_l->rn_p = x;
868 x->rn_r->rn_p = x;
869 }
870 goto out;
871 }
872 if (t->rn_l == tt)
873 x = t->rn_r;
874 else
875 x = t->rn_l;
876 p = t->rn_p;
877 if (p->rn_r == t)
878 p->rn_r = x;
879 else
880 p->rn_l = x;
881 x->rn_p = p;
882 /*
883 * Demote routes attached to us.
884 */
885 if (t->rn_mklist == NULL)
886 ;
887 else if (x->rn_b >= 0) {
888 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist)
889 ;
890 *mp = t->rn_mklist;
891 } else {
892 /* If there are any key,mask pairs in a sibling
893 duped-key chain, some subset will appear sorted
894 in the same order attached to our mklist */
895 for (m = t->rn_mklist;
896 m != NULL && x != NULL;
897 x = x->rn_dupedkey) {
898 if (m == x->rn_mklist) {
899 struct radix_mask *mm = m->rm_mklist;
900 x->rn_mklist = NULL;
901 if (--(m->rm_refs) < 0)
902 MKFree(m);
903 m = mm;
904 }
905 }
906 if (m != NULL) {
907 log(LOG_ERR, "rn_delete: Orphaned Mask %p at %p\n",
908 m, x);
909 }
910 }
911 /*
912 * We may be holding an active internal node in the tree.
913 */
914 x = tt + 1;
915 if (t != x) {
916 *t = *x;
917 t->rn_l->rn_p = t;
918 t->rn_r->rn_p = t;
919 p = x->rn_p;
920 if (p->rn_l == x)
921 p->rn_l = t;
922 else
923 p->rn_r = t;
924 }
925out:
926#ifdef RN_DEBUG
927 if (rn_debug) {
928 log(LOG_DEBUG, "%s: Coming Out:\n", __func__),
929 traverse(head, tt);
930 }
931#endif /* RN_DEBUG */
932 tt->rn_flags &= ~RNF_ACTIVE;
933 tt[1].rn_flags &= ~RNF_ACTIVE;
934 return tt;
935}
936
937struct radix_node *
938rn_delete(
939 const void *v_arg,
940 const void *netmask_arg,
941 struct radix_node_head *head)
942{
943 return rn_delete1(v_arg, netmask_arg, head, NULL);
944}
945
946static struct radix_node *
947rn_walknext(struct radix_node *rn, rn_printer_t printer, void *arg)
948{
949 /* If at right child go back up, otherwise, go right */
950 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) {
951 if (printer != NULL)
952 (*printer)(arg, SUBTREE_CLOSE);
953 rn = rn->rn_p;
954 }
955 if (printer)
956 rn_nodeprint(rn->rn_p, printer, arg, "");
957 /* Find the next *leaf* since next node might vanish, too */
958 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) {
959 if (printer != NULL)
960 (*printer)(arg, SUBTREE_OPEN);
961 rn = rn->rn_l;
962 }
963 return rn;
964}
965
966static struct radix_node *
967rn_walkfirst(struct radix_node *rn, rn_printer_t printer, void *arg)
968{
969 /* First time through node, go left */
970 while (rn->rn_b >= 0) {
971 if (printer != NULL)
972 (*printer)(arg, SUBTREE_OPEN);
973 rn = rn->rn_l;
974 }
975 return rn;
976}
977
978int
979rn_walktree(
980 struct radix_node_head *h,
981 int (*f)(struct radix_node *, void *),
982 void *w)
983{
984 int error;
985 struct radix_node *base, *next, *rn;
986 /*
987 * This gets complicated because we may delete the node
988 * while applying the function f to it, so we need to calculate
989 * the successor node in advance.
990 */
991 rn = rn_walkfirst(h->rnh_treetop, NULL, NULL);
992 for (;;) {
993 base = rn;
994 next = rn_walknext(rn, NULL, NULL);
995 /* Process leaves */
996 while ((rn = base) != NULL) {
997 base = rn->rn_dupedkey;
998 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
999 return error;
1000 }
1001 rn = next;
1002 if (rn->rn_flags & RNF_ROOT)
1003 return 0;
1004 }
1005 /* NOTREACHED */
1006}
1007
1008struct radix_node *
1009rn_search_matched(struct radix_node_head *h,
1010 int (*matcher)(struct radix_node *, void *), void *w)
1011{
1012 bool matched;
1013 struct radix_node *base, *next, *rn;
1014 /*
1015 * This gets complicated because we may delete the node
1016 * while applying the function f to it, so we need to calculate
1017 * the successor node in advance.
1018 */
1019 rn = rn_walkfirst(h->rnh_treetop, NULL, NULL);
1020 for (;;) {
1021 base = rn;
1022 next = rn_walknext(rn, NULL, NULL);
1023 /* Process leaves */
1024 while ((rn = base) != NULL) {
1025 base = rn->rn_dupedkey;
1026 if (!(rn->rn_flags & RNF_ROOT)) {
1027 matched = (*matcher)(rn, w);
1028 if (matched)
1029 return rn;
1030 }
1031 }
1032 rn = next;
1033 if (rn->rn_flags & RNF_ROOT)
1034 return NULL;
1035 }
1036 /* NOTREACHED */
1037}
1038
1039struct delayinit {
1040 void **head;
1041 int off;
1042 SLIST_ENTRY(delayinit) entries;
1043};
1044static SLIST_HEAD(, delayinit) delayinits = SLIST_HEAD_INITIALIZER(delayheads);
1045static int radix_initialized;
1046
1047/*
1048 * Initialize a radix tree once radix is initialized. Only for bootstrap.
1049 * Assume that no concurrency protection is necessary at this stage.
1050 */
1051void
1052rn_delayedinit(void **head, int off)
1053{
1054 struct delayinit *di;
1055
1056 KASSERT(radix_initialized == 0);
1057
1058 di = kmem_alloc(sizeof(*di), KM_SLEEP);
1059 di->head = head;
1060 di->off = off;
1061 SLIST_INSERT_HEAD(&delayinits, di, entries);
1062}
1063
1064int
1065rn_inithead(void **head, int off)
1066{
1067 struct radix_node_head *rnh;
1068
1069 if (*head != NULL)
1070 return 1;
1071 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh));
1072 if (rnh == NULL)
1073 return 0;
1074 *head = rnh;
1075 return rn_inithead0(rnh, off);
1076}
1077
1078int
1079rn_inithead0(struct radix_node_head *rnh, int off)
1080{
1081 struct radix_node *t;
1082 struct radix_node *tt;
1083 struct radix_node *ttt;
1084
1085 memset(rnh, 0, sizeof(*rnh));
1086 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
1087 ttt = rnh->rnh_nodes + 2;
1088 t->rn_r = ttt;
1089 t->rn_p = t;
1090 tt = t->rn_l;
1091 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
1092 tt->rn_b = -1 - off;
1093 *ttt = *tt;
1094 ttt->rn_key = rn_ones;
1095 rnh->rnh_addaddr = rn_addroute;
1096 rnh->rnh_deladdr = rn_delete;
1097 rnh->rnh_matchaddr = rn_match;
1098 rnh->rnh_lookup = rn_lookup;
1099 rnh->rnh_treetop = t;
1100 return 1;
1101}
1102
1103void
1104rn_init(void)
1105{
1106 char *cp, *cplim;
1107 struct delayinit *di;
1108#ifdef _KERNEL
1109 struct domain *dp;
1110
1111 if (radix_initialized)
1112 panic("radix already initialized");
1113 radix_initialized = 1;
1114
1115 DOMAIN_FOREACH(dp) {
1116 if (dp->dom_maxrtkey > max_keylen)
1117 max_keylen = dp->dom_maxrtkey;
1118 }
1119#endif
1120 if (max_keylen == 0) {
1121 log(LOG_ERR,
1122 "rn_init: radix functions require max_keylen be set\n");
1123 return;
1124 }
1125
1126 R_Malloc(rn_zeros, char *, 3 * max_keylen);
1127 if (rn_zeros == NULL)
1128 panic("rn_init");
1129 memset(rn_zeros, 0, 3 * max_keylen);
1130 rn_ones = cp = rn_zeros + max_keylen;
1131 addmask_key = cplim = rn_ones + max_keylen;
1132 while (cp < cplim)
1133 *cp++ = -1;
1134 if (rn_inithead((void *)&mask_rnhead, 0) == 0)
1135 panic("rn_init 2");
1136
1137 while ((di = SLIST_FIRST(&delayinits)) != NULL) {
1138 if (!rn_inithead(di->head, di->off))
1139 panic("delayed rn_inithead failed");
1140 SLIST_REMOVE_HEAD(&delayinits, entries);
1141 kmem_free(di, sizeof(*di));
1142 }
1143}
1144