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526e7c1d P |
1 | /* |
2 | * $Id: patricia.c,v 1.7 2005/12/07 20:46:41 dplonka Exp $ | |
3 | * Dave Plonka <plonka@doit.wisc.edu> | |
4 | * | |
5 | * This product includes software developed by the University of Michigan, | |
6 | * Merit Network, Inc., and their contributors. | |
7 | * | |
8 | * This file had been called "radix.c" in the MRT sources. | |
9 | * | |
10 | * I renamed it to "patricia.c" since it's not an implementation of a general | |
11 | * radix trie. Also I pulled in various requirements from "prefix.c" and | |
12 | * "demo.c" so that it could be used as a standalone API. | |
13 | */ | |
14 | ||
6f8dfee9 | 15 | char patricia_copyright[] = |
526e7c1d P |
16 | "This product includes software developed by the University of Michigan, Merit" |
17 | "Network, Inc., and their contributors."; | |
18 | ||
526e7c1d P |
19 | #include <assert.h> /* assert */ |
20 | #include <ctype.h> /* isdigit */ | |
21 | #include <errno.h> /* errno */ | |
22 | #include <math.h> /* sin */ | |
23 | #include <stddef.h> /* NULL */ | |
24 | #include <stdio.h> /* sprintf, fprintf, stderr */ | |
25 | #include <stdlib.h> /* free, atol, calloc */ | |
26 | #include <string.h> /* memcpy, strchr, strlen */ | |
27 | ||
28 | #include "patricia.h" | |
29 | ||
526e7c1d P |
30 | /* prefix_tochar |
31 | * convert prefix information to bytes | |
32 | */ | |
33 | u_char * | |
34 | prefix_tochar (prefix_t * prefix) | |
35 | { | |
36 | if (prefix == NULL) | |
37 | return (NULL); | |
38 | ||
39 | return ((u_char *) & prefix->sin); | |
40 | } | |
41 | ||
42 | int | |
43 | comp_with_mask (void *addr, void *dest, u_int mask) | |
44 | { | |
45 | ||
46 | if ( /* mask/8 == 0 || */ memcmp (addr, dest, mask / 8) == 0) { | |
47 | int n = mask / 8; | |
48 | int m = ((-1) << (8 - (mask % 8))); | |
49 | ||
50 | if (mask % 8 == 0 || (((u_char *)addr)[n] & m) == (((u_char *)dest)[n] & m)) | |
51 | return (1); | |
52 | } | |
53 | return (0); | |
54 | } | |
55 | ||
ba7e4a13 | 56 | |
526e7c1d P |
57 | prefix_t * |
58 | patricia_new_prefix (struct irc_in_addr *dest, int bitlen) | |
59 | { | |
7a25133f P |
60 | prefix_t *prefix = newprefix(); |
61 | assert (0 != prefix); | |
526e7c1d | 62 | |
526e7c1d | 63 | memcpy (&prefix->sin, dest, 16); |
526e7c1d P |
64 | prefix->bitlen = (bitlen >= 0)? bitlen: 128; |
65 | prefix->ref_count = 1; | |
7a25133f | 66 | |
526e7c1d P |
67 | return prefix; |
68 | } | |
69 | ||
70 | prefix_t * | |
71 | patricia_ref_prefix (prefix_t * prefix) | |
72 | { | |
73 | if (prefix == NULL) | |
74 | return (NULL); | |
75 | if (prefix->ref_count == 0) { | |
76 | /* make a copy in case of a static prefix */ | |
77 | return (patricia_new_prefix (&prefix->sin, prefix->bitlen)); | |
78 | } | |
79 | prefix->ref_count++; | |
526e7c1d P |
80 | return (prefix); |
81 | } | |
82 | ||
83 | void | |
84 | patricia_deref_prefix (prefix_t * prefix) | |
85 | { | |
86 | if (prefix == NULL) | |
87 | return; | |
88 | /* for secure programming, raise an assert. no static prefix can call this */ | |
89 | assert (prefix->ref_count > 0); | |
90 | ||
91 | prefix->ref_count--; | |
526e7c1d | 92 | if (prefix->ref_count <= 0) { |
801fd068 P |
93 | freeprefix(prefix); |
94 | return; | |
526e7c1d P |
95 | } |
96 | } | |
97 | ||
526e7c1d P |
98 | /* these routines support continuous mask only */ |
99 | ||
100 | patricia_tree_t * | |
101 | patricia_new_tree (int maxbits) | |
102 | { | |
103 | patricia_tree_t *patricia = calloc(1, sizeof *patricia); | |
104 | ||
105 | patricia->maxbits = maxbits; | |
106 | patricia->head = NULL; | |
107 | patricia->num_active_node = 0; | |
108 | assert (maxbits <= PATRICIA_MAXBITS); /* XXX */ | |
109 | return (patricia); | |
110 | } | |
111 | ||
112 | ||
113 | void | |
114 | patricia_clear_tree (patricia_tree_t *patricia, void_fn_t func) | |
115 | { | |
116 | assert (patricia); | |
117 | if (patricia->head) { | |
118 | ||
119 | patricia_node_t *Xstack[PATRICIA_MAXBITS+1]; | |
120 | patricia_node_t **Xsp = Xstack; | |
121 | patricia_node_t *Xrn = patricia->head; | |
122 | ||
123 | while (Xrn) { | |
124 | patricia_node_t *l = Xrn->l; | |
125 | patricia_node_t *r = Xrn->r; | |
126 | ||
127 | if (Xrn->prefix) { | |
a8ba1373 P |
128 | if (Xrn->exts && func) |
129 | func(Xrn->exts); | |
526e7c1d P |
130 | patricia_deref_prefix (Xrn->prefix); |
131 | } | |
7a25133f | 132 | freenode(Xrn); |
526e7c1d P |
133 | patricia->num_active_node--; |
134 | ||
135 | if (l) { | |
136 | if (r) { | |
137 | *Xsp++ = r; | |
138 | } | |
139 | Xrn = l; | |
140 | } else if (r) { | |
141 | Xrn = r; | |
142 | } else if (Xsp != Xstack) { | |
143 | Xrn = *(--Xsp); | |
144 | } else { | |
145 | Xrn = (patricia_node_t *) 0; | |
146 | } | |
147 | } | |
148 | } | |
149 | assert (patricia->num_active_node == 0); | |
526e7c1d P |
150 | } |
151 | ||
526e7c1d P |
152 | void |
153 | patricia_destroy_tree (patricia_tree_t *patricia, void_fn_t func) | |
154 | { | |
155 | patricia_clear_tree (patricia, func); | |
156 | free(patricia); | |
7a25133f | 157 | /*TODO: EXTENSIONS!*/ |
526e7c1d P |
158 | } |
159 | ||
160 | ||
161 | /* | |
162 | * if func is supplied, it will be called as func(node->prefix) | |
163 | */ | |
164 | ||
165 | void | |
166 | patricia_process (patricia_tree_t *patricia, void_fn_t func) | |
167 | { | |
168 | patricia_node_t *node; | |
169 | assert (func); | |
170 | ||
171 | PATRICIA_WALK (patricia->head, node) { | |
172 | func (node->prefix); | |
173 | } PATRICIA_WALK_END; | |
174 | } | |
175 | ||
176 | size_t | |
177 | patricia_walk_inorder(patricia_node_t *node, void_fn_t func) | |
178 | { | |
179 | size_t n = 0; | |
180 | assert(func); | |
181 | ||
182 | if (node->l) { | |
183 | n += patricia_walk_inorder(node->l, func); | |
184 | } | |
185 | ||
186 | if (node->prefix) { | |
187 | func(node->prefix); | |
188 | n++; | |
189 | } | |
190 | ||
191 | if (node->r) { | |
192 | n += patricia_walk_inorder(node->r, func); | |
193 | } | |
194 | ||
195 | return n; | |
196 | } | |
197 | ||
198 | ||
199 | patricia_node_t * | |
200 | patricia_search_exact (patricia_tree_t *patricia, struct irc_in_addr *sin, unsigned char bitlen) | |
201 | { | |
202 | patricia_node_t *node; | |
203 | u_char *addr; | |
204 | ||
205 | assert (patricia); | |
206 | assert (sin); | |
207 | assert (bitlen <= patricia->maxbits); | |
208 | ||
209 | if (patricia->head == NULL) | |
210 | return (NULL); | |
211 | ||
212 | node = patricia->head; | |
213 | addr = (u_char *)sin; | |
214 | ||
215 | while (node->bit < bitlen) { | |
a9b4ce08 | 216 | if (is_bit_set(addr,node->bit)) |
526e7c1d P |
217 | node = node->r; |
218 | else | |
219 | node = node->l; | |
220 | ||
221 | if (node == NULL) | |
222 | return (NULL); | |
223 | } | |
224 | ||
225 | if (node->bit > bitlen || node->prefix == NULL) | |
226 | return (NULL); | |
227 | assert (node->bit == bitlen); | |
228 | assert (node->bit == node->prefix->bitlen); | |
ba7e4a13 | 229 | if (comp_with_mask (prefix_tochar (node->prefix), addr, bitlen)) { |
526e7c1d P |
230 | return (node); |
231 | } | |
232 | return (NULL); | |
233 | } | |
234 | ||
235 | ||
236 | /* if inclusive != 0, "best" may be the given prefix itself */ | |
237 | patricia_node_t * | |
238 | patricia_search_best2 (patricia_tree_t *patricia, struct irc_in_addr *sin, unsigned char bitlen, int inclusive) | |
239 | { | |
240 | patricia_node_t *node; | |
241 | patricia_node_t *stack[PATRICIA_MAXBITS + 1]; | |
242 | u_char *addr; | |
243 | int cnt = 0; | |
244 | ||
245 | assert (patricia); | |
246 | assert (sin); | |
247 | assert (bitlen <= patricia->maxbits); | |
248 | ||
249 | if (patricia->head == NULL) | |
250 | return (NULL); | |
251 | ||
252 | node = patricia->head; | |
253 | addr = (u_char *)sin; | |
254 | ||
255 | while (node->bit < bitlen) { | |
256 | ||
257 | if (node->prefix) { | |
258 | stack[cnt++] = node; | |
259 | } | |
260 | ||
a9b4ce08 | 261 | if (is_bit_set(addr,node->bit)) { |
526e7c1d P |
262 | node = node->r; |
263 | } | |
264 | else { | |
265 | node = node->l; | |
266 | } | |
267 | ||
268 | if (node == NULL) | |
269 | break; | |
270 | } | |
271 | ||
272 | if (inclusive && node && node->prefix) | |
273 | stack[cnt++] = node; | |
274 | ||
275 | if (cnt <= 0) | |
276 | return (NULL); | |
277 | ||
278 | while (--cnt >= 0) { | |
279 | node = stack[cnt]; | |
280 | if (comp_with_mask (prefix_tochar (node->prefix), | |
281 | addr, | |
282 | node->prefix->bitlen)) { | |
283 | return (node); | |
284 | } | |
285 | } | |
286 | return (NULL); | |
287 | } | |
288 | ||
289 | ||
290 | patricia_node_t * | |
291 | patricia_search_best (patricia_tree_t *patricia, struct irc_in_addr *sin, unsigned char bitlen) | |
292 | { | |
293 | return (patricia_search_best2 (patricia, sin, bitlen, 1)); | |
294 | } | |
295 | ||
296 | ||
297 | patricia_node_t * | |
298 | patricia_lookup (patricia_tree_t *patricia, prefix_t *prefix) | |
299 | { | |
300 | patricia_node_t *node, *new_node, *parent, *glue; | |
301 | u_char *addr, *test_addr; | |
302 | u_int bitlen, check_bit, differ_bit; | |
303 | int i, j, r; | |
304 | ||
305 | assert (patricia); | |
306 | assert (prefix); | |
307 | assert (prefix->bitlen <= patricia->maxbits); | |
308 | ||
309 | /* if new trie, create the first node */ | |
310 | if (patricia->head == NULL) { | |
7a25133f | 311 | node = patricia_new_node(patricia, prefix->bitlen, patricia_ref_prefix (prefix)); |
526e7c1d | 312 | patricia->head = node; |
526e7c1d P |
313 | return (node); |
314 | } | |
315 | ||
316 | addr = prefix_touchar (prefix); | |
317 | bitlen = prefix->bitlen; | |
318 | node = patricia->head; | |
319 | ||
320 | /* while ( bitlength of tree node < bitlength of node we're searching for || the node has no prefix */ | |
321 | while (node->bit < bitlen || node->prefix == NULL) { | |
322 | /* check that we're not at the lowest leaf i.e. node->bit is less than max bits */ | |
323 | if (node->bit < patricia->maxbits && | |
a9b4ce08 | 324 | (is_bit_set(addr,node->bit))) { |
526e7c1d P |
325 | if (node->r == NULL) |
326 | break; | |
327 | node = node->r; | |
328 | } | |
329 | else { | |
330 | if (node->l == NULL) | |
331 | break; | |
332 | node = node->l; | |
333 | } | |
334 | ||
335 | assert (node); | |
336 | } | |
337 | ||
338 | assert (node->prefix); | |
339 | ||
340 | test_addr = prefix_touchar (node->prefix); | |
341 | /* find the first bit different */ | |
342 | check_bit = (node->bit < bitlen)? node->bit: bitlen; | |
343 | differ_bit = 0; | |
344 | for (i = 0; i*8 < check_bit; i++) { | |
345 | if ((r = (addr[i] ^ test_addr[i])) == 0) { | |
346 | differ_bit = (i + 1) * 8; | |
347 | continue; | |
348 | } | |
349 | /* I know the better way, but for now */ | |
ba7e4a13 | 350 | for (j = 0; j < 8; j++) { |
526e7c1d P |
351 | if ((r) & ((0x80 >> j))) |
352 | break; | |
353 | } | |
354 | /* must be found */ | |
355 | assert (j < 8); | |
356 | differ_bit = i * 8 + j; | |
357 | break; | |
358 | } | |
359 | if (differ_bit > check_bit) | |
360 | differ_bit = check_bit; | |
361 | ||
362 | ||
363 | parent = node->parent; | |
364 | while (parent && parent->bit >= differ_bit) { | |
365 | node = parent; | |
366 | parent = node->parent; | |
367 | } | |
368 | ||
369 | if (differ_bit == bitlen && node->bit == bitlen) { | |
950714ee P |
370 | if (!node->prefix) { |
371 | node->prefix = patricia_ref_prefix (prefix); | |
372 | } | |
526e7c1d P |
373 | return (node); |
374 | } | |
375 | ||
7a25133f | 376 | new_node = patricia_new_node(patricia, prefix->bitlen, patricia_ref_prefix (prefix)); |
526e7c1d P |
377 | if (node->bit == differ_bit) { |
378 | new_node->parent = node; | |
379 | if (node->bit < patricia->maxbits && | |
a9b4ce08 | 380 | (is_bit_set(addr, node->bit))) { |
526e7c1d P |
381 | assert (node->r == NULL); |
382 | node->r = new_node; | |
383 | } | |
384 | else { | |
385 | assert (node->l == NULL); | |
386 | node->l = new_node; | |
387 | } | |
388 | return (new_node); | |
389 | } | |
390 | ||
391 | if (bitlen == differ_bit) { | |
392 | if (bitlen < patricia->maxbits && | |
96644df6 | 393 | (is_bit_set(test_addr,bitlen))) { |
526e7c1d P |
394 | new_node->r = node; |
395 | } | |
396 | else { | |
397 | new_node->l = node; | |
398 | } | |
399 | new_node->parent = node->parent; | |
400 | if (node->parent == NULL) { | |
401 | assert (patricia->head == node); | |
402 | patricia->head = new_node; | |
403 | } | |
404 | else if (node->parent->r == node) { | |
405 | node->parent->r = new_node; | |
406 | } | |
407 | else { | |
408 | node->parent->l = new_node; | |
409 | } | |
410 | node->parent = new_node; | |
96644df6 | 411 | new_node->usercount = node->usercount; |
526e7c1d P |
412 | } |
413 | else { | |
7a25133f | 414 | glue = patricia_new_node(patricia, differ_bit, NULL); |
526e7c1d | 415 | glue->parent = node->parent; |
526e7c1d | 416 | if (differ_bit < patricia->maxbits && |
a9b4ce08 | 417 | (is_bit_set(addr, differ_bit))) { |
526e7c1d P |
418 | glue->r = new_node; |
419 | glue->l = node; | |
420 | } | |
421 | else { | |
422 | glue->r = node; | |
423 | glue->l = new_node; | |
424 | } | |
425 | new_node->parent = glue; | |
426 | ||
427 | if (node->parent == NULL) { | |
428 | assert (patricia->head == node); | |
429 | patricia->head = glue; | |
430 | } | |
431 | else if (node->parent->r == node) { | |
432 | node->parent->r = glue; | |
433 | } | |
434 | else { | |
435 | node->parent->l = glue; | |
436 | } | |
437 | node->parent = glue; | |
96644df6 | 438 | glue->usercount = node->usercount; |
526e7c1d | 439 | } |
96644df6 | 440 | |
526e7c1d P |
441 | return (new_node); |
442 | } | |
443 | ||
444 | void | |
445 | patricia_remove (patricia_tree_t *patricia, patricia_node_t *node) | |
446 | { | |
447 | patricia_node_t *parent, *child; | |
448 | ||
449 | assert (patricia); | |
450 | assert (node); | |
451 | ||
452 | if (node->r && node->l) { | |
453 | /* this might be a placeholder node -- have to check and make sure | |
454 | * there is a prefix aossciated with it ! */ | |
455 | if (node->prefix != NULL) | |
456 | patricia_deref_prefix (node->prefix); | |
457 | node->prefix = NULL; | |
458 | return; | |
459 | } | |
460 | ||
461 | if (node->r == NULL && node->l == NULL) { | |
462 | parent = node->parent; | |
463 | patricia_deref_prefix (node->prefix); | |
7a25133f | 464 | freenode(node); |
526e7c1d P |
465 | patricia->num_active_node--; |
466 | ||
467 | if (parent == NULL) { | |
468 | assert (patricia->head == node); | |
469 | patricia->head = NULL; | |
470 | return; | |
471 | } | |
472 | ||
473 | if (parent->r == node) { | |
474 | parent->r = NULL; | |
475 | child = parent->l; | |
476 | } | |
477 | else { | |
478 | assert (parent->l == node); | |
479 | parent->l = NULL; | |
480 | child = parent->r; | |
481 | } | |
482 | ||
483 | if (parent->prefix) | |
484 | return; | |
485 | ||
486 | /* we need to remove parent too */ | |
487 | ||
488 | if (parent->parent == NULL) { | |
489 | assert (patricia->head == parent); | |
490 | patricia->head = child; | |
491 | } | |
492 | else if (parent->parent->r == parent) { | |
493 | parent->parent->r = child; | |
494 | } | |
495 | else { | |
496 | assert (parent->parent->l == parent); | |
497 | parent->parent->l = child; | |
498 | } | |
499 | child->parent = parent->parent; | |
7a25133f | 500 | freenode(parent); |
526e7c1d P |
501 | patricia->num_active_node--; |
502 | return; | |
503 | } | |
504 | ||
505 | if (node->r) { | |
506 | child = node->r; | |
507 | } | |
508 | else { | |
509 | assert (node->l); | |
510 | child = node->l; | |
511 | } | |
512 | parent = node->parent; | |
513 | child->parent = parent; | |
514 | ||
515 | patricia_deref_prefix (node->prefix); | |
7a25133f | 516 | freenode(node); |
526e7c1d P |
517 | patricia->num_active_node--; |
518 | ||
519 | if (parent == NULL) { | |
520 | assert (patricia->head == node); | |
521 | patricia->head = child; | |
522 | return; | |
523 | } | |
524 | ||
525 | if (parent->r == node) { | |
526 | parent->r = child; | |
527 | } | |
528 | else { | |
529 | assert (parent->l == node); | |
530 | parent->l = child; | |
531 | } | |
532 | } | |
533 | ||
526e7c1d P |
534 | |
535 | patricia_node_t * | |
536 | refnode(patricia_tree_t *tree, struct irc_in_addr *sin, int bitlen) { | |
537 | patricia_node_t *node; | |
538 | prefix_t *prefix; | |
539 | ||
01a924c2 | 540 | node = patricia_search_exact(tree, sin, bitlen); |
526e7c1d P |
541 | |
542 | if (node == NULL) { | |
543 | prefix = patricia_new_prefix(sin, bitlen); | |
544 | node = patricia_lookup(tree, prefix); | |
526e7c1d P |
545 | patricia_deref_prefix(prefix); |
546 | } else if (node->prefix) { | |
547 | patricia_ref_prefix(node->prefix); | |
548 | } | |
549 | ||
550 | return node; | |
551 | } | |
552 | ||
553 | void | |
554 | derefnode(patricia_tree_t *tree, patricia_node_t *node) { | |
555 | if (!node || !node->prefix) | |
556 | return; | |
557 | ||
558 | if (node->prefix->ref_count == 1) { | |
526e7c1d P |
559 | patricia_remove(tree, node); |
560 | } else | |
561 | patricia_deref_prefix(node->prefix); | |
562 | } | |
7a25133f P |
563 | |
564 | patricia_node_t *patricia_new_node(patricia_tree_t *patricia, unsigned char bit,prefix_t *prefix ) { | |
565 | patricia_node_t *new_node = newnode(); | |
566 | memset(new_node->exts, 0, PATRICIA_MAXSLOTS * sizeof(void *)); | |
567 | new_node->bit = bit; | |
568 | new_node->prefix = prefix; | |
569 | new_node->usercount = 0; | |
570 | new_node->parent = NULL; | |
571 | new_node->l = new_node->r = NULL; | |
572 | patricia->num_active_node++; | |
573 | return new_node; | |
574 | } | |
575 | ||
96644df6 P |
576 | void node_increment_usercount( patricia_node_t *node) { |
577 | while(node) { | |
578 | node->usercount++; | |
579 | node=node->parent; | |
580 | } | |
581 | } | |
582 | ||
583 | void node_decrement_usercount( patricia_node_t *node) { | |
584 | while(node) { | |
585 | node->usercount--; | |
586 | node=node->parent; | |
587 | } | |
588 | } | |
2f726f77 P |
589 | |
590 | int is_normalized_ipmask( struct irc_in_addr *sin, unsigned char bitlen ) { | |
591 | u_char *addr = (u_char *)sin; | |
592 | ||
593 | while (bitlen < PATRICIA_MAXBITS) { | |
594 | if (is_bit_set(addr,bitlen)) | |
595 | return 0; | |
596 | bitlen++; | |
597 | } | |
598 | return 1; | |
599 | } |