1/*
2 * Copyright (C) 2007-2009, 2011-2014  Internet Systems Consortium, Inc. ("ISC")
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
9 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
10 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
11 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
12 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
13 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
14 * PERFORMANCE OF THIS SOFTWARE.
15 */
16
17/* $Id$ */
18
19/*
20 * This source was adapted from MRT's RCS Ids:
21 * Id: radix.c,v 1.10.2.1 1999/11/29 05:16:24 masaki Exp
22 * Id: prefix.c,v 1.37.2.9 2000/03/10 02:53:19 labovit Exp
23 */
24
25#include <config.h>
26
27#include <isc/mem.h>
28#include <isc/types.h>
29#include <isc/util.h>
30#include <isc/radix.h>
31
32static isc_result_t
33_new_prefix(isc_mem_t *mctx, isc_prefix_t **target, int family,
34	    void *dest, int bitlen);
35
36static void
37_deref_prefix(isc_prefix_t *prefix);
38
39static isc_result_t
40_ref_prefix(isc_mem_t *mctx, isc_prefix_t **target, isc_prefix_t *prefix);
41
42static int
43_comp_with_mask(void *addr, void *dest, u_int mask);
44
45static void
46_clear_radix(isc_radix_tree_t *radix, isc_radix_destroyfunc_t func);
47
48static isc_result_t
49_new_prefix(isc_mem_t *mctx, isc_prefix_t **target, int family, void *dest,
50	    int bitlen)
51{
52	isc_prefix_t *prefix;
53
54	REQUIRE(target != NULL);
55
56	if (family != AF_INET6 && family != AF_INET && family != AF_UNSPEC)
57		return (ISC_R_NOTIMPLEMENTED);
58
59	prefix = isc_mem_get(mctx, sizeof(isc_prefix_t));
60	if (prefix == NULL)
61		return (ISC_R_NOMEMORY);
62
63	if (family == AF_INET6) {
64		prefix->bitlen = (bitlen >= 0) ? bitlen : 128;
65		memmove(&prefix->add.sin6, dest, 16);
66	} else {
67		/* AF_UNSPEC is "any" or "none"--treat it as AF_INET */
68		prefix->bitlen = (bitlen >= 0) ? bitlen : 32;
69		memmove(&prefix->add.sin, dest, 4);
70	}
71
72	prefix->family = family;
73	prefix->mctx = NULL;
74	isc_mem_attach(mctx, &prefix->mctx);
75
76	isc_refcount_init(&prefix->refcount, 1);
77
78	*target = prefix;
79	return (ISC_R_SUCCESS);
80}
81
82static void
83_deref_prefix(isc_prefix_t *prefix) {
84	int refs;
85
86	if (prefix == NULL)
87		return;
88
89	isc_refcount_decrement(&prefix->refcount, &refs);
90
91	if (refs <= 0) {
92		isc_refcount_destroy(&prefix->refcount);
93		isc_mem_putanddetach(&prefix->mctx, prefix,
94				     sizeof(isc_prefix_t));
95	}
96}
97
98static isc_result_t
99_ref_prefix(isc_mem_t *mctx, isc_prefix_t **target, isc_prefix_t *prefix) {
100	INSIST(prefix != NULL);
101	INSIST((prefix->family == AF_INET && prefix->bitlen <= 32) ||
102	       (prefix->family == AF_INET6 && prefix->bitlen <= 128) ||
103	       (prefix->family == AF_UNSPEC && prefix->bitlen == 0));
104	REQUIRE(target != NULL && *target == NULL);
105
106	/*
107	 * If this prefix is a static allocation, copy it into new memory.
108	 * (Note, the refcount still has to be destroyed by the calling
109	 * routine.)
110	 */
111	if (isc_refcount_current(&prefix->refcount) == 0) {
112		isc_result_t ret;
113		ret = _new_prefix(mctx, target, prefix->family,
114				  &prefix->add, prefix->bitlen);
115		return (ret);
116	}
117
118	isc_refcount_increment(&prefix->refcount, NULL);
119
120	*target = prefix;
121	return (ISC_R_SUCCESS);
122}
123
124static int
125_comp_with_mask(void *addr, void *dest, u_int mask) {
126
127	/* Mask length of zero matches everything */
128	if (mask == 0)
129		return (1);
130
131	if (memcmp(addr, dest, mask / 8) == 0) {
132		int n = mask / 8;
133		int m = ((~0) << (8 - (mask % 8)));
134
135		if ((mask % 8) == 0 ||
136		    (((u_char *)addr)[n] & m) == (((u_char *)dest)[n] & m))
137			return (1);
138	}
139	return (0);
140}
141
142isc_result_t
143isc_radix_create(isc_mem_t *mctx, isc_radix_tree_t **target, int maxbits) {
144	isc_radix_tree_t *radix;
145
146	REQUIRE(target != NULL && *target == NULL);
147
148	radix = isc_mem_get(mctx, sizeof(isc_radix_tree_t));
149	if (radix == NULL)
150		return (ISC_R_NOMEMORY);
151
152	radix->mctx = NULL;
153	isc_mem_attach(mctx, &radix->mctx);
154	radix->maxbits = maxbits;
155	radix->head = NULL;
156	radix->num_active_node = 0;
157	radix->num_added_node = 0;
158	RUNTIME_CHECK(maxbits <= RADIX_MAXBITS); /* XXX */
159	radix->magic = RADIX_TREE_MAGIC;
160	*target = radix;
161	return (ISC_R_SUCCESS);
162}
163
164/*
165 * if func is supplied, it will be called as func(node->data)
166 * before deleting the node
167 */
168
169static void
170_clear_radix(isc_radix_tree_t *radix, isc_radix_destroyfunc_t func) {
171
172	REQUIRE(radix != NULL);
173
174	if (radix->head != NULL) {
175		isc_radix_node_t *Xstack[RADIX_MAXBITS+1];
176		isc_radix_node_t **Xsp = Xstack;
177		isc_radix_node_t *Xrn = radix->head;
178
179		while (Xrn != NULL) {
180			isc_radix_node_t *l = Xrn->l;
181			isc_radix_node_t *r = Xrn->r;
182
183			if (Xrn->prefix != NULL) {
184				_deref_prefix(Xrn->prefix);
185				if (func != NULL && (Xrn->data[0] != NULL ||
186						     Xrn->data[1] != NULL))
187					func(Xrn->data);
188			} else {
189				INSIST(Xrn->data[0] == NULL &&
190				       Xrn->data[1] == NULL);
191			}
192
193			isc_mem_put(radix->mctx, Xrn, sizeof(*Xrn));
194			radix->num_active_node--;
195
196			if (l != NULL) {
197				if (r != NULL) {
198					*Xsp++ = r;
199				}
200				Xrn = l;
201			} else if (r != NULL) {
202				Xrn = r;
203			} else if (Xsp != Xstack) {
204				Xrn = *(--Xsp);
205			} else {
206				Xrn = NULL;
207			}
208		}
209	}
210	RUNTIME_CHECK(radix->num_active_node == 0);
211}
212
213
214void
215isc_radix_destroy(isc_radix_tree_t *radix, isc_radix_destroyfunc_t func) {
216	REQUIRE(radix != NULL);
217	_clear_radix(radix, func);
218	isc_mem_putanddetach(&radix->mctx, radix, sizeof(*radix));
219}
220
221
222/*
223 * func will be called as func(node->prefix, node->data)
224 */
225void
226isc_radix_process(isc_radix_tree_t *radix, isc_radix_processfunc_t func) {
227	isc_radix_node_t *node;
228
229	REQUIRE(func != NULL);
230
231	RADIX_WALK(radix->head, node) {
232		func(node->prefix, node->data);
233	} RADIX_WALK_END;
234}
235
236
237isc_result_t
238isc_radix_search(isc_radix_tree_t *radix, isc_radix_node_t **target,
239		 isc_prefix_t *prefix)
240{
241	isc_radix_node_t *node;
242	isc_radix_node_t *stack[RADIX_MAXBITS + 1];
243	u_char *addr;
244	isc_uint32_t bitlen;
245	int tfamily = -1;
246	int cnt = 0;
247
248	REQUIRE(radix != NULL);
249	REQUIRE(prefix != NULL);
250	REQUIRE(target != NULL && *target == NULL);
251	RUNTIME_CHECK(prefix->bitlen <= radix->maxbits);
252
253	*target = NULL;
254
255	if (radix->head == NULL) {
256		return (ISC_R_NOTFOUND);
257	}
258
259	node = radix->head;
260	addr = isc_prefix_touchar(prefix);
261	bitlen = prefix->bitlen;
262
263	while (node->bit < bitlen) {
264		if (node->prefix)
265			stack[cnt++] = node;
266
267		if (BIT_TEST(addr[node->bit >> 3], 0x80 >> (node->bit & 0x07)))
268			node = node->r;
269		else
270			node = node->l;
271
272		if (node == NULL)
273			break;
274	}
275
276	if (node && node->prefix)
277		stack[cnt++] = node;
278
279	while (cnt-- > 0) {
280		node = stack[cnt];
281
282		if (_comp_with_mask(isc_prefix_tochar(node->prefix),
283				    isc_prefix_tochar(prefix),
284				    node->prefix->bitlen)) {
285			if (node->node_num[ISC_IS6(prefix->family)] != -1 &&
286				 ((*target == NULL) ||
287				  (*target)->node_num[ISC_IS6(tfamily)] >
288				   node->node_num[ISC_IS6(prefix->family)])) {
289				*target = node;
290				tfamily = prefix->family;
291			}
292		}
293	}
294
295	if (*target == NULL) {
296		return (ISC_R_NOTFOUND);
297	} else {
298		return (ISC_R_SUCCESS);
299	}
300}
301
302isc_result_t
303isc_radix_insert(isc_radix_tree_t *radix, isc_radix_node_t **target,
304		 isc_radix_node_t *source, isc_prefix_t *prefix)
305{
306	isc_radix_node_t *node, *new_node, *parent, *glue = NULL;
307	u_char *addr, *test_addr;
308	isc_uint32_t bitlen, fam, check_bit, differ_bit;
309	isc_uint32_t i, j, r;
310	isc_result_t result;
311
312	REQUIRE(radix != NULL);
313	REQUIRE(target != NULL && *target == NULL);
314	REQUIRE(prefix != NULL || (source != NULL && source->prefix != NULL));
315	RUNTIME_CHECK(prefix == NULL || prefix->bitlen <= radix->maxbits);
316
317	if (prefix == NULL)
318		prefix = source->prefix;
319
320	INSIST(prefix != NULL);
321
322	bitlen = prefix->bitlen;
323	fam = prefix->family;
324
325	if (radix->head == NULL) {
326		node = isc_mem_get(radix->mctx, sizeof(isc_radix_node_t));
327		if (node == NULL)
328			return (ISC_R_NOMEMORY);
329		node->bit = bitlen;
330		node->node_num[0] = node->node_num[1] = -1;
331		node->prefix = NULL;
332		result = _ref_prefix(radix->mctx, &node->prefix, prefix);
333		if (result != ISC_R_SUCCESS) {
334			isc_mem_put(radix->mctx, node,
335				    sizeof(isc_radix_node_t));
336			return (result);
337		}
338		node->parent = NULL;
339		node->l = node->r = NULL;
340		if (source != NULL) {
341			/*
342			 * If source is non-NULL, then we're merging in a
343			 * node from an existing radix tree.  To keep
344			 * the node_num values consistent, the calling
345			 * function will add the total number of nodes
346			 * added to num_added_node at the end of
347			 * the merge operation--we don't do it here.
348			 */
349			if (source->node_num[0] != -1)
350				node->node_num[0] = radix->num_added_node +
351						    source->node_num[0];
352			if (source->node_num[1] != -1)
353				node->node_num[1] = radix->num_added_node +
354						    source->node_num[1];
355			node->data[0] = source->data[0];
356			node->data[1] = source->data[1];
357		} else {
358			if (fam == AF_UNSPEC) {
359				/* "any" or "none" */
360				node->node_num[0] = node->node_num[1] =
361					++radix->num_added_node;
362			} else {
363				node->node_num[ISC_IS6(fam)] =
364					++radix->num_added_node;
365			}
366			node->data[0] = NULL;
367			node->data[1] = NULL;
368		}
369		radix->head = node;
370		radix->num_active_node++;
371		*target = node;
372		return (ISC_R_SUCCESS);
373	}
374
375	addr = isc_prefix_touchar(prefix);
376	node = radix->head;
377
378	while (node->bit < bitlen || node->prefix == NULL) {
379		if (node->bit < radix->maxbits &&
380		    BIT_TEST(addr[node->bit >> 3], 0x80 >> (node->bit & 0x07)))
381		{
382			if (node->r == NULL)
383				break;
384			node = node->r;
385		} else {
386			if (node->l == NULL)
387				break;
388			node = node->l;
389		}
390
391		INSIST(node != NULL);
392	}
393
394	INSIST(node->prefix != NULL);
395
396	test_addr = isc_prefix_touchar(node->prefix);
397	/* Find the first bit different. */
398	check_bit = (node->bit < bitlen) ? node->bit : bitlen;
399	differ_bit = 0;
400	for (i = 0; i*8 < check_bit; i++) {
401		if ((r = (addr[i] ^ test_addr[i])) == 0) {
402			differ_bit = (i + 1) * 8;
403			continue;
404		}
405		/* I know the better way, but for now. */
406		for (j = 0; j < 8; j++) {
407			if (BIT_TEST (r, (0x80 >> j)))
408				break;
409		}
410		/* Must be found. */
411		INSIST(j < 8);
412		differ_bit = i * 8 + j;
413		break;
414	}
415
416	if (differ_bit > check_bit)
417		differ_bit = check_bit;
418
419	parent = node->parent;
420	while (parent != NULL && parent->bit >= differ_bit) {
421		node = parent;
422		parent = node->parent;
423	}
424
425	if (differ_bit == bitlen && node->bit == bitlen) {
426		if (node->prefix != NULL) {
427			/* Set node_num only if it hasn't been set before */
428			if (source != NULL) {
429				/* Merging node */
430				if (node->node_num[0] == -1 &&
431				    source->node_num[0] != -1) {
432					node->node_num[0] =
433						radix->num_added_node +
434						source->node_num[0];
435					node->data[0] = source->data[0];
436				}
437				if (node->node_num[1] == -1 &&
438				    source->node_num[0] != -1) {
439					node->node_num[1] =
440						radix->num_added_node +
441						source->node_num[1];
442					node->data[1] = source->data[1];
443				}
444			} else {
445				if (fam == AF_UNSPEC) {
446					/* "any" or "none" */
447					int next = radix->num_added_node + 1;
448					if (node->node_num[0] == -1) {
449						node->node_num[0] = next;
450						radix->num_added_node = next;
451					}
452					if (node->node_num[1] == -1) {
453						node->node_num[1] = next;
454						radix->num_added_node = next;
455					}
456				} else {
457					if (node->node_num[ISC_IS6(fam)] == -1)
458						node->node_num[ISC_IS6(fam)]
459						   = ++radix->num_added_node;
460				}
461			}
462			*target = node;
463			return (ISC_R_SUCCESS);
464		} else {
465			result = _ref_prefix(radix->mctx,
466					     &node->prefix, prefix);
467			if (result != ISC_R_SUCCESS)
468				return (result);
469		}
470		INSIST(node->data[0] == NULL && node->node_num[0] == -1 &&
471		       node->data[1] == NULL && node->node_num[1] == -1);
472		if (source != NULL) {
473			/* Merging node */
474			if (source->node_num[0] != -1) {
475				node->node_num[0] = radix->num_added_node +
476						    source->node_num[0];
477				node->data[0] = source->data[0];
478			}
479			if (source->node_num[1] != -1) {
480				node->node_num[1] = radix->num_added_node +
481						    source->node_num[1];
482				node->data[1] = source->data[1];
483			}
484		} else {
485			if (fam == AF_UNSPEC) {
486				/* "any" or "none" */
487				node->node_num[0] = node->node_num[1] =
488					++radix->num_added_node;
489			} else {
490				node->node_num[ISC_IS6(fam)] =
491					++radix->num_added_node;
492			}
493		}
494		*target = node;
495		return (ISC_R_SUCCESS);
496	}
497
498	new_node = isc_mem_get(radix->mctx, sizeof(isc_radix_node_t));
499	if (new_node == NULL)
500		return (ISC_R_NOMEMORY);
501	if (node->bit != differ_bit && bitlen != differ_bit) {
502		glue = isc_mem_get(radix->mctx, sizeof(isc_radix_node_t));
503		if (glue == NULL) {
504			isc_mem_put(radix->mctx, new_node,
505				    sizeof(isc_radix_node_t));
506			return (ISC_R_NOMEMORY);
507		}
508	}
509	new_node->bit = bitlen;
510	new_node->prefix = NULL;
511	result = _ref_prefix(radix->mctx, &new_node->prefix, prefix);
512	if (result != ISC_R_SUCCESS) {
513		isc_mem_put(radix->mctx, new_node, sizeof(isc_radix_node_t));
514		if (glue != NULL)
515			isc_mem_put(radix->mctx, glue,
516				    sizeof(isc_radix_node_t));
517		return (result);
518	}
519	new_node->parent = NULL;
520	new_node->l = new_node->r = NULL;
521	new_node->node_num[0] = new_node->node_num[1] = -1;
522	radix->num_active_node++;
523
524	if (source != NULL) {
525		/* Merging node */
526		if (source->node_num[0] != -1)
527			new_node->node_num[0] = radix->num_added_node +
528						source->node_num[0];
529		if (source->node_num[1] != -1)
530			new_node->node_num[1] = radix->num_added_node +
531						source->node_num[1];
532		new_node->data[0] = source->data[0];
533		new_node->data[1] = source->data[1];
534	} else {
535		if (fam == AF_UNSPEC) {
536			/* "any" or "none" */
537			new_node->node_num[0] = new_node->node_num[1] =
538				++radix->num_added_node;
539		} else {
540			new_node->node_num[ISC_IS6(fam)] =
541				++radix->num_added_node;
542		}
543		new_node->data[0] = NULL;
544		new_node->data[1] = NULL;
545	}
546
547	if (node->bit == differ_bit) {
548		INSIST(glue == NULL);
549		new_node->parent = node;
550		if (node->bit < radix->maxbits &&
551		    BIT_TEST(addr[node->bit >> 3], 0x80 >> (node->bit & 0x07)))
552		{
553			INSIST(node->r == NULL);
554			node->r = new_node;
555		} else {
556			INSIST(node->l == NULL);
557			node->l = new_node;
558		}
559		*target = new_node;
560		return (ISC_R_SUCCESS);
561	}
562
563	if (bitlen == differ_bit) {
564		INSIST(glue == NULL);
565		if (bitlen < radix->maxbits &&
566		    BIT_TEST(test_addr[bitlen >> 3], 0x80 >> (bitlen & 0x07))) {
567			new_node->r = node;
568		} else {
569			new_node->l = node;
570		}
571		new_node->parent = node->parent;
572		if (node->parent == NULL) {
573			INSIST(radix->head == node);
574			radix->head = new_node;
575		} else if (node->parent->r == node) {
576			node->parent->r = new_node;
577		} else {
578			node->parent->l = new_node;
579		}
580		node->parent = new_node;
581	} else {
582		INSIST(glue != NULL);
583		glue->bit = differ_bit;
584		glue->prefix = NULL;
585		glue->parent = node->parent;
586		glue->data[0] = glue->data[1] = NULL;
587		glue->node_num[0] = glue->node_num[1] = -1;
588		radix->num_active_node++;
589		if (differ_bit < radix->maxbits &&
590		    BIT_TEST(addr[differ_bit>>3], 0x80 >> (differ_bit & 07))) {
591			glue->r = new_node;
592			glue->l = node;
593		} else {
594			glue->r = node;
595			glue->l = new_node;
596		}
597		new_node->parent = glue;
598
599		if (node->parent == NULL) {
600			INSIST(radix->head == node);
601			radix->head = glue;
602		} else if (node->parent->r == node) {
603			node->parent->r = glue;
604		} else {
605			node->parent->l = glue;
606		}
607		node->parent = glue;
608	}
609
610	*target = new_node;
611	return (ISC_R_SUCCESS);
612}
613
614void
615isc_radix_remove(isc_radix_tree_t *radix, isc_radix_node_t *node) {
616	isc_radix_node_t *parent, *child;
617
618	REQUIRE(radix != NULL);
619	REQUIRE(node != NULL);
620
621	if (node->r && node->l) {
622		/*
623		 * This might be a placeholder node -- have to check and
624		 * make sure there is a prefix associated with it!
625		 */
626		if (node->prefix != NULL)
627			_deref_prefix(node->prefix);
628
629		node->prefix = NULL;
630		node->data[0] = node->data[1] = NULL;
631		return;
632	}
633
634	if (node->r == NULL && node->l == NULL) {
635		parent = node->parent;
636		_deref_prefix(node->prefix);
637		isc_mem_put(radix->mctx, node, sizeof(*node));
638		radix->num_active_node--;
639
640		if (parent == NULL) {
641			INSIST(radix->head == node);
642			radix->head = NULL;
643			return;
644		}
645
646		if (parent->r == node) {
647			parent->r = NULL;
648			child = parent->l;
649		} else {
650			INSIST(parent->l == node);
651			parent->l = NULL;
652			child = parent->r;
653		}
654
655		if (parent->prefix)
656			return;
657
658		/* We need to remove parent too. */
659
660		if (parent->parent == NULL) {
661			INSIST(radix->head == parent);
662			radix->head = child;
663		} else if (parent->parent->r == parent) {
664			parent->parent->r = child;
665		} else {
666			INSIST(parent->parent->l == parent);
667			parent->parent->l = child;
668		}
669		child->parent = parent->parent;
670		isc_mem_put(radix->mctx, parent, sizeof(*parent));
671		radix->num_active_node--;
672		return;
673	}
674
675	if (node->r) {
676		child = node->r;
677	} else {
678		INSIST(node->l != NULL);
679		child = node->l;
680	}
681	parent = node->parent;
682	child->parent = parent;
683
684	_deref_prefix(node->prefix);
685	isc_mem_put(radix->mctx, node, sizeof(*node));
686	radix->num_active_node--;
687
688	if (parent == NULL) {
689		INSIST(radix->head == node);
690		radix->head = child;
691		return;
692	}
693
694	if (parent->r == node) {
695		parent->r = child;
696	} else {
697		INSIST(parent->l == node);
698		parent->l = child;
699	}
700}
701
702/*
703Local Variables:
704c-basic-offset: 4
705indent-tabs-mode: t
706End:
707*/
708