1 /*
2 * Copyright (C) 2004-2014 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2003 Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 /* $Id$ */
19
20 /*! \file */
21
22 #include <config.h>
23
24 #include <stdlib.h>
25
26 #include <isc/mem.h>
27 #include <isc/region.h>
28 #include <isc/string.h> /* Required for HP/UX (and others?) */
29 #include <isc/util.h>
30
31 #include <dns/result.h>
32 #include <dns/rdata.h>
33 #include <dns/rdataset.h>
34 #include <dns/rdataslab.h>
35
36 /*
37 * The rdataslab structure allows iteration to occur in both load order
38 * and DNSSEC order. The structure is as follows:
39 *
40 * header (reservelen bytes)
41 * record count (2 bytes)
42 * offset table (4 x record count bytes in load order)
43 * data records
44 * data length (2 bytes)
45 * order (2 bytes)
46 * meta data (1 byte for RRSIG's)
47 * data (data length bytes)
48 *
49 * If DNS_RDATASET_FIXED is defined to be zero (0) the format of a
50 * rdataslab is as follows:
51 *
52 * header (reservelen bytes)
53 * record count (2 bytes)
54 * data records
55 * data length (2 bytes)
56 * meta data (1 byte for RRSIG's)
57 * data (data length bytes)
58 *
59 * Offsets are from the end of the header.
60 *
61 * Load order traversal is performed by walking the offset table to find
62 * the start of the record (DNS_RDATASET_FIXED = 1).
63 *
64 * DNSSEC order traversal is performed by walking the data records.
65 *
66 * The order is stored with record to allow for efficient reconstruction
67 * of the offset table following a merge or subtraction.
68 *
69 * The iterator methods here currently only support DNSSEC order iteration.
70 *
71 * The iterator methods in rbtdb support both load order and DNSSEC order
72 * iteration.
73 *
74 * WARNING:
75 * rbtdb.c directly interacts with the slab's raw structures. If the
76 * structure changes then rbtdb.c also needs to be updated to reflect
77 * the changes. See the areas tagged with "RDATASLAB".
78 */
79
80 struct xrdata {
81 dns_rdata_t rdata;
82 unsigned int order;
83 };
84
85 /*% Note: the "const void *" are just to make qsort happy. */
86 static int
compare_rdata(const void * p1,const void * p2)87 compare_rdata(const void *p1, const void *p2) {
88 const struct xrdata *x1 = p1;
89 const struct xrdata *x2 = p2;
90 return (dns_rdata_compare(&x1->rdata, &x2->rdata));
91 }
92
93 #if DNS_RDATASET_FIXED
94 static void
fillin_offsets(unsigned char * offsetbase,unsigned int * offsettable,unsigned length)95 fillin_offsets(unsigned char *offsetbase, unsigned int *offsettable,
96 unsigned length)
97 {
98 unsigned int i, j;
99 unsigned char *raw;
100
101 for (i = 0, j = 0; i < length; i++) {
102
103 if (offsettable[i] == 0)
104 continue;
105
106 /*
107 * Fill in offset table.
108 */
109 raw = &offsetbase[j*4 + 2];
110 *raw++ = (offsettable[i] & 0xff000000) >> 24;
111 *raw++ = (offsettable[i] & 0xff0000) >> 16;
112 *raw++ = (offsettable[i] & 0xff00) >> 8;
113 *raw = offsettable[i] & 0xff;
114
115 /*
116 * Fill in table index.
117 */
118 raw = offsetbase + offsettable[i] + 2;
119 *raw++ = (j & 0xff00) >> 8;
120 *raw = j++ & 0xff;
121 }
122 }
123 #endif
124
125 isc_result_t
dns_rdataslab_fromrdataset(dns_rdataset_t * rdataset,isc_mem_t * mctx,isc_region_t * region,unsigned int reservelen)126 dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
127 isc_region_t *region, unsigned int reservelen)
128 {
129 /*
130 * Use &removed as a sentinal pointer for duplicate
131 * rdata as rdata.data == NULL is valid.
132 */
133 static unsigned char removed;
134 struct xrdata *x;
135 unsigned char *rawbuf;
136 #if DNS_RDATASET_FIXED
137 unsigned char *offsetbase;
138 #endif
139 unsigned int buflen;
140 isc_result_t result;
141 unsigned int nitems;
142 unsigned int nalloc;
143 unsigned int i;
144 #if DNS_RDATASET_FIXED
145 unsigned int *offsettable;
146 #endif
147 unsigned int length;
148
149 buflen = reservelen + 2;
150
151 nitems = dns_rdataset_count(rdataset);
152
153 /*
154 * If there are no rdata then we can just need to allocate a header
155 * with zero a record count.
156 */
157 if (nitems == 0) {
158 if (rdataset->type != 0)
159 return (ISC_R_FAILURE);
160 rawbuf = isc_mem_get(mctx, buflen);
161 if (rawbuf == NULL)
162 return (ISC_R_NOMEMORY);
163 region->base = rawbuf;
164 region->length = buflen;
165 rawbuf += reservelen;
166 *rawbuf++ = 0;
167 *rawbuf = 0;
168 return (ISC_R_SUCCESS);
169 }
170
171 if (nitems > 0xffff)
172 return (ISC_R_NOSPACE);
173
174 /*
175 * Remember the original number of items.
176 */
177 nalloc = nitems;
178 x = isc_mem_get(mctx, nalloc * sizeof(struct xrdata));
179 if (x == NULL)
180 return (ISC_R_NOMEMORY);
181
182 /*
183 * Save all of the rdata members into an array.
184 */
185 result = dns_rdataset_first(rdataset);
186 if (result != ISC_R_SUCCESS && result != ISC_R_NOMORE)
187 goto free_rdatas;
188 for (i = 0; i < nalloc && result == ISC_R_SUCCESS; i++) {
189 INSIST(result == ISC_R_SUCCESS);
190 dns_rdata_init(&x[i].rdata);
191 dns_rdataset_current(rdataset, &x[i].rdata);
192 INSIST(x[i].rdata.data != &removed);
193 #if DNS_RDATASET_FIXED
194 x[i].order = i;
195 #endif
196 result = dns_rdataset_next(rdataset);
197 }
198 if (i != nalloc || result != ISC_R_NOMORE) {
199 /*
200 * Somehow we iterated over fewer rdatas than
201 * dns_rdataset_count() said there were or there
202 * were more items than dns_rdataset_count said
203 * there were.
204 */
205 result = ISC_R_FAILURE;
206 goto free_rdatas;
207 }
208
209 /*
210 * Put into DNSSEC order.
211 */
212 if (nalloc > 1U)
213 qsort(x, nalloc, sizeof(struct xrdata), compare_rdata);
214
215 /*
216 * Remove duplicates and compute the total storage required.
217 *
218 * If an rdata is not a duplicate, accumulate the storage size
219 * required for the rdata. We do not store the class, type, etc,
220 * just the rdata, so our overhead is 2 bytes for the number of
221 * records, and 8 for each rdata, (length(2), offset(4) and order(2))
222 * and then the rdata itself.
223 */
224 for (i = 1; i < nalloc; i++) {
225 if (compare_rdata(&x[i-1].rdata, &x[i].rdata) == 0) {
226 x[i-1].rdata.data = &removed;
227 #if DNS_RDATASET_FIXED
228 /*
229 * Preserve the least order so A, B, A -> A, B
230 * after duplicate removal.
231 */
232 if (x[i-1].order < x[i].order)
233 x[i].order = x[i-1].order;
234 #endif
235 nitems--;
236 } else {
237 #if DNS_RDATASET_FIXED
238 buflen += (8 + x[i-1].rdata.length);
239 #else
240 buflen += (2 + x[i-1].rdata.length);
241 #endif
242 /*
243 * Provide space to store the per RR meta data.
244 */
245 if (rdataset->type == dns_rdatatype_rrsig)
246 buflen++;
247 }
248 }
249
250 /*
251 * Don't forget the last item!
252 */
253 #if DNS_RDATASET_FIXED
254 buflen += (8 + x[i-1].rdata.length);
255 #else
256 buflen += (2 + x[i-1].rdata.length);
257 #endif
258 /*
259 * Provide space to store the per RR meta data.
260 */
261 if (rdataset->type == dns_rdatatype_rrsig)
262 buflen++;
263
264 /*
265 * Ensure that singleton types are actually singletons.
266 */
267 if (nitems > 1 && dns_rdatatype_issingleton(rdataset->type)) {
268 /*
269 * We have a singleton type, but there's more than one
270 * RR in the rdataset.
271 */
272 result = DNS_R_SINGLETON;
273 goto free_rdatas;
274 }
275
276 /*
277 * Allocate the memory, set up a buffer, start copying in
278 * data.
279 */
280 rawbuf = isc_mem_get(mctx, buflen);
281 if (rawbuf == NULL) {
282 result = ISC_R_NOMEMORY;
283 goto free_rdatas;
284 }
285
286 #if DNS_RDATASET_FIXED
287 /* Allocate temporary offset table. */
288 offsettable = isc_mem_get(mctx, nalloc * sizeof(unsigned int));
289 if (offsettable == NULL) {
290 isc_mem_put(mctx, rawbuf, buflen);
291 result = ISC_R_NOMEMORY;
292 goto free_rdatas;
293 }
294 memset(offsettable, 0, nalloc * sizeof(unsigned int));
295 #endif
296
297 region->base = rawbuf;
298 region->length = buflen;
299
300 rawbuf += reservelen;
301 #if DNS_RDATASET_FIXED
302 offsetbase = rawbuf;
303 #endif
304
305 *rawbuf++ = (nitems & 0xff00) >> 8;
306 *rawbuf++ = (nitems & 0x00ff);
307
308 #if DNS_RDATASET_FIXED
309 /* Skip load order table. Filled in later. */
310 rawbuf += nitems * 4;
311 #endif
312
313 for (i = 0; i < nalloc; i++) {
314 if (x[i].rdata.data == &removed)
315 continue;
316 #if DNS_RDATASET_FIXED
317 offsettable[x[i].order] = rawbuf - offsetbase;
318 #endif
319 length = x[i].rdata.length;
320 if (rdataset->type == dns_rdatatype_rrsig)
321 length++;
322 INSIST(length <= 0xffff);
323 *rawbuf++ = (length & 0xff00) >> 8;
324 *rawbuf++ = (length & 0x00ff);
325 #if DNS_RDATASET_FIXED
326 rawbuf += 2; /* filled in later */
327 #endif
328 /*
329 * Store the per RR meta data.
330 */
331 if (rdataset->type == dns_rdatatype_rrsig) {
332 *rawbuf++ |= (x[i].rdata.flags & DNS_RDATA_OFFLINE) ?
333 DNS_RDATASLAB_OFFLINE : 0;
334 }
335 memmove(rawbuf, x[i].rdata.data, x[i].rdata.length);
336 rawbuf += x[i].rdata.length;
337 }
338
339 #if DNS_RDATASET_FIXED
340 fillin_offsets(offsetbase, offsettable, nalloc);
341 isc_mem_put(mctx, offsettable, nalloc * sizeof(unsigned int));
342 #endif
343
344 result = ISC_R_SUCCESS;
345
346 free_rdatas:
347 isc_mem_put(mctx, x, nalloc * sizeof(struct xrdata));
348 return (result);
349 }
350
351 static void
rdataset_disassociate(dns_rdataset_t * rdataset)352 rdataset_disassociate(dns_rdataset_t *rdataset) {
353 UNUSED(rdataset);
354 }
355
356 static isc_result_t
rdataset_first(dns_rdataset_t * rdataset)357 rdataset_first(dns_rdataset_t *rdataset) {
358 unsigned char *raw = rdataset->private3;
359 unsigned int count;
360
361 count = raw[0] * 256 + raw[1];
362 if (count == 0) {
363 rdataset->private5 = NULL;
364 return (ISC_R_NOMORE);
365 }
366 #if DNS_RDATASET_FIXED
367 raw += 2 + (4 * count);
368 #else
369 raw += 2;
370 #endif
371 /*
372 * The privateuint4 field is the number of rdata beyond the cursor
373 * position, so we decrement the total count by one before storing
374 * it.
375 */
376 count--;
377 rdataset->privateuint4 = count;
378 rdataset->private5 = raw;
379
380 return (ISC_R_SUCCESS);
381 }
382
383 static isc_result_t
rdataset_next(dns_rdataset_t * rdataset)384 rdataset_next(dns_rdataset_t *rdataset) {
385 unsigned int count;
386 unsigned int length;
387 unsigned char *raw;
388
389 count = rdataset->privateuint4;
390 if (count == 0)
391 return (ISC_R_NOMORE);
392 count--;
393 rdataset->privateuint4 = count;
394 raw = rdataset->private5;
395 length = raw[0] * 256 + raw[1];
396 #if DNS_RDATASET_FIXED
397 raw += length + 4;
398 #else
399 raw += length + 2;
400 #endif
401 rdataset->private5 = raw;
402
403 return (ISC_R_SUCCESS);
404 }
405
406 static void
rdataset_current(dns_rdataset_t * rdataset,dns_rdata_t * rdata)407 rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata) {
408 unsigned char *raw = rdataset->private5;
409 isc_region_t r;
410 unsigned int length;
411 unsigned int flags = 0;
412
413 REQUIRE(raw != NULL);
414
415 length = raw[0] * 256 + raw[1];
416 #if DNS_RDATASET_FIXED
417 raw += 4;
418 #else
419 raw += 2;
420 #endif
421 if (rdataset->type == dns_rdatatype_rrsig) {
422 if (*raw & DNS_RDATASLAB_OFFLINE)
423 flags |= DNS_RDATA_OFFLINE;
424 length--;
425 raw++;
426 }
427 r.length = length;
428 r.base = raw;
429 dns_rdata_fromregion(rdata, rdataset->rdclass, rdataset->type, &r);
430 rdata->flags |= flags;
431 }
432
433 static void
rdataset_clone(dns_rdataset_t * source,dns_rdataset_t * target)434 rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target) {
435 *target = *source;
436
437 /*
438 * Reset iterator state.
439 */
440 target->privateuint4 = 0;
441 target->private5 = NULL;
442 }
443
444 static unsigned int
rdataset_count(dns_rdataset_t * rdataset)445 rdataset_count(dns_rdataset_t *rdataset) {
446 unsigned char *raw = rdataset->private3;
447 unsigned int count;
448
449 count = raw[0] * 256 + raw[1];
450
451 return (count);
452 }
453
454 static dns_rdatasetmethods_t rdataset_methods = {
455 rdataset_disassociate,
456 rdataset_first,
457 rdataset_next,
458 rdataset_current,
459 rdataset_clone,
460 rdataset_count,
461 NULL,
462 NULL,
463 NULL,
464 NULL,
465 NULL,
466 NULL,
467 NULL,
468 NULL,
469 NULL
470 };
471
472 void
dns_rdataslab_tordataset(unsigned char * slab,unsigned int reservelen,dns_rdataclass_t rdclass,dns_rdatatype_t rdtype,dns_rdatatype_t covers,dns_ttl_t ttl,dns_rdataset_t * rdataset)473 dns_rdataslab_tordataset(unsigned char *slab, unsigned int reservelen,
474 dns_rdataclass_t rdclass, dns_rdatatype_t rdtype,
475 dns_rdatatype_t covers, dns_ttl_t ttl,
476 dns_rdataset_t *rdataset)
477 {
478 REQUIRE(slab != NULL);
479 REQUIRE(!dns_rdataset_isassociated(rdataset));
480
481 rdataset->methods = &rdataset_methods;
482 rdataset->rdclass = rdclass;
483 rdataset->type = rdtype;
484 rdataset->covers = covers;
485 rdataset->ttl = ttl;
486 rdataset->trust = 0;
487 rdataset->private1 = NULL;
488 rdataset->private2 = NULL;
489 rdataset->private3 = slab + reservelen;
490
491 /*
492 * Reset iterator state.
493 */
494 rdataset->privateuint4 = 0;
495 rdataset->private5 = NULL;
496 }
497
498 unsigned int
dns_rdataslab_size(unsigned char * slab,unsigned int reservelen)499 dns_rdataslab_size(unsigned char *slab, unsigned int reservelen) {
500 unsigned int count, length;
501 unsigned char *current;
502
503 REQUIRE(slab != NULL);
504
505 current = slab + reservelen;
506 count = *current++ * 256;
507 count += *current++;
508 #if DNS_RDATASET_FIXED
509 current += (4 * count);
510 #endif
511 while (count > 0) {
512 count--;
513 length = *current++ * 256;
514 length += *current++;
515 #if DNS_RDATASET_FIXED
516 current += length + 2;
517 #else
518 current += length;
519 #endif
520 }
521
522 return ((unsigned int)(current - slab));
523 }
524
525 /*
526 * Make the dns_rdata_t 'rdata' refer to the slab item
527 * beginning at '*current', which is part of a slab of type
528 * 'type' and class 'rdclass', and advance '*current' to
529 * point to the next item in the slab.
530 */
531 static inline void
rdata_from_slab(unsigned char ** current,dns_rdataclass_t rdclass,dns_rdatatype_t type,dns_rdata_t * rdata)532 rdata_from_slab(unsigned char **current,
533 dns_rdataclass_t rdclass, dns_rdatatype_t type,
534 dns_rdata_t *rdata)
535 {
536 unsigned char *tcurrent = *current;
537 isc_region_t region;
538 unsigned int length;
539 isc_boolean_t offline = ISC_FALSE;
540
541 length = *tcurrent++ * 256;
542 length += *tcurrent++;
543
544 if (type == dns_rdatatype_rrsig) {
545 if ((*tcurrent & DNS_RDATASLAB_OFFLINE) != 0)
546 offline = ISC_TRUE;
547 length--;
548 tcurrent++;
549 }
550 region.length = length;
551 #if DNS_RDATASET_FIXED
552 tcurrent += 2;
553 #endif
554 region.base = tcurrent;
555 tcurrent += region.length;
556 dns_rdata_fromregion(rdata, rdclass, type, ®ion);
557 if (offline)
558 rdata->flags |= DNS_RDATA_OFFLINE;
559 *current = tcurrent;
560 }
561
562 /*
563 * Return true iff 'slab' (slab data of type 'type' and class 'rdclass')
564 * contains an rdata identical to 'rdata'. This does case insensitive
565 * comparisons per DNSSEC.
566 */
567 static inline isc_boolean_t
rdata_in_slab(unsigned char * slab,unsigned int reservelen,dns_rdataclass_t rdclass,dns_rdatatype_t type,dns_rdata_t * rdata)568 rdata_in_slab(unsigned char *slab, unsigned int reservelen,
569 dns_rdataclass_t rdclass, dns_rdatatype_t type,
570 dns_rdata_t *rdata)
571 {
572 unsigned int count, i;
573 unsigned char *current;
574 dns_rdata_t trdata = DNS_RDATA_INIT;
575 int n;
576
577 current = slab + reservelen;
578 count = *current++ * 256;
579 count += *current++;
580
581 #if DNS_RDATASET_FIXED
582 current += (4 * count);
583 #endif
584
585 for (i = 0; i < count; i++) {
586 rdata_from_slab(¤t, rdclass, type, &trdata);
587
588 n = dns_rdata_compare(&trdata, rdata);
589 if (n == 0)
590 return (ISC_TRUE);
591 if (n > 0) /* In DNSSEC order. */
592 break;
593 dns_rdata_reset(&trdata);
594 }
595 return (ISC_FALSE);
596 }
597
598 isc_result_t
dns_rdataslab_merge(unsigned char * oslab,unsigned char * nslab,unsigned int reservelen,isc_mem_t * mctx,dns_rdataclass_t rdclass,dns_rdatatype_t type,unsigned int flags,unsigned char ** tslabp)599 dns_rdataslab_merge(unsigned char *oslab, unsigned char *nslab,
600 unsigned int reservelen, isc_mem_t *mctx,
601 dns_rdataclass_t rdclass, dns_rdatatype_t type,
602 unsigned int flags, unsigned char **tslabp)
603 {
604 unsigned char *ocurrent, *ostart, *ncurrent, *tstart, *tcurrent, *data;
605 unsigned int ocount, ncount, count, olength, tlength, tcount, length;
606 dns_rdata_t ordata = DNS_RDATA_INIT;
607 dns_rdata_t nrdata = DNS_RDATA_INIT;
608 isc_boolean_t added_something = ISC_FALSE;
609 unsigned int oadded = 0;
610 unsigned int nadded = 0;
611 unsigned int nncount = 0;
612 #if DNS_RDATASET_FIXED
613 unsigned int oncount;
614 unsigned int norder = 0;
615 unsigned int oorder = 0;
616 unsigned char *offsetbase;
617 unsigned int *offsettable;
618 #endif
619
620 /*
621 * XXX Need parameter to allow "delete rdatasets in nslab" merge,
622 * or perhaps another merge routine for this purpose.
623 */
624
625 REQUIRE(tslabp != NULL && *tslabp == NULL);
626 REQUIRE(oslab != NULL && nslab != NULL);
627
628 ocurrent = oslab + reservelen;
629 ocount = *ocurrent++ * 256;
630 ocount += *ocurrent++;
631 #if DNS_RDATASET_FIXED
632 ocurrent += (4 * ocount);
633 #endif
634 ostart = ocurrent;
635 ncurrent = nslab + reservelen;
636 ncount = *ncurrent++ * 256;
637 ncount += *ncurrent++;
638 #if DNS_RDATASET_FIXED
639 ncurrent += (4 * ncount);
640 #endif
641 INSIST(ocount > 0 && ncount > 0);
642
643 #if DNS_RDATASET_FIXED
644 oncount = ncount;
645 #endif
646
647 /*
648 * Yes, this is inefficient!
649 */
650
651 /*
652 * Figure out the length of the old slab's data.
653 */
654 olength = 0;
655 for (count = 0; count < ocount; count++) {
656 length = *ocurrent++ * 256;
657 length += *ocurrent++;
658 #if DNS_RDATASET_FIXED
659 olength += length + 8;
660 ocurrent += length + 2;
661 #else
662 olength += length + 2;
663 ocurrent += length;
664 #endif
665 }
666
667 /*
668 * Start figuring out the target length and count.
669 */
670 tlength = reservelen + 2 + olength;
671 tcount = ocount;
672
673 /*
674 * Add in the length of rdata in the new slab that aren't in
675 * the old slab.
676 */
677 do {
678 dns_rdata_init(&nrdata);
679 rdata_from_slab(&ncurrent, rdclass, type, &nrdata);
680 if (!rdata_in_slab(oslab, reservelen, rdclass, type, &nrdata))
681 {
682 /*
683 * This rdata isn't in the old slab.
684 */
685 #if DNS_RDATASET_FIXED
686 tlength += nrdata.length + 8;
687 #else
688 tlength += nrdata.length + 2;
689 #endif
690 if (type == dns_rdatatype_rrsig)
691 tlength++;
692 tcount++;
693 nncount++;
694 added_something = ISC_TRUE;
695 }
696 ncount--;
697 } while (ncount > 0);
698 ncount = nncount;
699
700 if (((flags & DNS_RDATASLAB_EXACT) != 0) &&
701 (tcount != ncount + ocount))
702 return (DNS_R_NOTEXACT);
703
704 if (!added_something && (flags & DNS_RDATASLAB_FORCE) == 0)
705 return (DNS_R_UNCHANGED);
706
707 /*
708 * Ensure that singleton types are actually singletons.
709 */
710 if (tcount > 1 && dns_rdatatype_issingleton(type)) {
711 /*
712 * We have a singleton type, but there's more than one
713 * RR in the rdataset.
714 */
715 return (DNS_R_SINGLETON);
716 }
717
718 if (tcount > 0xffff)
719 return (ISC_R_NOSPACE);
720
721 /*
722 * Copy the reserved area from the new slab.
723 */
724 tstart = isc_mem_get(mctx, tlength);
725 if (tstart == NULL)
726 return (ISC_R_NOMEMORY);
727 memmove(tstart, nslab, reservelen);
728 tcurrent = tstart + reservelen;
729 #if DNS_RDATASET_FIXED
730 offsetbase = tcurrent;
731 #endif
732
733 /*
734 * Write the new count.
735 */
736 *tcurrent++ = (tcount & 0xff00) >> 8;
737 *tcurrent++ = (tcount & 0x00ff);
738
739 #if DNS_RDATASET_FIXED
740 /*
741 * Skip offset table.
742 */
743 tcurrent += (tcount * 4);
744
745 offsettable = isc_mem_get(mctx,
746 (ocount + oncount) * sizeof(unsigned int));
747 if (offsettable == NULL) {
748 isc_mem_put(mctx, tstart, tlength);
749 return (ISC_R_NOMEMORY);
750 }
751 memset(offsettable, 0, (ocount + oncount) * sizeof(unsigned int));
752 #endif
753
754 /*
755 * Merge the two slabs.
756 */
757 ocurrent = ostart;
758 INSIST(ocount != 0);
759 #if DNS_RDATASET_FIXED
760 oorder = ocurrent[2] * 256 + ocurrent[3];
761 INSIST(oorder < ocount);
762 #endif
763 rdata_from_slab(&ocurrent, rdclass, type, &ordata);
764
765 ncurrent = nslab + reservelen + 2;
766 #if DNS_RDATASET_FIXED
767 ncurrent += (4 * oncount);
768 #endif
769
770 if (ncount > 0) {
771 do {
772 dns_rdata_reset(&nrdata);
773 #if DNS_RDATASET_FIXED
774 norder = ncurrent[2] * 256 + ncurrent[3];
775
776 INSIST(norder < oncount);
777 #endif
778 rdata_from_slab(&ncurrent, rdclass, type, &nrdata);
779 } while (rdata_in_slab(oslab, reservelen, rdclass,
780 type, &nrdata));
781 }
782
783 while (oadded < ocount || nadded < ncount) {
784 isc_boolean_t fromold;
785 if (oadded == ocount)
786 fromold = ISC_FALSE;
787 else if (nadded == ncount)
788 fromold = ISC_TRUE;
789 else
790 fromold = ISC_TF(compare_rdata(&ordata, &nrdata) < 0);
791 if (fromold) {
792 #if DNS_RDATASET_FIXED
793 offsettable[oorder] = tcurrent - offsetbase;
794 #endif
795 length = ordata.length;
796 data = ordata.data;
797 if (type == dns_rdatatype_rrsig) {
798 length++;
799 data--;
800 }
801 *tcurrent++ = (length & 0xff00) >> 8;
802 *tcurrent++ = (length & 0x00ff);
803 #if DNS_RDATASET_FIXED
804 tcurrent += 2; /* fill in later */
805 #endif
806 memmove(tcurrent, data, length);
807 tcurrent += length;
808 oadded++;
809 if (oadded < ocount) {
810 dns_rdata_reset(&ordata);
811 #if DNS_RDATASET_FIXED
812 oorder = ocurrent[2] * 256 + ocurrent[3];
813 INSIST(oorder < ocount);
814 #endif
815 rdata_from_slab(&ocurrent, rdclass, type,
816 &ordata);
817 }
818 } else {
819 #if DNS_RDATASET_FIXED
820 offsettable[ocount + norder] = tcurrent - offsetbase;
821 #endif
822 length = nrdata.length;
823 data = nrdata.data;
824 if (type == dns_rdatatype_rrsig) {
825 length++;
826 data--;
827 }
828 *tcurrent++ = (length & 0xff00) >> 8;
829 *tcurrent++ = (length & 0x00ff);
830 #if DNS_RDATASET_FIXED
831 tcurrent += 2; /* fill in later */
832 #endif
833 memmove(tcurrent, data, length);
834 tcurrent += length;
835 nadded++;
836 if (nadded < ncount) {
837 do {
838 dns_rdata_reset(&nrdata);
839 #if DNS_RDATASET_FIXED
840 norder = ncurrent[2] * 256 + ncurrent[3];
841 INSIST(norder < oncount);
842 #endif
843 rdata_from_slab(&ncurrent, rdclass,
844 type, &nrdata);
845 } while (rdata_in_slab(oslab, reservelen,
846 rdclass, type,
847 &nrdata));
848 }
849 }
850 }
851
852 #if DNS_RDATASET_FIXED
853 fillin_offsets(offsetbase, offsettable, ocount + oncount);
854
855 isc_mem_put(mctx, offsettable,
856 (ocount + oncount) * sizeof(unsigned int));
857 #endif
858
859 INSIST(tcurrent == tstart + tlength);
860
861 *tslabp = tstart;
862
863 return (ISC_R_SUCCESS);
864 }
865
866 isc_result_t
dns_rdataslab_subtract(unsigned char * mslab,unsigned char * sslab,unsigned int reservelen,isc_mem_t * mctx,dns_rdataclass_t rdclass,dns_rdatatype_t type,unsigned int flags,unsigned char ** tslabp)867 dns_rdataslab_subtract(unsigned char *mslab, unsigned char *sslab,
868 unsigned int reservelen, isc_mem_t *mctx,
869 dns_rdataclass_t rdclass, dns_rdatatype_t type,
870 unsigned int flags, unsigned char **tslabp)
871 {
872 unsigned char *mcurrent, *sstart, *scurrent, *tstart, *tcurrent;
873 unsigned int mcount, scount, rcount ,count, tlength, tcount, i;
874 dns_rdata_t srdata = DNS_RDATA_INIT;
875 dns_rdata_t mrdata = DNS_RDATA_INIT;
876 #if DNS_RDATASET_FIXED
877 unsigned char *offsetbase;
878 unsigned int *offsettable;
879 unsigned int order;
880 #endif
881
882 REQUIRE(tslabp != NULL && *tslabp == NULL);
883 REQUIRE(mslab != NULL && sslab != NULL);
884
885 mcurrent = mslab + reservelen;
886 mcount = *mcurrent++ * 256;
887 mcount += *mcurrent++;
888 scurrent = sslab + reservelen;
889 scount = *scurrent++ * 256;
890 scount += *scurrent++;
891 INSIST(mcount > 0 && scount > 0);
892
893 /*
894 * Yes, this is inefficient!
895 */
896
897 /*
898 * Start figuring out the target length and count.
899 */
900 tlength = reservelen + 2;
901 tcount = 0;
902 rcount = 0;
903
904 #if DNS_RDATASET_FIXED
905 mcurrent += 4 * mcount;
906 scurrent += 4 * scount;
907 #endif
908 sstart = scurrent;
909
910 /*
911 * Add in the length of rdata in the mslab that aren't in
912 * the sslab.
913 */
914 for (i = 0; i < mcount; i++) {
915 unsigned char *mrdatabegin = mcurrent;
916 rdata_from_slab(&mcurrent, rdclass, type, &mrdata);
917 scurrent = sstart;
918 for (count = 0; count < scount; count++) {
919 dns_rdata_reset(&srdata);
920 rdata_from_slab(&scurrent, rdclass, type, &srdata);
921 if (dns_rdata_compare(&mrdata, &srdata) == 0)
922 break;
923 }
924 if (count == scount) {
925 /*
926 * This rdata isn't in the sslab, and thus isn't
927 * being subtracted.
928 */
929 tlength += (unsigned int)(mcurrent - mrdatabegin);
930 tcount++;
931 } else
932 rcount++;
933 dns_rdata_reset(&mrdata);
934 }
935
936 #if DNS_RDATASET_FIXED
937 tlength += (4 * tcount);
938 #endif
939
940 /*
941 * Check that all the records originally existed. The numeric
942 * check only works as rdataslabs do not contain duplicates.
943 */
944 if (((flags & DNS_RDATASLAB_EXACT) != 0) && (rcount != scount))
945 return (DNS_R_NOTEXACT);
946
947 /*
948 * Don't continue if the new rdataslab would be empty.
949 */
950 if (tcount == 0)
951 return (DNS_R_NXRRSET);
952
953 /*
954 * If nothing is going to change, we can stop.
955 */
956 if (rcount == 0)
957 return (DNS_R_UNCHANGED);
958
959 /*
960 * Copy the reserved area from the mslab.
961 */
962 tstart = isc_mem_get(mctx, tlength);
963 if (tstart == NULL)
964 return (ISC_R_NOMEMORY);
965 memmove(tstart, mslab, reservelen);
966 tcurrent = tstart + reservelen;
967 #if DNS_RDATASET_FIXED
968 offsetbase = tcurrent;
969
970 offsettable = isc_mem_get(mctx, mcount * sizeof(unsigned int));
971 if (offsettable == NULL) {
972 isc_mem_put(mctx, tstart, tlength);
973 return (ISC_R_NOMEMORY);
974 }
975 memset(offsettable, 0, mcount * sizeof(unsigned int));
976 #endif
977
978 /*
979 * Write the new count.
980 */
981 *tcurrent++ = (tcount & 0xff00) >> 8;
982 *tcurrent++ = (tcount & 0x00ff);
983
984 #if DNS_RDATASET_FIXED
985 tcurrent += (4 * tcount);
986 #endif
987
988 /*
989 * Copy the parts of mslab not in sslab.
990 */
991 mcurrent = mslab + reservelen;
992 mcount = *mcurrent++ * 256;
993 mcount += *mcurrent++;
994 #if DNS_RDATASET_FIXED
995 mcurrent += (4 * mcount);
996 #endif
997 for (i = 0; i < mcount; i++) {
998 unsigned char *mrdatabegin = mcurrent;
999 #if DNS_RDATASET_FIXED
1000 order = mcurrent[2] * 256 + mcurrent[3];
1001 INSIST(order < mcount);
1002 #endif
1003 rdata_from_slab(&mcurrent, rdclass, type, &mrdata);
1004 scurrent = sstart;
1005 for (count = 0; count < scount; count++) {
1006 dns_rdata_reset(&srdata);
1007 rdata_from_slab(&scurrent, rdclass, type, &srdata);
1008 if (dns_rdata_compare(&mrdata, &srdata) == 0)
1009 break;
1010 }
1011 if (count == scount) {
1012 /*
1013 * This rdata isn't in the sslab, and thus should be
1014 * copied to the tslab.
1015 */
1016 unsigned int length;
1017 length = (unsigned int)(mcurrent - mrdatabegin);
1018 #if DNS_RDATASET_FIXED
1019 offsettable[order] = tcurrent - offsetbase;
1020 #endif
1021 memmove(tcurrent, mrdatabegin, length);
1022 tcurrent += length;
1023 }
1024 dns_rdata_reset(&mrdata);
1025 }
1026
1027 #if DNS_RDATASET_FIXED
1028 fillin_offsets(offsetbase, offsettable, mcount);
1029
1030 isc_mem_put(mctx, offsettable, mcount * sizeof(unsigned int));
1031 #endif
1032
1033 INSIST(tcurrent == tstart + tlength);
1034
1035 *tslabp = tstart;
1036
1037 return (ISC_R_SUCCESS);
1038 }
1039
1040 isc_boolean_t
dns_rdataslab_equal(unsigned char * slab1,unsigned char * slab2,unsigned int reservelen)1041 dns_rdataslab_equal(unsigned char *slab1, unsigned char *slab2,
1042 unsigned int reservelen)
1043 {
1044 unsigned char *current1, *current2;
1045 unsigned int count1, count2;
1046 unsigned int length1, length2;
1047
1048 current1 = slab1 + reservelen;
1049 count1 = *current1++ * 256;
1050 count1 += *current1++;
1051
1052 current2 = slab2 + reservelen;
1053 count2 = *current2++ * 256;
1054 count2 += *current2++;
1055
1056 if (count1 != count2)
1057 return (ISC_FALSE);
1058
1059 #if DNS_RDATASET_FIXED
1060 current1 += (4 * count1);
1061 current2 += (4 * count2);
1062 #endif
1063
1064 while (count1 > 0) {
1065 length1 = *current1++ * 256;
1066 length1 += *current1++;
1067
1068 length2 = *current2++ * 256;
1069 length2 += *current2++;
1070
1071 #if DNS_RDATASET_FIXED
1072 current1 += 2;
1073 current2 += 2;
1074 #endif
1075
1076 if (length1 != length2 ||
1077 memcmp(current1, current2, length1) != 0)
1078 return (ISC_FALSE);
1079
1080 current1 += length1;
1081 current2 += length1;
1082
1083 count1--;
1084 }
1085 return (ISC_TRUE);
1086 }
1087
1088 isc_boolean_t
dns_rdataslab_equalx(unsigned char * slab1,unsigned char * slab2,unsigned int reservelen,dns_rdataclass_t rdclass,dns_rdatatype_t type)1089 dns_rdataslab_equalx(unsigned char *slab1, unsigned char *slab2,
1090 unsigned int reservelen, dns_rdataclass_t rdclass,
1091 dns_rdatatype_t type)
1092 {
1093 unsigned char *current1, *current2;
1094 unsigned int count1, count2;
1095 dns_rdata_t rdata1 = DNS_RDATA_INIT;
1096 dns_rdata_t rdata2 = DNS_RDATA_INIT;
1097
1098 current1 = slab1 + reservelen;
1099 count1 = *current1++ * 256;
1100 count1 += *current1++;
1101
1102 current2 = slab2 + reservelen;
1103 count2 = *current2++ * 256;
1104 count2 += *current2++;
1105
1106 if (count1 != count2)
1107 return (ISC_FALSE);
1108
1109 #if DNS_RDATASET_FIXED
1110 current1 += (4 * count1);
1111 current2 += (4 * count2);
1112 #endif
1113
1114 while (count1-- > 0) {
1115 rdata_from_slab(¤t1, rdclass, type, &rdata1);
1116 rdata_from_slab(¤t2, rdclass, type, &rdata2);
1117 if (dns_rdata_compare(&rdata1, &rdata2) != 0)
1118 return (ISC_FALSE);
1119 dns_rdata_reset(&rdata1);
1120 dns_rdata_reset(&rdata2);
1121 }
1122 return (ISC_TRUE);
1123 }
1124