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-rw-r--r--lib/dns/rdataslab.c1005
1 files changed, 1005 insertions, 0 deletions
diff --git a/lib/dns/rdataslab.c b/lib/dns/rdataslab.c
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+++ b/lib/dns/rdataslab.c
@@ -0,0 +1,1005 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include <isc/mem.h>
+#include <isc/region.h>
+#include <isc/result.h>
+#include <isc/string.h> /* Required for HP/UX (and others?) */
+#include <isc/util.h>
+
+#include <dns/rdata.h>
+#include <dns/rdataset.h>
+#include <dns/rdataslab.h>
+
+/*
+ * The rdataslab structure allows iteration to occur in both load order
+ * and DNSSEC order. The structure is as follows:
+ *
+ * header (reservelen bytes)
+ * record count (2 bytes)
+ * offset table (4 x record count bytes in load order)
+ * data records
+ * data length (2 bytes)
+ * order (2 bytes)
+ * meta data (1 byte for RRSIG's)
+ * data (data length bytes)
+ *
+ * If DNS_RDATASET_FIXED is defined to be zero (0) the format of a
+ * rdataslab is as follows:
+ *
+ * header (reservelen bytes)
+ * record count (2 bytes)
+ * data records
+ * data length (2 bytes)
+ * meta data (1 byte for RRSIG's)
+ * data (data length bytes)
+ *
+ * Offsets are from the end of the header.
+ *
+ * Load order traversal is performed by walking the offset table to find
+ * the start of the record (DNS_RDATASET_FIXED = 1).
+ *
+ * DNSSEC order traversal is performed by walking the data records.
+ *
+ * The order is stored with record to allow for efficient reconstruction
+ * of the offset table following a merge or subtraction.
+ *
+ * The iterator methods in rbtdb support both load order and DNSSEC order
+ * iteration.
+ *
+ * WARNING:
+ * rbtdb.c directly interacts with the slab's raw structures. If the
+ * structure changes then rbtdb.c also needs to be updated to reflect
+ * the changes. See the areas tagged with "RDATASLAB".
+ */
+
+struct xrdata {
+ dns_rdata_t rdata;
+ unsigned int order;
+};
+
+/*% Note: the "const void *" are just to make qsort happy. */
+static int
+compare_rdata(const void *p1, const void *p2) {
+ const struct xrdata *x1 = p1;
+ const struct xrdata *x2 = p2;
+ return (dns_rdata_compare(&x1->rdata, &x2->rdata));
+}
+
+#if DNS_RDATASET_FIXED
+static void
+fillin_offsets(unsigned char *offsetbase, unsigned int *offsettable,
+ unsigned length) {
+ unsigned int i, j;
+ unsigned char *raw;
+
+ for (i = 0, j = 0; i < length; i++) {
+ if (offsettable[i] == 0) {
+ continue;
+ }
+
+ /*
+ * Fill in offset table.
+ */
+ raw = &offsetbase[j * 4 + 2];
+ *raw++ = (offsettable[i] & 0xff000000) >> 24;
+ *raw++ = (offsettable[i] & 0xff0000) >> 16;
+ *raw++ = (offsettable[i] & 0xff00) >> 8;
+ *raw = offsettable[i] & 0xff;
+
+ /*
+ * Fill in table index.
+ */
+ raw = offsetbase + offsettable[i] + 2;
+ *raw++ = (j & 0xff00) >> 8;
+ *raw = j++ & 0xff;
+ }
+}
+#endif /* if DNS_RDATASET_FIXED */
+
+isc_result_t
+dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
+ isc_region_t *region, unsigned int reservelen) {
+ /*
+ * Use &removed as a sentinel pointer for duplicate
+ * rdata as rdata.data == NULL is valid.
+ */
+ static unsigned char removed;
+ struct xrdata *x;
+ unsigned char *rawbuf;
+#if DNS_RDATASET_FIXED
+ unsigned char *offsetbase;
+#endif /* if DNS_RDATASET_FIXED */
+ unsigned int buflen;
+ isc_result_t result;
+ unsigned int nitems;
+ unsigned int nalloc;
+ unsigned int i;
+#if DNS_RDATASET_FIXED
+ unsigned int *offsettable;
+#endif /* if DNS_RDATASET_FIXED */
+ unsigned int length;
+
+ buflen = reservelen + 2;
+
+ nitems = dns_rdataset_count(rdataset);
+
+ /*
+ * If there are no rdata then we can just need to allocate a header
+ * with zero a record count.
+ */
+ if (nitems == 0) {
+ if (rdataset->type != 0) {
+ return (ISC_R_FAILURE);
+ }
+ rawbuf = isc_mem_get(mctx, buflen);
+ region->base = rawbuf;
+ region->length = buflen;
+ rawbuf += reservelen;
+ *rawbuf++ = 0;
+ *rawbuf = 0;
+ return (ISC_R_SUCCESS);
+ }
+
+ if (nitems > 0xffff) {
+ return (ISC_R_NOSPACE);
+ }
+
+ /*
+ * Remember the original number of items.
+ */
+ nalloc = nitems;
+ x = isc_mem_get(mctx, nalloc * sizeof(struct xrdata));
+
+ /*
+ * Save all of the rdata members into an array.
+ */
+ result = dns_rdataset_first(rdataset);
+ if (result != ISC_R_SUCCESS && result != ISC_R_NOMORE) {
+ goto free_rdatas;
+ }
+ for (i = 0; i < nalloc && result == ISC_R_SUCCESS; i++) {
+ INSIST(result == ISC_R_SUCCESS);
+ dns_rdata_init(&x[i].rdata);
+ dns_rdataset_current(rdataset, &x[i].rdata);
+ INSIST(x[i].rdata.data != &removed);
+#if DNS_RDATASET_FIXED
+ x[i].order = i;
+#endif /* if DNS_RDATASET_FIXED */
+ result = dns_rdataset_next(rdataset);
+ }
+ if (i != nalloc || result != ISC_R_NOMORE) {
+ /*
+ * Somehow we iterated over fewer rdatas than
+ * dns_rdataset_count() said there were or there
+ * were more items than dns_rdataset_count said
+ * there were.
+ */
+ result = ISC_R_FAILURE;
+ goto free_rdatas;
+ }
+
+ /*
+ * Put into DNSSEC order.
+ */
+ if (nalloc > 1U) {
+ qsort(x, nalloc, sizeof(struct xrdata), compare_rdata);
+ }
+
+ /*
+ * Remove duplicates and compute the total storage required.
+ *
+ * If an rdata is not a duplicate, accumulate the storage size
+ * required for the rdata. We do not store the class, type, etc,
+ * just the rdata, so our overhead is 2 bytes for the number of
+ * records, and 8 for each rdata, (length(2), offset(4) and order(2))
+ * and then the rdata itself.
+ */
+ for (i = 1; i < nalloc; i++) {
+ if (compare_rdata(&x[i - 1].rdata, &x[i].rdata) == 0) {
+ x[i - 1].rdata.data = &removed;
+#if DNS_RDATASET_FIXED
+ /*
+ * Preserve the least order so A, B, A -> A, B
+ * after duplicate removal.
+ */
+ if (x[i - 1].order < x[i].order) {
+ x[i].order = x[i - 1].order;
+ }
+#endif /* if DNS_RDATASET_FIXED */
+ nitems--;
+ } else {
+#if DNS_RDATASET_FIXED
+ buflen += (8 + x[i - 1].rdata.length);
+#else /* if DNS_RDATASET_FIXED */
+ buflen += (2 + x[i - 1].rdata.length);
+#endif /* if DNS_RDATASET_FIXED */
+ /*
+ * Provide space to store the per RR meta data.
+ */
+ if (rdataset->type == dns_rdatatype_rrsig) {
+ buflen++;
+ }
+ }
+ }
+
+ /*
+ * Don't forget the last item!
+ */
+#if DNS_RDATASET_FIXED
+ buflen += (8 + x[i - 1].rdata.length);
+#else /* if DNS_RDATASET_FIXED */
+ buflen += (2 + x[i - 1].rdata.length);
+#endif /* if DNS_RDATASET_FIXED */
+ /*
+ * Provide space to store the per RR meta data.
+ */
+ if (rdataset->type == dns_rdatatype_rrsig) {
+ buflen++;
+ }
+
+ /*
+ * Ensure that singleton types are actually singletons.
+ */
+ if (nitems > 1 && dns_rdatatype_issingleton(rdataset->type)) {
+ /*
+ * We have a singleton type, but there's more than one
+ * RR in the rdataset.
+ */
+ result = DNS_R_SINGLETON;
+ goto free_rdatas;
+ }
+
+ /*
+ * Allocate the memory, set up a buffer, start copying in
+ * data.
+ */
+ rawbuf = isc_mem_get(mctx, buflen);
+
+#if DNS_RDATASET_FIXED
+ /* Allocate temporary offset table. */
+ offsettable = isc_mem_get(mctx, nalloc * sizeof(unsigned int));
+ memset(offsettable, 0, nalloc * sizeof(unsigned int));
+#endif /* if DNS_RDATASET_FIXED */
+
+ region->base = rawbuf;
+ region->length = buflen;
+
+ memset(rawbuf, 0, buflen);
+ rawbuf += reservelen;
+
+#if DNS_RDATASET_FIXED
+ offsetbase = rawbuf;
+#endif /* if DNS_RDATASET_FIXED */
+
+ *rawbuf++ = (nitems & 0xff00) >> 8;
+ *rawbuf++ = (nitems & 0x00ff);
+
+#if DNS_RDATASET_FIXED
+ /* Skip load order table. Filled in later. */
+ rawbuf += nitems * 4;
+#endif /* if DNS_RDATASET_FIXED */
+
+ for (i = 0; i < nalloc; i++) {
+ if (x[i].rdata.data == &removed) {
+ continue;
+ }
+#if DNS_RDATASET_FIXED
+ offsettable[x[i].order] = rawbuf - offsetbase;
+#endif /* if DNS_RDATASET_FIXED */
+ length = x[i].rdata.length;
+ if (rdataset->type == dns_rdatatype_rrsig) {
+ length++;
+ }
+ INSIST(length <= 0xffff);
+ *rawbuf++ = (length & 0xff00) >> 8;
+ *rawbuf++ = (length & 0x00ff);
+#if DNS_RDATASET_FIXED
+ rawbuf += 2; /* filled in later */
+#endif /* if DNS_RDATASET_FIXED */
+ /*
+ * Store the per RR meta data.
+ */
+ if (rdataset->type == dns_rdatatype_rrsig) {
+ *rawbuf++ = (x[i].rdata.flags & DNS_RDATA_OFFLINE)
+ ? DNS_RDATASLAB_OFFLINE
+ : 0;
+ }
+ memmove(rawbuf, x[i].rdata.data, x[i].rdata.length);
+ rawbuf += x[i].rdata.length;
+ }
+
+#if DNS_RDATASET_FIXED
+ fillin_offsets(offsetbase, offsettable, nalloc);
+ isc_mem_put(mctx, offsettable, nalloc * sizeof(unsigned int));
+#endif /* if DNS_RDATASET_FIXED */
+
+ result = ISC_R_SUCCESS;
+
+free_rdatas:
+ isc_mem_put(mctx, x, nalloc * sizeof(struct xrdata));
+ return (result);
+}
+
+unsigned int
+dns_rdataslab_size(unsigned char *slab, unsigned int reservelen) {
+ unsigned int count, length;
+ unsigned char *current;
+
+ REQUIRE(slab != NULL);
+
+ current = slab + reservelen;
+ count = *current++ * 256;
+ count += *current++;
+#if DNS_RDATASET_FIXED
+ current += (4 * count);
+#endif /* if DNS_RDATASET_FIXED */
+ while (count > 0) {
+ count--;
+ length = *current++ * 256;
+ length += *current++;
+#if DNS_RDATASET_FIXED
+ current += length + 2;
+#else /* if DNS_RDATASET_FIXED */
+ current += length;
+#endif /* if DNS_RDATASET_FIXED */
+ }
+
+ return ((unsigned int)(current - slab));
+}
+
+unsigned int
+dns_rdataslab_rdatasize(unsigned char *slab, unsigned int reservelen) {
+ unsigned int count, length, rdatalen = 0;
+ unsigned char *current;
+
+ REQUIRE(slab != NULL);
+
+ current = slab + reservelen;
+ count = *current++ * 256;
+ count += *current++;
+#if DNS_RDATASET_FIXED
+ current += (4 * count);
+#endif /* if DNS_RDATASET_FIXED */
+ while (count > 0) {
+ count--;
+ length = *current++ * 256;
+ length += *current++;
+ rdatalen += length;
+#if DNS_RDATASET_FIXED
+ current += length + 2;
+#else /* if DNS_RDATASET_FIXED */
+ current += length;
+#endif /* if DNS_RDATASET_FIXED */
+ }
+
+ return (rdatalen);
+}
+
+unsigned int
+dns_rdataslab_count(unsigned char *slab, unsigned int reservelen) {
+ unsigned int count;
+ unsigned char *current;
+
+ REQUIRE(slab != NULL);
+
+ current = slab + reservelen;
+ count = *current++ * 256;
+ count += *current++;
+ return (count);
+}
+
+/*
+ * Make the dns_rdata_t 'rdata' refer to the slab item
+ * beginning at '*current', which is part of a slab of type
+ * 'type' and class 'rdclass', and advance '*current' to
+ * point to the next item in the slab.
+ */
+static void
+rdata_from_slab(unsigned char **current, dns_rdataclass_t rdclass,
+ dns_rdatatype_t type, dns_rdata_t *rdata) {
+ unsigned char *tcurrent = *current;
+ isc_region_t region;
+ unsigned int length;
+ bool offline = false;
+
+ length = *tcurrent++ * 256;
+ length += *tcurrent++;
+
+ if (type == dns_rdatatype_rrsig) {
+ if ((*tcurrent & DNS_RDATASLAB_OFFLINE) != 0) {
+ offline = true;
+ }
+ length--;
+ tcurrent++;
+ }
+ region.length = length;
+#if DNS_RDATASET_FIXED
+ tcurrent += 2;
+#endif /* if DNS_RDATASET_FIXED */
+ region.base = tcurrent;
+ tcurrent += region.length;
+ dns_rdata_fromregion(rdata, rdclass, type, &region);
+ if (offline) {
+ rdata->flags |= DNS_RDATA_OFFLINE;
+ }
+ *current = tcurrent;
+}
+
+/*
+ * Return true iff 'slab' (slab data of type 'type' and class 'rdclass')
+ * contains an rdata identical to 'rdata'. This does case insensitive
+ * comparisons per DNSSEC.
+ */
+static bool
+rdata_in_slab(unsigned char *slab, unsigned int reservelen,
+ dns_rdataclass_t rdclass, dns_rdatatype_t type,
+ dns_rdata_t *rdata) {
+ unsigned int count, i;
+ unsigned char *current;
+ dns_rdata_t trdata = DNS_RDATA_INIT;
+ int n;
+
+ current = slab + reservelen;
+ count = *current++ * 256;
+ count += *current++;
+
+#if DNS_RDATASET_FIXED
+ current += (4 * count);
+#endif /* if DNS_RDATASET_FIXED */
+
+ for (i = 0; i < count; i++) {
+ rdata_from_slab(&current, rdclass, type, &trdata);
+
+ n = dns_rdata_compare(&trdata, rdata);
+ if (n == 0) {
+ return (true);
+ }
+ if (n > 0) { /* In DNSSEC order. */
+ break;
+ }
+ dns_rdata_reset(&trdata);
+ }
+ return (false);
+}
+
+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) {
+ unsigned char *ocurrent, *ostart, *ncurrent, *tstart, *tcurrent, *data;
+ unsigned int ocount, ncount, count, olength, tlength, tcount, length;
+ dns_rdata_t ordata = DNS_RDATA_INIT;
+ dns_rdata_t nrdata = DNS_RDATA_INIT;
+ bool added_something = false;
+ unsigned int oadded = 0;
+ unsigned int nadded = 0;
+ unsigned int nncount = 0;
+#if DNS_RDATASET_FIXED
+ unsigned int oncount;
+ unsigned int norder = 0;
+ unsigned int oorder = 0;
+ unsigned char *offsetbase;
+ unsigned int *offsettable;
+#endif /* if DNS_RDATASET_FIXED */
+
+ /*
+ * XXX Need parameter to allow "delete rdatasets in nslab" merge,
+ * or perhaps another merge routine for this purpose.
+ */
+
+ REQUIRE(tslabp != NULL && *tslabp == NULL);
+ REQUIRE(oslab != NULL && nslab != NULL);
+
+ ocurrent = oslab + reservelen;
+ ocount = *ocurrent++ * 256;
+ ocount += *ocurrent++;
+#if DNS_RDATASET_FIXED
+ ocurrent += (4 * ocount);
+#endif /* if DNS_RDATASET_FIXED */
+ ostart = ocurrent;
+ ncurrent = nslab + reservelen;
+ ncount = *ncurrent++ * 256;
+ ncount += *ncurrent++;
+#if DNS_RDATASET_FIXED
+ ncurrent += (4 * ncount);
+#endif /* if DNS_RDATASET_FIXED */
+ INSIST(ocount > 0 && ncount > 0);
+
+#if DNS_RDATASET_FIXED
+ oncount = ncount;
+#endif /* if DNS_RDATASET_FIXED */
+
+ /*
+ * Yes, this is inefficient!
+ */
+
+ /*
+ * Figure out the length of the old slab's data.
+ */
+ olength = 0;
+ for (count = 0; count < ocount; count++) {
+ length = *ocurrent++ * 256;
+ length += *ocurrent++;
+#if DNS_RDATASET_FIXED
+ olength += length + 8;
+ ocurrent += length + 2;
+#else /* if DNS_RDATASET_FIXED */
+ olength += length + 2;
+ ocurrent += length;
+#endif /* if DNS_RDATASET_FIXED */
+ }
+
+ /*
+ * Start figuring out the target length and count.
+ */
+ tlength = reservelen + 2 + olength;
+ tcount = ocount;
+
+ /*
+ * Add in the length of rdata in the new slab that aren't in
+ * the old slab.
+ */
+ do {
+ dns_rdata_init(&nrdata);
+ rdata_from_slab(&ncurrent, rdclass, type, &nrdata);
+ if (!rdata_in_slab(oslab, reservelen, rdclass, type, &nrdata)) {
+ /*
+ * This rdata isn't in the old slab.
+ */
+#if DNS_RDATASET_FIXED
+ tlength += nrdata.length + 8;
+#else /* if DNS_RDATASET_FIXED */
+ tlength += nrdata.length + 2;
+#endif /* if DNS_RDATASET_FIXED */
+ if (type == dns_rdatatype_rrsig) {
+ tlength++;
+ }
+ tcount++;
+ nncount++;
+ added_something = true;
+ }
+ ncount--;
+ } while (ncount > 0);
+ ncount = nncount;
+
+ if (((flags & DNS_RDATASLAB_EXACT) != 0) && (tcount != ncount + ocount))
+ {
+ return (DNS_R_NOTEXACT);
+ }
+
+ if (!added_something && (flags & DNS_RDATASLAB_FORCE) == 0) {
+ return (DNS_R_UNCHANGED);
+ }
+
+ /*
+ * Ensure that singleton types are actually singletons.
+ */
+ if (tcount > 1 && dns_rdatatype_issingleton(type)) {
+ /*
+ * We have a singleton type, but there's more than one
+ * RR in the rdataset.
+ */
+ return (DNS_R_SINGLETON);
+ }
+
+ if (tcount > 0xffff) {
+ return (ISC_R_NOSPACE);
+ }
+
+ /*
+ * Copy the reserved area from the new slab.
+ */
+ tstart = isc_mem_get(mctx, tlength);
+ memmove(tstart, nslab, reservelen);
+ tcurrent = tstart + reservelen;
+#if DNS_RDATASET_FIXED
+ offsetbase = tcurrent;
+#endif /* if DNS_RDATASET_FIXED */
+
+ /*
+ * Write the new count.
+ */
+ *tcurrent++ = (tcount & 0xff00) >> 8;
+ *tcurrent++ = (tcount & 0x00ff);
+
+#if DNS_RDATASET_FIXED
+ /*
+ * Skip offset table.
+ */
+ tcurrent += (tcount * 4);
+
+ offsettable = isc_mem_get(mctx,
+ (ocount + oncount) * sizeof(unsigned int));
+ memset(offsettable, 0, (ocount + oncount) * sizeof(unsigned int));
+#endif /* if DNS_RDATASET_FIXED */
+
+ /*
+ * Merge the two slabs.
+ */
+ ocurrent = ostart;
+ INSIST(ocount != 0);
+#if DNS_RDATASET_FIXED
+ oorder = ocurrent[2] * 256 + ocurrent[3];
+ INSIST(oorder < ocount);
+#endif /* if DNS_RDATASET_FIXED */
+ rdata_from_slab(&ocurrent, rdclass, type, &ordata);
+
+ ncurrent = nslab + reservelen + 2;
+#if DNS_RDATASET_FIXED
+ ncurrent += (4 * oncount);
+#endif /* if DNS_RDATASET_FIXED */
+
+ if (ncount > 0) {
+ do {
+ dns_rdata_reset(&nrdata);
+#if DNS_RDATASET_FIXED
+ norder = ncurrent[2] * 256 + ncurrent[3];
+
+ INSIST(norder < oncount);
+#endif /* if DNS_RDATASET_FIXED */
+ rdata_from_slab(&ncurrent, rdclass, type, &nrdata);
+ } while (rdata_in_slab(oslab, reservelen, rdclass, type,
+ &nrdata));
+ }
+
+ while (oadded < ocount || nadded < ncount) {
+ bool fromold;
+ if (oadded == ocount) {
+ fromold = false;
+ } else if (nadded == ncount) {
+ fromold = true;
+ } else {
+ fromold = (dns_rdata_compare(&ordata, &nrdata) < 0);
+ }
+ if (fromold) {
+#if DNS_RDATASET_FIXED
+ offsettable[oorder] = tcurrent - offsetbase;
+#endif /* if DNS_RDATASET_FIXED */
+ length = ordata.length;
+ data = ordata.data;
+ if (type == dns_rdatatype_rrsig) {
+ length++;
+ data--;
+ }
+ *tcurrent++ = (length & 0xff00) >> 8;
+ *tcurrent++ = (length & 0x00ff);
+#if DNS_RDATASET_FIXED
+ tcurrent += 2; /* fill in later */
+#endif /* if DNS_RDATASET_FIXED */
+ memmove(tcurrent, data, length);
+ tcurrent += length;
+ oadded++;
+ if (oadded < ocount) {
+ dns_rdata_reset(&ordata);
+#if DNS_RDATASET_FIXED
+ oorder = ocurrent[2] * 256 + ocurrent[3];
+ INSIST(oorder < ocount);
+#endif /* if DNS_RDATASET_FIXED */
+ rdata_from_slab(&ocurrent, rdclass, type,
+ &ordata);
+ }
+ } else {
+#if DNS_RDATASET_FIXED
+ offsettable[ocount + norder] = tcurrent - offsetbase;
+#endif /* if DNS_RDATASET_FIXED */
+ length = nrdata.length;
+ data = nrdata.data;
+ if (type == dns_rdatatype_rrsig) {
+ length++;
+ data--;
+ }
+ *tcurrent++ = (length & 0xff00) >> 8;
+ *tcurrent++ = (length & 0x00ff);
+#if DNS_RDATASET_FIXED
+ tcurrent += 2; /* fill in later */
+#endif /* if DNS_RDATASET_FIXED */
+ memmove(tcurrent, data, length);
+ tcurrent += length;
+ nadded++;
+ if (nadded < ncount) {
+ do {
+ dns_rdata_reset(&nrdata);
+#if DNS_RDATASET_FIXED
+ norder = ncurrent[2] * 256 +
+ ncurrent[3];
+ INSIST(norder < oncount);
+#endif /* if DNS_RDATASET_FIXED */
+ rdata_from_slab(&ncurrent, rdclass,
+ type, &nrdata);
+ } while (rdata_in_slab(oslab, reservelen,
+ rdclass, type, &nrdata));
+ }
+ }
+ }
+
+#if DNS_RDATASET_FIXED
+ fillin_offsets(offsetbase, offsettable, ocount + oncount);
+
+ isc_mem_put(mctx, offsettable,
+ (ocount + oncount) * sizeof(unsigned int));
+#endif /* if DNS_RDATASET_FIXED */
+
+ INSIST(tcurrent == tstart + tlength);
+
+ *tslabp = tstart;
+
+ return (ISC_R_SUCCESS);
+}
+
+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) {
+ unsigned char *mcurrent, *sstart, *scurrent, *tstart, *tcurrent;
+ unsigned int mcount, scount, rcount, count, tlength, tcount, i;
+ dns_rdata_t srdata = DNS_RDATA_INIT;
+ dns_rdata_t mrdata = DNS_RDATA_INIT;
+#if DNS_RDATASET_FIXED
+ unsigned char *offsetbase;
+ unsigned int *offsettable;
+ unsigned int order;
+#endif /* if DNS_RDATASET_FIXED */
+
+ REQUIRE(tslabp != NULL && *tslabp == NULL);
+ REQUIRE(mslab != NULL && sslab != NULL);
+
+ mcurrent = mslab + reservelen;
+ mcount = *mcurrent++ * 256;
+ mcount += *mcurrent++;
+ scurrent = sslab + reservelen;
+ scount = *scurrent++ * 256;
+ scount += *scurrent++;
+ INSIST(mcount > 0 && scount > 0);
+
+ /*
+ * Yes, this is inefficient!
+ */
+
+ /*
+ * Start figuring out the target length and count.
+ */
+ tlength = reservelen + 2;
+ tcount = 0;
+ rcount = 0;
+
+#if DNS_RDATASET_FIXED
+ mcurrent += 4 * mcount;
+ scurrent += 4 * scount;
+#endif /* if DNS_RDATASET_FIXED */
+ sstart = scurrent;
+
+ /*
+ * Add in the length of rdata in the mslab that aren't in
+ * the sslab.
+ */
+ for (i = 0; i < mcount; i++) {
+ unsigned char *mrdatabegin = mcurrent;
+ rdata_from_slab(&mcurrent, rdclass, type, &mrdata);
+ scurrent = sstart;
+ for (count = 0; count < scount; count++) {
+ dns_rdata_reset(&srdata);
+ rdata_from_slab(&scurrent, rdclass, type, &srdata);
+ if (dns_rdata_compare(&mrdata, &srdata) == 0) {
+ break;
+ }
+ }
+ if (count == scount) {
+ /*
+ * This rdata isn't in the sslab, and thus isn't
+ * being subtracted.
+ */
+ tlength += (unsigned int)(mcurrent - mrdatabegin);
+ tcount++;
+ } else {
+ rcount++;
+ }
+ dns_rdata_reset(&mrdata);
+ }
+
+#if DNS_RDATASET_FIXED
+ tlength += (4 * tcount);
+#endif /* if DNS_RDATASET_FIXED */
+
+ /*
+ * Check that all the records originally existed. The numeric
+ * check only works as rdataslabs do not contain duplicates.
+ */
+ if (((flags & DNS_RDATASLAB_EXACT) != 0) && (rcount != scount)) {
+ return (DNS_R_NOTEXACT);
+ }
+
+ /*
+ * Don't continue if the new rdataslab would be empty.
+ */
+ if (tcount == 0) {
+ return (DNS_R_NXRRSET);
+ }
+
+ /*
+ * If nothing is going to change, we can stop.
+ */
+ if (rcount == 0) {
+ return (DNS_R_UNCHANGED);
+ }
+
+ /*
+ * Copy the reserved area from the mslab.
+ */
+ tstart = isc_mem_get(mctx, tlength);
+ memmove(tstart, mslab, reservelen);
+ tcurrent = tstart + reservelen;
+#if DNS_RDATASET_FIXED
+ offsetbase = tcurrent;
+
+ offsettable = isc_mem_get(mctx, mcount * sizeof(unsigned int));
+ memset(offsettable, 0, mcount * sizeof(unsigned int));
+#endif /* if DNS_RDATASET_FIXED */
+
+ /*
+ * Write the new count.
+ */
+ *tcurrent++ = (tcount & 0xff00) >> 8;
+ *tcurrent++ = (tcount & 0x00ff);
+
+#if DNS_RDATASET_FIXED
+ tcurrent += (4 * tcount);
+#endif /* if DNS_RDATASET_FIXED */
+
+ /*
+ * Copy the parts of mslab not in sslab.
+ */
+ mcurrent = mslab + reservelen;
+ mcount = *mcurrent++ * 256;
+ mcount += *mcurrent++;
+#if DNS_RDATASET_FIXED
+ mcurrent += (4 * mcount);
+#endif /* if DNS_RDATASET_FIXED */
+ for (i = 0; i < mcount; i++) {
+ unsigned char *mrdatabegin = mcurrent;
+#if DNS_RDATASET_FIXED
+ order = mcurrent[2] * 256 + mcurrent[3];
+ INSIST(order < mcount);
+#endif /* if DNS_RDATASET_FIXED */
+ rdata_from_slab(&mcurrent, rdclass, type, &mrdata);
+ scurrent = sstart;
+ for (count = 0; count < scount; count++) {
+ dns_rdata_reset(&srdata);
+ rdata_from_slab(&scurrent, rdclass, type, &srdata);
+ if (dns_rdata_compare(&mrdata, &srdata) == 0) {
+ break;
+ }
+ }
+ if (count == scount) {
+ /*
+ * This rdata isn't in the sslab, and thus should be
+ * copied to the tslab.
+ */
+ unsigned int length;
+ length = (unsigned int)(mcurrent - mrdatabegin);
+#if DNS_RDATASET_FIXED
+ offsettable[order] = tcurrent - offsetbase;
+#endif /* if DNS_RDATASET_FIXED */
+ memmove(tcurrent, mrdatabegin, length);
+ tcurrent += length;
+ }
+ dns_rdata_reset(&mrdata);
+ }
+
+#if DNS_RDATASET_FIXED
+ fillin_offsets(offsetbase, offsettable, mcount);
+
+ isc_mem_put(mctx, offsettable, mcount * sizeof(unsigned int));
+#endif /* if DNS_RDATASET_FIXED */
+
+ INSIST(tcurrent == tstart + tlength);
+
+ *tslabp = tstart;
+
+ return (ISC_R_SUCCESS);
+}
+
+bool
+dns_rdataslab_equal(unsigned char *slab1, unsigned char *slab2,
+ unsigned int reservelen) {
+ unsigned char *current1, *current2;
+ unsigned int count1, count2;
+ unsigned int length1, length2;
+
+ current1 = slab1 + reservelen;
+ count1 = *current1++ * 256;
+ count1 += *current1++;
+
+ current2 = slab2 + reservelen;
+ count2 = *current2++ * 256;
+ count2 += *current2++;
+
+ if (count1 != count2) {
+ return (false);
+ }
+
+#if DNS_RDATASET_FIXED
+ current1 += (4 * count1);
+ current2 += (4 * count2);
+#endif /* if DNS_RDATASET_FIXED */
+
+ while (count1 > 0) {
+ length1 = *current1++ * 256;
+ length1 += *current1++;
+
+ length2 = *current2++ * 256;
+ length2 += *current2++;
+
+#if DNS_RDATASET_FIXED
+ current1 += 2;
+ current2 += 2;
+#endif /* if DNS_RDATASET_FIXED */
+
+ if (length1 != length2 ||
+ memcmp(current1, current2, length1) != 0)
+ {
+ return (false);
+ }
+
+ current1 += length1;
+ current2 += length1;
+
+ count1--;
+ }
+ return (true);
+}
+
+bool
+dns_rdataslab_equalx(unsigned char *slab1, unsigned char *slab2,
+ unsigned int reservelen, dns_rdataclass_t rdclass,
+ dns_rdatatype_t type) {
+ unsigned char *current1, *current2;
+ unsigned int count1, count2;
+ dns_rdata_t rdata1 = DNS_RDATA_INIT;
+ dns_rdata_t rdata2 = DNS_RDATA_INIT;
+
+ current1 = slab1 + reservelen;
+ count1 = *current1++ * 256;
+ count1 += *current1++;
+
+ current2 = slab2 + reservelen;
+ count2 = *current2++ * 256;
+ count2 += *current2++;
+
+ if (count1 != count2) {
+ return (false);
+ }
+
+#if DNS_RDATASET_FIXED
+ current1 += (4 * count1);
+ current2 += (4 * count2);
+#endif /* if DNS_RDATASET_FIXED */
+
+ while (count1-- > 0) {
+ rdata_from_slab(&current1, rdclass, type, &rdata1);
+ rdata_from_slab(&current2, rdclass, type, &rdata2);
+ if (dns_rdata_compare(&rdata1, &rdata2) != 0) {
+ return (false);
+ }
+ dns_rdata_reset(&rdata1);
+ dns_rdata_reset(&rdata2);
+ }
+ return (true);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 18:11:06 +0000