rdataslab.c revision f9f2e770a992cb0ed2234b2f985162273059c6d3
/*
* Copyright (C) 1999-2001 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
* INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: rdataslab.c,v 1.31 2002/02/21 23:51:49 bwelling Exp $ */
#include <config.h>
#include <stdlib.h>
#include <isc/mem.h>
#include <isc/region.h>
#include <isc/string.h> /* Required for HP/UX (and others?) */
#include <isc/util.h>
#include <dns/result.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdataslab.h>
/* Note: the "const void *" are just to make qsort happy. */
static int
compare_rdata(const void *p1, const void *p2) {
const dns_rdata_t *rdata1 = p1;
const dns_rdata_t *rdata2 = p2;
return (dns_rdata_compare(rdata1, rdata2));
}
isc_result_t
dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
isc_region_t *region, unsigned int reservelen)
{
dns_rdata_t *rdatas;
unsigned char *rawbuf;
unsigned int buflen;
isc_result_t result;
unsigned int nitems;
unsigned int nalloc;
unsigned int i;
buflen = reservelen + 2;
nalloc = dns_rdataset_count(rdataset);
nitems = nalloc;
if (nitems == 0)
return (ISC_R_FAILURE);
rdatas = isc_mem_get(mctx, nalloc * sizeof(dns_rdata_t));
if (rdatas == NULL)
return (ISC_R_NOMEMORY);
/*
* Save all of the rdata members into an array.
*/
result = dns_rdataset_first(rdataset);
if (result != ISC_R_SUCCESS)
goto free_rdatas;
for (i = 0; i < nalloc && result == ISC_R_SUCCESS; i++) {
INSIST(result == ISC_R_SUCCESS);
dns_rdata_init(&rdatas[i]);
dns_rdataset_current(rdataset, &rdatas[i]);
result = dns_rdataset_next(rdataset);
}
if (result != ISC_R_NOMORE)
goto free_rdatas;
if (i != nalloc) {
/*
* Somehow we iterated over fewer rdatas than
* dns_rdataset_count() said there were!
*/
result = ISC_R_FAILURE;
goto free_rdatas;
}
qsort(rdatas, nalloc, sizeof(dns_rdata_t), 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 2 for each rdata length, and then the rdata itself.
*/
for (i = 1; i < nalloc; i++) {
if (compare_rdata(&rdatas[i-1], &rdatas[i]) == 0) {
rdatas[i-1].data = NULL;
rdatas[i-1].length = 0;
nitems--;
} else
buflen += (2 + rdatas[i-1].length);
}
/*
* Don't forget the last item!
*/
buflen += (2 + rdatas[i-1].length);
/*
* 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 (rawbuf == NULL) {
result = ISC_R_NOMEMORY;
goto free_rdatas;
}
region->base = rawbuf;
region->length = buflen;
rawbuf += reservelen;
*rawbuf++ = (nitems & 0xff00) >> 8;
*rawbuf++ = (nitems & 0x00ff);
for (i = 0; i < nalloc; i++) {
if (rdatas[i].data == NULL)
continue;
*rawbuf++ = (rdatas[i].length & 0xff00) >> 8;
*rawbuf++ = (rdatas[i].length & 0x00ff);
memcpy(rawbuf, rdatas[i].data, rdatas[i].length);
rawbuf += rdatas[i].length;
}
result = ISC_R_SUCCESS;
free_rdatas:
isc_mem_put(mctx, rdatas, nalloc * sizeof(dns_rdata_t));
return (result);
}
static void
rdataset_disassociate(dns_rdataset_t *rdataset) {
UNUSED(rdataset);
}
static isc_result_t
rdataset_first(dns_rdataset_t *rdataset) {
unsigned char *raw = rdataset->private3;
unsigned int count;
count = raw[0] * 256 + raw[1];
if (count == 0) {
rdataset->private5 = NULL;
return (ISC_R_NOMORE);
}
raw += 2;
/*
* The private4 field is the number of rdata beyond the cursor
* position, so we decrement the total count by one before storing
* it.
*/
count--;
rdataset->private4 = (void *)count;
rdataset->private5 = raw;
return (ISC_R_SUCCESS);
}
static isc_result_t
rdataset_next(dns_rdataset_t *rdataset) {
unsigned int count;
unsigned int length;
unsigned char *raw;
count = (unsigned int)rdataset->private4;
if (count == 0)
return (ISC_R_NOMORE);
count--;
rdataset->private4 = (void *)count;
raw = rdataset->private5;
length = raw[0] * 256 + raw[1];
raw += length + 2;
rdataset->private5 = raw;
return (ISC_R_SUCCESS);
}
static void
rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata) {
unsigned char *raw = rdataset->private5;
isc_region_t r;
REQUIRE(raw != NULL);
r.length = raw[0] * 256 + raw[1];
raw += 2;
r.base = raw;
dns_rdata_fromregion(rdata, rdataset->rdclass, rdataset->type, &r);
}
static void
rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target) {
*target = *source;
/*
* Reset iterator state.
*/
target->private4 = NULL;
target->private5 = NULL;
}
static unsigned int
rdataset_count(dns_rdataset_t *rdataset) {
unsigned char *raw = rdataset->private3;
unsigned int count;
count = raw[0] * 256 + raw[1];
return (count);
}
static dns_rdatasetmethods_t rdataset_methods = {
rdataset_disassociate,
rdataset_first,
rdataset_next,
rdataset_current,
rdataset_clone,
rdataset_count
};
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)
{
REQUIRE(slab != NULL);
REQUIRE(!dns_rdataset_isassociated(rdataset));
rdataset->methods = &rdataset_methods;
rdataset->rdclass = rdclass;
rdataset->type = rdtype;
rdataset->covers = covers;
rdataset->ttl = ttl;
rdataset->trust = 0;
rdataset->private1 = NULL;
rdataset->private2 = NULL;
rdataset->private3 = slab + reservelen;
/*
* Reset iterator state.
*/
rdataset->private4 = NULL;
rdataset->private5 = NULL;
}
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++;
while (count > 0) {
count--;
length = *current++ * 256;
length += *current++;
current += length;
}
return ((unsigned int)(current - slab));
}
/*
* 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 inline 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;
region.length = *tcurrent++ * 256;
region.length += *tcurrent++;
region.base = tcurrent;
tcurrent += region.length;
dns_rdata_fromregion(rdata, rdclass, type, &region);
*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 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)
{
unsigned int count, i;
unsigned char *current;
dns_rdata_t trdata = DNS_RDATA_INIT;
current = slab + reservelen;
count = *current++ * 256;
count += *current++;
for (i = 0; i < count; i++) {
rdata_from_slab(&current, rdclass, type, &trdata);
if (dns_rdata_compare(&trdata, rdata) == 0)
return (ISC_TRUE);
dns_rdata_reset(&trdata);
}
return (ISC_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;
unsigned int ocount, ncount, count, olength, tlength, tcount, length;
isc_region_t nregion;
dns_rdata_t ordata = DNS_RDATA_INIT;
dns_rdata_t nrdata = DNS_RDATA_INIT;
isc_boolean_t added_something = ISC_FALSE;
unsigned int oadded = 0;
unsigned int nadded = 0;
unsigned int nncount = 0;
/*
* 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++;
ostart = ocurrent;
ncurrent = nslab + reservelen;
ncount = *ncurrent++ * 256;
ncount += *ncurrent++;
INSIST(ocount > 0 && ncount > 0);
/*
* 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++;
olength += length + 2;
ocurrent += length;
}
/*
* 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 {
nregion.length = *ncurrent++ * 256;
nregion.length += *ncurrent++;
nregion.base = ncurrent;
dns_rdata_init(&nrdata);
dns_rdata_fromregion(&nrdata, rdclass, type, &nregion);
if (!rdata_in_slab(oslab, reservelen, rdclass, type, &nrdata))
{
/*
* This rdata isn't in the old slab.
*/
tlength += nregion.length + 2;
tcount++;
nncount++;
added_something = ISC_TRUE;
}
ncurrent += nregion.length;
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);
}
/*
* Copy the reserved area from the new slab.
*/
tstart = isc_mem_get(mctx, tlength);
if (tstart == NULL)
return (ISC_R_NOMEMORY);
memcpy(tstart, nslab, reservelen);
tcurrent = tstart + reservelen;
/*
* Write the new count.
*/
*tcurrent++ = (tcount & 0xff00) >> 8;
*tcurrent++ = (tcount & 0x00ff);
/*
* Merge the two slabs.
*/
ocurrent = ostart;
INSIST(ocount != 0);
rdata_from_slab(&ocurrent, rdclass, type, &ordata);
ncurrent = nslab + reservelen + 2;
if (ncount > 0) {
do {
dns_rdata_reset(&nrdata);
rdata_from_slab(&ncurrent, rdclass, type, &nrdata);
} while (rdata_in_slab(oslab, reservelen, rdclass,
type, &nrdata));
}
while (oadded < ocount || nadded < ncount) {
isc_boolean_t fromold;
if (oadded == ocount)
fromold = ISC_FALSE;
else if (nadded == ncount)
fromold = ISC_TRUE;
else
fromold = ISC_TF(compare_rdata(&ordata, &nrdata) < 0);
if (fromold) {
length = ordata.length;
*tcurrent++ = (length & 0xff00) >> 8;
*tcurrent++ = (length & 0x00ff);
memcpy(tcurrent, ordata.data, length);
tcurrent += length;
oadded++;
if (oadded < ocount) {
dns_rdata_reset(&ordata);
rdata_from_slab(&ocurrent, rdclass, type,
&ordata);
}
} else {
length = nrdata.length;
*tcurrent++ = (length & 0xff00) >> 8;
*tcurrent++ = (length & 0x00ff);
memcpy(tcurrent, nrdata.data, length);
tcurrent += length;
nadded++;
if (nadded < ncount) {
do {
dns_rdata_reset(&nrdata);
rdata_from_slab(&ncurrent, rdclass,
type, &nrdata);
} while (rdata_in_slab(oslab, reservelen,
rdclass, type,
&nrdata));
}
}
}
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;
dns_rdata_t srdata = DNS_RDATA_INIT;
dns_rdata_t mrdata = DNS_RDATA_INIT;
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++;
sstart = 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;
/*
* Add in the length of rdata in the mslab that aren't in
* the sslab.
*/
do {
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 += mcurrent - mrdatabegin;
tcount++;
} else
rcount++;
mcount--;
dns_rdata_reset(&mrdata);
} while (mcount > 0);
/*
* 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);
if (tstart == NULL)
return (ISC_R_NOMEMORY);
memcpy(tstart, mslab, reservelen);
tcurrent = tstart + reservelen;
/*
* Write the new count.
*/
*tcurrent++ = (tcount & 0xff00) >> 8;
*tcurrent++ = (tcount & 0x00ff);
/*
* Copy the parts of mslab not in sslab.
*/
mcurrent = mslab + reservelen;
mcount = *mcurrent++ * 256;
mcount += *mcurrent++;
do {
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 should be
* copied to the tslab.
*/
unsigned int length = mcurrent - mrdatabegin;
memcpy(tcurrent, mrdatabegin, length);
tcurrent += length;
}
dns_rdata_reset(&mrdata);
mcount--;
} while (mcount > 0);
INSIST(tcurrent == tstart + tlength);
*tslabp = tstart;
return (ISC_R_SUCCESS);
}
isc_boolean_t
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 (ISC_FALSE);
while (count1 > 0) {
length1 = *current1++ * 256;
length1 += *current1++;
length2 = *current2++ * 256;
length2 += *current2++;
if (length1 != length2 ||
memcmp(current1, current2, length1) != 0)
return (ISC_FALSE);
current1 += length1;
current2 += length1;
count1--;
}
return (ISC_TRUE);
}