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mirror of https://gitlab.isc.org/isc-projects/bind9 synced 2025-08-30 14:07:59 +00:00

fix and simplify dns_rdataset_equal() and _equalx()

if both rdataslabs being compared have zero length, return true.

also, since these functions are only ever called on slabheaders
with sizeof(dns_slabheader_t) as the reserve length, we can
simplify the API: remove the reservelen argument, and pass the
slabs as type dns_slabheader_t * instead of unsigned char *.
This commit is contained in:
Evan Hunt 2025-02-06 15:50:52 -08:00
parent 15fe68e50d
commit 4601d4299a
3 changed files with 16 additions and 20 deletions

View File

@ -251,8 +251,7 @@ dns_rdataslab_subtract(unsigned char *mslab, unsigned char *sslab,
*/
bool
dns_rdataslab_equal(unsigned char *slab1, unsigned char *slab2,
unsigned int reservelen);
dns_rdataslab_equal(dns_slabheader_t *slab1, dns_slabheader_t *slab2);
/*%<
* Compare two rdataslabs for equality. This does _not_ do a full
* DNSSEC comparison.
@ -264,9 +263,8 @@ dns_rdataslab_equal(unsigned char *slab1, unsigned char *slab2,
*\li true if the slabs are equal, false otherwise.
*/
bool
dns_rdataslab_equalx(unsigned char *slab1, unsigned char *slab2,
unsigned int reservelen, dns_rdataclass_t rdclass,
dns_rdatatype_t type);
dns_rdataslab_equalx(dns_slabheader_t *slab1, dns_slabheader_t *slab2,
dns_rdataclass_t rdclass, dns_rdatatype_t type);
/*%<
* Compare two rdataslabs for DNSSEC equality.
*

View File

@ -2884,9 +2884,7 @@ find_header:
if (ACTIVE(header, now) && header->type == dns_rdatatype_ns &&
EXISTS(header) && EXISTS(newheader) &&
header->trust >= newheader->trust &&
dns_rdataslab_equalx((unsigned char *)header,
(unsigned char *)newheader,
(unsigned int)(sizeof(*newheader)),
dns_rdataslab_equalx(header, newheader,
qpdb->common.rdclass,
(dns_rdatatype_t)header->type))
{
@ -2950,9 +2948,7 @@ find_header:
header->type == DNS_SIGTYPE(dns_rdatatype_ds)) &&
EXISTS(header) && EXISTS(newheader) &&
header->trust >= newheader->trust &&
dns_rdataslab_equal((unsigned char *)header,
(unsigned char *)newheader,
(unsigned int)(sizeof(*newheader))))
dns_rdataslab_equal(header, newheader))
{
/*
* Honour the new ttl if it is less than the

View File

@ -714,20 +714,21 @@ dns_rdataslab_subtract(unsigned char *mslab, unsigned char *sslab,
}
bool
dns_rdataslab_equal(unsigned char *slab1, unsigned char *slab2,
unsigned int reservelen) {
dns_rdataslab_equal(dns_slabheader_t *slab1, dns_slabheader_t *slab2) {
unsigned char *current1 = NULL, *current2 = NULL;
unsigned int count1, count2;
unsigned int length1, length2;
current1 = slab1 + reservelen;
current1 = (unsigned char *)slab1 + sizeof(dns_slabheader_t);
count1 = get_uint16(current1);
current2 = slab2 + reservelen;
current2 = (unsigned char *)slab2 + sizeof(dns_slabheader_t);
count2 = get_uint16(current2);
if (count1 != count2) {
return false;
} else if (count1 == 0) {
return true;
}
while (count1-- > 0) {
@ -747,22 +748,23 @@ dns_rdataslab_equal(unsigned char *slab1, unsigned char *slab2,
}
bool
dns_rdataslab_equalx(unsigned char *slab1, unsigned char *slab2,
unsigned int reservelen, dns_rdataclass_t rdclass,
dns_rdatatype_t type) {
dns_rdataslab_equalx(dns_slabheader_t *slab1, dns_slabheader_t *slab2,
dns_rdataclass_t rdclass, dns_rdatatype_t type) {
unsigned char *current1 = NULL, *current2 = NULL;
unsigned int count1, count2;
dns_rdata_t rdata1 = DNS_RDATA_INIT;
dns_rdata_t rdata2 = DNS_RDATA_INIT;
current1 = slab1 + reservelen;
current1 = (unsigned char *)slab1 + sizeof(dns_slabheader_t);
count1 = get_uint16(current1);
current2 = slab2 + reservelen;
current2 = (unsigned char *)slab2 + sizeof(dns_slabheader_t);
count2 = get_uint16(current2);
if (count1 != count2) {
return false;
} else if (count1 == 0) {
return true;
}
while (count1-- > 0) {