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Optimise sort_rrset for the case where the RR type no canonicalisation.

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Simon Kelley
2021-01-22 18:50:43 +00:00
parent 12af2b171d
commit 8ebdc364af
1 changed files with 49 additions and 22 deletions
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71
src/dnssec.c
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@@ -334,37 +334,64 @@ static int sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int
if (!CHECK_LEN(header, state2.ip, plen, rdlen2))
return rrsetidx; /* short packet */
state2.end = state2.ip + rdlen2;
while (1)
{
int ok1, ok2;
ok1 = get_rdata(header, plen, &state1);
ok2 = get_rdata(header, plen, &state2);
if (!ok1 && !ok2)
/* If the RR has no names in it then canonicalisation
is the identity function and we can compare
the RRs directly. If not we compare the
canonicalised RRs one byte at a time. */
if (*rr_desc == (u16)-1)
{
int rdmin = rdlen1 > rdlen2 ? rdlen2 : rdlen1;
int cmp = memcmp(state1.ip, state2.ip, rdmin);
if (cmp > 0 || (cmp == 0 && rdlen1 > rdmin))
{
unsigned char *tmp = rrset[i+1];
rrset[i+1] = rrset[i];
rrset[i] = tmp;
swap = 1;
}
else if (cmp == 0 && (rdlen1 == rdlen2))
{
/* Two RRs are equal, remove one copy. RFC 4034, para 6.3 */
for (j = i+1; j < rrsetidx-1; j++)
rrset[j] = rrset[j+1];
rrsetidx--;
i--;
break;
}
else if (ok1 && (!ok2 || *state1.op > *state2.op))
{
unsigned char *tmp = rrset[i+1];
rrset[i+1] = rrset[i];
rrset[i] = tmp;
swap = 1;
break;
}
else if (ok2 && (!ok1 || *state2.op > *state1.op))
break;
/* arrive here when bytes are equal, go round the loop again
and compare the next ones. */
}
else
/* Comparing canonicalised RRs, byte-at-a-time. */
while (1)
{
int ok1, ok2;
ok1 = get_rdata(header, plen, &state1);
ok2 = get_rdata(header, plen, &state2);
if (!ok1 && !ok2)
{
/* Two RRs are equal, remove one copy. RFC 4034, para 6.3 */
for (j = i+1; j < rrsetidx-1; j++)
rrset[j] = rrset[j+1];
rrsetidx--;
i--;
break;
}
else if (ok1 && (!ok2 || *state1.op > *state2.op))
{
unsigned char *tmp = rrset[i+1];
rrset[i+1] = rrset[i];
rrset[i] = tmp;
swap = 1;
break;
}
else if (ok2 && (!ok1 || *state2.op > *state1.op))
break;
/* arrive here when bytes are equal, go round the loop again
and compare the next ones. */
}
}
} while (swap);