/*
* Find the longest match of name in the table.
* If match is found return ISC_TRUE. prefix, suffix and offset are updated.
* If no match is found return ISC_FALSE.
*/
isc_boolean_t
dns_compress_findglobal(dns_compress_t *cctx, const dns_name_t *name,
dns_name_t *prefix, isc_uint16_t *offset)
{
dns_name_t tname, nname;
dns_compressnode_t *node = NULL;
unsigned int labels, hash, n;
REQUIRE(VALID_CCTX(cctx));
REQUIRE(dns_name_isabsolute(name) == ISC_TRUE);
REQUIRE(offset != NULL);
if (cctx->count == 0)
return (ISC_FALSE);
labels = dns_name_countlabels(name);
INSIST(labels > 0);
dns_name_init(&tname, NULL);
dns_name_init(&nname, NULL);
for (n = 0; n < labels - 1; n++) {
dns_name_getlabelsequence(name, n, labels - n, &tname);
hash = dns_name_hash(&tname, ISC_FALSE) %
DNS_COMPRESS_TABLESIZE;
for (node = cctx->table[hash]; node != NULL; node = node->next)
{
NODENAME(node, &nname);
if ((cctx->allowed & DNS_COMPRESS_CASESENSITIVE) != 0) {
if (dns_name_caseequal(&nname, &tname))
break;
} else {
if (dns_name_equal(&nname, &tname))
break;
}
}
if (node != NULL)
break;
}
/*
* If node == NULL, we found no match at all.
*/
if (node == NULL)
return (ISC_FALSE);
if (n == 0)
dns_name_reset(prefix);
else
dns_name_getlabelsequence(name, 0, n, prefix);
*offset = node->offset;
return (ISC_TRUE);
}
/*
* Find the longest match of name in the table.
* If match is found return ISC_TRUE. prefix, suffix and offset are updated.
* If no match is found return ISC_FALSE.
*/
isc_boolean_t
dns_compress_findglobal(dns_compress_t *cctx, const dns_name_t *name,
dns_name_t *prefix, isc_uint16_t *offset)
{
dns_name_t tname;
dns_compressnode_t *node = NULL;
unsigned int labels, i, n;
unsigned int numlabels;
unsigned char *p;
REQUIRE(VALID_CCTX(cctx));
REQUIRE(dns_name_isabsolute(name) == ISC_TRUE);
REQUIRE(offset != NULL);
if (ISC_UNLIKELY((cctx->allowed & DNS_COMPRESS_ENABLED) == 0))
return (ISC_FALSE);
if (cctx->count == 0)
return (ISC_FALSE);
labels = dns_name_countlabels(name);
INSIST(labels > 0);
dns_name_init(&tname, NULL);
numlabels = labels > 3U ? 3U : labels;
p = name->ndata;
for (n = 0; n < numlabels - 1; n++) {
unsigned char ch, llen;
unsigned int firstoffset, length;
firstoffset = (unsigned int)(p - name->ndata);
length = name->length - firstoffset;
/*
* We calculate the table index using the first
* character in the first label of the suffix name.
*/
ch = p[1];
i = tableindex[ch];
if (ISC_LIKELY((cctx->allowed &
DNS_COMPRESS_CASESENSITIVE) != 0))
{
for (node = cctx->table[i];
node != NULL;
node = node->next)
{
if (ISC_UNLIKELY(node->name.length != length))
continue;
if (ISC_LIKELY(memcmp(node->name.ndata,
p, length) == 0))
goto found;
}
} else {
for (node = cctx->table[i];
node != NULL;
node = node->next)
{
unsigned int l, count;
unsigned char c;
unsigned char *label1, *label2;
if (ISC_UNLIKELY(node->name.length != length))
continue;
l = labels - n;
if (ISC_UNLIKELY(node->name.labels != l))
continue;
label1 = node->name.ndata;
label2 = p;
while (ISC_LIKELY(l-- > 0)) {
count = *label1++;
if (count != *label2++)
goto cont1;
/* no bitstring support */
INSIST(count <= 63);
/* Loop unrolled for performance */
while (ISC_LIKELY(count > 3)) {
c = maptolower[label1[0]];
if (c != maptolower[label2[0]])
goto cont1;
c = maptolower[label1[1]];
if (c != maptolower[label2[1]])
goto cont1;
c = maptolower[label1[2]];
if (c != maptolower[label2[2]])
goto cont1;
c = maptolower[label1[3]];
if (c != maptolower[label2[3]])
goto cont1;
count -= 4;
label1 += 4;
label2 += 4;
}
while (ISC_LIKELY(count-- > 0)) {
c = maptolower[*label1++];
if (c != maptolower[*label2++])
goto cont1;
}
}
break;
cont1:
continue;
}
}
if (node != NULL)
break;
llen = *p;
p += llen + 1;
}
found:
/*
* If node == NULL, we found no match at all.
*/
if (node == NULL)
return (ISC_FALSE);
if (n == 0)
dns_name_reset(prefix);
else
dns_name_getlabelsequence(name, 0, n, prefix);
*offset = (node->offset & 0x7fff);
return (ISC_TRUE);
}
static int setup_follow_possible_cname(dnskey_glob *gs,
dnskey_lookup *dl)
{
int ret;
dl->cname_count++;
/*
* If we are on an odd cycle (starting with 1),
* then convert to dns_name_t so that we can compare later.
*
* This detects loops in the CNAME processing, while still
* allowing an arbitrary number of CNAMEs to be followed.
*/
if(dl->cname_count & 1)
{
isc_buffer_t fqdn_src;
isc_buffer_t *fqdn_dst;
if(dl->cname_count == 1)
{
memset(&dl->last_cname, 0, sizeof(dl->last_cname));
dns_name_init(&dl->last_cname, NULL);
}
else
{
dns_name_reset(&dl->last_cname);
}
fqdn_dst=NULL;
isc_buffer_init(&fqdn_src, dl->fqdn, strlen(dl->fqdn));
isc_buffer_add(&fqdn_src, strlen(dl->fqdn));
isc_buffer_allocate(gs->iscmem, &fqdn_dst, strlen(dl->fqdn)+1);
#if 0
if(dl->last_cname_used) {
dns_name_free(&dl->last_cname, gs->iscmem);
}
#endif
dl->last_cname_used = 1;
if(dns_name_fromtext(&dl->last_cname,
&fqdn_src,
NULL,
1,
fqdn_dst) != ISC_R_SUCCESS) {
return 0;
}
/* something else here ? */
}
ret = lwres_getrrsetbyname_init(dl->fqdn, dns_rdataclass_in,
dns_rdatatype_cname, 0 /*flags*/,
gs->lwctx,
&dl->las);
if(ret != ERRSET_SUCCESS) {
return 0;
}
lwres_getrrsetbyname_xmit(gs->lwctx, &dl->las);
return 1;
}