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Merged the private functions compress_add and compress_find into

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dns_compress_add and dns_compress_findglobal.
This commit is contained in:
Brian Wellington
2000-12-29 19:38:50 +00:00
parent bb88eab95f
commit dacf0cc454
1 changed files with 89 additions and 116 deletions
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205
lib/dns/compress.c
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@@ -15,7 +15,7 @@
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: compress.c,v 1.38 2000/12/29 18:49:36 bwelling Exp $ */
/* $Id: compress.c,v 1.39 2000/12/29 19:38:50 bwelling Exp $ */
#define DNS_NAME_USEINLINE 1
@@ -36,13 +36,6 @@
#define DCTX_MAGIC 0x44435458U /* DCTX */
#define VALID_DCTX(x) ISC_MAGIC_VALID(x, DCTX_MAGIC)
static isc_boolean_t
compress_find(dns_compress_t *cctx, dns_name_t *name, dns_name_t *prefix,
dns_name_t *suffix, isc_uint16_t *offset);
static void
compress_add(dns_compress_t *cctx, dns_name_t *name, isc_uint16_t offset);
/***
*** Compression
***/
@@ -109,24 +102,110 @@ dns_compress_getedns(dns_compress_t *cctx) {
return (cctx->edns);
}
/*
* 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, dns_name_t *name,
dns_name_t *prefix, dns_name_t *suffix,
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);
return (compress_find(cctx, name, prefix, suffix, offset));
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)
{
dns_name_fromregion(&nname, &node->r);
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);
dns_name_clone(&tname, suffix);
dns_name_getlabelsequence(name, 0, n, prefix);
*offset = node->offset;
return (ISC_TRUE);
}
void
dns_compress_add(dns_compress_t *cctx, dns_name_t *name, isc_uint16_t offset) {
dns_name_t tname, nname;
dns_label_t label;
unsigned int start;
unsigned int n;
unsigned int hash;
dns_compressnode_t *node;
REQUIRE(VALID_CCTX(cctx));
REQUIRE(dns_name_isabsolute(name));
compress_add(cctx, name, offset);
dns_name_init(&tname, NULL);
dns_name_init(&nname, NULL);
n = dns_name_countlabels(name);
start = 0;
while (n > 1) {
if (offset >= 0x4000)
break;
dns_name_getlabelsequence(name, start, n, &tname);
hash = dns_name_hash(&tname, ISC_FALSE) %
DNS_COMPRESS_TABLESIZE;
/*
* Look for the name in the hash bucket. If it's there,
* we're done.
*/
for (node = cctx->table[hash]; node != NULL; node = node->next)
{
dns_name_fromregion(&nname, &node->r);
if (dns_name_equal(&nname, &tname))
return;
}
/*
* It's not there. Create a new node and add it.
*/
if (cctx->count < DNS_COMPRESS_INITIALNODES)
node = &cctx->initialnodes[cctx->count];
else {
node = isc_mem_get(cctx->mctx,
sizeof(dns_compressnode_t));
if (node == NULL)
return;
}
node->count = cctx->count++;
node->offset = offset;
dns_name_toregion(&tname, &node->r);
node->next = cctx->table[hash];
cctx->table[hash] = node;
dns_name_getlabel(&tname, 0, &label);
offset += label.length;
start++;
n--;
}
}
void
@@ -216,109 +295,3 @@ dns_decompress_type(dns_decompress_t *dctx) {
return (dctx->type);
}
/***
*** Private
***/
/*
* Add the labels in prefix to the compression table.
*/
static void
compress_add(dns_compress_t *cctx, dns_name_t *name, isc_uint16_t offset) {
dns_name_t tname, nname;
dns_label_t label;
unsigned int start;
unsigned int n;
unsigned int hash;
dns_compressnode_t *node;
dns_name_init(&tname, NULL);
dns_name_init(&nname, NULL);
n = dns_name_countlabels(name);
start = 0;
while (n > 1) {
if (offset >= 0x4000)
break;
dns_name_getlabelsequence(name, start, n, &tname);
hash = dns_name_hash(&tname, ISC_FALSE) %
DNS_COMPRESS_TABLESIZE;
/*
* Look for the name in the hash bucket. If it's there,
* we're done.
*/
for (node = cctx->table[hash]; node != NULL; node = node->next)
{
dns_name_fromregion(&nname, &node->r);
if (dns_name_equal(&nname, &tname))
return;
}
/*
* It's not there. Create a new node and add it.
*/
if (cctx->count < DNS_COMPRESS_INITIALNODES)
node = &cctx->initialnodes[cctx->count];
else {
node = isc_mem_get(cctx->mctx,
sizeof(dns_compressnode_t));
if (node == NULL)
return;
}
node->count = cctx->count++;
node->offset = offset;
dns_name_toregion(&tname, &node->r);
node->next = cctx->table[hash];
cctx->table[hash] = node;
dns_name_getlabel(&tname, 0, &label);
offset += label.length;
start++;
n--;
}
}
/*
* 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.
*/
static isc_boolean_t
compress_find(dns_compress_t *cctx,
dns_name_t *name, dns_name_t *prefix,
dns_name_t *suffix, isc_uint16_t *offset)
{
dns_name_t tname, nname;
dns_compressnode_t *node = NULL;
unsigned int labels, hash, n;
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)
{
dns_name_fromregion(&nname, &node->r);
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);
dns_name_clone(&tname, suffix);
dns_name_getlabelsequence(name, 0, n, prefix);
*offset = node->offset;
return (ISC_TRUE);
}