* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
-/* $Id: compress.c,v 1.36 2000/11/14 23:29:49 bwelling Exp $ */
+/* $Id: compress.c,v 1.36.4.1 2001/01/06 01:33:31 gson Exp $ */
#define DNS_NAME_USEINLINE 1
#define DCTX_MAGIC 0x44435458U /* DCTX */
#define VALID_DCTX(x) ISC_MAGIC_VALID(x, DCTX_MAGIC)
-static void
-free_offset(void *offset, void *mctx);
-
-static isc_boolean_t
-compress_find(dns_rbt_t *root, dns_name_t *name, dns_name_t *prefix,
- dns_name_t *suffix, isc_uint16_t *offset,
- isc_buffer_t *workspace);
-
-static void
-compress_add(dns_rbt_t *root, dns_name_t *prefix, dns_name_t *suffix,
- isc_uint16_t offset, isc_boolean_t global16, isc_mem_t *mctx);
-
/***
*** Compression
***/
isc_result_t
dns_compress_init(dns_compress_t *cctx, int edns, isc_mem_t *mctx) {
- isc_result_t result;
+ unsigned int i;
REQUIRE(cctx != NULL);
REQUIRE(mctx != NULL);
cctx->allowed = 0;
- cctx->rdata = 0;
- cctx->global16 = ISC_FALSE;
cctx->edns = edns;
- cctx->global = NULL;
- result = dns_rbt_create(mctx, free_offset, mctx, &cctx->global);
- if (result != ISC_R_SUCCESS)
- return (result);
+ for (i = 0; i < DNS_COMPRESS_TABLESIZE; i++)
+ cctx->table[i] = NULL;
cctx->mctx = mctx;
+ cctx->count = 0;
cctx->magic = CCTX_MAGIC;
return (ISC_R_SUCCESS);
}
void
dns_compress_invalidate(dns_compress_t *cctx) {
+ dns_compressnode_t *node;
+ unsigned int i;
REQUIRE(VALID_CCTX(cctx));
cctx->magic = 0;
- if (cctx->global != NULL)
- dns_rbt_destroy(&cctx->global);
+ if (cctx->table != NULL) {
+ for (i = 0; i < DNS_COMPRESS_TABLESIZE; i++) {
+ while (cctx->table[i] != NULL) {
+ node = cctx->table[i];
+ cctx->table[i] = cctx->table[i]->next;
+ if (node->count < DNS_COMPRESS_INITIALNODES)
+ continue;
+ isc_mem_put(cctx->mctx, node,
+ sizeof(dns_compressnode_t));
+ }
+ }
+ }
cctx->allowed = 0;
- cctx->rdata = 0;
- cctx->global16 = ISC_FALSE;
cctx->edns = -1;
}
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, isc_buffer_t *workspace)
+ 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->global, name, prefix, suffix, offset,
- workspace));
+ 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 *prefix,
- dns_name_t *suffix, isc_uint16_t offset)
+dns_compress_add(dns_compress_t *cctx, dns_name_t *name, dns_name_t *prefix,
+ isc_uint16_t offset)
{
+ dns_name_t tname, nname;
+ dns_label_t label;
+ unsigned int start;
+ unsigned int n;
+ unsigned int count;
+ unsigned int hash;
+ dns_compressnode_t *node;
+
REQUIRE(VALID_CCTX(cctx));
+ REQUIRE(dns_name_isabsolute(name));
- compress_add(cctx->global, prefix, suffix, offset,
- cctx->global16, cctx->mctx);
+ dns_name_init(&tname, NULL);
+ dns_name_init(&nname, NULL);
+
+ n = dns_name_countlabels(name);
+ count = dns_name_countlabels(prefix);
+ if (dns_name_isabsolute(prefix))
+ count--;
+ start = 0;
+ while (count > 0) {
+ 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--;
+ count--;
+ }
}
void
dns_compress_rollback(dns_compress_t *cctx, isc_uint16_t offset) {
- dns_rbtnode_t *node;
- dns_fixedname_t foundfixed;
- dns_fixedname_t fullfixed;
- dns_fixedname_t originfixed;
- dns_name_t *foundname;
- dns_name_t *fullname;
- dns_name_t *origin;
- dns_rbtnodechain_t chain;
- isc_result_t result;
+ unsigned int i;
+ dns_compressnode_t *node;
REQUIRE(VALID_CCTX(cctx));
- /*
- * Initalise things.
- */
- dns_fixedname_init(&foundfixed);
- foundname = dns_fixedname_name(&foundfixed);
- dns_fixedname_init(&fullfixed);
- fullname = dns_fixedname_name(&fullfixed);
- dns_fixedname_init(&originfixed);
- origin = dns_fixedname_name(&originfixed);
- dns_rbtnodechain_init(&chain, cctx->mctx);
-
- again:
- result = dns_rbtnodechain_first(&chain, cctx->global, foundname,
- origin);
-
- while (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) {
- result = dns_rbtnodechain_current(&chain, foundname,
- origin, &node);
-
- if (result != ISC_R_SUCCESS)
- break;
-
- if (node->data != NULL &&
- (*(isc_uint16_t*)node->data >= offset)) {
- result = dns_name_concatenate(foundname,
- dns_name_isabsolute(foundname) ?
- NULL : origin,
- fullname, NULL);
-
- if (result != ISC_R_SUCCESS)
- break;
-
- result = dns_rbt_deletename(cctx->global, fullname,
- ISC_FALSE);
- if (result != ISC_R_SUCCESS)
- break;
- /*
- * If the delete is successful the chain is broken.
- */
- dns_rbtnodechain_reset(&chain);
- goto again;
+ for (i = 0; i < DNS_COMPRESS_TABLESIZE; i++) {
+ node = cctx->table[i];
+ while (node != NULL && node->offset >= offset) {
+ cctx->table[i] = node->next;
+ if (node->count >= DNS_COMPRESS_INITIALNODES)
+ isc_mem_put(cctx->mctx, node,
+ sizeof(dns_compressnode_t));
+ cctx->count--;
+ node = cctx->table[i];
}
-
- result = dns_rbtnodechain_next(&chain, foundname, origin);
}
- dns_rbtnodechain_invalidate(&chain);
}
/***
dctx->allowed = DNS_COMPRESS_NONE;
dctx->edns = edns;
dctx->type = type;
- dctx->rdata = 0;
dctx->magic = DCTX_MAGIC;
}
return (dctx->type);
}
-
-/***
- *** Private
- ***/
-
-static void
-free_offset(void *offset, void *mctx) {
- REQUIRE(offset != NULL);
- REQUIRE(mctx != NULL);
- isc_mem_put(mctx, offset, sizeof(isc_uint16_t));
-}
-
-/*
- * Add the labels in prefix to RBT.
- */
-static void
-compress_add(dns_rbt_t *root, dns_name_t *prefix, dns_name_t *suffix,
- isc_uint16_t offset, isc_boolean_t global16, isc_mem_t *mctx)
-{
-
- dns_name_t name;
- dns_name_t full;
- dns_label_t label;
- unsigned int count;
- unsigned int start;
- unsigned int n;
- isc_uint16_t *data;
- isc_result_t result;
- unsigned char buffer[255];
- isc_buffer_t target;
- dns_offsets_t offsets;
-
- count = dns_name_countlabels(prefix);
- if (dns_name_isabsolute(prefix))
- count--;
- start = 0;
- dns_name_init(&full, offsets);
- dns_name_init(&name, NULL);
- isc_buffer_init(&target, buffer, sizeof(buffer));
- result = dns_name_concatenate(prefix, suffix, &full, &target);
- if (result != ISC_R_SUCCESS)
- return;
- n = dns_name_countlabels(&full);
- while (count > 0) {
- if (offset >= 16384 && !global16)
- break;
- dns_name_getlabelsequence(&full, start, n, &name);
- data = isc_mem_get(mctx, sizeof *data);
- if (data == NULL)
- return;
- *data = offset;
- result = dns_rbt_addname(root, &name, data);
- if (result != ISC_R_SUCCESS) {
- isc_mem_put(mctx, data, sizeof *data);
- return;
- }
- dns_name_getlabel(&name, 0, &label);
- offset += label.length;
- start++;
- n--;
- count--;
- }
-}
-
-/*
- * Find the longest match of name in root.
- * 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_rbt_t *root, dns_name_t *name, dns_name_t *prefix,
- dns_name_t *suffix, isc_uint16_t *offset,
- isc_buffer_t *workspace)
-{
- dns_fixedname_t found;
- dns_name_t *foundname;
- dns_name_t tmpprefix;
- dns_name_t tmpsuffix;
- isc_result_t result;
- isc_uint16_t *data = NULL;
- dns_label_t foundlabel;
- dns_label_t namelabel;
- unsigned int foundlabels;
- unsigned int namelabels;
- unsigned int foundbits;
- unsigned int namebits;
- unsigned int bits;
- unsigned int prefixlen;
- unsigned int j;
- unsigned char buf[2 + 256/8]; /* size of biggest bit label */
- dns_bitlabel_t bit;
- isc_region_t region;
-
- dns_fixedname_init(&found);
- foundname = dns_fixedname_name(&found);
- /*
- * Getting rid of the offsets table for foundname improves
- * perfomance, since the offsets table is not needed and maintaining
- * it has costs.
- */
- foundname->offsets = NULL;
- result = dns_rbt_findname(root, name, 0, foundname, (void *)&data);
- if (result != ISC_R_SUCCESS && result != DNS_R_PARTIALMATCH)
- return (ISC_FALSE);
- if (data == NULL) /* root label */
- return (ISC_FALSE);
- /*
- * Do we have to do bit string processing?
- */
- dns_name_getlabel(foundname, 0, &foundlabel);
- foundlabels = dns_name_countlabels(foundname);
- INSIST(foundlabels > 1); /* root labels are not added to tree */
- namelabels = dns_name_countlabels(name);
- if (dns_label_type(&foundlabel) == dns_labeltype_bitstring) {
- dns_name_getlabel(name, namelabels - foundlabels, &namelabel);
- INSIST(dns_label_type(&namelabel) == dns_labeltype_bitstring);
- foundbits = dns_label_countbits(&foundlabel);
- namebits = dns_label_countbits(&namelabel);
- } else
- namebits = foundbits = 0;
-
- if (namebits == foundbits) {
- INSIST(namelabels >= foundlabels);
- prefixlen = namelabels - foundlabels;
- if (prefixlen == 0) {
- prefix->length = 0;
- prefix->labels = 0;
- } else
- dns_name_getlabelsequence(name, 0, prefixlen, prefix);
- result = dns_name_concatenate(NULL, foundname, suffix,
- workspace);
- if (result != ISC_R_SUCCESS)
- return (ISC_FALSE);
- *offset = *data;
- return (ISC_TRUE);
- }
- /*
- * At this stage we have a bit string label to split in two.
- * There is potentially a prefix before this label and definitly
- * a suffix after it (if only the root).
- */
- INSIST(result == DNS_R_PARTIALMATCH);
- result = dns_name_concatenate(NULL, foundname, suffix, workspace);
- if (result != ISC_R_SUCCESS)
- return (ISC_FALSE);
- prefixlen = namelabels - foundlabels;
- dns_name_init(&tmpprefix, NULL);
- dns_name_init(&tmpsuffix, NULL);
- if (prefixlen != 0) {
- dns_name_getlabelsequence(name, 0, prefixlen, &tmpprefix);
- }
- INSIST(namebits > foundbits);
- bits = namebits - foundbits;
- j = 0;
- memset(buf, 0, sizeof buf);
- INSIST((bits / 8 + 1) < sizeof buf);
- /*
- * Copy least significant bits.
- */
- while (j < bits) {
- bit = dns_label_getbit(&namelabel, foundbits + j);
- if (bit)
- buf[2 + j / 8] |= (1 << (7 - (j % 8)));
- j++;
- }
- buf[0] = DNS_LABELTYPE_BITSTRING;
- buf[1] = j;
- region.base = buf;
- region.length = 2 + (j + 7) / 8;
- dns_name_fromregion(&tmpsuffix, ®ion);
- result = dns_name_concatenate(&tmpprefix, &tmpsuffix, prefix,
- workspace);
- if (result != ISC_R_SUCCESS)
- return (ISC_FALSE);
- *offset = *data;
- return (ISC_TRUE);
-}
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
-/* $Id: compress.h,v 1.20 2000/12/28 00:42:56 bwelling Exp $ */
+/* $Id: compress.h,v 1.20.2.1 2001/01/06 01:33:34 gson Exp $ */
#ifndef DNS_COMPRESS_H
#define DNS_COMPRESS_H 1
#include <isc/lang.h>
+#include <isc/region.h>
#include <dns/types.h>
#define DNS_COMPRESS_NONE 0x00 /* no compression */
#define DNS_COMPRESS_GLOBAL14 0x01 /* "normal" compression. */
-#define DNS_COMPRESS_GLOBAL 0x01 /* all global comp. */
-/*
- * Synonymous with DNS_COMPRESS_GLOBAL. A genuine difference existed when
- * local compression was an IETF draft, but that draft has been retired without
- * becoming a standard. Numerous bits of code referred to DNS_COMPRESS_ALL
- * already, and rather than change them all, the DNS_COMPRESS_ALL definition
- * was left in, but no longer refers to local compression.
- */
-#define DNS_COMPRESS_ALL 0x03 /* all compression. */
+#define DNS_COMPRESS_ALL 0x01 /* all compression. */
/*
* Direct manipulation of the structures is strongly discouraged.
*/
+#define DNS_COMPRESS_TABLESIZE 64
+#define DNS_COMPRESS_INITIALNODES 16
+
+typedef struct dns_compressnode dns_compressnode_t;
+
+struct dns_compressnode {
+ isc_region_t r;
+ isc_uint16_t offset;
+ isc_uint16_t count;
+ dns_compressnode_t *next;
+};
+
struct dns_compress {
- unsigned int magic; /* Magic number. */
- unsigned int allowed; /* Allowed methods. */
- unsigned int rdata; /* Start of local rdata. */
- isc_boolean_t global16; /* 16 bit offsets allowed. */
- int edns; /* Edns version or -1. */
- dns_rbt_t *global; /* Global RBT. */
- isc_mem_t *mctx; /* Memeory context. */
+ unsigned int magic; /* Magic number. */
+ unsigned int allowed; /* Allowed methods. */
+ int edns; /* Edns version or -1. */
+ /* Global compression table. */
+ dns_compressnode_t *table[DNS_COMPRESS_TABLESIZE];
+ /* Preallocated nodes for the table. */
+ dns_compressnode_t initialnodes[DNS_COMPRESS_INITIALNODES];
+ isc_uint16_t count; /* Number of nodes. */
+ isc_mem_t *mctx; /* Memory context. */
};
typedef enum {
struct dns_decompress {
unsigned int magic; /* Magic number. */
unsigned int allowed; /* Allowed methods. */
- unsigned int rdata; /* Start of local rdata. */
int edns; /* Edns version or -1. */
dns_decompresstype_t type; /* Strict checking */
};
*
* Requires:
* 'cctx' is a valid dns_compress_t structure.
- * 'mctx' is a initalised memory context.
+ * 'mctx' is an initialized memory context.
* Ensures:
- * cctx->global is initalised.
+ * cctx->global is initialized.
*
* Returns:
* ISC_R_SUCCESS
/*
* Invalidate the compression structure pointed to by cctx.
- * Destroys 'cctx->glocal' and 'cctx->local' RBT.
*
* Requires:
- * 'cctx' to be initalised.
+ * 'cctx' to be initialized.
*/
void
* Sets allowed compression methods.
*
* Requires:
- * 'cctx' to be initalised.
+ * 'cctx' to be initialized.
*/
unsigned int
* Gets allowed compression methods.
*
* Requires:
- * 'cctx' to be initalised.
+ * 'cctx' to be initialized.
*
* Returns:
* allowed compression bitmap.
* Gets edns value.
*
* Requires:
- * 'cctx' to be initalised.
+ * 'cctx' to be initialized.
*
* Returns:
* -1 .. 255
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, isc_buffer_t *workspace);
+ isc_uint16_t *offset);
/*
- * Finds longest possible match of 'name' in the global compression
- * RBT. Workspace needs to be large enough to hold 'name' when split
- * in two (length->name + 3).
+ * Finds longest possible match of 'name' in the global compression table.
*
* Requires:
- * 'cctx' to be initalised.
+ * 'cctx' to be initialized.
* 'name' to be a absolute name.
- * 'prefix' to be initalised.
- * 'suffix' to be initalised.
+ * 'prefix' to be initialized.
+ * 'suffix' to be initialized.
* 'offset' to point it a isc_uint16_t.
- * 'workspace' to be initalised.
*
* Ensures:
* 'prefix', 'suffix' and 'offset' are valid if ISC_TRUE is
*/
void
-dns_compress_add(dns_compress_t *cctx, dns_name_t *prefix,
- dns_name_t *suffix, isc_uint16_t offset);
+dns_compress_add(dns_compress_t *cctx, dns_name_t *name, dns_name_t *prefix,
+ isc_uint16_t offset);
/*
- * Add compression pointers for labels in prefix to RBT's.
- * If 'prefix' is absolute 'suffix' must be NULL otherwise
- * suffix must be absolute.
+ * Add compression pointers for name to the compression table,
+ * not replacing existing pointers.
*
* Requires:
- * 'cctx' initalised
- * 'prefix' to be initalised
- * 'suffix' to be initalised or NULL
+ * 'cctx' initialized
+ * 'name' must be initialized and absolute, and must remain
+ * valid until the message compression is complete.
*/
void
dns_compress_rollback(dns_compress_t *cctx, isc_uint16_t offset);
/*
- * Remove any compression pointers from global RBT >= offset.
+ * Remove any compression pointers from global table >= offset.
*
* Requires:
- * 'cctx' is initalised.
+ * 'cctx' is initialized.
*/
void
* Invalidates 'dctx'.
*
* Requires:
- * 'dctx' to be initalised
+ * 'dctx' to be initialized
*/
void
* Sets 'dctx->allowed' to 'allowed'.
*
* Requires:
- * 'dctx' to be initalised
+ * 'dctx' to be initialized
*/
unsigned int
* Returns 'dctx->allowed'
*
* Requires:
- * 'dctx' to be initalised
+ * 'dctx' to be initialized
*/
int
* Returns 'dctx->edns'
*
* Requires:
- * 'dctx' to be initalised
+ * 'dctx' to be initialized
*/
dns_decompresstype_t
* Returns 'dctx->type'
*
* Requires:
- * 'dctx' to be initalised
+ * 'dctx' to be initialized
*/
ISC_LANG_ENDDECLS
projects / thirdparty / bind9.git / commitdiff
