arti/wrapsix
1
0
Fork 0
mirror of https://code.semirocket.science/wrapsix synced 2024-11-08 15:21:00 +02:00
Code

Revised radix tree

Browse Source 
Dropped chunker duplication and created one universal
Rewritten function for deleting entries from the tree
  (limiting the tree to 32 levels)
This commit is contained in:
Michal Zima 2012-04-27 15:25:29 +02:00
parent d7e506abed
commit 9ac06588a8
3 changed files with 54 additions and 85 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
src/nat.c
View File

@ -85,7 +85,7 @@ struct s_nat *nat_out(radixtree_t *nat_proto6, radixtree_t *nat_proto4,
radixsearch6.port_dst = port_dst;
if ((result = (struct s_nat *) radixtree_lookup(nat_proto6,
radixtree_ipv6_chunker, &radixsearch6)) == NULL) {
radixtree_chunker, &radixsearch6, sizeof(radixsearch6))) == NULL) {
/* if no connection is found, let's create one */
if ((connection =
(struct s_nat *) malloc(sizeof(struct s_nat))) == NULL) {
@ -109,14 +109,14 @@ struct s_nat *nat_out(radixtree_t *nat_proto6, radixtree_t *nat_proto4,
/* returns port from range 1024 - 65535 */
radixsearch4.port_dst = (rand() % 64511) + 1024;
result = radixtree_lookup(nat_proto4, radixtree_ipv4_chunker, &radixsearch4);
result = radixtree_lookup(nat_proto4, radixtree_chunker, &radixsearch4, sizeof(radixsearch4));
} while (result != NULL);
connection->ipv4_port_src = radixsearch4.port_dst;
/* save this connection to the NAT table (to *both* of them) */
radixtree_insert(nat_proto6, radixtree_ipv6_chunker, &radixsearch6, connection);
radixtree_insert(nat_proto4, radixtree_ipv4_chunker, &radixsearch4, connection);
radixtree_insert(nat_proto6, radixtree_chunker, &radixsearch6, sizeof(radixsearch6), connection);
radixtree_insert(nat_proto4, radixtree_chunker, &radixsearch4, sizeof(radixsearch4), connection);
return connection;
} else {
@ -138,7 +138,7 @@ struct s_nat *nat_in(radixtree_t *nat_proto4, struct s_ipv4_addr ipv4_src,
radixsearch4.port_dst = port_dst;
radixsearch4.zeros = 0x0;
if ((result = (struct s_nat *) radixtree_lookup(nat_proto4, radixtree_ipv4_chunker, &radixsearch4)) == NULL) {
if ((result = (struct s_nat *) radixtree_lookup(nat_proto4, radixtree_chunker, &radixsearch4, sizeof(radixsearch4))) == NULL) {
/* when connection is not found, drop the packet */
return NULL;
} else {

114
src/radixtree.c
View File

@ -52,14 +52,14 @@ void radixtree_destroy(radixtree_t *t, unsigned char depth)
}
void radixtree_insert(radixtree_t *root,
unsigned char *(chunker)(void *data, unsigned char *count),
void *search_data, void *data)
unsigned char *(chunker)(void *data, unsigned char size, unsigned char *count),
void *search_data, unsigned char size, void *data)
{
radixtree_t *tmp;
unsigned char i, chunk_count;
unsigned char *chunks;
chunks = chunker(search_data, &chunk_count);
chunks = chunker(search_data, size, &chunk_count);
tmp = root;
tmp->count++;
@ -86,71 +86,57 @@ void radixtree_insert(radixtree_t *root,
}
void radixtree_delete(radixtree_t *root,
unsigned char *(chunker)(void *data, unsigned char *count),
void *data)
unsigned char *(chunker)(void *data, unsigned char size, unsigned char *count),
void *data, unsigned char size)
{
radixtree_t *tmp,
*next;
unsigned char i, chunk_count;
unsigned char *chunks;
unsigned int flags = 0;
chunks = chunker(data, &chunk_count);
chunks = chunker(data, size, &chunk_count);
for (i = 0, tmp = root; i < chunk_count && tmp != NULL; i++, tmp = tmp->array[chunks[i]]) {
flags = tmp->count == 1 ? flags | (0x1 << i) : 0;
if (i + 1 == chunk_count) {
break;
}
}
/* if was at leaf, decrement counter */
if (i + 1 == chunk_count) {
tmp->count--;
}
tmp = root;
tmp->count--;
flags &= 0xfffffffe; /* unflag root */
for (i = 0; i < chunk_count; i++) {
unsigned char id;
id = chunks[i];
/* already deleted? may cause data inconsistency! */
if (tmp->array[id] == NULL) {
return;
next = tmp->array[chunks[i]];
if (flags & (0x1 << (i + 1))) {
tmp->array[chunks[i]] = NULL;
tmp->count--;
}
if (i == chunk_count - 1) {
if (tmp->count == 0) {
free(tmp);
} else {
tmp->array[id] = NULL;
}
/**
* now you *have to* call free on data too
* but probably not here...
**/
return;
}
next = tmp->array[id];
/* if it is the last entry in this tree branch */
if (next->count == 1) {
tmp->array[id] = NULL;
}
if (i != 0 && tmp->count == 0) {
if (flags & (0x1 << i)) {
free(tmp);
}
tmp = next;
tmp->count--;
}
free(chunks);
}
void *radixtree_lookup(radixtree_t *root,
unsigned char *(chunker)(void *data, unsigned char *count),
void *data)
unsigned char *(chunker)(void *data, unsigned char size, unsigned char *count),
void *data, unsigned char size)
{
radixtree_t *tmp;
unsigned char i, chunk_count, id;
unsigned char *chunks;
chunks = chunker(data, &chunk_count);
chunks = chunker(data, size, &chunk_count);
tmp = root;
@ -177,14 +163,24 @@ void *radixtree_lookup(radixtree_t *root,
/* we never get here ;c) */
}
unsigned char *radixtree_ipv6_chunker(void *data, unsigned char *count)
/**
* Universal chunker.
*
* @param data Data to chunk
* @param size Size of the data; must be divisible by 3
* @param count Variable into which is put information about number of
* chunks produced
*
* @return Array of chunks
*/
unsigned char *radixtree_chunker(void *data, unsigned char size, unsigned char *count)
{
short i;
unsigned char counter;
unsigned char *chunks;
unsigned char *cdata = (unsigned char *) data;
counter = 192 / 6;
counter = size * 8 / 6;
memcpy(count, &counter, sizeof(unsigned char));
if ((chunks = (unsigned char *) malloc(counter * sizeof(unsigned char))) == NULL) {
@ -202,33 +198,7 @@ unsigned char *radixtree_ipv6_chunker(void *data, unsigned char *count)
* 240 == 1111 0000 == 0xf0
* 252 == 1111 1100 == 0xfc
*/
for (i = 0, counter = 0; counter < *count; i++) {
chunks[counter++] = cdata[i] & 0x3f;
chunks[counter++] = ((cdata[i] & 0xc0) >> 6) | ((cdata[i + 1] & 0x0f) << 2);
i++;
chunks[counter++] = ((cdata[i] & 0xf0) >> 4) | ((cdata[i + 1] & 0x03) << 4);
i++;
chunks[counter++] = ((cdata[i] & 0xfc) >> 2);
}
return chunks;
}
unsigned char *radixtree_ipv4_chunker(void *data, unsigned char *count)
{
short i;
unsigned char counter;
unsigned char *chunks;
unsigned char *cdata = (unsigned char *) data;
counter = 72 / 6;
memcpy(count, &counter, sizeof(unsigned char));
if ((chunks = (unsigned char *) malloc(counter * sizeof(unsigned char))) == NULL) {
fprintf(stderr, "[Error] Lack of free memory\n");
return NULL;
}
/* processes 3 bytes at a time */
for (i = 0, counter = 0; counter < *count; i++) {
chunks[counter++] = cdata[i] & 0x3f;
chunks[counter++] = ((cdata[i] & 0xc0) >> 6) | ((cdata[i + 1] & 0x0f) << 2);

15
src/radixtree.h
View File

@ -30,15 +30,14 @@ typedef struct radixtree {
radixtree_t *radixtree_create(void);
void radixtree_destroy(radixtree_t *t, unsigned char depth);
void radixtree_insert(radixtree_t *root,
unsigned char *(chunker)(void *data, unsigned char *count),
void *search_data, void *data);
unsigned char *(chunker)(void *data, unsigned char size, unsigned char *count),
void *search_data, unsigned char size, void *data);
void radixtree_delete(radixtree_t *root,
unsigned char *(chunker)(void *data, unsigned char *count),
void *data);
unsigned char *(chunker)(void *data, unsigned char size, unsigned char *count),
void *data, unsigned char size);
void *radixtree_lookup(radixtree_t *root,
unsigned char *(chunker)(void *data, unsigned char *count),
void *data);
unsigned char *radixtree_ipv6_chunker(void *data, unsigned char *count);
unsigned char *radixtree_ipv4_chunker(void *data, unsigned char *count);
unsigned char *(chunker)(void *data, unsigned char size, unsigned char *count),
void *data, unsigned char size);
unsigned char *radixtree_chunker(void *data, unsigned char size, unsigned char *count);
#endif /* RADIXTREE_H */