/**
* Retrieve or create data structure via fragment identification.
*
* @param nat_proto4 Radix tree of fragments
* @param nat_timeout Linked list in which to watch for timeout
* @param ipv4_src Source IPv4 address
* @param id Fragment identification
*
* @return Structure for fragments (either retrieved or created)
* @return NULL when structure for fragments couldn't be created
*/
struct s_nat_fragments *nat_in_fragments(radixtree_t *nat_proto4,
linkedlist_t *nat_timeout,
struct s_ipv4_addr ipv4_src,
unsigned short id)
{
struct s_nat_fragments *result;
/* create structure to search in the tree */
struct s_radixtree_fragments4 radixsearch4;
radixsearch4.addr = ipv4_src;
radixsearch4.id = id;
if ((result = radixtree_lookup(nat_proto4, radixtree_chunker,
&radixsearch4, sizeof(radixsearch4))) != NULL) {
return result;
} else {
/* when fragmentation is not found, add one */
if ((result = (struct s_nat_fragments *)
malloc(sizeof(struct s_nat_fragments))) == NULL) {
log_error("Lack of free memory");
return NULL;
}
result->id = id;
result->connection = NULL;
result->queue = NULL;
radixtree_insert(nat_proto4, radixtree_chunker,
&radixsearch4, sizeof(radixsearch4),
result);
linkedlist_append(nat_timeout, result);
return result;
}
}
uint32_t string_pool_append(char *pool, uint32_t *n_pool, radixtree_t *r, const char *str) {
uint32_t location = radixtree_find_exact (r, str);
if (location == RADIXTREE_NONE) {
size_t n = strlen(str);
/* TODO: check if n_pool + n < max */
strncpy (&pool[*n_pool], str, n);
location = *n_pool;
*n_pool += n;
radixtree_insert(r, str, location);
}
return location;
}
/**
* Lookup or create NAT connection for outgoing IPv6 packet.
*
* @param nat_proto6 IPv6 NAT table
* @param nat_proto4 IPv4 NAT table
* @param eth_src Source MAC address
* @param ipv6_src Source IPv6 address
* @param ipv6_dst Destination IPv6 address
* @param port_src Source port
* @param port_dst Destination port
* @param create Whether or not to create new NAT entry
*
* @return NULL when it wasn't possible to create connection
* @return pointer to connection structure otherwise
*/
struct s_nat *nat_out(radixtree_t *nat_proto6, radixtree_t *nat_proto4,
struct s_mac_addr eth_src,
struct s_ipv6_addr ipv6_src, struct s_ipv6_addr ipv6_dst,
unsigned short port_src, unsigned short port_dst,
unsigned char create)
{
struct s_nat *result, *connection;
struct s_radixtree_nat4 radixsearch4;
struct s_radixtree_nat6 radixsearch6;
/* create structure to search in the tree */
radixsearch6.ipv6 = ipv6_src;
ipv6_to_ipv4(&ipv6_dst, &radixsearch6.ipv4);
radixsearch6.port_src = port_src;
radixsearch6.port_dst = port_dst;
if ((result = (struct s_nat *) radixtree_lookup(nat_proto6,
radixtree_chunker, &radixsearch6, sizeof(radixsearch6))) == NULL) {
if (create > 0) {
/* if no connection is found, let's create one */
if ((connection =
(struct s_nat *) malloc(sizeof(struct s_nat))) ==
NULL) {
log_error("Lack of free memory");
return NULL;
}
connection->mac = eth_src;
connection->ipv6 = ipv6_src;
connection->ipv4 = radixsearch6.ipv4;
connection->ipv6_port_src = port_src;
connection->ipv4_port_dst = port_dst;
connection->state = 1;
connection->llnode = NULL;
radixsearch4.addr = radixsearch6.ipv4;
radixsearch4.port_src = port_dst;
radixsearch4.zeros = 0x0;
/* generate some outgoing port */
do {
/* returns port from range 1024 - 65535 */
radixsearch4.port_dst = (rand() % 64511) + 1024;
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_chunker,
&radixsearch6, sizeof(radixsearch6),
connection);
radixtree_insert(nat_proto4, radixtree_chunker,
&radixsearch4, sizeof(radixsearch4),
connection);
return connection;
} else {
return NULL;
}
} else {
/* when connection is found, return it */
return result;
}
}