mirror of
https://code.semirocket.science/wrapsix
synced 2024-11-28 09:00:59 +02:00
Quite good implementation of NAT
This commit is contained in:
Michal Zima
parent
3d8d8ace2a
commit
f9f2bd501b
135
src/nat.c
Normal file
135
src/nat.c
Normal file
@ -0,0 +1,135 @@
|
|||||||
|
/*
|
||||||
|
* WrapSix
|
||||||
|
* Copyright (C) 2008-2010 Michal Zima <xhire@mujmalysvet.cz>
|
||||||
|
*
|
||||||
|
* This program is free software: you can redistribute it and/or modify
|
||||||
|
* it under the terms of the GNU Affero General Public License as
|
||||||
|
* published by the Free Software Foundation, either version 3 of the
|
||||||
|
* License, or (at your option) any later version.
|
||||||
|
*
|
||||||
|
* This program is distributed in the hope that it will be useful,
|
||||||
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||||
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||||
|
* GNU Affero General Public License for more details.
|
||||||
|
*
|
||||||
|
* You should have received a copy of the GNU Affero General Public License
|
||||||
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||||
|
*/
|
||||||
|
|
||||||
|
#include <stdio.h>
|
||||||
|
#include <stdlib.h> /* malloc */
|
||||||
|
#include <time.h> /* time */
|
||||||
|
|
||||||
|
#include "radixtree.h"
|
||||||
|
|
||||||
|
struct s_radixtree_nat6 {
|
||||||
|
struct s_ipv6_addr ipv6;
|
||||||
|
struct s_ipv4_addr ipv4;
|
||||||
|
unsigned short port_src;
|
||||||
|
unsigned short port_dst;
|
||||||
|
} __attribute__ ((__packed__));
|
||||||
|
|
||||||
|
struct s_radixtree_nat4 {
|
||||||
|
struct s_ipv4_addr addr;
|
||||||
|
unsigned short port_src;
|
||||||
|
unsigned short port_dst;
|
||||||
|
unsigned char zeros; /* unused space */
|
||||||
|
} __attribute__ ((__packed__));
|
||||||
|
|
||||||
|
radixtree_t *nat6_tcp, *nat6_udp, *nat6_icmp,
|
||||||
|
*nat4_tcp, *nat4_udp, *nat4_icmp;
|
||||||
|
|
||||||
|
void nat_init()
|
||||||
|
{
|
||||||
|
nat6_tcp = radixtree_create();
|
||||||
|
nat6_udp = radixtree_create();
|
||||||
|
nat6_icmp = radixtree_create();
|
||||||
|
|
||||||
|
nat4_tcp = radixtree_create();
|
||||||
|
nat4_udp = radixtree_create();
|
||||||
|
nat4_icmp = radixtree_create();
|
||||||
|
}
|
||||||
|
|
||||||
|
void nat_quit()
|
||||||
|
{
|
||||||
|
/* 128 + 16 + 32 + 16 = 198 / 6 = 33 */
|
||||||
|
radixtree_destroy(&nat6_tcp, 33);
|
||||||
|
radixtree_destroy(&nat6_udp, 33);
|
||||||
|
radixtree_destroy(&nat6_icmp, 33);
|
||||||
|
|
||||||
|
/* 32 + 16 + 16 + 8 = 72 / 6 = 12 */
|
||||||
|
radixtree_destroy(&nat4_tcp, 12);
|
||||||
|
radixtree_destroy(&nat4_udp, 12);
|
||||||
|
radixtree_destroy(&nat4_icmp, 12);
|
||||||
|
}
|
||||||
|
|
||||||
|
struct s_nat *nat_out(radixtree_t *nat_proto6, radixtree_t *nat_proto4,
|
||||||
|
struct s_ipv6_addr ipv6_src, struct s_ipv6_addr ipv6_dst,
|
||||||
|
unsigned short port_src, unsigned short port_dst)
|
||||||
|
{
|
||||||
|
radixtree_t *result, *connection;
|
||||||
|
|
||||||
|
/* create structure to search in the tree */
|
||||||
|
struct s_radixtree_nat6 radixsearch6;
|
||||||
|
radixsearch6.ipv6 = ipv6_src;
|
||||||
|
radixsearch6.ipv4 = ipv6_to_ipv4(&ipv6_dst);
|
||||||
|
radixsearch6.port_src = port_src;
|
||||||
|
radixsearch6.port_dst = port_dst;
|
||||||
|
|
||||||
|
if ((result = radixtree_lookup(nat_proto6, radixtree_outgoing_chunker, &radixsearch6)) == NULL) {
|
||||||
|
if ((connection = (struct s_nat *) malloc(sizeof(struct s_nat))) == NULL) {
|
||||||
|
fprintf(stderr, "[Error] Lack of free memory\n");
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
connection->ipv6 = ipv6_src;
|
||||||
|
connection->ipv4 = radixsearch6.ipv4;
|
||||||
|
connection->ipv6_port_src = port_src;
|
||||||
|
connection->ipv4_port_dst = port_dst;
|
||||||
|
result->last_packet = time(NULL);
|
||||||
|
|
||||||
|
/* generate some outgoing port */
|
||||||
|
srand((unsigned int) time(NULL));
|
||||||
|
do {
|
||||||
|
/* return port from range 1024 - 65535 */
|
||||||
|
connection->ipv4_port_src = (rand() % 64511) + 1024;
|
||||||
|
|
||||||
|
result = radixtree_lookup(nat_proto6, radixtree_outgoing_chunker, &radixsearch6);
|
||||||
|
} while (result != NULL);
|
||||||
|
|
||||||
|
/* save this connection to the NAT table (to *both* of them) */
|
||||||
|
struct s_radixtree_nat4 radixsearch4;
|
||||||
|
radixsearch4.addr = radixsearch6.ipv4;
|
||||||
|
radixsearch4.port_src = port_dst;
|
||||||
|
radixsearch4.port_dst = connection->ipv4_port_src;
|
||||||
|
radixsearch4.zeros = 0x0;
|
||||||
|
|
||||||
|
radixtree_insert(nat_proto6, radixtree_outgoing_chunker, &radixsearch6, connection);
|
||||||
|
radixtree_insert(nat_proto4, radixtree_incoming_chunker, &radixsearch4, connection);
|
||||||
|
|
||||||
|
return connection;
|
||||||
|
} else {
|
||||||
|
result->last_packet = time(NULL);
|
||||||
|
return result;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
struct s_nat *nat_in(radixtree_t *nat_proto, struct s_ipv4_addr ipv4_src,
|
||||||
|
unsigned short port_src, unsigned short port_dst)
|
||||||
|
{
|
||||||
|
radixtree_t *result;
|
||||||
|
|
||||||
|
/* create structure to search in the tree */
|
||||||
|
struct s_radixtree_nat4 radixsearch;
|
||||||
|
radixsearch.addr = ipv4_src;
|
||||||
|
radixsearch.port_src = port_src;
|
||||||
|
radixsearch.port_dst = port_dst;
|
||||||
|
radixsearch.zeros = 0x0;
|
||||||
|
|
||||||
|
if ((result = radixtree_lookup(nat_proto, radixtree_outgoing_chunker, &radixsearch)) == NULL) {
|
||||||
|
return NULL;
|
||||||
|
} else {
|
||||||
|
result->last_packet = time(NULL);
|
||||||
|
return result;
|
||||||
|
}
|
||||||
|
}
|
||||||
49
src/nat.h
Normal file
49
src/nat.h
Normal file
@ -0,0 +1,49 @@
|
|||||||
|
/*
|
||||||
|
* WrapSix
|
||||||
|
* Copyright (C) 2008-2010 Michal Zima <xhire@mujmalysvet.cz>
|
||||||
|
*
|
||||||
|
* This program is free software: you can redistribute it and/or modify
|
||||||
|
* it under the terms of the GNU Affero General Public License as
|
||||||
|
* published by the Free Software Foundation, either version 3 of the
|
||||||
|
* License, or (at your option) any later version.
|
||||||
|
*
|
||||||
|
* This program is distributed in the hope that it will be useful,
|
||||||
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||||
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||||
|
* GNU Affero General Public License for more details.
|
||||||
|
*
|
||||||
|
* You should have received a copy of the GNU Affero General Public License
|
||||||
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||||
|
*/
|
||||||
|
|
||||||
|
#ifndef NAT_H
|
||||||
|
#define NAT_H
|
||||||
|
|
||||||
|
#include <time.h> /* time_t */
|
||||||
|
|
||||||
|
#include "ipv4.h" /* s_ipv4_addr */
|
||||||
|
#include "ipv6.h" /* s_ipv6_addr */
|
||||||
|
#include "radixtree.h" /* radixtree_t */
|
||||||
|
|
||||||
|
struct s_nat {
|
||||||
|
struct s_ipv6_addr ipv6;
|
||||||
|
struct s_ipv4_addr ipv4;
|
||||||
|
unsigned short ipv6_port_src;
|
||||||
|
unsigned short ipv4_port_src;
|
||||||
|
unsigned short ipv4_port_dst;
|
||||||
|
time_t last_packet; /* time of processing last packet of the connection */
|
||||||
|
};
|
||||||
|
|
||||||
|
extern radixtree_t *nat6_tcp, *nat6_udp, *nat6_icmp,
|
||||||
|
*nat4_tcp, *nat4_udp, *nat4_icmp;
|
||||||
|
|
||||||
|
void nat_init();
|
||||||
|
void nat_quit();
|
||||||
|
|
||||||
|
struct s_nat *nat_out(radixtree_t *nat_proto6, radixtree_t *nat_proto4,
|
||||||
|
struct s_ipv6_addr ipv6_src, struct s_ipv6_addr ipv6_dst,
|
||||||
|
unsigned short port_src, unsigned short port_dst);
|
||||||
|
struct s_nat *nat_in(radixtree_t *nat_proto, struct s_ipv4_addr ipv4_src,
|
||||||
|
unsigned short port_src, unsigned short port_dst);
|
||||||
|
|
||||||
|
#endif /* NAT_H */
|
||||||
Loading…
Reference in New Issue
Block a user