| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu> |
| 2 | * |
| 3 | * This program is free software; you can redistribute it and/or modify |
| 4 | * it under the terms of the GNU General Public License version 2 as |
| 5 | * published by the Free Software Foundation. |
| 6 | * |
| 7 | * Version: 0.0.7 |
| 8 | * |
| 9 | * Thu 21 Mar 2002 Harald Welte <laforge@gnumonks.org> |
| 10 | * - Port to newnat API |
| 11 | * |
| 12 | * This module currently supports DNAT: |
| 13 | * iptables -t nat -A PREROUTING -d x.x.x.x -j DNAT --to-dest x.x.x.y |
| 14 | * |
| 15 | * and SNAT: |
| 16 | * iptables -t nat -A POSTROUTING { -j MASQUERADE , -j SNAT --to-source x.x.x.x } |
| 17 | * |
| 18 | * It has not been tested with |
| 19 | * -j SNAT --to-source x.x.x.x-x.x.x.y since I only have one external ip |
| 20 | * If you do test this please let me know if it works or not. |
| 21 | * |
| 22 | */ |
| 23 | |
| 24 | #include <linux/module.h> |
| 25 | #include <linux/netfilter_ipv4.h> |
| 26 | #include <linux/ip.h> |
| 27 | #include <linux/udp.h> |
| 28 | |
| 29 | #include <linux/netfilter.h> |
| 30 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 31 | #include <linux/netfilter_ipv4/ip_conntrack_helper.h> |
| 32 | #include <linux/netfilter_ipv4/ip_conntrack_tftp.h> |
| 33 | #include <linux/netfilter_ipv4/ip_nat_helper.h> |
| 34 | #include <linux/netfilter_ipv4/ip_nat_rule.h> |
| 35 | #include <linux/moduleparam.h> |
| 36 | |
| 37 | MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>"); |
| 38 | MODULE_DESCRIPTION("tftp NAT helper"); |
| 39 | MODULE_LICENSE("GPL"); |
| 40 | |
| 41 | static unsigned int help(struct sk_buff **pskb, |
| 42 | enum ip_conntrack_info ctinfo, |
| 43 | struct ip_conntrack_expect *exp) |
| 44 | { |
| 45 | exp->saved_proto.udp.port = exp->tuple.dst.u.tcp.port; |
| 46 | exp->dir = IP_CT_DIR_REPLY; |
| 47 | exp->expectfn = ip_nat_follow_master; |
| 48 | if (ip_conntrack_expect_related(exp) != 0) { |
| 49 | ip_conntrack_expect_free(exp); |
| 50 | return NF_DROP; |
| 51 | } |
| 52 | return NF_ACCEPT; |
| 53 | } |
| 54 | |
| 55 | static void __exit fini(void) |
| 56 | { |
| 57 | ip_nat_tftp_hook = NULL; |
| 58 | /* Make sure noone calls it, meanwhile. */ |
| 59 | synchronize_net(); |
| 60 | } |
| 61 | |
| 62 | static int __init init(void) |
| 63 | { |
| 64 | BUG_ON(ip_nat_tftp_hook); |
| 65 | ip_nat_tftp_hook = help; |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | module_init(init); |
| 70 | module_exit(fini); |