| /* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * Version: 0.0.7 |
| * |
| * Thu 21 Mar 2002 Harald Welte <laforge@gnumonks.org> |
| * - Port to newnat API |
| * |
| * This module currently supports DNAT: |
| * iptables -t nat -A PREROUTING -d x.x.x.x -j DNAT --to-dest x.x.x.y |
| * |
| * and SNAT: |
| * iptables -t nat -A POSTROUTING { -j MASQUERADE , -j SNAT --to-source x.x.x.x } |
| * |
| * It has not been tested with |
| * -j SNAT --to-source x.x.x.x-x.x.x.y since I only have one external ip |
| * If you do test this please let me know if it works or not. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/netfilter_ipv4.h> |
| #include <linux/ip.h> |
| #include <linux/udp.h> |
| |
| #include <linux/netfilter.h> |
| #include <linux/netfilter_ipv4/ip_tables.h> |
| #include <linux/netfilter_ipv4/ip_conntrack_helper.h> |
| #include <linux/netfilter_ipv4/ip_conntrack_tftp.h> |
| #include <linux/netfilter_ipv4/ip_nat_helper.h> |
| #include <linux/netfilter_ipv4/ip_nat_rule.h> |
| #include <linux/moduleparam.h> |
| |
| MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>"); |
| MODULE_DESCRIPTION("tftp NAT helper"); |
| MODULE_LICENSE("GPL"); |
| |
| static unsigned int help(struct sk_buff **pskb, |
| enum ip_conntrack_info ctinfo, |
| struct ip_conntrack_expect *exp) |
| { |
| struct ip_conntrack *ct = exp->master; |
| |
| exp->saved_proto.udp.port |
| = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port; |
| exp->dir = IP_CT_DIR_REPLY; |
| exp->expectfn = ip_nat_follow_master; |
| if (ip_conntrack_expect_related(exp) != 0) |
| return NF_DROP; |
| return NF_ACCEPT; |
| } |
| |
| static void __exit ip_nat_tftp_fini(void) |
| { |
| ip_nat_tftp_hook = NULL; |
| /* Make sure noone calls it, meanwhile. */ |
| synchronize_net(); |
| } |
| |
| static int __init ip_nat_tftp_init(void) |
| { |
| BUG_ON(ip_nat_tftp_hook); |
| ip_nat_tftp_hook = help; |
| return 0; |
| } |
| |
| module_init(ip_nat_tftp_init); |
| module_exit(ip_nat_tftp_fini); |