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 8#include <linux/module.h> 9#include <linux/moduleparam.h> 10#include <linux/udp.h> 11 12#include <net/netfilter/nf_nat_helper.h> 13#include <net/netfilter/nf_nat_rule.h> 14#include <net/netfilter/nf_conntrack_helper.h> 15#include <net/netfilter/nf_conntrack_expect.h> 16#include <linux/netfilter/nf_conntrack_tftp.h> 17 18MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>"); 19MODULE_DESCRIPTION("TFTP NAT helper"); 20MODULE_LICENSE("GPL"); 21MODULE_ALIAS("ip_nat_tftp"); 22 23static unsigned int help(struct sk_buff *skb, 24 enum ip_conntrack_info ctinfo, 25 struct nf_conntrack_expect *exp) 26{ 27 struct nf_conn *ct = exp->master; 28 29 exp->saved_proto.udp.port 30 = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port; 31 exp->dir = IP_CT_DIR_REPLY; 32 exp->expectfn = nf_nat_follow_master; 33 if (nf_ct_expect_related(exp) != 0) 34 return NF_DROP; 35 return NF_ACCEPT; 36} 37 38static void __exit nf_nat_tftp_fini(void) 39{ 40 rcu_assign_pointer(nf_nat_tftp_hook, NULL); 41 synchronize_rcu(); 42} 43 44static int __init nf_nat_tftp_init(void) 45{ 46 BUG_ON(nf_nat_tftp_hook != NULL); 47 rcu_assign_pointer(nf_nat_tftp_hook, help); 48 return 0; 49} 50 51module_init(nf_nat_tftp_init); 52module_exit(nf_nat_tftp_fini); 53