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