ipvs: convert lblc scheduler to rcu
[linux-3.10.git] / net / netfilter / nf_nat_tftp.c
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_conntrack_helper.h>
12 #include <net/netfilter/nf_conntrack_expect.h>
13 #include <net/netfilter/nf_nat_helper.h>
14 #include <linux/netfilter/nf_conntrack_tftp.h>
15
16 MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
17 MODULE_DESCRIPTION("TFTP NAT helper");
18 MODULE_LICENSE("GPL");
19 MODULE_ALIAS("ip_nat_tftp");
20
21 static unsigned int help(struct sk_buff *skb,
22                          enum ip_conntrack_info ctinfo,
23                          struct nf_conntrack_expect *exp)
24 {
25         const struct nf_conn *ct = exp->master;
26
27         exp->saved_proto.udp.port
28                 = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port;
29         exp->dir = IP_CT_DIR_REPLY;
30         exp->expectfn = nf_nat_follow_master;
31         if (nf_ct_expect_related(exp) != 0) {
32                 nf_ct_helper_log(skb, exp->master, "cannot add expectation");
33                 return NF_DROP;
34         }
35         return NF_ACCEPT;
36 }
37
38 static void __exit nf_nat_tftp_fini(void)
39 {
40         RCU_INIT_POINTER(nf_nat_tftp_hook, NULL);
41         synchronize_rcu();
42 }
43
44 static int __init nf_nat_tftp_init(void)
45 {
46         BUG_ON(nf_nat_tftp_hook != NULL);
47         RCU_INIT_POINTER(nf_nat_tftp_hook, help);
48         return 0;
49 }
50
51 module_init(nf_nat_tftp_init);
52 module_exit(nf_nat_tftp_fini);