2 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
5 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/netfilter_ipv4/ip_tables.h>
18 MODULE_LICENSE("GPL");
19 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
20 MODULE_DESCRIPTION("iptables filter table");
22 #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
23 (1 << NF_INET_FORWARD) | \
24 (1 << NF_INET_LOCAL_OUT))
28 struct ipt_replace repl
;
29 struct ipt_standard entries
[3];
30 struct ipt_error term
;
31 } initial_table __net_initdata
= {
34 .valid_hooks
= FILTER_VALID_HOOKS
,
36 .size
= sizeof(struct ipt_standard
) * 3 + sizeof(struct ipt_error
),
38 [NF_INET_LOCAL_IN
] = 0,
39 [NF_INET_FORWARD
] = sizeof(struct ipt_standard
),
40 [NF_INET_LOCAL_OUT
] = sizeof(struct ipt_standard
) * 2,
43 [NF_INET_LOCAL_IN
] = 0,
44 [NF_INET_FORWARD
] = sizeof(struct ipt_standard
),
45 [NF_INET_LOCAL_OUT
] = sizeof(struct ipt_standard
) * 2,
49 IPT_STANDARD_INIT(NF_ACCEPT
), /* LOCAL_IN */
50 IPT_STANDARD_INIT(NF_ACCEPT
), /* FORWARD */
51 IPT_STANDARD_INIT(NF_ACCEPT
), /* LOCAL_OUT */
53 .term
= IPT_ERROR_INIT
, /* ERROR */
56 static const struct xt_table packet_filter
= {
58 .valid_hooks
= FILTER_VALID_HOOKS
,
61 .priority
= NF_IP_PRI_FILTER
,
65 iptable_filter_hook(unsigned int hook
, struct sk_buff
*skb
,
66 const struct net_device
*in
, const struct net_device
*out
,
67 int (*okfn
)(struct sk_buff
*))
69 const struct net
*net
;
71 if (hook
== NF_INET_LOCAL_OUT
&&
72 (skb
->len
< sizeof(struct iphdr
) ||
73 ip_hdrlen(skb
) < sizeof(struct iphdr
)))
74 /* root is playing with raw sockets. */
77 net
= dev_net((in
!= NULL
) ? in
: out
);
78 return ipt_do_table(skb
, hook
, in
, out
, net
->ipv4
.iptable_filter
);
81 static struct nf_hook_ops
*filter_ops __read_mostly
;
83 /* Default to forward because I got too much mail already. */
84 static int forward
= NF_ACCEPT
;
85 module_param(forward
, bool, 0000);
87 static int __net_init
iptable_filter_net_init(struct net
*net
)
90 net
->ipv4
.iptable_filter
=
91 ipt_register_table(net
, &packet_filter
, &initial_table
.repl
);
92 if (IS_ERR(net
->ipv4
.iptable_filter
))
93 return PTR_ERR(net
->ipv4
.iptable_filter
);
97 static void __net_exit
iptable_filter_net_exit(struct net
*net
)
99 ipt_unregister_table(net
, net
->ipv4
.iptable_filter
);
102 static struct pernet_operations iptable_filter_net_ops
= {
103 .init
= iptable_filter_net_init
,
104 .exit
= iptable_filter_net_exit
,
107 static int __init
iptable_filter_init(void)
111 if (forward
< 0 || forward
> NF_MAX_VERDICT
) {
112 printk("iptables forward must be 0 or 1\n");
116 /* Entry 1 is the FORWARD hook */
117 initial_table
.entries
[1].target
.verdict
= -forward
- 1;
119 ret
= register_pernet_subsys(&iptable_filter_net_ops
);
124 filter_ops
= xt_hook_link(&packet_filter
, iptable_filter_hook
);
125 if (IS_ERR(filter_ops
)) {
126 ret
= PTR_ERR(filter_ops
);
133 unregister_pernet_subsys(&iptable_filter_net_ops
);
137 static void __exit
iptable_filter_fini(void)
139 xt_hook_unlink(&packet_filter
, filter_ops
);
140 unregister_pernet_subsys(&iptable_filter_net_ops
);
143 module_init(iptable_filter_init
);
144 module_exit(iptable_filter_fini
);