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,
64 iptable_filter_hook(unsigned int hook, struct sk_buff *skb,
65 const struct net_device *in, const struct net_device *out,
66 int (*okfn)(struct sk_buff *))
68 if (hook == NF_INET_LOCAL_OUT) {
69 if (skb->len < sizeof(struct iphdr) ||
70 ip_hdrlen(skb) < sizeof(struct iphdr))
71 /* root is playing with raw sockets. */
74 return ipt_do_table(skb, hook, in, out,
75 dev_net(out)->ipv4.iptable_filter);
78 /* LOCAL_IN/FORWARD: */
79 return ipt_do_table(skb, hook, in, out,
80 dev_net(in)->ipv4.iptable_filter);
83 static struct nf_hook_ops ipt_ops[] __read_mostly = {
85 .hook = iptable_filter_hook,
88 .hooknum = NF_INET_LOCAL_IN,
89 .priority = NF_IP_PRI_FILTER,
92 .hook = iptable_filter_hook,
95 .hooknum = NF_INET_FORWARD,
96 .priority = NF_IP_PRI_FILTER,
99 .hook = iptable_filter_hook,
100 .owner = THIS_MODULE,
102 .hooknum = NF_INET_LOCAL_OUT,
103 .priority = NF_IP_PRI_FILTER,
107 /* Default to forward because I got too much mail already. */
108 static int forward = NF_ACCEPT;
109 module_param(forward, bool, 0000);
111 static int __net_init iptable_filter_net_init(struct net *net)
114 net->ipv4.iptable_filter =
115 ipt_register_table(net, &packet_filter, &initial_table.repl);
116 if (IS_ERR(net->ipv4.iptable_filter))
117 return PTR_ERR(net->ipv4.iptable_filter);
121 static void __net_exit iptable_filter_net_exit(struct net *net)
123 ipt_unregister_table(net, net->ipv4.iptable_filter);
126 static struct pernet_operations iptable_filter_net_ops = {
127 .init = iptable_filter_net_init,
128 .exit = iptable_filter_net_exit,
131 static int __init iptable_filter_init(void)
135 if (forward < 0 || forward > NF_MAX_VERDICT) {
136 printk("iptables forward must be 0 or 1\n");
140 /* Entry 1 is the FORWARD hook */
141 initial_table.entries[1].target.verdict = -forward - 1;
143 ret = register_pernet_subsys(&iptable_filter_net_ops);
148 ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
155 unregister_pernet_subsys(&iptable_filter_net_ops);
159 static void __exit iptable_filter_fini(void)
161 nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
162 unregister_pernet_subsys(&iptable_filter_net_ops);
165 module_init(iptable_filter_init);
166 module_exit(iptable_filter_fini);