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 __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 struct xt_table packet_filter = {
58 .valid_hooks = FILTER_VALID_HOOKS,
59 .lock = RW_LOCK_UNLOCKED,
64 /* The work comes in here from netfilter.c. */
66 ipt_hook(unsigned int hook,
68 const struct net_device *in,
69 const struct net_device *out,
70 int (*okfn)(struct sk_buff *))
72 return ipt_do_table(skb, hook, in, out, &packet_filter);
76 ipt_local_out_hook(unsigned int hook,
78 const struct net_device *in,
79 const struct net_device *out,
80 int (*okfn)(struct sk_buff *))
82 /* root is playing with raw sockets. */
83 if (skb->len < sizeof(struct iphdr) ||
84 ip_hdrlen(skb) < sizeof(struct iphdr)) {
86 printk("iptable_filter: ignoring short SOCK_RAW "
91 return ipt_do_table(skb, hook, in, out, &packet_filter);
94 static struct nf_hook_ops ipt_ops[] = {
99 .hooknum = NF_INET_LOCAL_IN,
100 .priority = NF_IP_PRI_FILTER,
104 .owner = THIS_MODULE,
106 .hooknum = NF_INET_FORWARD,
107 .priority = NF_IP_PRI_FILTER,
110 .hook = ipt_local_out_hook,
111 .owner = THIS_MODULE,
113 .hooknum = NF_INET_LOCAL_OUT,
114 .priority = NF_IP_PRI_FILTER,
118 /* Default to forward because I got too much mail already. */
119 static int forward = NF_ACCEPT;
120 module_param(forward, bool, 0000);
122 static int __init iptable_filter_init(void)
126 if (forward < 0 || forward > NF_MAX_VERDICT) {
127 printk("iptables forward must be 0 or 1\n");
131 /* Entry 1 is the FORWARD hook */
132 initial_table.entries[1].target.verdict = -forward - 1;
135 ret = ipt_register_table(&packet_filter, &initial_table.repl);
140 ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
147 ipt_unregister_table(&packet_filter);
151 static void __exit iptable_filter_fini(void)
153 nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
154 ipt_unregister_table(&packet_filter);
157 module_init(iptable_filter_init);
158 module_exit(iptable_filter_fini);