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,
63 static struct xt_table *packet_filter;
65 /* The work comes in here from netfilter.c. */
67 ipt_hook(unsigned int hook,
69 const struct net_device *in,
70 const struct net_device *out,
71 int (*okfn)(struct sk_buff *))
73 return ipt_do_table(skb, hook, in, out, packet_filter);
77 ipt_local_out_hook(unsigned int hook,
79 const struct net_device *in,
80 const struct net_device *out,
81 int (*okfn)(struct sk_buff *))
83 /* root is playing with raw sockets. */
84 if (skb->len < sizeof(struct iphdr) ||
85 ip_hdrlen(skb) < sizeof(struct iphdr)) {
87 printk("iptable_filter: ignoring short SOCK_RAW "
92 return ipt_do_table(skb, hook, in, out, packet_filter);
95 static struct nf_hook_ops ipt_ops[] __read_mostly = {
100 .hooknum = NF_INET_LOCAL_IN,
101 .priority = NF_IP_PRI_FILTER,
105 .owner = THIS_MODULE,
107 .hooknum = NF_INET_FORWARD,
108 .priority = NF_IP_PRI_FILTER,
111 .hook = ipt_local_out_hook,
112 .owner = THIS_MODULE,
114 .hooknum = NF_INET_LOCAL_OUT,
115 .priority = NF_IP_PRI_FILTER,
119 /* Default to forward because I got too much mail already. */
120 static int forward = NF_ACCEPT;
121 module_param(forward, bool, 0000);
123 static int __init iptable_filter_init(void)
127 if (forward < 0 || forward > NF_MAX_VERDICT) {
128 printk("iptables forward must be 0 or 1\n");
132 /* Entry 1 is the FORWARD hook */
133 initial_table.entries[1].target.verdict = -forward - 1;
136 packet_filter = ipt_register_table(&init_net, &__packet_filter,
137 &initial_table.repl);
138 if (IS_ERR(packet_filter))
139 return PTR_ERR(packet_filter);
142 ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
149 ipt_unregister_table(packet_filter);
153 static void __exit iptable_filter_fini(void)
155 nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
156 ipt_unregister_table(packet_filter);
159 module_init(iptable_filter_init);
160 module_exit(iptable_filter_fini);