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/netfilter_ipv4/ip_tables.h>
16 MODULE_LICENSE("GPL");
17 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
18 MODULE_DESCRIPTION("iptables filter table");
20 #define FILTER_VALID_HOOKS ((1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD) | (1 << NF_IP_LOCAL_OUT))
25 struct ipt_entry entry;
26 struct ipt_standard_target target;
29 struct ipt_error_target
31 struct ipt_entry_target target;
32 char errorname[IPT_FUNCTION_MAXNAMELEN];
37 struct ipt_entry entry;
38 struct ipt_error_target target;
43 struct ipt_replace repl;
44 struct ipt_standard entries[3];
45 struct ipt_error term;
46 } initial_table __initdata
47 = { { "filter", FILTER_VALID_HOOKS, 4,
48 sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
49 { [NF_IP_LOCAL_IN] = 0,
50 [NF_IP_FORWARD] = sizeof(struct ipt_standard),
51 [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
52 { [NF_IP_LOCAL_IN] = 0,
53 [NF_IP_FORWARD] = sizeof(struct ipt_standard),
54 [NF_IP_LOCAL_OUT] = sizeof(struct ipt_standard) * 2 },
58 { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
60 sizeof(struct ipt_entry),
61 sizeof(struct ipt_standard),
63 { { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
66 { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
68 sizeof(struct ipt_entry),
69 sizeof(struct ipt_standard),
71 { { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
74 { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
76 sizeof(struct ipt_entry),
77 sizeof(struct ipt_standard),
79 { { { { IPT_ALIGN(sizeof(struct ipt_standard_target)), "" } }, { } },
83 { { { { 0 }, { 0 }, { 0 }, { 0 }, "", "", { 0 }, { 0 }, 0, 0, 0 },
85 sizeof(struct ipt_entry),
86 sizeof(struct ipt_error),
88 { { { { IPT_ALIGN(sizeof(struct ipt_error_target)), IPT_ERROR_TARGET } },
95 static struct ipt_table packet_filter = {
97 .table = &initial_table.repl,
98 .valid_hooks = FILTER_VALID_HOOKS,
99 .lock = RW_LOCK_UNLOCKED,
103 /* The work comes in here from netfilter.c. */
105 ipt_hook(unsigned int hook,
106 struct sk_buff **pskb,
107 const struct net_device *in,
108 const struct net_device *out,
109 int (*okfn)(struct sk_buff *))
111 return ipt_do_table(pskb, hook, in, out, &packet_filter, NULL);
115 ipt_local_out_hook(unsigned int hook,
116 struct sk_buff **pskb,
117 const struct net_device *in,
118 const struct net_device *out,
119 int (*okfn)(struct sk_buff *))
121 /* root is playing with raw sockets. */
122 if ((*pskb)->len < sizeof(struct iphdr)
123 || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
125 printk("ipt_hook: happy cracking.\n");
129 return ipt_do_table(pskb, hook, in, out, &packet_filter, NULL);
132 static struct nf_hook_ops ipt_ops[] = {
135 .owner = THIS_MODULE,
137 .hooknum = NF_IP_LOCAL_IN,
138 .priority = NF_IP_PRI_FILTER,
142 .owner = THIS_MODULE,
144 .hooknum = NF_IP_FORWARD,
145 .priority = NF_IP_PRI_FILTER,
148 .hook = ipt_local_out_hook,
149 .owner = THIS_MODULE,
151 .hooknum = NF_IP_LOCAL_OUT,
152 .priority = NF_IP_PRI_FILTER,
156 /* Default to forward because I got too much mail already. */
157 static int forward = NF_ACCEPT;
158 MODULE_PARM(forward, "i");
160 static int __init init(void)
164 if (forward < 0 || forward > NF_MAX_VERDICT) {
165 printk("iptables forward must be 0 or 1\n");
169 /* Entry 1 is the FORWARD hook */
170 initial_table.entries[1].target.verdict = -forward - 1;
173 ret = ipt_register_table(&packet_filter);
178 ret = nf_register_hook(&ipt_ops[0]);
182 ret = nf_register_hook(&ipt_ops[1]);
186 ret = nf_register_hook(&ipt_ops[2]);
193 nf_unregister_hook(&ipt_ops[1]);
195 nf_unregister_hook(&ipt_ops[0]);
197 ipt_unregister_table(&packet_filter);
202 static void __exit fini(void)
206 for (i = 0; i < sizeof(ipt_ops)/sizeof(struct nf_hook_ops); i++)
207 nf_unregister_hook(&ipt_ops[i]);
209 ipt_unregister_table(&packet_filter);