1 /*
2 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
3 *
4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
5 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
6 *
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.
10 *
11 */
12
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/netfilter_ipv4/ip_tables.h>
16 #include <net/ip.h>
17
18 MODULE_LICENSE("GPL");
19 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
20 MODULE_DESCRIPTION("iptables filter table");
21
22 #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
23 (1 << NF_INET_FORWARD) | \
24 (1 << NF_INET_LOCAL_OUT))
25
26 static struct
27 {
28 struct ipt_replace repl;
29 struct ipt_standard entries[3];
30 struct ipt_error term;
31 } initial_table __net_initdata = {
32 .repl = {
33 .name = "filter",
34 .valid_hooks = FILTER_VALID_HOOKS,
35 .num_entries = 4,
36 .size = sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
37 .hook_entry = {
38 [NF_INET_LOCAL_IN] = 0,
39 [NF_INET_FORWARD] = sizeof(struct ipt_standard),
40 [NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2,
41 },
42 .underflow = {
43 [NF_INET_LOCAL_IN] = 0,
44 [NF_INET_FORWARD] = sizeof(struct ipt_standard),
45 [NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2,
46 },
47 },
48 .entries = {
49 IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */
50 IPT_STANDARD_INIT(NF_ACCEPT), /* FORWARD */
51 IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */
52 },
53 .term = IPT_ERROR_INIT, /* ERROR */
54 };
55
56 static struct xt_table packet_filter = {
57 .name = "filter",
58 .valid_hooks = FILTER_VALID_HOOKS,
59 .lock = RW_LOCK_UNLOCKED,
60 .me = THIS_MODULE,
61 .af = AF_INET,
62 };
63
64 /* The work comes in here from netfilter.c. */
65 static unsigned int
66 ipt_hook(unsigned int hook,
67 struct sk_buff *skb,
68 const struct net_device *in,
69 const struct net_device *out,
70 int (*okfn)(struct sk_buff *))
71 {
72 return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_filter);
73 }
74
75 static unsigned int
76 ipt_local_out_hook(unsigned int hook,
77 struct sk_buff *skb,
78 const struct net_device *in,
79 const struct net_device *out,
80 int (*okfn)(struct sk_buff *))
81 {
82 /* root is playing with raw sockets. */
83 if (skb->len < sizeof(struct iphdr) ||
84 ip_hdrlen(skb) < sizeof(struct iphdr)) {
85 if (net_ratelimit())
86 printk("iptable_filter: ignoring short SOCK_RAW "
87 "packet.\n");
88 return NF_ACCEPT;
89 }
90
91 return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_filter);
92 }
93
94 static struct nf_hook_ops ipt_ops[] __read_mostly = {
95 {
96 .hook = ipt_hook,
97 .owner = THIS_MODULE,
98 .pf = PF_INET,
99 .hooknum = NF_INET_LOCAL_IN,
100 .priority = NF_IP_PRI_FILTER,
101 },
102 {
103 .hook = ipt_hook,
104 .owner = THIS_MODULE,
105 .pf = PF_INET,
106 .hooknum = NF_INET_FORWARD,
107 .priority = NF_IP_PRI_FILTER,
108 },
109 {
110 .hook = ipt_local_out_hook,
111 .owner = THIS_MODULE,
112 .pf = PF_INET,
113 .hooknum = NF_INET_LOCAL_OUT,
114 .priority = NF_IP_PRI_FILTER,
115 },
116 };
117
118 /* Default to forward because I got too much mail already. */
119 static int forward = NF_ACCEPT;
120 module_param(forward, bool, 0000);
121
122 static int __net_init iptable_filter_net_init(struct net *net)
123 {
124 /* Register table */
125 net->ipv4.iptable_filter =
126 ipt_register_table(net, &packet_filter, &initial_table.repl);
127 if (IS_ERR(net->ipv4.iptable_filter))
128 return PTR_ERR(net->ipv4.iptable_filter);
129 return 0;
130 }
131
132 static void __net_exit iptable_filter_net_exit(struct net *net)
133 {
134 ipt_unregister_table(net->ipv4.iptable_filter);
135 }
136
137 static struct pernet_operations iptable_filter_net_ops = {
138 .init = iptable_filter_net_init,
139 .exit = iptable_filter_net_exit,
140 };
141
142 static int __init iptable_filter_init(void)
143 {
144 int ret;
145
146 if (forward < 0 || forward > NF_MAX_VERDICT) {
147 printk("iptables forward must be 0 or 1\n");
148 return -EINVAL;
149 }
150
151 /* Entry 1 is the FORWARD hook */
152 initial_table.entries[1].target.verdict = -forward - 1;
153
154 ret = register_pernet_subsys(&iptable_filter_net_ops);
155 if (ret < 0)
156 return ret;
157
158 /* Register hooks */
159 ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
160 if (ret < 0)
161 goto cleanup_table;
162
163 return ret;
164
165 cleanup_table:
166 unregister_pernet_subsys(&iptable_filter_net_ops);
167 return ret;
168 }
169
170 static void __exit iptable_filter_fini(void)
171 {
172 nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
173 unregister_pernet_subsys(&iptable_filter_net_ops);
174 }
175
176 module_init(iptable_filter_init);
177 module_exit(iptable_filter_fini);
178
|
This page was automatically generated by the
LXR engine.
|