This source file includes following definitions.
- iptable_filter_hook
- iptable_filter_table_init
- iptable_filter_net_init
- iptable_filter_net_exit
- iptable_filter_init
- iptable_filter_fini
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9 #include <linux/module.h>
10 #include <linux/moduleparam.h>
11 #include <linux/netfilter_ipv4/ip_tables.h>
12 #include <linux/slab.h>
13 #include <net/ip.h>
14
15 MODULE_LICENSE("GPL");
16 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
17 MODULE_DESCRIPTION("iptables filter table");
18
19 #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
20 (1 << NF_INET_FORWARD) | \
21 (1 << NF_INET_LOCAL_OUT))
22 static int __net_init iptable_filter_table_init(struct net *net);
23
24 static const struct xt_table packet_filter = {
25 .name = "filter",
26 .valid_hooks = FILTER_VALID_HOOKS,
27 .me = THIS_MODULE,
28 .af = NFPROTO_IPV4,
29 .priority = NF_IP_PRI_FILTER,
30 .table_init = iptable_filter_table_init,
31 };
32
33 static unsigned int
34 iptable_filter_hook(void *priv, struct sk_buff *skb,
35 const struct nf_hook_state *state)
36 {
37 return ipt_do_table(skb, state, state->net->ipv4.iptable_filter);
38 }
39
40 static struct nf_hook_ops *filter_ops __read_mostly;
41
42
43 static bool forward __read_mostly = true;
44 module_param(forward, bool, 0000);
45
46 static int __net_init iptable_filter_table_init(struct net *net)
47 {
48 struct ipt_replace *repl;
49 int err;
50
51 if (net->ipv4.iptable_filter)
52 return 0;
53
54 repl = ipt_alloc_initial_table(&packet_filter);
55 if (repl == NULL)
56 return -ENOMEM;
57
58 ((struct ipt_standard *)repl->entries)[1].target.verdict =
59 forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
60
61 err = ipt_register_table(net, &packet_filter, repl, filter_ops,
62 &net->ipv4.iptable_filter);
63 kfree(repl);
64 return err;
65 }
66
67 static int __net_init iptable_filter_net_init(struct net *net)
68 {
69 if (net == &init_net || !forward)
70 return iptable_filter_table_init(net);
71
72 return 0;
73 }
74
75 static void __net_exit iptable_filter_net_exit(struct net *net)
76 {
77 if (!net->ipv4.iptable_filter)
78 return;
79 ipt_unregister_table(net, net->ipv4.iptable_filter, filter_ops);
80 net->ipv4.iptable_filter = NULL;
81 }
82
83 static struct pernet_operations iptable_filter_net_ops = {
84 .init = iptable_filter_net_init,
85 .exit = iptable_filter_net_exit,
86 };
87
88 static int __init iptable_filter_init(void)
89 {
90 int ret;
91
92 filter_ops = xt_hook_ops_alloc(&packet_filter, iptable_filter_hook);
93 if (IS_ERR(filter_ops))
94 return PTR_ERR(filter_ops);
95
96 ret = register_pernet_subsys(&iptable_filter_net_ops);
97 if (ret < 0)
98 kfree(filter_ops);
99
100 return ret;
101 }
102
103 static void __exit iptable_filter_fini(void)
104 {
105 unregister_pernet_subsys(&iptable_filter_net_ops);
106 kfree(filter_ops);
107 }
108
109 module_init(iptable_filter_init);
110 module_exit(iptable_filter_fini);