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6#include <linux/module.h>
7#include <linux/netfilter_ipv4/ip_tables.h>
8#include <linux/slab.h>
9#include <net/ip.h>
10
11#define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))
12
13static int __net_init iptable_raw_table_init(struct net *net);
14
15static const struct xt_table packet_raw = {
16 .name = "raw",
17 .valid_hooks = RAW_VALID_HOOKS,
18 .me = THIS_MODULE,
19 .af = NFPROTO_IPV4,
20 .priority = NF_IP_PRI_RAW,
21 .table_init = iptable_raw_table_init,
22};
23
24
25static unsigned int
26iptable_raw_hook(void *priv, struct sk_buff *skb,
27 const struct nf_hook_state *state)
28{
29 if (state->hook == NF_INET_LOCAL_OUT &&
30 (skb->len < sizeof(struct iphdr) ||
31 ip_hdrlen(skb) < sizeof(struct iphdr)))
32
33 return NF_ACCEPT;
34
35 return ipt_do_table(skb, state, state->net->ipv4.iptable_raw);
36}
37
38static struct nf_hook_ops *rawtable_ops __read_mostly;
39
40static int __net_init iptable_raw_table_init(struct net *net)
41{
42 struct ipt_replace *repl;
43 int ret;
44
45 if (net->ipv4.iptable_raw)
46 return 0;
47
48 repl = ipt_alloc_initial_table(&packet_raw);
49 if (repl == NULL)
50 return -ENOMEM;
51 ret = ipt_register_table(net, &packet_raw, repl, rawtable_ops,
52 &net->ipv4.iptable_raw);
53 kfree(repl);
54 return ret;
55}
56
57static void __net_exit iptable_raw_net_exit(struct net *net)
58{
59 if (!net->ipv4.iptable_raw)
60 return;
61 ipt_unregister_table(net, net->ipv4.iptable_raw, rawtable_ops);
62 net->ipv4.iptable_raw = NULL;
63}
64
65static struct pernet_operations iptable_raw_net_ops = {
66 .exit = iptable_raw_net_exit,
67};
68
69static int __init iptable_raw_init(void)
70{
71 int ret;
72
73 rawtable_ops = xt_hook_ops_alloc(&packet_raw, iptable_raw_hook);
74 if (IS_ERR(rawtable_ops))
75 return PTR_ERR(rawtable_ops);
76
77 ret = register_pernet_subsys(&iptable_raw_net_ops);
78 if (ret < 0) {
79 kfree(rawtable_ops);
80 return ret;
81 }
82
83 ret = iptable_raw_table_init(&init_net);
84 if (ret) {
85 unregister_pernet_subsys(&iptable_raw_net_ops);
86 kfree(rawtable_ops);
87 }
88
89 return ret;
90}
91
92static void __exit iptable_raw_fini(void)
93{
94 unregister_pernet_subsys(&iptable_raw_net_ops);
95 kfree(rawtable_ops);
96}
97
98module_init(iptable_raw_init);
99module_exit(iptable_raw_fini);
100MODULE_LICENSE("GPL");
101