1 /*
2 * 'raw' table, which is the very first hooked in at PRE_ROUTING and LOCAL_OUT .
3 *
4 * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
5 */
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
13 static const struct xt_table packet_raw = {
14 .name = "raw",
15 .valid_hooks = RAW_VALID_HOOKS,
16 .me = THIS_MODULE,
17 .af = NFPROTO_IPV4,
18 .priority = NF_IP_PRI_RAW,
19 };
20
21 /* The work comes in here from netfilter.c. */
22 static unsigned int
iptable_raw_hook(unsigned int hook,struct sk_buff * skb,const struct net_device * in,const struct net_device * out,int (* okfn)(struct sk_buff *))23 iptable_raw_hook(unsigned int hook, struct sk_buff *skb,
24 const struct net_device *in, const struct net_device *out,
25 int (*okfn)(struct sk_buff *))
26 {
27 const struct net *net;
28
29 if (hook == NF_INET_LOCAL_OUT &&
30 (skb->len < sizeof(struct iphdr) ||
31 ip_hdrlen(skb) < sizeof(struct iphdr)))
32 /* root is playing with raw sockets. */
33 return NF_ACCEPT;
34
35 net = dev_net((in != NULL) ? in : out);
36 return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_raw);
37 }
38
39 static struct nf_hook_ops *rawtable_ops __read_mostly;
40
iptable_raw_net_init(struct net * net)41 static int __net_init iptable_raw_net_init(struct net *net)
42 {
43 struct ipt_replace *repl;
44
45 repl = ipt_alloc_initial_table(&packet_raw);
46 if (repl == NULL)
47 return -ENOMEM;
48 net->ipv4.iptable_raw =
49 ipt_register_table(net, &packet_raw, repl);
50 kfree(repl);
51 if (IS_ERR(net->ipv4.iptable_raw))
52 return PTR_ERR(net->ipv4.iptable_raw);
53 return 0;
54 }
55
iptable_raw_net_exit(struct net * net)56 static void __net_exit iptable_raw_net_exit(struct net *net)
57 {
58 ipt_unregister_table(net, net->ipv4.iptable_raw);
59 }
60
61 static struct pernet_operations iptable_raw_net_ops = {
62 .init = iptable_raw_net_init,
63 .exit = iptable_raw_net_exit,
64 };
65
iptable_raw_init(void)66 static int __init iptable_raw_init(void)
67 {
68 int ret;
69
70 ret = register_pernet_subsys(&iptable_raw_net_ops);
71 if (ret < 0)
72 return ret;
73
74 /* Register hooks */
75 rawtable_ops = xt_hook_link(&packet_raw, iptable_raw_hook);
76 if (IS_ERR(rawtable_ops)) {
77 ret = PTR_ERR(rawtable_ops);
78 goto cleanup_table;
79 }
80
81 return ret;
82
83 cleanup_table:
84 unregister_pernet_subsys(&iptable_raw_net_ops);
85 return ret;
86 }
87
iptable_raw_fini(void)88 static void __exit iptable_raw_fini(void)
89 {
90 xt_hook_unlink(&packet_raw, rawtable_ops);
91 unregister_pernet_subsys(&iptable_raw_net_ops);
92 }
93
94 module_init(iptable_raw_init);
95 module_exit(iptable_raw_fini);
96 MODULE_LICENSE("GPL");
97