ipvs: convert lblc scheduler to rcu
[linux-3.10.git] / net / netfilter / xt_state.c
1 /* Kernel module to match connection tracking information. */
2
3 /* (C) 1999-2001 Paul `Rusty' Russell
4  * (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10
11 #include <linux/module.h>
12 #include <linux/skbuff.h>
13 #include <net/netfilter/nf_conntrack.h>
14 #include <linux/netfilter/x_tables.h>
15 #include <linux/netfilter/xt_state.h>
16
17 MODULE_LICENSE("GPL");
18 MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
19 MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module");
20 MODULE_ALIAS("ipt_state");
21 MODULE_ALIAS("ip6t_state");
22
23 static bool
24 state_mt(const struct sk_buff *skb, struct xt_action_param *par)
25 {
26         const struct xt_state_info *sinfo = par->matchinfo;
27         enum ip_conntrack_info ctinfo;
28         unsigned int statebit;
29         struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
30
31         if (!ct)
32                 statebit = XT_STATE_INVALID;
33         else {
34                 if (nf_ct_is_untracked(ct))
35                         statebit = XT_STATE_UNTRACKED;
36                 else
37                         statebit = XT_STATE_BIT(ctinfo);
38         }
39         return (sinfo->statemask & statebit);
40 }
41
42 static int state_mt_check(const struct xt_mtchk_param *par)
43 {
44         int ret;
45
46         ret = nf_ct_l3proto_try_module_get(par->family);
47         if (ret < 0)
48                 pr_info("cannot load conntrack support for proto=%u\n",
49                         par->family);
50         return ret;
51 }
52
53 static void state_mt_destroy(const struct xt_mtdtor_param *par)
54 {
55         nf_ct_l3proto_module_put(par->family);
56 }
57
58 static struct xt_match state_mt_reg __read_mostly = {
59         .name       = "state",
60         .family     = NFPROTO_UNSPEC,
61         .checkentry = state_mt_check,
62         .match      = state_mt,
63         .destroy    = state_mt_destroy,
64         .matchsize  = sizeof(struct xt_state_info),
65         .me         = THIS_MODULE,
66 };
67
68 static int __init state_mt_init(void)
69 {
70         return xt_register_match(&state_mt_reg);
71 }
72
73 static void __exit state_mt_exit(void)
74 {
75         xt_unregister_match(&state_mt_reg);
76 }
77
78 module_init(state_mt_init);
79 module_exit(state_mt_exit);