1/*
2 * (C) 2010 Pablo Neira Ayuso <pablo@netfilter.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation (or any later at your option).
7 */
8
9#include <linux/netfilter.h>
10#include <linux/slab.h>
11#include <linux/kernel.h>
12#include <linux/moduleparam.h>
13
14#include <net/netfilter/nf_conntrack.h>
15#include <net/netfilter/nf_conntrack_extend.h>
16#include <net/netfilter/nf_conntrack_timestamp.h>
17
18static bool nf_ct_tstamp __read_mostly;
19
20module_param_named(tstamp, nf_ct_tstamp, bool, 0644);
21MODULE_PARM_DESC(tstamp, "Enable connection tracking flow timestamping.");
22
23#ifdef CONFIG_SYSCTL
24static struct ctl_table tstamp_sysctl_table[] = {
25	{
26		.procname	= "nf_conntrack_timestamp",
27		.data		= &init_net.ct.sysctl_tstamp,
28		.maxlen		= sizeof(unsigned int),
29		.mode		= 0644,
30		.proc_handler	= proc_dointvec,
31	},
32	{}
33};
34#endif /* CONFIG_SYSCTL */
35
36static struct nf_ct_ext_type tstamp_extend __read_mostly = {
37	.len	= sizeof(struct nf_conn_tstamp),
38	.align	= __alignof__(struct nf_conn_tstamp),
39	.id	= NF_CT_EXT_TSTAMP,
40};
41
42#ifdef CONFIG_SYSCTL
43static int nf_conntrack_tstamp_init_sysctl(struct net *net)
44{
45	struct ctl_table *table;
46
47	table = kmemdup(tstamp_sysctl_table, sizeof(tstamp_sysctl_table),
48			GFP_KERNEL);
49	if (!table)
50		goto out;
51
52	table[0].data = &net->ct.sysctl_tstamp;
53
54	/* Don't export sysctls to unprivileged users */
55	if (net->user_ns != &init_user_ns)
56		table[0].procname = NULL;
57
58	net->ct.tstamp_sysctl_header = register_net_sysctl(net,	"net/netfilter",
59							   table);
60	if (!net->ct.tstamp_sysctl_header) {
61		printk(KERN_ERR "nf_ct_tstamp: can't register to sysctl.\n");
62		goto out_register;
63	}
64	return 0;
65
66out_register:
67	kfree(table);
68out:
69	return -ENOMEM;
70}
71
72static void nf_conntrack_tstamp_fini_sysctl(struct net *net)
73{
74	struct ctl_table *table;
75
76	table = net->ct.tstamp_sysctl_header->ctl_table_arg;
77	unregister_net_sysctl_table(net->ct.tstamp_sysctl_header);
78	kfree(table);
79}
80#else
81static int nf_conntrack_tstamp_init_sysctl(struct net *net)
82{
83	return 0;
84}
85
86static void nf_conntrack_tstamp_fini_sysctl(struct net *net)
87{
88}
89#endif
90
91int nf_conntrack_tstamp_pernet_init(struct net *net)
92{
93	net->ct.sysctl_tstamp = nf_ct_tstamp;
94	return nf_conntrack_tstamp_init_sysctl(net);
95}
96
97void nf_conntrack_tstamp_pernet_fini(struct net *net)
98{
99	nf_conntrack_tstamp_fini_sysctl(net);
100}
101
102int nf_conntrack_tstamp_init(void)
103{
104	int ret;
105	ret = nf_ct_extend_register(&tstamp_extend);
106	if (ret < 0)
107		pr_err("nf_ct_tstamp: Unable to register extension\n");
108	return ret;
109}
110
111void nf_conntrack_tstamp_fini(void)
112{
113	nf_ct_extend_unregister(&tstamp_extend);
114}
115