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
18 static bool nf_ct_tstamp __read_mostly;
19
20 module_param_named(tstamp, nf_ct_tstamp, bool, 0644);
21 MODULE_PARM_DESC(tstamp, "Enable connection tracking flow timestamping.");
22
23 #ifdef CONFIG_SYSCTL
24 static 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
36 static 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
nf_conntrack_tstamp_init_sysctl(struct net * net)43 static 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 net->ct.tstamp_sysctl_header = register_net_sysctl_table(net,
55 nf_net_netfilter_sysctl_path, table);
56 if (!net->ct.tstamp_sysctl_header) {
57 printk(KERN_ERR "nf_ct_tstamp: can't register to sysctl.\n");
58 goto out_register;
59 }
60 return 0;
61
62 out_register:
63 kfree(table);
64 out:
65 return -ENOMEM;
66 }
67
nf_conntrack_tstamp_fini_sysctl(struct net * net)68 static void nf_conntrack_tstamp_fini_sysctl(struct net *net)
69 {
70 struct ctl_table *table;
71
72 table = net->ct.tstamp_sysctl_header->ctl_table_arg;
73 unregister_net_sysctl_table(net->ct.tstamp_sysctl_header);
74 kfree(table);
75 }
76 #else
nf_conntrack_tstamp_init_sysctl(struct net * net)77 static int nf_conntrack_tstamp_init_sysctl(struct net *net)
78 {
79 return 0;
80 }
81
nf_conntrack_tstamp_fini_sysctl(struct net * net)82 static void nf_conntrack_tstamp_fini_sysctl(struct net *net)
83 {
84 }
85 #endif
86
nf_conntrack_tstamp_init(struct net * net)87 int nf_conntrack_tstamp_init(struct net *net)
88 {
89 int ret;
90
91 net->ct.sysctl_tstamp = nf_ct_tstamp;
92
93 if (net_eq(net, &init_net)) {
94 ret = nf_ct_extend_register(&tstamp_extend);
95 if (ret < 0) {
96 printk(KERN_ERR "nf_ct_tstamp: Unable to register "
97 "extension\n");
98 goto out_extend_register;
99 }
100 }
101
102 ret = nf_conntrack_tstamp_init_sysctl(net);
103 if (ret < 0)
104 goto out_sysctl;
105
106 return 0;
107
108 out_sysctl:
109 if (net_eq(net, &init_net))
110 nf_ct_extend_unregister(&tstamp_extend);
111 out_extend_register:
112 return ret;
113 }
114
nf_conntrack_tstamp_fini(struct net * net)115 void nf_conntrack_tstamp_fini(struct net *net)
116 {
117 nf_conntrack_tstamp_fini_sysctl(net);
118 if (net_eq(net, &init_net))
119 nf_ct_extend_unregister(&tstamp_extend);
120 }
121