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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/netfilter.h>
12 #include <linux/slab.h>
13 #include <linux/kernel.h>
14 #include <linux/moduleparam.h>
15
16 #include <net/netfilter/nf_conntrack.h>
17 #include <net/netfilter/nf_conntrack_extend.h>
18 #include <net/netfilter/nf_conntrack_timestamp.h>
19
20 static bool nf_ct_tstamp __read_mostly;
21
22 module_param_named(tstamp, nf_ct_tstamp, bool, 0644);
23 MODULE_PARM_DESC(tstamp, "Enable connection tracking flow timestamping.");
24
25 #ifdef CONFIG_SYSCTL
26 static struct ctl_table tstamp_sysctl_table[] = {
27 {
28 .procname = "nf_conntrack_timestamp",
29 .data = &init_net.ct.sysctl_tstamp,
30 .maxlen = sizeof(unsigned int),
31 .mode = 0644,
32 .proc_handler = proc_dointvec,
33 },
34 {}
35 };
36 #endif /* CONFIG_SYSCTL */
37
38 static const struct nf_ct_ext_type tstamp_extend = {
39 .len = sizeof(struct nf_conn_tstamp),
40 .align = __alignof__(struct nf_conn_tstamp),
41 .id = NF_CT_EXT_TSTAMP,
42 };
43
44 #ifdef CONFIG_SYSCTL
nf_conntrack_tstamp_init_sysctl(struct net * net)45 static int nf_conntrack_tstamp_init_sysctl(struct net *net)
46 {
47 struct ctl_table *table;
48
49 table = kmemdup(tstamp_sysctl_table, sizeof(tstamp_sysctl_table),
50 GFP_KERNEL);
51 if (!table)
52 goto out;
53
54 table[0].data = &net->ct.sysctl_tstamp;
55
56 /* Don't export sysctls to unprivileged users */
57 if (net->user_ns != &init_user_ns)
58 table[0].procname = NULL;
59
60 net->ct.tstamp_sysctl_header = register_net_sysctl(net, "net/netfilter",
61 table);
62 if (!net->ct.tstamp_sysctl_header) {
63 pr_err("can't register to sysctl\n");
64 goto out_register;
65 }
66 return 0;
67
68 out_register:
69 kfree(table);
70 out:
71 return -ENOMEM;
72 }
73
nf_conntrack_tstamp_fini_sysctl(struct net * net)74 static void nf_conntrack_tstamp_fini_sysctl(struct net *net)
75 {
76 struct ctl_table *table;
77
78 table = net->ct.tstamp_sysctl_header->ctl_table_arg;
79 unregister_net_sysctl_table(net->ct.tstamp_sysctl_header);
80 kfree(table);
81 }
82 #else
nf_conntrack_tstamp_init_sysctl(struct net * net)83 static int nf_conntrack_tstamp_init_sysctl(struct net *net)
84 {
85 return 0;
86 }
87
nf_conntrack_tstamp_fini_sysctl(struct net * net)88 static void nf_conntrack_tstamp_fini_sysctl(struct net *net)
89 {
90 }
91 #endif
92
nf_conntrack_tstamp_pernet_init(struct net * net)93 int nf_conntrack_tstamp_pernet_init(struct net *net)
94 {
95 net->ct.sysctl_tstamp = nf_ct_tstamp;
96 return nf_conntrack_tstamp_init_sysctl(net);
97 }
98
nf_conntrack_tstamp_pernet_fini(struct net * net)99 void nf_conntrack_tstamp_pernet_fini(struct net *net)
100 {
101 nf_conntrack_tstamp_fini_sysctl(net);
102 }
103
nf_conntrack_tstamp_init(void)104 int nf_conntrack_tstamp_init(void)
105 {
106 int ret;
107 ret = nf_ct_extend_register(&tstamp_extend);
108 if (ret < 0)
109 pr_err("Unable to register extension\n");
110 return ret;
111 }
112
nf_conntrack_tstamp_fini(void)113 void nf_conntrack_tstamp_fini(void)
114 {
115 nf_ct_extend_unregister(&tstamp_extend);
116 }
117
