1 /* Accouting handling for netfilter. */
2 
3 /*
4  * (C) 2008 Krzysztof Piotr Oledzki <ole@ans.pl>
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/netfilter.h>
14 #include <linux/slab.h>
15 #include <linux/kernel.h>
16 #include <linux/moduleparam.h>
17 #include <linux/export.h>
18 
19 #include <net/netfilter/nf_conntrack.h>
20 #include <net/netfilter/nf_conntrack_extend.h>
21 #include <net/netfilter/nf_conntrack_acct.h>
22 
23 static bool nf_ct_acct __read_mostly;
24 
25 module_param_named(acct, nf_ct_acct, bool, 0644);
26 MODULE_PARM_DESC(acct, "Enable connection tracking flow accounting.");
27 
28 #ifdef CONFIG_SYSCTL
29 static struct ctl_table acct_sysctl_table[] = {
30 	{
31 		.procname	= "nf_conntrack_acct",
32 		.data		= &init_net.ct.sysctl_acct,
33 		.maxlen		= sizeof(unsigned int),
34 		.mode		= 0644,
35 		.proc_handler	= proc_dointvec,
36 	},
37 	{}
38 };
39 #endif /* CONFIG_SYSCTL */
40 
41 unsigned int
seq_print_acct(struct seq_file * s,const struct nf_conn * ct,int dir)42 seq_print_acct(struct seq_file *s, const struct nf_conn *ct, int dir)
43 {
44 	struct nf_conn_acct *acct;
45 	struct nf_conn_counter *counter;
46 
47 	acct = nf_conn_acct_find(ct);
48 	if (!acct)
49 		return 0;
50 
51 	counter = acct->counter;
52 	seq_printf(s, "packets=%llu bytes=%llu ",
53 		   (unsigned long long)atomic64_read(&counter[dir].packets),
54 		   (unsigned long long)atomic64_read(&counter[dir].bytes));
55 
56 	return 0;
57 };
58 EXPORT_SYMBOL_GPL(seq_print_acct);
59 
60 static const struct nf_ct_ext_type acct_extend = {
61 	.len	= sizeof(struct nf_conn_acct),
62 	.align	= __alignof__(struct nf_conn_acct),
63 	.id	= NF_CT_EXT_ACCT,
64 };
65 
66 #ifdef CONFIG_SYSCTL
nf_conntrack_acct_init_sysctl(struct net * net)67 static int nf_conntrack_acct_init_sysctl(struct net *net)
68 {
69 	struct ctl_table *table;
70 
71 	table = kmemdup(acct_sysctl_table, sizeof(acct_sysctl_table),
72 			GFP_KERNEL);
73 	if (!table)
74 		goto out;
75 
76 	table[0].data = &net->ct.sysctl_acct;
77 
78 	/* Don't export sysctls to unprivileged users */
79 	if (net->user_ns != &init_user_ns)
80 		table[0].procname = NULL;
81 
82 	net->ct.acct_sysctl_header = register_net_sysctl(net, "net/netfilter",
83 							 table);
84 	if (!net->ct.acct_sysctl_header) {
85 		pr_err("can't register to sysctl\n");
86 		goto out_register;
87 	}
88 	return 0;
89 
90 out_register:
91 	kfree(table);
92 out:
93 	return -ENOMEM;
94 }
95 
nf_conntrack_acct_fini_sysctl(struct net * net)96 static void nf_conntrack_acct_fini_sysctl(struct net *net)
97 {
98 	struct ctl_table *table;
99 
100 	table = net->ct.acct_sysctl_header->ctl_table_arg;
101 	unregister_net_sysctl_table(net->ct.acct_sysctl_header);
102 	kfree(table);
103 }
104 #else
nf_conntrack_acct_init_sysctl(struct net * net)105 static int nf_conntrack_acct_init_sysctl(struct net *net)
106 {
107 	return 0;
108 }
109 
nf_conntrack_acct_fini_sysctl(struct net * net)110 static void nf_conntrack_acct_fini_sysctl(struct net *net)
111 {
112 }
113 #endif
114 
nf_conntrack_acct_pernet_init(struct net * net)115 int nf_conntrack_acct_pernet_init(struct net *net)
116 {
117 	net->ct.sysctl_acct = nf_ct_acct;
118 	return nf_conntrack_acct_init_sysctl(net);
119 }
120 
nf_conntrack_acct_pernet_fini(struct net * net)121 void nf_conntrack_acct_pernet_fini(struct net *net)
122 {
123 	nf_conntrack_acct_fini_sysctl(net);
124 }
125 
nf_conntrack_acct_init(void)126 int nf_conntrack_acct_init(void)
127 {
128 	int ret = nf_ct_extend_register(&acct_extend);
129 	if (ret < 0)
130 		pr_err("Unable to register extension\n");
131 	return ret;
132 }
133 
nf_conntrack_acct_fini(void)134 void nf_conntrack_acct_fini(void)
135 {
136 	nf_ct_extend_unregister(&acct_extend);
137 }
138