1/*
2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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.
7 *
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
9 */
10
11#include <linux/kernel.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/seqlock.h>
15#include <linux/netlink.h>
16#include <linux/netfilter.h>
17#include <linux/netfilter/nf_tables.h>
18#include <net/netfilter/nf_tables.h>
19
20struct nft_counter {
21	seqlock_t	lock;
22	u64		bytes;
23	u64		packets;
24};
25
26static void nft_counter_eval(const struct nft_expr *expr,
27			     struct nft_regs *regs,
28			     const struct nft_pktinfo *pkt)
29{
30	struct nft_counter *priv = nft_expr_priv(expr);
31
32	write_seqlock_bh(&priv->lock);
33	priv->bytes += pkt->skb->len;
34	priv->packets++;
35	write_sequnlock_bh(&priv->lock);
36}
37
38static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr)
39{
40	struct nft_counter *priv = nft_expr_priv(expr);
41	unsigned int seq;
42	u64 bytes;
43	u64 packets;
44
45	do {
46		seq = read_seqbegin(&priv->lock);
47		bytes	= priv->bytes;
48		packets	= priv->packets;
49	} while (read_seqretry(&priv->lock, seq));
50
51	if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(bytes)))
52		goto nla_put_failure;
53	if (nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(packets)))
54		goto nla_put_failure;
55	return 0;
56
57nla_put_failure:
58	return -1;
59}
60
61static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
62	[NFTA_COUNTER_PACKETS]	= { .type = NLA_U64 },
63	[NFTA_COUNTER_BYTES]	= { .type = NLA_U64 },
64};
65
66static int nft_counter_init(const struct nft_ctx *ctx,
67			    const struct nft_expr *expr,
68			    const struct nlattr * const tb[])
69{
70	struct nft_counter *priv = nft_expr_priv(expr);
71
72	if (tb[NFTA_COUNTER_PACKETS])
73	        priv->packets = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
74	if (tb[NFTA_COUNTER_BYTES])
75		priv->bytes = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
76
77	seqlock_init(&priv->lock);
78	return 0;
79}
80
81static struct nft_expr_type nft_counter_type;
82static const struct nft_expr_ops nft_counter_ops = {
83	.type		= &nft_counter_type,
84	.size		= NFT_EXPR_SIZE(sizeof(struct nft_counter)),
85	.eval		= nft_counter_eval,
86	.init		= nft_counter_init,
87	.dump		= nft_counter_dump,
88};
89
90static struct nft_expr_type nft_counter_type __read_mostly = {
91	.name		= "counter",
92	.ops		= &nft_counter_ops,
93	.policy		= nft_counter_policy,
94	.maxattr	= NFTA_COUNTER_MAX,
95	.flags		= NFT_EXPR_STATEFUL,
96	.owner		= THIS_MODULE,
97};
98
99static int __init nft_counter_module_init(void)
100{
101	return nft_register_expr(&nft_counter_type);
102}
103
104static void __exit nft_counter_module_exit(void)
105{
106	nft_unregister_expr(&nft_counter_type);
107}
108
109module_init(nft_counter_module_init);
110module_exit(nft_counter_module_exit);
111
112MODULE_LICENSE("GPL");
113MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
114MODULE_ALIAS_NFT_EXPR("counter");
115