remarkable-linux/net/netfilter/nft_counter.c
Patrick McHardy 151d799a61 netfilter: nf_tables: mark stateful expressions
Add a flag to mark stateful expressions.

This is used for dynamic expression instanstiation to limit the usable
expressions. Strictly speaking only the dynset expression can not be
used in order to avoid recursion, but since dynamically instantiating
non-stateful expressions will simply create an identical copy, which
behaves no differently than the original, this limits to expressions
where it actually makes sense to dynamically instantiate them.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 20:12:31 +02:00

115 lines
2.9 KiB
C

/*
* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Development of this code funded by Astaro AG (http://www.astaro.com/)
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/seqlock.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
struct nft_counter {
seqlock_t lock;
u64 bytes;
u64 packets;
};
static void nft_counter_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
struct nft_counter *priv = nft_expr_priv(expr);
write_seqlock_bh(&priv->lock);
priv->bytes += pkt->skb->len;
priv->packets++;
write_sequnlock_bh(&priv->lock);
}
static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
struct nft_counter *priv = nft_expr_priv(expr);
unsigned int seq;
u64 bytes;
u64 packets;
do {
seq = read_seqbegin(&priv->lock);
bytes = priv->bytes;
packets = priv->packets;
} while (read_seqretry(&priv->lock, seq));
if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(bytes)))
goto nla_put_failure;
if (nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(packets)))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
[NFTA_COUNTER_PACKETS] = { .type = NLA_U64 },
[NFTA_COUNTER_BYTES] = { .type = NLA_U64 },
};
static int nft_counter_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_counter *priv = nft_expr_priv(expr);
if (tb[NFTA_COUNTER_PACKETS])
priv->packets = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
if (tb[NFTA_COUNTER_BYTES])
priv->bytes = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
seqlock_init(&priv->lock);
return 0;
}
static struct nft_expr_type nft_counter_type;
static const struct nft_expr_ops nft_counter_ops = {
.type = &nft_counter_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_counter)),
.eval = nft_counter_eval,
.init = nft_counter_init,
.dump = nft_counter_dump,
};
static struct nft_expr_type nft_counter_type __read_mostly = {
.name = "counter",
.ops = &nft_counter_ops,
.policy = nft_counter_policy,
.maxattr = NFTA_COUNTER_MAX,
.flags = NFT_EXPR_STATEFUL,
.owner = THIS_MODULE,
};
static int __init nft_counter_module_init(void)
{
return nft_register_expr(&nft_counter_type);
}
static void __exit nft_counter_module_exit(void)
{
nft_unregister_expr(&nft_counter_type);
}
module_init(nft_counter_module_init);
module_exit(nft_counter_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_EXPR("counter");