diff options
Diffstat (limited to 'net/netfilter/nft_limit.c')
-rw-r--r-- | net/netfilter/nft_limit.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c new file mode 100644 index 0000000..85da5bd --- /dev/null +++ b/net/netfilter/nft_limit.c @@ -0,0 +1,119 @@ +/* + * 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/spinlock.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> + +static DEFINE_SPINLOCK(limit_lock); + +struct nft_limit { + u64 tokens; + u64 rate; + u64 unit; + unsigned long stamp; +}; + +static void nft_limit_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + struct nft_limit *priv = nft_expr_priv(expr); + + spin_lock_bh(&limit_lock); + if (time_after_eq(jiffies, priv->stamp)) { + priv->tokens = priv->rate; + priv->stamp = jiffies + priv->unit * HZ; + } + + if (priv->tokens >= 1) { + priv->tokens--; + spin_unlock_bh(&limit_lock); + return; + } + spin_unlock_bh(&limit_lock); + + data[NFT_REG_VERDICT].verdict = NFT_BREAK; +} + +static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = { + [NFTA_LIMIT_RATE] = { .type = NLA_U64 }, + [NFTA_LIMIT_UNIT] = { .type = NLA_U64 }, +}; + +static int nft_limit_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_limit *priv = nft_expr_priv(expr); + + if (tb[NFTA_LIMIT_RATE] == NULL || + tb[NFTA_LIMIT_UNIT] == NULL) + return -EINVAL; + + priv->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE])); + priv->unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT])); + priv->stamp = jiffies + priv->unit * HZ; + priv->tokens = priv->rate; + return 0; +} + +static int nft_limit_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_limit *priv = nft_expr_priv(expr); + + if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(priv->rate))) + goto nla_put_failure; + if (nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(priv->unit))) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_limit_type; +static const struct nft_expr_ops nft_limit_ops = { + .type = &nft_limit_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_limit)), + .eval = nft_limit_eval, + .init = nft_limit_init, + .dump = nft_limit_dump, +}; + +static struct nft_expr_type nft_limit_type __read_mostly = { + .name = "limit", + .ops = &nft_limit_ops, + .policy = nft_limit_policy, + .maxattr = NFTA_LIMIT_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_limit_module_init(void) +{ + return nft_register_expr(&nft_limit_type); +} + +static void __exit nft_limit_module_exit(void) +{ + nft_unregister_expr(&nft_limit_type); +} + +module_init(nft_limit_module_init); +module_exit(nft_limit_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_ALIAS_NFT_EXPR("limit"); |