120 lines
2.9 KiB
C
120 lines
2.9 KiB
C
/*
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* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Development of this code funded by Astaro AG (http://www.astaro.com/)
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables.h>
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static DEFINE_SPINLOCK(limit_lock);
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struct nft_limit {
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u64 tokens;
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u64 rate;
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u64 unit;
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unsigned long stamp;
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};
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static void nft_limit_eval(const struct nft_expr *expr,
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struct nft_data data[NFT_REG_MAX + 1],
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const struct nft_pktinfo *pkt)
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{
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struct nft_limit *priv = nft_expr_priv(expr);
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spin_lock_bh(&limit_lock);
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if (time_after_eq(jiffies, priv->stamp)) {
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priv->tokens = priv->rate;
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priv->stamp = jiffies + priv->unit * HZ;
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}
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if (priv->tokens >= 1) {
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priv->tokens--;
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spin_unlock_bh(&limit_lock);
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return;
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}
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spin_unlock_bh(&limit_lock);
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data[NFT_REG_VERDICT].verdict = NFT_BREAK;
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}
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static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = {
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[NFTA_LIMIT_RATE] = { .type = NLA_U64 },
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[NFTA_LIMIT_UNIT] = { .type = NLA_U64 },
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};
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static int nft_limit_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_limit *priv = nft_expr_priv(expr);
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if (tb[NFTA_LIMIT_RATE] == NULL ||
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tb[NFTA_LIMIT_UNIT] == NULL)
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return -EINVAL;
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priv->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE]));
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priv->unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT]));
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priv->stamp = jiffies + priv->unit * HZ;
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priv->tokens = priv->rate;
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return 0;
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}
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static int nft_limit_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_limit *priv = nft_expr_priv(expr);
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if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(priv->rate)))
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goto nla_put_failure;
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if (nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(priv->unit)))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static struct nft_expr_type nft_limit_type;
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static const struct nft_expr_ops nft_limit_ops = {
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.type = &nft_limit_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_limit)),
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.eval = nft_limit_eval,
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.init = nft_limit_init,
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.dump = nft_limit_dump,
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};
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static struct nft_expr_type nft_limit_type __read_mostly = {
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.name = "limit",
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.ops = &nft_limit_ops,
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.policy = nft_limit_policy,
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.maxattr = NFTA_LIMIT_MAX,
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.owner = THIS_MODULE,
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};
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static int __init nft_limit_module_init(void)
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{
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return nft_register_expr(&nft_limit_type);
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}
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static void __exit nft_limit_module_exit(void)
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{
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nft_unregister_expr(&nft_limit_type);
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}
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module_init(nft_limit_module_init);
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module_exit(nft_limit_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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MODULE_ALIAS_NFT_EXPR("limit");
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