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Commit f8d3a6bc authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nft_limit: factor out shared code with per-byte limiting 



This patch prepares the introduction of per-byte limiting.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent dba27ec1

net/netfilter/nft_limit.c

+53 −33
Original line number Diff line number Diff line
@@ -27,65 +27,54 @@ struct nft_limit { 
	u64		nsecs;

};



static void nft_limit_pkts_eval(const struct nft_expr *expr,

				struct nft_regs *regs,

				const struct nft_pktinfo *pkt)

static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost)

{

	struct nft_limit *priv = nft_expr_priv(expr);

	u64 now, tokens, cost = div_u64(priv->nsecs, priv->rate);

	u64 now, tokens;

	s64 delta;



	spin_lock_bh(&limit_lock);

	now = ktime_get_ns();

	tokens = priv->tokens + now - priv->last;

	if (tokens > priv->tokens_max)

		tokens = priv->tokens_max;

	tokens = limit->tokens + now - limit->last;

	if (tokens > limit->tokens_max)

		tokens = limit->tokens_max;



	priv->last = now;

	limit->last = now;

	delta = tokens - cost;

	if (delta >= 0) {

		priv->tokens = delta;

		limit->tokens = delta;

		spin_unlock_bh(&limit_lock);

		return;

		return false;

	}

	priv->tokens = tokens;

	limit->tokens = tokens;

	spin_unlock_bh(&limit_lock);



	regs->verdict.code = NFT_BREAK;

	return true;

}



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,

static int nft_limit_init(struct nft_limit *limit,

			  const struct nlattr * const tb[])

{

	struct nft_limit *priv = nft_expr_priv(expr);

	u64 unit;



	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]));

	limit->rate = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_RATE]));

	unit = be64_to_cpu(nla_get_be64(tb[NFTA_LIMIT_UNIT]));

	priv->nsecs = unit * NSEC_PER_SEC;

	if (priv->rate == 0 || priv->nsecs < unit)

	limit->nsecs = unit * NSEC_PER_SEC;

	if (limit->rate == 0 || limit->nsecs < unit)

		return -EOVERFLOW;

	priv->tokens = priv->tokens_max = priv->nsecs;

	priv->last = ktime_get_ns();

	limit->tokens = limit->tokens_max = limit->nsecs;

	limit->last = ktime_get_ns();



	return 0;

}



static int nft_limit_dump(struct sk_buff *skb, const struct nft_expr *expr)

static int nft_limit_dump(struct sk_buff *skb, const struct nft_limit *limit)

{

	const struct nft_limit *priv = nft_expr_priv(expr);

	u64 secs = div_u64(priv->nsecs, NSEC_PER_SEC);

	u64 secs = div_u64(limit->nsecs, NSEC_PER_SEC);



	if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(priv->rate)) ||

	if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(limit->rate)) ||

	    nla_put_be64(skb, NFTA_LIMIT_UNIT, cpu_to_be64(secs)))

		goto nla_put_failure;

	return 0;
@@ -94,13 +83,44 @@ static int nft_limit_dump(struct sk_buff *skb, const struct nft_expr *expr) 
	return -1;

}



static void nft_limit_pkts_eval(const struct nft_expr *expr,

				struct nft_regs *regs,

				const struct nft_pktinfo *pkt)

{

	struct nft_limit *priv = nft_expr_priv(expr);



	if (nft_limit_eval(priv, div_u64(priv->nsecs, priv->rate)))

		regs->verdict.code = 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_pkts_init(const struct nft_ctx *ctx,

			       const struct nft_expr *expr,

			       const struct nlattr * const tb[])

{

	struct nft_limit *priv = nft_expr_priv(expr);



	return nft_limit_init(priv, tb);

}



static int nft_limit_pkts_dump(struct sk_buff *skb, const struct nft_expr *expr)

{

	const struct nft_limit *priv = nft_expr_priv(expr);



	return nft_limit_dump(skb, priv);

}



static struct nft_expr_type nft_limit_type;

static const struct nft_expr_ops nft_limit_pkts_ops = {

	.type		= &nft_limit_type,

	.size		= NFT_EXPR_SIZE(sizeof(struct nft_limit)),

	.eval		= nft_limit_pkts_eval,

	.init		= nft_limit_init,

	.dump		= nft_limit_dump,

	.init		= nft_limit_pkts_init,

	.dump		= nft_limit_pkts_dump,

};



static struct nft_expr_type nft_limit_type __read_mostly = {