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Commit c7862a5f authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nft_limit: allow to invert matching criteria 



This patch allows you to invert the ratelimit matching criteria, so you
can match packets over the ratelimit. This is required to support what
hashlimit does.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 5913beaf

include/uapi/linux/netfilter/nf_tables.h

+6 −0
Original line number Diff line number Diff line
@@ -780,6 +780,10 @@ enum nft_limit_type { 
	NFT_LIMIT_PKT_BYTES

};



enum nft_limit_flags {

	NFT_LIMIT_F_INV	= (1 << 0),

};



/**

 * enum nft_limit_attributes - nf_tables limit expression netlink attributes

 *
@@ -787,6 +791,7 @@ enum nft_limit_type { 
 * @NFTA_LIMIT_UNIT: refill unit (NLA_U64)

 * @NFTA_LIMIT_BURST: burst (NLA_U32)

 * @NFTA_LIMIT_TYPE: type of limit (NLA_U32: enum nft_limit_type)

 * @NFTA_LIMIT_FLAGS: flags (NLA_U32: enum nft_limit_flags)

 */

enum nft_limit_attributes {

	NFTA_LIMIT_UNSPEC,
@@ -794,6 +799,7 @@ enum nft_limit_attributes { 
	NFTA_LIMIT_UNIT,

	NFTA_LIMIT_BURST,

	NFTA_LIMIT_TYPE,

	NFTA_LIMIT_FLAGS,

	__NFTA_LIMIT_MAX

};

#define NFTA_LIMIT_MAX		(__NFTA_LIMIT_MAX - 1)

net/netfilter/nft_limit.c

+13 −3
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ struct nft_limit { 
	u64		rate;

	u64		nsecs;

	u32		burst;

	bool		invert;

};



static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost)
@@ -44,11 +45,11 @@ static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost) 
	if (delta >= 0) {

		limit->tokens = delta;

		spin_unlock_bh(&limit_lock);

		return false;

		return limit->invert;

	}

	limit->tokens = tokens;

	spin_unlock_bh(&limit_lock);

	return true;

	return !limit->invert;

}



static int nft_limit_init(struct nft_limit *limit,
@@ -78,6 +79,12 @@ static int nft_limit_init(struct nft_limit *limit, 


		limit->rate = rate;

	}

	if (tb[NFTA_LIMIT_FLAGS]) {

		u32 flags = ntohl(nla_get_be32(tb[NFTA_LIMIT_FLAGS]));



		if (flags & NFT_LIMIT_F_INV)

			limit->invert = true;

	}

	limit->last = ktime_get_ns();



	return 0;
@@ -86,13 +93,15 @@ static int nft_limit_init(struct nft_limit *limit, 
static int nft_limit_dump(struct sk_buff *skb, const struct nft_limit *limit,

			  enum nft_limit_type type)

{

	u32 flags = limit->invert ? NFT_LIMIT_F_INV : 0;

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

	u64 rate = limit->rate - limit->burst;



	if (nla_put_be64(skb, NFTA_LIMIT_RATE, cpu_to_be64(rate)) ||

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

	    nla_put_be32(skb, NFTA_LIMIT_BURST, htonl(limit->burst)) ||

	    nla_put_be32(skb, NFTA_LIMIT_TYPE, htonl(type)))

	    nla_put_be32(skb, NFTA_LIMIT_TYPE, htonl(type)) ||

	    nla_put_be32(skb, NFTA_LIMIT_FLAGS, htonl(flags)))

		goto nla_put_failure;

	return 0;
@@ -120,6 +129,7 @@ static const struct nla_policy nft_limit_policy[NFTA_LIMIT_MAX + 1] = { 
	[NFTA_LIMIT_UNIT]	= { .type = NLA_U64 },

	[NFTA_LIMIT_BURST]	= { .type = NLA_U32 },

	[NFTA_LIMIT_TYPE]	= { .type = NLA_U32 },

	[NFTA_LIMIT_FLAGS]	= { .type = NLA_U32 },

};



static int nft_limit_pkts_init(const struct nft_ctx *ctx,