Commit 9b17afb2 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nft_meta: track register operations 



Check if the destination register already contains the data that this
meta store expression performs. This allows to skip this redundant
operation. If the destination contains a different selector, update
the register tracking information.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent a7c176bf

net/netfilter/nft_meta.c

+28 −0
Original line number Diff line number Diff line
@@ -750,12 +750,40 @@ static int nft_meta_get_offload(struct nft_offload_ctx *ctx, 
	return 0;

}



static bool nft_meta_get_reduce(struct nft_regs_track *track,

				const struct nft_expr *expr)

{

	const struct nft_meta *priv = nft_expr_priv(expr);

	const struct nft_meta *meta;



	if (!track->regs[priv->dreg].selector ||

	    track->regs[priv->dreg].selector->ops != expr->ops) {

		track->regs[priv->dreg].selector = expr;

		track->regs[priv->dreg].bitwise = NULL;

		return false;

	}



	meta = nft_expr_priv(track->regs[priv->dreg].selector);

	if (priv->key != meta->key ||

	    priv->dreg != meta->dreg) {

		track->regs[priv->dreg].selector = expr;

		track->regs[priv->dreg].bitwise = NULL;

		return false;

	}



	if (!track->regs[priv->dreg].bitwise)

		return true;



	return false;

}



static const struct nft_expr_ops nft_meta_get_ops = {

	.type		= &nft_meta_type,

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

	.eval		= nft_meta_get_eval,

	.init		= nft_meta_get_init,

	.dump		= nft_meta_get_dump,

	.reduce		= nft_meta_get_reduce,

	.validate	= nft_meta_get_validate,

	.offload	= nft_meta_get_offload,

};