From f0a0cbef6d300a4502ac3b6c655a848f67ceb38f Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 9 Jan 2022 17:11:23 +0100 Subject: [PATCH] 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: Pablo Neira Ayuso --- net/netfilter/nft_meta.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c index fe91ff5f8fbe8..430f40bc3cb4c 100644 --- a/net/netfilter/nft_meta.c +++ b/net/netfilter/nft_meta.c @@ -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, }; -- 2.39.5