[PATCH net-next 29/32] netfilter: nft_meta: track register operations
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2022-01-09 23:18:36
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <pablo@netfilter.org> --- 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 fe91ff5f8fbe..430f40bc3cb4 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, };
--
2.30.2