From a7c176bf9f0e916f7544f6a00d898b0c90de1887 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 9 Jan 2022 17:11:22 +0100 Subject: netfilter: nft_payload: track register operations Check if the destination register already contains the data that this payload 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_payload.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'net/netfilter') diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index f2e65df32a06..7a7c66e9a50e 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -210,6 +210,34 @@ nla_put_failure: return -1; } +static bool nft_payload_reduce(struct nft_regs_track *track, + const struct nft_expr *expr) +{ + const struct nft_payload *priv = nft_expr_priv(expr); + const struct nft_payload *payload; + + 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; + } + + payload = nft_expr_priv(track->regs[priv->dreg].selector); + if (priv->base != payload->base || + priv->offset != payload->offset || + priv->len != payload->len) { + 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 bool nft_payload_offload_mask(struct nft_offload_reg *reg, u32 priv_len, u32 field_len) { @@ -513,6 +541,7 @@ static const struct nft_expr_ops nft_payload_ops = { .eval = nft_payload_eval, .init = nft_payload_init, .dump = nft_payload_dump, + .reduce = nft_payload_reduce, .offload = nft_payload_offload, }; @@ -522,6 +551,7 @@ const struct nft_expr_ops nft_payload_fast_ops = { .eval = nft_payload_eval, .init = nft_payload_init, .dump = nft_payload_dump, + .reduce = nft_payload_reduce, .offload = nft_payload_offload, }; -- cgit v1.2.3-59-g8ed1b