From 48f1910326eaf7318cab8356302258faede4f6b5 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 14 Mar 2022 18:23:10 +0100 Subject: [PATCH] netfilter: nft_xfrm: track register operations Check if the destination register already contains the data that this xfrm 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_xfrm.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/net/netfilter/nft_xfrm.c b/net/netfilter/nft_xfrm.c index cbbbc4e..becb88f 100644 --- a/net/netfilter/nft_xfrm.c +++ b/net/netfilter/nft_xfrm.c @@ -27,6 +27,7 @@ struct nft_xfrm { u8 dreg; u8 dir; u8 spnum; + u8 len; }; static int nft_xfrm_get_init(const struct nft_ctx *ctx, @@ -86,6 +87,7 @@ static int nft_xfrm_get_init(const struct nft_ctx *ctx, priv->spnum = spnum; + priv->len = len; return nft_parse_register_store(ctx, tb[NFTA_XFRM_DREG], &priv->dreg, NULL, NFT_DATA_VALUE, len); } @@ -252,6 +254,31 @@ static int nft_xfrm_validate(const struct nft_ctx *ctx, const struct nft_expr *e return nft_chain_validate_hooks(ctx->chain, hooks); } +static bool nft_xfrm_reduce(struct nft_regs_track *track, + const struct nft_expr *expr) +{ + const struct nft_xfrm *priv = nft_expr_priv(expr); + const struct nft_xfrm *xfrm; + + if (!nft_reg_track_cmp(track, expr, priv->dreg)) { + nft_reg_track_update(track, expr, priv->dreg, priv->len); + return false; + } + + xfrm = nft_expr_priv(track->regs[priv->dreg].selector); + if (priv->key != xfrm->key || + priv->dreg != xfrm->dreg || + priv->dir != xfrm->dir || + priv->spnum != xfrm->spnum) { + nft_reg_track_update(track, expr, priv->dreg, priv->len); + return false; + } + + if (!track->regs[priv->dreg].bitwise) + return true; + + return nft_expr_reduce_bitwise(track, expr); +} static struct nft_expr_type nft_xfrm_type; static const struct nft_expr_ops nft_xfrm_get_ops = { @@ -261,6 +288,7 @@ static const struct nft_expr_ops nft_xfrm_get_ops = { .init = nft_xfrm_get_init, .dump = nft_xfrm_get_dump, .validate = nft_xfrm_validate, + .reduce = nft_xfrm_reduce, }; static struct nft_expr_type nft_xfrm_type __read_mostly = { -- 2.7.4