From 3c1eb413a45b6c6327fed394705081ec6202b31a Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 14 Mar 2022 18:23:12 +0100 Subject: netfilter: nft_fib: add reduce support The fib expression stores to a register, so we can't add empty stub. Check that the register that is being written is in fact redundant. In most cases, this is expected to cancel tracking as re-use is unlikely. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_fib.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'net/netfilter/nft_fib.c') diff --git a/net/netfilter/nft_fib.c b/net/netfilter/nft_fib.c index b10ce732b337..f198f2d9ef90 100644 --- a/net/netfilter/nft_fib.c +++ b/net/netfilter/nft_fib.c @@ -156,5 +156,47 @@ void nft_fib_store_result(void *reg, const struct nft_fib *priv, } EXPORT_SYMBOL_GPL(nft_fib_store_result); +bool nft_fib_reduce(struct nft_regs_track *track, + const struct nft_expr *expr) +{ + const struct nft_fib *priv = nft_expr_priv(expr); + unsigned int len = NFT_REG32_SIZE; + const struct nft_fib *fib; + + switch (priv->result) { + case NFT_FIB_RESULT_OIF: + break; + case NFT_FIB_RESULT_OIFNAME: + if (priv->flags & NFTA_FIB_F_PRESENT) + len = NFT_REG32_SIZE; + else + len = IFNAMSIZ; + break; + case NFT_FIB_RESULT_ADDRTYPE: + break; + default: + WARN_ON_ONCE(1); + break; + } + + if (!nft_reg_track_cmp(track, expr, priv->dreg)) { + nft_reg_track_update(track, expr, priv->dreg, len); + return false; + } + + fib = nft_expr_priv(track->regs[priv->dreg].selector); + if (priv->result != fib->result || + priv->flags != fib->flags) { + nft_reg_track_update(track, expr, priv->dreg, len); + return false; + } + + if (!track->regs[priv->dreg].bitwise) + return true; + + return false; +} +EXPORT_SYMBOL_GPL(nft_fib_reduce); + MODULE_LICENSE("GPL"); MODULE_AUTHOR("Florian Westphal "); -- cgit v1.2.3