From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D70B2C433F5 for ; Fri, 10 Dec 2021 00:29:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234897AbhLJAcm (ORCPT ); Thu, 9 Dec 2021 19:32:42 -0500 Received: from mail.netfilter.org ([217.70.188.207]:44420 "EHLO mail.netfilter.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234904AbhLJAck (ORCPT ); Thu, 9 Dec 2021 19:32:40 -0500 Received: from localhost.localdomain (unknown [78.30.32.163]) by mail.netfilter.org (Postfix) with ESMTPSA id 8D5AF60085 for ; Fri, 10 Dec 2021 01:26:41 +0100 (CET) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH nf-next 11/11] netfilter: nft_bitwise: track register operations Date: Fri, 10 Dec 2021 01:28:54 +0100 Message-Id: <20211210002854.144328-12-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211210002854.144328-1-pablo@netfilter.org> References: <20211210002854.144328-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Check if the destination register already contains the data that this bitwise store expression performs. This allows to skip this redundant operation. If the destination contains a different bitwise operation, cancel the register tracking information. Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_bitwise.c | 79 +++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c index 47b0dba95054..ad577b79bc31 100644 --- a/net/netfilter/nft_bitwise.c +++ b/net/netfilter/nft_bitwise.c @@ -278,12 +278,53 @@ static int nft_bitwise_offload(struct nft_offload_ctx *ctx, return 0; } +static bool nft_bitwise_reduce(struct nft_regs_track *track, + const struct nft_expr *expr) +{ + const struct nft_bitwise *priv = nft_expr_priv(expr); + const struct nft_bitwise *bitwise; + + if (!track->regs[priv->dreg].selector) + return false; + + if (!track->regs[priv->dreg].bitwise) { + track->regs[priv->dreg].bitwise = expr; + track->cur = expr; + return true; + } + + if (track->regs[priv->dreg].bitwise->ops != expr->ops) { + track->regs[priv->dreg].selector = NULL; + track->regs[priv->dreg].bitwise = NULL; + return false; + } + + bitwise = nft_expr_priv(track->regs[priv->dreg].bitwise); + if (memcmp(&priv->mask, &bitwise->mask, sizeof(priv->mask)) || + memcmp(&priv->xor, &bitwise->xor, sizeof(priv->xor)) || + memcmp(&priv->data, &bitwise->data, sizeof(priv->data)) || + priv->len != bitwise->len || + priv->op != bitwise->op || + priv->sreg != bitwise->sreg || + priv->dreg != bitwise->dreg) { + track->regs[priv->dreg].selector = NULL; + track->regs[priv->dreg].bitwise = NULL; + return false; + } + + track->cur = expr; + pr_info("expr `%s' already in register, skip\n", expr->ops->type->name); + + return true; +} + static const struct nft_expr_ops nft_bitwise_ops = { .type = &nft_bitwise_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)), .eval = nft_bitwise_eval, .init = nft_bitwise_init, .dump = nft_bitwise_dump, + .reduce = nft_bitwise_reduce, .offload = nft_bitwise_offload, }; @@ -385,12 +426,50 @@ static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx, return 0; } +static bool nft_bitwise_fast_reduce(struct nft_regs_track *track, + const struct nft_expr *expr) +{ + const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); + const struct nft_bitwise_fast_expr *bitwise; + + if (!track->regs[priv->dreg].selector) + return false; + + if (!track->regs[priv->dreg].bitwise) { + track->regs[priv->dreg].bitwise = expr; + track->cur = expr; + return true; + } + + if (track->regs[priv->dreg].bitwise->ops != expr->ops) { + track->regs[priv->dreg].selector = NULL; + track->regs[priv->dreg].bitwise = NULL; + return false; + } + + bitwise = nft_expr_priv(track->regs[priv->dreg].bitwise); + if (priv->mask != bitwise->mask || + priv->xor != bitwise->xor || + priv->sreg != bitwise->sreg || + priv->dreg != bitwise->dreg) { + track->regs[priv->dreg].selector = NULL; + track->regs[priv->dreg].bitwise = NULL; + return false; + } + + pr_info("expr `%s' already in register, skip\n", expr->ops->type->name); + track->cur = expr; + + return true; +} + const struct nft_expr_ops nft_bitwise_fast_ops = { .type = &nft_bitwise_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)), .eval = NULL, /* inlined */ .init = nft_bitwise_fast_init, .dump = nft_bitwise_fast_dump, + .reduce = nft_bitwise_fast_reduce, .offload = nft_bitwise_fast_offload, }; -- 2.30.2