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 555D4C433EF for ; Tue, 26 Apr 2022 11:55:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244673AbiDZL6Z (ORCPT ); Tue, 26 Apr 2022 07:58:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239701AbiDZL6V (ORCPT ); Tue, 26 Apr 2022 07:58:21 -0400 Received: from mail-yb1-xb30.google.com (mail-yb1-xb30.google.com [IPv6:2607:f8b0:4864:20::b30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F388EDEDC for ; Tue, 26 Apr 2022 04:55:13 -0700 (PDT) Received: by mail-yb1-xb30.google.com with SMTP id e12so3640922ybc.11 for ; Tue, 26 Apr 2022 04:55:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=N2BkINbzjFHfJOEzCr84LpvPBiQy96TIThqeM1mCi9E=; b=ToZ0Iq4eE8iEKoCNA5zyjQrmvkL5RMstlY1rRBTS9KkZIP/3jWqP5iIAAOW/DsLJul mKe+k4amfJIiF5r3VGblzouwWzQHRT3qiTw1zmpkCpBnSNvWR8EovqbfADYrut9uF3am ohjm4AFg5s6gNi1IEuRKqbw7hEY4aA616VwN9Zpw23BqWsXtZ8Cco39yEO+q+wNjnFwE 9Ums4R3thVXk607J72tvB7ip58Oht24Z5oE53XhVTwfikLK6S27S2WM2HHnweikwvxkL 7AYwbTUrVu0setmC06gsdntyFdpYEDVEmkQ8wqAcvM9i8VHkyKByvo651p+ch2iKKB7F y+3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=N2BkINbzjFHfJOEzCr84LpvPBiQy96TIThqeM1mCi9E=; b=Kl9kdPLORfqC5CXcmCm0eCmG3ZQAcxVGUYfW1XrBIubo8OELnRIo1MME1aVKnAWJoX avJY+lmQdFWczMW1ZPMalUxoYFmgiQsuHoaNzP3uaahJTnTJ7/FfoUhBNvp/JW8euB9c iQXgH2C5vvqixsx/MpTk6lXlSCbfGNCWEF+TpwWN3Lmz2tRKdLSaH//w989F/QHZbUfC JjIzt+n3xfY4q2Zj3Ftu+YB0XekD+CINoMsaUGDqU9Tk2uwwb0iMMP/jKvfnmAffuymv BjWCGsy5cJGuFUsOJ3p1q/nwimTnkj3MgghEJLfvah0EtnQOWMEM89DlfDXhgKQRklR9 kjZw== X-Gm-Message-State: AOAM532iv7mI3T5BDQvx1sYB5oY5NAacD+ogcTexKNMpUFsKXhJeFjOj 9krc/hm/xHnsuB/ppNn+FKHMPGnGkKgbyZEuOpIMOeqqIJ8= X-Google-Smtp-Source: ABdhPJxYx0jIaBwDxGNiYuFm5ezw42whPmd3hbxCQQ9rlriP9/mPDqULDcu73f1+M9NxqLf2LRTYJ9+a8RcK7isORJs= X-Received: by 2002:a25:d155:0:b0:648:757d:57b5 with SMTP id i82-20020a25d155000000b00648757d57b5mr7169498ybg.540.1650974113225; Tue, 26 Apr 2022 04:55:13 -0700 (PDT) MIME-Version: 1.0 References: <20220425080835.5765-1-ritarot634@gmail.com> In-Reply-To: From: =?UTF-8?B?44KK44Gf44KN44GG?= Date: Tue, 26 Apr 2022 20:55:02 +0900 Message-ID: Subject: Re: [PATCH] nf_flowtable: ensure dst.dev is not blackhole To: Pablo Neira Ayuso Cc: netfilter-devel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Thanks for your reply. > In 5.4, this check is only enabled for xfrm. Packet loss occurs with xmit_neigh (xfrm is not confirmed). I also experienced packet loss with 5.10, which runs dst_check() periodically. Route GC and flowtable GC are not synchronized, so it is necessary to check each packet. > dst_check() should deal with this. When dst_check() is used, the performance degradation is not negligible. >From 940 Mbps to 700 Mbps with QCA9563 simple firewall. On Tue, Apr 26, 2022 at 8:21 PM Pablo Neira Ayuso wrote: > > Hi, > > On Mon, Apr 25, 2022 at 05:08:38PM +0900, Ritaro Takenaka wrote: > > Fixes sporadic IPv6 packet loss when flow offloading is enabled. > > IPv6 route GC calls dst_dev_put() which makes dst.dev blackhole_netdev > > even if dst is cached in flow offload. If a packet passes through this > > invalid flow, packet loss will occur. > > This is from Commit 227e1e4d0d6c (netfilter: nf_flowtable: skip device > > lookup from interface index), as outdev was cached independently before. > > Packet loss is reported on OpenWrt with Linux 5.4 and later. > > dst_check() should deal with this. > > In 5.4, this check is only enabled for xfrm. > > > Signed-off-by: Ritaro Takenaka > > --- > > net/netfilter/nf_flow_table_ip.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c > > index 32c0eb1b4..12f81661d 100644 > > --- a/net/netfilter/nf_flow_table_ip.c > > +++ b/net/netfilter/nf_flow_table_ip.c > > @@ -624,6 +624,11 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb, > > if (nf_flow_state_check(flow, ip6h->nexthdr, skb, thoff)) > > return NF_ACCEPT; > > > > + if (unlikely(tuplehash->tuple.dst_cache->dev == blackhole_netdev)) { > > + flow_offload_teardown(flow); > > + return NF_ACCEPT; > > + } > > + > > if (skb_try_make_writable(skb, thoff + hdrsize)) > > return NF_DROP; > > > > -- > > 2.25.1 > >