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 5D24AC433EF for ; Wed, 4 May 2022 08:56:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242434AbiEDI7f (ORCPT ); Wed, 4 May 2022 04:59:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346631AbiEDI5z (ORCPT ); Wed, 4 May 2022 04:57:55 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0CA1125EAD for ; Wed, 4 May 2022 01:53:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1651654383; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7DfIcsOTB6mqPbbGYMVcOJUBywehrsvBjbW97FzGQuA=; b=RXs1B0QJh2w6dq+utLwr7HSVYnGU+d1A8d/WIxjcQAzyqCg1MhQSFdw3v8Y+CpUTzwAJaW 1aMr0lPig9SSF6AtTedS1K16Jd+I9iG4NM9uU/m3zuygFRwuuChotwvxeb7y+66dGK/iFz qZpGSB3K0YKvWDo8SBu8EPZZa3BX230= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-613-r5wduM1-M3i9qQE4t3bCzA-1; Wed, 04 May 2022 04:53:02 -0400 X-MC-Unique: r5wduM1-M3i9qQE4t3bCzA-1 Received: by mail-wr1-f71.google.com with SMTP id j27-20020adfb31b000000b0020c4ca11566so154772wrd.14 for ; Wed, 04 May 2022 01:53:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=7DfIcsOTB6mqPbbGYMVcOJUBywehrsvBjbW97FzGQuA=; b=nHrtG46PLzzqkZVxJRkOoBemkI1i262GhrHfXdG+RDykx/sirr1LVw8HajwqM4C+gn 5x/Zf1ypO7aEe5SviEQ6KS4W1wHIc+OSHoJ4KdB1DEaQsjt/SFR5eXQPAhDV+FuZGUwe HEFQakkzEYkP2z7DWqvz6AwucqPXzCPmW3BhXp8mHvto6dFj7Io6pwozwQBm4dPEJsQg k2slgLOJVsRyyVYD6EhyBOIpsKsuSPojQjxMS+TsMiERb7hVacKIUqv0a9Ohc3PFcXIf tUGvT2hKTYz8U9PEpRfX53nmzftOf4PhMg9kZ8mnYvbbdrP6SNrNtUhBhDa/XUF/Thnx yAIw== X-Gm-Message-State: AOAM531NX9bofvLRcQxTIx7gBZmjKgnSSe4tSGjdfKqaCawRNNC6MiY+ fJvtuevV/aZCsxFErP/+/IclUqy2wEZNtH4k/B76Ac/0COp7kTUZmVSOyrpeQKc2LRZxaFQELxX rhHQpyNiUNwxOZkUP X-Received: by 2002:a05:6000:145:b0:20a:ebb3:5c2c with SMTP id r5-20020a056000014500b0020aebb35c2cmr15732344wrx.545.1651654381221; Wed, 04 May 2022 01:53:01 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy63+5SdoEgWaR81Rh3nvkUcLWBHYG87PsXR7zWHjN3ES2SmO3HYwjRRgKC0hfaQk26njgxhQ== X-Received: by 2002:a05:6000:145:b0:20a:ebb3:5c2c with SMTP id r5-20020a056000014500b0020aebb35c2cmr15732334wrx.545.1651654381034; Wed, 04 May 2022 01:53:01 -0700 (PDT) Received: from gerbillo.redhat.com (146-241-115-66.dyn.eolo.it. [146.241.115.66]) by smtp.gmail.com with ESMTPSA id o4-20020a05600c338400b003942a244ec2sm3782448wmp.7.2022.05.04.01.53.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 May 2022 01:53:00 -0700 (PDT) Message-ID: Subject: Re: [PATCH net] net/sched: act_pedit: really ensure the skb is writable From: Paolo Abeni To: Jamal Hadi Salim , netdev@vger.kernel.org Cc: Cong Wang , Jiri Pirko Date: Wed, 04 May 2022 10:52:59 +0200 In-Reply-To: <7e4682da-6ed6-17cf-8e5a-dff7925aef1d@mojatatu.com> References: <6c1230ee0f348230a833f92063ff2f5fbae58b94.1651584976.git.pabeni@redhat.com> <7e4682da-6ed6-17cf-8e5a-dff7925aef1d@mojatatu.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.4 (3.42.4-2.fc35) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, 2022-05-03 at 16:10 -0400, Jamal Hadi Salim wrote: > What was the tc pedit command that triggered this? >From the mptcp self-tests, mptcp_join.sh: tc -n $ns2 filter add dev ns2eth$i egress \ protocol ip prio 1000 \ handle 42 fw \ action pedit munge offset 148 u8 invert \ pipe csum tcp \ index 100 || exit 1 It's used to corrupt a packet so that TCP csum is still correct while the MPTCP one is not. The relevant part is that the touched offset is outside the skb head. > Can we add it to tdc tests? What happens in the mptcp self-tests it that an almost simultaneous mptcp-level reinjection on another device using the same cloned data get unintentionally corrupted and we catch it - when it sporadically happens - via the MPTCP mibs. While we could add the above pedit command, but I fear that a meaningful test for the issue addressed here not fit the tdc infrastructure easily. Thanks, Paolo