netdev - Re: [PATCH v2] tcp: verify the checksum of the first data segment in a new connection

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Message-ID: <212193c0-2fee-7f88-5473-9f5f4c548cb8@gmail.com>
Date:   Tue, 12 Jun 2018 15:03:35 -0700
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     "van der Linden, Frank" <fllinden@...zon.com>,
        Eric Dumazet <eric.dumazet@...il.com>,
        "edumazet@...gle.com" <edumazet@...gle.com>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [PATCH v2] tcp: verify the checksum of the first data segment in
 a new connection



On 06/12/2018 02:53 PM, van der Linden, Frank wrote:
> The convention seems to be to call tcp_checksum_complete after tcp_filter has a chance to deal with the packet. I wanted to preserve that.
> 
> If that is not a concern, then I agree that this is a far better way to go.
> 
> Frank

Given that we can drop the packet earlier from :

if (skb_checksum_init(skb, IPPROTO_TCP, inet_compute_pseudo))
     goto csum_error;

I am quite sure we really do not care of tcp_filter() being
hit or not by packets with bad checksum.

Thanks