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

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Message-ID: <7E9F5CAC-0335-4E7C-A1B9-E83C2282BF48@amazon.com>
Date:   Tue, 12 Jun 2018 23:12:42 +0000
From:   "van der Linden, Frank" <fllinden@...zon.com>
To:     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

Ok, patch v3 sent.

It was rightly pointed out to me that I shouldn't commit the mortal sin of top posting - but bear with me guys, I'll dig up my 25-year old .muttrc :-)

Frank

On 6/12/18, 3:03 PM, "Eric Dumazet" <eric.dumazet@...il.com> wrote:

   
    
    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