netdev - Re: [PATCH net-next v3 1/2] tcp: randomize tcp timestamp offsets for each connection

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Message-Id: <20161202.125013.291984063589055137.davem@davemloft.net>
Date:   Fri, 02 Dec 2016 12:50:13 -0500 (EST)
From:   David Miller <davem@...emloft.net>
To:     fw@...len.de
Cc:     netdev@...r.kernel.org
Subject: Re: [PATCH net-next v3 1/2] tcp: randomize tcp timestamp offsets
 for each connection

From: Florian Westphal <fw@...len.de>
Date: Thu,  1 Dec 2016 11:32:06 +0100

> jiffies based timestamps allow for easy inference of number of devices
> behind NAT translators and also makes tracking of hosts simpler.
> 
> commit ceaa1fef65a7c2e ("tcp: adding a per-socket timestamp offset")
> added the main infrastructure that is needed for per-connection ts
> randomization, in particular writing/reading the on-wire tcp header
> format takes the offset into account so rest of stack can use normal
> tcp_time_stamp (jiffies).
> 
> So only two items are left:
>  - add a tsoffset for request sockets
>  - extend the tcp isn generator to also return another 32bit number
>    in addition to the ISN.
> 
> Re-use of ISN generator also means timestamps are still monotonically
> increasing for same connection quadruple, i.e. PAWS will still work.
> 
> Includes fixes from Eric Dumazet.
> 
> Signed-off-by: Florian Westphal <fw@...len.de>
> Acked-by: Eric Dumazet <edumazet@...gle.com>
> Acked-by: Yuchung Cheng <ycheng@...gle.com>

Applied.