netdev - Re: [PATCH net-next] tcp: change IPv6 flow-label upon receiving spurious retransmission

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20180831.230341.857947500854204329.davem@davemloft.net>
Date:   Fri, 31 Aug 2018 23:03:41 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     ycheng@...gle.com
Cc:     edumazet@...gle.com, netdev@...r.kernel.org, ncardwell@...gle.com
Subject: Re: [PATCH net-next] tcp: change IPv6 flow-label upon receiving
 spurious retransmission

From: Yuchung Cheng <ycheng@...gle.com>
Date: Wed, 29 Aug 2018 14:53:56 -0700

> Currently a Linux IPv6 TCP sender will change the flow label upon
> timeouts to potentially steer away from a data path that has gone
> bad. However this does not help if the problem is on the ACK path
> and the data path is healthy. In this case the receiver is likely
> to receive repeated spurious retransmission because the sender
> couldn't get the ACKs in time and has recurring timeouts.
> 
> This patch adds another feature to mitigate this problem. It
> leverages the DSACK states in the receiver to change the flow
> label of the ACKs to speculatively re-route the ACK packets.
> In order to allow triggering on the second consecutive spurious
> RTO, the receiver changes the flow label upon sending a second
> consecutive DSACK for a sequence number below RCV.NXT.
> 
> Signed-off-by: Yuchung Cheng <ycheng@...gle.com>
> Signed-off-by: Neal Cardwell <ncardwell@...gle.com>
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>

Applied.