mptcp: fix 3rd ack rtx timer

[PATCH net 0/2] mptcp: fix 3rd ack rtx timer

Posted by Paolo Abeni 2 years, 5 months ago

Eric noted that the MPTCP code do the wrong thing to schedule
the MPJ 3rd ack timer. He also provided a patch to address the
issues (patch 1/2).

To fix for good the MPJ 3rd ack retransmission timer, we additionally
need to set it after the current ack is transmitted (patch 2/2)

Note that the bug went unnotice so far because all the related
tests required some running data transfer, and that causes
MPTCP-level ack even on the opening MPJ subflow. We now have
explicit packet drill coverage for this code path.

Eric Dumazet (1):
  mptcp: fix delack timer

Paolo Abeni (1):
  mptcp: use delegate action to schedule 3rd ack retrans

 net/mptcp/options.c  | 32 ++++++++-------------------
 net/mptcp/protocol.c | 51 ++++++++++++++++++++++++++++++++++++--------
 net/mptcp/protocol.h | 17 ++++++++-------
 3 files changed, 60 insertions(+), 40 deletions(-)

-- 
2.33.1

Re: [PATCH net 0/2] mptcp: fix 3rd ack rtx timer

Posted by David Miller 2 years, 5 months ago

From: Paolo Abeni <pabeni@redhat.com>
Date: Fri, 19 Nov 2021 15:27:53 +0100

> Eric noted that the MPTCP code do the wrong thing to schedule
> the MPJ 3rd ack timer. He also provided a patch to address the
> issues (patch 1/2).
> 
> To fix for good the MPJ 3rd ack retransmission timer, we additionally
> need to set it after the current ack is transmitted (patch 2/2)
> 
> Note that the bug went unnotice so far because all the related
> tests required some running data transfer, and that causes
> MPTCP-level ack even on the opening MPJ subflow. We now have
> explicit packet drill coverage for this code path.

Acked-by: David S. Miller <davem@davemloft.net>

Re: [PATCH net 0/2] mptcp: fix 3rd ack rtx timer

Posted by patchwork-bot+netdevbpf@kernel.org 2 years, 5 months ago

Hello:

This series was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Fri, 19 Nov 2021 15:27:53 +0100 you wrote:
> Eric noted that the MPTCP code do the wrong thing to schedule
> the MPJ 3rd ack timer. He also provided a patch to address the
> issues (patch 1/2).
> 
> To fix for good the MPJ 3rd ack retransmission timer, we additionally
> need to set it after the current ack is transmitted (patch 2/2)
> 
> [...]

Here is the summary with links:
  - [net,1/2] mptcp: fix delack timer
    https://git.kernel.org/netdev/net/c/ee50e67ba0e1
  - [net,2/2] mptcp: use delegate action to schedule 3rd ack retrans
    https://git.kernel.org/netdev/net/c/bcd97734318d

You are awesome, thank you!
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