2023-09-17 05:49:30

by Matthieu Baerts

[permalink] [raw]
Subject: [PATCH net 0/5] mptcp: fix stalled connections

Daire reported a few issues with MPTCP where some connections were
stalled in different states. Paolo did a great job fixing them.

Patch 1 fixes bogus receive window shrinkage with multiple subflows. Due
to a race condition and unlucky circumstances, that may lead to
TCP-level window shrinkage, and the connection being stalled on the
sender end.

Patch 2 is a preparation for patch 3 which processes pending subflow
errors on close. Without that and under specific circumstances, the
MPTCP-level socket might not switch to the CLOSE state and stall.

Patch 4 is also a preparation patch for the next one. Patch 5 fixes
MPTCP connections not switching to the CLOSE state when all subflows
have been closed but no DATA_FIN have been exchanged to explicitly close
the MPTCP connection. Now connections in such state will switch to the
CLOSE state after a timeout, still allowing the "make-after-break"
feature but making sure connections don't stall forever. It will be
possible to modify this timeout -- currently matching TCP TIMEWAIT value
(60 seconds) -- in a future version.

Signed-off-by: Matthieu Baerts <[email protected]>
---
Paolo Abeni (5):
mptcp: fix bogus receive window shrinkage with multiple subflows
mptcp: move __mptcp_error_report in protocol.c
mptcp: process pending subflow error on close
mptcp: rename timer related helper to less confusing names
mptcp: fix dangling connection hang-up

net/mptcp/options.c | 5 +-
net/mptcp/protocol.c | 165 +++++++++++++++++++++++++++++++--------------------
net/mptcp/protocol.h | 24 +++++++-
net/mptcp/subflow.c | 39 +-----------
4 files changed, 130 insertions(+), 103 deletions(-)
---
base-commit: 615efed8b63f60ddd69c0b8f32f7783859034fc2
change-id: 20230915-upstream-net-20230915-mptcp-hanging-conn-0609338b1728

Best regards,
--
Matthieu Baerts <[email protected]>


2023-09-18 12:05:46

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH net 0/5] mptcp: fix stalled connections

Hello:

This series was applied to netdev/net.git (main)
by David S. Miller <[email protected]>:

On Sat, 16 Sep 2023 12:52:44 +0200 you wrote:
> Daire reported a few issues with MPTCP where some connections were
> stalled in different states. Paolo did a great job fixing them.
>
> Patch 1 fixes bogus receive window shrinkage with multiple subflows. Due
> to a race condition and unlucky circumstances, that may lead to
> TCP-level window shrinkage, and the connection being stalled on the
> sender end.
>
> [...]

Here is the summary with links:
- [net,1/5] mptcp: fix bogus receive window shrinkage with multiple subflows
https://git.kernel.org/netdev/net/c/6bec041147a2
- [net,2/5] mptcp: move __mptcp_error_report in protocol.c
https://git.kernel.org/netdev/net/c/d5fbeff1ab81
- [net,3/5] mptcp: process pending subflow error on close
https://git.kernel.org/netdev/net/c/9f1a98813b4b
- [net,4/5] mptcp: rename timer related helper to less confusing names
https://git.kernel.org/netdev/net/c/f6909dc1c1f4
- [net,5/5] mptcp: fix dangling connection hang-up
https://git.kernel.org/netdev/net/c/27e5ccc2d5a5

You are awesome, thank you!
--
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