mptcp: really share subflow snd_wnd

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As per RFC, mptcp subflows use a "shared" snd_wnd: the effective
window is the maximum among the current values received on all
subflows. Without such feature a data transfer using multiple
subflows could block.

Window sharing is currently implemented in the RX side:
__tcp_select_window uses the mptcp-level receive buffer to compute
the announced window.

That is not enough: the TCP stack will stick to the window size
received on the given subflow; we need to propagate the msk window
value on each subflow at xmit time.

Change the packet scheduler to ignore the subflow level window
and use instead the msk level one

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

...

This commit is contained in:

Paolo Abeni 2022-05-04 14:54:04 -07:00 • committed by Jakub Kicinski

parent 10b4a11fe7

commit b713d00675

1 changed files with 15 additions and 9 deletions

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net/mptcp/protocol.c

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