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| author | Matthieu Baerts (NGI0) <matttbe@kernel.org> | 2026-06-05 12:21:48 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-12 01:33:37 +0300 |
| commit | 30ff28fdc4da4e45ec1d35be864d416e18d969cc (patch) | |
| tree | 5a06cdaa1cba1ccd716e358fc8909659bf3588d6 /Documentation | |
| parent | 06c62385be856bc96acc0f49465a85fd047c77ad (diff) | |
| download | linux-30ff28fdc4da4e45ec1d35be864d416e18d969cc.tar.xz | |
mptcp: introduce add_addr_v6_port_drop_ts sysctl knob
This sysctl is going to be used in the next commits to drop TCP
timestamps option, to be able to send an ADD_ADDR with a v6 IP address
and a port number. It is enabled by default.
This knob is explicitly disabled in the MPTCP Join selftest, with the
"signal addr list progresses after tx drop" subtest, to continue
verifying the previous behaviour where the ADD_ADDR is not sent due to a
lack of space.
While at it, move syn_retrans_before_tcp_fallback down from struct
mptcp_pernet, to avoid creating another 3 bytes hole.
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-4-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/mptcp-sysctl.rst | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/networking/mptcp-sysctl.rst b/Documentation/networking/mptcp-sysctl.rst index 1eb6af26b4a7..b9b5f58e0625 100644 --- a/Documentation/networking/mptcp-sysctl.rst +++ b/Documentation/networking/mptcp-sysctl.rst @@ -21,6 +21,19 @@ add_addr_timeout - INTEGER (seconds) Default: 120 +add_addr_v6_port_drop_ts - BOOLEAN + Control whether preparing an ADD_ADDR with an IPv6 address and a port + should drop the TCP timestamps option to have enough option space to + send the signal. + + If there is not enough option space, and the TCP timestamps option + cannot be dropped, the signal cannot be sent. Note that dropping the TCP + timestamps option for one packet of the connection could disrupt some + middleboxes: even if it should be unlikely, they could drop the packet + or block the connection. This is a per-namespace sysctl. + + Default: 1 (enabled) + allow_join_initial_addr_port - BOOLEAN Allow peers to send join requests to the IP address and port number used by the initial subflow if the value is 1. This controls a flag that is |