mptcp: shrink struct mptcp_options_received

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struct mptcp_options_received is allocated on the stack while parsing
incoming MPTCP options. Several suboptions are mutually exclusive, as
enforced by mptcp_parse_option(), so their payloads can overlap.

Group fields by suboption and place the mutually exclusive payloads in
an anonymous union. Keep DSS and rm_list outside the union: they can
be combined with other suboptions. Move join_id into the MP_JOIN
group, and overlap token, thmac and hmac inside that group.

Further shrinking would require changing the parser so currently
coexisting fields (DSS mapping vs ACK, rm_list, status flags) can
overlap. That adds complexity for little gain, since the outer union is
already dominated by the MP_JOIN / ADD_ADDR members.

This reduces the structure size from 136 to 72 bytes on x86_64.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/625
Signed-off-by: Quanye Yang <quanyeyang@proton.me>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260926-net-next-mptcp-misc-feat-7-4-v1-3-67af4ab37406@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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Quanye Yang 2026-09-26 17:30:36 +02:00 • committed by Jakub Kicinski

parent 9f778b5678

commit d16d54dac0

1 changed files with 28 additions and 17 deletions

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net/mptcp/protocol.h

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