Re: [PATCH mptcp-next] selftests: mptcp: sockopt: test passive Fast Open early write push

[Matthieu Baerts]

Hi T S,

On 08/10/2026 13:10, T S Rameshkumar wrote:
> Add automated test coverage for passive Fast Open early write data
> push in mptcp_sockopt.c and mptcp_sockopt.sh.

Please next time join the test with the fix, otherwise this patch alone
will not work.

Also, if you use 'mptcp*' prefix in the subject, please don't Cc the
netdev mailing list. (and remove it from any replies here)

> The server enables TCP_FASTOPEN on an MPTCP listening socket, accepts
> an incoming connection with SYN payload data, and immediately writes
> reply bytes before the 3-way handshake fully completes. The client
> connects with TCP_FASTOPEN_CONNECT, sends request data, and validates
> reception of the server's reply over both IPv4 and IPv6.

A more efficient way of validating that is to add a packetdrill test
instead of increasing the complexity of the "sockopt" test to validate a
connection issue.

Can you add your new test in the MPTCP fork [1], and validate it with:

  # cd gtests/net
  # ./packetdrill/run_all.py -lv mptcp/fastopen/<test>.pkt

[1] https://github.com/multipath-tcp/packetdrill/

> Signed-off-by: T S Rameshkumar <rameshkumar.t@xxxxxxxxxxxxxxxxx>

If LLM is used, you need to add the Assisted-by tag:

  https://docs.kernel.org/process/coding-assistants.html

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.