mptcp: pm: fullmesh: select the right ID later

mptcp: pm: fullmesh: select the right ID later

When reacting upon the reception of an ADD_ADDR, the in-kernel PM first
looks for fullmesh endpoints. If there are some, it will pick them,
using their entry ID.

It should set the ID 0 when using the endpoint corresponding to the
initial subflow, it is a special case imposed by the MPTCP specs.

Note that msk->mpc_endpoint_id might not be set when receiving the first
ADD_ADDR from the server. So better to compare the addresses.

Fixes: 1a0d6136c5f0 ("mptcp: local addresses fullmesh")
Cc: [email protected]
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>