• Mat Martineau's avatar
    mptcp: Use full MPTCP-level disconnect state machine · 43b54c6e
    Mat Martineau authored
    RFC 8684 appendix D describes the connection state machine for
    MPTCP. This patch implements the DATA_FIN / DATA_ACK exchanges and
    MPTCP-level socket state changes described in that appendix, rather than
    simply sending DATA_FIN along with TCP FIN when disconnecting subflows.
    
    DATA_FIN is now sent and acknowledged before shutting down the
    subflows. Received DATA_FIN information (if not part of a data packet)
    is written to the MPTCP socket when the incoming DSS option is parsed by
    the subflow, and the MPTCP worker is scheduled to process the
    flag. DATA_FIN received as part of a full DSS mapping will be handled
    when the mapping is processed.
    
    The DATA_FIN is acknowledged by the worker if the reader is caught
    up. If there is still data to be moved to the MPTCP-level queue, ack_seq
    will be incremented to account for the DATA_FIN when it reaches the end
    of the stream and a DATA_ACK will be sent to the peer.
    Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    43b54c6e
options.c 28.3 KB