• lucien's avatar
    sctp: start t5 timer only when peer rwnd is 0 and local state is SHUTDOWN_PENDING · 8a0d19c5
    lucien authored
    when A sends a data to B, then A close() and enter into SHUTDOWN_PENDING
    state, if B neither claim his rwnd is 0 nor send SACK for this data, A
    will keep retransmitting this data until t5 timeout, Max.Retrans times
    can't work anymore, which is bad.
    
    if B's rwnd is not 0, it should send abort after Max.Retrans times, only
    when B's rwnd == 0 and A's retransmitting beyonds Max.Retrans times, A
    will start t5 timer, which is also commit f8d96052 ("sctp: Enforce
    retransmission limit during shutdown") means, but it lacks the condition
    peer rwnd == 0.
    
    so fix it by adding a bit (zero_window_announced) in peer to record if
    the last rwnd is 0. If it was, zero_window_announced will be set. and use
    this bit to decide if start t5 timer when local.state is SHUTDOWN_PENDING.
    
    Fixes: commit f8d96052 ("sctp: Enforce retransmission limit during shutdown")
    Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
    Signed-off-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    8a0d19c5
sm_statefuns.c 197 KB