• Gerrit Renker's avatar
    dccp ccid-2: Algorithm to update buffer state · 5753fdfe
    Gerrit Renker authored
    This provides a routine to consistently update the buffer state when the
    peer acknowledges receipt of Ack Vectors; updating state in the list of Ack
    Vectors as well as in the circular buffer.
    
    While based on RFC 4340, several additional (and necessary) precautions were
    added to protect the consistency of the buffer state. These additions are
    essential, since analysis and experience showed that the basic algorithm was
    insufficient for this task (which lead to problems that were hard to debug).
    
    The algorithm now
     * deals with HC-sender acknowledging to HC-receiver and vice versa,
     * keeps track of the last unacknowledged but received seqno in tail_ackno,
     * has special cases to reset the overflow condition when appropriate,
     * is protected against receiving older information (would mess up buffer state).
    Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
    5753fdfe
ackvec.c 14.1 KB