• Ido Schimmel's avatar
    neigh: Send a notification when DELAY_PROBE_TIME changes · 2a4501ae
    Ido Schimmel authored
    When the data plane is offloaded the traffic doesn't go through the
    networking stack. Therefore, after first resolving a neighbour the NUD
    state machine will transition it from REACHABLE to STALE until it's
    finally deleted by the garbage collector.
    
    To prevent such situations the offloading driver should notify the NUD
    state machine on any neighbours that were recently used. The driver's
    polling interval should be set so that the NUD state machine can
    function as if the traffic wasn't offloaded.
    
    Currently, there are no in-tree drivers that can report confirmation for
    a neighbour, but only 'used' indication. Therefore, the polling interval
    should be set according to DELAY_FIRST_PROBE_TIME, as a neighbour will
    transition from REACHABLE state to DELAY (instead of STALE) if "a packet
    was sent within the last DELAY_FIRST_PROBE_TIME seconds" (RFC 4861).
    
    Send a netevent whenever the DELAY_FIRST_PROBE_TIME changes - either via
    netlink or sysctl - so that offloading drivers can correctly set their
    polling interval.
    Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
    Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    2a4501ae
neighbour.c 78.7 KB