neigh: Better handling of transition to NUD_PROBE state

[1] When entering NUD_PROBE state via neigh_update(), perhaps received
    from userspace, correctly (re)initialize the probes count to zero.

    This is useful for forcing revalidation of a neighbor (for example
    if the host is attempting to do DNA [IPv4 4436, IPv6 6059]).

[2] Notify listeners when a neighbor goes into NUD_PROBE state.

    By sending notifications on entry to NUD_PROBE state listeners get
    more timely warnings of imminent connectivity issues.

    The current notifications on entry to NUD_STALE have somewhat
    limited usefulness: NUD_STALE is a perfectly normal state, as is
    NUD_DELAY, whereas notifications on entry to NUD_FAILURE come after
    a neighbor reachability problem has been confirmed (typically after
    three probes).

Signed-off-by: Erik Kline <[email protected]>
Acked-By: Lorenzo Colitti <[email protected]>
Acked-by: Hannes Frederic Sowa <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions