• Andrew Lunn's avatar
    net: dsa: Fix SWITCHDEV_ATTR_ID_PORT_PARENT_ID · a42c8e33
    Andrew Lunn authored
    SWITCHDEV_ATTR_ID_PORT_PARENT_ID is used by the software bridge when
    determining which ports to flood a packet out. If the packet
    originated from a switch, it assumes the switch has already flooded
    the packet out the switches ports, so the bridge should not flood the
    packet itself out switch ports. Ports on the same switch are expected
    to return the same parent ID when SWITCHDEV_ATTR_ID_PORT_PARENT_ID is
    called.
    
    DSA gets this wrong with clusters of switches. As far as the software
    bridge is concerned, the cluster is all one switch. A packet from any
    switch in the cluster can be assumed to have been flooded as needed
    out of all ports of the cluster, not just the switch it originated
    from. Hence all ports of a cluster should return the same parent. The
    old implementation did not, each switch in the cluster had its own ID.
    
    Also wrong was that the ID was not unique if multiple DSA instances
    are in operation.
    
    Use the tree ID as the parent ID, which is the same for all switches
    in a cluster and unique across switch clusters.
    Signed-off-by: default avatarAndrew Lunn <andrew@lunn.ch>
    Reviewed-by: default avatarVivien Didelot <vivien.didelot@savoirfairelinux.com>
    Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    a42c8e33
slave.c 34.6 KB