• Guillaume Nault's avatar
    l2tp: ignore L2TP_ATTR_MTU · e9697e2e
    Guillaume Nault authored
    This attribute's handling is broken. It can only be used when creating
    Ethernet pseudo-wires, in which case its value can be used as the
    initial MTU for the l2tpeth device.
    However, when handling update requests, L2TP_ATTR_MTU only modifies
    session->mtu. This value is never propagated to the l2tpeth device.
    Dump requests also return the value of session->mtu, which is not
    synchronised anymore with the device MTU.
    The same problem occurs if the device MTU is properly updated using the
    generic IFLA_MTU attribute. In this case, session->mtu is not updated,
    and L2TP_ATTR_MTU will report an invalid value again when dumping the
    It does not seem worthwhile to complexify l2tp_eth.c to synchronise
    session->mtu with the device MTU. Even the ip-l2tp manpage advises to
    use 'ip link' to initialise the MTU of l2tpeth devices (iproute2 does
    not handle L2TP_ATTR_MTU at all anyway). So let's just ignore it
    Signed-off-by: default avatarGuillaume Nault <g.nault@alphalink.fr>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
l2tp_debugfs.c 9.39 KB