• Davide Caratti's avatar
    net/sched: act_police: more accurate MTU policing · 4ddc844e
    Davide Caratti authored
    in current Linux, MTU policing does not take into account that packets at
    the TC ingress have the L2 header pulled. Thus, the same TC police action
    (with the same value of tcfp_mtu) behaves differently for ingress/egress.
    In addition, the full GSO size is compared to tcfp_mtu: as a consequence,
    the policer drops GSO packets even when individual segments have the L2 +
    L3 + L4 + payload length below the configured valued of tcfp_mtu.
    
    Improve the accuracy of MTU policing as follows:
     - account for mac_len for non-GSO packets at TC ingress.
     - compare MTU threshold with the segmented size for GSO packets.
    Also, add a kselftest that verifies the correct behavior.
    Signed-off-by: default avatarDavide Caratti <dcaratti@redhat.com>
    Reviewed-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    4ddc844e
tc_police.sh 11.8 KB