• David Ahern's avatar
    net: mpls: Fixups for GSO · 48d2ab60
    David Ahern authored
    As reported by Lennert the MPLS GSO code is failing to properly segment
    large packets. There are a couple of problems:
    
    1. the inner protocol is not set so the gso segment functions for inner
       protocol layers are not getting run, and
    
    2  MPLS labels for packets that use the "native" (non-OVS) MPLS code
       are not properly accounted for in mpls_gso_segment.
    
    The MPLS GSO code was added for OVS. It is re-using skb_mac_gso_segment
    to call the gso segment functions for the higher layer protocols. That
    means skb_mac_gso_segment is called twice -- once with the network
    protocol set to MPLS and again with the network protocol set to the
    inner protocol.
    
    This patch sets the inner skb protocol addressing item 1 above and sets
    the network_header and inner_network_header to mark where the MPLS labels
    start and end. The MPLS code in OVS is also updated to set the two
    network markers.
    
    >From there the MPLS GSO code uses the difference between the network
    header and the inner network header to know the size of the MPLS header
    that was pushed. It then pulls the MPLS header, resets the mac_len and
    protocol for the inner protocol and then calls skb_mac_gso_segment
    to segment the skb.
    
    Afterward the inner protocol segmentation is done the skb protocol
    is set to mpls for each segment and the network and mac headers
    restored.
    Reported-by: default avatarLennert Buytenhek <buytenh@wantstofly.org>
    Signed-off-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    48d2ab60
mpls_gso.c 2.5 KB