• Michael Chan's avatar
    [NET]: Add ECN support for TSO · b0da8537
    Michael Chan authored
    In the current TSO implementation, NETIF_F_TSO and ECN cannot be
    turned on together in a TCP connection.  The problem is that most
    hardware that supports TSO does not handle CWR correctly if it is set
    in the TSO packet.  Correct handling requires CWR to be set in the
    first packet only if it is set in the TSO header.
    This patch adds the ability to turn on NETIF_F_TSO and ECN using
    GSO if necessary to handle TSO packets with CWR set.  Hardware
    that handles CWR correctly can turn on NETIF_F_TSO_ECN in the dev->
    features flag.
    All TSO packets with CWR set will have the SKB_GSO_TCPV4_ECN set.  If
    the output device does not have the NETIF_F_TSO_ECN feature set, GSO
    will split the packet up correctly with CWR only set in the first
    With help from Herbert Xu <herbert@gondor.apana.org.au>.
    Since ECN can always be enabled with TSO, the SOCK_NO_LARGESEND sock
    flag is completely removed.
    Signed-off-by: default avatarMichael Chan <mchan@broadcom.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
sock.h 38.7 KB