• Herbert Xu's avatar
    [NET]: Merge TSO/UFO fields in sk_buff · 7967168c
    Herbert Xu authored
    Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not
    going to scale if we add any more segmentation methods (e.g., DCCP).  So
    let's merge them.
    They were used to tell the protocol of a packet.  This function has been
    subsumed by the new gso_type field.  This is essentially a set of netdev
    feature bits (shifted by 16 bits) that are required to process a specific
    skb.  As such it's easy to tell whether a given device can process a GSO
    skb: you just have to and the gso_type field and the netdev's features
    I've made gso_type a conjunction.  The idea is that you have a base type
    (e.g., SKB_GSO_TCPV4) that can be modified further to support new features.
    For example, if we add a hardware TSO type that supports ECN, they would
    declare NETIF_F_TSO | NETIF_F_TSO_ECN.  All TSO packets with CWR set would
    have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO
    packets would be SKB_GSO_TCPV4.  This means that only the CWR packets need
    to be emulated in software.
    Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>