On 05/03/2018 05:33 PM, Alexander Duyck wrote:
> From: Alexander Duyck <[email protected]>
>
> This patch adds support for a software provided checksum and GSO_PARTIAL
> segmentation support. With this we can offload UDP segmentation on devices
> that only have partial support for tunnels.
>
> Since we are no longer needing the hardware checksum we can drop the checks
> in the segmentation code that were verifying if it was present.
>
> Signed-off-by: Alexander Duyck <[email protected]>
> ---
> net/ipv4/udp_offload.c | 28 ++++++++++++++++++----------
> net/ipv6/udp_offload.c | 11 +----------
> 2 files changed, 19 insertions(+), 20 deletions(-)
>
> diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
> index 946d06d2aa0c..fd94bbb369b2 100644
> --- a/net/ipv4/udp_offload.c
> +++ b/net/ipv4/udp_offload.c
> @@ -217,6 +217,13 @@ struct sk_buff *__udp_gso_segment(struct sk_buff
> *gso_skb,
> return segs;
> }
>
> + /* GSO partial and frag_list segmentation only requires splitting
> + * the frame into an MSS multiple and possibly a remainder, both
> + * cases return a GSO skb. So update the mss now.
> + */
> + if (skb_is_gso(segs))
> + mss *= skb_shinfo(segs)->gso_segs;
> +
>
I do not understand this code.
I am also seeing it in tcp, after commit 07b26c9454a2a ("gso: Support partial
splitting at the frag_list pointer")
Presumably this broke tcp_gso_tstamp() , right ?
