On Fri, Feb 5, 2016 at 3:28 PM, Alexander Duyck <adu...@mirantis.com> wrote:
> This patch goes though and cleans up the logic related to several of the
> control flags used in UDP segmentation. Specifically the use of dont_encap
> isn't really needed as we can just check the skb for CHECKSUM_PARTIAL and
> if it isn't set then we don't need to update the internal headers. As such
> we can just drop that value.
>
> Signed-off-by: Alexander Duyck <adu...@mirantis.com>
Acked-by: Tom Herbert <t...@herbertland.com>
> ---
> net/ipv4/udp_offload.c | 37 ++++++++++++++++++-------------------
> 1 file changed, 18 insertions(+), 19 deletions(-)
>
> diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
> index 86687f58d613..9e4816fc9927 100644
> --- a/net/ipv4/udp_offload.c
> +++ b/net/ipv4/udp_offload.c
> @@ -33,16 +33,13 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct
> sk_buff *skb,
> __be16 new_protocol, bool is_ipv6)
> {
> struct sk_buff *segs = ERR_PTR(-EINVAL);
> + bool remcsum, need_csum, offload_csum;
> u16 mac_offset = skb->mac_header;
> int mac_len = skb->mac_len;
> int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
> __be16 protocol = skb->protocol;
> int udp_offset, outer_hlen;
> unsigned int oldlen;
> - bool need_csum = !!(skb_shinfo(skb)->gso_type &
> - SKB_GSO_UDP_TUNNEL_CSUM);
> - bool remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
> - bool offload_csum = false, dont_encap = (need_csum || remcsum);
>
> oldlen = (u16)~skb->len;
>
> @@ -55,14 +52,18 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct
> sk_buff *skb,
> skb_set_network_header(skb, skb_inner_network_offset(skb));
> skb->mac_len = skb_inner_network_offset(skb);
> skb->protocol = new_protocol;
> +
> + need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
> skb->encap_hdr_csum = need_csum;
> +
> + remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
> skb->remcsum_offload = remcsum;
>
> /* Try to offload checksum if possible */
> offload_csum = !!(need_csum &&
> - ((skb->dev->features & NETIF_F_HW_CSUM) ||
> - (skb->dev->features & (is_ipv6 ?
> - NETIF_F_IPV6_CSUM : NETIF_F_IP_CSUM))));
> + (skb->dev->features &
> + (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) :
> + (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM))));
>
> features &= skb->dev->hw_enc_features;
>
> @@ -92,13 +93,11 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct
> sk_buff *skb,
> int len;
> __be32 delta;
>
> - if (dont_encap) {
> - skb->encapsulation = 0;
> + if (remcsum)
> skb->ip_summed = CHECKSUM_NONE;
> - } else {
> - /* Only set up inner headers if we might be offloading
> - * inner checksum.
> - */
> +
> + /* Set up inner headers if we are offloading inner checksum */
> + if (skb->ip_summed == CHECKSUM_PARTIAL) {
> skb_reset_inner_headers(skb);
> skb->encapsulation = 1;
> }
> @@ -122,15 +121,15 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct
> sk_buff *skb,
> uh->check = ~csum_fold((__force __wsum)
> ((__force u32)uh->check +
> (__force u32)delta));
> - if (offload_csum) {
> - skb->ip_summed = CHECKSUM_PARTIAL;
> - skb->csum_start = skb_transport_header(skb) -
> skb->head;
> - skb->csum_offset = offsetof(struct udphdr, check);
> - } else {
> - uh->check = gso_make_checksum(skb, ~uh->check);
>
> + if (skb->encapsulation || !offload_csum) {
> + uh->check = gso_make_checksum(skb, ~uh->check);
> if (uh->check == 0)
> uh->check = CSUM_MANGLED_0;
> + } else {
> + skb->ip_summed = CHECKSUM_PARTIAL;
> + skb->csum_start = skb_transport_header(skb) -
> skb->head;
> + skb->csum_offset = offsetof(struct udphdr, check);
> }
> } while ((skb = skb->next));
> out:
>
