Subject: Re: [PATCH net-next] Driver: Vmxnet3: Copy TCP header to mapped frame for IPv6 packets

From: Sergei Shtylyov <[email-masked]>
Date: Sun, 01 Mar 2015 02:10:04 +0300

Hello.

On 02/28/2015 10:58 PM, Shrikrishna Khare wrote:

> Allows for packet parsing to be done by the fast path. This performance
> optimization already exists for IPv4. Add similar logic for IPv6.

> Signed-off-by: Amitabha Banerjee <[email-masked]>
> Signed-off-by: Shrikrishna Khare <[email-masked]>
> ---
>   drivers/net/vmxnet3/vmxnet3_drv.c | 26 ++++++++++++++++----------
>   drivers/net/vmxnet3/vmxnet3_int.h |  5 +++--
>   2 files changed, 19 insertions(+), 12 deletions(-)

> diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
> index 294214c..9216e6a 100644
> --- a/drivers/net/vmxnet3/vmxnet3_drv.c
> +++ b/drivers/net/vmxnet3/vmxnet3_drv.c
[...]
> @@ -831,16 +832,20 @@ vmxnet3_parse_and_copy_hdr(struct sk_buff *skb, struct vmxnet3_tx_queue *tq,
>   			if (ctx->ipv4) {
>   				const struct iphdr *iph = ip_hdr(skb);
>
> -				if (iph->protocol == IPPROTO_TCP)
> -					ctx->l4_hdr_size = tcp_hdrlen(skb);
> -				else if (iph->protocol == IPPROTO_UDP)
> -					ctx->l4_hdr_size = sizeof(struct udphdr);
> -				else
> -					ctx->l4_hdr_size = 0;
> -			} else {
> -				/* for simplicity, don't copy L4 headers */
> -				ctx->l4_hdr_size = 0;
> +				protocol = iph->protocol;
> +			} else if (ctx->ipv6) {
> +				const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
> +
> +				protocol = ipv6h->nexthdr;
>   			}
> +
> +			if (protocol == IPPROTO_TCP)
> +				ctx->l4_hdr_size = tcp_hdrlen(skb);
> +			else if (protocol == IPPROTO_UDP)
> +				ctx->l4_hdr_size = sizeof(struct udphdr);
> +			else
> +				ctx->l4_hdr_size = 0;
> +

    I think the above is asking to be a 'switch (protocol)' instead.

WBR, Sergei