Re: [PATCH] samples: bpf: xdp1: remove duplicate code to find protocol

[Yonghong Song]

On 8/8/21 5:24 AM, Muhammad Falak R Wani wrote:
> The code to find h_vlan_encapsulated_proto is duplicated.
> Remove the extra block.
>
> Signed-off-by: Muhammad Falak R Wani <falakreyaz@xxxxxxxxx>
> ---
>   samples/bpf/xdp1_kern.c | 9 ---------
>   1 file changed, 9 deletions(-)
>
> diff --git a/samples/bpf/xdp1_kern.c b/samples/bpf/xdp1_kern.c
> index 34b64394ed9c..a35e064d7726 100644
> --- a/samples/bpf/xdp1_kern.c
> +++ b/samples/bpf/xdp1_kern.c
> @@ -57,15 +57,6 @@ int xdp_prog1(struct xdp_md *ctx)
>   
>   	h_proto = eth->h_proto;
>   
> -	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
> -		struct vlan_hdr *vhdr;
> -
> -		vhdr = data + nh_off;
> -		nh_off += sizeof(struct vlan_hdr);
> -		if (data + nh_off > data_end)
> -			return rc;
> -		h_proto = vhdr->h_vlan_encapsulated_proto;

No. This is not a duplicate. The h_proto in the above line will be used
in the below "if" condition.

> -	}
>   	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
>   		struct vlan_hdr *vhdr;
>