Re: [PATCH] netfilter: nft_meta: Extend support for NFT_META_TSTAMP_NS

[Florian Westphal <fw@strlen.de>]

Karuna Grewal <karunagrewal98@gmail.com> wrote:
> Meta evaluation function is extended to suport NFT_META_TSTAMP_NS option
> by exposing the 64 bit timestamp of the packet to two 32 bit registers.

Please test patches first, see below.

> diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
> index 987d2d6ce624..adfa1f221946 100644
> --- a/net/netfilter/nft_meta.c
> +++ b/net/netfilter/nft_meta.c
> @@ -254,6 +254,13 @@ void nft_meta_get_eval(const struct nft_expr *expr,
>  			goto err;
>  		strncpy((char *)dest, out->rtnl_link_ops->kind, IFNAMSIZ);
>  		break;
> +	case NFT_META_TSTAMP_NS:
> +		if (skb->tstamp == 0)
> +			__net_timestamp((struct sk_buff *)skb);
> +		u64 timestamp = ktime_to_ns(skb->tstamp);
> +		*dest = (u32)(timestamp >> 32);
> +		*(dest + 1) = (u32) timestamp;
> +		break;

Please consider using u64 *dest64 or similar to avoid the need for
shifting.

>  	default:
>  		WARN_ON(1);
>  		goto err;
> @@ -371,6 +378,8 @@ static int nft_meta_get_init(const struct nft_ctx *ctx,
>  		len = IFNAMSIZ;
>  		break;
>  #endif
> +	case NFT_META_TSTAMP_NS:
> +		len = sizeof(u64);
>  	default:
>  		return -EOPNOTSUPP;

This is missing a break statement after len assignment.

Other than this, this patch looks good.  Please consider sending v3 once
you have nftables patches ready as well.