Re: [PATCH net-next v2 02/12] net-timestamp: open gate for bpf_setsockopt

[Martin KaFai Lau <martin.lau@linux.dev>]

On 10/11/24 9:06 PM, Jason Xing wrote:
> +static int bpf_sock_set_timestamping(struct sock *sk,
> +				     struct so_timestamping *timestamping)
> +{
> +	u32 flags = timestamping->flags;
> +
> +	if (flags & ~SOF_TIMESTAMPING_MASK)
> +		return -EINVAL;
> +
> +	if (!(flags & (SOF_TIMESTAMPING_TX_SCHED | SOF_TIMESTAMPING_TX_SOFTWARE |
> +	      SOF_TIMESTAMPING_TX_ACK)))

hmm... Does it mean at least one of the bit must be set and cannot be completely 
cleared once it has been set before?

> +		return -EINVAL;
> +
> +	WRITE_ONCE(sk->sk_tsflags[BPFPROG_TS_REQUESTOR], flags);
> +
> +	return 0;
> +}