Re: [PATCH net-next 3/9] net-timestamp: introduce TS_SW_OPT_CB to generate driver timestamp

[Vadim Fedorenko <vadim.fedorenko@linux.dev>]

On 08/10/2024 10:51, Jason Xing wrote:
> From: Jason Xing <kernelxing@tencent.com>
> 
> When the skb is about to send from driver to nic, we can print timestamp
> by setting BPF_SOCK_OPS_TS_SW_OPT_CB in bpf program.
> 
> Signed-off-by: Jason Xing <kernelxing@tencent.com>
> ---
>   include/uapi/linux/bpf.h       | 5 +++++
>   net/core/skbuff.c              | 8 +++++++-
>   tools/include/uapi/linux/bpf.h | 5 +++++
>   3 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 3cf3c9c896c7..0d00539f247a 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -7024,6 +7024,11 @@ enum {
>   					 * feature is on. It indicates the
>   					 * recorded timestamp.
>   					 */
> +	BPF_SOCK_OPS_TS_SW_OPT_CB,	/* Called when skb is about to send
> +					 * to the nic when SO_TIMESTAMPING
> +					 * feature is on. It indicates the
> +					 * recorded timestamp.
> +					 */
>   };
>   
>   /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index e697f50d1182..8faaa96c026b 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -5556,11 +5556,17 @@ static bool bpf_skb_tstamp_tx(struct sock *sk, u32 scm_flag,
>   		case SCM_TSTAMP_SCHED:
>   			cb_flag = BPF_SOCK_OPS_TS_SCHED_OPT_CB;
>   			break;
> +		case SCM_TSTAMP_SND:
> +			cb_flag = BPF_SOCK_OPS_TS_SW_OPT_CB;
> +			break;
>   		default:
>   			return true;
>   		}
>   
> -		tstamp = ktime_to_timespec64(ktime_get_real());
> +		if (hwtstamps)
> +			tstamp = ktime_to_timespec64(hwtstamps->hwtstamp);
> +		else
> +			tstamp = ktime_to_timespec64(ktime_get_real());

Looks like this chunk belongs to another patch?

>   		tcp_call_bpf_2arg(sk, cb_flag, tstamp.tv_sec, tstamp.tv_nsec);
>   		return true;
>   	}
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index d60675e1a5a0..020ec14ffae6 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -7023,6 +7023,11 @@ enum {
>   					 * feature is on. It indicates the
>   					 * recorded timestamp.
>   					 */
> +	BPF_SOCK_OPS_TS_SW_OPT_CB,	/* Called when skb is about to send
> +					 * to the nic when SO_TIMESTAMPING
> +					 * feature is on. It indicates the
> +					 * recorded timestamp.
> +					 */
>   };
>   
>   /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect