Re: [PATCH v3 1/5] net: timestamp: add helper returning skb's tx tstamp

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Pavel Begunkov wrote:
> Add a helper function skb_get_tx_timestamp() that returns a tx timestamp
> associated with an skb from an queue queue.

(minor) repeated queue
 
> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
> ---
>  include/net/sock.h |  9 +++++++++
>  net/socket.c       | 45 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 54 insertions(+)
> 
> diff --git a/include/net/sock.h b/include/net/sock.h
> index 92e7c1aae3cc..0b96196d8a34 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -2677,6 +2677,15 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
>  void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
>  			     struct sk_buff *skb);
>  
> +enum {
> +	NET_TIMESTAMP_ORIGIN_SW		= 0,
> +	NET_TIMESTAMP_ORIGIN_HW		= 1,
> +};
> +
> +bool skb_has_tx_timestamp(struct sk_buff *skb, const struct sock *sk);
> +int skb_get_tx_timestamp(struct sk_buff *skb, struct sock *sk,
> +			 struct timespec64 *ts);
> +
>  static inline void
>  sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
>  {
> diff --git a/net/socket.c b/net/socket.c
> index 9a0e720f0859..9bb618c32d65 100644
> --- a/net/socket.c
> +++ b/net/socket.c
> @@ -843,6 +843,51 @@ static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb,
>  		 sizeof(ts_pktinfo), &ts_pktinfo);
>  }
>  
> +bool skb_has_tx_timestamp(struct sk_buff *skb, const struct sock *sk)
> +{
> +	const struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
> +	u32 tsflags = READ_ONCE(sk->sk_tsflags);
> +
> +	if (serr->ee.ee_errno != ENOMSG ||
> +	   serr->ee.ee_origin != SO_EE_ORIGIN_TIMESTAMPING)
> +		return false;
> +
> +	/* software time stamp available and wanted */
> +	if ((tsflags & SOF_TIMESTAMPING_SOFTWARE) && skb->tstamp)
> +		return true;
> +	/* hardware time stamps available and wanted */
> +	return (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
> +		skb_hwtstamps(skb)->hwtstamp;
> +}
> +
> +int skb_get_tx_timestamp(struct sk_buff *skb, struct sock *sk,
> +			  struct timespec64 *ts)
> +{
> +	u32 tsflags = READ_ONCE(sk->sk_tsflags);
> +	ktime_t hwtstamp;
> +	int if_index = 0;
> +
> +	if ((tsflags & SOF_TIMESTAMPING_SOFTWARE) &&
> +	    ktime_to_timespec64_cond(skb->tstamp, ts))
> +		return NET_TIMESTAMP_ORIGIN_SW;
> +
> +	if (!(tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) ||
> +	    skb_is_swtx_tstamp(skb, false))
> +		return -ENOENT;
> +
> +	if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV)
> +		hwtstamp = get_timestamp(sk, skb, &if_index);
> +	else
> +		hwtstamp = skb_hwtstamps(skb)->hwtstamp;
> +
> +	if (tsflags & SOF_TIMESTAMPING_BIND_PHC)
> +		hwtstamp = ptp_convert_timestamp(&hwtstamp,
> +						READ_ONCE(sk->sk_bind_phc));
> +	if (!ktime_to_timespec64_cond(hwtstamp, ts))
> +		return -ENOENT;

(minor) consider an empty line between the branch and final return stmt.
> +	return NET_TIMESTAMP_ORIGIN_HW;
> +}
> +
>  /*
>   * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
>   */
> -- 
> 2.49.0
>