On Fri, Oct 19, 2018 at 10:11 PM Eric Dumazet <eduma...@google.com> wrote:
>
> At least UDP / TCP stacks can now cook skbs with a tstamp using
> MONOTONIC base (or arbitrary values with SCM_TXTIME)
>
> Since loopback driver does not call (directly or indirectly)
> skb_scrub_packet(), we need to clear skb->tstamp so that
> net_timestamp_check() can eventually resample the time,
> using ktime_get_real().
>
> Fixes: 80b14dee2bea ("net: Add a new socket option for a future transmit
> time.")
> Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Cc: Willem de Bruijn <will...@google.com>
> Cc: Soheil Hassas Yeganeh <soh...@google.com>
Acked-by: Soheil Hassas Yeganeh <soh...@google.com>
Thank you, Eric!
> ---
> drivers/net/loopback.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
> index
> a7207fa7e451311aed13cdeb100e0ea7922931bf..2df7f60fe05220c19896a251b6b15239f4b95112
> 100644
> --- a/drivers/net/loopback.c
> +++ b/drivers/net/loopback.c
> @@ -69,6 +69,10 @@ static netdev_tx_t loopback_xmit(struct sk_buff *skb,
> int len;
>
> skb_tx_timestamp(skb);
> +
> + /* do not fool net_timestamp_check() with various clock bases */
> + skb->tstamp = 0;
> +
> skb_orphan(skb);
>
> /* Before queueing this packet to netif_rx(),
> --
> 2.19.1.568.g152ad8e336-goog
>
