On Wed, Feb 5, 2025 at 11:36 PM Willem de Bruijn
<willemdebruijn.kernel@xxxxxxxxx> wrote:
>
> Jason Xing wrote:
> > Introducing SKBTX_BPF is used as an indicator telling us whether
> > the skb should be traced by the bpf prog.
>
> Should this say support the SCM_TSTAMP_SCHED case?
Will do it.
>
> Also: imperative mood: Introduce instead of Introducing.
Oh, sorry, I have to take an English lesson :S Apparently I didn't
know the difference :( Will adjust accordingly.
>
>
> > Signed-off-by: Jason Xing <kerneljasonxing@xxxxxxxxx>
> > ---
> > include/linux/skbuff.h | 6 +++++-
> > include/uapi/linux/bpf.h | 4 ++++
> > net/core/dev.c | 3 ++-
> > net/core/skbuff.c | 20 ++++++++++++++++++++
> > tools/include/uapi/linux/bpf.h | 4 ++++
> > 5 files changed, 35 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> > index dfc419281cc9..35c2e864dd4b 100644
> > --- a/include/linux/skbuff.h
> > +++ b/include/linux/skbuff.h
> > @@ -490,10 +490,14 @@ enum {
> >
> > /* generate software time stamp when entering packet scheduling */
> > SKBTX_SCHED_TSTAMP = 1 << 6,
> > +
> > + /* used for bpf extension when a bpf program is loaded */
> > + SKBTX_BPF = 1 << 7,
> > };
> >
> > #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
> > - SKBTX_SCHED_TSTAMP)
> > + SKBTX_SCHED_TSTAMP | \
> > + SKBTX_BPF)
> > #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \
> > SKBTX_HW_TSTAMP_USE_CYCLES | \
> > SKBTX_ANY_SW_TSTAMP)
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index 6116eb3d1515..30d2c078966b 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -7032,6 +7032,10 @@ enum {
> > * by the kernel or the
> > * earlier bpf-progs.
> > */
> > + BPF_SOCK_OPS_TS_SCHED_OPT_CB, /* Called when skb is passing through
> > + * dev layer when SK_BPF_CB_TX_TIMESTAMPING
> > + * feature is on.
> > + */
> > };
> >
> > /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
> > diff --git a/net/core/dev.c b/net/core/dev.c
> > index d77b8389753e..4f291459d6b1 100644
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -4500,7 +4500,8 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
> > skb_reset_mac_header(skb);
> > skb_assert_len(skb);
> >
> > - if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
> > + if (unlikely(skb_shinfo(skb)->tx_flags &
> > + (SKBTX_SCHED_TSTAMP | SKBTX_BPF)))
> > __skb_tstamp_tx(skb, NULL, NULL, skb->sk, true, SCM_TSTAMP_SCHED);
> >
> > /* Disable soft irqs for various locks below. Also
> > diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> > index 6042961dfc02..b7261e886529 100644
> > --- a/net/core/skbuff.c
> > +++ b/net/core/skbuff.c
> > @@ -5564,6 +5564,21 @@ static bool skb_enable_app_tstamp(struct sk_buff *skb, int tstype, bool sw)
> > return false;
> > }
> >
> > +static void skb_tstamp_tx_bpf(struct sk_buff *skb, struct sock *sk, int tstype)
> > +{
> > + int op;
> > +
> > + switch (tstype) {
> > + case SCM_TSTAMP_SCHED:
> > + op = BPF_SOCK_OPS_TS_SCHED_OPT_CB;
> > + break;
> > + default:
> > + return;
> > + }
> > +
> > + bpf_skops_tx_timestamping(sk, skb, op);
> > +}
> > +
> > void __skb_tstamp_tx(struct sk_buff *orig_skb,
> > const struct sk_buff *ack_skb,
> > struct skb_shared_hwtstamps *hwtstamps,
> > @@ -5576,6 +5591,11 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
> > if (!sk)
> > return;
> >
> > + /* bpf extension feature entry */
> > + if (skb_shinfo(orig_skb)->tx_flags & SKBTX_BPF)
> > + skb_tstamp_tx_bpf(orig_skb, sk, tstype);
> > +
> > + /* application feature entry */
> > if (!skb_enable_app_tstamp(orig_skb, tstype, sw))
> > return;
> >
> > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> > index 70366f74ef4e..eed91b7296b7 100644
> > --- a/tools/include/uapi/linux/bpf.h
> > +++ b/tools/include/uapi/linux/bpf.h
> > @@ -7025,6 +7025,10 @@ enum {
> > * by the kernel or the
> > * earlier bpf-progs.
> > */
> > + BPF_SOCK_OPS_TS_SCHED_OPT_CB, /* Called when skb is passing through
> > + * dev layer when SK_BPF_CB_TX_TIMESTAMPING
> > + * feature is on.
> > + */
> > };
> >
> > /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
> > --
> > 2.43.5
> >
>
>
