On Wed, Oct 30, 2024 at 7:00 AM Martin KaFai Lau <martin.lau@xxxxxxxxx> wrote:
>
> On 10/28/24 4:05 AM, Jason Xing wrote:
> > From: Jason Xing <kernelxing@xxxxxxxxxxx>
> >
> > This patch has introduced a separate sk_tsflags_bpf for bpf
> > extension, which helps us let two feature work nearly at the
> > same time.
> >
> > Each feature will finally take effect on skb_shinfo(skb)->tx_flags,
> > say, tcp_tx_timestamp() for TCP or skb_setup_tx_timestamp() for
> > other types, so in __skb_tstamp_tx() we are unable to know which
> > feature is turned on, unless we check each feature's own socket
> > flag field.
> >
> > Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx>
> > ---
> > include/net/sock.h | 1 +
> > net/core/skbuff.c | 39 +++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 40 insertions(+)
> >
> > diff --git a/include/net/sock.h b/include/net/sock.h
> > index 7464e9f9f47c..5384f1e49f5c 100644
> > --- a/include/net/sock.h
> > +++ b/include/net/sock.h
> > @@ -445,6 +445,7 @@ struct sock {
> > u32 sk_reserved_mem;
> > int sk_forward_alloc;
> > u32 sk_tsflags;
> > + u32 sk_tsflags_bpf;
> > __cacheline_group_end(sock_write_rxtx);
> >
> > __cacheline_group_begin(sock_write_tx);
> > diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> > index 1cf8416f4123..39309f75e105 100644
> > --- a/net/core/skbuff.c
> > +++ b/net/core/skbuff.c
> > @@ -5539,6 +5539,32 @@ void skb_complete_tx_timestamp(struct sk_buff *skb,
> > }
> > EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
> >
> > +/* This function is used to test if application SO_TIMESTAMPING feature
> > + * or bpf SO_TIMESTAMPING feature is loaded by checking its own socket flags.
> > + */
> > +static bool sk_tstamp_tx_flags(struct sock *sk, u32 tsflags, int tstype)
> > +{
> > + u32 testflag;
> > +
> > + switch (tstype) {
> > + case SCM_TSTAMP_SCHED:
> > + testflag = SOF_TIMESTAMPING_TX_SCHED;
> > + break;
> > + case SCM_TSTAMP_SND:
> > + testflag = SOF_TIMESTAMPING_TX_SOFTWARE;
> > + break;
> > + case SCM_TSTAMP_ACK:
> > + testflag = SOF_TIMESTAMPING_TX_ACK;
> > + break;
> > + default:
> > + return false;
> > + }
> > + if (tsflags & testflag)
> > + return true;
> > +
> > + return false;
> > +}
> > +
> > static void skb_tstamp_tx_output(struct sk_buff *orig_skb,
> > const struct sk_buff *ack_skb,
> > struct skb_shared_hwtstamps *hwtstamps,
> > @@ -5549,6 +5575,9 @@ static void skb_tstamp_tx_output(struct sk_buff *orig_skb,
> > u32 tsflags;
> >
> > tsflags = READ_ONCE(sk->sk_tsflags);
> > + if (!sk_tstamp_tx_flags(sk, tsflags, tstype))
>
> I still don't get this part since v2. How does it work with cmsg only
> SOF_TIMESTAMPING_TX_*?
>
> I tried with "./txtimestamp -6 -c 1 -C -N -L ::1" and it does not return any tx
> time stamp after this patch.
>
> I am likely missing something
> or v2 concluded that this behavior change is acceptable?
Sorry, I submitted this series accidentally removing one important
thing which is similar to what Vadim Fedorenko mentioned in the v1
[1]:
adding another member like sk_flags_bpf to handle the cmsg case.
Willem, would it be acceptable to add another field in struct sock to
help us recognise the case where BPF and cmsg works parallelly?
[1]: https://lore.kernel.org/all/662873cb-a897-464e-bdb3-edf01363c3b2@xxxxxxxxx/
Thanks,
Jason
