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?
Also: imperative mood: Introduce instead of Introducing.
> 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
>
