From: Jason Xing <kernelxing@xxxxxxxxxxx> When the skb is about to send from driver to nic, we can print timestamp by setting BPF_SOCK_OPS_TS_SW_OPT_CB in bpf program. Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx> --- include/uapi/linux/bpf.h | 5 +++++ net/core/skbuff.c | 8 +++++++- tools/include/uapi/linux/bpf.h | 5 +++++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 3cf3c9c896c7..0d00539f247a 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -7024,6 +7024,11 @@ enum { * feature is on. It indicates the * recorded timestamp. */ + BPF_SOCK_OPS_TS_SW_OPT_CB, /* Called when skb is about to send + * to the nic when SO_TIMESTAMPING + * feature is on. It indicates the + * recorded timestamp. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect diff --git a/net/core/skbuff.c b/net/core/skbuff.c index e697f50d1182..8faaa96c026b 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5556,11 +5556,17 @@ static bool bpf_skb_tstamp_tx(struct sock *sk, u32 scm_flag, case SCM_TSTAMP_SCHED: cb_flag = BPF_SOCK_OPS_TS_SCHED_OPT_CB; break; + case SCM_TSTAMP_SND: + cb_flag = BPF_SOCK_OPS_TS_SW_OPT_CB; + break; default: return true; } - tstamp = ktime_to_timespec64(ktime_get_real()); + if (hwtstamps) + tstamp = ktime_to_timespec64(hwtstamps->hwtstamp); + else + tstamp = ktime_to_timespec64(ktime_get_real()); tcp_call_bpf_2arg(sk, cb_flag, tstamp.tv_sec, tstamp.tv_nsec); return true; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index d60675e1a5a0..020ec14ffae6 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -7023,6 +7023,11 @@ enum { * feature is on. It indicates the * recorded timestamp. */ + BPF_SOCK_OPS_TS_SW_OPT_CB, /* Called when skb is about to send + * to the nic when SO_TIMESTAMPING + * feature is on. It indicates the + * recorded timestamp. + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect -- 2.37.3