Jason Xing wrote:
> Support the ACK timestamp case. Extend txstamp_ack to two bits:
> 1 stands for SO_TIMESTAMPING mode, 2 bpf extension. The latter
> will be used later.
>
> Signed-off-by: Jason Xing <kerneljasonxing@xxxxxxxxx>
> ---
> include/net/tcp.h | 4 ++--
> include/uapi/linux/bpf.h | 5 +++++
> net/core/skbuff.c | 5 ++++-
> tools/include/uapi/linux/bpf.h | 5 +++++
> 4 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/include/net/tcp.h b/include/net/tcp.h
> index 4c4dca59352b..ef30f3605e04 100644
> --- a/include/net/tcp.h
> +++ b/include/net/tcp.h
> @@ -958,10 +958,10 @@ struct tcp_skb_cb {
>
> __u8 sacked; /* State flags for SACK. */
> __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */
> - __u8 txstamp_ack:1, /* Record TX timestamp for ack? */
> + __u8 txstamp_ack:2, /* Record TX timestamp for ack? */
> eor:1, /* Is skb MSG_EOR marked? */
> has_rxtstamp:1, /* SKB has a RX timestamp */
> - unused:5;
> + unused:4;
> __u32 ack_seq; /* Sequence number ACK'd */
> union {
> struct {
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index e71a9b53e7bc..c04e788125a7 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -7044,6 +7044,11 @@ enum {
> * SK_BPF_CB_TX_TIMESTAMPING feature
> * is on.
> */
> + BPF_SOCK_OPS_TS_ACK_OPT_CB, /* Called when all the skbs in the
> + * same sendmsg call are acked
> + * 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/skbuff.c b/net/core/skbuff.c
> index ca1ba4252ca5..c0f4d6f6583d 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -5549,7 +5549,7 @@ static bool skb_tstamp_tx_report_so_timestamping(struct sk_buff *skb,
> return skb_shinfo(skb)->tx_flags & (sw ? SKBTX_SW_TSTAMP :
> SKBTX_HW_TSTAMP_NOBPF);
> case SCM_TSTAMP_ACK:
> - return TCP_SKB_CB(skb)->txstamp_ack;
> + return TCP_SKB_CB(skb)->txstamp_ack == 1;
For the two to coexist, this should be txstamp_ack & 1
And in the patch that introduces the BPF bit, txstamp_ack |= 2, rather than txstamp_ack = 2.
And let's define labels rather than use constants directly:
#define TSTAMP_ACK_SK 0x1
#define TSTAMP_ACK_BPF 0x2
