Jason Xing wrote:
> From: Jason Xing <kernelxing@xxxxxxxxxxx>
>
> This patch behaves like how cmsg feature works, that is to say,
> check and set on each call of udp_sendmsg before passing sk_tsflags_bpf
> to cork tsflags.
>
> Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx>
> ---
> include/net/sock.h | 1 +
> include/uapi/linux/bpf.h | 3 +++
> net/core/skbuff.c | 2 +-
> net/ipv4/udp.c | 1 +
> tools/include/uapi/linux/bpf.h | 3 +++
> 5 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/sock.h b/include/net/sock.h
> index 062f405c744e..cf7fea456455 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -2828,6 +2828,7 @@ static inline bool sk_listener_or_tw(const struct sock *sk)
> }
>
> void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
> +void timestamp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args);
> int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
> int type);
>
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 6fc3bd12b650..055ffa7c965c 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -7028,6 +7028,9 @@ enum {
> * feature is on. It indicates the
> * recorded timestamp.
> */
> + BPF_SOCK_OPS_TS_UDP_SND_CB, /* Called when every udp_sendmsg
> + * syscall is triggered
> + */
> };
>
> /* 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 8b2a79c0fe1c..0b571306f7ea 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -5622,7 +5622,7 @@ static void skb_tstamp_tx_output(struct sk_buff *orig_skb,
> __skb_complete_tx_timestamp(skb, sk, tstype, opt_stats);
> }
>
> -static void timestamp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args)
> +void timestamp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args)
> {
> struct bpf_sock_ops_kern sock_ops;
>
> diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
> index 9a20af41e272..e768421abc37 100644
> --- a/net/ipv4/udp.c
> +++ b/net/ipv4/udp.c
> @@ -1264,6 +1264,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
> if (!corkreq) {
> struct inet_cork cork;
>
> + timestamp_call_bpf(sk, BPF_SOCK_OPS_TS_UDP_SND_CB, 0, NULL);
> skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
> sizeof(struct udphdr), &ipc, &rt,
> &cork, msg->msg_flags);
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index 6fc3bd12b650..055ffa7c965c 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -7028,6 +7028,9 @@ enum {
> * feature is on. It indicates the
> * recorded timestamp.
> */
> + BPF_SOCK_OPS_TS_UDP_SND_CB, /* Called when every udp_sendmsg
> + * syscall is triggered
> + */
If adding a timestamp as close to syscall entry as possible, give it a
generic name, not specific to UDP.
And please explain in the commit message the reason for a new
timestamp recording point: with existing timestamping the application
can call clock_gettime before (and optionally after) the send call.
An admin using BPF does not have this option, so needs this as part of
the BPF timestamping API.
> };
>
> /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
> --
> 2.37.3
>
