# \[Patch net-next 11/13\] tcp: introduce tracepoint trace\_tcp\_v4\_rcv()

- From: Cong Wang \<hidden\>
- Date: 2021-08-05 18:58:13 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/08/11208697
- Thread: https://ratatoskr.run/netdev/2021/08/11208686/t.md

```text
From: Qitao Xu <redacted>

Tracepoint trace_tcp_v4_rcv() is introduced to trace skb at
the entrance of TCP layer on RX side.

Reviewed-by: Cong Wang <redacted>
Signed-off-by: Qitao Xu <redacted>
---
 include/trace/events/tcp.h | 7 +++++++
 net/ipv4/tcp_ipv4.c        | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h
index 6147528d93ba..adf84866dee9 100644
--- a/include/trace/events/tcp.h
+++ b/include/trace/events/tcp.h
@@ -109,6 +109,13 @@ DEFINE_EVENT(tcp_event_sk_skb, tcp_retransmit_skb,
 	TP_ARGS(sk, skb)
 );
 
+DEFINE_EVENT(tcp_event_sk_skb, tcp_v4_rcv,
+
+	TP_PROTO(const struct sock *sk, const struct sk_buff *skb),
+
+	TP_ARGS(sk, skb)
+);
+
 /*
  * skb of trace_tcp_send_reset is the skb that caused RST. In case of
  * active reset, skb should be NULL
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2e62e0d6373a..a0c4aa488659 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2093,6 +2093,8 @@ int tcp_v4_rcv(struct sk_buff *skb)
 	bh_unlock_sock(sk);
 	if (skb_to_free)
 		__kfree_skb(skb_to_free);
+	if (!ret)
+		trace_tcp_v4_rcv(sk, skb);
 
 put_and_return:
 	if (refcounted)
-- 
2.27.0

```