tcp: add tracepoint trace_tcp_send_reset

New tracepoint trace_tcp_send_reset is added and called from
tcp_v4_send_reset(), tcp_v6_send_reset() and tcp_send_active_reset().

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 988733f289c8..1f01f4c9c738 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3084,6 +3084,11 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority)
         /* Send it off. */
         if (tcp_transmit_skb(sk, skb, 0, priority))
                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTFAILED);
+
+        /* skb of trace_tcp_send_reset() keeps the skb that caused RST,
+         * skb here is different to the troublesome skb, so use NULL
+         */
+        trace_tcp_send_reset(sk, NULL);
 }
 
 /* Send a crossed SYN-ACK during socket establishment.