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, 8 insertions, 2 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index ae83615b7f6d..0e2529958b52 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -69,6 +69,8 @@
 #include <crypto/hash.h>
 #include <linux/scatterlist.h>
 
+#include <trace/events/tcp.h>
+
 static void     tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
 static void     tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
                                       struct request_sock *req);
@@ -890,7 +892,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
         int genhash;
         struct sock *sk1 = NULL;
 #endif
-        int oif;
+        int oif = 0;
 
         if (th->rst)
                 return;
@@ -939,7 +941,11 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
                 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
                           (th->doff << 2);
 
-        oif = sk ? sk->sk_bound_dev_if : 0;
+        if (sk) {
+                oif = sk->sk_bound_dev_if;
+                trace_tcp_send_reset(sk, skb);
+        }
+
         tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
 
 #ifdef CONFIG_TCP_MD5SIG