tcp: Update MIB counters for drops

This patch updates LINUX_MIB_LISTENDROPS in tcp_v4_conn_request() and
tcp_v4_err(). tcp_v4_conn_request() in particular can drop SYNs for various
reasons which are not currently tracked.

Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 629937d514eb..eadb693eef55 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -496,6 +496,7 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
                  * errors returned from accept().
                  */
                 inet_csk_reqsk_queue_drop(sk, req, prev);
+                NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
                 goto out;
 
         case TCP_SYN_SENT:
@@ -1502,7 +1503,6 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
          */
         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) {
                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
-                NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
                 goto drop;
         }
 
@@ -1669,6 +1669,7 @@ drop_and_release:
 drop_and_free:
         reqsk_free(req);
 drop:
+        NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
         return 0;
 }
 EXPORT_SYMBOL(tcp_v4_conn_request);