net: track success and failure of TCP PMTU probing

Track success and failure of TCP PMTU probing.

Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 1578fc2a6f39..cda3ffedadb6 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2593,6 +2593,7 @@ static void tcp_mtup_probe_failed(struct sock *sk)
 
         icsk->icsk_mtup.search_high = icsk->icsk_mtup.probe_size - 1;
         icsk->icsk_mtup.probe_size = 0;
+        NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMTUPFAIL);
 }
 
 static void tcp_mtup_probe_success(struct sock *sk)
@@ -2612,6 +2613,7 @@ static void tcp_mtup_probe_success(struct sock *sk)
         icsk->icsk_mtup.search_low = icsk->icsk_mtup.probe_size;
         icsk->icsk_mtup.probe_size = 0;
         tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+        NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMTUPSUCCESS);
 }
 
 /* Do a simple retransmit without using the backoff mechanisms in