tcp: add LINUX_MIB_TCPRETRANSFAIL counter
It might be useful to get a counter of failed tcp_retransmit_skb()
calls.
Reported-by: Satoru Moriya <satoru.moriya@hds.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 6afc807..02d6107 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -256,6 +256,7 @@
SNMP_MIB_ITEM("TCPTimeWaitOverflow", LINUX_MIB_TCPTIMEWAITOVERFLOW),
SNMP_MIB_ITEM("TCPReqQFullDoCookies", LINUX_MIB_TCPREQQFULLDOCOOKIES),
SNMP_MIB_ITEM("TCPReqQFullDrop", LINUX_MIB_TCPREQQFULLDROP),
+ SNMP_MIB_ITEM("TCPRetransFail", LINUX_MIB_TCPRETRANSFAIL),
SNMP_MIB_SENTINEL
};
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8c8de27..561550a 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2308,8 +2308,10 @@
if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))
continue;
- if (tcp_retransmit_skb(sk, skb))
+ if (tcp_retransmit_skb(sk, skb)) {
+ NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL);
return;
+ }
NET_INC_STATS_BH(sock_net(sk), mib_idx);
if (inet_csk(sk)->icsk_ca_state == TCP_CA_Recovery)