tcp: Replace time wait bucket msg by counter

Rather than printing the message to the log, use a mib counter to keep
track of the count of occurences of time wait bucket overflow.  Reduces
spam in logs.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/snmp.h

@@ -230,6 +230,7 @@ enum
 	LINUX_MIB_TCPMINTTLDROP, /* RFC 5082 */
 	LINUX_MIB_TCPDEFERACCEPTDROP,
 	LINUX_MIB_IPRPFILTER, /* IP Reverse Path Filter (rp_filter) */
+	LINUX_MIB_TCPTIMEWAITOVERFLOW,		/* TCPTimeWaitOverflow */
 	__LINUX_MIB_MAX
 };
 

net/ipv4/proc.c

@@ -253,6 +253,7 @@ static const struct snmp_mib snmp4_net_list[] = {
 	SNMP_MIB_ITEM("TCPMinTTLDrop", LINUX_MIB_TCPMINTTLDROP),
 	SNMP_MIB_ITEM("TCPDeferAcceptDrop", LINUX_MIB_TCPDEFERACCEPTDROP),
 	SNMP_MIB_ITEM("IPReversePathFilter", LINUX_MIB_IPRPFILTER),
+	SNMP_MIB_ITEM("TCPTimeWaitOverflow", LINUX_MIB_TCPTIMEWAITOVERFLOW),
 	SNMP_MIB_SENTINEL
 };
 

net/ipv4/tcp_minisocks.c

@@ -347,7 +347,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
 		 * socket up.  We've got bigger problems than
 		 * non-graceful socket closings.
 		 */
-		LIMIT_NETDEBUG(KERN_INFO "TCP: time wait bucket table overflow\n");
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPTIMEWAITOVERFLOW);
 	}
 
 	tcp_update_metrics(sk);