tcp: MD5: Use MIB counter instead of warning for MD5 mismatch.

From a report by Matti Aarnio, and preliminary patch by Adam Langley.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 834356e..8f5a403 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -232,6 +232,8 @@
 	SNMP_MIB_ITEM("TCPDSACKIgnoredOld", LINUX_MIB_TCPDSACKIGNOREDOLD),
 	SNMP_MIB_ITEM("TCPDSACKIgnoredNoUndo", LINUX_MIB_TCPDSACKIGNOREDNOUNDO),
 	SNMP_MIB_ITEM("TCPSpuriousRTOs", LINUX_MIB_TCPSPURIOUSRTOS),
+	SNMP_MIB_ITEM("TCPMD5NotFound", LINUX_MIB_TCPMD5NOTFOUND),
+	SNMP_MIB_ITEM("TCPMD5Unexpected", LINUX_MIB_TCPMD5UNEXPECTED),
 	SNMP_MIB_SENTINEL
 };
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index a2b06d0..b3875c0 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1116,18 +1116,12 @@
 		return 0;
 
 	if (hash_expected && !hash_location) {
-		LIMIT_NETDEBUG(KERN_INFO "MD5 Hash expected but NOT found "
-			       "(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)\n",
-			       NIPQUAD(iph->saddr), ntohs(th->source),
-			       NIPQUAD(iph->daddr), ntohs(th->dest));
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
 		return 1;
 	}
 
 	if (!hash_expected && hash_location) {
-		LIMIT_NETDEBUG(KERN_INFO "MD5 Hash NOT expected but found "
-			       "(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)\n",
-			       NIPQUAD(iph->saddr), ntohs(th->source),
-			       NIPQUAD(iph->daddr), ntohs(th->dest));
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
 		return 1;
 	}