commit 6a5dc9e598fe90160fee7de098fa319665f5253e
author Eric Dumazet <edumazet@google.com> Mon Apr 29 08:39:56 2013 +0000
committer David S. Miller <davem@davemloft.net> Mon Apr 29 15:14:03 2013 -0400
tree 7f2c2130e3dec81aea01e997cec7e87744f02694
parent f233a976ad15c3b8c54c0157f3c41d23f7514279

net: Add MIB counters for checksum errors

Add MIB counters for checksum errors in IP layer,
and TCP/UDP/ICMP layers, to help diagnose problems.

$ nstat -a | grep  Csum
IcmpInCsumErrors                72                 0.0
TcpInCsumErrors                 382                0.0
UdpInCsumErrors                 463221             0.0
Icmp6InCsumErrors               75                 0.0
Udp6InCsumErrors                173442             0.0
IpExtInCsumErrors               10884              0.0

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/udp.c

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index da6019b..d4defdd 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -483,12 +483,17 @@
 csum_copy_err:
 	slow = lock_sock_fast(sk);
 	if (!skb_kill_datagram(sk, skb, flags)) {
-		if (is_udp4)
+		if (is_udp4) {
+			UDP_INC_STATS_USER(sock_net(sk),
+					UDP_MIB_CSUMERRORS, is_udplite);
 			UDP_INC_STATS_USER(sock_net(sk),
 					UDP_MIB_INERRORS, is_udplite);
-		else
+		} else {
+			UDP6_INC_STATS_USER(sock_net(sk),
+					UDP_MIB_CSUMERRORS, is_udplite);
 			UDP6_INC_STATS_USER(sock_net(sk),
 					UDP_MIB_INERRORS, is_udplite);
+		}
 	}
 	unlock_sock_fast(sk, slow);
 
@@ -637,7 +642,7 @@
 
 	if (rcu_access_pointer(sk->sk_filter)) {
 		if (udp_lib_checksum_complete(skb))
-			goto drop;
+			goto csum_error;
 	}
 
 	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
@@ -656,6 +661,8 @@
 	bh_unlock_sock(sk);
 
 	return rc;
+csum_error:
+	UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
 drop:
 	UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 	atomic_inc(&sk->sk_drops);
@@ -817,7 +824,7 @@
 	}
 
 	if (udp6_csum_init(skb, uh, proto))
-		goto discard;
+		goto csum_error;
 
 	/*
 	 *	Multicast receive code
@@ -850,7 +857,7 @@
 		goto discard;
 
 	if (udp_lib_checksum_complete(skb))
-		goto discard;
+		goto csum_error;
 
 	UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
@@ -867,7 +874,9 @@
 		       skb->len,
 		       daddr,
 		       ntohs(uh->dest));
-
+	goto discard;
+csum_error:
+	UDP6_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
 discard:
 	UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
 	kfree_skb(skb);