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/ipv4/ip_input.c

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 2bdf802..3da817b 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -419,7 +419,7 @@
 	iph = ip_hdr(skb);
 
 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
-		goto inhdr_error;
+		goto csum_error;
 
 	len = ntohs(iph->tot_len);
 	if (skb->len < len) {
@@ -446,6 +446,8 @@
 	return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, dev, NULL,
 		       ip_rcv_finish);
 
+csum_error:
+	IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_CSUMERRORS);
 inhdr_error:
 	IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS);
 drop: