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>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 3ac5dff79627..76e10b47e053 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -881,7 +881,7 @@ int icmp_rcv(struct sk_buff *skb)
         case CHECKSUM_NONE:
                 skb->csum = 0;
                 if (__skb_checksum_complete(skb))
-                        goto error;
+                        goto csum_error;
         }
 
         if (!pskb_pull(skb, sizeof(*icmph)))
@@ -929,6 +929,8 @@ int icmp_rcv(struct sk_buff *skb)
 drop:
         kfree_skb(skb);
         return 0;
+csum_error:
+        ICMP_INC_STATS_BH(net, ICMP_MIB_CSUMERRORS);
 error:
         ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
         goto drop;