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/ip_input.c b/net/ipv4/ip_input.c
index 2bdf802e28e2..3da817b89e9b 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -419,7 +419,7 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
         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 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
         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: