tcp: md5: add LINUX_MIB_TCPMD5FAILURE counter
Adds SNMP counter for drops caused by MD5 mismatches.
The current syslog might help, but a counter is more precise and helps
monitoring.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 436d978..ad41e8e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1169,6 +1169,7 @@
NULL, skb);
if (genhash || memcmp(hash_location, newhash, 16) != 0) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
&iph->saddr, ntohs(th->source),
&iph->daddr, ntohs(th->dest),