[PATCH net-next] tcp: md5: increment sk_drops on syn_recv state

[Eric Dumazet]

From: Eric Dumazet <eduma...@google.com>

TCP MD5 mismatches do increment sk_drops counter in all states but
SYN_RECV.

This is very unlikely to happen in the real world, but worth adding
to help diagnostics.

We increase the parent (listener) sk_drops.

Signed-off-by: Eric Dumazet <eduma...@google.com>
---
 net/ipv4/tcp_ipv4.c |    1 +
 net/ipv6/tcp_ipv6.c |    1 +
 2 files changed, 2 insertions(+)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 
32b048e524d6773538918eca175b3f422f9c2aa7..436d978c6c3955dfa9a55f86b1412624ba2ed9fa
 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1602,6 +1602,7 @@ process:
 
                sk = req->rsk_listener;
                if (unlikely(tcp_v4_inbound_md5_hash(sk, skb))) {
+                       sk_drops_add(sk, skb);
                        reqsk_put(req);
                        goto discard_it;
                }
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 
e0f46439e391f2a8b2fac2e13b6f61a11c082715..ac0ed7bda4067a2630cc1cbb546ced3f3ded4c2c
 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1409,6 +1409,7 @@ process:
                sk = req->rsk_listener;
                tcp_v6_fill_cb(skb, hdr, th);
                if (tcp_v6_inbound_md5_hash(sk, skb)) {
+                       sk_drops_add(sk, skb);
                        reqsk_put(req);
                        goto discard_it;
                }