net: rx_dropped accounting

Under load, netif_rx() can drop incoming packets but administrators dont
have a chance to spot which device needs some tuning (RPS activation for
example)

This patch adds rx_dropped accounting in vlans and tunnels.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 11 insertions, 3 deletions

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 9289cecac4de..f6d9f683543e 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -725,7 +725,10 @@ static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
                 skb_tunnel_rx(skb, t->dev);
 
                 dscp_ecn_decapsulate(t, ipv6h, skb);
-                netif_rx(skb);
+
+                if (netif_rx(skb) == NET_RX_DROP)
+                        t->dev->stats.rx_dropped++;
+
                 rcu_read_unlock();
                 return 0;
         }
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 66078dad7fe8..2640c9be589d 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -666,7 +666,9 @@ static int pim6_rcv(struct sk_buff *skb)
 
         skb_tunnel_rx(skb, reg_dev);
 
-        netif_rx(skb);
+        if (netif_rx(skb) == NET_RX_DROP)
+                reg_dev->stats.rx_dropped++;
+
         dev_put(reg_dev);
         return 0;
  drop:
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 6822481ff766..8a0399822230 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -564,7 +564,10 @@ static int ipip6_rcv(struct sk_buff *skb)
                 skb_tunnel_rx(skb, tunnel->dev);
 
                 ipip6_ecn_decapsulate(iph, skb);
-                netif_rx(skb);
+
+                if (netif_rx(skb) == NET_RX_DROP)
+                        tunnel->dev->stats.rx_dropped++;
+
                 rcu_read_unlock();
                 return 0;
         }