bonding: don't increase rx_dropped after processing LACPDUs

Since commit 3aba891d, bonding processes LACP frames (802.3ad
mode) with bond_handle_frame(). Currently a copy of the skb is
made and the original is left to be processed by other
rx_handlers and the rest of the network stack by returning
RX_HANDLER_ANOTHER.  As there is no protocol handler for
PKT_TYPE_LACPDU, the frame is dropped and dev->rx_dropped
increased.

Fix this by making bond_handle_frame() return RX_HANDLER_CONSUMED
if bonding has processed the LACP frame.

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 62d2409..bc13b3d 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1444,8 +1444,9 @@
 	struct sk_buff *skb = *pskb;
 	struct slave *slave;
 	struct bonding *bond;
-	void (*recv_probe)(struct sk_buff *, struct bonding *,
+	int (*recv_probe)(struct sk_buff *, struct bonding *,
 				struct slave *);
+	int ret = RX_HANDLER_ANOTHER;
 
 	skb = skb_share_check(skb, GFP_ATOMIC);
 	if (unlikely(!skb))
@@ -1464,8 +1465,12 @@
 		struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
 
 		if (likely(nskb)) {
-			recv_probe(nskb, bond, slave);
+			ret = recv_probe(nskb, bond, slave);
 			dev_kfree_skb(nskb);
+			if (ret == RX_HANDLER_CONSUMED) {
+				consume_skb(skb);
+				return ret;
+			}
 		}
 	}
 
@@ -1487,7 +1492,7 @@
 		memcpy(eth_hdr(skb)->h_dest, bond->dev->dev_addr, ETH_ALEN);
 	}
 
-	return RX_HANDLER_ANOTHER;
+	return ret;
 }
 
 /* enslave device <slave> to bond device <master> */
@@ -2723,7 +2728,7 @@
 	}
 }
 
-static void bond_arp_rcv(struct sk_buff *skb, struct bonding *bond,
+static int bond_arp_rcv(struct sk_buff *skb, struct bonding *bond,
 			 struct slave *slave)
 {
 	struct arphdr *arp;
@@ -2731,7 +2736,7 @@
 	__be32 sip, tip;
 
 	if (skb->protocol != __cpu_to_be16(ETH_P_ARP))
-		return;
+		return RX_HANDLER_ANOTHER;
 
 	read_lock(&bond->lock);
 
@@ -2776,6 +2781,7 @@
 
 out_unlock:
 	read_unlock(&bond->lock);
+	return RX_HANDLER_ANOTHER;
 }
 
 /*