bonding: deliver link-local packets with skb->dev set to link that packets arrived on

Bonding driver changes the skb->dev to the bonding-master before
passing the packet to stack for further processing. This, however
does not make sense for the link-local packets and it loses "the
link info" once its skb->dev is changed to bonding-master.  This
patch changes this behavior for link-local packets by not changing
the skb->dev to the bonding-master and maintaining it as it is,
i.e. the link on which the packet arrived.
Signed-off-by: Chonggang Li <chonggangli@google.com>
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -1176,6 +1176,9 @@ static rx_handler_result_t bond_handle_frame(struct sk_buff **pskb)
 		}
 	}
 
+	/* don't change skb->dev for link-local packets */
+	if (is_link_local_ether_addr(eth_hdr(skb)->h_dest))
+		return RX_HANDLER_PASS;
 	if (bond_should_deliver_exact_match(skb, slave, bond))
 		return RX_HANDLER_EXACT;