bonding: remove packet cloning in recv_probe()

Cloning all packets in input path have a significant cost.

Use skb_header_pointer()/skb_copy_bits() instead of pskb_may_pull() so
that recv_probe handlers (bond_3ad_lacpdu_recv / bond_arp_rcv /
rlb_arp_recv ) dont touch input skb.

bond_handle_frame() can avoid the skb_clone()/dev_kfree_skb()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Nicolas de Pesloüan <nicolas.2p.debian@free.fr>
Cc: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 4581aa5..f8af2fc 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -218,8 +218,8 @@
 	struct   slave *primary_slave;
 	bool     force_primary;
 	s32      slave_cnt; /* never change this value outside the attach/detach wrappers */
-	int     (*recv_probe)(struct sk_buff *, struct bonding *,
-			       struct slave *);
+	int     (*recv_probe)(const struct sk_buff *, struct bonding *,
+			      struct slave *);
 	rwlock_t lock;
 	rwlock_t curr_slave_lock;
 	u8	 send_peer_notif;