etherdevice.h & bridge: netfilter: Add and use ether_addr_equal_masked

There are code duplications of a masked ethernet address comparison here
so make it a separate function instead.

Miscellanea:

o Neaten alignment of FWINV macro uses to make it clearer for the reader

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index 37ff4a6..6fec9e8 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -374,6 +374,29 @@
 }
 
 /**
+ * ether_addr_equal_masked - Compare two Ethernet addresses with a mask
+ * @addr1: Pointer to a six-byte array containing the 1st Ethernet address
+ * @addr2: Pointer to a six-byte array containing the 2nd Ethernet address
+ * @mask: Pointer to a six-byte array containing the Ethernet address bitmask
+ *
+ * Compare two Ethernet addresses with a mask, returns true if for every bit
+ * set in the bitmask the equivalent bits in the ethernet addresses are equal.
+ * Using a mask with all bits set is a slower ether_addr_equal.
+ */
+static inline bool ether_addr_equal_masked(const u8 *addr1, const u8 *addr2,
+					   const u8 *mask)
+{
+	int i;
+
+	for (i = 0; i < ETH_ALEN; i++) {
+		if ((addr1[i] ^ addr2[i]) & mask[i])
+			return false;
+	}
+
+	return true;
+}
+
+/**
  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
  * @dev: Pointer to a device structure
  * @addr: Pointer to a six-byte array containing the Ethernet address