net: add macros for VLAN metadata parsing

[ upstream commit b74087f15e16c42fe4ff9c4d603cc7a51a1aa1dc ]

Add common macros for extracting parts of VLAN tag.

Fixes: 4e9c73e ("net/netvsc: add Hyper-V network device")

Signed-off-by: Alan Elder <alan.elder@microsoft.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@amd.com>

.mailmap

@@ -31,6 +31,7 @@ Akshay Dorwat <akshay.dorwat@amd.com>
 Alain Leon <xerebz@gmail.com>
 Alan Carew <alan.carew@intel.com>
 Alan Dewar <alan.dewar@att.com> <adewar@brocade.com>
+Alan Elder <alan.elder@microsoft.com>
 Alan Liu <zaoxingliu@gmail.com>
 Alan Winkowski <walan@marvell.com>
 Alejandro Lucero <alejandro.lucero@netronome.com>

lib/net/rte_ether.h

@@ -46,6 +46,20 @@ extern "C" {
 
 #define RTE_ETHER_MIN_MTU 68 /**< Minimum MTU for IPv4 packets, see RFC 791. */
 
+/* VLAN header fields */
+#define RTE_VLAN_DEI_SHIFT	12
+#define RTE_VLAN_PRI_SHIFT	13
+#define RTE_VLAN_PRI_MASK	0xe000 /* Priority Code Point */
+#define RTE_VLAN_DEI_MASK	0x1000 /* Drop Eligible Indicator */
+#define RTE_VLAN_ID_MASK	0x0fff /* VLAN Identifier */
+
+#define RTE_VLAN_TCI_ID(vlan_tci)	((vlan_tci) & RTE_VLAN_ID_MASK)
+#define RTE_VLAN_TCI_PRI(vlan_tci)	(((vlan_tci) & RTE_VLAN_PRI_MASK) >> RTE_VLAN_PRI_SHIFT)
+#define RTE_VLAN_TCI_DEI(vlan_tci)	(((vlan_tci) & RTE_VLAN_DEI_MASK) >> RTE_VLAN_DEI_SHIFT)
+#define RTE_VLAN_TCI_MAKE(id, pri, dei)	((id) |					\
+					 ((pri) << RTE_VLAN_PRI_SHIFT) |	\
+					 ((dei) << RTE_VLAN_DEI_SHIFT))
+
 /**
  * Ethernet address:
  * A universally administered address is uniquely assigned to a device by its