mbuf: extend meaning of QinQ stripped bit

Certain hardware may be able to strip and/or save only the outermost
VLAN instead of both the VLANs in the mbuf in a QinQ scenario.
To handle such cases, we could re-interpret setting of just
PKT_RX_QINQ_STRIPPED to indicate that only the outermost VLAN has
been stripped and saved in mbuf->vlan_tci_outer.
Only When both PKT_RX_QINQ_STRIPPED and PKT_RX_VLAN_STRIPPED are set, the 2
VLANs have been stripped by the hardware and their TCI are saved in
mbuf->vlan_tci (inner) and mbuf->vlan_tci_outer (outer).

Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>

diff --git a/lib/librte_mbuf/rte_mbuf_core.h b/lib/librte_mbuf/rte_mbuf_core.h
index 8cd7137..a27968b 100644 (file)
--- a/lib/librte_mbuf/rte_mbuf_core.h
+++ b/lib/librte_mbuf/rte_mbuf_core.h
@@ -126,12 +126,19 @@ extern "C" {
 #define PKT_RX_FDIR_FLX      (1ULL << 14)
 
 /**
- * The 2 vlans have been stripped by the hardware and their tci are
- * saved in mbuf->vlan_tci (inner) and mbuf->vlan_tci_outer (outer).
- * This can only happen if vlan stripping is enabled in the RX
+ * The outer VLAN has been stripped by the hardware and its TCI is
+ * saved in mbuf->vlan_tci_outer (outer).
+ * This can only happen if VLAN stripping is enabled in the Rx
  * configuration of the PMD.
- * When PKT_RX_QINQ_STRIPPED is set, the flags (PKT_RX_VLAN |
- * PKT_RX_VLAN_STRIPPED | PKT_RX_QINQ) must also be set.
+ * When PKT_RX_QINQ_STRIPPED is set, the flags (PKT_RX_VLAN |  PKT_RX_QINQ)
+ * must also be set.
+ *
+ * - If both PKT_RX_QINQ_STRIPPED and PKT_RX_VLAN_STRIPPED are set, the 2 VLANs
+ *   have been stripped by the hardware and their TCIs are saved in
+ *   mbuf->vlan_tci (inner) and mbuf->vlan_tci_outer (outer).
+ * - If PKT_RX_QINQ_STRIPPED is set and PKT_RX_VLAN_STRIPPED is unset, only the
+ *   outer VLAN is removed from packet data, but both tci are saved in
+ *   mbuf->vlan_tci (inner) and mbuf->vlan_tci_outer (outer).
  */
 #define PKT_RX_QINQ_STRIPPED (1ULL << 15)
 
@@ -159,7 +166,9 @@ extern "C" {
 
 /**
  * The RX packet is a double VLAN, and the outer tci has been
- * saved in in mbuf->vlan_tci_outer. If PKT_RX_QINQ set, PKT_RX_VLAN
+ * saved in in mbuf->vlan_tci_outer. If this flag is set:
+ * - PKT_RX_VLAN must also be set
+ * -
  * also should be set and inner tci should be saved to mbuf->vlan_tci.
  * If the flag PKT_RX_QINQ_STRIPPED is also present, both VLANs
  * headers have been stripped from mbuf data, else they are still