[PATCH v2 4/4] net/af_packet: fix QinQ outer TPID on VLAN reinsertion

[William Bland <blandwwa@gmail.com>]

eth_af_packet_rx() called rte_vlan_insert(), which hardcodes EtherType
0x8100 (802.1Q). This was wrong when reinserting a stripped tag whose
original TPID was 0x88a8 (802.1ad QinQ).

Fix by reading the actual TPID from tp_vlan_tpid (struct tpacket2_hdr),
then passing it to rte_vlan_insert_tpid().

This depends on the rte_vlan_insert_tpid() function added by "net: add
VLAN insert function with a TPID argument".

Fixes: 23deeebfcfa8 ("net/af_packet: support 802.1Q VLAN")
Cc: stable@dpdk.org

Signed-off-by: William Bland <blandwwa@gmail.com>
---
 drivers/net/af_packet/rte_eth_af_packet.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/net/af_packet/rte_eth_af_packet.c b/drivers/net/af_packet/rte_eth_af_packet.c
index d95d045a37..e7fbb3c31d 100644
--- a/drivers/net/af_packet/rte_eth_af_packet.c
+++ b/drivers/net/af_packet/rte_eth_af_packet.c
@@ -222,14 +222,20 @@ eth_af_packet_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 
 		/* check for vlan info */
 		if (ppd->tp_status & TP_STATUS_VLAN_VALID) {
+			uint16_t tpid;
+
 			mbuf->vlan_tci = ppd->tp_vlan_tci;
 			mbuf->ol_flags |= RTE_MBUF_F_RX_VLAN;
 
 			if (pkt_q->vlan_strip) {
 				mbuf->ol_flags |= RTE_MBUF_F_RX_VLAN_STRIPPED;
-			} else if (rte_vlan_insert(&mbuf) != 0) {
-				PMD_LOG(ERR, "Failed to reinsert VLAN tag");
-				mbuf->ol_flags |= RTE_MBUF_F_RX_VLAN_STRIPPED;
+			} else {
+				tpid = (ppd->tp_status & TP_STATUS_VLAN_TPID_VALID) ?
+					ppd->tp_vlan_tpid : RTE_ETHER_TYPE_VLAN;
+				if (rte_vlan_insert_tpid(&mbuf, tpid) != 0) {
+					PMD_LOG(ERR, "Failed to reinsert VLAN tag");
+					mbuf->ol_flags |= RTE_MBUF_F_RX_VLAN_STRIPPED;
+				}
 			}
 		}
 
-- 
2.43.0