[PATCH] net: support VLAN stacking packet type parsing

[Dengdui Huang]

The current rte_net_get_ptype() only supports parsing packets with
one 0x8100 VLAN tag or two 0x88a8 VLAN tags. This patch extends it
to support parsing packets with two 0x8100 VLAN tags.

Signed-off-by: Dengdui Huang <huangdengdui at huawei.com>
---
 lib/net/rte_net.c | 34 ++++++++++++++++++++++------------
 lib/net/rte_net.h |  2 ++
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/lib/net/rte_net.c b/lib/net/rte_net.c
index 44fb6c0f51..fa8d023ca7 100644
--- a/lib/net/rte_net.c
+++ b/lib/net/rte_net.c
@@ -352,14 +352,19 @@ uint32_t rte_net_get_ptype(const struct rte_mbuf *m,
 	if (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN)) {
 		const struct rte_vlan_hdr *vh;
 		struct rte_vlan_hdr vh_copy;
+		uint8_t vlan_num = 1;
 
 		pkt_type = RTE_PTYPE_L2_ETHER_VLAN;
-		vh = rte_pktmbuf_read(m, off, sizeof(*vh), &vh_copy);
-		if (unlikely(vh == NULL))
-			return pkt_type;
-		off += sizeof(*vh);
-		hdr_lens->l2_len += sizeof(*vh);
-		proto = vh->eth_proto;
+		while (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN) &&
+		       vlan_num <= MAX_VLAN_STACKING_TAGS) {
+			vh = rte_pktmbuf_read(m, off, sizeof(*vh), &vh_copy);
+			if (unlikely(vh == NULL))
+				return pkt_type;
+			off += sizeof(*vh);
+			hdr_lens->l2_len += sizeof(*vh);
+			proto = vh->eth_proto;
+			vlan_num++;
+		}
 	} else if (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_QINQ)) {
 		const struct rte_vlan_hdr *vh;
 		struct rte_vlan_hdr vh_copy;
@@ -504,15 +509,20 @@ uint32_t rte_net_get_ptype(const struct rte_mbuf *m,
 	if (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN)) {
 		const struct rte_vlan_hdr *vh;
 		struct rte_vlan_hdr vh_copy;
+		uint8_t vlan_num = 1;
 
 		pkt_type &= ~RTE_PTYPE_INNER_L2_MASK;
 		pkt_type |= RTE_PTYPE_INNER_L2_ETHER_VLAN;
-		vh = rte_pktmbuf_read(m, off, sizeof(*vh), &vh_copy);
-		if (unlikely(vh == NULL))
-			return pkt_type;
-		off += sizeof(*vh);
-		hdr_lens->inner_l2_len += sizeof(*vh);
-		proto = vh->eth_proto;
+		while (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN) &&
+		       vlan_num <= MAX_VLAN_STACKING_TAGS) {
+			vh = rte_pktmbuf_read(m, off, sizeof(*vh), &vh_copy);
+			if (unlikely(vh == NULL))
+				return pkt_type;
+			off += sizeof(*vh);
+			hdr_lens->inner_l2_len += sizeof(*vh);
+			proto = vh->eth_proto;
+			vlan_num++;
+		}
 	} else if (proto == rte_cpu_to_be_16(RTE_ETHER_TYPE_QINQ)) {
 		const struct rte_vlan_hdr *vh;
 		struct rte_vlan_hdr vh_copy;
diff --git a/lib/net/rte_net.h b/lib/net/rte_net.h
index 65d724b84b..fdd55d57c8 100644
--- a/lib/net/rte_net.h
+++ b/lib/net/rte_net.h
@@ -13,6 +13,8 @@
 extern "C" {
 #endif
 
+#define MAX_VLAN_STACKING_TAGS	2
+
 /**
  * Structure containing header lengths associated to a packet, filled
  * by rte_net_get_ptype().
-- 
2.33.0