[PATCH 2/3] net: add VLAN insert function with a TPID argument

[William Bland <blandwwa@gmail.com>]

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

Add rte_vlan_insert_tpid() which takes an explicit tpid parameter, and
rewrite rte_vlan_insert() as a wrapper that passes RTE_ETHER_TYPE_VLAN.

Signed-off-by: William Bland <blandwwa@gmail.com>
---
 lib/net/rte_ether.h | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/lib/net/rte_ether.h b/lib/net/rte_ether.h
index cb10d8fb06..1410ec1968 100644
--- a/lib/net/rte_ether.h
+++ b/lib/net/rte_ether.h
@@ -379,19 +379,21 @@ static inline int rte_vlan_strip(struct rte_mbuf *m)
 }
 
 /**
- * Insert VLAN tag into mbuf.
+ * Insert VLAN tag with the given TPID into mbuf.
  *
- * Software version of VLAN unstripping
+ * Software version of VLAN unstripping.
  *
  * @param m
  *   The packet mbuf.
+ * @param tpid
+ *   Tag Protocol Identifier to insert (host order).
  * @return
  *   - 0: On success
  *   -EINVAL: overwriting would be unsafe because mbuf is shared or
  *            indirect, or mbuf's first segment is too short
  *   -ENOSPC: not enough headroom in mbuf
  */
-static inline int rte_vlan_insert(struct rte_mbuf **m)
+static inline int rte_vlan_insert_tpid(struct rte_mbuf **m, uint16_t tpid)
 {
 	struct rte_ether_hdr *oh, *nh;
 	struct rte_vlan_hdr *vh;
@@ -411,7 +413,7 @@ static inline int rte_vlan_insert(struct rte_mbuf **m)
 		return -ENOSPC;
 
 	memmove(nh, oh, 2 * RTE_ETHER_ADDR_LEN);
-	nh->ether_type = rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN);
+	nh->ether_type = rte_cpu_to_be_16(tpid);
 
 	vh = (struct rte_vlan_hdr *) (nh + 1);
 	vh->vlan_tci = rte_cpu_to_be_16((*m)->vlan_tci);
@@ -426,6 +428,26 @@ static inline int rte_vlan_insert(struct rte_mbuf **m)
 	return 0;
 }
 
+/**
+ * Insert VLAN tag into mbuf.
+ *
+ * Software version of VLAN unstripping. Always inserts an 802.1Q tag
+ * (TPID 0x8100). Use rte_vlan_insert_tpid() when the original TPID may
+ * differ (e.g. 802.1ad QinQ outer tags).
+ *
+ * @param m
+ *   The packet mbuf.
+ * @return
+ *   - 0: On success
+ *   -EINVAL: overwriting would be unsafe because mbuf is shared or
+ *            indirect, or mbuf's first segment is too short
+ *   -ENOSPC: not enough headroom in mbuf
+ */
+static inline int rte_vlan_insert(struct rte_mbuf **m)
+{
+	return rte_vlan_insert_tpid(m, RTE_ETHER_TYPE_VLAN);
+}
+
 #ifdef __cplusplus
 }
 #endif
-- 
2.43.0