It is helpful to allow device drivers that don't support hardware
VLAN stripping to emulate this in software. This allows application
to be device independent.
Avoid discarding shared mbufs. Make a copy in rte_vlan_insert() of any
packet to be tagged that has a reference count > 1.
Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
Signed-off-by: Changchun Ouyang <changchun.ouyang at intel.com>
---
lib/librte_ether/rte_ether.h | 76 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 76 insertions(+)
diff --git a/lib/librte_ether/rte_ether.h b/lib/librte_ether/rte_ether.h
index 187608d..3b6ab4b 100644
--- a/lib/librte_ether/rte_ether.h
+++ b/lib/librte_ether/rte_ether.h
@@ -49,6 +49,8 @@ extern "C" {
#include <rte_memcpy.h>
#include <rte_random.h>
+#include <rte_mbuf.h>
+#include <rte_byteorder.h>
#define ETHER_ADDR_LEN 6 /**< Length of Ethernet address. */
#define ETHER_TYPE_LEN 2 /**< Length of Ethernet type field. */
@@ -332,6 +334,80 @@ struct vxlan_hdr {
#define ETHER_VXLAN_HLEN (sizeof(struct udp_hdr) + sizeof(struct vxlan_hdr))
/**< VXLAN tunnel header length. */
+/**
+ * Extract VLAN tag information into mbuf
+ *
+ * Software version of VLAN stripping
+ *
+ * @param m
+ * The packet mbuf.
+ * @return
+ * - 0: Success
+ * - 1: not a vlan packet
+ */
+static inline int rte_vlan_strip(struct rte_mbuf *m)
+{
+ struct ether_hdr *eh
+ = rte_pktmbuf_mtod(m, struct ether_hdr *);
+
+ if (eh->ether_type != ETHER_TYPE_VLAN)
+ return -1;
+
+ struct vlan_hdr *vh = (struct vlan_hdr *)(eh + 1);
+ m->ol_flags |= PKT_RX_VLAN_PKT;
+ m->vlan_tci = rte_be_to_cpu_16(vh->vlan_tci);
+
+ /* Copy ether header over rather than moving whole packet */
+ memmove(rte_pktmbuf_adj(m, sizeof(struct vlan_hdr)),
+ eh, 2 * ETHER_ADDR_LEN);
+
+ return 0;
+}
+
+/**
+ * Insert VLAN tag into mbuf.
+ *
+ * Software version of VLAN unstripping
+ *
+ * @param m
+ * The packet mbuf.
+ * @return
+ * - 0: On success
+ * -EPERM: mbuf is is shared overwriting would be unsafe
+ * -ENOSPC: not enough headroom in mbuf
+ */
+static inline int rte_vlan_insert(struct rte_mbuf **m)
+{
+ struct ether_hdr *oh, *nh;
+ struct vlan_hdr *vh;
+
+#ifdef RTE_MBUF_REFCNT
+ /* Can't insert header if mbuf is shared */
+ if (rte_mbuf_refcnt_read(*m) > 1) {
+ struct rte_mbuf *copy;
+
+ copy = rte_pktmbuf_clone(*m, (*m)->pool);
+ if (unlikely(copy == NULL))
+ return -ENOMEM;
+ rte_pktmbuf_free(*m);
+ *m = copy;
+ }
+#endif
+ oh = rte_pktmbuf_mtod(*m, struct ether_hdr *);
+ nh = (struct ether_hdr *)
+ rte_pktmbuf_prepend(*m, sizeof(struct vlan_hdr));
+ if (nh == NULL)
+ return -ENOSPC;
+
+ memmove(nh, oh, 2 * ETHER_ADDR_LEN);
+ nh->ether_type = ETHER_TYPE_VLAN;
+
+ vh = (struct vlan_hdr *) (nh + 1);
+ vh->vlan_tci = rte_cpu_to_be_16((*m)->vlan_tci);
+
+ return 0;
+}
+
#ifdef __cplusplus
}
#endif
--
1.8.4.2
