[vlan] Provide vlan_netdev_rx() and vlan_netdev_rx_err()

The Hermon driver uses vlan_find() to identify the appropriate VLAN
device for packets that are received with the VLAN tag already
stripped out by the hardware.  Generalise this capability and expose
it for use by other network card drivers.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/infiniband/hermon.c

 				       struct ib_address_vector *source,
 				       struct io_buffer *iobuf, int rc ) {
 	struct net_device *netdev = ib_qp_get_ownerdata ( qp );
-	struct net_device *vlan;
-
-	/* Find VLAN device, if applicable */
-	if ( source->vlan_present ) {
-		if ( ( vlan = vlan_find ( netdev, source->vlan ) ) != NULL ) {
-			netdev = vlan;
-		} else if ( rc == 0 ) {
-			rc = -ENODEV;
-		}
-	}
+	unsigned int tag;
+
+	/* Identify VLAN tag, if applicable */
+	tag = ( source->vlan_present ? source->vlan : 0 );
 
 	/* Hand off to network layer */
 	if ( rc == 0 ) {
-		netdev_rx ( netdev, iobuf );
+		vlan_netdev_rx ( netdev, tag, iobuf );
 	} else {
-		netdev_rx_err ( netdev, iobuf, rc );
+		vlan_netdev_rx_err ( netdev, tag, iobuf, rc );
 	}
 }
 

src/include/ipxe/vlan.h

 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
+#include <ipxe/netdevice.h>
+
 /** A VLAN header */
 struct vlan_header {
 	/** Tag control information */
  */
 #define VLAN_PRIORITY_IS_VALID( priority ) ( (priority) <= 7 )
 
-extern struct net_device * vlan_find ( struct net_device *trunk,
-				       unsigned int tag );
 extern unsigned int vlan_tag ( struct net_device *netdev );
 extern int vlan_can_be_trunk ( struct net_device *trunk );
 extern int vlan_create ( struct net_device *trunk, unsigned int tag,
 			 unsigned int priority );
 extern int vlan_destroy ( struct net_device *netdev );
+extern void vlan_netdev_rx ( struct net_device *netdev, unsigned int tag,
+			     struct io_buffer *iobuf );
+extern void vlan_netdev_rx_err ( struct net_device *netdev, unsigned int tag,
+				 struct io_buffer *iobuf, int rc );
 
 #endif /* _IPXE_VLAN_H */

src/net/netdevice.c

 }
 
 /**
- * Identify VLAN device (when VLAN support is not present)
+ * Add VLAN tag-stripped packet to queue (when VLAN support is not present)
  *
- * @v trunk		Trunk network device
- * @v tag		VLAN tag
- * @ret netdev		VLAN device, if any
+ * @v netdev		Network device
+ * @v tag		VLAN tag, or zero
+ * @v iobuf		I/O buffer
  */
-__weak struct net_device * vlan_find ( struct net_device *trunk __unused,
-				       unsigned int tag __unused ) {
-	return NULL;
+__weak void vlan_netdev_rx ( struct net_device *netdev, unsigned int tag,
+			     struct io_buffer *iobuf ) {
+
+	if ( tag == 0 ) {
+		netdev_rx ( netdev, iobuf );
+	} else {
+		netdev_rx_err ( netdev, iobuf, -ENODEV );
+	}
+}
+
+/**
+ * Discard received VLAN tag-stripped packet (when VLAN support is not present)
+ *
+ * @v netdev		Network device
+ * @v tag		VLAN tag, or zero
+ * @v iobuf		I/O buffer, or NULL
+ * @v rc		Packet status code
+ */
+__weak void vlan_netdev_rx_err ( struct net_device *netdev,
+				 unsigned int tag __unused,
+				 struct io_buffer *iobuf, int rc ) {
+
+	netdev_rx_err ( netdev, iobuf, rc );
 }
 
 /** Networking stack process */

src/net/vlan.c

  * @v tag		VLAN tag
  * @ret netdev		VLAN device, if any
  */
-struct net_device * vlan_find ( struct net_device *trunk, unsigned int tag ) {
+static struct net_device * vlan_find ( struct net_device *trunk,
+				       unsigned int tag ) {
 	struct net_device *netdev;
 	struct vlan_device *vlan;
 
 	.notify = vlan_notify,
 	.remove = vlan_remove,
 };
+
+/**
+ * Add VLAN tag-stripped packet to receive queue
+ *
+ * @v netdev		Network device
+ * @v tag		VLAN tag, or zero
+ * @v iobuf		I/O buffer
+ */
+void vlan_netdev_rx ( struct net_device *netdev, unsigned int tag,
+		      struct io_buffer *iobuf ) {
+	struct net_device *vlan;
+
+	/* Identify VLAN device, if applicable */
+	if ( tag ) {
+		if ( ( vlan = vlan_find ( netdev, tag ) ) == NULL ) {
+			netdev_rx_err ( netdev, iobuf, -ENODEV );
+			return;
+		}
+		netdev = vlan;
+	}
+
+	/* Hand off to network device */
+	netdev_rx ( netdev, iobuf );
+}
+
+/**
+ * Discard received VLAN tag-stripped packet
+ *
+ * @v netdev		Network device
+ * @v tag		VLAN tag, or zero
+ * @v iobuf		I/O buffer, or NULL
+ * @v rc		Packet status code
+ */
+void vlan_netdev_rx_err ( struct net_device *netdev, unsigned int tag,
+			  struct io_buffer *iobuf, int rc ) {
+	struct net_device *vlan;
+
+	/* Identify VLAN device, if applicable */
+	if ( tag && ( ( vlan = vlan_find ( netdev, tag ) ) != NULL ) )
+		netdev = vlan;
+
+	/* Hand off to network device */
+	netdev_rx_err ( netdev, iobuf, rc );
+}