[netdevice] Separate VLAN support from presence of VLAN-supporting dr…

…ivers Some NICs (e.g. Hermon) provide hardware support for stripping the VLAN tag, but do not provide any way for this support to be disabled. Drivers for this hardware must therefore call vlan_find() to identify a suitable receiving network device. Provide a weak version of vlan_find() which will always return NULL if VLAN support has not been enabled (either directly, or by enabling a feature such as FCoE which requires VLAN support). This allows the VLAN code to be omitted from builds where the user has not requested support for VLANs. Inspired-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Michael Brown <mcb30@ipxe.org>
ipxe · Mar 1, 2013 · 77f64b1 · 77f64b1
1 parent 7d64abb
commit 77f64b1
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/src/net/netdevice.c b/src/net/netdevice.c
@@ -794,5 +794,17 @@ __weak unsigned int vlan_tag ( struct net_device *netdev __unused ) {
 	return 0;
 }
 
+/**
+ * Identify VLAN device (when VLAN support is not present)
+ *
+ * @v trunk		Trunk network device
+ * @v tag		VLAN tag
+ * @ret netdev		VLAN device, if any
+ */
+__weak struct net_device * vlan_find ( struct net_device *trunk __unused,
+				       unsigned int tag __unused ) {
+	return NULL;
+}
+
 /** Networking stack process */
 PERMANENT_PROCESS ( net_process, net_step );