Added the concept of a network interface (a network-layer concept) as

separate from a network device (a link-layer concept).

src/include/gpxe/netdevice.h

@@ -3,43 +3,31 @@
 
 /** @file
  *
- * Net device interface
+ * Network device and network interface
  *
  */
 
 #include <stdint.h>
 #include <gpxe/llh.h>
+#include <gpxe/list.h>
 
 struct net_device;
+struct net_interface;
 struct pk_buff;
 
 /**
  * A network device
  *
+ * This structure represents a piece of networking hardware.  It has
+ * properties such as a link-layer address and methods for
+ * transmitting and receiving raw packets.  It does not know anything
+ * about network-layer protocols (e.g. IP) or their addresses; these
+ * are handled by struct @c net_interface instead.
+ *
  * Note that this structure must represent a generic network device,
  * not just an Ethernet device.
  */
 struct net_device {
-	/** Build media-specific link-layer header
-	 *
-	 * @v netdev	Network device
-	 * @v pkb	Packet buffer
-	 * @ret rc	Return status code
-	 *
-	 * This method should convert the packet buffer's generic
-	 * link-layer header (a struct gpxehdr) into a media-specific
-	 * link-layer header (e.g. a struct ethhdr).  The generic
-	 * header should be removed from the buffer (via pkb_pull())
-	 * and the media-specific header should be prepended (via
-	 * pkb_push()) in its place.
-	 *
-	 * If a link-layer header cannot be constructed (e.g. because
-	 * of a missing ARP cache entry), then this method should
-	 * replace the contents of the packet buffer with an
-	 * appropriate ARP request or equivalent, and return -ENOENT.
-	 */
-	int ( * make_media_header ) ( struct net_device *netdev,
-				      struct pk_buff *pkb );
 	/** Transmit packet
 	 *
 	 * @v netdev	Network device
@@ -72,7 +60,27 @@ struct net_device {
 	 */
 	int ( * poll ) ( struct net_device *netdev, int retrieve,
 			 struct pk_buff *pkb );
-	/** Parse link-layer header
+	/** Build media-specific link-layer header
+	 *
+	 * @v netdev	Network device
+	 * @v pkb	Packet buffer
+	 * @ret rc	Return status code
+	 *
+	 * This method should convert the packet buffer's generic
+	 * link-layer header (a struct gpxehdr) into a media-specific
+	 * link-layer header (e.g. a struct ethhdr).  The generic
+	 * header should be removed from the buffer (via pkb_pull())
+	 * and the media-specific header should be prepended (via
+	 * pkb_push()) in its place.
+	 *
+	 * If a link-layer header cannot be constructed (e.g. because
+	 * of a missing ARP cache entry), then this method should
+	 * return an error (after transmitting an ARP request, if
+	 * applicable).
+	 */
+	int ( * make_media_header ) ( struct net_device *netdev,
+				      struct pk_buff *pkb );
+	/** Build media-independent link-layer header
 	 *
 	 * @v netdev	Network device
 	 * @v pkb	Packet buffer
@@ -91,7 +99,7 @@ struct net_device {
 					struct pk_buff *pkb );
 	/** Link-layer protocol
 	 *
-	 * This is an ARPHRD_XXX constant, in network-byte order.
+	 * This is an ARPHRD_XXX constant, in network byte order.
 	 */
 	uint16_t ll_proto;
 	/** Link-layer address length */
@@ -101,10 +109,83 @@ struct net_device {
 	 * For Ethernet, this is the MAC address.
 	 */
 	uint8_t ll_addr[MAX_LLH_ADDR_LEN];
+	/** List of network interfaces */
+	struct list_head interfaces;
 	/** Driver private data */
 	void *priv;
 };
 
+/**
+ * A network interface
+ *
+ * This structure represents a particular network layer protocol's
+ * interface to a piece of network hardware (a struct @c net_device).
+ *
+ */
+struct net_interface {
+	/** Underlying net device */
+	struct net_device *netdev;
+	/** Linked list of interfaces for this device */
+	struct list_head list;
+	/** Network-layer protocol
+	 *
+	 * This is an ETH_P_XXX constant, in network byte order.
+	 */
+	uint16_t net_proto;
+	/** Network-layer address length */
+	uint8_t net_addr_len;
+	/** Network-layer address */
+	uint8_t net_addr[MAX_NET_ADDR_LEN];
+	/** Packet processor
+	 *
+	 * @v netif	Network interface
+	 * @v pkb	Packet buffer
+	 * @ret rc	Return status code
+	 *
+	 * This method is called for packets arriving on the
+	 * associated network device that match this interface's
+	 * network-layer protocol.
+	 *
+	 * When this method is called, the link-layer header will
+	 * already have been stripped from the packet.
+	 */
+	int ( * process ) ( struct net_interface *netif,
+			    struct pk_buff *pkb );
+	/** Add media-independent link-layer header
+	 *
+	 * @v netif	Network interface
+	 * @v pkb	Packet buffer
+	 * @ret rc	Return status code
+	 *
+	 * This method should prepend a generic link-layer header (a
+	 * struct @c gpxehdr) to the packet buffer using pkb_push().
+	 */
+	int ( * add_generic_header ) ( struct net_interface *netif,
+				       struct pk_buff *pkb );
+};
+
+/**
+ * Find interface for a specific protocol
+ *
+ * @v netdev	Network device
+ * @v net_proto	Network-layer protocol, in network byte order
+ * @ret netif	Network interface, or NULL if none found
+ *
+ */
+static inline struct net_interface *
+netdev_find_netif ( const struct net_device *netdev, uint16_t net_proto ) {
+	struct net_interface *netif;
+
+	list_for_each_entry ( netif, &netdev->interfaces, list ) {
+		if ( netif->net_proto == net_proto )
+			return netif;
+	}
+	return NULL;
+}
+
+extern int netdev_send ( struct net_device *netdev, struct pk_buff *pkb );
+extern int netif_send ( struct net_interface *netif, struct pk_buff *pkb );
+
 extern struct net_device static_single_netdev;
 
 /* Must be a macro because priv_data[] is of variable size */