First version

src/include/gpxe/llh.h

@@ -0,0 +1,56 @@
+#ifndef _LLH_H
+#define _LLH_H
+
+/** @file
+ *
+ * Link-layer headers
+ *
+ * This file defines a media-independent link-layer header, used for
+ * communication between the network and link layers of the stack.
+ *
+ */
+
+#include <stdint.h>
+
+/** Maximum length of a link-layer address */
+#define MAX_LLH_ADDR_LEN 6
+
+/** Maximum length of a network-layer address */
+#define MAX_NET_ADDR_LEN 4
+
+/** A media-independent link-layer header
+ *
+ * This structure represents a generic link-layer header.  It never
+ * appears on the wire, but is used to communicate between different
+ * layers within the gPXE protocol stack.
+ */
+struct gpxehdr {
+	/** The network-layer protocol
+	 *
+	 * This is the network-layer protocol expressed as an
+	 * ETH_P_XXX constant, in network-byte order.
+	 */
+	uint16_t net_proto;
+	/** Broadcast flag
+	 *
+	 * Filled in only on outgoing packets.
+	 */
+	int broadcast : 1;
+	/** Multicast flag
+	 *
+	 * Filled in only on outgoing packets.
+	 */
+	int multicast : 1;
+	/** Network-layer address length 
+	 *
+	 * Filled in only on outgoing packets.
+	 */
+	uint8_t net_addr_len;
+	/** Network-layer address
+	 *
+	 * Filled in only on outgoing packets.
+	 */
+	uint8_t net_addr[MAX_NET_ADDR_LEN];
+} __attribute__ (( packed ));
+
+#endif /* _LLH_H */