Remove the concept of the media-independent link-layer header and replace

it with metadata in the pkb structure.  This is required since UNDI will
want to be able to parse the link-layer header without destroying it.

4 files changed, 59 insertions, 100 deletions

diff --git a/src/include/gpxe/arp.h b/src/include/gpxe/arp.h
index 64e6c2723..f6ec47af7 100644
--- a/src/include/gpxe/arp.h
+++ b/src/include/gpxe/arp.h
@@ -12,7 +12,7 @@ struct net_interface;
 struct pk_buff;
 
 extern int arp_resolve ( struct net_device *netdev, struct pk_buff *pkb,
-			 void *ll_addr );
+			 const void **ll_addr );
 
 extern int arp_process ( struct net_interface *arp_netif,
 			 struct pk_buff *pkb );
diff --git a/src/include/gpxe/llh.h b/src/include/gpxe/llh.h
deleted file mode 100644
index f60078149..000000000
--- a/src/include/gpxe/llh.h
+++ /dev/null
@@ -1,63 +0,0 @@
-#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
-
-/* Network-layer address may be required to contain a raw link-layer address */
-#if MAX_NET_ADDR_LEN < MAX_LLH_ADDR_LEN
-#undef MAX_NET_ADDR_LEN
-#define MAX_NET_ADDR_LEN MAX_LLH_ADDR_LEN
-#endif
-
-/** 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;
-	/** Flags
-	 *
-	 * Filled in only on outgoing packets.  Value is the
-	 * bitwise-OR of zero or more GPXE_FL_XXX constants.
-	 */
-	uint8_t flags;
-	/** 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 ));
-
-/* Media-independent link-layer header flags */
-#define GPXE_FL_BROADCAST	0x01
-#define GPXE_FL_MULTICAST	0x02
-#define GPXE_FL_RAW		0x04
-
-#endif /* _LLH_H */
diff --git a/src/include/gpxe/netdevice.h b/src/include/gpxe/netdevice.h
index dbb6be84a..7517c3e71 100644
--- a/src/include/gpxe/netdevice.h
+++ b/src/include/gpxe/netdevice.h
@@ -8,13 +8,18 @@
  */
 
 #include <stdint.h>
-#include <gpxe/llh.h>
 #include <gpxe/list.h>
 
 struct net_device;
 struct net_interface;
 struct pk_buff;
 
+/** 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 network device
  *
@@ -45,7 +50,6 @@ struct net_device {
 	/** Poll for received packet
 	 *
 	 * @v netdev	Network device
-	 * @v retrieve	Flag indicating whether or not to retrieve packet
 	 * @v pkb	Packet buffer to contain received packet
 	 * @ret rc	Return status code
 	 *
@@ -53,55 +57,42 @@ struct net_device {
 	 * received packet.  If no packet is available, the method
 	 * should return -EAGAIN (i.e. this method is *always*
 	 * considered to be a non-blocking read).  If a packet is
-	 * available, but @c retrieve is false, the method should
-	 * return zero for success.  If a packet is available and @c
-	 * retrieve is true, the method should fill the packet buffer
-	 * and return zero for success.
+	 * available, the method should fill the packet buffer and
+	 * return zero for success.
 	 */
-	int ( * poll ) ( struct net_device *netdev, int retrieve,
-			 struct pk_buff *pkb );
-	/** Build media-specific link-layer header
+	int ( * poll ) ( struct net_device *netdev, struct pk_buff *pkb );
+	/** Build 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.
+	 * This method should fill in the link-layer header based on
+	 * the metadata contained in @c pkb.
 	 *
 	 * 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
+	int ( * build_llh ) ( struct net_device *netdev, struct pk_buff *pkb );
+	/** Parse link-layer header
 	 *
 	 * @v netdev	Network device
 	 * @v pkb	Packet buffer
 	 * @ret rc	Return status code
 	 *
-	 * This method should convert the packet buffer's
-	 * media-specific link-layer header (e.g. a struct ethhdr)
-	 * into a generic link-layer header (a struct gpxehdr).  It
-	 * performs the converse function of make_media_header().
-	 *
-	 * Note that the gpxehdr::addr and gpxehdr::addrlen fields
-	 * will not be filled in by this function, since doing so
-	 * would require understanding the network-layer header.
+	 * This method should parse the link-layer header and fill in
+	 * the metadata in @c pkb.
 	 */
-	int ( * make_generic_header ) ( struct net_device *netdev,
-					struct pk_buff *pkb );
+	int ( * parse_llh ) ( struct net_device *netdev, struct pk_buff *pkb );
 	/** Link-layer protocol
 	 *
 	 * This is an ARPHRD_XXX constant, in network byte order.
 	 */
 	uint16_t ll_proto;
+	/** Link-layer header length */
+	uint8_t ll_hlen;
 	/** Link-layer address length */
 	uint8_t ll_addr_len;
 	/** Link-layer address
@@ -151,17 +142,18 @@ struct net_interface {
 	 */
 	int ( * process ) ( struct net_interface *netif,
 			    struct pk_buff *pkb );
-	/** Add media-independent link-layer header
+	/** Fill in packet metadata
 	 *
 	 * @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().
+	 * This method should fill in the @c pkb metadata with enough
+	 * information to enable net_device::build_llh to construct
+	 * the link-layer header.
 	 */
-	int ( * add_generic_header ) ( struct net_interface *netif,
-				       struct pk_buff *pkb );
+	int ( * add_llh_metadata ) ( struct net_interface *netif,
+				     struct pk_buff *pkb );
 };
 
 /**
@@ -196,9 +188,7 @@ extern struct net_device static_single_netdev;
 
 extern int register_netdevice ( struct net_device *netdev );
 
-static inline void unregister_netdevice ( struct net_device *netdev __unused ){
-	/* Do nothing */
-}
+extern void unregister_netdevice ( struct net_device *netdev );
 
 static inline void free_netdevice ( struct net_device *netdev __unused ) {
 	/* Do nothing */
diff --git a/src/include/gpxe/pkbuff.h b/src/include/gpxe/pkbuff.h
index bcc304977..f82f508ac 100644
--- a/src/include/gpxe/pkbuff.h
+++ b/src/include/gpxe/pkbuff.h
@@ -26,8 +26,40 @@ struct pk_buff {
 	void *tail;
 	/** End of the buffer */
         void *end;
+
+	/** 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;
+	/** Flags
+	 *
+	 * Filled in only on outgoing packets.  Value is the
+	 * bitwise-OR of zero or more PKB_FL_XXX constants.
+	 */
+	uint8_t flags;
+	/** Network-layer address length 
+	 *
+	 * Filled in only on outgoing packets.
+	 */
+	uint8_t net_addr_len;
+	/** Network-layer address
+	 *
+	 * Filled in only on outgoing packets.
+	 */
+	void *net_addr;
 };
 
+/** Packet is a broadcast packet */
+#define PKB_FL_BROADCAST 0x01
+
+/** Packet is a multicast packet */
+#define PKB_FL_MULTICAST 0x02
+
+/** Network-layer address is a raw hardware address */
+#define PKB_FL_RAW_NET_ADDR 0x04
+
 /**
  * Add data to start of packet buffer
  *