2 files changed, 58 insertions, 16 deletions

diff --git a/src/include/gpxe/open.h b/src/include/gpxe/open.h
index 8839dc28a..ad86d0951 100644
--- a/src/include/gpxe/open.h
+++ b/src/include/gpxe/open.h
@@ -41,7 +41,7 @@ struct uri_opener {
 	const char *scheme;
 	/** Open URI
 	 *
-	 * @v xfer		Data-transfer interface
+	 * @v xfer		Data transfer interface
 	 * @v uri		URI
 	 * @ret rc		Return status code
 	 *
@@ -62,7 +62,7 @@ struct socket_opener {
 	int type;
 	/** Open socket
 	 *
-	 * @v xfer		Data-transfer interface
+	 * @v xfer		Data transfer interface
 	 * @v sa		Socket address
 	 * @ret rc		Return status code
 	 */
diff --git a/src/include/gpxe/xfer.h b/src/include/gpxe/xfer.h
index 0b8bf4ce5..dfbde89d0 100644
--- a/src/include/gpxe/xfer.h
+++ b/src/include/gpxe/xfer.h
@@ -32,22 +32,29 @@ struct xfer_interface_operations {
 
 	/** Close interface
 	 *
-	 * @v xfer		Data-transfer interface
+	 * @v xfer		Data transfer interface
 	 * @v rc		Reason for close
 	 */
 	void ( * close ) ( struct xfer_interface *xfer, int rc );
 	/** Redirect to new location
 	 *
-	 * @v xfer		Data-transfer interface
+	 * @v xfer		Data transfer interface
 	 * @v type		New location type
 	 * @v args		Remaining arguments depend upon location type
 	 * @ret rc		Return status code
 	 */
 	int ( * vredirect ) ( struct xfer_interface *xfer, int type,
 			      va_list args );
+	/** Seek to position
+	 *
+	 * @v xfer		Data transfer interface
+	 * @v pos		New position
+	 * @ret rc		Return status code
+	 */
+	int ( * seek ) ( struct xfer_interface *xfer, size_t pos );
 	/** Deliver datagram
 	 *
-	 * @v xfer		Data-transfer interface
+	 * @v xfer		Data transfer interface
 	 * @v iobuf		Datagram I/O buffer
 	 * @ret rc		Return status code
 	 *
@@ -59,7 +66,7 @@ struct xfer_interface_operations {
 			    struct io_buffer *iobuf );
 	/** Deliver datagram as raw data
 	 *
-	 * @v xfer		Data-transfer interface
+	 * @v xfer		Data transfer interface
 	 * @v data		Data buffer
 	 * @v len		Length of data buffer
 	 * @ret rc		Return status code
@@ -83,32 +90,67 @@ struct xfer_interface {
 extern struct xfer_interface null_xfer;
 extern struct xfer_interface_operations null_xfer_ops;
 
+extern void close ( struct xfer_interface *xfer, int rc );
+extern int seek ( struct xfer_interface *xfer, size_t pos );
 extern int vredirect ( struct xfer_interface *xfer, int type, va_list args );
 extern int redirect ( struct xfer_interface *xfer, int type, ... );
 extern int deliver ( struct xfer_interface *xfer, struct io_buffer *iobuf );
 extern int deliver_raw ( struct xfer_interface *xfer,
 			 const void *data, size_t len );
 
+extern void ignore_close ( struct xfer_interface *xfer, int rc );
+extern int ignore_vredirect ( struct xfer_interface *xfer,
+			      int type, va_list args );
+extern int ignore_seek ( struct xfer_interface *xfer, size_t pos );
 extern int deliver_as_raw ( struct xfer_interface *xfer,
 			    struct io_buffer *iobuf );
 extern int deliver_as_iobuf ( struct xfer_interface *xfer,
 			      const void *data, size_t len );
+extern int ignore_deliver_raw ( struct xfer_interface *xfer,
+				const void *data __unused, size_t len );
+
+/**
+ * Initialise a data transfer interface
+ *
+ * @v xfer		Data transfer interface
+ * @v op		Data transfer interface operations
+ * @v refcnt		Data transfer interface reference counting method
+ */
+static inline void xfer_init ( struct xfer_interface *xfer,
+			       struct xfer_interface_operations *op,
+			       void ( * refcnt ) ( struct interface *intf,
+						   int delta ) ) {
+	xfer->intf.dest = &null_xfer.intf;
+	xfer->intf.refcnt = refcnt;
+	xfer->op = op;
+}
+
+/**
+ * Get data transfer interface from generic object communication interface
+ *
+ * @v intf		Generic object communication interface
+ * @ret xfer		Data transfer interface
+ */
+static inline struct xfer_interface *
+intf_to_xfer ( struct interface *intf ) {
+	return container_of ( intf, struct xfer_interface, intf );
+}
 
 /**
- * Get destination data-transfer interface
+ * Get destination data transfer interface
  *
- * @v xfer		Data-transfer interface
+ * @v xfer		Data transfer interface
  * @ret dest		Destination interface
  */
 static inline struct xfer_interface *
 xfer_dest ( struct xfer_interface *xfer ) {
-	return container_of ( xfer->intf.dest, struct xfer_interface, intf );
+	return intf_to_xfer ( xfer->intf.dest );
 }
 
 /**
- * Plug a data-transfer interface into a new destination interface
+ * Plug a data transfer interface into a new destination interface
  *
- * @v xfer		Data-transfer interface
+ * @v xfer		Data transfer interface
  * @v dest		New destination interface
  */
 static inline void xfer_plug ( struct xfer_interface *xfer,
@@ -117,23 +159,23 @@ static inline void xfer_plug ( struct xfer_interface *xfer,
 }
 
 /**
- * Unplug a data-transfer interface
+ * Unplug a data transfer interface
  *
- * @v xfer		Data-transfer interface
+ * @v xfer		Data transfer interface
  */
 static inline void xfer_unplug ( struct xfer_interface *xfer ) {
 	plug ( &xfer->intf, &null_xfer.intf );
 }
 
 /**
- * Terminate a data-transfer interface
+ * Stop using a data transfer interface
  *
- * @v xfer		Data-transfer interface
+ * @v xfer		Data transfer interface
  *
  * After calling this method, no further messages will be received via
  * the interface.
  */
-static inline void xfer_terminate ( struct xfer_interface *xfer ) {
+static inline void xfer_nullify ( struct xfer_interface *xfer ) {
 	xfer->op = &null_xfer_ops;
 };