src/include/gpxe/filter.h

   1 #ifndef _GPXE_FILTER_H
   2 #define _GPXE_FILTER_H
   3
   4 /** @file
   5  *
   6  * Data transfer filters
   7  *
   8  */
   9
  10 FILE_LICENCE ( GPL2_OR_LATER );
  11
  12 #include <stddef.h>
  13 #include <gpxe/xfer.h>
  14
  15 /**
  16  * Half of a data transfer filter
  17  *
  18  * Embed two of these structures within a structure implementing a
  19  * data transfer filter, and intialise with filter_init().  You can
  20  * then use the filter_xxx() methods as the data transfer interface
  21  * methods as required.
  22  */
  23 struct xfer_filter_half {
  24         /** Data transfer interface */
  25         struct xfer_interface xfer;
  26         /** Other half of the data transfer filter */
  27         struct xfer_filter_half *other;
  28 };
  29
  30 /**
  31  * Get data transfer interface for the other half of a data transfer filter
  32  *
  33  * @v xfer              Data transfer interface
  34  * @ret other           Other half's data transfer interface
  35  */
  36 static inline __attribute__ (( always_inline )) struct xfer_interface *
  37 filter_other_half ( struct xfer_interface *xfer ) {
  38         struct xfer_filter_half *half =
  39                 container_of ( xfer, struct xfer_filter_half, xfer );
  40         return &half->other->xfer;
  41 }
  42
  43 extern void filter_close ( struct xfer_interface *xfer, int rc );
  44 extern int filter_vredirect ( struct xfer_interface *xfer, int type,
  45                               va_list args );
  46 extern size_t filter_window ( struct xfer_interface *xfer );
  47 extern struct io_buffer * filter_alloc_iob ( struct xfer_interface *xfer,
  48                                              size_t len );
  49 extern int filter_deliver_iob ( struct xfer_interface *xfer,
  50                                 struct io_buffer *iobuf,
  51                                 struct xfer_metadata *meta );
  52 extern int filter_deliver_raw ( struct xfer_interface *xfer, const void *data,
  53                                 size_t len );
  54
  55 /**
  56  * Initialise a data transfer filter
  57  *
  58  * @v left              "Left" half of the filter
  59  * @v left_op           Data transfer interface operations for "left" half
  60  * @v right             "Right" half of the filter
  61  * @v right_op          Data transfer interface operations for "right" half
  62  * @v refcnt            Containing object reference counter, or NULL
  63  */
  64 static inline void filter_init ( struct xfer_filter_half *left,
  65                                  struct xfer_interface_operations *left_op,
  66                                  struct xfer_filter_half *right,
  67                                  struct xfer_interface_operations *right_op,
  68                                  struct refcnt *refcnt ) {
  69         xfer_init ( &left->xfer, left_op, refcnt );
  70         xfer_init ( &right->xfer, right_op, refcnt );
  71         left->other = right;
  72         right->other = left;
  73 }
  74
  75 #endif /* _GPXE_FILTER_H */