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