build: Rewrite the build system to be nicer.

[fwd] / endpt.h

/* -*-c-*-
 *
 * Generic endpoint abstraction
 *
 * (c) 1999 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of the `fw' port forwarder.
 *
 * `fw' is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * `fw' is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with `fw'; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef ENDPT_H
#define ENDPT_H

#ifdef __cplusplus
  extern "C" {
#endif

/*----- Header files ------------------------------------------------------*/

#ifndef REFFD_H
#  include "reffd.h"
#endif

/*----- Data structures ---------------------------------------------------*/

/* --- Basic endpoint structure --- */

typedef struct endpt {
  struct endpt_ops *ops;		/* Pointer to operations table */
  struct endpt *other;			/* Pointer to sibling endpoint */
  unsigned f;				/* Various flags */
  struct tango *t;			/* Private data structure */
  reffd *in, *out;			/* File descriptors */
} endpt;

/* --- Endpoint flags --- */

#define EPF_PENDING 1u			/* Endpoint creation in progress */
#define EPF_FILE 2u			/* Endpoint smells like a file */

/* --- Endpoint operations table --- */

typedef struct endpt_ops {

  /* --- @attach@ --- *
   *
   * Arguments:	@endpt *e@ = pointer to endpoint to be attached
   *		@reffd *in, *out@ = input and output file descriptors
   *
   * Returns:	---
   *
   * Use:	Instructs a non-file endpoint to attach itself to a pair of
   *		files.
   */

  void (*attach)(endpt */*e*/, reffd */*in*/, reffd */*out*/);

  /* --- @file@ --- *
   *
   * Arguments:	@endpt *e@ = pointer to endpoint in question
   *		@endpt *f@ = pointer to a file endpoint
   *
   * Returns:	---
   *
   * Use:	Informs a non-file endpoint of a file endpoint which will
   *		want to be closed when it's finished with.  At that time, the
   *		endpoint should arrange to have both itself and its partner
   *		closed.  If no file is registered, the endpoint manager will
   *		close both endpoints itself.
   */

  void (*file)(endpt */*e*/, endpt */*f*/);

  /* --- @wclose@ --- *
   *
   * Arguments:	@endpt *e@ = endpoint to be partially closed
   *
   * Returns:	---
   *
   * Use:	Announces that the endpoint will not be written to any more.
   */

  void (*wclose)(endpt */*e*/);

  /* --- @close@ --- *
   *
   * Arguments:	@endpt *e@ = endpoint to be closed
   *
   * Returns:	---
   *
   * Use:	Completely closes an endpoint.  The endpoint's data may be
   *		freed, although some endpoints may wish to delay freeing for
   *		some reason.
   */

  void (*close)(endpt */*e*/);

} endpt_ops;

/*----- Functions provided ------------------------------------------------*/

/* --- @endpt_kill@ --- *
 *
 * Arguments:	@endpt *a@ = an endpoint
 *
 * Returns:	---
 *
 * Use:		Kills an endpoint.  If the endpoint is joined to another, the
 *		other endpoint is also killed, as is the connection between
 *		them (and that's the tricky bit).
 */

extern void endpt_kill(endpt */*a*/);

/* --- @endpt_killall@ --- *
 *
 * Arguments:	---
 *
 * Returns:	---
 *
 * Use:		Destroys all current endpoint connections.  Used when
 *		shutting down.
 */

extern void endpt_killall(void);

/* --- @endpt_join@ --- *
 *
 * Arguments:	@endpt *a@ = pointer to first endpoint
 *		@endpt *b@ = pointer to second endpoint
 *
 * Returns:	---
 *
 * Use:		Joins two endpoints together.
 */

extern void endpt_join(endpt */*a*/, endpt */*b*/);

/*----- That's all, folks -------------------------------------------------*/

#ifdef __cplusplus
  }
#endif

#endif