mdw@git.distorted.org.uk Git - fwd/blob - chan.h

   1 /* -*-c-*-
   2  *
   3  * $Id: chan.h,v 1.3 2004/04/08 01:36:25 mdw Exp $
   4  *
   5  * Channel management
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of the `fw' port forwarder.
  13  *
  14  * `fw' is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * `fw' is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with `fw'; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 #ifndef CHAN_H
  30 #define CHAN_H
  31
  32 #ifdef __cplusplus
  33   extern "C" {
  34 #endif
  35
  36 /*----- Header files ------------------------------------------------------*/
  37
  38 #include <mLib/sel.h>
  39
  40 /*----- Magic numbers -----------------------------------------------------*/
  41
  42 #define CHAN_BUFSZ 4096
  43
  44 /*----- Data structures ---------------------------------------------------*/
  45
  46 typedef struct chan {
  47   unsigned base, len;                   /* Base and length of data */
  48   unsigned f;                           /* Various interesting flags */
  49   void (*func)(void */*p*/);            /* Function to call on closure */
  50   void *p;                              /* Argument to pass function */
  51   sel_file r, w;                        /* Reader and writer selectors */
  52   char buf[CHAN_BUFSZ];                 /* The actual data buffer */
  53 } chan;
  54
  55 #define CHANF_CLOSE 1u                  /* Close channel when buffer empty */
  56 #define CHANF_READY 2u                  /* The channel destination exists */
  57
  58 /*----- Functions provided ------------------------------------------------*/
  59
  60 /* --- @chan_close@ --- *
  61  *
  62  * Arguments:   @chan *c@ = pointer to channel
  63  *
  64  * Returns:     ---
  65  *
  66  * Use:         Closes down a channel prematurely.
  67  */
  68
  69 extern void chan_close(chan */*c*/);
  70
  71 /* --- @chan_dest@ --- *
  72  *
  73  * Arguments:   @chan *c@ = pointer to channel
  74  *              @int fd@ = destination file descriptor for channel
  75  *
  76  * Returns:     ---
  77  *
  78  * Use:         Sets the channel's destination so it knows where to put
  79  *              data.
  80  */
  81
  82 extern void chan_dest(chan */*c*/, int /*fd*/);
  83
  84 /* --- @chan_open@ --- *
  85  *
  86  * Arguments:   @chan *c@ = pointer to channel to open
  87  *              @int from, to@ = source and destination file descriptors
  88  *              @void (*func)(void *p)@ = function to call on closure
  89  *              @void *p@ = argument to pass to function
  90  *
  91  * Returns:     ---
  92  *
  93  * Use:         Opens a channel.  Data is copied from the source to the
  94  *              destination.  The @to@ argument may be @-1@ if the file
  95  *              descriptor isn't known yet.
  96  */
  97
  98 extern void chan_open(chan */*c*/, int /*from*/, int /*to*/,
  99                       void (*/*func*/)(void */*p*/), void */*p*/);
 100
 101 /*----- That's all, folks -------------------------------------------------*/
 102
 103 #ifdef __cplusplus
 104   }
 105 #endif
 106
 107 #endif