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

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