mdw@git.distorted.org.uk Git - fwd/blob - source.c

   1 /* -*-c-*-
   2  *
   3  * Standard routines for forwarding sources
   4  *
   5  * (c) 1999 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the `fwd' port forwarder.
  11  *
  12  * `fwd' 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  * `fwd' 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 `fwd'; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 #include "fwd.h"
  28
  29 /*----- Static variables --------------------------------------------------*/
  30
  31 static source *sources = 0;
  32
  33 /*----- Main code ---------------------------------------------------------*/
  34
  35 /* --- @source_add@ --- *
  36  *
  37  * Arguments:   @source *s@ = pointer to a source
  38  *
  39  * Returns:     ---
  40  *
  41  * Use:         Adds a source to the master list.  Only do this for passive
  42  *              sources (e.g., listening sockets), not active sources (e.g.,
  43  *              executable programs).
  44  */
  45
  46 void source_add(source *s)
  47 {
  48   assert(s->ops->shutdown);
  49   assert(!(s->f&SF_ACTIVE));
  50   s->next = sources;
  51   s->prev = 0;
  52   if (sources)
  53     sources->prev = s;
  54   sources = s;
  55   s->f |= SF_ACTIVE;
  56   source_inc(s);
  57 }
  58
  59 /* --- @source_remove@ --- *
  60  *
  61  * Arguments:   @source *s@ = pointer to a source
  62  *
  63  * Returns:     ---
  64  *
  65  * Use:         Removes a source from the master list.
  66  */
  67
  68 void source_remove(source *s)
  69 {
  70   assert(s->f&SF_ACTIVE);
  71   if (s->next)
  72     s->next->prev = s->prev;
  73   if (s->prev)
  74     s->prev->next = s->next;
  75   else
  76     sources = s->next;
  77   s->f &= ~SF_ACTIVE;
  78   source_dec(s);
  79 }
  80
  81 /* --- @source_inc@ --- *
  82  *
  83  * Arguments:   @source *s@ = pointer to a source
  84  *
  85  * Returns:     ---
  86  *
  87  * Use:         Increments a source's refcount.
  88  */
  89
  90 void source_inc(source *s) { s->ref++; }
  91
  92 /* --- @source_dec@ --- *
  93  *
  94  * Arguments:   @source *s@ = pointer to a source
  95  *
  96  * Returns:     ---
  97  *
  98  * Use:         Decrements a source's refcount, destroying it if necessary.
  99  */
 100
 101 void source_dec(source *s)
 102 {
 103   assert(s->ref > 0);
 104   s->ref--;
 105   if (!s->ref) {
 106     if (s->f&SF_ACTIVE) s->ops->shutdown(s);
 107     s->ops->destroy(s);
 108   }
 109 }
 110
 111 /* --- @source_killall@ --- *
 112  *
 113  * Arguments:   ---
 114  *
 115  * Returns:     ---
 116  *
 117  * Use:         Frees all sources.
 118  */
 119
 120 void source_killall(void)
 121 {
 122   source *s = sources;
 123   while (s) {
 124     source *ss = s;
 125     s = s->next;
 126     ss->ops->shutdown(ss);
 127   }
 128   sources = 0;
 129 }
 130
 131 /*----- That's all, folks -------------------------------------------------*/