src/hook.c

   1 /*
   2  * ircd-ratbox: an advanced Internet Relay Chat Daemon(ircd).
   3  * hook.c - code for dealing with the hook system
   4  *
   5  * This code is basically a slow leaking array.  Events are simply just a
   6  * position in this array.  When hooks are added, events will be created if
   7  * they dont exist - this means modules with hooks can be loaded in any
   8  * order, and events are preserved through module reloads.
   9  *
  10  * Copyright (C) 2004-2005 Lee Hardy <lee -at- leeh.co.uk>
  11  * Copyright (C) 2004-2005 ircd-ratbox development team
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions are
  15  * met:
  16  *
  17  * 1.Redistributions of source code must retain the above copyright notice,
  18  *   this list of conditions and the following disclaimer.
  19  * 2.Redistributions in binary form must reproduce the above copyright
  20  *   notice, this list of conditions and the following disclaimer in the
  21  *   documentation and/or other materials provided with the distribution.
  22  * 3.The name of the author may not be used to endorse or promote products
  23  *   derived from this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  27  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  28  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  29  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  30  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  31  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  33  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  34  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * $Id: hook.c 712 2006-02-06 04:42:14Z gxti $
  38  */
  39 #include "stdinc.h"
  40 #include "memory.h"
  41 #include "tools.h"
  42 #include "hook.h"
  43 #include "irc_string.h"
  44
  45 hook *hooks;
  46
  47 #define HOOK_INCREMENT 1000
  48
  49 int num_hooks = 0;
  50 int last_hook = 0;
  51 int max_hooks = HOOK_INCREMENT;
  52
  53 #ifdef USE_IODEBUG_HOOKS
  54 int h_iosend_id;
  55 int h_iorecv_id;
  56 int h_iorecvctrl_id;
  57 #endif
  58 int h_burst_client;
  59 int h_burst_channel;
  60 int h_burst_finished;
  61 int h_server_introduced;
  62 int h_server_eob;
  63 int h_client_exit;
  64 int h_new_local_user;
  65 int h_new_remote_user;
  66 int h_introduce_client;
  67
  68 void
  69 init_hook(void)
  70 {
  71         hooks = MyMalloc(sizeof(hook) * HOOK_INCREMENT);
  72
  73 #ifdef USE_IODEBUG_HOOKS
  74         h_iosend_id = register_hook("iosend");
  75         h_iorecv_id = register_hook("iorecv");
  76         h_iorecvctrl_id = register_hook("iorecvctrl");
  77 #endif
  78
  79         h_burst_client = register_hook("burst_client");
  80         h_burst_channel = register_hook("burst_channel");
  81         h_burst_finished = register_hook("burst_finished");
  82         h_server_introduced = register_hook("server_introduced");
  83         h_server_eob = register_hook("server_eob");
  84         h_client_exit = register_hook("client_exit");
  85         h_umode_changed = register_hook("umode_changed");
  86         h_new_local_user = register_hook("new_local_user");
  87         h_new_remote_user = register_hook("new_remote_user");
  88         h_introduce_client = register_hook("introduce_client");
  89 }
  90
  91 /* grow_hooktable()
  92  *   Enlarges the hook table by HOOK_INCREMENT
  93  */
  94 static void
  95 grow_hooktable(void)
  96 {
  97         hook *newhooks;
  98
  99         newhooks = MyMalloc(sizeof(hook) * (max_hooks + HOOK_INCREMENT));
 100         memcpy(newhooks, hooks, sizeof(hook) * num_hooks);
 101
 102         MyFree(hooks);
 103         hooks = newhooks;
 104         max_hooks += HOOK_INCREMENT;
 105 }
 106
 107 /* find_freehookslot()
 108  *   Finds the next free slot in the hook table, given by an entry with
 109  *   h->name being NULL.
 110  */
 111 static int
 112 find_freehookslot(void)
 113 {
 114         int i;
 115
 116         if((num_hooks + 1) > max_hooks)
 117                 grow_hooktable();
 118
 119         for(i = 0; i < max_hooks; i++)
 120         {
 121                 if(!hooks[i].name)
 122                         return i;
 123         }
 124
 125         /* shouldnt ever get here */
 126         return(max_hooks - 1);
 127 }
 128
 129 /* find_hook()
 130  *   Finds an event in the hook table.
 131  */
 132 static int
 133 find_hook(const char *name)
 134 {
 135         int i;
 136
 137         for(i = 0; i < max_hooks; i++)
 138         {
 139                 if(!hooks[i].name)
 140                         continue;
 141
 142                 if(!irccmp(hooks[i].name, name))
 143                         return i;
 144         }
 145
 146         return -1;
 147 }
 148
 149 /* register_hook()
 150  *   Finds an events position in the hook table, creating it if it doesnt
 151  *   exist.
 152  */
 153 int
 154 register_hook(const char *name)
 155 {
 156         int i;
 157
 158         if((i = find_hook(name)) < 0)
 159         {
 160                 i = find_freehookslot();
 161                 DupString(hooks[i].name, name);
 162                 num_hooks++;
 163         }
 164
 165         return i;
 166 }
 167
 168 /* add_hook()
 169  *   Adds a hook to an event in the hook table, creating event first if
 170  *   needed.
 171  */
 172 void
 173 add_hook(const char *name, hookfn fn)
 174 {
 175         int i;
 176
 177         i = register_hook(name);
 178
 179         dlinkAddAlloc(fn, &hooks[i].hooks);
 180 }
 181
 182 /* remove_hook()
 183  *   Removes a hook from an event in the hook table.
 184  */
 185 void
 186 remove_hook(const char *name, hookfn fn)
 187 {
 188         int i;
 189
 190         if((i = find_hook(name)) < 0)
 191                 return;
 192
 193         dlinkFindDestroy(fn, &hooks[i].hooks);
 194 }
 195
 196 /* call_hook()
 197  *   Calls functions from a given event in the hook table.
 198  */
 199 void
 200 call_hook(int id, void *arg)
 201 {
 202         hookfn fn;
 203         dlink_node *ptr;
 204
 205         /* The ID we were passed is the position in the hook table of this
 206          * hook
 207          */
 208         DLINK_FOREACH(ptr, hooks[id].hooks.head)
 209         {
 210                 fn = ptr->data;
 211                 fn(arg);
 212         }
 213 }
 214