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 #include "stdinc.h"
  38 #include "memory.h"
  39 #include "tools.h"
  40 #include "hook.h"
  41 #include "irc_string.h"
  42
  43 hook *hooks;
  44
  45 #define HOOK_INCREMENT 1000
  46
  47 int num_hooks = 0;
  48 int last_hook = 0;
  49 int max_hooks = HOOK_INCREMENT;
  50
  51 #ifdef USE_IODEBUG_HOOKS
  52 int h_iosend_id;
  53 int h_iorecv_id;
  54 int h_iorecvctrl_id;
  55 #endif
  56 int h_burst_client;
  57 int h_burst_channel;
  58 int h_burst_finished;
  59 int h_server_introduced;
  60 int h_server_eob;
  61 int h_client_exit;
  62 int h_new_local_user;
  63 int h_new_remote_user;
  64 int h_introduce_client;
  65
  66 void
  67 init_hook(void)
  68 {
  69         hooks = MyMalloc(sizeof(hook) * HOOK_INCREMENT);
  70
  71 #ifdef USE_IODEBUG_HOOKS
  72         h_iosend_id = register_hook("iosend");
  73         h_iorecv_id = register_hook("iorecv");
  74         h_iorecvctrl_id = register_hook("iorecvctrl");
  75 #endif
  76
  77         h_burst_client = register_hook("burst_client");
  78         h_burst_channel = register_hook("burst_channel");
  79         h_burst_finished = register_hook("burst_finished");
  80         h_server_introduced = register_hook("server_introduced");
  81         h_server_eob = register_hook("server_eob");
  82         h_client_exit = register_hook("client_exit");
  83         h_umode_changed = register_hook("umode_changed");
  84         h_new_local_user = register_hook("new_local_user");
  85         h_new_remote_user = register_hook("new_remote_user");
  86         h_introduce_client = register_hook("introduce_client");
  87 }
  88
  89 /* grow_hooktable()
  90  *   Enlarges the hook table by HOOK_INCREMENT
  91  */
  92 static void
  93 grow_hooktable(void)
  94 {
  95         hook *newhooks;
  96
  97         newhooks = MyMalloc(sizeof(hook) * (max_hooks + HOOK_INCREMENT));
  98         memcpy(newhooks, hooks, sizeof(hook) * num_hooks);
  99
 100         MyFree(hooks);
 101         hooks = newhooks;
 102         max_hooks += HOOK_INCREMENT;
 103 }
 104
 105 /* find_freehookslot()
 106  *   Finds the next free slot in the hook table, given by an entry with
 107  *   h->name being NULL.
 108  */
 109 static int
 110 find_freehookslot(void)
 111 {
 112         int i;
 113
 114         if((num_hooks + 1) > max_hooks)
 115                 grow_hooktable();
 116
 117         for(i = 0; i < max_hooks; i++)
 118         {
 119                 if(!hooks[i].name)
 120                         return i;
 121         }
 122
 123         /* shouldnt ever get here */
 124         return(max_hooks - 1);
 125 }
 126
 127 /* find_hook()
 128  *   Finds an event in the hook table.
 129  */
 130 static int
 131 find_hook(const char *name)
 132 {
 133         int i;
 134
 135         for(i = 0; i < max_hooks; i++)
 136         {
 137                 if(!hooks[i].name)
 138                         continue;
 139
 140                 if(!irccmp(hooks[i].name, name))
 141                         return i;
 142         }
 143
 144         return -1;
 145 }
 146
 147 /* register_hook()
 148  *   Finds an events position in the hook table, creating it if it doesnt
 149  *   exist.
 150  */
 151 int
 152 register_hook(const char *name)
 153 {
 154         int i;
 155
 156         if((i = find_hook(name)) < 0)
 157         {
 158                 i = find_freehookslot();
 159                 DupString(hooks[i].name, name);
 160                 num_hooks++;
 161         }
 162
 163         return i;
 164 }
 165
 166 /* add_hook()
 167  *   Adds a hook to an event in the hook table, creating event first if
 168  *   needed.
 169  */
 170 void
 171 add_hook(const char *name, hookfn fn)
 172 {
 173         int i;
 174
 175         i = register_hook(name);
 176
 177         dlinkAddAlloc(fn, &hooks[i].hooks);
 178 }
 179
 180 /* remove_hook()
 181  *   Removes a hook from an event in the hook table.
 182  */
 183 void
 184 remove_hook(const char *name, hookfn fn)
 185 {
 186         int i;
 187
 188         if((i = find_hook(name)) < 0)
 189                 return;
 190
 191         dlinkFindDestroy(fn, &hooks[i].hooks);
 192 }
 193
 194 /* call_hook()
 195  *   Calls functions from a given event in the hook table.
 196  */
 197 void
 198 call_hook(int id, void *arg)
 199 {
 200         hookfn fn;
 201         dlink_node *ptr;
 202
 203         /* The ID we were passed is the position in the hook table of this
 204          * hook
 205          */
 206         DLINK_FOREACH(ptr, hooks[id].hooks.head)
 207         {
 208                 fn = ptr->data;
 209                 fn(arg);
 210         }
 211 }
 212