ircd/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 "hook.h"
  39 #include "match.h"
  40
  41 hook *hooks;
  42
  43 #define HOOK_INCREMENT 1000
  44
  45 struct hook_entry
  46 {
  47         rb_dlink_node node;
  48         hookfn fn;
  49         enum hook_priority priority;
  50 };
  51
  52 int num_hooks = 0;
  53 int last_hook = 0;
  54 int max_hooks = HOOK_INCREMENT;
  55
  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_after_client_exit;
  63 int h_umode_changed;
  64 int h_new_local_user;
  65 int h_new_remote_user;
  66 int h_introduce_client;
  67 int h_can_kick;
  68 int h_privmsg_user;
  69 int h_privmsg_channel;
  70 int h_conf_read_start;
  71 int h_conf_read_end;
  72 int h_outbound_msgbuf;
  73 int h_rehash;
  74 int h_cap_change;
  75
  76 void
  77 init_hook(void)
  78 {
  79         hooks = rb_malloc(sizeof(hook) * HOOK_INCREMENT);
  80
  81         h_burst_client = register_hook("burst_client");
  82         h_burst_channel = register_hook("burst_channel");
  83         h_burst_finished = register_hook("burst_finished");
  84         h_server_introduced = register_hook("server_introduced");
  85         h_server_eob = register_hook("server_eob");
  86         h_client_exit = register_hook("client_exit");
  87         h_after_client_exit = register_hook("after_client_exit");
  88         h_umode_changed = register_hook("umode_changed");
  89         h_new_local_user = register_hook("new_local_user");
  90         h_new_remote_user = register_hook("new_remote_user");
  91         h_introduce_client = register_hook("introduce_client");
  92         h_can_kick = register_hook("can_kick");
  93         h_privmsg_user = register_hook("privmsg_user");
  94         h_privmsg_channel = register_hook("privmsg_channel");
  95         h_conf_read_start = register_hook("conf_read_start");
  96         h_conf_read_end = register_hook("conf_read_end");
  97         h_outbound_msgbuf = register_hook("outbound_msgbuf");
  98         h_rehash = register_hook("rehash");
  99         h_cap_change = register_hook("cap_change");
 100 }
 101
 102 /* grow_hooktable()
 103  *   Enlarges the hook table by HOOK_INCREMENT
 104  */
 105 static void
 106 grow_hooktable(void)
 107 {
 108         hook *newhooks;
 109
 110         newhooks = rb_malloc(sizeof(hook) * (max_hooks + HOOK_INCREMENT));
 111         memcpy(newhooks, hooks, sizeof(hook) * num_hooks);
 112
 113         rb_free(hooks);
 114         hooks = newhooks;
 115         max_hooks += HOOK_INCREMENT;
 116 }
 117
 118 /* find_freehookslot()
 119  *   Finds the next free slot in the hook table, given by an entry with
 120  *   h->name being NULL.
 121  */
 122 static int
 123 find_freehookslot(void)
 124 {
 125         int i;
 126
 127         if((num_hooks + 1) > max_hooks)
 128                 grow_hooktable();
 129
 130         for(i = 0; i < max_hooks; i++)
 131         {
 132                 if(!hooks[i].name)
 133                         return i;
 134         }
 135
 136         /* shouldnt ever get here */
 137         return(max_hooks - 1);
 138 }
 139
 140 /* find_hook()
 141  *   Finds an event in the hook table.
 142  */
 143 static int
 144 find_hook(const char *name)
 145 {
 146         int i;
 147
 148         for(i = 0; i < max_hooks; i++)
 149         {
 150                 if(!hooks[i].name)
 151                         continue;
 152
 153                 if(!irccmp(hooks[i].name, name))
 154                         return i;
 155         }
 156
 157         return -1;
 158 }
 159
 160 /* register_hook()
 161  *   Finds an events position in the hook table, creating it if it doesnt
 162  *   exist.
 163  */
 164 int
 165 register_hook(const char *name)
 166 {
 167         int i;
 168
 169         if((i = find_hook(name)) < 0)
 170         {
 171                 i = find_freehookslot();
 172                 hooks[i].name = rb_strdup(name);
 173                 num_hooks++;
 174         }
 175
 176         return i;
 177 }
 178
 179 /* add_hook()
 180  *   Adds a hook to an event in the hook table, creating event first if
 181  *   needed.
 182  */
 183 void
 184 add_hook(const char *name, hookfn fn)
 185 {
 186         add_hook_prio(name, fn, HOOK_NORMAL);
 187 }
 188
 189 /* add_hook_prio()
 190  *   Adds a hook with the specified priority
 191  */
 192 void
 193 add_hook_prio(const char *name, hookfn fn, enum hook_priority priority)
 194 {
 195         rb_dlink_node *ptr;
 196         struct hook_entry *entry = rb_malloc(sizeof *entry);
 197         int i;
 198
 199         i = register_hook(name);
 200         entry->fn = fn;
 201         entry->priority = priority;
 202
 203         RB_DLINK_FOREACH(ptr, hooks[i].hooks.head)
 204         {
 205                 struct hook_entry *o = ptr->data;
 206                 if (entry->priority <= o->priority)
 207                 {
 208                         rb_dlinkAddBefore(ptr, entry, &entry->node, &hooks[i].hooks);
 209                         return;
 210                 }
 211         }
 212
 213         rb_dlinkAddTail(entry, &entry->node, &hooks[i].hooks);
 214 }
 215
 216 /* remove_hook()
 217  *   Removes a hook from an event in the hook table.
 218  */
 219 void
 220 remove_hook(const char *name, hookfn fn)
 221 {
 222         rb_dlink_node *ptr, *scratch;
 223         int i;
 224
 225         if((i = find_hook(name)) < 0)
 226                 return;
 227
 228         RB_DLINK_FOREACH_SAFE(ptr, scratch, hooks[i].hooks.head)
 229         {
 230                 struct hook_entry *entry = ptr->data;
 231                 if (entry->fn == fn)
 232                 {
 233                         rb_dlinkDelete(ptr, &hooks[i].hooks);
 234                         return;
 235                 }
 236         }
 237 }
 238
 239 /* call_hook()
 240  *   Calls functions from a given event in the hook table.
 241  */
 242 void
 243 call_hook(int id, void *arg)
 244 {
 245         rb_dlink_node *ptr;
 246
 247         /* The ID we were passed is the position in the hook table of this
 248          * hook
 249          */
 250         RB_DLINK_FOREACH(ptr, hooks[id].hooks.head)
 251         {
 252                 struct hook_entry *entry = ptr->data;
 253                 entry->fn(arg);
 254         }
 255 }
 256