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