server/hook.c

   1 /*
   2  * Server-side window hooks support
   3  *
   4  * Copyright (C) 2002 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <stdio.h>
  26
  27 #include "winbase.h"
  28 #include "winuser.h"
  29
  30 #include "object.h"
  31 #include "request.h"
  32 #include "user.h"
  33
  34 struct hook_table;
  35
  36 struct hook
  37 {
  38     struct list         chain;    /* hook chain entry */
  39     user_handle_t       handle;   /* user handle for this hook */
  40     struct thread      *thread;   /* thread owning the hook */
  41     int                 index;    /* hook table index */
  42     void               *proc;     /* hook function */
  43     int                 unicode;  /* is it a unicode hook? */
  44     WCHAR              *module;   /* module name for global hooks */
  45     size_t              module_size;
  46 };
  47
  48 #define NB_HOOKS (WH_MAXHOOK-WH_MINHOOK+1)
  49 #define HOOK_ENTRY(p)  LIST_ENTRY( (p), struct hook, chain )
  50
  51 struct hook_table
  52 {
  53     struct object obj;              /* object header */
  54     struct list   hooks[NB_HOOKS];  /* array of hook chains */
  55     int           counts[NB_HOOKS]; /* use counts for each hook chain */
  56 };
  57
  58 static void hook_table_dump( struct object *obj, int verbose );
  59 static void hook_table_destroy( struct object *obj );
  60
  61 static const struct object_ops hook_table_ops =
  62 {
  63     sizeof(struct hook_table),    /* size */
  64     hook_table_dump,              /* dump */
  65     no_add_queue,                 /* add_queue */
  66     NULL,                         /* remove_queue */
  67     NULL,                         /* signaled */
  68     NULL,                         /* satisfied */
  69     NULL,                         /* get_poll_events */
  70     NULL,                         /* poll_event */
  71     no_get_fd,                    /* get_fd */
  72     no_flush,                     /* flush */
  73     no_get_file_info,             /* get_file_info */
  74     NULL,                         /* queue_async */
  75     hook_table_destroy            /* destroy */
  76 };
  77
  78
  79 static struct hook_table *global_hooks;
  80
  81 /* create a new hook table */
  82 static struct hook_table *alloc_hook_table(void)
  83 {
  84     struct hook_table *table;
  85     int i;
  86
  87     if ((table = alloc_object( &hook_table_ops, -1 )))
  88     {
  89         for (i = 0; i < NB_HOOKS; i++)
  90         {
  91             list_init( &table->hooks[i] );
  92             table->counts[i] = 0;
  93         }
  94     }
  95     return table;
  96 }
  97
  98 /* create a new hook and add it to the specified table */
  99 static struct hook *add_hook( struct thread *thread, int index )
 100 {
 101     struct hook *hook;
 102     struct hook_table *table = thread ? thread->hooks : global_hooks;
 103
 104     if (!table)
 105     {
 106         if (!(table = alloc_hook_table())) return NULL;
 107         if (thread) thread->hooks = table;
 108         else global_hooks = table;
 109     }
 110     if (!(hook = mem_alloc( sizeof(*hook) ))) return NULL;
 111
 112     if (!(hook->handle = alloc_user_handle( hook, USER_HOOK )))
 113     {
 114         free( hook );
 115         return NULL;
 116     }
 117     hook->thread = thread ? (struct thread *)grab_object( thread ) : NULL;
 118     hook->index  = index;
 119     list_add_head( &table->hooks[index], &hook->chain );
 120     return hook;
 121 }
 122
 123 /* free a hook, removing it from its chain */
 124 static void free_hook( struct hook *hook )
 125 {
 126     free_user_handle( hook->handle );
 127     if (hook->module) free( hook->module );
 128     if (hook->thread) release_object( hook->thread );
 129     list_remove( &hook->chain );
 130     free( hook );
 131 }
 132
 133 /* find a hook from its index and proc */
 134 static struct hook *find_hook( struct thread *thread, int index, void *proc )
 135 {
 136     struct list *p;
 137     struct hook_table *table = thread->hooks;
 138
 139     if (table)
 140     {
 141         LIST_FOR_EACH( p, &table->hooks[index] )
 142         {
 143             struct hook *hook = HOOK_ENTRY( p );
 144             if (hook->proc == proc) return hook;
 145         }
 146     }
 147     return NULL;
 148 }
 149
 150 /* get the hook table that a given hook belongs to */
 151 inline static struct hook_table *get_table( struct hook *hook )
 152 {
 153     return hook->thread ? hook->thread->hooks : global_hooks;
 154 }
 155
 156 /* get the first hook in the chain */
 157 inline static struct hook *get_first_hook( struct hook_table *table, int index )
 158 {
 159     struct list *elem = list_head( &table->hooks[index] );
 160     return elem ? HOOK_ENTRY( elem ) : NULL;
 161 }
 162
 163 /* find the first non-deleted hook in the chain */
 164 inline static struct hook *get_first_valid_hook( struct hook_table *table, int index )
 165 {
 166     struct hook *hook = get_first_hook( table, index );
 167     while (hook && !hook->proc)
 168         hook = HOOK_ENTRY( list_next( &table->hooks[index], &hook->chain ) );
 169     return hook;
 170 }
 171
 172 /* find the next hook in the chain, skipping the deleted ones */
 173 static struct hook *get_next_hook( struct hook *hook )
 174 {
 175     struct hook_table *table = get_table( hook );
 176     int index = hook->index;
 177
 178     while ((hook = HOOK_ENTRY( list_next( &table->hooks[index], &hook->chain ) )))
 179     {
 180         if (hook->proc) return hook;
 181     }
 182     if (global_hooks && table != global_hooks)  /* now search through the global table */
 183     {
 184         hook = get_first_valid_hook( global_hooks, index );
 185     }
 186     return hook;
 187 }
 188
 189 static void hook_table_dump( struct object *obj, int verbose )
 190 {
 191     struct hook_table *table = (struct hook_table *)obj;
 192     if (table == global_hooks) fprintf( stderr, "Global hook table\n" );
 193     else fprintf( stderr, "Hook table\n" );
 194 }
 195
 196 static void hook_table_destroy( struct object *obj )
 197 {
 198     int i;
 199     struct hook *hook;
 200     struct hook_table *table = (struct hook_table *)obj;
 201
 202     for (i = 0; i < NB_HOOKS; i++)
 203     {
 204         while ((hook = get_first_hook( table, i )) != NULL) free_hook( hook );
 205     }
 206 }
 207
 208 /* free the global hooks table */
 209 void close_global_hooks(void)
 210 {
 211     if (global_hooks) release_object( global_hooks );
 212 }
 213
 214 /* remove a hook, freeing it if the chain is not in use */
 215 static void remove_hook( struct hook *hook )
 216 {
 217     struct hook_table *table = get_table( hook );
 218     if (table->counts[hook->index])
 219         hook->proc = NULL; /* chain is in use, just mark it and return */
 220     else
 221         free_hook( hook );
 222 }
 223
 224 /* release a hook chain, removing deleted hooks if the use count drops to 0 */
 225 static void release_hook_chain( struct hook_table *table, int index )
 226 {
 227     if (!table->counts[index])  /* use count shouldn't already be 0 */
 228     {
 229         set_error( STATUS_INVALID_PARAMETER );
 230         return;
 231     }
 232     if (!--table->counts[index])
 233     {
 234         struct hook *hook = get_first_hook( table, index );
 235         while (hook)
 236         {
 237             struct hook *next = HOOK_ENTRY( list_next( &table->hooks[hook->index], &hook->chain ) );
 238             if (!hook->proc) free_hook( hook );
 239             hook = next;
 240         }
 241     }
 242 }
 243
 244
 245 /* set a window hook */
 246 DECL_HANDLER(set_hook)
 247 {
 248     struct thread *thread;
 249     struct hook *hook;
 250     WCHAR *module;
 251     size_t module_size = get_req_data_size();
 252
 253     if (!req->proc || req->id < WH_MINHOOK || req->id > WH_MAXHOOK)
 254     {
 255         set_error( STATUS_INVALID_PARAMETER );
 256         return;
 257     }
 258     if (!req->tid)
 259     {
 260         if (!module_size)
 261         {
 262             set_error( STATUS_INVALID_PARAMETER );
 263             return;
 264         }
 265         if (!(module = memdup( get_req_data(), module_size ))) return;
 266         thread = NULL;
 267     }
 268     else
 269     {
 270         module = NULL;
 271         if (!(thread = get_thread_from_id( req->tid ))) return;
 272     }
 273
 274     if ((hook = add_hook( thread, req->id - WH_MINHOOK )))
 275     {
 276         hook->proc        = req->proc;
 277         hook->unicode     = req->unicode;
 278         hook->module      = module;
 279         hook->module_size = module_size;
 280         reply->handle = hook->handle;
 281     }
 282     else if (module) free( module );
 283
 284     if (thread) release_object( thread );
 285 }
 286
 287
 288 /* remove a window hook */
 289 DECL_HANDLER(remove_hook)
 290 {
 291     struct hook *hook;
 292
 293     if (req->handle) hook = get_user_object( req->handle, USER_HOOK );
 294     else
 295     {
 296         if (!req->proc || req->id < WH_MINHOOK || req->id > WH_MAXHOOK)
 297         {
 298             set_error( STATUS_INVALID_PARAMETER );
 299             return;
 300         }
 301         if (!(hook = find_hook( current, req->id - WH_MINHOOK, req->proc )))
 302             set_error( STATUS_INVALID_PARAMETER );
 303     }
 304     if (hook) remove_hook( hook );
 305 }
 306
 307
 308 /* start calling a hook chain */
 309 DECL_HANDLER(start_hook_chain)
 310 {
 311     struct hook *hook;
 312     struct hook_table *table = current->hooks;
 313
 314     if (req->id < WH_MINHOOK || req->id > WH_MAXHOOK)
 315     {
 316         set_error( STATUS_INVALID_PARAMETER );
 317         return;
 318     }
 319
 320     if (!table || !(hook = get_first_valid_hook( table, req->id - WH_MINHOOK )))
 321     {
 322         /* try global table */
 323         if (!(table = global_hooks) ||
 324             !(hook = get_first_valid_hook( global_hooks, req->id - WH_MINHOOK )))
 325             return;  /* no hook set */
 326     }
 327     reply->handle  = hook->handle;
 328     reply->proc    = hook->proc;
 329     reply->unicode = hook->unicode;
 330     table->counts[hook->index]++;
 331     if (hook->module) set_reply_data( hook->module, hook->module_size );
 332 }
 333
 334
 335 /* finished calling a hook chain */
 336 DECL_HANDLER(finish_hook_chain)
 337 {
 338     struct hook_table *table = current->hooks;
 339     int index = req->id - WH_MINHOOK;
 340
 341     if (req->id < WH_MINHOOK || req->id > WH_MAXHOOK)
 342     {
 343         set_error( STATUS_INVALID_PARAMETER );
 344         return;
 345     }
 346     if (table) release_hook_chain( table, index );
 347     if (global_hooks) release_hook_chain( global_hooks, index );
 348 }
 349
 350
 351 /* get the next hook to call */
 352 DECL_HANDLER(get_next_hook)
 353 {
 354     struct hook *hook, *next;
 355
 356     if (!(hook = get_user_object( req->handle, USER_HOOK ))) return;
 357     if (hook->thread && (hook->thread != current))
 358     {
 359         set_error( STATUS_INVALID_HANDLE );
 360         return;
 361     }
 362     if ((next = get_next_hook( hook )))
 363     {
 364         reply->next = next->handle;
 365         reply->id   = next->index + WH_MINHOOK;
 366         reply->proc = next->proc;
 367         reply->prev_unicode = hook->unicode;
 368         reply->next_unicode = next->unicode;
 369         if (next->module) set_reply_data( next->module, next->module_size );
 370     }
 371 }