widl: Allow unsized in,out string parameters.
[wine] / server / winstation.c
1 /*
2  * Server-side window stations and desktops handling
3  *
4  * Copyright (C) 2002, 2005 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
19  */
20
21 #include "config.h"
22 #include "wine/port.h"
23
24 #include <stdio.h>
25 #include <stdarg.h>
26
27 #include "ntstatus.h"
28 #define WIN32_NO_STATUS
29 #include "windef.h"
30 #include "winbase.h"
31 #include "winuser.h"
32 #include "winternl.h"
33
34 #include "object.h"
35 #include "handle.h"
36 #include "request.h"
37 #include "process.h"
38 #include "user.h"
39 #include "file.h"
40 #include "security.h"
41 #include "wine/unicode.h"
42
43
44 static struct list winstation_list = LIST_INIT(winstation_list);
45 static struct namespace *winstation_namespace;
46
47 static void winstation_dump( struct object *obj, int verbose );
48 static struct object_type *winstation_get_type( struct object *obj );
49 static int winstation_close_handle( struct object *obj, struct process *process, obj_handle_t handle );
50 static void winstation_destroy( struct object *obj );
51 static unsigned int winstation_map_access( struct object *obj, unsigned int access );
52 static void desktop_dump( struct object *obj, int verbose );
53 static struct object_type *desktop_get_type( struct object *obj );
54 static int desktop_close_handle( struct object *obj, struct process *process, obj_handle_t handle );
55 static void desktop_destroy( struct object *obj );
56 static unsigned int desktop_map_access( struct object *obj, unsigned int access );
57
58 static const struct object_ops winstation_ops =
59 {
60     sizeof(struct winstation),    /* size */
61     winstation_dump,              /* dump */
62     winstation_get_type,          /* get_type */
63     no_add_queue,                 /* add_queue */
64     NULL,                         /* remove_queue */
65     NULL,                         /* signaled */
66     NULL,                         /* satisfied */
67     no_signal,                    /* signal */
68     no_get_fd,                    /* get_fd */
69     winstation_map_access,        /* map_access */
70     default_get_sd,               /* get_sd */
71     default_set_sd,               /* set_sd */
72     no_lookup_name,               /* lookup_name */
73     no_open_file,                 /* open_file */
74     winstation_close_handle,      /* close_handle */
75     winstation_destroy            /* destroy */
76 };
77
78
79 static const struct object_ops desktop_ops =
80 {
81     sizeof(struct desktop),       /* size */
82     desktop_dump,                 /* dump */
83     desktop_get_type,             /* get_type */
84     no_add_queue,                 /* add_queue */
85     NULL,                         /* remove_queue */
86     NULL,                         /* signaled */
87     NULL,                         /* satisfied */
88     no_signal,                    /* signal */
89     no_get_fd,                    /* get_fd */
90     desktop_map_access,           /* map_access */
91     default_get_sd,               /* get_sd */
92     default_set_sd,               /* set_sd */
93     no_lookup_name,               /* lookup_name */
94     no_open_file,                 /* open_file */
95     desktop_close_handle,         /* close_handle */
96     desktop_destroy               /* destroy */
97 };
98
99 #define DESKTOP_ALL_ACCESS 0x01ff
100
101 /* create a winstation object */
102 static struct winstation *create_winstation( const struct unicode_str *name, unsigned int attr,
103                                              unsigned int flags )
104 {
105     struct winstation *winstation;
106
107     if (!winstation_namespace && !(winstation_namespace = create_namespace( 7 )))
108         return NULL;
109
110     if (memchrW( name->str, '\\', name->len / sizeof(WCHAR) ))  /* no backslash allowed in name */
111     {
112         set_error( STATUS_INVALID_PARAMETER );
113         return NULL;
114     }
115
116     if ((winstation = create_named_object( winstation_namespace, &winstation_ops, name, attr )))
117     {
118         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
119         {
120             /* initialize it if it didn't already exist */
121             winstation->flags = flags;
122             winstation->clipboard = NULL;
123             winstation->atom_table = NULL;
124             list_add_tail( &winstation_list, &winstation->entry );
125             list_init( &winstation->desktops );
126         }
127     }
128     return winstation;
129 }
130
131 static void winstation_dump( struct object *obj, int verbose )
132 {
133     struct winstation *winstation = (struct winstation *)obj;
134
135     fprintf( stderr, "Winstation flags=%x clipboard=%p atoms=%p ",
136              winstation->flags, winstation->clipboard, winstation->atom_table );
137     dump_object_name( &winstation->obj );
138     fputc( '\n', stderr );
139 }
140
141 static struct object_type *winstation_get_type( struct object *obj )
142 {
143     static const WCHAR name[] = {'W','i','n','d','o','w','S','t','a','t','i','o','n'};
144     static const struct unicode_str str = { name, sizeof(name) };
145     return get_object_type( &str );
146 }
147
148 static int winstation_close_handle( struct object *obj, struct process *process, obj_handle_t handle )
149 {
150     return (process->winstation != handle);
151 }
152
153 static void winstation_destroy( struct object *obj )
154 {
155     struct winstation *winstation = (struct winstation *)obj;
156
157     list_remove( &winstation->entry );
158     if (winstation->clipboard) release_object( winstation->clipboard );
159     if (winstation->atom_table) release_object( winstation->atom_table );
160 }
161
162 static unsigned int winstation_map_access( struct object *obj, unsigned int access )
163 {
164     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | WINSTA_ENUMDESKTOPS | WINSTA_READATTRIBUTES |
165                                             WINSTA_ENUMERATE | WINSTA_READSCREEN;
166     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE | WINSTA_ACCESSCLIPBOARD | WINSTA_CREATEDESKTOP |
167                                             WINSTA_WRITEATTRIBUTES;
168     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE | WINSTA_ACCESSGLOBALATOMS | WINSTA_EXITWINDOWS;
169     if (access & GENERIC_ALL)     access |= STANDARD_RIGHTS_REQUIRED | WINSTA_ALL_ACCESS;
170     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
171 }
172
173 /* retrieve the process window station, checking the handle access rights */
174 struct winstation *get_process_winstation( struct process *process, unsigned int access )
175 {
176     return (struct winstation *)get_handle_obj( process, process->winstation,
177                                                 access, &winstation_ops );
178 }
179
180 /* build the full name of a desktop object */
181 static WCHAR *build_desktop_name( const struct unicode_str *name,
182                                   struct winstation *winstation, struct unicode_str *res )
183 {
184     const WCHAR *winstation_name;
185     WCHAR *full_name;
186     data_size_t winstation_len;
187
188     if (memchrW( name->str, '\\', name->len / sizeof(WCHAR) ))
189     {
190         set_error( STATUS_INVALID_PARAMETER );
191         return NULL;
192     }
193
194     if (!(winstation_name = get_object_name( &winstation->obj, &winstation_len )))
195         winstation_len = 0;
196
197     res->len = winstation_len + name->len + sizeof(WCHAR);
198     if (!(full_name = mem_alloc( res->len ))) return NULL;
199     memcpy( full_name, winstation_name, winstation_len );
200     full_name[winstation_len / sizeof(WCHAR)] = '\\';
201     memcpy( full_name + winstation_len / sizeof(WCHAR) + 1, name->str, name->len );
202     res->str = full_name;
203     return full_name;
204 }
205
206 /* retrieve a pointer to a desktop object */
207 struct desktop *get_desktop_obj( struct process *process, obj_handle_t handle, unsigned int access )
208 {
209     return (struct desktop *)get_handle_obj( process, handle, access, &desktop_ops );
210 }
211
212 /* create a desktop object */
213 static struct desktop *create_desktop( const struct unicode_str *name, unsigned int attr,
214                                        unsigned int flags, struct winstation *winstation )
215 {
216     struct desktop *desktop;
217     struct unicode_str full_str;
218     WCHAR *full_name;
219
220     if (!(full_name = build_desktop_name( name, winstation, &full_str ))) return NULL;
221
222     if ((desktop = create_named_object( winstation_namespace, &desktop_ops, &full_str, attr )))
223     {
224         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
225         {
226             /* initialize it if it didn't already exist */
227             desktop->flags = flags;
228             desktop->winstation = (struct winstation *)grab_object( winstation );
229             desktop->top_window = NULL;
230             desktop->msg_window = NULL;
231             desktop->global_hooks = NULL;
232             desktop->close_timeout = NULL;
233             desktop->foreground_input = NULL;
234             desktop->users = 0;
235             memset( &desktop->cursor, 0, sizeof(desktop->cursor) );
236             memset( desktop->keystate, 0, sizeof(desktop->keystate) );
237             list_add_tail( &winstation->desktops, &desktop->entry );
238         }
239     }
240     free( full_name );
241     return desktop;
242 }
243
244 static void desktop_dump( struct object *obj, int verbose )
245 {
246     struct desktop *desktop = (struct desktop *)obj;
247
248     fprintf( stderr, "Desktop flags=%x winstation=%p top_win=%p hooks=%p ",
249              desktop->flags, desktop->winstation, desktop->top_window, desktop->global_hooks );
250     dump_object_name( &desktop->obj );
251     fputc( '\n', stderr );
252 }
253
254 static struct object_type *desktop_get_type( struct object *obj )
255 {
256     static const WCHAR name[] = {'D','e','s','k','t','o','p'};
257     static const struct unicode_str str = { name, sizeof(name) };
258     return get_object_type( &str );
259 }
260
261 static int desktop_close_handle( struct object *obj, struct process *process, obj_handle_t handle )
262 {
263     struct thread *thread;
264
265     /* check if the handle is currently used by the process or one of its threads */
266     if (process->desktop == handle) return 0;
267     LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
268         if (thread->desktop == handle) return 0;
269     return 1;
270 }
271
272 static void desktop_destroy( struct object *obj )
273 {
274     struct desktop *desktop = (struct desktop *)obj;
275
276     if (desktop->top_window) destroy_window( desktop->top_window );
277     if (desktop->msg_window) destroy_window( desktop->msg_window );
278     if (desktop->global_hooks) release_object( desktop->global_hooks );
279     if (desktop->close_timeout) remove_timeout_user( desktop->close_timeout );
280     list_remove( &desktop->entry );
281     release_object( desktop->winstation );
282 }
283
284 static unsigned int desktop_map_access( struct object *obj, unsigned int access )
285 {
286     if (access & GENERIC_READ)    access |= STANDARD_RIGHTS_READ | DESKTOP_READOBJECTS | DESKTOP_ENUMERATE;
287     if (access & GENERIC_WRITE)   access |= STANDARD_RIGHTS_WRITE | DESKTOP_CREATEMENU | DESKTOP_CREATEWINDOW |
288                                             DESKTOP_HOOKCONTROL | DESKTOP_JOURNALRECORD | DESKTOP_JOURNALPLAYBACK |
289                                             DESKTOP_WRITEOBJECTS;
290     if (access & GENERIC_EXECUTE) access |= STANDARD_RIGHTS_EXECUTE | DESKTOP_SWITCHDESKTOP;
291     if (access & GENERIC_ALL)     access |= STANDARD_RIGHTS_REQUIRED | DESKTOP_ALL_ACCESS;
292     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
293 }
294
295 /* retrieve the thread desktop, checking the handle access rights */
296 struct desktop *get_thread_desktop( struct thread *thread, unsigned int access )
297 {
298     return get_desktop_obj( thread->process, thread->desktop, access );
299 }
300
301 /* set the process default desktop handle */
302 void set_process_default_desktop( struct process *process, struct desktop *desktop,
303                                   obj_handle_t handle )
304 {
305     struct thread *thread;
306     struct desktop *old_desktop;
307
308     if (process->desktop == handle) return;  /* nothing to do */
309
310     if (!(old_desktop = get_desktop_obj( process, process->desktop, 0 ))) clear_error();
311     process->desktop = handle;
312
313     /* set desktop for threads that don't have one yet */
314     LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
315         if (!thread->desktop) thread->desktop = handle;
316
317     if (!process->is_system)
318     {
319         desktop->users++;
320         if (desktop->close_timeout)
321         {
322             remove_timeout_user( desktop->close_timeout );
323             desktop->close_timeout = NULL;
324         }
325         if (old_desktop) old_desktop->users--;
326     }
327
328     if (old_desktop) release_object( old_desktop );
329 }
330
331 /* connect a process to its window station */
332 void connect_process_winstation( struct process *process, struct thread *parent )
333 {
334     struct winstation *winstation = NULL;
335     struct desktop *desktop = NULL;
336     obj_handle_t handle;
337
338     /* check for an inherited winstation handle (don't ask...) */
339     if ((handle = find_inherited_handle( process, &winstation_ops )))
340     {
341         winstation = (struct winstation *)get_handle_obj( process, handle, 0, &winstation_ops );
342     }
343     else if (parent && parent->process->winstation)
344     {
345         handle = duplicate_handle( parent->process, parent->process->winstation,
346                                    process, 0, 0, DUP_HANDLE_SAME_ACCESS );
347         winstation = (struct winstation *)get_handle_obj( process, handle, 0, &winstation_ops );
348     }
349     if (!winstation) goto done;
350     process->winstation = handle;
351
352     if ((handle = find_inherited_handle( process, &desktop_ops )))
353     {
354         desktop = get_desktop_obj( process, handle, 0 );
355         if (!desktop || desktop->winstation != winstation) goto done;
356     }
357     else if (parent && parent->desktop)
358     {
359         desktop = get_desktop_obj( parent->process, parent->desktop, 0 );
360         if (!desktop || desktop->winstation != winstation) goto done;
361         handle = duplicate_handle( parent->process, parent->desktop,
362                                    process, 0, 0, DUP_HANDLE_SAME_ACCESS );
363     }
364
365     if (handle) set_process_default_desktop( process, desktop, handle );
366
367 done:
368     if (desktop) release_object( desktop );
369     if (winstation) release_object( winstation );
370     clear_error();
371 }
372
373 static void close_desktop_timeout( void *private )
374 {
375     struct desktop *desktop = private;
376
377     desktop->close_timeout = NULL;
378     unlink_named_object( &desktop->obj );  /* make sure no other process can open it */
379     post_desktop_message( desktop, WM_CLOSE, 0, 0 );  /* and signal the owner to quit */
380 }
381
382 /* close the desktop of a given process */
383 void close_process_desktop( struct process *process )
384 {
385     struct desktop *desktop;
386
387     if (process->desktop && (desktop = get_desktop_obj( process, process->desktop, 0 )))
388     {
389         assert( desktop->users > 0 );
390         desktop->users--;
391         /* if we have one remaining user, it has to be the manager of the desktop window */
392         if (desktop->users == 1 && get_top_window_owner( desktop ))
393         {
394             assert( !desktop->close_timeout );
395             desktop->close_timeout = add_timeout_user( -TICKS_PER_SEC, close_desktop_timeout, desktop );
396         }
397         release_object( desktop );
398     }
399     clear_error();  /* ignore errors */
400 }
401
402 /* close the desktop of a given thread */
403 void close_thread_desktop( struct thread *thread )
404 {
405     obj_handle_t handle = thread->desktop;
406
407     thread->desktop = 0;
408     if (handle) close_handle( thread->process, handle );
409 }
410
411 /* set the reply data from the object name */
412 static void set_reply_data_obj_name( struct object *obj )
413 {
414     data_size_t len;
415     const WCHAR *ptr, *name = get_object_name( obj, &len );
416
417     /* if there is a backslash return the part of the name after it */
418     if (name && (ptr = memchrW( name, '\\', len/sizeof(WCHAR) )))
419     {
420         len -= (ptr + 1 - name) * sizeof(WCHAR);
421         name = ptr + 1;
422     }
423     if (name) set_reply_data( name, min( len, get_reply_max_size() ));
424 }
425
426 /* create a window station */
427 DECL_HANDLER(create_winstation)
428 {
429     struct winstation *winstation;
430     struct unicode_str name;
431
432     reply->handle = 0;
433     get_req_unicode_str( &name );
434     if ((winstation = create_winstation( &name, req->attributes, req->flags )))
435     {
436         reply->handle = alloc_handle( current->process, winstation, req->access, req->attributes );
437         release_object( winstation );
438     }
439 }
440
441 /* open a handle to a window station */
442 DECL_HANDLER(open_winstation)
443 {
444     struct unicode_str name;
445
446     get_req_unicode_str( &name );
447     if (winstation_namespace)
448         reply->handle = open_object( winstation_namespace, &name, &winstation_ops, req->access,
449                                      req->attributes );
450     else
451         set_error( STATUS_OBJECT_NAME_NOT_FOUND );
452 }
453
454
455 /* close a window station */
456 DECL_HANDLER(close_winstation)
457 {
458     struct winstation *winstation;
459
460     if ((winstation = (struct winstation *)get_handle_obj( current->process, req->handle,
461                                                            0, &winstation_ops )))
462     {
463         if (close_handle( current->process, req->handle )) set_error( STATUS_ACCESS_DENIED );
464         release_object( winstation );
465     }
466 }
467
468
469 /* get the process current window station */
470 DECL_HANDLER(get_process_winstation)
471 {
472     reply->handle = current->process->winstation;
473 }
474
475
476 /* set the process current window station */
477 DECL_HANDLER(set_process_winstation)
478 {
479     struct winstation *winstation;
480
481     if ((winstation = (struct winstation *)get_handle_obj( current->process, req->handle,
482                                                            0, &winstation_ops )))
483     {
484         /* FIXME: should we close the old one? */
485         current->process->winstation = req->handle;
486         release_object( winstation );
487     }
488 }
489
490 /* create a desktop */
491 DECL_HANDLER(create_desktop)
492 {
493     struct desktop *desktop;
494     struct winstation *winstation;
495     struct unicode_str name;
496
497     reply->handle = 0;
498     get_req_unicode_str( &name );
499     if ((winstation = get_process_winstation( current->process, WINSTA_CREATEDESKTOP )))
500     {
501         if ((desktop = create_desktop( &name, req->attributes, req->flags, winstation )))
502         {
503             reply->handle = alloc_handle( current->process, desktop, req->access, req->attributes );
504             release_object( desktop );
505         }
506         release_object( winstation );
507     }
508 }
509
510 /* open a handle to a desktop */
511 DECL_HANDLER(open_desktop)
512 {
513     struct winstation *winstation;
514     struct unicode_str name;
515
516     get_req_unicode_str( &name );
517
518     /* FIXME: check access rights */
519     if (!req->winsta)
520         winstation = get_process_winstation( current->process, 0 );
521     else
522         winstation = (struct winstation *)get_handle_obj( current->process, req->winsta, 0, &winstation_ops );
523
524     if (winstation)
525     {
526         struct unicode_str full_str;
527         WCHAR *full_name;
528
529         if ((full_name = build_desktop_name( &name, winstation, &full_str )))
530         {
531             reply->handle = open_object( winstation_namespace, &full_str, &desktop_ops, req->access,
532                                          req->attributes );
533             free( full_name );
534         }
535         release_object( winstation );
536     }
537 }
538
539
540 /* close a desktop */
541 DECL_HANDLER(close_desktop)
542 {
543     struct desktop *desktop;
544
545     /* make sure it is a desktop handle */
546     if ((desktop = (struct desktop *)get_handle_obj( current->process, req->handle,
547                                                      0, &desktop_ops )))
548     {
549         if (close_handle( current->process, req->handle )) set_error( STATUS_DEVICE_BUSY );
550         release_object( desktop );
551     }
552 }
553
554
555 /* get the thread current desktop */
556 DECL_HANDLER(get_thread_desktop)
557 {
558     struct thread *thread;
559
560     if (!(thread = get_thread_from_id( req->tid ))) return;
561     reply->handle = thread->desktop;
562     release_object( thread );
563 }
564
565
566 /* set the thread current desktop */
567 DECL_HANDLER(set_thread_desktop)
568 {
569     struct desktop *old_desktop, *new_desktop;
570     struct winstation *winstation;
571
572     if (!(winstation = get_process_winstation( current->process, 0 /* FIXME: access rights? */ )))
573         return;
574
575     if (!(new_desktop = get_desktop_obj( current->process, req->handle, 0 )))
576     {
577         release_object( winstation );
578         return;
579     }
580     if (new_desktop->winstation != winstation)
581     {
582         set_error( STATUS_ACCESS_DENIED );
583         release_object( new_desktop );
584         release_object( winstation );
585         return;
586     }
587
588     /* check if we are changing to a new desktop */
589
590     if (!(old_desktop = get_desktop_obj( current->process, current->desktop, 0)))
591         clear_error();  /* ignore error */
592
593     /* when changing desktop, we can't have any users on the current one */
594     if (old_desktop != new_desktop && current->desktop_users > 0)
595         set_error( STATUS_DEVICE_BUSY );
596     else
597         current->desktop = req->handle;  /* FIXME: should we close the old one? */
598
599     if (!current->process->desktop)
600         set_process_default_desktop( current->process, new_desktop, req->handle );
601
602     if (old_desktop != new_desktop && current->queue) detach_thread_input( current );
603
604     if (old_desktop) release_object( old_desktop );
605     release_object( new_desktop );
606     release_object( winstation );
607 }
608
609
610 /* get/set information about a user object (window station or desktop) */
611 DECL_HANDLER(set_user_object_info)
612 {
613     struct object *obj;
614
615     if (!(obj = get_handle_obj( current->process, req->handle, 0, NULL ))) return;
616
617     if (obj->ops == &desktop_ops)
618     {
619         struct desktop *desktop = (struct desktop *)obj;
620         reply->is_desktop = 1;
621         reply->old_obj_flags = desktop->flags;
622         if (req->flags & SET_USER_OBJECT_FLAGS) desktop->flags = req->obj_flags;
623     }
624     else if (obj->ops == &winstation_ops)
625     {
626         struct winstation *winstation = (struct winstation *)obj;
627         reply->is_desktop = 0;
628         reply->old_obj_flags = winstation->flags;
629         if (req->flags & SET_USER_OBJECT_FLAGS) winstation->flags = req->obj_flags;
630     }
631     else
632     {
633         set_error( STATUS_OBJECT_TYPE_MISMATCH );
634         release_object( obj );
635         return;
636     }
637     if (get_reply_max_size()) set_reply_data_obj_name( obj );
638     release_object( obj );
639 }
640
641
642 /* enumerate window stations */
643 DECL_HANDLER(enum_winstation)
644 {
645     unsigned int index = 0;
646     struct winstation *winsta;
647
648     LIST_FOR_EACH_ENTRY( winsta, &winstation_list, struct winstation, entry )
649     {
650         unsigned int access = WINSTA_ENUMERATE;
651         if (req->index > index++) continue;
652         if (!check_object_access( &winsta->obj, &access )) continue;
653         set_reply_data_obj_name( &winsta->obj );
654         clear_error();
655         reply->next = index;
656         return;
657     }
658     set_error( STATUS_NO_MORE_ENTRIES );
659 }
660
661
662 /* enumerate desktops */
663 DECL_HANDLER(enum_desktop)
664 {
665     struct winstation *winstation;
666     struct desktop *desktop;
667     unsigned int index = 0;
668
669     if (!(winstation = (struct winstation *)get_handle_obj( current->process, req->winstation,
670                                                             WINSTA_ENUMDESKTOPS, &winstation_ops )))
671         return;
672
673     LIST_FOR_EACH_ENTRY( desktop, &winstation->desktops, struct desktop, entry )
674     {
675         unsigned int access = DESKTOP_ENUMERATE;
676         if (req->index > index++) continue;
677         if (!desktop->obj.name) continue;
678         if (!check_object_access( &desktop->obj, &access )) continue;
679         set_reply_data_obj_name( &desktop->obj );
680         release_object( winstation );
681         clear_error();
682         reply->next = index;
683         return;
684     }
685
686     release_object( winstation );
687     set_error( STATUS_NO_MORE_ENTRIES );
688 }