1 /*
2  * Copyright © 2001, 2007 Red Hat, Inc.
3  *
4  * Permission to use, copy, modify, distribute, and sell this software and its
5  * documentation for any purpose is hereby granted without fee, provided that
6  * the above copyright notice appear in all copies and that both that
7  * copyright notice and this permission notice appear in supporting
8  * documentation, and that the name of Red Hat not be used in advertising or
9  * publicity pertaining to distribution of the software without specific,
10  * written prior permission.  Red Hat makes no representations about the
11  * suitability of this software for any purpose.  It is provided "as is"
12  * without express or implied warranty.
13  *
14  * RED HAT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL RED HAT
16  * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
18  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
19  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20  *
21  * Author:  Owen Taylor, Red Hat, Inc.
22  */
23 #include "clutter-build-config.h"
24 #include <limits.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 
29 #include <X11/Xlib.h>
30 #include <X11/Xmd.h>		/* For CARD16 */
31 
32 #include "xsettings-client.h"
33 
34 struct _XSettingsClient
35 {
36   Display *display;
37   int screen;
38   XSettingsNotifyFunc notify;
39   XSettingsWatchFunc watch;
40   void *cb_data;
41 
42   XSettingsGrabFunc grab;
43   XSettingsGrabFunc ungrab;
44 
45   Window manager_window;
46   Atom manager_atom;
47   Atom selection_atom;
48   Atom xsettings_atom;
49 
50   XSettingsList *settings;
51 };
52 
53 static void
notify_changes(XSettingsClient * client,XSettingsList * old_list)54 notify_changes (XSettingsClient *client,
55 		XSettingsList   *old_list)
56 {
57   XSettingsList *old_iter = old_list;
58   XSettingsList *new_iter = client->settings;
59 
60   if (!client->notify)
61     return;
62 
63   while (old_iter || new_iter)
64     {
65       int cmp;
66 
67       if (old_iter && new_iter)
68 	cmp = strcmp (old_iter->setting->name, new_iter->setting->name);
69       else if (old_iter)
70 	cmp = -1;
71       else
72 	cmp = 1;
73 
74       if (cmp < 0)
75 	{
76 	  client->notify (old_iter->setting->name,
77 			  XSETTINGS_ACTION_DELETED,
78 			  NULL,
79 			  client->cb_data);
80 	}
81       else if (cmp == 0)
82 	{
83 	  if (!xsettings_setting_equal (old_iter->setting,
84 					new_iter->setting))
85 	    client->notify (old_iter->setting->name,
86 			    XSETTINGS_ACTION_CHANGED,
87 			    new_iter->setting,
88 			    client->cb_data);
89 	}
90       else
91 	{
92 	  client->notify (new_iter->setting->name,
93 			  XSETTINGS_ACTION_NEW,
94 			  new_iter->setting,
95 			  client->cb_data);
96 	}
97 
98       if (old_iter)
99 	old_iter = old_iter->next;
100       if (new_iter)
101 	new_iter = new_iter->next;
102     }
103 }
104 
105 static int
ignore_errors(Display * display,XErrorEvent * event)106 ignore_errors (Display *display, XErrorEvent *event)
107 {
108   return True;
109 }
110 
111 static char local_byte_order = '\0';
112 
113 #define BYTES_LEFT(buffer) ((buffer)->data + (buffer)->len - (buffer)->pos)
114 
115 static XSettingsResult
fetch_card16(XSettingsBuffer * buffer,CARD16 * result)116 fetch_card16 (XSettingsBuffer *buffer,
117 	      CARD16          *result)
118 {
119   CARD16 x;
120 
121   if (BYTES_LEFT (buffer) < 2)
122     return XSETTINGS_ACCESS;
123 
124   x = *(CARD16 *)buffer->pos;
125   buffer->pos += 2;
126 
127   if (buffer->byte_order == local_byte_order)
128     *result = x;
129   else
130     *result = (x << 8) | (x >> 8);
131 
132   return XSETTINGS_SUCCESS;
133 }
134 
135 static XSettingsResult
fetch_ushort(XSettingsBuffer * buffer,unsigned short * result)136 fetch_ushort (XSettingsBuffer *buffer,
137 	      unsigned short  *result)
138 {
139   CARD16 x;
140   XSettingsResult r;
141 
142   r = fetch_card16 (buffer, &x);
143   if (r == XSETTINGS_SUCCESS)
144     *result = x;
145 
146   return r;
147 }
148 
149 static XSettingsResult
fetch_card32(XSettingsBuffer * buffer,CARD32 * result)150 fetch_card32 (XSettingsBuffer *buffer,
151 	      CARD32          *result)
152 {
153   CARD32 x;
154 
155   if (BYTES_LEFT (buffer) < 4)
156     return XSETTINGS_ACCESS;
157 
158   x = *(CARD32 *)buffer->pos;
159   buffer->pos += 4;
160 
161   if (buffer->byte_order == local_byte_order)
162     *result = x;
163   else
164     *result = (x << 24) | ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | (x >> 24);
165 
166   return XSETTINGS_SUCCESS;
167 }
168 
169 static XSettingsResult
fetch_card8(XSettingsBuffer * buffer,CARD8 * result)170 fetch_card8 (XSettingsBuffer *buffer,
171 	     CARD8           *result)
172 {
173   if (BYTES_LEFT (buffer) < 1)
174     return XSETTINGS_ACCESS;
175 
176   *result = *(CARD8 *)buffer->pos;
177   buffer->pos += 1;
178 
179   return XSETTINGS_SUCCESS;
180 }
181 
182 #define XSETTINGS_PAD(n,m) ((n + m - 1) & (~(m-1)))
183 
184 static XSettingsList *
parse_settings(unsigned char * data,size_t len)185 parse_settings (unsigned char *data,
186 		size_t         len)
187 {
188   XSettingsBuffer buffer;
189   XSettingsResult result = XSETTINGS_SUCCESS;
190   XSettingsList *settings = NULL;
191   CARD32 serial;
192   CARD32 n_entries;
193   CARD32 i;
194   XSettingsSetting *setting = NULL;
195 
196   local_byte_order = xsettings_byte_order ();
197 
198   buffer.pos = buffer.data = data;
199   buffer.len = len;
200 
201   result = fetch_card8 (&buffer, (unsigned char *)&buffer.byte_order);
202   if (buffer.byte_order != MSBFirst &&
203       buffer.byte_order != LSBFirst)
204     {
205       fprintf (stderr, "Invalid byte order in XSETTINGS property\n");
206       result = XSETTINGS_FAILED;
207       goto out;
208     }
209 
210   buffer.pos += 3;
211 
212   result = fetch_card32 (&buffer, &serial);
213   if (result != XSETTINGS_SUCCESS)
214     goto out;
215 
216   result = fetch_card32 (&buffer, &n_entries);
217   if (result != XSETTINGS_SUCCESS)
218     goto out;
219 
220   for (i = 0; i < n_entries; i++)
221     {
222       CARD8 type;
223       CARD16 name_len;
224       CARD32 v_int;
225       size_t pad_len;
226 
227       result = fetch_card8 (&buffer, &type);
228       if (result != XSETTINGS_SUCCESS)
229 	goto out;
230 
231       buffer.pos += 1;
232 
233       result = fetch_card16 (&buffer, &name_len);
234       if (result != XSETTINGS_SUCCESS)
235 	goto out;
236 
237       pad_len = XSETTINGS_PAD(name_len, 4);
238       if (BYTES_LEFT (&buffer) < pad_len)
239 	{
240 	  result = XSETTINGS_ACCESS;
241 	  goto out;
242 	}
243 
244       setting = malloc (sizeof *setting);
245       if (!setting)
246 	{
247 	  result = XSETTINGS_NO_MEM;
248 	  goto out;
249 	}
250       setting->type = XSETTINGS_TYPE_INT; /* No allocated memory */
251 
252       setting->name = malloc (name_len + 1);
253       if (!setting->name)
254 	{
255 	  result = XSETTINGS_NO_MEM;
256 	  goto out;
257 	}
258 
259       memcpy (setting->name, buffer.pos, name_len);
260       setting->name[name_len] = '\0';
261       buffer.pos += pad_len;
262 
263       result = fetch_card32 (&buffer, &v_int);
264       if (result != XSETTINGS_SUCCESS)
265 	goto out;
266       setting->last_change_serial = v_int;
267 
268       switch (type)
269 	{
270 	case XSETTINGS_TYPE_INT:
271 	  result = fetch_card32 (&buffer, &v_int);
272 	  if (result != XSETTINGS_SUCCESS)
273 	    goto out;
274 
275 	  setting->data.v_int = (INT32)v_int;
276 	  break;
277 	case XSETTINGS_TYPE_STRING:
278 	  result = fetch_card32 (&buffer, &v_int);
279 	  if (result != XSETTINGS_SUCCESS)
280 	    goto out;
281 
282 	  pad_len = XSETTINGS_PAD (v_int, 4);
283 	  if (v_int + 1 == 0 || /* Guard against wrap-around */
284 	      BYTES_LEFT (&buffer) < pad_len)
285 	    {
286 	      result = XSETTINGS_ACCESS;
287 	      goto out;
288 	    }
289 
290 	  setting->data.v_string = malloc (v_int + 1);
291 	  if (!setting->data.v_string)
292 	    {
293 	      result = XSETTINGS_NO_MEM;
294 	      goto out;
295 	    }
296 
297 	  memcpy (setting->data.v_string, buffer.pos, v_int);
298 	  setting->data.v_string[v_int] = '\0';
299 	  buffer.pos += pad_len;
300 
301 	  break;
302 	case XSETTINGS_TYPE_COLOR:
303 	  result = fetch_ushort (&buffer, &setting->data.v_color.red);
304 	  if (result != XSETTINGS_SUCCESS)
305 	    goto out;
306 	  result = fetch_ushort (&buffer, &setting->data.v_color.green);
307 	  if (result != XSETTINGS_SUCCESS)
308 	    goto out;
309 	  result = fetch_ushort (&buffer, &setting->data.v_color.blue);
310 	  if (result != XSETTINGS_SUCCESS)
311 	    goto out;
312 	  result = fetch_ushort (&buffer, &setting->data.v_color.alpha);
313 	  if (result != XSETTINGS_SUCCESS)
314 	    goto out;
315 
316 	  break;
317 	default:
318 	  /* Quietly ignore unknown types */
319 	  break;
320 	}
321 
322       setting->type = type;
323 
324       result = xsettings_list_insert (&settings, setting);
325       if (result != XSETTINGS_SUCCESS)
326 	goto out;
327 
328       setting = NULL;
329     }
330 
331  out:
332 
333   if (result != XSETTINGS_SUCCESS)
334     {
335       switch (result)
336 	{
337 	case XSETTINGS_NO_MEM:
338 	  fprintf(stderr, "Out of memory reading XSETTINGS property\n");
339 	  break;
340 	case XSETTINGS_ACCESS:
341 	  fprintf(stderr, "Invalid XSETTINGS property (read off end)\n");
342 	  break;
343 	case XSETTINGS_DUPLICATE_ENTRY:
344 	  fprintf (stderr, "Duplicate XSETTINGS entry for '%s'\n", setting->name);
345 	case XSETTINGS_FAILED:
346 	case XSETTINGS_SUCCESS:
347 	case XSETTINGS_NO_ENTRY:
348 	  break;
349 	}
350 
351       if (setting)
352 	xsettings_setting_free (setting);
353 
354       xsettings_list_free (settings);
355       settings = NULL;
356 
357     }
358 
359   return settings;
360 }
361 
362 static void
read_settings(XSettingsClient * client)363 read_settings (XSettingsClient *client)
364 {
365   Atom type;
366   int format;
367   unsigned long n_items;
368   unsigned long bytes_after;
369   unsigned char *data;
370   int result;
371 
372   int (*old_handler) (Display *, XErrorEvent *);
373 
374   XSettingsList *old_list = client->settings;
375 
376   client->settings = NULL;
377 
378   if (client->manager_window)
379     {
380       old_handler = XSetErrorHandler (ignore_errors);
381       result = XGetWindowProperty (client->display, client->manager_window,
382 				   client->xsettings_atom, 0, LONG_MAX,
383 				   False, client->xsettings_atom,
384 				   &type, &format, &n_items, &bytes_after, &data);
385       XSetErrorHandler (old_handler);
386 
387       if (result == Success && type != None)
388 	{
389 	  if (type != client->xsettings_atom)
390 	    {
391 	      fprintf (stderr, "Invalid type for XSETTINGS property");
392 	    }
393 	  else if (format != 8)
394 	    {
395 	      fprintf (stderr, "Invalid format for XSETTINGS property %d", format);
396 	    }
397 	  else
398 	    client->settings = parse_settings (data, n_items);
399 
400 	  XFree (data);
401 	}
402     }
403 
404   notify_changes (client, old_list);
405   xsettings_list_free (old_list);
406 }
407 
408 static void
add_events(Display * display,Window window,long mask)409 add_events (Display *display,
410 	    Window   window,
411 	    long     mask)
412 {
413   XWindowAttributes attr;
414 
415   XGetWindowAttributes (display, window, &attr);
416   XSelectInput (display, window, attr.your_event_mask | mask);
417 }
418 
419 static void
check_manager_window(XSettingsClient * client)420 check_manager_window (XSettingsClient *client)
421 {
422   if (client->manager_window && client->watch)
423     client->watch (client->manager_window, False, 0, client->cb_data);
424 
425   if (client->grab)
426     client->grab (client->display);
427   else
428     XGrabServer (client->display);
429 
430   client->manager_window = XGetSelectionOwner (client->display,
431 					       client->selection_atom);
432   if (client->manager_window)
433     XSelectInput (client->display, client->manager_window,
434 		  PropertyChangeMask | StructureNotifyMask);
435 
436   if (client->ungrab)
437     client->ungrab (client->display);
438   else
439     XUngrabServer (client->display);
440 
441   XFlush (client->display);
442 
443   if (client->manager_window && client->watch)
444     {
445       if (!client->watch (client->manager_window, True,
446 			  PropertyChangeMask | StructureNotifyMask,
447 			  client->cb_data))
448 	{
449 	  /* Inability to watch the window probably means that it was destroyed
450 	   * after we ungrabbed
451 	   */
452 	  client->manager_window = None;
453 	  return;
454 	}
455     }
456 
457 
458   read_settings (client);
459 }
460 
461 XSettingsClient *
xsettings_client_new(Display * display,int screen,XSettingsNotifyFunc notify,XSettingsWatchFunc watch,void * cb_data)462 xsettings_client_new (Display             *display,
463 		      int                  screen,
464 		      XSettingsNotifyFunc  notify,
465 		      XSettingsWatchFunc   watch,
466 		      void                *cb_data)
467 {
468   return xsettings_client_new_with_grab_funcs (display, screen, notify, watch, cb_data,
469                                                NULL, NULL);
470 }
471 
472 XSettingsClient *
xsettings_client_new_with_grab_funcs(Display * display,int screen,XSettingsNotifyFunc notify,XSettingsWatchFunc watch,void * cb_data,XSettingsGrabFunc grab,XSettingsGrabFunc ungrab)473 xsettings_client_new_with_grab_funcs (Display             *display,
474 		                      int                  screen,
475 		                      XSettingsNotifyFunc  notify,
476 		                      XSettingsWatchFunc   watch,
477 		                      void                *cb_data,
478 		                      XSettingsGrabFunc    grab,
479 		                      XSettingsGrabFunc    ungrab)
480 {
481   XSettingsClient *client;
482   char buffer[256];
483   char *atom_names[3];
484   Atom atoms[3];
485 
486   client = malloc (sizeof *client);
487   if (!client)
488     return NULL;
489 
490   client->display = display;
491   client->screen = screen;
492   client->notify = notify;
493   client->watch = watch;
494   client->cb_data = cb_data;
495   client->grab = grab;
496   client->ungrab = ungrab;
497 
498   client->manager_window = None;
499   client->settings = NULL;
500 
501   sprintf(buffer, "_XSETTINGS_S%d", screen);
502   atom_names[0] = buffer;
503   atom_names[1] = "_XSETTINGS_SETTINGS";
504   atom_names[2] = "MANAGER";
505 
506 #ifdef HAVE_XINTERNATOMS
507   XInternAtoms (display, atom_names, 3, False, atoms);
508 #else
509   atoms[0] = XInternAtom (display, atom_names[0], False);
510   atoms[1] = XInternAtom (display, atom_names[1], False);
511   atoms[2] = XInternAtom (display, atom_names[2], False);
512 #endif
513 
514   client->selection_atom = atoms[0];
515   client->xsettings_atom = atoms[1];
516   client->manager_atom = atoms[2];
517 
518   /* Select on StructureNotify so we get MANAGER events
519    */
520   add_events (display, RootWindow (display, screen), StructureNotifyMask);
521 
522   if (client->watch)
523     client->watch (RootWindow (display, screen), True, StructureNotifyMask,
524 		   client->cb_data);
525 
526   check_manager_window (client);
527 
528   return client;
529 }
530 
531 
532 void
xsettings_client_set_grab_func(XSettingsClient * client,XSettingsGrabFunc grab)533 xsettings_client_set_grab_func   (XSettingsClient      *client,
534 				  XSettingsGrabFunc     grab)
535 {
536   client->grab = grab;
537 }
538 
539 void
xsettings_client_set_ungrab_func(XSettingsClient * client,XSettingsGrabFunc ungrab)540 xsettings_client_set_ungrab_func (XSettingsClient      *client,
541 				  XSettingsGrabFunc     ungrab)
542 {
543   client->ungrab = ungrab;
544 }
545 
546 void
xsettings_client_destroy(XSettingsClient * client)547 xsettings_client_destroy (XSettingsClient *client)
548 {
549   if (client->watch)
550     client->watch (RootWindow (client->display, client->screen),
551 		   False, 0, client->cb_data);
552   if (client->manager_window && client->watch)
553     client->watch (client->manager_window, False, 0, client->cb_data);
554 
555   xsettings_list_free (client->settings);
556   free (client);
557 }
558 
559 XSettingsResult
xsettings_client_get_setting(XSettingsClient * client,const char * name,XSettingsSetting ** setting)560 xsettings_client_get_setting (XSettingsClient   *client,
561 			      const char        *name,
562 			      XSettingsSetting **setting)
563 {
564   XSettingsSetting *search = xsettings_list_lookup (client->settings, name);
565   if (search)
566     {
567       *setting = xsettings_setting_copy (search);
568       return *setting ? XSETTINGS_SUCCESS : XSETTINGS_NO_MEM;
569     }
570   else
571     return XSETTINGS_NO_ENTRY;
572 }
573 
574 Bool
xsettings_client_process_event(XSettingsClient * client,XEvent * xev)575 xsettings_client_process_event (XSettingsClient *client,
576 				XEvent          *xev)
577 {
578   /* The checks here will not unlikely cause us to reread
579    * the properties from the manager window a number of
580    * times when the manager changes from A->B. But manager changes
581    * are going to be pretty rare.
582    */
583   if (xev->xany.window == RootWindow (client->display, client->screen))
584     {
585       if (xev->xany.type == ClientMessage &&
586 	  xev->xclient.message_type == client->manager_atom &&
587 	  xev->xclient.data.l[1] == client->selection_atom)
588 	{
589 	  check_manager_window (client);
590 	  return True;
591 	}
592     }
593   else if (xev->xany.window == client->manager_window)
594     {
595       if (xev->xany.type == DestroyNotify)
596 	{
597 	  check_manager_window (client);
598           /* let GDK do its cleanup */
599 	  return False;
600 	}
601       else if (xev->xany.type == PropertyNotify)
602 	{
603 	  read_settings (client);
604 	  return True;
605 	}
606     }
607 
608   return False;
609 }
610