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user32: Avoid releasing a potentially null pointer.
[wine.git] / server / change.c
blobf6d56b0d719962a519e1e19f852a1a6f1706a06d
1 /*
2 * Server-side change notification management
3 *
4 * Copyright (C) 1998 Alexandre Julliard
5 * Copyright (C) 2006 Mike McCormack
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
20 */
21
22 #include "config.h"
23 #include "wine/port.h"
24
25 #include <assert.h>
26 #include <fcntl.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <signal.h>
30 #include <sys/stat.h>
31 #include <sys/types.h>
32 #include <limits.h>
33 #include <dirent.h>
34 #include <errno.h>
35
36 #include "ntstatus.h"
37 #define WIN32_NO_STATUS
38 #include "windef.h"
39
40 #include "file.h"
41 #include "handle.h"
42 #include "thread.h"
43 #include "request.h"
44 #include "process.h"
45 #include "security.h"
46 #include "winternl.h"
47
48 /* dnotify support */
49
50 #ifdef linux
51 #ifndef F_NOTIFY
52 #define F_NOTIFY 1026
53 #define DN_ACCESS 0x00000001 /* File accessed */
54 #define DN_MODIFY 0x00000002 /* File modified */
55 #define DN_CREATE 0x00000004 /* File created */
56 #define DN_DELETE 0x00000008 /* File removed */
57 #define DN_RENAME 0x00000010 /* File renamed */
58 #define DN_ATTRIB 0x00000020 /* File changed attributes */
59 #define DN_MULTISHOT 0x80000000 /* Don't remove notifier */
60 #endif
61 #endif
62
63 /* inotify support */
64
65 #ifdef HAVE_SYS_INOTIFY_H
66 #include <sys/inotify.h>
67 #define USE_INOTIFY
68 #elif defined(__linux__) && defined(__i386__)
69
70 #define SYS_inotify_init 291
71 #define SYS_inotify_add_watch 292
72 #define SYS_inotify_rm_watch 293
73
74 struct inotify_event {
75 int wd;
76 unsigned int mask;
77 unsigned int cookie;
78 unsigned int len;
79 char name[1];
80 };
81
82 #define IN_ACCESS 0x00000001
83 #define IN_MODIFY 0x00000002
84 #define IN_ATTRIB 0x00000004
85 #define IN_CLOSE_WRITE 0x00000008
86 #define IN_CLOSE_NOWRITE 0x00000010
87 #define IN_OPEN 0x00000020
88 #define IN_MOVED_FROM 0x00000040
89 #define IN_MOVED_TO 0x00000080
90 #define IN_CREATE 0x00000100
91 #define IN_DELETE 0x00000200
92 #define IN_DELETE_SELF 0x00000400
93
94 #define IN_ISDIR 0x40000000
95
96 static inline int inotify_init( void )
97 {
98 return syscall( SYS_inotify_init );
99 }
100
101 static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
102 {
103 return syscall( SYS_inotify_add_watch, fd, name, mask );
104 }
105
106 static inline int inotify_rm_watch( int fd, int wd )
107 {
108 return syscall( SYS_inotify_rm_watch, fd, wd );
109 }
110
111 #define USE_INOTIFY
112
113 #endif
114
115 struct inode;
116
117 static void free_inode( struct inode *inode );
118
119 static struct fd *inotify_fd;
120
121 struct change_record {
122 struct list entry;
123 unsigned int cookie;
124 struct filesystem_event event;
125 };
126
127 struct dir
128 {
129 struct object obj; /* object header */
130 struct fd *fd; /* file descriptor to the directory */
131 mode_t mode; /* file stat.st_mode */
132 uid_t uid; /* file stat.st_uid */
133 struct list entry; /* entry in global change notifications list */
134 unsigned int filter; /* notification filter */
135 int notified; /* SIGIO counter */
136 int want_data; /* return change data */
137 int subtree; /* do we want to watch subdirectories? */
138 struct list change_records; /* data for the change */
139 struct list in_entry; /* entry in the inode dirs list */
140 struct inode *inode; /* inode of the associated directory */
141 };
142
143 static struct fd *dir_get_fd( struct object *obj );
144 static struct security_descriptor *dir_get_sd( struct object *obj );
145 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
146 unsigned int set_info );
147 static void dir_dump( struct object *obj, int verbose );
148 static void dir_destroy( struct object *obj );
149
150 static const struct object_ops dir_ops =
151 {
152 sizeof(struct dir), /* size */
153 dir_dump, /* dump */
154 no_get_type, /* get_type */
155 add_queue, /* add_queue */
156 remove_queue, /* remove_queue */
157 default_fd_signaled, /* signaled */
158 no_satisfied, /* satisfied */
159 no_signal, /* signal */
160 dir_get_fd, /* get_fd */
161 default_fd_map_access, /* map_access */
162 dir_get_sd, /* get_sd */
163 dir_set_sd, /* set_sd */
164 no_lookup_name, /* lookup_name */
165 no_open_file, /* open_file */
166 fd_close_handle, /* close_handle */
167 dir_destroy /* destroy */
168 };
169
170 static int dir_get_poll_events( struct fd *fd );
171 static enum server_fd_type dir_get_fd_type( struct fd *fd );
172
173 static const struct fd_ops dir_fd_ops =
174 {
175 dir_get_poll_events, /* get_poll_events */
176 default_poll_event, /* poll_event */
177 no_flush, /* flush */
178 dir_get_fd_type, /* get_fd_type */
179 default_fd_ioctl, /* ioctl */
180 default_fd_queue_async, /* queue_async */
181 default_fd_reselect_async, /* reselect_async */
182 default_fd_cancel_async /* cancel_async */
183 };
184
185 static struct list change_list = LIST_INIT(change_list);
186
187 static void dnotify_adjust_changes( struct dir *dir )
188 {
189 #if defined(F_SETSIG) && defined(F_NOTIFY)
190 int fd = get_unix_fd( dir->fd );
191 unsigned int filter = dir->filter;
192 unsigned int val;
193 if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
194 return;
195
196 val = DN_MULTISHOT;
197 if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
198 val |= DN_RENAME | DN_DELETE | DN_CREATE;
199 if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
200 val |= DN_RENAME | DN_DELETE | DN_CREATE;
201 if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
202 val |= DN_ATTRIB;
203 if (filter & FILE_NOTIFY_CHANGE_SIZE)
204 val |= DN_MODIFY;
205 if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
206 val |= DN_MODIFY;
207 if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
208 val |= DN_ACCESS;
209 if (filter & FILE_NOTIFY_CHANGE_CREATION)
210 val |= DN_CREATE;
211 if (filter & FILE_NOTIFY_CHANGE_SECURITY)
212 val |= DN_ATTRIB;
213 fcntl( fd, F_NOTIFY, val );
214 #endif
215 }
216
217 /* insert change in the global list */
218 static inline void insert_change( struct dir *dir )
219 {
220 sigset_t sigset;
221
222 sigemptyset( &sigset );
223 sigaddset( &sigset, SIGIO );
224 sigprocmask( SIG_BLOCK, &sigset, NULL );
225 list_add_head( &change_list, &dir->entry );
226 sigprocmask( SIG_UNBLOCK, &sigset, NULL );
227 }
228
229 /* remove change from the global list */
230 static inline void remove_change( struct dir *dir )
231 {
232 sigset_t sigset;
233
234 sigemptyset( &sigset );
235 sigaddset( &sigset, SIGIO );
236 sigprocmask( SIG_BLOCK, &sigset, NULL );
237 list_remove( &dir->entry );
238 sigprocmask( SIG_UNBLOCK, &sigset, NULL );
239 }
240
241 static void dir_dump( struct object *obj, int verbose )
242 {
243 struct dir *dir = (struct dir *)obj;
244 assert( obj->ops == &dir_ops );
245 fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
246 }
247
248 /* enter here directly from SIGIO signal handler */
249 void do_change_notify( int unix_fd )
250 {
251 struct dir *dir;
252
253 /* FIXME: this is O(n) ... probably can be improved */
254 LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
255 {
256 if (get_unix_fd( dir->fd ) != unix_fd) continue;
257 interlocked_xchg_add( &dir->notified, 1 );
258 break;
259 }
260 }
261
262 /* SIGIO callback, called synchronously with the poll loop */
263 void sigio_callback(void)
264 {
265 struct dir *dir;
266
267 LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
268 {
269 if (interlocked_xchg( &dir->notified, 0 ))
270 fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_NOTIFY_ENUM_DIR );
271 }
272 }
273
274 static struct fd *dir_get_fd( struct object *obj )
275 {
276 struct dir *dir = (struct dir *)obj;
277 assert( obj->ops == &dir_ops );
278 return (struct fd *)grab_object( dir->fd );
279 }
280
281 static int get_dir_unix_fd( struct dir *dir )
282 {
283 return get_unix_fd( dir->fd );
284 }
285
286 static struct security_descriptor *dir_get_sd( struct object *obj )
287 {
288 struct dir *dir = (struct dir *)obj;
289 int unix_fd;
290 struct stat st;
291 struct security_descriptor *sd;
292 assert( obj->ops == &dir_ops );
293
294 unix_fd = get_dir_unix_fd( dir );
295
296 if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
297 return obj->sd;
298
299 /* mode and uid the same? if so, no need to re-generate security descriptor */
300 if (obj->sd &&
301 (st.st_mode & (S_IRWXU|S_IRWXO)) == (dir->mode & (S_IRWXU|S_IRWXO)) &&
302 (st.st_uid == dir->uid))
303 return obj->sd;
304
305 sd = mode_to_sd( st.st_mode,
306 security_unix_uid_to_sid( st.st_uid ),
307 token_get_primary_group( current->process->token ));
308 if (!sd) return obj->sd;
309
310 dir->mode = st.st_mode;
311 dir->uid = st.st_uid;
312 free( obj->sd );
313 obj->sd = sd;
314 return sd;
315 }
316
317 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
318 unsigned int set_info )
319 {
320 struct dir *dir = (struct dir *)obj;
321 const SID *owner;
322 struct stat st;
323 mode_t mode;
324 int unix_fd;
325
326 assert( obj->ops == &dir_ops );
327
328 unix_fd = get_dir_unix_fd( dir );
329
330 if (unix_fd == -1 || fstat( unix_fd, &st ) == -1) return 1;
331
332 if (set_info & OWNER_SECURITY_INFORMATION)
333 {
334 owner = sd_get_owner( sd );
335 if (!owner)
336 {
337 set_error( STATUS_INVALID_SECURITY_DESCR );
338 return 0;
339 }
340 if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
341 {
342 /* FIXME: get Unix uid and call fchown */
343 }
344 }
345 else if (obj->sd)
346 owner = sd_get_owner( obj->sd );
347 else
348 owner = token_get_user( current->process->token );
349
350 if (set_info & DACL_SECURITY_INFORMATION)
351 {
352 /* keep the bits that we don't map to access rights in the ACL */
353 mode = st.st_mode & (S_ISUID|S_ISGID|S_ISVTX);
354 mode |= sd_to_mode( sd, owner );
355
356 if (((st.st_mode ^ mode) & (S_IRWXU|S_IRWXG|S_IRWXO)) && fchmod( unix_fd, mode ) == -1)
357 {
358 file_set_error();
359 return 0;
360 }
361 }
362 return 1;
363 }
364
365 static struct change_record *get_first_change_record( struct dir *dir )
366 {
367 struct list *ptr = list_head( &dir->change_records );
368 if (!ptr) return NULL;
369 list_remove( ptr );
370 return LIST_ENTRY( ptr, struct change_record, entry );
371 }
372
373 static void dir_destroy( struct object *obj )
374 {
375 struct change_record *record;
376 struct dir *dir = (struct dir *)obj;
377 assert (obj->ops == &dir_ops);
378
379 if (dir->filter)
380 remove_change( dir );
381
382 if (dir->inode)
383 {
384 list_remove( &dir->in_entry );
385 free_inode( dir->inode );
386 }
387
388 while ((record = get_first_change_record( dir ))) free( record );
389
390 release_object( dir->fd );
391
392 if (inotify_fd && list_empty( &change_list ))
393 {
394 release_object( inotify_fd );
395 inotify_fd = NULL;
396 }
397 }
398
399 struct dir *get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
400 {
401 return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
402 }
403
404 static int dir_get_poll_events( struct fd *fd )
405 {
406 return 0;
407 }
408
409 static enum server_fd_type dir_get_fd_type( struct fd *fd )
410 {
411 return FD_TYPE_DIR;
412 }
413
414 #ifdef USE_INOTIFY
415
416 #define HASH_SIZE 31
417
418 struct inode {
419 struct list ch_entry; /* entry in the children list */
420 struct list children; /* children of this inode */
421 struct inode *parent; /* parent of this inode */
422 struct list dirs; /* directory handles watching this inode */
423 struct list ino_entry; /* entry in the inode hash */
424 struct list wd_entry; /* entry in the watch descriptor hash */
425 dev_t dev; /* device number */
426 ino_t ino; /* device's inode number */
427 int wd; /* inotify's watch descriptor */
428 char *name; /* basename name of the inode */
429 };
430
431 static struct list inode_hash[ HASH_SIZE ];
432 static struct list wd_hash[ HASH_SIZE ];
433
434 static int inotify_add_dir( char *path, unsigned int filter );
435
436 static struct inode *inode_from_wd( int wd )
437 {
438 struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
439 struct inode *inode;
440
441 LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
442 if (inode->wd == wd)
443 return inode;
444
445 return NULL;
446 }
447
448 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
449 {
450 return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
451 }
452
453 static struct inode *find_inode( dev_t dev, ino_t ino )
454 {
455 struct list *bucket = get_hash_list( dev, ino );
456 struct inode *inode;
457
458 LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
459 if (inode->ino == ino && inode->dev == dev)
460 return inode;
461
462 return NULL;
463 }
464
465 static struct inode *create_inode( dev_t dev, ino_t ino )
466 {
467 struct inode *inode;
468
469 inode = malloc( sizeof *inode );
470 if (inode)
471 {
472 list_init( &inode->children );
473 list_init( &inode->dirs );
474 inode->ino = ino;
475 inode->dev = dev;
476 inode->wd = -1;
477 inode->parent = NULL;
478 inode->name = NULL;
479 list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
480 }
481 return inode;
482 }
483
484 static struct inode *get_inode( dev_t dev, ino_t ino )
485 {
486 struct inode *inode;
487
488 inode = find_inode( dev, ino );
489 if (inode)
490 return inode;
491 return create_inode( dev, ino );
492 }
493
494 static void inode_set_wd( struct inode *inode, int wd )
495 {
496 if (inode->wd != -1)
497 list_remove( &inode->wd_entry );
498 inode->wd = wd;
499 list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
500 }
501
502 static void inode_set_name( struct inode *inode, const char *name )
503 {
504 free (inode->name);
505 inode->name = name ? strdup( name ) : NULL;
506 }
507
508 static void free_inode( struct inode *inode )
509 {
510 int subtree = 0, watches = 0;
511 struct inode *tmp, *next;
512 struct dir *dir;
513
514 LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
515 {
516 subtree |= dir->subtree;
517 watches++;
518 }
519
520 if (!subtree && !inode->parent)
521 {
522 LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
523 struct inode, ch_entry )
524 {
525 assert( tmp != inode );
526 assert( tmp->parent == inode );
527 free_inode( tmp );
528 }
529 }
530
531 if (watches)
532 return;
533
534 if (inode->parent)
535 list_remove( &inode->ch_entry );
536
537 /* disconnect remaining children from the parent */
538 LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children, struct inode, ch_entry )
539 {
540 list_remove( &tmp->ch_entry );
541 tmp->parent = NULL;
542 }
543
544 if (inode->wd != -1)
545 {
546 inotify_rm_watch( get_unix_fd( inotify_fd ), inode->wd );
547 list_remove( &inode->wd_entry );
548 }
549 list_remove( &inode->ino_entry );
550
551 free( inode->name );
552 free( inode );
553 }
554
555 static struct inode *inode_add( struct inode *parent,
556 dev_t dev, ino_t ino, const char *name )
557 {
558 struct inode *inode;
559
560 inode = get_inode( dev, ino );
561 if (!inode)
562 return NULL;
563
564 if (!inode->parent)
565 {
566 list_add_tail( &parent->children, &inode->ch_entry );
567 inode->parent = parent;
568 assert( inode != parent );
569 }
570 inode_set_name( inode, name );
571
572 return inode;
573 }
574
575 static struct inode *inode_from_name( struct inode *inode, const char *name )
576 {
577 struct inode *i;
578
579 LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
580 if (i->name && !strcmp( i->name, name ))
581 return i;
582 return NULL;
583 }
584
585 static int inotify_get_poll_events( struct fd *fd );
586 static void inotify_poll_event( struct fd *fd, int event );
587
588 static const struct fd_ops inotify_fd_ops =
589 {
590 inotify_get_poll_events, /* get_poll_events */
591 inotify_poll_event, /* poll_event */
592 NULL, /* flush */
593 NULL, /* get_fd_type */
594 NULL, /* ioctl */
595 NULL, /* queue_async */
596 NULL, /* reselect_async */
597 NULL, /* cancel_async */
598 };
599
600 static int inotify_get_poll_events( struct fd *fd )
601 {
602 return POLLIN;
603 }
604
605 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
606 unsigned int cookie, const char *relpath )
607 {
608 struct change_record *record;
609
610 assert( dir->obj.ops == &dir_ops );
611
612 if (dir->want_data)
613 {
614 size_t len = strlen(relpath);
615 record = malloc( offsetof(struct change_record, event.name[len]) );
616 if (!record)
617 return;
618
619 record->cookie = cookie;
620 record->event.action = action;
621 memcpy( record->event.name, relpath, len );
622 record->event.len = len;
623
624 list_add_tail( &dir->change_records, &record->entry );
625 }
626
627 fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
628 }
629
630 static unsigned int filter_from_event( struct inotify_event *ie )
631 {
632 unsigned int filter = 0;
633
634 if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
635 filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
636 if (ie->mask & IN_MODIFY)
637 filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
638 if (ie->mask & IN_ATTRIB)
639 filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
640 if (ie->mask & IN_ACCESS)
641 filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
642 if (ie->mask & IN_CREATE)
643 filter |= FILE_NOTIFY_CHANGE_CREATION;
644
645 if (ie->mask & IN_ISDIR)
646 filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
647 else
648 filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
649
650 return filter;
651 }
652
653 /* scan up the parent directories for watches */
654 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
655 {
656 unsigned int filter = 0;
657 struct dir *dir;
658
659 /* combine filters from parents watching subtrees */
660 while (inode)
661 {
662 LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
663 if (dir->subtree || !is_parent)
664 filter |= dir->filter;
665 is_parent = 1;
666 inode = inode->parent;
667 }
668
669 return filter;
670 }
671
672 static char *inode_get_path( struct inode *inode, int sz )
673 {
674 struct list *head;
675 char *path;
676 int len;
677
678 if (!inode)
679 return NULL;
680
681 head = list_head( &inode->dirs );
682 if (head)
683 {
684 int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
685 path = malloc ( 32 + sz );
686 if (path)
687 sprintf( path, "/proc/self/fd/%u/", unix_fd );
688 return path;
689 }
690
691 if (!inode->name)
692 return NULL;
693
694 len = strlen( inode->name );
695 path = inode_get_path( inode->parent, sz + len + 1 );
696 if (!path)
697 return NULL;
698
699 strcat( path, inode->name );
700 strcat( path, "/" );
701
702 return path;
703 }
704
705 static void inode_check_dir( struct inode *parent, const char *name )
706 {
707 char *path;
708 unsigned int filter;
709 struct inode *inode;
710 struct stat st;
711 int wd = -1;
712
713 path = inode_get_path( parent, strlen(name) );
714 if (!path)
715 return;
716
717 strcat( path, name );
718
719 if (stat( path, &st ) < 0)
720 goto end;
721
722 filter = filter_from_inode( parent, 1 );
723 if (!filter)
724 goto end;
725
726 inode = inode_add( parent, st.st_dev, st.st_ino, name );
727 if (!inode || inode->wd != -1)
728 goto end;
729
730 wd = inotify_add_dir( path, filter );
731 if (wd != -1)
732 inode_set_wd( inode, wd );
733 else
734 free_inode( inode );
735
736 end:
737 free( path );
738 }
739
740 static int prepend( char **path, const char *segment )
741 {
742 int extra;
743 char *p;
744
745 extra = strlen( segment ) + 1;
746 if (*path)
747 {
748 int len = strlen( *path ) + 1;
749 p = realloc( *path, len + extra );
750 if (!p) return 0;
751 memmove( &p[ extra ], p, len );
752 p[ extra - 1 ] = '/';
753 memcpy( p, segment, extra - 1 );
754 }
755 else
756 {
757 p = malloc( extra );
758 if (!p) return 0;
759 memcpy( p, segment, extra );
760 }
761
762 *path = p;
763
764 return 1;
765 }
766
767 static void inotify_notify_all( struct inotify_event *ie )
768 {
769 unsigned int filter, action;
770 struct inode *inode, *i;
771 char *path = NULL;
772 struct dir *dir;
773
774 inode = inode_from_wd( ie->wd );
775 if (!inode)
776 {
777 fprintf( stderr, "no inode matches %d\n", ie->wd);
778 return;
779 }
780
781 filter = filter_from_event( ie );
782
783 if (ie->mask & IN_CREATE)
784 {
785 if (ie->mask & IN_ISDIR)
786 inode_check_dir( inode, ie->name );
787
788 action = FILE_ACTION_ADDED;
789 }
790 else if (ie->mask & IN_DELETE)
791 action = FILE_ACTION_REMOVED;
792 else if (ie->mask & IN_MOVED_FROM)
793 action = FILE_ACTION_RENAMED_OLD_NAME;
794 else if (ie->mask & IN_MOVED_TO)
795 action = FILE_ACTION_RENAMED_NEW_NAME;
796 else
797 action = FILE_ACTION_MODIFIED;
798
799 /*
800 * Work our way up the inode hierarchy
801 * extending the relative path as we go
802 * and notifying all recursive watches.
803 */
804 if (!prepend( &path, ie->name ))
805 return;
806
807 for (i = inode; i; i = i->parent)
808 {
809 LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
810 if ((filter & dir->filter) && (i==inode || dir->subtree))
811 inotify_do_change_notify( dir, action, ie->cookie, path );
812
813 if (!i->name || !prepend( &path, i->name ))
814 break;
815 }
816
817 free( path );
818
819 if (ie->mask & IN_DELETE)
820 {
821 i = inode_from_name( inode, ie->name );
822 if (i)
823 free_inode( i );
824 }
825 }
826
827 static void inotify_poll_event( struct fd *fd, int event )
828 {
829 int r, ofs, unix_fd;
830 char buffer[0x1000];
831 struct inotify_event *ie;
832
833 unix_fd = get_unix_fd( fd );
834 r = read( unix_fd, buffer, sizeof buffer );
835 if (r < 0)
836 {
837 fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
838 return;
839 }
840
841 for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
842 {
843 ie = (struct inotify_event*) &buffer[ofs];
844 if (!ie->len)
845 break;
846 ofs += offsetof( struct inotify_event, name[ie->len] );
847 if (ofs > r) break;
848 inotify_notify_all( ie );
849 }
850 }
851
852 static inline struct fd *create_inotify_fd( void )
853 {
854 int unix_fd;
855
856 unix_fd = inotify_init();
857 if (unix_fd<0)
858 return NULL;
859 return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
860 }
861
862 static int map_flags( unsigned int filter )
863 {
864 unsigned int mask;
865
866 /* always watch these so we can track subdirectories in recursive watches */
867 mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
868
869 if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
870 mask |= IN_ATTRIB;
871 if (filter & FILE_NOTIFY_CHANGE_SIZE)
872 mask |= IN_MODIFY;
873 if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
874 mask |= IN_MODIFY;
875 if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
876 mask |= IN_ACCESS;
877 if (filter & FILE_NOTIFY_CHANGE_SECURITY)
878 mask |= IN_ATTRIB;
879
880 return mask;
881 }
882
883 static int inotify_add_dir( char *path, unsigned int filter )
884 {
885 int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
886 path, map_flags( filter ) );
887 if (wd != -1)
888 set_fd_events( inotify_fd, POLLIN );
889 return wd;
890 }
891
892 static int init_inotify( void )
893 {
894 int i;
895
896 if (inotify_fd)
897 return 1;
898
899 inotify_fd = create_inotify_fd();
900 if (!inotify_fd)
901 return 0;
902
903 for (i=0; i<HASH_SIZE; i++)
904 {
905 list_init( &inode_hash[i] );
906 list_init( &wd_hash[i] );
907 }
908
909 return 1;
910 }
911
912 static int inotify_adjust_changes( struct dir *dir )
913 {
914 unsigned int filter;
915 struct inode *inode;
916 struct stat st;
917 char path[32];
918 int wd, unix_fd;
919
920 if (!inotify_fd)
921 return 0;
922
923 unix_fd = get_unix_fd( dir->fd );
924
925 inode = dir->inode;
926 if (!inode)
927 {
928 /* check if this fd is already being watched */
929 if (-1 == fstat( unix_fd, &st ))
930 return 0;
931
932 inode = get_inode( st.st_dev, st.st_ino );
933 if (!inode)
934 inode = create_inode( st.st_dev, st.st_ino );
935 if (!inode)
936 return 0;
937 list_add_tail( &inode->dirs, &dir->in_entry );
938 dir->inode = inode;
939 }
940
941 filter = filter_from_inode( inode, 0 );
942
943 sprintf( path, "/proc/self/fd/%u", unix_fd );
944 wd = inotify_add_dir( path, filter );
945 if (wd == -1) return 0;
946
947 inode_set_wd( inode, wd );
948
949 return 1;
950 }
951
952 static char *get_basename( const char *link )
953 {
954 char *buffer, *name = NULL;
955 int r, n = 0x100;
956
957 while (1)
958 {
959 buffer = malloc( n );
960 if (!buffer) return NULL;
961
962 r = readlink( link, buffer, n );
963 if (r < 0)
964 break;
965
966 if (r < n)
967 {
968 name = buffer;
969 break;
970 }
971 free( buffer );
972 n *= 2;
973 }
974
975 if (name)
976 {
977 while (r > 0 && name[ r - 1 ] == '/' )
978 r--;
979 name[ r ] = 0;
980
981 name = strrchr( name, '/' );
982 if (name)
983 name = strdup( &name[1] );
984 }
985
986 free( buffer );
987 return name;
988 }
989
990 static int dir_add_to_existing_notify( struct dir *dir )
991 {
992 struct inode *inode, *parent;
993 unsigned int filter = 0;
994 struct stat st, st_new;
995 char link[35], *name;
996 int wd, unix_fd;
997
998 if (!inotify_fd)
999 return 0;
1000
1001 unix_fd = get_unix_fd( dir->fd );
1002
1003 /* check if it's in the list of inodes we want to watch */
1004 if (-1 == fstat( unix_fd, &st_new ))
1005 return 0;
1006 inode = find_inode( st_new.st_dev, st_new.st_ino );
1007 if (inode)
1008 return 0;
1009
1010 /* lookup the parent */
1011 sprintf( link, "/proc/self/fd/%u/..", unix_fd );
1012 if (-1 == stat( link, &st ))
1013 return 0;
1014
1015 /*
1016 * If there's no parent, stop. We could keep going adding
1017 * ../ to the path until we hit the root of the tree or
1018 * find a recursively watched ancestor.
1019 * Assume it's too expensive to search up the tree for now.
1020 */
1021 parent = find_inode( st.st_dev, st.st_ino );
1022 if (!parent)
1023 return 0;
1024
1025 if (parent->wd == -1)
1026 return 0;
1027
1028 filter = filter_from_inode( parent, 1 );
1029 if (!filter)
1030 return 0;
1031
1032 sprintf( link, "/proc/self/fd/%u", unix_fd );
1033 name = get_basename( link );
1034 if (!name)
1035 return 0;
1036 inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
1037 free( name );
1038 if (!inode)
1039 return 0;
1040
1041 /* Couldn't find this inode at the start of the function, must be new */
1042 assert( inode->wd == -1 );
1043
1044 wd = inotify_add_dir( link, filter );
1045 if (wd != -1)
1046 inode_set_wd( inode, wd );
1047
1048 return 1;
1049 }
1050
1051 #else
1052
1053 static int init_inotify( void )
1054 {
1055 return 0;
1056 }
1057
1058 static int inotify_adjust_changes( struct dir *dir )
1059 {
1060 return 0;
1061 }
1062
1063 static void free_inode( struct inode *inode )
1064 {
1065 assert( 0 );
1066 }
1067
1068 static int dir_add_to_existing_notify( struct dir *dir )
1069 {
1070 return 0;
1071 }
1072
1073 #endif /* USE_INOTIFY */
1074
1075 struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
1076 {
1077 struct dir *dir;
1078
1079 dir = alloc_object( &dir_ops );
1080 if (!dir)
1081 return NULL;
1082
1083 list_init( &dir->change_records );
1084 dir->filter = 0;
1085 dir->notified = 0;
1086 dir->want_data = 0;
1087 dir->inode = NULL;
1088 grab_object( fd );
1089 dir->fd = fd;
1090 dir->mode = mode;
1091 dir->uid = ~(uid_t)0;
1092 set_fd_user( fd, &dir_fd_ops, &dir->obj );
1093
1094 dir_add_to_existing_notify( dir );
1095
1096 return &dir->obj;
1097 }
1098
1099 /* enable change notifications for a directory */
1100 DECL_HANDLER(read_directory_changes)
1101 {
1102 struct dir *dir;
1103 struct async *async;
1104
1105 if (!req->filter)
1106 {
1107 set_error(STATUS_INVALID_PARAMETER);
1108 return;
1109 }
1110
1111 dir = get_dir_obj( current->process, req->async.handle, 0 );
1112 if (!dir)
1113 return;
1114
1115 /* requests don't timeout */
1116 if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT ))) goto end;
1117
1118 /* assign it once */
1119 if (!dir->filter)
1120 {
1121 init_inotify();
1122 insert_change( dir );
1123 dir->filter = req->filter;
1124 dir->subtree = req->subtree;
1125 dir->want_data = req->want_data;
1126 }
1127
1128 /* if there's already a change in the queue, send it */
1129 if (!list_empty( &dir->change_records ))
1130 fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1131
1132 /* setup the real notification */
1133 if (!inotify_adjust_changes( dir ))
1134 dnotify_adjust_changes( dir );
1135
1136 release_object( async );
1137 set_error(STATUS_PENDING);
1138
1139 end:
1140 release_object( dir );
1141 }
1142
1143 DECL_HANDLER(read_change)
1144 {
1145 struct change_record *record, *next;
1146 struct dir *dir;
1147 struct list events;
1148 char *data, *event;
1149 int size = 0;
1150
1151 dir = get_dir_obj( current->process, req->handle, 0 );
1152 if (!dir)
1153 return;
1154
1155 list_init( &events );
1156 list_move_tail( &events, &dir->change_records );
1157 release_object( dir );
1158
1159 if (list_empty( &events ))
1160 {
1161 set_error( STATUS_NO_DATA_DETECTED );
1162 return;
1163 }
1164
1165 LIST_FOR_EACH_ENTRY( record, &events, struct change_record, entry )
1166 {
1167 size += (offsetof(struct filesystem_event, name[record->event.len])
1168 + sizeof(int)-1) / sizeof(int) * sizeof(int);
1169 }
1170
1171 if (size > get_reply_max_size())
1172 set_error( STATUS_BUFFER_TOO_SMALL );
1173 else if ((data = mem_alloc( size )) != NULL)
1174 {
1175 event = data;
1176 LIST_FOR_EACH_ENTRY( record, &events, struct change_record, entry )
1177 {
1178 data_size_t len = offsetof( struct filesystem_event, name[record->event.len] );
1179
1180 /* FIXME: rename events are sometimes reported as delete/create */
1181 if (record->event.action == FILE_ACTION_RENAMED_OLD_NAME)
1182 {
1183 struct list *elem = list_next( &events, &record->entry );
1184 if (elem)
1185 next = LIST_ENTRY(elem, struct change_record, entry);
1186
1187 if (elem && next->cookie == record->cookie)
1188 next->cookie = 0;
1189 else
1190 record->event.action = FILE_ACTION_REMOVED;
1191 }
1192 else if (record->event.action == FILE_ACTION_RENAMED_NEW_NAME && record->cookie)
1193 record->event.action = FILE_ACTION_ADDED;
1194
1195 memcpy( event, &record->event, len );
1196 event += len;
1197 if (len % sizeof(int))
1198 {
1199 memset( event, 0, sizeof(int) - len % sizeof(int) );
1200 event += sizeof(int) - len % sizeof(int);
1201 }
1202 }
1203 set_reply_data_ptr( data, size );
1204 }
1205
1206 LIST_FOR_EACH_ENTRY_SAFE( record, next, &events, struct change_record, entry )
1207 {
1208 list_remove( &record->entry );
1209 free( record );
1210 }
1211 }
Windows API implementation