server/change.c

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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 <errno.h>
  32 #ifdef HAVE_SYS_ERRNO_H
  33 #include <sys/errno.h>
  34 #endif
  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 "winternl.h"
  45
  46 /* dnotify support */
  47
  48 #ifdef linux
  49 #ifndef F_NOTIFY
  50 #define F_NOTIFY 1026
  51 #define DN_ACCESS       0x00000001      /* File accessed */
  52 #define DN_MODIFY       0x00000002      /* File modified */
  53 #define DN_CREATE       0x00000004      /* File created */
  54 #define DN_DELETE       0x00000008      /* File removed */
  55 #define DN_RENAME       0x00000010      /* File renamed */
  56 #define DN_ATTRIB       0x00000020      /* File changed attibutes */
  57 #define DN_MULTISHOT    0x80000000      /* Don't remove notifier */
  58 #endif
  59 #endif
  60
  61 /* inotify support */
  62
  63 #if defined(__linux__) && defined(__i386__)
  64
  65 #define SYS_inotify_init        291
  66 #define SYS_inotify_add_watch   292
  67 #define SYS_inotify_rm_watch    293
  68
  69 struct inotify_event {
  70     int           wd;
  71     unsigned int  mask;
  72     unsigned int  cookie;
  73     unsigned int  len;
  74     char          name[1];
  75 };
  76
  77 #define IN_ACCESS        0x00000001
  78 #define IN_MODIFY        0x00000002
  79 #define IN_ATTRIB        0x00000004
  80 #define IN_CLOSE_WRITE   0x00000008
  81 #define IN_CLOSE_NOWRITE 0x00000010
  82 #define IN_OPEN          0x00000020
  83 #define IN_MOVED_FROM    0x00000040
  84 #define IN_MOVED_TO      0x00000080
  85 #define IN_CREATE        0x00000100
  86 #define IN_DELETE        0x00000200
  87 #define IN_DELETE_SELF   0x00000400
  88
  89 static inline int inotify_init( void )
  90 {
  91     int ret;
  92     __asm__ __volatile__( "int $0x80"
  93                           : "=a" (ret)
  94                           : "0" (SYS_inotify_init));
  95     if (ret<0) { errno = -ret; ret = -1; }
  96     return ret;
  97 }
  98
  99 static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
 100 {
 101     int ret;
 102     __asm__ __volatile__( "pushl %%ebx;\n\t"
 103                           "movl %2,%%ebx;\n\t"
 104                           "int $0x80;\n\t"
 105                           "popl %%ebx"
 106                           : "=a" (ret) : "0" (SYS_inotify_add_watch),
 107                             "r" (fd), "c" (name), "d" (mask) );
 108     if (ret<0) { errno = -ret; ret = -1; }
 109     return ret;
 110 }
 111
 112 static inline int inotify_remove_watch( int fd, int wd )
 113 {
 114     int ret;
 115     __asm__ __volatile__( "pushl %%ebx;\n\t"
 116                           "movl %2,%%ebx;\n\t"
 117                           "int $0x80;\n\t"
 118                           "popl %%ebx"
 119                           : "=a" (ret) : "0" (SYS_inotify_rm_watch),
 120                             "r" (fd), "c" (wd) );
 121     if (ret<0) { errno = -ret; ret = -1; }
 122     return ret;
 123 }
 124
 125 #define USE_INOTIFY
 126
 127 #endif
 128
 129 struct dir
 130 {
 131     struct object  obj;      /* object header */
 132     struct fd     *fd;       /* file descriptor to the directory */
 133     struct list    entry;    /* entry in global change notifications list */
 134     struct event  *event;
 135     unsigned int   filter;   /* notification filter */
 136     int            notified; /* SIGIO counter */
 137     long           signaled; /* the file changed */
 138     struct fd     *inotify_fd; /* inotify file descriptor */
 139     int            wd;       /* inotify watch descriptor */
 140 };
 141
 142 static struct fd *dir_get_fd( struct object *obj );
 143 static unsigned int dir_map_access( struct object *obj, unsigned int access );
 144 static void dir_dump( struct object *obj, int verbose );
 145 static void dir_destroy( struct object *obj );
 146 static int dir_signaled( struct object *obj, struct thread *thread );
 147
 148 static const struct object_ops dir_ops =
 149 {
 150     sizeof(struct dir),       /* size */
 151     dir_dump,                 /* dump */
 152     add_queue,                /* add_queue */
 153     remove_queue,             /* remove_queue */
 154     dir_signaled,             /* signaled */
 155     no_satisfied,             /* satisfied */
 156     no_signal,                /* signal */
 157     dir_get_fd,               /* get_fd */
 158     dir_map_access,           /* map_access */
 159     no_lookup_name,           /* lookup_name */
 160     no_close_handle,          /* close_handle */
 161     dir_destroy               /* destroy */
 162 };
 163
 164 static int dir_get_poll_events( struct fd *fd );
 165 static int dir_get_info( struct fd *fd );
 166
 167 static const struct fd_ops dir_fd_ops =
 168 {
 169     dir_get_poll_events,      /* get_poll_events */
 170     default_poll_event,       /* poll_event */
 171     no_flush,                 /* flush */
 172     dir_get_info,             /* get_file_info */
 173     default_fd_queue_async,   /* queue_async */
 174     default_fd_cancel_async   /* cancel_async */
 175 };
 176
 177 static struct list change_list = LIST_INIT(change_list);
 178
 179 static void dnotify_adjust_changes( struct dir *dir )
 180 {
 181 #if defined(F_SETSIG) && defined(F_NOTIFY)
 182     int fd = get_unix_fd( dir->fd );
 183     unsigned int filter = dir->filter;
 184     unsigned int val;
 185     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 186         return;
 187
 188     val = DN_MULTISHOT;
 189     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 190         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 191     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 192         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 193     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 194         val |= DN_ATTRIB;
 195     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 196         val |= DN_MODIFY;
 197     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 198         val |= DN_MODIFY;
 199     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 200         val |= DN_ACCESS;
 201     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 202         val |= DN_CREATE;
 203     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 204         val |= DN_ATTRIB;
 205     fcntl( fd, F_NOTIFY, val );
 206 #endif
 207 }
 208
 209 /* insert change in the global list */
 210 static inline void insert_change( struct dir *dir )
 211 {
 212     sigset_t sigset;
 213
 214     sigemptyset( &sigset );
 215     sigaddset( &sigset, SIGIO );
 216     sigprocmask( SIG_BLOCK, &sigset, NULL );
 217     list_add_head( &change_list, &dir->entry );
 218     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 219 }
 220
 221 /* remove change from the global list */
 222 static inline void remove_change( struct dir *dir )
 223 {
 224     sigset_t sigset;
 225
 226     sigemptyset( &sigset );
 227     sigaddset( &sigset, SIGIO );
 228     sigprocmask( SIG_BLOCK, &sigset, NULL );
 229     list_remove( &dir->entry );
 230     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 231 }
 232
 233 struct object *create_dir_obj( struct fd *fd )
 234 {
 235     struct dir *dir;
 236
 237     dir = alloc_object( &dir_ops );
 238     if (!dir)
 239         return NULL;
 240
 241     dir->event = NULL;
 242     dir->filter = 0;
 243     dir->notified = 0;
 244     dir->signaled = 0;
 245     dir->inotify_fd = NULL;
 246     dir->wd = -1;
 247     grab_object( fd );
 248     dir->fd = fd;
 249     set_fd_user( fd, &dir_fd_ops, &dir->obj );
 250
 251     return &dir->obj;
 252 }
 253
 254 static void dir_dump( struct object *obj, int verbose )
 255 {
 256     struct dir *dir = (struct dir *)obj;
 257     assert( obj->ops == &dir_ops );
 258     fprintf( stderr, "Dirfile fd=%p event=%p filter=%08x\n",
 259              dir->fd, dir->event, dir->filter );
 260 }
 261
 262 static int dir_signaled( struct object *obj, struct thread *thread )
 263 {
 264     struct dir *dir = (struct dir *)obj;
 265     assert (obj->ops == &dir_ops);
 266     return (dir->event == NULL) && dir->signaled;
 267 }
 268
 269 /* enter here directly from SIGIO signal handler */
 270 void do_change_notify( int unix_fd )
 271 {
 272     struct dir *dir;
 273
 274     /* FIXME: this is O(n) ... probably can be improved */
 275     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 276     {
 277         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 278         interlocked_xchg_add( &dir->notified, 1 );
 279         break;
 280     }
 281 }
 282
 283 static void dir_signal_changed( struct dir *dir )
 284 {
 285     if (dir->event)
 286         set_event( dir->event );
 287     else
 288         wake_up( &dir->obj, 0 );
 289 }
 290
 291 /* SIGIO callback, called synchronously with the poll loop */
 292 void sigio_callback(void)
 293 {
 294     struct dir *dir;
 295
 296     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 297     {
 298         long count = interlocked_xchg( &dir->notified, 0 );
 299         if (count)
 300         {
 301             dir->signaled += count;
 302             if (dir->signaled == count)  /* was it 0? */
 303                 dir_signal_changed( dir );
 304         }
 305     }
 306 }
 307
 308 static struct fd *dir_get_fd( struct object *obj )
 309 {
 310     struct dir *dir = (struct dir *)obj;
 311     assert( obj->ops == &dir_ops );
 312     return (struct fd *)grab_object( dir->fd );
 313 }
 314
 315 static unsigned int dir_map_access( struct object *obj, unsigned int access )
 316 {
 317     if (access & GENERIC_READ)    access |= FILE_GENERIC_READ;
 318     if (access & GENERIC_WRITE)   access |= FILE_GENERIC_WRITE;
 319     if (access & GENERIC_EXECUTE) access |= FILE_GENERIC_EXECUTE;
 320     if (access & GENERIC_ALL)     access |= FILE_ALL_ACCESS;
 321     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 322 }
 323
 324 static void dir_destroy( struct object *obj )
 325 {
 326     struct dir *dir = (struct dir *)obj;
 327     assert (obj->ops == &dir_ops);
 328
 329     if (dir->filter)
 330         remove_change( dir );
 331
 332     if (dir->inotify_fd)
 333         release_object( dir->inotify_fd );
 334
 335     if (dir->event)
 336     {
 337         set_event( dir->event );
 338         release_object( dir->event );
 339     }
 340     release_object( dir->fd );
 341 }
 342
 343 static struct dir *
 344 get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 345 {
 346     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 347 }
 348
 349 static int dir_get_poll_events( struct fd *fd )
 350 {
 351     return 0;
 352 }
 353
 354 static int dir_get_info( struct fd *fd )
 355 {
 356     return 0;
 357 }
 358
 359
 360 #ifdef USE_INOTIFY
 361
 362 static int inotify_get_poll_events( struct fd *fd );
 363 static void inotify_poll_event( struct fd *fd, int event );
 364 static int inotify_get_info( struct fd *fd );
 365
 366 static const struct fd_ops inotify_fd_ops =
 367 {
 368     inotify_get_poll_events,  /* get_poll_events */
 369     inotify_poll_event,       /* poll_event */
 370     no_flush,                 /* flush */
 371     inotify_get_info,         /* get_file_info */
 372     default_fd_queue_async,   /* queue_async */
 373     default_fd_cancel_async,  /* cancel_async */
 374 };
 375
 376 static int inotify_get_poll_events( struct fd *fd )
 377 {
 378     return POLLIN;
 379 }
 380
 381 static void inotify_do_change_notify( struct dir *dir )
 382 {
 383     dir->signaled++;
 384     dir_signal_changed( dir );
 385 }
 386
 387 static void inotify_poll_event( struct fd *fd, int event )
 388 {
 389     int r, ofs, unix_fd;
 390     char buffer[0x1000];
 391     struct inotify_event *ie;
 392     struct dir *dir = get_fd_user( fd );
 393
 394     unix_fd = get_unix_fd( fd );
 395     r = read( unix_fd, buffer, sizeof buffer );
 396     if (r < 0)
 397     {
 398         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 399         return;
 400     }
 401
 402     for( ofs = 0; ofs < r; )
 403     {
 404         ie = (struct inotify_event*) &buffer[ofs];
 405         if (!ie->len)
 406             break;
 407         inotify_do_change_notify( dir );
 408         ofs += (sizeof (*ie) + ie->len - 1);
 409     }
 410 }
 411
 412 static int inotify_get_info( struct fd *fd )
 413 {
 414     return 0;
 415 }
 416
 417 static inline struct fd *create_inotify_fd( struct dir *dir )
 418 {
 419     int unix_fd;
 420
 421     unix_fd = inotify_init();
 422     if (unix_fd<0)
 423         return NULL;
 424     return create_anonymous_fd( &inotify_fd_ops, unix_fd, &dir->obj );
 425 }
 426
 427 static int inotify_adjust_changes( struct dir *dir )
 428 {
 429     unsigned int filter = dir->filter;
 430     unsigned int mask = 0;
 431     char link[32];
 432
 433     if (!dir->inotify_fd)
 434     {
 435         if (!(dir->inotify_fd = create_inotify_fd( dir ))) return 0;
 436     }
 437
 438     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 439         mask |= (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE);
 440     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 441         mask |= (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 442     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 443         mask |= IN_ATTRIB;
 444     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 445         mask |= IN_MODIFY;
 446     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 447         mask |= IN_MODIFY;
 448     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 449         mask |= IN_ACCESS;
 450     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 451         mask |= IN_CREATE;
 452     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 453         mask |= IN_ATTRIB;
 454
 455     sprintf( link, "/proc/self/fd/%u", get_unix_fd( dir->fd ) );
 456     dir->wd = inotify_add_watch( get_unix_fd( dir->inotify_fd ), link, mask );
 457     if (dir->wd != -1)
 458         set_fd_events( dir->inotify_fd, POLLIN );
 459     return 1;
 460 }
 461
 462 #endif  /* USE_INOTIFY */
 463
 464 /* enable change notifications for a directory */
 465 DECL_HANDLER(read_directory_changes)
 466 {
 467     struct event *event = NULL;
 468     struct dir *dir;
 469
 470     if (!req->filter)
 471     {
 472         set_error(STATUS_INVALID_PARAMETER);
 473         return;
 474     }
 475
 476     dir = get_dir_obj( current->process, req->handle, 0 );
 477     if (!dir)
 478         return;
 479
 480     /* possibly send changes through an event flag */
 481     if (req->event)
 482     {
 483         event = get_event_obj( current->process, req->event, EVENT_MODIFY_STATE );
 484         if (!event)
 485             goto end;
 486     }
 487
 488     /* discard the current data, and move onto the next event */
 489     if (dir->event) release_object( dir->event );
 490     dir->event = event;
 491
 492     /* assign it once */
 493     if (!dir->filter)
 494     {
 495         insert_change( dir );
 496         dir->filter = req->filter;
 497     }
 498
 499     /* remove any notifications */
 500     if (dir->signaled>0)
 501         dir->signaled--;
 502
 503     /* setup the real notification */
 504 #ifdef USE_INOTIFY
 505     if (!inotify_adjust_changes( dir ))
 506 #endif
 507         dnotify_adjust_changes( dir );
 508
 509     set_error(STATUS_PENDING);
 510
 511 end:
 512     release_object( dir );
 513 }