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 #else
 126
 127 static inline int inotify_init( void )
 128 {
 129     errno = ENOSYS;
 130     return -1;
 131 }
 132
 133 static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
 134 {
 135     errno = ENOSYS;
 136     return -1;
 137 }
 138
 139 static inline int inotify_remove_watch( int fd, int wd )
 140 {
 141     errno = ENOSYS;
 142     return -1;
 143 }
 144
 145 #endif
 146
 147 struct dir
 148 {
 149     struct object  obj;      /* object header */
 150     struct fd     *fd;       /* file descriptor to the directory */
 151     struct list    entry;    /* entry in global change notifications list */
 152     struct event  *event;
 153     unsigned int   filter;   /* notification filter */
 154     int            notified; /* SIGIO counter */
 155     long           signaled; /* the file changed */
 156     struct fd     *inotify_fd; /* inotify file descriptor */
 157     int            wd;       /* inotify watch descriptor */
 158 };
 159
 160 static struct fd *dir_get_fd( struct object *obj );
 161 static unsigned int dir_map_access( struct object *obj, unsigned int access );
 162 static void dir_dump( struct object *obj, int verbose );
 163 static void dir_destroy( struct object *obj );
 164 static int dir_signaled( struct object *obj, struct thread *thread );
 165
 166 static const struct object_ops dir_ops =
 167 {
 168     sizeof(struct dir),       /* size */
 169     dir_dump,                 /* dump */
 170     add_queue,                /* add_queue */
 171     remove_queue,             /* remove_queue */
 172     dir_signaled,             /* signaled */
 173     no_satisfied,             /* satisfied */
 174     no_signal,                /* signal */
 175     dir_get_fd,               /* get_fd */
 176     dir_map_access,           /* map_access */
 177     no_lookup_name,           /* lookup_name */
 178     no_close_handle,          /* close_handle */
 179     dir_destroy               /* destroy */
 180 };
 181
 182 static int dir_get_poll_events( struct fd *fd );
 183 static int dir_get_info( struct fd *fd );
 184
 185 static const struct fd_ops dir_fd_ops =
 186 {
 187     dir_get_poll_events,      /* get_poll_events */
 188     default_poll_event,       /* poll_event */
 189     no_flush,                 /* flush */
 190     dir_get_info,             /* get_file_info */
 191     default_fd_queue_async,   /* queue_async */
 192     default_fd_cancel_async   /* cancel_async */
 193 };
 194
 195 static struct list change_list = LIST_INIT(change_list);
 196
 197 static void dnotify_adjust_changes( struct dir *dir )
 198 {
 199 #if defined(F_SETSIG) && defined(F_NOTIFY)
 200     int fd = get_unix_fd( dir->fd );
 201     unsigned int filter = dir->filter;
 202     unsigned int val;
 203     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 204         return;
 205
 206     val = DN_MULTISHOT;
 207     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 208         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 209     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 210         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 211     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 212         val |= DN_ATTRIB;
 213     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 214         val |= DN_MODIFY;
 215     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 216         val |= DN_MODIFY;
 217     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 218         val |= DN_ACCESS;
 219     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 220         val |= DN_CREATE;
 221     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 222         val |= DN_ATTRIB;
 223     fcntl( fd, F_NOTIFY, val );
 224 #endif
 225 }
 226
 227 /* insert change in the global list */
 228 static inline void insert_change( struct dir *dir )
 229 {
 230     sigset_t sigset;
 231
 232     sigemptyset( &sigset );
 233     sigaddset( &sigset, SIGIO );
 234     sigprocmask( SIG_BLOCK, &sigset, NULL );
 235     list_add_head( &change_list, &dir->entry );
 236     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 237 }
 238
 239 /* remove change from the global list */
 240 static inline void remove_change( struct dir *dir )
 241 {
 242     sigset_t sigset;
 243
 244     sigemptyset( &sigset );
 245     sigaddset( &sigset, SIGIO );
 246     sigprocmask( SIG_BLOCK, &sigset, NULL );
 247     list_remove( &dir->entry );
 248     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 249 }
 250
 251 struct object *create_dir_obj( struct fd *fd )
 252 {
 253     struct dir *dir;
 254
 255     dir = alloc_object( &dir_ops );
 256     if (!dir)
 257         return NULL;
 258
 259     dir->event = NULL;
 260     dir->filter = 0;
 261     dir->notified = 0;
 262     dir->signaled = 0;
 263     dir->inotify_fd = NULL;
 264     dir->wd = -1;
 265     grab_object( fd );
 266     dir->fd = fd;
 267     set_fd_user( fd, &dir_fd_ops, &dir->obj );
 268
 269     return &dir->obj;
 270 }
 271
 272 static void dir_dump( struct object *obj, int verbose )
 273 {
 274     struct dir *dir = (struct dir *)obj;
 275     assert( obj->ops == &dir_ops );
 276     fprintf( stderr, "Dirfile fd=%p event=%p filter=%08x\n",
 277              dir->fd, dir->event, dir->filter );
 278 }
 279
 280 static int dir_signaled( struct object *obj, struct thread *thread )
 281 {
 282     struct dir *dir = (struct dir *)obj;
 283     assert (obj->ops == &dir_ops);
 284     return (dir->event == NULL) && dir->signaled;
 285 }
 286
 287 /* enter here directly from SIGIO signal handler */
 288 void do_change_notify( int unix_fd )
 289 {
 290     struct dir *dir;
 291
 292     /* FIXME: this is O(n) ... probably can be improved */
 293     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 294     {
 295         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 296         interlocked_xchg_add( &dir->notified, 1 );
 297         break;
 298     }
 299 }
 300
 301 static void dir_signal_changed( struct dir *dir )
 302 {
 303     if (dir->event)
 304         set_event( dir->event );
 305     else
 306         wake_up( &dir->obj, 0 );
 307 }
 308
 309 /* SIGIO callback, called synchronously with the poll loop */
 310 void sigio_callback(void)
 311 {
 312     struct dir *dir;
 313
 314     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 315     {
 316         long count = interlocked_xchg( &dir->notified, 0 );
 317         if (count)
 318         {
 319             dir->signaled += count;
 320             if (dir->signaled == count)  /* was it 0? */
 321                 dir_signal_changed( dir );
 322         }
 323     }
 324 }
 325
 326 static struct fd *dir_get_fd( struct object *obj )
 327 {
 328     struct dir *dir = (struct dir *)obj;
 329     assert( obj->ops == &dir_ops );
 330     return (struct fd *)grab_object( dir->fd );
 331 }
 332
 333 static unsigned int dir_map_access( struct object *obj, unsigned int access )
 334 {
 335     if (access & GENERIC_READ)    access |= FILE_GENERIC_READ;
 336     if (access & GENERIC_WRITE)   access |= FILE_GENERIC_WRITE;
 337     if (access & GENERIC_EXECUTE) access |= FILE_GENERIC_EXECUTE;
 338     if (access & GENERIC_ALL)     access |= FILE_ALL_ACCESS;
 339     return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL);
 340 }
 341
 342 static void dir_destroy( struct object *obj )
 343 {
 344     struct dir *dir = (struct dir *)obj;
 345     assert (obj->ops == &dir_ops);
 346
 347     if (dir->filter)
 348         remove_change( dir );
 349
 350     if (dir->inotify_fd)
 351     {
 352         if (dir->wd != -1)
 353             inotify_remove_watch( get_unix_fd( dir->inotify_fd ), dir->wd );
 354         release_object( dir->inotify_fd );
 355     }
 356
 357     if (dir->event)
 358     {
 359         set_event( dir->event );
 360         release_object( dir->event );
 361     }
 362     release_object( dir->fd );
 363 }
 364
 365 static struct dir *
 366 get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 367 {
 368     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 369 }
 370
 371 static int dir_get_poll_events( struct fd *fd )
 372 {
 373     return 0;
 374 }
 375
 376 static int dir_get_info( struct fd *fd )
 377 {
 378     return 0;
 379 }
 380
 381
 382 static int inotify_get_poll_events( struct fd *fd );
 383 static void inotify_poll_event( struct fd *fd, int event );
 384 static int inotify_get_info( struct fd *fd );
 385
 386 static const struct fd_ops inotify_fd_ops =
 387 {
 388     inotify_get_poll_events,  /* get_poll_events */
 389     inotify_poll_event,       /* poll_event */
 390     no_flush,                 /* flush */
 391     inotify_get_info,         /* get_file_info */
 392     default_fd_queue_async,   /* queue_async */
 393     default_fd_cancel_async,  /* cancel_async */
 394 };
 395
 396 static int inotify_get_poll_events( struct fd *fd )
 397 {
 398     return POLLIN;
 399 }
 400
 401 static void inotify_do_change_notify( struct dir *dir )
 402 {
 403     dir->signaled++;
 404     dir_signal_changed( dir );
 405 }
 406
 407 static void inotify_poll_event( struct fd *fd, int event )
 408 {
 409     int r, ofs, unix_fd;
 410     char buffer[0x1000];
 411     struct inotify_event *ie;
 412     struct dir *dir = get_fd_user( fd );
 413
 414     unix_fd = get_unix_fd( fd );
 415     r = read( unix_fd, buffer, sizeof buffer );
 416     if (r < 0)
 417     {
 418         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 419         return;
 420     }
 421
 422     for( ofs = 0; ofs < r; )
 423     {
 424         ie = (struct inotify_event*) &buffer[ofs];
 425         if (!ie->len)
 426             break;
 427         inotify_do_change_notify( dir );
 428         ofs += (sizeof (*ie) + ie->len - 1);
 429     }
 430 }
 431
 432 static int inotify_get_info( struct fd *fd )
 433 {
 434     return 0;
 435 }
 436
 437 static void inotify_adjust_changes( struct dir *dir )
 438 {
 439     int filter = dir->filter;
 440     unsigned int mask = 0;
 441     char link[32];
 442
 443     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 444         mask |= (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE);
 445     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 446         mask |= (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 447     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 448         mask |= IN_ATTRIB;
 449     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 450         mask |= IN_MODIFY;
 451     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 452         mask |= IN_MODIFY;
 453     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 454         mask |= IN_ACCESS;
 455     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 456         mask |= IN_CREATE;
 457     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 458         mask |= IN_ATTRIB;
 459
 460     sprintf( link, "/proc/self/fd/%u", get_unix_fd( dir->fd ) );
 461     dir->wd = inotify_add_watch( get_unix_fd( dir->inotify_fd ), link, mask );
 462     if (dir->wd != -1)
 463         set_fd_events( dir->inotify_fd, POLLIN );
 464 }
 465
 466 static struct fd *create_inotify_fd( struct dir *dir )
 467 {
 468     int unix_fd;
 469
 470     unix_fd = inotify_init();
 471     if (unix_fd<0)
 472         return NULL;
 473     return create_anonymous_fd( &inotify_fd_ops, unix_fd, &dir->obj );
 474 }
 475
 476 /* enable change notifications for a directory */
 477 DECL_HANDLER(read_directory_changes)
 478 {
 479     struct event *event = NULL;
 480     struct dir *dir;
 481
 482     if (!req->filter)
 483     {
 484         set_error(STATUS_INVALID_PARAMETER);
 485         return;
 486     }
 487
 488     dir = get_dir_obj( current->process, req->handle, 0 );
 489     if (!dir)
 490         return;
 491
 492     /* possibly send changes through an event flag */
 493     if (req->event)
 494     {
 495         event = get_event_obj( current->process, req->event, EVENT_MODIFY_STATE );
 496         if (!event)
 497             goto end;
 498     }
 499
 500     /* discard the current data, and move onto the next event */
 501     if (dir->event) release_object( dir->event );
 502     dir->event = event;
 503
 504     /* assign it once */
 505     if (!dir->filter)
 506     {
 507         insert_change( dir );
 508         dir->filter = req->filter;
 509     }
 510
 511     /* remove any notifications */
 512     if (dir->signaled>0)
 513         dir->signaled--;
 514
 515     if (!dir->inotify_fd)
 516         dir->inotify_fd = create_inotify_fd( dir );
 517
 518     /* setup the real notification */
 519     if (dir->inotify_fd)
 520         inotify_adjust_changes( dir );
 521     else
 522         dnotify_adjust_changes( dir );
 523
 524     set_error(STATUS_PENDING);
 525
 526 end:
 527     release_object( dir );
 528 }