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., 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 #ifdef HAVE_SYS_ERRNO_H
  36 #include <sys/errno.h>
  37 #endif
  38
  39 #include "ntstatus.h"
  40 #define WIN32_NO_STATUS
  41 #include "windef.h"
  42
  43 #include "file.h"
  44 #include "handle.h"
  45 #include "thread.h"
  46 #include "request.h"
  47 #include "process.h"
  48 #include "security.h"
  49 #include "winternl.h"
  50
  51 /* dnotify support */
  52
  53 #ifdef linux
  54 #ifndef F_NOTIFY
  55 #define F_NOTIFY 1026
  56 #define DN_ACCESS       0x00000001      /* File accessed */
  57 #define DN_MODIFY       0x00000002      /* File modified */
  58 #define DN_CREATE       0x00000004      /* File created */
  59 #define DN_DELETE       0x00000008      /* File removed */
  60 #define DN_RENAME       0x00000010      /* File renamed */
  61 #define DN_ATTRIB       0x00000020      /* File changed attributes */
  62 #define DN_MULTISHOT    0x80000000      /* Don't remove notifier */
  63 #endif
  64 #endif
  65
  66 /* inotify support */
  67
  68 #ifdef HAVE_SYS_INOTIFY_H
  69 #include <sys/inotify.h>
  70 #define USE_INOTIFY
  71 #elif defined(__linux__) && defined(__i386__)
  72
  73 #define SYS_inotify_init        291
  74 #define SYS_inotify_add_watch   292
  75 #define SYS_inotify_rm_watch    293
  76
  77 struct inotify_event {
  78     int           wd;
  79     unsigned int  mask;
  80     unsigned int  cookie;
  81     unsigned int  len;
  82     char          name[1];
  83 };
  84
  85 #define IN_ACCESS        0x00000001
  86 #define IN_MODIFY        0x00000002
  87 #define IN_ATTRIB        0x00000004
  88 #define IN_CLOSE_WRITE   0x00000008
  89 #define IN_CLOSE_NOWRITE 0x00000010
  90 #define IN_OPEN          0x00000020
  91 #define IN_MOVED_FROM    0x00000040
  92 #define IN_MOVED_TO      0x00000080
  93 #define IN_CREATE        0x00000100
  94 #define IN_DELETE        0x00000200
  95 #define IN_DELETE_SELF   0x00000400
  96
  97 #define IN_ISDIR         0x40000000
  98
  99 static inline int inotify_init( void )
 100 {
 101     int ret;
 102     __asm__ __volatile__( "int $0x80"
 103                           : "=a" (ret)
 104                           : "0" (SYS_inotify_init));
 105     if (ret<0) { errno = -ret; ret = -1; }
 106     return ret;
 107 }
 108
 109 static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
 110 {
 111     int ret;
 112     __asm__ __volatile__( "pushl %%ebx;\n\t"
 113                           "movl %2,%%ebx;\n\t"
 114                           "int $0x80;\n\t"
 115                           "popl %%ebx"
 116                           : "=a" (ret) : "0" (SYS_inotify_add_watch),
 117                             "r" (fd), "c" (name), "d" (mask) );
 118     if (ret<0) { errno = -ret; ret = -1; }
 119     return ret;
 120 }
 121
 122 static inline int inotify_rm_watch( int fd, int wd )
 123 {
 124     int ret;
 125     __asm__ __volatile__( "pushl %%ebx;\n\t"
 126                           "movl %2,%%ebx;\n\t"
 127                           "int $0x80;\n\t"
 128                           "popl %%ebx"
 129                           : "=a" (ret) : "0" (SYS_inotify_rm_watch),
 130                             "r" (fd), "c" (wd) );
 131     if (ret<0) { errno = -ret; ret = -1; }
 132     return ret;
 133 }
 134
 135 #define USE_INOTIFY
 136
 137 #endif
 138
 139 struct inode;
 140
 141 static void free_inode( struct inode *inode );
 142
 143 static struct fd *inotify_fd;
 144
 145 struct change_record {
 146     struct list entry;
 147     int action;
 148     int len;
 149     char name[1];
 150 };
 151
 152 struct dir
 153 {
 154     struct object  obj;      /* object header */
 155     struct fd     *fd;       /* file descriptor to the directory */
 156     mode_t         mode;     /* file stat.st_mode */
 157     uid_t          uid;      /* file stat.st_uid */
 158     struct list    entry;    /* entry in global change notifications list */
 159     unsigned int   filter;   /* notification filter */
 160     int            notified; /* SIGIO counter */
 161     int            want_data; /* return change data */
 162     int            subtree;  /* do we want to watch subdirectories? */
 163     struct list    change_records;   /* data for the change */
 164     struct list    in_entry; /* entry in the inode dirs list */
 165     struct inode  *inode;    /* inode of the associated directory */
 166 };
 167
 168 static struct fd *dir_get_fd( struct object *obj );
 169 static struct security_descriptor *dir_get_sd( struct object *obj );
 170 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
 171                        unsigned int set_info );
 172 static void dir_dump( struct object *obj, int verbose );
 173 static void dir_destroy( struct object *obj );
 174
 175 static const struct object_ops dir_ops =
 176 {
 177     sizeof(struct dir),       /* size */
 178     dir_dump,                 /* dump */
 179     no_get_type,              /* get_type */
 180     add_queue,                /* add_queue */
 181     remove_queue,             /* remove_queue */
 182     default_fd_signaled,      /* signaled */
 183     no_satisfied,             /* satisfied */
 184     no_signal,                /* signal */
 185     dir_get_fd,               /* get_fd */
 186     default_fd_map_access,    /* map_access */
 187     dir_get_sd,               /* get_sd */
 188     dir_set_sd,               /* set_sd */
 189     no_lookup_name,           /* lookup_name */
 190     no_open_file,             /* open_file */
 191     fd_close_handle,          /* close_handle */
 192     dir_destroy               /* destroy */
 193 };
 194
 195 static int dir_get_poll_events( struct fd *fd );
 196 static enum server_fd_type dir_get_fd_type( struct fd *fd );
 197
 198 static const struct fd_ops dir_fd_ops =
 199 {
 200     dir_get_poll_events,         /* get_poll_events */
 201     default_poll_event,          /* poll_event */
 202     no_flush,                    /* flush */
 203     dir_get_fd_type,             /* get_fd_type */
 204     default_fd_ioctl,            /* ioctl */
 205     default_fd_queue_async,      /* queue_async */
 206     default_fd_reselect_async,   /* reselect_async */
 207     default_fd_cancel_async      /* cancel_async */
 208 };
 209
 210 static struct list change_list = LIST_INIT(change_list);
 211
 212 static void dnotify_adjust_changes( struct dir *dir )
 213 {
 214 #if defined(F_SETSIG) && defined(F_NOTIFY)
 215     int fd = get_unix_fd( dir->fd );
 216     unsigned int filter = dir->filter;
 217     unsigned int val;
 218     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 219         return;
 220
 221     val = DN_MULTISHOT;
 222     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 223         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 224     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 225         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 226     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 227         val |= DN_ATTRIB;
 228     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 229         val |= DN_MODIFY;
 230     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 231         val |= DN_MODIFY;
 232     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 233         val |= DN_ACCESS;
 234     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 235         val |= DN_CREATE;
 236     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 237         val |= DN_ATTRIB;
 238     fcntl( fd, F_NOTIFY, val );
 239 #endif
 240 }
 241
 242 /* insert change in the global list */
 243 static inline void insert_change( struct dir *dir )
 244 {
 245     sigset_t sigset;
 246
 247     sigemptyset( &sigset );
 248     sigaddset( &sigset, SIGIO );
 249     sigprocmask( SIG_BLOCK, &sigset, NULL );
 250     list_add_head( &change_list, &dir->entry );
 251     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 252 }
 253
 254 /* remove change from the global list */
 255 static inline void remove_change( struct dir *dir )
 256 {
 257     sigset_t sigset;
 258
 259     sigemptyset( &sigset );
 260     sigaddset( &sigset, SIGIO );
 261     sigprocmask( SIG_BLOCK, &sigset, NULL );
 262     list_remove( &dir->entry );
 263     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 264 }
 265
 266 static void dir_dump( struct object *obj, int verbose )
 267 {
 268     struct dir *dir = (struct dir *)obj;
 269     assert( obj->ops == &dir_ops );
 270     fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
 271 }
 272
 273 /* enter here directly from SIGIO signal handler */
 274 void do_change_notify( int unix_fd )
 275 {
 276     struct dir *dir;
 277
 278     /* FIXME: this is O(n) ... probably can be improved */
 279     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 280     {
 281         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 282         interlocked_xchg_add( &dir->notified, 1 );
 283         break;
 284     }
 285 }
 286
 287 /* SIGIO callback, called synchronously with the poll loop */
 288 void sigio_callback(void)
 289 {
 290     struct dir *dir;
 291
 292     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 293     {
 294         if (interlocked_xchg( &dir->notified, 0 ))
 295             fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_NOTIFY_ENUM_DIR );
 296     }
 297 }
 298
 299 static struct fd *dir_get_fd( struct object *obj )
 300 {
 301     struct dir *dir = (struct dir *)obj;
 302     assert( obj->ops == &dir_ops );
 303     return (struct fd *)grab_object( dir->fd );
 304 }
 305
 306 static int get_dir_unix_fd( struct dir *dir )
 307 {
 308     return get_unix_fd( dir->fd );
 309 }
 310
 311 static struct security_descriptor *dir_get_sd( struct object *obj )
 312 {
 313     struct dir *dir = (struct dir *)obj;
 314     int unix_fd;
 315     struct stat st;
 316     struct security_descriptor *sd;
 317     assert( obj->ops == &dir_ops );
 318
 319     unix_fd = get_dir_unix_fd( dir );
 320
 321     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
 322         return obj->sd;
 323
 324     /* mode and uid the same? if so, no need to re-generate security descriptor */
 325     if (obj->sd &&
 326         (st.st_mode & (S_IRWXU|S_IRWXO)) == (dir->mode & (S_IRWXU|S_IRWXO)) &&
 327         (st.st_uid == dir->uid))
 328         return obj->sd;
 329
 330     sd = mode_to_sd( st.st_mode,
 331                      security_unix_uid_to_sid( st.st_uid ),
 332                      token_get_primary_group( current->process->token ));
 333     if (!sd) return obj->sd;
 334
 335     dir->mode = st.st_mode;
 336     dir->uid = st.st_uid;
 337     free( obj->sd );
 338     obj->sd = sd;
 339     return sd;
 340 }
 341
 342 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
 343                        unsigned int set_info )
 344 {
 345     struct dir *dir = (struct dir *)obj;
 346     const SID *owner;
 347     struct stat st;
 348     mode_t mode;
 349     int unix_fd;
 350
 351     assert( obj->ops == &dir_ops );
 352
 353     unix_fd = get_dir_unix_fd( dir );
 354
 355     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1) return 1;
 356
 357     if (set_info & OWNER_SECURITY_INFORMATION)
 358     {
 359         owner = sd_get_owner( sd );
 360         if (!owner)
 361         {
 362             set_error( STATUS_INVALID_SECURITY_DESCR );
 363             return 0;
 364         }
 365         if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
 366         {
 367             /* FIXME: get Unix uid and call fchown */
 368         }
 369     }
 370     else if (obj->sd)
 371         owner = sd_get_owner( obj->sd );
 372     else
 373         owner = token_get_user( current->process->token );
 374
 375     if (set_info & DACL_SECURITY_INFORMATION)
 376     {
 377         /* keep the bits that we don't map to access rights in the ACL */
 378         mode = st.st_mode & (S_ISUID|S_ISGID|S_ISVTX);
 379         mode |= sd_to_mode( sd, owner );
 380
 381         if (((st.st_mode ^ mode) & (S_IRWXU|S_IRWXG|S_IRWXO)) && fchmod( unix_fd, mode ) == -1)
 382         {
 383             file_set_error();
 384             return 0;
 385         }
 386     }
 387     return 1;
 388 }
 389
 390 static struct change_record *get_first_change_record( struct dir *dir )
 391 {
 392     struct list *ptr = list_head( &dir->change_records );
 393     if (!ptr) return NULL;
 394     list_remove( ptr );
 395     return LIST_ENTRY( ptr, struct change_record, entry );
 396 }
 397
 398 static void dir_destroy( struct object *obj )
 399 {
 400     struct change_record *record;
 401     struct dir *dir = (struct dir *)obj;
 402     assert (obj->ops == &dir_ops);
 403
 404     if (dir->filter)
 405         remove_change( dir );
 406
 407     if (dir->inode)
 408     {
 409         list_remove( &dir->in_entry );
 410         free_inode( dir->inode );
 411     }
 412
 413     while ((record = get_first_change_record( dir ))) free( record );
 414
 415     release_object( dir->fd );
 416
 417     if (inotify_fd && list_empty( &change_list ))
 418     {
 419         release_object( inotify_fd );
 420         inotify_fd = NULL;
 421     }
 422 }
 423
 424 struct dir *get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 425 {
 426     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 427 }
 428
 429 static int dir_get_poll_events( struct fd *fd )
 430 {
 431     return 0;
 432 }
 433
 434 static enum server_fd_type dir_get_fd_type( struct fd *fd )
 435 {
 436     return FD_TYPE_DIR;
 437 }
 438
 439 #ifdef USE_INOTIFY
 440
 441 #define HASH_SIZE 31
 442
 443 struct inode {
 444     struct list ch_entry;    /* entry in the children list */
 445     struct list children;    /* children of this inode */
 446     struct inode *parent;    /* parent of this inode */
 447     struct list dirs;        /* directory handles watching this inode */
 448     struct list ino_entry;   /* entry in the inode hash */
 449     struct list wd_entry;    /* entry in the watch descriptor hash */
 450     dev_t dev;               /* device number */
 451     ino_t ino;               /* device's inode number */
 452     int wd;                  /* inotify's watch descriptor */
 453     char *name;              /* basename name of the inode */
 454 };
 455
 456 static struct list inode_hash[ HASH_SIZE ];
 457 static struct list wd_hash[ HASH_SIZE ];
 458
 459 static int inotify_add_dir( char *path, unsigned int filter );
 460
 461 static struct inode *inode_from_wd( int wd )
 462 {
 463     struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
 464     struct inode *inode;
 465
 466     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
 467         if (inode->wd == wd)
 468             return inode;
 469
 470     return NULL;
 471 }
 472
 473 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
 474 {
 475     return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
 476 }
 477
 478 static struct inode *find_inode( dev_t dev, ino_t ino )
 479 {
 480     struct list *bucket = get_hash_list( dev, ino );
 481     struct inode *inode;
 482
 483     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
 484         if (inode->ino == ino && inode->dev == dev)
 485              return inode;
 486
 487     return NULL;
 488 }
 489
 490 static struct inode *create_inode( dev_t dev, ino_t ino )
 491 {
 492     struct inode *inode;
 493
 494     inode = malloc( sizeof *inode );
 495     if (inode)
 496     {
 497         list_init( &inode->children );
 498         list_init( &inode->dirs );
 499         inode->ino = ino;
 500         inode->dev = dev;
 501         inode->wd = -1;
 502         inode->parent = NULL;
 503         inode->name = NULL;
 504         list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
 505     }
 506     return inode;
 507 }
 508
 509 static struct inode *get_inode( dev_t dev, ino_t ino )
 510 {
 511     struct inode *inode;
 512
 513     inode = find_inode( dev, ino );
 514     if (inode)
 515         return inode;
 516     return create_inode( dev, ino );
 517 }
 518
 519 static void inode_set_wd( struct inode *inode, int wd )
 520 {
 521     if (inode->wd != -1)
 522         list_remove( &inode->wd_entry );
 523     inode->wd = wd;
 524     list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
 525 }
 526
 527 static void inode_set_name( struct inode *inode, const char *name )
 528 {
 529     free (inode->name);
 530     inode->name = name ? strdup( name ) : NULL;
 531 }
 532
 533 static void free_inode( struct inode *inode )
 534 {
 535     int subtree = 0, watches = 0;
 536     struct inode *tmp, *next;
 537     struct dir *dir;
 538
 539     LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 540     {
 541         subtree |= dir->subtree;
 542         watches++;
 543     }
 544
 545     if (!subtree && !inode->parent)
 546     {
 547         LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
 548                                   struct inode, ch_entry )
 549         {
 550             assert( tmp != inode );
 551             assert( tmp->parent == inode );
 552             free_inode( tmp );
 553         }
 554     }
 555
 556     if (watches)
 557         return;
 558
 559     if (inode->parent)
 560         list_remove( &inode->ch_entry );
 561
 562     /* disconnect remaining children from the parent */
 563     LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children, struct inode, ch_entry )
 564     {
 565         list_remove( &tmp->ch_entry );
 566         tmp->parent = NULL;
 567     }
 568
 569     if (inode->wd != -1)
 570     {
 571         inotify_rm_watch( get_unix_fd( inotify_fd ), inode->wd );
 572         list_remove( &inode->wd_entry );
 573     }
 574     list_remove( &inode->ino_entry );
 575
 576     free( inode->name );
 577     free( inode );
 578 }
 579
 580 static struct inode *inode_add( struct inode *parent,
 581                                 dev_t dev, ino_t ino, const char *name )
 582 {
 583     struct inode *inode;
 584
 585     inode = get_inode( dev, ino );
 586     if (!inode)
 587         return NULL;
 588
 589     if (!inode->parent)
 590     {
 591         list_add_tail( &parent->children, &inode->ch_entry );
 592         inode->parent = parent;
 593         assert( inode != parent );
 594     }
 595     inode_set_name( inode, name );
 596
 597     return inode;
 598 }
 599
 600 static struct inode *inode_from_name( struct inode *inode, const char *name )
 601 {
 602     struct inode *i;
 603
 604     LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
 605         if (i->name && !strcmp( i->name, name ))
 606             return i;
 607     return NULL;
 608 }
 609
 610 static int inotify_get_poll_events( struct fd *fd );
 611 static void inotify_poll_event( struct fd *fd, int event );
 612
 613 static const struct fd_ops inotify_fd_ops =
 614 {
 615     inotify_get_poll_events,     /* get_poll_events */
 616     inotify_poll_event,          /* poll_event */
 617     NULL,                        /* flush */
 618     NULL,                        /* get_fd_type */
 619     NULL,                        /* ioctl */
 620     NULL,                        /* queue_async */
 621     NULL,                        /* reselect_async */
 622     NULL,                        /* cancel_async */
 623 };
 624
 625 static int inotify_get_poll_events( struct fd *fd )
 626 {
 627     return POLLIN;
 628 }
 629
 630 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
 631                                       const char *relpath )
 632 {
 633     struct change_record *record;
 634
 635     assert( dir->obj.ops == &dir_ops );
 636
 637     if (dir->want_data)
 638     {
 639         size_t len = strlen(relpath);
 640         record = malloc( offsetof(struct change_record, name[len]) );
 641         if (!record)
 642             return;
 643
 644         record->action = action;
 645         memcpy( record->name, relpath, len );
 646         record->len = len;
 647
 648         list_add_tail( &dir->change_records, &record->entry );
 649     }
 650
 651     fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 652 }
 653
 654 static unsigned int filter_from_event( struct inotify_event *ie )
 655 {
 656     unsigned int filter = 0;
 657
 658     if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
 659         filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
 660     if (ie->mask & IN_MODIFY)
 661         filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
 662     if (ie->mask & IN_ATTRIB)
 663         filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
 664     if (ie->mask & IN_ACCESS)
 665         filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
 666     if (ie->mask & IN_CREATE)
 667         filter |= FILE_NOTIFY_CHANGE_CREATION;
 668
 669     if (ie->mask & IN_ISDIR)
 670         filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
 671     else
 672         filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
 673
 674     return filter;
 675 }
 676
 677 /* scan up the parent directories for watches */
 678 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
 679 {
 680     unsigned int filter = 0;
 681     struct dir *dir;
 682
 683     /* combine filters from parents watching subtrees */
 684     while (inode)
 685     {
 686         LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 687             if (dir->subtree || !is_parent)
 688                 filter |= dir->filter;
 689         is_parent = 1;
 690         inode = inode->parent;
 691     }
 692
 693     return filter;
 694 }
 695
 696 static char *inode_get_path( struct inode *inode, int sz )
 697 {
 698     struct list *head;
 699     char *path;
 700     int len;
 701
 702     if (!inode)
 703         return NULL;
 704
 705     head = list_head( &inode->dirs );
 706     if (head)
 707     {
 708         int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
 709         path = malloc ( 32 + sz );
 710         if (path)
 711             sprintf( path, "/proc/self/fd/%u/", unix_fd );
 712         return path;
 713     }
 714
 715     if (!inode->name)
 716         return NULL;
 717
 718     len = strlen( inode->name );
 719     path = inode_get_path( inode->parent, sz + len + 1 );
 720     if (!path)
 721         return NULL;
 722
 723     strcat( path, inode->name );
 724     strcat( path, "/" );
 725
 726     return path;
 727 }
 728
 729 static void inode_check_dir( struct inode *parent, const char *name )
 730 {
 731     char *path;
 732     unsigned int filter;
 733     struct inode *inode;
 734     struct stat st;
 735     int wd = -1;
 736
 737     path = inode_get_path( parent, strlen(name) );
 738     if (!path)
 739         return;
 740
 741     strcat( path, name );
 742
 743     if (stat( path, &st ) < 0)
 744         goto end;
 745
 746     filter = filter_from_inode( parent, 1 );
 747     if (!filter)
 748         goto end;
 749
 750     inode = inode_add( parent, st.st_dev, st.st_ino, name );
 751     if (!inode || inode->wd != -1)
 752         goto end;
 753
 754     wd = inotify_add_dir( path, filter );
 755     if (wd != -1)
 756         inode_set_wd( inode, wd );
 757     else
 758         free_inode( inode );
 759
 760 end:
 761     free( path );
 762 }
 763
 764 static int prepend( char **path, const char *segment )
 765 {
 766     int extra;
 767     char *p;
 768
 769     extra = strlen( segment ) + 1;
 770     if (*path)
 771     {
 772         int len = strlen( *path ) + 1;
 773         p = realloc( *path, len + extra );
 774         if (!p) return 0;
 775         memmove( &p[ extra ], p, len );
 776         p[ extra - 1 ] = '/';
 777         memcpy( p, segment, extra - 1 );
 778     }
 779     else
 780     {
 781         p = malloc( extra );
 782         if (!p) return 0;
 783         memcpy( p, segment, extra );
 784     }
 785
 786     *path = p;
 787
 788     return 1;
 789 }
 790
 791 static void inotify_notify_all( struct inotify_event *ie )
 792 {
 793     unsigned int filter, action;
 794     struct inode *inode, *i;
 795     char *path = NULL;
 796     struct dir *dir;
 797
 798     inode = inode_from_wd( ie->wd );
 799     if (!inode)
 800     {
 801         fprintf( stderr, "no inode matches %d\n", ie->wd);
 802         return;
 803     }
 804
 805     filter = filter_from_event( ie );
 806
 807     if (ie->mask & IN_CREATE)
 808     {
 809         if (ie->mask & IN_ISDIR)
 810             inode_check_dir( inode, ie->name );
 811
 812         action = FILE_ACTION_ADDED;
 813     }
 814     else if (ie->mask & IN_DELETE)
 815         action = FILE_ACTION_REMOVED;
 816     else if (ie->mask & IN_MOVED_FROM)
 817         action = FILE_ACTION_RENAMED_OLD_NAME;
 818     else if (ie->mask & IN_MOVED_TO)
 819         action = FILE_ACTION_RENAMED_NEW_NAME;
 820     else
 821         action = FILE_ACTION_MODIFIED;
 822
 823     /*
 824      * Work our way up the inode hierarchy
 825      *  extending the relative path as we go
 826      *  and notifying all recursive watches.
 827      */
 828     if (!prepend( &path, ie->name ))
 829         return;
 830
 831     for (i = inode; i; i = i->parent)
 832     {
 833         LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
 834             if ((filter & dir->filter) && (i==inode || dir->subtree))
 835                 inotify_do_change_notify( dir, action, path );
 836
 837         if (!i->name || !prepend( &path, i->name ))
 838             break;
 839     }
 840
 841     free( path );
 842
 843     if (ie->mask & IN_DELETE)
 844     {
 845         i = inode_from_name( inode, ie->name );
 846         if (i)
 847             free_inode( i );
 848     }
 849 }
 850
 851 static void inotify_poll_event( struct fd *fd, int event )
 852 {
 853     int r, ofs, unix_fd;
 854     char buffer[0x1000];
 855     struct inotify_event *ie;
 856
 857     unix_fd = get_unix_fd( fd );
 858     r = read( unix_fd, buffer, sizeof buffer );
 859     if (r < 0)
 860     {
 861         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 862         return;
 863     }
 864
 865     for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
 866     {
 867         ie = (struct inotify_event*) &buffer[ofs];
 868         if (!ie->len)
 869             break;
 870         ofs += offsetof( struct inotify_event, name[ie->len] );
 871         if (ofs > r) break;
 872         inotify_notify_all( ie );
 873     }
 874 }
 875
 876 static inline struct fd *create_inotify_fd( void )
 877 {
 878     int unix_fd;
 879
 880     unix_fd = inotify_init();
 881     if (unix_fd<0)
 882         return NULL;
 883     return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
 884 }
 885
 886 static int map_flags( unsigned int filter )
 887 {
 888     unsigned int mask;
 889
 890     /* always watch these so we can track subdirectories in recursive watches */
 891     mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 892
 893     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 894         mask |= IN_ATTRIB;
 895     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 896         mask |= IN_MODIFY;
 897     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 898         mask |= IN_MODIFY;
 899     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 900         mask |= IN_ACCESS;
 901     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 902         mask |= IN_ATTRIB;
 903
 904     return mask;
 905 }
 906
 907 static int inotify_add_dir( char *path, unsigned int filter )
 908 {
 909     int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
 910                                 path, map_flags( filter ) );
 911     if (wd != -1)
 912         set_fd_events( inotify_fd, POLLIN );
 913     return wd;
 914 }
 915
 916 static int init_inotify( void )
 917 {
 918     int i;
 919
 920     if (inotify_fd)
 921         return 1;
 922
 923     inotify_fd = create_inotify_fd();
 924     if (!inotify_fd)
 925         return 0;
 926
 927     for (i=0; i<HASH_SIZE; i++)
 928     {
 929         list_init( &inode_hash[i] );
 930         list_init( &wd_hash[i] );
 931     }
 932
 933     return 1;
 934 }
 935
 936 static int inotify_adjust_changes( struct dir *dir )
 937 {
 938     unsigned int filter;
 939     struct inode *inode;
 940     struct stat st;
 941     char path[32];
 942     int wd, unix_fd;
 943
 944     if (!inotify_fd)
 945         return 0;
 946
 947     unix_fd = get_unix_fd( dir->fd );
 948
 949     inode = dir->inode;
 950     if (!inode)
 951     {
 952         /* check if this fd is already being watched */
 953         if (-1 == fstat( unix_fd, &st ))
 954             return 0;
 955
 956         inode = get_inode( st.st_dev, st.st_ino );
 957         if (!inode)
 958             inode = create_inode( st.st_dev, st.st_ino );
 959         if (!inode)
 960             return 0;
 961         list_add_tail( &inode->dirs, &dir->in_entry );
 962         dir->inode = inode;
 963     }
 964
 965     filter = filter_from_inode( inode, 0 );
 966
 967     sprintf( path, "/proc/self/fd/%u", unix_fd );
 968     wd = inotify_add_dir( path, filter );
 969     if (wd == -1) return 0;
 970
 971     inode_set_wd( inode, wd );
 972
 973     return 1;
 974 }
 975
 976 static char *get_basename( const char *link )
 977 {
 978     char *buffer, *name = NULL;
 979     int r, n = 0x100;
 980
 981     while (1)
 982     {
 983         buffer = malloc( n );
 984         if (!buffer) return NULL;
 985
 986         r = readlink( link, buffer, n );
 987         if (r < 0)
 988             break;
 989
 990         if (r < n)
 991         {
 992             name = buffer;
 993             break;
 994         }
 995         free( buffer );
 996         n *= 2;
 997     }
 998
 999     if (name)
1000     {
1001         while (r > 0 && name[ r - 1 ] == '/' )
1002             r--;
1003         name[ r ] = 0;
1004
1005         name = strrchr( name, '/' );
1006         if (name)
1007             name = strdup( &name[1] );
1008     }
1009
1010     free( buffer );
1011     return name;
1012 }
1013
1014 static int dir_add_to_existing_notify( struct dir *dir )
1015 {
1016     struct inode *inode, *parent;
1017     unsigned int filter = 0;
1018     struct stat st, st_new;
1019     char link[35], *name;
1020     int wd, unix_fd;
1021
1022     if (!inotify_fd)
1023         return 0;
1024
1025     unix_fd = get_unix_fd( dir->fd );
1026
1027     /* check if it's in the list of inodes we want to watch */
1028     if (-1 == fstat( unix_fd, &st_new ))
1029         return 0;
1030     inode = find_inode( st_new.st_dev, st_new.st_ino );
1031     if (inode)
1032         return 0;
1033
1034     /* lookup the parent */
1035     sprintf( link, "/proc/self/fd/%u/..", unix_fd );
1036     if (-1 == stat( link, &st ))
1037         return 0;
1038
1039     /*
1040      * If there's no parent, stop.  We could keep going adding
1041      *  ../ to the path until we hit the root of the tree or
1042      *  find a recursively watched ancestor.
1043      * Assume it's too expensive to search up the tree for now.
1044      */
1045     parent = find_inode( st.st_dev, st.st_ino );
1046     if (!parent)
1047         return 0;
1048
1049     if (parent->wd == -1)
1050         return 0;
1051
1052     filter = filter_from_inode( parent, 1 );
1053     if (!filter)
1054         return 0;
1055
1056     sprintf( link, "/proc/self/fd/%u", unix_fd );
1057     name = get_basename( link );
1058     if (!name)
1059         return 0;
1060     inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
1061     free( name );
1062     if (!inode)
1063         return 0;
1064
1065     /* Couldn't find this inode at the start of the function, must be new */
1066     assert( inode->wd == -1 );
1067
1068     wd = inotify_add_dir( link, filter );
1069     if (wd != -1)
1070         inode_set_wd( inode, wd );
1071
1072     return 1;
1073 }
1074
1075 #else
1076
1077 static int init_inotify( void )
1078 {
1079     return 0;
1080 }
1081
1082 static int inotify_adjust_changes( struct dir *dir )
1083 {
1084     return 0;
1085 }
1086
1087 static void free_inode( struct inode *inode )
1088 {
1089     assert( 0 );
1090 }
1091
1092 static int dir_add_to_existing_notify( struct dir *dir )
1093 {
1094     return 0;
1095 }
1096
1097 #endif  /* USE_INOTIFY */
1098
1099 struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
1100 {
1101     struct dir *dir;
1102
1103     dir = alloc_object( &dir_ops );
1104     if (!dir)
1105         return NULL;
1106
1107     list_init( &dir->change_records );
1108     dir->filter = 0;
1109     dir->notified = 0;
1110     dir->want_data = 0;
1111     dir->inode = NULL;
1112     grab_object( fd );
1113     dir->fd = fd;
1114     dir->mode = mode;
1115     dir->uid  = ~(uid_t)0;
1116     set_fd_user( fd, &dir_fd_ops, &dir->obj );
1117
1118     dir_add_to_existing_notify( dir );
1119
1120     return &dir->obj;
1121 }
1122
1123 /* enable change notifications for a directory */
1124 DECL_HANDLER(read_directory_changes)
1125 {
1126     struct dir *dir;
1127     struct async *async;
1128
1129     if (!req->filter)
1130     {
1131         set_error(STATUS_INVALID_PARAMETER);
1132         return;
1133     }
1134
1135     dir = get_dir_obj( current->process, req->async.handle, 0 );
1136     if (!dir)
1137         return;
1138
1139     /* requests don't timeout */
1140     if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT ))) goto end;
1141
1142     /* assign it once */
1143     if (!dir->filter)
1144     {
1145         init_inotify();
1146         insert_change( dir );
1147         dir->filter = req->filter;
1148         dir->subtree = req->subtree;
1149         dir->want_data = req->want_data;
1150     }
1151
1152     /* if there's already a change in the queue, send it */
1153     if (!list_empty( &dir->change_records ))
1154         fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1155
1156     /* setup the real notification */
1157     if (!inotify_adjust_changes( dir ))
1158         dnotify_adjust_changes( dir );
1159
1160     release_object( async );
1161     set_error(STATUS_PENDING);
1162
1163 end:
1164     release_object( dir );
1165 }
1166
1167 DECL_HANDLER(read_change)
1168 {
1169     struct change_record *record;
1170     struct dir *dir;
1171
1172     dir = get_dir_obj( current->process, req->handle, 0 );
1173     if (!dir)
1174         return;
1175
1176     if ((record = get_first_change_record( dir )) != NULL)
1177     {
1178         reply->action = record->action;
1179         set_reply_data( record->name, record->len );
1180         free( record );
1181     }
1182     else
1183         set_error( STATUS_NO_DATA_DETECTED );
1184
1185     release_object( dir );
1186 }