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_POLL_H
  36 # include <poll.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     return syscall( SYS_inotify_init );
 102 }
 103
 104 static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
 105 {
 106     return syscall( SYS_inotify_add_watch, fd, name, mask );
 107 }
 108
 109 static inline int inotify_rm_watch( int fd, int wd )
 110 {
 111     return syscall( SYS_inotify_rm_watch, fd, wd );
 112 }
 113
 114 #define USE_INOTIFY
 115
 116 #endif
 117
 118 struct inode;
 119
 120 static void free_inode( struct inode *inode );
 121
 122 static struct fd *inotify_fd;
 123
 124 struct change_record {
 125     struct list entry;
 126     unsigned int cookie;
 127     struct filesystem_event event;
 128 };
 129
 130 struct dir
 131 {
 132     struct object  obj;      /* object header */
 133     struct fd     *fd;       /* file descriptor to the directory */
 134     mode_t         mode;     /* file stat.st_mode */
 135     uid_t          uid;      /* file stat.st_uid */
 136     struct list    entry;    /* entry in global change notifications list */
 137     unsigned int   filter;   /* notification filter */
 138     int            notified; /* SIGIO counter */
 139     int            want_data; /* return change data */
 140     int            subtree;  /* do we want to watch subdirectories? */
 141     struct list    change_records;   /* data for the change */
 142     struct list    in_entry; /* entry in the inode dirs list */
 143     struct inode  *inode;    /* inode of the associated directory */
 144 };
 145
 146 static struct fd *dir_get_fd( struct object *obj );
 147 static struct security_descriptor *dir_get_sd( struct object *obj );
 148 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
 149                        unsigned int set_info );
 150 static void dir_dump( struct object *obj, int verbose );
 151 static struct object_type *dir_get_type( struct object *obj );
 152 static void dir_destroy( struct object *obj );
 153
 154 static const struct object_ops dir_ops =
 155 {
 156     sizeof(struct dir),       /* size */
 157     dir_dump,                 /* dump */
 158     dir_get_type,             /* get_type */
 159     add_queue,                /* add_queue */
 160     remove_queue,             /* remove_queue */
 161     default_fd_signaled,      /* signaled */
 162     no_satisfied,             /* satisfied */
 163     no_signal,                /* signal */
 164     dir_get_fd,               /* get_fd */
 165     default_fd_map_access,    /* map_access */
 166     dir_get_sd,               /* get_sd */
 167     dir_set_sd,               /* set_sd */
 168     no_lookup_name,           /* lookup_name */
 169     no_open_file,             /* open_file */
 170     fd_close_handle,          /* close_handle */
 171     dir_destroy               /* destroy */
 172 };
 173
 174 static int dir_get_poll_events( struct fd *fd );
 175 static enum server_fd_type dir_get_fd_type( struct fd *fd );
 176
 177 static const struct fd_ops dir_fd_ops =
 178 {
 179     dir_get_poll_events,         /* get_poll_events */
 180     default_poll_event,          /* poll_event */
 181     dir_get_fd_type,             /* get_fd_type */
 182     no_fd_read,                  /* read */
 183     no_fd_write,                 /* write */
 184     no_fd_flush,                 /* flush */
 185     default_fd_ioctl,            /* ioctl */
 186     default_fd_queue_async,      /* queue_async */
 187     default_fd_reselect_async,   /* reselect_async */
 188     default_fd_cancel_async      /* cancel_async */
 189 };
 190
 191 static struct list change_list = LIST_INIT(change_list);
 192
 193 static void dnotify_adjust_changes( struct dir *dir )
 194 {
 195 #if defined(F_SETSIG) && defined(F_NOTIFY)
 196     int fd = get_unix_fd( dir->fd );
 197     unsigned int filter = dir->filter;
 198     unsigned int val;
 199     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 200         return;
 201
 202     val = DN_MULTISHOT;
 203     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 204         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 205     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 206         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 207     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 208         val |= DN_ATTRIB;
 209     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 210         val |= DN_MODIFY;
 211     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 212         val |= DN_MODIFY;
 213     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 214         val |= DN_ACCESS;
 215     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 216         val |= DN_CREATE;
 217     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 218         val |= DN_ATTRIB;
 219     fcntl( fd, F_NOTIFY, val );
 220 #endif
 221 }
 222
 223 /* insert change in the global list */
 224 static inline void insert_change( struct dir *dir )
 225 {
 226     sigset_t sigset;
 227
 228     sigemptyset( &sigset );
 229     sigaddset( &sigset, SIGIO );
 230     sigprocmask( SIG_BLOCK, &sigset, NULL );
 231     list_add_head( &change_list, &dir->entry );
 232     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 233 }
 234
 235 /* remove change from the global list */
 236 static inline void remove_change( struct dir *dir )
 237 {
 238     sigset_t sigset;
 239
 240     sigemptyset( &sigset );
 241     sigaddset( &sigset, SIGIO );
 242     sigprocmask( SIG_BLOCK, &sigset, NULL );
 243     list_remove( &dir->entry );
 244     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 245 }
 246
 247 static void dir_dump( struct object *obj, int verbose )
 248 {
 249     struct dir *dir = (struct dir *)obj;
 250     assert( obj->ops == &dir_ops );
 251     fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
 252 }
 253
 254 static struct object_type *dir_get_type( struct object *obj )
 255 {
 256     static const WCHAR name[] = {'F','i','l','e'};
 257     static const struct unicode_str str = { name, sizeof(name) };
 258     return get_object_type( &str );
 259 }
 260
 261 /* enter here directly from SIGIO signal handler */
 262 void do_change_notify( int unix_fd )
 263 {
 264     struct dir *dir;
 265
 266     /* FIXME: this is O(n) ... probably can be improved */
 267     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 268     {
 269         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 270         interlocked_xchg_add( &dir->notified, 1 );
 271         break;
 272     }
 273 }
 274
 275 /* SIGIO callback, called synchronously with the poll loop */
 276 void sigio_callback(void)
 277 {
 278     struct dir *dir;
 279
 280     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 281     {
 282         if (interlocked_xchg( &dir->notified, 0 ))
 283             fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 284     }
 285 }
 286
 287 static struct fd *dir_get_fd( struct object *obj )
 288 {
 289     struct dir *dir = (struct dir *)obj;
 290     assert( obj->ops == &dir_ops );
 291     return (struct fd *)grab_object( dir->fd );
 292 }
 293
 294 static int get_dir_unix_fd( struct dir *dir )
 295 {
 296     return get_unix_fd( dir->fd );
 297 }
 298
 299 static struct security_descriptor *dir_get_sd( struct object *obj )
 300 {
 301     struct dir *dir = (struct dir *)obj;
 302     int unix_fd;
 303     struct stat st;
 304     struct security_descriptor *sd;
 305     assert( obj->ops == &dir_ops );
 306
 307     unix_fd = get_dir_unix_fd( dir );
 308
 309     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
 310         return obj->sd;
 311
 312     /* mode and uid the same? if so, no need to re-generate security descriptor */
 313     if (obj->sd &&
 314         (st.st_mode & (S_IRWXU|S_IRWXO)) == (dir->mode & (S_IRWXU|S_IRWXO)) &&
 315         (st.st_uid == dir->uid))
 316         return obj->sd;
 317
 318     sd = mode_to_sd( st.st_mode,
 319                      security_unix_uid_to_sid( st.st_uid ),
 320                      token_get_primary_group( current->process->token ));
 321     if (!sd) return obj->sd;
 322
 323     dir->mode = st.st_mode;
 324     dir->uid = st.st_uid;
 325     free( obj->sd );
 326     obj->sd = sd;
 327     return sd;
 328 }
 329
 330 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
 331                        unsigned int set_info )
 332 {
 333     struct dir *dir = (struct dir *)obj;
 334     const SID *owner;
 335     struct stat st;
 336     mode_t mode;
 337     int unix_fd;
 338
 339     assert( obj->ops == &dir_ops );
 340
 341     unix_fd = get_dir_unix_fd( dir );
 342
 343     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1) return 1;
 344
 345     if (set_info & OWNER_SECURITY_INFORMATION)
 346     {
 347         owner = sd_get_owner( sd );
 348         if (!owner)
 349         {
 350             set_error( STATUS_INVALID_SECURITY_DESCR );
 351             return 0;
 352         }
 353         if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
 354         {
 355             /* FIXME: get Unix uid and call fchown */
 356         }
 357     }
 358     else if (obj->sd)
 359         owner = sd_get_owner( obj->sd );
 360     else
 361         owner = token_get_user( current->process->token );
 362
 363     if (set_info & DACL_SECURITY_INFORMATION)
 364     {
 365         /* keep the bits that we don't map to access rights in the ACL */
 366         mode = st.st_mode & (S_ISUID|S_ISGID|S_ISVTX);
 367         mode |= sd_to_mode( sd, owner );
 368
 369         if (((st.st_mode ^ mode) & (S_IRWXU|S_IRWXG|S_IRWXO)) && fchmod( unix_fd, mode ) == -1)
 370         {
 371             file_set_error();
 372             return 0;
 373         }
 374     }
 375     return 1;
 376 }
 377
 378 static struct change_record *get_first_change_record( struct dir *dir )
 379 {
 380     struct list *ptr = list_head( &dir->change_records );
 381     if (!ptr) return NULL;
 382     list_remove( ptr );
 383     return LIST_ENTRY( ptr, struct change_record, entry );
 384 }
 385
 386 static void dir_destroy( struct object *obj )
 387 {
 388     struct change_record *record;
 389     struct dir *dir = (struct dir *)obj;
 390     assert (obj->ops == &dir_ops);
 391
 392     if (dir->filter)
 393         remove_change( dir );
 394
 395     if (dir->inode)
 396     {
 397         list_remove( &dir->in_entry );
 398         free_inode( dir->inode );
 399     }
 400
 401     while ((record = get_first_change_record( dir ))) free( record );
 402
 403     release_object( dir->fd );
 404
 405     if (inotify_fd && list_empty( &change_list ))
 406     {
 407         release_object( inotify_fd );
 408         inotify_fd = NULL;
 409     }
 410 }
 411
 412 struct dir *get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 413 {
 414     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 415 }
 416
 417 static int dir_get_poll_events( struct fd *fd )
 418 {
 419     return 0;
 420 }
 421
 422 static enum server_fd_type dir_get_fd_type( struct fd *fd )
 423 {
 424     return FD_TYPE_DIR;
 425 }
 426
 427 #ifdef USE_INOTIFY
 428
 429 #define HASH_SIZE 31
 430
 431 struct inode {
 432     struct list ch_entry;    /* entry in the children list */
 433     struct list children;    /* children of this inode */
 434     struct inode *parent;    /* parent of this inode */
 435     struct list dirs;        /* directory handles watching this inode */
 436     struct list ino_entry;   /* entry in the inode hash */
 437     struct list wd_entry;    /* entry in the watch descriptor hash */
 438     dev_t dev;               /* device number */
 439     ino_t ino;               /* device's inode number */
 440     int wd;                  /* inotify's watch descriptor */
 441     char *name;              /* basename name of the inode */
 442 };
 443
 444 static struct list inode_hash[ HASH_SIZE ];
 445 static struct list wd_hash[ HASH_SIZE ];
 446
 447 static int inotify_add_dir( char *path, unsigned int filter );
 448
 449 static struct inode *inode_from_wd( int wd )
 450 {
 451     struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
 452     struct inode *inode;
 453
 454     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
 455         if (inode->wd == wd)
 456             return inode;
 457
 458     return NULL;
 459 }
 460
 461 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
 462 {
 463     return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
 464 }
 465
 466 static struct inode *find_inode( dev_t dev, ino_t ino )
 467 {
 468     struct list *bucket = get_hash_list( dev, ino );
 469     struct inode *inode;
 470
 471     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
 472         if (inode->ino == ino && inode->dev == dev)
 473              return inode;
 474
 475     return NULL;
 476 }
 477
 478 static struct inode *create_inode( dev_t dev, ino_t ino )
 479 {
 480     struct inode *inode;
 481
 482     inode = malloc( sizeof *inode );
 483     if (inode)
 484     {
 485         list_init( &inode->children );
 486         list_init( &inode->dirs );
 487         inode->ino = ino;
 488         inode->dev = dev;
 489         inode->wd = -1;
 490         inode->parent = NULL;
 491         inode->name = NULL;
 492         list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
 493     }
 494     return inode;
 495 }
 496
 497 static struct inode *get_inode( dev_t dev, ino_t ino )
 498 {
 499     struct inode *inode;
 500
 501     inode = find_inode( dev, ino );
 502     if (inode)
 503         return inode;
 504     return create_inode( dev, ino );
 505 }
 506
 507 static void inode_set_wd( struct inode *inode, int wd )
 508 {
 509     if (inode->wd != -1)
 510         list_remove( &inode->wd_entry );
 511     inode->wd = wd;
 512     list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
 513 }
 514
 515 static void inode_set_name( struct inode *inode, const char *name )
 516 {
 517     free (inode->name);
 518     inode->name = name ? strdup( name ) : NULL;
 519 }
 520
 521 static void free_inode( struct inode *inode )
 522 {
 523     int subtree = 0, watches = 0;
 524     struct inode *tmp, *next;
 525     struct dir *dir;
 526
 527     LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 528     {
 529         subtree |= dir->subtree;
 530         watches++;
 531     }
 532
 533     if (!subtree && !inode->parent)
 534     {
 535         LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
 536                                   struct inode, ch_entry )
 537         {
 538             assert( tmp != inode );
 539             assert( tmp->parent == inode );
 540             free_inode( tmp );
 541         }
 542     }
 543
 544     if (watches)
 545         return;
 546
 547     if (inode->parent)
 548         list_remove( &inode->ch_entry );
 549
 550     /* disconnect remaining children from the parent */
 551     LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children, struct inode, ch_entry )
 552     {
 553         list_remove( &tmp->ch_entry );
 554         tmp->parent = NULL;
 555     }
 556
 557     if (inode->wd != -1)
 558     {
 559         inotify_rm_watch( get_unix_fd( inotify_fd ), inode->wd );
 560         list_remove( &inode->wd_entry );
 561     }
 562     list_remove( &inode->ino_entry );
 563
 564     free( inode->name );
 565     free( inode );
 566 }
 567
 568 static struct inode *inode_add( struct inode *parent,
 569                                 dev_t dev, ino_t ino, const char *name )
 570 {
 571     struct inode *inode;
 572
 573     inode = get_inode( dev, ino );
 574     if (!inode)
 575         return NULL;
 576
 577     if (!inode->parent)
 578     {
 579         list_add_tail( &parent->children, &inode->ch_entry );
 580         inode->parent = parent;
 581         assert( inode != parent );
 582     }
 583     inode_set_name( inode, name );
 584
 585     return inode;
 586 }
 587
 588 static struct inode *inode_from_name( struct inode *inode, const char *name )
 589 {
 590     struct inode *i;
 591
 592     LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
 593         if (i->name && !strcmp( i->name, name ))
 594             return i;
 595     return NULL;
 596 }
 597
 598 static int inotify_get_poll_events( struct fd *fd );
 599 static void inotify_poll_event( struct fd *fd, int event );
 600
 601 static const struct fd_ops inotify_fd_ops =
 602 {
 603     inotify_get_poll_events,     /* get_poll_events */
 604     inotify_poll_event,          /* poll_event */
 605     NULL,                        /* flush */
 606     NULL,                        /* get_fd_type */
 607     NULL,                        /* ioctl */
 608     NULL,                        /* queue_async */
 609     NULL,                        /* reselect_async */
 610     NULL,                        /* cancel_async */
 611 };
 612
 613 static int inotify_get_poll_events( struct fd *fd )
 614 {
 615     return POLLIN;
 616 }
 617
 618 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
 619                                       unsigned int cookie, const char *relpath )
 620 {
 621     struct change_record *record;
 622
 623     assert( dir->obj.ops == &dir_ops );
 624
 625     if (dir->want_data)
 626     {
 627         size_t len = strlen(relpath);
 628         record = malloc( offsetof(struct change_record, event.name[len]) );
 629         if (!record)
 630             return;
 631
 632         record->cookie = cookie;
 633         record->event.action = action;
 634         memcpy( record->event.name, relpath, len );
 635         record->event.len = len;
 636
 637         list_add_tail( &dir->change_records, &record->entry );
 638     }
 639
 640     fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 641 }
 642
 643 static unsigned int filter_from_event( struct inotify_event *ie )
 644 {
 645     unsigned int filter = 0;
 646
 647     if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
 648         filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
 649     if (ie->mask & IN_MODIFY)
 650         filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
 651     if (ie->mask & IN_ATTRIB)
 652         filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
 653     if (ie->mask & IN_ACCESS)
 654         filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
 655     if (ie->mask & IN_CREATE)
 656         filter |= FILE_NOTIFY_CHANGE_CREATION;
 657
 658     if (ie->mask & IN_ISDIR)
 659         filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
 660     else
 661         filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
 662
 663     return filter;
 664 }
 665
 666 /* scan up the parent directories for watches */
 667 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
 668 {
 669     unsigned int filter = 0;
 670     struct dir *dir;
 671
 672     /* combine filters from parents watching subtrees */
 673     while (inode)
 674     {
 675         LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 676             if (dir->subtree || !is_parent)
 677                 filter |= dir->filter;
 678         is_parent = 1;
 679         inode = inode->parent;
 680     }
 681
 682     return filter;
 683 }
 684
 685 static char *inode_get_path( struct inode *inode, int sz )
 686 {
 687     struct list *head;
 688     char *path;
 689     int len;
 690
 691     if (!inode)
 692         return NULL;
 693
 694     head = list_head( &inode->dirs );
 695     if (head)
 696     {
 697         int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
 698         path = malloc ( 32 + sz );
 699         if (path)
 700             sprintf( path, "/proc/self/fd/%u/", unix_fd );
 701         return path;
 702     }
 703
 704     if (!inode->name)
 705         return NULL;
 706
 707     len = strlen( inode->name );
 708     path = inode_get_path( inode->parent, sz + len + 1 );
 709     if (!path)
 710         return NULL;
 711
 712     strcat( path, inode->name );
 713     strcat( path, "/" );
 714
 715     return path;
 716 }
 717
 718 static void inode_check_dir( struct inode *parent, const char *name )
 719 {
 720     char *path;
 721     unsigned int filter;
 722     struct inode *inode;
 723     struct stat st;
 724     int wd = -1;
 725
 726     path = inode_get_path( parent, strlen(name) );
 727     if (!path)
 728         return;
 729
 730     strcat( path, name );
 731
 732     if (stat( path, &st ) < 0)
 733         goto end;
 734
 735     filter = filter_from_inode( parent, 1 );
 736     if (!filter)
 737         goto end;
 738
 739     inode = inode_add( parent, st.st_dev, st.st_ino, name );
 740     if (!inode || inode->wd != -1)
 741         goto end;
 742
 743     wd = inotify_add_dir( path, filter );
 744     if (wd != -1)
 745         inode_set_wd( inode, wd );
 746     else
 747         free_inode( inode );
 748
 749 end:
 750     free( path );
 751 }
 752
 753 static int prepend( char **path, const char *segment )
 754 {
 755     int extra;
 756     char *p;
 757
 758     extra = strlen( segment ) + 1;
 759     if (*path)
 760     {
 761         int len = strlen( *path ) + 1;
 762         p = realloc( *path, len + extra );
 763         if (!p) return 0;
 764         memmove( &p[ extra ], p, len );
 765         p[ extra - 1 ] = '/';
 766         memcpy( p, segment, extra - 1 );
 767     }
 768     else
 769     {
 770         p = malloc( extra );
 771         if (!p) return 0;
 772         memcpy( p, segment, extra );
 773     }
 774
 775     *path = p;
 776
 777     return 1;
 778 }
 779
 780 static void inotify_notify_all( struct inotify_event *ie )
 781 {
 782     unsigned int filter, action;
 783     struct inode *inode, *i;
 784     char *path = NULL;
 785     struct dir *dir;
 786
 787     inode = inode_from_wd( ie->wd );
 788     if (!inode)
 789     {
 790         fprintf( stderr, "no inode matches %d\n", ie->wd);
 791         return;
 792     }
 793
 794     filter = filter_from_event( ie );
 795
 796     if (ie->mask & IN_CREATE)
 797     {
 798         if (ie->mask & IN_ISDIR)
 799             inode_check_dir( inode, ie->name );
 800
 801         action = FILE_ACTION_ADDED;
 802     }
 803     else if (ie->mask & IN_DELETE)
 804         action = FILE_ACTION_REMOVED;
 805     else if (ie->mask & IN_MOVED_FROM)
 806         action = FILE_ACTION_RENAMED_OLD_NAME;
 807     else if (ie->mask & IN_MOVED_TO)
 808         action = FILE_ACTION_RENAMED_NEW_NAME;
 809     else
 810         action = FILE_ACTION_MODIFIED;
 811
 812     /*
 813      * Work our way up the inode hierarchy
 814      *  extending the relative path as we go
 815      *  and notifying all recursive watches.
 816      */
 817     if (!prepend( &path, ie->name ))
 818         return;
 819
 820     for (i = inode; i; i = i->parent)
 821     {
 822         LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
 823             if ((filter & dir->filter) && (i==inode || dir->subtree))
 824                 inotify_do_change_notify( dir, action, ie->cookie, path );
 825
 826         if (!i->name || !prepend( &path, i->name ))
 827             break;
 828     }
 829
 830     free( path );
 831
 832     if (ie->mask & IN_DELETE)
 833     {
 834         i = inode_from_name( inode, ie->name );
 835         if (i)
 836             free_inode( i );
 837     }
 838 }
 839
 840 static void inotify_poll_event( struct fd *fd, int event )
 841 {
 842     int r, ofs, unix_fd;
 843     char buffer[0x1000];
 844     struct inotify_event *ie;
 845
 846     unix_fd = get_unix_fd( fd );
 847     r = read( unix_fd, buffer, sizeof buffer );
 848     if (r < 0)
 849     {
 850         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 851         return;
 852     }
 853
 854     for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
 855     {
 856         ie = (struct inotify_event*) &buffer[ofs];
 857         if (!ie->len)
 858             break;
 859         ofs += offsetof( struct inotify_event, name[ie->len] );
 860         if (ofs > r) break;
 861         inotify_notify_all( ie );
 862     }
 863 }
 864
 865 static inline struct fd *create_inotify_fd( void )
 866 {
 867     int unix_fd;
 868
 869     unix_fd = inotify_init();
 870     if (unix_fd<0)
 871         return NULL;
 872     return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
 873 }
 874
 875 static int map_flags( unsigned int filter )
 876 {
 877     unsigned int mask;
 878
 879     /* always watch these so we can track subdirectories in recursive watches */
 880     mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 881
 882     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 883         mask |= IN_ATTRIB;
 884     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 885         mask |= IN_MODIFY;
 886     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 887         mask |= IN_MODIFY;
 888     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 889         mask |= IN_ACCESS;
 890     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 891         mask |= IN_ATTRIB;
 892
 893     return mask;
 894 }
 895
 896 static int inotify_add_dir( char *path, unsigned int filter )
 897 {
 898     int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
 899                                 path, map_flags( filter ) );
 900     if (wd != -1)
 901         set_fd_events( inotify_fd, POLLIN );
 902     return wd;
 903 }
 904
 905 static int init_inotify( void )
 906 {
 907     int i;
 908
 909     if (inotify_fd)
 910         return 1;
 911
 912     inotify_fd = create_inotify_fd();
 913     if (!inotify_fd)
 914         return 0;
 915
 916     for (i=0; i<HASH_SIZE; i++)
 917     {
 918         list_init( &inode_hash[i] );
 919         list_init( &wd_hash[i] );
 920     }
 921
 922     return 1;
 923 }
 924
 925 static int inotify_adjust_changes( struct dir *dir )
 926 {
 927     unsigned int filter;
 928     struct inode *inode;
 929     struct stat st;
 930     char path[32];
 931     int wd, unix_fd;
 932
 933     if (!inotify_fd)
 934         return 0;
 935
 936     unix_fd = get_unix_fd( dir->fd );
 937
 938     inode = dir->inode;
 939     if (!inode)
 940     {
 941         /* check if this fd is already being watched */
 942         if (-1 == fstat( unix_fd, &st ))
 943             return 0;
 944
 945         inode = get_inode( st.st_dev, st.st_ino );
 946         if (!inode)
 947             inode = create_inode( st.st_dev, st.st_ino );
 948         if (!inode)
 949             return 0;
 950         list_add_tail( &inode->dirs, &dir->in_entry );
 951         dir->inode = inode;
 952     }
 953
 954     filter = filter_from_inode( inode, 0 );
 955
 956     sprintf( path, "/proc/self/fd/%u", unix_fd );
 957     wd = inotify_add_dir( path, filter );
 958     if (wd == -1) return 0;
 959
 960     inode_set_wd( inode, wd );
 961
 962     return 1;
 963 }
 964
 965 static char *get_basename( const char *link )
 966 {
 967     char *buffer, *name = NULL;
 968     int r, n = 0x100;
 969
 970     while (1)
 971     {
 972         buffer = malloc( n );
 973         if (!buffer) return NULL;
 974
 975         r = readlink( link, buffer, n );
 976         if (r < 0)
 977             break;
 978
 979         if (r < n)
 980         {
 981             name = buffer;
 982             break;
 983         }
 984         free( buffer );
 985         n *= 2;
 986     }
 987
 988     if (name)
 989     {
 990         while (r > 0 && name[ r - 1 ] == '/' )
 991             r--;
 992         name[ r ] = 0;
 993
 994         name = strrchr( name, '/' );
 995         if (name)
 996             name = strdup( &name[1] );
 997     }
 998
 999     free( buffer );
1000     return name;
1001 }
1002
1003 static int dir_add_to_existing_notify( struct dir *dir )
1004 {
1005     struct inode *inode, *parent;
1006     unsigned int filter = 0;
1007     struct stat st, st_new;
1008     char link[35], *name;
1009     int wd, unix_fd;
1010
1011     if (!inotify_fd)
1012         return 0;
1013
1014     unix_fd = get_unix_fd( dir->fd );
1015
1016     /* check if it's in the list of inodes we want to watch */
1017     if (-1 == fstat( unix_fd, &st_new ))
1018         return 0;
1019     inode = find_inode( st_new.st_dev, st_new.st_ino );
1020     if (inode)
1021         return 0;
1022
1023     /* lookup the parent */
1024     sprintf( link, "/proc/self/fd/%u/..", unix_fd );
1025     if (-1 == stat( link, &st ))
1026         return 0;
1027
1028     /*
1029      * If there's no parent, stop.  We could keep going adding
1030      *  ../ to the path until we hit the root of the tree or
1031      *  find a recursively watched ancestor.
1032      * Assume it's too expensive to search up the tree for now.
1033      */
1034     parent = find_inode( st.st_dev, st.st_ino );
1035     if (!parent)
1036         return 0;
1037
1038     if (parent->wd == -1)
1039         return 0;
1040
1041     filter = filter_from_inode( parent, 1 );
1042     if (!filter)
1043         return 0;
1044
1045     sprintf( link, "/proc/self/fd/%u", unix_fd );
1046     name = get_basename( link );
1047     if (!name)
1048         return 0;
1049     inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
1050     free( name );
1051     if (!inode)
1052         return 0;
1053
1054     /* Couldn't find this inode at the start of the function, must be new */
1055     assert( inode->wd == -1 );
1056
1057     wd = inotify_add_dir( link, filter );
1058     if (wd != -1)
1059         inode_set_wd( inode, wd );
1060
1061     return 1;
1062 }
1063
1064 #else
1065
1066 static int init_inotify( void )
1067 {
1068     return 0;
1069 }
1070
1071 static int inotify_adjust_changes( struct dir *dir )
1072 {
1073     return 0;
1074 }
1075
1076 static void free_inode( struct inode *inode )
1077 {
1078     assert( 0 );
1079 }
1080
1081 static int dir_add_to_existing_notify( struct dir *dir )
1082 {
1083     return 0;
1084 }
1085
1086 #endif  /* USE_INOTIFY */
1087
1088 struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
1089 {
1090     struct dir *dir;
1091
1092     dir = alloc_object( &dir_ops );
1093     if (!dir)
1094         return NULL;
1095
1096     list_init( &dir->change_records );
1097     dir->filter = 0;
1098     dir->notified = 0;
1099     dir->want_data = 0;
1100     dir->inode = NULL;
1101     grab_object( fd );
1102     dir->fd = fd;
1103     dir->mode = mode;
1104     dir->uid  = ~(uid_t)0;
1105     set_fd_user( fd, &dir_fd_ops, &dir->obj );
1106
1107     dir_add_to_existing_notify( dir );
1108
1109     return &dir->obj;
1110 }
1111
1112 /* enable change notifications for a directory */
1113 DECL_HANDLER(read_directory_changes)
1114 {
1115     struct dir *dir;
1116     struct async *async;
1117
1118     if (!req->filter)
1119     {
1120         set_error(STATUS_INVALID_PARAMETER);
1121         return;
1122     }
1123
1124     dir = get_dir_obj( current->process, req->async.handle, 0 );
1125     if (!dir)
1126         return;
1127
1128     /* requests don't timeout */
1129     if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT ))) goto end;
1130
1131     /* assign it once */
1132     if (!dir->filter)
1133     {
1134         init_inotify();
1135         insert_change( dir );
1136         dir->filter = req->filter;
1137         dir->subtree = req->subtree;
1138         dir->want_data = req->want_data;
1139     }
1140
1141     /* if there's already a change in the queue, send it */
1142     if (!list_empty( &dir->change_records ))
1143         fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1144
1145     /* setup the real notification */
1146     if (!inotify_adjust_changes( dir ))
1147         dnotify_adjust_changes( dir );
1148
1149     release_object( async );
1150     set_error(STATUS_PENDING);
1151
1152 end:
1153     release_object( dir );
1154 }
1155
1156 DECL_HANDLER(read_change)
1157 {
1158     struct change_record *record, *next;
1159     struct dir *dir;
1160     struct list events;
1161     char *data, *event;
1162     int size = 0;
1163
1164     dir = get_dir_obj( current->process, req->handle, 0 );
1165     if (!dir)
1166         return;
1167
1168     list_init( &events );
1169     list_move_tail( &events, &dir->change_records );
1170     release_object( dir );
1171
1172     if (list_empty( &events ))
1173     {
1174         set_error( STATUS_NO_DATA_DETECTED );
1175         return;
1176     }
1177
1178     LIST_FOR_EACH_ENTRY( record, &events, struct change_record, entry )
1179     {
1180         size += (offsetof(struct filesystem_event, name[record->event.len])
1181                 + sizeof(int)-1) / sizeof(int) * sizeof(int);
1182     }
1183
1184     if (size > get_reply_max_size())
1185         set_error( STATUS_BUFFER_TOO_SMALL );
1186     else if ((data = mem_alloc( size )) != NULL)
1187     {
1188         event = data;
1189         LIST_FOR_EACH_ENTRY( record, &events, struct change_record, entry )
1190         {
1191             data_size_t len = offsetof( struct filesystem_event, name[record->event.len] );
1192
1193             /* FIXME: rename events are sometimes reported as delete/create */
1194             if (record->event.action == FILE_ACTION_RENAMED_OLD_NAME)
1195             {
1196                 struct list *elem = list_next( &events, &record->entry );
1197                 if (elem)
1198                     next = LIST_ENTRY(elem, struct change_record, entry);
1199
1200                 if (elem && next->cookie == record->cookie)
1201                     next->cookie = 0;
1202                 else
1203                     record->event.action = FILE_ACTION_REMOVED;
1204             }
1205             else if (record->event.action == FILE_ACTION_RENAMED_NEW_NAME && record->cookie)
1206                 record->event.action = FILE_ACTION_ADDED;
1207
1208             memcpy( event, &record->event, len );
1209             event += len;
1210             if (len % sizeof(int))
1211             {
1212                 memset( event, 0, sizeof(int) - len % sizeof(int) );
1213                 event += sizeof(int) - len % sizeof(int);
1214             }
1215         }
1216         set_reply_data_ptr( data, size );
1217     }
1218
1219     LIST_FOR_EACH_ENTRY_SAFE( record, next, &events, struct change_record, entry )
1220     {
1221         list_remove( &record->entry );
1222         free( record );
1223     }
1224 }