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 static inline int inotify_init( void )
  98 {
  99     int ret;
 100     __asm__ __volatile__( "int $0x80"
 101                           : "=a" (ret)
 102                           : "0" (SYS_inotify_init));
 103     if (ret<0) { errno = -ret; ret = -1; }
 104     return ret;
 105 }
 106
 107 static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
 108 {
 109     int ret;
 110     __asm__ __volatile__( "pushl %%ebx;\n\t"
 111                           "movl %2,%%ebx;\n\t"
 112                           "int $0x80;\n\t"
 113                           "popl %%ebx"
 114                           : "=a" (ret) : "0" (SYS_inotify_add_watch),
 115                             "r" (fd), "c" (name), "d" (mask) );
 116     if (ret<0) { errno = -ret; ret = -1; }
 117     return ret;
 118 }
 119
 120 static inline int inotify_rm_watch( int fd, int wd )
 121 {
 122     int ret;
 123     __asm__ __volatile__( "pushl %%ebx;\n\t"
 124                           "movl %2,%%ebx;\n\t"
 125                           "int $0x80;\n\t"
 126                           "popl %%ebx"
 127                           : "=a" (ret) : "0" (SYS_inotify_rm_watch),
 128                             "r" (fd), "c" (wd) );
 129     if (ret<0) { errno = -ret; ret = -1; }
 130     return ret;
 131 }
 132
 133 #define USE_INOTIFY
 134
 135 #endif
 136
 137 struct inode;
 138
 139 static void free_inode( struct inode *inode );
 140
 141 static struct fd *inotify_fd;
 142
 143 struct change_record {
 144     struct list entry;
 145     int action;
 146     int len;
 147     char name[1];
 148 };
 149
 150 struct dir
 151 {
 152     struct object  obj;      /* object header */
 153     struct fd     *fd;       /* file descriptor to the directory */
 154     mode_t         mode;     /* file stat.st_mode */
 155     uid_t          uid;      /* file stat.st_uid */
 156     struct list    entry;    /* entry in global change notifications list */
 157     unsigned int   filter;   /* notification filter */
 158     int            notified; /* SIGIO counter */
 159     int            want_data; /* return change data */
 160     int            subtree;  /* do we want to watch subdirectories? */
 161     struct list    change_records;   /* data for the change */
 162     struct list    in_entry; /* entry in the inode dirs list */
 163     struct inode  *inode;    /* inode of the associated directory */
 164 };
 165
 166 static struct fd *dir_get_fd( struct object *obj );
 167 static struct security_descriptor *dir_get_sd( struct object *obj );
 168 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
 169                        unsigned int set_info );
 170 static void dir_dump( struct object *obj, int verbose );
 171 static void dir_destroy( struct object *obj );
 172
 173 static const struct object_ops dir_ops =
 174 {
 175     sizeof(struct dir),       /* size */
 176     dir_dump,                 /* dump */
 177     no_get_type,              /* get_type */
 178     add_queue,                /* add_queue */
 179     remove_queue,             /* remove_queue */
 180     default_fd_signaled,      /* signaled */
 181     no_satisfied,             /* satisfied */
 182     no_signal,                /* signal */
 183     dir_get_fd,               /* get_fd */
 184     default_fd_map_access,    /* map_access */
 185     dir_get_sd,               /* get_sd */
 186     dir_set_sd,               /* set_sd */
 187     no_lookup_name,           /* lookup_name */
 188     no_open_file,             /* open_file */
 189     fd_close_handle,          /* close_handle */
 190     dir_destroy               /* destroy */
 191 };
 192
 193 static int dir_get_poll_events( struct fd *fd );
 194 static enum server_fd_type dir_get_fd_type( struct fd *fd );
 195
 196 static const struct fd_ops dir_fd_ops =
 197 {
 198     dir_get_poll_events,         /* get_poll_events */
 199     default_poll_event,          /* poll_event */
 200     no_flush,                    /* flush */
 201     dir_get_fd_type,             /* get_fd_type */
 202     default_fd_removable,        /* removable */
 203     default_fd_ioctl,            /* ioctl */
 204     default_fd_queue_async,      /* queue_async */
 205     default_fd_async_event,      /* async_event */
 206     default_fd_cancel_async      /* cancel_async */
 207 };
 208
 209 static struct list change_list = LIST_INIT(change_list);
 210
 211 static void dnotify_adjust_changes( struct dir *dir )
 212 {
 213 #if defined(F_SETSIG) && defined(F_NOTIFY)
 214     int fd = get_unix_fd( dir->fd );
 215     unsigned int filter = dir->filter;
 216     unsigned int val;
 217     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 218         return;
 219
 220     val = DN_MULTISHOT;
 221     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 222         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 223     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 224         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 225     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 226         val |= DN_ATTRIB;
 227     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 228         val |= DN_MODIFY;
 229     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 230         val |= DN_MODIFY;
 231     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 232         val |= DN_ACCESS;
 233     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 234         val |= DN_CREATE;
 235     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 236         val |= DN_ATTRIB;
 237     fcntl( fd, F_NOTIFY, val );
 238 #endif
 239 }
 240
 241 /* insert change in the global list */
 242 static inline void insert_change( struct dir *dir )
 243 {
 244     sigset_t sigset;
 245
 246     sigemptyset( &sigset );
 247     sigaddset( &sigset, SIGIO );
 248     sigprocmask( SIG_BLOCK, &sigset, NULL );
 249     list_add_head( &change_list, &dir->entry );
 250     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 251 }
 252
 253 /* remove change from the global list */
 254 static inline void remove_change( struct dir *dir )
 255 {
 256     sigset_t sigset;
 257
 258     sigemptyset( &sigset );
 259     sigaddset( &sigset, SIGIO );
 260     sigprocmask( SIG_BLOCK, &sigset, NULL );
 261     list_remove( &dir->entry );
 262     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 263 }
 264
 265 static void dir_dump( struct object *obj, int verbose )
 266 {
 267     struct dir *dir = (struct dir *)obj;
 268     assert( obj->ops == &dir_ops );
 269     fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
 270 }
 271
 272 /* enter here directly from SIGIO signal handler */
 273 void do_change_notify( int unix_fd )
 274 {
 275     struct dir *dir;
 276
 277     /* FIXME: this is O(n) ... probably can be improved */
 278     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 279     {
 280         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 281         interlocked_xchg_add( &dir->notified, 1 );
 282         break;
 283     }
 284 }
 285
 286 /* SIGIO callback, called synchronously with the poll loop */
 287 void sigio_callback(void)
 288 {
 289     struct dir *dir;
 290
 291     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 292     {
 293         if (interlocked_xchg( &dir->notified, 0 ))
 294             fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_NOTIFY_ENUM_DIR );
 295     }
 296 }
 297
 298 static struct fd *dir_get_fd( struct object *obj )
 299 {
 300     struct dir *dir = (struct dir *)obj;
 301     assert( obj->ops == &dir_ops );
 302     return (struct fd *)grab_object( dir->fd );
 303 }
 304
 305 static int get_dir_unix_fd( struct dir *dir )
 306 {
 307     return get_unix_fd( dir->fd );
 308 }
 309
 310 static struct security_descriptor *dir_get_sd( struct object *obj )
 311 {
 312     struct dir *dir = (struct dir *)obj;
 313     int unix_fd;
 314     struct stat st;
 315     struct security_descriptor *sd;
 316     assert( obj->ops == &dir_ops );
 317
 318     unix_fd = get_dir_unix_fd( dir );
 319
 320     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
 321         return obj->sd;
 322
 323     /* mode and uid the same? if so, no need to re-generate security descriptor */
 324     if (obj->sd &&
 325         (st.st_mode & (S_IRWXU|S_IRWXO)) == (dir->mode & (S_IRWXU|S_IRWXO)) &&
 326         (st.st_uid == dir->uid))
 327         return obj->sd;
 328
 329     sd = mode_to_sd( st.st_mode,
 330                      security_unix_uid_to_sid( st.st_uid ),
 331                      token_get_primary_group( current->process->token ));
 332     if (!sd) return obj->sd;
 333
 334     dir->mode = st.st_mode;
 335     dir->uid = st.st_uid;
 336     free( obj->sd );
 337     obj->sd = sd;
 338     return sd;
 339 }
 340
 341 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
 342                        unsigned int set_info )
 343 {
 344     struct dir *dir = (struct dir *)obj;
 345     const SID *owner;
 346     struct stat st;
 347     mode_t mode;
 348     int unix_fd;
 349
 350     assert( obj->ops == &dir_ops );
 351
 352     unix_fd = get_dir_unix_fd( dir );
 353
 354     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1) return 1;
 355
 356     if (set_info & OWNER_SECURITY_INFORMATION)
 357     {
 358         owner = sd_get_owner( sd );
 359         if (!owner)
 360         {
 361             set_error( STATUS_INVALID_SECURITY_DESCR );
 362             return 0;
 363         }
 364         if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
 365         {
 366             /* FIXME: get Unix uid and call fchown */
 367         }
 368     }
 369     else if (obj->sd)
 370         owner = sd_get_owner( obj->sd );
 371     else
 372         owner = token_get_user( current->process->token );
 373
 374     if (set_info & DACL_SECURITY_INFORMATION)
 375     {
 376         /* keep the bits that we don't map to access rights in the ACL */
 377         mode = st.st_mode & (S_ISUID|S_ISGID|S_ISVTX);
 378         mode |= sd_to_mode( sd, owner );
 379
 380         if (((st.st_mode ^ mode) & (S_IRWXU|S_IRWXG|S_IRWXO)) && fchmod( unix_fd, mode ) == -1)
 381         {
 382             file_set_error();
 383             return 0;
 384         }
 385     }
 386     return 1;
 387 }
 388
 389 static struct change_record *get_first_change_record( struct dir *dir )
 390 {
 391     struct list *ptr = list_head( &dir->change_records );
 392     if (!ptr) return NULL;
 393     list_remove( ptr );
 394     return LIST_ENTRY( ptr, struct change_record, entry );
 395 }
 396
 397 static void dir_destroy( struct object *obj )
 398 {
 399     struct change_record *record;
 400     struct dir *dir = (struct dir *)obj;
 401     assert (obj->ops == &dir_ops);
 402
 403     if (dir->filter)
 404         remove_change( dir );
 405
 406     if (dir->inode)
 407     {
 408         list_remove( &dir->in_entry );
 409         free_inode( dir->inode );
 410     }
 411
 412     while ((record = get_first_change_record( dir ))) free( record );
 413
 414     release_object( dir->fd );
 415
 416     if (inotify_fd && list_empty( &change_list ))
 417     {
 418         release_object( inotify_fd );
 419         inotify_fd = NULL;
 420     }
 421 }
 422
 423 struct dir *get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 424 {
 425     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 426 }
 427
 428 static int dir_get_poll_events( struct fd *fd )
 429 {
 430     return 0;
 431 }
 432
 433 static enum server_fd_type dir_get_fd_type( struct fd *fd )
 434 {
 435     return FD_TYPE_DIR;
 436 }
 437
 438 #ifdef USE_INOTIFY
 439
 440 #define HASH_SIZE 31
 441
 442 struct inode {
 443     struct list ch_entry;    /* entry in the children list */
 444     struct list children;    /* children of this inode */
 445     struct inode *parent;    /* parent of this inode */
 446     struct list dirs;        /* directory handles watching this inode */
 447     struct list ino_entry;   /* entry in the inode hash */
 448     struct list wd_entry;    /* entry in the watch descriptor hash */
 449     dev_t dev;               /* device number */
 450     ino_t ino;               /* device's inode number */
 451     int wd;                  /* inotify's watch descriptor */
 452     char *name;              /* basename name of the inode */
 453 };
 454
 455 static struct list inode_hash[ HASH_SIZE ];
 456 static struct list wd_hash[ HASH_SIZE ];
 457
 458 static int inotify_add_dir( char *path, unsigned int filter );
 459
 460 static struct inode *inode_from_wd( int wd )
 461 {
 462     struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
 463     struct inode *inode;
 464
 465     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
 466         if (inode->wd == wd)
 467             return inode;
 468
 469     return NULL;
 470 }
 471
 472 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
 473 {
 474     return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
 475 }
 476
 477 static struct inode *find_inode( dev_t dev, ino_t ino )
 478 {
 479     struct list *bucket = get_hash_list( dev, ino );
 480     struct inode *inode;
 481
 482     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
 483         if (inode->ino == ino && inode->dev == dev)
 484              return inode;
 485
 486     return NULL;
 487 }
 488
 489 static struct inode *create_inode( dev_t dev, ino_t ino )
 490 {
 491     struct inode *inode;
 492
 493     inode = malloc( sizeof *inode );
 494     if (inode)
 495     {
 496         list_init( &inode->children );
 497         list_init( &inode->dirs );
 498         inode->ino = ino;
 499         inode->dev = dev;
 500         inode->wd = -1;
 501         inode->parent = NULL;
 502         inode->name = NULL;
 503         list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
 504     }
 505     return inode;
 506 }
 507
 508 static struct inode *get_inode( dev_t dev, ino_t ino )
 509 {
 510     struct inode *inode;
 511
 512     inode = find_inode( dev, ino );
 513     if (inode)
 514         return inode;
 515     return create_inode( dev, ino );
 516 }
 517
 518 static void inode_set_wd( struct inode *inode, int wd )
 519 {
 520     if (inode->wd != -1)
 521         list_remove( &inode->wd_entry );
 522     inode->wd = wd;
 523     list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
 524 }
 525
 526 static void inode_set_name( struct inode *inode, const char *name )
 527 {
 528     free (inode->name);
 529     inode->name = name ? strdup( name ) : NULL;
 530 }
 531
 532 static void free_inode( struct inode *inode )
 533 {
 534     int subtree = 0, watches = 0;
 535     struct inode *tmp, *next;
 536     struct dir *dir;
 537
 538     LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 539     {
 540         subtree |= dir->subtree;
 541         watches++;
 542     }
 543
 544     if (!subtree && !inode->parent)
 545     {
 546         LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
 547                                   struct inode, ch_entry )
 548         {
 549             assert( tmp != inode );
 550             assert( tmp->parent == inode );
 551             free_inode( tmp );
 552         }
 553     }
 554
 555     if (watches)
 556         return;
 557
 558     if (inode->parent)
 559         list_remove( &inode->ch_entry );
 560
 561     /* disconnect remaining children from the parent */
 562     LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children, struct inode, ch_entry )
 563     {
 564         list_remove( &tmp->ch_entry );
 565         tmp->parent = NULL;
 566     }
 567
 568     if (inode->wd != -1)
 569     {
 570         inotify_rm_watch( get_unix_fd( inotify_fd ), inode->wd );
 571         list_remove( &inode->wd_entry );
 572     }
 573     list_remove( &inode->ino_entry );
 574
 575     free( inode->name );
 576     free( inode );
 577 }
 578
 579 static struct inode *inode_add( struct inode *parent,
 580                                 dev_t dev, ino_t ino, const char *name )
 581 {
 582     struct inode *inode;
 583
 584     inode = get_inode( dev, ino );
 585     if (!inode)
 586         return NULL;
 587
 588     if (!inode->parent)
 589     {
 590         list_add_tail( &parent->children, &inode->ch_entry );
 591         inode->parent = parent;
 592         assert( inode != parent );
 593     }
 594     inode_set_name( inode, name );
 595
 596     return inode;
 597 }
 598
 599 static struct inode *inode_from_name( struct inode *inode, const char *name )
 600 {
 601     struct inode *i;
 602
 603     LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
 604         if (i->name && !strcmp( i->name, name ))
 605             return i;
 606     return NULL;
 607 }
 608
 609 static int inotify_get_poll_events( struct fd *fd );
 610 static void inotify_poll_event( struct fd *fd, int event );
 611
 612 static const struct fd_ops inotify_fd_ops =
 613 {
 614     inotify_get_poll_events,     /* get_poll_events */
 615     inotify_poll_event,          /* poll_event */
 616     NULL,                        /* flush */
 617     NULL,                        /* get_fd_type */
 618     NULL,                        /* removable */
 619     NULL,                        /* ioctl */
 620     NULL,                        /* queue_async */
 621     NULL,                        /* async_event */
 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     return filter;
 670 }
 671
 672 /* scan up the parent directories for watches */
 673 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
 674 {
 675     unsigned int filter = 0;
 676     struct dir *dir;
 677
 678     /* combine filters from parents watching subtrees */
 679     while (inode)
 680     {
 681         LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 682             if (dir->subtree || !is_parent)
 683                 filter |= dir->filter;
 684         is_parent = 1;
 685         inode = inode->parent;
 686     }
 687
 688     return filter;
 689 }
 690
 691 static char *inode_get_path( struct inode *inode, int sz )
 692 {
 693     struct list *head;
 694     char *path;
 695     int len;
 696
 697     if (!inode)
 698         return NULL;
 699
 700     head = list_head( &inode->dirs );
 701     if (head)
 702     {
 703         int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
 704         path = malloc ( 32 + sz );
 705         if (path)
 706             sprintf( path, "/proc/self/fd/%u/", unix_fd );
 707         return path;
 708     }
 709
 710     if (!inode->name)
 711         return NULL;
 712
 713     len = strlen( inode->name );
 714     path = inode_get_path( inode->parent, sz + len + 1 );
 715     if (!path)
 716         return NULL;
 717
 718     strcat( path, inode->name );
 719     strcat( path, "/" );
 720
 721     return path;
 722 }
 723
 724 static int inode_check_dir( struct inode *parent, const char *name )
 725 {
 726     char *path;
 727     unsigned int filter;
 728     struct inode *inode;
 729     struct stat st;
 730     int wd = -1, r = -1;
 731
 732     path = inode_get_path( parent, strlen(name) );
 733     if (!path)
 734         return r;
 735
 736     strcat( path, name );
 737
 738     r = stat( path, &st );
 739     if (r < 0) goto end;
 740
 741     if (!S_ISDIR(st.st_mode))
 742     {
 743         r = 0;
 744         goto end;
 745     }
 746
 747     r = 1;
 748
 749     filter = filter_from_inode( parent, 1 );
 750     if (!filter)
 751         goto end;
 752
 753     inode = inode_add( parent, st.st_dev, st.st_ino, name );
 754     if (!inode || inode->wd != -1)
 755         goto end;
 756
 757     wd = inotify_add_dir( path, filter );
 758     if (wd != -1)
 759         inode_set_wd( inode, wd );
 760     else
 761         free_inode( inode );
 762
 763 end:
 764     free( path );
 765     return r;
 766 }
 767
 768 static int prepend( char **path, const char *segment )
 769 {
 770     int extra;
 771     char *p;
 772
 773     extra = strlen( segment ) + 1;
 774     if (*path)
 775     {
 776         int len = strlen( *path ) + 1;
 777         p = realloc( *path, len + extra );
 778         if (!p) return 0;
 779         memmove( &p[ extra ], p, len );
 780         p[ extra - 1 ] = '/';
 781         memcpy( p, segment, extra - 1 );
 782     }
 783     else
 784     {
 785         p = malloc( extra );
 786         if (!p) return 0;
 787         memcpy( p, segment, extra );
 788     }
 789
 790     *path = p;
 791
 792     return 1;
 793 }
 794
 795 static void inotify_notify_all( struct inotify_event *ie )
 796 {
 797     unsigned int filter, action;
 798     struct inode *inode, *i;
 799     char *path = NULL;
 800     struct dir *dir;
 801
 802     inode = inode_from_wd( ie->wd );
 803     if (!inode)
 804     {
 805         fprintf( stderr, "no inode matches %d\n", ie->wd);
 806         return;
 807     }
 808
 809     filter = filter_from_event( ie );
 810
 811     if (ie->mask & IN_CREATE)
 812     {
 813         switch (inode_check_dir( inode, ie->name ))
 814         {
 815         case 1:
 816             filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
 817             break;
 818         case 0:
 819             filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
 820             break;
 821         default:
 822             break;
 823             /* Maybe the file disappeared before we could check it? */
 824         }
 825         action = FILE_ACTION_ADDED;
 826     }
 827     else if (ie->mask & IN_DELETE)
 828         action = FILE_ACTION_REMOVED;
 829     else
 830         action = FILE_ACTION_MODIFIED;
 831
 832     /*
 833      * Work our way up the inode hierarchy
 834      *  extending the relative path as we go
 835      *  and notifying all recursive watches.
 836      */
 837     if (!prepend( &path, ie->name ))
 838         return;
 839
 840     for (i = inode; i; i = i->parent)
 841     {
 842         LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
 843             if ((filter & dir->filter) && (i==inode || dir->subtree))
 844                 inotify_do_change_notify( dir, action, path );
 845
 846         if (!i->name || !prepend( &path, i->name ))
 847             break;
 848     }
 849
 850     free( path );
 851
 852     if (ie->mask & IN_DELETE)
 853     {
 854         i = inode_from_name( inode, ie->name );
 855         if (i)
 856             free_inode( i );
 857     }
 858 }
 859
 860 static void inotify_poll_event( struct fd *fd, int event )
 861 {
 862     int r, ofs, unix_fd;
 863     char buffer[0x1000];
 864     struct inotify_event *ie;
 865
 866     unix_fd = get_unix_fd( fd );
 867     r = read( unix_fd, buffer, sizeof buffer );
 868     if (r < 0)
 869     {
 870         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 871         return;
 872     }
 873
 874     for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
 875     {
 876         ie = (struct inotify_event*) &buffer[ofs];
 877         if (!ie->len)
 878             break;
 879         ofs += offsetof( struct inotify_event, name[ie->len] );
 880         if (ofs > r) break;
 881         inotify_notify_all( ie );
 882     }
 883 }
 884
 885 static inline struct fd *create_inotify_fd( void )
 886 {
 887     int unix_fd;
 888
 889     unix_fd = inotify_init();
 890     if (unix_fd<0)
 891         return NULL;
 892     return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
 893 }
 894
 895 static int map_flags( unsigned int filter )
 896 {
 897     unsigned int mask;
 898
 899     /* always watch these so we can track subdirectories in recursive watches */
 900     mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 901
 902     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 903         mask |= IN_ATTRIB;
 904     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 905         mask |= IN_MODIFY;
 906     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 907         mask |= IN_MODIFY;
 908     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 909         mask |= IN_ACCESS;
 910     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 911         mask |= IN_ATTRIB;
 912
 913     return mask;
 914 }
 915
 916 static int inotify_add_dir( char *path, unsigned int filter )
 917 {
 918     int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
 919                                 path, map_flags( filter ) );
 920     if (wd != -1)
 921         set_fd_events( inotify_fd, POLLIN );
 922     return wd;
 923 }
 924
 925 static int init_inotify( void )
 926 {
 927     int i;
 928
 929     if (inotify_fd)
 930         return 1;
 931
 932     inotify_fd = create_inotify_fd();
 933     if (!inotify_fd)
 934         return 0;
 935
 936     for (i=0; i<HASH_SIZE; i++)
 937     {
 938         list_init( &inode_hash[i] );
 939         list_init( &wd_hash[i] );
 940     }
 941
 942     return 1;
 943 }
 944
 945 static int inotify_adjust_changes( struct dir *dir )
 946 {
 947     unsigned int filter;
 948     struct inode *inode;
 949     struct stat st;
 950     char path[32];
 951     int wd, unix_fd;
 952
 953     if (!inotify_fd)
 954         return 0;
 955
 956     unix_fd = get_unix_fd( dir->fd );
 957
 958     inode = dir->inode;
 959     if (!inode)
 960     {
 961         /* check if this fd is already being watched */
 962         if (-1 == fstat( unix_fd, &st ))
 963             return 0;
 964
 965         inode = get_inode( st.st_dev, st.st_ino );
 966         if (!inode)
 967             inode = create_inode( st.st_dev, st.st_ino );
 968         if (!inode)
 969             return 0;
 970         list_add_tail( &inode->dirs, &dir->in_entry );
 971         dir->inode = inode;
 972     }
 973
 974     filter = filter_from_inode( inode, 0 );
 975
 976     sprintf( path, "/proc/self/fd/%u", unix_fd );
 977     wd = inotify_add_dir( path, filter );
 978     if (wd == -1) return 0;
 979
 980     inode_set_wd( inode, wd );
 981
 982     return 1;
 983 }
 984
 985 static char *get_basename( const char *link )
 986 {
 987     char *buffer, *name = NULL;
 988     int r, n = 0x100;
 989
 990     while (1)
 991     {
 992         buffer = malloc( n );
 993         if (!buffer) return NULL;
 994
 995         r = readlink( link, buffer, n );
 996         if (r < 0)
 997             break;
 998
 999         if (r < n)
1000         {
1001             name = buffer;
1002             break;
1003         }
1004         free( buffer );
1005         n *= 2;
1006     }
1007
1008     if (name)
1009     {
1010         while (r > 0 && name[ r - 1 ] == '/' )
1011             r--;
1012         name[ r ] = 0;
1013
1014         name = strrchr( name, '/' );
1015         if (name)
1016             name = strdup( &name[1] );
1017     }
1018
1019     free( buffer );
1020     return name;
1021 }
1022
1023 static int dir_add_to_existing_notify( struct dir *dir )
1024 {
1025     struct inode *inode, *parent;
1026     unsigned int filter = 0;
1027     struct stat st, st_new;
1028     char link[35], *name;
1029     int wd, unix_fd;
1030
1031     if (!inotify_fd)
1032         return 0;
1033
1034     unix_fd = get_unix_fd( dir->fd );
1035
1036     /* check if it's in the list of inodes we want to watch */
1037     if (-1 == fstat( unix_fd, &st_new ))
1038         return 0;
1039     inode = find_inode( st_new.st_dev, st_new.st_ino );
1040     if (inode)
1041         return 0;
1042
1043     /* lookup the parent */
1044     sprintf( link, "/proc/self/fd/%u/..", unix_fd );
1045     if (-1 == stat( link, &st ))
1046         return 0;
1047
1048     /*
1049      * If there's no parent, stop.  We could keep going adding
1050      *  ../ to the path until we hit the root of the tree or
1051      *  find a recursively watched ancestor.
1052      * Assume it's too expensive to search up the tree for now.
1053      */
1054     parent = find_inode( st.st_dev, st.st_ino );
1055     if (!parent)
1056         return 0;
1057
1058     if (parent->wd == -1)
1059         return 0;
1060
1061     filter = filter_from_inode( parent, 1 );
1062     if (!filter)
1063         return 0;
1064
1065     sprintf( link, "/proc/self/fd/%u", unix_fd );
1066     name = get_basename( link );
1067     if (!name)
1068         return 0;
1069     inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
1070     free( name );
1071     if (!inode)
1072         return 0;
1073
1074     /* Couldn't find this inode at the start of the function, must be new */
1075     assert( inode->wd == -1 );
1076
1077     wd = inotify_add_dir( link, filter );
1078     if (wd != -1)
1079         inode_set_wd( inode, wd );
1080
1081     return 1;
1082 }
1083
1084 #else
1085
1086 static int init_inotify( void )
1087 {
1088     return 0;
1089 }
1090
1091 static int inotify_adjust_changes( struct dir *dir )
1092 {
1093     return 0;
1094 }
1095
1096 static void free_inode( struct inode *inode )
1097 {
1098     assert( 0 );
1099 }
1100
1101 static int dir_add_to_existing_notify( struct dir *dir )
1102 {
1103     return 0;
1104 }
1105
1106 #endif  /* USE_INOTIFY */
1107
1108 struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
1109 {
1110     struct dir *dir;
1111
1112     dir = alloc_object( &dir_ops );
1113     if (!dir)
1114         return NULL;
1115
1116     list_init( &dir->change_records );
1117     dir->filter = 0;
1118     dir->notified = 0;
1119     dir->want_data = 0;
1120     dir->inode = NULL;
1121     grab_object( fd );
1122     dir->fd = fd;
1123     dir->mode = mode;
1124     dir->uid  = ~(uid_t)0;
1125     set_fd_user( fd, &dir_fd_ops, &dir->obj );
1126
1127     dir_add_to_existing_notify( dir );
1128
1129     return &dir->obj;
1130 }
1131
1132 /* enable change notifications for a directory */
1133 DECL_HANDLER(read_directory_changes)
1134 {
1135     struct dir *dir;
1136     struct async *async;
1137
1138     if (!req->filter)
1139     {
1140         set_error(STATUS_INVALID_PARAMETER);
1141         return;
1142     }
1143
1144     dir = get_dir_obj( current->process, req->async.handle, 0 );
1145     if (!dir)
1146         return;
1147
1148     /* requests don't timeout */
1149     if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT ))) goto end;
1150
1151     /* assign it once */
1152     if (!dir->filter)
1153     {
1154         init_inotify();
1155         insert_change( dir );
1156         dir->filter = req->filter;
1157         dir->subtree = req->subtree;
1158         dir->want_data = req->want_data;
1159     }
1160
1161     /* if there's already a change in the queue, send it */
1162     if (!list_empty( &dir->change_records ))
1163         fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1164
1165     /* setup the real notification */
1166     if (!inotify_adjust_changes( dir ))
1167         dnotify_adjust_changes( dir );
1168
1169     release_object( async );
1170     set_error(STATUS_PENDING);
1171
1172 end:
1173     release_object( dir );
1174 }
1175
1176 DECL_HANDLER(read_change)
1177 {
1178     struct change_record *record;
1179     struct dir *dir;
1180
1181     dir = get_dir_obj( current->process, req->handle, 0 );
1182     if (!dir)
1183         return;
1184
1185     if ((record = get_first_change_record( dir )) != NULL)
1186     {
1187         reply->action = record->action;
1188         set_reply_data( record->name, record->len );
1189         free( record );
1190     }
1191     else
1192         set_error( STATUS_NO_DATA_DETECTED );
1193
1194     release_object( dir );
1195 }