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