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     struct stat st;
 346     mode_t mode;
 347     int unix_fd;
 348
 349     assert( obj->ops == &dir_ops );
 350
 351     unix_fd = get_dir_unix_fd( dir );
 352
 353     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1) return 1;
 354
 355     if (set_info & OWNER_SECURITY_INFORMATION)
 356     {
 357         owner = sd_get_owner( sd );
 358         if (!owner)
 359         {
 360             set_error( STATUS_INVALID_SECURITY_DESCR );
 361             return 0;
 362         }
 363         if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
 364         {
 365             /* FIXME: get Unix uid and call fchown */
 366         }
 367     }
 368     else if (obj->sd)
 369         owner = sd_get_owner( obj->sd );
 370     else
 371         owner = token_get_user( current->process->token );
 372
 373     if (set_info & DACL_SECURITY_INFORMATION)
 374     {
 375         /* keep the bits that we don't map to access rights in the ACL */
 376         mode = st.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXG);
 377         mode |= sd_to_mode( sd, owner );
 378
 379         if (st.st_mode != mode && fchmod( unix_fd, mode ) == -1)
 380         {
 381             file_set_error();
 382             return 0;
 383         }
 384     }
 385     return 1;
 386 }
 387
 388 static struct change_record *get_first_change_record( struct dir *dir )
 389 {
 390     struct list *ptr = list_head( &dir->change_records );
 391     if (!ptr) return NULL;
 392     list_remove( ptr );
 393     return LIST_ENTRY( ptr, struct change_record, entry );
 394 }
 395
 396 static void dir_destroy( struct object *obj )
 397 {
 398     struct change_record *record;
 399     struct dir *dir = (struct dir *)obj;
 400     assert (obj->ops == &dir_ops);
 401
 402     if (dir->filter)
 403         remove_change( dir );
 404
 405     if (dir->inode)
 406     {
 407         list_remove( &dir->in_entry );
 408         free_inode( dir->inode );
 409     }
 410
 411     while ((record = get_first_change_record( dir ))) free( record );
 412
 413     release_object( dir->fd );
 414
 415     if (inotify_fd && list_empty( &change_list ))
 416     {
 417         release_object( inotify_fd );
 418         inotify_fd = NULL;
 419     }
 420 }
 421
 422 static struct dir *
 423 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 struct list inode_hash[ HASH_SIZE ];
 456 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,                        /* ioctl */
 619     NULL,                        /* queue_async */
 620     NULL,                        /* reselect_async */
 621     NULL,                        /* cancel_async */
 622 };
 623
 624 static int inotify_get_poll_events( struct fd *fd )
 625 {
 626     return POLLIN;
 627 }
 628
 629 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
 630                                       const char *relpath )
 631 {
 632     struct change_record *record;
 633
 634     assert( dir->obj.ops == &dir_ops );
 635
 636     if (dir->want_data)
 637     {
 638         size_t len = strlen(relpath);
 639         record = malloc( offsetof(struct change_record, name[len]) );
 640         if (!record)
 641             return;
 642
 643         record->action = action;
 644         memcpy( record->name, relpath, len );
 645         record->len = len;
 646
 647         list_add_tail( &dir->change_records, &record->entry );
 648     }
 649
 650     fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 651 }
 652
 653 static unsigned int filter_from_event( struct inotify_event *ie )
 654 {
 655     unsigned int filter = 0;
 656
 657     if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
 658         filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
 659     if (ie->mask & IN_MODIFY)
 660         filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
 661     if (ie->mask & IN_ATTRIB)
 662         filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
 663     if (ie->mask & IN_ACCESS)
 664         filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
 665     if (ie->mask & IN_CREATE)
 666         filter |= FILE_NOTIFY_CHANGE_CREATION;
 667
 668     return filter;
 669 }
 670
 671 /* scan up the parent directories for watches */
 672 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
 673 {
 674     unsigned int filter = 0;
 675     struct dir *dir;
 676
 677     /* combine filters from parents watching subtrees */
 678     while (inode)
 679     {
 680         LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 681             if (dir->subtree || !is_parent)
 682                 filter |= dir->filter;
 683         is_parent = 1;
 684         inode = inode->parent;
 685     }
 686
 687     return filter;
 688 }
 689
 690 static char *inode_get_path( struct inode *inode, int sz )
 691 {
 692     struct list *head;
 693     char *path;
 694     int len;
 695
 696     if (!inode)
 697         return NULL;
 698
 699     head = list_head( &inode->dirs );
 700     if (head)
 701     {
 702         int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
 703         path = malloc ( 32 + sz );
 704         if (path)
 705             sprintf( path, "/proc/self/fd/%u/", unix_fd );
 706         return path;
 707     }
 708
 709     if (!inode->name)
 710         return NULL;
 711
 712     len = strlen( inode->name );
 713     path = inode_get_path( inode->parent, sz + len + 1 );
 714     if (!path)
 715         return NULL;
 716
 717     strcat( path, inode->name );
 718     strcat( path, "/" );
 719
 720     return path;
 721 }
 722
 723 static int inode_check_dir( struct inode *parent, const char *name )
 724 {
 725     char *path;
 726     unsigned int filter;
 727     struct inode *inode;
 728     struct stat st;
 729     int wd = -1, r = -1;
 730
 731     path = inode_get_path( parent, strlen(name) );
 732     if (!path)
 733         return r;
 734
 735     strcat( path, name );
 736
 737     r = stat( path, &st );
 738     if (r < 0) goto end;
 739
 740     if (!S_ISDIR(st.st_mode))
 741     {
 742         r = 0;
 743         goto end;
 744     }
 745
 746     r = 1;
 747
 748     filter = filter_from_inode( parent, 1 );
 749     if (!filter)
 750         goto end;
 751
 752     inode = inode_add( parent, st.st_dev, st.st_ino, name );
 753     if (!inode || inode->wd != -1)
 754         goto end;
 755
 756     wd = inotify_add_dir( path, filter );
 757     if (wd != -1)
 758         inode_set_wd( inode, wd );
 759     else
 760         free_inode( inode );
 761
 762 end:
 763     free( path );
 764     return r;
 765 }
 766
 767 static int prepend( char **path, const char *segment )
 768 {
 769     int extra;
 770     char *p;
 771
 772     extra = strlen( segment ) + 1;
 773     if (*path)
 774     {
 775         int len = strlen( *path ) + 1;
 776         p = realloc( *path, len + extra );
 777         if (!p) return 0;
 778         memmove( &p[ extra ], p, len );
 779         p[ extra - 1 ] = '/';
 780         memcpy( p, segment, extra - 1 );
 781     }
 782     else
 783     {
 784         p = malloc( extra );
 785         if (!p) return 0;
 786         memcpy( p, segment, extra );
 787     }
 788
 789     *path = p;
 790
 791     return 1;
 792 }
 793
 794 static void inotify_notify_all( struct inotify_event *ie )
 795 {
 796     unsigned int filter, action;
 797     struct inode *inode, *i;
 798     char *path = NULL;
 799     struct dir *dir;
 800
 801     inode = inode_from_wd( ie->wd );
 802     if (!inode)
 803     {
 804         fprintf( stderr, "no inode matches %d\n", ie->wd);
 805         return;
 806     }
 807
 808     filter = filter_from_event( ie );
 809
 810     if (ie->mask & IN_CREATE)
 811     {
 812         switch (inode_check_dir( inode, ie->name ))
 813         {
 814         case 1:
 815             filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
 816             break;
 817         case 0:
 818             filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
 819             break;
 820         default:
 821             break;
 822             /* Maybe the file disappeared before we could check it? */
 823         }
 824         action = FILE_ACTION_ADDED;
 825     }
 826     else if (ie->mask & IN_DELETE)
 827         action = FILE_ACTION_REMOVED;
 828     else
 829         action = FILE_ACTION_MODIFIED;
 830
 831     /*
 832      * Work our way up the inode hierarchy
 833      *  extending the relative path as we go
 834      *  and notifying all recursive watches.
 835      */
 836     if (!prepend( &path, ie->name ))
 837         return;
 838
 839     for (i = inode; i; i = i->parent)
 840     {
 841         LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
 842             if ((filter & dir->filter) && (i==inode || dir->subtree))
 843                 inotify_do_change_notify( dir, action, path );
 844
 845         if (!i->name || !prepend( &path, i->name ))
 846             break;
 847     }
 848
 849     free( path );
 850
 851     if (ie->mask & IN_DELETE)
 852     {
 853         i = inode_from_name( inode, ie->name );
 854         if (i)
 855             free_inode( i );
 856     }
 857 }
 858
 859 static void inotify_poll_event( struct fd *fd, int event )
 860 {
 861     int r, ofs, unix_fd;
 862     char buffer[0x1000];
 863     struct inotify_event *ie;
 864
 865     unix_fd = get_unix_fd( fd );
 866     r = read( unix_fd, buffer, sizeof buffer );
 867     if (r < 0)
 868     {
 869         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 870         return;
 871     }
 872
 873     for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
 874     {
 875         ie = (struct inotify_event*) &buffer[ofs];
 876         if (!ie->len)
 877             break;
 878         ofs += offsetof( struct inotify_event, name[ie->len] );
 879         if (ofs > r) break;
 880         inotify_notify_all( ie );
 881     }
 882 }
 883
 884 static inline struct fd *create_inotify_fd( void )
 885 {
 886     int unix_fd;
 887
 888     unix_fd = inotify_init();
 889     if (unix_fd<0)
 890         return NULL;
 891     return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
 892 }
 893
 894 static int map_flags( unsigned int filter )
 895 {
 896     unsigned int mask;
 897
 898     /* always watch these so we can track subdirectories in recursive watches */
 899     mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 900
 901     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 902         mask |= IN_ATTRIB;
 903     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 904         mask |= IN_MODIFY;
 905     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 906         mask |= IN_MODIFY;
 907     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 908         mask |= IN_ACCESS;
 909     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 910         mask |= IN_ATTRIB;
 911
 912     return mask;
 913 }
 914
 915 static int inotify_add_dir( char *path, unsigned int filter )
 916 {
 917     int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
 918                                 path, map_flags( filter ) );
 919     if (wd != -1)
 920         set_fd_events( inotify_fd, POLLIN );
 921     return wd;
 922 }
 923
 924 static int init_inotify( void )
 925 {
 926     int i;
 927
 928     if (inotify_fd)
 929         return 1;
 930
 931     inotify_fd = create_inotify_fd();
 932     if (!inotify_fd)
 933         return 0;
 934
 935     for (i=0; i<HASH_SIZE; i++)
 936     {
 937         list_init( &inode_hash[i] );
 938         list_init( &wd_hash[i] );
 939     }
 940
 941     return 1;
 942 }
 943
 944 static int inotify_adjust_changes( struct dir *dir )
 945 {
 946     unsigned int filter;
 947     struct inode *inode;
 948     struct stat st;
 949     char path[32];
 950     int wd, unix_fd;
 951
 952     if (!inotify_fd)
 953         return 0;
 954
 955     unix_fd = get_unix_fd( dir->fd );
 956
 957     inode = dir->inode;
 958     if (!inode)
 959     {
 960         /* check if this fd is already being watched */
 961         if (-1 == fstat( unix_fd, &st ))
 962             return 0;
 963
 964         inode = get_inode( st.st_dev, st.st_ino );
 965         if (!inode)
 966             inode = create_inode( st.st_dev, st.st_ino );
 967         if (!inode)
 968             return 0;
 969         list_add_tail( &inode->dirs, &dir->in_entry );
 970         dir->inode = inode;
 971     }
 972
 973     filter = filter_from_inode( inode, 0 );
 974
 975     sprintf( path, "/proc/self/fd/%u", unix_fd );
 976     wd = inotify_add_dir( path, filter );
 977     if (wd == -1) return 0;
 978
 979     inode_set_wd( inode, wd );
 980
 981     return 1;
 982 }
 983
 984 static char *get_basename( const char *link )
 985 {
 986     char *buffer, *name = NULL;
 987     int r, n = 0x100;
 988
 989     while (1)
 990     {
 991         buffer = malloc( n );
 992         if (!buffer) return NULL;
 993
 994         r = readlink( link, buffer, n );
 995         if (r < 0)
 996             break;
 997
 998         if (r < n)
 999         {
1000             name = buffer;
1001             break;
1002         }
1003         free( buffer );
1004         n *= 2;
1005     }
1006
1007     if (name)
1008     {
1009         while (r > 0 && name[ r - 1 ] == '/' )
1010             r--;
1011         name[ r ] = 0;
1012
1013         name = strrchr( name, '/' );
1014         if (name)
1015             name = strdup( &name[1] );
1016     }
1017
1018     free( buffer );
1019     return name;
1020 }
1021
1022 static int dir_add_to_existing_notify( struct dir *dir )
1023 {
1024     struct inode *inode, *parent;
1025     unsigned int filter = 0;
1026     struct stat st, st_new;
1027     char link[35], *name;
1028     int wd, unix_fd;
1029
1030     if (!inotify_fd)
1031         return 0;
1032
1033     unix_fd = get_unix_fd( dir->fd );
1034
1035     /* check if it's in the list of inodes we want to watch */
1036     if (-1 == fstat( unix_fd, &st_new ))
1037         return 0;
1038     inode = find_inode( st_new.st_dev, st_new.st_ino );
1039     if (inode)
1040         return 0;
1041
1042     /* lookup the parent */
1043     sprintf( link, "/proc/self/fd/%u/..", unix_fd );
1044     if (-1 == stat( link, &st ))
1045         return 0;
1046
1047     /*
1048      * If there's no parent, stop.  We could keep going adding
1049      *  ../ to the path until we hit the root of the tree or
1050      *  find a recursively watched ancestor.
1051      * Assume it's too expensive to search up the tree for now.
1052      */
1053     parent = find_inode( st.st_dev, st.st_ino );
1054     if (!parent)
1055         return 0;
1056
1057     if (parent->wd == -1)
1058         return 0;
1059
1060     filter = filter_from_inode( parent, 1 );
1061     if (!filter)
1062         return 0;
1063
1064     sprintf( link, "/proc/self/fd/%u", unix_fd );
1065     name = get_basename( link );
1066     if (!name)
1067         return 0;
1068     inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
1069     free( name );
1070     if (!inode)
1071         return 0;
1072
1073     /* Couldn't find this inode at the start of the function, must be new */
1074     assert( inode->wd == -1 );
1075
1076     wd = inotify_add_dir( link, filter );
1077     if (wd != -1)
1078         inode_set_wd( inode, wd );
1079
1080     return 1;
1081 }
1082
1083 #else
1084
1085 static int init_inotify( void )
1086 {
1087     return 0;
1088 }
1089
1090 static int inotify_adjust_changes( struct dir *dir )
1091 {
1092     return 0;
1093 }
1094
1095 static void free_inode( struct inode *inode )
1096 {
1097     assert( 0 );
1098 }
1099
1100 static int dir_add_to_existing_notify( struct dir *dir )
1101 {
1102     return 0;
1103 }
1104
1105 #endif  /* USE_INOTIFY */
1106
1107 struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
1108 {
1109     struct dir *dir;
1110
1111     dir = alloc_object( &dir_ops );
1112     if (!dir)
1113         return NULL;
1114
1115     list_init( &dir->change_records );
1116     dir->filter = 0;
1117     dir->notified = 0;
1118     dir->want_data = 0;
1119     dir->inode = NULL;
1120     grab_object( fd );
1121     dir->fd = fd;
1122     dir->mode = mode;
1123     dir->uid  = ~(uid_t)0;
1124     set_fd_user( fd, &dir_fd_ops, &dir->obj );
1125
1126     dir_add_to_existing_notify( dir );
1127
1128     return &dir->obj;
1129 }
1130
1131 /* enable change notifications for a directory */
1132 DECL_HANDLER(read_directory_changes)
1133 {
1134     struct dir *dir;
1135     struct async *async;
1136
1137     if (!req->filter)
1138     {
1139         set_error(STATUS_INVALID_PARAMETER);
1140         return;
1141     }
1142
1143     dir = get_dir_obj( current->process, req->async.handle, 0 );
1144     if (!dir)
1145         return;
1146
1147     /* requests don't timeout */
1148     if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT ))) goto end;
1149
1150     /* assign it once */
1151     if (!dir->filter)
1152     {
1153         init_inotify();
1154         insert_change( dir );
1155         dir->filter = req->filter;
1156         dir->subtree = req->subtree;
1157         dir->want_data = req->want_data;
1158     }
1159
1160     /* if there's already a change in the queue, send it */
1161     if (!list_empty( &dir->change_records ))
1162         fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1163
1164     /* setup the real notification */
1165     if (!inotify_adjust_changes( dir ))
1166         dnotify_adjust_changes( dir );
1167
1168     release_object( async );
1169     set_error(STATUS_PENDING);
1170
1171 end:
1172     release_object( dir );
1173 }
1174
1175 DECL_HANDLER(read_change)
1176 {
1177     struct change_record *record;
1178     struct dir *dir;
1179
1180     dir = get_dir_obj( current->process, req->handle, 0 );
1181     if (!dir)
1182         return;
1183
1184     if ((record = get_first_change_record( dir )) != NULL)
1185     {
1186         reply->action = record->action;
1187         set_reply_data( record->name, record->len );
1188         free( record );
1189     }
1190     else
1191         set_error( STATUS_NO_DATA_DETECTED );
1192
1193     release_object( dir );
1194 }