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 #if defined(__linux__) && defined(__i386__)
  69
  70 #define SYS_inotify_init        291
  71 #define SYS_inotify_add_watch   292
  72 #define SYS_inotify_rm_watch    293
  73
  74 struct inotify_event {
  75     int           wd;
  76     unsigned int  mask;
  77     unsigned int  cookie;
  78     unsigned int  len;
  79     char          name[1];
  80 };
  81
  82 #define IN_ACCESS        0x00000001
  83 #define IN_MODIFY        0x00000002
  84 #define IN_ATTRIB        0x00000004
  85 #define IN_CLOSE_WRITE   0x00000008
  86 #define IN_CLOSE_NOWRITE 0x00000010
  87 #define IN_OPEN          0x00000020
  88 #define IN_MOVED_FROM    0x00000040
  89 #define IN_MOVED_TO      0x00000080
  90 #define IN_CREATE        0x00000100
  91 #define IN_DELETE        0x00000200
  92 #define IN_DELETE_SELF   0x00000400
  93
  94 static inline int inotify_init( void )
  95 {
  96     int ret;
  97     __asm__ __volatile__( "int $0x80"
  98                           : "=a" (ret)
  99                           : "0" (SYS_inotify_init));
 100     if (ret<0) { errno = -ret; ret = -1; }
 101     return ret;
 102 }
 103
 104 static inline int inotify_add_watch( int fd, const char *name, unsigned int mask )
 105 {
 106     int ret;
 107     __asm__ __volatile__( "pushl %%ebx;\n\t"
 108                           "movl %2,%%ebx;\n\t"
 109                           "int $0x80;\n\t"
 110                           "popl %%ebx"
 111                           : "=a" (ret) : "0" (SYS_inotify_add_watch),
 112                             "r" (fd), "c" (name), "d" (mask) );
 113     if (ret<0) { errno = -ret; ret = -1; }
 114     return ret;
 115 }
 116
 117 static inline int inotify_remove_watch( int fd, int wd )
 118 {
 119     int ret;
 120     __asm__ __volatile__( "pushl %%ebx;\n\t"
 121                           "movl %2,%%ebx;\n\t"
 122                           "int $0x80;\n\t"
 123                           "popl %%ebx"
 124                           : "=a" (ret) : "0" (SYS_inotify_rm_watch),
 125                             "r" (fd), "c" (wd) );
 126     if (ret<0) { errno = -ret; ret = -1; }
 127     return ret;
 128 }
 129
 130 #define USE_INOTIFY
 131
 132 #endif
 133
 134 struct inode;
 135
 136 static void free_inode( struct inode *inode );
 137
 138 static struct fd *inotify_fd;
 139
 140 struct change_record {
 141     struct list entry;
 142     int action;
 143     int len;
 144     char name[1];
 145 };
 146
 147 struct dir
 148 {
 149     struct object  obj;      /* object header */
 150     struct fd     *fd;       /* file descriptor to the directory */
 151     mode_t         mode;     /* file stat.st_mode */
 152     uid_t          uid;      /* file stat.st_uid */
 153     struct list    entry;    /* entry in global change notifications list */
 154     unsigned int   filter;   /* notification filter */
 155     int            notified; /* SIGIO counter */
 156     int            want_data; /* return change data */
 157     int            subtree;  /* do we want to watch subdirectories? */
 158     struct list    change_records;   /* data for the change */
 159     struct list    in_entry; /* entry in the inode dirs list */
 160     struct inode  *inode;    /* inode of the associated directory */
 161 };
 162
 163 static struct fd *dir_get_fd( struct object *obj );
 164 static struct security_descriptor *dir_get_sd( struct object *obj );
 165 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
 166                        unsigned int set_info );
 167 static void dir_dump( struct object *obj, int verbose );
 168 static void dir_destroy( struct object *obj );
 169
 170 static const struct object_ops dir_ops =
 171 {
 172     sizeof(struct dir),       /* size */
 173     dir_dump,                 /* dump */
 174     no_get_type,              /* get_type */
 175     add_queue,                /* add_queue */
 176     remove_queue,             /* remove_queue */
 177     default_fd_signaled,      /* signaled */
 178     no_satisfied,             /* satisfied */
 179     no_signal,                /* signal */
 180     dir_get_fd,               /* get_fd */
 181     default_fd_map_access,    /* map_access */
 182     dir_get_sd,               /* get_sd */
 183     dir_set_sd,               /* set_sd */
 184     no_lookup_name,           /* lookup_name */
 185     no_open_file,             /* open_file */
 186     fd_close_handle,          /* close_handle */
 187     dir_destroy               /* destroy */
 188 };
 189
 190 static int dir_get_poll_events( struct fd *fd );
 191 static enum server_fd_type dir_get_fd_type( struct fd *fd );
 192
 193 static const struct fd_ops dir_fd_ops =
 194 {
 195     dir_get_poll_events,         /* get_poll_events */
 196     default_poll_event,          /* poll_event */
 197     no_flush,                    /* flush */
 198     dir_get_fd_type,             /* get_fd_type */
 199     default_fd_ioctl,            /* ioctl */
 200     default_fd_queue_async,      /* queue_async */
 201     default_fd_reselect_async,   /* reselect_async */
 202     default_fd_cancel_async      /* cancel_async */
 203 };
 204
 205 static struct list change_list = LIST_INIT(change_list);
 206
 207 static void dnotify_adjust_changes( struct dir *dir )
 208 {
 209 #if defined(F_SETSIG) && defined(F_NOTIFY)
 210     int fd = get_unix_fd( dir->fd );
 211     unsigned int filter = dir->filter;
 212     unsigned int val;
 213     if ( 0 > fcntl( fd, F_SETSIG, SIGIO) )
 214         return;
 215
 216     val = DN_MULTISHOT;
 217     if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 218         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 219     if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 220         val |= DN_RENAME | DN_DELETE | DN_CREATE;
 221     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 222         val |= DN_ATTRIB;
 223     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 224         val |= DN_MODIFY;
 225     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 226         val |= DN_MODIFY;
 227     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 228         val |= DN_ACCESS;
 229     if (filter & FILE_NOTIFY_CHANGE_CREATION)
 230         val |= DN_CREATE;
 231     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 232         val |= DN_ATTRIB;
 233     fcntl( fd, F_NOTIFY, val );
 234 #endif
 235 }
 236
 237 /* insert change in the global list */
 238 static inline void insert_change( struct dir *dir )
 239 {
 240     sigset_t sigset;
 241
 242     sigemptyset( &sigset );
 243     sigaddset( &sigset, SIGIO );
 244     sigprocmask( SIG_BLOCK, &sigset, NULL );
 245     list_add_head( &change_list, &dir->entry );
 246     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 247 }
 248
 249 /* remove change from the global list */
 250 static inline void remove_change( struct dir *dir )
 251 {
 252     sigset_t sigset;
 253
 254     sigemptyset( &sigset );
 255     sigaddset( &sigset, SIGIO );
 256     sigprocmask( SIG_BLOCK, &sigset, NULL );
 257     list_remove( &dir->entry );
 258     sigprocmask( SIG_UNBLOCK, &sigset, NULL );
 259 }
 260
 261 static void dir_dump( struct object *obj, int verbose )
 262 {
 263     struct dir *dir = (struct dir *)obj;
 264     assert( obj->ops == &dir_ops );
 265     fprintf( stderr, "Dirfile fd=%p filter=%08x\n", dir->fd, dir->filter );
 266 }
 267
 268 /* enter here directly from SIGIO signal handler */
 269 void do_change_notify( int unix_fd )
 270 {
 271     struct dir *dir;
 272
 273     /* FIXME: this is O(n) ... probably can be improved */
 274     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 275     {
 276         if (get_unix_fd( dir->fd ) != unix_fd) continue;
 277         interlocked_xchg_add( &dir->notified, 1 );
 278         break;
 279     }
 280 }
 281
 282 /* SIGIO callback, called synchronously with the poll loop */
 283 void sigio_callback(void)
 284 {
 285     struct dir *dir;
 286
 287     LIST_FOR_EACH_ENTRY( dir, &change_list, struct dir, entry )
 288     {
 289         if (interlocked_xchg( &dir->notified, 0 ))
 290             fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_NOTIFY_ENUM_DIR );
 291     }
 292 }
 293
 294 static struct fd *dir_get_fd( struct object *obj )
 295 {
 296     struct dir *dir = (struct dir *)obj;
 297     assert( obj->ops == &dir_ops );
 298     return (struct fd *)grab_object( dir->fd );
 299 }
 300
 301 static int get_dir_unix_fd( struct dir *dir )
 302 {
 303     return get_unix_fd( dir->fd );
 304 }
 305
 306 static struct security_descriptor *dir_get_sd( struct object *obj )
 307 {
 308     struct dir *dir = (struct dir *)obj;
 309     int unix_fd;
 310     struct stat st;
 311     struct security_descriptor *sd;
 312     assert( obj->ops == &dir_ops );
 313
 314     unix_fd = get_dir_unix_fd( dir );
 315
 316     if (unix_fd == -1 || fstat( unix_fd, &st ) == -1)
 317         return obj->sd;
 318
 319     /* mode and uid the same? if so, no need to re-generate security descriptor */
 320     if (obj->sd &&
 321         (st.st_mode & (S_IRWXU|S_IRWXO)) == (dir->mode & (S_IRWXU|S_IRWXO)) &&
 322         (st.st_uid == dir->uid))
 323         return obj->sd;
 324
 325     sd = mode_to_sd( st.st_mode,
 326                      security_unix_uid_to_sid( st.st_uid ),
 327                      token_get_primary_group( current->process->token ));
 328     if (!sd) return obj->sd;
 329
 330     dir->mode = st.st_mode;
 331     dir->uid = st.st_uid;
 332     free( obj->sd );
 333     obj->sd = sd;
 334     return sd;
 335 }
 336
 337 static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
 338                        unsigned int set_info )
 339 {
 340     struct dir *dir = (struct dir *)obj;
 341     const SID *owner;
 342     mode_t mode;
 343     int unix_fd;
 344
 345     assert( obj->ops == &dir_ops );
 346
 347     unix_fd = get_dir_unix_fd( dir );
 348
 349     if (unix_fd == -1) return 1;
 350
 351     if (set_info & OWNER_SECURITY_INFORMATION)
 352     {
 353         owner = sd_get_owner( sd );
 354         if (!owner)
 355         {
 356             set_error( STATUS_INVALID_SECURITY_DESCR );
 357             return 0;
 358         }
 359         if (!obj->sd || !security_equal_sid( owner, sd_get_owner( obj->sd ) ))
 360         {
 361             /* FIXME: get Unix uid and call fchown */
 362         }
 363     }
 364     else if (obj->sd)
 365         owner = sd_get_owner( obj->sd );
 366     else
 367         owner = token_get_user( current->process->token );
 368
 369     if (set_info & DACL_SECURITY_INFORMATION)
 370     {
 371         /* keep the bits that we don't map to access rights in the ACL */
 372         mode = dir->mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXG);
 373         mode |= sd_to_mode( sd, owner );
 374
 375         if (dir->mode != mode)
 376         {
 377             if (fchmod( unix_fd, mode ) == -1)
 378             {
 379                 file_set_error();
 380                 return 0;
 381             }
 382
 383             dir->mode = mode;
 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 static struct dir *
 424 get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 425 {
 426     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 427 }
 428
 429 static int dir_get_poll_events( struct fd *fd )
 430 {
 431     return 0;
 432 }
 433
 434 static enum server_fd_type dir_get_fd_type( struct fd *fd )
 435 {
 436     return FD_TYPE_DIR;
 437 }
 438
 439 #ifdef USE_INOTIFY
 440
 441 #define HASH_SIZE 31
 442
 443 struct inode {
 444     struct list ch_entry;    /* entry in the children list */
 445     struct list children;    /* children of this inode */
 446     struct inode *parent;    /* parent of this inode */
 447     struct list dirs;        /* directory handles watching this inode */
 448     struct list ino_entry;   /* entry in the inode hash */
 449     struct list wd_entry;    /* entry in the watch descriptor hash */
 450     dev_t dev;               /* device number */
 451     ino_t ino;               /* device's inode number */
 452     int wd;                  /* inotify's watch descriptor */
 453     char *name;              /* basename name of the inode */
 454 };
 455
 456 struct list inode_hash[ HASH_SIZE ];
 457 struct list wd_hash[ HASH_SIZE ];
 458
 459 static int inotify_add_dir( char *path, unsigned int filter );
 460
 461 static struct inode *inode_from_wd( int wd )
 462 {
 463     struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
 464     struct inode *inode;
 465
 466     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
 467         if (inode->wd == wd)
 468             return inode;
 469
 470     return NULL;
 471 }
 472
 473 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
 474 {
 475     return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
 476 }
 477
 478 static struct inode *find_inode( dev_t dev, ino_t ino )
 479 {
 480     struct list *bucket = get_hash_list( dev, ino );
 481     struct inode *inode;
 482
 483     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
 484         if (inode->ino == ino && inode->dev == dev)
 485              return inode;
 486
 487     return NULL;
 488 }
 489
 490 static struct inode *create_inode( dev_t dev, ino_t ino )
 491 {
 492     struct inode *inode;
 493
 494     inode = malloc( sizeof *inode );
 495     if (inode)
 496     {
 497         list_init( &inode->children );
 498         list_init( &inode->dirs );
 499         inode->ino = ino;
 500         inode->dev = dev;
 501         inode->wd = -1;
 502         inode->parent = NULL;
 503         inode->name = NULL;
 504         list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
 505     }
 506     return inode;
 507 }
 508
 509 static struct inode *get_inode( dev_t dev, ino_t ino )
 510 {
 511     struct inode *inode;
 512
 513     inode = find_inode( dev, ino );
 514     if (inode)
 515         return inode;
 516     return create_inode( dev, ino );
 517 }
 518
 519 static void inode_set_wd( struct inode *inode, int wd )
 520 {
 521     if (inode->wd != -1)
 522         list_remove( &inode->wd_entry );
 523     inode->wd = wd;
 524     list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
 525 }
 526
 527 static void inode_set_name( struct inode *inode, const char *name )
 528 {
 529     free (inode->name);
 530     inode->name = name ? strdup( name ) : NULL;
 531 }
 532
 533 static void free_inode( struct inode *inode )
 534 {
 535     int subtree = 0, watches = 0;
 536     struct inode *tmp, *next;
 537     struct dir *dir;
 538
 539     LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 540     {
 541         subtree |= dir->subtree;
 542         watches++;
 543     }
 544
 545     if (!subtree && !inode->parent)
 546     {
 547         LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
 548                                   struct inode, ch_entry )
 549         {
 550             assert( tmp != inode );
 551             assert( tmp->parent == inode );
 552             free_inode( tmp );
 553         }
 554     }
 555
 556     if (watches)
 557         return;
 558
 559     if (inode->parent)
 560         list_remove( &inode->ch_entry );
 561
 562     /* disconnect remaining children from the parent */
 563     LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children, struct inode, ch_entry )
 564     {
 565         list_remove( &tmp->ch_entry );
 566         tmp->parent = NULL;
 567     }
 568
 569     if (inode->wd != -1)
 570     {
 571         inotify_remove_watch( get_unix_fd( inotify_fd ), inode->wd );
 572         list_remove( &inode->wd_entry );
 573     }
 574     list_remove( &inode->ino_entry );
 575
 576     free( inode->name );
 577     free( inode );
 578 }
 579
 580 static struct inode *inode_add( struct inode *parent,
 581                                 dev_t dev, ino_t ino, const char *name )
 582 {
 583     struct inode *inode;
 584
 585     inode = get_inode( dev, ino );
 586     if (!inode)
 587         return NULL;
 588
 589     if (!inode->parent)
 590     {
 591         list_add_tail( &parent->children, &inode->ch_entry );
 592         inode->parent = parent;
 593         assert( inode != parent );
 594     }
 595     inode_set_name( inode, name );
 596
 597     return inode;
 598 }
 599
 600 static struct inode *inode_from_name( struct inode *inode, const char *name )
 601 {
 602     struct inode *i;
 603
 604     LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
 605         if (i->name && !strcmp( i->name, name ))
 606             return i;
 607     return NULL;
 608 }
 609
 610 static int inotify_get_poll_events( struct fd *fd );
 611 static void inotify_poll_event( struct fd *fd, int event );
 612
 613 static const struct fd_ops inotify_fd_ops =
 614 {
 615     inotify_get_poll_events,     /* get_poll_events */
 616     inotify_poll_event,          /* poll_event */
 617     NULL,                        /* flush */
 618     NULL,                        /* get_fd_type */
 619     NULL,                        /* ioctl */
 620     NULL,                        /* queue_async */
 621     NULL,                        /* reselect_async */
 622     NULL,                        /* cancel_async */
 623 };
 624
 625 static int inotify_get_poll_events( struct fd *fd )
 626 {
 627     return POLLIN;
 628 }
 629
 630 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
 631                                       const char *relpath )
 632 {
 633     struct change_record *record;
 634
 635     assert( dir->obj.ops == &dir_ops );
 636
 637     if (dir->want_data)
 638     {
 639         size_t len = strlen(relpath);
 640         record = malloc( offsetof(struct change_record, name[len]) );
 641         if (!record)
 642             return;
 643
 644         record->action = action;
 645         memcpy( record->name, relpath, len );
 646         record->len = len;
 647
 648         list_add_tail( &dir->change_records, &record->entry );
 649     }
 650
 651     fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 652 }
 653
 654 static unsigned int filter_from_event( struct inotify_event *ie )
 655 {
 656     unsigned int filter = 0;
 657
 658     if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
 659         filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
 660     if (ie->mask & IN_MODIFY)
 661         filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
 662     if (ie->mask & IN_ATTRIB)
 663         filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
 664     if (ie->mask & IN_ACCESS)
 665         filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
 666     if (ie->mask & IN_CREATE)
 667         filter |= FILE_NOTIFY_CHANGE_CREATION;
 668
 669     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 )
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     set_fd_user( fd, &dir_fd_ops, &dir->obj );
1124
1125     dir_add_to_existing_notify( dir );
1126
1127     return &dir->obj;
1128 }
1129
1130 /* enable change notifications for a directory */
1131 DECL_HANDLER(read_directory_changes)
1132 {
1133     struct dir *dir;
1134     struct async *async;
1135
1136     if (!req->filter)
1137     {
1138         set_error(STATUS_INVALID_PARAMETER);
1139         return;
1140     }
1141
1142     dir = get_dir_obj( current->process, req->async.handle, 0 );
1143     if (!dir)
1144         return;
1145
1146     /* requests don't timeout */
1147     if (!(async = fd_queue_async( dir->fd, &req->async, ASYNC_TYPE_WAIT ))) goto end;
1148
1149     /* assign it once */
1150     if (!dir->filter)
1151     {
1152         init_inotify();
1153         insert_change( dir );
1154         dir->filter = req->filter;
1155         dir->subtree = req->subtree;
1156         dir->want_data = req->want_data;
1157     }
1158
1159     /* if there's already a change in the queue, send it */
1160     if (!list_empty( &dir->change_records ))
1161         fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
1162
1163     /* setup the real notification */
1164     if (!inotify_adjust_changes( dir ))
1165         dnotify_adjust_changes( dir );
1166
1167     release_object( async );
1168     set_error(STATUS_PENDING);
1169
1170 end:
1171     release_object( dir );
1172 }
1173
1174 DECL_HANDLER(read_change)
1175 {
1176     struct change_record *record;
1177     struct dir *dir;
1178
1179     dir = get_dir_obj( current->process, req->handle, 0 );
1180     if (!dir)
1181         return;
1182
1183     if ((record = get_first_change_record( dir )) != NULL)
1184     {
1185         reply->action = record->action;
1186         set_reply_data( record->name, record->len );
1187         free( record );
1188     }
1189     else
1190         set_error( STATUS_NO_DATA_DETECTED );
1191
1192     release_object( dir );
1193 }