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 struct dir *get_dir_obj( struct process *process, obj_handle_t handle, unsigned int access )
 423 {
 424     return (struct dir *)get_handle_obj( process, handle, access, &dir_ops );
 425 }
 426
 427 static int dir_get_poll_events( struct fd *fd )
 428 {
 429     return 0;
 430 }
 431
 432 static enum server_fd_type dir_get_fd_type( struct fd *fd )
 433 {
 434     return FD_TYPE_DIR;
 435 }
 436
 437 #ifdef USE_INOTIFY
 438
 439 #define HASH_SIZE 31
 440
 441 struct inode {
 442     struct list ch_entry;    /* entry in the children list */
 443     struct list children;    /* children of this inode */
 444     struct inode *parent;    /* parent of this inode */
 445     struct list dirs;        /* directory handles watching this inode */
 446     struct list ino_entry;   /* entry in the inode hash */
 447     struct list wd_entry;    /* entry in the watch descriptor hash */
 448     dev_t dev;               /* device number */
 449     ino_t ino;               /* device's inode number */
 450     int wd;                  /* inotify's watch descriptor */
 451     char *name;              /* basename name of the inode */
 452 };
 453
 454 struct list inode_hash[ HASH_SIZE ];
 455 struct list wd_hash[ HASH_SIZE ];
 456
 457 static int inotify_add_dir( char *path, unsigned int filter );
 458
 459 static struct inode *inode_from_wd( int wd )
 460 {
 461     struct list *bucket = &wd_hash[ wd % HASH_SIZE ];
 462     struct inode *inode;
 463
 464     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, wd_entry )
 465         if (inode->wd == wd)
 466             return inode;
 467
 468     return NULL;
 469 }
 470
 471 static inline struct list *get_hash_list( dev_t dev, ino_t ino )
 472 {
 473     return &inode_hash[ (ino ^ dev) % HASH_SIZE ];
 474 }
 475
 476 static struct inode *find_inode( dev_t dev, ino_t ino )
 477 {
 478     struct list *bucket = get_hash_list( dev, ino );
 479     struct inode *inode;
 480
 481     LIST_FOR_EACH_ENTRY( inode, bucket, struct inode, ino_entry )
 482         if (inode->ino == ino && inode->dev == dev)
 483              return inode;
 484
 485     return NULL;
 486 }
 487
 488 static struct inode *create_inode( dev_t dev, ino_t ino )
 489 {
 490     struct inode *inode;
 491
 492     inode = malloc( sizeof *inode );
 493     if (inode)
 494     {
 495         list_init( &inode->children );
 496         list_init( &inode->dirs );
 497         inode->ino = ino;
 498         inode->dev = dev;
 499         inode->wd = -1;
 500         inode->parent = NULL;
 501         inode->name = NULL;
 502         list_add_tail( get_hash_list( dev, ino ), &inode->ino_entry );
 503     }
 504     return inode;
 505 }
 506
 507 static struct inode *get_inode( dev_t dev, ino_t ino )
 508 {
 509     struct inode *inode;
 510
 511     inode = find_inode( dev, ino );
 512     if (inode)
 513         return inode;
 514     return create_inode( dev, ino );
 515 }
 516
 517 static void inode_set_wd( struct inode *inode, int wd )
 518 {
 519     if (inode->wd != -1)
 520         list_remove( &inode->wd_entry );
 521     inode->wd = wd;
 522     list_add_tail( &wd_hash[ wd % HASH_SIZE ], &inode->wd_entry );
 523 }
 524
 525 static void inode_set_name( struct inode *inode, const char *name )
 526 {
 527     free (inode->name);
 528     inode->name = name ? strdup( name ) : NULL;
 529 }
 530
 531 static void free_inode( struct inode *inode )
 532 {
 533     int subtree = 0, watches = 0;
 534     struct inode *tmp, *next;
 535     struct dir *dir;
 536
 537     LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 538     {
 539         subtree |= dir->subtree;
 540         watches++;
 541     }
 542
 543     if (!subtree && !inode->parent)
 544     {
 545         LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children,
 546                                   struct inode, ch_entry )
 547         {
 548             assert( tmp != inode );
 549             assert( tmp->parent == inode );
 550             free_inode( tmp );
 551         }
 552     }
 553
 554     if (watches)
 555         return;
 556
 557     if (inode->parent)
 558         list_remove( &inode->ch_entry );
 559
 560     /* disconnect remaining children from the parent */
 561     LIST_FOR_EACH_ENTRY_SAFE( tmp, next, &inode->children, struct inode, ch_entry )
 562     {
 563         list_remove( &tmp->ch_entry );
 564         tmp->parent = NULL;
 565     }
 566
 567     if (inode->wd != -1)
 568     {
 569         inotify_rm_watch( get_unix_fd( inotify_fd ), inode->wd );
 570         list_remove( &inode->wd_entry );
 571     }
 572     list_remove( &inode->ino_entry );
 573
 574     free( inode->name );
 575     free( inode );
 576 }
 577
 578 static struct inode *inode_add( struct inode *parent,
 579                                 dev_t dev, ino_t ino, const char *name )
 580 {
 581     struct inode *inode;
 582
 583     inode = get_inode( dev, ino );
 584     if (!inode)
 585         return NULL;
 586
 587     if (!inode->parent)
 588     {
 589         list_add_tail( &parent->children, &inode->ch_entry );
 590         inode->parent = parent;
 591         assert( inode != parent );
 592     }
 593     inode_set_name( inode, name );
 594
 595     return inode;
 596 }
 597
 598 static struct inode *inode_from_name( struct inode *inode, const char *name )
 599 {
 600     struct inode *i;
 601
 602     LIST_FOR_EACH_ENTRY( i, &inode->children, struct inode, ch_entry )
 603         if (i->name && !strcmp( i->name, name ))
 604             return i;
 605     return NULL;
 606 }
 607
 608 static int inotify_get_poll_events( struct fd *fd );
 609 static void inotify_poll_event( struct fd *fd, int event );
 610
 611 static const struct fd_ops inotify_fd_ops =
 612 {
 613     inotify_get_poll_events,     /* get_poll_events */
 614     inotify_poll_event,          /* poll_event */
 615     NULL,                        /* flush */
 616     NULL,                        /* get_fd_type */
 617     NULL,                        /* ioctl */
 618     NULL,                        /* queue_async */
 619     NULL,                        /* reselect_async */
 620     NULL,                        /* cancel_async */
 621 };
 622
 623 static int inotify_get_poll_events( struct fd *fd )
 624 {
 625     return POLLIN;
 626 }
 627
 628 static void inotify_do_change_notify( struct dir *dir, unsigned int action,
 629                                       const char *relpath )
 630 {
 631     struct change_record *record;
 632
 633     assert( dir->obj.ops == &dir_ops );
 634
 635     if (dir->want_data)
 636     {
 637         size_t len = strlen(relpath);
 638         record = malloc( offsetof(struct change_record, name[len]) );
 639         if (!record)
 640             return;
 641
 642         record->action = action;
 643         memcpy( record->name, relpath, len );
 644         record->len = len;
 645
 646         list_add_tail( &dir->change_records, &record->entry );
 647     }
 648
 649     fd_async_wake_up( dir->fd, ASYNC_TYPE_WAIT, STATUS_ALERTED );
 650 }
 651
 652 static unsigned int filter_from_event( struct inotify_event *ie )
 653 {
 654     unsigned int filter = 0;
 655
 656     if (ie->mask & (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE))
 657         filter |= FILE_NOTIFY_CHANGE_FILE_NAME | FILE_NOTIFY_CHANGE_DIR_NAME;
 658     if (ie->mask & IN_MODIFY)
 659         filter |= FILE_NOTIFY_CHANGE_SIZE | FILE_NOTIFY_CHANGE_LAST_WRITE;
 660     if (ie->mask & IN_ATTRIB)
 661         filter |= FILE_NOTIFY_CHANGE_ATTRIBUTES | FILE_NOTIFY_CHANGE_SECURITY;
 662     if (ie->mask & IN_ACCESS)
 663         filter |= FILE_NOTIFY_CHANGE_LAST_ACCESS;
 664     if (ie->mask & IN_CREATE)
 665         filter |= FILE_NOTIFY_CHANGE_CREATION;
 666
 667     return filter;
 668 }
 669
 670 /* scan up the parent directories for watches */
 671 static unsigned int filter_from_inode( struct inode *inode, int is_parent )
 672 {
 673     unsigned int filter = 0;
 674     struct dir *dir;
 675
 676     /* combine filters from parents watching subtrees */
 677     while (inode)
 678     {
 679         LIST_FOR_EACH_ENTRY( dir, &inode->dirs, struct dir, in_entry )
 680             if (dir->subtree || !is_parent)
 681                 filter |= dir->filter;
 682         is_parent = 1;
 683         inode = inode->parent;
 684     }
 685
 686     return filter;
 687 }
 688
 689 static char *inode_get_path( struct inode *inode, int sz )
 690 {
 691     struct list *head;
 692     char *path;
 693     int len;
 694
 695     if (!inode)
 696         return NULL;
 697
 698     head = list_head( &inode->dirs );
 699     if (head)
 700     {
 701         int unix_fd = get_unix_fd( LIST_ENTRY( head, struct dir, in_entry )->fd );
 702         path = malloc ( 32 + sz );
 703         if (path)
 704             sprintf( path, "/proc/self/fd/%u/", unix_fd );
 705         return path;
 706     }
 707
 708     if (!inode->name)
 709         return NULL;
 710
 711     len = strlen( inode->name );
 712     path = inode_get_path( inode->parent, sz + len + 1 );
 713     if (!path)
 714         return NULL;
 715
 716     strcat( path, inode->name );
 717     strcat( path, "/" );
 718
 719     return path;
 720 }
 721
 722 static int inode_check_dir( struct inode *parent, const char *name )
 723 {
 724     char *path;
 725     unsigned int filter;
 726     struct inode *inode;
 727     struct stat st;
 728     int wd = -1, r = -1;
 729
 730     path = inode_get_path( parent, strlen(name) );
 731     if (!path)
 732         return r;
 733
 734     strcat( path, name );
 735
 736     r = stat( path, &st );
 737     if (r < 0) goto end;
 738
 739     if (!S_ISDIR(st.st_mode))
 740     {
 741         r = 0;
 742         goto end;
 743     }
 744
 745     r = 1;
 746
 747     filter = filter_from_inode( parent, 1 );
 748     if (!filter)
 749         goto end;
 750
 751     inode = inode_add( parent, st.st_dev, st.st_ino, name );
 752     if (!inode || inode->wd != -1)
 753         goto end;
 754
 755     wd = inotify_add_dir( path, filter );
 756     if (wd != -1)
 757         inode_set_wd( inode, wd );
 758     else
 759         free_inode( inode );
 760
 761 end:
 762     free( path );
 763     return r;
 764 }
 765
 766 static int prepend( char **path, const char *segment )
 767 {
 768     int extra;
 769     char *p;
 770
 771     extra = strlen( segment ) + 1;
 772     if (*path)
 773     {
 774         int len = strlen( *path ) + 1;
 775         p = realloc( *path, len + extra );
 776         if (!p) return 0;
 777         memmove( &p[ extra ], p, len );
 778         p[ extra - 1 ] = '/';
 779         memcpy( p, segment, extra - 1 );
 780     }
 781     else
 782     {
 783         p = malloc( extra );
 784         if (!p) return 0;
 785         memcpy( p, segment, extra );
 786     }
 787
 788     *path = p;
 789
 790     return 1;
 791 }
 792
 793 static void inotify_notify_all( struct inotify_event *ie )
 794 {
 795     unsigned int filter, action;
 796     struct inode *inode, *i;
 797     char *path = NULL;
 798     struct dir *dir;
 799
 800     inode = inode_from_wd( ie->wd );
 801     if (!inode)
 802     {
 803         fprintf( stderr, "no inode matches %d\n", ie->wd);
 804         return;
 805     }
 806
 807     filter = filter_from_event( ie );
 808
 809     if (ie->mask & IN_CREATE)
 810     {
 811         switch (inode_check_dir( inode, ie->name ))
 812         {
 813         case 1:
 814             filter &= ~FILE_NOTIFY_CHANGE_FILE_NAME;
 815             break;
 816         case 0:
 817             filter &= ~FILE_NOTIFY_CHANGE_DIR_NAME;
 818             break;
 819         default:
 820             break;
 821             /* Maybe the file disappeared before we could check it? */
 822         }
 823         action = FILE_ACTION_ADDED;
 824     }
 825     else if (ie->mask & IN_DELETE)
 826         action = FILE_ACTION_REMOVED;
 827     else
 828         action = FILE_ACTION_MODIFIED;
 829
 830     /*
 831      * Work our way up the inode hierarchy
 832      *  extending the relative path as we go
 833      *  and notifying all recursive watches.
 834      */
 835     if (!prepend( &path, ie->name ))
 836         return;
 837
 838     for (i = inode; i; i = i->parent)
 839     {
 840         LIST_FOR_EACH_ENTRY( dir, &i->dirs, struct dir, in_entry )
 841             if ((filter & dir->filter) && (i==inode || dir->subtree))
 842                 inotify_do_change_notify( dir, action, path );
 843
 844         if (!i->name || !prepend( &path, i->name ))
 845             break;
 846     }
 847
 848     free( path );
 849
 850     if (ie->mask & IN_DELETE)
 851     {
 852         i = inode_from_name( inode, ie->name );
 853         if (i)
 854             free_inode( i );
 855     }
 856 }
 857
 858 static void inotify_poll_event( struct fd *fd, int event )
 859 {
 860     int r, ofs, unix_fd;
 861     char buffer[0x1000];
 862     struct inotify_event *ie;
 863
 864     unix_fd = get_unix_fd( fd );
 865     r = read( unix_fd, buffer, sizeof buffer );
 866     if (r < 0)
 867     {
 868         fprintf(stderr,"inotify_poll_event(): inotify read failed!\n");
 869         return;
 870     }
 871
 872     for( ofs = 0; ofs < r - offsetof(struct inotify_event, name); )
 873     {
 874         ie = (struct inotify_event*) &buffer[ofs];
 875         if (!ie->len)
 876             break;
 877         ofs += offsetof( struct inotify_event, name[ie->len] );
 878         if (ofs > r) break;
 879         inotify_notify_all( ie );
 880     }
 881 }
 882
 883 static inline struct fd *create_inotify_fd( void )
 884 {
 885     int unix_fd;
 886
 887     unix_fd = inotify_init();
 888     if (unix_fd<0)
 889         return NULL;
 890     return create_anonymous_fd( &inotify_fd_ops, unix_fd, NULL, 0 );
 891 }
 892
 893 static int map_flags( unsigned int filter )
 894 {
 895     unsigned int mask;
 896
 897     /* always watch these so we can track subdirectories in recursive watches */
 898     mask = (IN_MOVED_FROM | IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF);
 899
 900     if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 901         mask |= IN_ATTRIB;
 902     if (filter & FILE_NOTIFY_CHANGE_SIZE)
 903         mask |= IN_MODIFY;
 904     if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 905         mask |= IN_MODIFY;
 906     if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 907         mask |= IN_ACCESS;
 908     if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 909         mask |= IN_ATTRIB;
 910
 911     return mask;
 912 }
 913
 914 static int inotify_add_dir( char *path, unsigned int filter )
 915 {
 916     int wd = inotify_add_watch( get_unix_fd( inotify_fd ),
 917                                 path, map_flags( filter ) );
 918     if (wd != -1)
 919         set_fd_events( inotify_fd, POLLIN );
 920     return wd;
 921 }
 922
 923 static int init_inotify( void )
 924 {
 925     int i;
 926
 927     if (inotify_fd)
 928         return 1;
 929
 930     inotify_fd = create_inotify_fd();
 931     if (!inotify_fd)
 932         return 0;
 933
 934     for (i=0; i<HASH_SIZE; i++)
 935     {
 936         list_init( &inode_hash[i] );
 937         list_init( &wd_hash[i] );
 938     }
 939
 940     return 1;
 941 }
 942
 943 static int inotify_adjust_changes( struct dir *dir )
 944 {
 945     unsigned int filter;
 946     struct inode *inode;
 947     struct stat st;
 948     char path[32];
 949     int wd, unix_fd;
 950
 951     if (!inotify_fd)
 952         return 0;
 953
 954     unix_fd = get_unix_fd( dir->fd );
 955
 956     inode = dir->inode;
 957     if (!inode)
 958     {
 959         /* check if this fd is already being watched */
 960         if (-1 == fstat( unix_fd, &st ))
 961             return 0;
 962
 963         inode = get_inode( st.st_dev, st.st_ino );
 964         if (!inode)
 965             inode = create_inode( st.st_dev, st.st_ino );
 966         if (!inode)
 967             return 0;
 968         list_add_tail( &inode->dirs, &dir->in_entry );
 969         dir->inode = inode;
 970     }
 971
 972     filter = filter_from_inode( inode, 0 );
 973
 974     sprintf( path, "/proc/self/fd/%u", unix_fd );
 975     wd = inotify_add_dir( path, filter );
 976     if (wd == -1) return 0;
 977
 978     inode_set_wd( inode, wd );
 979
 980     return 1;
 981 }
 982
 983 static char *get_basename( const char *link )
 984 {
 985     char *buffer, *name = NULL;
 986     int r, n = 0x100;
 987
 988     while (1)
 989     {
 990         buffer = malloc( n );
 991         if (!buffer) return NULL;
 992
 993         r = readlink( link, buffer, n );
 994         if (r < 0)
 995             break;
 996
 997         if (r < n)
 998         {
 999             name = buffer;
1000             break;
1001         }
1002         free( buffer );
1003         n *= 2;
1004     }
1005
1006     if (name)
1007     {
1008         while (r > 0 && name[ r - 1 ] == '/' )
1009             r--;
1010         name[ r ] = 0;
1011
1012         name = strrchr( name, '/' );
1013         if (name)
1014             name = strdup( &name[1] );
1015     }
1016
1017     free( buffer );
1018     return name;
1019 }
1020
1021 static int dir_add_to_existing_notify( struct dir *dir )
1022 {
1023     struct inode *inode, *parent;
1024     unsigned int filter = 0;
1025     struct stat st, st_new;
1026     char link[35], *name;
1027     int wd, unix_fd;
1028
1029     if (!inotify_fd)
1030         return 0;
1031
1032     unix_fd = get_unix_fd( dir->fd );
1033
1034     /* check if it's in the list of inodes we want to watch */
1035     if (-1 == fstat( unix_fd, &st_new ))
1036         return 0;
1037     inode = find_inode( st_new.st_dev, st_new.st_ino );
1038     if (inode)
1039         return 0;
1040
1041     /* lookup the parent */
1042     sprintf( link, "/proc/self/fd/%u/..", unix_fd );
1043     if (-1 == stat( link, &st ))
1044         return 0;
1045
1046     /*
1047      * If there's no parent, stop.  We could keep going adding
1048      *  ../ to the path until we hit the root of the tree or
1049      *  find a recursively watched ancestor.
1050      * Assume it's too expensive to search up the tree for now.
1051      */
1052     parent = find_inode( st.st_dev, st.st_ino );
1053     if (!parent)
1054         return 0;
1055
1056     if (parent->wd == -1)
1057         return 0;
1058
1059     filter = filter_from_inode( parent, 1 );
1060     if (!filter)
1061         return 0;
1062
1063     sprintf( link, "/proc/self/fd/%u", unix_fd );
1064     name = get_basename( link );
1065     if (!name)
1066         return 0;
1067     inode = inode_add( parent, st_new.st_dev, st_new.st_ino, name );
1068     free( name );
1069     if (!inode)
1070         return 0;
1071
1072     /* Couldn't find this inode at the start of the function, must be new */
1073     assert( inode->wd == -1 );
1074
1075     wd = inotify_add_dir( link, filter );
1076     if (wd != -1)
1077         inode_set_wd( inode, wd );
1078
1079     return 1;
1080 }
1081
1082 #else
1083
1084 static int init_inotify( void )
1085 {
1086     return 0;
1087 }
1088
1089 static int inotify_adjust_changes( struct dir *dir )
1090 {
1091     return 0;
1092 }
1093
1094 static void free_inode( struct inode *inode )
1095 {
1096     assert( 0 );
1097 }
1098
1099 static int dir_add_to_existing_notify( struct dir *dir )
1100 {
1101     return 0;
1102 }
1103
1104 #endif  /* USE_INOTIFY */
1105
1106 struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
1107 {
1108     struct dir *dir;
1109
1110     dir = alloc_object( &dir_ops );
1111     if (!dir)
1112         return NULL;
1113
1114     list_init( &dir->change_records );
1115     dir->filter = 0;
1116     dir->notified = 0;
1117     dir->want_data = 0;
1118     dir->inode = NULL;
1119     grab_object( fd );
1120     dir->fd = fd;
1121     dir->mode = mode;
1122     dir->uid  = ~(uid_t)0;
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 }