src/text/filesystem.c

   1 /*****************************************************************************
   2  * filesystem.c: File system helpers
   3  *****************************************************************************
   4  * Copyright (C) 2005-2006 the VideoLAN team
   5  * Copyright © 2005-2008 Rémi Denis-Courmont
   6  *
   7  * Authors: Rémi Denis-Courmont <rem # videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_charset.h>
  33 #include <vlc_fs.h>
  34 #include "libvlc.h" /* vlc_mkdir */
  35 #include <vlc_rand.h>
  36
  37 #include <assert.h>
  38
  39 #include <stdio.h>
  40 #include <limits.h> /* NAME_MAX */
  41 #if !defined(NAME_MAX) && defined(_POSIX_NAME_MAX)
  42 # define NAME_MAX _POSIX_NAME_MAX
  43 #endif
  44 #include <errno.h>
  45 #include <sys/types.h>
  46 #include <dirent.h>
  47 #ifdef HAVE_SYS_STAT_H
  48 # include <sys/stat.h>
  49 #endif
  50 #ifdef HAVE_FCNTL_H
  51 # include <fcntl.h>
  52 #endif
  53 #ifdef WIN32
  54 # include <io.h>
  55 # include <winsock2.h>
  56 # ifndef UNDER_CE
  57 #  include <direct.h>
  58 # else
  59 #  include <tchar.h>
  60 # endif
  61 #else
  62 # include <unistd.h>
  63 # include <sys/socket.h>
  64 #endif
  65
  66 #ifndef HAVE_LSTAT
  67 # define lstat( a, b ) stat(a, b)
  68 #endif
  69
  70 #ifdef WIN32
  71 static int convert_path (const char *restrict path, wchar_t *restrict wpath)
  72 {
  73     if (!MultiByteToWideChar (CP_UTF8, 0, path, -1, wpath, MAX_PATH))
  74     {
  75         errno = ENOENT;
  76         return -1;
  77     }
  78     wpath[MAX_PATH] = L'\0';
  79     return 0;
  80 }
  81 # define CONVERT_PATH(path, wpath, err) \
  82   wchar_t wpath[MAX_PATH+1]; \
  83   if (convert_path (path, wpath)) \
  84       return (err)
  85 #endif
  86
  87 /**
  88  * Opens a system file handle.
  89  *
  90  * @param filename file path to open (with UTF-8 encoding)
  91  * @param flags open() flags, see the C library open() documentation
  92  * @return a file handle on success, -1 on error (see errno).
  93  * @note Contrary to standard open(), this function returns file handles
  94  * with the close-on-exec flag enabled.
  95  */
  96 int vlc_open (const char *filename, int flags, ...)
  97 {
  98     unsigned int mode = 0;
  99     va_list ap;
 100
 101     va_start (ap, flags);
 102     if (flags & O_CREAT)
 103         mode = va_arg (ap, unsigned int);
 104     va_end (ap);
 105
 106 #ifdef O_CLOEXEC
 107     flags |= O_CLOEXEC;
 108 #endif
 109
 110 #ifdef UNDER_CE
 111     /*_open translates to wchar internally on WinCE*/
 112     return _open (filename, flags, mode);
 113 #elif defined (WIN32)
 114     /*
 115      * open() cannot open files with non-“ANSI” characters on Windows.
 116      * We use _wopen() instead. Same thing for mkdir() and stat().
 117      */
 118     CONVERT_PATH(filename, wpath, -1);
 119     return _wopen (wpath, flags, mode);
 120
 121 #endif
 122     const char *local_name = ToLocale (filename);
 123
 124     if (local_name == NULL)
 125     {
 126         errno = ENOENT;
 127         return -1;
 128     }
 129
 130     int fd = open (local_name, flags, mode);
 131 #ifdef HAVE_FCNTL
 132     if (fd != -1)
 133         fcntl (fd, F_SETFD, FD_CLOEXEC);
 134 #endif
 135
 136     LocaleFree (local_name);
 137     return fd;
 138 }
 139
 140 /**
 141  * Opens a FILE pointer.
 142  * @param filename file path, using UTF-8 encoding
 143  * @param mode fopen file open mode
 144  * @return NULL on error, an open FILE pointer on success.
 145  */
 146 FILE *vlc_fopen (const char *filename, const char *mode)
 147 {
 148     int rwflags = 0, oflags = 0;
 149     bool append = false;
 150
 151     for (const char *ptr = mode; *ptr; ptr++)
 152     {
 153         switch (*ptr)
 154         {
 155             case 'r':
 156                 rwflags = O_RDONLY;
 157                 break;
 158
 159             case 'a':
 160                 rwflags = O_WRONLY;
 161                 oflags |= O_CREAT;
 162                 append = true;
 163                 break;
 164
 165             case 'w':
 166                 rwflags = O_WRONLY;
 167                 oflags |= O_CREAT | O_TRUNC;
 168                 break;
 169
 170             case '+':
 171                 rwflags = O_RDWR;
 172                 break;
 173
 174 #ifdef O_TEXT
 175             case 't':
 176                 oflags |= O_TEXT;
 177                 break;
 178 #endif
 179         }
 180     }
 181
 182     int fd = vlc_open (filename, rwflags | oflags, 0666);
 183     if (fd == -1)
 184         return NULL;
 185
 186     if (append && (lseek (fd, 0, SEEK_END) == -1))
 187     {
 188         close (fd);
 189         return NULL;
 190     }
 191
 192     FILE *stream = fdopen (fd, mode);
 193     if (stream == NULL)
 194         close (fd);
 195
 196     return stream;
 197 }
 198
 199 /**
 200  * Opens a system file handle relative to an existing directory handle.
 201  *
 202  * @param dir directory file descriptor
 203  * @param filename file path to open (with UTF-8 encoding)
 204  * @param flags open() flags, see the C library open() documentation
 205  * @return a file handle on success, -1 on error (see errno).
 206  * @note Contrary to standard open(), this function returns file handles
 207  * with the close-on-exec flag enabled.
 208  */
 209 int vlc_openat (int dir, const char *filename, int flags, ...)
 210 {
 211     unsigned int mode = 0;
 212     va_list ap;
 213
 214     va_start (ap, flags);
 215     if (flags & O_CREAT)
 216         mode = va_arg (ap, unsigned int);
 217     va_end (ap);
 218
 219 #ifdef O_CLOEXEC
 220     flags |= O_CLOEXEC;
 221 #endif
 222
 223     const char *local_name = ToLocale (filename);
 224     if (local_name == NULL)
 225     {
 226         errno = ENOENT;
 227         return -1;
 228     }
 229
 230 #ifdef HAVE_OPENAT
 231     int fd = openat (dir, local_name, flags, mode);
 232 # ifdef HAVE_FCNTL
 233     if (fd != -1)
 234         fcntl (fd, F_SETFD, FD_CLOEXEC);
 235 # endif
 236 #else
 237     int fd = -1;
 238     errno = ENOSYS;
 239 #endif
 240
 241     LocaleFree (local_name);
 242     return fd;
 243 }
 244
 245
 246 /**
 247  * Creates a directory using UTF-8 paths.
 248  *
 249  * @param dirname a UTF-8 string with the name of the directory that you
 250  *        want to create.
 251  * @param mode directory permissions
 252  * @return 0 on success, -1 on error (see errno).
 253  */
 254 int vlc_mkdir( const char *dirname, mode_t mode )
 255 {
 256 #if defined (UNDER_CE)
 257     (void) mode;
 258     /* mkdir converts internally to wchar */
 259     return _mkdir(dirname);
 260 #elif defined (WIN32)
 261     (void) mode;
 262     CONVERT_PATH (dirname, wpath, -1);
 263     return _wmkdir (wpath);
 264
 265 #else
 266     char *locname = ToLocale( dirname );
 267     int res;
 268
 269     if( locname == NULL )
 270     {
 271         errno = ENOENT;
 272         return -1;
 273     }
 274     res = mkdir( locname, mode );
 275
 276     LocaleFree( locname );
 277     return res;
 278 #endif
 279 }
 280
 281 /**
 282  * Opens a DIR pointer.
 283  *
 284  * @param dirname UTF-8 representation of the directory name
 285  * @return a pointer to the DIR struct, or NULL in case of error.
 286  * Release with standard closedir().
 287  */
 288 DIR *vlc_opendir( const char *dirname )
 289 {
 290 #ifdef WIN32
 291     CONVERT_PATH (dirname, wpath, NULL);
 292     return (DIR *)vlc_wopendir (wpath);
 293
 294 #else
 295     const char *local_name = ToLocale( dirname );
 296
 297     if( local_name != NULL )
 298     {
 299         DIR *dir = opendir( local_name );
 300         LocaleFree( local_name );
 301         return dir;
 302     }
 303 #endif
 304
 305     errno = ENOENT;
 306     return NULL;
 307 }
 308
 309 /**
 310  * Reads the next file name from an open directory.
 311  *
 312  * @param dir The directory that is being read
 313  *
 314  * @return a UTF-8 string of the directory entry. Use free() to release it.
 315  * If there are no more entries in the directory, NULL is returned.
 316  * If an error occurs, errno is set and NULL is returned.
 317  */
 318 char *vlc_readdir( DIR *dir )
 319 {
 320 #ifdef WIN32
 321     struct _wdirent *ent = vlc_wreaddir (dir);
 322     if (ent == NULL)
 323         return NULL;
 324
 325     return FromWide (ent->d_name);
 326 #else
 327     struct dirent *ent;
 328     struct
 329     {
 330         struct dirent ent;
 331         char buf[NAME_MAX + 1];
 332     } buf;
 333     int val = readdir_r (dir, &buf.ent, &ent);
 334     if (val)
 335     {
 336         errno = val;
 337         return NULL;
 338     }
 339     return ent ? vlc_fix_readdir( ent->d_name ) : NULL;
 340 #endif
 341 }
 342
 343 static int dummy_select( const char *str )
 344 {
 345     (void)str;
 346     return 1;
 347 }
 348
 349 /**
 350  * Does the same as vlc_scandir(), but takes an open directory pointer
 351  * instead of a directory path.
 352  */
 353 int vlc_loaddir( DIR *dir, char ***namelist,
 354                   int (*select)( const char * ),
 355                   int (*compar)( const char **, const char ** ) )
 356 {
 357     assert (dir);
 358
 359     if (select == NULL)
 360         select = dummy_select;
 361
 362     char **tab = NULL;
 363     unsigned num = 0;
 364
 365     rewinddir (dir);
 366
 367     for (unsigned size = 0;;)
 368     {
 369         errno = 0;
 370         char *entry = vlc_readdir (dir);
 371         if (entry == NULL)
 372         {
 373             if (errno)
 374                 goto error;
 375             break;
 376         }
 377
 378         if (!select (entry))
 379         {
 380             free (entry);
 381             continue;
 382         }
 383
 384         if (num >= size)
 385         {
 386             size = size ? (2 * size) : 16;
 387             char **newtab = realloc (tab, sizeof (*tab) * (size));
 388
 389             if (unlikely(newtab == NULL))
 390             {
 391                 free (entry);
 392                 goto error;
 393             }
 394             tab = newtab;
 395         }
 396
 397         tab[num++] = entry;
 398     }
 399
 400     if (compar != NULL)
 401         qsort (tab, num, sizeof (*tab),
 402                (int (*)( const void *, const void *))compar);
 403     *namelist = tab;
 404     return num;
 405
 406 error:
 407     for (unsigned i = 0; i < num; i++)
 408         free (tab[i]);
 409     free (tab);
 410     return -1;
 411 }
 412
 413 /**
 414  * Selects file entries from a directory, as GNU C scandir().
 415  *
 416  * @param dirname UTF-8 diretory path
 417  * @param pointer [OUT] pointer set, on successful completion, to the address
 418  * of a table of UTF-8 filenames. All filenames must be freed with free().
 419  * The table itself must be freed with free() as well.
 420  *
 421  * @return How many file names were selected (possibly 0),
 422  * or -1 in case of error.
 423  */
 424 int vlc_scandir( const char *dirname, char ***namelist,
 425                   int (*select)( const char * ),
 426                   int (*compar)( const char **, const char ** ) )
 427 {
 428     DIR *dir = vlc_opendir (dirname);
 429     int val = -1;
 430
 431     if (dir != NULL)
 432     {
 433         val = vlc_loaddir (dir, namelist, select, compar);
 434         closedir (dir);
 435     }
 436     return val;
 437 }
 438
 439 static int vlc_statEx( const char *filename, struct stat *buf,
 440                         bool deref )
 441 {
 442 #ifdef UNDER_CE
 443     /*_stat translates to wchar internally on WinCE*/
 444     return _stat( filename, buf );
 445 #elif defined (WIN32)
 446     CONVERT_PATH (filename, wpath, -1);
 447     return _wstati64 (wpath, buf);
 448
 449 #endif
 450 #ifdef HAVE_SYS_STAT_H
 451     const char *local_name = ToLocale( filename );
 452
 453     if( local_name != NULL )
 454     {
 455         int res = deref ? stat( local_name, buf )
 456                        : lstat( local_name, buf );
 457         LocaleFree( local_name );
 458         return res;
 459     }
 460     errno = ENOENT;
 461 #endif
 462     return -1;
 463 }
 464
 465 /**
 466  * Finds file/inode information, as stat().
 467  * Consider using fstat() instead, if possible.
 468  *
 469  * @param filename UTF-8 file path
 470  */
 471 int vlc_stat( const char *filename, struct stat *buf)
 472 {
 473     return vlc_statEx( filename, buf, true );
 474 }
 475
 476 /**
 477  * Finds file/inode information, as lstat().
 478  * Consider using fstat() instead, if possible.
 479  *
 480  * @param filename UTF-8 file path
 481  */
 482 int vlc_lstat( const char *filename, struct stat *buf)
 483 {
 484     return vlc_statEx( filename, buf, false );
 485 }
 486
 487 /**
 488  * Removes a file.
 489  *
 490  * @param filename a UTF-8 string with the name of the file you want to delete.
 491  * @return A 0 return value indicates success. A -1 return value indicates an
 492  *        error, and an error code is stored in errno
 493  */
 494 int vlc_unlink( const char *filename )
 495 {
 496 #ifdef UNDER_CE
 497     /*_open translates to wchar internally on WinCE*/
 498     return _unlink( filename );
 499 #elif defined (WIN32)
 500     CONVERT_PATH (filename, wpath, -1);
 501     return _wunlink (wpath);
 502
 503 #endif
 504     const char *local_name = ToLocale( filename );
 505
 506     if( local_name == NULL )
 507     {
 508         errno = ENOENT;
 509         return -1;
 510     }
 511
 512     int ret = unlink( local_name );
 513     LocaleFree( local_name );
 514     return ret;
 515 }
 516
 517 /**
 518  * Moves a file atomically. This only works within a single file system.
 519  *
 520  * @param oldpath path to the file before the move
 521  * @param newpath intended path to the file after the move
 522  * @return A 0 return value indicates success. A -1 return value indicates an
 523  *        error, and an error code is stored in errno
 524  */
 525 int vlc_rename (const char *oldpath, const char *newpath)
 526 {
 527 #if defined (WIN32)
 528     CONVERT_PATH (oldpath, wold, -1);
 529     CONVERT_PATH (newpath, wnew, -1);
 530 # ifdef UNDER_CE
 531     /* FIXME: errno support */
 532     if (MoveFileW (wold, wnew))
 533         return 0;
 534     else
 535         return -1;
 536 #else
 537     if (_wrename (wold, wnew) && errno == EACCES)
 538     {   /* Windows does not allow atomic file replacement */
 539         if (_wremove (wnew))
 540         {
 541             errno = EACCES; /* restore errno */
 542             return -1;
 543         }
 544         if (_wrename (wold, wnew))
 545             return -1;
 546     }
 547     return 0;
 548 #endif
 549
 550 #endif
 551     const char *lo = ToLocale (oldpath);
 552     if (lo == NULL)
 553         goto error;
 554
 555     const char *ln = ToLocale (newpath);
 556     if (ln == NULL)
 557     {
 558         LocaleFree (lo);
 559 error:
 560         errno = ENOENT;
 561         return -1;
 562     }
 563
 564     int ret = rename (lo, ln);
 565     LocaleFree (lo);
 566     LocaleFree (ln);
 567     return ret;
 568 }
 569
 570 int vlc_mkstemp( char *template )
 571 {
 572     static const char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 573     static const int i_digits = sizeof(digits)/sizeof(*digits) - 1;
 574
 575     /* */
 576     assert( template );
 577
 578     /* Check template validity */
 579     const size_t i_length = strlen( template );
 580     char *psz_rand = &template[i_length-6];
 581
 582     if( i_length < 6 || strcmp( psz_rand, "XXXXXX" ) )
 583     {
 584         errno = EINVAL;
 585         return -1;
 586     }
 587
 588     /* */
 589     for( int i = 0; i < 256; i++ )
 590     {
 591         /* Create a pseudo random file name */
 592         uint8_t pi_rand[6];
 593
 594         vlc_rand_bytes( pi_rand, sizeof(pi_rand) );
 595         for( int j = 0; j < 6; j++ )
 596             psz_rand[j] = digits[pi_rand[j] % i_digits];
 597
 598         /* */
 599         int fd = vlc_open( template, O_CREAT | O_EXCL | O_RDWR, 0600 );
 600         if( fd >= 0 )
 601             return fd;
 602         if( errno != EEXIST )
 603             return -1;
 604     }
 605
 606     errno = EEXIST;
 607     return -1;
 608 }
 609
 610 #ifdef UNDER_CE
 611 # define dup(fd) (fd, -1)
 612 #endif
 613
 614 /**
 615  * Duplicates a file descriptor. The new file descriptor has the close-on-exec
 616  * descriptor flag set.
 617  * @return a new file descriptor or -1
 618  */
 619 int vlc_dup (int oldfd)
 620 {
 621     int newfd;
 622
 623 #ifdef HAVE_DUP3
 624     /* Unfortunately, dup3() works like dup2(), not like plain dup(). So we
 625      * need such contortion to find the new file descriptor while preserving
 626      * thread safety of the file descriptor table. */
 627     newfd = vlc_open ("/dev/null", O_RDONLY);
 628     if (likely(newfd != -1))
 629     {
 630         if (likely(dup3 (oldfd, newfd, O_CLOEXEC) == newfd))
 631             return newfd;
 632         close (newfd);
 633     }
 634 #endif
 635
 636     newfd = dup (oldfd);
 637 #ifdef HAVE_FCNTL
 638     if (likely(newfd != -1))
 639         fcntl (newfd, F_SETFD, FD_CLOEXEC);
 640 #endif
 641     return newfd;
 642 }
 643
 644 #include <vlc_network.h>
 645
 646 /**
 647  * Creates a socket file descriptor. The new file descriptor has the
 648  * close-on-exec flag set.
 649  * @param pf protocol family
 650  * @param type socket type
 651  * @param proto network protocol
 652  * @param nonblock true to create a non-blocking socket
 653  * @return a new file descriptor or -1
 654  */
 655 int vlc_socket (int pf, int type, int proto, bool nonblock)
 656 {
 657     int fd;
 658
 659 #ifdef SOCK_CLOEXEC
 660     type |= SOCK_CLOEXEC;
 661     if (nonblock)
 662         type |= SOCK_NONBLOCK;
 663     fd = socket (pf, type, proto);
 664     if (fd != -1 || errno != EINVAL)
 665         return fd;
 666
 667     type &= ~(SOCK_CLOEXEC|SOCK_NONBLOCK);
 668 #endif
 669
 670     fd = socket (pf, type, proto);
 671     if (fd == -1)
 672         return -1;
 673
 674 #ifndef WIN32
 675     fcntl (fd, F_SETFD, FD_CLOEXEC);
 676     if (nonblock)
 677         fcntl (fd, F_SETFL, fcntl (fd, F_GETFL, 0) | O_NONBLOCK);
 678 #else
 679     if (nonblock)
 680         ioctlsocket (fd, FIONBIO, &(unsigned long){ 1 });
 681 #endif
 682     return fd;
 683 }
 684
 685 /**
 686  * Accepts an inbound connection request on a listening socket.
 687  * The new file descriptor has the close-on-exec flag set.
 688  * @param lfd listening socket file descriptor
 689  * @param addr pointer to the peer address or NULL [OUT]
 690  * @param alen pointer to the length of the peer address or NULL [OUT]
 691  * @param nonblock whether to put the new socket in non-blocking mode
 692  * @return a new file descriptor, or -1 on error.
 693  */
 694 int vlc_accept (int lfd, struct sockaddr *addr, socklen_t *alen, bool nonblock)
 695 {
 696 #ifdef HAVE_ACCEPT4
 697     int flags = SOCK_CLOEXEC;
 698     if (nonblock)
 699         flags |= SOCK_NONBLOCK;
 700
 701     do
 702     {
 703         int fd = accept4 (lfd, addr, alen, flags);
 704         if (fd != -1)
 705             return fd;
 706     }
 707     while (errno == EINTR);
 708
 709     if (errno != ENOSYS)
 710         return -1;
 711 #endif
 712 #ifdef WIN32
 713     errno = 0;
 714 #endif
 715
 716     do
 717     {
 718         int fd = accept (lfd, addr, alen);
 719         if (fd != -1)
 720         {
 721 #ifndef WIN32
 722             fcntl (fd, F_SETFD, FD_CLOEXEC);
 723             if (nonblock)
 724                 fcntl (fd, F_SETFL, fcntl (fd, F_GETFL, 0) | O_NONBLOCK);
 725 #else
 726             if (nonblock)
 727                 ioctlsocket (fd, FIONBIO, &(unsigned long){ 1 });
 728 #endif
 729             return fd;
 730         }
 731     }
 732     while (errno == EINTR);
 733
 734     return -1;
 735 }