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