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