src/data/make-file.c

   1 /* PSPP - a program for statistical analysis.
   2    Copyright (C) 2004, 2010, 2015 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
  16
  17 #include <config.h>
  18
  19 #include "data/make-file.h"
  20 #include "libpspp/i18n.h"
  21
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <sys/stat.h>
  28 #include <unistd.h>
  29
  30 #include "data/file-name.h"
  31 #include "data/file-handle-def.h"
  32 #include "libpspp/ll.h"
  33 #include "libpspp/message.h"
  34
  35 #include "gl/fatal-signal.h"
  36 #include "gl/tempname.h"
  37 #include "gl/xalloc.h"
  38 #include "gl/xvasprintf.h"
  39 #include "gl/localcharset.h"
  40
  41 #include "gettext.h"
  42 #define _(msgid) gettext (msgid)
  43
  44
  45 #if defined _WIN32 || defined __WIN32__
  46 #define WIN32_LEAN_AND_MEAN  /* avoid including junk */
  47 #include <windows.h>
  48 #define TS_stat _stat
  49 #define Tunlink _wunlink
  50 #define Topen _wopen
  51 #define Tstat _wstat
  52
  53 /* Shamelessly lifted and modified from the rpl_rename function in Gnulib */
  54 static int
  55 Trename (TCHAR const *src, TCHAR const *dst)
  56 {
  57   int error;
  58
  59   /* MoveFileExW works if SRC is a directory without any flags, but
  60      fails with MOVEFILE_REPLACE_EXISTING, so try without flags first.
  61      Thankfully, MoveFileExW handles hard links correctly, even though
  62      rename() does not.  */
  63   if (MoveFileExW (src, dst, 0))
  64     return 0;
  65
  66   /* Retry with MOVEFILE_REPLACE_EXISTING if the move failed
  67      due to the destination already existing.  */
  68   error = GetLastError ();
  69   if (error == ERROR_FILE_EXISTS || error == ERROR_ALREADY_EXISTS)
  70     {
  71       if (MoveFileExW (src, dst, MOVEFILE_REPLACE_EXISTING))
  72         return 0;
  73
  74       error = GetLastError ();
  75     }
  76
  77   switch (error)
  78     {
  79     case ERROR_FILE_NOT_FOUND:
  80     case ERROR_PATH_NOT_FOUND:
  81     case ERROR_BAD_PATHNAME:
  82     case ERROR_DIRECTORY:
  83       errno = ENOENT;
  84       break;
  85
  86     case ERROR_ACCESS_DENIED:
  87     case ERROR_SHARING_VIOLATION:
  88       errno = EACCES;
  89       break;
  90
  91     case ERROR_OUTOFMEMORY:
  92       errno = ENOMEM;
  93       break;
  94
  95     case ERROR_CURRENT_DIRECTORY:
  96       errno = EBUSY;
  97       break;
  98
  99     case ERROR_NOT_SAME_DEVICE:
 100       errno = EXDEV;
 101       break;
 102
 103     case ERROR_WRITE_PROTECT:
 104       errno = EROFS;
 105       break;
 106
 107     case ERROR_WRITE_FAULT:
 108     case ERROR_READ_FAULT:
 109     case ERROR_GEN_FAILURE:
 110       errno = EIO;
 111       break;
 112
 113     case ERROR_HANDLE_DISK_FULL:
 114     case ERROR_DISK_FULL:
 115     case ERROR_DISK_TOO_FRAGMENTED:
 116       errno = ENOSPC;
 117       break;
 118
 119     case ERROR_FILE_EXISTS:
 120     case ERROR_ALREADY_EXISTS:
 121       errno = EEXIST;
 122       break;
 123
 124     case ERROR_BUFFER_OVERFLOW:
 125     case ERROR_FILENAME_EXCED_RANGE:
 126       errno = ENAMETOOLONG;
 127       break;
 128
 129     case ERROR_INVALID_NAME:
 130     case ERROR_DELETE_PENDING:
 131       errno = EPERM;        /* ? */
 132       break;
 133
 134 # ifndef ERROR_FILE_TOO_LARGE
 135 /* This value is documented but not defined in all versions of windows.h.  */
 136 #  define ERROR_FILE_TOO_LARGE 223
 137 # endif
 138     case ERROR_FILE_TOO_LARGE:
 139       errno = EFBIG;
 140       break;
 141
 142     default:
 143       errno = EINVAL;
 144       break;
 145     }
 146
 147   return -1;
 148 }
 149
 150 TCHAR *
 151 convert_to_filename_encoding (const char *s, size_t len, const char *current_encoding)
 152 {
 153   const char *enc = current_encoding;
 154   if (NULL == enc || 0 == strcmp (enc, "Auto"))
 155     enc = locale_charset ();
 156
 157   return (TCHAR *) recode_string ("UTF-16LE", enc, s, len);
 158 }
 159
 160
 161 #else
 162 #define TS_stat stat
 163 #define Trename rename
 164 #define Tunlink unlink
 165 #define Topen open
 166 #define Tstat stat
 167
 168 TCHAR *
 169 convert_to_filename_encoding (const char *s, size_t len UNUSED, const char *current_encoding UNUSED)
 170 {
 171   /* Non-windows systems don't care about the encoding.
 172      The string is copied here, to be consistent with the w32 case.  */
 173   return xstrdup (s);
 174 }
 175
 176 #endif
 177
 178
 179 struct replace_file
 180 {
 181   struct ll ll;
 182   TCHAR *file_name;
 183   TCHAR *tmp_name;
 184
 185   char *tmp_name_verbatim;
 186   const char *file_name_verbatim;
 187 };
 188
 189 static struct ll_list all_files = LL_INITIALIZER (all_files);
 190
 191 static void free_replace_file (struct replace_file *);
 192 static void unlink_replace_files (int sig);
 193
 194 struct replace_file *
 195 replace_file_start (const struct file_handle *fh, const char *mode,
 196                     mode_t permissions, FILE **fp)
 197 {
 198   static bool registered;
 199   struct TS_stat s;
 200   struct replace_file *rf;
 201   int fd;
 202   int saved_errno = errno;
 203
 204   const char *file_name = fh_get_file_name (fh);
 205
 206   TCHAR * Tfile_name = convert_to_filename_encoding (file_name, strlen (file_name), fh_get_file_name_encoding (fh));
 207
 208   /* If FILE_NAME represents a special file, write to it directly
 209      instead of trying to replace it. */
 210   if (Tstat (Tfile_name, &s) == 0 && !S_ISREG (s.st_mode))
 211     {
 212       /* Open file descriptor. */
 213       fd = Topen (Tfile_name, O_WRONLY);
 214       if (fd < 0)
 215         {
 216           saved_errno = errno;
 217           msg (ME, _("Opening %s for writing: %s."),
 218                file_name, strerror (saved_errno));
 219           free (Tfile_name);
 220           return NULL;
 221         }
 222
 223       /* Open file as stream. */
 224       *fp = fdopen (fd, mode);
 225       if (*fp == NULL)
 226         {
 227           saved_errno = errno;
 228           msg (ME, _("Opening stream for %s: %s."),
 229                file_name, strerror (saved_errno));
 230           close (fd);
 231           free (Tfile_name);
 232           return NULL;
 233         }
 234
 235       rf = xzalloc (sizeof *rf);
 236       rf->file_name = NULL;
 237       rf->tmp_name = Tfile_name;
 238       return rf;
 239     }
 240
 241   if (!registered)
 242     {
 243       at_fatal_signal (unlink_replace_files);
 244       registered = true;
 245     }
 246   block_fatal_signals ();
 247
 248   rf = xzalloc (sizeof *rf);
 249   rf->file_name = Tfile_name;
 250   rf->file_name_verbatim = file_name;
 251
 252   for (;;)
 253     {
 254       /* Generate unique temporary file name. */
 255       free (rf->tmp_name_verbatim);
 256       rf->tmp_name_verbatim = xasprintf ("%stmpXXXXXX", file_name);
 257       if (gen_tempname (rf->tmp_name_verbatim, 0, 0600, GT_NOCREATE) < 0)
 258         {
 259           saved_errno = errno;
 260           msg (ME, _("Creating temporary file to replace %s: %s."),
 261                file_name, strerror (saved_errno));
 262           goto error;
 263         }
 264
 265       rf->tmp_name = convert_to_filename_encoding (rf->tmp_name_verbatim, strlen (rf->tmp_name_verbatim), fh_get_file_name_encoding (fh));
 266
 267       /* Create file by that name. */
 268       bool binary = strchr (mode, 'b') != NULL;
 269       fd = Topen (rf->tmp_name,
 270                   O_WRONLY | O_CREAT | O_EXCL | (binary ? O_BINARY : O_TEXT),
 271                   permissions);
 272       if (fd >= 0)
 273         break;
 274       if (errno != EEXIST)
 275         {
 276           saved_errno = errno;
 277           msg (ME, _("Creating temporary file %s: %s."),
 278                rf->tmp_name_verbatim, strerror (saved_errno));
 279           goto error;
 280         }
 281     }
 282
 283
 284   /* Open file as stream. */
 285   *fp = fdopen (fd, mode);
 286   if (*fp == NULL)
 287     {
 288       saved_errno = errno;
 289       msg (ME, _("Opening stream for temporary file %s: %s."),
 290            rf->tmp_name_verbatim, strerror (saved_errno));
 291       close (fd);
 292       Tunlink (rf->tmp_name);
 293       goto error;
 294     }
 295
 296   /* Register file for deletion. */
 297   ll_push_head (&all_files, &rf->ll);
 298   unblock_fatal_signals ();
 299
 300   return rf;
 301
 302  error:
 303   unblock_fatal_signals ();
 304   free_replace_file (rf);
 305   *fp = NULL;
 306   errno = saved_errno;
 307   return NULL;
 308 }
 309
 310 bool
 311 replace_file_commit (struct replace_file *rf)
 312 {
 313   bool ok = true;
 314
 315   if (rf->file_name != NULL)
 316     {
 317       int save_errno;
 318
 319       block_fatal_signals ();
 320       ok = Trename (rf->tmp_name, rf->file_name) == 0;
 321       save_errno = errno;
 322       ll_remove (&rf->ll);
 323       unblock_fatal_signals ();
 324
 325       if (!ok)
 326         msg (ME, _("Replacing %s by %s: %s."),
 327              rf->file_name_verbatim, rf->tmp_name_verbatim, strerror (save_errno));
 328     }
 329   else
 330     {
 331       /* Special file: no temporary file to rename. */
 332     }
 333   free_replace_file (rf);
 334
 335   return ok;
 336 }
 337
 338 bool
 339 replace_file_abort (struct replace_file *rf)
 340 {
 341   bool ok = true;
 342
 343   if (rf->file_name != NULL)
 344     {
 345       int save_errno;
 346
 347       block_fatal_signals ();
 348       ok = Tunlink (rf->tmp_name) == 0;
 349       save_errno = errno;
 350       ll_remove (&rf->ll);
 351       unblock_fatal_signals ();
 352
 353       if (!ok)
 354         msg (ME, _("Removing %s: %s."), rf->tmp_name_verbatim, strerror (save_errno));
 355     }
 356   else
 357     {
 358       /* Special file: no temporary file to unlink. */
 359     }
 360   free_replace_file (rf);
 361
 362   return ok;
 363 }
 364
 365 static void
 366 free_replace_file (struct replace_file *rf)
 367 {
 368   free (rf->file_name);
 369   free (rf->tmp_name);
 370   free (rf->tmp_name_verbatim);
 371   free (rf);
 372 }
 373
 374 static void
 375 unlink_replace_files (int sig UNUSED)
 376 {
 377   struct replace_file *rf;
 378
 379   block_fatal_signals ();
 380   ll_for_each (rf, struct replace_file, ll, &all_files)
 381     {
 382       /* We don't free_replace_file(RF) because calling free is unsafe
 383          from an asynchronous signal handler. */
 384       Tunlink (rf->tmp_name);
 385     }
 386   unblock_fatal_signals ();
 387 }