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