support/temp_file.c

   1 /* Temporary file handling for tests.
   2    Copyright (C) 1998-2022 Free Software Foundation, Inc.
   3    Copyright The GNU Tools Authors.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 /* This is required to get an mkstemp which can create large files on
  21    some 32-bit platforms. */
  22 #define _FILE_OFFSET_BITS 64
  23
  24 #include <support/check.h>
  25 #include <support/temp_file.h>
  26 #include <support/temp_file-internal.h>
  27 #include <support/support.h>
  28
  29 #include <errno.h>
  30 #include <paths.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <xunistd.h>
  35
  36 /* List of temporary files.  */
  37 static struct temp_name_list
  38 {
  39   struct temp_name_list *next;
  40   char *name;
  41   pid_t owner;
  42   bool toolong;
  43 } *temp_name_list;
  44
  45 /* Location of the temporary files.  Set by the test skeleton via
  46    support_set_test_dir.  The string is not be freed.  */
  47 static const char *test_dir = _PATH_TMP;
  48
  49 /* Name of subdirectories in a too long temporary directory tree.  */
  50 static char toolong_subdir[NAME_MAX + 1];
  51 static bool toolong_initialized;
  52 static size_t toolong_path_max;
  53
  54 static void
  55 add_temp_file_internal (const char *name, bool toolong)
  56 {
  57   struct temp_name_list *newp
  58     = (struct temp_name_list *) xcalloc (sizeof (*newp), 1);
  59   char *newname = strdup (name);
  60   if (newname != NULL)
  61     {
  62       newp->name = newname;
  63       newp->next = temp_name_list;
  64       newp->owner = getpid ();
  65       newp->toolong = toolong;
  66       temp_name_list = newp;
  67     }
  68   else
  69     free (newp);
  70 }
  71
  72 void
  73 add_temp_file (const char *name)
  74 {
  75   add_temp_file_internal (name, false);
  76 }
  77
  78 int
  79 create_temp_file_in_dir (const char *base, const char *dir, char **filename)
  80 {
  81   char *fname;
  82   int fd;
  83
  84   fname = xasprintf ("%s/%sXXXXXX", dir, base);
  85
  86   fd = mkstemp (fname);
  87   if (fd == -1)
  88     {
  89       printf ("cannot open temporary file '%s': %m\n", fname);
  90       free (fname);
  91       return -1;
  92     }
  93
  94   add_temp_file (fname);
  95   if (filename != NULL)
  96     *filename = fname;
  97   else
  98     free (fname);
  99
 100   return fd;
 101 }
 102
 103 int
 104 create_temp_file (const char *base, char **filename)
 105 {
 106   return create_temp_file_in_dir (base, test_dir, filename);
 107 }
 108
 109 static char *
 110 create_temp_directory_internal (const char *base, bool toolong)
 111 {
 112   char *path = xasprintf ("%s/%sXXXXXX", test_dir, base);
 113   if (mkdtemp (path) == NULL)
 114     {
 115       printf ("error: mkdtemp (\"%s\"): %m", path);
 116       exit (1);
 117     }
 118   add_temp_file_internal (path, toolong);
 119   return path;
 120 }
 121
 122 char *
 123 support_create_temp_directory (const char *base)
 124 {
 125   return create_temp_directory_internal (base, false);
 126 }
 127
 128 static void
 129 ensure_toolong_initialized (void)
 130 {
 131   if (!toolong_initialized)
 132     FAIL_EXIT1 ("uninitialized toolong directory tree\n");
 133 }
 134
 135 static void
 136 initialize_toolong (const char *base)
 137 {
 138   long name_max = pathconf (base, _PC_NAME_MAX);
 139   name_max = (name_max < 0 ? 64
 140               : (name_max < sizeof (toolong_subdir) ? name_max
 141                  : sizeof (toolong_subdir) - 1));
 142
 143   long path_max = pathconf (base, _PC_PATH_MAX);
 144   path_max = (path_max < 0 ? 1024
 145               : path_max <= PTRDIFF_MAX ? path_max : PTRDIFF_MAX);
 146
 147   /* Sanity check to ensure that the test does not create temporary directories
 148      in different filesystems because this API doesn't support it.  */
 149   if (toolong_initialized)
 150     {
 151       if (name_max != strlen (toolong_subdir))
 152         FAIL_UNSUPPORTED ("name_max: Temporary directories in different"
 153                           " filesystems not supported yet\n");
 154       if (path_max != toolong_path_max)
 155         FAIL_UNSUPPORTED ("path_max: Temporary directories in different"
 156                           " filesystems not supported yet\n");
 157       return;
 158     }
 159
 160   toolong_path_max = path_max;
 161
 162   size_t len = name_max;
 163   memset (toolong_subdir, 'X', len);
 164   toolong_initialized = true;
 165 }
 166
 167 char *
 168 support_create_and_chdir_toolong_temp_directory (const char *basename)
 169 {
 170   char *base = create_temp_directory_internal (basename, true);
 171   xchdir (base);
 172
 173   initialize_toolong (base);
 174
 175   size_t sz = strlen (toolong_subdir);
 176
 177   /* Create directories and descend into them so that the final path is larger
 178      than PATH_MAX.  */
 179   for (size_t i = 0; i <= toolong_path_max / sz; i++)
 180     {
 181       int ret = mkdir (toolong_subdir, S_IRWXU);
 182       if (ret != 0 && errno == ENAMETOOLONG)
 183         FAIL_UNSUPPORTED ("Filesystem does not support creating too long "
 184                           "directory trees\n");
 185       else if (ret != 0)
 186         FAIL_EXIT1 ("Failed to create directory tree: %m\n");
 187       xchdir (toolong_subdir);
 188     }
 189   return base;
 190 }
 191
 192 void
 193 support_chdir_toolong_temp_directory (const char *base)
 194 {
 195   ensure_toolong_initialized ();
 196
 197   xchdir (base);
 198
 199   size_t sz = strlen (toolong_subdir);
 200   for (size_t i = 0; i <= toolong_path_max / sz; i++)
 201     xchdir (toolong_subdir);
 202 }
 203
 204 /* Helper functions called by the test skeleton follow.  */
 205
 206 static void
 207 remove_toolong_subdirs (const char *base)
 208 {
 209   ensure_toolong_initialized ();
 210
 211   if (chdir (base) != 0)
 212     {
 213       printf ("warning: toolong cleanup base failed: chdir (\"%s\"): %m\n",
 214               base);
 215       return;
 216     }
 217
 218   /* Descend.  */
 219   int levels = 0;
 220   size_t sz = strlen (toolong_subdir);
 221   for (levels = 0; levels <= toolong_path_max / sz; levels++)
 222     if (chdir (toolong_subdir) != 0)
 223       {
 224         printf ("warning: toolong cleanup failed: chdir (\"%s\"): %m\n",
 225                 toolong_subdir);
 226         break;
 227       }
 228
 229   /* Ascend and remove.  */
 230   while (--levels >= 0)
 231     {
 232       if (chdir ("..") != 0)
 233         {
 234           printf ("warning: toolong cleanup failed: chdir (\"..\"): %m\n");
 235           return;
 236         }
 237       if (remove (toolong_subdir) != 0)
 238         {
 239           printf ("warning: could not remove subdirectory: %s: %m\n",
 240                   toolong_subdir);
 241           return;
 242         }
 243     }
 244 }
 245
 246 void
 247 support_delete_temp_files (void)
 248 {
 249   pid_t pid = getpid ();
 250   while (temp_name_list != NULL)
 251     {
 252       /* Only perform the removal if the path was registed in the same
 253          process, as identified by the PID.  (This assumes that the
 254          parent process which registered the temporary file sticks
 255          around, to prevent PID reuse.)  */
 256       if (temp_name_list->owner == pid)
 257         {
 258           if (temp_name_list->toolong)
 259             remove_toolong_subdirs (temp_name_list->name);
 260
 261           if (remove (temp_name_list->name) != 0)
 262             printf ("warning: could not remove temporary file: %s: %m\n",
 263                     temp_name_list->name);
 264         }
 265       free (temp_name_list->name);
 266
 267       struct temp_name_list *next = temp_name_list->next;
 268       free (temp_name_list);
 269       temp_name_list = next;
 270     }
 271 }
 272
 273 void
 274 support_print_temp_files (FILE *f)
 275 {
 276   if (temp_name_list != NULL)
 277     {
 278       struct temp_name_list *n;
 279       fprintf (f, "temp_files=(\n");
 280       for (n = temp_name_list; n != NULL; n = n->next)
 281         fprintf (f, "  '%s'\n", n->name);
 282       fprintf (f, ")\n");
 283     }
 284 }
 285
 286 void
 287 support_set_test_dir (const char *path)
 288 {
 289   test_dir = path;
 290 }