gshadow/tst-fgetsgent_r.c

   1 /* Test for fgetsgent_r and buffer sizes.
   2    Copyright (C) 2020-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <array_length.h>
  20 #include <errno.h>
  21 #include <gshadow.h>
  22 #include <stdbool.h>
  23 #include <stdlib.h>
  24 #include <support/check.h>
  25 #include <support/support.h>
  26 #include <support/temp_file.h>
  27 #include <support/xmemstream.h>
  28 #include <support/xstdio.h>
  29
  30 /* Turn a parsed struct back into a line string.  The returned string
  31    should be freed.  */
  32 static char *
  33 format_ent (const struct sgrp *e)
  34 {
  35   struct xmemstream stream;
  36   xopen_memstream (&stream);
  37   TEST_COMPARE (putsgent (e, stream.out), 0);
  38   xfclose_memstream (&stream);
  39   return stream.buffer;
  40 }
  41
  42 /* An entry in the input file along with the expected output.  */
  43 struct input
  44 {
  45   const char *line;             /* Line in the file.  */
  46   const char *expected;         /* Expected output.  NULL if skipped.  */
  47 };
  48
  49 const struct input inputs[] =
  50   {
  51    /* Regular entries.  */
  52    { "g1:x1::\n", "g1:x1::\n" },
  53    { "g2:x2:a1:\n", "g2:x2:a1:\n" },
  54    { "g3:x3:a2:u1\n", "g3:x3:a2:u1\n" },
  55    { "g4:x4:a3,a4:u2,u3,u4\n", "g4:x4:a3,a4:u2,u3,u4\n" },
  56
  57    /* Comments and empty lines.  */
  58    { "\n", NULL },
  59    { " \n", NULL },
  60    { "\t\n", NULL },
  61    { "#g:x::\n", NULL },
  62    { " #g:x::\n", NULL },
  63    { "\t#g:x::\n", NULL },
  64    { " \t#g:x::\n", NULL },
  65
  66    /* Marker for synchronization.  */
  67    { "g5:x5::\n", "g5:x5::\n" },
  68
  69    /* Leading whitespace.  */
  70    { " g6:x6::\n", "g6:x6::\n" },
  71    { "\tg7:x7::\n", "g7:x7::\n" },
  72
  73    /* This is expected to trigger buffer exhaustion during parsing
  74       (bug 20338).  */
  75    {
  76     "g8:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:u5,u6,u7,u8,u9:\n",
  77     "g8:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:u5,u6,u7,u8,u9:\n",
  78    },
  79    {
  80     "g9:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx::a5,a6,a7,a8,a9,a10\n",
  81     "g9:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx::a5,a6,a7,a8,a9,a10\n",
  82    },
  83   };
  84
  85 /* Writes the test data to a temporary file and returns its name.  The
  86    returned pointer should be freed.  */
  87 static char *
  88 create_test_file (void)
  89 {
  90   char *path;
  91   int fd = create_temp_file ("tst-fgetsgent_r-", &path);
  92   FILE *fp = fdopen (fd, "w");
  93   TEST_VERIFY_EXIT (fp != NULL);
  94
  95   for (size_t i = 0; i < array_length (inputs); ++i)
  96     fputs (inputs[i].line, fp);
  97
  98   xfclose (fp);
  99   return path;
 100 }
 101
 102 /* Read the test file with the indicated start buffer size.  Return
 103    true if the buffer size had to be increased during reading.  */
 104 static bool
 105 run_test (const char *path, size_t buffer_size)
 106 {
 107   bool resized = false;
 108   FILE *fp = xfopen (path, "r");
 109
 110   /* This avoids repeated lseek system calls (bug 26257).  */
 111   TEST_COMPARE (fseeko64 (fp, 0, SEEK_SET), 0);
 112
 113   size_t i = 0;
 114   while (true)
 115     {
 116       /* Skip over unused expected entries.  */
 117       while (i < array_length (inputs) && inputs[i].expected == NULL)
 118         ++i;
 119
 120       /* Store the data on the heap, to help valgrind to detect
 121          invalid accesses.  */
 122       struct sgrp *result_storage = xmalloc (sizeof (*result_storage));
 123       char *buffer = xmalloc (buffer_size);
 124       struct sgrp **result_pointer_storage
 125         = xmalloc (sizeof (*result_pointer_storage));
 126
 127       int ret = fgetsgent_r (fp, result_storage, buffer, buffer_size,
 128                              result_pointer_storage);
 129       if (ret == 0)
 130         {
 131           TEST_VERIFY (*result_pointer_storage != NULL);
 132           TEST_VERIFY (i < array_length (inputs));
 133           if (*result_pointer_storage != NULL
 134               && i < array_length (inputs))
 135             {
 136               char * actual = format_ent (*result_pointer_storage);
 137               TEST_COMPARE_STRING (inputs[i].expected, actual);
 138               free (actual);
 139               ++i;
 140             }
 141           else
 142             break;
 143         }
 144       else
 145         {
 146           TEST_VERIFY (*result_pointer_storage == NULL);
 147           TEST_COMPARE (ret, errno);
 148
 149           if (ret == ENOENT)
 150             {
 151               TEST_COMPARE (i, array_length (inputs));
 152               free (result_pointer_storage);
 153               free (buffer);
 154               free (result_storage);
 155               break;
 156             }
 157           else if (ret == ERANGE)
 158             {
 159               resized = true;
 160               ++buffer_size;
 161             }
 162           else
 163             FAIL_EXIT1 ("read failure: %m");
 164         }
 165
 166       free (result_pointer_storage);
 167       free (buffer);
 168       free (result_storage);
 169     }
 170
 171   xfclose (fp);
 172   return resized;
 173 }
 174
 175 static int
 176 do_test (void)
 177 {
 178   char *path = create_test_file ();
 179
 180   for (size_t buffer_size = 3; ; ++buffer_size)
 181     {
 182       bool resized = run_test (path, buffer_size);
 183       if (!resized)
 184         break;
 185     }
 186
 187   free (path);
 188
 189   return 0;
 190 }
 191
 192 #include <support/test-driver.c>