support/tst-support_descriptors.c

   1 /* Tests for monitoring file descriptor usage.
   2    Copyright (C) 2018-2024 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 <fcntl.h>
  20 #include <stdbool.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <support/capture_subprocess.h>
  24 #include <support/check.h>
  25 #include <support/descriptors.h>
  26 #include <support/support.h>
  27 #include <support/xunistd.h>
  28
  29 /* This is the next free descriptor that the subprocess will pick.  */
  30 static int free_descriptor;
  31
  32 static void
  33 subprocess_no_change (void *closure)
  34 {
  35   struct support_descriptors *descrs = support_descriptors_list ();
  36   int fd = xopen ("/dev/null", O_WRONLY, 0);
  37   TEST_COMPARE (fd, free_descriptor);
  38   xclose (fd);
  39   support_descriptors_free (descrs);
  40 }
  41
  42 static void
  43 subprocess_closed_descriptor (void *closure)
  44 {
  45   int fd = xopen ("/dev/null", O_WRONLY, 0);
  46   TEST_COMPARE (fd, free_descriptor);
  47   struct support_descriptors *descrs = support_descriptors_list ();
  48   xclose (fd);
  49   support_descriptors_check (descrs); /* Will report failure.  */
  50   puts ("EOT");
  51   support_descriptors_free (descrs);
  52 }
  53
  54 static void
  55 subprocess_opened_descriptor (void *closure)
  56 {
  57   struct support_descriptors *descrs = support_descriptors_list ();
  58   int fd = xopen ("/dev/null", O_WRONLY, 0);
  59   TEST_COMPARE (fd, free_descriptor);
  60   support_descriptors_check (descrs); /* Will report failure.  */
  61   puts ("EOT");
  62   support_descriptors_free (descrs);
  63 }
  64
  65 static void
  66 subprocess_changed_descriptor (void *closure)
  67 {
  68   int fd = xopen ("/dev/null", O_WRONLY, 0);
  69   TEST_COMPARE (fd, free_descriptor);
  70   struct support_descriptors *descrs = support_descriptors_list ();
  71   xclose (fd);
  72   TEST_COMPARE (xopen ("/dev", O_DIRECTORY | O_RDONLY, 0), fd);
  73   support_descriptors_check (descrs); /* Will report failure.  */
  74   puts ("EOT");
  75   support_descriptors_free (descrs);
  76 }
  77
  78 static void
  79 report_subprocess_output (const char *name,
  80                           struct support_capture_subprocess *proc)
  81 {
  82   printf ("info: BEGIN %s output\n"
  83           "%s"
  84           "info: END %s output\n",
  85           name, proc->out.buffer, name);
  86 }
  87
  88 /* Use an explicit flag to preserve failure status across
  89    support_record_failure_reset calls.  */
  90 static bool good = true;
  91
  92 static void
  93 test_run (void)
  94 {
  95   struct support_capture_subprocess proc = support_capture_subprocess
  96     (&subprocess_no_change, NULL);
  97   support_capture_subprocess_check (&proc, "subprocess_no_change",
  98                                     0, sc_allow_none);
  99   support_capture_subprocess_free (&proc);
 100
 101   char *expected = xasprintf ("\nDifferences:\n"
 102                               "error: descriptor %d was closed\n"
 103                               "EOT\n",
 104                               free_descriptor);
 105   good = good && !support_record_failure_is_failed ();
 106   proc = support_capture_subprocess (&subprocess_closed_descriptor, NULL);
 107   good = good && support_record_failure_is_failed ();
 108   support_record_failure_reset (); /* Discard the reported error.  */
 109   report_subprocess_output ("subprocess_closed_descriptor", &proc);
 110   TEST_VERIFY (strstr (proc.out.buffer, expected) != NULL);
 111   support_capture_subprocess_check (&proc, "subprocess_closed_descriptor",
 112                                     0, sc_allow_stdout);
 113   support_capture_subprocess_free (&proc);
 114   free (expected);
 115
 116   expected = xasprintf ("\nDifferences:\n"
 117                         "error: descriptor %d was opened (\"/dev/null\")\n"
 118                         "EOT\n",
 119                         free_descriptor);
 120   good = good && !support_record_failure_is_failed ();
 121   proc = support_capture_subprocess (&subprocess_opened_descriptor, NULL);
 122   good = good && support_record_failure_is_failed ();
 123   support_record_failure_reset (); /* Discard the reported error.  */
 124   report_subprocess_output ("subprocess_opened_descriptor", &proc);
 125   TEST_VERIFY (strstr (proc.out.buffer, expected) != NULL);
 126   support_capture_subprocess_check (&proc, "subprocess_opened_descriptor",
 127                                     0, sc_allow_stdout);
 128   support_capture_subprocess_free (&proc);
 129   free (expected);
 130
 131   expected = xasprintf ("\nDifferences:\n"
 132                         "error: descriptor %d changed from \"/dev/null\""
 133                         " to \"/dev\"\n"
 134                         "error: descriptor %d changed ino ",
 135                         free_descriptor, free_descriptor);
 136   good = good && !support_record_failure_is_failed ();
 137   proc = support_capture_subprocess (&subprocess_changed_descriptor, NULL);
 138   good = good && support_record_failure_is_failed ();
 139   support_record_failure_reset (); /* Discard the reported error.  */
 140   report_subprocess_output ("subprocess_changed_descriptor", &proc);
 141   TEST_VERIFY (strstr (proc.out.buffer, expected) != NULL);
 142   support_capture_subprocess_check (&proc, "subprocess_changed_descriptor",
 143                                     0, sc_allow_stdout);
 144   support_capture_subprocess_free (&proc);
 145   free (expected);
 146 }
 147
 148 static int
 149 do_test (void)
 150 {
 151   puts ("info: initial descriptor set");
 152   {
 153     struct support_descriptors *descrs = support_descriptors_list ();
 154     support_descriptors_dump (descrs, "info:  ", stdout);
 155     support_descriptors_free (descrs);
 156   }
 157
 158   free_descriptor = xopen ("/dev/null", O_WRONLY, 0);
 159   puts ("info: descriptor set with additional free descriptor");
 160   {
 161     struct support_descriptors *descrs = support_descriptors_list ();
 162     support_descriptors_dump (descrs, "info:  ", stdout);
 163     support_descriptors_free (descrs);
 164   }
 165   TEST_VERIFY (free_descriptor >= 3);
 166   xclose (free_descriptor);
 167
 168   /* Initial test run without a sentinel descriptor.  The presence of
 169      such a descriptor exercises different conditions in the list
 170      comparison in support_descriptors_check.  */
 171   test_run ();
 172
 173   /* Allocate a sentinel descriptor at the end of the descriptor list,
 174      after free_descriptor.  */
 175   int sentinel_fd;
 176   {
 177     int fd = xopen ("/dev/full", O_WRONLY, 0);
 178     TEST_COMPARE (fd, free_descriptor);
 179     sentinel_fd = dup (fd);
 180     TEST_VERIFY_EXIT (sentinel_fd > fd);
 181     xclose (fd);
 182   }
 183   puts ("info: descriptor set with sentinel descriptor");
 184   {
 185     struct support_descriptors *descrs = support_descriptors_list ();
 186     support_descriptors_dump (descrs, "info:  ", stdout);
 187     support_descriptors_free (descrs);
 188   }
 189
 190   /* Second test run with sentinel descriptor.  */
 191   test_run ();
 192
 193   xclose (sentinel_fd);
 194
 195   return !good;
 196 }
 197
 198 #include <support/test-driver.c>