tests/df/no-mtab-status.sh

   1 #!/bin/sh
   2 # Test df's behavior when the mount list cannot be read.
   3 # This test is skipped on systems that lack LD_PRELOAD support; that's fine.
   4
   5 # Copyright (C) 2012-2024 Free Software Foundation, Inc.
   6
   7 # This program is free software: you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation, either version 3 of the License, or
  10 # (at your option) any later version.
  11
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19
  20 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  21 print_ver_ df
  22 require_gcc_shared_
  23
  24 # Protect against inaccessible remote mounts etc.
  25 timeout 10 df || skip_ "df fails"
  26
  27 grep '^#define HAVE_GETMNTENT 1' $CONFIG_HEADER > /dev/null \
  28       || skip_ "getmntent is not used on this system"
  29
  30 # Simulate "mtab" failure.
  31 cat > k.c <<EOF || framework_failure_
  32 #define _GNU_SOURCE
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <errno.h>
  36 #include <fcntl.h>
  37 #include <mntent.h>
  38 #include <string.h>
  39 #include <stdarg.h>
  40 #include <dlfcn.h>
  41
  42 #define STREQ(a, b) (strcmp (a, b) == 0)
  43
  44 int open(const char *path, int flags, ...)
  45 {
  46   static int (*open_func)(const char *, int, ...);
  47
  48   /* get reference to original (libc provided) open */
  49   if (!open_func)
  50     {
  51       open_func = (int(*)(const char *, int, ...))
  52                    dlsym(RTLD_NEXT, "open");
  53       if (!open_func)
  54         {
  55           fprintf (stderr, "Failed to find open()\n");
  56           errno = ESRCH;
  57           return -1;
  58         }
  59     }
  60
  61   va_list ap;
  62   va_start (ap, flags);
  63   mode_t mode = (sizeof (mode_t) < sizeof (int)
  64                  ? va_arg (ap, int)
  65                  : va_arg (ap, mode_t));
  66   va_end (ap);
  67
  68   /* Returning ENOENT here will get read_file_system_list()
  69      to fall back to using getmntent() below.  */
  70   if (STREQ (path, "/proc/self/mountinfo"))
  71     {
  72       errno = ENOENT;
  73       return -1;
  74     }
  75   else
  76     return open_func(path, flags, mode);
  77 }
  78
  79 struct mntent *getmntent (FILE *fp)
  80 {
  81   /* Prove that LD_PRELOAD works. */
  82   static int done = 0;
  83   if (!done)
  84     {
  85       fclose (fopen ("x", "w"));
  86       ++done;
  87     }
  88   /* Now simulate the failure. */
  89   errno = ENOENT;
  90   return NULL;
  91 }
  92 EOF
  93
  94 # Then compile/link it:
  95 gcc_shared_ k.c k.so \
  96   || framework_failure_ 'failed to build shared library'
  97
  98 cleanup_() { unset LD_PRELOAD; }
  99
 100 export LD_PRELOAD=$LD_PRELOAD:./k.so
 101
 102 # Test if LD_PRELOAD works:
 103 df 2>/dev/null
 104 test -f x || skip_ "internal test failure: maybe LD_PRELOAD doesn't work?"
 105
 106 # These tests are supposed to succeed:
 107 df '.' || fail=1
 108 df -i '.' || fail=1
 109 df -T '.' || fail=1
 110 df -Ti '.' || fail=1
 111 df --total '.' || fail=1
 112
 113 # These tests are supposed to fail:
 114 returns_ 1 df || fail=1
 115 returns_ 1 df -i || fail=1
 116 returns_ 1 df -T || fail=1
 117 returns_ 1 df -Ti || fail=1
 118 returns_ 1 df --total || fail=1
 119
 120 returns_ 1 df -a || fail=1
 121 returns_ 1 df -a '.' || fail=1
 122
 123 returns_ 1 df -l || fail=1
 124 returns_ 1 df -l '.' || fail=1
 125
 126 returns_ 1 df -t hello || fail=1
 127 returns_ 1 df -t hello '.' || fail=1
 128
 129 returns_ 1 df -x hello || fail=1
 130 returns_ 1 df -x hello '.' || fail=1
 131
 132 Exit $fail