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) 2012-2023 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
21print_ver_ df
22require_gcc_shared_
23
24# Protect against inaccessible remote mounts etc.
25timeout 10 df || skip_ "df fails"
26
27grep '^#define HAVE_MNTENT_H 1' $CONFIG_HEADER > /dev/null \
28      || skip_ "no mntent.h available to confirm the interface"
29
30grep '^#define HAVE_GETMNTENT 1' $CONFIG_HEADER > /dev/null \
31      || skip_ "getmntent is not used on this system"
32
33# Simulate "mtab" failure.
34cat > k.c <<EOF || framework_failure_
35#define _GNU_SOURCE
36#include <stdio.h>
37#include <errno.h>
38#include <mntent.h>
39#include <string.h>
40#include <dlfcn.h>
41
42#define STREQ(a, b) (strcmp (a, b) == 0)
43
44FILE* fopen(const char *path, const char *mode)
45{
46  static FILE* (*fopen_func)(char const *, char const *);
47
48  /* get reference to original (libc provided) fopen */
49  if (!fopen_func)
50    {
51      fopen_func = (FILE*(*)(char const *, char const *))
52                   dlsym(RTLD_NEXT, "fopen");
53      if (!fopen_func)
54        {
55          fprintf (stderr, "Failed to find fopen()\n");
56          errno = ESRCH;
57          return NULL;
58        }
59    }
60
61  /* Returning ENOENT here will get read_file_system_list()
62     to fall back to using getmntent() below.  */
63  if (STREQ (path, "/proc/self/mountinfo"))
64    {
65      errno = ENOENT;
66      return NULL;
67    }
68  else
69    return fopen_func(path, mode);
70}
71
72struct mntent *getmntent (FILE *fp)
73{
74  /* Prove that LD_PRELOAD works. */
75  static int done = 0;
76  if (!done)
77    {
78      fclose (fopen ("x", "w"));
79      ++done;
80    }
81  /* Now simulate the failure. */
82  errno = ENOENT;
83  return NULL;
84}
85EOF
86
87# Then compile/link it:
88gcc_shared_ k.c k.so \
89  || framework_failure_ 'failed to build shared library'
90
91cleanup_() { unset LD_PRELOAD; }
92
93export LD_PRELOAD=$LD_PRELOAD:./k.so
94
95# Test if LD_PRELOAD works:
96df 2>/dev/null
97test -f x || skip_ "internal test failure: maybe LD_PRELOAD doesn't work?"
98
99# These tests are supposed to succeed:
100df '.' || fail=1
101df -i '.' || fail=1
102df -T '.' || fail=1
103df -Ti '.' || fail=1
104df --total '.' || fail=1
105
106# These tests are supposed to fail:
107returns_ 1 df || fail=1
108returns_ 1 df -i || fail=1
109returns_ 1 df -T || fail=1
110returns_ 1 df -Ti || fail=1
111returns_ 1 df --total || fail=1
112
113returns_ 1 df -a || fail=1
114returns_ 1 df -a '.' || fail=1
115
116returns_ 1 df -l || fail=1
117returns_ 1 df -l '.' || fail=1
118
119returns_ 1 df -t hello || fail=1
120returns_ 1 df -t hello '.' || fail=1
121
122returns_ 1 df -x hello || fail=1
123returns_ 1 df -x hello '.' || fail=1
124
125Exit $fail
126