1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
/* Test that dup_safer leaves standard fds alone.
Copyright (C) 2009-2017 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Eric Blake <ebb9@byu.net>, 2009. */
#include <config.h>
#include "unistd--.h"
#include <fcntl.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>
#include "binary-io.h"
#include "cloexec.h"
#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
/* Get declarations of the native Windows API functions. */
# define WIN32_LEAN_AND_MEAN
# include <windows.h>
/* Get _get_osfhandle. */
# if GNULIB_MSVC_NOTHROW
# include "msvc-nothrow.h"
# else
# include <io.h>
# endif
#endif
#if !O_BINARY
# define setmode(f,m) zero ()
static int zero (void) { return 0; }
#endif
/* This test intentionally closes stderr. So, we arrange to have fd 10
(outside the range of interesting fd's during the test) set up to
duplicate the original stderr. */
#define BACKUP_STDERR_FILENO 10
#define ASSERT_STREAM myerr
#include "macros.h"
static FILE *myerr;
/* Return true if FD is open. */
static bool
is_open (int fd)
{
#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
/* On native Windows, the initial state of unassigned standard file
descriptors is that they are open but point to an
INVALID_HANDLE_VALUE, and there is no fcntl. */
return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
#else
# ifndef F_GETFL
# error Please port fcntl to your platform
# endif
return 0 <= fcntl (fd, F_GETFL);
#endif
}
/* Return true if FD is open and inheritable across exec/spawn. */
static bool
is_inheritable (int fd)
{
#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
/* On native Windows, the initial state of unassigned standard file
descriptors is that they are open but point to an
INVALID_HANDLE_VALUE, and there is no fcntl. */
HANDLE h = (HANDLE) _get_osfhandle (fd);
DWORD flags;
if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0)
return 0;
return (flags & HANDLE_FLAG_INHERIT) != 0;
#else
# ifndef F_GETFD
# error Please port fcntl to your platform
# endif
int i = fcntl (fd, F_GETFD);
return 0 <= i && (i & FD_CLOEXEC) == 0;
#endif
}
/* Return true if FD is open in the given MODE, which is either
O_TEXT or O_BINARY. */
static bool
is_mode (int fd, int mode)
{
int value = setmode (fd, O_BINARY);
setmode (fd, value);
return mode == value;
}
#define witness "test-dup-safer.txt"
int
main (void)
{
int i;
int fd;
int bad_fd = getdtablesize ();
/* We close fd 2 later, so save it in fd 10. */
if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
|| (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
return 2;
/* Create file for later checks. */
fd = creat (witness, 0600);
ASSERT (STDERR_FILENO < fd);
/* Four iterations, with progressively more standard descriptors
closed. */
for (i = -1; i <= STDERR_FILENO; i++)
{
if (0 <= i)
ASSERT (close (i) == 0);
/* Detect errors. */
errno = 0;
ASSERT (dup (-1) == -1);
ASSERT (errno == EBADF);
errno = 0;
ASSERT (dup (bad_fd) == -1);
ASSERT (errno == EBADF);
close (fd + 1);
errno = 0;
ASSERT (dup (fd + 1) == -1);
ASSERT (errno == EBADF);
/* Preserve text vs. binary. */
setmode (fd, O_BINARY);
ASSERT (dup (fd) == fd + 1);
ASSERT (is_open (fd + 1));
ASSERT (is_inheritable (fd + 1));
ASSERT (is_mode (fd + 1, O_BINARY));
ASSERT (close (fd + 1) == 0);
setmode (fd, O_TEXT);
ASSERT (dup (fd) == fd + 1);
ASSERT (is_open (fd + 1));
ASSERT (is_inheritable (fd + 1));
ASSERT (is_mode (fd + 1, O_TEXT));
/* Create cloexec copy. */
ASSERT (close (fd + 1) == 0);
ASSERT (fd_safer_flag (dup_cloexec (fd), O_CLOEXEC) == fd + 1);
ASSERT (set_cloexec_flag (fd + 1, true) == 0);
ASSERT (is_open (fd + 1));
ASSERT (!is_inheritable (fd + 1));
ASSERT (close (fd) == 0);
/* dup always creates inheritable copies. Also, check that
earliest slot past std fds is used. */
ASSERT (dup (fd + 1) == fd);
ASSERT (is_open (fd));
ASSERT (is_inheritable (fd));
ASSERT (close (fd + 1) == 0);
}
/* Cleanup. */
ASSERT (close (fd) == 0);
ASSERT (unlink (witness) == 0);
return 0;
}
|
