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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
/* Test duplicating file descriptors.
Copyright (C) 2009-2023 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 "signature.h"
SIGNATURE_CHECK (dup2, int, (int, int));
#include <errno.h>
#include <fcntl.h>
#if HAVE_SYS_RESOURCE_H
# include <sys/resource.h>
#endif
#include "binary-io.h"
#if GNULIB_TEST_CLOEXEC
# include "cloexec.h"
#endif
#if 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
#include "macros.h"
/* Return non-zero if FD is open. */
static int
is_open (int fd)
{
#if 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
}
#if GNULIB_TEST_CLOEXEC
/* Return non-zero if FD is open and inheritable across exec/spawn. */
static int
is_inheritable (int fd)
{
# if 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
}
#endif /* GNULIB_TEST_CLOEXEC */
#if !O_BINARY
# define set_binary_mode(f,m) zero ()
static int zero (void) { return 0; }
#endif
/* Return non-zero if FD is open in the given MODE, which is either
O_TEXT or O_BINARY. */
static int
is_mode (int fd, int mode)
{
int value = set_binary_mode (fd, O_BINARY);
set_binary_mode (fd, value);
return mode == value;
}
int
main (void)
{
const char *file = "test-dup2.tmp";
char buffer[1];
int bad_fd = getdtablesize ();
int fd = open (file, O_CREAT | O_TRUNC | O_RDWR, 0600);
/* Assume std descriptors were provided by invoker. */
ASSERT (STDERR_FILENO < fd);
ASSERT (is_open (fd));
/* Ignore any other fd's leaked into this process. */
close (fd + 1);
close (fd + 2);
ASSERT (!is_open (fd + 1));
ASSERT (!is_open (fd + 2));
/* Assigning to self must be a no-op. */
ASSERT (dup2 (fd, fd) == fd);
ASSERT (is_open (fd));
/* The source must be valid. */
errno = 0;
ASSERT (dup2 (-1, fd) == -1);
ASSERT (errno == EBADF);
close (99);
errno = 0;
ASSERT (dup2 (99, fd) == -1);
ASSERT (errno == EBADF);
errno = 0;
ASSERT (dup2 (AT_FDCWD, fd) == -1);
ASSERT (errno == EBADF);
ASSERT (is_open (fd));
/* If the source is not open, then the destination is unaffected. */
errno = 0;
ASSERT (dup2 (fd + 1, fd + 1) == -1);
ASSERT (errno == EBADF);
ASSERT (!is_open (fd + 1));
errno = 0;
ASSERT (dup2 (fd + 1, fd) == -1);
ASSERT (errno == EBADF);
ASSERT (is_open (fd));
/* The destination must be valid. */
errno = 0;
ASSERT (dup2 (fd, -2) == -1);
ASSERT (errno == EBADF);
if (bad_fd > 256)
{
ASSERT (dup2 (fd, 255) == 255);
ASSERT (dup2 (fd, 256) == 256);
ASSERT (close (255) == 0);
ASSERT (close (256) == 0);
}
ASSERT (dup2 (fd, bad_fd - 1) == bad_fd - 1);
ASSERT (close (bad_fd - 1) == 0);
errno = 0;
ASSERT (dup2 (fd, bad_fd) == -1);
ASSERT (errno == EBADF);
/* Using dup2 can skip fds. */
ASSERT (dup2 (fd, fd + 2) == fd + 2);
ASSERT (is_open (fd));
ASSERT (!is_open (fd + 1));
ASSERT (is_open (fd + 2));
/* Verify that dup2 closes the previous occupant of a fd. */
ASSERT (open ("/dev/null", O_WRONLY, 0600) == fd + 1);
ASSERT (dup2 (fd + 1, fd) == fd);
ASSERT (close (fd + 1) == 0);
ASSERT (write (fd, "1", 1) == 1);
ASSERT (dup2 (fd + 2, fd) == fd);
ASSERT (lseek (fd, 0, SEEK_END) == 0);
ASSERT (write (fd + 2, "2", 1) == 1);
ASSERT (lseek (fd, 0, SEEK_SET) == 0);
ASSERT (read (fd, buffer, 1) == 1);
ASSERT (*buffer == '2');
#if GNULIB_TEST_CLOEXEC
/* Any new fd created by dup2 must not be cloexec. */
ASSERT (close (fd + 2) == 0);
ASSERT (dup_cloexec (fd) == fd + 1);
ASSERT (!is_inheritable (fd + 1));
ASSERT (dup2 (fd + 1, fd + 1) == fd + 1);
ASSERT (!is_inheritable (fd + 1));
ASSERT (dup2 (fd + 1, fd + 2) == fd + 2);
ASSERT (!is_inheritable (fd + 1));
ASSERT (is_inheritable (fd + 2));
errno = 0;
ASSERT (dup2 (fd + 1, -1) == -1);
ASSERT (errno == EBADF);
ASSERT (!is_inheritable (fd + 1));
#endif
/* On systems that distinguish between text and binary mode, dup2
reuses the mode of the source. */
set_binary_mode (fd, O_BINARY);
ASSERT (is_mode (fd, O_BINARY));
ASSERT (dup2 (fd, fd + 1) == fd + 1);
ASSERT (is_mode (fd + 1, O_BINARY));
set_binary_mode (fd, O_TEXT);
ASSERT (is_mode (fd, O_TEXT));
ASSERT (dup2 (fd, fd + 1) == fd + 1);
ASSERT (is_mode (fd + 1, O_TEXT));
/* Clean up. */
ASSERT (close (fd + 2) == 0);
ASSERT (close (fd + 1) == 0);
ASSERT (close (fd) == 0);
ASSERT (unlink (file) == 0);
return 0;
}
|
