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
|
/* Test duplicating file descriptors.
Copyright (C) 2009-2020 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,
and Bruno Haible <bruno@clisp.org>, 2009. */
#include <config.h>
#include <unistd.h>
#include "signature.h"
SIGNATURE_CHECK (dup3, int, (int, int, int));
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#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 "binary-io.h"
#include "macros.h"
/* Return true if FD is open. */
static bool
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
}
/* Return true if FD is not inherited to child processes. */
static bool
is_cloexec (int fd)
{
#if defined _WIN32 && ! defined __CYGWIN__
HANDLE h = (HANDLE) _get_osfhandle (fd);
DWORD flags;
ASSERT (GetHandleInformation (h, &flags));
return (flags & HANDLE_FLAG_INHERIT) == 0;
#else
int flags;
ASSERT ((flags = fcntl (fd, F_GETFD)) >= 0);
return (flags & FD_CLOEXEC) != 0;
#endif
}
int
main ()
{
int use_cloexec;
int bad_fd = getdtablesize ();
#if O_CLOEXEC
for (use_cloexec = 0; use_cloexec <= 1; use_cloexec++)
#else
use_cloexec = 0;
#endif
{
const char *file = "test-dup3.tmp";
int fd = open (file, O_CREAT | O_TRUNC | O_RDWR, 0600);
int o_flags;
char buffer[1];
o_flags = 0;
#if O_CLOEXEC
if (use_cloexec)
o_flags |= O_CLOEXEC;
#endif
/* 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 is invalid. */
errno = 0;
ASSERT (dup3 (fd, fd, o_flags) == -1);
ASSERT (errno == EINVAL);
ASSERT (is_open (fd));
/* If the source is not open, then the destination is unaffected. */
errno = 0;
ASSERT (dup3 (fd + 1, fd + 2, o_flags) == -1);
ASSERT (errno == EBADF);
ASSERT (!is_open (fd + 2));
errno = 0;
ASSERT (dup3 (fd + 1, fd, o_flags) == -1);
ASSERT (errno == EBADF);
ASSERT (is_open (fd));
/* The destination must be valid. */
errno = 0;
ASSERT (dup3 (fd, -2, o_flags) == -1);
ASSERT (errno == EBADF);
if (bad_fd > 256)
{
ASSERT (dup3 (fd, 255, 0) == 255);
ASSERT (dup3 (fd, 256, 0) == 256);
ASSERT (close (255) == 0);
ASSERT (close (256) == 0);
}
ASSERT (dup3 (fd, bad_fd - 1, 0) == bad_fd - 1);
ASSERT (close (bad_fd - 1) == 0);
errno = 0;
ASSERT (dup3 (fd, bad_fd, o_flags) == -1);
ASSERT (errno == EBADF);
/* Using dup3 can skip fds. */
ASSERT (dup3 (fd, fd + 2, o_flags) == fd + 2);
ASSERT (is_open (fd));
ASSERT (!is_open (fd + 1));
ASSERT (is_open (fd + 2));
if (use_cloexec)
ASSERT (is_cloexec (fd + 2));
else
ASSERT (!is_cloexec (fd + 2));
/* Verify that dup3 closes the previous occupant of a fd. */
ASSERT (open ("/dev/null", O_WRONLY, 0600) == fd + 1);
ASSERT (dup3 (fd + 1, fd, o_flags) == fd);
ASSERT (close (fd + 1) == 0);
ASSERT (write (fd, "1", 1) == 1);
ASSERT (dup3 (fd + 2, fd, o_flags) == 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');
/* Clean up. */
ASSERT (close (fd + 2) == 0);
ASSERT (close (fd) == 0);
ASSERT (unlink (file) == 0);
}
return 0;
}
|
