1 /* Test that dup_safer leaves standard fds alone.
2 Copyright (C) 2009-2011 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Written by Eric Blake <ebb9@byu.net>, 2009. */
28 #include "binary-io.h"
31 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
32 /* Get declarations of the Win32 API functions. */
33 # define WIN32_LEAN_AND_MEAN
38 # define setmode(f,m) zero ()
39 static int zero (void) { return 0; }
42 /* This test intentionally closes stderr. So, we arrange to have fd 10
43 (outside the range of interesting fd's during the test) set up to
44 duplicate the original stderr. */
46 #define BACKUP_STDERR_FILENO 10
47 #define ASSERT_STREAM myerr
52 /* Return true if FD is open. */
56 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
57 /* On Win32, the initial state of unassigned standard file
58 descriptors is that they are open but point to an
59 INVALID_HANDLE_VALUE, and there is no fcntl. */
60 return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
63 # error Please port fcntl to your platform
65 return 0 <= fcntl (fd, F_GETFL);
69 /* Return true if FD is open and inheritable across exec/spawn. */
71 is_inheritable (int fd)
73 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
74 /* On Win32, the initial state of unassigned standard file
75 descriptors is that they are open but point to an
76 INVALID_HANDLE_VALUE, and there is no fcntl. */
77 HANDLE h = (HANDLE) _get_osfhandle (fd);
79 if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0)
81 return (flags & HANDLE_FLAG_INHERIT) != 0;
84 # error Please port fcntl to your platform
86 int i = fcntl (fd, F_GETFD);
87 return 0 <= i && (i & FD_CLOEXEC) == 0;
91 /* Return true if FD is open in the given MODE, which is either
92 O_TEXT or O_BINARY. */
94 is_mode (int fd, int mode)
96 int value = setmode (fd, O_BINARY);
101 #define witness "test-dup-safer.txt"
109 /* We close fd 2 later, so save it in fd 10. */
110 if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
111 || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
114 /* Create file for later checks. */
115 fd = creat (witness, 0600);
116 ASSERT (STDERR_FILENO < fd);
118 /* Four iterations, with progressively more standard descriptors
120 for (i = -1; i <= STDERR_FILENO; i++)
123 ASSERT (close (i) == 0);
127 ASSERT (dup (-1) == -1);
128 ASSERT (errno == EBADF);
130 ASSERT (dup (10000000) == -1);
131 ASSERT (errno == EBADF);
134 ASSERT (dup (fd + 1) == -1);
135 ASSERT (errno == EBADF);
137 /* Preserve text vs. binary. */
138 setmode (fd, O_BINARY);
139 ASSERT (dup (fd) == fd + 1);
140 ASSERT (is_open (fd + 1));
141 ASSERT (is_inheritable (fd + 1));
142 ASSERT (is_mode (fd + 1, O_BINARY));
144 ASSERT (close (fd + 1) == 0);
145 setmode (fd, O_TEXT);
146 ASSERT (dup (fd) == fd + 1);
147 ASSERT (is_open (fd + 1));
148 ASSERT (is_inheritable (fd + 1));
149 ASSERT (is_mode (fd + 1, O_TEXT));
151 /* Create cloexec copy. */
152 ASSERT (close (fd + 1) == 0);
153 ASSERT (fd_safer_flag (dup_cloexec (fd), O_CLOEXEC) == fd + 1);
154 ASSERT (set_cloexec_flag (fd + 1, true) == 0);
155 ASSERT (is_open (fd + 1));
156 ASSERT (!is_inheritable (fd + 1));
157 ASSERT (close (fd) == 0);
159 /* dup always creates inheritable copies. Also, check that
160 earliest slot past std fds is used. */
161 ASSERT (dup (fd + 1) == fd);
162 ASSERT (is_open (fd));
163 ASSERT (is_inheritable (fd));
164 ASSERT (close (fd + 1) == 0);
168 ASSERT (close (fd) == 0);
169 ASSERT (unlink (witness) == 0);