1 /* Test that dup_safer leaves standard fds alone.
2 Copyright (C) 2009 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. */
30 #include "binary-io.h"
33 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
34 /* Get declarations of the Win32 API functions. */
35 # define WIN32_LEAN_AND_MEAN
40 # define setmode(f,m) zero ()
41 static int zero (void) { return 0; }
47 /* This test intentionally closes stderr. So, we arrange to have fd 10
48 (outside the range of interesting fd's during the test) set up to
49 duplicate the original stderr. */
51 #define BACKUP_STDERR_FILENO 10
54 #define ASSERT(expr) \
59 fprintf (myerr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
66 /* Return true if FD is open. */
70 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
71 /* On Win32, the initial state of unassigned standard file
72 descriptors is that they are open but point to an
73 INVALID_HANDLE_VALUE, and there is no fcntl. */
74 return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
77 # error Please port fcntl to your platform
79 return 0 <= fcntl (fd, F_GETFL);
83 /* Return true if FD is open and inheritable across exec/spawn. */
85 is_inheritable (int fd)
87 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
88 /* On Win32, the initial state of unassigned standard file
89 descriptors is that they are open but point to an
90 INVALID_HANDLE_VALUE, and there is no fcntl. */
91 HANDLE h = (HANDLE) _get_osfhandle (fd);
93 if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0)
95 return (flags & HANDLE_FLAG_INHERIT) != 0;
98 # error Please port fcntl to your platform
100 int i = fcntl (fd, F_GETFD);
101 return 0 <= i && (i & FD_CLOEXEC) == 0;
105 /* Return true if FD is open in the given MODE, which is either
106 O_TEXT or O_BINARY. */
108 is_mode (int fd, int mode)
110 int value = setmode (fd, O_BINARY);
112 return mode == value;
115 #define witness "test-dup-safer.txt"
123 /* We close fd 2 later, so save it in fd 10. */
124 if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
125 || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
128 /* Create file for later checks. */
129 fd = creat (witness, 0600);
130 ASSERT (STDERR_FILENO < fd);
132 /* Four iterations, with progressively more standard descriptors
134 for (i = -1; i <= STDERR_FILENO; i++)
137 ASSERT (close (i) == 0);
141 ASSERT (dup (-1) == -1);
142 ASSERT (errno == EBADF);
144 ASSERT (dup (10000000) == -1);
145 ASSERT (errno == EBADF);
148 ASSERT (dup (fd + 1) == -1);
149 ASSERT (errno == EBADF);
151 /* Preserve text vs. binary. */
152 setmode (fd, O_BINARY);
153 ASSERT (dup (fd) == fd + 1);
154 ASSERT (is_open (fd + 1));
155 ASSERT (is_inheritable (fd + 1));
156 ASSERT (is_mode (fd + 1, O_BINARY));
158 ASSERT (close (fd + 1) == 0);
159 setmode (fd, O_TEXT);
160 ASSERT (dup (fd) == fd + 1);
161 ASSERT (is_open (fd + 1));
162 ASSERT (is_inheritable (fd + 1));
163 ASSERT (is_mode (fd + 1, O_TEXT));
165 /* Create cloexec copy. */
166 ASSERT (close (fd + 1) == 0);
167 ASSERT (fd_safer_flag (dup_cloexec (fd), O_CLOEXEC) == fd + 1);
168 ASSERT (set_cloexec_flag (fd + 1, true) == 0);
169 ASSERT (is_open (fd + 1));
170 ASSERT (!is_inheritable (fd + 1));
171 ASSERT (close (fd) == 0);
173 /* dup always creates inheritable copies. Also, check that
174 earliest slot past std fds is used. */
175 ASSERT (dup (fd + 1) == fd);
176 ASSERT (is_open (fd));
177 ASSERT (is_inheritable (fd));
178 ASSERT (close (fd + 1) == 0);
182 ASSERT (close (fd) == 0);
183 ASSERT (unlink (witness) == 0);