1 /* Child program invoked by test-spawn-pipe-main.
2 Copyright (C) 2009-2021 Free Software Foundation, Inc.
3
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, or (at your option)
7 any later version.
8
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.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, see <https://www.gnu.org/licenses/>. */
16
17 #include <config.h>
18
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <stdbool.h>
22 #include <stdint.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27
28 #if defined _WIN32 && ! defined __CYGWIN__
29 /* Get declarations of the native Windows API functions. */
30 # define WIN32_LEAN_AND_MEAN
31 # include <windows.h>
32 #endif
33
34 /* Depending on arguments, this test intentionally closes stderr or
35 starts life with stderr closed. So, we arrange to have fd 10
36 (outside the range of interesting fd's during the test) set up to
37 duplicate the original stderr. */
38
39 #define BACKUP_STDERR_FILENO 10
40 #define ASSERT_STREAM myerr
41 #include "macros.h"
42
43 static FILE *myerr;
44
45 /* In this file, we use only system functions, no overrides from gnulib. */
46 #undef atoi
47 #undef close
48 #undef fcntl
49 #undef fdopen
50 #undef fflush
51 #undef fprintf
52 #undef open
53 #undef read
54 #undef strcasestr
55 #undef strstr
56 #undef write
57 #if defined _WIN32 && !defined __CYGWIN__
58 # define fdopen _fdopen
59 #endif
60
61 #include "qemu.h"
62
63 #if HAVE_MSVC_INVALID_PARAMETER_HANDLER
64 static void __cdecl
65 gl_msvc_invalid_parameter_handler (const wchar_t *expression,
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*/
66 const wchar_t *function,
67 const wchar_t *file,
68 unsigned int line,
69 uintptr_t dummy)
70 {
71 }
72 #endif
73
74 /* Return non-zero if FD is open. */
75 static int
76 is_open (int fd)
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*/
77 {
78 #if defined _WIN32 && ! defined __CYGWIN__
79 /* On native Windows, the initial state of unassigned standard file
80 descriptors is that they are open but point to an
81 INVALID_HANDLE_VALUE, and there is no fcntl. */
82 return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE;
83 #else
84 # ifndef F_GETFL
85 # error Please port fcntl to your platform
86 # endif
87 return 0 <= fcntl (fd, F_GETFL);
88 #endif
89 }
90
91 int
92 main (int argc, char *argv[])
/* ![[previous]](../icons/left.png)
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*/
93 {
94 /* fd 2 might be closed, but fd BACKUP_STDERR_FILENO is the original
95 stderr. */
96 myerr = fdopen (BACKUP_STDERR_FILENO, "w");
97 if (!myerr)
98 return 2;
99
100 ASSERT (argc == 2);
101
102 #if HAVE_MSVC_INVALID_PARAMETER_HANDLER
103 /* Avoid exceptions from within _get_osfhandle. */
104 _set_invalid_parameter_handler (gl_msvc_invalid_parameter_handler);
105 #endif
106
107 /* QEMU 6.1 in user-mode passes an open fd, usually = 3, that references
108 /dev/urandom. We need to ignore this fd. */
109 bool is_qemu = is_running_under_qemu_user ();
110
111 /* Read one byte from fd 0, and write its value plus one to fd 1.
112 fd 2 should be closed iff the argument is 1. Check that no other file
113 descriptors leaked. */
114
115 char buffer[2] = { 's', 't' };
116
117 ASSERT (read (STDIN_FILENO, buffer, 2) == 1);
118
119 buffer[0]++;
120 ASSERT (write (STDOUT_FILENO, buffer, 1) == 1);
121
122 switch (atoi (argv[1]))
123 {
124 case 0:
125 /* Expect fd 2 is open. */
126 ASSERT (is_open (STDERR_FILENO));
127 break;
128 case 1:
129 /* Expect fd 2 is closed.
130 But on HP-UX 11, fd 2 gets automatically re-opened to /dev/null if it
131 was closed. Similarly on native Windows. Future POSIX will allow
132 this, see <http://austingroupbugs.net/view.php?id=173>. */
133 #if !(defined __hpux || (defined _WIN32 && ! defined __CYGWIN__))
134 if (!is_qemu)
135 ASSERT (! is_open (STDERR_FILENO));
136 #endif
137 break;
138 default:
139 ASSERT (0);
140 }
141
142 int fd;
143 for (fd = 3; fd < 7; fd++)
144 if (!(is_qemu && fd == 3))
145 {
146 errno = 0;
147 ASSERT (close (fd) == -1);
148 ASSERT (errno == EBADF);
149 }
150
151 return 0;
152 }