1 /* Tests for monitoring file descriptor usage.
2 Copyright (C) 2018-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <fcntl.h>
20 #include <stdbool.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <support/capture_subprocess.h>
24 #include <support/check.h>
25 #include <support/descriptors.h>
26 #include <support/support.h>
27 #include <support/xunistd.h>
28
29 /* This is the next free descriptor that the subprocess will pick. */
30 static int free_descriptor;
31
32 static void
33 subprocess_no_change (void *closure)
34 {
35 struct support_descriptors *descrs = support_descriptors_list ();
36 int fd = xopen ("/dev/null", O_WRONLY, 0);
37 TEST_COMPARE (fd, free_descriptor);
38 xclose (fd);
39 support_descriptors_free (descrs);
40 }
41
42 static void
43 subprocess_closed_descriptor (void *closure)
44 {
45 int fd = xopen ("/dev/null", O_WRONLY, 0);
46 TEST_COMPARE (fd, free_descriptor);
47 struct support_descriptors *descrs = support_descriptors_list ();
48 xclose (fd);
49 support_descriptors_check (descrs); /* Will report failure. */
50 puts ("EOT");
51 support_descriptors_free (descrs);
52 }
53
54 static void
55 subprocess_opened_descriptor (void *closure)
56 {
57 struct support_descriptors *descrs = support_descriptors_list ();
58 int fd = xopen ("/dev/null", O_WRONLY, 0);
59 TEST_COMPARE (fd, free_descriptor);
60 support_descriptors_check (descrs); /* Will report failure. */
61 puts ("EOT");
62 support_descriptors_free (descrs);
63 }
64
65 static void
66 subprocess_changed_descriptor (void *closure)
67 {
68 int fd = xopen ("/dev/null", O_WRONLY, 0);
69 TEST_COMPARE (fd, free_descriptor);
70 struct support_descriptors *descrs = support_descriptors_list ();
71 xclose (fd);
72 TEST_COMPARE (xopen ("/dev", O_DIRECTORY | O_RDONLY, 0), fd);
73 support_descriptors_check (descrs); /* Will report failure. */
74 puts ("EOT");
75 support_descriptors_free (descrs);
76 }
77
78 static void
79 report_subprocess_output (const char *name,
80 struct support_capture_subprocess *proc)
81 {
82 printf ("info: BEGIN %s output\n"
83 "%s"
84 "info: END %s output\n",
85 name, proc->out.buffer, name);
86 }
87
88 /* Use an explicit flag to preserve failure status across
89 support_record_failure_reset calls. */
90 static bool good = true;
91
92 static void
93 test_run (void)
94 {
95 struct support_capture_subprocess proc = support_capture_subprocess
96 (&subprocess_no_change, NULL);
97 support_capture_subprocess_check (&proc, "subprocess_no_change",
98 0, sc_allow_none);
99 support_capture_subprocess_free (&proc);
100
101 char *expected = xasprintf ("\nDifferences:\n"
102 "error: descriptor %d was closed\n"
103 "EOT\n",
104 free_descriptor);
105 good = good && !support_record_failure_is_failed ();
106 proc = support_capture_subprocess (&subprocess_closed_descriptor, NULL);
107 good = good && support_record_failure_is_failed ();
108 support_record_failure_reset (); /* Discard the reported error. */
109 report_subprocess_output ("subprocess_closed_descriptor", &proc);
110 TEST_VERIFY (strstr (proc.out.buffer, expected) != NULL);
111 support_capture_subprocess_check (&proc, "subprocess_closed_descriptor",
112 0, sc_allow_stdout);
113 support_capture_subprocess_free (&proc);
114 free (expected);
115
116 expected = xasprintf ("\nDifferences:\n"
117 "error: descriptor %d was opened (\"/dev/null\")\n"
118 "EOT\n",
119 free_descriptor);
120 good = good && !support_record_failure_is_failed ();
121 proc = support_capture_subprocess (&subprocess_opened_descriptor, NULL);
122 good = good && support_record_failure_is_failed ();
123 support_record_failure_reset (); /* Discard the reported error. */
124 report_subprocess_output ("subprocess_opened_descriptor", &proc);
125 TEST_VERIFY (strstr (proc.out.buffer, expected) != NULL);
126 support_capture_subprocess_check (&proc, "subprocess_opened_descriptor",
127 0, sc_allow_stdout);
128 support_capture_subprocess_free (&proc);
129 free (expected);
130
131 expected = xasprintf ("\nDifferences:\n"
132 "error: descriptor %d changed from \"/dev/null\""
133 " to \"/dev\"\n"
134 "error: descriptor %d changed ino ",
135 free_descriptor, free_descriptor);
136 good = good && !support_record_failure_is_failed ();
137 proc = support_capture_subprocess (&subprocess_changed_descriptor, NULL);
138 good = good && support_record_failure_is_failed ();
139 support_record_failure_reset (); /* Discard the reported error. */
140 report_subprocess_output ("subprocess_changed_descriptor", &proc);
141 TEST_VERIFY (strstr (proc.out.buffer, expected) != NULL);
142 support_capture_subprocess_check (&proc, "subprocess_changed_descriptor",
143 0, sc_allow_stdout);
144 support_capture_subprocess_free (&proc);
145 free (expected);
146 }
147
148 static int
149 do_test (void)
150 {
151 puts ("info: initial descriptor set");
152 {
153 struct support_descriptors *descrs = support_descriptors_list ();
154 support_descriptors_dump (descrs, "info: ", stdout);
155 support_descriptors_free (descrs);
156 }
157
158 free_descriptor = xopen ("/dev/null", O_WRONLY, 0);
159 puts ("info: descriptor set with additional free descriptor");
160 {
161 struct support_descriptors *descrs = support_descriptors_list ();
162 support_descriptors_dump (descrs, "info: ", stdout);
163 support_descriptors_free (descrs);
164 }
165 TEST_VERIFY (free_descriptor >= 3);
166 xclose (free_descriptor);
167
168 /* Initial test run without a sentinel descriptor. The presence of
169 such a descriptor exercises different conditions in the list
170 comparison in support_descriptors_check. */
171 test_run ();
172
173 /* Allocate a sentinel descriptor at the end of the descriptor list,
174 after free_descriptor. */
175 int sentinel_fd;
176 {
177 int fd = xopen ("/dev/full", O_WRONLY, 0);
178 TEST_COMPARE (fd, free_descriptor);
179 sentinel_fd = dup (fd);
180 TEST_VERIFY_EXIT (sentinel_fd > fd);
181 xclose (fd);
182 }
183 puts ("info: descriptor set with sentinel descriptor");
184 {
185 struct support_descriptors *descrs = support_descriptors_list ();
186 support_descriptors_dump (descrs, "info: ", stdout);
187 support_descriptors_free (descrs);
188 }
189
190 /* Second test run with sentinel descriptor. */
191 test_run ();
192
193 xclose (sentinel_fd);
194
195 return !good;
196 }
197
198 #include <support/test-driver.c>