1 | /* Smoke test for the closefrom. |
2 | Copyright (C) 2021-2022 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 <errno.h> |
20 | #include <fcntl.h> |
21 | #include <sys/resource.h> |
22 | #include <unistd.h> |
23 | |
24 | #include <support/check.h> |
25 | #include <support/descriptors.h> |
26 | #include <support/xunistd.h> |
27 | #include <support/support.h> |
28 | |
29 | #include <array_length.h> |
30 | |
31 | #define NFDS 100 |
32 | |
33 | static int |
34 | closefrom_test (void) |
35 | { |
36 | struct support_descriptors *descrs = support_descriptors_list (); |
37 | |
38 | int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, mode: 0600); |
39 | |
40 | const int maximum_fd = lowfd + NFDS - 1; |
41 | const int half_fd = lowfd + NFDS / 2; |
42 | const int gap = lowfd + NFDS / 4; |
43 | |
44 | /* Close half of the descriptors and check result. */ |
45 | closefrom (lowfd: half_fd); |
46 | |
47 | for (int i = half_fd; i <= maximum_fd; i++) |
48 | { |
49 | TEST_COMPARE (fcntl (i, F_GETFL), -1); |
50 | TEST_COMPARE (errno, EBADF); |
51 | } |
52 | for (int i = lowfd; i < half_fd; i++) |
53 | TEST_VERIFY (fcntl (i, F_GETFL) > -1); |
54 | |
55 | /* Create some gaps, close up to a threshold, and check result. */ |
56 | xclose (lowfd + 35); |
57 | xclose (lowfd + 38); |
58 | xclose (lowfd + 42); |
59 | xclose (lowfd + 46); |
60 | |
61 | /* Close half of the descriptors and check result. */ |
62 | closefrom (lowfd: gap); |
63 | for (int i = gap + 1; i < maximum_fd; i++) |
64 | { |
65 | TEST_COMPARE (fcntl (i, F_GETFL), -1); |
66 | TEST_COMPARE (errno, EBADF); |
67 | } |
68 | for (int i = lowfd; i < gap; i++) |
69 | TEST_VERIFY (fcntl (i, F_GETFL) > -1); |
70 | |
71 | /* Close the remmaining but the last one. */ |
72 | closefrom (lowfd: lowfd + 1); |
73 | for (int i = lowfd + 1; i <= maximum_fd; i++) |
74 | { |
75 | TEST_COMPARE (fcntl (i, F_GETFL), -1); |
76 | TEST_COMPARE (errno, EBADF); |
77 | } |
78 | TEST_VERIFY (fcntl (lowfd, F_GETFL) > -1); |
79 | |
80 | /* Close the last one. */ |
81 | closefrom (lowfd: lowfd); |
82 | TEST_COMPARE (fcntl (lowfd, F_GETFL), -1); |
83 | TEST_COMPARE (errno, EBADF); |
84 | |
85 | /* Double check by check the /proc. */ |
86 | support_descriptors_check (descrs); |
87 | support_descriptors_free (descrs); |
88 | |
89 | return 0; |
90 | } |
91 | |
92 | /* Check if closefrom works even when no new file descriptors can be |
93 | created. */ |
94 | static int |
95 | closefrom_test_file_desc_limit (void) |
96 | { |
97 | int max_fd = NFDS; |
98 | { |
99 | struct rlimit rl; |
100 | if (getrlimit (RLIMIT_NOFILE, rlimits: &rl) == -1) |
101 | FAIL_EXIT1 ("getrlimit (RLIMIT_NOFILE): %m" ); |
102 | |
103 | max_fd = (rl.rlim_cur < max_fd ? rl.rlim_cur : max_fd); |
104 | rl.rlim_cur = max_fd; |
105 | |
106 | if (setrlimit (RLIMIT_NOFILE, rlimits: &rl) == 1) |
107 | FAIL_EXIT1 ("setrlimit (RLIMIT_NOFILE): %m" ); |
108 | } |
109 | |
110 | /* Exhauste the file descriptor limit. */ |
111 | int lowfd = xopen (path: "/dev/null" , O_RDONLY, 0600); |
112 | for (;;) |
113 | { |
114 | int fd = open (file: "/dev/null" , O_RDONLY, 0600); |
115 | if (fd == -1) |
116 | { |
117 | if (errno != EMFILE) |
118 | FAIL_EXIT1 ("open: %m" ); |
119 | break; |
120 | } |
121 | TEST_VERIFY_EXIT (fd < max_fd); |
122 | } |
123 | |
124 | closefrom (lowfd: lowfd); |
125 | for (int i = lowfd; i < NFDS; i++) |
126 | { |
127 | TEST_COMPARE (fcntl (i, F_GETFL), -1); |
128 | TEST_COMPARE (errno, EBADF); |
129 | } |
130 | |
131 | return 0; |
132 | } |
133 | |
134 | static int |
135 | do_test (void) |
136 | { |
137 | closefrom_test (); |
138 | closefrom_test_file_desc_limit (); |
139 | |
140 | return 0; |
141 | } |
142 | |
143 | #include <support/test-driver.c> |
144 | |