1 | /* Tests for support_open_dev_null_range. |
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 <dirent.h> |
21 | #include <fcntl.h> |
22 | #include <limits.h> |
23 | #include <support/check.h> |
24 | #include <support/support.h> |
25 | #include <support/xunistd.h> |
26 | #include <sys/resource.h> |
27 | #include <stdlib.h> |
28 | |
29 | #ifndef PATH_MAX |
30 | # define PATH_MAX 1024 |
31 | #endif |
32 | |
33 | #include <stdio.h> |
34 | |
35 | static void |
36 | check_path (int fd) |
37 | { |
38 | char *proc_fd_path = xasprintf (format: "/proc/self/fd/%d" , fd); |
39 | char file_path[PATH_MAX]; |
40 | ssize_t file_path_length |
41 | = readlink (path: proc_fd_path, buf: file_path, len: sizeof (file_path)); |
42 | if (file_path_length < 0) |
43 | FAIL_EXIT1 ("readlink (%s, %p, %zu)" , proc_fd_path, file_path, |
44 | sizeof (file_path)); |
45 | |
46 | free (ptr: proc_fd_path); |
47 | file_path[file_path_length] = '\0'; |
48 | TEST_COMPARE_STRING (file_path, "/dev/null" ); |
49 | } |
50 | |
51 | static int |
52 | number_of_opened_files (void) |
53 | { |
54 | DIR *fds = opendir (name: "/proc/self/fd" ); |
55 | if (fds == NULL) |
56 | FAIL_EXIT1 ("opendir (\"/proc/self/fd\"): %m" ); |
57 | |
58 | int r = 0; |
59 | while (true) |
60 | { |
61 | errno = 0; |
62 | struct dirent64 *e = readdir64 (dirp: fds); |
63 | if (e == NULL) |
64 | { |
65 | if (errno != 0) |
66 | FAIL_EXIT1 ("readdir: %m" ); |
67 | break; |
68 | } |
69 | |
70 | if (e->d_name[0] == '.') |
71 | continue; |
72 | |
73 | char *endptr; |
74 | long int fd = strtol (nptr: e->d_name, endptr: &endptr, base: 10); |
75 | if (*endptr != '\0' || fd < 0 || fd > INT_MAX) |
76 | FAIL_EXIT1 ("readdir: invalid file descriptor name: /proc/self/fd/%s" , |
77 | e->d_name); |
78 | |
79 | /* Skip the descriptor which is used to enumerate the |
80 | descriptors. */ |
81 | if (fd == dirfd (fds)) |
82 | continue; |
83 | |
84 | r = r + 1; |
85 | } |
86 | |
87 | closedir (dirp: fds); |
88 | |
89 | return r; |
90 | } |
91 | |
92 | static int |
93 | do_test (void) |
94 | { |
95 | const int nfds1 = 8; |
96 | int lowfd = support_open_dev_null_range (num: nfds1, O_RDONLY, mode: 0600); |
97 | for (int i = 0; i < nfds1; i++) |
98 | { |
99 | TEST_VERIFY (fcntl (lowfd + i, F_GETFL) > -1); |
100 | check_path (fd: lowfd + i); |
101 | } |
102 | |
103 | /* create some gaps. */ |
104 | xclose (lowfd + 1); |
105 | xclose (lowfd + 5); |
106 | xclose (lowfd + 6); |
107 | |
108 | const int nfds2 = 16; |
109 | int lowfd2 = support_open_dev_null_range (num: nfds2, O_RDONLY, mode: 0600); |
110 | for (int i = 0; i < nfds2; i++) |
111 | { |
112 | TEST_VERIFY (fcntl (lowfd2 + i, F_GETFL) > -1); |
113 | check_path (fd: lowfd2 + i); |
114 | } |
115 | |
116 | /* Decrease the maximum number of files. */ |
117 | { |
118 | struct rlimit rl; |
119 | if (getrlimit (RLIMIT_NOFILE, rlimits: &rl) == -1) |
120 | FAIL_EXIT1 ("getrlimit (RLIMIT_NOFILE): %m" ); |
121 | |
122 | rl.rlim_cur = number_of_opened_files (); |
123 | |
124 | if (setrlimit (RLIMIT_NOFILE, rlimits: &rl) == 1) |
125 | FAIL_EXIT1 ("setrlimit (RLIMIT_NOFILE): %m" ); |
126 | } |
127 | |
128 | const int nfds3 = 16; |
129 | int lowfd3 = support_open_dev_null_range (num: nfds3, O_RDONLY, mode: 0600); |
130 | for (int i = 0; i < nfds3; i++) |
131 | { |
132 | TEST_VERIFY (fcntl (lowfd3 + i, F_GETFL) > -1); |
133 | check_path (fd: lowfd3 + i); |
134 | } |
135 | |
136 | /* create a lot of gaps to trigger the range extension. */ |
137 | xclose (lowfd3 + 1); |
138 | xclose (lowfd3 + 3); |
139 | xclose (lowfd3 + 5); |
140 | xclose (lowfd3 + 7); |
141 | xclose (lowfd3 + 9); |
142 | xclose (lowfd3 + 11); |
143 | xclose (lowfd3 + 13); |
144 | |
145 | const int nfds4 = 16; |
146 | int lowfd4 = support_open_dev_null_range (num: nfds4, O_RDONLY, mode: 0600); |
147 | for (int i = 0; i < nfds4; i++) |
148 | { |
149 | TEST_VERIFY (fcntl (lowfd4 + i, F_GETFL) > -1); |
150 | check_path (fd: lowfd4 + i); |
151 | } |
152 | |
153 | return 0; |
154 | } |
155 | |
156 | #include <support/test-driver.c> |
157 | |