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8fcde012 LP |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2010-2012 Lennart Poettering | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU Lesser General Public License as published by | |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public License | |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
18 | ***/ | |
19 | ||
11c3a366 TA |
20 | #include <dirent.h> |
21 | #include <errno.h> | |
8fcde012 | 22 | #include <fcntl.h> |
11c3a366 TA |
23 | #include <sys/stat.h> |
24 | #include <sys/types.h> | |
8fcde012 LP |
25 | #include <linux/magic.h> |
26 | #include <sys/statvfs.h> | |
27 | #include <unistd.h> | |
28 | ||
29 | #include "dirent-util.h" | |
30 | #include "fd-util.h" | |
7dcdb24e | 31 | #include "fs-util.h" |
8fcde012 LP |
32 | #include "macro.h" |
33 | #include "missing.h" | |
34 | #include "stat-util.h" | |
35 | #include "string-util.h" | |
36 | ||
37 | int is_symlink(const char *path) { | |
38 | struct stat info; | |
39 | ||
40 | assert(path); | |
41 | ||
42 | if (lstat(path, &info) < 0) | |
43 | return -errno; | |
44 | ||
45 | return !!S_ISLNK(info.st_mode); | |
46 | } | |
47 | ||
48 | int is_dir(const char* path, bool follow) { | |
49 | struct stat st; | |
50 | int r; | |
51 | ||
52 | assert(path); | |
53 | ||
54 | if (follow) | |
55 | r = stat(path, &st); | |
56 | else | |
57 | r = lstat(path, &st); | |
58 | if (r < 0) | |
59 | return -errno; | |
60 | ||
61 | return !!S_ISDIR(st.st_mode); | |
62 | } | |
63 | ||
64 | int is_device_node(const char *path) { | |
65 | struct stat info; | |
66 | ||
67 | assert(path); | |
68 | ||
69 | if (lstat(path, &info) < 0) | |
70 | return -errno; | |
71 | ||
72 | return !!(S_ISBLK(info.st_mode) || S_ISCHR(info.st_mode)); | |
73 | } | |
74 | ||
75 | int dir_is_empty(const char *path) { | |
76 | _cleanup_closedir_ DIR *d; | |
77 | struct dirent *de; | |
78 | ||
79 | d = opendir(path); | |
80 | if (!d) | |
81 | return -errno; | |
82 | ||
83 | FOREACH_DIRENT(de, d, return -errno) | |
84 | return 0; | |
85 | ||
86 | return 1; | |
87 | } | |
88 | ||
89 | bool null_or_empty(struct stat *st) { | |
90 | assert(st); | |
91 | ||
92 | if (S_ISREG(st->st_mode) && st->st_size <= 0) | |
93 | return true; | |
94 | ||
95 | /* We don't want to hardcode the major/minor of /dev/null, | |
96 | * hence we do a simpler "is this a device node?" check. */ | |
97 | ||
98 | if (S_ISCHR(st->st_mode) || S_ISBLK(st->st_mode)) | |
99 | return true; | |
100 | ||
101 | return false; | |
102 | } | |
103 | ||
104 | int null_or_empty_path(const char *fn) { | |
105 | struct stat st; | |
106 | ||
107 | assert(fn); | |
108 | ||
109 | if (stat(fn, &st) < 0) | |
110 | return -errno; | |
111 | ||
112 | return null_or_empty(&st); | |
113 | } | |
114 | ||
115 | int null_or_empty_fd(int fd) { | |
116 | struct stat st; | |
117 | ||
118 | assert(fd >= 0); | |
119 | ||
120 | if (fstat(fd, &st) < 0) | |
121 | return -errno; | |
122 | ||
123 | return null_or_empty(&st); | |
124 | } | |
125 | ||
126 | int path_is_read_only_fs(const char *path) { | |
127 | struct statvfs st; | |
128 | ||
129 | assert(path); | |
130 | ||
131 | if (statvfs(path, &st) < 0) | |
132 | return -errno; | |
133 | ||
134 | if (st.f_flag & ST_RDONLY) | |
135 | return true; | |
136 | ||
137 | /* On NFS, statvfs() might not reflect whether we can actually | |
138 | * write to the remote share. Let's try again with | |
139 | * access(W_OK) which is more reliable, at least sometimes. */ | |
140 | if (access(path, W_OK) < 0 && errno == EROFS) | |
141 | return true; | |
142 | ||
143 | return false; | |
144 | } | |
145 | ||
146 | int path_is_os_tree(const char *path) { | |
8fcde012 LP |
147 | int r; |
148 | ||
149 | assert(path); | |
150 | ||
7dcdb24e LP |
151 | /* Does the path exist at all? If not, generate an error immediately. This is useful so that a missing root dir |
152 | * always results in -ENOENT, and we can properly distuingish the case where the whole root doesn't exist from | |
153 | * the case where just the os-release file is missing. */ | |
154 | if (laccess(path, F_OK) < 0) | |
155 | return -errno; | |
8fcde012 | 156 | |
7dcdb24e LP |
157 | /* We use /usr/lib/os-release as flag file if something is an OS */ |
158 | r = chase_symlinks("/usr/lib/os-release", path, CHASE_PREFIX_ROOT, NULL); | |
159 | if (r == -ENOENT) { | |
160 | ||
161 | /* Also check for the old location in /etc, just in case. */ | |
162 | r = chase_symlinks("/etc/os-release", path, CHASE_PREFIX_ROOT, NULL); | |
163 | if (r == -ENOENT) | |
164 | return 0; /* We got nothing */ | |
165 | } | |
166 | if (r < 0) | |
167 | return r; | |
8fcde012 | 168 | |
7dcdb24e | 169 | return 1; |
8fcde012 LP |
170 | } |
171 | ||
172 | int files_same(const char *filea, const char *fileb) { | |
173 | struct stat a, b; | |
174 | ||
175 | assert(filea); | |
176 | assert(fileb); | |
177 | ||
178 | if (stat(filea, &a) < 0) | |
179 | return -errno; | |
180 | ||
181 | if (stat(fileb, &b) < 0) | |
182 | return -errno; | |
183 | ||
184 | return a.st_dev == b.st_dev && | |
185 | a.st_ino == b.st_ino; | |
186 | } | |
187 | ||
188 | bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) { | |
189 | assert(s); | |
190 | assert_cc(sizeof(statfs_f_type_t) >= sizeof(s->f_type)); | |
191 | ||
192 | return F_TYPE_EQUAL(s->f_type, magic_value); | |
193 | } | |
194 | ||
195 | int fd_check_fstype(int fd, statfs_f_type_t magic_value) { | |
196 | struct statfs s; | |
197 | ||
198 | if (fstatfs(fd, &s) < 0) | |
199 | return -errno; | |
200 | ||
201 | return is_fs_type(&s, magic_value); | |
202 | } | |
203 | ||
204 | int path_check_fstype(const char *path, statfs_f_type_t magic_value) { | |
205 | _cleanup_close_ int fd = -1; | |
206 | ||
08cea7df | 207 | fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY); |
8fcde012 LP |
208 | if (fd < 0) |
209 | return -errno; | |
210 | ||
211 | return fd_check_fstype(fd, magic_value); | |
212 | } | |
213 | ||
214 | bool is_temporary_fs(const struct statfs *s) { | |
215 | return is_fs_type(s, TMPFS_MAGIC) || | |
216 | is_fs_type(s, RAMFS_MAGIC); | |
217 | } | |
218 | ||
219 | int fd_is_temporary_fs(int fd) { | |
220 | struct statfs s; | |
221 | ||
222 | if (fstatfs(fd, &s) < 0) | |
223 | return -errno; | |
224 | ||
225 | return is_temporary_fs(&s); | |
226 | } |