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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
a1164ae3 LP |
2 | |
3 | #include <sys/types.h> | |
4 | #include <sys/stat.h> | |
5 | #include <fcntl.h> | |
6 | ||
7 | #include "user-util.h" | |
8 | #include "macro.h" | |
9 | #include "fd-util.h" | |
10 | #include "dirent-util.h" | |
11 | #include "chown-recursive.h" | |
12 | ||
13 | static int chown_one(int fd, const char *name, const struct stat *st, uid_t uid, gid_t gid) { | |
14 | int r; | |
15 | ||
16 | assert(fd >= 0); | |
17 | assert(st); | |
18 | ||
19 | if ((!uid_is_valid(uid) || st->st_uid == uid) && | |
20 | (!gid_is_valid(gid) || st->st_gid == gid)) | |
21 | return 0; | |
22 | ||
23 | if (name) | |
24 | r = fchownat(fd, name, uid, gid, AT_SYMLINK_NOFOLLOW); | |
25 | else | |
26 | r = fchown(fd, uid, gid); | |
27 | if (r < 0) | |
28 | return -errno; | |
29 | ||
30 | /* The linux kernel alters the mode in some cases of chown(). Let's undo this. */ | |
31 | if (name) { | |
32 | if (!S_ISLNK(st->st_mode)) | |
33 | r = fchmodat(fd, name, st->st_mode, 0); | |
34 | else /* There's currently no AT_SYMLINK_NOFOLLOW for fchmodat() */ | |
35 | r = 0; | |
36 | } else | |
37 | r = fchmod(fd, st->st_mode); | |
38 | if (r < 0) | |
39 | return -errno; | |
40 | ||
41 | return 1; | |
42 | } | |
43 | ||
44 | static int chown_recursive_internal(int fd, const struct stat *st, uid_t uid, gid_t gid) { | |
45 | bool changed = false; | |
46 | int r; | |
47 | ||
48 | assert(fd >= 0); | |
49 | assert(st); | |
50 | ||
51 | if (S_ISDIR(st->st_mode)) { | |
52 | _cleanup_closedir_ DIR *d = NULL; | |
53 | struct dirent *de; | |
54 | ||
55 | d = fdopendir(fd); | |
56 | if (!d) { | |
57 | r = -errno; | |
58 | goto finish; | |
59 | } | |
60 | fd = -1; | |
61 | ||
62 | FOREACH_DIRENT_ALL(de, d, r = -errno; goto finish) { | |
63 | struct stat fst; | |
64 | ||
65 | if (dot_or_dot_dot(de->d_name)) | |
66 | continue; | |
67 | ||
68 | if (fstatat(dirfd(d), de->d_name, &fst, AT_SYMLINK_NOFOLLOW) < 0) { | |
69 | r = -errno; | |
70 | goto finish; | |
71 | } | |
72 | ||
73 | if (S_ISDIR(fst.st_mode)) { | |
74 | int subdir_fd; | |
75 | ||
76 | subdir_fd = openat(dirfd(d), de->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME); | |
77 | if (subdir_fd < 0) { | |
78 | r = -errno; | |
79 | goto finish; | |
80 | } | |
81 | ||
82 | r = chown_recursive_internal(subdir_fd, &fst, uid, gid); | |
83 | if (r < 0) | |
84 | goto finish; | |
85 | if (r > 0) | |
86 | changed = true; | |
87 | } else { | |
88 | r = chown_one(dirfd(d), de->d_name, &fst, uid, gid); | |
89 | if (r < 0) | |
90 | goto finish; | |
91 | if (r > 0) | |
92 | changed = true; | |
93 | } | |
94 | } | |
95 | ||
96 | r = chown_one(dirfd(d), NULL, st, uid, gid); | |
97 | } else | |
98 | r = chown_one(fd, NULL, st, uid, gid); | |
99 | if (r < 0) | |
100 | goto finish; | |
101 | ||
102 | r = r > 0 || changed; | |
103 | ||
104 | finish: | |
105 | safe_close(fd); | |
106 | return r; | |
107 | } | |
108 | ||
109 | int path_chown_recursive(const char *path, uid_t uid, gid_t gid) { | |
110 | _cleanup_close_ int fd = -1; | |
111 | struct stat st; | |
112 | int r; | |
113 | ||
114 | fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME); | |
115 | if (fd < 0) | |
116 | return -errno; | |
117 | ||
118 | if (!uid_is_valid(uid) && !gid_is_valid(gid)) | |
119 | return 0; /* nothing to do */ | |
120 | ||
121 | if (fstat(fd, &st) < 0) | |
122 | return -errno; | |
123 | ||
124 | /* Let's take a shortcut: if the top-level directory is properly owned, we don't descend into the whole tree, | |
125 | * under the assumption that all is OK anyway. */ | |
126 | ||
127 | if ((!uid_is_valid(uid) || st.st_uid == uid) && | |
128 | (!gid_is_valid(gid) || st.st_gid == gid)) | |
129 | return 0; | |
130 | ||
131 | r = chown_recursive_internal(fd, &st, uid, gid); | |
132 | fd = -1; /* we donated the fd to the call, regardless if it succeeded or failed */ | |
133 | ||
134 | return r; | |
135 | } |