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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
5eda94dd LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2011 Lennart Poettering | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
8 | under the terms of the GNU Lesser General Public License as published by |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
5eda94dd LP |
10 | (at your option) any later version. |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 15 | Lesser General Public License for more details. |
5eda94dd | 16 | |
5430f7f2 | 17 | You should have received a copy of the GNU Lesser General Public License |
5eda94dd LP |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
19 | ***/ | |
20 | ||
5eda94dd LP |
21 | #include <errno.h> |
22 | #include <string.h> | |
23 | ||
79c07722 | 24 | #include "acl-util.h" |
b5efdb8a | 25 | #include "alloc-util.h" |
a0956174 | 26 | #include "dirent-util.h" |
4f5dd394 | 27 | #include "escape.h" |
3ffd4af2 | 28 | #include "fd-util.h" |
f97b34a6 | 29 | #include "format-util.h" |
3ffd4af2 | 30 | #include "logind-acl.h" |
6b78df0a | 31 | #include "set.h" |
07630cea | 32 | #include "string-util.h" |
bf5332d2 | 33 | #include "udev-util.h" |
4f5dd394 | 34 | #include "util.h" |
5eda94dd LP |
35 | |
36 | static int flush_acl(acl_t acl) { | |
37 | acl_entry_t i; | |
38 | int found; | |
39 | bool changed = false; | |
40 | ||
41 | assert(acl); | |
42 | ||
43 | for (found = acl_get_entry(acl, ACL_FIRST_ENTRY, &i); | |
44 | found > 0; | |
45 | found = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) { | |
46 | ||
47 | acl_tag_t tag; | |
48 | ||
49 | if (acl_get_tag_type(i, &tag) < 0) | |
50 | return -errno; | |
51 | ||
52 | if (tag != ACL_USER) | |
53 | continue; | |
54 | ||
55 | if (acl_delete_entry(acl, i) < 0) | |
56 | return -errno; | |
57 | ||
58 | changed = true; | |
59 | } | |
60 | ||
61 | if (found < 0) | |
62 | return -errno; | |
63 | ||
64 | return changed; | |
65 | } | |
66 | ||
67 | int devnode_acl(const char *path, | |
68 | bool flush, | |
69 | bool del, uid_t old_uid, | |
70 | bool add, uid_t new_uid) { | |
71 | ||
72 | acl_t acl; | |
501c92c4 | 73 | int r = 0; |
5eda94dd LP |
74 | bool changed = false; |
75 | ||
76 | assert(path); | |
77 | ||
78 | acl = acl_get_file(path, ACL_TYPE_ACCESS); | |
79 | if (!acl) | |
80 | return -errno; | |
81 | ||
82 | if (flush) { | |
83 | ||
84 | r = flush_acl(acl); | |
85 | if (r < 0) | |
86 | goto finish; | |
87 | if (r > 0) | |
88 | changed = true; | |
89 | ||
90 | } else if (del && old_uid > 0) { | |
91 | acl_entry_t entry; | |
92 | ||
f4b47811 | 93 | r = acl_find_uid(acl, old_uid, &entry); |
5eda94dd LP |
94 | if (r < 0) |
95 | goto finish; | |
96 | ||
97 | if (r > 0) { | |
98 | if (acl_delete_entry(acl, entry) < 0) { | |
99 | r = -errno; | |
100 | goto finish; | |
101 | } | |
102 | ||
103 | changed = true; | |
104 | } | |
105 | } | |
106 | ||
107 | if (add && new_uid > 0) { | |
108 | acl_entry_t entry; | |
109 | acl_permset_t permset; | |
110 | int rd, wt; | |
111 | ||
f4b47811 | 112 | r = acl_find_uid(acl, new_uid, &entry); |
5eda94dd LP |
113 | if (r < 0) |
114 | goto finish; | |
115 | ||
116 | if (r == 0) { | |
117 | if (acl_create_entry(&acl, &entry) < 0) { | |
118 | r = -errno; | |
119 | goto finish; | |
120 | } | |
121 | ||
122 | if (acl_set_tag_type(entry, ACL_USER) < 0 || | |
123 | acl_set_qualifier(entry, &new_uid) < 0) { | |
124 | r = -errno; | |
125 | goto finish; | |
126 | } | |
127 | } | |
128 | ||
129 | if (acl_get_permset(entry, &permset) < 0) { | |
130 | r = -errno; | |
131 | goto finish; | |
132 | } | |
133 | ||
134 | rd = acl_get_perm(permset, ACL_READ); | |
135 | if (rd < 0) { | |
136 | r = -errno; | |
137 | goto finish; | |
138 | } | |
139 | ||
140 | wt = acl_get_perm(permset, ACL_WRITE); | |
141 | if (wt < 0) { | |
142 | r = -errno; | |
143 | goto finish; | |
144 | } | |
145 | ||
146 | if (!rd || !wt) { | |
147 | ||
148 | if (acl_add_perm(permset, ACL_READ|ACL_WRITE) < 0) { | |
149 | r = -errno; | |
150 | goto finish; | |
151 | } | |
152 | ||
153 | changed = true; | |
154 | } | |
155 | } | |
156 | ||
157 | if (!changed) | |
158 | goto finish; | |
159 | ||
160 | if (acl_calc_mask(&acl) < 0) { | |
161 | r = -errno; | |
162 | goto finish; | |
163 | } | |
164 | ||
165 | if (acl_set_file(path, ACL_TYPE_ACCESS, acl) < 0) { | |
166 | r = -errno; | |
167 | goto finish; | |
168 | } | |
169 | ||
170 | r = 0; | |
171 | ||
172 | finish: | |
173 | acl_free(acl); | |
174 | ||
175 | return r; | |
176 | } | |
177 | ||
178 | int devnode_acl_all(struct udev *udev, | |
179 | const char *seat, | |
180 | bool flush, | |
181 | bool del, uid_t old_uid, | |
182 | bool add, uid_t new_uid) { | |
183 | ||
bf5332d2 | 184 | _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL; |
5eda94dd | 185 | struct udev_list_entry *item = NULL, *first = NULL; |
bf5332d2 | 186 | _cleanup_set_free_free_ Set *nodes = NULL; |
db0c1e3b | 187 | _cleanup_closedir_ DIR *dir = NULL; |
6b78df0a | 188 | struct dirent *dent; |
bf5332d2 LP |
189 | Iterator i; |
190 | char *n; | |
5eda94dd LP |
191 | int r; |
192 | ||
193 | assert(udev); | |
194 | ||
d5099efc | 195 | nodes = set_new(&string_hash_ops); |
cc377381 | 196 | if (!nodes) |
6b78df0a | 197 | return -ENOMEM; |
5eda94dd LP |
198 | |
199 | e = udev_enumerate_new(udev); | |
bf5332d2 LP |
200 | if (!e) |
201 | return -ENOMEM; | |
6b78df0a TG |
202 | |
203 | if (isempty(seat)) | |
204 | seat = "seat0"; | |
5eda94dd | 205 | |
7b3afbac LP |
206 | /* We can only match by one tag in libudev. We choose |
207 | * "uaccess" for that. If we could match for two tags here we | |
208 | * could add the seat name as second match tag, but this would | |
209 | * be hardly optimizable in libudev, and hence checking the | |
210 | * second tag manually in our loop is a good solution. */ | |
5eda94dd LP |
211 | r = udev_enumerate_add_match_tag(e, "uaccess"); |
212 | if (r < 0) | |
bf5332d2 | 213 | return r; |
5eda94dd | 214 | |
e1202047 LP |
215 | r = udev_enumerate_add_match_is_initialized(e); |
216 | if (r < 0) | |
217 | return r; | |
218 | ||
5eda94dd LP |
219 | r = udev_enumerate_scan_devices(e); |
220 | if (r < 0) | |
bf5332d2 | 221 | return r; |
5eda94dd LP |
222 | |
223 | first = udev_enumerate_get_list_entry(e); | |
224 | udev_list_entry_foreach(item, first) { | |
bf5332d2 | 225 | _cleanup_udev_device_unref_ struct udev_device *d = NULL; |
5eda94dd LP |
226 | const char *node, *sn; |
227 | ||
228 | d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)); | |
bf5332d2 LP |
229 | if (!d) |
230 | return -ENOMEM; | |
231 | ||
53907215 LP |
232 | sn = udev_device_get_property_value(d, "ID_SEAT"); |
233 | if (isempty(sn)) | |
5eda94dd LP |
234 | sn = "seat0"; |
235 | ||
bf5332d2 | 236 | if (!streq(seat, sn)) |
5eda94dd | 237 | continue; |
5eda94dd LP |
238 | |
239 | node = udev_device_get_devnode(d); | |
bf5332d2 LP |
240 | /* In case people mistag devices with nodes, we need to ignore this */ |
241 | if (!node) | |
d2d4b038 | 242 | continue; |
5eda94dd | 243 | |
6b78df0a | 244 | n = strdup(node); |
6b78df0a | 245 | if (!n) |
bf5332d2 | 246 | return -ENOMEM; |
ce0f7c97 | 247 | |
6b78df0a | 248 | log_debug("Found udev node %s for seat %s", n, seat); |
bf5332d2 | 249 | r = set_consume(nodes, n); |
5eda94dd | 250 | if (r < 0) |
bf5332d2 | 251 | return r; |
5eda94dd LP |
252 | } |
253 | ||
6b78df0a TG |
254 | /* udev exports "dead" device nodes to allow module on-demand loading, |
255 | * these devices are not known to the kernel at this moment */ | |
256 | dir = opendir("/run/udev/static_node-tags/uaccess"); | |
257 | if (dir) { | |
bf5332d2 | 258 | FOREACH_DIRENT(dent, dir, return -errno) { |
6b78df0a | 259 | _cleanup_free_ char *unescaped_devname = NULL; |
5eda94dd | 260 | |
527b7a42 | 261 | if (cunescape(dent->d_name, UNESCAPE_RELAX, &unescaped_devname) < 0) |
bf5332d2 | 262 | return -ENOMEM; |
6b78df0a TG |
263 | |
264 | n = strappend("/dev/", unescaped_devname); | |
bf5332d2 LP |
265 | if (!n) |
266 | return -ENOMEM; | |
6b78df0a TG |
267 | |
268 | log_debug("Found static node %s for seat %s", n, seat); | |
bf5332d2 LP |
269 | r = set_consume(nodes, n); |
270 | if (r == -EEXIST) | |
271 | continue; | |
272 | if (r < 0) | |
273 | return r; | |
6b78df0a | 274 | } |
6b78df0a TG |
275 | } |
276 | ||
bf5332d2 | 277 | r = 0; |
6b78df0a | 278 | SET_FOREACH(n, nodes, i) { |
bf5332d2 LP |
279 | int k; |
280 | ||
6b9732b2 ZJS |
281 | log_debug("Changing ACLs at %s for seat %s (uid "UID_FMT"→"UID_FMT"%s%s)", |
282 | n, seat, old_uid, new_uid, | |
283 | del ? " del" : "", add ? " add" : ""); | |
284 | ||
bf5332d2 | 285 | k = devnode_acl(n, flush, del, old_uid, add, new_uid); |
8016b904 DH |
286 | if (k == -ENOENT) |
287 | log_debug("Device %s disappeared while setting ACLs", n); | |
f7a5bb28 | 288 | else if (k < 0 && r == 0) |
bf5332d2 | 289 | r = k; |
6b78df0a TG |
290 | } |
291 | ||
5eda94dd LP |
292 | return r; |
293 | } |