1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2011 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
26 #include "formats-util.h"
29 #include "logind-acl.h"
30 #include "udev-util.h"
32 static int flush_acl(acl_t acl) {
39 for (found = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
41 found = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) {
45 if (acl_get_tag_type(i, &tag) < 0)
51 if (acl_delete_entry(acl, i) < 0)
63 int devnode_acl(const char *path,
65 bool del, uid_t old_uid,
66 bool add, uid_t new_uid) {
74 acl = acl_get_file(path, ACL_TYPE_ACCESS);
86 } else if (del && old_uid > 0) {
89 r = acl_find_uid(acl, old_uid, &entry);
94 if (acl_delete_entry(acl, entry) < 0) {
103 if (add && new_uid > 0) {
105 acl_permset_t permset;
108 r = acl_find_uid(acl, new_uid, &entry);
113 if (acl_create_entry(&acl, &entry) < 0) {
118 if (acl_set_tag_type(entry, ACL_USER) < 0 ||
119 acl_set_qualifier(entry, &new_uid) < 0) {
125 if (acl_get_permset(entry, &permset) < 0) {
130 rd = acl_get_perm(permset, ACL_READ);
136 wt = acl_get_perm(permset, ACL_WRITE);
144 if (acl_add_perm(permset, ACL_READ|ACL_WRITE) < 0) {
156 if (acl_calc_mask(&acl) < 0) {
161 if (acl_set_file(path, ACL_TYPE_ACCESS, acl) < 0) {
174 int devnode_acl_all(struct udev *udev,
177 bool del, uid_t old_uid,
178 bool add, uid_t new_uid) {
180 _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
181 struct udev_list_entry *item = NULL, *first = NULL;
182 _cleanup_set_free_free_ Set *nodes = NULL;
183 _cleanup_closedir_ DIR *dir = NULL;
191 nodes = set_new(&string_hash_ops);
195 e = udev_enumerate_new(udev);
202 /* We can only match by one tag in libudev. We choose
203 * "uaccess" for that. If we could match for two tags here we
204 * could add the seat name as second match tag, but this would
205 * be hardly optimizable in libudev, and hence checking the
206 * second tag manually in our loop is a good solution. */
207 r = udev_enumerate_add_match_tag(e, "uaccess");
211 r = udev_enumerate_add_match_is_initialized(e);
215 r = udev_enumerate_scan_devices(e);
219 first = udev_enumerate_get_list_entry(e);
220 udev_list_entry_foreach(item, first) {
221 _cleanup_udev_device_unref_ struct udev_device *d = NULL;
222 const char *node, *sn;
224 d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
228 sn = udev_device_get_property_value(d, "ID_SEAT");
232 if (!streq(seat, sn))
235 node = udev_device_get_devnode(d);
236 /* In case people mistag devices with nodes, we need to ignore this */
244 log_debug("Found udev node %s for seat %s", n, seat);
245 r = set_consume(nodes, n);
250 /* udev exports "dead" device nodes to allow module on-demand loading,
251 * these devices are not known to the kernel at this moment */
252 dir = opendir("/run/udev/static_node-tags/uaccess");
254 FOREACH_DIRENT(dent, dir, return -errno) {
255 _cleanup_free_ char *unescaped_devname = NULL;
257 if (cunescape(dent->d_name, UNESCAPE_RELAX, &unescaped_devname) < 0)
260 n = strappend("/dev/", unescaped_devname);
264 log_debug("Found static node %s for seat %s", n, seat);
265 r = set_consume(nodes, n);
274 SET_FOREACH(n, nodes, i) {
277 log_debug("Changing ACLs at %s for seat %s (uid "UID_FMT"→"UID_FMT"%s%s)",
278 n, seat, old_uid, new_uid,
279 del ? " del" : "", add ? " add" : "");
281 k = devnode_acl(n, flush, del, old_uid, add, new_uid);
283 log_debug("Device %s disappeared while setting ACLs", n);
284 else if (k < 0 && r == 0)