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Diffstat (limited to 'src/grp-login/systemd-logind/logind-acl.c')
-rw-r--r--src/grp-login/systemd-logind/logind-acl.c293
1 files changed, 293 insertions, 0 deletions
diff --git a/src/grp-login/systemd-logind/logind-acl.c b/src/grp-login/systemd-logind/logind-acl.c
new file mode 100644
index 0000000000..44e49c1dad
--- /dev/null
+++ b/src/grp-login/systemd-logind/logind-acl.c
@@ -0,0 +1,293 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2011 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <string.h>
+
+#include "basic/alloc-util.h"
+#include "basic/dirent-util.h"
+#include "basic/escape.h"
+#include "basic/fd-util.h"
+#include "basic/formats-util.h"
+#include "basic/set.h"
+#include "basic/string-util.h"
+#include "basic/util.h"
+#include "shared/acl-util.h"
+#include "shared/udev-util.h"
+
+#include "logind-acl.h"
+
+static int flush_acl(acl_t acl) {
+ acl_entry_t i;
+ int found;
+ bool changed = false;
+
+ assert(acl);
+
+ for (found = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
+ found > 0;
+ found = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) {
+
+ acl_tag_t tag;
+
+ if (acl_get_tag_type(i, &tag) < 0)
+ return -errno;
+
+ if (tag != ACL_USER)
+ continue;
+
+ if (acl_delete_entry(acl, i) < 0)
+ return -errno;
+
+ changed = true;
+ }
+
+ if (found < 0)
+ return -errno;
+
+ return changed;
+}
+
+int devnode_acl(const char *path,
+ bool flush,
+ bool del, uid_t old_uid,
+ bool add, uid_t new_uid) {
+
+ acl_t acl;
+ int r = 0;
+ bool changed = false;
+
+ assert(path);
+
+ acl = acl_get_file(path, ACL_TYPE_ACCESS);
+ if (!acl)
+ return -errno;
+
+ if (flush) {
+
+ r = flush_acl(acl);
+ if (r < 0)
+ goto finish;
+ if (r > 0)
+ changed = true;
+
+ } else if (del && old_uid > 0) {
+ acl_entry_t entry;
+
+ r = acl_find_uid(acl, old_uid, &entry);
+ if (r < 0)
+ goto finish;
+
+ if (r > 0) {
+ if (acl_delete_entry(acl, entry) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ changed = true;
+ }
+ }
+
+ if (add && new_uid > 0) {
+ acl_entry_t entry;
+ acl_permset_t permset;
+ int rd, wt;
+
+ r = acl_find_uid(acl, new_uid, &entry);
+ if (r < 0)
+ goto finish;
+
+ if (r == 0) {
+ if (acl_create_entry(&acl, &entry) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ if (acl_set_tag_type(entry, ACL_USER) < 0 ||
+ acl_set_qualifier(entry, &new_uid) < 0) {
+ r = -errno;
+ goto finish;
+ }
+ }
+
+ if (acl_get_permset(entry, &permset) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ rd = acl_get_perm(permset, ACL_READ);
+ if (rd < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ wt = acl_get_perm(permset, ACL_WRITE);
+ if (wt < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ if (!rd || !wt) {
+
+ if (acl_add_perm(permset, ACL_READ|ACL_WRITE) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ changed = true;
+ }
+ }
+
+ if (!changed)
+ goto finish;
+
+ if (acl_calc_mask(&acl) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ if (acl_set_file(path, ACL_TYPE_ACCESS, acl) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ r = 0;
+
+finish:
+ acl_free(acl);
+
+ return r;
+}
+
+int devnode_acl_all(struct udev *udev,
+ const char *seat,
+ bool flush,
+ bool del, uid_t old_uid,
+ bool add, uid_t new_uid) {
+
+ _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
+ struct udev_list_entry *item = NULL, *first = NULL;
+ _cleanup_set_free_free_ Set *nodes = NULL;
+ _cleanup_closedir_ DIR *dir = NULL;
+ struct dirent *dent;
+ Iterator i;
+ char *n;
+ int r;
+
+ assert(udev);
+
+ nodes = set_new(&string_hash_ops);
+ if (!nodes)
+ return -ENOMEM;
+
+ e = udev_enumerate_new(udev);
+ if (!e)
+ return -ENOMEM;
+
+ if (isempty(seat))
+ seat = "seat0";
+
+ /* We can only match by one tag in libudev. We choose
+ * "uaccess" for that. If we could match for two tags here we
+ * could add the seat name as second match tag, but this would
+ * be hardly optimizable in libudev, and hence checking the
+ * second tag manually in our loop is a good solution. */
+ r = udev_enumerate_add_match_tag(e, "uaccess");
+ if (r < 0)
+ return r;
+
+ r = udev_enumerate_add_match_is_initialized(e);
+ if (r < 0)
+ return r;
+
+ r = udev_enumerate_scan_devices(e);
+ if (r < 0)
+ return r;
+
+ first = udev_enumerate_get_list_entry(e);
+ udev_list_entry_foreach(item, first) {
+ _cleanup_udev_device_unref_ struct udev_device *d = NULL;
+ const char *node, *sn;
+
+ d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
+ if (!d)
+ return -ENOMEM;
+
+ sn = udev_device_get_property_value(d, "ID_SEAT");
+ if (isempty(sn))
+ sn = "seat0";
+
+ if (!streq(seat, sn))
+ continue;
+
+ node = udev_device_get_devnode(d);
+ /* In case people mistag devices with nodes, we need to ignore this */
+ if (!node)
+ continue;
+
+ n = strdup(node);
+ if (!n)
+ return -ENOMEM;
+
+ log_debug("Found udev node %s for seat %s", n, seat);
+ r = set_consume(nodes, n);
+ if (r < 0)
+ return r;
+ }
+
+ /* udev exports "dead" device nodes to allow module on-demand loading,
+ * these devices are not known to the kernel at this moment */
+ dir = opendir("/run/udev/static_node-tags/uaccess");
+ if (dir) {
+ FOREACH_DIRENT(dent, dir, return -errno) {
+ _cleanup_free_ char *unescaped_devname = NULL;
+
+ if (cunescape(dent->d_name, UNESCAPE_RELAX, &unescaped_devname) < 0)
+ return -ENOMEM;
+
+ n = strappend("/dev/", unescaped_devname);
+ if (!n)
+ return -ENOMEM;
+
+ log_debug("Found static node %s for seat %s", n, seat);
+ r = set_consume(nodes, n);
+ if (r == -EEXIST)
+ continue;
+ if (r < 0)
+ return r;
+ }
+ }
+
+ r = 0;
+ SET_FOREACH(n, nodes, i) {
+ int k;
+
+ log_debug("Changing ACLs at %s for seat %s (uid "UID_FMT"→"UID_FMT"%s%s)",
+ n, seat, old_uid, new_uid,
+ del ? " del" : "", add ? " add" : "");
+
+ k = devnode_acl(n, flush, del, old_uid, add, new_uid);
+ if (k == -ENOENT)
+ log_debug("Device %s disappeared while setting ACLs", n);
+ else if (k < 0 && r == 0)
+ r = k;
+ }
+
+ return r;
+}
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