2 * Copyright (C) 2004-2010 Kay Sievers <kay.sievers@vrfy.org>
3 * Copyright (C) 2009 Canonical Ltd.
4 * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <sys/types.h>
29 #include <sys/inotify.h>
33 static int inotify_fd = -1;
35 /* inotify descriptor, will be shared with rules directory;
36 * set to cloexec since we need our children to be able to add
39 int udev_watch_init(struct udev *udev)
41 inotify_fd = inotify_init1(IN_CLOEXEC);
43 err(udev, "inotify_init failed: %m\n");
47 /* move any old watches directory out of the way, and then restore
50 void udev_watch_restore(struct udev *udev)
52 char filename[UTIL_PATH_SIZE], oldname[UTIL_PATH_SIZE];
57 util_strscpyl(oldname, sizeof(oldname), udev_get_dev_path(udev), "/.udev/watch.old", NULL);
58 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/watch", NULL);
59 if (rename(filename, oldname) == 0) {
63 dir = opendir(oldname);
65 err(udev, "unable to open old watches dir '%s', old watches will not be restored: %m", oldname);
69 for (ent = readdir(dir); ent != NULL; ent = readdir(dir)) {
70 char device[UTIL_PATH_SIZE];
74 struct udev_device *dev;
78 if (ent->d_name[0] == '.')
82 l = util_strpcpy(&s, sizeof(device), udev_get_sys_path(udev));
83 len = readlinkat(dirfd(dir), ent->d_name, s, l);
84 if (len <= 0 || len >= (ssize_t)l)
88 if (sscanf(s, "%c%i:%i", &type, &maj, &min) != 3)
90 dev = udev_device_new_from_devnum(udev, type, makedev(maj, min));
94 info(udev, "restoring old watch on '%s'\n", udev_device_get_devnode(dev));
95 udev_watch_begin(udev, dev);
96 udev_device_unref(dev);
98 unlinkat(dirfd(dir), ent->d_name, 0);
104 } else if (errno != ENOENT) {
105 err(udev, "unable to move watches dir '%s', old watches will not be restored: %m", filename);
109 void udev_watch_begin(struct udev *udev, struct udev_device *dev)
111 char filename[UTIL_PATH_SIZE];
112 char majmin[UTIL_PATH_SIZE];
118 info(udev, "adding watch on '%s'\n", udev_device_get_devnode(dev));
119 wd = inotify_add_watch(inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
121 err(udev, "inotify_add_watch(%d, %s, %o) failed: %m\n",
122 inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
126 snprintf(majmin, sizeof(majmin), "%c%i:%i",
127 strcmp(udev_device_get_subsystem(dev), "block") == 0 ? 'b' : 'c',
128 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
129 snprintf(filename, sizeof(filename), "%s/.udev/watch/%d", udev_get_dev_path(udev), wd);
130 util_create_path(udev, filename);
132 symlink(majmin, filename);
134 udev_device_set_watch_handle(dev, wd);
137 void udev_watch_end(struct udev *udev, struct udev_device *dev)
140 char filename[UTIL_PATH_SIZE];
145 wd = udev_device_get_watch_handle(dev);
149 info(udev, "removing watch on '%s'\n", udev_device_get_devnode(dev));
150 inotify_rm_watch(inotify_fd, wd);
152 snprintf(filename, sizeof(filename), "%s/.udev/watch/%d", udev_get_dev_path(udev), wd);
155 udev_device_set_watch_handle(dev, -1);
158 struct udev_device *udev_watch_lookup(struct udev *udev, int wd)
160 char filename[UTIL_PATH_SIZE];
161 char majmin[UTIL_PATH_SIZE];
169 if (inotify_fd < 0 || wd < 0)
172 snprintf(filename, sizeof(filename), "%s/.udev/watch/%d", udev_get_dev_path(udev), wd);
174 l = util_strpcpy(&s, sizeof(majmin), udev_get_sys_path(udev));
175 len = readlink(filename, s, l);
176 if (len < 0 || (size_t)len >= l)
180 if (sscanf(s, "%c%i:%i", &type, &maj, &min) != 3)
182 devnum = makedev(maj, min);
183 return udev_device_new_from_devnum(udev, type, devnum);