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/*
* Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
* Copyright (C) 2009 Canonical Ltd.
* Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <sys/types.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <dirent.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef HAVE_INOTIFY
#include <sys/inotify.h>
#endif
#include "udev.h"
int inotify_fd = -1;
/* inotify descriptor, will be shared with rules directory;
* set to cloexec since we need our children to be able to add
* watches for us
*/
void udev_watch_init(struct udev *udev)
{
inotify_fd = inotify_init();
if (inotify_fd >= 0) {
int flags;
flags = fcntl(inotify_fd, F_GETFD);
if (flags < 0)
flags = FD_CLOEXEC;
else
flags |= FD_CLOEXEC;
fcntl(inotify_fd, F_SETFD, flags);
} else if (errno == ENOSYS)
info(udev, "unable to use inotify, udevd will not monitor rule files changes\n");
else
err(udev, "inotify_init failed: %m\n");
}
/* move any old watches directory out of the way, and then restore
* the watches
*/
void udev_watch_restore(struct udev *udev)
{
char filename[UTIL_PATH_SIZE], oldname[UTIL_PATH_SIZE];
if (inotify_fd < 0)
return;
util_strlcpy(oldname, udev_get_dev_path(udev), sizeof(oldname));
util_strlcat(oldname, "/.udev/watch.old", sizeof(oldname));
util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
util_strlcat(filename, "/.udev/watch", sizeof(filename));
if (rename(filename, oldname) == 0) {
DIR *dir;
struct dirent *ent;
dir = opendir(oldname);
if (dir == NULL) {
err(udev, "unable to open old watches dir '%s', old watches will not be restored: %m", oldname);
return;
}
while ((ent = readdir(dir)) != NULL) {
char path[UTIL_PATH_SIZE];
char buf[UTIL_PATH_SIZE];
ssize_t len;
struct udev_device *dev;
if (ent->d_name[0] < '0' || ent->d_name[0] > '9')
continue;
util_strlcpy(path, oldname, sizeof(path));
util_strlcat(path, "/", sizeof(path));
util_strlcat(path, ent->d_name, sizeof(path));
len = readlink(path, buf, sizeof(buf));
if (len <= 0) {
unlink(path);
continue;
}
buf[len] = '\0';
dbg(udev, "old watch to '%s' found\n", buf);
dev = udev_device_new_from_syspath(udev, buf);
if (dev == NULL) {
unlink(path);
continue;
}
info(udev, "restoring old watch on '%s'\n", udev_device_get_devnode(dev));
udev_watch_begin(udev, dev);
udev_device_unref(dev);
unlink(path);
}
closedir(dir);
rmdir(oldname);
} else if (errno != ENOENT) {
err(udev, "unable to move watches dir '%s', old watches will not be restored: %m", filename);
}
}
static const char *udev_watch_filename(struct udev *udev, int wd)
{
static char filename[UTIL_PATH_SIZE];
char str[32];
sprintf(str, "%d", wd);
util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
util_strlcat(filename, "/.udev/watch/", sizeof(filename));
util_strlcat(filename, str, sizeof(filename));
return filename;
}
void udev_watch_begin(struct udev *udev, struct udev_device *dev)
{
const char *filename;
int wd;
if (inotify_fd < 0 || major(udev_device_get_devnum(dev)) == 0)
return;
info(udev, "adding watch on '%s'\n", udev_device_get_devnode(dev));
wd = inotify_add_watch(inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
if (wd < 0) {
err(udev, "inotify_add_watch(%d, %s, %o) failed: %m\n",
inotify_fd, udev_device_get_devnode(dev), IN_CLOSE_WRITE);
}
filename = udev_watch_filename(udev, wd);
util_create_path(udev, filename);
unlink(filename);
symlink(udev_device_get_syspath(dev), filename);
udev_device_set_watch_handle(dev, wd);
udev_device_update_db(dev);
}
void udev_watch_end(struct udev *udev, struct udev_device *dev)
{
int wd;
const char *filename;
if (inotify_fd < 0 || major(udev_device_get_devnum(dev)) == 0)
return;
wd = udev_device_get_watch_handle(dev);
if (wd < 0)
return;
info(udev, "removing watch on '%s'\n", udev_device_get_devnode(dev));
inotify_rm_watch(inotify_fd, wd);
filename = udev_watch_filename(udev, wd);
unlink(filename);
udev_device_set_watch_handle(dev, -1);
udev_device_update_db(dev);
}
struct udev_device *udev_watch_lookup(struct udev *udev, int wd)
{
const char *filename;
char buf[UTIL_PATH_SIZE];
ssize_t len;
if (inotify_fd < 0 || wd < 0)
return NULL;
filename = udev_watch_filename(udev, wd);
len = readlink(filename, buf, sizeof(buf));
if (len > 0) {
buf[len] = '\0';
return udev_device_new_from_syspath(udev, buf);
}
return NULL;
}
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