X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev%2Flib%2Flibudev-device.c;h=4cdc9570935bd4d6d29de4b2ab89a1a9a4b49c97;hp=e13146599cbe1354bd1b9c75e7bae90c210ae5d0;hb=659353f5a9a52336c41cf595d933311b8dc48937;hpb=e88a82b5976b8066583936a2521ba3c70dd460dd

diff --git a/udev/lib/libudev-device.c b/udev/lib/libudev-device.c
index e13146599..4cdc95709 100644
--- a/udev/lib/libudev-device.c
+++ b/udev/lib/libudev-device.c
@@ -17,8 +17,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "config.h"
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>
@@ -26,22 +24,25 @@
 #include <errno.h>
 #include <string.h>
 #include <dirent.h>
+#include <fcntl.h>
 #include <sys/stat.h>
 
 #include "libudev.h"
 #include "libudev-private.h"
-#include "../udev.h"
 
 struct udev_device {
 	int refcount;
 	struct udev *udev;
-	char *devpath;
+	struct udev_device *parent_device;
 	char *syspath;
-	char *devname;
+	const char *devpath;
+	const char *sysname;
+	char *devnode;
 	char *subsystem;
-	struct list_head link_list;
-	struct list_head env_list;
+	struct list_node devlink_list;
+	struct list_node properties_list;
 	char *action;
+	int event_timeout;
 	char *driver;
 	char *devpath_old;
 	char *physdevpath;
@@ -51,60 +52,59 @@ struct udev_device {
 	int num_fake_partitions;
 	int devlink_priority;
 	int ignore_remove;
+	struct list_node attr_list;
+	int info_loaded;
 };
 
-static size_t devpath_to_db_path(struct udev *udev, const char *devpath, char *filename, size_t len)
+static size_t syspath_to_db_path(struct udev_device *udev_device, char *filename, size_t len)
 {
 	size_t start;
 
 	/* translate to location of db file */
-	strlcpy(filename, udev_get_dev_path(udev), len);
-	start = strlcat(filename, "/.udev/db/", len);
-	strlcat(filename, devpath, len);
-	return path_encode(&filename[start], len - start);
+	util_strlcpy(filename, udev_get_dev_path(udev_device->udev), len);
+	start = util_strlcat(filename, "/.udev/db/", len);
+	util_strlcat(filename, udev_device->devpath, len);
+	return util_path_encode(&filename[start], len - start);
 }
 
 static int device_read_db(struct udev_device *udev_device)
 {
 	struct stat stats;
-	char filename[PATH_SIZE];
-	char line[PATH_SIZE];
+	char filename[UTIL_PATH_SIZE];
+	char line[UTIL_LINE_SIZE];
 	FILE *f;
-	int rc = 0;
 
-	devpath_to_db_path(udev_device->udev, udev_device->devpath, filename, sizeof(filename));
+	syspath_to_db_path(udev_device, filename, sizeof(filename));
 
 	if (lstat(filename, &stats) != 0) {
-		info(udev_device->udev, "no db file to read %s: %s\n", filename, strerror(errno));
+		info(udev_device->udev, "no db file to read %s: %m\n", filename);
 		return -1;
 	}
 	if ((stats.st_mode & S_IFMT) == S_IFLNK) {
-		char target[NAME_SIZE];
+		char target[UTIL_PATH_SIZE];
 		int target_len;
 
-		info(udev_device->udev, "found a symlink as db file\n");
 		target_len = readlink(filename, target, sizeof(target));
 		if (target_len > 0)
 			target[target_len] = '\0';
 		else {
-			info(udev_device->udev, "error reading db link %s: %s\n", filename, strerror(errno));
+			info(udev_device->udev, "error reading db link %s: %m\n", filename);
 			return -1;
 		}
-		dbg(udev_device->udev, "db link points to '%s'\n", target);
-		if (asprintf(&udev_device->devname, "%s/%s", udev_get_dev_path(udev_device->udev), target) < 0)
+		if (asprintf(&udev_device->devnode, "%s/%s", udev_get_dev_path(udev_device->udev), target) < 0)
 			return -ENOMEM;
+		info(udev_device->udev, "device %p filled with db symlink data '%s'\n", udev_device, udev_device->devnode);
 		return 0;
 	}
 
 	f = fopen(filename, "r");
 	if (f == NULL) {
-		info(udev_device->udev, "error reading db file %s: %s\n", filename, strerror(errno));
+		info(udev_device->udev, "error reading db file %s: %m\n", filename);
 		return -1;
 	}
 	while (fgets(line, sizeof(line), f)) {
 		ssize_t len;
 		const char *val;
-		unsigned int maj, min;
 
 		len = strlen(line);
 		if (len < 4)
@@ -114,23 +114,19 @@ static int device_read_db(struct udev_device *udev_device)
 
 		switch(line[0]) {
 		case 'N':
-			asprintf(&udev_device->devname, "%s/%s", udev_get_dev_path(udev_device->udev), val);
-			break;
-		case 'M':
-			sscanf(val, "%u:%u", &maj, &min);
-			device_set_devnum(udev_device, makedev(maj, min));
+			asprintf(&udev_device->devnode, "%s/%s", udev_get_dev_path(udev_device->udev), val);
 			break;
 		case 'S':
-			strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
-			strlcat(filename, "/", sizeof(filename));
-			strlcat(filename, val, sizeof(filename));
+			util_strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
+			util_strlcat(filename, "/", sizeof(filename));
+			util_strlcat(filename, val, sizeof(filename));
 			device_add_devlink(udev_device, filename);
 			break;
 		case 'L':
 			device_set_devlink_priority(udev_device, atoi(val));
 			break;
 		case 'T':
-			device_set_timeout(udev_device,  atoi(val));
+			device_set_event_timeout(udev_device, atoi(val));
 			break;
 		case 'A':
 			device_set_num_fake_partitions(udev_device, atoi(val));
@@ -139,13 +135,62 @@ static int device_read_db(struct udev_device *udev_device)
 			device_set_ignore_remove(udev_device, atoi(val));
 			break;
 		case 'E':
-			device_add_property(udev_device, val);
+			device_add_property_from_string(udev_device, val);
 			break;
 		}
 	}
 	fclose(f);
 
-	return rc;
+	info(udev_device->udev, "device %p filled with db file data\n", udev_device);
+	return 0;
+}
+
+static int device_read_uevent_file(struct udev_device *udev_device)
+{
+	char filename[UTIL_PATH_SIZE];
+	FILE *f;
+	char line[UTIL_LINE_SIZE];
+	int maj = 0;
+	int min = 0;
+
+	util_strlcpy(filename, udev_device->syspath, sizeof(filename));
+	util_strlcat(filename, "/uevent", sizeof(filename));
+	f = fopen(filename, "r");
+	if (f == NULL)
+		return -1;
+
+	while (fgets(line, sizeof(line), f)) {
+		char *pos;
+
+		pos = strchr(line, '\n');
+		if (pos == NULL)
+			continue;
+		pos[0] = '\0';
+
+		if (strncmp(line, "MAJOR=", 6) == 0)
+			maj = strtoull(&line[6], NULL, 10);
+		else if (strncmp(line, "MINOR=", 6) == 0)
+			min = strtoull(&line[6], NULL, 10);
+
+		device_add_property_from_string(udev_device, line);
+	}
+
+	udev_device->devnum = makedev(maj, min);
+
+	fclose(f);
+	return 0;
+}
+
+static void device_load_info(struct udev_device *device)
+{
+	device_read_uevent_file(device);
+	device_read_db(device);
+	device->info_loaded = 1;
+}
+
+void device_set_info_loaded(struct udev_device *device)
+{
+	device->info_loaded = 1;
 }
 
 struct udev_device *device_init(struct udev *udev)
@@ -161,60 +206,189 @@ struct udev_device *device_init(struct udev *udev)
 	memset(udev_device, 0x00, sizeof(struct udev_device));
 	udev_device->refcount = 1;
 	udev_device->udev = udev;
-	INIT_LIST_HEAD(&udev_device->link_list);
-	INIT_LIST_HEAD(&udev_device->env_list);
+	list_init(&udev_device->devlink_list);
+	list_init(&udev_device->properties_list);
+	list_init(&udev_device->attr_list);
 	info(udev_device->udev, "udev_device: %p created\n", udev_device);
 	return udev_device;
 }
 
 /**
- * udev_device_new_from_devpath:
+ * udev_device_new_from_syspath:
  * @udev: udev library context
- * @devpath: sys device path
+ * @syspath: sys device path including sys directory
  *
- * Create new udev device, and fill in information from the sysfs
- * device and the udev database entry. The devpath must not contain
- * the sysfs mount path, and must contain a leading '/'.
+ * Create new udev device, and fill in information from the sys
+ * device and the udev database entry. The sypath is the absolute
+ * path to the device, including the sys mount point.
  *
  * The initial refcount is 1, and needs to be decremented to
  * release the ressources of the udev device.
  *
  * Returns: a new udev device, or #NULL, if it does not exist
  **/
-struct udev_device *udev_device_new_from_devpath(struct udev *udev, const char *devpath)
+struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
 {
-	char path[PATH_SIZE];
+	size_t len;
+	const char *subdir;
+	const char *pos;
+	char path[UTIL_PATH_SIZE];
 	struct stat statbuf;
 	struct udev_device *udev_device;
 
 	if (udev == NULL)
 		return NULL;
-	if (devpath == NULL)
+	if (syspath == NULL)
 		return NULL;
 
-	strlcpy(path, udev_get_sys_path(udev), sizeof(path));
-	strlcat(path, devpath, sizeof(path));
-	if (stat(path, &statbuf) != 0)
+	/* path starts in sys */
+	len = strlen(udev_get_sys_path(udev));
+	if (strncmp(syspath, udev_get_sys_path(udev), len) != 0) {
+		info(udev, "not in sys :%s\n", syspath);
 		return NULL;
-	if (!S_ISDIR(statbuf.st_mode))
+	}
+
+	/* path is not a root directory */
+	subdir = &syspath[len+1];
+	pos = strrchr(subdir, '/');
+	if (pos == NULL || pos < &subdir[2]) {
+		info(udev, "not a subdir :%s\n", syspath);
 		return NULL;
+	}
+
+	/* resolve possible symlink to real path */
+	util_strlcpy(path, syspath, sizeof(path));
+	util_resolve_sys_link(udev, path, sizeof(path));
+
+	/* path exists in sys */
+	if (strncmp(&syspath[len], "/devices/", 9) == 0 ||
+	    strncmp(&syspath[len], "/class/", 7) == 0 ||
+	    strncmp(&syspath[len], "/block/", 7) == 0) {
+		char file[UTIL_PATH_SIZE];
+
+		/* all "devices" require a "uevent" file */
+		util_strlcpy(file, path, sizeof(file));
+		util_strlcat(file, "/uevent", sizeof(file));
+		if (stat(file, &statbuf) != 0) {
+			info(udev, "not a device: %s\n", syspath);
+			return NULL;
+		}
+	} else {
+		/* everything else just needs to be a directory */
+		if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) {
+			info(udev, "directory not found: %s\n", syspath);
+			return NULL;
+		}
+	}
 
 	udev_device = device_init(udev);
 	if (udev_device == NULL)
 		return NULL;
 
-	/* resolve possible symlink to real path */
-	strlcpy(path, devpath, sizeof(path));
-	sysfs_resolve_link(udev, path, sizeof(path));
-	device_set_devpath(udev_device, path);
+	device_set_syspath(udev_device, path);
 	info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
 
-	if (device_read_db(udev_device) >= 0)
-		info(udev, "device %p filled with udev database data\n", udev_device);
-
 	return udev_device;
 }
 
+struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
+{
+	char path[UTIL_PATH_SIZE];
+	const char *type_str;
+	struct udev_enumerate *udev_enumerate;
+	struct udev_list_entry *list_entry;
+	struct udev_device *device = NULL;
+
+	if (type == 'b')
+		type_str = "block";
+	else if (type == 'c')
+		type_str = "char";
+	else
+		return NULL;
+
+	/* /sys/dev/{block,char}/<maj>:<min> link */
+	snprintf(path, sizeof(path), "%s/dev/%s/%u:%u", udev_get_sys_path(udev),
+		 type_str, major(devnum), minor(devnum));
+	if (util_resolve_sys_link(udev, path, sizeof(path)) == 0)
+		return udev_device_new_from_syspath(udev, path);
+
+	udev_enumerate = udev_enumerate_new(udev);
+	if (udev_enumerate == NULL)
+		return NULL;
+
+	/* fallback to search sys devices for the major/minor */
+	if (type == 'b')
+		udev_enumerate_scan_devices(udev_enumerate, "block", NULL);
+	else if (type == 'c')
+		udev_enumerate_scan_devices(udev_enumerate, "!block", NULL);
+	udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
+		struct udev_device *device_loop;
+
+		device_loop = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
+		if (device_loop != NULL) {
+			if (udev_device_get_devnum(device_loop) == devnum) {
+				const char *subsystem;
+
+				subsystem = udev_device_get_subsystem(device_loop);
+				if (type == 'b' && strcmp(subsystem, "block") != 0)
+					continue;
+				if (type == 'c' && strcmp(subsystem, "block") == 0)
+					continue;
+				device = device_loop;
+				break;
+			}
+			udev_device_unref(device_loop);
+		}
+	}
+	udev_enumerate_unref(udev_enumerate);
+	return device;
+}
+
+static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
+{
+	struct udev_device *udev_device_parent = NULL;
+	char path[UTIL_PATH_SIZE];
+	const char *subdir;
+
+	/* follow "device" link in deprecated sys layout */
+	if (strncmp(udev_device->devpath, "/class/", 7) == 0 ||
+	    strncmp(udev_device->devpath, "/block/", 7) == 0) {
+		util_strlcpy(path, udev_device->syspath, sizeof(path));
+		util_strlcat(path, "/device", sizeof(path));
+		if (util_resolve_sys_link(udev_device->udev, path, sizeof(path)) == 0)
+			udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
+		return udev_device_parent;
+	}
+
+	util_strlcpy(path, udev_device->syspath, sizeof(path));
+	subdir = &path[strlen(udev_get_sys_path(udev_device->udev))+1];
+	while (1) {
+		char *pos;
+
+		pos = strrchr(subdir, '/');
+		if (pos == NULL || pos < &subdir[2])
+			break;
+		pos[0] = '\0';
+		udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
+		if (udev_device_parent != NULL)
+			return udev_device_parent;
+	}
+	return NULL;
+}
+
+struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
+{
+	if (udev_device == NULL)
+		return NULL;
+
+	if (udev_device->parent_device != NULL) {
+		info(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
+		return udev_device->parent_device;
+	}
+	udev_device->parent_device = device_new_from_parent(udev_device);
+	return udev_device->parent_device;
+}
+
 /**
  * udev_device_get_udev:
  * @udev_device: udev device
@@ -261,15 +435,18 @@ void udev_device_unref(struct udev_device *udev_device)
 	udev_device->refcount--;
 	if (udev_device->refcount > 0)
 		return;
+	if (udev_device->parent_device != NULL)
+		udev_device_unref(udev_device->parent_device);
 	free(udev_device->syspath);
-	free(udev_device->devname);
+	free(udev_device->devnode);
 	free(udev_device->subsystem);
-	name_list_cleanup(udev_device->udev, &udev_device->link_list);
-	name_list_cleanup(udev_device->udev, &udev_device->env_list);
+	list_cleanup(udev_device->udev, &udev_device->devlink_list);
+	list_cleanup(udev_device->udev, &udev_device->properties_list);
 	free(udev_device->action);
 	free(udev_device->driver);
 	free(udev_device->devpath_old);
 	free(udev_device->physdevpath);
+	list_cleanup(udev_device->udev, &udev_device->attr_list);
 	info(udev_device->udev, "udev_device: %p released\n", udev_device);
 	free(udev_device);
 }
@@ -306,8 +483,15 @@ const char *udev_device_get_syspath(struct udev_device *udev_device)
 	return udev_device->syspath;
 }
 
+const char *udev_device_get_sysname(struct udev_device *udev_device)
+{
+	if (udev_device == NULL)
+		return NULL;
+	return udev_device->sysname;
+}
+
 /**
- * udev_device_get_devname:
+ * udev_device_get_devnode:
  * @udev_device: udev device
  *
  * Retrieve the device node file name belonging to the udev device.
@@ -315,11 +499,13 @@ const char *udev_device_get_syspath(struct udev_device *udev_device)
  *
  * Returns: the device node file name of the udev device, or #NULL if no device node exists
  **/
-const char *udev_device_get_devname(struct udev_device *udev_device)
+const char *udev_device_get_devnode(struct udev_device *udev_device)
 {
 	if (udev_device == NULL)
 		return NULL;
-	return udev_device->devname;
+	if (!udev_device->info_loaded)
+		device_load_info(udev_device);
+	return udev_device->devnode;
 }
 
 /**
@@ -333,98 +519,89 @@ const char *udev_device_get_devname(struct udev_device *udev_device)
  **/
 const char *udev_device_get_subsystem(struct udev_device *udev_device)
 {
-	char subsystem[NAME_SIZE];
+	char subsystem[UTIL_NAME_SIZE];
 
 	if (udev_device == NULL)
 		return NULL;
 	if (udev_device->subsystem != NULL)
 		return udev_device->subsystem;
-	if (util_get_sys_subsystem(udev_device->udev, udev_device->devpath, subsystem, sizeof(subsystem)) < 2)
-		return NULL;
-	udev_device->subsystem = strdup(subsystem);
-	return udev_device->subsystem;
+
+	/* read "subsytem" link */
+	if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
+		udev_device->subsystem = strdup(subsystem);
+		return udev_device->subsystem;
+	}
+
+	/* implicit names */
+	if (strncmp(udev_device->devpath, "/module/", 8) == 0) {
+		udev_device->subsystem = strdup("module");
+		return udev_device->subsystem;
+	}
+	if (strstr(udev_device->devpath, "/drivers/") != NULL) {
+		udev_device->subsystem = strdup("drivers");
+		return udev_device->subsystem;
+	}
+	if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 ||
+	    strncmp(udev_device->devpath, "/class/", 7) == 0 ||
+	    strncmp(udev_device->devpath, "/bus/", 5) == 0) {
+		udev_device->subsystem = strdup("subsystem");
+		return udev_device->subsystem;
+	}
+	return NULL;
 }
 
 /**
- * udev_device_get_devlinks:
+ * udev_device_get_devlinks_list_entry:
  * @udev_device: udev device
- * @cb: function to be called for every device link found
- * @data: data to be passed to the function
  *
- * Retrieve the device links pointing to the device file of the
- * udev device. For every device link, the passed function will be
- * called with the device link string.
- * The path is an absolute path, and starts with the device directory.
- * If the function returns 1, remaning device links will be ignored.
+ * Retrieve the list of device links pointing to the device file of
+ * the udev device. The next list entry can be retrieved with
+ * udev_list_entry_next(), which returns #NULL if no more entries exist.
+ * The devlink path can be retrieved from the list entry by
+ * udev_list_entry_get_name(). The path is an absolute path, and starts with
+ * the device directory.
  *
- * Returns: the number of device links passed to the caller, or a negative value on error
+ * Returns: the first entry of the device node link list
  **/
-int udev_device_get_devlinks(struct udev_device *udev_device,
-			      int (*cb)(struct udev_device *udev_device, const char *value, void *data),
-			      void *data)
+struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
 {
-	struct name_entry *name_loop;
-	int count = 0;
-
 	if (udev_device == NULL)
-		return -1;
-	list_for_each_entry(name_loop, &udev_device->link_list, node) {
-		count++;
-		if (cb(udev_device, name_loop->name, data) != 0)
-			break;
-	}
-	return count;
+		return NULL;
+	if (!udev_device->info_loaded)
+		device_load_info(udev_device);
+	return list_get_entry(&udev_device->devlink_list);
 }
 
 /**
- * udev_device_get_properties:
+ * udev_device_get_properties_list_entry:
  * @udev_device: udev device
- * @cb: function to be called for every property found
- * @data: data to be passed to the function
  *
- * Retrieve the property key/value pairs belonging to the
- * udev device. For every key/value pair, the passed function will be
- * called. If the function returns 1, remaning properties will be
- * ignored.
+ * Retrieve the list of key/value device properties of the udev
+ * device. The next list entry can be retrieved with udev_list_entry_next(),
+ * which returns #NULL if no more entries exist. The property name
+ * can be retrieved from the list entry by udev_list_get_name(),
+ * the property value by udev_list_get_value().
  *
- * Returns: the number of properties passed to the caller, or a negative value on error
+ * Returns: the first entry of the property list
  **/
-int udev_device_get_properties(struct udev_device *udev_device,
-				int (*cb)(struct udev_device *udev_device, const char *key, const char *value, void *data),
-				void *data)
+struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
 {
-	struct name_entry *name_loop;
-	int count = 0;
-
 	if (udev_device == NULL)
-		return -1;
-	list_for_each_entry(name_loop, &udev_device->env_list, node) {
-		char name[PATH_SIZE];
-		char *val;
-
-		strncpy(name, name_loop->name, PATH_SIZE);
-		name[PATH_SIZE-1] = '\0';
-		val = strchr(name, '=');
-		if (val == NULL)
-			continue;
-		val[0] = '\0';
-		val = &val[1];
-		count++;
-		if (cb(udev_device, name, val, data) != 0)
-			break;
-	}
-	return count;
+		return NULL;
+	if (!udev_device->info_loaded)
+		device_load_info(udev_device);
+	return list_get_entry(&udev_device->properties_list);
 }
 
 const char *udev_device_get_driver(struct udev_device *udev_device)
 {
-	char driver[NAME_SIZE];
+	char driver[UTIL_NAME_SIZE];
 
 	if (udev_device == NULL)
 		return NULL;
 	if (udev_device->driver != NULL)
 		return udev_device->driver;
-	if (util_get_sys_driver(udev_device->udev, udev_device->devpath, driver, sizeof(driver)) < 2)
+	if (util_get_sys_driver(udev_device->udev, udev_device->syspath, driver, sizeof(driver)) < 2)
 		return NULL;
 	udev_device->driver = strdup(driver);
 	return udev_device->driver;
@@ -434,6 +611,8 @@ dev_t udev_device_get_devnum(struct udev_device *udev_device)
 {
 	if (udev_device == NULL)
 		return makedev(0, 0);
+	if (!udev_device->info_loaded)
+		device_load_info(udev_device);
 	return udev_device->devnum;
 }
 
@@ -451,11 +630,95 @@ unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
 	return udev_device->seqnum;
 }
 
-int device_set_devpath(struct udev_device *udev_device, const char *devpath)
+const char *udev_device_get_attr_value(struct udev_device *udev_device, const char *attr)
 {
-	if (asprintf(&udev_device->syspath, "%s%s", udev_get_sys_path(udev_device->udev), devpath) < 0)
+	struct udev_list_entry *list_entry;
+	char path[UTIL_PATH_SIZE];
+	char value[UTIL_NAME_SIZE];
+	struct stat statbuf;
+	int fd;
+	ssize_t size;
+	const char *val = NULL;
+
+	/* look for possibly already cached result */
+	udev_list_entry_foreach(list_entry, list_get_entry(&udev_device->attr_list)) {
+		if (strcmp(udev_list_entry_get_name(list_entry), attr) == 0) {
+			info(udev_device->udev, "got '%s' (%s) from cache\n", attr, udev_list_entry_get_value(list_entry));
+			return udev_list_entry_get_value(list_entry);
+		}
+	}
+
+	util_strlcpy(path, udev_device_get_syspath(udev_device), sizeof(path));
+	util_strlcat(path, "/", sizeof(path));
+	util_strlcat(path, attr, sizeof(path));
+
+	if (lstat(path, &statbuf) != 0) {
+		info(udev_device->udev, "stat '%s' failed: %m\n", path);
+		goto out;
+	}
+
+	if (S_ISLNK(statbuf.st_mode)) {
+		/* links return the last element of the target path */
+		char target[UTIL_NAME_SIZE];
+		int len;
+		char *pos;
+
+		len = readlink(path, target, sizeof(target));
+		if (len > 0) {
+			target[len] = '\0';
+			pos = strrchr(target, '/');
+			if (pos != NULL) {
+				pos = &pos[1];
+				info(udev_device->udev, "cache '%s' with link value '%s'\n", attr, pos);
+				list_entry = list_entry_add(udev_device->udev, &udev_device->attr_list, attr, pos, 0, 0);
+				val = udev_list_entry_get_value(list_entry);
+			}
+		}
+		goto out;
+	}
+
+	/* skip directories */
+	if (S_ISDIR(statbuf.st_mode))
+		goto out;
+
+	/* skip non-readable files */
+	if ((statbuf.st_mode & S_IRUSR) == 0)
+		goto out;
+
+	/* read attribute value */
+	fd = open(path, O_RDONLY);
+	if (fd < 0) {
+		info(udev_device->udev, "attribute '%s' can not be opened\n", path);
+		goto out;
+	}
+	size = read(fd, value, sizeof(value));
+	close(fd);
+	if (size < 0)
+		goto out;
+	if (size == sizeof(value))
+		goto out;
+
+	/* got a valid value, store it in cache and return it */
+	value[size] = '\0';
+	util_remove_trailing_chars(value, '\n');
+	info(udev_device->udev, "'%s' has attribute value '%s'\n", path, value);
+	list_entry = list_entry_add(udev_device->udev, &udev_device->attr_list, attr, value, 0, 0);
+	val = udev_list_entry_get_value(list_entry);
+out:
+	return val;
+}
+int device_set_syspath(struct udev_device *udev_device, const char *syspath)
+{
+	const char *pos;
+
+	udev_device->syspath = strdup(syspath);
+	if (udev_device->syspath ==  NULL)
 		return -ENOMEM;
 	udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))];
+	pos = strrchr(udev_device->syspath, '/');
+	if (pos == NULL)
+		return -EINVAL;
+	udev_device->sysname = &pos[1];
 	return 0;
 }
 
@@ -467,28 +730,45 @@ int device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
 	return 0;
 }
 
-int device_set_devname(struct udev_device *udev_device, const char *devname)
+int device_set_devnode(struct udev_device *udev_device, const char *devnode)
 {
-	udev_device->devname = strdup(devname);
-	if (udev_device->devname == NULL)
+	udev_device->devnode = strdup(devnode);
+	if (udev_device->devnode == NULL)
 		return -ENOMEM;
 	return 0;
 }
 
 int device_add_devlink(struct udev_device *udev_device, const char *devlink)
 {
-	if (name_list_add(udev_device->udev, &udev_device->link_list, devlink, 0) == NULL)
+	if (list_entry_add(udev_device->udev, &udev_device->devlink_list, devlink, NULL, 1, 0) == NULL)
 		return -ENOMEM;
 	return 0;
 }
 
-int device_add_property(struct udev_device *udev_device, const char *property)
+int device_add_property(struct udev_device *udev_device, const char *key, const char *value)
 {
-	if (name_list_add(udev_device->udev, &udev_device->env_list, property, 0) == NULL)
+	if (list_entry_add(udev_device->udev, &udev_device->properties_list, key, value, 1, 0) == NULL)
 		return -ENOMEM;
 	return 0;
 }
 
+int device_add_property_from_string(struct udev_device *udev_device, const char *property)
+{
+	char name[UTIL_PATH_SIZE];
+	char *val;
+
+	strncpy(name, property, sizeof(name));
+	val = strchr(name, '=');
+	if (val == NULL)
+		return -1;
+	val[0] = '\0';
+	val = &val[1];
+	if (val[0] == '\0')
+		val = NULL;
+	device_add_property(udev_device, name, val);
+	return 0;
+}
+
 int device_set_action(struct udev_device *udev_device, const char *action)
 {
 	udev_device->action = strdup(action);
@@ -507,8 +787,6 @@ int device_set_driver(struct udev_device *udev_device, const char *driver)
 
 const char *device_get_devpath_old(struct udev_device *udev_device)
 {
-	if (udev_device == NULL)
-		return NULL;
 	return udev_device->devpath_old;
 }
 
@@ -522,8 +800,6 @@ int device_set_devpath_old(struct udev_device *udev_device, const char *devpath_
 
 const char *device_get_physdevpath(struct udev_device *udev_device)
 {
-	if (udev_device == NULL)
-		return NULL;
 	return udev_device->physdevpath;
 }
 
@@ -537,8 +813,6 @@ int device_set_physdevpath(struct udev_device *udev_device, const char *physdevp
 
 int device_get_timeout(struct udev_device *udev_device)
 {
-	if (udev_device == NULL)
-		return -1;
 	return udev_device->timeout;
 }
 
@@ -547,6 +821,18 @@ int device_set_timeout(struct udev_device *udev_device, int timeout)
 	udev_device->timeout = timeout;
 	return 0;
 }
+int device_get_event_timeout(struct udev_device *udev_device)
+{
+	if (!udev_device->info_loaded)
+		device_load_info(udev_device);
+	return udev_device->event_timeout;
+}
+
+int device_set_event_timeout(struct udev_device *udev_device, int event_timeout)
+{
+	udev_device->event_timeout = event_timeout;
+	return 0;
+}
 
 int device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
 {
@@ -562,8 +848,8 @@ int device_set_devnum(struct udev_device *udev_device, dev_t devnum)
 
 int device_get_num_fake_partitions(struct udev_device *udev_device)
 {
-	if (udev_device == NULL)
-		return -1;
+	if (!udev_device->info_loaded)
+		device_load_info(udev_device);
 	return udev_device->num_fake_partitions;
 }
 
@@ -575,8 +861,8 @@ int device_set_num_fake_partitions(struct udev_device *udev_device, int num)
 
 int device_get_devlink_priority(struct udev_device *udev_device)
 {
-	if (udev_device == NULL)
-		return -1;
+	if (!udev_device->info_loaded)
+		device_load_info(udev_device);
 	return udev_device->devlink_priority;
 }
 
@@ -588,8 +874,8 @@ int device_set_devlink_priority(struct udev_device *udev_device, int prio)
 
 int device_get_ignore_remove(struct udev_device *udev_device)
 {
-	if (udev_device == NULL)
-		return -1;
+	if (!udev_device->info_loaded)
+		device_load_info(udev_device);
 	return udev_device->ignore_remove;
 }