udevd: use dev_t or netif ifindex as database key

We need to preserve the database of network interfaces while we
rename them. Use the kernel's numbers wherever possible, instead
of the device names.

Fix wrong database filenames which contain a '/', translated
from '!' in the kernel name.

Fix segfault for kobject pathes where the subsystem can not be
determined from sysfs.

1 files changed, 15 insertions, 14 deletions

diff --git a/libudev/libudev-device-private.c b/libudev/libudev-device-private.c
index a4b2fb0169..63f947e16b 100644
--- a/libudev/libudev-device-private.c
+++ b/libudev/libudev-device-private.c
@@ -24,23 +24,18 @@
 
 static void udev_device_tag(struct udev_device *dev, const char *tag, bool add)
 {
+	const char *id;
 	struct udev *udev = udev_device_get_udev(dev);
 	char filename[UTIL_PATH_SIZE];
 
-	util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/tags/", tag, "/",
-		      udev_device_get_subsystem(dev), ":", udev_device_get_sysname(dev), NULL);
+	id = udev_device_get_id_filename(dev);
+	if (id == NULL)
+		return;
+	util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/tags/", tag, "/", id, NULL);
 
 	if (add) {
 		util_create_path(udev, filename);
 		symlink(udev_device_get_devpath(dev), filename);
-		/* possibly cleanup old entries after a device renaming */
-		if (udev_device_get_sysname_old(dev) != NULL) {
-			char filename_old[UTIL_PATH_SIZE];
-
-			util_strscpyl(filename_old, sizeof(filename_old), udev_get_dev_path(udev), "/.udev/tags/", tag, "/",
-				      udev_device_get_subsystem(dev), ":", udev_device_get_sysname_old(dev), NULL);
-			unlink(filename_old);
-		}
 	} else {
 		unlink(filename);
 	}
@@ -79,6 +74,7 @@ int udev_device_tag_index(struct udev_device *dev, struct udev_device *dev_old,
 
 int udev_device_update_db(struct udev_device *udev_device)
 {
+	const char *id;
 	struct udev *udev = udev_device_get_udev(udev_device);
 	char filename[UTIL_PATH_SIZE];
 	char filename_tmp[UTIL_PATH_SIZE];
@@ -90,8 +86,10 @@ int udev_device_update_db(struct udev_device *udev_device)
 	struct udev_list_entry *list_entry;
 	int ret;
 
-	util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db/",
-		      udev_device_get_subsystem(udev_device), ":", udev_device_get_sysname(udev_device), NULL);
+	id = udev_device_get_id_filename(udev_device);
+	if (id == NULL)
+		return -1;
+	util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
 	util_strscpyl(filename_tmp, sizeof(filename_tmp), filename, ".tmp", NULL);
 
 	udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device))
@@ -169,11 +167,14 @@ out:
 
 int udev_device_delete_db(struct udev_device *udev_device)
 {
+	const char *id;
 	struct udev *udev = udev_device_get_udev(udev_device);
 	char filename[UTIL_PATH_SIZE];
 
-	util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db/",
-		      udev_device_get_subsystem(udev_device), ":", udev_device_get_sysname(udev_device), NULL);
+	id = udev_device_get_id_filename(udev_device);
+	if (id == NULL)
+		return -1;
+	util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
 	unlink(filename);
 	return 0;
 }