From: Kay Sievers <kay.sievers@vrfy.org>
Date: Tue, 16 Sep 2008 16:53:36 +0000 (-0700)
Subject: fix broken symlink resolving
X-Git-Tag: 174~1543
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=44589a0c7366c79139bbb7f96b238cb0dcc32d44

fix broken symlink resolving
---

diff --git a/udev/udev_sysfs.c b/udev/udev_sysfs.c
index 97dcd0311..3e395a280 100644
--- a/udev/udev_sysfs.c
+++ b/udev/udev_sysfs.c
@@ -40,6 +40,39 @@ struct sysfs_attr {
 	char value_local[UTIL_NAME_SIZE];
 };
 
+static int resolve_sys_link(struct udev *udev, char *path, size_t size)
+{
+	char link_path[UTIL_PATH_SIZE];
+	char link_target[UTIL_PATH_SIZE];
+
+	int len;
+	int i;
+	int back;
+
+	util_strlcpy(link_path, udev_get_sys_path(udev), sizeof(link_path));
+	util_strlcat(link_path, path, sizeof(link_path));
+	len = readlink(link_path, link_target, sizeof(link_target));
+	if (len <= 0)
+		return -1;
+	link_target[len] = '\0';
+	dbg(udev, "path link '%s' points to '%s'\n", path, link_target);
+
+	for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
+		;
+	dbg(udev, "base '%s', tail '%s', back %i\n", path, &link_target[back * 3], back);
+	for (i = 0; i <= back; i++) {
+		char *pos = strrchr(path, '/');
+
+		if (pos == NULL)
+			return -1;
+		pos[0] = '\0';
+	}
+	dbg(udev, "after moving back '%s'\n", path);
+	util_strlcat(path, "/", size);
+	util_strlcat(path, &link_target[back * 3], size);
+	return 0;
+}
+
 int sysfs_init(void)
 {
 	INIT_LIST_HEAD(&dev_list);
@@ -144,7 +177,7 @@ struct sysfs_device *sysfs_device_get(struct udev *udev, const char *devpath)
 		return NULL;
 	}
 	if (S_ISLNK(statbuf.st_mode)) {
-		if (util_resolve_sys_link(udev, devpath_real, sizeof(devpath_real)) != 0)
+		if (resolve_sys_link(udev, devpath_real, sizeof(devpath_real)) != 0)
 			return NULL;
 
 		/* now look for device in cache after path translation */
@@ -258,7 +291,7 @@ struct sysfs_device *sysfs_device_get_parent(struct udev *udev, struct sysfs_dev
 device_link:
 	util_strlcpy(parent_devpath, dev->devpath, sizeof(parent_devpath));
 	util_strlcat(parent_devpath, "/device", sizeof(parent_devpath));
-	if (util_resolve_sys_link(udev, parent_devpath, sizeof(parent_devpath)) != 0)
+	if (resolve_sys_link(udev, parent_devpath, sizeof(parent_devpath)) != 0)
 		return NULL;
 
 	/* get parent and remember it */
@@ -460,7 +493,7 @@ out:
 	return 0;
 found:
 	if (S_ISLNK(statbuf.st_mode))
-		util_resolve_sys_link(udev, path, sizeof(path_full) - sysfs_len);
+		resolve_sys_link(udev, path, sizeof(path_full) - sysfs_len);
 	util_strlcpy(devpath_full, path, len);
 	return 1;
 }
diff --git a/udev/udevadm-trigger.c b/udev/udevadm-trigger.c
index f0535f5eb..8a2c12566 100644
--- a/udev/udevadm-trigger.c
+++ b/udev/udevadm-trigger.c
@@ -65,7 +65,6 @@ static int delay_device(const char *devpath)
 static int device_list_insert(struct udev *udev, const char *path)
 {
 	char filename[UTIL_PATH_SIZE];
-	char devpath[UTIL_PATH_SIZE];
 	struct stat statbuf;
 
 	dbg(udev, "add '%s'\n" , path);
@@ -78,16 +77,15 @@ static int device_list_insert(struct udev *udev, const char *path)
 	if (!(statbuf.st_mode & S_IWUSR))
 		return -1;
 
-	util_strlcpy(devpath, &path[strlen(udev_get_sys_path(udev))], sizeof(devpath));
-
 	/* resolve possible link to real target */
-	if (lstat(path, &statbuf) < 0)
+	util_strlcpy(filename, path, sizeof(filename));
+	if (lstat(filename, &statbuf) < 0)
 		return -1;
 	if (S_ISLNK(statbuf.st_mode))
-		if (util_resolve_sys_link(udev, devpath, sizeof(devpath)) != 0)
+		if (util_resolve_sys_link(udev, filename, sizeof(filename)) != 0)
 			return -1;
 
-	name_list_add(udev, &device_list, devpath, 1);
+	name_list_add(udev, &device_list, filename, 1);
 	return 0;
 }