udev: use path_make_relative()

src/udev/udev-node.c

@@ -20,34 +20,19 @@
 #include "udev.h"
 
 static int node_symlink(struct udev_device *dev, const char *node, const char *slink) {
-        struct stat stats;
-        char target[UTIL_PATH_SIZE];
-        char *s;
-        size_t l;
+        _cleanup_free_ char *slink_dirname = NULL, *target = NULL;
         char slink_tmp[UTIL_PATH_SIZE + 32];
-        int i = 0;
-        int tail = 0;
-        int err = 0;
+        struct stat stats;
+        int r, err = 0;
+
+        slink_dirname = dirname_malloc(slink);
+        if (!slink_dirname)
+                return log_oom();
 
         /* use relative link */
-        target[0] = '\0';
-        while (node[i] && (node[i] == slink[i])) {
-                if (node[i] == '/')
-                        tail = i+1;
-                i++;
-        }
-        s = target;
-        l = sizeof(target);
-        while (slink[i] != '\0') {
-                if (slink[i] == '/')
-                        l = strpcpy(&s, l, "../");
-                i++;
-        }
-        l = strscpy(s, l, &node[tail]);
-        if (l == 0) {
-                err = -EINVAL;
-                goto exit;
-        }
+        r = path_make_relative(slink_dirname, node, &target);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get relative path from '%s' to '%s': %m", slink, node);
 
         /* preserve link with correct target, do not replace node of other device */
         if (lstat(slink, &stats) == 0) {