obj: implement object_namespace_get_object()

obj/namespace.c

@@ -60,11 +60,6 @@ struct object_namespace *object_namespace_create(void)
 	return ns;
 }
 
-kern_status_t object_namespace_get_object(struct object_namespace *ns, const char *path, struct object **out)
-{
-	return KERN_OK;
-}
-
 static void cleanup_object_path(char *path, size_t len, size_t *parts)
 {
 	while (path[len - 1] == '/') {
@@ -102,6 +97,58 @@ struct object *ns_header(struct object_namespace *ns)
 	return &ns->ns_base;
 }
 
+kern_status_t object_namespace_get_object(struct object_namespace *ns, const char *path, struct object **out)
+{
+	if (*path != '/') {
+		return KERN_INVALID_ARGUMENT;
+	}
+
+	while (*path == '/') {
+		path++;
+	}
+
+	size_t path_len = strlen(path);
+	if (path_len == 0) {
+		*out = object_ref(ns->ns_root);
+		return KERN_OK;
+	}
+
+	size_t parts = 0;
+	char *rpath = kmalloc(path_len, 0);
+	if (!rpath) {
+		return KERN_NO_MEMORY;
+	}
+
+	memcpy(rpath, path, path_len);
+	cleanup_object_path(rpath, path_len, &parts);
+
+	char *sp;
+	char *tok = strtok_r(rpath, "/", &sp);
+	struct object *cur = ns->ns_root;
+
+	unsigned long flags;
+	while (tok) {
+		object_lock(cur, &flags);
+
+		struct object *next;
+		kern_status_t status = object_get_child_named(cur, tok, &next);
+		if (status != KERN_OK) {
+			object_unlock(cur, flags);
+			kfree(rpath);
+			return status;
+		}
+
+		object_unlock(cur, flags);
+		cur = next;
+		tok = strtok_r(NULL, "/", &sp);
+	}
+
+	kfree(rpath);
+
+	*out = object_ref(cur);
+	return KERN_OK;
+}
+
 kern_status_t object_publish(struct object_namespace *ns, const char *path, struct object *obj)
 {
 	if (*path != '/') {