+
+#define CONTROLLER_VALID \
+ "0123456789" \
+ "abcdefghijklmnopqrstuvwxyz" \
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
+ "_"
+
+bool cg_controller_is_valid(const char *p, bool allow_named) {
+ const char *t, *s;
+
+ if (!p)
+ return false;
+
+ if (allow_named) {
+ s = startswith(p, "name=");
+ if (s)
+ p = s;
+ }
+
+ if (*p == 0 || *p == '_')
+ return false;
+
+ for (t = p; *t; t++)
+ if (!strchr(CONTROLLER_VALID, *t))
+ return false;
+
+ if (t - p > FILENAME_MAX)
+ return false;
+
+ return true;
+}