- struct ofproto *ofproto; /* The ofproto that contains this rule. */
- struct cls_rule cr; /* In owning ofproto's classifier. */
+ /* Where this rule resides in an OpenFlow switch.
+ *
+ * These are immutable once the rule is constructed, hence 'const'. */
+ struct ofproto *const ofproto; /* The ofproto that contains this rule. */
+ const struct cls_rule cr; /* In owning ofproto's classifier. */
+ const uint8_t table_id; /* Index in ofproto's 'tables' array. */
+