openflow_input: add inheritance
diff --git a/openflow_input/bsn_bw b/openflow_input/bsn_bw
index e0ff3e3..50c9267 100644
--- a/openflow_input/bsn_bw
+++ b/openflow_input/bsn_bw
@@ -30,7 +30,7 @@
 
 #version any
 
-struct of_bsn_bw_enable_set_request {
+struct of_bsn_bw_enable_set_request : of_bsn_header {
     uint8_t version;
     uint8_t type == 4;
     uint16_t length;
@@ -40,7 +40,7 @@
     uint32_t enable;        // 0 to disable the extension, 1 to enable it
 };
 
-struct of_bsn_bw_enable_set_reply {
+struct of_bsn_bw_enable_set_reply : of_bsn_header {
     uint8_t version;
     uint8_t type == 4;
     uint16_t length;
@@ -51,7 +51,7 @@
     uint32_t status;        // Result code: 0 success
 };
 
-struct of_bsn_bw_enable_get_request {
+struct of_bsn_bw_enable_get_request : of_bsn_header {
     uint8_t version;
     uint8_t type == 4;
     uint16_t length;
@@ -60,7 +60,7 @@
     uint32_t subtype == 19;
 };
 
-struct of_bsn_bw_enable_get_reply {
+struct of_bsn_bw_enable_get_reply : of_bsn_header {
     uint8_t version;
     uint8_t type == 4;
     uint16_t length;
@@ -70,7 +70,7 @@
     uint32_t enabled;       // 0 if feature is disabled; 1 if feature enabled
 };
 
-struct of_bsn_bw_clear_data_request {
+struct of_bsn_bw_clear_data_request : of_bsn_header {
     uint8_t version;
     uint8_t type == 4;
     uint16_t length;
@@ -79,7 +79,7 @@
     uint32_t subtype == 21;
 };
 
-struct of_bsn_bw_clear_data_reply {
+struct of_bsn_bw_clear_data_reply : of_bsn_header {
     uint8_t version;
     uint8_t type == 4;
     uint16_t length;