--- a/include/waaad/message-api.h	Thu Jun 11 16:59:45 2009 +0900
+++ b/include/waaad/message-api.h	Thu Jun 11 18:08:17 2009 +0900
@@ -106,7 +106,8 @@
 /* Flags for the msg_new and msg_avp_new functions */
 #define MSGFL_FROM_TEMPLATE	0x01	/* When creating an object, if it can contain children, also create the children using the "template" values in the dictionary */
 #define MSGFL_ALLOW_ETEID	0x02	/* When creating a message, a new end-to-end ID is allocated and set in the message */
-#define MSGFL_MAX		MSGFL_ALLOW_ETEID	/* The biggest valid flag value */
+#define MSGFL_ANSW_ERROR	0x04	/* When creating an answer message, set the 'E' bit and use the generic error ABNF instead of command-specific ABNF */
+#define MSGFL_MAX		MSGFL_ANSW_ERROR	/* The biggest valid flag value */
 
 
 #ifndef IN_EXTENSION

--- a/waaad/message.c	Thu Jun 11 16:59:45 2009 +0900
+++ b/waaad/message.c	Thu Jun 11 18:08:17 2009 +0900
@@ -1502,12 +1502,24 @@
 	qry = _M(*msg);
 	
 	/* Find the model for the answer */
-	CHECK_FCT(  _mpd_do_msg(qry, 0, 1)  );
-	CHECK_FCT(  dict_search ( DICT_COMMAND, CMD_ANSWER, qry->msg_model, &model, EINVAL )  );
+	if (flags & MSGFL_ANSW_ERROR) {
+		/* The model is the generic error format */
+		model = dict_cmd_error;
+	} else {
+		/* The model is the answer corresponding to the query. It supposes that these are defined in the dictionary */
+		CHECK_FCT(  _mpd_do_msg(qry, 0, 1)  );
+		CHECK_FCT(  dict_search ( DICT_COMMAND, CMD_ANSWER, qry->msg_model, &model, EINVAL )  );
+	}
 	
 	/* Create the answer */
 	CHECK_FCT(  msg_new( model, flags, msg )  );
 	
+	/* Set informations in the answer as in the query */
+	_M(*msg)->msg_public.msg_code = qry->msg_public.msg_code; /* useful for MSGFL_ANSW_ERROR */
+	_M(*msg)->msg_public.msg_appl = qry->msg_public.msg_appl;
+	_M(*msg)->msg_public.msg_eteid = qry->msg_public.msg_eteid;
+	_M(*msg)->msg_public.msg_hbhid = qry->msg_public.msg_hbhid;
+	
 	/* associate with query */
 	 /* may do that but this is faster... CHECK_FCT(  msg_answ_associate( *msg, (msg_t *)qry )  ); */
 	_M(*msg)->msg_query = (msg_t *)qry;
@@ -2320,8 +2332,8 @@
 	return 0;
 }
 
-/* Create an anwer to a query */
-int msg_new_answer_from_req ( msg_t ** msg )
+/* Create an anwer to a query, possibly an error message */
+int msg_new_answer_from_req ( msg_t ** msg, int error )
 {
 	_msg_t *qry;
 	
@@ -2333,7 +2345,7 @@
 	CHECK_PARAMS(  qry->msg_public.msg_flags & CMD_FLAG_REQUEST  );
 	
 	/* Create the new message */
-	CHECK_FCT(  msg_new_answ(msg, 0)  );
+	CHECK_FCT(  msg_new_answ(msg, error ? MSGFL_ANSW_ERROR : 0)  );
 	
 	/* If the first AVP of the query is a Session-Id, copy it to the answer */
 	{
@@ -2463,12 +2475,15 @@
 			
 	}
 	
-	if (set_e_bit) {
+	{
 		msg_data_t * hdr = NULL;
 		
 		CHECK_FCT(  msg_data( msg, &hdr )  );
 		
-		hdr->msg_flags |= CMD_FLAG_ERROR;
+		if (set_e_bit)
+			hdr->msg_flags |= CMD_FLAG_ERROR;
+		else
+			hdr->msg_flags &= ! CMD_FLAG_ERROR;
 	}
 	
 	if (std_err_msg || errormsg) {

--- a/waaad/message.h	Thu Jun 11 16:59:45 2009 +0900
+++ b/waaad/message.h	Thu Jun 11 18:08:17 2009 +0900
@@ -197,6 +197,7 @@
  *
  * PARAMETERS:
  *  msg		: The location of the query on entry, and of answer on return.
+ *  error       : Boolean to indicate if the answer is an error message (with 'E' bit set)
  *
  * DESCRIPTION: 
  *   This function creates the empty answer message for a request.
@@ -209,7 +210,7 @@
  *  0      	: Operation complete.
  *  !0      	: an error occurred.
  */
-int msg_new_answer_from_req ( msg_t ** msg );
+int msg_new_answer_from_req ( msg_t ** msg, int error );
 
 /*
  * FUNCTION:	msg_rescode_set

--- a/waaad/routing.c	Thu Jun 11 16:59:45 2009 +0900
+++ b/waaad/routing.c	Thu Jun 11 18:08:17 2009 +0900
@@ -563,7 +563,7 @@
 			
 			if (is_req) {
 				/* Create the answer message */
-				CHECK_FCT_DO( msg_new_answer_from_req(&msg), goto error  );
+				CHECK_FCT_DO( msg_new_answer_from_req(&msg, 1), goto error  );
 
 				/* Set the result code */
 				CHECK_FCT_DO( msg_rescode_set(msg, "DIAMETER_APPLICATION_UNSUPPORTED", NULL, NULL, 1), goto error  );
@@ -706,7 +706,7 @@
 			msg_dump_walk(FULL, msg);
 			
 			/* Create the answer message */
-			CHECK_FCT_DO( msg_new_answer_from_req(&msg), goto error  );
+			CHECK_FCT_DO( msg_new_answer_from_req(&msg, 1), goto error  );
 			
 			/* Set the result code */
 			CHECK_FCT_DO( msg_rescode_set(msg, "DIAMETER_UNABLE_TO_DELIVER", NULL, NULL, 1), goto error  );

--- a/waaad/tests/testrt.c	Thu Jun 11 16:59:45 2009 +0900
+++ b/waaad/tests/testrt.c	Thu Jun 11 18:08:17 2009 +0900
@@ -288,7 +288,7 @@
 		alarm(2);
 		
 		/* Now create an answer to that message */
-		CHECK( 0, msg_new_answer_from_req( &msg ) );
+		CHECK( 0, msg_new_answer_from_req( &msg, 0 ) );
 		CHECK( 0, msg_rescode_set( msg, "DIAMETER_SUCCESS", NULL, NULL, 1 )  );
 		
 		/* Do as if we had received this answer; it must be forwarded to peer1 */