static upper size limit for PA-TNC messages

src/libimcv/ietf/ietf_attr_pa_tnc_error.c

@@ -192,6 +192,10 @@ METHOD(pa_tnc_attr_t, build, void,
 {
 	bio_writer_t *writer;
 
+	if (this->value.ptr)
+	{
+		return;
+	}
 	writer = bio_writer_create(PA_ERROR_HEADER_SIZE + PA_ERROR_MSG_INFO_SIZE);
 	writer->write_uint8 (writer, PA_ERROR_RESERVED);
 	writer->write_uint24(writer, this->error_vendor_id);

src/libimcv/ietf/ietf_attr_port_filter.c

@@ -125,6 +125,10 @@ METHOD(pa_tnc_attr_t, build, void,
 	enumerator_t *enumerator;
 	port_entry_t *entry;
 
+	if (this->value.ptr)
+	{
+		return;
+	}
 	writer = bio_writer_create(this->ports->get_count(this->ports) *
 							   PORT_FILTER_ENTRY_SIZE);
 

src/libimcv/ietf/ietf_attr_product_info.c

@@ -122,6 +122,10 @@ METHOD(pa_tnc_attr_t, build, void,
 	bio_writer_t *writer;
 	chunk_t product_name;
 
+	if (this->value.ptr)
+	{
+		return;
+	}
 	product_name = chunk_create(this->product_name, strlen(this->product_name));
 
 	writer = bio_writer_create(PRODUCT_INFO_MIN_SIZE);