--- port_user.c.orig	2004-01-24 15:48:53.000000000 +1030
+++ port_user.c	2004-01-27 15:05:40.000000000 +1030
@@ -35,6 +35,11 @@
 	char *end;
 	int port;
 
+	if(sys_sendfile() == -1){
+		printk("port_init : host kernel doesn't support sendfile()\n");
+		return(NULL);
+	}
+
 	if(*str != ':'){
 		printk("port_init : channel type 'port' must specify a "
 		       "port number\n");