#include "u.h"#include "../port/lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "../port/error.h" #include "ip.h" static voidnullbind(Ipifc*, int, char**){	error("cannot bind null device");} static voidnullunbind(Ipifc*){} static voidnullbwrite(Ipifc*, Block*, int, uchar*){	error("nullbwrite");} Medium nullmedium ={.name=		"null",.bind=		nullbind,.unbind=	nullunbind,.bwrite=	nullbwrite,}; voidnullmediumlink(void){	addipmedium(&nullmedium);}