#include "u.h"#include "lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "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);}