#include <errno.h>#include <stdio.h>#include <string.h>#include <sys/ioctl.h>#include <sys/socket.h>#include <netinet/in.h>#include <net/gen/in.h>#include <net/gen/tcp.h>#include <net/gen/tcp_io.h>#include <net/gen/udp.h>#include <net/gen/udp_io.h>#define DEBUG 0int listen(int socket, int backlog){	int r;	r= ioctl(socket, NWIOTCPLISTENQ, &backlog);	if (r != -1 || errno != EBADIOCTL)		return r;#if DEBUG	fprintf(stderr, "listen: not implemented for fd %d\n", socket);#endif	errno= ENOSYS;	return -1;}