#include <assert.h>#include <errno.h>#include <stdio.h>#include <sys/ioctl.h>#include <sys/socket.h>#include <sys/types.h>#include <net/gen/in.h>#include <net/gen/tcp.h>#include <net/gen/tcp_io.h>#define DEBUG 0static int _tcp_setsockopt(int socket, int level, int option_name,	const void *option_value, socklen_t option_len);int setsockopt(int socket, int level, int option_name,        const void *option_value, socklen_t option_len){	int r;	nwio_tcpopt_t tcpopt;	r= ioctl(socket, NWIOGTCPOPT, &tcpopt);	if (r != -1 || errno != ENOTTY)	{		if (r == -1)		{			/* Bad file descriptor */			return -1;		}		return _tcp_setsockopt(socket, level, option_name,			option_value, option_len);	}#if DEBUG	fprintf(stderr, "setsockopt: not implemented for fd %d\n", socket);#endif	errno= ENOSYS;	return -1;}static int _tcp_setsockopt(int socket, int level, int option_name,	const void *option_value, socklen_t option_len){	int i;	if (level == SOL_SOCKET && option_name == SO_KEEPALIVE)	{		if (option_len != sizeof(i))		{			errno= EINVAL;			return -1;		}		i= *(int *)option_value;		if (!i)		{			/* At the moment there is no way to turn off 			 * keepalives.			 */			errno= ENOSYS;			return -1;		}		return 0;	}#if DEBUG	fprintf(stderr, "_tcp_setsocketopt: level %d, name %d\n",		level, option_name);#endif	errno= ENOSYS;	return -1;}