#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>			/* for IPPROTO_TCP value */
#include <netinet/tcp.h>		/* for TCP_MAXSEG value */

int
main(int argc, char **argv)
{
	int		sockfd, mss, sendbuff;
	int	optlen;

	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if (sockfd < 0) perror("can't create socket");

	/* Fetch and print the TCP maximum segment size.  */
	optlen = sizeof(mss);
	if (getsockopt(sockfd, IPPROTO_TCP, TCP_MAXSEG, &mss, &optlen) < 0)
		perror("TCP_MAXSEG getsockopt error");
	printf("TCP mss = %d\n", mss);

	/* Set the send buffer size, then fetch it and print its value.  */
	sendbuff = 65536;
	if (setsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &sendbuff, sizeof(sendbuff)) < 0)
		perror("SO_SNDBUF setsockopt error");

	optlen = sizeof(sendbuff);
	if (getsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &sendbuff, &optlen) < 0)
		perror("SO_SNDBUF getsockopt error");
		
	printf("send buffer size = %d\n", sendbuff);


	/* set and print the send and receive timeout */
	int rcvtimeout=2;
	if (setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, &rcvtimeout, sizeof(rcvtimeout)) < 0)
		perror("SO_RCVTIMEO setsockopt error");
	int sndtimeout=3;
	if (setsockopt(sockfd, SOL_SOCKET, SO_SNDTIMEO, &sndtimeout, sizeof(sndtimeout)) < 0)
		perror("SO_SNDTIMEO setsockopt error");

	optlen = sizeof(sendbuff);
	if (getsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, &sendbuff, &optlen) < 0)
		perror("SO_RCVTIMEO getsockopt error");
	printf ("receive timeout = %d\n", sendbuff);
	if (getsockopt(sockfd, SOL_SOCKET, SO_SNDTIMEO, &sendbuff, &optlen) < 0)
		perror("SO_SNDTIMEO getsockopt error");
	printf ("send timeout = %d\n", sendbuff);

	exit(0);
}