#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>

#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define	N	4000000

int
main(int argc, char **argv)
{
	struct sockaddr_in6 sin;
	socklen_t optlen;
	int fd, setval, getval, i;
	pid_t pid;

	if ((fd = socket(AF_INET6, SOCK_STREAM, 0)) == -1)
		err(1, "socket");

	pid = fork();

	if (pid == -1)
		err(1, "fork");

	if (pid != 0) {
		/*
		 * Parent.
		 */
		for (i = 0; i < N; i++) {
			for (setval = 0; setval <= 1; setval++) {
				if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
					&setval, sizeof(setval)) == -1) {
					err(1, "setsockopt");
				}

				if (getsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
					&getval, &optlen) == -1) {
					err(1, "getsockopt");
				}

				if (setval != getval) {
					errx(1, "setval (%d) != getval (%d) "
					    "(after %d iterations)", setval,
					    getval, i);
				}
			}
		}
		printf("parent exiting.\n");
		exit(0);
	}

	/* exit(0); */

	/*
	 * Children.
	 */

	if (fork() == -1)
		err(1, "fork");

	for (i = 0; i < N; i++) {
		for (setval = 0; setval <= 2; setval++) {
			if (setsockopt(fd, IPPROTO_IPV6, IPV6_PORTRANGE,
				&setval, sizeof(setval)) == -1) {
				err(1, "setsockopt");
			}
		}
	}

	printf("child exiting.\n");

	exit(0);
}