#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
int
main(void)
{
struct sockaddr_in sock;
socklen_t len;
int listen_sock, connect_sock;
u_short port;
listen_sock = -1;
if ((shutdown(listen_sock, SHUT_RDWR) != -1) && (errno != EBADF))
errx(-1, "shutdown() for invalid file descriptor does not "
"return EBADF");
listen_sock = socket(PF_INET, SOCK_STREAM, 0);
if (listen_sock == -1)
errx(-1,
"socket(PF_INET, SOCK_STREAM, 0) for listen socket: %s",
strerror(errno));
bzero(&sock, sizeof(sock));
sock.sin_len = sizeof(sock);
sock.sin_family = AF_INET;
sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
sock.sin_port = 0;
if (bind(listen_sock, (struct sockaddr *)&sock, sizeof(sock)) < 0)
errx(-1, "bind(%s, %d) for listen socket: %s",
inet_ntoa(sock.sin_addr), sock.sin_port, strerror(errno));
len = sizeof(sock);
if (getsockname(listen_sock, (struct sockaddr *)&sock, &len) < 0)
errx(-1, "getsockname() for listen socket: %s",
strerror(errno));
port = sock.sin_port;
if (listen(listen_sock, -1) < 0)
errx(-1, "listen() for listen socket: %s", strerror(errno));
connect_sock = socket(PF_INET, SOCK_STREAM, 0);
if (connect_sock == -1)
errx(-1, "socket(PF_INET, SOCK_STREAM, 0) for connect "
"socket: %s", strerror(errno));
bzero(&sock, sizeof(sock));
sock.sin_len = sizeof(sock);
sock.sin_family = AF_INET;
sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
sock.sin_port = port;
if (connect(connect_sock, (struct sockaddr *)&sock, sizeof(sock)) < 0)
errx(-1, "connect() for connect socket: %s", strerror(errno));
if ((shutdown(connect_sock, SHUT_RD - 1) != -1) && (errno != EINVAL))
errx(-1, "shutdown(SHUT_RD - 1) does not return EINVAL");
if ((shutdown(connect_sock, SHUT_RDWR + 1) != -1) && (errno != EINVAL))
errx(-1, "shutdown(SHUT_RDWR + 1) does not return EINVAL");
if (shutdown(connect_sock, SHUT_RD) < 0)
errx(-1, "shutdown(SHUT_RD) for connect socket: %s",
strerror(errno));
if (shutdown(connect_sock, SHUT_WR) < 0)
errx(-1, "shutdown(SHUT_WR) for connect socket: %s",
strerror(errno));
close(connect_sock);
close(listen_sock);
return (0);
}