Function iperf_connect

src/iperf_client_api.c:420–550

iperf_connect -- client to server connection function */

/* iperf_connect -- client to server connection function */
int
iperf_connect(struct iperf_test *test)
{
    int opt;
    socklen_t len;

    if (NULL == test)
    {
        iperf_err(NULL, "No test\n");
        return -1;
    }
    FD_ZERO(&test->read_set);
    FD_ZERO(&test->write_set);

    make_cookie(test->cookie);

    /* Create and connect the control channel */
    if (test->ctrl_sck < 0)
	// Create the control channel using an ephemeral port
	test->ctrl_sck = netdial(test->settings->domain, Ptcp, test->bind_address, test->bind_dev, 0, test->server_hostname, test->server_port, test->settings->connect_timeout);
    if (test->ctrl_sck < 0) {
        i_errno = IECONNECT;
        return -1;
    }

    // set TCP_NODELAY for lower latency on control messages
    int flag = 1;
    if (setsockopt(test->ctrl_sck, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int))) {
        i_errno = IESETNODELAY;
        return -1;
    }

#if defined (HAVE_TCP_KEEPALIVE)
        // Set Control Connection TCP Keepalive (especially useful for long UDP test sessions)
        if (iperf_set_control_keepalive(test) < 0)
            return -1;
#endif //HAVE_TCP_KEEPALIVE

#if defined(HAVE_TCP_USER_TIMEOUT)
    if ((opt = test->settings->snd_timeout)) {
        if (setsockopt(test->ctrl_sck, IPPROTO_TCP, TCP_USER_TIMEOUT, &opt, sizeof(opt)) < 0) {
            i_errno = IESETUSERTIMEOUT;
            return -1;
        }
    }
#endif /* HAVE_TCP_USER_TIMEOUT */

    if (Nwrite(test->ctrl_sck, test->cookie, COOKIE_SIZE, Ptcp) < 0) {
        i_errno = IESENDCOOKIE;
        return -1;
    }

    FD_SET(test->ctrl_sck, &test->read_set);
    if (test->ctrl_sck > test->max_fd) test->max_fd = test->ctrl_sck;

    len = sizeof(opt);
    if (getsockopt(test->ctrl_sck, IPPROTO_TCP, TCP_MAXSEG, &opt, &len) < 0) {
        test->ctrl_sck_mss = 0;