test_sendsrcaddr
if (test_sendsrcaddr(s, &remote, &src) < 0)
if (test_sendsrcaddr(s2, &remote, &src) < 0)
if (test_sendsrcaddr(s, &remote, &src) > 0)
n = test_sendsrcaddr(s, NULL, &src);
n = test_sendsrcaddr(s, NULL, &src);