Function loopback

test/sockets/test_tcp_client_bind.c:48–55

}

struct sockaddr_in loopback(uint16_t port) {
  struct sockaddr_in a;
  memset(&a, 0, sizeof(a));
  a.sin_family = AF_INET;
  a.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  a.sin_port = htons(port);
  return a;
}

void main_loop(void) {
  fd_set fdr, fdw;