rx_vcc
if (rx_vcc(curr)) return;
if (rx_vcc(curr)) return;
vcc = vc->rx_vcc;
vcc = vc->rx_vcc;
vc->rx_vcc = vcc;
vc->rx_vcc = NULL;
if (vc->rx_vcc)
vcc = vc->rx_vcc;
struct atm_vcc *rx_vcc;
vc->rx_vcc = vcc;
vcc = vc->rx_vcc;
struct atm_vcc *tx_vcc, *rx_vcc;