int ax25_check_iframes_acked(ax25_cb *ax25, unsigned short nr)
{
    if (ax25->vs == nr) {
        ax25_frames_acked(ax25, nr);
        ax25_calculate_rtt(ax25);
        ax25_stop_t1timer(ax25);
        ax25_start_t3timer(ax25);
        return 1;
    } else {
        if (ax25->va != nr) {
            ax25_frames_acked(ax25, nr);
            ax25_calculate_t1(ax25);
            ax25_start_t1timer(ax25);
            return 1;
        }
    }
    return 0;
}
Esempio n. 2
0
/*
 *	State machine for state 3, Connected State.
 *	The handling of the timer(s) is in file ax25_timer.c
 *	Handling of state 0 and connection release is in ax25.c.
 */
static int ax25_ds_state3_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int ns, int nr, int pf, int type)
{
    int queued = 0;

    switch (frametype) {
    case AX25_SABM:
    case AX25_SABME:
        if (frametype == AX25_SABM) {
            ax25->modulus   = AX25_MODULUS;
            ax25->window    = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
        } else {
            ax25->modulus   = AX25_EMODULUS;
            ax25->window    = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
        }
        ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
        ax25_stop_t1timer(ax25);
        ax25_start_t3timer(ax25);
        ax25_start_idletimer(ax25);
        ax25->condition = 0x00;
        ax25->vs        = 0;
        ax25->va        = 0;
        ax25->vr        = 0;
        ax25_requeue_frames(ax25);
        ax25_dama_on(ax25);
        break;

    case AX25_DISC:
        ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
        ax25_dama_off(ax25);
        ax25_disconnect(ax25, 0);
        break;

    case AX25_DM:
        ax25_dama_off(ax25);
        ax25_disconnect(ax25, ECONNRESET);
        break;

    case AX25_RR:
    case AX25_RNR:
        if (frametype == AX25_RR)
            ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
        else
            ax25->condition |= AX25_COND_PEER_RX_BUSY;

        if (ax25_validate_nr(ax25, nr)) {
            if (ax25_check_iframes_acked(ax25, nr))
                ax25->n2count=0;
            if (type == AX25_COMMAND && pf)
                ax25_ds_enquiry_response(ax25);
        } else {
            ax25_ds_nr_error_recovery(ax25);
            ax25->state = AX25_STATE_1;
        }
        break;

    case AX25_REJ:
        ax25->condition &= ~AX25_COND_PEER_RX_BUSY;

        if (ax25_validate_nr(ax25, nr)) {
            if (ax25->va != nr)
                ax25->n2count=0;

            ax25_frames_acked(ax25, nr);
            ax25_calculate_rtt(ax25);
            ax25_stop_t1timer(ax25);
            ax25_start_t3timer(ax25);
            ax25_requeue_frames(ax25);

            if (type == AX25_COMMAND && pf)
                ax25_ds_enquiry_response(ax25);
        } else {
            ax25_ds_nr_error_recovery(ax25);
            ax25->state = AX25_STATE_1;
        }
        break;

    case AX25_I:
        if (!ax25_validate_nr(ax25, nr)) {
            ax25_ds_nr_error_recovery(ax25);
            ax25->state = AX25_STATE_1;
            break;
        }
        if (ax25->condition & AX25_COND_PEER_RX_BUSY) {
            ax25_frames_acked(ax25, nr);
            ax25->n2count = 0;
        } else {
            if (ax25_check_iframes_acked(ax25, nr))
                ax25->n2count = 0;
        }
        if (ax25->condition & AX25_COND_OWN_RX_BUSY) {
            if (pf) ax25_ds_enquiry_response(ax25);
            break;
        }
        if (ns == ax25->vr) {
            ax25->vr = (ax25->vr + 1) % ax25->modulus;
            queued = ax25_rx_iframe(ax25, skb);
            if (ax25->condition & AX25_COND_OWN_RX_BUSY)
                ax25->vr = ns;	/* ax25->vr - 1 */
            ax25->condition &= ~AX25_COND_REJECT;
            if (pf) {
                ax25_ds_enquiry_response(ax25);
            } else {
                if (!(ax25->condition & AX25_COND_ACK_PENDING)) {
                    ax25->condition |= AX25_COND_ACK_PENDING;
                    ax25_start_t2timer(ax25);
                }
            }
        } else {
            if (ax25->condition & AX25_COND_REJECT) {
                if (pf) ax25_ds_enquiry_response(ax25);
            } else {
                ax25->condition |= AX25_COND_REJECT;
                ax25_ds_enquiry_response(ax25);
                ax25->condition &= ~AX25_COND_ACK_PENDING;
            }
        }
        break;

    case AX25_FRMR:
    case AX25_ILLEGAL:
        ax25_ds_establish_data_link(ax25);
        ax25->state = AX25_STATE_1;
        break;

    default:
        break;
    }

    return queued;
}