/*
* State machine for state 4, Awaiting Reset Confirmation State.
* The handling of the timer(s) is in file x25_timer.c
* Handling of state 0 and connection release is in af_x25.c.
*/
static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
switch (frametype) {
case X25_RESET_REQUEST:
x25_write_internal(sk, X25_RESET_CONFIRMATION);
case X25_RESET_CONFIRMATION: {
struct x25_sock *x25 = x25_sk(sk);
x25_stop_timer(sk);
x25->condition = 0x00;
x25->va = 0;
x25->vr = 0;
x25->vs = 0;
x25->vl = 0;
x25->state = X25_STATE_3;
x25_requeue_frames(sk);
break;
}
case X25_CLEAR_REQUEST:
x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
break;
default:
break;
}
return 0;
}
void x25_enquiry_response(struct sock *sk)
{
if (sk->protinfo.x25->condition & X25_COND_OWN_RX_BUSY)
x25_write_internal(sk, X25_RNR);
else
x25_write_internal(sk, X25_RR);
sk->protinfo.x25->vl = sk->protinfo.x25->vr;
sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING;
x25_stop_timer(sk);
}
void x25_enquiry_response(struct sock *sk)
{
struct x25_opt *x25 = x25_sk(sk);
if (x25->condition & X25_COND_OWN_RX_BUSY)
x25_write_internal(sk, X25_RNR);
else
x25_write_internal(sk, X25_RR);
x25->vl = x25->vr;
x25->condition &= ~X25_COND_ACK_PENDING;
x25_stop_timer(sk);
}
/*
* Timer has expired, it may have been T2, T21, T22, or T23. We can tell
* by the state machine state.
*/
static inline void x25_do_timer_expiry(struct sock * sk)
{
struct x25_opt *x25 = x25_sk(sk);
switch (x25->state) {
case X25_STATE_3: /* T2 */
if (x25->condition & X25_COND_ACK_PENDING) {
x25->condition &= ~X25_COND_ACK_PENDING;
x25_enquiry_response(sk);
}
break;
case X25_STATE_1: /* T21 */
case X25_STATE_4: /* T22 */
x25_write_internal(sk, X25_CLEAR_REQUEST);
x25->state = X25_STATE_2;
x25_start_t23timer(sk);
break;
case X25_STATE_2: /* T23 */
x25_disconnect(sk, ETIMEDOUT, 0, 0);
break;
}
}
int x25_clear_request(struct x25_cs * x25) {
if (!x25)
return 0;
struct x25_cs_internal * x25_int = x25_get_internal(x25);
switch (x25_int->state) {
case X25_STATE_0:
case X25_STATE_2:
x25_disconnect(x25, 0, 0, 0);
break;
case X25_STATE_1:
case X25_STATE_3:
case X25_STATE_4:
x25_clear_queues(x25);
x25->callbacks->debug(2, "[X25] S%d TX CLEAR_REQUEST", x25_int->state);
_uchar old_state = x25_int->state;
x25_int->state = X25_STATE_2;
x25_write_internal(x25, X25_CLEAR_REQUEST);
x25_start_timer(x25, &x25_int->ClearTimer);
x25->callbacks->debug(1, "[X25] S%d -> S2", old_state);
break;
};
return 0;
}
int x25_call_request(struct x25_cs * x25, struct x25_address *dest_addr) {
int rc = X25_BADTOKEN;
if (!x25)
goto out;
struct x25_cs_internal * x25_int = x25_get_internal(x25);
rc = X25_NOTCONNECTED;
if (x25_int->state == X25_STATE_1)
goto out;
rc = X25_CONNECTED;
if (x25_int->state == X25_STATE_3)
goto out;
x25_limit_facilities(x25);
x25->dest_addr = *dest_addr;
x25->callbacks->debug(1, "[X25] S%d Make Call to %s", x25_int->state, dest_addr->x25_addr);
x25->callbacks->debug(2, "[X25] S%d TX CALL_REQUEST", x25_int->state);
x25->callbacks->debug(1, "[X25] S%d -> S1", x25_int->state);
x25_int->state = X25_STATE_1;
x25_write_internal(x25, X25_CALL_REQUEST);
x25_start_timer(x25, &x25_int->CallTimer);
rc = 0;
out:
return rc;
}
/*
* State machine for state 1, Awaiting Call Accepted State.
* The handling of the timer(s) is in file x25_timer.c.
* Handling of state 0 and connection release is in af_x25.c.
*/
static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
struct x25_address source_addr, dest_addr;
switch (frametype) {
case X25_CALL_ACCEPTED: {
struct x25_sock *x25 = x25_sk(sk);
x25_stop_timer(sk);
x25->condition = 0x00;
x25->vs = 0;
x25->va = 0;
x25->vr = 0;
x25->vl = 0;
x25->state = X25_STATE_3;
sk->sk_state = TCP_ESTABLISHED;
/*
* Parse the data in the frame.
*/
skb_pull(skb, X25_STD_MIN_LEN);
skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr));
skb_pull(skb,
x25_parse_facilities(skb, &x25->facilities,
&x25->dte_facilities,
&x25->vc_facil_mask));
/*
* Copy any Call User Data.
*/
if (skb->len >= 0) {
memcpy(x25->calluserdata.cuddata, skb->data,
skb->len);
x25->calluserdata.cudlength = skb->len;
}
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_state_change(sk);
break;
}
case X25_CLEAR_REQUEST:
x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
break;
default:
break;
}
return 0;
}
/*
* State machine for state 2, Awaiting Clear Confirmation State.
* The handling of the timer(s) is in file x25_timer.c
* Handling of state 0 and connection release is in af_x25.c.
*/
static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
switch (frametype) {
case X25_CLEAR_REQUEST:
x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
break;
case X25_CLEAR_CONFIRMATION:
x25_disconnect(sk, 0, 0, 0);
break;
default:
break;
}
return 0;
}
int x25_pvc_setup(struct x25_cs * x25) {
int rc = X25_BADTOKEN;
if (!x25)
goto out;
struct x25_cs_internal * x25_int = x25_get_internal(x25);
x25_limit_facilities(x25);
x25->callbacks->debug(1, "[X25] S%d PVC setup", x25_int->state);
x25->callbacks->debug(2, "[X25] S%d TX RESET_REQUEST", x25_int->state);
x25->callbacks->debug(1, "[X25] S%d -> S4", x25_int->state);
x25_int->state = X25_STATE_4;
x25_write_internal(x25, X25_RESET_REQUEST);
x25_start_timer(x25, &x25_int->ResetTimer);
rc = 0;
out:
return rc;
}
/*
* State machine for state 3, Connected State.
* The handling of the timer(s) is in file x25_timer.c
* Handling of state 0 and connection release is in af_x25.c.
*/
static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m)
{
int queued = 0;
int modulus;
struct x25_sock *x25 = x25_sk(sk);
modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;
switch (frametype) {
case X25_RESET_REQUEST:
x25_write_internal(sk, X25_RESET_CONFIRMATION);
x25_stop_timer(sk);
x25->condition = 0x00;
x25->vs = 0;
x25->vr = 0;
x25->va = 0;
x25->vl = 0;
x25_requeue_frames(sk);
break;
case X25_CLEAR_REQUEST:
x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
break;
case X25_RR:
case X25_RNR:
if (!x25_validate_nr(sk, nr)) {
x25_clear_queues(sk);
x25_write_internal(sk, X25_RESET_REQUEST);
x25_start_t22timer(sk);
x25->condition = 0x00;
x25->vs = 0;
x25->vr = 0;
x25->va = 0;
x25->vl = 0;
x25->state = X25_STATE_4;
} else {
x25_frames_acked(sk, nr);
if (frametype == X25_RNR) {
x25->condition |= X25_COND_PEER_RX_BUSY;
} else {
x25->condition &= ~X25_COND_PEER_RX_BUSY;
}
}
break;
case X25_DATA: /* XXX */
x25->condition &= ~X25_COND_PEER_RX_BUSY;
if ((ns != x25->vr) || !x25_validate_nr(sk, nr)) {
x25_clear_queues(sk);
x25_write_internal(sk, X25_RESET_REQUEST);
x25_start_t22timer(sk);
x25->condition = 0x00;
x25->vs = 0;
x25->vr = 0;
x25->va = 0;
x25->vl = 0;
x25->state = X25_STATE_4;
break;
}
x25_frames_acked(sk, nr);
if (ns == x25->vr) {
if (x25_queue_rx_frame(sk, skb, m) == 0) {
x25->vr = (x25->vr + 1) % modulus;
queued = 1;
} else {
/* Should never happen */
x25_clear_queues(sk);
x25_write_internal(sk, X25_RESET_REQUEST);
x25_start_t22timer(sk);
x25->condition = 0x00;
x25->vs = 0;
x25->vr = 0;
x25->va = 0;
x25->vl = 0;
x25->state = X25_STATE_4;
break;
}
if (atomic_read(&sk->sk_rmem_alloc) >
(sk->sk_rcvbuf / 2))
x25->condition |= X25_COND_OWN_RX_BUSY;
}
/*
* If the window is full Ack it immediately, else
* start the holdback timer.
*/
if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) {
x25->condition &= ~X25_COND_ACK_PENDING;
x25_stop_timer(sk);
x25_enquiry_response(sk);
} else {
x25->condition |= X25_COND_ACK_PENDING;
x25_start_t2timer(sk);
}
break;
case X25_INTERRUPT_CONFIRMATION:
x25->intflag = 0;
break;
case X25_INTERRUPT:
if (sock_flag(sk, SOCK_URGINLINE))
queued = !sock_queue_rcv_skb(sk, skb);
else {
skb_set_owner_r(skb, sk);
skb_queue_tail(&x25->interrupt_in_queue, skb);
queued = 1;
}
sk_send_sigurg(sk);
x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION);
break;
default:
printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype);
break;
}
return queued;
}
