static void x25_heartbeat_expiry(unsigned long param)
{
struct sock *sk = (struct sock *)param;
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) /* can currently only occur in state 3 */
goto restart_heartbeat;
switch (x25_sk(sk)->state) {
case X25_STATE_0:
/*
* Magic here: If we listen() and a new link dies
* before it is accepted() it isn't 'dead' so doesn't
* get removed.
*/
if (sock_flag(sk, SOCK_DESTROY) ||
(sk->sk_state == TCP_LISTEN &&
sock_flag(sk, SOCK_DEAD))) {
x25_destroy_socket(sk);
goto unlock;
}
break;
case X25_STATE_3:
/*
* Check for the state of the receive buffer.
*/
x25_check_rbuf(sk);
break;
}
restart_heartbeat:
x25_start_heartbeat(sk);
unlock:
bh_unlock_sock(sk);
}
/*
* 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;
}
/*
* This is where all X.25 information frames pass.
*
* Returns the amount of user data bytes sent on success
* or a negative error code on failure.
*/
int x25_output(struct sock *sk, struct sk_buff *skb)
{
struct sk_buff *skbn;
unsigned char header[X25_EXT_MIN_LEN];
int err, frontlen, len;
int sent=0, noblock = X25_SKB_CB(skb)->flags & MSG_DONTWAIT;
struct x25_opt *x25 = x25_sk(sk);
int header_len = x25->neighbour->extended ? X25_EXT_MIN_LEN :
X25_STD_MIN_LEN;
int max_len = x25_pacsize_to_bytes(x25->facilities.pacsize_out);
if (skb->len - header_len > max_len) {
/* Save a copy of the Header */
memcpy(header, skb->data, header_len);
skb_pull(skb, header_len);
frontlen = skb_headroom(skb);
while (skb->len > 0) {
if ((skbn = sock_alloc_send_skb(sk, frontlen + max_len,
noblock, &err)) == NULL){
if (err == -EWOULDBLOCK && noblock){
kfree_skb(skb);
return sent;
}
SOCK_DEBUG(sk, "x25_output: fragment alloc"
" failed, err=%d, %d bytes "
"sent\n", err, sent);
return err;
}
skb_reserve(skbn, frontlen);
len = max_len > skb->len ? skb->len : max_len;
/* Copy the user data */
memcpy(skb_put(skbn, len), skb->data, len);
skb_pull(skb, len);
/* Duplicate the Header */
skb_push(skbn, header_len);
memcpy(skbn->data, header, header_len);
if (skb->len > 0) {
if (x25->neighbour->extended)
skbn->data[3] |= X25_EXT_M_BIT;
else
skbn->data[2] |= X25_STD_M_BIT;
}
skb_queue_tail(&sk->sk_write_queue, skbn);
sent += len;
}
kfree_skb(skb);
} else {
skb_queue_tail(&sk->sk_write_queue, skb);
sent = skb->len - header_len;
}
return sent;
}
void x25_kick(struct sock *sk)
{
struct sk_buff *skb, *skbn;
unsigned short start, end;
int modulus;
struct x25_opt *x25 = x25_sk(sk);
if (x25->state != X25_STATE_3)
return;
/*
* Transmit interrupt data.
*/
if (!x25->intflag && skb_peek(&x25->interrupt_out_queue) != NULL) {
x25->intflag = 1;
skb = skb_dequeue(&x25->interrupt_out_queue);
x25_transmit_link(skb, x25->neighbour);
}
if (x25->condition & X25_COND_PEER_RX_BUSY)
return;
if (!skb_peek(&sk->sk_write_queue))
return;
modulus = x25->neighbour->extended ? X25_EMODULUS : X25_SMODULUS;
start = skb_peek(&x25->ack_queue) ? x25->vs : x25->va;
end = (x25->va + x25->facilities.winsize_out) % modulus;
if (start == end)
return;
x25->vs = start;
/*
* Transmit data until either we're out of data to send or
* the window is full.
*/
skb = skb_dequeue(&sk->sk_write_queue);
do {
if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
skb_queue_head(&sk->sk_write_queue, skb);
break;
}
skb_set_owner_w(skbn, sk);
/*
* Transmit the frame copy.
*/
x25_send_iframe(sk, skbn);
x25->vs = (x25->vs + 1) % modulus;
/*
* Requeue the original data frame.
*/
skb_queue_tail(&x25->ack_queue, skb);
} while (x25->vs != end &&
(skb = skb_dequeue(&sk->sk_write_queue)) != NULL);
x25->vl = x25->vr;
x25->condition &= ~X25_COND_ACK_PENDING;
x25_stop_timer(sk);
}
void x25_stop_timer(struct sock *sk)
{
del_timer(&x25_sk(sk)->timer);
}
void x25_start_t23timer(struct sock *sk)
{
struct x25_opt *x25 = x25_sk(sk);
mod_timer(&x25->timer, jiffies + x25->t23);
}