/*
* Higher level upcall for a LAPB frame
*/
int ax25_std_frame_in(ax25_cb *ax25, struct sk_buff *skb, int type)
{
int queued = 0, frametype, ns, nr, pf;
frametype = ax25_decode(ax25, skb, &ns, &nr, &pf);
switch (ax25->state) {
case AX25_STATE_1:
queued = ax25_std_state1_machine(ax25, skb, frametype, pf, type);
break;
case AX25_STATE_2:
queued = ax25_std_state2_machine(ax25, skb, frametype, pf, type);
break;
case AX25_STATE_3:
queued = ax25_std_state3_machine(ax25, skb, frametype, ns, nr, pf, type);
break;
case AX25_STATE_4:
queued = ax25_std_state4_machine(ax25, skb, frametype, ns, nr, pf, type);
break;
}
ax25_kick(ax25);
return queued;
}
/*
* All outgoing AX.25 I frames pass via this routine. Therefore this is
* where the fragmentation of frames takes place. If fragment is set to
* zero then we are not allowed to do fragmentation, even if the frame
* is too large.
*/
void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb)
{
struct sk_buff *skbn;
unsigned char *p;
int frontlen, len, fragno, ka9qfrag, first = 1;
if (paclen < 16) {
WARN_ON_ONCE(1);
kfree_skb(skb);
return;
}
if ((skb->len - 1) > paclen) {
if (*skb->data == AX25_P_TEXT) {
skb_pull(skb, 1); /* skip PID */
ka9qfrag = 0;
} else {
paclen -= 2; /* Allow for fragment control info */
ka9qfrag = 1;
}
fragno = skb->len / paclen;
if (skb->len % paclen == 0) fragno--;
frontlen = skb_headroom(skb); /* Address space + CTRL */
while (skb->len > 0) {
spin_lock_bh(&ax25_frag_lock);
if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) {
spin_unlock_bh(&ax25_frag_lock);
printk(KERN_CRIT "AX.25: ax25_output - out of memory\n");
return;
}
if (skb->sk != NULL)
skb_set_owner_w(skbn, skb->sk);
spin_unlock_bh(&ax25_frag_lock);
len = (paclen > skb->len) ? skb->len : paclen;
if (ka9qfrag == 1) {
skb_reserve(skbn, frontlen + 2);
skb_set_network_header(skbn,
skb_network_offset(skb));
skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
p = skb_push(skbn, 2);
*p++ = AX25_P_SEGMENT;
*p = fragno--;
if (first) {
*p |= AX25_SEG_FIRST;
first = 0;
}
} else {
skb_reserve(skbn, frontlen + 1);
skb_set_network_header(skbn,
skb_network_offset(skb));
skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
p = skb_push(skbn, 1);
*p = AX25_P_TEXT;
}
skb_pull(skb, len);
skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */
}
kfree_skb(skb);
} else {
skb_queue_tail(&ax25->write_queue, skb); /* Throw it on the queue */
}
switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
case AX25_PROTO_STD_SIMPLEX:
case AX25_PROTO_STD_DUPLEX:
ax25_kick(ax25);
break;
#ifdef CONFIG_AX25_DAMA_SLAVE
/*
* A DAMA slave is _required_ to work as normal AX.25L2V2
* if no DAMA master is available.
*/
case AX25_PROTO_DAMA_SLAVE:
if (!ax25->ax25_dev->dama.slave) ax25_kick(ax25);
break;
#endif
}
}
/*
* All outgoing AX.25 I frames pass via this routine. Therefore this is
* where the fragmentation of frames takes place.
*/
void ax25_output(ax25_cb *ax25, struct sk_buff *skb)
{
struct sk_buff *skbn;
unsigned char *p;
int frontlen, mtu, len, fragno, ka9qfrag, first = 1;
long flags;
/*
* dl1bke 960301: We use the new PACLEN parameter as MTU of the AX.25 layer.
* This will (hopefully) allow user programs to write() data
* w/o having to think of the maximal amount of data we can
* send with one call. It's called PACLEN to (1) avoid confusion
* with (IP) MTU and (2) TAPR calls this PACLEN, too ;-)
*/
mtu = ax25->paclen;
if ((skb->len - 1) > mtu) {
if (*skb->data == AX25_P_TEXT) {
skb_pull(skb, 1); /* skip PID */
ka9qfrag = 0;
} else {
mtu -= 2; /* Allow for fragment control info */
ka9qfrag = 1;
}
fragno = skb->len / mtu;
if (skb->len % mtu == 0) fragno--;
frontlen = skb_headroom(skb); /* Address space + CTRL */
while (skb->len > 0) {
save_flags(flags);
cli();
/*
* do _not_ use sock_alloc_send_skb, our socket may have
* sk->shutdown set...
*/
if ((skbn = alloc_skb(mtu + 2 + frontlen, GFP_ATOMIC)) == NULL) {
restore_flags(flags);
printk(KERN_DEBUG "ax25_output: alloc_skb returned NULL\n");
if (skb_device_locked(skb))
skb_device_unlock(skb);
return;
}
skbn->sk = skb->sk;
if (skbn->sk)
atomic_add(skbn->truesize, &skbn->sk->wmem_alloc);
restore_flags(flags);
skbn->free = 1;
skbn->arp = 1;
len = (mtu > skb->len) ? skb->len : mtu;
if (ka9qfrag == 1) {
skb_reserve(skbn, frontlen + 2);
memcpy(skb_put(skbn, len), skb->data, len);
p = skb_push(skbn, 2);
*p++ = AX25_P_SEGMENT;
*p = fragno--;
if (first) {
*p |= SEG_FIRST;
first = 0;
}
} else {
skb_reserve(skbn, frontlen + 1);
memcpy(skb_put(skbn, len), skb->data, len);
p = skb_push(skbn, 1);
*p = AX25_P_TEXT;
}
skb_pull(skb, len);
skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */
}
skb->free = 1;
kfree_skb(skb, FREE_WRITE);
} else {
skb_queue_tail(&ax25->write_queue, skb); /* Throw it on the queue */
}
if (ax25->state == AX25_STATE_3 || ax25->state == AX25_STATE_4) {
if (!ax25->dama_slave) /* bke 960114: we aren't allowed to transmit */
ax25_kick(ax25); /* in DAMA mode unless we received a Poll */
}
}
/*
* AX.25 TIMER
*
* This routine is called every 500ms. Decrement timer by this
* amount - if expired then process the event.
*/
static void ax25_timer(unsigned long param)
{
ax25_cb *ax25 = (ax25_cb *)param;
switch (ax25->state) {
case AX25_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 (ax25->sk == NULL || ax25->sk->destroy || (ax25->sk->state == TCP_LISTEN && ax25->sk->dead)) {
del_timer(&ax25->timer);
ax25_destroy_socket(ax25);
return;
}
break;
case AX25_STATE_3:
case AX25_STATE_4:
/*
* Check the state of the receive buffer.
*/
if (ax25->sk != NULL) {
if (ax25->sk->rmem_alloc < (ax25->sk->rcvbuf / 2) && (ax25->condition & OWN_RX_BUSY_CONDITION)) {
ax25->condition &= ~OWN_RX_BUSY_CONDITION;
if (!ax25->dama_slave)
ax25_send_control(ax25, RR, POLLOFF, C_RESPONSE);
ax25->condition &= ~ACK_PENDING_CONDITION;
break;
}
}
/*
* Check for frames to transmit.
*/
if (!ax25->dama_slave)
ax25_kick(ax25);
break;
default:
break;
}
if (ax25->t2timer > 0 && --ax25->t2timer == 0) {
if (ax25->state == AX25_STATE_3 || ax25->state == AX25_STATE_4) {
if (ax25->condition & ACK_PENDING_CONDITION) {
ax25->condition &= ~ACK_PENDING_CONDITION;
if (!ax25->dama_slave)
ax25_timeout_response(ax25);
}
}
}
if (ax25->t3timer > 0 && --ax25->t3timer == 0) {
/* dl1bke 960114: T3 expires and we are in DAMA mode: */
/* send a DISC and abort the connection */
if (ax25->dama_slave) {
#ifdef CONFIG_NETROM
nr_link_failed(&ax25->dest_addr, ax25->device);
#endif
ax25_clear_queues(ax25);
ax25_send_control(ax25, DISC, POLLON, C_COMMAND);
ax25->state = AX25_STATE_0;
if (ax25->sk != NULL) {
if (ax25->sk->debug)
printk("T3 Timeout\n");
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = ETIMEDOUT;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 1;
}
ax25_reset_timer(ax25);
return;
}
if (ax25->state == AX25_STATE_3) {
ax25->n2count = 0;
ax25_transmit_enquiry(ax25);
ax25->state = AX25_STATE_4;
}
ax25->t3timer = ax25->t3;
}
if (ax25->idletimer > 0 && --ax25->idletimer == 0) {
/* dl1bke 960228: close the connection when IDLE expires */
/* similar to DAMA T3 timeout but with */
/* a "clean" disconnect of the connection */
ax25_clear_queues(ax25);
ax25->n2count = 0;
if (!ax25->dama_slave) {
ax25->t3timer = 0;
ax25_send_control(ax25, DISC, POLLON, C_COMMAND);
} else {
ax25->t3timer = ax25->t3;
}
/* state 1 or 2 should not happen, but... */
if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2)
ax25->state = AX25_STATE_0;
else
ax25->state = AX25_STATE_2;
ax25->t1timer = ax25->t1 = ax25_calculate_t1(ax25);
if (ax25->sk != NULL) {
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = 0;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 1;
ax25->sk->destroy = 1;
}
}
/* dl1bke 960114: DAMA T1 timeouts are handled in ax25_dama_slave_transmit */
/* nevertheless we have to re-enqueue the timer struct... */
if (ax25->t1timer == 0 || --ax25->t1timer > 0) {
ax25_reset_timer(ax25);
return;
}
if (!ax25_dev_is_dama_slave(ax25->device)) {
if (ax25->dama_slave)
ax25->dama_slave = 0;
ax25_t1_timeout(ax25);
}
}