/*
* State machine for state 2, Awaiting Release State.
* The handling of the timer(s) is in file ax25_std_timer.c
* Handling of state 0 and connection release is in ax25.c.
*/
static int ax25_std_state2_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type)
{
switch (frametype) {
case AX25_SABM:
case AX25_SABME:
ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
break;
case AX25_DISC:
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
ax25_disconnect(ax25, 0);
break;
case AX25_DM:
case AX25_UA:
if (pf)
ax25_disconnect(ax25, 0);
break;
case AX25_I:
case AX25_REJ:
case AX25_RNR:
case AX25_RR:
if (pf) ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
break;
default:
break;
}
return 0;
}
/* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
* within the poll of any connected channel. Remember
* that we are not allowed to send anything unless we
* get polled by the Master.
*
* Thus we'll have to do parts of our T1 handling in
* ax25_enquiry_response().
*/
void ax25_t1_timeout(ax25_cb *ax25)
{
switch (ax25->state) {
case AX25_STATE_1:
if (ax25->n2count == ax25->n2) {
if (ax25->modulus == AX25_MODULUS) {
ax25_disconnect(ax25, ETIMEDOUT);
} else {
ax25->modulus = AX25_MODULUS;
ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_WINDOW);
ax25->n2count = 0;
ax25_send_control(ax25, AX25_SABM, ax25_dev_is_dama_slave(ax25->device) ? AX25_POLLOFF : AX25_POLLON, AX25_COMMAND);
}
} else {
ax25->n2count++;
if (ax25->modulus == AX25_MODULUS)
ax25_send_control(ax25, AX25_SABM, ax25_dev_is_dama_slave(ax25->device) ? AX25_POLLOFF : AX25_POLLON, AX25_COMMAND);
else
ax25_send_control(ax25, AX25_SABME, ax25_dev_is_dama_slave(ax25->device) ? AX25_POLLOFF : AX25_POLLON, AX25_COMMAND);
}
break;
case AX25_STATE_2:
if (ax25->n2count == ax25->n2) {
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
ax25_disconnect(ax25, ETIMEDOUT);
} else {
ax25->n2count++;
if (!ax25_dev_is_dama_slave(ax25->device))
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
}
break;
case AX25_STATE_3:
ax25->n2count = 1;
if (!ax25->dama_slave)
ax25_transmit_enquiry(ax25);
ax25->state = AX25_STATE_4;
break;
case AX25_STATE_4:
if (ax25->n2count == ax25->n2) {
ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
ax25_disconnect(ax25, ETIMEDOUT);
} else {
ax25->n2count++;
if (!ax25->dama_slave)
ax25_transmit_enquiry(ax25);
}
break;
}
ax25->t1timer = ax25->t1 = ax25_calculate_t1(ax25);
ax25_set_timer(ax25);
}
void ax25_std_t1timer_expiry(ax25_cb *ax25)
{
switch (ax25->state) {
case AX25_STATE_1:
if (ax25->n2count == ax25->n2) {
if (ax25->modulus == AX25_MODULUS) {
ax25_disconnect(ax25, ETIMEDOUT);
return;
} else {
ax25->modulus = AX25_MODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
ax25->n2count = 0;
ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
}
} else {
ax25->n2count++;
if (ax25->modulus == AX25_MODULUS)
ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
else
ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND);
}
break;
case AX25_STATE_2:
if (ax25->n2count == ax25->n2) {
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
ax25_disconnect(ax25, ETIMEDOUT);
return;
} else {
ax25->n2count++;
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
}
break;
case AX25_STATE_3:
ax25->n2count = 1;
ax25_std_transmit_enquiry(ax25);
ax25->state = AX25_STATE_4;
break;
case AX25_STATE_4:
if (ax25->n2count == ax25->n2) {
ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
ax25_disconnect(ax25, ETIMEDOUT);
return;
} else {
ax25->n2count++;
ax25_std_transmit_enquiry(ax25);
}
break;
}
ax25_calculate_t1(ax25);
ax25_start_t1timer(ax25);
}
void ax25_transmit_buffer(ax25_cb *ax25, struct sk_buff *skb, int type)
{
struct sk_buff *skbn;
unsigned char *ptr;
int headroom;
if (ax25->ax25_dev == NULL) {
ax25_disconnect(ax25, ENETUNREACH);
return;
}
headroom = ax25_addr_size(ax25->digipeat);
if (skb_headroom(skb) < headroom) {
if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) {
printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");
kfree_skb(skb);
return;
}
if (skb->sk != NULL)
skb_set_owner_w(skbn, skb->sk);
kfree_skb(skb);
skb = skbn;
}
ptr = skb_push(skb, headroom);
ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus);
ax25_queue_xmit(skb, ax25->ax25_dev->dev);
}
/*
* State machine for state 1, Awaiting Connection 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_state1_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type, int dama)
{
switch (frametype) {
case AX25_SABM:
ax25->modulus = AX25_MODULUS;
ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_WINDOW);
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
break;
case AX25_SABME:
ax25->modulus = AX25_EMODULUS;
ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_EWINDOW);
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
break;
case AX25_DISC:
ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
break;
case AX25_UA:
if (pf || dama) {
if (dama) ax25_dama_on(ax25); /* bke */
ax25_calculate_rtt(ax25);
ax25->t1timer = 0;
ax25->t3timer = ax25->t3;
ax25->idletimer = ax25->idle;
ax25->vs = 0;
ax25->va = 0;
ax25->vr = 0;
ax25->state = AX25_STATE_3;
ax25->n2count = 0;
ax25->dama_slave = dama; /* bke */
if (ax25->sk != NULL) {
ax25->sk->state = TCP_ESTABLISHED;
/* For WAIT_SABM connections we will produce an accept ready socket here */
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
}
}
break;
case AX25_DM:
if (pf) {
if (ax25->modulus == AX25_MODULUS) {
ax25_disconnect(ax25, ECONNREFUSED);
} else {
ax25->modulus = AX25_MODULUS;
ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_WINDOW);
}
}
break;
default:
if (dama && pf)
ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
break;
}
return 0;
}
/*
* State machine for state 1, Awaiting Connection State.
* The handling of the timer(s) is in file ax25_std_timer.c.
* Handling of state 0 and connection release is in ax25.c.
*/
static int ax25_std_state1_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type)
{
switch (frametype) {
case AX25_SABM:
ax25->modulus = AX25_MODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
break;
case AX25_SABME:
ax25->modulus = AX25_EMODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
break;
case AX25_DISC:
ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
break;
case AX25_UA:
if (pf) {
ax25_calculate_rtt(ax25);
ax25_stop_t1timer(ax25);
ax25_start_t3timer(ax25);
ax25_start_idletimer(ax25);
ax25->vs = 0;
ax25->va = 0;
ax25->vr = 0;
ax25->state = AX25_STATE_3;
ax25->n2count = 0;
if (ax25->sk != NULL) {
bh_lock_sock(ax25->sk);
ax25->sk->sk_state = TCP_ESTABLISHED;
/* For WAIT_SABM connections we will produce an accept ready socket here */
if (!sock_flag(ax25->sk, SOCK_DEAD))
ax25->sk->sk_state_change(ax25->sk);
bh_unlock_sock(ax25->sk);
}
}
break;
case AX25_DM:
if (pf) {
if (ax25->modulus == AX25_MODULUS) {
ax25_disconnect(ax25, ECONNREFUSED);
} else {
ax25->modulus = AX25_MODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
}
}
break;
default:
break;
}
return 0;
}
/*
* State machine for state 1, Awaiting Connection State.
* The handling of the timer(s) is in file ax25_ds_timer.c.
* Handling of state 0 and connection release is in ax25.c.
*/
static int ax25_ds_state1_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type)
{
switch (frametype) {
case AX25_SABM:
ax25->modulus = AX25_MODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
break;
case AX25_SABME:
ax25->modulus = AX25_EMODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
break;
case AX25_DISC:
ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
break;
case AX25_UA:
ax25_calculate_rtt(ax25);
ax25_stop_t1timer(ax25);
ax25_start_t3timer(ax25);
ax25_start_idletimer(ax25);
ax25->vs = 0;
ax25->va = 0;
ax25->vr = 0;
ax25->state = AX25_STATE_3;
ax25->n2count = 0;
if (ax25->sk != NULL) {
ax25->sk->state = TCP_ESTABLISHED;
/* For WAIT_SABM connections we will produce an accept ready socket here */
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
}
ax25_dama_on(ax25);
/* according to DK4EG´s spec we are required to
* send a RR RESPONSE FINAL NR=0. Please mail
* <*****@*****.**> if this causes problems
* with the TheNetNode DAMA Master implementation.
*/
ax25_std_enquiry_response(ax25);
break;
case AX25_DM:
if (pf) ax25_disconnect(ax25, ECONNREFUSED);
break;
default:
if (pf) ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
break;
}
return 0;
}
/*
* Kill all bound sockets on a dropped device.
*/
static void ax25_kill_by_device(struct device *dev)
{
ax25_dev *ax25_dev;
ax25_cb *s;
if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
return;
for (s = ax25_list; s != NULL; s = s->next) {
if (s->ax25_dev == ax25_dev) {
s->ax25_dev = NULL;
ax25_disconnect(s, ENETUNREACH);
}
}
}
/*
* 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;
}
/*
* State machine for state 1, Awaiting Connection State.
* The handling of the timer(s) is in file ax25_ds_timer.c.
* Handling of state 0 and connection release is in ax25.c.
*/
static int ax25_ds_state1_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type)
{
switch (frametype) {
case AX25_SABM:
ax25->modulus = AX25_MODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
break;
case AX25_SABME:
ax25->modulus = AX25_EMODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
break;
case AX25_DISC:
ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
break;
case AX25_UA:
ax25_calculate_rtt(ax25);
ax25_stop_t1timer(ax25);
ax25_start_t3timer(ax25);
ax25_start_idletimer(ax25);
ax25->vs = 0;
ax25->va = 0;
ax25->vr = 0;
ax25->state = AX25_STATE_3;
ax25->n2count = 0;
if (ax25->sk != NULL) {
bh_lock_sock(ax25->sk);
ax25->sk->sk_state = TCP_ESTABLISHED;
/*
* For WAIT_SABM connections we will produce an accept
* ready socket here
*/
if (!sock_flag(ax25->sk, SOCK_DEAD))
ax25->sk->sk_state_change(ax25->sk);
bh_unlock_sock(ax25->sk);
}
ax25_dama_on(ax25);
/* according to DK4EG's spec we are required to
* send a RR RESPONSE FINAL NR=0.
*/
ax25_std_enquiry_response(ax25);
break;
case AX25_DM:
if (pf)
ax25_disconnect(ax25, ECONNREFUSED);
break;
default:
if (pf)
ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
break;
}
return 0;
}
/*
* AX.25 TIMER
*
* This routine is called every 100ms. 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)) {
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 & AX25_COND_OWN_RX_BUSY)) {
ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
ax25->condition &= ~AX25_COND_ACK_PENDING;
if (!ax25->dama_slave)
ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
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 & AX25_COND_ACK_PENDING) {
ax25->condition &= ~AX25_COND_ACK_PENDING;
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) {
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
ax25_disconnect(ax25, ETIMEDOUT);
ax25_set_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, AX25_DISC, AX25_POLLON, AX25_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);
ax25->t2timer = 0;
if (ax25->sk != NULL) {
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = 0;
ax25->sk->shutdown |= SEND_SHUTDOWN;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 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_set_timer(ax25);
return;
}
if (!ax25_dev_is_dama_slave(ax25->device)) {
if (ax25->dama_slave)
ax25->dama_slave = 0;
ax25_t1_timeout(ax25);
}
}