/*
* 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;
}
/*
* 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;
}
void ax25_std_timeout_response(ax25_cb *ax25)
{
if (ax25->condition & AX25_COND_OWN_RX_BUSY)
ax25_send_control(ax25, AX25_RNR, AX25_POLLOFF, AX25_RESPONSE);
else
ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
ax25->condition &= ~AX25_COND_ACK_PENDING;
}
void ax25_std_transmit_enquiry(ax25_cb *ax25)
{
if (ax25->condition & AX25_COND_OWN_RX_BUSY)
ax25_send_control(ax25, AX25_RNR, AX25_POLLON, AX25_COMMAND);
else
ax25_send_control(ax25, AX25_RR, AX25_POLLON, AX25_COMMAND);
ax25->condition &= ~AX25_COND_ACK_PENDING;
ax25_calculate_t1(ax25);
ax25_start_t1timer(ax25);
}
void ax25_std_establish_data_link(ax25_cb *ax25)
{
ax25->condition = 0x00;
ax25->n2count = 0;
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);
ax25_calculate_t1(ax25);
ax25_stop_idletimer(ax25);
ax25_stop_t3timer(ax25);
ax25_stop_t2timer(ax25);
ax25_start_t1timer(ax25);
}
void ax25_std_idletimer_expiry(ax25_cb *ax25)
{
ax25_clear_queues(ax25);
ax25->n2count = 0;
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
ax25->state = AX25_STATE_2;
ax25_calculate_t1(ax25);
ax25_start_t1timer(ax25);
ax25_stop_t2timer(ax25);
ax25_stop_t3timer(ax25);
if (ax25->sk != NULL) {
bh_lock_sock(ax25->sk);
ax25->sk->sk_state = TCP_CLOSE;
ax25->sk->sk_err = 0;
ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
if (!sock_flag(ax25->sk, SOCK_DEAD)) {
ax25->sk->sk_state_change(ax25->sk);
sock_set_flag(ax25->sk, SOCK_DEAD);
}
bh_unlock_sock(ax25->sk);
}
}
/* 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_std_heartbeat_expiry(ax25_cb *ax25)
{
struct sock *sk=ax25->sk;
if (sk)
bh_lock_sock(sk);
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 (!sk || sock_flag(sk, SOCK_DESTROY) ||
(sk->sk_state == TCP_LISTEN &&
sock_flag(sk, SOCK_DEAD))) {
if (sk) {
sock_hold(sk);
ax25_destroy_socket(ax25);
bh_unlock_sock(sk);
sock_put(sk);
} else
ax25_destroy_socket(ax25);
return;
}
break;
case AX25_STATE_3:
case AX25_STATE_4:
/*
* Check the state of the receive buffer.
*/
if (sk != NULL) {
if (atomic_read(&sk->sk_rmem_alloc) <
(sk->sk_rcvbuf / 2) &&
(ax25->condition & AX25_COND_OWN_RX_BUSY)) {
ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
ax25->condition &= ~AX25_COND_ACK_PENDING;
ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
break;
}
}
}
if (sk)
bh_unlock_sock(sk);
ax25_start_heartbeat(ax25);
}
static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
ax25_address *dev_addr, struct packet_type *ptype)
{
ax25_address src, dest, *next_digi = NULL;
int type = 0, mine = 0, dama;
struct sock *make, *sk;
ax25_digi dp, reverse_dp;
ax25_cb *ax25;
ax25_dev *ax25_dev;
/*
* Process the AX.25/LAPB frame.
*/
skb_reset_transport_header(skb);
if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
kfree_skb(skb);
return 0;
}
/*
* Parse the address header.
*/
if (ax25_addr_parse(skb->data, skb->len, &src, &dest, &dp, &type, &dama) == NULL) {
kfree_skb(skb);
return 0;
}
/*
* Ours perhaps ?
*/
if (dp.lastrepeat + 1 < dp.ndigi) /* Not yet digipeated completely */
next_digi = &dp.calls[dp.lastrepeat + 1];
/*
* Pull of the AX.25 headers leaving the CTRL/PID bytes
*/
skb_pull(skb, ax25_addr_size(&dp));
/* For our port addresses ? */
if (ax25cmp(&dest, dev_addr) == 0 && dp.lastrepeat + 1 == dp.ndigi)
mine = 1;
/* Also match on any registered callsign from L3/4 */
if (!mine && ax25_listen_mine(&dest, dev) && dp.lastrepeat + 1 == dp.ndigi)
mine = 1;
/* UI frame - bypass LAPB processing */
if ((*skb->data & ~0x10) == AX25_UI && dp.lastrepeat + 1 == dp.ndigi) {
skb_set_transport_header(skb, 2); /* skip control and pid */
ax25_send_to_raw(&dest, skb, skb->data[1]);
if (!mine && ax25cmp(&dest, (ax25_address *)dev->broadcast) != 0) {
kfree_skb(skb);
return 0;
}
/* Now we are pointing at the pid byte */
switch (skb->data[1]) {
case AX25_P_IP:
skb_pull(skb,2); /* drop PID/CTRL */
skb_reset_transport_header(skb);
skb_reset_network_header(skb);
skb->dev = dev;
skb->pkt_type = PACKET_HOST;
skb->protocol = htons(ETH_P_IP);
netif_rx(skb);
break;
case AX25_P_ARP:
skb_pull(skb,2);
skb_reset_transport_header(skb);
skb_reset_network_header(skb);
skb->dev = dev;
skb->pkt_type = PACKET_HOST;
skb->protocol = htons(ETH_P_ARP);
netif_rx(skb);
break;
case AX25_P_TEXT:
/* Now find a suitable dgram socket */
sk = ax25_get_socket(&dest, &src, SOCK_DGRAM);
if (sk != NULL) {
bh_lock_sock(sk);
if (atomic_read(&sk->sk_rmem_alloc) >=
sk->sk_rcvbuf) {
kfree_skb(skb);
} else {
/*
* Remove the control and PID.
*/
skb_pull(skb, 2);
if (sock_queue_rcv_skb(sk, skb) != 0)
kfree_skb(skb);
}
bh_unlock_sock(sk);
sock_put(sk);
} else {
kfree_skb(skb);
}
break;
default:
kfree_skb(skb); /* Will scan SOCK_AX25 RAW sockets */
break;
}
return 0;
}
/*
* Is connected mode supported on this device ?
* If not, should we DM the incoming frame (except DMs) or
* silently ignore them. For now we stay quiet.
*/
if (ax25_dev->values[AX25_VALUES_CONMODE] == 0) {
kfree_skb(skb);
return 0;
}
/* LAPB */
/* AX.25 state 1-4 */
ax25_digi_invert(&dp, &reverse_dp);
if ((ax25 = ax25_find_cb(&dest, &src, &reverse_dp, dev)) != NULL) {
/*
* Process the frame. If it is queued up internally it
* returns one otherwise we free it immediately. This
* routine itself wakes the user context layers so we do
* no further work
*/
if (ax25_process_rx_frame(ax25, skb, type, dama) == 0)
kfree_skb(skb);
ax25_cb_put(ax25);
return 0;
}
/* AX.25 state 0 (disconnected) */
/* a) received not a SABM(E) */
if ((*skb->data & ~AX25_PF) != AX25_SABM &&
(*skb->data & ~AX25_PF) != AX25_SABME) {
/*
* Never reply to a DM. Also ignore any connects for
* addresses that are not our interfaces and not a socket.
*/
if ((*skb->data & ~AX25_PF) != AX25_DM && mine)
ax25_return_dm(dev, &src, &dest, &dp);
kfree_skb(skb);
return 0;
}
/* b) received SABM(E) */
if (dp.lastrepeat + 1 == dp.ndigi)
sk = ax25_find_listener(&dest, 0, dev, SOCK_SEQPACKET);
else
sk = ax25_find_listener(next_digi, 1, dev, SOCK_SEQPACKET);
if (sk != NULL) {
bh_lock_sock(sk);
if (sk_acceptq_is_full(sk) ||
(make = ax25_make_new(sk, ax25_dev)) == NULL) {
if (mine)
ax25_return_dm(dev, &src, &dest, &dp);
kfree_skb(skb);
bh_unlock_sock(sk);
sock_put(sk);
return 0;
}
ax25 = ax25_sk(make);
skb_set_owner_r(skb, make);
skb_queue_head(&sk->sk_receive_queue, skb);
make->sk_state = TCP_ESTABLISHED;
sk->sk_ack_backlog++;
bh_unlock_sock(sk);
} else {
if (!mine) {
kfree_skb(skb);
return 0;
}
if ((ax25 = ax25_create_cb()) == NULL) {
ax25_return_dm(dev, &src, &dest, &dp);
kfree_skb(skb);
return 0;
}
ax25_fillin_cb(ax25, ax25_dev);
}
ax25->source_addr = dest;
ax25->dest_addr = src;
/*
* Sort out any digipeated paths.
*/
if (dp.ndigi && !ax25->digipeat &&
(ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
kfree_skb(skb);
ax25_destroy_socket(ax25);
if (sk)
sock_put(sk);
return 0;
}
if (dp.ndigi == 0) {
kfree(ax25->digipeat);
ax25->digipeat = NULL;
} else {
/* Reverse the source SABM's path */
memcpy(ax25->digipeat, &reverse_dp, sizeof(ax25_digi));
}
if ((*skb->data & ~AX25_PF) == AX25_SABME) {
ax25->modulus = AX25_EMODULUS;
ax25->window = ax25_dev->values[AX25_VALUES_EWINDOW];
} else {
ax25->modulus = AX25_MODULUS;
ax25->window = ax25_dev->values[AX25_VALUES_WINDOW];
}
ax25_send_control(ax25, AX25_UA, AX25_POLLON, AX25_RESPONSE);
#ifdef CONFIG_AX25_DAMA_SLAVE
if (dama && ax25->ax25_dev->values[AX25_VALUES_PROTOCOL] == AX25_PROTO_DAMA_SLAVE)
ax25_dama_on(ax25);
#endif
ax25->state = AX25_STATE_3;
ax25_cb_add(ax25);
ax25_start_heartbeat(ax25);
ax25_start_t3timer(ax25);
ax25_start_idletimer(ax25);
if (sk) {
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_data_ready(sk, skb->len);
sock_put(sk);
} else
kfree_skb(skb);
return 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;
}
/*
* 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 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);
}
}
/* 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 == MODULUS) {
#ifdef CONFIG_NETROM
nr_link_failed(&ax25->dest_addr, ax25->device);
#endif
ax25_clear_queues(ax25);
ax25->state = AX25_STATE_0;
if (ax25->sk != NULL) {
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = ETIMEDOUT;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 1;
}
} else {
ax25->modulus = MODULUS;
ax25->window = ax25_dev_get_value(ax25->device, AX25_VALUES_WINDOW);
ax25->n2count = 0;
ax25_send_control(ax25, SABM, ax25_dev_is_dama_slave(ax25->device)? POLLOFF : POLLON, C_COMMAND);
}
} else {
ax25->n2count++;
if (ax25->modulus == MODULUS) {
ax25_send_control(ax25, SABM, ax25_dev_is_dama_slave(ax25->device)? POLLOFF : POLLON, C_COMMAND);
} else {
ax25_send_control(ax25, SABME, ax25_dev_is_dama_slave(ax25->device)? POLLOFF : POLLON, C_COMMAND);
}
}
break;
case AX25_STATE_2:
if (ax25->n2count == ax25->n2) {
#ifdef CONFIG_NETROM
nr_link_failed(&ax25->dest_addr, ax25->device);
#endif
ax25_clear_queues(ax25);
ax25->state = AX25_STATE_0;
ax25_send_control(ax25, DISC, POLLON, C_COMMAND);
if (ax25->sk != NULL) {
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = ETIMEDOUT;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 1;
}
} else {
ax25->n2count++;
if (!ax25_dev_is_dama_slave(ax25->device))
ax25_send_control(ax25, DISC, POLLON, C_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) {
#ifdef CONFIG_NETROM
nr_link_failed(&ax25->dest_addr, ax25->device);
#endif
ax25_clear_queues(ax25);
ax25_send_control(ax25, DM, POLLON, C_RESPONSE);
ax25->state = AX25_STATE_0;
if (ax25->sk != NULL) {
if (ax25->sk->debug)
printk("Link Failure\n");
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = ETIMEDOUT;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 1;
}
} else {
ax25->n2count++;
if (!ax25->dama_slave)
ax25_transmit_enquiry(ax25);
}
break;
}
ax25->t1timer = ax25->t1 = ax25_calculate_t1(ax25);
ax25_set_timer(ax25);
}
