void nr_transmit_buffer(struct sock *sk, struct sk_buff *skb)
{
struct nr_sock *nr = nr_sk(sk);
unsigned char *dptr;
/*
* Add the protocol byte and network header.
*/
dptr = skb_push(skb, NR_NETWORK_LEN);
memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
dptr[6] &= ~AX25_CBIT;
dptr[6] &= ~AX25_EBIT;
dptr[6] |= AX25_SSSID_SPARE;
dptr += AX25_ADDR_LEN;
memcpy(dptr, &nr->dest_addr, AX25_ADDR_LEN);
dptr[6] &= ~AX25_CBIT;
dptr[6] |= AX25_EBIT;
dptr[6] |= AX25_SSSID_SPARE;
dptr += AX25_ADDR_LEN;
*dptr++ = sysctl_netrom_network_ttl_initialiser;
if (!nr_route_frame(skb, NULL)) {
kfree_skb(skb);
nr_disconnect(sk, ENETUNREACH);
}
}
static void nr_idletimer_expiry(unsigned long param)
{
struct sock *sk = (struct sock *)param;
struct nr_sock *nr = nr_sk(sk);
bh_lock_sock(sk);
nr_clear_queues(sk);
nr->n2count = 0;
nr_write_internal(sk, NR_DISCREQ);
nr->state = NR_STATE_2;
nr_start_t1timer(sk);
nr_stop_t2timer(sk);
nr_stop_t4timer(sk);
sk->sk_state = TCP_CLOSE;
sk->sk_err = 0;
sk->sk_shutdown |= SEND_SHUTDOWN;
if (!sock_flag(sk, SOCK_DEAD)) {
sk->sk_state_change(sk);
sock_set_flag(sk, SOCK_DEAD);
}
bh_unlock_sock(sk);
}
void nr_start_idletimer(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);
if (nr->idle > 0)
mod_timer(&nr->idletimer, jiffies + nr->idle);
}
/* Higher level upcall for a LAPB frame - called with sk locked */
int nr_process_rx_frame(struct sock *sk, struct sk_buff *skb)
{
struct nr_sock *nr = nr_sk(sk);
int queued = 0, frametype;
if (nr->state == NR_STATE_0)
return 0;
frametype = skb->data[19];
switch (nr->state) {
case NR_STATE_1:
queued = nr_state1_machine(sk, skb, frametype);
break;
case NR_STATE_2:
queued = nr_state2_machine(sk, skb, frametype);
break;
case NR_STATE_3:
queued = nr_state3_machine(sk, skb, frametype);
break;
}
nr_kick(sk);
return queued;
}
static void nr_t4timer_expiry(unsigned long param)
{
struct sock *sk = (struct sock *)param;
bh_lock_sock(sk);
nr_sk(sk)->condition &= ~NR_COND_PEER_RX_BUSY;
bh_unlock_sock(sk);
}
/*
* This routine purges all of the queues of frames.
*/
void nr_clear_queues(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);
skb_queue_purge(&sk->sk_write_queue);
skb_queue_purge(&nr->ack_queue);
skb_queue_purge(&nr->reseq_queue);
skb_queue_purge(&nr->frag_queue);
}
/*
* Kill all bound sockets on a dropped device.
*/
static void nr_kill_by_device(struct net_device *dev)
{
struct sock *s;
spin_lock_bh(&nr_list_lock);
sk_for_each(s, &nr_list)
if (nr_sk(s)->device == dev)
nr_disconnect(s, ENETUNREACH);
spin_unlock_bh(&nr_list_lock);
}
static void nr_t2timer_expiry(unsigned long param)
{
struct sock *sk = (struct sock *)param;
struct nr_sock *nr = nr_sk(sk);
bh_lock_sock(sk);
if (nr->condition & NR_COND_ACK_PENDING) {
nr->condition &= ~NR_COND_ACK_PENDING;
nr_enquiry_response(sk);
}
bh_unlock_sock(sk);
}
/*
* Validate that the value of nr is between va and vs. Return true or
* false for testing.
*/
int nr_validate_nr(struct sock *sk, unsigned short nr)
{
struct nr_sock *nrom = nr_sk(sk);
unsigned short vc = nrom->va;
while (vc != nrom->vs) {
if (nr == vc) return 1;
vc = (vc + 1) % NR_MODULUS;
}
return nr == nrom->vs;
}
/*
* Requeue all the un-ack-ed frames on the output queue to be picked
* up by nr_kick called from the timer. This arrangement handles the
* possibility of an empty output queue.
*/
void nr_requeue_frames(struct sock *sk)
{
struct sk_buff *skb, *skb_prev = NULL;
while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) {
if (skb_prev == NULL)
skb_queue_head(&sk->sk_write_queue, skb);
else
skb_append(skb_prev, skb, &sk->sk_write_queue);
skb_prev = skb;
}
}
/*
* Check that ns is within the receive window.
*/
int nr_in_rx_window(struct sock *sk, unsigned short ns)
{
struct nr_sock *nr = nr_sk(sk);
unsigned short vc = nr->vr;
unsigned short vt = (nr->vl + nr->window) % NR_MODULUS;
while (vc != vt) {
if (ns == vc) return 1;
vc = (vc + 1) % NR_MODULUS;
}
return 0;
}
void nr_init_timers(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);
setup_timer(&nr->t1timer, nr_t1timer_expiry, (unsigned long)sk);
setup_timer(&nr->t2timer, nr_t2timer_expiry, (unsigned long)sk);
setup_timer(&nr->t4timer, nr_t4timer_expiry, (unsigned long)sk);
setup_timer(&nr->idletimer, nr_idletimer_expiry, (unsigned long)sk);
/* initialized by sock_init_data */
sk->sk_timer.data = (unsigned long)sk;
sk->sk_timer.function = &nr_heartbeat_expiry;
}
void nr_establish_data_link(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);
nr->condition = 0x00;
nr->n2count = 0;
nr_write_internal(sk, NR_CONNREQ);
nr_stop_t2timer(sk);
nr_stop_t4timer(sk);
nr_stop_idletimer(sk);
nr_start_t1timer(sk);
}
void nr_frames_acked(struct sock *sk, unsigned short nr)
{
struct nr_sock *nrom = nr_sk(sk);
struct sk_buff *skb;
if (nrom->va != nr) {
while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) {
skb = skb_dequeue(&nrom->ack_queue);
kfree_skb(skb);
nrom->va = (nrom->va + 1) % NR_MODULUS;
}
}
}
void nr_check_iframes_acked(struct sock *sk, unsigned short nr)
{
struct nr_sock *nrom = nr_sk(sk);
if (nrom->vs == nr) {
nr_frames_acked(sk, nr);
nr_stop_t1timer(sk);
nrom->n2count = 0;
} else {
if (nrom->va != nr) {
nr_frames_acked(sk, nr);
nr_start_t1timer(sk);
}
}
}
static void nr_send_iframe(struct sock *sk, struct sk_buff *skb)
{
struct nr_sock *nr = nr_sk(sk);
if (skb == NULL)
return;
skb->data[2] = nr->vs;
skb->data[3] = nr->vr;
if (nr->condition & NR_COND_OWN_RX_BUSY)
skb->data[4] |= NR_CHOKE_FLAG;
nr_start_idletimer(sk);
nr_transmit_buffer(sk, skb);
}
void nr_enquiry_response(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);
int frametype = NR_INFOACK;
if (nr->condition & NR_COND_OWN_RX_BUSY) {
frametype |= NR_CHOKE_FLAG;
} else {
if (skb_peek(&nr->reseq_queue) != NULL)
frametype |= NR_NAK_FLAG;
}
nr_write_internal(sk, frametype);
nr->vl = nr->vr;
nr->condition &= ~NR_COND_ACK_PENDING;
}
static void nr_t1timer_expiry(unsigned long param)
{
struct sock *sk = (struct sock *)param;
struct nr_sock *nr = nr_sk(sk);
bh_lock_sock(sk);
switch (nr->state) {
case NR_STATE_1:
if (nr->n2count == nr->n2) {
nr_disconnect(sk, ETIMEDOUT);
bh_unlock_sock(sk);
return;
} else {
nr->n2count++;
nr_write_internal(sk, NR_CONNREQ);
}
break;
case NR_STATE_2:
if (nr->n2count == nr->n2) {
nr_disconnect(sk, ETIMEDOUT);
bh_unlock_sock(sk);
return;
} else {
nr->n2count++;
nr_write_internal(sk, NR_DISCREQ);
}
break;
case NR_STATE_3:
if (nr->n2count == nr->n2) {
nr_disconnect(sk, ETIMEDOUT);
bh_unlock_sock(sk);
return;
} else {
nr->n2count++;
nr_requeue_frames(sk);
}
break;
}
nr_start_t1timer(sk);
bh_unlock_sock(sk);
}
void nr_disconnect(struct sock *sk, int reason)
{
nr_stop_t1timer(sk);
nr_stop_t2timer(sk);
nr_stop_t4timer(sk);
nr_stop_idletimer(sk);
nr_clear_queues(sk);
nr_sk(sk)->state = NR_STATE_0;
sk->sk_state = TCP_CLOSE;
sk->sk_err = reason;
sk->sk_shutdown |= SEND_SHUTDOWN;
if (!sock_flag(sk, SOCK_DEAD)) {
sk->sk_state_change(sk);
sock_set_flag(sk, SOCK_DEAD);
}
}
/*
* State machine for state 1, Awaiting Connection State.
* The handling of the timer(s) is in file nr_timer.c.
* Handling of state 0 and connection release is in netrom.c.
*/
static int nr_state1_machine(struct sock *sk, struct sk_buff *skb,
int frametype)
{
switch (frametype) {
case NR_CONNACK: {
struct nr_sock *nr = nr_sk(sk);
nr_stop_t1timer(sk);
nr_start_idletimer(sk);
nr->your_index = skb->data[17];
nr->your_id = skb->data[18];
nr->vs = 0;
nr->va = 0;
nr->vr = 0;
nr->vl = 0;
nr->state = NR_STATE_3;
nr->n2count = 0;
nr->window = skb->data[20];
sk->sk_state = TCP_ESTABLISHED;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_state_change(sk);
break;
}
case NR_CONNACK | NR_CHOKE_FLAG:
nr_disconnect(sk, ECONNREFUSED);
break;
case NR_RESET:
if (sysctl_netrom_reset_circuit)
nr_disconnect(sk, ECONNRESET);
break;
default:
break;
}
return 0;
}
static void nr_heartbeat_expiry(unsigned long param)
{
struct sock *sk = (struct sock *)param;
struct nr_sock *nr = nr_sk(sk);
bh_lock_sock(sk);
switch (nr->state) {
case NR_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))) {
sock_hold(sk);
bh_unlock_sock(sk);
nr_destroy_socket(sk);
sock_put(sk);
return;
}
break;
case NR_STATE_3:
/*
* Check for the state of the receive buffer.
*/
if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
(nr->condition & NR_COND_OWN_RX_BUSY)) {
nr->condition &= ~NR_COND_OWN_RX_BUSY;
nr->condition &= ~NR_COND_ACK_PENDING;
nr->vl = nr->vr;
nr_write_internal(sk, NR_INFOACK);
break;
}
break;
}
nr_start_heartbeat(sk);
bh_unlock_sock(sk);
}
void nr_send_nak_frame(struct sock *sk)
{
struct sk_buff *skb, *skbn;
struct nr_sock *nr = nr_sk(sk);
if ((skb = skb_peek(&nr->ack_queue)) == NULL)
return;
if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL)
return;
skbn->data[2] = nr->va;
skbn->data[3] = nr->vr;
if (nr->condition & NR_COND_OWN_RX_BUSY)
skbn->data[4] |= NR_CHOKE_FLAG;
nr_transmit_buffer(sk, skbn);
nr->condition &= ~NR_COND_ACK_PENDING;
nr->vl = nr->vr;
nr_stop_t1timer(sk);
}
static int nr_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
{
struct sk_buff *skbo, *skbn = skb;
struct nr_sock *nr = nr_sk(sk);
skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
nr_start_idletimer(sk);
if (more) {
nr->fraglen += skb->len;
skb_queue_tail(&nr->frag_queue, skb);
return 0;
}
if (!more && nr->fraglen > 0) { /* End of fragment */
nr->fraglen += skb->len;
skb_queue_tail(&nr->frag_queue, skb);
if ((skbn = alloc_skb(nr->fraglen, GFP_ATOMIC)) == NULL)
return 1;
skb_reset_transport_header(skbn);
while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
skb_copy_from_linear_data(skbo,
skb_put(skbn, skbo->len),
skbo->len);
kfree_skb(skbo);
}
nr->fraglen = 0;
}
return sock_queue_rcv_skb(sk, skbn);
}
/*
* State machine for state 3, Connected State.
* The handling of the timer(s) is in file nr_timer.c
* Handling of state 0 and connection release is in netrom.c.
*/
static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
struct nr_sock *nrom = nr_sk(sk);
struct sk_buff_head temp_queue;
struct sk_buff *skbn;
unsigned short save_vr;
unsigned short nr, ns;
int queued = 0;
nr = skb->data[18];
ns = skb->data[17];
switch (frametype) {
case NR_CONNREQ:
nr_write_internal(sk, NR_CONNACK);
break;
case NR_DISCREQ:
nr_write_internal(sk, NR_DISCACK);
nr_disconnect(sk, 0);
break;
case NR_CONNACK | NR_CHOKE_FLAG:
case NR_DISCACK:
nr_disconnect(sk, ECONNRESET);
break;
case NR_INFOACK:
case NR_INFOACK | NR_CHOKE_FLAG:
case NR_INFOACK | NR_NAK_FLAG:
case NR_INFOACK | NR_NAK_FLAG | NR_CHOKE_FLAG:
if (frametype & NR_CHOKE_FLAG) {
nrom->condition |= NR_COND_PEER_RX_BUSY;
nr_start_t4timer(sk);
} else {
nrom->condition &= ~NR_COND_PEER_RX_BUSY;
nr_stop_t4timer(sk);
}
if (!nr_validate_nr(sk, nr)) {
break;
}
if (frametype & NR_NAK_FLAG) {
nr_frames_acked(sk, nr);
nr_send_nak_frame(sk);
} else {
if (nrom->condition & NR_COND_PEER_RX_BUSY) {
nr_frames_acked(sk, nr);
} else {
nr_check_iframes_acked(sk, nr);
}
}
break;
case NR_INFO:
case NR_INFO | NR_NAK_FLAG:
case NR_INFO | NR_CHOKE_FLAG:
case NR_INFO | NR_MORE_FLAG:
case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG:
case NR_INFO | NR_CHOKE_FLAG | NR_MORE_FLAG:
case NR_INFO | NR_NAK_FLAG | NR_MORE_FLAG:
case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG | NR_MORE_FLAG:
if (frametype & NR_CHOKE_FLAG) {
nrom->condition |= NR_COND_PEER_RX_BUSY;
nr_start_t4timer(sk);
} else {
nrom->condition &= ~NR_COND_PEER_RX_BUSY;
nr_stop_t4timer(sk);
}
if (nr_validate_nr(sk, nr)) {
if (frametype & NR_NAK_FLAG) {
nr_frames_acked(sk, nr);
nr_send_nak_frame(sk);
} else {
if (nrom->condition & NR_COND_PEER_RX_BUSY) {
nr_frames_acked(sk, nr);
} else {
nr_check_iframes_acked(sk, nr);
}
}
}
queued = 1;
skb_queue_head(&nrom->reseq_queue, skb);
if (nrom->condition & NR_COND_OWN_RX_BUSY)
break;
skb_queue_head_init(&temp_queue);
do {
save_vr = nrom->vr;
while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) {
ns = skbn->data[17];
if (ns == nrom->vr) {
if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) {
nrom->vr = (nrom->vr + 1) % NR_MODULUS;
} else {
nrom->condition |= NR_COND_OWN_RX_BUSY;
skb_queue_tail(&temp_queue, skbn);
}
} else if (nr_in_rx_window(sk, ns)) {
skb_queue_tail(&temp_queue, skbn);
} else {
kfree_skb(skbn);
}
}
while ((skbn = skb_dequeue(&temp_queue)) != NULL) {
skb_queue_tail(&nrom->reseq_queue, skbn);
}
} while (save_vr != nrom->vr);
/*
* Window is full, ack it immediately.
*/
if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) {
nr_enquiry_response(sk);
} else {
if (!(nrom->condition & NR_COND_ACK_PENDING)) {
nrom->condition |= NR_COND_ACK_PENDING;
nr_start_t2timer(sk);
}
}
break;
case NR_RESET:
if (sysctl_netrom_reset_circuit)
nr_disconnect(sk, ECONNRESET);
break;
default:
break;
}
return queued;
}
/*
* This routine is called when the HDLC layer internally generates a
* control frame.
*/
void nr_write_internal(struct sock *sk, int frametype)
{
struct nr_sock *nr = nr_sk(sk);
struct sk_buff *skb;
unsigned char *dptr;
int len, timeout;
len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
switch (frametype & 0x0F) {
case NR_CONNREQ:
len += 17;
break;
case NR_CONNACK:
len += (nr->bpqext) ? 2 : 1;
break;
case NR_DISCREQ:
case NR_DISCACK:
case NR_INFOACK:
break;
default:
;
return;
}
if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
return;
/*
* Space for AX.25 and NET/ROM network header
*/
skb_reserve(skb, NR_NETWORK_LEN);
dptr = skb_put(skb, skb_tailroom(skb));
switch (frametype & 0x0F) {
case NR_CONNREQ:
timeout = nr->t1 / HZ;
*dptr++ = nr->my_index;
*dptr++ = nr->my_id;
*dptr++ = 0;
*dptr++ = 0;
*dptr++ = frametype;
*dptr++ = nr->window;
memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN);
dptr[6] &= ~AX25_CBIT;
dptr[6] &= ~AX25_EBIT;
dptr[6] |= AX25_SSSID_SPARE;
dptr += AX25_ADDR_LEN;
memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
dptr[6] &= ~AX25_CBIT;
dptr[6] &= ~AX25_EBIT;
dptr[6] |= AX25_SSSID_SPARE;
dptr += AX25_ADDR_LEN;
*dptr++ = timeout % 256;
*dptr++ = timeout / 256;
break;
case NR_CONNACK:
*dptr++ = nr->your_index;
*dptr++ = nr->your_id;
*dptr++ = nr->my_index;
*dptr++ = nr->my_id;
*dptr++ = frametype;
*dptr++ = nr->window;
if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
break;
case NR_DISCREQ:
case NR_DISCACK:
*dptr++ = nr->your_index;
*dptr++ = nr->your_id;
*dptr++ = 0;
*dptr++ = 0;
*dptr++ = frametype;
break;
case NR_INFOACK:
*dptr++ = nr->your_index;
*dptr++ = nr->your_id;
*dptr++ = 0;
*dptr++ = nr->vr;
*dptr++ = frametype;
break;
}
nr_transmit_buffer(sk, skb);
}
int nr_t1timer_running(struct sock *sk)
{
return timer_pending(&nr_sk(sk)->t1timer);
}
void nr_stop_idletimer(struct sock *sk)
{
del_timer(&nr_sk(sk)->idletimer);
}
void nr_stop_t4timer(struct sock *sk)
{
del_timer(&nr_sk(sk)->t4timer);
}
void nr_start_t4timer(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);
mod_timer(&nr->t4timer, jiffies + nr->t4);
}
void nr_kick(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);
struct sk_buff *skb, *skbn;
unsigned short start, end;
if (nr->state != NR_STATE_3)
return;
if (nr->condition & NR_COND_PEER_RX_BUSY)
return;
if (!skb_peek(&sk->sk_write_queue))
return;
start = (skb_peek(&nr->ack_queue) == NULL) ? nr->va : nr->vs;
end = (nr->va + nr->window) % NR_MODULUS;
if (start == end)
return;
nr->vs = start;
/*
* Transmit data until either we're out of data to send or
* the window is full.
*/
/*
* Dequeue the frame and copy it.
*/
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.
*/
nr_send_iframe(sk, skbn);
nr->vs = (nr->vs + 1) % NR_MODULUS;
/*
* Requeue the original data frame.
*/
skb_queue_tail(&nr->ack_queue, skb);
} while (nr->vs != end &&
(skb = skb_dequeue(&sk->sk_write_queue)) != NULL);
nr->vl = nr->vr;
nr->condition &= ~NR_COND_ACK_PENDING;
if (!nr_t1timer_running(sk))
nr_start_t1timer(sk);
}
