/*
* Given a fragment, queue it on the fragment queue and if the fragment
* is complete, send it back to ax25_rx_iframe.
*/
static int ax25_rx_fragment(ax25_cb *ax25, struct sk_buff *skb)
{
struct sk_buff *skbn, *skbo;
if (ax25->fragno != 0) {
if (!(*skb->data & AX25_SEG_FIRST)) {
if ((ax25->fragno - 1) == (*skb->data & AX25_SEG_REM)) {
/* Enqueue fragment */
ax25->fragno = *skb->data & AX25_SEG_REM;
skb_pull(skb, 1); /* skip fragno */
ax25->fraglen += skb->len;
skb_queue_tail(&ax25->frag_queue, skb);
/* Last fragment received ? */
if (ax25->fragno == 0) {
skbn = alloc_skb(AX25_MAX_HEADER_LEN +
ax25->fraglen,
GFP_ATOMIC);
if (!skbn) {
skb_queue_purge(&ax25->frag_queue);
return 1;
}
skb_reserve(skbn, AX25_MAX_HEADER_LEN);
skbn->dev = ax25->ax25_dev->dev;
skb_reset_network_header(skbn);
skb_reset_transport_header(skbn);
/* Copy data from the fragments */
while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL) {
skb_copy_from_linear_data(skbo,
skb_put(skbn, skbo->len),
skbo->len);
kfree_skb(skbo);
}
ax25->fraglen = 0;
if (ax25_rx_iframe(ax25, skbn) == 0)
kfree_skb(skbn);
}
return 1;
}
}
} else {
/* First fragment received */
if (*skb->data & AX25_SEG_FIRST) {
skb_queue_purge(&ax25->frag_queue);
ax25->fragno = *skb->data & AX25_SEG_REM;
skb_pull(skb, 1); /* skip fragno */
ax25->fraglen = skb->len;
skb_queue_tail(&ax25->frag_queue, skb);
return 1;
}
}
return 0;
}
/*
* Given a fragment, queue it on the fragment queue and if the fragment
* is complete, send it back to ax25_rx_iframe.
*/
static int ax25_rx_fragment(ax25_cb *ax25, struct sk_buff *skb)
{
struct sk_buff *skbn, *skbo;
if (ax25->fragno != 0) {
if (!(*skb->data & AX25_SEG_FIRST)) {
if ((ax25->fragno - 1) == (*skb->data & AX25_SEG_REM)) {
/* Enqueue fragment */
ax25->fragno = *skb->data & AX25_SEG_REM;
skb_pull(skb, 1); /* skip fragno */
ax25->fraglen += skb->len;
skb_queue_tail(&ax25->frag_queue, skb);
/* Last fragment received ? */
if (ax25->fragno == 0) {
if ((skbn = alloc_skb(AX25_MAX_HEADER_LEN + ax25->fraglen, GFP_ATOMIC)) == NULL) {
while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL)
kfree_skb(skbo, FREE_READ);
return 1;
}
skb_reserve(skbn, AX25_MAX_HEADER_LEN);
skbn->free = 1;
skbn->dev = ax25->device;
skbn->h.raw = skbn->data;
/* Copy data from the fragments */
while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL) {
memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len);
kfree_skb(skbo, FREE_READ);
}
ax25->fraglen = 0;
if (ax25_rx_iframe(ax25, skbn) == 0)
kfree_skb(skbn, FREE_READ);
}
return 1;
}
}
} else {
/* First fragment received */
if (*skb->data & AX25_SEG_FIRST) {
while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL)
kfree_skb(skbo, FREE_READ);
ax25->fragno = *skb->data & AX25_SEG_REM;
skb_pull(skb, 1); /* skip fragno */
ax25->fraglen = skb->len;
skb_queue_tail(&ax25->frag_queue, skb);
return 1;
}
}
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;
}