mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
122 lines
2.6 KiB
122 lines
2.6 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* |
|
* Copyright (C) Jonathan Naylor G4KLX ([email protected]) |
|
*/ |
|
#include <linux/errno.h> |
|
#include <linux/types.h> |
|
#include <linux/socket.h> |
|
#include <linux/in.h> |
|
#include <linux/kernel.h> |
|
#include <linux/timer.h> |
|
#include <linux/string.h> |
|
#include <linux/sockios.h> |
|
#include <linux/net.h> |
|
#include <linux/gfp.h> |
|
#include <net/ax25.h> |
|
#include <linux/inet.h> |
|
#include <linux/netdevice.h> |
|
#include <linux/skbuff.h> |
|
#include <net/sock.h> |
|
#include <linux/fcntl.h> |
|
#include <linux/mm.h> |
|
#include <linux/interrupt.h> |
|
#include <net/rose.h> |
|
|
|
/* |
|
* This procedure is passed a buffer descriptor for an iframe. It builds |
|
* the rest of the control part of the frame and then writes it out. |
|
*/ |
|
static void rose_send_iframe(struct sock *sk, struct sk_buff *skb) |
|
{ |
|
struct rose_sock *rose = rose_sk(sk); |
|
|
|
if (skb == NULL) |
|
return; |
|
|
|
skb->data[2] |= (rose->vr << 5) & 0xE0; |
|
skb->data[2] |= (rose->vs << 1) & 0x0E; |
|
|
|
rose_start_idletimer(sk); |
|
|
|
rose_transmit_link(skb, rose->neighbour); |
|
} |
|
|
|
void rose_kick(struct sock *sk) |
|
{ |
|
struct rose_sock *rose = rose_sk(sk); |
|
struct sk_buff *skb, *skbn; |
|
unsigned short start, end; |
|
|
|
if (rose->state != ROSE_STATE_3) |
|
return; |
|
|
|
if (rose->condition & ROSE_COND_PEER_RX_BUSY) |
|
return; |
|
|
|
if (!skb_peek(&sk->sk_write_queue)) |
|
return; |
|
|
|
start = (skb_peek(&rose->ack_queue) == NULL) ? rose->va : rose->vs; |
|
end = (rose->va + sysctl_rose_window_size) % ROSE_MODULUS; |
|
|
|
if (start == end) |
|
return; |
|
|
|
rose->vs = start; |
|
|
|
/* |
|
* Transmit data until either we're out of data to send or |
|
* the window is full. |
|
*/ |
|
|
|
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. |
|
*/ |
|
rose_send_iframe(sk, skbn); |
|
|
|
rose->vs = (rose->vs + 1) % ROSE_MODULUS; |
|
|
|
/* |
|
* Requeue the original data frame. |
|
*/ |
|
skb_queue_tail(&rose->ack_queue, skb); |
|
|
|
} while (rose->vs != end && |
|
(skb = skb_dequeue(&sk->sk_write_queue)) != NULL); |
|
|
|
rose->vl = rose->vr; |
|
rose->condition &= ~ROSE_COND_ACK_PENDING; |
|
|
|
rose_stop_timer(sk); |
|
} |
|
|
|
/* |
|
* The following routines are taken from page 170 of the 7th ARRL Computer |
|
* Networking Conference paper, as is the whole state machine. |
|
*/ |
|
|
|
void rose_enquiry_response(struct sock *sk) |
|
{ |
|
struct rose_sock *rose = rose_sk(sk); |
|
|
|
if (rose->condition & ROSE_COND_OWN_RX_BUSY) |
|
rose_write_internal(sk, ROSE_RNR); |
|
else |
|
rose_write_internal(sk, ROSE_RR); |
|
|
|
rose->vl = rose->vr; |
|
rose->condition &= ~ROSE_COND_ACK_PENDING; |
|
|
|
rose_stop_timer(sk); |
|
}
|
|
|