mirror of
https://github.com/torvalds/linux.git
synced 2024-11-01 09:41:44 +00:00
126 lines
2.8 KiB
C
126 lines
2.8 KiB
C
|
/*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License as published by
|
||
|
|
* the Free Software Foundation; either version 2 of the License, or
|
||
|
|
* (at your option) any later version.
|
||
|
|
*
|
||
|
|
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
|
||
|
|
*/
|
||
|
|
#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 <net/ax25.h>
|
||
|
|
#include <linux/inet.h>
|
||
|
|
#include <linux/netdevice.h>
|
||
|
|
#include <linux/skbuff.h>
|
||
|
|
#include <net/sock.h>
|
||
|
|
#include <asm/system.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);
|
||
|
|
}
|