cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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rose_out.c (2633B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *
      4 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
      5 */
      6#include <linux/errno.h>
      7#include <linux/types.h>
      8#include <linux/socket.h>
      9#include <linux/in.h>
     10#include <linux/kernel.h>
     11#include <linux/timer.h>
     12#include <linux/string.h>
     13#include <linux/sockios.h>
     14#include <linux/net.h>
     15#include <linux/gfp.h>
     16#include <net/ax25.h>
     17#include <linux/inet.h>
     18#include <linux/netdevice.h>
     19#include <linux/skbuff.h>
     20#include <net/sock.h>
     21#include <linux/fcntl.h>
     22#include <linux/mm.h>
     23#include <linux/interrupt.h>
     24#include <net/rose.h>
     25
     26/*
     27 *	This procedure is passed a buffer descriptor for an iframe. It builds
     28 *	the rest of the control part of the frame and then writes it out.
     29 */
     30static void rose_send_iframe(struct sock *sk, struct sk_buff *skb)
     31{
     32	struct rose_sock *rose = rose_sk(sk);
     33
     34	if (skb == NULL)
     35		return;
     36
     37	skb->data[2] |= (rose->vr << 5) & 0xE0;
     38	skb->data[2] |= (rose->vs << 1) & 0x0E;
     39
     40	rose_start_idletimer(sk);
     41
     42	rose_transmit_link(skb, rose->neighbour);
     43}
     44
     45void rose_kick(struct sock *sk)
     46{
     47	struct rose_sock *rose = rose_sk(sk);
     48	struct sk_buff *skb, *skbn;
     49	unsigned short start, end;
     50
     51	if (rose->state != ROSE_STATE_3)
     52		return;
     53
     54	if (rose->condition & ROSE_COND_PEER_RX_BUSY)
     55		return;
     56
     57	if (!skb_peek(&sk->sk_write_queue))
     58		return;
     59
     60	start = (skb_peek(&rose->ack_queue) == NULL) ? rose->va : rose->vs;
     61	end   = (rose->va + sysctl_rose_window_size) % ROSE_MODULUS;
     62
     63	if (start == end)
     64		return;
     65
     66	rose->vs = start;
     67
     68	/*
     69	 * Transmit data until either we're out of data to send or
     70	 * the window is full.
     71	 */
     72
     73	skb  = skb_dequeue(&sk->sk_write_queue);
     74
     75	do {
     76		if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
     77			skb_queue_head(&sk->sk_write_queue, skb);
     78			break;
     79		}
     80
     81		skb_set_owner_w(skbn, sk);
     82
     83		/*
     84		 * Transmit the frame copy.
     85		 */
     86		rose_send_iframe(sk, skbn);
     87
     88		rose->vs = (rose->vs + 1) % ROSE_MODULUS;
     89
     90		/*
     91		 * Requeue the original data frame.
     92		 */
     93		skb_queue_tail(&rose->ack_queue, skb);
     94
     95	} while (rose->vs != end &&
     96		 (skb = skb_dequeue(&sk->sk_write_queue)) != NULL);
     97
     98	rose->vl         = rose->vr;
     99	rose->condition &= ~ROSE_COND_ACK_PENDING;
    100
    101	rose_stop_timer(sk);
    102}
    103
    104/*
    105 * The following routines are taken from page 170 of the 7th ARRL Computer
    106 * Networking Conference paper, as is the whole state machine.
    107 */
    108
    109void rose_enquiry_response(struct sock *sk)
    110{
    111	struct rose_sock *rose = rose_sk(sk);
    112
    113	if (rose->condition & ROSE_COND_OWN_RX_BUSY)
    114		rose_write_internal(sk, ROSE_RNR);
    115	else
    116		rose_write_internal(sk, ROSE_RR);
    117
    118	rose->vl         = rose->vr;
    119	rose->condition &= ~ROSE_COND_ACK_PENDING;
    120
    121	rose_stop_timer(sk);
    122}