2874c5fd28
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
123 lines
2.6 KiB
C
123 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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*
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* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
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*/
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/in.h>
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#include <linux/kernel.h>
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#include <linux/timer.h>
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#include <linux/string.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <linux/gfp.h>
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#include <net/ax25.h>
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#include <linux/inet.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <net/sock.h>
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#include <linux/fcntl.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <net/rose.h>
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/*
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* This procedure is passed a buffer descriptor for an iframe. It builds
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* the rest of the control part of the frame and then writes it out.
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*/
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static void rose_send_iframe(struct sock *sk, struct sk_buff *skb)
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{
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struct rose_sock *rose = rose_sk(sk);
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if (skb == NULL)
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return;
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skb->data[2] |= (rose->vr << 5) & 0xE0;
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skb->data[2] |= (rose->vs << 1) & 0x0E;
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rose_start_idletimer(sk);
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rose_transmit_link(skb, rose->neighbour);
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}
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void rose_kick(struct sock *sk)
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{
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struct rose_sock *rose = rose_sk(sk);
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struct sk_buff *skb, *skbn;
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unsigned short start, end;
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if (rose->state != ROSE_STATE_3)
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return;
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if (rose->condition & ROSE_COND_PEER_RX_BUSY)
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return;
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if (!skb_peek(&sk->sk_write_queue))
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return;
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start = (skb_peek(&rose->ack_queue) == NULL) ? rose->va : rose->vs;
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end = (rose->va + sysctl_rose_window_size) % ROSE_MODULUS;
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if (start == end)
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return;
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rose->vs = start;
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/*
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* Transmit data until either we're out of data to send or
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* the window is full.
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*/
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skb = skb_dequeue(&sk->sk_write_queue);
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do {
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if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
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skb_queue_head(&sk->sk_write_queue, skb);
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break;
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}
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skb_set_owner_w(skbn, sk);
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/*
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* Transmit the frame copy.
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*/
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rose_send_iframe(sk, skbn);
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rose->vs = (rose->vs + 1) % ROSE_MODULUS;
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/*
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* Requeue the original data frame.
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*/
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skb_queue_tail(&rose->ack_queue, skb);
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} while (rose->vs != end &&
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(skb = skb_dequeue(&sk->sk_write_queue)) != NULL);
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rose->vl = rose->vr;
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rose->condition &= ~ROSE_COND_ACK_PENDING;
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rose_stop_timer(sk);
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}
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/*
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* The following routines are taken from page 170 of the 7th ARRL Computer
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* Networking Conference paper, as is the whole state machine.
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*/
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void rose_enquiry_response(struct sock *sk)
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{
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struct rose_sock *rose = rose_sk(sk);
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if (rose->condition & ROSE_COND_OWN_RX_BUSY)
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rose_write_internal(sk, ROSE_RNR);
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else
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rose_write_internal(sk, ROSE_RR);
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rose->vl = rose->vr;
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rose->condition &= ~ROSE_COND_ACK_PENDING;
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rose_stop_timer(sk);
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}
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