linux/net/ax25/ax25_std_subr.c
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   1/*
   2 * This program is free software; you can redistribute it and/or modify
   3 * it under the terms of the GNU General Public License as published by
   4 * the Free Software Foundation; either version 2 of the License, or
   5 * (at your option) any later version.
   6 *
   7 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   8 */
   9#include <linux/errno.h>
  10#include <linux/types.h>
  11#include <linux/socket.h>
  12#include <linux/in.h>
  13#include <linux/kernel.h>
  14#include <linux/timer.h>
  15#include <linux/string.h>
  16#include <linux/sockios.h>
  17#include <linux/net.h>
  18#include <net/ax25.h>
  19#include <linux/inet.h>
  20#include <linux/netdevice.h>
  21#include <linux/skbuff.h>
  22#include <net/sock.h>
  23#include <asm/uaccess.h>
  24#include <linux/fcntl.h>
  25#include <linux/mm.h>
  26#include <linux/interrupt.h>
  27
  28/*
  29 * The following routines are taken from page 170 of the 7th ARRL Computer
  30 * Networking Conference paper, as is the whole state machine.
  31 */
  32
  33void ax25_std_nr_error_recovery(ax25_cb *ax25)
  34{
  35        ax25_std_establish_data_link(ax25);
  36}
  37
  38void ax25_std_establish_data_link(ax25_cb *ax25)
  39{
  40        ax25->condition = 0x00;
  41        ax25->n2count   = 0;
  42
  43        if (ax25->modulus == AX25_MODULUS)
  44                ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
  45        else
  46                ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND);
  47
  48        ax25_calculate_t1(ax25);
  49        ax25_stop_idletimer(ax25);
  50        ax25_stop_t3timer(ax25);
  51        ax25_stop_t2timer(ax25);
  52        ax25_start_t1timer(ax25);
  53}
  54
  55void ax25_std_transmit_enquiry(ax25_cb *ax25)
  56{
  57        if (ax25->condition & AX25_COND_OWN_RX_BUSY)
  58                ax25_send_control(ax25, AX25_RNR, AX25_POLLON, AX25_COMMAND);
  59        else
  60                ax25_send_control(ax25, AX25_RR, AX25_POLLON, AX25_COMMAND);
  61
  62        ax25->condition &= ~AX25_COND_ACK_PENDING;
  63
  64        ax25_calculate_t1(ax25);
  65        ax25_start_t1timer(ax25);
  66}
  67
  68void ax25_std_enquiry_response(ax25_cb *ax25)
  69{
  70        if (ax25->condition & AX25_COND_OWN_RX_BUSY)
  71                ax25_send_control(ax25, AX25_RNR, AX25_POLLON, AX25_RESPONSE);
  72        else
  73                ax25_send_control(ax25, AX25_RR, AX25_POLLON, AX25_RESPONSE);
  74
  75        ax25->condition &= ~AX25_COND_ACK_PENDING;
  76}
  77
  78void ax25_std_timeout_response(ax25_cb *ax25)
  79{
  80        if (ax25->condition & AX25_COND_OWN_RX_BUSY)
  81                ax25_send_control(ax25, AX25_RNR, AX25_POLLOFF, AX25_RESPONSE);
  82        else
  83                ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
  84
  85        ax25->condition &= ~AX25_COND_ACK_PENDING;
  86}
  87
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