net/ax25/ax25_std_subr.c

   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 <asm/system.h>
  25 #include <linux/fcntl.h>
  26 #include <linux/mm.h>
  27 #include <linux/interrupt.h>
  28
  29 /*
  30  * The following routines are taken from page 170 of the 7th ARRL Computer
  31  * Networking Conference paper, as is the whole state machine.
  32  */
  33
  34 void ax25_std_nr_error_recovery(ax25_cb *ax25)
  35 {
  36         ax25_std_establish_data_link(ax25);
  37 }
  38
  39 void ax25_std_establish_data_link(ax25_cb *ax25)
  40 {
  41         ax25->condition = 0x00;
  42         ax25->n2count   = 0;
  43
  44         if (ax25->modulus == AX25_MODULUS)
  45                 ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
  46         else
  47                 ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND);
  48
  49         ax25_calculate_t1(ax25);
  50         ax25_stop_idletimer(ax25);
  51         ax25_stop_t3timer(ax25);
  52         ax25_stop_t2timer(ax25);
  53         ax25_start_t1timer(ax25);
  54 }
  55
  56 void ax25_std_transmit_enquiry(ax25_cb *ax25)
  57 {
  58         if (ax25->condition & AX25_COND_OWN_RX_BUSY)
  59                 ax25_send_control(ax25, AX25_RNR, AX25_POLLON, AX25_COMMAND);
  60         else
  61                 ax25_send_control(ax25, AX25_RR, AX25_POLLON, AX25_COMMAND);
  62
  63         ax25->condition &= ~AX25_COND_ACK_PENDING;
  64
  65         ax25_calculate_t1(ax25);
  66         ax25_start_t1timer(ax25);
  67 }
  68
  69 void ax25_std_enquiry_response(ax25_cb *ax25)
  70 {
  71         if (ax25->condition & AX25_COND_OWN_RX_BUSY)
  72                 ax25_send_control(ax25, AX25_RNR, AX25_POLLON, AX25_RESPONSE);
  73         else
  74                 ax25_send_control(ax25, AX25_RR, AX25_POLLON, AX25_RESPONSE);
  75
  76         ax25->condition &= ~AX25_COND_ACK_PENDING;
  77 }
  78
  79 void ax25_std_timeout_response(ax25_cb *ax25)
  80 {
  81         if (ax25->condition & AX25_COND_OWN_RX_BUSY)
  82                 ax25_send_control(ax25, AX25_RNR, AX25_POLLOFF, AX25_RESPONSE);
  83         else
  84                 ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
  85
  86         ax25->condition &= ~AX25_COND_ACK_PENDING;
  87 }