LXR linux/net/lapb/lapb

   1/*
   2 *      LAPB release 002
   3 *
   4 *      This code REQUIRES 2.1.15 or higher/ NET3.038
   5 *
   6 *      This module:
   7 *              This module is free software; you can redistribute it and/or
   8 *              modify it under the terms of the GNU General Public License
   9 *              as published by the Free Software Foundation; either version
  10 *              2 of the License, or (at your option) any later version.
  11 *
  12 *      History
  13 *      LAPB 001        Jonathan Naylor Started Coding
  14 *      LAPB 002        Jonathan Naylor New timer architecture.
  15 */
  16
  17#include <linux/errno.h>
  18#include <linux/types.h>
  19#include <linux/socket.h>
  20#include <linux/in.h>
  21#include <linux/kernel.h>
  22#include <linux/jiffies.h>
  23#include <linux/timer.h>
  24#include <linux/string.h>
  25#include <linux/sockios.h>
  26#include <linux/net.h>
  27#include <linux/inet.h>
  28#include <linux/skbuff.h>
  29#include <net/sock.h>
  30#include <asm/uaccess.h>
  31#include <asm/system.h>
  32#include <linux/fcntl.h>
  33#include <linux/mm.h>
  34#include <linux/interrupt.h>
  35#include <net/lapb.h>
  36
  37static void lapb_t1timer_expiry(unsigned long);
  38static void lapb_t2timer_expiry(unsigned long);
  39
  40void lapb_start_t1timer(struct lapb_cb *lapb)
  41{
  42        del_timer(&lapb->t1timer);
  43
  44        lapb->t1timer.data     = (unsigned long)lapb;
  45        lapb->t1timer.function = &lapb_t1timer_expiry;
  46        lapb->t1timer.expires  = jiffies + lapb->t1;
  47
  48        add_timer(&lapb->t1timer);
  49}
  50
  51void lapb_start_t2timer(struct lapb_cb *lapb)
  52{
  53        del_timer(&lapb->t2timer);
  54
  55        lapb->t2timer.data     = (unsigned long)lapb;
  56        lapb->t2timer.function = &lapb_t2timer_expiry;
  57        lapb->t2timer.expires  = jiffies + lapb->t2;
  58
  59        add_timer(&lapb->t2timer);
  60}
  61
  62void lapb_stop_t1timer(struct lapb_cb *lapb)
  63{
  64        del_timer(&lapb->t1timer);
  65}
  66
  67void lapb_stop_t2timer(struct lapb_cb *lapb)
  68{
  69        del_timer(&lapb->t2timer);
  70}
  71
  72int lapb_t1timer_running(struct lapb_cb *lapb)
  73{
  74        return timer_pending(&lapb->t1timer);
  75}
  76
  77static void lapb_t2timer_expiry(unsigned long param)
  78{
  79        struct lapb_cb *lapb = (struct lapb_cb *)param;
  80
  81        if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
  82                lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
  83                lapb_timeout_response(lapb);
  84        }
  85}
  86
  87static void lapb_t1timer_expiry(unsigned long param)
  88{
  89        struct lapb_cb *lapb = (struct lapb_cb *)param;
  90
  91        switch (lapb->state) {
  92
  93                /*
  94                 *      If we are a DCE, keep going DM .. DM .. DM
  95                 */
  96                case LAPB_STATE_0:
  97                        if (lapb->mode & LAPB_DCE)
  98                                lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE);
  99                        break;
 100
 101                /*
 102                 *      Awaiting connection state, send SABM(E), up to N2 times.
 103                 */
 104                case LAPB_STATE_1:
 105                        if (lapb->n2count == lapb->n2) {
 106                                lapb_clear_queues(lapb);
 107                                lapb->state = LAPB_STATE_0;
 108                                lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
 109#if LAPB_DEBUG > 0
 110                                printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->dev);
 111#endif
 112                                return;
 113                        } else {
 114                                lapb->n2count++;
 115                                if (lapb->mode & LAPB_EXTENDED) {
 116#if LAPB_DEBUG > 1
 117                                        printk(KERN_DEBUG "lapb: (%p) S1 TX SABME(1)\n", lapb->dev);
 118#endif
 119                                        lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
 120                                } else {
 121#if LAPB_DEBUG > 1
 122                                        printk(KERN_DEBUG "lapb: (%p) S1 TX SABM(1)\n", lapb->dev);
 123#endif
 124                                        lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
 125                                }
 126                        }
 127                        break;
 128
 129                /*
 130                 *      Awaiting disconnection state, send DISC, up to N2 times.
 131                 */
 132                case LAPB_STATE_2:
 133                        if (lapb->n2count == lapb->n2) {
 134                                lapb_clear_queues(lapb);
 135                                lapb->state = LAPB_STATE_0;
 136                                lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT);
 137#if LAPB_DEBUG > 0
 138                                printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->dev);
 139#endif
 140                                return;
 141                        } else {
 142                                lapb->n2count++;
 143#if LAPB_DEBUG > 1
 144                                printk(KERN_DEBUG "lapb: (%p) S2 TX DISC(1)\n", lapb->dev);
 145#endif
 146                                lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
 147                        }
 148                        break;
 149
 150                /*
 151                 *      Data transfer state, restransmit I frames, up to N2 times.
 152                 */
 153                case LAPB_STATE_3:
 154                        if (lapb->n2count == lapb->n2) {
 155                                lapb_clear_queues(lapb);
 156                                lapb->state = LAPB_STATE_0;
 157                                lapb_stop_t2timer(lapb);
 158                                lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
 159#if LAPB_DEBUG > 0
 160                                printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->dev);
 161#endif
 162                                return;
 163                        } else {
 164                                lapb->n2count++;
 165                                lapb_requeue_frames(lapb);
 166                        }
 167                        break;
 168
 169                /*
 170                 *      Frame reject state, restransmit FRMR frames, up to N2 times.
 171                 */
 172                case LAPB_STATE_4:
 173                        if (lapb->n2count == lapb->n2) {
 174                                lapb_clear_queues(lapb);
 175                                lapb->state = LAPB_STATE_0;
 176                                lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
 177#if LAPB_DEBUG > 0
 178                                printk(KERN_DEBUG "lapb: (%p) S4 -> S0\n", lapb->dev);
 179#endif
 180                                return;
 181                        } else {
 182                                lapb->n2count++;
 183                                lapb_transmit_frmr(lapb);
 184                        }
 185                        break;
 186        }
 187
 188        lapb_start_t1timer(lapb);
 189}
 190