net/lapb/lapb_timer.c

   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
  37 static void lapb_t1timer_expiry(unsigned long);
  38 static void lapb_t2timer_expiry(unsigned long);
  39
  40 void 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
  51 void 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
  62 void lapb_stop_t1timer(struct lapb_cb *lapb)
  63 {
  64         del_timer(&lapb->t1timer);
  65 }
  66
  67 void lapb_stop_t2timer(struct lapb_cb *lapb)
  68 {
  69         del_timer(&lapb->t2timer);
  70 }
  71
  72 int lapb_t1timer_running(struct lapb_cb *lapb)
  73 {
  74         return timer_pending(&lapb->t1timer);
  75 }
  76
  77 static 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
  87 static 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 }