i386/linux-2.3.21/net/ax25/ax25_ds_timer.c

   1 /*
   2  *      AX.25 release 037
   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  *      AX.25 036       Jonathan(G4KLX) Cloned from ax25_timer.c.
  14  *                      Joerg(DL1BKE)   Added DAMA Slave Timeout timer
  15  *      AX.25 037       Jonathan(G4KLX) New timer architecture.
  16  */
  17
  18 #include <linux/config.h>
  19 #if defined(CONFIG_AX25_DAMA_SLAVE)
  20 #include <linux/errno.h>
  21 #include <linux/types.h>
  22 #include <linux/socket.h>
  23 #include <linux/in.h>
  24 #include <linux/kernel.h>
  25 #include <linux/sched.h>
  26 #include <linux/timer.h>
  27 #include <linux/string.h>
  28 #include <linux/sockios.h>
  29 #include <linux/net.h>
  30 #include <net/ax25.h>
  31 #include <linux/inet.h>
  32 #include <linux/netdevice.h>
  33 #include <linux/skbuff.h>
  34 #include <net/sock.h>
  35 #include <asm/uaccess.h>
  36 #include <asm/system.h>
  37 #include <linux/fcntl.h>
  38 #include <linux/mm.h>
  39 #include <linux/interrupt.h>
  40
  41 static void ax25_ds_timeout(unsigned long);
  42
  43 /*
  44  *      Add DAMA slave timeout timer to timer list.
  45  *      Unlike the connection based timers the timeout function gets
  46  *      triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT
  47  *      (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in
  48  *      1/10th of a second.
  49  */
  50
  51 static void ax25_ds_add_timer(ax25_dev *ax25_dev)
  52 {
  53         struct timer_list *t = &ax25_dev->dama.slave_timer;
  54         t->data         = (unsigned long) ax25_dev;
  55         t->function     = &ax25_ds_timeout;
  56         t->expires      = jiffies + HZ;
  57         add_timer(t);
  58 }
  59
  60 void ax25_ds_del_timer(ax25_dev *ax25_dev)
  61 {
  62         if (ax25_dev) del_timer(&ax25_dev->dama.slave_timer);
  63 }
  64
  65 void ax25_ds_set_timer(ax25_dev *ax25_dev)
  66 {
  67         if (ax25_dev == NULL)           /* paranoia */
  68                 return;
  69
  70         del_timer(&ax25_dev->dama.slave_timer);
  71         ax25_dev->dama.slave_timeout = ax25_dev->values[AX25_VALUES_DS_TIMEOUT] / 10;
  72         ax25_ds_add_timer(ax25_dev);
  73 }
  74
  75 /*
  76  *      DAMA Slave Timeout
  77  *      Silently discard all (slave) connections in case our master forgot us...
  78  */
  79
  80 static void ax25_ds_timeout(unsigned long arg)
  81 {
  82         ax25_dev *ax25_dev = (struct ax25_dev *) arg;
  83         ax25_cb *ax25;
  84
  85         if (ax25_dev == NULL || !ax25_dev->dama.slave)
  86                 return;                 /* Yikes! */
  87
  88         if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) {
  89                 ax25_ds_set_timer(ax25_dev);
  90                 return;
  91         }
  92
  93         for (ax25=ax25_list; ax25 != NULL; ax25 = ax25->next) {
  94                 if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE))
  95                         continue;
  96
  97                 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
  98                 ax25_disconnect(ax25, ETIMEDOUT);
  99         }
 100
 101         ax25_dev_dama_off(ax25_dev);
 102 }
 103
 104 void ax25_ds_heartbeat_expiry(ax25_cb *ax25)
 105 {
 106         switch (ax25->state) {
 107
 108                 case AX25_STATE_0:
 109                         /* Magic here: If we listen() and a new link dies before it
 110                            is accepted() it isn't 'dead' so doesn't get removed. */
 111                         if (ax25->sk == NULL || ax25->sk->destroy || (ax25->sk->state == TCP_LISTEN && ax25->sk->dead)) {
 112                                 ax25_destroy_socket(ax25);
 113                                 return;
 114                         }
 115                         break;
 116
 117                 case AX25_STATE_3:
 118                         /*
 119                          * Check the state of the receive buffer.
 120                          */
 121                         if (ax25->sk != NULL) {
 122                                 if (atomic_read(&ax25->sk->rmem_alloc) < (ax25->sk->rcvbuf / 2) &&
 123                                     (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
 124                                         ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
 125                                         ax25->condition &= ~AX25_COND_ACK_PENDING;
 126                                         break;
 127                                 }
 128                         }
 129                         break;
 130         }
 131
 132         ax25_start_heartbeat(ax25);
 133 }
 134
 135 /* dl1bke 960114: T3 works much like the IDLE timeout, but
 136  *                gets reloaded with every frame for this
 137  *                connection.
 138  */
 139 void ax25_ds_t3timer_expiry(ax25_cb *ax25)
 140 {
 141         ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 142         ax25_dama_off(ax25);
 143         ax25_disconnect(ax25, ETIMEDOUT);
 144 }
 145
 146 /* dl1bke 960228: close the connection when IDLE expires.
 147  *                unlike T3 this timer gets reloaded only on
 148  *                I frames.
 149  */
 150 void ax25_ds_idletimer_expiry(ax25_cb *ax25)
 151 {
 152         ax25_clear_queues(ax25);
 153
 154         ax25->n2count = 0;
 155         ax25->state = AX25_STATE_2;
 156
 157         ax25_calculate_t1(ax25);
 158         ax25_start_t1timer(ax25);
 159         ax25_stop_t3timer(ax25);
 160
 161         if (ax25->sk != NULL) {
 162                 ax25->sk->state     = TCP_CLOSE;
 163                 ax25->sk->err       = 0;
 164                 ax25->sk->shutdown |= SEND_SHUTDOWN;
 165                 if (!ax25->sk->dead)
 166                         ax25->sk->state_change(ax25->sk);
 167                 ax25->sk->dead      = 1;
 168         }
 169 }
 170
 171 /* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
 172  *                within the poll of any connected channel. Remember
 173  *                that we are not allowed to send anything unless we
 174  *                get polled by the Master.
 175  *
 176  *                Thus we'll have to do parts of our T1 handling in
 177  *                ax25_enquiry_response().
 178  */
 179 void ax25_ds_t1_timeout(ax25_cb *ax25)
 180 {
 181         switch (ax25->state) {
 182
 183                 case AX25_STATE_1:
 184                         if (ax25->n2count == ax25->n2) {
 185                                 if (ax25->modulus == AX25_MODULUS) {
 186                                         ax25_disconnect(ax25, ETIMEDOUT);
 187                                         return;
 188                                 } else {
 189                                         ax25->modulus = AX25_MODULUS;
 190                                         ax25->window  = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
 191                                         ax25->n2count = 0;
 192                                         ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
 193                                 }
 194                         } else {
 195                                 ax25->n2count++;
 196                                 if (ax25->modulus == AX25_MODULUS)
 197                                         ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
 198                                 else
 199                                         ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND);
 200                         }
 201                         break;
 202
 203                 case AX25_STATE_2:
 204                         if (ax25->n2count == ax25->n2) {
 205                                 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 206                                 ax25_disconnect(ax25, ETIMEDOUT);
 207                                 return;
 208                         } else {
 209                                 ax25->n2count++;
 210                         }
 211                         break;
 212
 213                 case AX25_STATE_3:
 214                         if (ax25->n2count == ax25->n2) {
 215                                 ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
 216                                 ax25_disconnect(ax25, ETIMEDOUT);
 217                                 return;
 218                         } else {
 219                                 ax25->n2count++;
 220                         }
 221                         break;
 222         }
 223
 224         ax25_calculate_t1(ax25);
 225         ax25_start_t1timer(ax25);
 226 }
 227
 228 #endif