linux/net/ax25/ax25_ds_timer.c
<<
>>
Prefs
   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 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
   9 */
  10#include <linux/errno.h>
  11#include <linux/types.h>
  12#include <linux/socket.h>
  13#include <linux/spinlock.h>
  14#include <linux/in.h>
  15#include <linux/kernel.h>
  16#include <linux/jiffies.h>
  17#include <linux/timer.h>
  18#include <linux/string.h>
  19#include <linux/sockios.h>
  20#include <linux/net.h>
  21#include <net/tcp_states.h>
  22#include <net/ax25.h>
  23#include <linux/inet.h>
  24#include <linux/netdevice.h>
  25#include <linux/skbuff.h>
  26#include <net/sock.h>
  27#include <asm/uaccess.h>
  28#include <linux/fcntl.h>
  29#include <linux/mm.h>
  30#include <linux/interrupt.h>
  31
  32static void ax25_ds_timeout(unsigned long);
  33
  34/*
  35 *      Add DAMA slave timeout timer to timer list.
  36 *      Unlike the connection based timers the timeout function gets
  37 *      triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT
  38 *      (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in
  39 *      1/10th of a second.
  40 */
  41
  42void ax25_ds_setup_timer(ax25_dev *ax25_dev)
  43{
  44        setup_timer(&ax25_dev->dama.slave_timer, ax25_ds_timeout,
  45                    (unsigned long)ax25_dev);
  46}
  47
  48void ax25_ds_del_timer(ax25_dev *ax25_dev)
  49{
  50        if (ax25_dev)
  51                del_timer(&ax25_dev->dama.slave_timer);
  52}
  53
  54void ax25_ds_set_timer(ax25_dev *ax25_dev)
  55{
  56        if (ax25_dev == NULL)           /* paranoia */
  57                return;
  58
  59        ax25_dev->dama.slave_timeout =
  60                msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10;
  61        mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ);
  62}
  63
  64/*
  65 *      DAMA Slave Timeout
  66 *      Silently discard all (slave) connections in case our master forgot us...
  67 */
  68
  69static void ax25_ds_timeout(unsigned long arg)
  70{
  71        ax25_dev *ax25_dev = (struct ax25_dev *) arg;
  72        ax25_cb *ax25;
  73        struct hlist_node *node;
  74
  75        if (ax25_dev == NULL || !ax25_dev->dama.slave)
  76                return;                 /* Yikes! */
  77
  78        if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) {
  79                ax25_ds_set_timer(ax25_dev);
  80                return;
  81        }
  82
  83        spin_lock(&ax25_list_lock);
  84        ax25_for_each(ax25, node, &ax25_list) {
  85                if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE))
  86                        continue;
  87
  88                ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
  89                ax25_disconnect(ax25, ETIMEDOUT);
  90        }
  91        spin_unlock(&ax25_list_lock);
  92
  93        ax25_dev_dama_off(ax25_dev);
  94}
  95
  96void ax25_ds_heartbeat_expiry(ax25_cb *ax25)
  97{
  98        struct sock *sk=ax25->sk;
  99
 100        if (sk)
 101                bh_lock_sock(sk);
 102
 103        switch (ax25->state) {
 104
 105        case AX25_STATE_0:
 106                /* Magic here: If we listen() and a new link dies before it
 107                   is accepted() it isn't 'dead' so doesn't get removed. */
 108                if (!sk || sock_flag(sk, SOCK_DESTROY) ||
 109                    (sk->sk_state == TCP_LISTEN &&
 110                     sock_flag(sk, SOCK_DEAD))) {
 111                        if (sk) {
 112                                sock_hold(sk);
 113                                ax25_destroy_socket(ax25);
 114                                bh_unlock_sock(sk);
 115                                sock_put(sk);
 116                        } else
 117                                ax25_destroy_socket(ax25);
 118                        return;
 119                }
 120                break;
 121
 122        case AX25_STATE_3:
 123                /*
 124                 * Check the state of the receive buffer.
 125                 */
 126                if (sk != NULL) {
 127                        if (atomic_read(&sk->sk_rmem_alloc) <
 128                            (sk->sk_rcvbuf >> 1) &&
 129                            (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
 130                                ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
 131                                ax25->condition &= ~AX25_COND_ACK_PENDING;
 132                                break;
 133                        }
 134                }
 135                break;
 136        }
 137
 138        if (sk)
 139                bh_unlock_sock(sk);
 140
 141        ax25_start_heartbeat(ax25);
 142}
 143
 144/* dl1bke 960114: T3 works much like the IDLE timeout, but
 145 *                gets reloaded with every frame for this
 146 *                connection.
 147 */
 148void ax25_ds_t3timer_expiry(ax25_cb *ax25)
 149{
 150        ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 151        ax25_dama_off(ax25);
 152        ax25_disconnect(ax25, ETIMEDOUT);
 153}
 154
 155/* dl1bke 960228: close the connection when IDLE expires.
 156 *                unlike T3 this timer gets reloaded only on
 157 *                I frames.
 158 */
 159void ax25_ds_idletimer_expiry(ax25_cb *ax25)
 160{
 161        ax25_clear_queues(ax25);
 162
 163        ax25->n2count = 0;
 164        ax25->state = AX25_STATE_2;
 165
 166        ax25_calculate_t1(ax25);
 167        ax25_start_t1timer(ax25);
 168        ax25_stop_t3timer(ax25);
 169
 170        if (ax25->sk != NULL) {
 171                bh_lock_sock(ax25->sk);
 172                ax25->sk->sk_state     = TCP_CLOSE;
 173                ax25->sk->sk_err       = 0;
 174                ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
 175                if (!sock_flag(ax25->sk, SOCK_DEAD)) {
 176                        ax25->sk->sk_state_change(ax25->sk);
 177                        sock_set_flag(ax25->sk, SOCK_DEAD);
 178                }
 179                bh_unlock_sock(ax25->sk);
 180        }
 181}
 182
 183/* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
 184 *                within the poll of any connected channel. Remember
 185 *                that we are not allowed to send anything unless we
 186 *                get polled by the Master.
 187 *
 188 *                Thus we'll have to do parts of our T1 handling in
 189 *                ax25_enquiry_response().
 190 */
 191void ax25_ds_t1_timeout(ax25_cb *ax25)
 192{
 193        switch (ax25->state) {
 194        case AX25_STATE_1:
 195                if (ax25->n2count == ax25->n2) {
 196                        if (ax25->modulus == AX25_MODULUS) {
 197                                ax25_disconnect(ax25, ETIMEDOUT);
 198                                return;
 199                        } else {
 200                                ax25->modulus = AX25_MODULUS;
 201                                ax25->window  = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
 202                                ax25->n2count = 0;
 203                                ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
 204                        }
 205                } else {
 206                        ax25->n2count++;
 207                        if (ax25->modulus == AX25_MODULUS)
 208                                ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
 209                        else
 210                                ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND);
 211                }
 212                break;
 213
 214        case AX25_STATE_2:
 215                if (ax25->n2count == ax25->n2) {
 216                        ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 217                        ax25_disconnect(ax25, ETIMEDOUT);
 218                        return;
 219                } else {
 220                        ax25->n2count++;
 221                }
 222                break;
 223
 224        case AX25_STATE_3:
 225                if (ax25->n2count == ax25->n2) {
 226                        ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
 227                        ax25_disconnect(ax25, ETIMEDOUT);
 228                        return;
 229                } else {
 230                        ax25->n2count++;
 231                }
 232                break;
 233        }
 234
 235        ax25_calculate_t1(ax25);
 236        ax25_start_t1timer(ax25);
 237}
 238
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.