linux/net/ax25/ax25_std_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) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
   8 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   9 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
  10 * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
  11 */
  12#include <linux/errno.h>
  13#include <linux/types.h>
  14#include <linux/socket.h>
  15#include <linux/in.h>
  16#include <linux/kernel.h>
  17#include <linux/timer.h>
  18#include <linux/string.h>
  19#include <linux/sockios.h>
  20#include <linux/net.h>
  21#include <net/ax25.h>
  22#include <linux/inet.h>
  23#include <linux/netdevice.h>
  24#include <linux/skbuff.h>
  25#include <net/sock.h>
  26#include <net/tcp_states.h>
  27#include <linux/uaccess.h>
  28#include <linux/fcntl.h>
  29#include <linux/mm.h>
  30#include <linux/interrupt.h>
  31
  32void ax25_std_heartbeat_expiry(ax25_cb *ax25)
  33{
  34        struct sock *sk = ax25->sk;
  35
  36        if (sk)
  37                bh_lock_sock(sk);
  38
  39        switch (ax25->state) {
  40        case AX25_STATE_0:
  41        case AX25_STATE_2:
  42                /* Magic here: If we listen() and a new link dies before it
  43                   is accepted() it isn't 'dead' so doesn't get removed. */
  44                if (!sk || sock_flag(sk, SOCK_DESTROY) ||
  45                    (sk->sk_state == TCP_LISTEN &&
  46                     sock_flag(sk, SOCK_DEAD))) {
  47                        if (sk) {
  48                                sock_hold(sk);
  49                                ax25_destroy_socket(ax25);
  50                                bh_unlock_sock(sk);
  51                                /* Ungrab socket and destroy it */
  52                                sock_put(sk);
  53                        } else
  54                                ax25_destroy_socket(ax25);
  55                        return;
  56                }
  57                break;
  58
  59        case AX25_STATE_3:
  60        case AX25_STATE_4:
  61                /*
  62                 * Check the state of the receive buffer.
  63                 */
  64                if (sk != NULL) {
  65                        if (atomic_read(&sk->sk_rmem_alloc) <
  66                            (sk->sk_rcvbuf >> 1) &&
  67                            (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
  68                                ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
  69                                ax25->condition &= ~AX25_COND_ACK_PENDING;
  70                                ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
  71                                break;
  72                        }
  73                }
  74        }
  75
  76        if (sk)
  77                bh_unlock_sock(sk);
  78
  79        ax25_start_heartbeat(ax25);
  80}
  81
  82void ax25_std_t2timer_expiry(ax25_cb *ax25)
  83{
  84        if (ax25->condition & AX25_COND_ACK_PENDING) {
  85                ax25->condition &= ~AX25_COND_ACK_PENDING;
  86                ax25_std_timeout_response(ax25);
  87        }
  88}
  89
  90void ax25_std_t3timer_expiry(ax25_cb *ax25)
  91{
  92        ax25->n2count = 0;
  93        ax25_std_transmit_enquiry(ax25);
  94        ax25->state   = AX25_STATE_4;
  95}
  96
  97void ax25_std_idletimer_expiry(ax25_cb *ax25)
  98{
  99        ax25_clear_queues(ax25);
 100
 101        ax25->n2count = 0;
 102        ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 103        ax25->state   = AX25_STATE_2;
 104
 105        ax25_calculate_t1(ax25);
 106        ax25_start_t1timer(ax25);
 107        ax25_stop_t2timer(ax25);
 108        ax25_stop_t3timer(ax25);
 109
 110        if (ax25->sk != NULL) {
 111                bh_lock_sock(ax25->sk);
 112                ax25->sk->sk_state     = TCP_CLOSE;
 113                ax25->sk->sk_err       = 0;
 114                ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
 115                if (!sock_flag(ax25->sk, SOCK_DEAD)) {
 116                        ax25->sk->sk_state_change(ax25->sk);
 117                        sock_set_flag(ax25->sk, SOCK_DEAD);
 118                }
 119                bh_unlock_sock(ax25->sk);
 120        }
 121}
 122
 123void ax25_std_t1timer_expiry(ax25_cb *ax25)
 124{
 125        switch (ax25->state) {
 126        case AX25_STATE_1:
 127                if (ax25->n2count == ax25->n2) {
 128                        if (ax25->modulus == AX25_MODULUS) {
 129                                ax25_disconnect(ax25, ETIMEDOUT);
 130                                return;
 131                        } else {
 132                                ax25->modulus = AX25_MODULUS;
 133                                ax25->window  = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
 134                                ax25->n2count = 0;
 135                                ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
 136                        }
 137                } else {
 138                        ax25->n2count++;
 139                        if (ax25->modulus == AX25_MODULUS)
 140                                ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
 141                        else
 142                                ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND);
 143                }
 144                break;
 145
 146        case AX25_STATE_2:
 147                if (ax25->n2count == ax25->n2) {
 148                        ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 149                        if (!sock_flag(ax25->sk, SOCK_DESTROY))
 150                                ax25_disconnect(ax25, ETIMEDOUT);
 151                        return;
 152                } else {
 153                        ax25->n2count++;
 154                        ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 155                }
 156                break;
 157
 158        case AX25_STATE_3:
 159                ax25->n2count = 1;
 160                ax25_std_transmit_enquiry(ax25);
 161                ax25->state   = AX25_STATE_4;
 162                break;
 163
 164        case AX25_STATE_4:
 165                if (ax25->n2count == ax25->n2) {
 166                        ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
 167                        ax25_disconnect(ax25, ETIMEDOUT);
 168                        return;
 169                } else {
 170                        ax25->n2count++;
 171                        ax25_std_transmit_enquiry(ax25);
 172                }
 173                break;
 174        }
 175
 176        ax25_calculate_t1(ax25);
 177        ax25_start_t1timer(ax25);
 178}
 179