net/ax25/ax25_std_timer.c

   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 <asm/uaccess.h>
  28 #include <asm/system.h>
  29 #include <linux/fcntl.h>
  30 #include <linux/mm.h>
  31 #include <linux/interrupt.h>
  32
  33 void ax25_std_heartbeat_expiry(ax25_cb *ax25)
  34 {
  35         struct sock *sk = ax25->sk;
  36
  37         if (sk)
  38                 bh_lock_sock(sk);
  39
  40         switch (ax25->state) {
  41         case AX25_STATE_0:
  42                 if (!sk ||
  43                     sock_flag(sk, SOCK_DESTROY) ||
  44                     sock_flag(sk, SOCK_DEAD)) {
  45                         if (sk) {
  46                                 sock_hold(sk);
  47                                 ax25_destroy_socket(ax25);
  48                                 bh_unlock_sock(sk);
  49                                 sock_put(sk);
  50                         } else
  51                                 ax25_destroy_socket(ax25);
  52                         return;
  53                 }
  54                 break;
  55
  56         case AX25_STATE_3:
  57         case AX25_STATE_4:
  58                 /*
  59                  * Check the state of the receive buffer.
  60                  */
  61                 if (sk != NULL) {
  62                         if (atomic_read(&sk->sk_rmem_alloc) <
  63                             (sk->sk_rcvbuf >> 1) &&
  64                             (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
  65                                 ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
  66                                 ax25->condition &= ~AX25_COND_ACK_PENDING;
  67                                 ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
  68                                 break;
  69                         }
  70                 }
  71         }
  72
  73         if (sk)
  74                 bh_unlock_sock(sk);
  75
  76         ax25_start_heartbeat(ax25);
  77 }
  78
  79 void ax25_std_t2timer_expiry(ax25_cb *ax25)
  80 {
  81         if (ax25->condition & AX25_COND_ACK_PENDING) {
  82                 ax25->condition &= ~AX25_COND_ACK_PENDING;
  83                 ax25_std_timeout_response(ax25);
  84         }
  85 }
  86
  87 void ax25_std_t3timer_expiry(ax25_cb *ax25)
  88 {
  89         ax25->n2count = 0;
  90         ax25_std_transmit_enquiry(ax25);
  91         ax25->state   = AX25_STATE_4;
  92 }
  93
  94 void ax25_std_idletimer_expiry(ax25_cb *ax25)
  95 {
  96         ax25_clear_queues(ax25);
  97
  98         ax25->n2count = 0;
  99         ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 100         ax25->state   = AX25_STATE_2;
 101
 102         ax25_calculate_t1(ax25);
 103         ax25_start_t1timer(ax25);
 104         ax25_stop_t2timer(ax25);
 105         ax25_stop_t3timer(ax25);
 106
 107         if (ax25->sk != NULL) {
 108                 bh_lock_sock(ax25->sk);
 109                 ax25->sk->sk_state     = TCP_CLOSE;
 110                 ax25->sk->sk_err       = 0;
 111                 ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
 112                 if (!sock_flag(ax25->sk, SOCK_DEAD)) {
 113                         ax25->sk->sk_state_change(ax25->sk);
 114                         sock_set_flag(ax25->sk, SOCK_DEAD);
 115                 }
 116                 bh_unlock_sock(ax25->sk);
 117         }
 118 }
 119
 120 void ax25_std_t1timer_expiry(ax25_cb *ax25)
 121 {
 122         switch (ax25->state) {
 123         case AX25_STATE_1:
 124                 if (ax25->n2count == ax25->n2) {
 125                         if (ax25->modulus == AX25_MODULUS) {
 126                                 ax25_disconnect(ax25, ETIMEDOUT);
 127                                 return;
 128                         } else {
 129                                 ax25->modulus = AX25_MODULUS;
 130                                 ax25->window  = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
 131                                 ax25->n2count = 0;
 132                                 ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
 133                         }
 134                 } else {
 135                         ax25->n2count++;
 136                         if (ax25->modulus == AX25_MODULUS)
 137                                 ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
 138                         else
 139                                 ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND);
 140                 }
 141                 break;
 142
 143         case AX25_STATE_2:
 144                 if (ax25->n2count == ax25->n2) {
 145                         ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 146                         ax25_disconnect(ax25, ETIMEDOUT);
 147                         return;
 148                 } else {
 149                         ax25->n2count++;
 150                         ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
 151                 }
 152                 break;
 153
 154         case AX25_STATE_3:
 155                 ax25->n2count = 1;
 156                 ax25_std_transmit_enquiry(ax25);
 157                 ax25->state   = AX25_STATE_4;
 158                 break;
 159
 160         case AX25_STATE_4:
 161                 if (ax25->n2count == ax25->n2) {
 162                         ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
 163                         ax25_disconnect(ax25, ETIMEDOUT);
 164                         return;
 165                 } else {
 166                         ax25->n2count++;
 167                         ax25_std_transmit_enquiry(ax25);
 168                 }
 169                 break;
 170         }
 171
 172         ax25_calculate_t1(ax25);
 173         ax25_start_t1timer(ax25);
 174 }