net/netrom/nr_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) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   8  * Copyright (C) 2002 Ralf Baechle DO1GRB (ralf@gnu.org)
   9  */
  10 #include <linux/errno.h>
  11 #include <linux/types.h>
  12 #include <linux/socket.h>
  13 #include <linux/in.h>
  14 #include <linux/kernel.h>
  15 #include <linux/jiffies.h>
  16 #include <linux/timer.h>
  17 #include <linux/string.h>
  18 #include <linux/sockios.h>
  19 #include <linux/net.h>
  20 #include <net/ax25.h>
  21 #include <linux/inet.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/skbuff.h>
  24 #include <net/sock.h>
  25 #include <net/tcp_states.h>
  26 #include <asm/uaccess.h>
  27 #include <asm/system.h>
  28 #include <linux/fcntl.h>
  29 #include <linux/mm.h>
  30 #include <linux/interrupt.h>
  31 #include <net/netrom.h>
  32
  33 static void nr_heartbeat_expiry(unsigned long);
  34 static void nr_t1timer_expiry(unsigned long);
  35 static void nr_t2timer_expiry(unsigned long);
  36 static void nr_t4timer_expiry(unsigned long);
  37 static void nr_idletimer_expiry(unsigned long);
  38
  39 void nr_init_timers(struct sock *sk)
  40 {
  41         struct nr_sock *nr = nr_sk(sk);
  42
  43         setup_timer(&nr->t1timer, nr_t1timer_expiry, (unsigned long)sk);
  44         setup_timer(&nr->t2timer, nr_t2timer_expiry, (unsigned long)sk);
  45         setup_timer(&nr->t4timer, nr_t4timer_expiry, (unsigned long)sk);
  46         setup_timer(&nr->idletimer, nr_idletimer_expiry, (unsigned long)sk);
  47
  48         /* initialized by sock_init_data */
  49         sk->sk_timer.data     = (unsigned long)sk;
  50         sk->sk_timer.function = &nr_heartbeat_expiry;
  51 }
  52
  53 void nr_start_t1timer(struct sock *sk)
  54 {
  55         struct nr_sock *nr = nr_sk(sk);
  56
  57         mod_timer(&nr->t1timer, jiffies + nr->t1);
  58 }
  59
  60 void nr_start_t2timer(struct sock *sk)
  61 {
  62         struct nr_sock *nr = nr_sk(sk);
  63
  64         mod_timer(&nr->t2timer, jiffies + nr->t2);
  65 }
  66
  67 void nr_start_t4timer(struct sock *sk)
  68 {
  69         struct nr_sock *nr = nr_sk(sk);
  70
  71         mod_timer(&nr->t4timer, jiffies + nr->t4);
  72 }
  73
  74 void nr_start_idletimer(struct sock *sk)
  75 {
  76         struct nr_sock *nr = nr_sk(sk);
  77
  78         if (nr->idle > 0)
  79                 mod_timer(&nr->idletimer, jiffies + nr->idle);
  80 }
  81
  82 void nr_start_heartbeat(struct sock *sk)
  83 {
  84         mod_timer(&sk->sk_timer, jiffies + 5 * HZ);
  85 }
  86
  87 void nr_stop_t1timer(struct sock *sk)
  88 {
  89         del_timer(&nr_sk(sk)->t1timer);
  90 }
  91
  92 void nr_stop_t2timer(struct sock *sk)
  93 {
  94         del_timer(&nr_sk(sk)->t2timer);
  95 }
  96
  97 void nr_stop_t4timer(struct sock *sk)
  98 {
  99         del_timer(&nr_sk(sk)->t4timer);
 100 }
 101
 102 void nr_stop_idletimer(struct sock *sk)
 103 {
 104         del_timer(&nr_sk(sk)->idletimer);
 105 }
 106
 107 void nr_stop_heartbeat(struct sock *sk)
 108 {
 109         del_timer(&sk->sk_timer);
 110 }
 111
 112 int nr_t1timer_running(struct sock *sk)
 113 {
 114         return timer_pending(&nr_sk(sk)->t1timer);
 115 }
 116
 117 static void nr_heartbeat_expiry(unsigned long param)
 118 {
 119         struct sock *sk = (struct sock *)param;
 120         struct nr_sock *nr = nr_sk(sk);
 121
 122         bh_lock_sock(sk);
 123         switch (nr->state) {
 124         case NR_STATE_0:
 125                 /* Magic here: If we listen() and a new link dies before it
 126                    is accepted() it isn't 'dead' so doesn't get removed. */
 127                 if (sock_flag(sk, SOCK_DESTROY) ||
 128                     (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {
 129                         sock_hold(sk);
 130                         bh_unlock_sock(sk);
 131                         nr_destroy_socket(sk);
 132                         sock_put(sk);
 133                         return;
 134                 }
 135                 break;
 136
 137         case NR_STATE_3:
 138                 /*
 139                  * Check for the state of the receive buffer.
 140                  */
 141                 if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
 142                     (nr->condition & NR_COND_OWN_RX_BUSY)) {
 143                         nr->condition &= ~NR_COND_OWN_RX_BUSY;
 144                         nr->condition &= ~NR_COND_ACK_PENDING;
 145                         nr->vl         = nr->vr;
 146                         nr_write_internal(sk, NR_INFOACK);
 147                         break;
 148                 }
 149                 break;
 150         }
 151
 152         nr_start_heartbeat(sk);
 153         bh_unlock_sock(sk);
 154 }
 155
 156 static void nr_t2timer_expiry(unsigned long param)
 157 {
 158         struct sock *sk = (struct sock *)param;
 159         struct nr_sock *nr = nr_sk(sk);
 160
 161         bh_lock_sock(sk);
 162         if (nr->condition & NR_COND_ACK_PENDING) {
 163                 nr->condition &= ~NR_COND_ACK_PENDING;
 164                 nr_enquiry_response(sk);
 165         }
 166         bh_unlock_sock(sk);
 167 }
 168
 169 static void nr_t4timer_expiry(unsigned long param)
 170 {
 171         struct sock *sk = (struct sock *)param;
 172
 173         bh_lock_sock(sk);
 174         nr_sk(sk)->condition &= ~NR_COND_PEER_RX_BUSY;
 175         bh_unlock_sock(sk);
 176 }
 177
 178 static void nr_idletimer_expiry(unsigned long param)
 179 {
 180         struct sock *sk = (struct sock *)param;
 181         struct nr_sock *nr = nr_sk(sk);
 182
 183         bh_lock_sock(sk);
 184
 185         nr_clear_queues(sk);
 186
 187         nr->n2count = 0;
 188         nr_write_internal(sk, NR_DISCREQ);
 189         nr->state = NR_STATE_2;
 190
 191         nr_start_t1timer(sk);
 192         nr_stop_t2timer(sk);
 193         nr_stop_t4timer(sk);
 194
 195         sk->sk_state     = TCP_CLOSE;
 196         sk->sk_err       = 0;
 197         sk->sk_shutdown |= SEND_SHUTDOWN;
 198
 199         if (!sock_flag(sk, SOCK_DEAD)) {
 200                 sk->sk_state_change(sk);
 201                 sock_set_flag(sk, SOCK_DEAD);
 202         }
 203         bh_unlock_sock(sk);
 204 }
 205
 206 static void nr_t1timer_expiry(unsigned long param)
 207 {
 208         struct sock *sk = (struct sock *)param;
 209         struct nr_sock *nr = nr_sk(sk);
 210
 211         bh_lock_sock(sk);
 212         switch (nr->state) {
 213         case NR_STATE_1:
 214                 if (nr->n2count == nr->n2) {
 215                         nr_disconnect(sk, ETIMEDOUT);
 216                         bh_unlock_sock(sk);
 217                         return;
 218                 } else {
 219                         nr->n2count++;
 220                         nr_write_internal(sk, NR_CONNREQ);
 221                 }
 222                 break;
 223
 224         case NR_STATE_2:
 225                 if (nr->n2count == nr->n2) {
 226                         nr_disconnect(sk, ETIMEDOUT);
 227                         bh_unlock_sock(sk);
 228                         return;
 229                 } else {
 230                         nr->n2count++;
 231                         nr_write_internal(sk, NR_DISCREQ);
 232                 }
 233                 break;
 234
 235         case NR_STATE_3:
 236                 if (nr->n2count == nr->n2) {
 237                         nr_disconnect(sk, ETIMEDOUT);
 238                         bh_unlock_sock(sk);
 239                         return;
 240                 } else {
 241                         nr->n2count++;
 242                         nr_requeue_frames(sk);
 243                 }
 244                 break;
 245         }
 246
 247         nr_start_t1timer(sk);
 248         bh_unlock_sock(sk);
 249 }