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