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         init_timer(&nr->t1timer);
  44         nr->t1timer.data     = (unsigned long)sk;
  45         nr->t1timer.function = &nr_t1timer_expiry;
  46
  47         init_timer(&nr->t2timer);
  48         nr->t2timer.data     = (unsigned long)sk;
  49         nr->t2timer.function = &nr_t2timer_expiry;
  50
  51         init_timer(&nr->t4timer);
  52         nr->t4timer.data     = (unsigned long)sk;
  53         nr->t4timer.function = &nr_t4timer_expiry;
  54
  55         init_timer(&nr->idletimer);
  56         nr->idletimer.data     = (unsigned long)sk;
  57         nr->idletimer.function = &nr_idletimer_expiry;
  58
  59         /* initialized by sock_init_data */
  60         sk->sk_timer.data     = (unsigned long)sk;
  61         sk->sk_timer.function = &nr_heartbeat_expiry;
  62 }
  63
  64 void nr_start_t1timer(struct sock *sk)
  65 {
  66         struct nr_sock *nr = nr_sk(sk);
  67
  68         mod_timer(&nr->t1timer, jiffies + nr->t1);
  69 }
  70
  71 void nr_start_t2timer(struct sock *sk)
  72 {
  73         struct nr_sock *nr = nr_sk(sk);
  74
  75         mod_timer(&nr->t2timer, jiffies + nr->t2);
  76 }
  77
  78 void nr_start_t4timer(struct sock *sk)
  79 {
  80         struct nr_sock *nr = nr_sk(sk);
  81
  82         mod_timer(&nr->t4timer, jiffies + nr->t4);
  83 }
  84
  85 void nr_start_idletimer(struct sock *sk)
  86 {
  87         struct nr_sock *nr = nr_sk(sk);
  88
  89         if (nr->idle > 0)
  90                 mod_timer(&nr->idletimer, jiffies + nr->idle);
  91 }
  92
  93 void nr_start_heartbeat(struct sock *sk)
  94 {
  95         mod_timer(&sk->sk_timer, jiffies + 5 * HZ);
  96 }
  97
  98 void nr_stop_t1timer(struct sock *sk)
  99 {
 100         del_timer(&nr_sk(sk)->t1timer);
 101 }
 102
 103 void nr_stop_t2timer(struct sock *sk)
 104 {
 105         del_timer(&nr_sk(sk)->t2timer);
 106 }
 107
 108 void nr_stop_t4timer(struct sock *sk)
 109 {
 110         del_timer(&nr_sk(sk)->t4timer);
 111 }
 112
 113 void nr_stop_idletimer(struct sock *sk)
 114 {
 115         del_timer(&nr_sk(sk)->idletimer);
 116 }
 117
 118 void nr_stop_heartbeat(struct sock *sk)
 119 {
 120         del_timer(&sk->sk_timer);
 121 }
 122
 123 int nr_t1timer_running(struct sock *sk)
 124 {
 125         return timer_pending(&nr_sk(sk)->t1timer);
 126 }
 127
 128 static void nr_heartbeat_expiry(unsigned long param)
 129 {
 130         struct sock *sk = (struct sock *)param;
 131         struct nr_sock *nr = nr_sk(sk);
 132
 133         bh_lock_sock(sk);
 134         switch (nr->state) {
 135         case NR_STATE_0:
 136                 /* Magic here: If we listen() and a new link dies before it
 137                    is accepted() it isn't 'dead' so doesn't get removed. */
 138                 if (sock_flag(sk, SOCK_DESTROY) ||
 139                     (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {
 140                         sock_hold(sk);
 141                         bh_unlock_sock(sk);
 142                         nr_destroy_socket(sk);
 143                         sock_put(sk);
 144                         return;
 145                 }
 146                 break;
 147
 148         case NR_STATE_3:
 149                 /*
 150                  * Check for the state of the receive buffer.
 151                  */
 152                 if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
 153                     (nr->condition & NR_COND_OWN_RX_BUSY)) {
 154                         nr->condition &= ~NR_COND_OWN_RX_BUSY;
 155                         nr->condition &= ~NR_COND_ACK_PENDING;
 156                         nr->vl         = nr->vr;
 157                         nr_write_internal(sk, NR_INFOACK);
 158                         break;
 159                 }
 160                 break;
 161         }
 162
 163         nr_start_heartbeat(sk);
 164         bh_unlock_sock(sk);
 165 }
 166
 167 static void nr_t2timer_expiry(unsigned long param)
 168 {
 169         struct sock *sk = (struct sock *)param;
 170         struct nr_sock *nr = nr_sk(sk);
 171
 172         bh_lock_sock(sk);
 173         if (nr->condition & NR_COND_ACK_PENDING) {
 174                 nr->condition &= ~NR_COND_ACK_PENDING;
 175                 nr_enquiry_response(sk);
 176         }
 177         bh_unlock_sock(sk);
 178 }
 179
 180 static void nr_t4timer_expiry(unsigned long param)
 181 {
 182         struct sock *sk = (struct sock *)param;
 183
 184         bh_lock_sock(sk);
 185         nr_sk(sk)->condition &= ~NR_COND_PEER_RX_BUSY;
 186         bh_unlock_sock(sk);
 187 }
 188
 189 static void nr_idletimer_expiry(unsigned long param)
 190 {
 191         struct sock *sk = (struct sock *)param;
 192         struct nr_sock *nr = nr_sk(sk);
 193
 194         bh_lock_sock(sk);
 195
 196         nr_clear_queues(sk);
 197
 198         nr->n2count = 0;
 199         nr_write_internal(sk, NR_DISCREQ);
 200         nr->state = NR_STATE_2;
 201
 202         nr_start_t1timer(sk);
 203         nr_stop_t2timer(sk);
 204         nr_stop_t4timer(sk);
 205
 206         sk->sk_state     = TCP_CLOSE;
 207         sk->sk_err       = 0;
 208         sk->sk_shutdown |= SEND_SHUTDOWN;
 209
 210         if (!sock_flag(sk, SOCK_DEAD)) {
 211                 sk->sk_state_change(sk);
 212                 sock_set_flag(sk, SOCK_DEAD);
 213         }
 214         bh_unlock_sock(sk);
 215 }
 216
 217 static void nr_t1timer_expiry(unsigned long param)
 218 {
 219         struct sock *sk = (struct sock *)param;
 220         struct nr_sock *nr = nr_sk(sk);
 221
 222         bh_lock_sock(sk);
 223         switch (nr->state) {
 224         case NR_STATE_1:
 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_CONNREQ);
 232                 }
 233                 break;
 234
 235         case NR_STATE_2:
 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_write_internal(sk, NR_DISCREQ);
 243                 }
 244                 break;
 245
 246         case NR_STATE_3:
 247                 if (nr->n2count == nr->n2) {
 248                         nr_disconnect(sk, ETIMEDOUT);
 249                         bh_unlock_sock(sk);
 250                         return;
 251                 } else {
 252                         nr->n2count++;
 253                         nr_requeue_frames(sk);
 254                 }
 255                 break;
 256         }
 257
 258         nr_start_t1timer(sk);
 259         bh_unlock_sock(sk);
 260 }