net/netrom/nr_timer.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *
   4  * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   5  * Copyright (C) 2002 Ralf Baechle DO1GRB (ralf@gnu.org)
   6  */
   7 #include <linux/errno.h>
   8 #include <linux/types.h>
   9 #include <linux/socket.h>
  10 #include <linux/in.h>
  11 #include <linux/kernel.h>
  12 #include <linux/jiffies.h>
  13 #include <linux/timer.h>
  14 #include <linux/string.h>
  15 #include <linux/sockios.h>
  16 #include <linux/net.h>
  17 #include <net/ax25.h>
  18 #include <linux/inet.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/skbuff.h>
  21 #include <net/sock.h>
  22 #include <net/tcp_states.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/fcntl.h>
  25 #include <linux/mm.h>
  26 #include <linux/interrupt.h>
  27 #include <net/netrom.h>
  28
  29 static void nr_heartbeat_expiry(struct timer_list *);
  30 static void nr_t1timer_expiry(struct timer_list *);
  31 static void nr_t2timer_expiry(struct timer_list *);
  32 static void nr_t4timer_expiry(struct timer_list *);
  33 static void nr_idletimer_expiry(struct timer_list *);
  34
  35 void nr_init_timers(struct sock *sk)
  36 {
  37         struct nr_sock *nr = nr_sk(sk);
  38
  39         timer_setup(&nr->t1timer, nr_t1timer_expiry, 0);
  40         timer_setup(&nr->t2timer, nr_t2timer_expiry, 0);
  41         timer_setup(&nr->t4timer, nr_t4timer_expiry, 0);
  42         timer_setup(&nr->idletimer, nr_idletimer_expiry, 0);
  43
  44         /* initialized by sock_init_data */
  45         sk->sk_timer.function = nr_heartbeat_expiry;
  46 }
  47
  48 void nr_start_t1timer(struct sock *sk)
  49 {
  50         struct nr_sock *nr = nr_sk(sk);
  51
  52         sk_reset_timer(sk, &nr->t1timer, jiffies + nr->t1);
  53 }
  54
  55 void nr_start_t2timer(struct sock *sk)
  56 {
  57         struct nr_sock *nr = nr_sk(sk);
  58
  59         sk_reset_timer(sk, &nr->t2timer, jiffies + nr->t2);
  60 }
  61
  62 void nr_start_t4timer(struct sock *sk)
  63 {
  64         struct nr_sock *nr = nr_sk(sk);
  65
  66         sk_reset_timer(sk, &nr->t4timer, jiffies + nr->t4);
  67 }
  68
  69 void nr_start_idletimer(struct sock *sk)
  70 {
  71         struct nr_sock *nr = nr_sk(sk);
  72
  73         if (nr->idle > 0)
  74                 sk_reset_timer(sk, &nr->idletimer, jiffies + nr->idle);
  75 }
  76
  77 void nr_start_heartbeat(struct sock *sk)
  78 {
  79         sk_reset_timer(sk, &sk->sk_timer, jiffies + 5 * HZ);
  80 }
  81
  82 void nr_stop_t1timer(struct sock *sk)
  83 {
  84         sk_stop_timer(sk, &nr_sk(sk)->t1timer);
  85 }
  86
  87 void nr_stop_t2timer(struct sock *sk)
  88 {
  89         sk_stop_timer(sk, &nr_sk(sk)->t2timer);
  90 }
  91
  92 void nr_stop_t4timer(struct sock *sk)
  93 {
  94         sk_stop_timer(sk, &nr_sk(sk)->t4timer);
  95 }
  96
  97 void nr_stop_idletimer(struct sock *sk)
  98 {
  99         sk_stop_timer(sk, &nr_sk(sk)->idletimer);
 100 }
 101
 102 void nr_stop_heartbeat(struct sock *sk)
 103 {
 104         sk_stop_timer(sk, &sk->sk_timer);
 105 }
 106
 107 int nr_t1timer_running(struct sock *sk)
 108 {
 109         return timer_pending(&nr_sk(sk)->t1timer);
 110 }
 111
 112 static void nr_heartbeat_expiry(struct timer_list *t)
 113 {
 114         struct sock *sk = from_timer(sk, t, sk_timer);
 115         struct nr_sock *nr = nr_sk(sk);
 116
 117         bh_lock_sock(sk);
 118         switch (nr->state) {
 119         case NR_STATE_0:
 120                 /* Magic here: If we listen() and a new link dies before it
 121                    is accepted() it isn't 'dead' so doesn't get removed. */
 122                 if (sock_flag(sk, SOCK_DESTROY) ||
 123                     (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {
 124                         if (sk->sk_state == TCP_LISTEN)
 125                                 sock_hold(sk);
 126                         bh_unlock_sock(sk);
 127                         nr_destroy_socket(sk);
 128                         goto out;
 129                 }
 130                 break;
 131
 132         case NR_STATE_3:
 133                 /*
 134                  * Check for the state of the receive buffer.
 135                  */
 136                 if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
 137                     (nr->condition & NR_COND_OWN_RX_BUSY)) {
 138                         nr->condition &= ~NR_COND_OWN_RX_BUSY;
 139                         nr->condition &= ~NR_COND_ACK_PENDING;
 140                         nr->vl         = nr->vr;
 141                         nr_write_internal(sk, NR_INFOACK);
 142                         break;
 143                 }
 144                 break;
 145         }
 146
 147         nr_start_heartbeat(sk);
 148         bh_unlock_sock(sk);
 149 out:
 150         sock_put(sk);
 151 }
 152
 153 static void nr_t2timer_expiry(struct timer_list *t)
 154 {
 155         struct nr_sock *nr = from_timer(nr, t, t2timer);
 156         struct sock *sk = &nr->sock;
 157
 158         bh_lock_sock(sk);
 159         if (nr->condition & NR_COND_ACK_PENDING) {
 160                 nr->condition &= ~NR_COND_ACK_PENDING;
 161                 nr_enquiry_response(sk);
 162         }
 163         bh_unlock_sock(sk);
 164         sock_put(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         sock_put(sk);
 176 }
 177
 178 static void nr_idletimer_expiry(struct timer_list *t)
 179 {
 180         struct nr_sock *nr = from_timer(nr, t, idletimer);
 181         struct sock *sk = &nr->sock;
 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         sock_put(sk);
 205 }
 206
 207 static void nr_t1timer_expiry(struct timer_list *t)
 208 {
 209         struct nr_sock *nr = from_timer(nr, t, t1timer);
 210         struct sock *sk = &nr->sock;
 211
 212         bh_lock_sock(sk);
 213         switch (nr->state) {
 214         case NR_STATE_1:
 215                 if (nr->n2count == nr->n2) {
 216                         nr_disconnect(sk, ETIMEDOUT);
 217                         goto out;
 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                         goto out;
 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                         goto out;
 238                 } else {
 239                         nr->n2count++;
 240                         nr_requeue_frames(sk);
 241                 }
 242                 break;
 243         }
 244
 245         nr_start_t1timer(sk);
 246 out:
 247         bh_unlock_sock(sk);
 248         sock_put(sk);
 249 }