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                         sock_hold(sk);
 125                         bh_unlock_sock(sk);
 126                         nr_destroy_socket(sk);
 127                         sock_put(sk);
 128                         return;
 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 }
 150
 151 static void nr_t2timer_expiry(struct timer_list *t)
 152 {
 153         struct nr_sock *nr = from_timer(nr, t, t2timer);
 154         struct sock *sk = &nr->sock;
 155
 156         bh_lock_sock(sk);
 157         if (nr->condition & NR_COND_ACK_PENDING) {
 158                 nr->condition &= ~NR_COND_ACK_PENDING;
 159                 nr_enquiry_response(sk);
 160         }
 161         bh_unlock_sock(sk);
 162 }
 163
 164 static void nr_t4timer_expiry(struct timer_list *t)
 165 {
 166         struct nr_sock *nr = from_timer(nr, t, t4timer);
 167         struct sock *sk = &nr->sock;
 168
 169         bh_lock_sock(sk);
 170         nr_sk(sk)->condition &= ~NR_COND_PEER_RX_BUSY;
 171         bh_unlock_sock(sk);
 172 }
 173
 174 static void nr_idletimer_expiry(struct timer_list *t)
 175 {
 176         struct nr_sock *nr = from_timer(nr, t, idletimer);
 177         struct sock *sk = &nr->sock;
 178
 179         bh_lock_sock(sk);
 180
 181         nr_clear_queues(sk);
 182
 183         nr->n2count = 0;
 184         nr_write_internal(sk, NR_DISCREQ);
 185         nr->state = NR_STATE_2;
 186
 187         nr_start_t1timer(sk);
 188         nr_stop_t2timer(sk);
 189         nr_stop_t4timer(sk);
 190
 191         sk->sk_state     = TCP_CLOSE;
 192         sk->sk_err       = 0;
 193         sk->sk_shutdown |= SEND_SHUTDOWN;
 194
 195         if (!sock_flag(sk, SOCK_DEAD)) {
 196                 sk->sk_state_change(sk);
 197                 sock_set_flag(sk, SOCK_DEAD);
 198         }
 199         bh_unlock_sock(sk);
 200 }
 201
 202 static void nr_t1timer_expiry(struct timer_list *t)
 203 {
 204         struct nr_sock *nr = from_timer(nr, t, t1timer);
 205         struct sock *sk = &nr->sock;
 206
 207         bh_lock_sock(sk);
 208         switch (nr->state) {
 209         case NR_STATE_1:
 210                 if (nr->n2count == nr->n2) {
 211                         nr_disconnect(sk, ETIMEDOUT);
 212                         bh_unlock_sock(sk);
 213                         return;
 214                 } else {
 215                         nr->n2count++;
 216                         nr_write_internal(sk, NR_CONNREQ);
 217                 }
 218                 break;
 219
 220         case NR_STATE_2:
 221                 if (nr->n2count == nr->n2) {
 222                         nr_disconnect(sk, ETIMEDOUT);
 223                         bh_unlock_sock(sk);
 224                         return;
 225                 } else {
 226                         nr->n2count++;
 227                         nr_write_internal(sk, NR_DISCREQ);
 228                 }
 229                 break;
 230
 231         case NR_STATE_3:
 232                 if (nr->n2count == nr->n2) {
 233                         nr_disconnect(sk, ETIMEDOUT);
 234                         bh_unlock_sock(sk);
 235                         return;
 236                 } else {
 237                         nr->n2count++;
 238                         nr_requeue_frames(sk);
 239                 }
 240                 break;
 241         }
 242
 243         nr_start_t1timer(sk);
 244         bh_unlock_sock(sk);
 245 }