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                         goto out;
 128                 }
 129                 break;
 130
 131         case NR_STATE_3:
 132                 /*
 133                  * Check for the state of the receive buffer.
 134                  */
 135                 if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
 136                     (nr->condition & NR_COND_OWN_RX_BUSY)) {
 137                         nr->condition &= ~NR_COND_OWN_RX_BUSY;
 138                         nr->condition &= ~NR_COND_ACK_PENDING;
 139                         nr->vl         = nr->vr;
 140                         nr_write_internal(sk, NR_INFOACK);
 141                         break;
 142                 }
 143                 break;
 144         }
 145
 146         nr_start_heartbeat(sk);
 147         bh_unlock_sock(sk);
 148 out:
 149         sock_put(sk);
 150 }
 151
 152 static void nr_t2timer_expiry(struct timer_list *t)
 153 {
 154         struct nr_sock *nr = from_timer(nr, t, t2timer);
 155         struct sock *sk = &nr->sock;
 156
 157         bh_lock_sock(sk);
 158         if (nr->condition & NR_COND_ACK_PENDING) {
 159                 nr->condition &= ~NR_COND_ACK_PENDING;
 160                 nr_enquiry_response(sk);
 161         }
 162         bh_unlock_sock(sk);
 163         sock_put(sk);
 164 }
 165
 166 static void nr_t4timer_expiry(struct timer_list *t)
 167 {
 168         struct nr_sock *nr = from_timer(nr, t, t4timer);
 169         struct sock *sk = &nr->sock;
 170
 171         bh_lock_sock(sk);
 172         nr_sk(sk)->condition &= ~NR_COND_PEER_RX_BUSY;
 173         bh_unlock_sock(sk);
 174         sock_put(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         sock_put(sk);
 204 }
 205
 206 static void nr_t1timer_expiry(struct timer_list *t)
 207 {
 208         struct nr_sock *nr = from_timer(nr, t, t1timer);
 209         struct sock *sk = &nr->sock;
 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                         goto out;
 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                         goto out;
 227                 } else {
 228                         nr->n2count++;
 229                         nr_write_internal(sk, NR_DISCREQ);
 230                 }
 231                 break;
 232
 233         case NR_STATE_3:
 234                 if (nr->n2count == nr->n2) {
 235                         nr_disconnect(sk, ETIMEDOUT);
 236                         goto out;
 237                 } else {
 238                         nr->n2count++;
 239                         nr_requeue_frames(sk);
 240                 }
 241                 break;
 242         }
 243
 244         nr_start_t1timer(sk);
 245 out:
 246         bh_unlock_sock(sk);
 247         sock_put(sk);
 248 }