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 } 249