// SPDX-License-Identifier: GPL-2.0-or-later/* * * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) * Copyright (C) 2002 Ralf Baechle DO1GRB (ralf@gnu.org) */#include <linux/errno.h>#include <linux/types.h>#include <linux/socket.h>#include <linux/in.h>#include <linux/kernel.h>#include <linux/jiffies.h>#include <linux/timer.h>#include <linux/string.h>#include <linux/sockios.h>#include <linux/net.h>#include <net/ax25.h>#include <linux/inet.h>#include <linux/netdevice.h>#include <linux/skbuff.h>#include <net/sock.h>#include <net/tcp_states.h>#include <linux/uaccess.h>#include <linux/fcntl.h>#include <linux/mm.h>#include <linux/interrupt.h>#include <net/netrom.h> static void nr_heartbeat_expiry(struct timer_list *);static void nr_t1timer_expiry(struct timer_list *);static void nr_t2timer_expiry(struct timer_list *);static void nr_t4timer_expiry(struct timer_list *);static void nr_idletimer_expiry(struct timer_list *); void nr_init_timers(struct sock *sk){	struct nr_sock *nr = nr_sk(sk); 	timer_setup(&nr->t1timer, nr_t1timer_expiry, 0);	timer_setup(&nr->t2timer, nr_t2timer_expiry, 0);	timer_setup(&nr->t4timer, nr_t4timer_expiry, 0);	timer_setup(&nr->idletimer, nr_idletimer_expiry, 0); 	/* initialized by sock_init_data */	sk->sk_timer.function = nr_heartbeat_expiry;} void nr_start_t1timer(struct sock *sk){	struct nr_sock *nr = nr_sk(sk); 	sk_reset_timer(sk, &nr->t1timer, jiffies + nr->t1);} void nr_start_t2timer(struct sock *sk){	struct nr_sock *nr = nr_sk(sk); 	sk_reset_timer(sk, &nr->t2timer, jiffies + nr->t2);} void nr_start_t4timer(struct sock *sk){	struct nr_sock *nr = nr_sk(sk); 	sk_reset_timer(sk, &nr->t4timer, jiffies + nr->t4);} void nr_start_idletimer(struct sock *sk){	struct nr_sock *nr = nr_sk(sk); 	if (nr->idle > 0)		sk_reset_timer(sk, &nr->idletimer, jiffies + nr->idle);} void nr_start_heartbeat(struct sock *sk){	sk_reset_timer(sk, &sk->sk_timer, jiffies + 5 * HZ);} void nr_stop_t1timer(struct sock *sk){	sk_stop_timer(sk, &nr_sk(sk)->t1timer);} void nr_stop_t2timer(struct sock *sk){	sk_stop_timer(sk, &nr_sk(sk)->t2timer);} void nr_stop_t4timer(struct sock *sk){	sk_stop_timer(sk, &nr_sk(sk)->t4timer);} void nr_stop_idletimer(struct sock *sk){	sk_stop_timer(sk, &nr_sk(sk)->idletimer);} void nr_stop_heartbeat(struct sock *sk){	sk_stop_timer(sk, &sk->sk_timer);} int nr_t1timer_running(struct sock *sk){	return timer_pending(&nr_sk(sk)->t1timer);} static void nr_heartbeat_expiry(struct timer_list *t){	struct sock *sk = from_timer(sk, t, sk_timer);	struct nr_sock *nr = nr_sk(sk); 	bh_lock_sock(sk);	switch (nr->state) {	case NR_STATE_0:		/* Magic here: If we listen() and a new link dies before it		   is accepted() it isn't 'dead' so doesn't get removed. */		if (sock_flag(sk, SOCK_DESTROY) ||		    (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {			sock_hold(sk);			bh_unlock_sock(sk);			nr_destroy_socket(sk);			sock_put(sk);			return;		}		break; 	case NR_STATE_3:		/*		 * Check for the state of the receive buffer.		 */		if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&		    (nr->condition & NR_COND_OWN_RX_BUSY)) {			nr->condition &= ~NR_COND_OWN_RX_BUSY;			nr->condition &= ~NR_COND_ACK_PENDING;			nr->vl         = nr->vr;			nr_write_internal(sk, NR_INFOACK);			break;		}		break;	} 	nr_start_heartbeat(sk);	bh_unlock_sock(sk);} static void nr_t2timer_expiry(struct timer_list *t){	struct nr_sock *nr = from_timer(nr, t, t2timer);	struct sock *sk = &nr->sock; 	bh_lock_sock(sk);	if (nr->condition & NR_COND_ACK_PENDING) {		nr->condition &= ~NR_COND_ACK_PENDING;		nr_enquiry_response(sk);	}	bh_unlock_sock(sk);} static void nr_t4timer_expiry(struct timer_list *t){	struct nr_sock *nr = from_timer(nr, t, t4timer);	struct sock *sk = &nr->sock; 	bh_lock_sock(sk);	nr_sk(sk)->condition &= ~NR_COND_PEER_RX_BUSY;	bh_unlock_sock(sk);} static void nr_idletimer_expiry(struct timer_list *t){	struct nr_sock *nr = from_timer(nr, t, idletimer);	struct sock *sk = &nr->sock; 	bh_lock_sock(sk); 	nr_clear_queues(sk); 	nr->n2count = 0;	nr_write_internal(sk, NR_DISCREQ);	nr->state = NR_STATE_2; 	nr_start_t1timer(sk);	nr_stop_t2timer(sk);	nr_stop_t4timer(sk); 	sk->sk_state     = TCP_CLOSE;	sk->sk_err       = 0;	sk->sk_shutdown |= SEND_SHUTDOWN; 	if (!sock_flag(sk, SOCK_DEAD)) {		sk->sk_state_change(sk);		sock_set_flag(sk, SOCK_DEAD);	}	bh_unlock_sock(sk);} static void nr_t1timer_expiry(struct timer_list *t){	struct nr_sock *nr = from_timer(nr, t, t1timer);	struct sock *sk = &nr->sock; 	bh_lock_sock(sk);	switch (nr->state) {	case NR_STATE_1:		if (nr->n2count == nr->n2) {			nr_disconnect(sk, ETIMEDOUT);			bh_unlock_sock(sk);			return;		} else {			nr->n2count++;			nr_write_internal(sk, NR_CONNREQ);		}		break; 	case NR_STATE_2:		if (nr->n2count == nr->n2) {			nr_disconnect(sk, ETIMEDOUT);			bh_unlock_sock(sk);			return;		} else {			nr->n2count++;			nr_write_internal(sk, NR_DISCREQ);		}		break; 	case NR_STATE_3:		if (nr->n2count == nr->n2) {			nr_disconnect(sk, ETIMEDOUT);			bh_unlock_sock(sk);			return;		} else {			nr->n2count++;			nr_requeue_frames(sk);		}		break;	} 	nr_start_t1timer(sk);	bh_unlock_sock(sk);}