Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	X.25 Packet Layer release 002
 *
 *	This is ALPHA test software. This code may break your machine,
 *	randomly fail to work with new releases, misbehave and/or generally
 *	screw up. It might even work.
 *
 *	This code REQUIRES 2.1.15 or higher
 *
 *	History
 *	X.25 001	Jonathan Naylor	Started coding.
 *	X.25 002	Jonathan Naylor	New timer architecture.
 *					Centralised disconnection processing.
 */
 
#include <linux/errno.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/x25.h>
 
static void x25_heartbeat_expiry(struct timer_list *t);
static void x25_timer_expiry(struct timer_list *t);
 
void x25_init_timers(struct sock *sk)
{
<------>struct x25_sock *x25 = x25_sk(sk);
 
<------>timer_setup(&x25->timer, x25_timer_expiry, 0);
 
<------>/* initialized by sock_init_data */
<------>sk->sk_timer.function = x25_heartbeat_expiry;
}
 
void x25_start_heartbeat(struct sock *sk)
{
<------>mod_timer(&sk->sk_timer, jiffies + 5 * HZ);
}
 
void x25_stop_heartbeat(struct sock *sk)
{
<------>del_timer(&sk->sk_timer);
}
 
void x25_start_t2timer(struct sock *sk)
{
<------>struct x25_sock *x25 = x25_sk(sk);
 
<------>mod_timer(&x25->timer, jiffies + x25->t2);
}
 
void x25_start_t21timer(struct sock *sk)
{
<------>struct x25_sock *x25 = x25_sk(sk);
 
<------>mod_timer(&x25->timer, jiffies + x25->t21);
}
 
void x25_start_t22timer(struct sock *sk)
{
<------>struct x25_sock *x25 = x25_sk(sk);
 
<------>mod_timer(&x25->timer, jiffies + x25->t22);
}
 
void x25_start_t23timer(struct sock *sk)
{
<------>struct x25_sock *x25 = x25_sk(sk);
 
<------>mod_timer(&x25->timer, jiffies + x25->t23);
}
 
void x25_stop_timer(struct sock *sk)
{
<------>del_timer(&x25_sk(sk)->timer);
}
 
unsigned long x25_display_timer(struct sock *sk)
{
<------>struct x25_sock *x25 = x25_sk(sk);
 
<------>if (!timer_pending(&x25->timer))
<------><------>return 0;
 
<------>return x25->timer.expires - jiffies;
}
 
static void x25_heartbeat_expiry(struct timer_list *t)
{
<------>struct sock *sk = from_timer(sk, t, sk_timer);
 
<------>bh_lock_sock(sk);
<------>if (sock_owned_by_user(sk)) /* can currently only occur in state 3 */
<------><------>goto restart_heartbeat;
 
<------>switch (x25_sk(sk)->state) {
 
<------><------>case X25_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))) {
<------><------><------><------>bh_unlock_sock(sk);
<------><------><------><------>x25_destroy_socket_from_timer(sk);
<------><------><------><------>return;
<------><------><------>}
<------><------><------>break;
 
<------><------>case X25_STATE_3:
<------><------><------>/*
<------><------><------> * Check for the state of the receive buffer.
<------><------><------> */
<------><------><------>x25_check_rbuf(sk);
<------><------><------>break;
<------>}
restart_heartbeat:
<------>x25_start_heartbeat(sk);
<------>bh_unlock_sock(sk);
}
 
/*
 *	Timer has expired, it may have been T2, T21, T22, or T23. We can tell
 *	by the state machine state.
 */
static inline void x25_do_timer_expiry(struct sock * sk)
{
<------>struct x25_sock *x25 = x25_sk(sk);
 
<------>switch (x25->state) {
 
<------><------>case X25_STATE_3:	/* T2 */
<------><------><------>if (x25->condition & X25_COND_ACK_PENDING) {
<------><------><------><------>x25->condition &= ~X25_COND_ACK_PENDING;
<------><------><------><------>x25_enquiry_response(sk);
<------><------><------>}
<------><------><------>break;
 
<------><------>case X25_STATE_1:	/* T21 */
<------><------>case X25_STATE_4:	/* T22 */
<------><------><------>x25_write_internal(sk, X25_CLEAR_REQUEST);
<------><------><------>x25->state = X25_STATE_2;
<------><------><------>x25_start_t23timer(sk);
<------><------><------>break;
 
<------><------>case X25_STATE_2:	/* T23 */
<------><------><------>x25_disconnect(sk, ETIMEDOUT, 0, 0);
<------><------><------>break;
<------>}
}
 
static void x25_timer_expiry(struct timer_list *t)
{
<------>struct x25_sock *x25 = from_timer(x25, t, timer);
<------>struct sock *sk = &x25->sk;
 
<------>bh_lock_sock(sk);
<------>if (sock_owned_by_user(sk)) { /* can currently only occur in state 3 */
<------><------>if (x25_sk(sk)->state == X25_STATE_3)
<------><------><------>x25_start_t2timer(sk);
<------>} else
<------><------>x25_do_timer_expiry(sk);
<------>bh_unlock_sock(sk);
}