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169 lines
3.6 KiB
169 lines
3.6 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* X.25 Packet Layer release 002 |
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* |
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* This is ALPHA test software. This code may break your machine, |
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* randomly fail to work with new releases, misbehave and/or generally |
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* screw up. It might even work. |
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* |
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* This code REQUIRES 2.1.15 or higher |
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* |
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* History |
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* X.25 001 Jonathan Naylor Started coding. |
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* X.25 002 Jonathan Naylor New timer architecture. |
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* Centralised disconnection processing. |
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*/ |
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#include <linux/errno.h> |
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#include <linux/jiffies.h> |
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#include <linux/timer.h> |
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#include <net/sock.h> |
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#include <net/tcp_states.h> |
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#include <net/x25.h> |
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static void x25_heartbeat_expiry(struct timer_list *t); |
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static void x25_timer_expiry(struct timer_list *t); |
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void x25_init_timers(struct sock *sk) |
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{ |
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struct x25_sock *x25 = x25_sk(sk); |
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timer_setup(&x25->timer, x25_timer_expiry, 0); |
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/* initialized by sock_init_data */ |
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sk->sk_timer.function = x25_heartbeat_expiry; |
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} |
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void x25_start_heartbeat(struct sock *sk) |
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{ |
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mod_timer(&sk->sk_timer, jiffies + 5 * HZ); |
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} |
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void x25_stop_heartbeat(struct sock *sk) |
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{ |
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del_timer(&sk->sk_timer); |
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} |
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void x25_start_t2timer(struct sock *sk) |
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{ |
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struct x25_sock *x25 = x25_sk(sk); |
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mod_timer(&x25->timer, jiffies + x25->t2); |
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} |
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void x25_start_t21timer(struct sock *sk) |
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{ |
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struct x25_sock *x25 = x25_sk(sk); |
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mod_timer(&x25->timer, jiffies + x25->t21); |
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} |
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void x25_start_t22timer(struct sock *sk) |
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{ |
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struct x25_sock *x25 = x25_sk(sk); |
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mod_timer(&x25->timer, jiffies + x25->t22); |
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} |
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void x25_start_t23timer(struct sock *sk) |
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{ |
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struct x25_sock *x25 = x25_sk(sk); |
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mod_timer(&x25->timer, jiffies + x25->t23); |
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} |
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void x25_stop_timer(struct sock *sk) |
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{ |
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del_timer(&x25_sk(sk)->timer); |
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} |
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unsigned long x25_display_timer(struct sock *sk) |
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{ |
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struct x25_sock *x25 = x25_sk(sk); |
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if (!timer_pending(&x25->timer)) |
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return 0; |
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return x25->timer.expires - jiffies; |
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} |
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static void x25_heartbeat_expiry(struct timer_list *t) |
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{ |
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struct sock *sk = from_timer(sk, t, sk_timer); |
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bh_lock_sock(sk); |
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if (sock_owned_by_user(sk)) /* can currently only occur in state 3 */ |
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goto restart_heartbeat; |
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switch (x25_sk(sk)->state) { |
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case X25_STATE_0: |
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/* |
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* Magic here: If we listen() and a new link dies |
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* before it is accepted() it isn't 'dead' so doesn't |
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* get removed. |
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*/ |
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if (sock_flag(sk, SOCK_DESTROY) || |
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(sk->sk_state == TCP_LISTEN && |
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sock_flag(sk, SOCK_DEAD))) { |
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bh_unlock_sock(sk); |
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x25_destroy_socket_from_timer(sk); |
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return; |
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} |
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break; |
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case X25_STATE_3: |
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/* |
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* Check for the state of the receive buffer. |
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*/ |
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x25_check_rbuf(sk); |
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break; |
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} |
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restart_heartbeat: |
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x25_start_heartbeat(sk); |
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bh_unlock_sock(sk); |
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} |
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/* |
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* Timer has expired, it may have been T2, T21, T22, or T23. We can tell |
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* by the state machine state. |
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*/ |
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static inline void x25_do_timer_expiry(struct sock * sk) |
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{ |
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struct x25_sock *x25 = x25_sk(sk); |
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switch (x25->state) { |
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case X25_STATE_3: /* T2 */ |
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if (x25->condition & X25_COND_ACK_PENDING) { |
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x25->condition &= ~X25_COND_ACK_PENDING; |
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x25_enquiry_response(sk); |
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} |
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break; |
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case X25_STATE_1: /* T21 */ |
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case X25_STATE_4: /* T22 */ |
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x25_write_internal(sk, X25_CLEAR_REQUEST); |
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x25->state = X25_STATE_2; |
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x25_start_t23timer(sk); |
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break; |
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case X25_STATE_2: /* T23 */ |
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x25_disconnect(sk, ETIMEDOUT, 0, 0); |
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break; |
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} |
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} |
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static void x25_timer_expiry(struct timer_list *t) |
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{ |
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struct x25_sock *x25 = from_timer(x25, t, timer); |
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struct sock *sk = &x25->sk; |
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bh_lock_sock(sk); |
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if (sock_owned_by_user(sk)) { /* can currently only occur in state 3 */ |
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if (x25_sk(sk)->state == X25_STATE_3) |
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x25_start_t2timer(sk); |
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} else |
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x25_do_timer_expiry(sk); |
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bh_unlock_sock(sk); |
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}
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