/* * 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 * * This module: * This module is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * History * X.25 001 Jonathan Naylor Started coding. * X.25 002 Jonathan Naylor New timer architecture. * Centralised disconnection processing. */ #include #include #include #include #include #include static void x25_heartbeat_expiry(unsigned long); static void x25_timer_expiry(unsigned long); void x25_init_timers(struct sock *sk) { struct x25_sock *x25 = x25_sk(sk); init_timer(&x25->timer); x25->timer.data = (unsigned long)sk; x25->timer.function = &x25_timer_expiry; /* initialized by sock_init_data */ sk->sk_timer.data = (unsigned long)sk; 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(unsigned long param) { struct sock *sk = (struct sock *)param; 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(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(unsigned long param) { struct sock *sk = (struct sock *)param; 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); }
