/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include static void x25_heartbeat_expiry(unsigned long); static void x25_timer_expiry(unsigned long); void x25_start_heartbeat(struct sock *sk) { del_timer(&sk->timer); sk->timer.data = (unsigned long)sk; sk->timer.function = &x25_heartbeat_expiry; sk->timer.expires = jiffies + 5 * HZ; add_timer(&sk->timer); } void x25_stop_heartbeat(struct sock *sk) { del_timer(&sk->timer); } void x25_start_t2timer(struct sock *sk) { del_timer(&sk->protinfo.x25->timer); sk->protinfo.x25->timer.data = (unsigned long)sk; sk->protinfo.x25->timer.function = &x25_timer_expiry; sk->protinfo.x25->timer.expires = jiffies + sk->protinfo.x25->t2; add_timer(&sk->protinfo.x25->timer); } void x25_start_t21timer(struct sock *sk) { del_timer(&sk->protinfo.x25->timer); sk->protinfo.x25->timer.data = (unsigned long)sk; sk->protinfo.x25->timer.function = &x25_timer_expiry; sk->protinfo.x25->timer.expires = jiffies + sk->protinfo.x25->t21; add_timer(&sk->protinfo.x25->timer); } void x25_start_t22timer(struct sock *sk) { del_timer(&sk->protinfo.x25->timer); sk->protinfo.x25->timer.data = (unsigned long)sk; sk->protinfo.x25->timer.function = &x25_timer_expiry; sk->protinfo.x25->timer.expires = jiffies + sk->protinfo.x25->t22; add_timer(&sk->protinfo.x25->timer); } void x25_start_t23timer(struct sock *sk) { del_timer(&sk->protinfo.x25->timer); sk->protinfo.x25->timer.data = (unsigned long)sk; sk->protinfo.x25->timer.function = &x25_timer_expiry; sk->protinfo.x25->timer.expires = jiffies + sk->protinfo.x25->t23; add_timer(&sk->protinfo.x25->timer); } void x25_stop_timer(struct sock *sk) { del_timer(&sk->protinfo.x25->timer); } unsigned long x25_display_timer(struct sock *sk) { if (!timer_pending(&sk->protinfo.x25->timer)) return 0; return sk->protinfo.x25->timer.expires - jiffies; } static void x25_heartbeat_expiry(unsigned long param) { struct sock *sk = (struct sock *)param; bh_lock_sock(sk); if (sk->lock.users) { /* can currently only occur in state 3 */ goto restart_heartbeat; } switch (sk->protinfo.x25->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 (sk->destroy || (sk->state == TCP_LISTEN && sk->dead)) { x25_destroy_socket(sk); goto unlock; } break; case X25_STATE_3: /* * Check for the state of the receive buffer. */ x25_check_rbuf(sk); break; } restart_heartbeat: x25_start_heartbeat(sk); unlock: 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) { switch (sk->protinfo.x25->state) { case X25_STATE_3: /* T2 */ if (sk->protinfo.x25->condition & X25_COND_ACK_PENDING) { sk->protinfo.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); sk->protinfo.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 (sk->lock.users) { /* can currently only occur in state 3 */ if (sk->protinfo.x25->state == X25_STATE_3) { x25_start_t2timer(sk); } } else { x25_do_timer_expiry(sk); } bh_unlock_sock(sk); }
