/* * This program 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. * * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de) */ #include <linux/errno.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/spinlock.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/tcp_states.h> #include <net/ax25.h> #include <linux/inet.h> #include <linux/netdevice.h> #include <linux/skbuff.h> #include <net/sock.h> #include <asm/uaccess.h> #include <asm/system.h> #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> static void ax25_ds_timeout(unsigned long); /* * Add DAMA slave timeout timer to timer list. * Unlike the connection based timers the timeout function gets * triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT * (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in * 1/10th of a second. */ static void ax25_ds_add_timer(ax25_dev *ax25_dev) { struct timer_list *t = &ax25_dev->dama.slave_timer; t->data = (unsigned long) ax25_dev; t->function = &ax25_ds_timeout; t->expires = jiffies + HZ; add_timer(t); } void ax25_ds_del_timer(ax25_dev *ax25_dev) { if (ax25_dev) del_timer(&ax25_dev->dama.slave_timer); } void ax25_ds_set_timer(ax25_dev *ax25_dev) { if (ax25_dev == NULL) /* paranoia */ return; del_timer(&ax25_dev->dama.slave_timer); ax25_dev->dama.slave_timeout = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10; ax25_ds_add_timer(ax25_dev); } /* * DAMA Slave Timeout * Silently discard all (slave) connections in case our master forgot us... */ static void ax25_ds_timeout(unsigned long arg) { ax25_dev *ax25_dev = (struct ax25_dev *) arg; ax25_cb *ax25; struct hlist_node *node; if (ax25_dev == NULL || !ax25_dev->dama.slave) return; /* Yikes! */ if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) { ax25_ds_set_timer(ax25_dev); return; } spin_lock(&ax25_list_lock); ax25_for_each(ax25, node, &ax25_list) { if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE)) continue; ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); ax25_disconnect(ax25, ETIMEDOUT); } spin_unlock(&ax25_list_lock); ax25_dev_dama_off(ax25_dev); } void ax25_ds_heartbeat_expiry(ax25_cb *ax25) { struct sock *sk=ax25->sk; if (sk) bh_lock_sock(sk); switch (ax25->state) { case AX25_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 || sock_flag(sk, SOCK_DESTROY) || (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) { if (sk) { sock_hold(sk); ax25_destroy_socket(ax25); sock_put(sk); bh_unlock_sock(sk); } else ax25_destroy_socket(ax25); return; } break; case AX25_STATE_3: /* * Check the state of the receive buffer. */ if (sk != NULL) { if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) && (ax25->condition & AX25_COND_OWN_RX_BUSY)) { ax25->condition &= ~AX25_COND_OWN_RX_BUSY; ax25->condition &= ~AX25_COND_ACK_PENDING; break; } } break; } if (sk) bh_unlock_sock(sk); ax25_start_heartbeat(ax25); } /* dl1bke 960114: T3 works much like the IDLE timeout, but * gets reloaded with every frame for this * connection. */ void ax25_ds_t3timer_expiry(ax25_cb *ax25) { ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); ax25_dama_off(ax25); ax25_disconnect(ax25, ETIMEDOUT); } /* dl1bke 960228: close the connection when IDLE expires. * unlike T3 this timer gets reloaded only on * I frames. */ void ax25_ds_idletimer_expiry(ax25_cb *ax25) { ax25_clear_queues(ax25); ax25->n2count = 0; ax25->state = AX25_STATE_2; ax25_calculate_t1(ax25); ax25_start_t1timer(ax25); ax25_stop_t3timer(ax25); if (ax25->sk != NULL) { bh_lock_sock(ax25->sk); ax25->sk->sk_state = TCP_CLOSE; ax25->sk->sk_err = 0; ax25->sk->sk_shutdown |= SEND_SHUTDOWN; if (!sock_flag(ax25->sk, SOCK_DEAD)) { ax25->sk->sk_state_change(ax25->sk); sock_set_flag(ax25->sk, SOCK_DEAD); } bh_unlock_sock(ax25->sk); } } /* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC * within the poll of any connected channel. Remember * that we are not allowed to send anything unless we * get polled by the Master. * * Thus we'll have to do parts of our T1 handling in * ax25_enquiry_response(). */ void ax25_ds_t1_timeout(ax25_cb *ax25) { switch (ax25->state) { case AX25_STATE_1: if (ax25->n2count == ax25->n2) { if (ax25->modulus == AX25_MODULUS) { ax25_disconnect(ax25, ETIMEDOUT); return; } else { ax25->modulus = AX25_MODULUS; ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW]; ax25->n2count = 0; ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND); } } else { ax25->n2count++; if (ax25->modulus == AX25_MODULUS) ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND); else ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND); } break; case AX25_STATE_2: if (ax25->n2count == ax25->n2) { ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); ax25_disconnect(ax25, ETIMEDOUT); return; } else { ax25->n2count++; } break; case AX25_STATE_3: if (ax25->n2count == ax25->n2) { ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE); ax25_disconnect(ax25, ETIMEDOUT); return; } else { ax25->n2count++; } break; } ax25_calculate_t1(ax25); ax25_start_t1timer(ax25); }