[linux.git] / net / ax25 / ax25_ds_timer.c

/*
 * 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 ([email protected])
 * Copyright (C) Joerg Reuter DL1BKE ([email protected])
 */
#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_bh(&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_bh(&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);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License as published by
	4	* the Free Software Foundation; either version 2 of the License, or
	5	* (at your option) any later version.
	6	*
	7	* Copyright (C) Jonathan Naylor G4KLX ([email protected])
	8	* Copyright (C) Joerg Reuter DL1BKE ([email protected])
	9	*/
	10	#include <linux/errno.h>
	11	#include <linux/types.h>
	12	#include <linux/socket.h>
	13	#include <linux/spinlock.h>
	14	#include <linux/in.h>
	15	#include <linux/kernel.h>
	16	#include <linux/jiffies.h>
	17	#include <linux/timer.h>
	18	#include <linux/string.h>
	19	#include <linux/sockios.h>
	20	#include <linux/net.h>
c752f073	21	#include <net/tcp_states.h>
1da177e4 LT	22	#include <net/ax25.h>
	23	#include <linux/inet.h>
	24	#include <linux/netdevice.h>
	25	#include <linux/skbuff.h>
	26	#include <net/sock.h>
	27	#include <asm/uaccess.h>
	28	#include <asm/system.h>
	29	#include <linux/fcntl.h>
	30	#include <linux/mm.h>
	31	#include <linux/interrupt.h>
	32
	33	static void ax25_ds_timeout(unsigned long);
	34
	35	/*
	36	* Add DAMA slave timeout timer to timer list.
	37	* Unlike the connection based timers the timeout function gets
	38	* triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT
	39	* (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in
	40	* 1/10th of a second.
	41	*/
	42
	43	static void ax25_ds_add_timer(ax25_dev *ax25_dev)
	44	{
	45	struct timer_list *t = &ax25_dev->dama.slave_timer;
	46	t->data = (unsigned long) ax25_dev;
	47	t->function = &ax25_ds_timeout;
	48	t->expires = jiffies + HZ;
	49	add_timer(t);
	50	}
	51
	52	void ax25_ds_del_timer(ax25_dev *ax25_dev)
	53	{
	54	if (ax25_dev)
	55	del_timer(&ax25_dev->dama.slave_timer);
	56	}
	57
	58	void ax25_ds_set_timer(ax25_dev *ax25_dev)
	59	{
	60	if (ax25_dev == NULL) /* paranoia */
	61	return;
	62
	63	del_timer(&ax25_dev->dama.slave_timer);
e1fdb5b3 RB	64	ax25_dev->dama.slave_timeout =
e1fdb5b3 RB	65	msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10;
1da177e4 LT	66	ax25_ds_add_timer(ax25_dev);
	67	}
	68
	69	/*
	70	* DAMA Slave Timeout
	71	* Silently discard all (slave) connections in case our master forgot us...
	72	*/
	73
	74	static void ax25_ds_timeout(unsigned long arg)
	75	{
	76	ax25_dev ax25_dev = (struct ax25_dev ) arg;
	77	ax25_cb *ax25;
	78	struct hlist_node *node;
	79
	80	if (ax25_dev == NULL \|\| !ax25_dev->dama.slave)
	81	return; /* Yikes! */
	82
	83	if (!ax25_dev->dama.slave_timeout \|\| --ax25_dev->dama.slave_timeout) {
	84	ax25_ds_set_timer(ax25_dev);
	85	return;
	86	}
	87
	88	spin_lock_bh(&ax25_list_lock);
	89	ax25_for_each(ax25, node, &ax25_list) {
	90	if (ax25->ax25_dev != ax25_dev \|\| !(ax25->condition & AX25_COND_DAMA_MODE))
	91	continue;
	92
	93	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	94	ax25_disconnect(ax25, ETIMEDOUT);
	95	}
	96	spin_unlock_bh(&ax25_list_lock);
	97
	98	ax25_dev_dama_off(ax25_dev);
	99	}
	100
	101	void ax25_ds_heartbeat_expiry(ax25_cb *ax25)
	102	{
	103	struct sock *sk=ax25->sk;
	104
	105	if (sk)
	106	bh_lock_sock(sk);
	107
	108	switch (ax25->state) {
	109
	110	case AX25_STATE_0:
	111	/* Magic here: If we listen() and a new link dies before it
	112	is accepted() it isn't 'dead' so doesn't get removed. */
	113	if (!sk \|\| sock_flag(sk, SOCK_DESTROY) \|\|
	114	(sk->sk_state == TCP_LISTEN &&
	115	sock_flag(sk, SOCK_DEAD))) {
	116	if (sk) {
	117	sock_hold(sk);
	118	ax25_destroy_socket(ax25);
	119	sock_put(sk);
	120	bh_unlock_sock(sk);
	121	} else
	122	ax25_destroy_socket(ax25);
	123	return;
	124	}
	125	break;
	126
	127	case AX25_STATE_3:
	128	/*
	129	* Check the state of the receive buffer.
130	*/
131	if (sk != NULL) {
132	if (atomic_read(&sk->sk_rmem_alloc) <
133	(sk->sk_rcvbuf / 2) &&
134	(ax25->condition & AX25_COND_OWN_RX_BUSY)) {
135	ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
136	ax25->condition &= ~AX25_COND_ACK_PENDING;
137	break;
138	}
139	}
140	break;
141	}
142
143	if (sk)
144	bh_unlock_sock(sk);
145
146	ax25_start_heartbeat(ax25);
147	}
148
149	/* dl1bke 960114: T3 works much like the IDLE timeout, but
150	* gets reloaded with every frame for this
151	* connection.
152	*/
153	void ax25_ds_t3timer_expiry(ax25_cb *ax25)
154	{
155	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
156	ax25_dama_off(ax25);
157	ax25_disconnect(ax25, ETIMEDOUT);
158	}
159
160	/* dl1bke 960228: close the connection when IDLE expires.
161	* unlike T3 this timer gets reloaded only on
162	* I frames.
163	*/
164	void ax25_ds_idletimer_expiry(ax25_cb *ax25)
165	{
166	ax25_clear_queues(ax25);
167
168	ax25->n2count = 0;
169	ax25->state = AX25_STATE_2;
170
171	ax25_calculate_t1(ax25);
172	ax25_start_t1timer(ax25);
173	ax25_stop_t3timer(ax25);
174
175	if (ax25->sk != NULL) {
176	bh_lock_sock(ax25->sk);
177	ax25->sk->sk_state = TCP_CLOSE;
178	ax25->sk->sk_err = 0;
179	ax25->sk->sk_shutdown \|= SEND_SHUTDOWN;
180	if (!sock_flag(ax25->sk, SOCK_DEAD)) {
181	ax25->sk->sk_state_change(ax25->sk);
182	sock_set_flag(ax25->sk, SOCK_DEAD);
183	}
184	bh_unlock_sock(ax25->sk);
185	}
186	}
187
188	/* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
189	* within the poll of any connected channel. Remember
190	* that we are not allowed to send anything unless we
191	* get polled by the Master.
192	*
193	* Thus we'll have to do parts of our T1 handling in
194	* ax25_enquiry_response().
195	*/
196	void ax25_ds_t1_timeout(ax25_cb *ax25)
197	{
198	switch (ax25->state) {
199	case AX25_STATE_1:
200	if (ax25->n2count == ax25->n2) {
201	if (ax25->modulus == AX25_MODULUS) {
202	ax25_disconnect(ax25, ETIMEDOUT);
203	return;
204	} else {
205	ax25->modulus = AX25_MODULUS;
206	ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
207	ax25->n2count = 0;
208	ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
209	}
210	} else {
211	ax25->n2count++;
212	if (ax25->modulus == AX25_MODULUS)
213	ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
214	else
215	ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND);
216	}
217	break;
218
219	case AX25_STATE_2:
220	if (ax25->n2count == ax25->n2) {
221	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
222	ax25_disconnect(ax25, ETIMEDOUT);
223	return;
224	} else {
225	ax25->n2count++;
226	}
227	break;
228
229	case AX25_STATE_3:
230	if (ax25->n2count == ax25->n2) {
231	ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
232	ax25_disconnect(ax25, ETIMEDOUT);
233	return;
234	} else {
235	ax25->n2count++;
236	}
237	break;
238	}
239
240	ax25_calculate_t1(ax25);
241	ax25_start_t1timer(ax25);
242	}