[mirror_ubuntu-zesty-kernel.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 (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 <linux/uaccess.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.
 */

void ax25_ds_setup_timer(ax25_dev *ax25_dev)
{
	setup_timer(&ax25_dev->dama.slave_timer, ax25_ds_timeout,
		    (unsigned long)ax25_dev);
}

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;

	ax25_dev->dama.slave_timeout =
		msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10;
	mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ);
}

/*
 *	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;

	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, &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:
	case AX25_STATE_2:
		/* 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);
				bh_unlock_sock(sk);
				/* Ungrab socket and destroy it */
				sock_put(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 >> 1) &&
			    (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);
			if (!sock_flag(ax25->sk, SOCK_DESTROY))
				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 (g4klx@g4klx.demon.co.uk)
	8	* Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
	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>
7c0f6ba6	27	#include <linux/uaccess.h>
1da177e4 LT	28	#include <linux/fcntl.h>
	29	#include <linux/mm.h>
	30	#include <linux/interrupt.h>
	31
	32	static void ax25_ds_timeout(unsigned long);
	33
	34	/*
	35	* Add DAMA slave timeout timer to timer list.
	36	* Unlike the connection based timers the timeout function gets
	37	* triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT
	38	* (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in
	39	* 1/10th of a second.
	40	*/
	41
e848b583	42	void ax25_ds_setup_timer(ax25_dev *ax25_dev)
1da177e4	43	{
e848b583 JP	44	setup_timer(&ax25_dev->dama.slave_timer, ax25_ds_timeout,
e848b583 JP	45	(unsigned long)ax25_dev);
1da177e4 LT	46	}
	47
	48	void ax25_ds_del_timer(ax25_dev *ax25_dev)
	49	{
	50	if (ax25_dev)
	51	del_timer(&ax25_dev->dama.slave_timer);
	52	}
	53
	54	void ax25_ds_set_timer(ax25_dev *ax25_dev)
	55	{
	56	if (ax25_dev == NULL) /* paranoia */
	57	return;
	58
e1fdb5b3 RB	59	ax25_dev->dama.slave_timeout =
e1fdb5b3 RB	60	msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10;
e848b583	61	mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ);
1da177e4 LT	62	}
	63
	64	/*
	65	* DAMA Slave Timeout
	66	* Silently discard all (slave) connections in case our master forgot us...
	67	*/
	68
	69	static void ax25_ds_timeout(unsigned long arg)
	70	{
	71	ax25_dev ax25_dev = (struct ax25_dev ) arg;
	72	ax25_cb *ax25;
1da177e4 LT	73
	74	if (ax25_dev == NULL \|\| !ax25_dev->dama.slave)
	75	return; /* Yikes! */
	76
	77	if (!ax25_dev->dama.slave_timeout \|\| --ax25_dev->dama.slave_timeout) {
	78	ax25_ds_set_timer(ax25_dev);
	79	return;
	80	}
	81
c19c4b9c	82	spin_lock(&ax25_list_lock);
b67bfe0d	83	ax25_for_each(ax25, &ax25_list) {
1da177e4 LT	84	if (ax25->ax25_dev != ax25_dev \|\| !(ax25->condition & AX25_COND_DAMA_MODE))
	85	continue;
	86
	87	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	88	ax25_disconnect(ax25, ETIMEDOUT);
	89	}
c19c4b9c	90	spin_unlock(&ax25_list_lock);
1da177e4 LT	91
	92	ax25_dev_dama_off(ax25_dev);
	93	}
	94
	95	void ax25_ds_heartbeat_expiry(ax25_cb *ax25)
	96	{
	97	struct sock *sk=ax25->sk;
	98
	99	if (sk)
	100	bh_lock_sock(sk);
	101
	102	switch (ax25->state) {
	103
	104	case AX25_STATE_0:
4a7d99ea	105	case AX25_STATE_2:
1da177e4 LT	106	/* Magic here: If we listen() and a new link dies before it
	107	is accepted() it isn't 'dead' so doesn't get removed. */
	108	if (!sk \|\| sock_flag(sk, SOCK_DESTROY) \|\|
	109	(sk->sk_state == TCP_LISTEN &&
	110	sock_flag(sk, SOCK_DEAD))) {
	111	if (sk) {
	112	sock_hold(sk);
	113	ax25_destroy_socket(ax25);
1da177e4	114	bh_unlock_sock(sk);
4a7d99ea	115	/* Ungrab socket and destroy it */
d71b0e9c	116	sock_put(sk);
1da177e4 LT	117	} else
	118	ax25_destroy_socket(ax25);
	119	return;
	120	}
	121	break;
	122
	123	case AX25_STATE_3:
	124	/*
	125	* Check the state of the receive buffer.
	126	*/
	127	if (sk != NULL) {
	128	if (atomic_read(&sk->sk_rmem_alloc) <
f16f3026	129	(sk->sk_rcvbuf >> 1) &&
1da177e4 LT	130	(ax25->condition & AX25_COND_OWN_RX_BUSY)) {
	131	ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
	132	ax25->condition &= ~AX25_COND_ACK_PENDING;
	133	break;
	134	}
	135	}
	136	break;
	137	}
	138
	139	if (sk)
	140	bh_unlock_sock(sk);
	141
	142	ax25_start_heartbeat(ax25);
	143	}
	144
	145	/* dl1bke 960114: T3 works much like the IDLE timeout, but
	146	* gets reloaded with every frame for this
	147	* connection.
	148	*/
	149	void ax25_ds_t3timer_expiry(ax25_cb *ax25)
	150	{
	151	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	152	ax25_dama_off(ax25);
	153	ax25_disconnect(ax25, ETIMEDOUT);
	154	}
	155
	156	/* dl1bke 960228: close the connection when IDLE expires.
	157	* unlike T3 this timer gets reloaded only on
	158	* I frames.
	159	*/
	160	void ax25_ds_idletimer_expiry(ax25_cb *ax25)
	161	{
	162	ax25_clear_queues(ax25);
	163
	164	ax25->n2count = 0;
	165	ax25->state = AX25_STATE_2;
	166
	167	ax25_calculate_t1(ax25);
	168	ax25_start_t1timer(ax25);
	169	ax25_stop_t3timer(ax25);
	170
	171	if (ax25->sk != NULL) {
	172	bh_lock_sock(ax25->sk);
	173	ax25->sk->sk_state = TCP_CLOSE;
	174	ax25->sk->sk_err = 0;
	175	ax25->sk->sk_shutdown \|= SEND_SHUTDOWN;
	176	if (!sock_flag(ax25->sk, SOCK_DEAD)) {
	177	ax25->sk->sk_state_change(ax25->sk);
	178	sock_set_flag(ax25->sk, SOCK_DEAD);
	179	}
	180	bh_unlock_sock(ax25->sk);
	181	}
	182	}
	183
	184	/* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
	185	* within the poll of any connected channel. Remember
	186	* that we are not allowed to send anything unless we
	187	* get polled by the Master.
	188	*
	189	* Thus we'll have to do parts of our T1 handling in
	190	* ax25_enquiry_response().
	191	*/
	192	void ax25_ds_t1_timeout(ax25_cb *ax25)
	193	{
194	switch (ax25->state) {
195	case AX25_STATE_1:
196	if (ax25->n2count == ax25->n2) {
197	if (ax25->modulus == AX25_MODULUS) {
198	ax25_disconnect(ax25, ETIMEDOUT);
199	return;
200	} else {
201	ax25->modulus = AX25_MODULUS;
202	ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
203	ax25->n2count = 0;
204	ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
205	}
206	} else {
207	ax25->n2count++;
208	if (ax25->modulus == AX25_MODULUS)
209	ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
210	else
211	ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND);
212	}
213	break;
214
215	case AX25_STATE_2:
216	if (ax25->n2count == ax25->n2) {
217	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
4a7d99ea BG	218	if (!sock_flag(ax25->sk, SOCK_DESTROY))
4a7d99ea BG	219	ax25_disconnect(ax25, ETIMEDOUT);
1da177e4 LT	220	return;
	221	} else {
	222	ax25->n2count++;
	223	}
	224	break;
	225
	226	case AX25_STATE_3:
	227	if (ax25->n2count == ax25->n2) {
	228	ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
	229	ax25_disconnect(ax25, ETIMEDOUT);
	230	return;
	231	} else {
	232	ax25->n2count++;
	233	}
	234	break;
	235	}
	236
	237	ax25_calculate_t1(ax25);
	238	ax25_start_t1timer(ax25);
	239	}