[mirror_ubuntu-bionic-kernel.git] / net / ax25 / ax25_std_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) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
 * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>

void ax25_std_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:
	case AX25_STATE_4:
		/*
		 * 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;
				ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
				break;
			}
		}
	}

	if (sk)
		bh_unlock_sock(sk);

	ax25_start_heartbeat(ax25);
}

void ax25_std_t2timer_expiry(ax25_cb *ax25)
{
	if (ax25->condition & AX25_COND_ACK_PENDING) {
		ax25->condition &= ~AX25_COND_ACK_PENDING;
		ax25_std_timeout_response(ax25);
	}
}

void ax25_std_t3timer_expiry(ax25_cb *ax25)
{
	ax25->n2count = 0;
	ax25_std_transmit_enquiry(ax25);
	ax25->state   = AX25_STATE_4;
}

void ax25_std_idletimer_expiry(ax25_cb *ax25)
{
	ax25_clear_queues(ax25);

	ax25->n2count = 0;
	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	ax25->state   = AX25_STATE_2;

	ax25_calculate_t1(ax25);
	ax25_start_t1timer(ax25);
	ax25_stop_t2timer(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);
	}
}

void ax25_std_t1timer_expiry(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_POLLON, AX25_COMMAND);
			}
		} else {
			ax25->n2count++;
			if (ax25->modulus == AX25_MODULUS)
				ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
			else
				ax25_send_control(ax25, AX25_SABME, AX25_POLLON, 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++;
			ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
		}
		break;

	case AX25_STATE_3:
		ax25->n2count = 1;
		ax25_std_transmit_enquiry(ax25);
		ax25->state   = AX25_STATE_4;
		break;

	case AX25_STATE_4:
		if (ax25->n2count == ax25->n2) {
			ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
			ax25_disconnect(ax25, ETIMEDOUT);
			return;
		} else {
			ax25->n2count++;
			ax25_std_transmit_enquiry(ax25);
		}
		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) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
	8	* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
	9	* Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
	10	* Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
	11	*/
	12	#include <linux/errno.h>
	13	#include <linux/types.h>
	14	#include <linux/socket.h>
	15	#include <linux/in.h>
	16	#include <linux/kernel.h>
1da177e4 LT	17	#include <linux/timer.h>
	18	#include <linux/string.h>
	19	#include <linux/sockios.h>
	20	#include <linux/net.h>
	21	#include <net/ax25.h>
	22	#include <linux/inet.h>
	23	#include <linux/netdevice.h>
	24	#include <linux/skbuff.h>
	25	#include <net/sock.h>
c752f073	26	#include <net/tcp_states.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	void ax25_std_heartbeat_expiry(ax25_cb *ax25)
	33	{
f16f3026	34	struct sock *sk = ax25->sk;
528930b9	35
1da177e4 LT	36	if (sk)
	37	bh_lock_sock(sk);
	38
	39	switch (ax25->state) {
	40	case AX25_STATE_0:
4a7d99ea	41	case AX25_STATE_2:
88a944ee DM	42	/* Magic here: If we listen() and a new link dies before it
	43	is accepted() it isn't 'dead' so doesn't get removed. */
	44	if (!sk \|\| sock_flag(sk, SOCK_DESTROY) \|\|
	45	(sk->sk_state == TCP_LISTEN &&
	46	sock_flag(sk, SOCK_DEAD))) {
1da177e4 LT	47	if (sk) {
	48	sock_hold(sk);
	49	ax25_destroy_socket(ax25);
	50	bh_unlock_sock(sk);
4a7d99ea	51	/* Ungrab socket and destroy it */
1da177e4 LT	52	sock_put(sk);
	53	} else
	54	ax25_destroy_socket(ax25);
	55	return;
	56	}
	57	break;
	58
	59	case AX25_STATE_3:
	60	case AX25_STATE_4:
	61	/*
	62	* Check the state of the receive buffer.
	63	*/
	64	if (sk != NULL) {
	65	if (atomic_read(&sk->sk_rmem_alloc) <
f16f3026	66	(sk->sk_rcvbuf >> 1) &&
1da177e4 LT	67	(ax25->condition & AX25_COND_OWN_RX_BUSY)) {
	68	ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
	69	ax25->condition &= ~AX25_COND_ACK_PENDING;
	70	ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
	71	break;
	72	}
	73	}
	74	}
	75
	76	if (sk)
	77	bh_unlock_sock(sk);
	78
	79	ax25_start_heartbeat(ax25);
	80	}
	81
	82	void ax25_std_t2timer_expiry(ax25_cb *ax25)
	83	{
	84	if (ax25->condition & AX25_COND_ACK_PENDING) {
	85	ax25->condition &= ~AX25_COND_ACK_PENDING;
	86	ax25_std_timeout_response(ax25);
	87	}
	88	}
	89
	90	void ax25_std_t3timer_expiry(ax25_cb *ax25)
	91	{
	92	ax25->n2count = 0;
	93	ax25_std_transmit_enquiry(ax25);
	94	ax25->state = AX25_STATE_4;
	95	}
	96
	97	void ax25_std_idletimer_expiry(ax25_cb *ax25)
	98	{
	99	ax25_clear_queues(ax25);
	100
	101	ax25->n2count = 0;
	102	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	103	ax25->state = AX25_STATE_2;
	104
	105	ax25_calculate_t1(ax25);
	106	ax25_start_t1timer(ax25);
	107	ax25_stop_t2timer(ax25);
	108	ax25_stop_t3timer(ax25);
	109
	110	if (ax25->sk != NULL) {
	111	bh_lock_sock(ax25->sk);
	112	ax25->sk->sk_state = TCP_CLOSE;
	113	ax25->sk->sk_err = 0;
	114	ax25->sk->sk_shutdown \|= SEND_SHUTDOWN;
	115	if (!sock_flag(ax25->sk, SOCK_DEAD)) {
	116	ax25->sk->sk_state_change(ax25->sk);
	117	sock_set_flag(ax25->sk, SOCK_DEAD);
	118	}
	119	bh_unlock_sock(ax25->sk);
	120	}
	121	}
	122
	123	void ax25_std_t1timer_expiry(ax25_cb *ax25)
	124	{
	125	switch (ax25->state) {
	126	case AX25_STATE_1:
	127	if (ax25->n2count == ax25->n2) {
	128	if (ax25->modulus == AX25_MODULUS) {
	129	ax25_disconnect(ax25, ETIMEDOUT);
	130	return;
131	} else {
132	ax25->modulus = AX25_MODULUS;
133	ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
134	ax25->n2count = 0;
135	ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
136	}
137	} else {
138	ax25->n2count++;
139	if (ax25->modulus == AX25_MODULUS)
140	ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
141	else
142	ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND);
143	}
144	break;
145
146	case AX25_STATE_2:
147	if (ax25->n2count == ax25->n2) {
148	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
4a7d99ea BG	149	if (!sock_flag(ax25->sk, SOCK_DESTROY))
4a7d99ea BG	150	ax25_disconnect(ax25, ETIMEDOUT);
1da177e4 LT	151	return;
	152	} else {
	153	ax25->n2count++;
	154	ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
	155	}
	156	break;
	157
	158	case AX25_STATE_3:
	159	ax25->n2count = 1;
	160	ax25_std_transmit_enquiry(ax25);
	161	ax25->state = AX25_STATE_4;
	162	break;
	163
	164	case AX25_STATE_4:
	165	if (ax25->n2count == ax25->n2) {
	166	ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
	167	ax25_disconnect(ax25, ETIMEDOUT);
	168	return;
	169	} else {
	170	ax25->n2count++;
	171	ax25_std_transmit_enquiry(ax25);
	172	}
	173	break;
	174	}
	175
	176	ax25_calculate_t1(ax25);
	177	ax25_start_t1timer(ax25);
	178	}