[net-next-2.6.git] / net / ax25 / ax25_ds_subr.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/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/spinlock.h>
#include <linux/net.h>
#include <linux/gfp.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>

void ax25_ds_nr_error_recovery(ax25_cb *ax25)
{
	ax25_ds_establish_data_link(ax25);
}

/*
 *	dl1bke 960114: transmit I frames on DAMA poll
 */
void ax25_ds_enquiry_response(ax25_cb *ax25)
{
	ax25_cb *ax25o;
	struct hlist_node *node;

	/* Please note that neither DK4EG's nor DG2FEF's
	 * DAMA spec mention the following behaviour as seen
	 * with TheFirmware:
	 *
	 * 	DB0ACH->DL1BKE <RR C P R0> [DAMA]
	 *	DL1BKE->DB0ACH <I NR=0 NS=0>
	 *	DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
	 *	DL1BKE->DB0ACH <RR R F R0>
	 *
	 * The Flexnet DAMA Master implementation apparently
	 * insists on the "proper" AX.25 behaviour:
	 *
	 * 	DB0ACH->DL1BKE <RR C P R0> [DAMA]
	 *	DL1BKE->DB0ACH <RR R F R0>
	 *	DL1BKE->DB0ACH <I NR=0 NS=0>
	 *	DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
	 *
	 * Flexnet refuses to send us *any* I frame if we send
	 * a REJ in case AX25_COND_REJECT is set. It is superfluous in
	 * this mode anyway (a RR or RNR invokes the retransmission).
	 * Is this a Flexnet bug?
	 */

	ax25_std_enquiry_response(ax25);

	if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) {
		ax25_requeue_frames(ax25);
		ax25_kick(ax25);
	}

	if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL)
		ax25_ds_t1_timeout(ax25);
	else
		ax25->n2count = 0;

	ax25_start_t3timer(ax25);
	ax25_ds_set_timer(ax25->ax25_dev);

	spin_lock(&ax25_list_lock);
	ax25_for_each(ax25o, node, &ax25_list) {
		if (ax25o == ax25)
			continue;

		if (ax25o->ax25_dev != ax25->ax25_dev)
			continue;

		if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) {
			ax25_ds_t1_timeout(ax25o);
			continue;
		}

		if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) {
			ax25_requeue_frames(ax25o);
			ax25_kick(ax25o);
		}

		if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL)
			ax25_ds_t1_timeout(ax25o);

		/* do not start T3 for listening sockets (tnx DD8NE) */

		if (ax25o->state != AX25_STATE_0)
			ax25_start_t3timer(ax25o);
	}
	spin_unlock(&ax25_list_lock);
}

void ax25_ds_establish_data_link(ax25_cb *ax25)
{
	ax25->condition &= AX25_COND_DAMA_MODE;
	ax25->n2count    = 0;
	ax25_calculate_t1(ax25);
	ax25_start_t1timer(ax25);
	ax25_stop_t2timer(ax25);
	ax25_start_t3timer(ax25);
}

/*
 *	:::FIXME:::
 *	This is a kludge. Not all drivers recognize kiss commands.
 *	We need a driver level  request to switch duplex mode, that does
 *	either SCC changing, PI config or KISS as required. Currently
 *	this request isn't reliable.
 */
static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param)
{
	struct sk_buff *skb;
	unsigned char *p;

	if (ax25_dev->dev == NULL)
		return;

	if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL)
		return;

	skb_reset_network_header(skb);
	p = skb_put(skb, 2);

	*p++ = cmd;
	*p++ = param;

	skb->protocol = ax25_type_trans(skb, ax25_dev->dev);

	dev_queue_xmit(skb);
}

/*
 *	A nasty problem arises if we count the number of DAMA connections
 *	wrong, especially when connections on the device already existed
 *	and our network node (or the sysop) decides to turn on DAMA Master
 *	mode. We thus flag the 'real' slave connections with
 *	ax25->dama_slave=1 and look on every disconnect if still slave
 *	connections exist.
 */
static int ax25_check_dama_slave(ax25_dev *ax25_dev)
{
	ax25_cb *ax25;
	int res = 0;
	struct hlist_node *node;

	spin_lock(&ax25_list_lock);
	ax25_for_each(ax25, node, &ax25_list)
		if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) {
			res = 1;
			break;
		}
	spin_unlock(&ax25_list_lock);

	return res;
}

static void ax25_dev_dama_on(ax25_dev *ax25_dev)
{
	if (ax25_dev == NULL)
		return;

	if (ax25_dev->dama.slave == 0)
		ax25_kiss_cmd(ax25_dev, 5, 1);

	ax25_dev->dama.slave = 1;
	ax25_ds_set_timer(ax25_dev);
}

void ax25_dev_dama_off(ax25_dev *ax25_dev)
{
	if (ax25_dev == NULL)
		return;

	if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) {
		ax25_kiss_cmd(ax25_dev, 5, 0);
		ax25_dev->dama.slave = 0;
		ax25_ds_del_timer(ax25_dev);
	}
}

void ax25_dama_on(ax25_cb *ax25)
{
	ax25_dev_dama_on(ax25->ax25_dev);
	ax25->condition |= AX25_COND_DAMA_MODE;
}

void ax25_dama_off(ax25_cb *ax25)
{
	ax25->condition &= ~AX25_COND_DAMA_MODE;
	ax25_dev_dama_off(ax25->ax25_dev);
}
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/in.h>
	14	#include <linux/kernel.h>
1da177e4 LT	15	#include <linux/timer.h>
	16	#include <linux/string.h>
	17	#include <linux/sockios.h>
	18	#include <linux/spinlock.h>
	19	#include <linux/net.h>
5a0e3ad6	20	#include <linux/gfp.h>
1da177e4 LT	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>
	26	#include <asm/uaccess.h>
	27	#include <asm/system.h>
	28	#include <linux/fcntl.h>
	29	#include <linux/mm.h>
	30	#include <linux/interrupt.h>
	31
	32	void ax25_ds_nr_error_recovery(ax25_cb *ax25)
	33	{
	34	ax25_ds_establish_data_link(ax25);
	35	}
	36
	37	/*
	38	* dl1bke 960114: transmit I frames on DAMA poll
	39	*/
	40	void ax25_ds_enquiry_response(ax25_cb *ax25)
	41	{
	42	ax25_cb *ax25o;
	43	struct hlist_node *node;
	44
96de0e25	45	/* Please note that neither DK4EG's nor DG2FEF's
1da177e4 LT	46	* DAMA spec mention the following behaviour as seen
	47	* with TheFirmware:
	48	*
	49	* DB0ACH->DL1BKE <RR C P R0> [DAMA]
	50	* DL1BKE->DB0ACH <I NR=0 NS=0>
	51	* DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
	52	* DL1BKE->DB0ACH <RR R F R0>
	53	*
	54	* The Flexnet DAMA Master implementation apparently
	55	* insists on the "proper" AX.25 behaviour:
	56	*
	57	* DB0ACH->DL1BKE <RR C P R0> [DAMA]
	58	* DL1BKE->DB0ACH <RR R F R0>
	59	* DL1BKE->DB0ACH <I NR=0 NS=0>
	60	* DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
	61	*
	62	* Flexnet refuses to send us any I frame if we send
	63	* a REJ in case AX25_COND_REJECT is set. It is superfluous in
	64	* this mode anyway (a RR or RNR invokes the retransmission).
	65	* Is this a Flexnet bug?
	66	*/
	67
	68	ax25_std_enquiry_response(ax25);
	69
	70	if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) {
	71	ax25_requeue_frames(ax25);
	72	ax25_kick(ax25);
	73	}
	74
	75	if (ax25->state == AX25_STATE_1 \|\| ax25->state == AX25_STATE_2 \|\| skb_peek(&ax25->ack_queue) != NULL)
	76	ax25_ds_t1_timeout(ax25);
	77	else
	78	ax25->n2count = 0;
	79
	80	ax25_start_t3timer(ax25);
	81	ax25_ds_set_timer(ax25->ax25_dev);
	82
c19c4b9c	83	spin_lock(&ax25_list_lock);
1da177e4 LT	84	ax25_for_each(ax25o, node, &ax25_list) {
	85	if (ax25o == ax25)
	86	continue;
	87
	88	if (ax25o->ax25_dev != ax25->ax25_dev)
	89	continue;
	90
	91	if (ax25o->state == AX25_STATE_1 \|\| ax25o->state == AX25_STATE_2) {
	92	ax25_ds_t1_timeout(ax25o);
	93	continue;
	94	}
	95
	96	if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) {
	97	ax25_requeue_frames(ax25o);
	98	ax25_kick(ax25o);
	99	}
	100
	101	if (ax25o->state == AX25_STATE_1 \|\| ax25o->state == AX25_STATE_2 \|\| skb_peek(&ax25o->ack_queue) != NULL)
	102	ax25_ds_t1_timeout(ax25o);
	103
	104	/* do not start T3 for listening sockets (tnx DD8NE) */
	105
	106	if (ax25o->state != AX25_STATE_0)
	107	ax25_start_t3timer(ax25o);
	108	}
c19c4b9c	109	spin_unlock(&ax25_list_lock);
1da177e4 LT	110	}
	111
	112	void ax25_ds_establish_data_link(ax25_cb *ax25)
	113	{
	114	ax25->condition &= AX25_COND_DAMA_MODE;
	115	ax25->n2count = 0;
	116	ax25_calculate_t1(ax25);
	117	ax25_start_t1timer(ax25);
	118	ax25_stop_t2timer(ax25);
	119	ax25_start_t3timer(ax25);
	120	}
	121
	122	/*
	123	* :::FIXME:::
	124	* This is a kludge. Not all drivers recognize kiss commands.
	125	* We need a driver level request to switch duplex mode, that does
	126	* either SCC changing, PI config or KISS as required. Currently
	127	* this request isn't reliable.
	128	*/
	129	static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param)
	130	{
	131	struct sk_buff *skb;
	132	unsigned char *p;
	133
	134	if (ax25_dev->dev == NULL)
	135	return;
	136
	137	if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL)
	138	return;
	139
c1d2bbe1	140	skb_reset_network_header(skb);
1da177e4 LT	141	p = skb_put(skb, 2);
	142
	143	*p++ = cmd;
	144	*p++ = param;
	145
56cb5156	146	skb->protocol = ax25_type_trans(skb, ax25_dev->dev);
1da177e4 LT	147
	148	dev_queue_xmit(skb);
	149	}
	150
	151	/*
	152	* A nasty problem arises if we count the number of DAMA connections
	153	* wrong, especially when connections on the device already existed
	154	* and our network node (or the sysop) decides to turn on DAMA Master
	155	* mode. We thus flag the 'real' slave connections with
	156	* ax25->dama_slave=1 and look on every disconnect if still slave
	157	* connections exist.
	158	*/
	159	static int ax25_check_dama_slave(ax25_dev *ax25_dev)
	160	{
	161	ax25_cb *ax25;
	162	int res = 0;
	163	struct hlist_node *node;
	164
c19c4b9c	165	spin_lock(&ax25_list_lock);
1da177e4 LT	166	ax25_for_each(ax25, node, &ax25_list)
	167	if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) {
	168	res = 1;
	169	break;
	170	}
c19c4b9c	171	spin_unlock(&ax25_list_lock);
1da177e4 LT	172
	173	return res;
	174	}
	175
	176	static void ax25_dev_dama_on(ax25_dev *ax25_dev)
	177	{
	178	if (ax25_dev == NULL)
	179	return;
	180
	181	if (ax25_dev->dama.slave == 0)
	182	ax25_kiss_cmd(ax25_dev, 5, 1);
	183
	184	ax25_dev->dama.slave = 1;
	185	ax25_ds_set_timer(ax25_dev);
	186	}
	187
	188	void ax25_dev_dama_off(ax25_dev *ax25_dev)
	189	{
	190	if (ax25_dev == NULL)
	191	return;
	192
	193	if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) {
	194	ax25_kiss_cmd(ax25_dev, 5, 0);
	195	ax25_dev->dama.slave = 0;
	196	ax25_ds_del_timer(ax25_dev);
	197	}
	198	}
	199
	200	void ax25_dama_on(ax25_cb *ax25)
	201	{
	202	ax25_dev_dama_on(ax25->ax25_dev);
	203	ax25->condition \|= AX25_COND_DAMA_MODE;
	204	}
	205
	206	void ax25_dama_off(ax25_cb *ax25)
	207	{
	208	ax25->condition &= ~AX25_COND_DAMA_MODE;
	209	ax25_dev_dama_off(ax25->ax25_dev);
	210	}
	211