[people/arne_f/kernel.git] / drivers / net / wan / lapbether.c

/*
 *	"LAPB via ethernet" driver release 001
 *
 *	This code REQUIRES 2.1.15 or higher/ NET3.038
 *
 *	This module:
 *		This module 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.
 *
 *	This is a "pseudo" network driver to allow LAPB over Ethernet.
 *
 *	This driver can use any ethernet destination address, and can be 
 *	limited to accept frames from one dedicated ethernet card only.
 *
 *	History
 *	LAPBETH 001	Jonathan Naylor		Cloned from bpqether.c
 *	2000-10-29	Henner Eisen	lapb_data_indication() return status.
 *	2000-11-14	Henner Eisen	dev_hold/put, NETDEV_GOING_DOWN support
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/stat.h>
#include <linux/module.h>
#include <linux/lapb.h>
#include <linux/init.h>

#include <net/x25device.h>

static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

/* If this number is made larger, check that the temporary string buffer
 * in lapbeth_new_device is large enough to store the probe device name.*/
#define MAXLAPBDEV 100

struct lapbethdev {
	struct list_head	node;
	struct net_device	*ethdev;	/* link to ethernet device */
	struct net_device	*axdev;		/* lapbeth device (lapb#) */
};

static LIST_HEAD(lapbeth_devices);

/* ------------------------------------------------------------------------ */

/*
 *	Get the LAPB device for the ethernet device
 */
static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev)
{
	struct lapbethdev *lapbeth;

	list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node) {
		if (lapbeth->ethdev == dev) 
			return lapbeth;
	}
	return NULL;
}

static __inline__ int dev_is_ethdev(struct net_device *dev)
{
	return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
}

/* ------------------------------------------------------------------------ */

/*
 *	Receive a LAPB frame via an ethernet interface.
 */
static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
{
	int len, err;
	struct lapbethdev *lapbeth;

	if (dev_net(dev) != &init_net)
		goto drop;

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
		return NET_RX_DROP;

	if (!pskb_may_pull(skb, 2))
		goto drop;

	rcu_read_lock();
	lapbeth = lapbeth_get_x25_dev(dev);
	if (!lapbeth)
		goto drop_unlock;
	if (!netif_running(lapbeth->axdev))
		goto drop_unlock;

	len = skb->data[0] + skb->data[1] * 256;
	dev->stats.rx_packets++;
	dev->stats.rx_bytes += len;

	skb_pull(skb, 2);	/* Remove the length bytes */
	skb_trim(skb, len);	/* Set the length of the data */

	if ((err = lapb_data_received(lapbeth->axdev, skb)) != LAPB_OK) {
		printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err);
		goto drop_unlock;
	}
out:
	rcu_read_unlock();
	return 0;
drop_unlock:
	kfree_skb(skb);
	goto out;
drop:
	kfree_skb(skb);
	return 0;
}

static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb)
{
	unsigned char *ptr;

	skb_push(skb, 1);

	if (skb_cow(skb, 1))
		return NET_RX_DROP;

	ptr  = skb->data;
	*ptr = X25_IFACE_DATA;

	skb->protocol = x25_type_trans(skb, dev);
	return netif_rx(skb);
}

/*
 *	Send a LAPB frame via an ethernet interface
 */
static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
				      struct net_device *dev)
{
	int err;

	/*
	 * Just to be *really* sure not to send anything if the interface
	 * is down, the ethernet device may have gone.
	 */
	if (!netif_running(dev))
		goto drop;

	/* There should be a pseudo header of 1 byte added by upper layers.
	 * Check to make sure it is there before reading it.
	 */
	if (skb->len < 1)
		goto drop;

	switch (skb->data[0]) {
	case X25_IFACE_DATA:
		break;
	case X25_IFACE_CONNECT:
		if ((err = lapb_connect_request(dev)) != LAPB_OK)
			pr_err("lapb_connect_request error: %d\n", err);
		goto drop;
	case X25_IFACE_DISCONNECT:
		if ((err = lapb_disconnect_request(dev)) != LAPB_OK)
			pr_err("lapb_disconnect_request err: %d\n", err);
		/* Fall thru */
	default:
		goto drop;
	}

	skb_pull(skb, 1);

	if ((err = lapb_data_request(dev, skb)) != LAPB_OK) {
		pr_err("lapb_data_request error - %d\n", err);
		goto drop;
	}
out:
	return NETDEV_TX_OK;
drop:
	kfree_skb(skb);
	goto out;
}

static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
{
	struct lapbethdev *lapbeth = netdev_priv(ndev);
	unsigned char *ptr;
	struct net_device *dev;
	int size = skb->len;

	skb->protocol = htons(ETH_P_X25);

	ptr = skb_push(skb, 2);

	*ptr++ = size % 256;
	*ptr++ = size / 256;

	ndev->stats.tx_packets++;
	ndev->stats.tx_bytes += size;

	skb->dev = dev = lapbeth->ethdev;

	skb_reset_network_header(skb);

	dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);

	dev_queue_xmit(skb);
}

static void lapbeth_connected(struct net_device *dev, int reason)
{
	unsigned char *ptr;
	struct sk_buff *skb = dev_alloc_skb(1);

	if (!skb) {
		pr_err("out of memory\n");
		return;
	}

	ptr  = skb_put(skb, 1);
	*ptr = X25_IFACE_CONNECT;

	skb->protocol = x25_type_trans(skb, dev);
	netif_rx(skb);
}

static void lapbeth_disconnected(struct net_device *dev, int reason)
{
	unsigned char *ptr;
	struct sk_buff *skb = dev_alloc_skb(1);

	if (!skb) {
		pr_err("out of memory\n");
		return;
	}

	ptr  = skb_put(skb, 1);
	*ptr = X25_IFACE_DISCONNECT;

	skb->protocol = x25_type_trans(skb, dev);
	netif_rx(skb);
}

/*
 *	Set AX.25 callsign
 */
static int lapbeth_set_mac_address(struct net_device *dev, void *addr)
{
	struct sockaddr *sa = addr;
	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
	return 0;
}


static const struct lapb_register_struct lapbeth_callbacks = {
	.connect_confirmation    = lapbeth_connected,
	.connect_indication      = lapbeth_connected,
	.disconnect_confirmation = lapbeth_disconnected,
	.disconnect_indication   = lapbeth_disconnected,
	.data_indication         = lapbeth_data_indication,
	.data_transmit           = lapbeth_data_transmit,
};

/*
 * open/close a device
 */
static int lapbeth_open(struct net_device *dev)
{
	int err;

	if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) {
		pr_err("lapb_register error: %d\n", err);
		return -ENODEV;
	}

	netif_start_queue(dev);
	return 0;
}

static int lapbeth_close(struct net_device *dev)
{
	int err;

	netif_stop_queue(dev);

	if ((err = lapb_unregister(dev)) != LAPB_OK)
		pr_err("lapb_unregister error: %d\n", err);

	return 0;
}

/* ------------------------------------------------------------------------ */

static const struct net_device_ops lapbeth_netdev_ops = {
	.ndo_open	     = lapbeth_open,
	.ndo_stop	     = lapbeth_close,
	.ndo_start_xmit	     = lapbeth_xmit,
	.ndo_set_mac_address = lapbeth_set_mac_address,
};

static void lapbeth_setup(struct net_device *dev)
{
	dev->netdev_ops	     = &lapbeth_netdev_ops;
	dev->needs_free_netdev = true;
	dev->type            = ARPHRD_X25;
	dev->hard_header_len = 0;
	dev->mtu             = 1000;
	dev->addr_len        = 0;
}

/*
 *	Setup a new device.
 */
static int lapbeth_new_device(struct net_device *dev)
{
	struct net_device *ndev;
	struct lapbethdev *lapbeth;
	int rc = -ENOMEM;

	ASSERT_RTNL();

	ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN,
			    lapbeth_setup);
	if (!ndev)
		goto out;

	/* When transmitting data:
	 * first this driver removes a pseudo header of 1 byte,
	 * then the lapb module prepends an LAPB header of at most 3 bytes,
	 * then this driver prepends a length field of 2 bytes,
	 * then the underlying Ethernet device prepends its own header.
	 */
	ndev->needed_headroom = -1 + 3 + 2 + dev->hard_header_len
					   + dev->needed_headroom;
	ndev->needed_tailroom = dev->needed_tailroom;

	lapbeth = netdev_priv(ndev);
	lapbeth->axdev = ndev;

	dev_hold(dev);
	lapbeth->ethdev = dev;

	rc = -EIO;
	if (register_netdevice(ndev))
		goto fail;

	list_add_rcu(&lapbeth->node, &lapbeth_devices);
	rc = 0;
out:
	return rc;
fail:
	dev_put(dev);
	free_netdev(ndev);
	goto out;
}

/*
 *	Free a lapb network device.
 */
static void lapbeth_free_device(struct lapbethdev *lapbeth)
{
	dev_put(lapbeth->ethdev);
	list_del_rcu(&lapbeth->node);
	unregister_netdevice(lapbeth->axdev);
}

/*
 *	Handle device status changes.
 *
 * Called from notifier with RTNL held.
 */
static int lapbeth_device_event(struct notifier_block *this,
				unsigned long event, void *ptr)
{
	struct lapbethdev *lapbeth;
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);

	if (dev_net(dev) != &init_net)
		return NOTIFY_DONE;

	if (!dev_is_ethdev(dev))
		return NOTIFY_DONE;

	switch (event) {
	case NETDEV_UP:
		/* New ethernet device -> new LAPB interface	 */
		if (lapbeth_get_x25_dev(dev) == NULL)
			lapbeth_new_device(dev);
		break;
	case NETDEV_DOWN:	
		/* ethernet device closed -> close LAPB interface */
		lapbeth = lapbeth_get_x25_dev(dev);
		if (lapbeth) 
			dev_close(lapbeth->axdev);
		break;
	case NETDEV_UNREGISTER:
		/* ethernet device disappears -> remove LAPB interface */
		lapbeth = lapbeth_get_x25_dev(dev);
		if (lapbeth)
			lapbeth_free_device(lapbeth);
		break;
	}

	return NOTIFY_DONE;
}

/* ------------------------------------------------------------------------ */

static struct packet_type lapbeth_packet_type __read_mostly = {
	.type = cpu_to_be16(ETH_P_DEC),
	.func = lapbeth_rcv,
};

static struct notifier_block lapbeth_dev_notifier = {
	.notifier_call = lapbeth_device_event,
};

static const char banner[] __initconst =
	KERN_INFO "LAPB Ethernet driver version 0.02\n";

static int __init lapbeth_init_driver(void)
{
	dev_add_pack(&lapbeth_packet_type);

	register_netdevice_notifier(&lapbeth_dev_notifier);

	printk(banner);

	return 0;
}
module_init(lapbeth_init_driver);

static void __exit lapbeth_cleanup_driver(void)
{
	struct lapbethdev *lapbeth;
	struct list_head *entry, *tmp;

	dev_remove_pack(&lapbeth_packet_type);
	unregister_netdevice_notifier(&lapbeth_dev_notifier);

	rtnl_lock();
	list_for_each_safe(entry, tmp, &lapbeth_devices) {
		lapbeth = list_entry(entry, struct lapbethdev, node);

		dev_put(lapbeth->ethdev);
		unregister_netdevice(lapbeth->axdev);
	}
	rtnl_unlock();
}
module_exit(lapbeth_cleanup_driver);

MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* "LAPB via ethernet" driver release 001
	3	*
	4	* This code REQUIRES 2.1.15 or higher/ NET3.038
	5	*
	6	* This module:
	7	* This module is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*
	12	* This is a "pseudo" network driver to allow LAPB over Ethernet.
	13	*
	14	* This driver can use any ethernet destination address, and can be
	15	* limited to accept frames from one dedicated ethernet card only.
	16	*
	17	* History
	18	* LAPBETH 001 Jonathan Naylor Cloned from bpqether.c
	19	* 2000-10-29 Henner Eisen lapb_data_indication() return status.
	20	* 2000-11-14 Henner Eisen dev_hold/put, NETDEV_GOING_DOWN support
	21	*/
	22
23efcb73 JP	23	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23efcb73 JP	24
1da177e4 LT	25	#include <linux/errno.h>
	26	#include <linux/types.h>
	27	#include <linux/socket.h>
	28	#include <linux/in.h>
5a0e3ad6	29	#include <linux/slab.h>
1da177e4 LT	30	#include <linux/kernel.h>
	31	#include <linux/string.h>
	32	#include <linux/net.h>
	33	#include <linux/inet.h>
	34	#include <linux/netdevice.h>
	35	#include <linux/if_arp.h>
	36	#include <linux/skbuff.h>
	37	#include <net/sock.h>
7c0f6ba6	38	#include <linux/uaccess.h>
1da177e4 LT	39	#include <linux/mm.h>
	40	#include <linux/interrupt.h>
	41	#include <linux/notifier.h>
	42	#include <linux/stat.h>
1da177e4 LT	43	#include <linux/module.h>
	44	#include <linux/lapb.h>
	45	#include <linux/init.h>
	46
	47	#include <net/x25device.h>
	48
dcfc5d78	49	static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
1da177e4 LT	50
	51	/* If this number is made larger, check that the temporary string buffer
	52	* in lapbeth_new_device is large enough to store the probe device name.*/
	53	#define MAXLAPBDEV 100
	54
	55	struct lapbethdev {
	56	struct list_head node;
	57	struct net_device ethdev; / link to ethernet device */
	58	struct net_device axdev; / lapbeth device (lapb#) */
1da177e4 LT	59	};
1da177e4 LT	60
293a3839	61	static LIST_HEAD(lapbeth_devices);
1da177e4 LT	62
	63	/* ------------------------------------------------------------------------ */
	64
	65	/*
	66	* Get the LAPB device for the ethernet device
	67	*/
	68	static struct lapbethdev lapbeth_get_x25_dev(struct net_device dev)
	69	{
	70	struct lapbethdev *lapbeth;
	71
	72	list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node) {
	73	if (lapbeth->ethdev == dev)
	74	return lapbeth;
	75	}
	76	return NULL;
	77	}
	78
	79	static __inline__ int dev_is_ethdev(struct net_device *dev)
	80	{
	81	return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
	82	}
	83
	84	/* ------------------------------------------------------------------------ */
	85
	86	/*
	87	* Receive a LAPB frame via an ethernet interface.
	88	*/
f2ccd8fa	89	static int lapbeth_rcv(struct sk_buff skb, struct net_device dev, struct packet_type ptype, struct net_device orig_dev)
1da177e4 LT	90	{
	91	int len, err;
	92	struct lapbethdev *lapbeth;
	93
c346dca1	94	if (dev_net(dev) != &init_net)
e730c155 EB	95	goto drop;
e730c155 EB	96
1da177e4 LT	97	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
	98	return NET_RX_DROP;
	99
	100	if (!pskb_may_pull(skb, 2))
	101	goto drop;
	102
	103	rcu_read_lock();
	104	lapbeth = lapbeth_get_x25_dev(dev);
	105	if (!lapbeth)
	106	goto drop_unlock;
	107	if (!netif_running(lapbeth->axdev))
	108	goto drop_unlock;
	109
1da177e4	110	len = skb->data[0] + skb->data[1] * 256;
ea2ebaf8 SH	111	dev->stats.rx_packets++;
ea2ebaf8 SH	112	dev->stats.rx_bytes += len;
1da177e4 LT	113
	114	skb_pull(skb, 2); /* Remove the length bytes */
	115	skb_trim(skb, len); /* Set the length of the data */
	116
	117	if ((err = lapb_data_received(lapbeth->axdev, skb)) != LAPB_OK) {
	118	printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err);
	119	goto drop_unlock;
	120	}
	121	out:
	122	rcu_read_unlock();
	123	return 0;
	124	drop_unlock:
	125	kfree_skb(skb);
	126	goto out;
	127	drop:
	128	kfree_skb(skb);
	129	return 0;
	130	}
	131
	132	static int lapbeth_data_indication(struct net_device dev, struct sk_buff skb)
	133	{
	134	unsigned char *ptr;
	135
	136	skb_push(skb, 1);
	137
	138	if (skb_cow(skb, 1))
	139	return NET_RX_DROP;
	140
	141	ptr = skb->data;
4d99503e	142	*ptr = X25_IFACE_DATA;
1da177e4 LT	143
1da177e4 LT	144	skb->protocol = x25_type_trans(skb, dev);
1da177e4 LT	145	return netif_rx(skb);
	146	}
	147
	148	/*
	149	* Send a LAPB frame via an ethernet interface
	150	*/
d71a6749 SH	151	static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
d71a6749 SH	152	struct net_device *dev)
1da177e4	153	{
d77eeb70	154	int err;
1da177e4 LT	155
	156	/*
	157	* Just to be really sure not to send anything if the interface
	158	* is down, the ethernet device may have gone.
	159	*/
d77eeb70	160	if (!netif_running(dev))
1da177e4	161	goto drop;
1da177e4	162
beafe1d0 XH	163	/* There should be a pseudo header of 1 byte added by upper layers.
	164	* Check to make sure it is there before reading it.
	165	*/
	166	if (skb->len < 1)
	167	goto drop;
	168
1da177e4	169	switch (skb->data[0]) {
4d99503e	170	case X25_IFACE_DATA:
1da177e4	171	break;
4d99503e	172	case X25_IFACE_CONNECT:
1da177e4	173	if ((err = lapb_connect_request(dev)) != LAPB_OK)
23efcb73	174	pr_err("lapb_connect_request error: %d\n", err);
d77eeb70	175	goto drop;
4d99503e	176	case X25_IFACE_DISCONNECT:
1da177e4	177	if ((err = lapb_disconnect_request(dev)) != LAPB_OK)
23efcb73	178	pr_err("lapb_disconnect_request err: %d\n", err);
1da177e4 LT	179	/* Fall thru */
1da177e4 LT	180	default:
d77eeb70	181	goto drop;
1da177e4 LT	182	}
	183
	184	skb_pull(skb, 1);
	185
	186	if ((err = lapb_data_request(dev, skb)) != LAPB_OK) {
23efcb73	187	pr_err("lapb_data_request error - %d\n", err);
1da177e4 LT	188	goto drop;
1da177e4 LT	189	}
1da177e4	190	out:
d77eeb70	191	return NETDEV_TX_OK;
1da177e4 LT	192	drop:
	193	kfree_skb(skb);
	194	goto out;
	195	}
	196
	197	static void lapbeth_data_transmit(struct net_device ndev, struct sk_buff skb)
	198	{
	199	struct lapbethdev *lapbeth = netdev_priv(ndev);
	200	unsigned char *ptr;
	201	struct net_device *dev;
	202	int size = skb->len;
	203
	204	skb->protocol = htons(ETH_P_X25);
	205
	206	ptr = skb_push(skb, 2);
	207
	208	*ptr++ = size % 256;
	209	*ptr++ = size / 256;
	210
ea2ebaf8 SH	211	ndev->stats.tx_packets++;
ea2ebaf8 SH	212	ndev->stats.tx_bytes += size;
1da177e4 LT	213
	214	skb->dev = dev = lapbeth->ethdev;
	215
479fb037 XH	216	skb_reset_network_header(skb);
479fb037 XH	217
0c4e8581	218	dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
1da177e4 LT	219
	220	dev_queue_xmit(skb);
	221	}
	222
	223	static void lapbeth_connected(struct net_device *dev, int reason)
	224	{
	225	unsigned char *ptr;
	226	struct sk_buff *skb = dev_alloc_skb(1);
	227
	228	if (!skb) {
23efcb73	229	pr_err("out of memory\n");
1da177e4 LT	230	return;
	231	}
	232
	233	ptr = skb_put(skb, 1);
4d99503e	234	*ptr = X25_IFACE_CONNECT;
1da177e4 LT	235
1da177e4 LT	236	skb->protocol = x25_type_trans(skb, dev);
1da177e4 LT	237	netif_rx(skb);
	238	}
	239
	240	static void lapbeth_disconnected(struct net_device *dev, int reason)
	241	{
	242	unsigned char *ptr;
	243	struct sk_buff *skb = dev_alloc_skb(1);
	244
	245	if (!skb) {
23efcb73	246	pr_err("out of memory\n");
1da177e4 LT	247	return;
	248	}
	249
	250	ptr = skb_put(skb, 1);
4d99503e	251	*ptr = X25_IFACE_DISCONNECT;
1da177e4 LT	252
1da177e4 LT	253	skb->protocol = x25_type_trans(skb, dev);
1da177e4 LT	254	netif_rx(skb);
	255	}
	256
1da177e4 LT	257	/*
	258	* Set AX.25 callsign
	259	*/
	260	static int lapbeth_set_mac_address(struct net_device dev, void addr)
	261	{
	262	struct sockaddr *sa = addr;
	263	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
	264	return 0;
	265	}
	266
	267
d97a077a	268	static const struct lapb_register_struct lapbeth_callbacks = {
1da177e4 LT	269	.connect_confirmation = lapbeth_connected,
	270	.connect_indication = lapbeth_connected,
	271	.disconnect_confirmation = lapbeth_disconnected,
	272	.disconnect_indication = lapbeth_disconnected,
	273	.data_indication = lapbeth_data_indication,
	274	.data_transmit = lapbeth_data_transmit,
1da177e4 LT	275	};
	276
	277	/*
	278	* open/close a device
	279	*/
	280	static int lapbeth_open(struct net_device *dev)
	281	{
	282	int err;
	283
	284	if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) {
23efcb73	285	pr_err("lapb_register error: %d\n", err);
1da177e4 LT	286	return -ENODEV;
	287	}
	288
	289	netif_start_queue(dev);
	290	return 0;
	291	}
	292
	293	static int lapbeth_close(struct net_device *dev)
	294	{
	295	int err;
	296
	297	netif_stop_queue(dev);
	298
	299	if ((err = lapb_unregister(dev)) != LAPB_OK)
23efcb73	300	pr_err("lapb_unregister error: %d\n", err);
1da177e4 LT	301
	302	return 0;
	303	}
	304
	305	/* ------------------------------------------------------------------------ */
	306
39549b1e SH	307	static const struct net_device_ops lapbeth_netdev_ops = {
	308	.ndo_open = lapbeth_open,
	309	.ndo_stop = lapbeth_close,
	310	.ndo_start_xmit = lapbeth_xmit,
	311	.ndo_set_mac_address = lapbeth_set_mac_address,
	312	};
	313
1da177e4 LT	314	static void lapbeth_setup(struct net_device *dev)
1da177e4 LT	315	{
39549b1e	316	dev->netdev_ops = &lapbeth_netdev_ops;
cf124db5	317	dev->needs_free_netdev = true;
1da177e4	318	dev->type = ARPHRD_X25;
beafe1d0	319	dev->hard_header_len = 0;
1da177e4 LT	320	dev->mtu = 1000;
1da177e4 LT	321	dev->addr_len = 0;
1da177e4 LT	322	}
	323
	324	/*
	325	* Setup a new device.
	326	*/
	327	static int lapbeth_new_device(struct net_device *dev)
	328	{
	329	struct net_device *ndev;
	330	struct lapbethdev *lapbeth;
	331	int rc = -ENOMEM;
	332
	333	ASSERT_RTNL();
	334
c835a677 TG	335	ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN,
c835a677 TG	336	lapbeth_setup);
1da177e4 LT	337	if (!ndev)
	338	goto out;
	339
2ba6bea9 XH	340	/* When transmitting data:
	341	* first this driver removes a pseudo header of 1 byte,
	342	* then the lapb module prepends an LAPB header of at most 3 bytes,
	343	* then this driver prepends a length field of 2 bytes,
	344	* then the underlying Ethernet device prepends its own header.
	345	*/
beafe1d0 XH	346	ndev->needed_headroom = -1 + 3 + 2 + dev->hard_header_len
beafe1d0 XH	347	+ dev->needed_headroom;
ac10e8c9	348	ndev->needed_tailroom = dev->needed_tailroom;
2ba6bea9	349
1da177e4 LT	350	lapbeth = netdev_priv(ndev);
	351	lapbeth->axdev = ndev;
	352
	353	dev_hold(dev);
	354	lapbeth->ethdev = dev;
	355
1da177e4 LT	356	rc = -EIO;
	357	if (register_netdevice(ndev))
	358	goto fail;
	359
	360	list_add_rcu(&lapbeth->node, &lapbeth_devices);
	361	rc = 0;
	362	out:
	363	return rc;
	364	fail:
	365	dev_put(dev);
	366	free_netdev(ndev);
1da177e4 LT	367	goto out;
	368	}
	369
	370	/*
	371	* Free a lapb network device.
	372	*/
	373	static void lapbeth_free_device(struct lapbethdev *lapbeth)
	374	{
	375	dev_put(lapbeth->ethdev);
	376	list_del_rcu(&lapbeth->node);
	377	unregister_netdevice(lapbeth->axdev);
	378	}
	379
	380	/*
	381	* Handle device status changes.
	382	*
	383	* Called from notifier with RTNL held.
	384	*/
	385	static int lapbeth_device_event(struct notifier_block *this,
	386	unsigned long event, void *ptr)
	387	{
	388	struct lapbethdev *lapbeth;
351638e7	389	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1da177e4	390
c346dca1	391	if (dev_net(dev) != &init_net)
e9dc8653 EB	392	return NOTIFY_DONE;
e9dc8653 EB	393
1da177e4 LT	394	if (!dev_is_ethdev(dev))
	395	return NOTIFY_DONE;
	396
	397	switch (event) {
	398	case NETDEV_UP:
	399	/* New ethernet device -> new LAPB interface */
	400	if (lapbeth_get_x25_dev(dev) == NULL)
	401	lapbeth_new_device(dev);
	402	break;
	403	case NETDEV_DOWN:
	404	/* ethernet device closed -> close LAPB interface */
	405	lapbeth = lapbeth_get_x25_dev(dev);
	406	if (lapbeth)
	407	dev_close(lapbeth->axdev);
	408	break;
	409	case NETDEV_UNREGISTER:
	410	/* ethernet device disappears -> remove LAPB interface */
	411	lapbeth = lapbeth_get_x25_dev(dev);
	412	if (lapbeth)
	413	lapbeth_free_device(lapbeth);
	414	break;
	415	}
	416
	417	return NOTIFY_DONE;
	418	}
	419
	420	/* ------------------------------------------------------------------------ */
	421
7546dd97	422	static struct packet_type lapbeth_packet_type __read_mostly = {
09640e63	423	.type = cpu_to_be16(ETH_P_DEC),
1da177e4 LT	424	.func = lapbeth_rcv,
	425	};
	426
	427	static struct notifier_block lapbeth_dev_notifier = {
	428	.notifier_call = lapbeth_device_event,
	429	};
	430
81b700b1	431	static const char banner[] __initconst =
5ee0d593	432	KERN_INFO "LAPB Ethernet driver version 0.02\n";
1da177e4 LT	433
	434	static int __init lapbeth_init_driver(void)
	435	{
	436	dev_add_pack(&lapbeth_packet_type);
	437
	438	register_netdevice_notifier(&lapbeth_dev_notifier);
	439
	440	printk(banner);
	441
	442	return 0;
	443	}
	444	module_init(lapbeth_init_driver);
	445
	446	static void __exit lapbeth_cleanup_driver(void)
	447	{
	448	struct lapbethdev *lapbeth;
	449	struct list_head entry, tmp;
	450
	451	dev_remove_pack(&lapbeth_packet_type);
	452	unregister_netdevice_notifier(&lapbeth_dev_notifier);
	453
	454	rtnl_lock();
	455	list_for_each_safe(entry, tmp, &lapbeth_devices) {
	456	lapbeth = list_entry(entry, struct lapbethdev, node);
	457
e544ff00	458	dev_put(lapbeth->ethdev);
1da177e4 LT	459	unregister_netdevice(lapbeth->axdev);
	460	}
	461	rtnl_unlock();
	462	}
	463	module_exit(lapbeth_cleanup_driver);
	464
	465	MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
	466	MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
	467	MODULE_LICENSE("GPL");