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v4.10.11
 
  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
 23#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 24
 25#include <linux/errno.h>
 26#include <linux/types.h>
 27#include <linux/socket.h>
 28#include <linux/in.h>
 29#include <linux/slab.h>
 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>
 38#include <linux/uaccess.h>
 39#include <linux/mm.h>
 40#include <linux/interrupt.h>
 41#include <linux/notifier.h>
 42#include <linux/stat.h>
 43#include <linux/module.h>
 44#include <linux/lapb.h>
 45#include <linux/init.h>
 46
 47#include <net/x25device.h>
 48
 49static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
 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
 55struct lapbethdev {
 56	struct list_head	node;
 57	struct net_device	*ethdev;	/* link to ethernet device */
 58	struct net_device	*axdev;		/* lapbeth device (lapb#) */
 59};
 60
 61static LIST_HEAD(lapbeth_devices);
 62
 63/* ------------------------------------------------------------------------ */
 64
 65/*
 66 *	Get the LAPB device for the ethernet device
 67 */
 68static 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
 79static __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 */
 89static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
 90{
 91	int len, err;
 92	struct lapbethdev *lapbeth;
 93
 94	if (dev_net(dev) != &init_net)
 95		goto drop;
 96
 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
110	len = skb->data[0] + skb->data[1] * 256;
111	dev->stats.rx_packets++;
112	dev->stats.rx_bytes += len;
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	}
121out:
122	rcu_read_unlock();
123	return 0;
124drop_unlock:
125	kfree_skb(skb);
126	goto out;
127drop:
128	kfree_skb(skb);
129	return 0;
130}
131
132static 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;
142	*ptr = X25_IFACE_DATA;
143
144	skb->protocol = x25_type_trans(skb, dev);
145	return netif_rx(skb);
146}
147
148/*
149 *	Send a LAPB frame via an ethernet interface
150 */
151static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
152				      struct net_device *dev)
153{
154	int err;
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	 */
160	if (!netif_running(dev))
161		goto drop;
162
163	switch (skb->data[0]) {
164	case X25_IFACE_DATA:
165		break;
166	case X25_IFACE_CONNECT:
167		if ((err = lapb_connect_request(dev)) != LAPB_OK)
168			pr_err("lapb_connect_request error: %d\n", err);
169		goto drop;
170	case X25_IFACE_DISCONNECT:
171		if ((err = lapb_disconnect_request(dev)) != LAPB_OK)
172			pr_err("lapb_disconnect_request err: %d\n", err);
173		/* Fall thru */
174	default:
175		goto drop;
176	}
177
178	skb_pull(skb, 1);
179
180	if ((err = lapb_data_request(dev, skb)) != LAPB_OK) {
181		pr_err("lapb_data_request error - %d\n", err);
182		goto drop;
183	}
184out:
185	return NETDEV_TX_OK;
186drop:
187	kfree_skb(skb);
188	goto out;
189}
190
191static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
192{
193	struct lapbethdev *lapbeth = netdev_priv(ndev);
194	unsigned char *ptr;
195	struct net_device *dev;
196	int size = skb->len;
197
198	skb->protocol = htons(ETH_P_X25);
199
200	ptr = skb_push(skb, 2);
201
202	*ptr++ = size % 256;
203	*ptr++ = size / 256;
204
205	ndev->stats.tx_packets++;
206	ndev->stats.tx_bytes += size;
207
208	skb->dev = dev = lapbeth->ethdev;
209
210	dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
211
212	dev_queue_xmit(skb);
213}
214
215static void lapbeth_connected(struct net_device *dev, int reason)
216{
217	unsigned char *ptr;
218	struct sk_buff *skb = dev_alloc_skb(1);
219
220	if (!skb) {
221		pr_err("out of memory\n");
222		return;
223	}
224
225	ptr  = skb_put(skb, 1);
226	*ptr = X25_IFACE_CONNECT;
227
228	skb->protocol = x25_type_trans(skb, dev);
229	netif_rx(skb);
230}
231
232static void lapbeth_disconnected(struct net_device *dev, int reason)
233{
234	unsigned char *ptr;
235	struct sk_buff *skb = dev_alloc_skb(1);
236
237	if (!skb) {
238		pr_err("out of memory\n");
239		return;
240	}
241
242	ptr  = skb_put(skb, 1);
243	*ptr = X25_IFACE_DISCONNECT;
244
245	skb->protocol = x25_type_trans(skb, dev);
246	netif_rx(skb);
247}
248
249/*
250 *	Set AX.25 callsign
251 */
252static int lapbeth_set_mac_address(struct net_device *dev, void *addr)
253{
254	struct sockaddr *sa = addr;
255	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
256	return 0;
257}
258
259
260static const struct lapb_register_struct lapbeth_callbacks = {
261	.connect_confirmation    = lapbeth_connected,
262	.connect_indication      = lapbeth_connected,
263	.disconnect_confirmation = lapbeth_disconnected,
264	.disconnect_indication   = lapbeth_disconnected,
265	.data_indication         = lapbeth_data_indication,
266	.data_transmit           = lapbeth_data_transmit,
267};
268
269/*
270 * open/close a device
271 */
272static int lapbeth_open(struct net_device *dev)
273{
274	int err;
275
276	if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) {
277		pr_err("lapb_register error: %d\n", err);
278		return -ENODEV;
279	}
280
281	netif_start_queue(dev);
282	return 0;
283}
284
285static int lapbeth_close(struct net_device *dev)
286{
287	int err;
288
289	netif_stop_queue(dev);
290
291	if ((err = lapb_unregister(dev)) != LAPB_OK)
292		pr_err("lapb_unregister error: %d\n", err);
293
294	return 0;
295}
296
297/* ------------------------------------------------------------------------ */
298
299static const struct net_device_ops lapbeth_netdev_ops = {
300	.ndo_open	     = lapbeth_open,
301	.ndo_stop	     = lapbeth_close,
302	.ndo_start_xmit	     = lapbeth_xmit,
303	.ndo_set_mac_address = lapbeth_set_mac_address,
304};
305
306static void lapbeth_setup(struct net_device *dev)
307{
308	dev->netdev_ops	     = &lapbeth_netdev_ops;
309	dev->destructor	     = free_netdev;
310	dev->type            = ARPHRD_X25;
311	dev->hard_header_len = 3;
312	dev->mtu             = 1000;
313	dev->addr_len        = 0;
314}
315
316/*
317 *	Setup a new device.
318 */
319static int lapbeth_new_device(struct net_device *dev)
320{
321	struct net_device *ndev;
322	struct lapbethdev *lapbeth;
323	int rc = -ENOMEM;
324
325	ASSERT_RTNL();
326
327	ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN,
328			    lapbeth_setup);
329	if (!ndev)
330		goto out;
331
332	lapbeth = netdev_priv(ndev);
333	lapbeth->axdev = ndev;
334
335	dev_hold(dev);
336	lapbeth->ethdev = dev;
337
338	rc = -EIO;
339	if (register_netdevice(ndev))
340		goto fail;
341
342	list_add_rcu(&lapbeth->node, &lapbeth_devices);
343	rc = 0;
344out:
345	return rc;
346fail:
347	dev_put(dev);
348	free_netdev(ndev);
349	kfree(lapbeth);
350	goto out;
351}
352
353/*
354 *	Free a lapb network device.
355 */
356static void lapbeth_free_device(struct lapbethdev *lapbeth)
357{
358	dev_put(lapbeth->ethdev);
359	list_del_rcu(&lapbeth->node);
360	unregister_netdevice(lapbeth->axdev);
361}
362
363/*
364 *	Handle device status changes.
365 *
366 * Called from notifier with RTNL held.
367 */
368static int lapbeth_device_event(struct notifier_block *this,
369				unsigned long event, void *ptr)
370{
371	struct lapbethdev *lapbeth;
372	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
373
374	if (dev_net(dev) != &init_net)
375		return NOTIFY_DONE;
376
377	if (!dev_is_ethdev(dev))
378		return NOTIFY_DONE;
379
380	switch (event) {
381	case NETDEV_UP:
382		/* New ethernet device -> new LAPB interface	 */
383		if (lapbeth_get_x25_dev(dev) == NULL)
384			lapbeth_new_device(dev);
385		break;
386	case NETDEV_DOWN:	
387		/* ethernet device closed -> close LAPB interface */
388		lapbeth = lapbeth_get_x25_dev(dev);
389		if (lapbeth) 
390			dev_close(lapbeth->axdev);
391		break;
392	case NETDEV_UNREGISTER:
393		/* ethernet device disappears -> remove LAPB interface */
394		lapbeth = lapbeth_get_x25_dev(dev);
395		if (lapbeth)
396			lapbeth_free_device(lapbeth);
397		break;
398	}
399
400	return NOTIFY_DONE;
401}
402
403/* ------------------------------------------------------------------------ */
404
405static struct packet_type lapbeth_packet_type __read_mostly = {
406	.type = cpu_to_be16(ETH_P_DEC),
407	.func = lapbeth_rcv,
408};
409
410static struct notifier_block lapbeth_dev_notifier = {
411	.notifier_call = lapbeth_device_event,
412};
413
414static const char banner[] __initconst =
415	KERN_INFO "LAPB Ethernet driver version 0.02\n";
416
417static int __init lapbeth_init_driver(void)
418{
419	dev_add_pack(&lapbeth_packet_type);
420
421	register_netdevice_notifier(&lapbeth_dev_notifier);
422
423	printk(banner);
424
425	return 0;
426}
427module_init(lapbeth_init_driver);
428
429static void __exit lapbeth_cleanup_driver(void)
430{
431	struct lapbethdev *lapbeth;
432	struct list_head *entry, *tmp;
433
434	dev_remove_pack(&lapbeth_packet_type);
435	unregister_netdevice_notifier(&lapbeth_dev_notifier);
436
437	rtnl_lock();
438	list_for_each_safe(entry, tmp, &lapbeth_devices) {
439		lapbeth = list_entry(entry, struct lapbethdev, node);
440
441		dev_put(lapbeth->ethdev);
442		unregister_netdevice(lapbeth->axdev);
443	}
444	rtnl_unlock();
445}
446module_exit(lapbeth_cleanup_driver);
447
448MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
449MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
450MODULE_LICENSE("GPL");
v5.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *	"LAPB via ethernet" driver release 001
  4 *
  5 *	This code REQUIRES 2.1.15 or higher/ NET3.038
  6 *
 
 
 
 
 
 
  7 *	This is a "pseudo" network driver to allow LAPB over Ethernet.
  8 *
  9 *	This driver can use any ethernet destination address, and can be 
 10 *	limited to accept frames from one dedicated ethernet card only.
 11 *
 12 *	History
 13 *	LAPBETH 001	Jonathan Naylor		Cloned from bpqether.c
 14 *	2000-10-29	Henner Eisen	lapb_data_indication() return status.
 15 *	2000-11-14	Henner Eisen	dev_hold/put, NETDEV_GOING_DOWN support
 16 */
 17
 18#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 19
 20#include <linux/errno.h>
 21#include <linux/types.h>
 22#include <linux/socket.h>
 23#include <linux/in.h>
 24#include <linux/slab.h>
 25#include <linux/kernel.h>
 26#include <linux/string.h>
 27#include <linux/net.h>
 28#include <linux/inet.h>
 29#include <linux/netdevice.h>
 30#include <linux/if_arp.h>
 31#include <linux/skbuff.h>
 32#include <net/sock.h>
 33#include <linux/uaccess.h>
 34#include <linux/mm.h>
 35#include <linux/interrupt.h>
 36#include <linux/notifier.h>
 37#include <linux/stat.h>
 38#include <linux/module.h>
 39#include <linux/lapb.h>
 40#include <linux/init.h>
 41
 42#include <net/x25device.h>
 43
 44static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
 45
 46/* If this number is made larger, check that the temporary string buffer
 47 * in lapbeth_new_device is large enough to store the probe device name.*/
 48#define MAXLAPBDEV 100
 49
 50struct lapbethdev {
 51	struct list_head	node;
 52	struct net_device	*ethdev;	/* link to ethernet device */
 53	struct net_device	*axdev;		/* lapbeth device (lapb#) */
 54};
 55
 56static LIST_HEAD(lapbeth_devices);
 57
 58/* ------------------------------------------------------------------------ */
 59
 60/*
 61 *	Get the LAPB device for the ethernet device
 62 */
 63static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev)
 64{
 65	struct lapbethdev *lapbeth;
 66
 67	list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node) {
 68		if (lapbeth->ethdev == dev) 
 69			return lapbeth;
 70	}
 71	return NULL;
 72}
 73
 74static __inline__ int dev_is_ethdev(struct net_device *dev)
 75{
 76	return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
 77}
 78
 79/* ------------------------------------------------------------------------ */
 80
 81/*
 82 *	Receive a LAPB frame via an ethernet interface.
 83 */
 84static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
 85{
 86	int len, err;
 87	struct lapbethdev *lapbeth;
 88
 89	if (dev_net(dev) != &init_net)
 90		goto drop;
 91
 92	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 93		return NET_RX_DROP;
 94
 95	if (!pskb_may_pull(skb, 2))
 96		goto drop;
 97
 98	rcu_read_lock();
 99	lapbeth = lapbeth_get_x25_dev(dev);
100	if (!lapbeth)
101		goto drop_unlock;
102	if (!netif_running(lapbeth->axdev))
103		goto drop_unlock;
104
105	len = skb->data[0] + skb->data[1] * 256;
106	dev->stats.rx_packets++;
107	dev->stats.rx_bytes += len;
108
109	skb_pull(skb, 2);	/* Remove the length bytes */
110	skb_trim(skb, len);	/* Set the length of the data */
111
112	if ((err = lapb_data_received(lapbeth->axdev, skb)) != LAPB_OK) {
113		printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err);
114		goto drop_unlock;
115	}
116out:
117	rcu_read_unlock();
118	return 0;
119drop_unlock:
120	kfree_skb(skb);
121	goto out;
122drop:
123	kfree_skb(skb);
124	return 0;
125}
126
127static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb)
128{
129	unsigned char *ptr;
130
131	skb_push(skb, 1);
132
133	if (skb_cow(skb, 1))
134		return NET_RX_DROP;
135
136	ptr  = skb->data;
137	*ptr = X25_IFACE_DATA;
138
139	skb->protocol = x25_type_trans(skb, dev);
140	return netif_rx(skb);
141}
142
143/*
144 *	Send a LAPB frame via an ethernet interface
145 */
146static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
147				      struct net_device *dev)
148{
149	int err;
150
151	/*
152	 * Just to be *really* sure not to send anything if the interface
153	 * is down, the ethernet device may have gone.
154	 */
155	if (!netif_running(dev))
156		goto drop;
157
158	switch (skb->data[0]) {
159	case X25_IFACE_DATA:
160		break;
161	case X25_IFACE_CONNECT:
162		if ((err = lapb_connect_request(dev)) != LAPB_OK)
163			pr_err("lapb_connect_request error: %d\n", err);
164		goto drop;
165	case X25_IFACE_DISCONNECT:
166		if ((err = lapb_disconnect_request(dev)) != LAPB_OK)
167			pr_err("lapb_disconnect_request err: %d\n", err);
168		/* Fall thru */
169	default:
170		goto drop;
171	}
172
173	skb_pull(skb, 1);
174
175	if ((err = lapb_data_request(dev, skb)) != LAPB_OK) {
176		pr_err("lapb_data_request error - %d\n", err);
177		goto drop;
178	}
179out:
180	return NETDEV_TX_OK;
181drop:
182	kfree_skb(skb);
183	goto out;
184}
185
186static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
187{
188	struct lapbethdev *lapbeth = netdev_priv(ndev);
189	unsigned char *ptr;
190	struct net_device *dev;
191	int size = skb->len;
192
193	skb->protocol = htons(ETH_P_X25);
194
195	ptr = skb_push(skb, 2);
196
197	*ptr++ = size % 256;
198	*ptr++ = size / 256;
199
200	ndev->stats.tx_packets++;
201	ndev->stats.tx_bytes += size;
202
203	skb->dev = dev = lapbeth->ethdev;
204
205	dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
206
207	dev_queue_xmit(skb);
208}
209
210static void lapbeth_connected(struct net_device *dev, int reason)
211{
212	unsigned char *ptr;
213	struct sk_buff *skb = dev_alloc_skb(1);
214
215	if (!skb) {
216		pr_err("out of memory\n");
217		return;
218	}
219
220	ptr  = skb_put(skb, 1);
221	*ptr = X25_IFACE_CONNECT;
222
223	skb->protocol = x25_type_trans(skb, dev);
224	netif_rx(skb);
225}
226
227static void lapbeth_disconnected(struct net_device *dev, int reason)
228{
229	unsigned char *ptr;
230	struct sk_buff *skb = dev_alloc_skb(1);
231
232	if (!skb) {
233		pr_err("out of memory\n");
234		return;
235	}
236
237	ptr  = skb_put(skb, 1);
238	*ptr = X25_IFACE_DISCONNECT;
239
240	skb->protocol = x25_type_trans(skb, dev);
241	netif_rx(skb);
242}
243
244/*
245 *	Set AX.25 callsign
246 */
247static int lapbeth_set_mac_address(struct net_device *dev, void *addr)
248{
249	struct sockaddr *sa = addr;
250	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
251	return 0;
252}
253
254
255static const struct lapb_register_struct lapbeth_callbacks = {
256	.connect_confirmation    = lapbeth_connected,
257	.connect_indication      = lapbeth_connected,
258	.disconnect_confirmation = lapbeth_disconnected,
259	.disconnect_indication   = lapbeth_disconnected,
260	.data_indication         = lapbeth_data_indication,
261	.data_transmit           = lapbeth_data_transmit,
262};
263
264/*
265 * open/close a device
266 */
267static int lapbeth_open(struct net_device *dev)
268{
269	int err;
270
271	if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) {
272		pr_err("lapb_register error: %d\n", err);
273		return -ENODEV;
274	}
275
276	netif_start_queue(dev);
277	return 0;
278}
279
280static int lapbeth_close(struct net_device *dev)
281{
282	int err;
283
284	netif_stop_queue(dev);
285
286	if ((err = lapb_unregister(dev)) != LAPB_OK)
287		pr_err("lapb_unregister error: %d\n", err);
288
289	return 0;
290}
291
292/* ------------------------------------------------------------------------ */
293
294static const struct net_device_ops lapbeth_netdev_ops = {
295	.ndo_open	     = lapbeth_open,
296	.ndo_stop	     = lapbeth_close,
297	.ndo_start_xmit	     = lapbeth_xmit,
298	.ndo_set_mac_address = lapbeth_set_mac_address,
299};
300
301static void lapbeth_setup(struct net_device *dev)
302{
303	dev->netdev_ops	     = &lapbeth_netdev_ops;
304	dev->needs_free_netdev = true;
305	dev->type            = ARPHRD_X25;
306	dev->hard_header_len = 3;
307	dev->mtu             = 1000;
308	dev->addr_len        = 0;
309}
310
311/*
312 *	Setup a new device.
313 */
314static int lapbeth_new_device(struct net_device *dev)
315{
316	struct net_device *ndev;
317	struct lapbethdev *lapbeth;
318	int rc = -ENOMEM;
319
320	ASSERT_RTNL();
321
322	ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN,
323			    lapbeth_setup);
324	if (!ndev)
325		goto out;
326
327	lapbeth = netdev_priv(ndev);
328	lapbeth->axdev = ndev;
329
330	dev_hold(dev);
331	lapbeth->ethdev = dev;
332
333	rc = -EIO;
334	if (register_netdevice(ndev))
335		goto fail;
336
337	list_add_rcu(&lapbeth->node, &lapbeth_devices);
338	rc = 0;
339out:
340	return rc;
341fail:
342	dev_put(dev);
343	free_netdev(ndev);
 
344	goto out;
345}
346
347/*
348 *	Free a lapb network device.
349 */
350static void lapbeth_free_device(struct lapbethdev *lapbeth)
351{
352	dev_put(lapbeth->ethdev);
353	list_del_rcu(&lapbeth->node);
354	unregister_netdevice(lapbeth->axdev);
355}
356
357/*
358 *	Handle device status changes.
359 *
360 * Called from notifier with RTNL held.
361 */
362static int lapbeth_device_event(struct notifier_block *this,
363				unsigned long event, void *ptr)
364{
365	struct lapbethdev *lapbeth;
366	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
367
368	if (dev_net(dev) != &init_net)
369		return NOTIFY_DONE;
370
371	if (!dev_is_ethdev(dev))
372		return NOTIFY_DONE;
373
374	switch (event) {
375	case NETDEV_UP:
376		/* New ethernet device -> new LAPB interface	 */
377		if (lapbeth_get_x25_dev(dev) == NULL)
378			lapbeth_new_device(dev);
379		break;
380	case NETDEV_DOWN:	
381		/* ethernet device closed -> close LAPB interface */
382		lapbeth = lapbeth_get_x25_dev(dev);
383		if (lapbeth) 
384			dev_close(lapbeth->axdev);
385		break;
386	case NETDEV_UNREGISTER:
387		/* ethernet device disappears -> remove LAPB interface */
388		lapbeth = lapbeth_get_x25_dev(dev);
389		if (lapbeth)
390			lapbeth_free_device(lapbeth);
391		break;
392	}
393
394	return NOTIFY_DONE;
395}
396
397/* ------------------------------------------------------------------------ */
398
399static struct packet_type lapbeth_packet_type __read_mostly = {
400	.type = cpu_to_be16(ETH_P_DEC),
401	.func = lapbeth_rcv,
402};
403
404static struct notifier_block lapbeth_dev_notifier = {
405	.notifier_call = lapbeth_device_event,
406};
407
408static const char banner[] __initconst =
409	KERN_INFO "LAPB Ethernet driver version 0.02\n";
410
411static int __init lapbeth_init_driver(void)
412{
413	dev_add_pack(&lapbeth_packet_type);
414
415	register_netdevice_notifier(&lapbeth_dev_notifier);
416
417	printk(banner);
418
419	return 0;
420}
421module_init(lapbeth_init_driver);
422
423static void __exit lapbeth_cleanup_driver(void)
424{
425	struct lapbethdev *lapbeth;
426	struct list_head *entry, *tmp;
427
428	dev_remove_pack(&lapbeth_packet_type);
429	unregister_netdevice_notifier(&lapbeth_dev_notifier);
430
431	rtnl_lock();
432	list_for_each_safe(entry, tmp, &lapbeth_devices) {
433		lapbeth = list_entry(entry, struct lapbethdev, node);
434
435		dev_put(lapbeth->ethdev);
436		unregister_netdevice(lapbeth->axdev);
437	}
438	rtnl_unlock();
439}
440module_exit(lapbeth_cleanup_driver);
441
442MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
443MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
444MODULE_LICENSE("GPL");