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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");
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, lockdep_rtnl_is_held()) {
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 if (skb_cow(skb, 1)) {
132 kfree_skb(skb);
133 return NET_RX_DROP;
134 }
135
136 skb_push(skb, 1);
137
138 ptr = skb->data;
139 *ptr = X25_IFACE_DATA;
140
141 skb->protocol = x25_type_trans(skb, dev);
142 return netif_rx(skb);
143}
144
145/*
146 * Send a LAPB frame via an ethernet interface
147 */
148static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
149 struct net_device *dev)
150{
151 int err;
152
153 /*
154 * Just to be *really* sure not to send anything if the interface
155 * is down, the ethernet device may have gone.
156 */
157 if (!netif_running(dev))
158 goto drop;
159
160 /* There should be a pseudo header of 1 byte added by upper layers.
161 * Check to make sure it is there before reading it.
162 */
163 if (skb->len < 1)
164 goto drop;
165
166 switch (skb->data[0]) {
167 case X25_IFACE_DATA:
168 break;
169 case X25_IFACE_CONNECT:
170 if ((err = lapb_connect_request(dev)) != LAPB_OK)
171 pr_err("lapb_connect_request error: %d\n", err);
172 goto drop;
173 case X25_IFACE_DISCONNECT:
174 if ((err = lapb_disconnect_request(dev)) != LAPB_OK)
175 pr_err("lapb_disconnect_request err: %d\n", err);
176 fallthrough;
177 default:
178 goto drop;
179 }
180
181 skb_pull(skb, 1);
182
183 if ((err = lapb_data_request(dev, skb)) != LAPB_OK) {
184 pr_err("lapb_data_request error - %d\n", err);
185 goto drop;
186 }
187out:
188 return NETDEV_TX_OK;
189drop:
190 kfree_skb(skb);
191 goto out;
192}
193
194static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
195{
196 struct lapbethdev *lapbeth = netdev_priv(ndev);
197 unsigned char *ptr;
198 struct net_device *dev;
199 int size = skb->len;
200
201 ptr = skb_push(skb, 2);
202
203 *ptr++ = size % 256;
204 *ptr++ = size / 256;
205
206 ndev->stats.tx_packets++;
207 ndev->stats.tx_bytes += size;
208
209 skb->dev = dev = lapbeth->ethdev;
210
211 skb->protocol = htons(ETH_P_DEC);
212
213 skb_reset_network_header(skb);
214
215 dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
216
217 dev_queue_xmit(skb);
218}
219
220static void lapbeth_connected(struct net_device *dev, int reason)
221{
222 unsigned char *ptr;
223 struct sk_buff *skb = dev_alloc_skb(1);
224
225 if (!skb) {
226 pr_err("out of memory\n");
227 return;
228 }
229
230 ptr = skb_put(skb, 1);
231 *ptr = X25_IFACE_CONNECT;
232
233 skb->protocol = x25_type_trans(skb, dev);
234 netif_rx(skb);
235}
236
237static void lapbeth_disconnected(struct net_device *dev, int reason)
238{
239 unsigned char *ptr;
240 struct sk_buff *skb = dev_alloc_skb(1);
241
242 if (!skb) {
243 pr_err("out of memory\n");
244 return;
245 }
246
247 ptr = skb_put(skb, 1);
248 *ptr = X25_IFACE_DISCONNECT;
249
250 skb->protocol = x25_type_trans(skb, dev);
251 netif_rx(skb);
252}
253
254/*
255 * Set AX.25 callsign
256 */
257static int lapbeth_set_mac_address(struct net_device *dev, void *addr)
258{
259 struct sockaddr *sa = addr;
260 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
261 return 0;
262}
263
264
265static const struct lapb_register_struct lapbeth_callbacks = {
266 .connect_confirmation = lapbeth_connected,
267 .connect_indication = lapbeth_connected,
268 .disconnect_confirmation = lapbeth_disconnected,
269 .disconnect_indication = lapbeth_disconnected,
270 .data_indication = lapbeth_data_indication,
271 .data_transmit = lapbeth_data_transmit,
272};
273
274/*
275 * open/close a device
276 */
277static int lapbeth_open(struct net_device *dev)
278{
279 int err;
280
281 if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) {
282 pr_err("lapb_register error: %d\n", err);
283 return -ENODEV;
284 }
285
286 netif_start_queue(dev);
287 return 0;
288}
289
290static int lapbeth_close(struct net_device *dev)
291{
292 int err;
293
294 netif_stop_queue(dev);
295
296 if ((err = lapb_unregister(dev)) != LAPB_OK)
297 pr_err("lapb_unregister error: %d\n", err);
298
299 return 0;
300}
301
302/* ------------------------------------------------------------------------ */
303
304static const struct net_device_ops lapbeth_netdev_ops = {
305 .ndo_open = lapbeth_open,
306 .ndo_stop = lapbeth_close,
307 .ndo_start_xmit = lapbeth_xmit,
308 .ndo_set_mac_address = lapbeth_set_mac_address,
309};
310
311static void lapbeth_setup(struct net_device *dev)
312{
313 dev->netdev_ops = &lapbeth_netdev_ops;
314 dev->needs_free_netdev = true;
315 dev->type = ARPHRD_X25;
316 dev->hard_header_len = 0;
317 dev->mtu = 1000;
318 dev->addr_len = 0;
319}
320
321/*
322 * Setup a new device.
323 */
324static int lapbeth_new_device(struct net_device *dev)
325{
326 struct net_device *ndev;
327 struct lapbethdev *lapbeth;
328 int rc = -ENOMEM;
329
330 ASSERT_RTNL();
331
332 ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN,
333 lapbeth_setup);
334 if (!ndev)
335 goto out;
336
337 /* When transmitting data:
338 * first this driver removes a pseudo header of 1 byte,
339 * then the lapb module prepends an LAPB header of at most 3 bytes,
340 * then this driver prepends a length field of 2 bytes,
341 * then the underlying Ethernet device prepends its own header.
342 */
343 ndev->needed_headroom = -1 + 3 + 2 + dev->hard_header_len
344 + dev->needed_headroom;
345 ndev->needed_tailroom = dev->needed_tailroom;
346
347 lapbeth = netdev_priv(ndev);
348 lapbeth->axdev = ndev;
349
350 dev_hold(dev);
351 lapbeth->ethdev = dev;
352
353 rc = -EIO;
354 if (register_netdevice(ndev))
355 goto fail;
356
357 list_add_rcu(&lapbeth->node, &lapbeth_devices);
358 rc = 0;
359out:
360 return rc;
361fail:
362 dev_put(dev);
363 free_netdev(ndev);
364 goto out;
365}
366
367/*
368 * Free a lapb network device.
369 */
370static void lapbeth_free_device(struct lapbethdev *lapbeth)
371{
372 dev_put(lapbeth->ethdev);
373 list_del_rcu(&lapbeth->node);
374 unregister_netdevice(lapbeth->axdev);
375}
376
377/*
378 * Handle device status changes.
379 *
380 * Called from notifier with RTNL held.
381 */
382static int lapbeth_device_event(struct notifier_block *this,
383 unsigned long event, void *ptr)
384{
385 struct lapbethdev *lapbeth;
386 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
387
388 if (dev_net(dev) != &init_net)
389 return NOTIFY_DONE;
390
391 if (!dev_is_ethdev(dev))
392 return NOTIFY_DONE;
393
394 switch (event) {
395 case NETDEV_UP:
396 /* New ethernet device -> new LAPB interface */
397 if (lapbeth_get_x25_dev(dev) == NULL)
398 lapbeth_new_device(dev);
399 break;
400 case NETDEV_DOWN:
401 /* ethernet device closed -> close LAPB interface */
402 lapbeth = lapbeth_get_x25_dev(dev);
403 if (lapbeth)
404 dev_close(lapbeth->axdev);
405 break;
406 case NETDEV_UNREGISTER:
407 /* ethernet device disappears -> remove LAPB interface */
408 lapbeth = lapbeth_get_x25_dev(dev);
409 if (lapbeth)
410 lapbeth_free_device(lapbeth);
411 break;
412 }
413
414 return NOTIFY_DONE;
415}
416
417/* ------------------------------------------------------------------------ */
418
419static struct packet_type lapbeth_packet_type __read_mostly = {
420 .type = cpu_to_be16(ETH_P_DEC),
421 .func = lapbeth_rcv,
422};
423
424static struct notifier_block lapbeth_dev_notifier = {
425 .notifier_call = lapbeth_device_event,
426};
427
428static const char banner[] __initconst =
429 KERN_INFO "LAPB Ethernet driver version 0.02\n";
430
431static int __init lapbeth_init_driver(void)
432{
433 dev_add_pack(&lapbeth_packet_type);
434
435 register_netdevice_notifier(&lapbeth_dev_notifier);
436
437 printk(banner);
438
439 return 0;
440}
441module_init(lapbeth_init_driver);
442
443static void __exit lapbeth_cleanup_driver(void)
444{
445 struct lapbethdev *lapbeth;
446 struct list_head *entry, *tmp;
447
448 dev_remove_pack(&lapbeth_packet_type);
449 unregister_netdevice_notifier(&lapbeth_dev_notifier);
450
451 rtnl_lock();
452 list_for_each_safe(entry, tmp, &lapbeth_devices) {
453 lapbeth = list_entry(entry, struct lapbethdev, node);
454
455 dev_put(lapbeth->ethdev);
456 unregister_netdevice(lapbeth->axdev);
457 }
458 rtnl_unlock();
459}
460module_exit(lapbeth_cleanup_driver);
461
462MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
463MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
464MODULE_LICENSE("GPL");