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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 */
49#define MAXLAPBDEV 100
50
51struct lapbethdev {
52 struct list_head node;
53 struct net_device *ethdev; /* link to ethernet device */
54 struct net_device *axdev; /* lapbeth device (lapb#) */
55 bool up;
56 spinlock_t up_lock; /* Protects "up" */
57 struct sk_buff_head rx_queue;
58 struct napi_struct napi;
59};
60
61static LIST_HEAD(lapbeth_devices);
62
63static void lapbeth_connected(struct net_device *dev, int reason);
64static void lapbeth_disconnected(struct net_device *dev, int reason);
65
66/* ------------------------------------------------------------------------ */
67
68/* Get the LAPB device for the ethernet device
69 */
70static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev)
71{
72 struct lapbethdev *lapbeth;
73
74 list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node, lockdep_rtnl_is_held()) {
75 if (lapbeth->ethdev == dev)
76 return lapbeth;
77 }
78 return NULL;
79}
80
81static __inline__ int dev_is_ethdev(struct net_device *dev)
82{
83 return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
84}
85
86/* ------------------------------------------------------------------------ */
87
88static int lapbeth_napi_poll(struct napi_struct *napi, int budget)
89{
90 struct lapbethdev *lapbeth = container_of(napi, struct lapbethdev,
91 napi);
92 struct sk_buff *skb;
93 int processed = 0;
94
95 for (; processed < budget; ++processed) {
96 skb = skb_dequeue(&lapbeth->rx_queue);
97 if (!skb)
98 break;
99 netif_receive_skb_core(skb);
100 }
101
102 if (processed < budget)
103 napi_complete(napi);
104
105 return processed;
106}
107
108/* Receive a LAPB frame via an ethernet interface.
109 */
110static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev,
111 struct packet_type *ptype, struct net_device *orig_dev)
112{
113 int len, err;
114 struct lapbethdev *lapbeth;
115
116 if (dev_net(dev) != &init_net)
117 goto drop;
118
119 skb = skb_share_check(skb, GFP_ATOMIC);
120 if (!skb)
121 return NET_RX_DROP;
122
123 if (!pskb_may_pull(skb, 2))
124 goto drop;
125
126 rcu_read_lock();
127 lapbeth = lapbeth_get_x25_dev(dev);
128 if (!lapbeth)
129 goto drop_unlock_rcu;
130 spin_lock_bh(&lapbeth->up_lock);
131 if (!lapbeth->up)
132 goto drop_unlock;
133
134 len = skb->data[0] + skb->data[1] * 256;
135 dev->stats.rx_packets++;
136 dev->stats.rx_bytes += len;
137
138 skb_pull(skb, 2); /* Remove the length bytes */
139 skb_trim(skb, len); /* Set the length of the data */
140
141 err = lapb_data_received(lapbeth->axdev, skb);
142 if (err != LAPB_OK) {
143 printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err);
144 goto drop_unlock;
145 }
146out:
147 spin_unlock_bh(&lapbeth->up_lock);
148 rcu_read_unlock();
149 return 0;
150drop_unlock:
151 kfree_skb(skb);
152 goto out;
153drop_unlock_rcu:
154 rcu_read_unlock();
155drop:
156 kfree_skb(skb);
157 return 0;
158}
159
160static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb)
161{
162 struct lapbethdev *lapbeth = netdev_priv(dev);
163 unsigned char *ptr;
164
165 if (skb_cow(skb, 1)) {
166 kfree_skb(skb);
167 return NET_RX_DROP;
168 }
169
170 skb_push(skb, 1);
171
172 ptr = skb->data;
173 *ptr = X25_IFACE_DATA;
174
175 skb->protocol = x25_type_trans(skb, dev);
176
177 skb_queue_tail(&lapbeth->rx_queue, skb);
178 napi_schedule(&lapbeth->napi);
179 return NET_RX_SUCCESS;
180}
181
182/* Send a LAPB frame via an ethernet interface
183 */
184static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
185 struct net_device *dev)
186{
187 struct lapbethdev *lapbeth = netdev_priv(dev);
188 int err;
189
190 spin_lock_bh(&lapbeth->up_lock);
191 if (!lapbeth->up)
192 goto drop;
193
194 /* There should be a pseudo header of 1 byte added by upper layers.
195 * Check to make sure it is there before reading it.
196 */
197 if (skb->len < 1)
198 goto drop;
199
200 switch (skb->data[0]) {
201 case X25_IFACE_DATA:
202 break;
203 case X25_IFACE_CONNECT:
204 err = lapb_connect_request(dev);
205 if (err == LAPB_CONNECTED)
206 lapbeth_connected(dev, LAPB_OK);
207 else if (err != LAPB_OK)
208 pr_err("lapb_connect_request error: %d\n", err);
209 goto drop;
210 case X25_IFACE_DISCONNECT:
211 err = lapb_disconnect_request(dev);
212 if (err == LAPB_NOTCONNECTED)
213 lapbeth_disconnected(dev, LAPB_OK);
214 else if (err != LAPB_OK)
215 pr_err("lapb_disconnect_request err: %d\n", err);
216 fallthrough;
217 default:
218 goto drop;
219 }
220
221 skb_pull(skb, 1);
222
223 err = lapb_data_request(dev, skb);
224 if (err != LAPB_OK) {
225 pr_err("lapb_data_request error - %d\n", err);
226 goto drop;
227 }
228out:
229 spin_unlock_bh(&lapbeth->up_lock);
230 return NETDEV_TX_OK;
231drop:
232 kfree_skb(skb);
233 goto out;
234}
235
236static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
237{
238 struct lapbethdev *lapbeth = netdev_priv(ndev);
239 unsigned char *ptr;
240 struct net_device *dev;
241 int size = skb->len;
242
243 ptr = skb_push(skb, 2);
244
245 *ptr++ = size % 256;
246 *ptr++ = size / 256;
247
248 ndev->stats.tx_packets++;
249 ndev->stats.tx_bytes += size;
250
251 skb->dev = dev = lapbeth->ethdev;
252
253 skb->protocol = htons(ETH_P_DEC);
254
255 skb_reset_network_header(skb);
256
257 dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
258
259 dev_queue_xmit(skb);
260}
261
262static void lapbeth_connected(struct net_device *dev, int reason)
263{
264 struct lapbethdev *lapbeth = netdev_priv(dev);
265 unsigned char *ptr;
266 struct sk_buff *skb = __dev_alloc_skb(1, GFP_ATOMIC | __GFP_NOMEMALLOC);
267
268 if (!skb)
269 return;
270
271 ptr = skb_put(skb, 1);
272 *ptr = X25_IFACE_CONNECT;
273
274 skb->protocol = x25_type_trans(skb, dev);
275
276 skb_queue_tail(&lapbeth->rx_queue, skb);
277 napi_schedule(&lapbeth->napi);
278}
279
280static void lapbeth_disconnected(struct net_device *dev, int reason)
281{
282 struct lapbethdev *lapbeth = netdev_priv(dev);
283 unsigned char *ptr;
284 struct sk_buff *skb = __dev_alloc_skb(1, GFP_ATOMIC | __GFP_NOMEMALLOC);
285
286 if (!skb)
287 return;
288
289 ptr = skb_put(skb, 1);
290 *ptr = X25_IFACE_DISCONNECT;
291
292 skb->protocol = x25_type_trans(skb, dev);
293
294 skb_queue_tail(&lapbeth->rx_queue, skb);
295 napi_schedule(&lapbeth->napi);
296}
297
298/* Set AX.25 callsign
299 */
300static int lapbeth_set_mac_address(struct net_device *dev, void *addr)
301{
302 struct sockaddr *sa = addr;
303
304 dev_addr_set(dev, sa->sa_data);
305 return 0;
306}
307
308static const struct lapb_register_struct lapbeth_callbacks = {
309 .connect_confirmation = lapbeth_connected,
310 .connect_indication = lapbeth_connected,
311 .disconnect_confirmation = lapbeth_disconnected,
312 .disconnect_indication = lapbeth_disconnected,
313 .data_indication = lapbeth_data_indication,
314 .data_transmit = lapbeth_data_transmit,
315};
316
317/* open/close a device
318 */
319static int lapbeth_open(struct net_device *dev)
320{
321 struct lapbethdev *lapbeth = netdev_priv(dev);
322 int err;
323
324 napi_enable(&lapbeth->napi);
325
326 err = lapb_register(dev, &lapbeth_callbacks);
327 if (err != LAPB_OK) {
328 napi_disable(&lapbeth->napi);
329 pr_err("lapb_register error: %d\n", err);
330 return -ENODEV;
331 }
332
333 spin_lock_bh(&lapbeth->up_lock);
334 lapbeth->up = true;
335 spin_unlock_bh(&lapbeth->up_lock);
336
337 return 0;
338}
339
340static int lapbeth_close(struct net_device *dev)
341{
342 struct lapbethdev *lapbeth = netdev_priv(dev);
343 int err;
344
345 spin_lock_bh(&lapbeth->up_lock);
346 lapbeth->up = false;
347 spin_unlock_bh(&lapbeth->up_lock);
348
349 err = lapb_unregister(dev);
350 if (err != LAPB_OK)
351 pr_err("lapb_unregister error: %d\n", err);
352
353 napi_disable(&lapbeth->napi);
354
355 return 0;
356}
357
358/* ------------------------------------------------------------------------ */
359
360static const struct net_device_ops lapbeth_netdev_ops = {
361 .ndo_open = lapbeth_open,
362 .ndo_stop = lapbeth_close,
363 .ndo_start_xmit = lapbeth_xmit,
364 .ndo_set_mac_address = lapbeth_set_mac_address,
365};
366
367static void lapbeth_setup(struct net_device *dev)
368{
369 dev->netdev_ops = &lapbeth_netdev_ops;
370 dev->needs_free_netdev = true;
371 dev->type = ARPHRD_X25;
372 dev->hard_header_len = 0;
373 dev->mtu = 1000;
374 dev->addr_len = 0;
375}
376
377/* Setup a new device.
378 */
379static int lapbeth_new_device(struct net_device *dev)
380{
381 struct net_device *ndev;
382 struct lapbethdev *lapbeth;
383 int rc = -ENOMEM;
384
385 ASSERT_RTNL();
386
387 if (dev->type != ARPHRD_ETHER)
388 return -EINVAL;
389
390 ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN,
391 lapbeth_setup);
392 if (!ndev)
393 goto out;
394
395 /* When transmitting data:
396 * first this driver removes a pseudo header of 1 byte,
397 * then the lapb module prepends an LAPB header of at most 3 bytes,
398 * then this driver prepends a length field of 2 bytes,
399 * then the underlying Ethernet device prepends its own header.
400 */
401 ndev->needed_headroom = -1 + 3 + 2 + dev->hard_header_len
402 + dev->needed_headroom;
403 ndev->needed_tailroom = dev->needed_tailroom;
404
405 lapbeth = netdev_priv(ndev);
406 lapbeth->axdev = ndev;
407
408 dev_hold(dev);
409 lapbeth->ethdev = dev;
410
411 lapbeth->up = false;
412 spin_lock_init(&lapbeth->up_lock);
413
414 skb_queue_head_init(&lapbeth->rx_queue);
415 netif_napi_add_weight(ndev, &lapbeth->napi, lapbeth_napi_poll, 16);
416
417 rc = -EIO;
418 if (register_netdevice(ndev))
419 goto fail;
420
421 list_add_rcu(&lapbeth->node, &lapbeth_devices);
422 rc = 0;
423out:
424 return rc;
425fail:
426 dev_put(dev);
427 free_netdev(ndev);
428 goto out;
429}
430
431/* Free a lapb network device.
432 */
433static void lapbeth_free_device(struct lapbethdev *lapbeth)
434{
435 dev_put(lapbeth->ethdev);
436 list_del_rcu(&lapbeth->node);
437 unregister_netdevice(lapbeth->axdev);
438}
439
440/* Handle device status changes.
441 *
442 * Called from notifier with RTNL held.
443 */
444static int lapbeth_device_event(struct notifier_block *this,
445 unsigned long event, void *ptr)
446{
447 struct lapbethdev *lapbeth;
448 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
449
450 if (dev_net(dev) != &init_net)
451 return NOTIFY_DONE;
452
453 if (!dev_is_ethdev(dev) && !lapbeth_get_x25_dev(dev))
454 return NOTIFY_DONE;
455
456 switch (event) {
457 case NETDEV_UP:
458 /* New ethernet device -> new LAPB interface */
459 if (!lapbeth_get_x25_dev(dev))
460 lapbeth_new_device(dev);
461 break;
462 case NETDEV_GOING_DOWN:
463 /* ethernet device closes -> close LAPB interface */
464 lapbeth = lapbeth_get_x25_dev(dev);
465 if (lapbeth)
466 dev_close(lapbeth->axdev);
467 break;
468 case NETDEV_UNREGISTER:
469 /* ethernet device disappears -> remove LAPB interface */
470 lapbeth = lapbeth_get_x25_dev(dev);
471 if (lapbeth)
472 lapbeth_free_device(lapbeth);
473 break;
474 }
475
476 return NOTIFY_DONE;
477}
478
479/* ------------------------------------------------------------------------ */
480
481static struct packet_type lapbeth_packet_type __read_mostly = {
482 .type = cpu_to_be16(ETH_P_DEC),
483 .func = lapbeth_rcv,
484};
485
486static struct notifier_block lapbeth_dev_notifier = {
487 .notifier_call = lapbeth_device_event,
488};
489
490static const char banner[] __initconst =
491 KERN_INFO "LAPB Ethernet driver version 0.02\n";
492
493static int __init lapbeth_init_driver(void)
494{
495 dev_add_pack(&lapbeth_packet_type);
496
497 register_netdevice_notifier(&lapbeth_dev_notifier);
498
499 printk(banner);
500
501 return 0;
502}
503module_init(lapbeth_init_driver);
504
505static void __exit lapbeth_cleanup_driver(void)
506{
507 struct lapbethdev *lapbeth;
508 struct list_head *entry, *tmp;
509
510 dev_remove_pack(&lapbeth_packet_type);
511 unregister_netdevice_notifier(&lapbeth_dev_notifier);
512
513 rtnl_lock();
514 list_for_each_safe(entry, tmp, &lapbeth_devices) {
515 lapbeth = list_entry(entry, struct lapbethdev, node);
516
517 dev_put(lapbeth->ethdev);
518 unregister_netdevice(lapbeth->axdev);
519 }
520 rtnl_unlock();
521}
522module_exit(lapbeth_cleanup_driver);
523
524MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
525MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
526MODULE_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) {
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");