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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 | ||
23 | #include <linux/errno.h> | |
24 | #include <linux/types.h> | |
25 | #include <linux/socket.h> | |
26 | #include <linux/in.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/string.h> | |
29 | #include <linux/net.h> | |
30 | #include <linux/inet.h> | |
31 | #include <linux/netdevice.h> | |
32 | #include <linux/if_arp.h> | |
33 | #include <linux/skbuff.h> | |
34 | #include <net/sock.h> | |
35 | #include <asm/system.h> | |
36 | #include <asm/uaccess.h> | |
37 | #include <linux/mm.h> | |
38 | #include <linux/interrupt.h> | |
39 | #include <linux/notifier.h> | |
40 | #include <linux/stat.h> | |
41 | #include <linux/netfilter.h> | |
42 | #include <linux/module.h> | |
43 | #include <linux/lapb.h> | |
44 | #include <linux/init.h> | |
45 | ||
46 | #include <net/x25device.h> | |
47 | ||
48 | static char bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; | |
49 | ||
50 | /* If this number is made larger, check that the temporary string buffer | |
51 | * in lapbeth_new_device is large enough to store the probe device name.*/ | |
52 | #define MAXLAPBDEV 100 | |
53 | ||
54 | struct lapbethdev { | |
55 | struct list_head node; | |
56 | struct net_device *ethdev; /* link to ethernet device */ | |
57 | struct net_device *axdev; /* lapbeth device (lapb#) */ | |
58 | struct net_device_stats stats; /* some statistics */ | |
59 | }; | |
60 | ||
61 | static struct list_head lapbeth_devices = LIST_HEAD_INIT(lapbeth_devices); | |
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 | ||
e730c155 EB |
94 | if (dev->nd_net != &init_net) |
95 | goto drop; | |
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 | ||
110 | lapbeth->stats.rx_packets++; | |
111 | ||
112 | len = skb->data[0] + skb->data[1] * 256; | |
113 | lapbeth->stats.rx_bytes += len; | |
114 | ||
115 | skb_pull(skb, 2); /* Remove the length bytes */ | |
116 | skb_trim(skb, len); /* Set the length of the data */ | |
117 | ||
118 | if ((err = lapb_data_received(lapbeth->axdev, skb)) != LAPB_OK) { | |
119 | printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err); | |
120 | goto drop_unlock; | |
121 | } | |
122 | out: | |
123 | rcu_read_unlock(); | |
124 | return 0; | |
125 | drop_unlock: | |
126 | kfree_skb(skb); | |
127 | goto out; | |
128 | drop: | |
129 | kfree_skb(skb); | |
130 | return 0; | |
131 | } | |
132 | ||
133 | static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb) | |
134 | { | |
135 | unsigned char *ptr; | |
136 | ||
137 | skb_push(skb, 1); | |
138 | ||
139 | if (skb_cow(skb, 1)) | |
140 | return NET_RX_DROP; | |
141 | ||
142 | ptr = skb->data; | |
143 | *ptr = 0x00; | |
144 | ||
145 | skb->protocol = x25_type_trans(skb, dev); | |
146 | skb->dev->last_rx = jiffies; | |
147 | return netif_rx(skb); | |
148 | } | |
149 | ||
150 | /* | |
151 | * Send a LAPB frame via an ethernet interface | |
152 | */ | |
153 | static int lapbeth_xmit(struct sk_buff *skb, struct net_device *dev) | |
154 | { | |
155 | int err = -ENODEV; | |
156 | ||
157 | /* | |
158 | * Just to be *really* sure not to send anything if the interface | |
159 | * is down, the ethernet device may have gone. | |
160 | */ | |
161 | if (!netif_running(dev)) { | |
162 | goto drop; | |
163 | } | |
164 | ||
165 | switch (skb->data[0]) { | |
166 | case 0x00: | |
167 | err = 0; | |
168 | break; | |
169 | case 0x01: | |
170 | if ((err = lapb_connect_request(dev)) != LAPB_OK) | |
171 | printk(KERN_ERR "lapbeth: lapb_connect_request " | |
172 | "error: %d\n", err); | |
173 | goto drop_ok; | |
174 | case 0x02: | |
175 | if ((err = lapb_disconnect_request(dev)) != LAPB_OK) | |
176 | printk(KERN_ERR "lapbeth: lapb_disconnect_request " | |
177 | "err: %d\n", err); | |
178 | /* Fall thru */ | |
179 | default: | |
180 | goto drop_ok; | |
181 | } | |
182 | ||
183 | skb_pull(skb, 1); | |
184 | ||
185 | if ((err = lapb_data_request(dev, skb)) != LAPB_OK) { | |
186 | printk(KERN_ERR "lapbeth: lapb_data_request error - %d\n", err); | |
187 | err = -ENOMEM; | |
188 | goto drop; | |
189 | } | |
190 | err = 0; | |
191 | out: | |
192 | return err; | |
193 | drop_ok: | |
194 | err = 0; | |
195 | drop: | |
196 | kfree_skb(skb); | |
197 | goto out; | |
198 | } | |
199 | ||
200 | static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb) | |
201 | { | |
202 | struct lapbethdev *lapbeth = netdev_priv(ndev); | |
203 | unsigned char *ptr; | |
204 | struct net_device *dev; | |
205 | int size = skb->len; | |
206 | ||
207 | skb->protocol = htons(ETH_P_X25); | |
208 | ||
209 | ptr = skb_push(skb, 2); | |
210 | ||
211 | *ptr++ = size % 256; | |
212 | *ptr++ = size / 256; | |
213 | ||
214 | lapbeth->stats.tx_packets++; | |
215 | lapbeth->stats.tx_bytes += size; | |
216 | ||
217 | skb->dev = dev = lapbeth->ethdev; | |
218 | ||
219 | dev->hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0); | |
220 | ||
221 | dev_queue_xmit(skb); | |
222 | } | |
223 | ||
224 | static void lapbeth_connected(struct net_device *dev, int reason) | |
225 | { | |
226 | unsigned char *ptr; | |
227 | struct sk_buff *skb = dev_alloc_skb(1); | |
228 | ||
229 | if (!skb) { | |
230 | printk(KERN_ERR "lapbeth: out of memory\n"); | |
231 | return; | |
232 | } | |
233 | ||
234 | ptr = skb_put(skb, 1); | |
235 | *ptr = 0x01; | |
236 | ||
237 | skb->protocol = x25_type_trans(skb, dev); | |
238 | skb->dev->last_rx = jiffies; | |
239 | netif_rx(skb); | |
240 | } | |
241 | ||
242 | static void lapbeth_disconnected(struct net_device *dev, int reason) | |
243 | { | |
244 | unsigned char *ptr; | |
245 | struct sk_buff *skb = dev_alloc_skb(1); | |
246 | ||
247 | if (!skb) { | |
248 | printk(KERN_ERR "lapbeth: out of memory\n"); | |
249 | return; | |
250 | } | |
251 | ||
252 | ptr = skb_put(skb, 1); | |
253 | *ptr = 0x02; | |
254 | ||
255 | skb->protocol = x25_type_trans(skb, dev); | |
256 | skb->dev->last_rx = jiffies; | |
257 | netif_rx(skb); | |
258 | } | |
259 | ||
260 | /* | |
261 | * Statistics | |
262 | */ | |
263 | static struct net_device_stats *lapbeth_get_stats(struct net_device *dev) | |
264 | { | |
265 | struct lapbethdev *lapbeth = netdev_priv(dev); | |
266 | return &lapbeth->stats; | |
267 | } | |
268 | ||
269 | /* | |
270 | * Set AX.25 callsign | |
271 | */ | |
272 | static int lapbeth_set_mac_address(struct net_device *dev, void *addr) | |
273 | { | |
274 | struct sockaddr *sa = addr; | |
275 | memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); | |
276 | return 0; | |
277 | } | |
278 | ||
279 | ||
280 | static struct lapb_register_struct lapbeth_callbacks = { | |
281 | .connect_confirmation = lapbeth_connected, | |
282 | .connect_indication = lapbeth_connected, | |
283 | .disconnect_confirmation = lapbeth_disconnected, | |
284 | .disconnect_indication = lapbeth_disconnected, | |
285 | .data_indication = lapbeth_data_indication, | |
286 | .data_transmit = lapbeth_data_transmit, | |
287 | ||
288 | }; | |
289 | ||
290 | /* | |
291 | * open/close a device | |
292 | */ | |
293 | static int lapbeth_open(struct net_device *dev) | |
294 | { | |
295 | int err; | |
296 | ||
297 | if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) { | |
298 | printk(KERN_ERR "lapbeth: lapb_register error - %d\n", err); | |
299 | return -ENODEV; | |
300 | } | |
301 | ||
302 | netif_start_queue(dev); | |
303 | return 0; | |
304 | } | |
305 | ||
306 | static int lapbeth_close(struct net_device *dev) | |
307 | { | |
308 | int err; | |
309 | ||
310 | netif_stop_queue(dev); | |
311 | ||
312 | if ((err = lapb_unregister(dev)) != LAPB_OK) | |
313 | printk(KERN_ERR "lapbeth: lapb_unregister error - %d\n", err); | |
314 | ||
315 | return 0; | |
316 | } | |
317 | ||
318 | /* ------------------------------------------------------------------------ */ | |
319 | ||
320 | static void lapbeth_setup(struct net_device *dev) | |
321 | { | |
322 | dev->hard_start_xmit = lapbeth_xmit; | |
323 | dev->open = lapbeth_open; | |
324 | dev->stop = lapbeth_close; | |
325 | dev->destructor = free_netdev; | |
326 | dev->set_mac_address = lapbeth_set_mac_address; | |
327 | dev->get_stats = lapbeth_get_stats; | |
328 | dev->type = ARPHRD_X25; | |
329 | dev->hard_header_len = 3; | |
330 | dev->mtu = 1000; | |
331 | dev->addr_len = 0; | |
1da177e4 LT |
332 | } |
333 | ||
334 | /* | |
335 | * Setup a new device. | |
336 | */ | |
337 | static int lapbeth_new_device(struct net_device *dev) | |
338 | { | |
339 | struct net_device *ndev; | |
340 | struct lapbethdev *lapbeth; | |
341 | int rc = -ENOMEM; | |
342 | ||
343 | ASSERT_RTNL(); | |
344 | ||
345 | ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", | |
346 | lapbeth_setup); | |
347 | if (!ndev) | |
348 | goto out; | |
349 | ||
350 | lapbeth = netdev_priv(ndev); | |
351 | lapbeth->axdev = ndev; | |
352 | ||
353 | dev_hold(dev); | |
354 | lapbeth->ethdev = dev; | |
355 | ||
356 | rc = dev_alloc_name(ndev, ndev->name); | |
357 | if (rc < 0) | |
358 | goto fail; | |
359 | ||
360 | rc = -EIO; | |
361 | if (register_netdevice(ndev)) | |
362 | goto fail; | |
363 | ||
364 | list_add_rcu(&lapbeth->node, &lapbeth_devices); | |
365 | rc = 0; | |
366 | out: | |
367 | return rc; | |
368 | fail: | |
369 | dev_put(dev); | |
370 | free_netdev(ndev); | |
371 | kfree(lapbeth); | |
372 | goto out; | |
373 | } | |
374 | ||
375 | /* | |
376 | * Free a lapb network device. | |
377 | */ | |
378 | static void lapbeth_free_device(struct lapbethdev *lapbeth) | |
379 | { | |
380 | dev_put(lapbeth->ethdev); | |
381 | list_del_rcu(&lapbeth->node); | |
382 | unregister_netdevice(lapbeth->axdev); | |
383 | } | |
384 | ||
385 | /* | |
386 | * Handle device status changes. | |
387 | * | |
388 | * Called from notifier with RTNL held. | |
389 | */ | |
390 | static int lapbeth_device_event(struct notifier_block *this, | |
391 | unsigned long event, void *ptr) | |
392 | { | |
393 | struct lapbethdev *lapbeth; | |
394 | struct net_device *dev = ptr; | |
395 | ||
e9dc8653 EB |
396 | if (dev->nd_net != &init_net) |
397 | return NOTIFY_DONE; | |
398 | ||
1da177e4 LT |
399 | if (!dev_is_ethdev(dev)) |
400 | return NOTIFY_DONE; | |
401 | ||
402 | switch (event) { | |
403 | case NETDEV_UP: | |
404 | /* New ethernet device -> new LAPB interface */ | |
405 | if (lapbeth_get_x25_dev(dev) == NULL) | |
406 | lapbeth_new_device(dev); | |
407 | break; | |
408 | case NETDEV_DOWN: | |
409 | /* ethernet device closed -> close LAPB interface */ | |
410 | lapbeth = lapbeth_get_x25_dev(dev); | |
411 | if (lapbeth) | |
412 | dev_close(lapbeth->axdev); | |
413 | break; | |
414 | case NETDEV_UNREGISTER: | |
415 | /* ethernet device disappears -> remove LAPB interface */ | |
416 | lapbeth = lapbeth_get_x25_dev(dev); | |
417 | if (lapbeth) | |
418 | lapbeth_free_device(lapbeth); | |
419 | break; | |
420 | } | |
421 | ||
422 | return NOTIFY_DONE; | |
423 | } | |
424 | ||
425 | /* ------------------------------------------------------------------------ */ | |
426 | ||
427 | static struct packet_type lapbeth_packet_type = { | |
428 | .type = __constant_htons(ETH_P_DEC), | |
429 | .func = lapbeth_rcv, | |
430 | }; | |
431 | ||
432 | static struct notifier_block lapbeth_dev_notifier = { | |
433 | .notifier_call = lapbeth_device_event, | |
434 | }; | |
435 | ||
436 | static char banner[] __initdata = KERN_INFO "LAPB Ethernet driver version 0.02\n"; | |
437 | ||
438 | static int __init lapbeth_init_driver(void) | |
439 | { | |
440 | dev_add_pack(&lapbeth_packet_type); | |
441 | ||
442 | register_netdevice_notifier(&lapbeth_dev_notifier); | |
443 | ||
444 | printk(banner); | |
445 | ||
446 | return 0; | |
447 | } | |
448 | module_init(lapbeth_init_driver); | |
449 | ||
450 | static void __exit lapbeth_cleanup_driver(void) | |
451 | { | |
452 | struct lapbethdev *lapbeth; | |
453 | struct list_head *entry, *tmp; | |
454 | ||
455 | dev_remove_pack(&lapbeth_packet_type); | |
456 | unregister_netdevice_notifier(&lapbeth_dev_notifier); | |
457 | ||
458 | rtnl_lock(); | |
459 | list_for_each_safe(entry, tmp, &lapbeth_devices) { | |
460 | lapbeth = list_entry(entry, struct lapbethdev, node); | |
461 | ||
462 | unregister_netdevice(lapbeth->axdev); | |
463 | } | |
464 | rtnl_unlock(); | |
465 | } | |
466 | module_exit(lapbeth_cleanup_driver); | |
467 | ||
468 | MODULE_AUTHOR("Jonathan Naylor <[email protected]>"); | |
469 | MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver"); | |
470 | MODULE_LICENSE("GPL"); |