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Commit | Line | Data |
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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#) */ | |
1da177e4 LT |
58 | }; |
59 | ||
293a3839 | 60 | static LIST_HEAD(lapbeth_devices); |
1da177e4 LT |
61 | |
62 | /* ------------------------------------------------------------------------ */ | |
63 | ||
64 | /* | |
65 | * Get the LAPB device for the ethernet device | |
66 | */ | |
67 | static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev) | |
68 | { | |
69 | struct lapbethdev *lapbeth; | |
70 | ||
71 | list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node) { | |
72 | if (lapbeth->ethdev == dev) | |
73 | return lapbeth; | |
74 | } | |
75 | return NULL; | |
76 | } | |
77 | ||
78 | static __inline__ int dev_is_ethdev(struct net_device *dev) | |
79 | { | |
80 | return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5); | |
81 | } | |
82 | ||
83 | /* ------------------------------------------------------------------------ */ | |
84 | ||
85 | /* | |
86 | * Receive a LAPB frame via an ethernet interface. | |
87 | */ | |
f2ccd8fa | 88 | static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev) |
1da177e4 LT |
89 | { |
90 | int len, err; | |
91 | struct lapbethdev *lapbeth; | |
92 | ||
c346dca1 | 93 | if (dev_net(dev) != &init_net) |
e730c155 EB |
94 | goto drop; |
95 | ||
1da177e4 LT |
96 | if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) |
97 | return NET_RX_DROP; | |
98 | ||
99 | if (!pskb_may_pull(skb, 2)) | |
100 | goto drop; | |
101 | ||
102 | rcu_read_lock(); | |
103 | lapbeth = lapbeth_get_x25_dev(dev); | |
104 | if (!lapbeth) | |
105 | goto drop_unlock; | |
106 | if (!netif_running(lapbeth->axdev)) | |
107 | goto drop_unlock; | |
108 | ||
1da177e4 | 109 | len = skb->data[0] + skb->data[1] * 256; |
ea2ebaf8 SH |
110 | dev->stats.rx_packets++; |
111 | dev->stats.rx_bytes += len; | |
1da177e4 LT |
112 | |
113 | skb_pull(skb, 2); /* Remove the length bytes */ | |
114 | skb_trim(skb, len); /* Set the length of the data */ | |
115 | ||
116 | if ((err = lapb_data_received(lapbeth->axdev, skb)) != LAPB_OK) { | |
117 | printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err); | |
118 | goto drop_unlock; | |
119 | } | |
120 | out: | |
121 | rcu_read_unlock(); | |
122 | return 0; | |
123 | drop_unlock: | |
124 | kfree_skb(skb); | |
125 | goto out; | |
126 | drop: | |
127 | kfree_skb(skb); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb) | |
132 | { | |
133 | unsigned char *ptr; | |
134 | ||
135 | skb_push(skb, 1); | |
136 | ||
137 | if (skb_cow(skb, 1)) | |
138 | return NET_RX_DROP; | |
139 | ||
140 | ptr = skb->data; | |
141 | *ptr = 0x00; | |
142 | ||
143 | skb->protocol = x25_type_trans(skb, dev); | |
1da177e4 LT |
144 | return netif_rx(skb); |
145 | } | |
146 | ||
147 | /* | |
148 | * Send a LAPB frame via an ethernet interface | |
149 | */ | |
150 | static int lapbeth_xmit(struct sk_buff *skb, struct net_device *dev) | |
151 | { | |
d77eeb70 | 152 | int err; |
1da177e4 LT |
153 | |
154 | /* | |
155 | * Just to be *really* sure not to send anything if the interface | |
156 | * is down, the ethernet device may have gone. | |
157 | */ | |
d77eeb70 | 158 | if (!netif_running(dev)) |
1da177e4 | 159 | goto drop; |
1da177e4 LT |
160 | |
161 | switch (skb->data[0]) { | |
162 | case 0x00: | |
1da177e4 LT |
163 | break; |
164 | case 0x01: | |
165 | if ((err = lapb_connect_request(dev)) != LAPB_OK) | |
166 | printk(KERN_ERR "lapbeth: lapb_connect_request " | |
167 | "error: %d\n", err); | |
d77eeb70 | 168 | goto drop; |
1da177e4 LT |
169 | case 0x02: |
170 | if ((err = lapb_disconnect_request(dev)) != LAPB_OK) | |
171 | printk(KERN_ERR "lapbeth: lapb_disconnect_request " | |
172 | "err: %d\n", err); | |
173 | /* Fall thru */ | |
174 | default: | |
d77eeb70 | 175 | goto drop; |
1da177e4 LT |
176 | } |
177 | ||
178 | skb_pull(skb, 1); | |
179 | ||
180 | if ((err = lapb_data_request(dev, skb)) != LAPB_OK) { | |
181 | printk(KERN_ERR "lapbeth: lapb_data_request error - %d\n", err); | |
1da177e4 LT |
182 | goto drop; |
183 | } | |
1da177e4 | 184 | out: |
d77eeb70 | 185 | return NETDEV_TX_OK; |
1da177e4 LT |
186 | drop: |
187 | kfree_skb(skb); | |
188 | goto out; | |
189 | } | |
190 | ||
191 | static 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 | ||
ea2ebaf8 SH |
205 | ndev->stats.tx_packets++; |
206 | ndev->stats.tx_bytes += size; | |
1da177e4 LT |
207 | |
208 | skb->dev = dev = lapbeth->ethdev; | |
209 | ||
0c4e8581 | 210 | dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0); |
1da177e4 LT |
211 | |
212 | dev_queue_xmit(skb); | |
213 | } | |
214 | ||
215 | static 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 | printk(KERN_ERR "lapbeth: out of memory\n"); | |
222 | return; | |
223 | } | |
224 | ||
225 | ptr = skb_put(skb, 1); | |
226 | *ptr = 0x01; | |
227 | ||
228 | skb->protocol = x25_type_trans(skb, dev); | |
1da177e4 LT |
229 | netif_rx(skb); |
230 | } | |
231 | ||
232 | static 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 | printk(KERN_ERR "lapbeth: out of memory\n"); | |
239 | return; | |
240 | } | |
241 | ||
242 | ptr = skb_put(skb, 1); | |
243 | *ptr = 0x02; | |
244 | ||
245 | skb->protocol = x25_type_trans(skb, dev); | |
1da177e4 LT |
246 | netif_rx(skb); |
247 | } | |
248 | ||
1da177e4 LT |
249 | /* |
250 | * Set AX.25 callsign | |
251 | */ | |
252 | static 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 | ||
260 | static 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 | /* | |
271 | * open/close a device | |
272 | */ | |
273 | static int lapbeth_open(struct net_device *dev) | |
274 | { | |
275 | int err; | |
276 | ||
277 | if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) { | |
278 | printk(KERN_ERR "lapbeth: lapb_register error - %d\n", err); | |
279 | return -ENODEV; | |
280 | } | |
281 | ||
282 | netif_start_queue(dev); | |
283 | return 0; | |
284 | } | |
285 | ||
286 | static int lapbeth_close(struct net_device *dev) | |
287 | { | |
288 | int err; | |
289 | ||
290 | netif_stop_queue(dev); | |
291 | ||
292 | if ((err = lapb_unregister(dev)) != LAPB_OK) | |
293 | printk(KERN_ERR "lapbeth: lapb_unregister error - %d\n", err); | |
294 | ||
295 | return 0; | |
296 | } | |
297 | ||
298 | /* ------------------------------------------------------------------------ */ | |
299 | ||
39549b1e SH |
300 | static const struct net_device_ops lapbeth_netdev_ops = { |
301 | .ndo_open = lapbeth_open, | |
302 | .ndo_stop = lapbeth_close, | |
303 | .ndo_start_xmit = lapbeth_xmit, | |
304 | .ndo_set_mac_address = lapbeth_set_mac_address, | |
305 | }; | |
306 | ||
1da177e4 LT |
307 | static void lapbeth_setup(struct net_device *dev) |
308 | { | |
39549b1e | 309 | dev->netdev_ops = &lapbeth_netdev_ops; |
1da177e4 | 310 | dev->destructor = free_netdev; |
1da177e4 LT |
311 | dev->type = ARPHRD_X25; |
312 | dev->hard_header_len = 3; | |
313 | dev->mtu = 1000; | |
314 | dev->addr_len = 0; | |
1da177e4 LT |
315 | } |
316 | ||
317 | /* | |
318 | * Setup a new device. | |
319 | */ | |
320 | static int lapbeth_new_device(struct net_device *dev) | |
321 | { | |
322 | struct net_device *ndev; | |
323 | struct lapbethdev *lapbeth; | |
324 | int rc = -ENOMEM; | |
325 | ||
326 | ASSERT_RTNL(); | |
327 | ||
328 | ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", | |
329 | lapbeth_setup); | |
330 | if (!ndev) | |
331 | goto out; | |
332 | ||
333 | lapbeth = netdev_priv(ndev); | |
334 | lapbeth->axdev = ndev; | |
335 | ||
336 | dev_hold(dev); | |
337 | lapbeth->ethdev = dev; | |
338 | ||
339 | rc = dev_alloc_name(ndev, ndev->name); | |
340 | if (rc < 0) | |
341 | goto fail; | |
342 | ||
343 | rc = -EIO; | |
344 | if (register_netdevice(ndev)) | |
345 | goto fail; | |
346 | ||
347 | list_add_rcu(&lapbeth->node, &lapbeth_devices); | |
348 | rc = 0; | |
349 | out: | |
350 | return rc; | |
351 | fail: | |
352 | dev_put(dev); | |
353 | free_netdev(ndev); | |
354 | kfree(lapbeth); | |
355 | goto out; | |
356 | } | |
357 | ||
358 | /* | |
359 | * Free a lapb network device. | |
360 | */ | |
361 | static void lapbeth_free_device(struct lapbethdev *lapbeth) | |
362 | { | |
363 | dev_put(lapbeth->ethdev); | |
364 | list_del_rcu(&lapbeth->node); | |
365 | unregister_netdevice(lapbeth->axdev); | |
366 | } | |
367 | ||
368 | /* | |
369 | * Handle device status changes. | |
370 | * | |
371 | * Called from notifier with RTNL held. | |
372 | */ | |
373 | static int lapbeth_device_event(struct notifier_block *this, | |
374 | unsigned long event, void *ptr) | |
375 | { | |
376 | struct lapbethdev *lapbeth; | |
377 | struct net_device *dev = ptr; | |
378 | ||
c346dca1 | 379 | if (dev_net(dev) != &init_net) |
e9dc8653 EB |
380 | return NOTIFY_DONE; |
381 | ||
1da177e4 LT |
382 | if (!dev_is_ethdev(dev)) |
383 | return NOTIFY_DONE; | |
384 | ||
385 | switch (event) { | |
386 | case NETDEV_UP: | |
387 | /* New ethernet device -> new LAPB interface */ | |
388 | if (lapbeth_get_x25_dev(dev) == NULL) | |
389 | lapbeth_new_device(dev); | |
390 | break; | |
391 | case NETDEV_DOWN: | |
392 | /* ethernet device closed -> close LAPB interface */ | |
393 | lapbeth = lapbeth_get_x25_dev(dev); | |
394 | if (lapbeth) | |
395 | dev_close(lapbeth->axdev); | |
396 | break; | |
397 | case NETDEV_UNREGISTER: | |
398 | /* ethernet device disappears -> remove LAPB interface */ | |
399 | lapbeth = lapbeth_get_x25_dev(dev); | |
400 | if (lapbeth) | |
401 | lapbeth_free_device(lapbeth); | |
402 | break; | |
403 | } | |
404 | ||
405 | return NOTIFY_DONE; | |
406 | } | |
407 | ||
408 | /* ------------------------------------------------------------------------ */ | |
409 | ||
7546dd97 | 410 | static struct packet_type lapbeth_packet_type __read_mostly = { |
09640e63 | 411 | .type = cpu_to_be16(ETH_P_DEC), |
1da177e4 LT |
412 | .func = lapbeth_rcv, |
413 | }; | |
414 | ||
415 | static struct notifier_block lapbeth_dev_notifier = { | |
416 | .notifier_call = lapbeth_device_event, | |
417 | }; | |
418 | ||
81b700b1 | 419 | static const char banner[] __initconst = |
5ee0d593 | 420 | KERN_INFO "LAPB Ethernet driver version 0.02\n"; |
1da177e4 LT |
421 | |
422 | static int __init lapbeth_init_driver(void) | |
423 | { | |
424 | dev_add_pack(&lapbeth_packet_type); | |
425 | ||
426 | register_netdevice_notifier(&lapbeth_dev_notifier); | |
427 | ||
428 | printk(banner); | |
429 | ||
430 | return 0; | |
431 | } | |
432 | module_init(lapbeth_init_driver); | |
433 | ||
434 | static void __exit lapbeth_cleanup_driver(void) | |
435 | { | |
436 | struct lapbethdev *lapbeth; | |
437 | struct list_head *entry, *tmp; | |
438 | ||
439 | dev_remove_pack(&lapbeth_packet_type); | |
440 | unregister_netdevice_notifier(&lapbeth_dev_notifier); | |
441 | ||
442 | rtnl_lock(); | |
443 | list_for_each_safe(entry, tmp, &lapbeth_devices) { | |
444 | lapbeth = list_entry(entry, struct lapbethdev, node); | |
445 | ||
e544ff00 | 446 | dev_put(lapbeth->ethdev); |
1da177e4 LT |
447 | unregister_netdevice(lapbeth->axdev); |
448 | } | |
449 | rtnl_unlock(); | |
450 | } | |
451 | module_exit(lapbeth_cleanup_driver); | |
452 | ||
453 | MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>"); | |
454 | MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver"); | |
455 | MODULE_LICENSE("GPL"); |