Commit | Line | Data |
---|---|---|
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 | ||
23efcb73 JP |
23 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
24 | ||
1da177e4 LT |
25 | #include <linux/errno.h> |
26 | #include <linux/types.h> | |
27 | #include <linux/socket.h> | |
28 | #include <linux/in.h> | |
5a0e3ad6 | 29 | #include <linux/slab.h> |
1da177e4 LT |
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 <asm/system.h> | |
39 | #include <asm/uaccess.h> | |
40 | #include <linux/mm.h> | |
41 | #include <linux/interrupt.h> | |
42 | #include <linux/notifier.h> | |
43 | #include <linux/stat.h> | |
44 | #include <linux/netfilter.h> | |
45 | #include <linux/module.h> | |
46 | #include <linux/lapb.h> | |
47 | #include <linux/init.h> | |
48 | ||
49 | #include <net/x25device.h> | |
50 | ||
dcfc5d78 | 51 | static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; |
1da177e4 LT |
52 | |
53 | /* If this number is made larger, check that the temporary string buffer | |
54 | * in lapbeth_new_device is large enough to store the probe device name.*/ | |
55 | #define MAXLAPBDEV 100 | |
56 | ||
57 | struct lapbethdev { | |
58 | struct list_head node; | |
59 | struct net_device *ethdev; /* link to ethernet device */ | |
60 | struct net_device *axdev; /* lapbeth device (lapb#) */ | |
1da177e4 LT |
61 | }; |
62 | ||
293a3839 | 63 | static LIST_HEAD(lapbeth_devices); |
1da177e4 LT |
64 | |
65 | /* ------------------------------------------------------------------------ */ | |
66 | ||
67 | /* | |
68 | * Get the LAPB device for the ethernet device | |
69 | */ | |
70 | static 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) { | |
75 | if (lapbeth->ethdev == dev) | |
76 | return lapbeth; | |
77 | } | |
78 | return NULL; | |
79 | } | |
80 | ||
81 | static __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 | ||
88 | /* | |
89 | * Receive a LAPB frame via an ethernet interface. | |
90 | */ | |
f2ccd8fa | 91 | static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev) |
1da177e4 LT |
92 | { |
93 | int len, err; | |
94 | struct lapbethdev *lapbeth; | |
95 | ||
c346dca1 | 96 | if (dev_net(dev) != &init_net) |
e730c155 EB |
97 | goto drop; |
98 | ||
1da177e4 LT |
99 | if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) |
100 | return NET_RX_DROP; | |
101 | ||
102 | if (!pskb_may_pull(skb, 2)) | |
103 | goto drop; | |
104 | ||
105 | rcu_read_lock(); | |
106 | lapbeth = lapbeth_get_x25_dev(dev); | |
107 | if (!lapbeth) | |
108 | goto drop_unlock; | |
109 | if (!netif_running(lapbeth->axdev)) | |
110 | goto drop_unlock; | |
111 | ||
1da177e4 | 112 | len = skb->data[0] + skb->data[1] * 256; |
ea2ebaf8 SH |
113 | dev->stats.rx_packets++; |
114 | dev->stats.rx_bytes += len; | |
1da177e4 LT |
115 | |
116 | skb_pull(skb, 2); /* Remove the length bytes */ | |
117 | skb_trim(skb, len); /* Set the length of the data */ | |
118 | ||
119 | if ((err = lapb_data_received(lapbeth->axdev, skb)) != LAPB_OK) { | |
120 | printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err); | |
121 | goto drop_unlock; | |
122 | } | |
123 | out: | |
124 | rcu_read_unlock(); | |
125 | return 0; | |
126 | drop_unlock: | |
127 | kfree_skb(skb); | |
128 | goto out; | |
129 | drop: | |
130 | kfree_skb(skb); | |
131 | return 0; | |
132 | } | |
133 | ||
134 | static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb) | |
135 | { | |
136 | unsigned char *ptr; | |
137 | ||
138 | skb_push(skb, 1); | |
139 | ||
140 | if (skb_cow(skb, 1)) | |
141 | return NET_RX_DROP; | |
142 | ||
143 | ptr = skb->data; | |
4d99503e | 144 | *ptr = X25_IFACE_DATA; |
1da177e4 LT |
145 | |
146 | skb->protocol = x25_type_trans(skb, dev); | |
1da177e4 LT |
147 | return netif_rx(skb); |
148 | } | |
149 | ||
150 | /* | |
151 | * Send a LAPB frame via an ethernet interface | |
152 | */ | |
d71a6749 SH |
153 | static netdev_tx_t lapbeth_xmit(struct sk_buff *skb, |
154 | struct net_device *dev) | |
1da177e4 | 155 | { |
d77eeb70 | 156 | int err; |
1da177e4 LT |
157 | |
158 | /* | |
159 | * Just to be *really* sure not to send anything if the interface | |
160 | * is down, the ethernet device may have gone. | |
161 | */ | |
d77eeb70 | 162 | if (!netif_running(dev)) |
1da177e4 | 163 | goto drop; |
1da177e4 LT |
164 | |
165 | switch (skb->data[0]) { | |
4d99503e | 166 | case X25_IFACE_DATA: |
1da177e4 | 167 | break; |
4d99503e | 168 | case X25_IFACE_CONNECT: |
1da177e4 | 169 | if ((err = lapb_connect_request(dev)) != LAPB_OK) |
23efcb73 | 170 | pr_err("lapb_connect_request error: %d\n", err); |
d77eeb70 | 171 | goto drop; |
4d99503e | 172 | case X25_IFACE_DISCONNECT: |
1da177e4 | 173 | if ((err = lapb_disconnect_request(dev)) != LAPB_OK) |
23efcb73 | 174 | pr_err("lapb_disconnect_request err: %d\n", err); |
1da177e4 LT |
175 | /* Fall thru */ |
176 | default: | |
d77eeb70 | 177 | goto drop; |
1da177e4 LT |
178 | } |
179 | ||
180 | skb_pull(skb, 1); | |
181 | ||
182 | if ((err = lapb_data_request(dev, skb)) != LAPB_OK) { | |
23efcb73 | 183 | pr_err("lapb_data_request error - %d\n", err); |
1da177e4 LT |
184 | goto drop; |
185 | } | |
1da177e4 | 186 | out: |
d77eeb70 | 187 | return NETDEV_TX_OK; |
1da177e4 LT |
188 | drop: |
189 | kfree_skb(skb); | |
190 | goto out; | |
191 | } | |
192 | ||
193 | static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb) | |
194 | { | |
195 | struct lapbethdev *lapbeth = netdev_priv(ndev); | |
196 | unsigned char *ptr; | |
197 | struct net_device *dev; | |
198 | int size = skb->len; | |
199 | ||
200 | skb->protocol = htons(ETH_P_X25); | |
201 | ||
202 | ptr = skb_push(skb, 2); | |
203 | ||
204 | *ptr++ = size % 256; | |
205 | *ptr++ = size / 256; | |
206 | ||
ea2ebaf8 SH |
207 | ndev->stats.tx_packets++; |
208 | ndev->stats.tx_bytes += size; | |
1da177e4 LT |
209 | |
210 | skb->dev = dev = lapbeth->ethdev; | |
211 | ||
0c4e8581 | 212 | dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0); |
1da177e4 LT |
213 | |
214 | dev_queue_xmit(skb); | |
215 | } | |
216 | ||
217 | static void lapbeth_connected(struct net_device *dev, int reason) | |
218 | { | |
219 | unsigned char *ptr; | |
220 | struct sk_buff *skb = dev_alloc_skb(1); | |
221 | ||
222 | if (!skb) { | |
23efcb73 | 223 | pr_err("out of memory\n"); |
1da177e4 LT |
224 | return; |
225 | } | |
226 | ||
227 | ptr = skb_put(skb, 1); | |
4d99503e | 228 | *ptr = X25_IFACE_CONNECT; |
1da177e4 LT |
229 | |
230 | skb->protocol = x25_type_trans(skb, dev); | |
1da177e4 LT |
231 | netif_rx(skb); |
232 | } | |
233 | ||
234 | static void lapbeth_disconnected(struct net_device *dev, int reason) | |
235 | { | |
236 | unsigned char *ptr; | |
237 | struct sk_buff *skb = dev_alloc_skb(1); | |
238 | ||
239 | if (!skb) { | |
23efcb73 | 240 | pr_err("out of memory\n"); |
1da177e4 LT |
241 | return; |
242 | } | |
243 | ||
244 | ptr = skb_put(skb, 1); | |
4d99503e | 245 | *ptr = X25_IFACE_DISCONNECT; |
1da177e4 LT |
246 | |
247 | skb->protocol = x25_type_trans(skb, dev); | |
1da177e4 LT |
248 | netif_rx(skb); |
249 | } | |
250 | ||
1da177e4 LT |
251 | /* |
252 | * Set AX.25 callsign | |
253 | */ | |
254 | static int lapbeth_set_mac_address(struct net_device *dev, void *addr) | |
255 | { | |
256 | struct sockaddr *sa = addr; | |
257 | memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); | |
258 | return 0; | |
259 | } | |
260 | ||
261 | ||
d97a077a | 262 | static const struct lapb_register_struct lapbeth_callbacks = { |
1da177e4 LT |
263 | .connect_confirmation = lapbeth_connected, |
264 | .connect_indication = lapbeth_connected, | |
265 | .disconnect_confirmation = lapbeth_disconnected, | |
266 | .disconnect_indication = lapbeth_disconnected, | |
267 | .data_indication = lapbeth_data_indication, | |
268 | .data_transmit = lapbeth_data_transmit, | |
1da177e4 LT |
269 | }; |
270 | ||
271 | /* | |
272 | * open/close a device | |
273 | */ | |
274 | static int lapbeth_open(struct net_device *dev) | |
275 | { | |
276 | int err; | |
277 | ||
278 | if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) { | |
23efcb73 | 279 | pr_err("lapb_register error: %d\n", err); |
1da177e4 LT |
280 | return -ENODEV; |
281 | } | |
282 | ||
283 | netif_start_queue(dev); | |
284 | return 0; | |
285 | } | |
286 | ||
287 | static int lapbeth_close(struct net_device *dev) | |
288 | { | |
289 | int err; | |
290 | ||
291 | netif_stop_queue(dev); | |
292 | ||
293 | if ((err = lapb_unregister(dev)) != LAPB_OK) | |
23efcb73 | 294 | pr_err("lapb_unregister error: %d\n", err); |
1da177e4 LT |
295 | |
296 | return 0; | |
297 | } | |
298 | ||
299 | /* ------------------------------------------------------------------------ */ | |
300 | ||
39549b1e SH |
301 | static const struct net_device_ops lapbeth_netdev_ops = { |
302 | .ndo_open = lapbeth_open, | |
303 | .ndo_stop = lapbeth_close, | |
304 | .ndo_start_xmit = lapbeth_xmit, | |
305 | .ndo_set_mac_address = lapbeth_set_mac_address, | |
306 | }; | |
307 | ||
1da177e4 LT |
308 | static void lapbeth_setup(struct net_device *dev) |
309 | { | |
39549b1e | 310 | dev->netdev_ops = &lapbeth_netdev_ops; |
1da177e4 | 311 | dev->destructor = free_netdev; |
1da177e4 LT |
312 | dev->type = ARPHRD_X25; |
313 | dev->hard_header_len = 3; | |
314 | dev->mtu = 1000; | |
315 | dev->addr_len = 0; | |
1da177e4 LT |
316 | } |
317 | ||
318 | /* | |
319 | * Setup a new device. | |
320 | */ | |
321 | static int lapbeth_new_device(struct net_device *dev) | |
322 | { | |
323 | struct net_device *ndev; | |
324 | struct lapbethdev *lapbeth; | |
325 | int rc = -ENOMEM; | |
326 | ||
327 | ASSERT_RTNL(); | |
328 | ||
329 | ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", | |
330 | lapbeth_setup); | |
331 | if (!ndev) | |
332 | goto out; | |
333 | ||
334 | lapbeth = netdev_priv(ndev); | |
335 | lapbeth->axdev = ndev; | |
336 | ||
337 | dev_hold(dev); | |
338 | lapbeth->ethdev = dev; | |
339 | ||
1da177e4 LT |
340 | rc = -EIO; |
341 | if (register_netdevice(ndev)) | |
342 | goto fail; | |
343 | ||
344 | list_add_rcu(&lapbeth->node, &lapbeth_devices); | |
345 | rc = 0; | |
346 | out: | |
347 | return rc; | |
348 | fail: | |
349 | dev_put(dev); | |
350 | free_netdev(ndev); | |
351 | kfree(lapbeth); | |
352 | goto out; | |
353 | } | |
354 | ||
355 | /* | |
356 | * Free a lapb network device. | |
357 | */ | |
358 | static void lapbeth_free_device(struct lapbethdev *lapbeth) | |
359 | { | |
360 | dev_put(lapbeth->ethdev); | |
361 | list_del_rcu(&lapbeth->node); | |
362 | unregister_netdevice(lapbeth->axdev); | |
363 | } | |
364 | ||
365 | /* | |
366 | * Handle device status changes. | |
367 | * | |
368 | * Called from notifier with RTNL held. | |
369 | */ | |
370 | static int lapbeth_device_event(struct notifier_block *this, | |
371 | unsigned long event, void *ptr) | |
372 | { | |
373 | struct lapbethdev *lapbeth; | |
374 | struct net_device *dev = ptr; | |
375 | ||
c346dca1 | 376 | if (dev_net(dev) != &init_net) |
e9dc8653 EB |
377 | return NOTIFY_DONE; |
378 | ||
1da177e4 LT |
379 | if (!dev_is_ethdev(dev)) |
380 | return NOTIFY_DONE; | |
381 | ||
382 | switch (event) { | |
383 | case NETDEV_UP: | |
384 | /* New ethernet device -> new LAPB interface */ | |
385 | if (lapbeth_get_x25_dev(dev) == NULL) | |
386 | lapbeth_new_device(dev); | |
387 | break; | |
388 | case NETDEV_DOWN: | |
389 | /* ethernet device closed -> close LAPB interface */ | |
390 | lapbeth = lapbeth_get_x25_dev(dev); | |
391 | if (lapbeth) | |
392 | dev_close(lapbeth->axdev); | |
393 | break; | |
394 | case NETDEV_UNREGISTER: | |
395 | /* ethernet device disappears -> remove LAPB interface */ | |
396 | lapbeth = lapbeth_get_x25_dev(dev); | |
397 | if (lapbeth) | |
398 | lapbeth_free_device(lapbeth); | |
399 | break; | |
400 | } | |
401 | ||
402 | return NOTIFY_DONE; | |
403 | } | |
404 | ||
405 | /* ------------------------------------------------------------------------ */ | |
406 | ||
7546dd97 | 407 | static struct packet_type lapbeth_packet_type __read_mostly = { |
09640e63 | 408 | .type = cpu_to_be16(ETH_P_DEC), |
1da177e4 LT |
409 | .func = lapbeth_rcv, |
410 | }; | |
411 | ||
412 | static struct notifier_block lapbeth_dev_notifier = { | |
413 | .notifier_call = lapbeth_device_event, | |
414 | }; | |
415 | ||
81b700b1 | 416 | static const char banner[] __initconst = |
5ee0d593 | 417 | KERN_INFO "LAPB Ethernet driver version 0.02\n"; |
1da177e4 LT |
418 | |
419 | static int __init lapbeth_init_driver(void) | |
420 | { | |
421 | dev_add_pack(&lapbeth_packet_type); | |
422 | ||
423 | register_netdevice_notifier(&lapbeth_dev_notifier); | |
424 | ||
425 | printk(banner); | |
426 | ||
427 | return 0; | |
428 | } | |
429 | module_init(lapbeth_init_driver); | |
430 | ||
431 | static void __exit lapbeth_cleanup_driver(void) | |
432 | { | |
433 | struct lapbethdev *lapbeth; | |
434 | struct list_head *entry, *tmp; | |
435 | ||
436 | dev_remove_pack(&lapbeth_packet_type); | |
437 | unregister_netdevice_notifier(&lapbeth_dev_notifier); | |
438 | ||
439 | rtnl_lock(); | |
440 | list_for_each_safe(entry, tmp, &lapbeth_devices) { | |
441 | lapbeth = list_entry(entry, struct lapbethdev, node); | |
442 | ||
e544ff00 | 443 | dev_put(lapbeth->ethdev); |
1da177e4 LT |
444 | unregister_netdevice(lapbeth->axdev); |
445 | } | |
446 | rtnl_unlock(); | |
447 | } | |
448 | module_exit(lapbeth_cleanup_driver); | |
449 | ||
450 | MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>"); | |
451 | MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver"); | |
452 | MODULE_LICENSE("GPL"); |