blob: a33a46fa88dd0216871502622a0f06b976ac94d5 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Joe Perches23efcb72011-06-26 19:01:35 +000023#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/errno.h>
26#include <linux/types.h>
27#include <linux/socket.h>
28#include <linux/in.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <asm/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/netfilter.h>
44#include <linux/module.h>
45#include <linux/lapb.h>
46#include <linux/init.h>
47
48#include <net/x25device.h>
49
stephen hemmingerdcfc5d72010-09-02 14:29:35 +000050static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52/* If this number is made larger, check that the temporary string buffer
53 * in lapbeth_new_device is large enough to store the probe device name.*/
54#define MAXLAPBDEV 100
55
56struct lapbethdev {
57 struct list_head node;
58 struct net_device *ethdev; /* link to ethernet device */
59 struct net_device *axdev; /* lapbeth device (lapb#) */
Linus Torvalds1da177e2005-04-16 15:20:36 -070060};
61
Robert P. J. Day293a3832008-03-28 16:16:39 -070062static LIST_HEAD(lapbeth_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64/* ------------------------------------------------------------------------ */
65
66/*
67 * Get the LAPB device for the ethernet device
68 */
69static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev)
70{
71 struct lapbethdev *lapbeth;
72
73 list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node) {
74 if (lapbeth->ethdev == dev)
75 return lapbeth;
76 }
77 return NULL;
78}
79
80static __inline__ int dev_is_ethdev(struct net_device *dev)
81{
82 return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
83}
84
85/* ------------------------------------------------------------------------ */
86
87/*
88 * Receive a LAPB frame via an ethernet interface.
89 */
David S. Millerf2ccd8f2005-08-09 19:34:12 -070090static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
92 int len, err;
93 struct lapbethdev *lapbeth;
94
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +090095 if (dev_net(dev) != &init_net)
Eric W. Biedermane730c152007-09-17 11:53:39 -070096 goto drop;
97
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
99 return NET_RX_DROP;
100
101 if (!pskb_may_pull(skb, 2))
102 goto drop;
103
104 rcu_read_lock();
105 lapbeth = lapbeth_get_x25_dev(dev);
106 if (!lapbeth)
107 goto drop_unlock;
108 if (!netif_running(lapbeth->axdev))
109 goto drop_unlock;
110
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 len = skb->data[0] + skb->data[1] * 256;
Stephen Hemmingerea2ebaf2009-03-20 19:36:17 +0000112 dev->stats.rx_packets++;
113 dev->stats.rx_bytes += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
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 }
122out:
123 rcu_read_unlock();
124 return 0;
125drop_unlock:
126 kfree_skb(skb);
127 goto out;
128drop:
129 kfree_skb(skb);
130 return 0;
131}
132
133static 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;
andrew hendry4d995032010-04-19 13:30:02 +0000143 *ptr = X25_IFACE_DATA;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
145 skb->protocol = x25_type_trans(skb, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 return netif_rx(skb);
147}
148
149/*
150 * Send a LAPB frame via an ethernet interface
151 */
Stephen Hemmingerd71a6742009-08-31 19:50:47 +0000152static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
153 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154{
Patrick McHardyd77eeb72009-06-15 23:33:24 +0000155 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
157 /*
158 * Just to be *really* sure not to send anything if the interface
159 * is down, the ethernet device may have gone.
160 */
Patrick McHardyd77eeb72009-06-15 23:33:24 +0000161 if (!netif_running(dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 goto drop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
164 switch (skb->data[0]) {
andrew hendry4d995032010-04-19 13:30:02 +0000165 case X25_IFACE_DATA:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 break;
andrew hendry4d995032010-04-19 13:30:02 +0000167 case X25_IFACE_CONNECT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 if ((err = lapb_connect_request(dev)) != LAPB_OK)
Joe Perches23efcb72011-06-26 19:01:35 +0000169 pr_err("lapb_connect_request error: %d\n", err);
Patrick McHardyd77eeb72009-06-15 23:33:24 +0000170 goto drop;
andrew hendry4d995032010-04-19 13:30:02 +0000171 case X25_IFACE_DISCONNECT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 if ((err = lapb_disconnect_request(dev)) != LAPB_OK)
Joe Perches23efcb72011-06-26 19:01:35 +0000173 pr_err("lapb_disconnect_request err: %d\n", err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 /* Fall thru */
175 default:
Patrick McHardyd77eeb72009-06-15 23:33:24 +0000176 goto drop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 }
178
179 skb_pull(skb, 1);
180
181 if ((err = lapb_data_request(dev, skb)) != LAPB_OK) {
Joe Perches23efcb72011-06-26 19:01:35 +0000182 pr_err("lapb_data_request error - %d\n", err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 goto drop;
184 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185out:
Patrick McHardyd77eeb72009-06-15 23:33:24 +0000186 return NETDEV_TX_OK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187drop:
188 kfree_skb(skb);
189 goto out;
190}
191
192static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
193{
194 struct lapbethdev *lapbeth = netdev_priv(ndev);
195 unsigned char *ptr;
196 struct net_device *dev;
197 int size = skb->len;
198
199 skb->protocol = htons(ETH_P_X25);
200
201 ptr = skb_push(skb, 2);
202
203 *ptr++ = size % 256;
204 *ptr++ = size / 256;
205
Stephen Hemmingerea2ebaf2009-03-20 19:36:17 +0000206 ndev->stats.tx_packets++;
207 ndev->stats.tx_bytes += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
209 skb->dev = dev = lapbeth->ethdev;
210
Stephen Hemminger0c4e8582007-10-09 01:36:32 -0700211 dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
213 dev_queue_xmit(skb);
214}
215
216static void lapbeth_connected(struct net_device *dev, int reason)
217{
218 unsigned char *ptr;
219 struct sk_buff *skb = dev_alloc_skb(1);
220
221 if (!skb) {
Joe Perches23efcb72011-06-26 19:01:35 +0000222 pr_err("out of memory\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 return;
224 }
225
226 ptr = skb_put(skb, 1);
andrew hendry4d995032010-04-19 13:30:02 +0000227 *ptr = X25_IFACE_CONNECT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
229 skb->protocol = x25_type_trans(skb, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 netif_rx(skb);
231}
232
233static void lapbeth_disconnected(struct net_device *dev, int reason)
234{
235 unsigned char *ptr;
236 struct sk_buff *skb = dev_alloc_skb(1);
237
238 if (!skb) {
Joe Perches23efcb72011-06-26 19:01:35 +0000239 pr_err("out of memory\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 return;
241 }
242
243 ptr = skb_put(skb, 1);
andrew hendry4d995032010-04-19 13:30:02 +0000244 *ptr = X25_IFACE_DISCONNECT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
246 skb->protocol = x25_type_trans(skb, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 netif_rx(skb);
248}
249
250/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 * Set AX.25 callsign
252 */
253static int lapbeth_set_mac_address(struct net_device *dev, void *addr)
254{
255 struct sockaddr *sa = addr;
256 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
257 return 0;
258}
259
260
stephen hemmingerd97a0772011-09-16 11:04:29 +0000261static const struct lapb_register_struct lapbeth_callbacks = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 .connect_confirmation = lapbeth_connected,
263 .connect_indication = lapbeth_connected,
264 .disconnect_confirmation = lapbeth_disconnected,
265 .disconnect_indication = lapbeth_disconnected,
266 .data_indication = lapbeth_data_indication,
267 .data_transmit = lapbeth_data_transmit,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268};
269
270/*
271 * open/close a device
272 */
273static int lapbeth_open(struct net_device *dev)
274{
275 int err;
276
277 if ((err = lapb_register(dev, &lapbeth_callbacks)) != LAPB_OK) {
Joe Perches23efcb72011-06-26 19:01:35 +0000278 pr_err("lapb_register error: %d\n", err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 return -ENODEV;
280 }
281
282 netif_start_queue(dev);
283 return 0;
284}
285
286static 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)
Joe Perches23efcb72011-06-26 19:01:35 +0000293 pr_err("lapb_unregister error: %d\n", err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294
295 return 0;
296}
297
298/* ------------------------------------------------------------------------ */
299
Stephen Hemminger39549b12009-03-20 19:36:18 +0000300static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307static void lapbeth_setup(struct net_device *dev)
308{
Stephen Hemminger39549b12009-03-20 19:36:18 +0000309 dev->netdev_ops = &lapbeth_netdev_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 dev->destructor = free_netdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 dev->type = ARPHRD_X25;
312 dev->hard_header_len = 3;
313 dev->mtu = 1000;
314 dev->addr_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315}
316
317/*
318 * Setup a new device.
319 */
320static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 rc = -EIO;
340 if (register_netdevice(ndev))
341 goto fail;
342
343 list_add_rcu(&lapbeth->node, &lapbeth_devices);
344 rc = 0;
345out:
346 return rc;
347fail:
348 dev_put(dev);
349 free_netdev(ndev);
350 kfree(lapbeth);
351 goto out;
352}
353
354/*
355 * Free a lapb network device.
356 */
357static void lapbeth_free_device(struct lapbethdev *lapbeth)
358{
359 dev_put(lapbeth->ethdev);
360 list_del_rcu(&lapbeth->node);
361 unregister_netdevice(lapbeth->axdev);
362}
363
364/*
365 * Handle device status changes.
366 *
367 * Called from notifier with RTNL held.
368 */
369static int lapbeth_device_event(struct notifier_block *this,
370 unsigned long event, void *ptr)
371{
372 struct lapbethdev *lapbeth;
Jiri Pirko351638e2013-05-28 01:30:21 +0000373 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900375 if (dev_net(dev) != &init_net)
Eric W. Biedermane9dc8652007-09-12 13:02:17 +0200376 return NOTIFY_DONE;
377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 if (!dev_is_ethdev(dev))
379 return NOTIFY_DONE;
380
381 switch (event) {
382 case NETDEV_UP:
383 /* New ethernet device -> new LAPB interface */
384 if (lapbeth_get_x25_dev(dev) == NULL)
385 lapbeth_new_device(dev);
386 break;
387 case NETDEV_DOWN:
388 /* ethernet device closed -> close LAPB interface */
389 lapbeth = lapbeth_get_x25_dev(dev);
390 if (lapbeth)
391 dev_close(lapbeth->axdev);
392 break;
393 case NETDEV_UNREGISTER:
394 /* ethernet device disappears -> remove LAPB interface */
395 lapbeth = lapbeth_get_x25_dev(dev);
396 if (lapbeth)
397 lapbeth_free_device(lapbeth);
398 break;
399 }
400
401 return NOTIFY_DONE;
402}
403
404/* ------------------------------------------------------------------------ */
405
Stephen Hemminger7546dd92009-03-09 08:18:29 +0000406static struct packet_type lapbeth_packet_type __read_mostly = {
Harvey Harrison09640e62009-02-01 00:45:17 -0800407 .type = cpu_to_be16(ETH_P_DEC),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 .func = lapbeth_rcv,
409};
410
411static struct notifier_block lapbeth_dev_notifier = {
412 .notifier_call = lapbeth_device_event,
413};
414
Stephen Hemminger81b700b2009-02-26 10:19:23 +0000415static const char banner[] __initconst =
Hannes Eder5ee0d592009-02-14 11:48:07 +0000416 KERN_INFO "LAPB Ethernet driver version 0.02\n";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418static int __init lapbeth_init_driver(void)
419{
420 dev_add_pack(&lapbeth_packet_type);
421
422 register_netdevice_notifier(&lapbeth_dev_notifier);
423
424 printk(banner);
425
426 return 0;
427}
428module_init(lapbeth_init_driver);
429
430static void __exit lapbeth_cleanup_driver(void)
431{
432 struct lapbethdev *lapbeth;
433 struct list_head *entry, *tmp;
434
435 dev_remove_pack(&lapbeth_packet_type);
436 unregister_netdevice_notifier(&lapbeth_dev_notifier);
437
438 rtnl_lock();
439 list_for_each_safe(entry, tmp, &lapbeth_devices) {
440 lapbeth = list_entry(entry, struct lapbethdev, node);
441
David S. Millere544ff02008-05-03 21:10:58 -0700442 dev_put(lapbeth->ethdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 unregister_netdevice(lapbeth->axdev);
444 }
445 rtnl_unlock();
446}
447module_exit(lapbeth_cleanup_driver);
448
449MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
450MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
451MODULE_LICENSE("GPL");