aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/wan/dlci.c
blob: 66be20c292b6dcd8855ec84830a15e7850c70baa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
/*
 * DLCI		Implementation of Frame Relay protocol for Linux, according to
 *		RFC 1490.  This generic device provides en/decapsulation for an
 *		underlying hardware driver.  Routes & IPs are assigned to these
 *		interfaces.  Requires 'dlcicfg' program to create usable 
 *		interfaces, the initial one, 'dlci' is for IOCTL use only.
 *
 * Version:	@(#)dlci.c	0.35	4 Jan 1997
 *
 * Author:	Mike McLagan <mike.mclagan@linux.org>
 *
 * Changes:
 *
 *		0.15	Mike Mclagan	Packet freeing, bug in kmalloc call
 *					DLCI_RET handling
 *		0.20	Mike McLagan	More conservative on which packets
 *					are returned for retry and which are
 *					are dropped.  If DLCI_RET_DROP is
 *					returned from the FRAD, the packet is
 *				 	sent back to Linux for re-transmission
 *		0.25	Mike McLagan	Converted to use SIOC IOCTL calls
 *		0.30	Jim Freeman	Fixed to allow IPX traffic
 *		0.35	Michael Elizabeth	Fixed incorrect memcpy_fromfs
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/if_frad.h>
#include <linux/bitops.h>

#include <net/sock.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/uaccess.h>

static const char version[] = "DLCI driver v0.35, 4 Jan 1997, mike.mclagan@linux.org";

static LIST_HEAD(dlci_devs);

static void dlci_setup(struct net_device *);

/* 
 * these encapsulate the RFC 1490 requirements as well as 
 * deal with packet transmission and reception, working with
 * the upper network layers 
 */

static int dlci_header(struct sk_buff *skb, struct net_device *dev, 
                           unsigned short type, void *daddr, void *saddr, 
                           unsigned len)
{
	struct frhdr		hdr;
	struct dlci_local	*dlp;
	unsigned int		hlen;
	char			*dest;

	dlp = dev->priv;

	hdr.control = FRAD_I_UI;
	switch(type)
	{
		case ETH_P_IP:
			hdr.IP_NLPID = FRAD_P_IP;
			hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
			break;

		/* feel free to add other types, if necessary */

		default:
			hdr.pad = FRAD_P_PADDING;
			hdr.NLPID = FRAD_P_SNAP;
			memset(hdr.OUI, 0, sizeof(hdr.OUI));
			hdr.PID = htons(type);
			hlen = sizeof(hdr);
			break;
	}

	dest = skb_push(skb, hlen);
	if (!dest)
		return(0);

	memcpy(dest, &hdr, hlen);

	return(hlen);
}

static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
{
	struct dlci_local *dlp;
	struct frhdr		*hdr;
	int					process, header;

	dlp = dev->priv;
	if (!pskb_may_pull(skb, sizeof(*hdr))) {
		printk(KERN_NOTICE "%s: invalid data no header\n",
		       dev->name);
		dlp->stats.rx_errors++;
		kfree_skb(skb);
		return;
	}

	hdr = (struct frhdr *) skb->data;
	process = 0;
	header = 0;
	skb->dev = dev;

	if (hdr->control != FRAD_I_UI)
	{
		printk(KERN_NOTICE "%s: Invalid header flag 0x%02X.\n", dev->name, hdr->control);
		dlp->stats.rx_errors++;
	}
	else
		switch(hdr->IP_NLPID)
		{
			case FRAD_P_PADDING:
				if (hdr->NLPID != FRAD_P_SNAP)
				{
					printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->NLPID);
					dlp->stats.rx_errors++;
					break;
				}
	 
				if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
				{
					printk(KERN_NOTICE "%s: Unsupported organizationally unique identifier 0x%02X-%02X-%02X.\n", dev->name, hdr->OUI[0], hdr->OUI[1], hdr->OUI[2]);
					dlp->stats.rx_errors++;
					break;
				}

				/* at this point, it's an EtherType frame */
				header = sizeof(struct frhdr);
				/* Already in network order ! */
				skb->protocol = hdr->PID;
				process = 1;
				break;

			case FRAD_P_IP:
				header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
				skb->protocol = htons(ETH_P_IP);
				process = 1;
				break;

			case FRAD_P_SNAP:
			case FRAD_P_Q933:
			case FRAD_P_CLNP:
				printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->pad);
				dlp->stats.rx_errors++;
				break;

			default:
				printk(KERN_NOTICE "%s: Invalid pad byte 0x%02X.\n", dev->name, hdr->pad);
				dlp->stats.rx_errors++;
				break;				
		}

	if (process)
	{
		/* we've set up the protocol, so discard the header */
		skb_reset_mac_header(skb);
		skb_pull(skb, header);
		dlp->stats.rx_bytes += skb->len;
		netif_rx(skb);
		dlp->stats.rx_packets++;
		dev->last_rx = jiffies;
	}
	else
		dev_kfree_skb(skb);
}

static int dlci_transmit(struct sk_buff *skb, struct net_device *dev)
{
	struct dlci_local *dlp;
	int					ret;

	ret = 0;

	if (!skb || !dev)
		return(0);

	dlp = dev->priv;

	netif_stop_queue(dev);
	
	ret = dlp->slave->hard_start_xmit(skb, dlp->slave);
	switch (ret)
	{
		case DLCI_RET_OK:
			dlp->stats.tx_packets++;
			ret = 0;
			break;
			case DLCI_RET_ERR:
			dlp->stats.tx_errors++;
			ret = 0;
			break;
			case DLCI_RET_DROP:
			dlp->stats.tx_dropped++;
			ret = 1;
			break;
	}
	/* Alan Cox recommends always returning 0, and always freeing the packet */
	/* experience suggest a slightly more conservative approach */

	if (!ret)
	{
		dev_kfree_skb(skb);
		netif_wake_queue(dev);
	}
	return(ret);
}

static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
{
	struct dlci_conf	config;
	struct dlci_local	*dlp;
	struct frad_local	*flp;
	int			err;

	dlp = dev->priv;

	flp = dlp->slave->priv;

	if (!get)
	{
		if(copy_from_user(&config, conf, sizeof(struct dlci_conf)))
			return -EFAULT;
		if (config.flags & ~DLCI_VALID_FLAGS)
			return(-EINVAL);
		memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
		dlp->configured = 1;
	}

	err = (*flp->dlci_conf)(dlp->slave, dev, get);
	if (err)
		return(err);

	if (get)
	{
		if(copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
			return -EFAULT;
	}

	return(0);
}

static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	struct dlci_local *dlp;

	if (!capable(CAP_NET_ADMIN))
		return(-EPERM);

	dlp = dev->priv;

	switch(cmd)
	{
		case DLCI_GET_SLAVE:
			if (!*(short *)(dev->dev_addr))
				return(-EINVAL);

			strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
			break;

		case DLCI_GET_CONF:
		case DLCI_SET_CONF:
			if (!*(short *)(dev->dev_addr))
				return(-EINVAL);

			return(dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF));
			break;

		default: 
			return(-EOPNOTSUPP);
	}
	return(0);
}

static int dlci_change_mtu(struct net_device *dev, int new_mtu)
{
	struct dlci_local *dlp;

	dlp = dev->priv;

	return((*dlp->slave->change_mtu)(dlp->slave, new_mtu));
}

static int dlci_open(struct net_device *dev)
{
	struct dlci_local	*dlp;
	struct frad_local	*flp;
	int			err;

	dlp = dev->priv;

	if (!*(short *)(dev->dev_addr))
		return(-EINVAL);

	if (!netif_running(dlp->slave))
		return(-ENOTCONN);

	flp = dlp->slave->priv;
	err = (*flp->activate)(dlp->slave, dev);
	if (err)
		return(err);

	netif_start_queue(dev);

	return 0;
}

static int dlci_close(struct net_device *dev)
{
	struct dlci_local	*dlp;
	struct frad_local	*flp;
	int			err;

	netif_stop_queue(dev);

	dlp = dev->priv;

	flp = dlp->slave->priv;
	err = (*flp->deactivate)(dlp->slave, dev);

	return 0;
}

static struct net_device_stats *dlci_get_stats(struct net_device *dev)
{
	struct dlci_local *dlp;

	dlp = dev->priv;

	return(&dlp->stats);
}

static int dlci_add(struct dlci_add *dlci)
{
	struct net_device	*master, *slave;
	struct dlci_local	*dlp;
	struct frad_local	*flp;
	int			err = -EINVAL;


	/* validate slave device */
	slave = dev_get_by_name(dlci->devname);
	if (!slave)
		return -ENODEV;

	if (slave->type != ARPHRD_FRAD || slave->priv == NULL)
		goto err1;

	/* create device name */
	master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
			      dlci_setup);
	if (!master) {
		err = -ENOMEM;
		goto err1;
	}

	/* make sure same slave not already registered */
	rtnl_lock();
	list_for_each_entry(dlp, &dlci_devs, list) {
		if (dlp->slave == slave) {
			err = -EBUSY;
			goto err2;
		}
	}

	err = dev_alloc_name(master, master->name);
	if (err < 0)
		goto err2;

	*(short *)(master->dev_addr) = dlci->dlci;

	dlp = (struct dlci_local *) master->priv;
	dlp->slave = slave;
	dlp->master = master;

	flp = slave->priv;
	err = (*flp->assoc)(slave, master);
	if (err < 0)
		goto err2;

	err = register_netdevice(master);
	if (err < 0) 
		goto err2;

	strcpy(dlci->devname, master->name);

	list_add(&dlp->list, &dlci_devs);
	rtnl_unlock();

	return(0);

 err2:
	rtnl_unlock();
	free_netdev(master);
 err1:
	dev_put(slave);
	return(err);
}

static int dlci_del(struct dlci_add *dlci)
{
	struct dlci_local	*dlp;
	struct frad_local	*flp;
	struct net_device	*master, *slave;
	int			err;

	/* validate slave device */
	master = __dev_get_by_name(dlci->devname);
	if (!master)
		return(-ENODEV);

	if (netif_running(master)) {
		return(-EBUSY);
	}

	dlp = master->priv;
	slave = dlp->slave;
	flp = slave->priv;

	rtnl_lock();
	err = (*flp->deassoc)(slave, master);
	if (!err) {
		list_del(&dlp->list);

		unregister_netdevice(master);

		dev_put(slave);
	}
	rtnl_unlock();

	return(err);
}

static int dlci_ioctl(unsigned int cmd, void __user *arg)
{
	struct dlci_add add;
	int err;
	
	if (!capable(CAP_NET_ADMIN))
		return(-EPERM);

	if(copy_from_user(&add, arg, sizeof(struct dlci_add)))
		return -EFAULT;

	switch (cmd)
	{
		case SIOCADDDLCI:
			err = dlci_add(&add);

			if (!err)
				if(copy_to_user(arg, &add, sizeof(struct dlci_add)))
					return -EFAULT;
			break;

		case SIOCDELDLCI:
			err = dlci_del(&add);
			break;

		default:
			err = -EINVAL;
	}

	return(err);
}

static void dlci_setup(struct net_device *dev)
{
	struct dlci_local *dlp = dev->priv;

	dev->flags		= 0;
	dev->open		= dlci_open;
	dev->stop		= dlci_close;
	dev->do_ioctl		= dlci_dev_ioctl;
	dev->hard_start_xmit	= dlci_transmit;
	dev->hard_header	= dlci_header;
	dev->get_stats		= dlci_get_stats;
	dev->change_mtu		= dlci_change_mtu;
	dev->destructor		= free_netdev;

	dlp->receive		= dlci_receive;

	dev->type		= ARPHRD_DLCI;
	dev->hard_header_len	= sizeof(struct frhdr);
	dev->addr_len		= sizeof(short);

}

/* if slave is unregistering, then cleanup master */
static int dlci_dev_event(struct notifier_block *unused,
			  unsigned long event, void *ptr)
{
	struct net_device *dev = (struct net_device *) ptr;

	if (event == NETDEV_UNREGISTER) {
		struct dlci_local *dlp;

		list_for_each_entry(dlp, &dlci_devs, list) {
			if (dlp->slave == dev) {
				list_del(&dlp->list);
				unregister_netdevice(dlp->master);
				dev_put(dlp->slave);
				break;
			}
		}
	}
	return NOTIFY_DONE;
}

static struct notifier_block dlci_notifier = {
	.notifier_call = dlci_dev_event,
};

static int __init init_dlci(void)
{
	dlci_ioctl_set(dlci_ioctl);
	register_netdevice_notifier(&dlci_notifier);

	printk("%s.\n", version);

	return 0;
}

static void __exit dlci_exit(void)
{
	struct dlci_local	*dlp, *nxt;
	
	dlci_ioctl_set(NULL);
	unregister_netdevice_notifier(&dlci_notifier);

	rtnl_lock();
	list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
		unregister_netdevice(dlp->master);
		dev_put(dlp->slave);
	}
	rtnl_unlock();
}

module_init(init_dlci);
module_exit(dlci_exit);

MODULE_AUTHOR("Mike McLagan");
MODULE_DESCRIPTION("Frame Relay DLCI layer");
MODULE_LICENSE("GPL");