summaryrefslogtreecommitdiffstats
path: root/drivers/net/wan/hdlc_generic.c
blob: cdd4c09c2d90355adee28e09d42f560ab42d040f (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
/*
 * Generic HDLC support routines for Linux
 *
 * Copyright (C) 1999 - 2005 Krzysztof Halasa <khc@pm.waw.pl>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 *
 * Currently supported:
 *	* raw IP-in-HDLC
 *	* Cisco HDLC
 *	* Frame Relay with ANSI or CCITT LMI (both user and network side)
 *	* PPP
 *	* X.25
 *
 * Use sethdlc utility to set line parameters, protocol and PVCs
 *
 * How does it work:
 * - proto.open(), close(), start(), stop() calls are serialized.
 *   The order is: open, [ start, stop ... ] close ...
 * - proto.start() and stop() are called with spin_lock_irq held.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/pkt_sched.h>
#include <linux/inetdevice.h>
#include <linux/lapb.h>
#include <linux/rtnetlink.h>
#include <linux/hdlc.h>


static const char* version = "HDLC support module revision 1.18";

#undef DEBUG_LINK


static int hdlc_change_mtu(struct net_device *dev, int new_mtu)
{
	if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}



static struct net_device_stats *hdlc_get_stats(struct net_device *dev)
{
	return hdlc_stats(dev);
}



static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
		    struct packet_type *p, struct net_device *orig_dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	if (hdlc->proto.netif_rx)
		return hdlc->proto.netif_rx(skb);

	hdlc->stats.rx_dropped++; /* Shouldn't happen */
	dev_kfree_skb(skb);
	return NET_RX_DROP;
}



static void __hdlc_set_carrier_on(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	if (hdlc->proto.start)
		return hdlc->proto.start(dev);
#ifdef DEBUG_LINK
	if (netif_carrier_ok(dev))
		printk(KERN_ERR "hdlc_set_carrier_on(): already on\n");
#endif
	netif_carrier_on(dev);
}



static void __hdlc_set_carrier_off(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	if (hdlc->proto.stop)
		return hdlc->proto.stop(dev);

#ifdef DEBUG_LINK
	if (!netif_carrier_ok(dev))
		printk(KERN_ERR "hdlc_set_carrier_off(): already off\n");
#endif
	netif_carrier_off(dev);
}



void hdlc_set_carrier(int on, struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	unsigned long flags;
	on = on ? 1 : 0;

#ifdef DEBUG_LINK
	printk(KERN_DEBUG "hdlc_set_carrier %i\n", on);
#endif

	spin_lock_irqsave(&hdlc->state_lock, flags);

	if (hdlc->carrier == on)
		goto carrier_exit; /* no change in DCD line level */

#ifdef DEBUG_LINK
	printk(KERN_INFO "%s: carrier %s\n", dev->name, on ? "ON" : "off");
#endif
	hdlc->carrier = on;

	if (!hdlc->open)
		goto carrier_exit;

	if (hdlc->carrier) {
		printk(KERN_INFO "%s: Carrier detected\n", dev->name);
		__hdlc_set_carrier_on(dev);
	} else {
		printk(KERN_INFO "%s: Carrier lost\n", dev->name);
		__hdlc_set_carrier_off(dev);
	}

carrier_exit:
	spin_unlock_irqrestore(&hdlc->state_lock, flags);
}



/* Must be called by hardware driver when HDLC device is being opened */
int hdlc_open(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
#ifdef DEBUG_LINK
	printk(KERN_DEBUG "hdlc_open() carrier %i open %i\n",
	       hdlc->carrier, hdlc->open);
#endif

	if (hdlc->proto.id == -1)
		return -ENOSYS;	/* no protocol attached */

	if (hdlc->proto.open) {
		int result = hdlc->proto.open(dev);
		if (result)
			return result;
	}

	spin_lock_irq(&hdlc->state_lock);

	if (hdlc->carrier) {
		printk(KERN_INFO "%s: Carrier detected\n", dev->name);
		__hdlc_set_carrier_on(dev);
	} else
		printk(KERN_INFO "%s: No carrier\n", dev->name);

	hdlc->open = 1;

	spin_unlock_irq(&hdlc->state_lock);
	return 0;
}



/* Must be called by hardware driver when HDLC device is being closed */
void hdlc_close(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
#ifdef DEBUG_LINK
	printk(KERN_DEBUG "hdlc_close() carrier %i open %i\n",
	       hdlc->carrier, hdlc->open);
#endif

	spin_lock_irq(&hdlc->state_lock);

	hdlc->open = 0;
	if (hdlc->carrier)
		__hdlc_set_carrier_off(dev);

	spin_unlock_irq(&hdlc->state_lock);

	if (hdlc->proto.close)
		hdlc->proto.close(dev);
}



#ifndef CONFIG_HDLC_RAW
#define hdlc_raw_ioctl(dev, ifr)	-ENOSYS
#endif

#ifndef CONFIG_HDLC_RAW_ETH
#define hdlc_raw_eth_ioctl(dev, ifr)	-ENOSYS
#endif

#ifndef CONFIG_HDLC_PPP
#define hdlc_ppp_ioctl(dev, ifr)	-ENOSYS
#endif

#ifndef CONFIG_HDLC_CISCO
#define hdlc_cisco_ioctl(dev, ifr)	-ENOSYS
#endif

#ifndef CONFIG_HDLC_FR
#define hdlc_fr_ioctl(dev, ifr)		-ENOSYS
#endif

#ifndef CONFIG_HDLC_X25
#define hdlc_x25_ioctl(dev, ifr)	-ENOSYS
#endif


int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	unsigned int proto;

	if (cmd != SIOCWANDEV)
		return -EINVAL;

	switch(ifr->ifr_settings.type) {
	case IF_PROTO_HDLC:
	case IF_PROTO_HDLC_ETH:
	case IF_PROTO_PPP:
	case IF_PROTO_CISCO:
	case IF_PROTO_FR:
	case IF_PROTO_X25:
		proto = ifr->ifr_settings.type;
		break;

	default:
		proto = hdlc->proto.id;
	}

	switch(proto) {
	case IF_PROTO_HDLC:	return hdlc_raw_ioctl(dev, ifr);
	case IF_PROTO_HDLC_ETH:	return hdlc_raw_eth_ioctl(dev, ifr);
	case IF_PROTO_PPP:	return hdlc_ppp_ioctl(dev, ifr);
	case IF_PROTO_CISCO:	return hdlc_cisco_ioctl(dev, ifr);
	case IF_PROTO_FR:	return hdlc_fr_ioctl(dev, ifr);
	case IF_PROTO_X25:	return hdlc_x25_ioctl(dev, ifr);
	default:		return -EINVAL;
	}
}

static void hdlc_setup(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);

	dev->get_stats = hdlc_get_stats;
	dev->change_mtu = hdlc_change_mtu;
	dev->mtu = HDLC_MAX_MTU;

	dev->type = ARPHRD_RAWHDLC;
	dev->hard_header_len = 16;

	dev->flags = IFF_POINTOPOINT | IFF_NOARP;

	hdlc->proto.id = -1;
	hdlc->proto.detach = NULL;
	hdlc->carrier = 1;
	hdlc->open = 0;
	spin_lock_init(&hdlc->state_lock);
}

struct net_device *alloc_hdlcdev(void *priv)
{
	struct net_device *dev;
	dev = alloc_netdev(sizeof(hdlc_device), "hdlc%d", hdlc_setup);
	if (dev)
		dev_to_hdlc(dev)->priv = priv;
	return dev;
}

int register_hdlc_device(struct net_device *dev)
{
	int result = dev_alloc_name(dev, "hdlc%d");
	if (result < 0)
		return result;

	result = register_netdev(dev);
	if (result != 0)
		return -EIO;

	if (netif_carrier_ok(dev))
		netif_carrier_off(dev); /* no carrier until DCD goes up */

	return 0;
}



void unregister_hdlc_device(struct net_device *dev)
{
	rtnl_lock();
	hdlc_proto_detach(dev_to_hdlc(dev));
	unregister_netdevice(dev);
	rtnl_unlock();
}



MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
MODULE_DESCRIPTION("HDLC support module");
MODULE_LICENSE("GPL v2");

EXPORT_SYMBOL(hdlc_open);
EXPORT_SYMBOL(hdlc_close);
EXPORT_SYMBOL(hdlc_set_carrier);
EXPORT_SYMBOL(hdlc_ioctl);
EXPORT_SYMBOL(alloc_hdlcdev);
EXPORT_SYMBOL(register_hdlc_device);
EXPORT_SYMBOL(unregister_hdlc_device);

static struct packet_type hdlc_packet_type = {
	.type = __constant_htons(ETH_P_HDLC),
	.func = hdlc_rcv,
};


static int __init hdlc_module_init(void)
{
	printk(KERN_INFO "%s\n", version);
        dev_add_pack(&hdlc_packet_type);
	return 0;
}



static void __exit hdlc_module_exit(void)
{
	dev_remove_pack(&hdlc_packet_type);
}


module_init(hdlc_module_init);
module_exit(hdlc_module_exit);