WAN: Generic HDLC now uses IFF_WAN_HDLC private flag.
[deliverable/linux.git] / drivers / net / wan / hdlc.c
CommitLineData
1da177e4
LT
1/*
2 * Generic HDLC support routines for Linux
3 *
40d25142 4 * Copyright (C) 1999 - 2008 Krzysztof Halasa <khc@pm.waw.pl>
1da177e4
LT
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of version 2 of the GNU General Public License
8 * as published by the Free Software Foundation.
9 *
10 * Currently supported:
11 * * raw IP-in-HDLC
12 * * Cisco HDLC
13 * * Frame Relay with ANSI or CCITT LMI (both user and network side)
14 * * PPP
15 * * X.25
16 *
17 * Use sethdlc utility to set line parameters, protocol and PVCs
18 *
19 * How does it work:
eb2a2fd9 20 * - proto->open(), close(), start(), stop() calls are serialized.
1da177e4 21 * The order is: open, [ start, stop ... ] close ...
eb2a2fd9 22 * - proto->start() and stop() are called with spin_lock_irq held.
1da177e4
LT
23 */
24
1da177e4 25#include <linux/errno.h>
4dfce407 26#include <linux/hdlc.h>
1da177e4 27#include <linux/if_arp.h>
4dfce407 28#include <linux/inetdevice.h>
1da177e4 29#include <linux/init.h>
4dfce407
KH
30#include <linux/kernel.h>
31#include <linux/module.h>
32#include <linux/notifier.h>
1da177e4 33#include <linux/pkt_sched.h>
4dfce407 34#include <linux/poll.h>
1da177e4 35#include <linux/rtnetlink.h>
4dfce407
KH
36#include <linux/skbuff.h>
37#include <linux/slab.h>
e730c155 38#include <net/net_namespace.h>
1da177e4
LT
39
40
40d25142 41static const char* version = "HDLC support module revision 1.22";
1da177e4
LT
42
43#undef DEBUG_LINK
44
fa701bd2 45static struct hdlc_proto *first_proto;
1da177e4
LT
46
47static int hdlc_change_mtu(struct net_device *dev, int new_mtu)
48{
49 if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
50 return -EINVAL;
51 dev->mtu = new_mtu;
52 return 0;
53}
54
55
56
57static struct net_device_stats *hdlc_get_stats(struct net_device *dev)
58{
198191c4 59 return &dev->stats;
1da177e4
LT
60}
61
62
63
64static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
f2ccd8fa 65 struct packet_type *p, struct net_device *orig_dev)
1da177e4 66{
40d25142 67 struct hdlc_device *hdlc = dev_to_hdlc(dev);
e730c155 68
c346dca1 69 if (dev_net(dev) != &init_net) {
e730c155
EB
70 kfree_skb(skb);
71 return 0;
72 }
73
40d25142
KH
74 BUG_ON(!hdlc->proto->netif_rx);
75 return hdlc->proto->netif_rx(skb);
1da177e4
LT
76}
77
78
79
c2ce9204 80static inline void hdlc_proto_start(struct net_device *dev)
1da177e4
LT
81{
82 hdlc_device *hdlc = dev_to_hdlc(dev);
eb2a2fd9 83 if (hdlc->proto->start)
40d25142 84 hdlc->proto->start(dev);
1da177e4
LT
85}
86
87
88
c2ce9204 89static inline void hdlc_proto_stop(struct net_device *dev)
1da177e4
LT
90{
91 hdlc_device *hdlc = dev_to_hdlc(dev);
eb2a2fd9 92 if (hdlc->proto->stop)
40d25142 93 hdlc->proto->stop(dev);
1da177e4
LT
94}
95
96
97
c2ce9204
KH
98static int hdlc_device_event(struct notifier_block *this, unsigned long event,
99 void *ptr)
1da177e4 100{
c2ce9204
KH
101 struct net_device *dev = ptr;
102 hdlc_device *hdlc;
1da177e4 103 unsigned long flags;
c2ce9204
KH
104 int on;
105
c346dca1 106 if (dev_net(dev) != &init_net)
e9dc8653
EB
107 return NOTIFY_DONE;
108
7cdc15f5 109 if (!(dev->priv_flags & IFF_WAN_HDLC))
c2ce9204 110 return NOTIFY_DONE; /* not an HDLC device */
4dfce407 111
c2ce9204
KH
112 if (event != NETDEV_CHANGE)
113 return NOTIFY_DONE; /* Only interrested in carrier changes */
114
115 on = netif_carrier_ok(dev);
1da177e4
LT
116
117#ifdef DEBUG_LINK
c2ce9204
KH
118 printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
119 dev->name, on);
1da177e4
LT
120#endif
121
c2ce9204 122 hdlc = dev_to_hdlc(dev);
1da177e4
LT
123 spin_lock_irqsave(&hdlc->state_lock, flags);
124
125 if (hdlc->carrier == on)
126 goto carrier_exit; /* no change in DCD line level */
127
1da177e4
LT
128 hdlc->carrier = on;
129
130 if (!hdlc->open)
131 goto carrier_exit;
132
b3dd65f9
KH
133 if (hdlc->carrier) {
134 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
c2ce9204 135 hdlc_proto_start(dev);
b3dd65f9
KH
136 } else {
137 printk(KERN_INFO "%s: Carrier lost\n", dev->name);
c2ce9204 138 hdlc_proto_stop(dev);
b3dd65f9 139 }
1da177e4
LT
140
141carrier_exit:
142 spin_unlock_irqrestore(&hdlc->state_lock, flags);
c2ce9204 143 return NOTIFY_DONE;
1da177e4
LT
144}
145
146
147
148/* Must be called by hardware driver when HDLC device is being opened */
149int hdlc_open(struct net_device *dev)
150{
151 hdlc_device *hdlc = dev_to_hdlc(dev);
152#ifdef DEBUG_LINK
eb2a2fd9 153 printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
1da177e4
LT
154 hdlc->carrier, hdlc->open);
155#endif
156
eb2a2fd9 157 if (hdlc->proto == NULL)
1da177e4
LT
158 return -ENOSYS; /* no protocol attached */
159
eb2a2fd9
KH
160 if (hdlc->proto->open) {
161 int result = hdlc->proto->open(dev);
1da177e4
LT
162 if (result)
163 return result;
164 }
165
166 spin_lock_irq(&hdlc->state_lock);
167
b3dd65f9
KH
168 if (hdlc->carrier) {
169 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
c2ce9204 170 hdlc_proto_start(dev);
b3dd65f9
KH
171 } else
172 printk(KERN_INFO "%s: No carrier\n", dev->name);
1da177e4
LT
173
174 hdlc->open = 1;
175
176 spin_unlock_irq(&hdlc->state_lock);
177 return 0;
178}
179
180
181
182/* Must be called by hardware driver when HDLC device is being closed */
183void hdlc_close(struct net_device *dev)
184{
185 hdlc_device *hdlc = dev_to_hdlc(dev);
186#ifdef DEBUG_LINK
eb2a2fd9 187 printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
1da177e4
LT
188 hdlc->carrier, hdlc->open);
189#endif
190
191 spin_lock_irq(&hdlc->state_lock);
192
193 hdlc->open = 0;
194 if (hdlc->carrier)
c2ce9204 195 hdlc_proto_stop(dev);
1da177e4
LT
196
197 spin_unlock_irq(&hdlc->state_lock);
198
eb2a2fd9
KH
199 if (hdlc->proto->close)
200 hdlc->proto->close(dev);
1da177e4
LT
201}
202
203
204
1da177e4
LT
205int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
206{
eb2a2fd9
KH
207 struct hdlc_proto *proto = first_proto;
208 int result;
1da177e4
LT
209
210 if (cmd != SIOCWANDEV)
211 return -EINVAL;
212
eb2a2fd9
KH
213 if (dev_to_hdlc(dev)->proto) {
214 result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
215 if (result != -EINVAL)
216 return result;
1da177e4
LT
217 }
218
eb2a2fd9
KH
219 /* Not handled by currently attached protocol (if any) */
220
221 while (proto) {
222 if ((result = proto->ioctl(dev, ifr)) != -EINVAL)
223 return result;
224 proto = proto->next;
1da177e4 225 }
eb2a2fd9 226 return -EINVAL;
1da177e4
LT
227}
228
3b04ddde
SH
229static const struct header_ops hdlc_null_ops;
230
b5284e5a
KH
231static void hdlc_setup_dev(struct net_device *dev)
232{
233 /* Re-init all variables changed by HDLC protocol drivers,
234 * including ether_setup() called from hdlc_raw_eth.c.
235 */
236 dev->get_stats = hdlc_get_stats;
237 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
7cdc15f5 238 dev->priv_flags = IFF_WAN_HDLC;
b5284e5a
KH
239 dev->mtu = HDLC_MAX_MTU;
240 dev->type = ARPHRD_RAWHDLC;
241 dev->hard_header_len = 16;
242 dev->addr_len = 0;
3b04ddde
SH
243 dev->header_ops = &hdlc_null_ops;
244
b5284e5a 245 dev->change_mtu = hdlc_change_mtu;
b5284e5a
KH
246}
247
0bf94faf 248static void hdlc_setup(struct net_device *dev)
1da177e4
LT
249{
250 hdlc_device *hdlc = dev_to_hdlc(dev);
251
b5284e5a 252 hdlc_setup_dev(dev);
1da177e4
LT
253 hdlc->carrier = 1;
254 hdlc->open = 0;
255 spin_lock_init(&hdlc->state_lock);
256}
257
258struct net_device *alloc_hdlcdev(void *priv)
259{
260 struct net_device *dev;
40d25142 261 dev = alloc_netdev(sizeof(struct hdlc_device), "hdlc%d", hdlc_setup);
1da177e4
LT
262 if (dev)
263 dev_to_hdlc(dev)->priv = priv;
264 return dev;
265}
266
1da177e4
LT
267void unregister_hdlc_device(struct net_device *dev)
268{
269 rtnl_lock();
1da177e4 270 unregister_netdevice(dev);
eb2a2fd9 271 detach_hdlc_protocol(dev);
1da177e4
LT
272 rtnl_unlock();
273}
274
275
276
eb2a2fd9 277int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
40d25142 278 size_t size)
eb2a2fd9
KH
279{
280 detach_hdlc_protocol(dev);
281
282 if (!try_module_get(proto->module))
283 return -ENOSYS;
284
285 if (size)
286 if ((dev_to_hdlc(dev)->state = kmalloc(size,
287 GFP_KERNEL)) == NULL) {
288 printk(KERN_WARNING "Memory squeeze on"
289 " hdlc_proto_attach()\n");
290 module_put(proto->module);
291 return -ENOBUFS;
292 }
293 dev_to_hdlc(dev)->proto = proto;
eb2a2fd9
KH
294 return 0;
295}
296
297
298void detach_hdlc_protocol(struct net_device *dev)
299{
300 hdlc_device *hdlc = dev_to_hdlc(dev);
301
302 if (hdlc->proto) {
303 if (hdlc->proto->detach)
304 hdlc->proto->detach(dev);
305 module_put(hdlc->proto->module);
306 hdlc->proto = NULL;
307 }
308 kfree(hdlc->state);
309 hdlc->state = NULL;
b5284e5a 310 hdlc_setup_dev(dev);
eb2a2fd9
KH
311}
312
313
314void register_hdlc_protocol(struct hdlc_proto *proto)
315{
fa701bd2 316 rtnl_lock();
eb2a2fd9
KH
317 proto->next = first_proto;
318 first_proto = proto;
fa701bd2 319 rtnl_unlock();
eb2a2fd9
KH
320}
321
322
323void unregister_hdlc_protocol(struct hdlc_proto *proto)
324{
fa701bd2
KH
325 struct hdlc_proto **p;
326
327 rtnl_lock();
328 p = &first_proto;
329 while (*p != proto) {
330 BUG_ON(!*p);
eb2a2fd9
KH
331 p = &((*p)->next);
332 }
fa701bd2
KH
333 *p = proto->next;
334 rtnl_unlock();
eb2a2fd9
KH
335}
336
337
338
1da177e4
LT
339MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
340MODULE_DESCRIPTION("HDLC support module");
341MODULE_LICENSE("GPL v2");
342
343EXPORT_SYMBOL(hdlc_open);
344EXPORT_SYMBOL(hdlc_close);
1da177e4
LT
345EXPORT_SYMBOL(hdlc_ioctl);
346EXPORT_SYMBOL(alloc_hdlcdev);
1da177e4 347EXPORT_SYMBOL(unregister_hdlc_device);
eb2a2fd9
KH
348EXPORT_SYMBOL(register_hdlc_protocol);
349EXPORT_SYMBOL(unregister_hdlc_protocol);
350EXPORT_SYMBOL(attach_hdlc_protocol);
351EXPORT_SYMBOL(detach_hdlc_protocol);
1da177e4
LT
352
353static struct packet_type hdlc_packet_type = {
354 .type = __constant_htons(ETH_P_HDLC),
355 .func = hdlc_rcv,
356};
357
358
c2ce9204 359static struct notifier_block hdlc_notifier = {
4dfce407 360 .notifier_call = hdlc_device_event,
c2ce9204
KH
361};
362
363
1da177e4
LT
364static int __init hdlc_module_init(void)
365{
c2ce9204
KH
366 int result;
367
1da177e4 368 printk(KERN_INFO "%s\n", version);
c2ce9204 369 if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
4dfce407
KH
370 return result;
371 dev_add_pack(&hdlc_packet_type);
1da177e4
LT
372 return 0;
373}
374
375
376
377static void __exit hdlc_module_exit(void)
378{
379 dev_remove_pack(&hdlc_packet_type);
c2ce9204 380 unregister_netdevice_notifier(&hdlc_notifier);
1da177e4
LT
381}
382
383
384module_init(hdlc_module_init);
385module_exit(hdlc_module_exit);
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