make hdlc_setup() static again
[linux-3.10.git] / drivers / net / wan / hdlc.c
1 /*
2  * Generic HDLC support routines for Linux
3  *
4  * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
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:
20  * - proto->open(), close(), start(), stop() calls are serialized.
21  *   The order is: open, [ start, stop ... ] close ...
22  * - proto->start() and stop() are called with spin_lock_irq held.
23  */
24
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/slab.h>
28 #include <linux/poll.h>
29 #include <linux/errno.h>
30 #include <linux/if_arp.h>
31 #include <linux/init.h>
32 #include <linux/skbuff.h>
33 #include <linux/pkt_sched.h>
34 #include <linux/inetdevice.h>
35 #include <linux/lapb.h>
36 #include <linux/rtnetlink.h>
37 #include <linux/notifier.h>
38 #include <linux/hdlc.h>
39
40
41 static const char* version = "HDLC support module revision 1.20";
42
43 #undef DEBUG_LINK
44
45 static struct hdlc_proto *first_proto = NULL;
46
47
48 static int hdlc_change_mtu(struct net_device *dev, int new_mtu)
49 {
50         if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
51                 return -EINVAL;
52         dev->mtu = new_mtu;
53         return 0;
54 }
55
56
57
58 static struct net_device_stats *hdlc_get_stats(struct net_device *dev)
59 {
60         return hdlc_stats(dev);
61 }
62
63
64
65 static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
66                     struct packet_type *p, struct net_device *orig_dev)
67 {
68         struct hdlc_device_desc *desc = dev_to_desc(dev);
69         if (desc->netif_rx)
70                 return desc->netif_rx(skb);
71
72         desc->stats.rx_dropped++; /* Shouldn't happen */
73         dev_kfree_skb(skb);
74         return NET_RX_DROP;
75 }
76
77
78
79 static inline void hdlc_proto_start(struct net_device *dev)
80 {
81         hdlc_device *hdlc = dev_to_hdlc(dev);
82         if (hdlc->proto->start)
83                 return hdlc->proto->start(dev);
84 }
85
86
87
88 static inline void hdlc_proto_stop(struct net_device *dev)
89 {
90         hdlc_device *hdlc = dev_to_hdlc(dev);
91         if (hdlc->proto->stop)
92                 return hdlc->proto->stop(dev);
93 }
94
95
96
97 static int hdlc_device_event(struct notifier_block *this, unsigned long event,
98                              void *ptr)
99 {
100         struct net_device *dev = ptr;
101         hdlc_device *hdlc;
102         unsigned long flags;
103         int on;
104  
105         if (dev->get_stats != hdlc_get_stats)
106                 return NOTIFY_DONE; /* not an HDLC device */
107  
108         if (event != NETDEV_CHANGE)
109                 return NOTIFY_DONE; /* Only interrested in carrier changes */
110
111         on = netif_carrier_ok(dev);
112
113 #ifdef DEBUG_LINK
114         printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
115                dev->name, on);
116 #endif
117
118         hdlc = dev_to_hdlc(dev);
119         spin_lock_irqsave(&hdlc->state_lock, flags);
120
121         if (hdlc->carrier == on)
122                 goto carrier_exit; /* no change in DCD line level */
123
124         hdlc->carrier = on;
125
126         if (!hdlc->open)
127                 goto carrier_exit;
128
129         if (hdlc->carrier) {
130                 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
131                 hdlc_proto_start(dev);
132         } else {
133                 printk(KERN_INFO "%s: Carrier lost\n", dev->name);
134                 hdlc_proto_stop(dev);
135         }
136
137 carrier_exit:
138         spin_unlock_irqrestore(&hdlc->state_lock, flags);
139         return NOTIFY_DONE;
140 }
141
142
143
144 /* Must be called by hardware driver when HDLC device is being opened */
145 int hdlc_open(struct net_device *dev)
146 {
147         hdlc_device *hdlc = dev_to_hdlc(dev);
148 #ifdef DEBUG_LINK
149         printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
150                hdlc->carrier, hdlc->open);
151 #endif
152
153         if (hdlc->proto == NULL)
154                 return -ENOSYS; /* no protocol attached */
155
156         if (hdlc->proto->open) {
157                 int result = hdlc->proto->open(dev);
158                 if (result)
159                         return result;
160         }
161
162         spin_lock_irq(&hdlc->state_lock);
163
164         if (hdlc->carrier) {
165                 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
166                 hdlc_proto_start(dev);
167         } else
168                 printk(KERN_INFO "%s: No carrier\n", dev->name);
169
170         hdlc->open = 1;
171
172         spin_unlock_irq(&hdlc->state_lock);
173         return 0;
174 }
175
176
177
178 /* Must be called by hardware driver when HDLC device is being closed */
179 void hdlc_close(struct net_device *dev)
180 {
181         hdlc_device *hdlc = dev_to_hdlc(dev);
182 #ifdef DEBUG_LINK
183         printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
184                hdlc->carrier, hdlc->open);
185 #endif
186
187         spin_lock_irq(&hdlc->state_lock);
188
189         hdlc->open = 0;
190         if (hdlc->carrier)
191                 hdlc_proto_stop(dev);
192
193         spin_unlock_irq(&hdlc->state_lock);
194
195         if (hdlc->proto->close)
196                 hdlc->proto->close(dev);
197 }
198
199
200
201 int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
202 {
203         struct hdlc_proto *proto = first_proto;
204         int result;
205
206         if (cmd != SIOCWANDEV)
207                 return -EINVAL;
208
209         if (dev_to_hdlc(dev)->proto) {
210                 result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
211                 if (result != -EINVAL)
212                         return result;
213         }
214
215         /* Not handled by currently attached protocol (if any) */
216
217         while (proto) {
218                 if ((result = proto->ioctl(dev, ifr)) != -EINVAL)
219                         return result;
220                 proto = proto->next;
221         }
222         return -EINVAL;
223 }
224
225 static void hdlc_setup(struct net_device *dev)
226 {
227         hdlc_device *hdlc = dev_to_hdlc(dev);
228
229         dev->get_stats = hdlc_get_stats;
230         dev->change_mtu = hdlc_change_mtu;
231         dev->mtu = HDLC_MAX_MTU;
232
233         dev->type = ARPHRD_RAWHDLC;
234         dev->hard_header_len = 16;
235
236         dev->flags = IFF_POINTOPOINT | IFF_NOARP;
237
238         hdlc->carrier = 1;
239         hdlc->open = 0;
240         spin_lock_init(&hdlc->state_lock);
241 }
242
243 struct net_device *alloc_hdlcdev(void *priv)
244 {
245         struct net_device *dev;
246         dev = alloc_netdev(sizeof(struct hdlc_device_desc) +
247                            sizeof(hdlc_device), "hdlc%d", hdlc_setup);
248         if (dev)
249                 dev_to_hdlc(dev)->priv = priv;
250         return dev;
251 }
252
253 void unregister_hdlc_device(struct net_device *dev)
254 {
255         rtnl_lock();
256         unregister_netdevice(dev);
257         detach_hdlc_protocol(dev);
258         rtnl_unlock();
259 }
260
261
262
263 int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
264                          int (*rx)(struct sk_buff *skb), size_t size)
265 {
266         detach_hdlc_protocol(dev);
267
268         if (!try_module_get(proto->module))
269                 return -ENOSYS;
270
271         if (size)
272                 if ((dev_to_hdlc(dev)->state = kmalloc(size,
273                                                        GFP_KERNEL)) == NULL) {
274                         printk(KERN_WARNING "Memory squeeze on"
275                                " hdlc_proto_attach()\n");
276                         module_put(proto->module);
277                         return -ENOBUFS;
278                 }
279         dev_to_hdlc(dev)->proto = proto;
280         dev_to_desc(dev)->netif_rx = rx;
281         return 0;
282 }
283
284
285 void detach_hdlc_protocol(struct net_device *dev)
286 {
287         hdlc_device *hdlc = dev_to_hdlc(dev);
288
289         if (hdlc->proto) {
290                 if (hdlc->proto->detach)
291                         hdlc->proto->detach(dev);
292                 module_put(hdlc->proto->module);
293                 hdlc->proto = NULL;
294         }
295         kfree(hdlc->state);
296         hdlc->state = NULL;
297 }
298
299
300 void register_hdlc_protocol(struct hdlc_proto *proto)
301 {
302         proto->next = first_proto;
303         first_proto = proto;
304 }
305
306
307 void unregister_hdlc_protocol(struct hdlc_proto *proto)
308 {
309         struct hdlc_proto **p = &first_proto;
310         while (*p) {
311                 if (*p == proto) {
312                         *p = proto->next;
313                         return;
314                 }
315                 p = &((*p)->next);
316         }
317 }
318
319
320
321 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
322 MODULE_DESCRIPTION("HDLC support module");
323 MODULE_LICENSE("GPL v2");
324
325 EXPORT_SYMBOL(hdlc_open);
326 EXPORT_SYMBOL(hdlc_close);
327 EXPORT_SYMBOL(hdlc_ioctl);
328 EXPORT_SYMBOL(alloc_hdlcdev);
329 EXPORT_SYMBOL(unregister_hdlc_device);
330 EXPORT_SYMBOL(register_hdlc_protocol);
331 EXPORT_SYMBOL(unregister_hdlc_protocol);
332 EXPORT_SYMBOL(attach_hdlc_protocol);
333 EXPORT_SYMBOL(detach_hdlc_protocol);
334
335 static struct packet_type hdlc_packet_type = {
336         .type = __constant_htons(ETH_P_HDLC),
337         .func = hdlc_rcv,
338 };
339
340
341 static struct notifier_block hdlc_notifier = {
342         .notifier_call = hdlc_device_event,
343 };
344
345
346 static int __init hdlc_module_init(void)
347 {
348         int result;
349
350         printk(KERN_INFO "%s\n", version);
351         if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
352                 return result;
353         dev_add_pack(&hdlc_packet_type);
354         return 0;
355 }
356
357
358
359 static void __exit hdlc_module_exit(void)
360 {
361         dev_remove_pack(&hdlc_packet_type);
362         unregister_netdevice_notifier(&hdlc_notifier);
363 }
364
365
366 module_init(hdlc_module_init);
367 module_exit(hdlc_module_exit);