Commit | Line | Data |
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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 | 41 | static const char* version = "HDLC support module revision 1.22"; |
1da177e4 LT |
42 | |
43 | #undef DEBUG_LINK | |
44 | ||
fa701bd2 | 45 | static struct hdlc_proto *first_proto; |
1da177e4 LT |
46 | |
47 | static 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 | ||
1da177e4 | 55 | static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev, |
f2ccd8fa | 56 | struct packet_type *p, struct net_device *orig_dev) |
1da177e4 | 57 | { |
40d25142 | 58 | struct hdlc_device *hdlc = dev_to_hdlc(dev); |
e730c155 | 59 | |
c346dca1 | 60 | if (dev_net(dev) != &init_net) { |
e730c155 EB |
61 | kfree_skb(skb); |
62 | return 0; | |
63 | } | |
64 | ||
40d25142 KH |
65 | BUG_ON(!hdlc->proto->netif_rx); |
66 | return hdlc->proto->netif_rx(skb); | |
1da177e4 LT |
67 | } |
68 | ||
69 | ||
70 | ||
c2ce9204 | 71 | static inline void hdlc_proto_start(struct net_device *dev) |
1da177e4 LT |
72 | { |
73 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
eb2a2fd9 | 74 | if (hdlc->proto->start) |
40d25142 | 75 | hdlc->proto->start(dev); |
1da177e4 LT |
76 | } |
77 | ||
78 | ||
79 | ||
c2ce9204 | 80 | static inline void hdlc_proto_stop(struct net_device *dev) |
1da177e4 LT |
81 | { |
82 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
eb2a2fd9 | 83 | if (hdlc->proto->stop) |
40d25142 | 84 | hdlc->proto->stop(dev); |
1da177e4 LT |
85 | } |
86 | ||
87 | ||
88 | ||
c2ce9204 KH |
89 | static int hdlc_device_event(struct notifier_block *this, unsigned long event, |
90 | void *ptr) | |
1da177e4 | 91 | { |
c2ce9204 KH |
92 | struct net_device *dev = ptr; |
93 | hdlc_device *hdlc; | |
1da177e4 | 94 | unsigned long flags; |
c2ce9204 | 95 | int on; |
dff3fde7 | 96 | |
c346dca1 | 97 | if (dev_net(dev) != &init_net) |
e9dc8653 EB |
98 | return NOTIFY_DONE; |
99 | ||
7cdc15f5 | 100 | if (!(dev->priv_flags & IFF_WAN_HDLC)) |
c2ce9204 | 101 | return NOTIFY_DONE; /* not an HDLC device */ |
4dfce407 | 102 | |
c2ce9204 KH |
103 | if (event != NETDEV_CHANGE) |
104 | return NOTIFY_DONE; /* Only interrested in carrier changes */ | |
105 | ||
106 | on = netif_carrier_ok(dev); | |
1da177e4 LT |
107 | |
108 | #ifdef DEBUG_LINK | |
c2ce9204 KH |
109 | printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n", |
110 | dev->name, on); | |
1da177e4 LT |
111 | #endif |
112 | ||
c2ce9204 | 113 | hdlc = dev_to_hdlc(dev); |
1da177e4 LT |
114 | spin_lock_irqsave(&hdlc->state_lock, flags); |
115 | ||
116 | if (hdlc->carrier == on) | |
117 | goto carrier_exit; /* no change in DCD line level */ | |
118 | ||
1da177e4 LT |
119 | hdlc->carrier = on; |
120 | ||
121 | if (!hdlc->open) | |
122 | goto carrier_exit; | |
123 | ||
b3dd65f9 KH |
124 | if (hdlc->carrier) { |
125 | printk(KERN_INFO "%s: Carrier detected\n", dev->name); | |
c2ce9204 | 126 | hdlc_proto_start(dev); |
b3dd65f9 KH |
127 | } else { |
128 | printk(KERN_INFO "%s: Carrier lost\n", dev->name); | |
c2ce9204 | 129 | hdlc_proto_stop(dev); |
b3dd65f9 | 130 | } |
1da177e4 LT |
131 | |
132 | carrier_exit: | |
133 | spin_unlock_irqrestore(&hdlc->state_lock, flags); | |
c2ce9204 | 134 | return NOTIFY_DONE; |
1da177e4 LT |
135 | } |
136 | ||
137 | ||
138 | ||
139 | /* Must be called by hardware driver when HDLC device is being opened */ | |
140 | int hdlc_open(struct net_device *dev) | |
141 | { | |
142 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
143 | #ifdef DEBUG_LINK | |
eb2a2fd9 | 144 | printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name, |
1da177e4 LT |
145 | hdlc->carrier, hdlc->open); |
146 | #endif | |
147 | ||
eb2a2fd9 | 148 | if (hdlc->proto == NULL) |
1da177e4 LT |
149 | return -ENOSYS; /* no protocol attached */ |
150 | ||
eb2a2fd9 KH |
151 | if (hdlc->proto->open) { |
152 | int result = hdlc->proto->open(dev); | |
1da177e4 LT |
153 | if (result) |
154 | return result; | |
155 | } | |
156 | ||
157 | spin_lock_irq(&hdlc->state_lock); | |
158 | ||
b3dd65f9 KH |
159 | if (hdlc->carrier) { |
160 | printk(KERN_INFO "%s: Carrier detected\n", dev->name); | |
c2ce9204 | 161 | hdlc_proto_start(dev); |
b3dd65f9 KH |
162 | } else |
163 | printk(KERN_INFO "%s: No carrier\n", dev->name); | |
1da177e4 LT |
164 | |
165 | hdlc->open = 1; | |
166 | ||
167 | spin_unlock_irq(&hdlc->state_lock); | |
168 | return 0; | |
169 | } | |
170 | ||
171 | ||
172 | ||
173 | /* Must be called by hardware driver when HDLC device is being closed */ | |
174 | void hdlc_close(struct net_device *dev) | |
175 | { | |
176 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
177 | #ifdef DEBUG_LINK | |
eb2a2fd9 | 178 | printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name, |
1da177e4 LT |
179 | hdlc->carrier, hdlc->open); |
180 | #endif | |
181 | ||
182 | spin_lock_irq(&hdlc->state_lock); | |
183 | ||
184 | hdlc->open = 0; | |
185 | if (hdlc->carrier) | |
c2ce9204 | 186 | hdlc_proto_stop(dev); |
1da177e4 LT |
187 | |
188 | spin_unlock_irq(&hdlc->state_lock); | |
189 | ||
eb2a2fd9 KH |
190 | if (hdlc->proto->close) |
191 | hdlc->proto->close(dev); | |
1da177e4 LT |
192 | } |
193 | ||
194 | ||
195 | ||
1da177e4 LT |
196 | int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) |
197 | { | |
eb2a2fd9 KH |
198 | struct hdlc_proto *proto = first_proto; |
199 | int result; | |
1da177e4 LT |
200 | |
201 | if (cmd != SIOCWANDEV) | |
202 | return -EINVAL; | |
203 | ||
eb2a2fd9 KH |
204 | if (dev_to_hdlc(dev)->proto) { |
205 | result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr); | |
206 | if (result != -EINVAL) | |
207 | return result; | |
1da177e4 LT |
208 | } |
209 | ||
eb2a2fd9 KH |
210 | /* Not handled by currently attached protocol (if any) */ |
211 | ||
212 | while (proto) { | |
213 | if ((result = proto->ioctl(dev, ifr)) != -EINVAL) | |
214 | return result; | |
215 | proto = proto->next; | |
1da177e4 | 216 | } |
eb2a2fd9 | 217 | return -EINVAL; |
1da177e4 LT |
218 | } |
219 | ||
3b04ddde SH |
220 | static const struct header_ops hdlc_null_ops; |
221 | ||
b5284e5a KH |
222 | static void hdlc_setup_dev(struct net_device *dev) |
223 | { | |
224 | /* Re-init all variables changed by HDLC protocol drivers, | |
225 | * including ether_setup() called from hdlc_raw_eth.c. | |
226 | */ | |
b5284e5a | 227 | dev->flags = IFF_POINTOPOINT | IFF_NOARP; |
7cdc15f5 | 228 | dev->priv_flags = IFF_WAN_HDLC; |
b5284e5a KH |
229 | dev->mtu = HDLC_MAX_MTU; |
230 | dev->type = ARPHRD_RAWHDLC; | |
231 | dev->hard_header_len = 16; | |
232 | dev->addr_len = 0; | |
3b04ddde SH |
233 | dev->header_ops = &hdlc_null_ops; |
234 | ||
b5284e5a | 235 | dev->change_mtu = hdlc_change_mtu; |
b5284e5a KH |
236 | } |
237 | ||
0bf94faf | 238 | static void hdlc_setup(struct net_device *dev) |
1da177e4 LT |
239 | { |
240 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
241 | ||
b5284e5a | 242 | hdlc_setup_dev(dev); |
1da177e4 LT |
243 | hdlc->carrier = 1; |
244 | hdlc->open = 0; | |
245 | spin_lock_init(&hdlc->state_lock); | |
246 | } | |
247 | ||
248 | struct net_device *alloc_hdlcdev(void *priv) | |
249 | { | |
250 | struct net_device *dev; | |
40d25142 | 251 | dev = alloc_netdev(sizeof(struct hdlc_device), "hdlc%d", hdlc_setup); |
1da177e4 LT |
252 | if (dev) |
253 | dev_to_hdlc(dev)->priv = priv; | |
254 | return dev; | |
255 | } | |
256 | ||
1da177e4 LT |
257 | void unregister_hdlc_device(struct net_device *dev) |
258 | { | |
259 | rtnl_lock(); | |
1da177e4 | 260 | unregister_netdevice(dev); |
eb2a2fd9 | 261 | detach_hdlc_protocol(dev); |
1da177e4 LT |
262 | rtnl_unlock(); |
263 | } | |
264 | ||
265 | ||
266 | ||
eb2a2fd9 | 267 | int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto, |
40d25142 | 268 | size_t size) |
eb2a2fd9 KH |
269 | { |
270 | detach_hdlc_protocol(dev); | |
271 | ||
272 | if (!try_module_get(proto->module)) | |
273 | return -ENOSYS; | |
274 | ||
275 | if (size) | |
276 | if ((dev_to_hdlc(dev)->state = kmalloc(size, | |
277 | GFP_KERNEL)) == NULL) { | |
278 | printk(KERN_WARNING "Memory squeeze on" | |
279 | " hdlc_proto_attach()\n"); | |
280 | module_put(proto->module); | |
281 | return -ENOBUFS; | |
282 | } | |
283 | dev_to_hdlc(dev)->proto = proto; | |
eb2a2fd9 KH |
284 | return 0; |
285 | } | |
286 | ||
287 | ||
288 | void detach_hdlc_protocol(struct net_device *dev) | |
289 | { | |
290 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
291 | ||
292 | if (hdlc->proto) { | |
293 | if (hdlc->proto->detach) | |
294 | hdlc->proto->detach(dev); | |
295 | module_put(hdlc->proto->module); | |
296 | hdlc->proto = NULL; | |
297 | } | |
298 | kfree(hdlc->state); | |
299 | hdlc->state = NULL; | |
b5284e5a | 300 | hdlc_setup_dev(dev); |
eb2a2fd9 KH |
301 | } |
302 | ||
303 | ||
304 | void register_hdlc_protocol(struct hdlc_proto *proto) | |
305 | { | |
fa701bd2 | 306 | rtnl_lock(); |
eb2a2fd9 KH |
307 | proto->next = first_proto; |
308 | first_proto = proto; | |
fa701bd2 | 309 | rtnl_unlock(); |
eb2a2fd9 KH |
310 | } |
311 | ||
312 | ||
313 | void unregister_hdlc_protocol(struct hdlc_proto *proto) | |
314 | { | |
fa701bd2 KH |
315 | struct hdlc_proto **p; |
316 | ||
317 | rtnl_lock(); | |
318 | p = &first_proto; | |
319 | while (*p != proto) { | |
320 | BUG_ON(!*p); | |
eb2a2fd9 KH |
321 | p = &((*p)->next); |
322 | } | |
fa701bd2 KH |
323 | *p = proto->next; |
324 | rtnl_unlock(); | |
eb2a2fd9 KH |
325 | } |
326 | ||
327 | ||
328 | ||
1da177e4 LT |
329 | MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); |
330 | MODULE_DESCRIPTION("HDLC support module"); | |
331 | MODULE_LICENSE("GPL v2"); | |
332 | ||
333 | EXPORT_SYMBOL(hdlc_open); | |
334 | EXPORT_SYMBOL(hdlc_close); | |
1da177e4 LT |
335 | EXPORT_SYMBOL(hdlc_ioctl); |
336 | EXPORT_SYMBOL(alloc_hdlcdev); | |
1da177e4 | 337 | EXPORT_SYMBOL(unregister_hdlc_device); |
eb2a2fd9 KH |
338 | EXPORT_SYMBOL(register_hdlc_protocol); |
339 | EXPORT_SYMBOL(unregister_hdlc_protocol); | |
340 | EXPORT_SYMBOL(attach_hdlc_protocol); | |
341 | EXPORT_SYMBOL(detach_hdlc_protocol); | |
1da177e4 LT |
342 | |
343 | static struct packet_type hdlc_packet_type = { | |
344 | .type = __constant_htons(ETH_P_HDLC), | |
345 | .func = hdlc_rcv, | |
346 | }; | |
347 | ||
348 | ||
c2ce9204 | 349 | static struct notifier_block hdlc_notifier = { |
4dfce407 | 350 | .notifier_call = hdlc_device_event, |
c2ce9204 KH |
351 | }; |
352 | ||
353 | ||
1da177e4 LT |
354 | static int __init hdlc_module_init(void) |
355 | { | |
c2ce9204 KH |
356 | int result; |
357 | ||
1da177e4 | 358 | printk(KERN_INFO "%s\n", version); |
c2ce9204 | 359 | if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0) |
4dfce407 KH |
360 | return result; |
361 | dev_add_pack(&hdlc_packet_type); | |
1da177e4 LT |
362 | return 0; |
363 | } | |
364 | ||
365 | ||
366 | ||
367 | static void __exit hdlc_module_exit(void) | |
368 | { | |
369 | dev_remove_pack(&hdlc_packet_type); | |
c2ce9204 | 370 | unregister_netdevice_notifier(&hdlc_notifier); |
1da177e4 LT |
371 | } |
372 | ||
373 | ||
374 | module_init(hdlc_module_init); | |
375 | module_exit(hdlc_module_exit); |