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 | 46 | |
991990a1 | 47 | int hdlc_change_mtu(struct net_device *dev, int new_mtu) |
1da177e4 LT |
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 | ||
d71a6749 | 69 | netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev) |
991990a1 KH |
70 | { |
71 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
1da177e4 | 72 | |
991990a1 KH |
73 | if (hdlc->proto->xmit) |
74 | return hdlc->proto->xmit(skb, dev); | |
75 | ||
76 | return hdlc->xmit(skb, dev); /* call hardware driver directly */ | |
77 | } | |
1da177e4 | 78 | |
c2ce9204 | 79 | static inline void hdlc_proto_start(struct net_device *dev) |
1da177e4 LT |
80 | { |
81 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
eb2a2fd9 | 82 | if (hdlc->proto->start) |
40d25142 | 83 | hdlc->proto->start(dev); |
1da177e4 LT |
84 | } |
85 | ||
86 | ||
87 | ||
c2ce9204 | 88 | static inline void hdlc_proto_stop(struct net_device *dev) |
1da177e4 LT |
89 | { |
90 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
eb2a2fd9 | 91 | if (hdlc->proto->stop) |
40d25142 | 92 | hdlc->proto->stop(dev); |
1da177e4 LT |
93 | } |
94 | ||
95 | ||
96 | ||
c2ce9204 KH |
97 | static int hdlc_device_event(struct notifier_block *this, unsigned long event, |
98 | void *ptr) | |
1da177e4 | 99 | { |
c2ce9204 KH |
100 | struct net_device *dev = ptr; |
101 | hdlc_device *hdlc; | |
1da177e4 | 102 | unsigned long flags; |
c2ce9204 | 103 | int on; |
dff3fde7 | 104 | |
c346dca1 | 105 | if (dev_net(dev) != &init_net) |
e9dc8653 EB |
106 | return NOTIFY_DONE; |
107 | ||
7cdc15f5 | 108 | if (!(dev->priv_flags & IFF_WAN_HDLC)) |
c2ce9204 | 109 | return NOTIFY_DONE; /* not an HDLC device */ |
4dfce407 | 110 | |
c2ce9204 KH |
111 | if (event != NETDEV_CHANGE) |
112 | return NOTIFY_DONE; /* Only interrested in carrier changes */ | |
113 | ||
114 | on = netif_carrier_ok(dev); | |
1da177e4 LT |
115 | |
116 | #ifdef DEBUG_LINK | |
c2ce9204 KH |
117 | printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n", |
118 | dev->name, on); | |
1da177e4 LT |
119 | #endif |
120 | ||
c2ce9204 | 121 | hdlc = dev_to_hdlc(dev); |
1da177e4 LT |
122 | spin_lock_irqsave(&hdlc->state_lock, flags); |
123 | ||
124 | if (hdlc->carrier == on) | |
125 | goto carrier_exit; /* no change in DCD line level */ | |
126 | ||
1da177e4 LT |
127 | hdlc->carrier = on; |
128 | ||
129 | if (!hdlc->open) | |
130 | goto carrier_exit; | |
131 | ||
b3dd65f9 KH |
132 | if (hdlc->carrier) { |
133 | printk(KERN_INFO "%s: Carrier detected\n", dev->name); | |
c2ce9204 | 134 | hdlc_proto_start(dev); |
b3dd65f9 KH |
135 | } else { |
136 | printk(KERN_INFO "%s: Carrier lost\n", dev->name); | |
c2ce9204 | 137 | hdlc_proto_stop(dev); |
b3dd65f9 | 138 | } |
1da177e4 LT |
139 | |
140 | carrier_exit: | |
141 | spin_unlock_irqrestore(&hdlc->state_lock, flags); | |
c2ce9204 | 142 | return NOTIFY_DONE; |
1da177e4 LT |
143 | } |
144 | ||
145 | ||
146 | ||
147 | /* Must be called by hardware driver when HDLC device is being opened */ | |
148 | int hdlc_open(struct net_device *dev) | |
149 | { | |
150 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
151 | #ifdef DEBUG_LINK | |
eb2a2fd9 | 152 | printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name, |
1da177e4 LT |
153 | hdlc->carrier, hdlc->open); |
154 | #endif | |
155 | ||
eb2a2fd9 | 156 | if (hdlc->proto == NULL) |
1da177e4 LT |
157 | return -ENOSYS; /* no protocol attached */ |
158 | ||
eb2a2fd9 KH |
159 | if (hdlc->proto->open) { |
160 | int result = hdlc->proto->open(dev); | |
1da177e4 LT |
161 | if (result) |
162 | return result; | |
163 | } | |
164 | ||
165 | spin_lock_irq(&hdlc->state_lock); | |
166 | ||
b3dd65f9 KH |
167 | if (hdlc->carrier) { |
168 | printk(KERN_INFO "%s: Carrier detected\n", dev->name); | |
c2ce9204 | 169 | hdlc_proto_start(dev); |
b3dd65f9 KH |
170 | } else |
171 | printk(KERN_INFO "%s: No carrier\n", dev->name); | |
1da177e4 LT |
172 | |
173 | hdlc->open = 1; | |
174 | ||
175 | spin_unlock_irq(&hdlc->state_lock); | |
176 | return 0; | |
177 | } | |
178 | ||
179 | ||
180 | ||
181 | /* Must be called by hardware driver when HDLC device is being closed */ | |
182 | void hdlc_close(struct net_device *dev) | |
183 | { | |
184 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
185 | #ifdef DEBUG_LINK | |
eb2a2fd9 | 186 | printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name, |
1da177e4 LT |
187 | hdlc->carrier, hdlc->open); |
188 | #endif | |
189 | ||
190 | spin_lock_irq(&hdlc->state_lock); | |
191 | ||
192 | hdlc->open = 0; | |
193 | if (hdlc->carrier) | |
c2ce9204 | 194 | hdlc_proto_stop(dev); |
1da177e4 LT |
195 | |
196 | spin_unlock_irq(&hdlc->state_lock); | |
197 | ||
eb2a2fd9 KH |
198 | if (hdlc->proto->close) |
199 | hdlc->proto->close(dev); | |
1da177e4 LT |
200 | } |
201 | ||
202 | ||
203 | ||
1da177e4 LT |
204 | int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) |
205 | { | |
eb2a2fd9 KH |
206 | struct hdlc_proto *proto = first_proto; |
207 | int result; | |
1da177e4 LT |
208 | |
209 | if (cmd != SIOCWANDEV) | |
210 | return -EINVAL; | |
211 | ||
eb2a2fd9 KH |
212 | if (dev_to_hdlc(dev)->proto) { |
213 | result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr); | |
214 | if (result != -EINVAL) | |
215 | return result; | |
1da177e4 LT |
216 | } |
217 | ||
eb2a2fd9 KH |
218 | /* Not handled by currently attached protocol (if any) */ |
219 | ||
220 | while (proto) { | |
221 | if ((result = proto->ioctl(dev, ifr)) != -EINVAL) | |
222 | return result; | |
223 | proto = proto->next; | |
1da177e4 | 224 | } |
eb2a2fd9 | 225 | return -EINVAL; |
1da177e4 LT |
226 | } |
227 | ||
3b04ddde SH |
228 | static const struct header_ops hdlc_null_ops; |
229 | ||
b5284e5a KH |
230 | static void hdlc_setup_dev(struct net_device *dev) |
231 | { | |
232 | /* Re-init all variables changed by HDLC protocol drivers, | |
233 | * including ether_setup() called from hdlc_raw_eth.c. | |
234 | */ | |
b5284e5a | 235 | dev->flags = IFF_POINTOPOINT | IFF_NOARP; |
7cdc15f5 | 236 | dev->priv_flags = IFF_WAN_HDLC; |
b5284e5a KH |
237 | dev->mtu = HDLC_MAX_MTU; |
238 | dev->type = ARPHRD_RAWHDLC; | |
239 | dev->hard_header_len = 16; | |
240 | dev->addr_len = 0; | |
3b04ddde | 241 | dev->header_ops = &hdlc_null_ops; |
b5284e5a KH |
242 | } |
243 | ||
0bf94faf | 244 | static void hdlc_setup(struct net_device *dev) |
1da177e4 LT |
245 | { |
246 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
247 | ||
b5284e5a | 248 | hdlc_setup_dev(dev); |
1da177e4 LT |
249 | hdlc->carrier = 1; |
250 | hdlc->open = 0; | |
251 | spin_lock_init(&hdlc->state_lock); | |
252 | } | |
253 | ||
254 | struct net_device *alloc_hdlcdev(void *priv) | |
255 | { | |
256 | struct net_device *dev; | |
40d25142 | 257 | dev = alloc_netdev(sizeof(struct hdlc_device), "hdlc%d", hdlc_setup); |
1da177e4 LT |
258 | if (dev) |
259 | dev_to_hdlc(dev)->priv = priv; | |
260 | return dev; | |
261 | } | |
262 | ||
1da177e4 LT |
263 | void unregister_hdlc_device(struct net_device *dev) |
264 | { | |
265 | rtnl_lock(); | |
1da177e4 | 266 | unregister_netdevice(dev); |
eb2a2fd9 | 267 | detach_hdlc_protocol(dev); |
1da177e4 LT |
268 | rtnl_unlock(); |
269 | } | |
270 | ||
271 | ||
272 | ||
eb2a2fd9 | 273 | int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto, |
40d25142 | 274 | size_t size) |
eb2a2fd9 KH |
275 | { |
276 | detach_hdlc_protocol(dev); | |
277 | ||
278 | if (!try_module_get(proto->module)) | |
279 | return -ENOSYS; | |
280 | ||
281 | if (size) | |
282 | if ((dev_to_hdlc(dev)->state = kmalloc(size, | |
283 | GFP_KERNEL)) == NULL) { | |
284 | printk(KERN_WARNING "Memory squeeze on" | |
285 | " hdlc_proto_attach()\n"); | |
286 | module_put(proto->module); | |
287 | return -ENOBUFS; | |
288 | } | |
289 | dev_to_hdlc(dev)->proto = proto; | |
eb2a2fd9 KH |
290 | return 0; |
291 | } | |
292 | ||
293 | ||
294 | void detach_hdlc_protocol(struct net_device *dev) | |
295 | { | |
296 | hdlc_device *hdlc = dev_to_hdlc(dev); | |
297 | ||
298 | if (hdlc->proto) { | |
299 | if (hdlc->proto->detach) | |
300 | hdlc->proto->detach(dev); | |
301 | module_put(hdlc->proto->module); | |
302 | hdlc->proto = NULL; | |
303 | } | |
304 | kfree(hdlc->state); | |
305 | hdlc->state = NULL; | |
b5284e5a | 306 | hdlc_setup_dev(dev); |
eb2a2fd9 KH |
307 | } |
308 | ||
309 | ||
310 | void register_hdlc_protocol(struct hdlc_proto *proto) | |
311 | { | |
fa701bd2 | 312 | rtnl_lock(); |
eb2a2fd9 KH |
313 | proto->next = first_proto; |
314 | first_proto = proto; | |
fa701bd2 | 315 | rtnl_unlock(); |
eb2a2fd9 KH |
316 | } |
317 | ||
318 | ||
319 | void unregister_hdlc_protocol(struct hdlc_proto *proto) | |
320 | { | |
fa701bd2 KH |
321 | struct hdlc_proto **p; |
322 | ||
323 | rtnl_lock(); | |
324 | p = &first_proto; | |
325 | while (*p != proto) { | |
326 | BUG_ON(!*p); | |
eb2a2fd9 KH |
327 | p = &((*p)->next); |
328 | } | |
fa701bd2 KH |
329 | *p = proto->next; |
330 | rtnl_unlock(); | |
eb2a2fd9 KH |
331 | } |
332 | ||
333 | ||
334 | ||
1da177e4 LT |
335 | MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); |
336 | MODULE_DESCRIPTION("HDLC support module"); | |
337 | MODULE_LICENSE("GPL v2"); | |
338 | ||
991990a1 KH |
339 | EXPORT_SYMBOL(hdlc_change_mtu); |
340 | EXPORT_SYMBOL(hdlc_start_xmit); | |
1da177e4 LT |
341 | EXPORT_SYMBOL(hdlc_open); |
342 | EXPORT_SYMBOL(hdlc_close); | |
1da177e4 LT |
343 | EXPORT_SYMBOL(hdlc_ioctl); |
344 | EXPORT_SYMBOL(alloc_hdlcdev); | |
1da177e4 | 345 | EXPORT_SYMBOL(unregister_hdlc_device); |
eb2a2fd9 KH |
346 | EXPORT_SYMBOL(register_hdlc_protocol); |
347 | EXPORT_SYMBOL(unregister_hdlc_protocol); | |
348 | EXPORT_SYMBOL(attach_hdlc_protocol); | |
349 | EXPORT_SYMBOL(detach_hdlc_protocol); | |
1da177e4 | 350 | |
7546dd97 | 351 | static struct packet_type hdlc_packet_type __read_mostly = { |
09640e63 | 352 | .type = cpu_to_be16(ETH_P_HDLC), |
1da177e4 LT |
353 | .func = hdlc_rcv, |
354 | }; | |
355 | ||
356 | ||
c2ce9204 | 357 | static struct notifier_block hdlc_notifier = { |
4dfce407 | 358 | .notifier_call = hdlc_device_event, |
c2ce9204 KH |
359 | }; |
360 | ||
361 | ||
1da177e4 LT |
362 | static int __init hdlc_module_init(void) |
363 | { | |
c2ce9204 KH |
364 | int result; |
365 | ||
1da177e4 | 366 | printk(KERN_INFO "%s\n", version); |
c2ce9204 | 367 | if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0) |
4dfce407 KH |
368 | return result; |
369 | dev_add_pack(&hdlc_packet_type); | |
1da177e4 LT |
370 | return 0; |
371 | } | |
372 | ||
373 | ||
374 | ||
375 | static void __exit hdlc_module_exit(void) | |
376 | { | |
377 | dev_remove_pack(&hdlc_packet_type); | |
c2ce9204 | 378 | unregister_netdevice_notifier(&hdlc_notifier); |
1da177e4 LT |
379 | } |
380 | ||
381 | ||
382 | module_init(hdlc_module_init); | |
383 | module_exit(hdlc_module_exit); |