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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Generic HDLC support routines for Linux
3 *
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +02004 * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
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:
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +020020 * - proto->open(), close(), start(), stop() calls are serialized.
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 * The order is: open, [ start, stop ... ] close ...
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +020022 * - proto->start() and stop() are called with spin_lock_irq held.
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 */
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#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>
Krzysztof Halasac2ce9202006-07-12 13:46:12 -070037#include <linux/notifier.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <linux/hdlc.h>
39
40
Krzysztof Halasab5284e52007-03-02 15:52:22 -080041static const char* version = "HDLC support module revision 1.21";
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
43#undef DEBUG_LINK
44
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +020045static struct hdlc_proto *first_proto = NULL;
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
48static 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
58static struct net_device_stats *hdlc_get_stats(struct net_device *dev)
59{
60 return hdlc_stats(dev);
61}
62
63
64
65static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
David S. Millerf2ccd8f2005-08-09 19:34:12 -070066 struct packet_type *p, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +020068 struct hdlc_device_desc *desc = dev_to_desc(dev);
69 if (desc->netif_rx)
70 return desc->netif_rx(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +020072 desc->stats.rx_dropped++; /* Shouldn't happen */
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 dev_kfree_skb(skb);
74 return NET_RX_DROP;
75}
76
77
78
Krzysztof Halasac2ce9202006-07-12 13:46:12 -070079static inline void hdlc_proto_start(struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080{
81 hdlc_device *hdlc = dev_to_hdlc(dev);
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +020082 if (hdlc->proto->start)
83 return hdlc->proto->start(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084}
85
86
87
Krzysztof Halasac2ce9202006-07-12 13:46:12 -070088static inline void hdlc_proto_stop(struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070089{
90 hdlc_device *hdlc = dev_to_hdlc(dev);
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +020091 if (hdlc->proto->stop)
92 return hdlc->proto->stop(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093}
94
95
96
Krzysztof Halasac2ce9202006-07-12 13:46:12 -070097static int hdlc_device_event(struct notifier_block *this, unsigned long event,
98 void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070099{
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700100 struct net_device *dev = ptr;
101 hdlc_device *hdlc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 unsigned long flags;
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700103 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
113#ifdef DEBUG_LINK
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700114 printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
115 dev->name, on);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116#endif
117
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700118 hdlc = dev_to_hdlc(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 spin_lock_irqsave(&hdlc->state_lock, flags);
120
121 if (hdlc->carrier == on)
122 goto carrier_exit; /* no change in DCD line level */
123
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 hdlc->carrier = on;
125
126 if (!hdlc->open)
127 goto carrier_exit;
128
Krzysztof Halasab3dd65f2005-04-21 15:57:25 +0200129 if (hdlc->carrier) {
130 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700131 hdlc_proto_start(dev);
Krzysztof Halasab3dd65f2005-04-21 15:57:25 +0200132 } else {
133 printk(KERN_INFO "%s: Carrier lost\n", dev->name);
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700134 hdlc_proto_stop(dev);
Krzysztof Halasab3dd65f2005-04-21 15:57:25 +0200135 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137carrier_exit:
138 spin_unlock_irqrestore(&hdlc->state_lock, flags);
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700139 return NOTIFY_DONE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140}
141
142
143
144/* Must be called by hardware driver when HDLC device is being opened */
145int hdlc_open(struct net_device *dev)
146{
147 hdlc_device *hdlc = dev_to_hdlc(dev);
148#ifdef DEBUG_LINK
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200149 printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 hdlc->carrier, hdlc->open);
151#endif
152
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200153 if (hdlc->proto == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 return -ENOSYS; /* no protocol attached */
155
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200156 if (hdlc->proto->open) {
157 int result = hdlc->proto->open(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 if (result)
159 return result;
160 }
161
162 spin_lock_irq(&hdlc->state_lock);
163
Krzysztof Halasab3dd65f2005-04-21 15:57:25 +0200164 if (hdlc->carrier) {
165 printk(KERN_INFO "%s: Carrier detected\n", dev->name);
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700166 hdlc_proto_start(dev);
Krzysztof Halasab3dd65f2005-04-21 15:57:25 +0200167 } else
168 printk(KERN_INFO "%s: No carrier\n", dev->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
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 */
179void hdlc_close(struct net_device *dev)
180{
181 hdlc_device *hdlc = dev_to_hdlc(dev);
182#ifdef DEBUG_LINK
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200183 printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 hdlc->carrier, hdlc->open);
185#endif
186
187 spin_lock_irq(&hdlc->state_lock);
188
189 hdlc->open = 0;
190 if (hdlc->carrier)
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700191 hdlc_proto_stop(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
193 spin_unlock_irq(&hdlc->state_lock);
194
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200195 if (hdlc->proto->close)
196 hdlc->proto->close(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197}
198
199
200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
202{
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200203 struct hdlc_proto *proto = first_proto;
204 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206 if (cmd != SIOCWANDEV)
207 return -EINVAL;
208
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200209 if (dev_to_hdlc(dev)->proto) {
210 result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
211 if (result != -EINVAL)
212 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 }
214
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200215 /* 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 }
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200222 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223}
224
Krzysztof Halasab5284e52007-03-02 15:52:22 -0800225static void hdlc_setup_dev(struct net_device *dev)
226{
227 /* Re-init all variables changed by HDLC protocol drivers,
228 * including ether_setup() called from hdlc_raw_eth.c.
229 */
230 dev->get_stats = hdlc_get_stats;
231 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
232 dev->mtu = HDLC_MAX_MTU;
233 dev->type = ARPHRD_RAWHDLC;
234 dev->hard_header_len = 16;
235 dev->addr_len = 0;
236 dev->hard_header = NULL;
237 dev->rebuild_header = NULL;
238 dev->set_mac_address = NULL;
239 dev->hard_header_cache = NULL;
240 dev->header_cache_update = NULL;
241 dev->change_mtu = hdlc_change_mtu;
242 dev->hard_header_parse = NULL;
243}
244
Adrian Bunk0bf94fa2007-01-11 14:48:59 +0100245static void hdlc_setup(struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246{
247 hdlc_device *hdlc = dev_to_hdlc(dev);
248
Krzysztof Halasab5284e52007-03-02 15:52:22 -0800249 hdlc_setup_dev(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 hdlc->carrier = 1;
251 hdlc->open = 0;
252 spin_lock_init(&hdlc->state_lock);
253}
254
255struct net_device *alloc_hdlcdev(void *priv)
256{
257 struct net_device *dev;
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200258 dev = alloc_netdev(sizeof(struct hdlc_device_desc) +
259 sizeof(hdlc_device), "hdlc%d", hdlc_setup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 if (dev)
261 dev_to_hdlc(dev)->priv = priv;
262 return dev;
263}
264
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265void unregister_hdlc_device(struct net_device *dev)
266{
267 rtnl_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 unregister_netdevice(dev);
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200269 detach_hdlc_protocol(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 rtnl_unlock();
271}
272
273
274
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200275int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
276 int (*rx)(struct sk_buff *skb), size_t size)
277{
278 detach_hdlc_protocol(dev);
279
280 if (!try_module_get(proto->module))
281 return -ENOSYS;
282
283 if (size)
284 if ((dev_to_hdlc(dev)->state = kmalloc(size,
285 GFP_KERNEL)) == NULL) {
286 printk(KERN_WARNING "Memory squeeze on"
287 " hdlc_proto_attach()\n");
288 module_put(proto->module);
289 return -ENOBUFS;
290 }
291 dev_to_hdlc(dev)->proto = proto;
292 dev_to_desc(dev)->netif_rx = rx;
293 return 0;
294}
295
296
297void detach_hdlc_protocol(struct net_device *dev)
298{
299 hdlc_device *hdlc = dev_to_hdlc(dev);
300
301 if (hdlc->proto) {
302 if (hdlc->proto->detach)
303 hdlc->proto->detach(dev);
304 module_put(hdlc->proto->module);
305 hdlc->proto = NULL;
306 }
307 kfree(hdlc->state);
308 hdlc->state = NULL;
Krzysztof Halasab5284e52007-03-02 15:52:22 -0800309 hdlc_setup_dev(dev);
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200310}
311
312
313void register_hdlc_protocol(struct hdlc_proto *proto)
314{
315 proto->next = first_proto;
316 first_proto = proto;
317}
318
319
320void unregister_hdlc_protocol(struct hdlc_proto *proto)
321{
322 struct hdlc_proto **p = &first_proto;
323 while (*p) {
324 if (*p == proto) {
325 *p = proto->next;
326 return;
327 }
328 p = &((*p)->next);
329 }
330}
331
332
333
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
335MODULE_DESCRIPTION("HDLC support module");
336MODULE_LICENSE("GPL v2");
337
338EXPORT_SYMBOL(hdlc_open);
339EXPORT_SYMBOL(hdlc_close);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340EXPORT_SYMBOL(hdlc_ioctl);
341EXPORT_SYMBOL(alloc_hdlcdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342EXPORT_SYMBOL(unregister_hdlc_device);
Krzysztof Halasaeb2a2fd2006-09-26 23:23:45 +0200343EXPORT_SYMBOL(register_hdlc_protocol);
344EXPORT_SYMBOL(unregister_hdlc_protocol);
345EXPORT_SYMBOL(attach_hdlc_protocol);
346EXPORT_SYMBOL(detach_hdlc_protocol);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
348static struct packet_type hdlc_packet_type = {
349 .type = __constant_htons(ETH_P_HDLC),
350 .func = hdlc_rcv,
351};
352
353
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700354static struct notifier_block hdlc_notifier = {
355 .notifier_call = hdlc_device_event,
356};
357
358
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359static int __init hdlc_module_init(void)
360{
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700361 int result;
362
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 printk(KERN_INFO "%s\n", version);
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700364 if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
365 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 dev_add_pack(&hdlc_packet_type);
367 return 0;
368}
369
370
371
372static void __exit hdlc_module_exit(void)
373{
374 dev_remove_pack(&hdlc_packet_type);
Krzysztof Halasac2ce9202006-07-12 13:46:12 -0700375 unregister_netdevice_notifier(&hdlc_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376}
377
378
379module_init(hdlc_module_init);
380module_exit(hdlc_module_exit);