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1/*
2 * Generic HDLC support routines for Linux
3 *
4 * Copyright (C) 1999 - 2008 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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
26
27#include <linux/errno.h>
28#include <linux/hdlc.h>
29#include <linux/if_arp.h>
30#include <linux/inetdevice.h>
31#include <linux/init.h>
32#include <linux/kernel.h>
33#include <linux/module.h>
34#include <linux/notifier.h>
35#include <linux/pkt_sched.h>
36#include <linux/poll.h>
37#include <linux/rtnetlink.h>
38#include <linux/skbuff.h>
39#include <linux/slab.h>
40#include <net/net_namespace.h>
41
42
43static const char* version = "HDLC support module revision 1.22";
44
45#undef DEBUG_LINK
46
47static struct hdlc_proto *first_proto;
48
49int hdlc_change_mtu(struct net_device *dev, int new_mtu)
50{
51 if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
52 return -EINVAL;
53 dev->mtu = new_mtu;
54 return 0;
55}
56
57static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
58 struct packet_type *p, struct net_device *orig_dev)
59{
60 struct hdlc_device *hdlc = dev_to_hdlc(dev);
61
62 if (!net_eq(dev_net(dev), &init_net)) {
63 kfree_skb(skb);
64 return 0;
65 }
66
67 BUG_ON(!hdlc->proto->netif_rx);
68 return hdlc->proto->netif_rx(skb);
69}
70
71netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev)
72{
73 hdlc_device *hdlc = dev_to_hdlc(dev);
74
75 if (hdlc->proto->xmit)
76 return hdlc->proto->xmit(skb, dev);
77
78 return hdlc->xmit(skb, dev); /* call hardware driver directly */
79}
80
81static inline void hdlc_proto_start(struct net_device *dev)
82{
83 hdlc_device *hdlc = dev_to_hdlc(dev);
84 if (hdlc->proto->start)
85 hdlc->proto->start(dev);
86}
87
88
89
90static inline void hdlc_proto_stop(struct net_device *dev)
91{
92 hdlc_device *hdlc = dev_to_hdlc(dev);
93 if (hdlc->proto->stop)
94 hdlc->proto->stop(dev);
95}
96
97
98
99static int hdlc_device_event(struct notifier_block *this, unsigned long event,
100 void *ptr)
101{
102 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
103 hdlc_device *hdlc;
104 unsigned long flags;
105 int on;
106
107 if (!net_eq(dev_net(dev), &init_net))
108 return NOTIFY_DONE;
109
110 if (!(dev->priv_flags & IFF_WAN_HDLC))
111 return NOTIFY_DONE; /* not an HDLC device */
112
113 if (event != NETDEV_CHANGE)
114 return NOTIFY_DONE; /* Only interested in carrier changes */
115
116 on = netif_carrier_ok(dev);
117
118#ifdef DEBUG_LINK
119 printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
120 dev->name, on);
121#endif
122
123 hdlc = dev_to_hdlc(dev);
124 spin_lock_irqsave(&hdlc->state_lock, flags);
125
126 if (hdlc->carrier == on)
127 goto carrier_exit; /* no change in DCD line level */
128
129 hdlc->carrier = on;
130
131 if (!hdlc->open)
132 goto carrier_exit;
133
134 if (hdlc->carrier) {
135 netdev_info(dev, "Carrier detected\n");
136 hdlc_proto_start(dev);
137 } else {
138 netdev_info(dev, "Carrier lost\n");
139 hdlc_proto_stop(dev);
140 }
141
142carrier_exit:
143 spin_unlock_irqrestore(&hdlc->state_lock, flags);
144 return NOTIFY_DONE;
145}
146
147
148
149/* Must be called by hardware driver when HDLC device is being opened */
150int hdlc_open(struct net_device *dev)
151{
152 hdlc_device *hdlc = dev_to_hdlc(dev);
153#ifdef DEBUG_LINK
154 printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
155 hdlc->carrier, hdlc->open);
156#endif
157
158 if (hdlc->proto == NULL)
159 return -ENOSYS; /* no protocol attached */
160
161 if (hdlc->proto->open) {
162 int result = hdlc->proto->open(dev);
163 if (result)
164 return result;
165 }
166
167 spin_lock_irq(&hdlc->state_lock);
168
169 if (hdlc->carrier) {
170 netdev_info(dev, "Carrier detected\n");
171 hdlc_proto_start(dev);
172 } else
173 netdev_info(dev, "No carrier\n");
174
175 hdlc->open = 1;
176
177 spin_unlock_irq(&hdlc->state_lock);
178 return 0;
179}
180
181
182
183/* Must be called by hardware driver when HDLC device is being closed */
184void hdlc_close(struct net_device *dev)
185{
186 hdlc_device *hdlc = dev_to_hdlc(dev);
187#ifdef DEBUG_LINK
188 printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
189 hdlc->carrier, hdlc->open);
190#endif
191
192 spin_lock_irq(&hdlc->state_lock);
193
194 hdlc->open = 0;
195 if (hdlc->carrier)
196 hdlc_proto_stop(dev);
197
198 spin_unlock_irq(&hdlc->state_lock);
199
200 if (hdlc->proto->close)
201 hdlc->proto->close(dev);
202}
203
204
205
206int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
207{
208 struct hdlc_proto *proto = first_proto;
209 int result;
210
211 if (cmd != SIOCWANDEV)
212 return -EINVAL;
213
214 if (dev_to_hdlc(dev)->proto) {
215 result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
216 if (result != -EINVAL)
217 return result;
218 }
219
220 /* Not handled by currently attached protocol (if any) */
221
222 while (proto) {
223 if ((result = proto->ioctl(dev, ifr)) != -EINVAL)
224 return result;
225 proto = proto->next;
226 }
227 return -EINVAL;
228}
229
230static const struct header_ops hdlc_null_ops;
231
232static void hdlc_setup_dev(struct net_device *dev)
233{
234 /* Re-init all variables changed by HDLC protocol drivers,
235 * including ether_setup() called from hdlc_raw_eth.c.
236 */
237 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
238 dev->priv_flags = IFF_WAN_HDLC;
239 dev->mtu = HDLC_MAX_MTU;
240 dev->type = ARPHRD_RAWHDLC;
241 dev->hard_header_len = 16;
242 dev->addr_len = 0;
243 dev->header_ops = &hdlc_null_ops;
244}
245
246static void hdlc_setup(struct net_device *dev)
247{
248 hdlc_device *hdlc = dev_to_hdlc(dev);
249
250 hdlc_setup_dev(dev);
251 hdlc->carrier = 1;
252 hdlc->open = 0;
253 spin_lock_init(&hdlc->state_lock);
254}
255
256struct net_device *alloc_hdlcdev(void *priv)
257{
258 struct net_device *dev;
259 dev = alloc_netdev(sizeof(struct hdlc_device), "hdlc%d", hdlc_setup);
260 if (dev)
261 dev_to_hdlc(dev)->priv = priv;
262 return dev;
263}
264
265void unregister_hdlc_device(struct net_device *dev)
266{
267 rtnl_lock();
268 unregister_netdevice(dev);
269 detach_hdlc_protocol(dev);
270 rtnl_unlock();
271}
272
273
274
275int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
276 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 dev_to_hdlc(dev)->state = kmalloc(size, GFP_KERNEL);
285 if (dev_to_hdlc(dev)->state == NULL) {
286 module_put(proto->module);
287 return -ENOBUFS;
288 }
289 }
290 dev_to_hdlc(dev)->proto = proto;
291 return 0;
292}
293
294
295void detach_hdlc_protocol(struct net_device *dev)
296{
297 hdlc_device *hdlc = dev_to_hdlc(dev);
298
299 if (hdlc->proto) {
300 if (hdlc->proto->detach)
301 hdlc->proto->detach(dev);
302 module_put(hdlc->proto->module);
303 hdlc->proto = NULL;
304 }
305 kfree(hdlc->state);
306 hdlc->state = NULL;
307 hdlc_setup_dev(dev);
308}
309
310
311void register_hdlc_protocol(struct hdlc_proto *proto)
312{
313 rtnl_lock();
314 proto->next = first_proto;
315 first_proto = proto;
316 rtnl_unlock();
317}
318
319
320void unregister_hdlc_protocol(struct hdlc_proto *proto)
321{
322 struct hdlc_proto **p;
323
324 rtnl_lock();
325 p = &first_proto;
326 while (*p != proto) {
327 BUG_ON(!*p);
328 p = &((*p)->next);
329 }
330 *p = proto->next;
331 rtnl_unlock();
332}
333
334
335
336MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
337MODULE_DESCRIPTION("HDLC support module");
338MODULE_LICENSE("GPL v2");
339
340EXPORT_SYMBOL(hdlc_change_mtu);
341EXPORT_SYMBOL(hdlc_start_xmit);
342EXPORT_SYMBOL(hdlc_open);
343EXPORT_SYMBOL(hdlc_close);
344EXPORT_SYMBOL(hdlc_ioctl);
345EXPORT_SYMBOL(alloc_hdlcdev);
346EXPORT_SYMBOL(unregister_hdlc_device);
347EXPORT_SYMBOL(register_hdlc_protocol);
348EXPORT_SYMBOL(unregister_hdlc_protocol);
349EXPORT_SYMBOL(attach_hdlc_protocol);
350EXPORT_SYMBOL(detach_hdlc_protocol);
351
352static struct packet_type hdlc_packet_type __read_mostly = {
353 .type = cpu_to_be16(ETH_P_HDLC),
354 .func = hdlc_rcv,
355};
356
357
358static struct notifier_block hdlc_notifier = {
359 .notifier_call = hdlc_device_event,
360};
361
362
363static int __init hdlc_module_init(void)
364{
365 int result;
366
367 pr_info("%s\n", version);
368 if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
369 return result;
370 dev_add_pack(&hdlc_packet_type);
371 return 0;
372}
373
374
375
376static void __exit hdlc_module_exit(void)
377{
378 dev_remove_pack(&hdlc_packet_type);
379 unregister_netdevice_notifier(&hdlc_notifier);
380}
381
382
383module_init(hdlc_module_init);
384module_exit(hdlc_module_exit);
1/*
2 * Generic HDLC support routines for Linux
3 *
4 * Copyright (C) 1999 - 2008 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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
26
27#include <linux/errno.h>
28#include <linux/hdlc.h>
29#include <linux/if_arp.h>
30#include <linux/inetdevice.h>
31#include <linux/init.h>
32#include <linux/kernel.h>
33#include <linux/module.h>
34#include <linux/notifier.h>
35#include <linux/pkt_sched.h>
36#include <linux/poll.h>
37#include <linux/rtnetlink.h>
38#include <linux/skbuff.h>
39#include <linux/slab.h>
40#include <net/net_namespace.h>
41
42
43static const char* version = "HDLC support module revision 1.22";
44
45#undef DEBUG_LINK
46
47static struct hdlc_proto *first_proto;
48
49int hdlc_change_mtu(struct net_device *dev, int new_mtu)
50{
51 if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
52 return -EINVAL;
53 dev->mtu = new_mtu;
54 return 0;
55}
56
57static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
58 struct packet_type *p, struct net_device *orig_dev)
59{
60 struct hdlc_device *hdlc = dev_to_hdlc(dev);
61
62 if (!net_eq(dev_net(dev), &init_net)) {
63 kfree_skb(skb);
64 return 0;
65 }
66
67 BUG_ON(!hdlc->proto->netif_rx);
68 return hdlc->proto->netif_rx(skb);
69}
70
71netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev)
72{
73 hdlc_device *hdlc = dev_to_hdlc(dev);
74
75 if (hdlc->proto->xmit)
76 return hdlc->proto->xmit(skb, dev);
77
78 return hdlc->xmit(skb, dev); /* call hardware driver directly */
79}
80
81static inline void hdlc_proto_start(struct net_device *dev)
82{
83 hdlc_device *hdlc = dev_to_hdlc(dev);
84 if (hdlc->proto->start)
85 hdlc->proto->start(dev);
86}
87
88
89
90static inline void hdlc_proto_stop(struct net_device *dev)
91{
92 hdlc_device *hdlc = dev_to_hdlc(dev);
93 if (hdlc->proto->stop)
94 hdlc->proto->stop(dev);
95}
96
97
98
99static int hdlc_device_event(struct notifier_block *this, unsigned long event,
100 void *ptr)
101{
102 struct net_device *dev = ptr;
103 hdlc_device *hdlc;
104 unsigned long flags;
105 int on;
106
107 if (!net_eq(dev_net(dev), &init_net))
108 return NOTIFY_DONE;
109
110 if (!(dev->priv_flags & IFF_WAN_HDLC))
111 return NOTIFY_DONE; /* not an HDLC device */
112
113 if (event != NETDEV_CHANGE)
114 return NOTIFY_DONE; /* Only interested in carrier changes */
115
116 on = netif_carrier_ok(dev);
117
118#ifdef DEBUG_LINK
119 printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
120 dev->name, on);
121#endif
122
123 hdlc = dev_to_hdlc(dev);
124 spin_lock_irqsave(&hdlc->state_lock, flags);
125
126 if (hdlc->carrier == on)
127 goto carrier_exit; /* no change in DCD line level */
128
129 hdlc->carrier = on;
130
131 if (!hdlc->open)
132 goto carrier_exit;
133
134 if (hdlc->carrier) {
135 netdev_info(dev, "Carrier detected\n");
136 hdlc_proto_start(dev);
137 } else {
138 netdev_info(dev, "Carrier lost\n");
139 hdlc_proto_stop(dev);
140 }
141
142carrier_exit:
143 spin_unlock_irqrestore(&hdlc->state_lock, flags);
144 return NOTIFY_DONE;
145}
146
147
148
149/* Must be called by hardware driver when HDLC device is being opened */
150int hdlc_open(struct net_device *dev)
151{
152 hdlc_device *hdlc = dev_to_hdlc(dev);
153#ifdef DEBUG_LINK
154 printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
155 hdlc->carrier, hdlc->open);
156#endif
157
158 if (hdlc->proto == NULL)
159 return -ENOSYS; /* no protocol attached */
160
161 if (hdlc->proto->open) {
162 int result = hdlc->proto->open(dev);
163 if (result)
164 return result;
165 }
166
167 spin_lock_irq(&hdlc->state_lock);
168
169 if (hdlc->carrier) {
170 netdev_info(dev, "Carrier detected\n");
171 hdlc_proto_start(dev);
172 } else
173 netdev_info(dev, "No carrier\n");
174
175 hdlc->open = 1;
176
177 spin_unlock_irq(&hdlc->state_lock);
178 return 0;
179}
180
181
182
183/* Must be called by hardware driver when HDLC device is being closed */
184void hdlc_close(struct net_device *dev)
185{
186 hdlc_device *hdlc = dev_to_hdlc(dev);
187#ifdef DEBUG_LINK
188 printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
189 hdlc->carrier, hdlc->open);
190#endif
191
192 spin_lock_irq(&hdlc->state_lock);
193
194 hdlc->open = 0;
195 if (hdlc->carrier)
196 hdlc_proto_stop(dev);
197
198 spin_unlock_irq(&hdlc->state_lock);
199
200 if (hdlc->proto->close)
201 hdlc->proto->close(dev);
202}
203
204
205
206int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
207{
208 struct hdlc_proto *proto = first_proto;
209 int result;
210
211 if (cmd != SIOCWANDEV)
212 return -EINVAL;
213
214 if (dev_to_hdlc(dev)->proto) {
215 result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
216 if (result != -EINVAL)
217 return result;
218 }
219
220 /* Not handled by currently attached protocol (if any) */
221
222 while (proto) {
223 if ((result = proto->ioctl(dev, ifr)) != -EINVAL)
224 return result;
225 proto = proto->next;
226 }
227 return -EINVAL;
228}
229
230static const struct header_ops hdlc_null_ops;
231
232static void hdlc_setup_dev(struct net_device *dev)
233{
234 /* Re-init all variables changed by HDLC protocol drivers,
235 * including ether_setup() called from hdlc_raw_eth.c.
236 */
237 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
238 dev->priv_flags = IFF_WAN_HDLC;
239 dev->mtu = HDLC_MAX_MTU;
240 dev->type = ARPHRD_RAWHDLC;
241 dev->hard_header_len = 16;
242 dev->addr_len = 0;
243 dev->header_ops = &hdlc_null_ops;
244}
245
246static void hdlc_setup(struct net_device *dev)
247{
248 hdlc_device *hdlc = dev_to_hdlc(dev);
249
250 hdlc_setup_dev(dev);
251 hdlc->carrier = 1;
252 hdlc->open = 0;
253 spin_lock_init(&hdlc->state_lock);
254}
255
256struct net_device *alloc_hdlcdev(void *priv)
257{
258 struct net_device *dev;
259 dev = alloc_netdev(sizeof(struct hdlc_device), "hdlc%d", hdlc_setup);
260 if (dev)
261 dev_to_hdlc(dev)->priv = priv;
262 return dev;
263}
264
265void unregister_hdlc_device(struct net_device *dev)
266{
267 rtnl_lock();
268 unregister_netdevice(dev);
269 detach_hdlc_protocol(dev);
270 rtnl_unlock();
271}
272
273
274
275int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
276 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 netdev_warn(dev,
287 "Memory squeeze on hdlc_proto_attach()\n");
288 module_put(proto->module);
289 return -ENOBUFS;
290 }
291 dev_to_hdlc(dev)->proto = proto;
292 return 0;
293}
294
295
296void detach_hdlc_protocol(struct net_device *dev)
297{
298 hdlc_device *hdlc = dev_to_hdlc(dev);
299
300 if (hdlc->proto) {
301 if (hdlc->proto->detach)
302 hdlc->proto->detach(dev);
303 module_put(hdlc->proto->module);
304 hdlc->proto = NULL;
305 }
306 kfree(hdlc->state);
307 hdlc->state = NULL;
308 hdlc_setup_dev(dev);
309}
310
311
312void register_hdlc_protocol(struct hdlc_proto *proto)
313{
314 rtnl_lock();
315 proto->next = first_proto;
316 first_proto = proto;
317 rtnl_unlock();
318}
319
320
321void unregister_hdlc_protocol(struct hdlc_proto *proto)
322{
323 struct hdlc_proto **p;
324
325 rtnl_lock();
326 p = &first_proto;
327 while (*p != proto) {
328 BUG_ON(!*p);
329 p = &((*p)->next);
330 }
331 *p = proto->next;
332 rtnl_unlock();
333}
334
335
336
337MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
338MODULE_DESCRIPTION("HDLC support module");
339MODULE_LICENSE("GPL v2");
340
341EXPORT_SYMBOL(hdlc_change_mtu);
342EXPORT_SYMBOL(hdlc_start_xmit);
343EXPORT_SYMBOL(hdlc_open);
344EXPORT_SYMBOL(hdlc_close);
345EXPORT_SYMBOL(hdlc_ioctl);
346EXPORT_SYMBOL(alloc_hdlcdev);
347EXPORT_SYMBOL(unregister_hdlc_device);
348EXPORT_SYMBOL(register_hdlc_protocol);
349EXPORT_SYMBOL(unregister_hdlc_protocol);
350EXPORT_SYMBOL(attach_hdlc_protocol);
351EXPORT_SYMBOL(detach_hdlc_protocol);
352
353static struct packet_type hdlc_packet_type __read_mostly = {
354 .type = cpu_to_be16(ETH_P_HDLC),
355 .func = hdlc_rcv,
356};
357
358
359static struct notifier_block hdlc_notifier = {
360 .notifier_call = hdlc_device_event,
361};
362
363
364static int __init hdlc_module_init(void)
365{
366 int result;
367
368 pr_info("%s\n", version);
369 if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
370 return result;
371 dev_add_pack(&hdlc_packet_type);
372 return 0;
373}
374
375
376
377static void __exit hdlc_module_exit(void)
378{
379 dev_remove_pack(&hdlc_packet_type);
380 unregister_netdevice_notifier(&hdlc_notifier);
381}
382
383
384module_init(hdlc_module_init);
385module_exit(hdlc_module_exit);