[deliverable/linux.git] / drivers / net / wan / hdlc.c

/*
 * Generic HDLC support routines for Linux
 *
 * Copyright (C) 1999 - 2008 Krzysztof Halasa <khc@pm.waw.pl>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 *
 * Currently supported:
 *	* raw IP-in-HDLC
 *	* Cisco HDLC
 *	* Frame Relay with ANSI or CCITT LMI (both user and network side)
 *	* PPP
 *	* X.25
 *
 * Use sethdlc utility to set line parameters, protocol and PVCs
 *
 * How does it work:
 * - proto->open(), close(), start(), stop() calls are serialized.
 *   The order is: open, [ start, stop ... ] close ...
 * - proto->start() and stop() are called with spin_lock_irq held.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/pkt_sched.h>
#include <linux/inetdevice.h>
#include <linux/lapb.h>
#include <linux/rtnetlink.h>
#include <linux/notifier.h>
#include <linux/hdlc.h>
#include <net/net_namespace.h>


static const char* version = "HDLC support module revision 1.22";

#undef DEBUG_LINK

static struct hdlc_proto *first_proto = NULL;


static int hdlc_change_mtu(struct net_device *dev, int new_mtu)
{
	if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}


static struct net_device_stats *hdlc_get_stats(struct net_device *dev)
{
	return hdlc_stats(dev);
}


static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
		    struct packet_type *p, struct net_device *orig_dev)
{
	struct hdlc_device *hdlc = dev_to_hdlc(dev);

	if (dev_net(dev) != &init_net) {
		kfree_skb(skb);
		return 0;
	}

	BUG_ON(!hdlc->proto->netif_rx);
	return hdlc->proto->netif_rx(skb);
}


static inline void hdlc_proto_start(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	if (hdlc->proto->start)
		hdlc->proto->start(dev);
}


static inline void hdlc_proto_stop(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	if (hdlc->proto->stop)
		hdlc->proto->stop(dev);
}


static int hdlc_device_event(struct notifier_block *this, unsigned long event,
			     void *ptr)
{
	struct net_device *dev = ptr;
	hdlc_device *hdlc;
	unsigned long flags;
	int on;
 
	if (dev_net(dev) != &init_net)
		return NOTIFY_DONE;

	if (dev->get_stats != hdlc_get_stats)
		return NOTIFY_DONE; /* not an HDLC device */
 
	if (event != NETDEV_CHANGE)
		return NOTIFY_DONE; /* Only interrested in carrier changes */

	on = netif_carrier_ok(dev);

#ifdef DEBUG_LINK
	printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
	       dev->name, on);
#endif

	hdlc = dev_to_hdlc(dev);
	spin_lock_irqsave(&hdlc->state_lock, flags);

	if (hdlc->carrier == on)
		goto carrier_exit; /* no change in DCD line level */

	hdlc->carrier = on;

	if (!hdlc->open)
		goto carrier_exit;

	if (hdlc->carrier) {
		printk(KERN_INFO "%s: Carrier detected\n", dev->name);
		hdlc_proto_start(dev);
	} else {
		printk(KERN_INFO "%s: Carrier lost\n", dev->name);
		hdlc_proto_stop(dev);
	}

carrier_exit:
	spin_unlock_irqrestore(&hdlc->state_lock, flags);
	return NOTIFY_DONE;
}


/* Must be called by hardware driver when HDLC device is being opened */
int hdlc_open(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
#ifdef DEBUG_LINK
	printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
	       hdlc->carrier, hdlc->open);
#endif

	if (hdlc->proto == NULL)
		return -ENOSYS;	/* no protocol attached */

	if (hdlc->proto->open) {
		int result = hdlc->proto->open(dev);
		if (result)
			return result;
	}

	spin_lock_irq(&hdlc->state_lock);

	if (hdlc->carrier) {
		printk(KERN_INFO "%s: Carrier detected\n", dev->name);
		hdlc_proto_start(dev);
	} else
		printk(KERN_INFO "%s: No carrier\n", dev->name);

	hdlc->open = 1;

	spin_unlock_irq(&hdlc->state_lock);
	return 0;
}


/* Must be called by hardware driver when HDLC device is being closed */
void hdlc_close(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
#ifdef DEBUG_LINK
	printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
	       hdlc->carrier, hdlc->open);
#endif

	spin_lock_irq(&hdlc->state_lock);

	hdlc->open = 0;
	if (hdlc->carrier)
		hdlc_proto_stop(dev);

	spin_unlock_irq(&hdlc->state_lock);

	if (hdlc->proto->close)
		hdlc->proto->close(dev);
}


int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	struct hdlc_proto *proto = first_proto;
	int result;

	if (cmd != SIOCWANDEV)
		return -EINVAL;

	if (dev_to_hdlc(dev)->proto) {
		result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
		if (result != -EINVAL)
			return result;
	}

	/* Not handled by currently attached protocol (if any) */

	while (proto) {
		if ((result = proto->ioctl(dev, ifr)) != -EINVAL)
			return result;
		proto = proto->next;
	}
	return -EINVAL;
}

static const struct header_ops hdlc_null_ops;

static void hdlc_setup_dev(struct net_device *dev)
{
	/* Re-init all variables changed by HDLC protocol drivers,
	 * including ether_setup() called from hdlc_raw_eth.c.
	 */
	dev->get_stats		 = hdlc_get_stats;
	dev->flags		 = IFF_POINTOPOINT | IFF_NOARP;
	dev->mtu		 = HDLC_MAX_MTU;
	dev->type		 = ARPHRD_RAWHDLC;
	dev->hard_header_len	 = 16;
	dev->addr_len		 = 0;
	dev->header_ops		 = &hdlc_null_ops;

	dev->change_mtu		 = hdlc_change_mtu;
}

static void hdlc_setup(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);

	hdlc_setup_dev(dev);
	hdlc->carrier = 1;
	hdlc->open = 0;
	spin_lock_init(&hdlc->state_lock);
}

struct net_device *alloc_hdlcdev(void *priv)
{
	struct net_device *dev;
	dev = alloc_netdev(sizeof(struct hdlc_device), "hdlc%d", hdlc_setup);
	if (dev)
		dev_to_hdlc(dev)->priv = priv;
	return dev;
}

void unregister_hdlc_device(struct net_device *dev)
{
	rtnl_lock();
	unregister_netdevice(dev);
	detach_hdlc_protocol(dev);
	rtnl_unlock();
}


int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
			 size_t size)
{
	detach_hdlc_protocol(dev);

	if (!try_module_get(proto->module))
		return -ENOSYS;

	if (size)
		if ((dev_to_hdlc(dev)->state = kmalloc(size,
						       GFP_KERNEL)) == NULL) {
			printk(KERN_WARNING "Memory squeeze on"
			       " hdlc_proto_attach()\n");
			module_put(proto->module);
			return -ENOBUFS;
		}
	dev_to_hdlc(dev)->proto = proto;
	return 0;
}


void detach_hdlc_protocol(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);

	if (hdlc->proto) {
		if (hdlc->proto->detach)
			hdlc->proto->detach(dev);
		module_put(hdlc->proto->module);
		hdlc->proto = NULL;
	}
	kfree(hdlc->state);
	hdlc->state = NULL;
	hdlc_setup_dev(dev);
}


void register_hdlc_protocol(struct hdlc_proto *proto)
{
	proto->next = first_proto;
	first_proto = proto;
}


void unregister_hdlc_protocol(struct hdlc_proto *proto)
{
	struct hdlc_proto **p = &first_proto;
	while (*p) {
		if (*p == proto) {
			*p = proto->next;
			return;
		}
		p = &((*p)->next);
	}
}


MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
MODULE_DESCRIPTION("HDLC support module");
MODULE_LICENSE("GPL v2");

EXPORT_SYMBOL(hdlc_open);
EXPORT_SYMBOL(hdlc_close);
EXPORT_SYMBOL(hdlc_ioctl);
EXPORT_SYMBOL(alloc_hdlcdev);
EXPORT_SYMBOL(unregister_hdlc_device);
EXPORT_SYMBOL(register_hdlc_protocol);
EXPORT_SYMBOL(unregister_hdlc_protocol);
EXPORT_SYMBOL(attach_hdlc_protocol);
EXPORT_SYMBOL(detach_hdlc_protocol);

static struct packet_type hdlc_packet_type = {
	.type = __constant_htons(ETH_P_HDLC),
	.func = hdlc_rcv,
};


static struct notifier_block hdlc_notifier = {
        .notifier_call = hdlc_device_event,
};


static int __init hdlc_module_init(void)
{
	int result;

	printk(KERN_INFO "%s\n", version);
	if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
                return result;
        dev_add_pack(&hdlc_packet_type);
	return 0;
}


static void __exit hdlc_module_exit(void)
{
	dev_remove_pack(&hdlc_packet_type);
	unregister_netdevice_notifier(&hdlc_notifier);
}


module_init(hdlc_module_init);
module_exit(hdlc_module_exit);
Commit	Line	Data
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	*/
1da177e4 LT	24
1da177e4 LT	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>
c2ce9204	37	#include <linux/notifier.h>
1da177e4	38	#include <linux/hdlc.h>
e730c155	39	#include <net/net_namespace.h>
1da177e4 LT	40
1da177e4 LT	41
40d25142	42	static const char* version = "HDLC support module revision 1.22";
1da177e4 LT	43
	44	#undef DEBUG_LINK
	45
eb2a2fd9 KH	46	static struct hdlc_proto *first_proto = NULL;
eb2a2fd9 KH	47
1da177e4 LT	48
	49	static int 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
	57
	58
	59	static struct net_device_stats hdlc_get_stats(struct net_device dev)
	60	{
	61	return hdlc_stats(dev);
	62	}
	63
	64
	65
	66	static int hdlc_rcv(struct sk_buff skb, struct net_device dev,
f2ccd8fa	67	struct packet_type p, struct net_device orig_dev)
1da177e4	68	{
40d25142	69	struct hdlc_device *hdlc = dev_to_hdlc(dev);
e730c155	70
c346dca1	71	if (dev_net(dev) != &init_net) {
e730c155 EB	72	kfree_skb(skb);
	73	return 0;
	74	}
	75
40d25142 KH	76	BUG_ON(!hdlc->proto->netif_rx);
40d25142 KH	77	return hdlc->proto->netif_rx(skb);
1da177e4 LT	78	}
	79
	80
	81
c2ce9204	82	static inline void hdlc_proto_start(struct net_device *dev)
1da177e4 LT	83	{
1da177e4 LT	84	hdlc_device *hdlc = dev_to_hdlc(dev);
eb2a2fd9	85	if (hdlc->proto->start)
40d25142	86	hdlc->proto->start(dev);
1da177e4 LT	87	}
	88
	89
	90
c2ce9204	91	static inline void hdlc_proto_stop(struct net_device *dev)
1da177e4 LT	92	{
1da177e4 LT	93	hdlc_device *hdlc = dev_to_hdlc(dev);
eb2a2fd9	94	if (hdlc->proto->stop)
40d25142	95	hdlc->proto->stop(dev);
1da177e4 LT	96	}
	97
	98
	99
c2ce9204 KH	100	static int hdlc_device_event(struct notifier_block *this, unsigned long event,
c2ce9204 KH	101	void *ptr)
1da177e4	102	{
c2ce9204 KH	103	struct net_device *dev = ptr;
c2ce9204 KH	104	hdlc_device *hdlc;
1da177e4	105	unsigned long flags;
c2ce9204 KH	106	int on;
c2ce9204 KH	107
c346dca1	108	if (dev_net(dev) != &init_net)
e9dc8653 EB	109	return NOTIFY_DONE;
e9dc8653 EB	110
c2ce9204 KH	111	if (dev->get_stats != hdlc_get_stats)
	112	return NOTIFY_DONE; /* not an HDLC device */
	113
	114	if (event != NETDEV_CHANGE)
	115	return NOTIFY_DONE; /* Only interrested in carrier changes */
	116
	117	on = netif_carrier_ok(dev);
1da177e4 LT	118
1da177e4 LT	119	#ifdef DEBUG_LINK
c2ce9204 KH	120	printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
c2ce9204 KH	121	dev->name, on);
1da177e4 LT	122	#endif
1da177e4 LT	123
c2ce9204	124	hdlc = dev_to_hdlc(dev);
1da177e4 LT	125	spin_lock_irqsave(&hdlc->state_lock, flags);
	126
	127	if (hdlc->carrier == on)
	128	goto carrier_exit; /* no change in DCD line level */
	129
1da177e4 LT	130	hdlc->carrier = on;
	131
	132	if (!hdlc->open)
	133	goto carrier_exit;
	134
b3dd65f9 KH	135	if (hdlc->carrier) {
b3dd65f9 KH	136	printk(KERN_INFO "%s: Carrier detected\n", dev->name);
c2ce9204	137	hdlc_proto_start(dev);
b3dd65f9 KH	138	} else {
b3dd65f9 KH	139	printk(KERN_INFO "%s: Carrier lost\n", dev->name);
c2ce9204	140	hdlc_proto_stop(dev);
b3dd65f9	141	}
1da177e4 LT	142
	143	carrier_exit:
	144	spin_unlock_irqrestore(&hdlc->state_lock, flags);
c2ce9204	145	return NOTIFY_DONE;
1da177e4 LT	146	}
	147
	148
	149
	150	/* Must be called by hardware driver when HDLC device is being opened */
	151	int hdlc_open(struct net_device *dev)
	152	{
	153	hdlc_device *hdlc = dev_to_hdlc(dev);
	154	#ifdef DEBUG_LINK
eb2a2fd9	155	printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
1da177e4 LT	156	hdlc->carrier, hdlc->open);
	157	#endif
	158
eb2a2fd9	159	if (hdlc->proto == NULL)
1da177e4 LT	160	return -ENOSYS; /* no protocol attached */
1da177e4 LT	161
eb2a2fd9 KH	162	if (hdlc->proto->open) {
eb2a2fd9 KH	163	int result = hdlc->proto->open(dev);
1da177e4 LT	164	if (result)
	165	return result;
	166	}
	167
	168	spin_lock_irq(&hdlc->state_lock);
	169
b3dd65f9 KH	170	if (hdlc->carrier) {
b3dd65f9 KH	171	printk(KERN_INFO "%s: Carrier detected\n", dev->name);
c2ce9204	172	hdlc_proto_start(dev);
b3dd65f9 KH	173	} else
b3dd65f9 KH	174	printk(KERN_INFO "%s: No carrier\n", dev->name);
1da177e4 LT	175
	176	hdlc->open = 1;
	177
	178	spin_unlock_irq(&hdlc->state_lock);
	179	return 0;
	180	}
	181
	182
	183
	184	/* Must be called by hardware driver when HDLC device is being closed */
	185	void hdlc_close(struct net_device *dev)
	186	{
	187	hdlc_device *hdlc = dev_to_hdlc(dev);
	188	#ifdef DEBUG_LINK
eb2a2fd9	189	printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
1da177e4 LT	190	hdlc->carrier, hdlc->open);
	191	#endif
	192
	193	spin_lock_irq(&hdlc->state_lock);
	194
	195	hdlc->open = 0;
	196	if (hdlc->carrier)
c2ce9204	197	hdlc_proto_stop(dev);
1da177e4 LT	198
	199	spin_unlock_irq(&hdlc->state_lock);
	200
eb2a2fd9 KH	201	if (hdlc->proto->close)
eb2a2fd9 KH	202	hdlc->proto->close(dev);
1da177e4 LT	203	}
	204
	205
	206
1da177e4 LT	207	int hdlc_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
1da177e4 LT	208	{
eb2a2fd9 KH	209	struct hdlc_proto *proto = first_proto;
eb2a2fd9 KH	210	int result;
1da177e4 LT	211
	212	if (cmd != SIOCWANDEV)
	213	return -EINVAL;
	214
eb2a2fd9 KH	215	if (dev_to_hdlc(dev)->proto) {
	216	result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
	217	if (result != -EINVAL)
	218	return result;
1da177e4 LT	219	}
1da177e4 LT	220
eb2a2fd9 KH	221	/* Not handled by currently attached protocol (if any) */
	222
	223	while (proto) {
	224	if ((result = proto->ioctl(dev, ifr)) != -EINVAL)
	225	return result;
	226	proto = proto->next;
1da177e4	227	}
eb2a2fd9	228	return -EINVAL;
1da177e4 LT	229	}
1da177e4 LT	230
3b04ddde SH	231	static const struct header_ops hdlc_null_ops;
3b04ddde SH	232
b5284e5a KH	233	static void hdlc_setup_dev(struct net_device *dev)
	234	{
	235	/* Re-init all variables changed by HDLC protocol drivers,
	236	* including ether_setup() called from hdlc_raw_eth.c.
	237	*/
	238	dev->get_stats = hdlc_get_stats;
	239	dev->flags = IFF_POINTOPOINT \| IFF_NOARP;
	240	dev->mtu = HDLC_MAX_MTU;
	241	dev->type = ARPHRD_RAWHDLC;
	242	dev->hard_header_len = 16;
	243	dev->addr_len = 0;
3b04ddde SH	244	dev->header_ops = &hdlc_null_ops;
3b04ddde SH	245
b5284e5a	246	dev->change_mtu = hdlc_change_mtu;
b5284e5a KH	247	}
b5284e5a KH	248
0bf94faf	249	static void hdlc_setup(struct net_device *dev)
1da177e4 LT	250	{
	251	hdlc_device *hdlc = dev_to_hdlc(dev);
	252
b5284e5a	253	hdlc_setup_dev(dev);
1da177e4 LT	254	hdlc->carrier = 1;
	255	hdlc->open = 0;
	256	spin_lock_init(&hdlc->state_lock);
	257	}
	258
	259	struct net_device alloc_hdlcdev(void priv)
	260	{
	261	struct net_device *dev;
40d25142	262	dev = alloc_netdev(sizeof(struct hdlc_device), "hdlc%d", hdlc_setup);
1da177e4 LT	263	if (dev)
	264	dev_to_hdlc(dev)->priv = priv;
	265	return dev;
	266	}
	267
1da177e4 LT	268	void unregister_hdlc_device(struct net_device *dev)
	269	{
	270	rtnl_lock();
1da177e4	271	unregister_netdevice(dev);
eb2a2fd9	272	detach_hdlc_protocol(dev);
1da177e4 LT	273	rtnl_unlock();
	274	}
	275
	276
	277
eb2a2fd9	278	int attach_hdlc_protocol(struct net_device dev, struct hdlc_proto proto,
40d25142	279	size_t size)
eb2a2fd9 KH	280	{
	281	detach_hdlc_protocol(dev);
	282
	283	if (!try_module_get(proto->module))
	284	return -ENOSYS;
	285
	286	if (size)
	287	if ((dev_to_hdlc(dev)->state = kmalloc(size,
	288	GFP_KERNEL)) == NULL) {
	289	printk(KERN_WARNING "Memory squeeze on"
	290	" hdlc_proto_attach()\n");
	291	module_put(proto->module);
	292	return -ENOBUFS;
	293	}
	294	dev_to_hdlc(dev)->proto = proto;
eb2a2fd9 KH	295	return 0;
	296	}
	297
	298
	299	void detach_hdlc_protocol(struct net_device *dev)
	300	{
	301	hdlc_device *hdlc = dev_to_hdlc(dev);
	302
	303	if (hdlc->proto) {
	304	if (hdlc->proto->detach)
	305	hdlc->proto->detach(dev);
	306	module_put(hdlc->proto->module);
	307	hdlc->proto = NULL;
	308	}
	309	kfree(hdlc->state);
	310	hdlc->state = NULL;
b5284e5a	311	hdlc_setup_dev(dev);
eb2a2fd9 KH	312	}
	313
	314
	315	void register_hdlc_protocol(struct hdlc_proto *proto)
	316	{
	317	proto->next = first_proto;
	318	first_proto = proto;
	319	}
	320
	321
	322	void unregister_hdlc_protocol(struct hdlc_proto *proto)
	323	{
	324	struct hdlc_proto **p = &first_proto;
	325	while (*p) {
	326	if (*p == proto) {
	327	*p = proto->next;
	328	return;
	329	}
	330	p = &((*p)->next);
	331	}
	332	}
	333
	334
	335
1da177e4 LT	336	MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
	337	MODULE_DESCRIPTION("HDLC support module");
	338	MODULE_LICENSE("GPL v2");
	339
	340	EXPORT_SYMBOL(hdlc_open);
	341	EXPORT_SYMBOL(hdlc_close);
1da177e4 LT	342	EXPORT_SYMBOL(hdlc_ioctl);
1da177e4 LT	343	EXPORT_SYMBOL(alloc_hdlcdev);
1da177e4	344	EXPORT_SYMBOL(unregister_hdlc_device);
eb2a2fd9 KH	345	EXPORT_SYMBOL(register_hdlc_protocol);
	346	EXPORT_SYMBOL(unregister_hdlc_protocol);
	347	EXPORT_SYMBOL(attach_hdlc_protocol);
	348	EXPORT_SYMBOL(detach_hdlc_protocol);
1da177e4 LT	349
	350	static struct packet_type hdlc_packet_type = {
	351	.type = __constant_htons(ETH_P_HDLC),
	352	.func = hdlc_rcv,
	353	};
	354
	355
c2ce9204 KH	356	static struct notifier_block hdlc_notifier = {
	357	.notifier_call = hdlc_device_event,
	358	};
	359
	360
1da177e4 LT	361	static int __init hdlc_module_init(void)
1da177e4 LT	362	{
c2ce9204 KH	363	int result;
c2ce9204 KH	364
1da177e4	365	printk(KERN_INFO "%s\n", version);
c2ce9204 KH	366	if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
c2ce9204 KH	367	return result;
1da177e4 LT	368	dev_add_pack(&hdlc_packet_type);
	369	return 0;
	370	}
	371
	372
	373
	374	static void __exit hdlc_module_exit(void)
	375	{
	376	dev_remove_pack(&hdlc_packet_type);
c2ce9204	377	unregister_netdevice_notifier(&hdlc_notifier);
1da177e4 LT	378	}
	379
	380
	381	module_init(hdlc_module_init);
	382	module_exit(hdlc_module_exit);