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

/*
 * Generic HDLC support routines for Linux
 *
 * Copyright (C) 1999 - 2006 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>


static const char* version = "HDLC support module revision 1.21";

#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_desc *desc = dev_to_desc(dev);
	if (desc->netif_rx)
		return desc->netif_rx(skb);

	desc->stats.rx_dropped++; /* Shouldn't happen */
	dev_kfree_skb(skb);
	return NET_RX_DROP;
}


static inline void hdlc_proto_start(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	if (hdlc->proto->start)
		return 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)
		return 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->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 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->hard_header	 = NULL;
	dev->rebuild_header	 = NULL;
	dev->set_mac_address	 = NULL;
	dev->hard_header_cache	 = NULL;
	dev->header_cache_update = NULL;
	dev->change_mtu		 = hdlc_change_mtu;
	dev->hard_header_parse	 = NULL;
}

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_desc) +
			   sizeof(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,
			 int (*rx)(struct sk_buff *skb), 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;
	dev_to_desc(dev)->netif_rx = rx;
	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	*
eb2a2fd9	4	* Copyright (C) 1999 - 2006 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 LT	38	#include <linux/hdlc.h>
	39
	40
b5284e5a	41	static const char* version = "HDLC support module revision 1.21";
1da177e4 LT	42
	43	#undef DEBUG_LINK
	44
eb2a2fd9 KH	45	static struct hdlc_proto *first_proto = NULL;
eb2a2fd9 KH	46
1da177e4 LT	47
	48	static 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
	58	static struct net_device_stats hdlc_get_stats(struct net_device dev)
	59	{
	60	return hdlc_stats(dev);
	61	}
	62
	63
	64
	65	static int hdlc_rcv(struct sk_buff skb, struct net_device dev,
f2ccd8fa	66	struct packet_type p, struct net_device orig_dev)
1da177e4	67	{
eb2a2fd9 KH	68	struct hdlc_device_desc *desc = dev_to_desc(dev);
	69	if (desc->netif_rx)
	70	return desc->netif_rx(skb);
1da177e4	71
eb2a2fd9	72	desc->stats.rx_dropped++; /* Shouldn't happen */
1da177e4 LT	73	dev_kfree_skb(skb);
	74	return NET_RX_DROP;
	75	}
	76
	77
	78
c2ce9204	79	static inline void hdlc_proto_start(struct net_device *dev)
1da177e4 LT	80	{
1da177e4 LT	81	hdlc_device *hdlc = dev_to_hdlc(dev);
eb2a2fd9 KH	82	if (hdlc->proto->start)
eb2a2fd9 KH	83	return 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	{
1da177e4 LT	90	hdlc_device *hdlc = dev_to_hdlc(dev);
eb2a2fd9 KH	91	if (hdlc->proto->stop)
eb2a2fd9 KH	92	return 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,
c2ce9204 KH	98	void *ptr)
1da177e4	99	{
c2ce9204 KH	100	struct net_device *dev = ptr;
c2ce9204 KH	101	hdlc_device *hdlc;
1da177e4	102	unsigned long flags;
c2ce9204 KH	103	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);
1da177e4 LT	112
1da177e4 LT	113	#ifdef DEBUG_LINK
c2ce9204 KH	114	printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
c2ce9204 KH	115	dev->name, on);
1da177e4 LT	116	#endif
1da177e4 LT	117
c2ce9204	118	hdlc = dev_to_hdlc(dev);
1da177e4 LT	119	spin_lock_irqsave(&hdlc->state_lock, flags);
	120
	121	if (hdlc->carrier == on)
	122	goto carrier_exit; /* no change in DCD line level */
	123
1da177e4 LT	124	hdlc->carrier = on;
	125
	126	if (!hdlc->open)
	127	goto carrier_exit;
	128
b3dd65f9 KH	129	if (hdlc->carrier) {
b3dd65f9 KH	130	printk(KERN_INFO "%s: Carrier detected\n", dev->name);
c2ce9204	131	hdlc_proto_start(dev);
b3dd65f9 KH	132	} else {
b3dd65f9 KH	133	printk(KERN_INFO "%s: Carrier lost\n", dev->name);
c2ce9204	134	hdlc_proto_stop(dev);
b3dd65f9	135	}
1da177e4 LT	136
	137	carrier_exit:
	138	spin_unlock_irqrestore(&hdlc->state_lock, flags);
c2ce9204	139	return NOTIFY_DONE;
1da177e4 LT	140	}
	141
	142
	143
	144	/* Must be called by hardware driver when HDLC device is being opened */
	145	int hdlc_open(struct net_device *dev)
	146	{
	147	hdlc_device *hdlc = dev_to_hdlc(dev);
	148	#ifdef DEBUG_LINK
eb2a2fd9	149	printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
1da177e4 LT	150	hdlc->carrier, hdlc->open);
	151	#endif
	152
eb2a2fd9	153	if (hdlc->proto == NULL)
1da177e4 LT	154	return -ENOSYS; /* no protocol attached */
1da177e4 LT	155
eb2a2fd9 KH	156	if (hdlc->proto->open) {
eb2a2fd9 KH	157	int result = hdlc->proto->open(dev);
1da177e4 LT	158	if (result)
	159	return result;
	160	}
	161
	162	spin_lock_irq(&hdlc->state_lock);
	163
b3dd65f9 KH	164	if (hdlc->carrier) {
b3dd65f9 KH	165	printk(KERN_INFO "%s: Carrier detected\n", dev->name);
c2ce9204	166	hdlc_proto_start(dev);
b3dd65f9 KH	167	} else
b3dd65f9 KH	168	printk(KERN_INFO "%s: No carrier\n", dev->name);
1da177e4 LT	169
	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 */
	179	void hdlc_close(struct net_device *dev)
	180	{
	181	hdlc_device *hdlc = dev_to_hdlc(dev);
	182	#ifdef DEBUG_LINK
eb2a2fd9	183	printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
1da177e4 LT	184	hdlc->carrier, hdlc->open);
	185	#endif
	186
	187	spin_lock_irq(&hdlc->state_lock);
	188
	189	hdlc->open = 0;
	190	if (hdlc->carrier)
c2ce9204	191	hdlc_proto_stop(dev);
1da177e4 LT	192
	193	spin_unlock_irq(&hdlc->state_lock);
	194
eb2a2fd9 KH	195	if (hdlc->proto->close)
eb2a2fd9 KH	196	hdlc->proto->close(dev);
1da177e4 LT	197	}
	198
	199
	200
1da177e4 LT	201	int hdlc_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
1da177e4 LT	202	{
eb2a2fd9 KH	203	struct hdlc_proto *proto = first_proto;
eb2a2fd9 KH	204	int result;
1da177e4 LT	205
	206	if (cmd != SIOCWANDEV)
	207	return -EINVAL;
	208
eb2a2fd9 KH	209	if (dev_to_hdlc(dev)->proto) {
	210	result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
	211	if (result != -EINVAL)
	212	return result;
1da177e4 LT	213	}
1da177e4 LT	214
eb2a2fd9 KH	215	/* 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;
1da177e4	221	}
eb2a2fd9	222	return -EINVAL;
1da177e4 LT	223	}
1da177e4 LT	224
b5284e5a KH	225	static 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
0bf94faf	245	static void hdlc_setup(struct net_device *dev)
1da177e4 LT	246	{
	247	hdlc_device *hdlc = dev_to_hdlc(dev);
	248
b5284e5a	249	hdlc_setup_dev(dev);
1da177e4 LT	250	hdlc->carrier = 1;
	251	hdlc->open = 0;
	252	spin_lock_init(&hdlc->state_lock);
	253	}
	254
	255	struct net_device alloc_hdlcdev(void priv)
	256	{
	257	struct net_device *dev;
eb2a2fd9 KH	258	dev = alloc_netdev(sizeof(struct hdlc_device_desc) +
eb2a2fd9 KH	259	sizeof(hdlc_device), "hdlc%d", hdlc_setup);
1da177e4 LT	260	if (dev)
	261	dev_to_hdlc(dev)->priv = priv;
	262	return dev;
	263	}
	264
1da177e4 LT	265	void unregister_hdlc_device(struct net_device *dev)
	266	{
	267	rtnl_lock();
1da177e4	268	unregister_netdevice(dev);
eb2a2fd9	269	detach_hdlc_protocol(dev);
1da177e4 LT	270	rtnl_unlock();
	271	}
	272
	273
	274
eb2a2fd9 KH	275	int 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
	297	void 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;
b5284e5a	309	hdlc_setup_dev(dev);
eb2a2fd9 KH	310	}
	311
	312
	313	void register_hdlc_protocol(struct hdlc_proto *proto)
	314	{
	315	proto->next = first_proto;
	316	first_proto = proto;
	317	}
	318
	319
	320	void 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
1da177e4 LT	334	MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
	335	MODULE_DESCRIPTION("HDLC support module");
	336	MODULE_LICENSE("GPL v2");
	337
	338	EXPORT_SYMBOL(hdlc_open);
	339	EXPORT_SYMBOL(hdlc_close);
1da177e4 LT	340	EXPORT_SYMBOL(hdlc_ioctl);
1da177e4 LT	341	EXPORT_SYMBOL(alloc_hdlcdev);
1da177e4	342	EXPORT_SYMBOL(unregister_hdlc_device);
eb2a2fd9 KH	343	EXPORT_SYMBOL(register_hdlc_protocol);
	344	EXPORT_SYMBOL(unregister_hdlc_protocol);
	345	EXPORT_SYMBOL(attach_hdlc_protocol);
	346	EXPORT_SYMBOL(detach_hdlc_protocol);
1da177e4 LT	347
	348	static struct packet_type hdlc_packet_type = {
	349	.type = __constant_htons(ETH_P_HDLC),
	350	.func = hdlc_rcv,
	351	};
	352
	353
c2ce9204 KH	354	static struct notifier_block hdlc_notifier = {
	355	.notifier_call = hdlc_device_event,
	356	};
	357
	358
1da177e4 LT	359	static int __init hdlc_module_init(void)
1da177e4 LT	360	{
c2ce9204 KH	361	int result;
c2ce9204 KH	362
1da177e4	363	printk(KERN_INFO "%s\n", version);
c2ce9204 KH	364	if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
c2ce9204 KH	365	return result;
1da177e4 LT	366	dev_add_pack(&hdlc_packet_type);
	367	return 0;
	368	}
	369
	370
	371
	372	static void __exit hdlc_module_exit(void)
	373	{
	374	dev_remove_pack(&hdlc_packet_type);
c2ce9204	375	unregister_netdevice_notifier(&hdlc_notifier);
1da177e4 LT	376	}
	377
	378
	379	module_init(hdlc_module_init);
	380	module_exit(hdlc_module_exit);