[net-next-2.6.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/errno.h>
#include <linux/hdlc.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/pkt_sched.h>
#include <linux/poll.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/slab.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;

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 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 (!net_eq(dev_net(dev), &init_net)) {
		kfree_skb(skb);
		return 0;
	}

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

netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);

	if (hdlc->proto->xmit)
		return hdlc->proto->xmit(skb, dev);

	return hdlc->xmit(skb, dev); /* call hardware driver directly */
}

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 (!net_eq(dev_net(dev), &init_net))
		return NOTIFY_DONE;

	if (!(dev->priv_flags & IFF_WAN_HDLC))
		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->flags		 = IFF_POINTOPOINT | IFF_NOARP;
	dev->priv_flags		 = IFF_WAN_HDLC;
	dev->mtu		 = HDLC_MAX_MTU;
	dev->type		 = ARPHRD_RAWHDLC;
	dev->hard_header_len	 = 16;
	dev->addr_len		 = 0;
	dev->header_ops		 = &hdlc_null_ops;
}

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)
{
	rtnl_lock();
	proto->next = first_proto;
	first_proto = proto;
	rtnl_unlock();
}


void unregister_hdlc_protocol(struct hdlc_proto *proto)
{
	struct hdlc_proto **p;

	rtnl_lock();
	p = &first_proto;
	while (*p != proto) {
		BUG_ON(!*p);
		p = &((*p)->next);
	}
	*p = proto->next;
	rtnl_unlock();
}


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

EXPORT_SYMBOL(hdlc_change_mtu);
EXPORT_SYMBOL(hdlc_start_xmit);
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 __read_mostly = {
	.type = cpu_to_be16(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	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>
4dfce407 KH	37	#include <linux/slab.h>
e730c155	38	#include <net/net_namespace.h>
1da177e4 LT	39
1da177e4 LT	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
09ad9bc7	60	if (!net_eq(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);
40d25142 KH	66	return hdlc->proto->netif_rx(skb);
1da177e4 LT	67	}
1da177e4 LT	68
d71a6749	69	netdev_tx_t hdlc_start_xmit(struct sk_buff skb, struct net_device dev)
991990a1 KH	70	{
991990a1 KH	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	{
1da177e4 LT	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	{
1da177e4 LT	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,
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	103	int on;
dff3fde7	104
09ad9bc7	105	if (!net_eq(dev_net(dev), &init_net))
e9dc8653 EB	106	return NOTIFY_DONE;
e9dc8653 EB	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
1da177e4 LT	116	#ifdef DEBUG_LINK
c2ce9204 KH	117	printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
c2ce9204 KH	118	dev->name, on);
1da177e4 LT	119	#endif
1da177e4 LT	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) {
b3dd65f9 KH	133	printk(KERN_INFO "%s: Carrier detected\n", dev->name);
c2ce9204	134	hdlc_proto_start(dev);
b3dd65f9 KH	135	} else {
b3dd65f9 KH	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 */
1da177e4 LT	158
eb2a2fd9 KH	159	if (hdlc->proto->open) {
eb2a2fd9 KH	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) {
b3dd65f9 KH	168	printk(KERN_INFO "%s: Carrier detected\n", dev->name);
c2ce9204	169	hdlc_proto_start(dev);
b3dd65f9 KH	170	} else
b3dd65f9 KH	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)
eb2a2fd9 KH	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)
1da177e4 LT	205	{
eb2a2fd9 KH	206	struct hdlc_proto *proto = first_proto;
eb2a2fd9 KH	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	}
1da177e4 LT	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	}
1da177e4 LT	227
3b04ddde SH	228	static const struct header_ops hdlc_null_ops;
3b04ddde SH	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	}
b5284e5a KH	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;
eb2a2fd9 KH	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);
eb2a2fd9 KH	328	}
fa701bd2 KH	329	*p = proto->next;
fa701bd2 KH	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);
991990a1 KH	340	EXPORT_SYMBOL(hdlc_start_xmit);
1da177e4 LT	341	EXPORT_SYMBOL(hdlc_open);
1da177e4 LT	342	EXPORT_SYMBOL(hdlc_close);
1da177e4 LT	343	EXPORT_SYMBOL(hdlc_ioctl);
1da177e4 LT	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)
1da177e4 LT	363	{
c2ce9204 KH	364	int result;
c2ce9204 KH	365
1da177e4	366	printk(KERN_INFO "%s\n", version);
c2ce9204	367	if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
4dfce407 KH	368	return result;
4dfce407 KH	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);