[linux-2.6-block.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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 interested 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) {
		netdev_info(dev, "Carrier detected\n");
		hdlc_proto_start(dev);
	} else {
		netdev_info(dev, "Carrier lost\n");
		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) {
		netdev_info(dev, "Carrier detected\n");
		hdlc_proto_start(dev);
	} else
		netdev_info(dev, "No carrier\n");

	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) {
		dev_to_hdlc(dev)->state = kmalloc(size, GFP_KERNEL);
		if (dev_to_hdlc(dev)->state == NULL) {
			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;

	pr_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
12a3bfef JP	25	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12a3bfef JP	26
1da177e4	27	#include <linux/errno.h>
4dfce407	28	#include <linux/hdlc.h>
1da177e4	29	#include <linux/if_arp.h>
4dfce407	30	#include <linux/inetdevice.h>
1da177e4	31	#include <linux/init.h>
4dfce407 KH	32	#include <linux/kernel.h>
	33	#include <linux/module.h>
	34	#include <linux/notifier.h>
1da177e4	35	#include <linux/pkt_sched.h>
4dfce407	36	#include <linux/poll.h>
1da177e4	37	#include <linux/rtnetlink.h>
4dfce407 KH	38	#include <linux/skbuff.h>
4dfce407 KH	39	#include <linux/slab.h>
e730c155	40	#include <net/net_namespace.h>
1da177e4 LT	41
1da177e4 LT	42
40d25142	43	static const char* version = "HDLC support module revision 1.22";
1da177e4 LT	44
	45	#undef DEBUG_LINK
	46
fa701bd2	47	static struct hdlc_proto *first_proto;
1da177e4	48
991990a1	49	int hdlc_change_mtu(struct net_device *dev, int new_mtu)
1da177e4 LT	50	{
	51	if ((new_mtu < 68) \|\| (new_mtu > HDLC_MAX_MTU))
	52	return -EINVAL;
	53	dev->mtu = new_mtu;
	54	return 0;
	55	}
	56
1da177e4	57	static int hdlc_rcv(struct sk_buff skb, struct net_device dev,
f2ccd8fa	58	struct packet_type p, struct net_device orig_dev)
1da177e4	59	{
40d25142	60	struct hdlc_device *hdlc = dev_to_hdlc(dev);
e730c155	61
09ad9bc7	62	if (!net_eq(dev_net(dev), &init_net)) {
e730c155 EB	63	kfree_skb(skb);
	64	return 0;
	65	}
	66
40d25142 KH	67	BUG_ON(!hdlc->proto->netif_rx);
40d25142 KH	68	return hdlc->proto->netif_rx(skb);
1da177e4 LT	69	}
1da177e4 LT	70
d71a6749	71	netdev_tx_t hdlc_start_xmit(struct sk_buff skb, struct net_device dev)
991990a1 KH	72	{
991990a1 KH	73	hdlc_device *hdlc = dev_to_hdlc(dev);
1da177e4	74
991990a1 KH	75	if (hdlc->proto->xmit)
	76	return hdlc->proto->xmit(skb, dev);
	77
	78	return hdlc->xmit(skb, dev); /* call hardware driver directly */
	79	}
1da177e4	80
c2ce9204	81	static inline void hdlc_proto_start(struct net_device *dev)
1da177e4 LT	82	{
1da177e4 LT	83	hdlc_device *hdlc = dev_to_hdlc(dev);
eb2a2fd9	84	if (hdlc->proto->start)
40d25142	85	hdlc->proto->start(dev);
1da177e4 LT	86	}
	87
	88
	89
c2ce9204	90	static inline void hdlc_proto_stop(struct net_device *dev)
1da177e4 LT	91	{
1da177e4 LT	92	hdlc_device *hdlc = dev_to_hdlc(dev);
eb2a2fd9	93	if (hdlc->proto->stop)
40d25142	94	hdlc->proto->stop(dev);
1da177e4 LT	95	}
	96
	97
	98
c2ce9204 KH	99	static int hdlc_device_event(struct notifier_block *this, unsigned long event,
c2ce9204 KH	100	void *ptr)
1da177e4	101	{
c2ce9204 KH	102	struct net_device *dev = ptr;
c2ce9204 KH	103	hdlc_device *hdlc;
1da177e4	104	unsigned long flags;
c2ce9204	105	int on;
dff3fde7	106
09ad9bc7	107	if (!net_eq(dev_net(dev), &init_net))
e9dc8653 EB	108	return NOTIFY_DONE;
e9dc8653 EB	109
7cdc15f5	110	if (!(dev->priv_flags & IFF_WAN_HDLC))
c2ce9204	111	return NOTIFY_DONE; /* not an HDLC device */
4dfce407	112
c2ce9204	113	if (event != NETDEV_CHANGE)
6f0b31c3	114	return NOTIFY_DONE; /* Only interested in carrier changes */
c2ce9204 KH	115
c2ce9204 KH	116	on = netif_carrier_ok(dev);
1da177e4 LT	117
1da177e4 LT	118	#ifdef DEBUG_LINK
c2ce9204 KH	119	printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
c2ce9204 KH	120	dev->name, on);
1da177e4 LT	121	#endif
1da177e4 LT	122
c2ce9204	123	hdlc = dev_to_hdlc(dev);
1da177e4 LT	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
1da177e4 LT	129	hdlc->carrier = on;
	130
	131	if (!hdlc->open)
	132	goto carrier_exit;
	133
b3dd65f9	134	if (hdlc->carrier) {
12a3bfef	135	netdev_info(dev, "Carrier detected\n");
c2ce9204	136	hdlc_proto_start(dev);
b3dd65f9	137	} else {
12a3bfef	138	netdev_info(dev, "Carrier lost\n");
c2ce9204	139	hdlc_proto_stop(dev);
b3dd65f9	140	}
1da177e4 LT	141
	142	carrier_exit:
	143	spin_unlock_irqrestore(&hdlc->state_lock, flags);
c2ce9204	144	return NOTIFY_DONE;
1da177e4 LT	145	}
	146
	147
	148
	149	/* Must be called by hardware driver when HDLC device is being opened */
	150	int hdlc_open(struct net_device *dev)
	151	{
	152	hdlc_device *hdlc = dev_to_hdlc(dev);
	153	#ifdef DEBUG_LINK
eb2a2fd9	154	printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name,
1da177e4 LT	155	hdlc->carrier, hdlc->open);
	156	#endif
	157
eb2a2fd9	158	if (hdlc->proto == NULL)
1da177e4 LT	159	return -ENOSYS; /* no protocol attached */
1da177e4 LT	160
eb2a2fd9 KH	161	if (hdlc->proto->open) {
eb2a2fd9 KH	162	int result = hdlc->proto->open(dev);
1da177e4 LT	163	if (result)
	164	return result;
	165	}
	166
	167	spin_lock_irq(&hdlc->state_lock);
	168
b3dd65f9	169	if (hdlc->carrier) {
12a3bfef	170	netdev_info(dev, "Carrier detected\n");
c2ce9204	171	hdlc_proto_start(dev);
b3dd65f9	172	} else
12a3bfef	173	netdev_info(dev, "No carrier\n");
1da177e4 LT	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 */
	184	void hdlc_close(struct net_device *dev)
	185	{
	186	hdlc_device *hdlc = dev_to_hdlc(dev);
	187	#ifdef DEBUG_LINK
eb2a2fd9	188	printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name,
1da177e4 LT	189	hdlc->carrier, hdlc->open);
	190	#endif
	191
	192	spin_lock_irq(&hdlc->state_lock);
	193
	194	hdlc->open = 0;
	195	if (hdlc->carrier)
c2ce9204	196	hdlc_proto_stop(dev);
1da177e4 LT	197
	198	spin_unlock_irq(&hdlc->state_lock);
	199
eb2a2fd9 KH	200	if (hdlc->proto->close)
eb2a2fd9 KH	201	hdlc->proto->close(dev);
1da177e4 LT	202	}
	203
	204
	205
1da177e4 LT	206	int hdlc_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
1da177e4 LT	207	{
eb2a2fd9 KH	208	struct hdlc_proto *proto = first_proto;
eb2a2fd9 KH	209	int result;
1da177e4 LT	210
	211	if (cmd != SIOCWANDEV)
	212	return -EINVAL;
	213
eb2a2fd9 KH	214	if (dev_to_hdlc(dev)->proto) {
	215	result = dev_to_hdlc(dev)->proto->ioctl(dev, ifr);
	216	if (result != -EINVAL)
	217	return result;
1da177e4 LT	218	}
1da177e4 LT	219
eb2a2fd9 KH	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;
1da177e4	226	}
eb2a2fd9	227	return -EINVAL;
1da177e4 LT	228	}
1da177e4 LT	229
3b04ddde SH	230	static const struct header_ops hdlc_null_ops;
3b04ddde SH	231
b5284e5a KH	232	static 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	*/
b5284e5a	237	dev->flags = IFF_POINTOPOINT \| IFF_NOARP;
7cdc15f5	238	dev->priv_flags = IFF_WAN_HDLC;
b5284e5a KH	239	dev->mtu = HDLC_MAX_MTU;
	240	dev->type = ARPHRD_RAWHDLC;
	241	dev->hard_header_len = 16;
	242	dev->addr_len = 0;
3b04ddde	243	dev->header_ops = &hdlc_null_ops;
b5284e5a KH	244	}
b5284e5a KH	245
0bf94faf	246	static void hdlc_setup(struct net_device *dev)
1da177e4 LT	247	{
	248	hdlc_device *hdlc = dev_to_hdlc(dev);
	249
b5284e5a	250	hdlc_setup_dev(dev);
1da177e4 LT	251	hdlc->carrier = 1;
	252	hdlc->open = 0;
	253	spin_lock_init(&hdlc->state_lock);
	254	}
	255
	256	struct net_device alloc_hdlcdev(void priv)
	257	{
	258	struct net_device *dev;
40d25142	259	dev = alloc_netdev(sizeof(struct 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	275	int attach_hdlc_protocol(struct net_device dev, struct hdlc_proto proto,
40d25142	276	size_t size)
eb2a2fd9 KH	277	{
	278	detach_hdlc_protocol(dev);
	279
	280	if (!try_module_get(proto->module))
	281	return -ENOSYS;
	282
1d5d1fdc JP	283	if (size) {
	284	dev_to_hdlc(dev)->state = kmalloc(size, GFP_KERNEL);
	285	if (dev_to_hdlc(dev)->state == NULL) {
eb2a2fd9 KH	286	module_put(proto->module);
	287	return -ENOBUFS;
	288	}
1d5d1fdc	289	}
eb2a2fd9	290	dev_to_hdlc(dev)->proto = proto;
eb2a2fd9 KH	291	return 0;
	292	}
	293
	294
	295	void 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;
b5284e5a	307	hdlc_setup_dev(dev);
eb2a2fd9 KH	308	}
	309
	310
	311	void register_hdlc_protocol(struct hdlc_proto *proto)
	312	{
fa701bd2	313	rtnl_lock();
eb2a2fd9 KH	314	proto->next = first_proto;
eb2a2fd9 KH	315	first_proto = proto;
fa701bd2	316	rtnl_unlock();
eb2a2fd9 KH	317	}
	318
	319
	320	void unregister_hdlc_protocol(struct hdlc_proto *proto)
	321	{
fa701bd2 KH	322	struct hdlc_proto **p;
	323
	324	rtnl_lock();
	325	p = &first_proto;
	326	while (*p != proto) {
	327	BUG_ON(!*p);
eb2a2fd9 KH	328	p = &((*p)->next);
eb2a2fd9 KH	329	}
fa701bd2 KH	330	*p = proto->next;
fa701bd2 KH	331	rtnl_unlock();
eb2a2fd9 KH	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
991990a1 KH	340	EXPORT_SYMBOL(hdlc_change_mtu);
991990a1 KH	341	EXPORT_SYMBOL(hdlc_start_xmit);
1da177e4 LT	342	EXPORT_SYMBOL(hdlc_open);
1da177e4 LT	343	EXPORT_SYMBOL(hdlc_close);
1da177e4 LT	344	EXPORT_SYMBOL(hdlc_ioctl);
1da177e4 LT	345	EXPORT_SYMBOL(alloc_hdlcdev);
1da177e4	346	EXPORT_SYMBOL(unregister_hdlc_device);
eb2a2fd9 KH	347	EXPORT_SYMBOL(register_hdlc_protocol);
	348	EXPORT_SYMBOL(unregister_hdlc_protocol);
	349	EXPORT_SYMBOL(attach_hdlc_protocol);
	350	EXPORT_SYMBOL(detach_hdlc_protocol);
1da177e4	351
7546dd97	352	static struct packet_type hdlc_packet_type __read_mostly = {
09640e63	353	.type = cpu_to_be16(ETH_P_HDLC),
1da177e4 LT	354	.func = hdlc_rcv,
	355	};
	356
	357
c2ce9204	358	static struct notifier_block hdlc_notifier = {
4dfce407	359	.notifier_call = hdlc_device_event,
c2ce9204 KH	360	};
	361
	362
1da177e4 LT	363	static int __init hdlc_module_init(void)
1da177e4 LT	364	{
c2ce9204 KH	365	int result;
c2ce9204 KH	366
12a3bfef	367	pr_info("%s\n", version);
c2ce9204	368	if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
4dfce407 KH	369	return result;
4dfce407 KH	370	dev_add_pack(&hdlc_packet_type);
1da177e4 LT	371	return 0;
	372	}
	373
	374
	375
	376	static void __exit hdlc_module_exit(void)
	377	{
	378	dev_remove_pack(&hdlc_packet_type);
c2ce9204	379	unregister_netdevice_notifier(&hdlc_notifier);
1da177e4 LT	380	}
	381
	382
	383	module_init(hdlc_module_init);
	384	module_exit(hdlc_module_exit);