drivers/net/wan/hdlc_cisco.c - android_kernel_htc_msm8960 - Gitiles

 /*
  * Generic HDLC support routines for Linux
  * Cisco HDLC support
  *
  * Copyright (C) 2000 - 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.
  */

 #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/pkt_sched.h>
 #include <linux/poll.h>
 #include <linux/rtnetlink.h>
 #include <linux/skbuff.h>

 #undef DEBUG_HARD_HEADER

 #define CISCO_MULTICAST		0x8F	/* Cisco multicast address */
 #define CISCO_UNICAST		0x0F	/* Cisco unicast address */
 #define CISCO_KEEPALIVE		0x8035	/* Cisco keepalive protocol */
 #define CISCO_SYS_INFO		0x2000	/* Cisco interface/system info */
 #define CISCO_ADDR_REQ		0	/* Cisco address request */
 #define CISCO_ADDR_REPLY	1	/* Cisco address reply */
 #define CISCO_KEEPALIVE_REQ	2	/* Cisco keepalive request */


 struct hdlc_header {
 	u8 address;
 	u8 control;
 	__be16 protocol;
 }__packed;


 struct cisco_packet {
 	__be32 type;		/* code */
 	__be32 par1;
 	__be32 par2;
 	__be16 rel;		/* reliability */
 	__be32 time;
 }__packed;
 #define	CISCO_PACKET_LEN	18
 #define	CISCO_BIG_PACKET_LEN	20


 struct cisco_state {
 	cisco_proto settings;

 	struct timer_list timer;
 	spinlock_t lock;
 	unsigned long last_poll;
 	int up;
 	u32 txseq; /* TX sequence number, 0 = none */
 	u32 rxseq; /* RX sequence number */
 };


 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr);


 static inline struct cisco_state* state(hdlc_device *hdlc)
 {
 	return (struct cisco_state *)hdlc->state;
 }


 static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,
 			     u16 type, const void *daddr, const void *saddr,
 			     unsigned int len)
 {
 	struct hdlc_header *data;
 #ifdef DEBUG_HARD_HEADER
 	printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);
 #endif

 	skb_push(skb, sizeof(struct hdlc_header));
 	data = (struct hdlc_header*)skb->data;
 	if (type == CISCO_KEEPALIVE)
 		data->address = CISCO_MULTICAST;
 	else
 		data->address = CISCO_UNICAST;
 	data->control = 0;
 	data->protocol = htons(type);

 	return sizeof(struct hdlc_header);
 }


 static void cisco_keepalive_send(struct net_device *dev, u32 type,
 				 __be32 par1, __be32 par2)
 {
 	struct sk_buff *skb;
 	struct cisco_packet *data;

 	skb = dev_alloc_skb(sizeof(struct hdlc_header) +
 			    sizeof(struct cisco_packet));
 	if (!skb) {
 		printk(KERN_WARNING
 		       "%s: Memory squeeze on cisco_keepalive_send()\n",
 		       dev->name);
 		return;
 	}
 	skb_reserve(skb, 4);
 	cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
 	data = (struct cisco_packet*)(skb->data + 4);

 	data->type = htonl(type);
 	data->par1 = par1;
 	data->par2 = par2;
 	data->rel = cpu_to_be16(0xFFFF);
 	/* we will need do_div here if 1000 % HZ != 0 */
 	data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));

 	skb_put(skb, sizeof(struct cisco_packet));
 	skb->priority = TC_PRIO_CONTROL;
 	skb->dev = dev;
 	skb_reset_network_header(skb);

 	dev_queue_xmit(skb);
 }


 static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev)
 {
 	struct hdlc_header *data = (struct hdlc_header*)skb->data;

 	if (skb->len < sizeof(struct hdlc_header))
 		return cpu_to_be16(ETH_P_HDLC);

 	if (data->address != CISCO_MULTICAST &&
 	    data->address != CISCO_UNICAST)
 		return cpu_to_be16(ETH_P_HDLC);

 	switch (data->protocol) {
 	case cpu_to_be16(ETH_P_IP):
 	case cpu_to_be16(ETH_P_IPX):
 	case cpu_to_be16(ETH_P_IPV6):
 		skb_pull(skb, sizeof(struct hdlc_header));
 		return data->protocol;
 	default:
 		return cpu_to_be16(ETH_P_HDLC);
 	}
 }


 static int cisco_rx(struct sk_buff *skb)
 {
 	struct net_device *dev = skb->dev;
 	hdlc_device *hdlc = dev_to_hdlc(dev);
 	struct cisco_state *st = state(hdlc);
 	struct hdlc_header *data = (struct hdlc_header*)skb->data;
 	struct cisco_packet *cisco_data;
 	struct in_device *in_dev;
 	__be32 addr, mask;
 	u32 ack;

 	if (skb->len < sizeof(struct hdlc_header))
 		goto rx_error;

 	if (data->address != CISCO_MULTICAST &&
 	    data->address != CISCO_UNICAST)
 		goto rx_error;

 	switch (ntohs(data->protocol)) {
 	case CISCO_SYS_INFO:
 		/* Packet is not needed, drop it. */
 		dev_kfree_skb_any(skb);
 		return NET_RX_SUCCESS;

 	case CISCO_KEEPALIVE:
 		if ((skb->len != sizeof(struct hdlc_header) +
 		     CISCO_PACKET_LEN) &&
 		    (skb->len != sizeof(struct hdlc_header) +
 		     CISCO_BIG_PACKET_LEN)) {
 			printk(KERN_INFO "%s: Invalid length of Cisco control"
 			       " packet (%d bytes)\n", dev->name, skb->len);
 			goto rx_error;
 		}

 		cisco_data = (struct cisco_packet*)(skb->data + sizeof
 						    (struct hdlc_header));

 		switch (ntohl (cisco_data->type)) {
 		case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
 			rcu_read_lock();
 			in_dev = __in_dev_get_rcu(dev);
 			addr = 0;
 			mask = ~cpu_to_be32(0); /* is the mask correct? */

 			if (in_dev != NULL) {
 				struct in_ifaddr **ifap = &in_dev->ifa_list;

 				while (*ifap != NULL) {
 					if (strcmp(dev->name,
 						   (*ifap)->ifa_label) == 0) {
 						addr = (*ifap)->ifa_local;
 						mask = (*ifap)->ifa_mask;
 						break;
 					}
 					ifap = &(*ifap)->ifa_next;
 				}

 				cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
 						     addr, mask);
 			}
 			rcu_read_unlock();
 			dev_kfree_skb_any(skb);
 			return NET_RX_SUCCESS;

 		case CISCO_ADDR_REPLY:
 			printk(KERN_INFO "%s: Unexpected Cisco IP address "
 			       "reply\n", dev->name);
 			goto rx_error;

 		case CISCO_KEEPALIVE_REQ:
 			spin_lock(&st->lock);
 			st->rxseq = ntohl(cisco_data->par1);
 			ack = ntohl(cisco_data->par2);
 			if (ack && (ack == st->txseq ||
 				    /* our current REQ may be in transit */
 				    ack == st->txseq - 1)) {
 				st->last_poll = jiffies;
 				if (!st->up) {
 					u32 sec, min, hrs, days;
 					sec = ntohl(cisco_data->time) / 1000;
 					min = sec / 60; sec -= min * 60;
 					hrs = min / 60; min -= hrs * 60;
 					days = hrs / 24; hrs -= days * 24;
 					printk(KERN_INFO "%s: Link up (peer "
 					       "uptime %ud%uh%um%us)\n",
 					       dev->name, days, hrs, min, sec);
 					netif_dormant_off(dev);
 					st->up = 1;
 				}
 			}
 			spin_unlock(&st->lock);

 			dev_kfree_skb_any(skb);
 			return NET_RX_SUCCESS;
 		} /* switch (keepalive type) */
 	} /* switch (protocol) */

 	printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name,
 	       ntohs(data->protocol));
 	dev_kfree_skb_any(skb);
 	return NET_RX_DROP;

 rx_error:
 	dev->stats.rx_errors++; /* Mark error */
 	dev_kfree_skb_any(skb);
 	return NET_RX_DROP;
 }


 static void cisco_timer(unsigned long arg)
 {
 	struct net_device *dev = (struct net_device *)arg;
 	hdlc_device *hdlc = dev_to_hdlc(dev);
 	struct cisco_state *st = state(hdlc);

 	spin_lock(&st->lock);
 	if (st->up &&
 	    time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) {
 		st->up = 0;
 		printk(KERN_INFO "%s: Link down\n", dev->name);
 		netif_dormant_on(dev);
 	}

 	cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq),
 			     htonl(st->rxseq));
 	spin_unlock(&st->lock);

 	st->timer.expires = jiffies + st->settings.interval * HZ;
 	st->timer.function = cisco_timer;
 	st->timer.data = arg;
 	add_timer(&st->timer);
 }


 static void cisco_start(struct net_device *dev)
 {
 	hdlc_device *hdlc = dev_to_hdlc(dev);
 	struct cisco_state *st = state(hdlc);
 	unsigned long flags;

 	spin_lock_irqsave(&st->lock, flags);
 	st->up = st->txseq = st->rxseq = 0;
 	spin_unlock_irqrestore(&st->lock, flags);

 	init_timer(&st->timer);
 	st->timer.expires = jiffies + HZ; /* First poll after 1 s */
 	st->timer.function = cisco_timer;
 	st->timer.data = (unsigned long)dev;
 	add_timer(&st->timer);
 }


 static void cisco_stop(struct net_device *dev)
 {
 	hdlc_device *hdlc = dev_to_hdlc(dev);
 	struct cisco_state *st = state(hdlc);
 	unsigned long flags;

 	del_timer_sync(&st->timer);

 	spin_lock_irqsave(&st->lock, flags);
 	netif_dormant_on(dev);
 	st->up = st->txseq = 0;
 	spin_unlock_irqrestore(&st->lock, flags);
 }


 static struct hdlc_proto proto = {
 	.start		= cisco_start,
 	.stop		= cisco_stop,
 	.type_trans	= cisco_type_trans,
 	.ioctl		= cisco_ioctl,
 	.netif_rx	= cisco_rx,
 	.module		= THIS_MODULE,
 };

 static const struct header_ops cisco_header_ops = {
 	.create = cisco_hard_header,
 };

 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
 {
 	cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
 	const size_t size = sizeof(cisco_proto);
 	cisco_proto new_settings;
 	hdlc_device *hdlc = dev_to_hdlc(dev);
 	int result;

 	switch (ifr->ifr_settings.type) {
 	case IF_GET_PROTO:
 		if (dev_to_hdlc(dev)->proto != &proto)
 			return -EINVAL;
 		ifr->ifr_settings.type = IF_PROTO_CISCO;
 		if (ifr->ifr_settings.size < size) {
 			ifr->ifr_settings.size = size; /* data size wanted */
 			return -ENOBUFS;
 		}
 		if (copy_to_user(cisco_s, &state(hdlc)->settings, size))
 			return -EFAULT;
 		return 0;

 	case IF_PROTO_CISCO:
 		if (!capable(CAP_NET_ADMIN))
 			return -EPERM;

 		if (dev->flags & IFF_UP)
 			return -EBUSY;

 		if (copy_from_user(&new_settings, cisco_s, size))
 			return -EFAULT;

 		if (new_settings.interval < 1 ||
 		    new_settings.timeout < 2)
 			return -EINVAL;

 		result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
 		if (result)
 			return result;

 		result = attach_hdlc_protocol(dev, &proto,
 					      sizeof(struct cisco_state));
 		if (result)
 			return result;

 		memcpy(&state(hdlc)->settings, &new_settings, size);
 		spin_lock_init(&state(hdlc)->lock);
 		dev->header_ops = &cisco_header_ops;
 		dev->type = ARPHRD_CISCO;
 		netif_dormant_on(dev);
 		return 0;
 	}

 	return -EINVAL;
 }


 static int __init mod_init(void)
 {
 	register_hdlc_protocol(&proto);
 	return 0;
 }


 static void __exit mod_exit(void)
 {
 	unregister_hdlc_protocol(&proto);
 }


 module_init(mod_init);
 module_exit(mod_exit);

 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC");
 MODULE_LICENSE("GPL v2");
	/*
	* Generic HDLC support routines for Linux
	* Cisco HDLC support
	*
	* Copyright (C) 2000 - 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.
	*/

	#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/pkt_sched.h>
	#include <linux/poll.h>
	#include <linux/rtnetlink.h>
	#include <linux/skbuff.h>

	#undef DEBUG_HARD_HEADER

	#define CISCO_MULTICAST 0x8F /* Cisco multicast address */
	#define CISCO_UNICAST 0x0F /* Cisco unicast address */
	#define CISCO_KEEPALIVE 0x8035 /* Cisco keepalive protocol */
	#define CISCO_SYS_INFO 0x2000 /* Cisco interface/system info */
	#define CISCO_ADDR_REQ 0 /* Cisco address request */
	#define CISCO_ADDR_REPLY 1 /* Cisco address reply */
	#define CISCO_KEEPALIVE_REQ 2 /* Cisco keepalive request */


	struct hdlc_header {
	u8 address;
	u8 control;
	__be16 protocol;
	}__packed;


	struct cisco_packet {
	__be32 type; /* code */
	__be32 par1;
	__be32 par2;
	__be16 rel; /* reliability */
	__be32 time;
	}__packed;
	#define CISCO_PACKET_LEN 18
	#define CISCO_BIG_PACKET_LEN 20


	struct cisco_state {
	cisco_proto settings;

	struct timer_list timer;
	spinlock_t lock;
	unsigned long last_poll;
	int up;
	u32 txseq; /* TX sequence number, 0 = none */
	u32 rxseq; /* RX sequence number */
	};


	static int cisco_ioctl(struct net_device dev, struct ifreq ifr);


	static inline struct cisco_state* state(hdlc_device *hdlc)
	{
	return (struct cisco_state *)hdlc->state;
	}


	static int cisco_hard_header(struct sk_buff skb, struct net_device dev,
	u16 type, const void daddr, const void saddr,
	unsigned int len)
	{
	struct hdlc_header *data;
	#ifdef DEBUG_HARD_HEADER
	printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);
	#endif

	skb_push(skb, sizeof(struct hdlc_header));
	data = (struct hdlc_header*)skb->data;
	if (type == CISCO_KEEPALIVE)
	data->address = CISCO_MULTICAST;
	else
	data->address = CISCO_UNICAST;
	data->control = 0;
	data->protocol = htons(type);

	return sizeof(struct hdlc_header);
	}



	static void cisco_keepalive_send(struct net_device *dev, u32 type,
	__be32 par1, __be32 par2)
	{
	struct sk_buff *skb;
	struct cisco_packet *data;

	skb = dev_alloc_skb(sizeof(struct hdlc_header) +
	sizeof(struct cisco_packet));
	if (!skb) {
	printk(KERN_WARNING
	"%s: Memory squeeze on cisco_keepalive_send()\n",
	dev->name);
	return;
	}
	skb_reserve(skb, 4);
	cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
	data = (struct cisco_packet*)(skb->data + 4);

	data->type = htonl(type);
	data->par1 = par1;
	data->par2 = par2;
	data->rel = cpu_to_be16(0xFFFF);
	/* we will need do_div here if 1000 % HZ != 0 */
	data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));

	skb_put(skb, sizeof(struct cisco_packet));
	skb->priority = TC_PRIO_CONTROL;
	skb->dev = dev;
	skb_reset_network_header(skb);

	dev_queue_xmit(skb);
	}



	static __be16 cisco_type_trans(struct sk_buff skb, struct net_device dev)
	{
	struct hdlc_header data = (struct hdlc_header)skb->data;

	if (skb->len < sizeof(struct hdlc_header))
	return cpu_to_be16(ETH_P_HDLC);

	if (data->address != CISCO_MULTICAST &&
	data->address != CISCO_UNICAST)
	return cpu_to_be16(ETH_P_HDLC);

	switch (data->protocol) {
	case cpu_to_be16(ETH_P_IP):
	case cpu_to_be16(ETH_P_IPX):
	case cpu_to_be16(ETH_P_IPV6):
	skb_pull(skb, sizeof(struct hdlc_header));
	return data->protocol;
	default:
	return cpu_to_be16(ETH_P_HDLC);
	}
	}


	static int cisco_rx(struct sk_buff *skb)
	{
	struct net_device *dev = skb->dev;
	hdlc_device *hdlc = dev_to_hdlc(dev);
	struct cisco_state *st = state(hdlc);
	struct hdlc_header data = (struct hdlc_header)skb->data;
	struct cisco_packet *cisco_data;
	struct in_device *in_dev;
	__be32 addr, mask;
	u32 ack;

	if (skb->len < sizeof(struct hdlc_header))
	goto rx_error;

	if (data->address != CISCO_MULTICAST &&
	data->address != CISCO_UNICAST)
	goto rx_error;

	switch (ntohs(data->protocol)) {
	case CISCO_SYS_INFO:
	/* Packet is not needed, drop it. */
	dev_kfree_skb_any(skb);
	return NET_RX_SUCCESS;

	case CISCO_KEEPALIVE:
	if ((skb->len != sizeof(struct hdlc_header) +
	CISCO_PACKET_LEN) &&
	(skb->len != sizeof(struct hdlc_header) +
	CISCO_BIG_PACKET_LEN)) {
	printk(KERN_INFO "%s: Invalid length of Cisco control"
	" packet (%d bytes)\n", dev->name, skb->len);
	goto rx_error;
	}

	cisco_data = (struct cisco_packet*)(skb->data + sizeof
	(struct hdlc_header));

	switch (ntohl (cisco_data->type)) {
	case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
	rcu_read_lock();
	in_dev = __in_dev_get_rcu(dev);
	addr = 0;
	mask = ~cpu_to_be32(0); /* is the mask correct? */

	if (in_dev != NULL) {
	struct in_ifaddr **ifap = &in_dev->ifa_list;

	while (*ifap != NULL) {
	if (strcmp(dev->name,
	(*ifap)->ifa_label) == 0) {
	addr = (*ifap)->ifa_local;
	mask = (*ifap)->ifa_mask;
	break;
	}
	ifap = &(*ifap)->ifa_next;
	}

	cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
	addr, mask);
	}
	rcu_read_unlock();
	dev_kfree_skb_any(skb);
	return NET_RX_SUCCESS;

	case CISCO_ADDR_REPLY:
	printk(KERN_INFO "%s: Unexpected Cisco IP address "
	"reply\n", dev->name);
	goto rx_error;

	case CISCO_KEEPALIVE_REQ:
	spin_lock(&st->lock);
	st->rxseq = ntohl(cisco_data->par1);
	ack = ntohl(cisco_data->par2);
	if (ack && (ack == st->txseq \|\|
	/* our current REQ may be in transit */
	ack == st->txseq - 1)) {
	st->last_poll = jiffies;
	if (!st->up) {
	u32 sec, min, hrs, days;
	sec = ntohl(cisco_data->time) / 1000;
	min = sec / 60; sec -= min * 60;
	hrs = min / 60; min -= hrs * 60;
	days = hrs / 24; hrs -= days * 24;
	printk(KERN_INFO "%s: Link up (peer "
	"uptime %ud%uh%um%us)\n",
	dev->name, days, hrs, min, sec);
	netif_dormant_off(dev);
	st->up = 1;
	}
	}
	spin_unlock(&st->lock);

	dev_kfree_skb_any(skb);
	return NET_RX_SUCCESS;
	} /* switch (keepalive type) */
	} /* switch (protocol) */

	printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name,
	ntohs(data->protocol));
	dev_kfree_skb_any(skb);
	return NET_RX_DROP;

	rx_error:
	dev->stats.rx_errors++; /* Mark error */
	dev_kfree_skb_any(skb);
	return NET_RX_DROP;
	}



	static void cisco_timer(unsigned long arg)
	{
	struct net_device dev = (struct net_device )arg;
	hdlc_device *hdlc = dev_to_hdlc(dev);
	struct cisco_state *st = state(hdlc);

	spin_lock(&st->lock);
	if (st->up &&
	time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) {
	st->up = 0;
	printk(KERN_INFO "%s: Link down\n", dev->name);
	netif_dormant_on(dev);
	}

	cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq),
	htonl(st->rxseq));
	spin_unlock(&st->lock);

	st->timer.expires = jiffies + st->settings.interval * HZ;
	st->timer.function = cisco_timer;
	st->timer.data = arg;
	add_timer(&st->timer);
	}



	static void cisco_start(struct net_device *dev)
	{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	struct cisco_state *st = state(hdlc);
	unsigned long flags;

	spin_lock_irqsave(&st->lock, flags);
	st->up = st->txseq = st->rxseq = 0;
	spin_unlock_irqrestore(&st->lock, flags);

	init_timer(&st->timer);
	st->timer.expires = jiffies + HZ; /* First poll after 1 s */
	st->timer.function = cisco_timer;
	st->timer.data = (unsigned long)dev;
	add_timer(&st->timer);
	}



	static void cisco_stop(struct net_device *dev)
	{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	struct cisco_state *st = state(hdlc);
	unsigned long flags;

	del_timer_sync(&st->timer);

	spin_lock_irqsave(&st->lock, flags);
	netif_dormant_on(dev);
	st->up = st->txseq = 0;
	spin_unlock_irqrestore(&st->lock, flags);
	}


	static struct hdlc_proto proto = {
	.start = cisco_start,
	.stop = cisco_stop,
	.type_trans = cisco_type_trans,
	.ioctl = cisco_ioctl,
	.netif_rx = cisco_rx,
	.module = THIS_MODULE,
	};

	static const struct header_ops cisco_header_ops = {
	.create = cisco_hard_header,
	};

	static int cisco_ioctl(struct net_device dev, struct ifreq ifr)
	{
	cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
	const size_t size = sizeof(cisco_proto);
	cisco_proto new_settings;
	hdlc_device *hdlc = dev_to_hdlc(dev);
	int result;

	switch (ifr->ifr_settings.type) {
	case IF_GET_PROTO:
	if (dev_to_hdlc(dev)->proto != &proto)
	return -EINVAL;
	ifr->ifr_settings.type = IF_PROTO_CISCO;
	if (ifr->ifr_settings.size < size) {
	ifr->ifr_settings.size = size; /* data size wanted */
	return -ENOBUFS;
	}
	if (copy_to_user(cisco_s, &state(hdlc)->settings, size))
	return -EFAULT;
	return 0;

	case IF_PROTO_CISCO:
	if (!capable(CAP_NET_ADMIN))
	return -EPERM;

	if (dev->flags & IFF_UP)
	return -EBUSY;

	if (copy_from_user(&new_settings, cisco_s, size))
	return -EFAULT;

	if (new_settings.interval < 1 \|\|
	new_settings.timeout < 2)
	return -EINVAL;

	result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
	if (result)
	return result;

	result = attach_hdlc_protocol(dev, &proto,
	sizeof(struct cisco_state));
	if (result)
	return result;

	memcpy(&state(hdlc)->settings, &new_settings, size);
	spin_lock_init(&state(hdlc)->lock);
	dev->header_ops = &cisco_header_ops;
	dev->type = ARPHRD_CISCO;
	netif_dormant_on(dev);
	return 0;
	}

	return -EINVAL;
	}


	static int __init mod_init(void)
	{
	register_hdlc_protocol(&proto);
	return 0;
	}



	static void __exit mod_exit(void)
	{
	unregister_hdlc_protocol(&proto);
	}


	module_init(mod_init);
	module_exit(mod_exit);

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