[linux-2.6-block.git] / drivers / net / hamradio / bpqether.c

/*
 *	G8BPQ compatible "AX.25 via ethernet" driver release 004
 *
 *	This code REQUIRES 2.0.0 or higher/ NET3.029
 *
 *	This module:
 *		This module is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 *	This is a "pseudo" network driver to allow AX.25 over Ethernet
 *	using G8BPQ encapsulation. It has been extracted from the protocol
 *	implementation because
 *
 *		- things got unreadable within the protocol stack
 *		- to cure the protocol stack from "feature-ism"
 *		- a protocol implementation shouldn't need to know on
 *		  which hardware it is running
 *		- user-level programs like the AX.25 utilities shouldn't
 *		  need to know about the hardware.
 *		- IP over ethernet encapsulated AX.25 was impossible
 *		- rxecho.c did not work
 *		- to have room for extensions
 *		- it just deserves to "live" as an own driver
 *
 *	This driver can use any ethernet destination address, and can be
 *	limited to accept frames from one dedicated ethernet card only.
 *
 *	Note that the driver sets up the BPQ devices automagically on
 *	startup or (if started before the "insmod" of an ethernet device)
 *	on "ifconfig up". It hopefully will remove the BPQ on "rmmod"ing
 *	the ethernet device (in fact: as soon as another ethernet or bpq
 *	device gets "ifconfig"ured).
 *
 *	I have heard that several people are thinking of experiments
 *	with highspeed packet radio using existing ethernet cards.
 *	Well, this driver is prepared for this purpose, just add
 *	your tx key control and a txdelay / tailtime algorithm,
 *	probably some buffering, and /voila/...
 *
 *	History
 *	BPQ   001	Joerg(DL1BKE)		Extracted BPQ code from AX.25
 *						protocol stack and added my own
 *						yet existing patches
 *	BPQ   002	Joerg(DL1BKE)		Scan network device list on
 *						startup.
 *	BPQ   003	Joerg(DL1BKE)		Ethernet destination address
 *						and accepted source address
 *						can be configured by an ioctl()
 *						call.
 *						Fixed to match Linux networking
 *						changes - 2.1.15.
 *	BPQ   004	Joerg(DL1BKE)		Fixed to not lock up on ifconfig.
 */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stat.h>
#include <linux/netfilter.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rtnetlink.h>

#include <net/ip.h>
#include <net/arp.h>
#include <net/net_namespace.h>

#include <linux/bpqether.h>

static const char banner[] __initdata = KERN_INFO \
	"AX.25: bpqether driver version 004\n";

static char bcast_addr[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};

static char bpq_eth_addr[6];

static int bpq_rcv(struct sk_buff *, struct net_device *, struct packet_type *, struct net_device *);
static int bpq_device_event(struct notifier_block *, unsigned long, void *);

static struct packet_type bpq_packet_type __read_mostly = {
	.type	= cpu_to_be16(ETH_P_BPQ),
	.func	= bpq_rcv,
};

static struct notifier_block bpq_dev_notifier = {
	.notifier_call =bpq_device_event,
};


struct bpqdev {
	struct list_head bpq_list;	/* list of bpq devices chain */
	struct net_device *ethdev;	/* link to ethernet device */
	struct net_device *axdev;	/* bpq device (bpq#) */
	char   dest_addr[6];		/* ether destination address */
	char   acpt_addr[6];		/* accept ether frames from this address only */
};

static LIST_HEAD(bpq_devices);

/*
 * bpqether network devices are paired with ethernet devices below them, so
 * form a special "super class" of normal ethernet devices; split their locks
 * off into a separate class since they always nest.
 */
static struct lock_class_key bpq_netdev_xmit_lock_key;
static struct lock_class_key bpq_netdev_addr_lock_key;

static void bpq_set_lockdep_class_one(struct net_device *dev,
				      struct netdev_queue *txq,
				      void *_unused)
{
	lockdep_set_class(&txq->_xmit_lock, &bpq_netdev_xmit_lock_key);
}

static void bpq_set_lockdep_class(struct net_device *dev)
{
	lockdep_set_class(&dev->addr_list_lock, &bpq_netdev_addr_lock_key);
	netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL);
}

/* ------------------------------------------------------------------------ */


/*
 *	Get the ethernet device for a BPQ device
 */
static inline struct net_device *bpq_get_ether_dev(struct net_device *dev)
{
	struct bpqdev *bpq = netdev_priv(dev);

	return bpq ? bpq->ethdev : NULL;
}

/*
 *	Get the BPQ device for the ethernet device
 */
static inline struct net_device *bpq_get_ax25_dev(struct net_device *dev)
{
	struct bpqdev *bpq;

	list_for_each_entry_rcu(bpq, &bpq_devices, bpq_list) {
		if (bpq->ethdev == dev)
			return bpq->axdev;
	}
	return NULL;
}

static inline int dev_is_ethdev(struct net_device *dev)
{
	return (dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5));
}

/* ------------------------------------------------------------------------ */


/*
 *	Receive an AX.25 frame via an ethernet interface.
 */
static int bpq_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev)
{
	int len;
	char * ptr;
	struct ethhdr *eth;
	struct bpqdev *bpq;

	if (!net_eq(dev_net(dev), &init_net))
		goto drop;

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
		return NET_RX_DROP;

	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
		goto drop;

	rcu_read_lock();
	dev = bpq_get_ax25_dev(dev);

	if (dev == NULL || !netif_running(dev)) 
		goto drop_unlock;

	/*
	 * if we want to accept frames from just one ethernet device
	 * we check the source address of the sender.
	 */

	bpq = netdev_priv(dev);

	eth = eth_hdr(skb);

	if (!(bpq->acpt_addr[0] & 0x01) &&
	    memcmp(eth->h_source, bpq->acpt_addr, ETH_ALEN))
		goto drop_unlock;

	if (skb_cow(skb, sizeof(struct ethhdr)))
		goto drop_unlock;

	len = skb->data[0] + skb->data[1] * 256 - 5;

	skb_pull(skb, 2);	/* Remove the length bytes */
	skb_trim(skb, len);	/* Set the length of the data */

	dev->stats.rx_packets++;
	dev->stats.rx_bytes += len;

	ptr = skb_push(skb, 1);
	*ptr = 0;

	skb->protocol = ax25_type_trans(skb, dev);
	netif_rx(skb);
unlock:

	rcu_read_unlock();

	return 0;
drop_unlock:
	kfree_skb(skb);
	goto unlock;

drop:
	kfree_skb(skb);
	return 0;
}

/*
 * 	Send an AX.25 frame via an ethernet interface
 */
static netdev_tx_t bpq_xmit(struct sk_buff *skb, struct net_device *dev)
{
	unsigned char *ptr;
	struct bpqdev *bpq;
	struct net_device *orig_dev;
	int size;

	/*
	 * Just to be *really* sure not to send anything if the interface
	 * is down, the ethernet device may have gone.
	 */
	if (!netif_running(dev)) {
		kfree_skb(skb);
		return NETDEV_TX_OK;
	}

	skb_pull(skb, 1);			/* Drop KISS byte */
	size = skb->len;

	/*
	 * We're about to mess with the skb which may still shared with the
	 * generic networking code so unshare and ensure it's got enough
	 * space for the BPQ headers.
	 */
	if (skb_cow(skb, AX25_BPQ_HEADER_LEN)) {
		if (net_ratelimit())
			pr_err("bpqether: out of memory\n");
		kfree_skb(skb);

		return NETDEV_TX_OK;
	}

	ptr = skb_push(skb, 2);			/* Make space for length */

	*ptr++ = (size + 5) % 256;
	*ptr++ = (size + 5) / 256;

	bpq = netdev_priv(dev);

	orig_dev = dev;
	if ((dev = bpq_get_ether_dev(dev)) == NULL) {
		orig_dev->stats.tx_dropped++;
		kfree_skb(skb);
		return NETDEV_TX_OK;
	}

	skb->protocol = ax25_type_trans(skb, dev);
	skb_reset_network_header(skb);
	dev_hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
	dev->stats.tx_packets++;
	dev->stats.tx_bytes+=skb->len;
  
	dev_queue_xmit(skb);
	netif_wake_queue(dev);
	return NETDEV_TX_OK;
}

/*
 *	Set AX.25 callsign
 */
static int bpq_set_mac_address(struct net_device *dev, void *addr)
{
    struct sockaddr *sa = (struct sockaddr *)addr;

    memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);

    return 0;
}

/*	Ioctl commands
 *
 *		SIOCSBPQETHOPT		reserved for enhancements
 *		SIOCSBPQETHADDR		set the destination and accepted
 *					source ethernet address (broadcast
 *					or multicast: accept all)
 */
static int bpq_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	struct bpq_ethaddr __user *ethaddr = ifr->ifr_data;
	struct bpqdev *bpq = netdev_priv(dev);
	struct bpq_req req;

	if (!capable(CAP_NET_ADMIN))
		return -EPERM;

	switch (cmd) {
		case SIOCSBPQETHOPT:
			if (copy_from_user(&req, ifr->ifr_data, sizeof(struct bpq_req)))
				return -EFAULT;
			switch (req.cmd) {
				case SIOCGBPQETHPARAM:
				case SIOCSBPQETHPARAM:
				default:
					return -EINVAL;
			}

			break;

		case SIOCSBPQETHADDR:
			if (copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN))
				return -EFAULT;
			if (copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN))
				return -EFAULT;
			break;

		default:
			return -EINVAL;
	}

	return 0;
}

/*
 * open/close a device
 */
static int bpq_open(struct net_device *dev)
{
	netif_start_queue(dev);
	return 0;
}

static int bpq_close(struct net_device *dev)
{
	netif_stop_queue(dev);
	return 0;
}


/* ------------------------------------------------------------------------ */


/*
 *	Proc filesystem
 */
static void *bpq_seq_start(struct seq_file *seq, loff_t *pos)
	__acquires(RCU)
{
	int i = 1;
	struct bpqdev *bpqdev;

	rcu_read_lock();

	if (*pos == 0)
		return SEQ_START_TOKEN;
	
	list_for_each_entry_rcu(bpqdev, &bpq_devices, bpq_list) {
		if (i == *pos)
			return bpqdev;
	}
	return NULL;
}

static void *bpq_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct list_head *p;

	++*pos;

	if (v == SEQ_START_TOKEN)
		p = rcu_dereference(bpq_devices.next);
	else
		p = rcu_dereference(((struct bpqdev *)v)->bpq_list.next);

	return (p == &bpq_devices) ? NULL 
		: list_entry(p, struct bpqdev, bpq_list);
}

static void bpq_seq_stop(struct seq_file *seq, void *v)
	__releases(RCU)
{
	rcu_read_unlock();
}


static int bpq_seq_show(struct seq_file *seq, void *v)
{
	if (v == SEQ_START_TOKEN)
		seq_puts(seq, 
			 "dev   ether      destination        accept from\n");
	else {
		const struct bpqdev *bpqdev = v;

		seq_printf(seq, "%-5s %-10s %pM  ",
			bpqdev->axdev->name, bpqdev->ethdev->name,
			bpqdev->dest_addr);

		if (is_multicast_ether_addr(bpqdev->acpt_addr))
			seq_printf(seq, "*\n");
		else
			seq_printf(seq, "%pM\n", bpqdev->acpt_addr);

	}
	return 0;
}

static const struct seq_operations bpq_seqops = {
	.start = bpq_seq_start,
	.next = bpq_seq_next,
	.stop = bpq_seq_stop,
	.show = bpq_seq_show,
};

static int bpq_info_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &bpq_seqops);
}

static const struct file_operations bpq_info_fops = {
	.owner = THIS_MODULE,
	.open = bpq_info_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
};


/* ------------------------------------------------------------------------ */

static const struct net_device_ops bpq_netdev_ops = {
	.ndo_open	     = bpq_open,
	.ndo_stop	     = bpq_close,
	.ndo_start_xmit	     = bpq_xmit,
	.ndo_set_mac_address = bpq_set_mac_address,
	.ndo_do_ioctl	     = bpq_ioctl,
};

static void bpq_setup(struct net_device *dev)
{
	dev->netdev_ops	     = &bpq_netdev_ops;
	dev->destructor	     = free_netdev;

	memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
	memcpy(dev->dev_addr,  &ax25_defaddr, AX25_ADDR_LEN);

	dev->flags      = 0;

#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
	dev->header_ops      = &ax25_header_ops;
#endif

	dev->type            = ARPHRD_AX25;
	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
	dev->mtu             = AX25_DEF_PACLEN;
	dev->addr_len        = AX25_ADDR_LEN;

}

/*
 *	Setup a new device.
 */
static int bpq_new_device(struct net_device *edev)
{
	int err;
	struct net_device *ndev;
	struct bpqdev *bpq;

	ndev = alloc_netdev(sizeof(struct bpqdev), "bpq%d",
			   bpq_setup);
	if (!ndev)
		return -ENOMEM;

		
	bpq = netdev_priv(ndev);
	dev_hold(edev);
	bpq->ethdev = edev;
	bpq->axdev = ndev;

	memcpy(bpq->dest_addr, bcast_addr, sizeof(bpq_eth_addr));
	memcpy(bpq->acpt_addr, bcast_addr, sizeof(bpq_eth_addr));

	err = dev_alloc_name(ndev, ndev->name);
	if (err < 0) 
		goto error;

	err = register_netdevice(ndev);
	if (err)
		goto error;
	bpq_set_lockdep_class(ndev);

	/* List protected by RTNL */
	list_add_rcu(&bpq->bpq_list, &bpq_devices);
	return 0;

 error:
	dev_put(edev);
	free_netdev(ndev);
	return err;
	
}

static void bpq_free_device(struct net_device *ndev)
{
	struct bpqdev *bpq = netdev_priv(ndev);

	dev_put(bpq->ethdev);
	list_del_rcu(&bpq->bpq_list);

	unregister_netdevice(ndev);
}

/*
 *	Handle device status changes.
 */
static int bpq_device_event(struct notifier_block *this,unsigned long event, void *ptr)
{
	struct net_device *dev = (struct net_device *)ptr;

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

	if (!dev_is_ethdev(dev))
		return NOTIFY_DONE;

	switch (event) {
	case NETDEV_UP:		/* new ethernet device -> new BPQ interface */
		if (bpq_get_ax25_dev(dev) == NULL)
			bpq_new_device(dev);
		break;

	case NETDEV_DOWN:	/* ethernet device closed -> close BPQ interface */
		if ((dev = bpq_get_ax25_dev(dev)) != NULL)
			dev_close(dev);
		break;

	case NETDEV_UNREGISTER:	/* ethernet device removed -> free BPQ interface */
		if ((dev = bpq_get_ax25_dev(dev)) != NULL)
			bpq_free_device(dev);
		break;
	default:
		break;
	}

	return NOTIFY_DONE;
}


/* ------------------------------------------------------------------------ */

/*
 * Initialize driver. To be called from af_ax25 if not compiled as a
 * module
 */
static int __init bpq_init_driver(void)
{
#ifdef CONFIG_PROC_FS
	if (!proc_net_fops_create(&init_net, "bpqether", S_IRUGO, &bpq_info_fops)) {
		printk(KERN_ERR
			"bpq: cannot create /proc/net/bpqether entry.\n");
		return -ENOENT;
	}
#endif  /* CONFIG_PROC_FS */

	dev_add_pack(&bpq_packet_type);

	register_netdevice_notifier(&bpq_dev_notifier);

	printk(banner);

	return 0;
}

static void __exit bpq_cleanup_driver(void)
{
	struct bpqdev *bpq;

	dev_remove_pack(&bpq_packet_type);

	unregister_netdevice_notifier(&bpq_dev_notifier);

	proc_net_remove(&init_net, "bpqether");

	rtnl_lock();
	while (!list_empty(&bpq_devices)) {
		bpq = list_entry(bpq_devices.next, struct bpqdev, bpq_list);
		bpq_free_device(bpq->axdev);
	}
	rtnl_unlock();
}

MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>");
MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet");
MODULE_LICENSE("GPL");
module_init(bpq_init_driver);
module_exit(bpq_cleanup_driver);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* G8BPQ compatible "AX.25 via ethernet" driver release 004
	3	*
	4	* This code REQUIRES 2.0.0 or higher/ NET3.029
	5	*
	6	* This module:
	7	* This module is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*
	12	* This is a "pseudo" network driver to allow AX.25 over Ethernet
	13	* using G8BPQ encapsulation. It has been extracted from the protocol
	14	* implementation because
	15	*
	16	* - things got unreadable within the protocol stack
	17	* - to cure the protocol stack from "feature-ism"
	18	* - a protocol implementation shouldn't need to know on
	19	* which hardware it is running
	20	* - user-level programs like the AX.25 utilities shouldn't
	21	* need to know about the hardware.
	22	* - IP over ethernet encapsulated AX.25 was impossible
	23	* - rxecho.c did not work
	24	* - to have room for extensions
	25	* - it just deserves to "live" as an own driver
	26	*
	27	* This driver can use any ethernet destination address, and can be
	28	* limited to accept frames from one dedicated ethernet card only.
	29	*
	30	* Note that the driver sets up the BPQ devices automagically on
	31	* startup or (if started before the "insmod" of an ethernet device)
	32	* on "ifconfig up". It hopefully will remove the BPQ on "rmmod"ing
	33	* the ethernet device (in fact: as soon as another ethernet or bpq
	34	* device gets "ifconfig"ured).
	35	*
	36	* I have heard that several people are thinking of experiments
	37	* with highspeed packet radio using existing ethernet cards.
	38	* Well, this driver is prepared for this purpose, just add
	39	* your tx key control and a txdelay / tailtime algorithm,
	40	* probably some buffering, and /voila/...
	41	*
	42	* History
	43	* BPQ 001 Joerg(DL1BKE) Extracted BPQ code from AX.25
	44	* protocol stack and added my own
	45	* yet existing patches
	46	* BPQ 002 Joerg(DL1BKE) Scan network device list on
	47	* startup.
	48	* BPQ 003 Joerg(DL1BKE) Ethernet destination address
	49	* and accepted source address
	50	* can be configured by an ioctl()
	51	* call.
	52	* Fixed to match Linux networking
	53	* changes - 2.1.15.
	54	* BPQ 004 Joerg(DL1BKE) Fixed to not lock up on ifconfig.
	55	*/
	56
1da177e4 LT	57	#include <linux/errno.h>
	58	#include <linux/types.h>
	59	#include <linux/socket.h>
	60	#include <linux/in.h>
	61	#include <linux/kernel.h>
	62	#include <linux/string.h>
	63	#include <linux/net.h>
	64	#include <net/ax25.h>
	65	#include <linux/inet.h>
	66	#include <linux/netdevice.h>
0795af57	67	#include <linux/etherdevice.h>
1da177e4 LT	68	#include <linux/if_arp.h>
	69	#include <linux/skbuff.h>
	70	#include <net/sock.h>
	71	#include <asm/system.h>
	72	#include <asm/uaccess.h>
	73	#include <linux/mm.h>
	74	#include <linux/interrupt.h>
	75	#include <linux/notifier.h>
	76	#include <linux/proc_fs.h>
	77	#include <linux/seq_file.h>
	78	#include <linux/stat.h>
	79	#include <linux/netfilter.h>
	80	#include <linux/module.h>
	81	#include <linux/init.h>
	82	#include <linux/rtnetlink.h>
	83
	84	#include <net/ip.h>
	85	#include <net/arp.h>
457c4cbc	86	#include <net/net_namespace.h>
1da177e4 LT	87
	88	#include <linux/bpqether.h>
	89
eb33ae24 HE	90	static const char banner[] __initdata = KERN_INFO \
eb33ae24 HE	91	"AX.25: bpqether driver version 004\n";
1da177e4	92
1da177e4 LT	93	static char bcast_addr[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
	94
	95	static char bpq_eth_addr[6];
	96
f2ccd8fa	97	static int bpq_rcv(struct sk_buff , struct net_device , struct packet_type , struct net_device );
1da177e4	98	static int bpq_device_event(struct notifier_block , unsigned long, void );
1da177e4	99
7546dd97	100	static struct packet_type bpq_packet_type __read_mostly = {
09640e63	101	.type = cpu_to_be16(ETH_P_BPQ),
1da177e4 LT	102	.func = bpq_rcv,
	103	};
	104
	105	static struct notifier_block bpq_dev_notifier = {
	106	.notifier_call =bpq_device_event,
	107	};
	108
	109
	110	struct bpqdev {
	111	struct list_head bpq_list; /* list of bpq devices chain */
	112	struct net_device ethdev; / link to ethernet device */
	113	struct net_device axdev; / bpq device (bpq#) */
1da177e4 LT	114	char dest_addr[6]; /* ether destination address */
	115	char acpt_addr[6]; /* accept ether frames from this address only */
	116	};
	117
	118	static LIST_HEAD(bpq_devices);
	119
1eeb7e42 RB	120	/*
	121	* bpqether network devices are paired with ethernet devices below them, so
	122	* form a special "super class" of normal ethernet devices; split their locks
	123	* off into a separate class since they always nest.
	124	*/
	125	static struct lock_class_key bpq_netdev_xmit_lock_key;
cf508b12	126	static struct lock_class_key bpq_netdev_addr_lock_key;
1da177e4	127
e8a0464c DM	128	static void bpq_set_lockdep_class_one(struct net_device *dev,
	129	struct netdev_queue *txq,
	130	void *_unused)
c773e847 DM	131	{
	132	lockdep_set_class(&txq->_xmit_lock, &bpq_netdev_xmit_lock_key);
	133	}
	134
	135	static void bpq_set_lockdep_class(struct net_device *dev)
	136	{
cf508b12	137	lockdep_set_class(&dev->addr_list_lock, &bpq_netdev_addr_lock_key);
e8a0464c	138	netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL);
c773e847 DM	139	}
c773e847 DM	140
1da177e4 LT	141	/* ------------------------------------------------------------------------ */
	142
	143
	144	/*
	145	* Get the ethernet device for a BPQ device
	146	*/
	147	static inline struct net_device bpq_get_ether_dev(struct net_device dev)
	148	{
	149	struct bpqdev *bpq = netdev_priv(dev);
	150
	151	return bpq ? bpq->ethdev : NULL;
	152	}
	153
	154	/*
	155	* Get the BPQ device for the ethernet device
	156	*/
	157	static inline struct net_device bpq_get_ax25_dev(struct net_device dev)
	158	{
	159	struct bpqdev *bpq;
	160
bc0a7438	161	list_for_each_entry_rcu(bpq, &bpq_devices, bpq_list) {
1da177e4 LT	162	if (bpq->ethdev == dev)
	163	return bpq->axdev;
	164	}
	165	return NULL;
	166	}
	167
	168	static inline int dev_is_ethdev(struct net_device *dev)
	169	{
8e95a202	170	return (dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5));
1da177e4 LT	171	}
	172
	173	/* ------------------------------------------------------------------------ */
	174
	175
	176	/*
	177	* Receive an AX.25 frame via an ethernet interface.
	178	*/
f2ccd8fa	179	static int bpq_rcv(struct sk_buff skb, struct net_device dev, struct packet_type ptype, struct net_device orig_dev)
1da177e4 LT	180	{
	181	int len;
	182	char * ptr;
	183	struct ethhdr *eth;
	184	struct bpqdev *bpq;
	185
09ad9bc7	186	if (!net_eq(dev_net(dev), &init_net))
e730c155 EB	187	goto drop;
e730c155 EB	188
1da177e4 LT	189	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
	190	return NET_RX_DROP;
	191
	192	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
	193	goto drop;
	194
	195	rcu_read_lock();
	196	dev = bpq_get_ax25_dev(dev);
	197
	198	if (dev == NULL \|\| !netif_running(dev))
	199	goto drop_unlock;
	200
	201	/*
	202	* if we want to accept frames from just one ethernet device
	203	* we check the source address of the sender.
	204	*/
	205
	206	bpq = netdev_priv(dev);
	207
	208	eth = eth_hdr(skb);
	209
	210	if (!(bpq->acpt_addr[0] & 0x01) &&
	211	memcmp(eth->h_source, bpq->acpt_addr, ETH_ALEN))
	212	goto drop_unlock;
	213
	214	if (skb_cow(skb, sizeof(struct ethhdr)))
	215	goto drop_unlock;
	216
	217	len = skb->data[0] + skb->data[1] * 256 - 5;
	218
	219	skb_pull(skb, 2); /* Remove the length bytes */
	220	skb_trim(skb, len); /* Set the length of the data */
	221
f57505fd SH	222	dev->stats.rx_packets++;
f57505fd SH	223	dev->stats.rx_bytes += len;
1da177e4 LT	224
	225	ptr = skb_push(skb, 1);
	226	*ptr = 0;
	227
56cb5156	228	skb->protocol = ax25_type_trans(skb, dev);
1da177e4	229	netif_rx(skb);
1da177e4 LT	230	unlock:
	231
	232	rcu_read_unlock();
	233
	234	return 0;
	235	drop_unlock:
	236	kfree_skb(skb);
	237	goto unlock;
	238
	239	drop:
	240	kfree_skb(skb);
	241	return 0;
	242	}
	243
	244	/*
	245	* Send an AX.25 frame via an ethernet interface
	246	*/
36e4d64a	247	static netdev_tx_t bpq_xmit(struct sk_buff skb, struct net_device dev)
1da177e4	248	{
1da177e4 LT	249	unsigned char *ptr;
1da177e4 LT	250	struct bpqdev *bpq;
f65d1f08	251	struct net_device *orig_dev;
1da177e4 LT	252	int size;
	253
	254	/*
	255	* Just to be really sure not to send anything if the interface
	256	* is down, the ethernet device may have gone.
	257	*/
	258	if (!netif_running(dev)) {
	259	kfree_skb(skb);
d77eeb70	260	return NETDEV_TX_OK;
1da177e4 LT	261	}
1da177e4 LT	262
3eb00275	263	skb_pull(skb, 1); /* Drop KISS byte */
1da177e4 LT	264	size = skb->len;
	265
	266	/*
3eb00275 RB	267	* We're about to mess with the skb which may still shared with the
	268	* generic networking code so unshare and ensure it's got enough
	269	* space for the BPQ headers.
1da177e4	270	*/
3eb00275 RB	271	if (skb_cow(skb, AX25_BPQ_HEADER_LEN)) {
	272	if (net_ratelimit())
	273	pr_err("bpqether: out of memory\n");
1da177e4	274	kfree_skb(skb);
3eb00275 RB	275
3eb00275 RB	276	return NETDEV_TX_OK;
1da177e4 LT	277	}
1da177e4 LT	278
3eb00275	279	ptr = skb_push(skb, 2); /* Make space for length */
1da177e4 LT	280
	281	*ptr++ = (size + 5) % 256;
	282	*ptr++ = (size + 5) / 256;
	283
	284	bpq = netdev_priv(dev);
	285
f65d1f08	286	orig_dev = dev;
1da177e4	287	if ((dev = bpq_get_ether_dev(dev)) == NULL) {
f65d1f08	288	orig_dev->stats.tx_dropped++;
1da177e4	289	kfree_skb(skb);
98ca4a46	290	return NETDEV_TX_OK;
1da177e4 LT	291	}
1da177e4 LT	292
56cb5156	293	skb->protocol = ax25_type_trans(skb, dev);
c1d2bbe1	294	skb_reset_network_header(skb);
0c4e8581	295	dev_hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
f57505fd SH	296	dev->stats.tx_packets++;
f57505fd SH	297	dev->stats.tx_bytes+=skb->len;
1da177e4 LT	298
	299	dev_queue_xmit(skb);
	300	netif_wake_queue(dev);
6ed10654	301	return NETDEV_TX_OK;
1da177e4 LT	302	}
1da177e4 LT	303
1da177e4 LT	304	/*
	305	* Set AX.25 callsign
	306	*/
	307	static int bpq_set_mac_address(struct net_device dev, void addr)
	308	{
	309	struct sockaddr sa = (struct sockaddr )addr;
	310
	311	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
	312
	313	return 0;
	314	}
	315
	316	/* Ioctl commands
	317	*
	318	* SIOCSBPQETHOPT reserved for enhancements
	319	* SIOCSBPQETHADDR set the destination and accepted
	320	* source ethernet address (broadcast
	321	* or multicast: accept all)
	322	*/
	323	static int bpq_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
	324	{
	325	struct bpq_ethaddr __user *ethaddr = ifr->ifr_data;
	326	struct bpqdev *bpq = netdev_priv(dev);
	327	struct bpq_req req;
	328
	329	if (!capable(CAP_NET_ADMIN))
	330	return -EPERM;
	331
	332	switch (cmd) {
	333	case SIOCSBPQETHOPT:
	334	if (copy_from_user(&req, ifr->ifr_data, sizeof(struct bpq_req)))
	335	return -EFAULT;
	336	switch (req.cmd) {
	337	case SIOCGBPQETHPARAM:
	338	case SIOCSBPQETHPARAM:
	339	default:
	340	return -EINVAL;
	341	}
	342
	343	break;
	344
	345	case SIOCSBPQETHADDR:
	346	if (copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN))
	347	return -EFAULT;
	348	if (copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN))
	349	return -EFAULT;
	350	break;
	351
	352	default:
	353	return -EINVAL;
	354	}
	355
	356	return 0;
	357	}
	358
	359	/*
	360	* open/close a device
	361	*/
	362	static int bpq_open(struct net_device *dev)
	363	{
	364	netif_start_queue(dev);
	365	return 0;
	366	}
	367
368	static int bpq_close(struct net_device *dev)
369	{
370	netif_stop_queue(dev);
371	return 0;
372	}
373
374
375	/* ------------------------------------------------------------------------ */
376
377
378	/*
379	* Proc filesystem
380	*/
1da177e4	381	static void bpq_seq_start(struct seq_file seq, loff_t *pos)
e334f564	382	__acquires(RCU)
1da177e4 LT	383	{
	384	int i = 1;
	385	struct bpqdev *bpqdev;
	386
	387	rcu_read_lock();
	388
	389	if (*pos == 0)
	390	return SEQ_START_TOKEN;
	391
bc0a7438	392	list_for_each_entry_rcu(bpqdev, &bpq_devices, bpq_list) {
1da177e4 LT	393	if (i == *pos)
	394	return bpqdev;
	395	}
	396	return NULL;
	397	}
	398
	399	static void bpq_seq_next(struct seq_file seq, void v, loff_t pos)
	400	{
	401	struct list_head *p;
	402
	403	++*pos;
	404
	405	if (v == SEQ_START_TOKEN)
b34bd06e	406	p = rcu_dereference(bpq_devices.next);
1da177e4	407	else
b34bd06e	408	p = rcu_dereference(((struct bpqdev *)v)->bpq_list.next);
1da177e4 LT	409
1da177e4 LT	410	return (p == &bpq_devices) ? NULL
b34bd06e	411	: list_entry(p, struct bpqdev, bpq_list);
1da177e4 LT	412	}
	413
	414	static void bpq_seq_stop(struct seq_file seq, void v)
e334f564	415	__releases(RCU)
1da177e4 LT	416	{
	417	rcu_read_unlock();
	418	}
	419
	420
	421	static int bpq_seq_show(struct seq_file seq, void v)
	422	{
	423	if (v == SEQ_START_TOKEN)
	424	seq_puts(seq,
	425	"dev ether destination accept from\n");
	426	else {
	427	const struct bpqdev *bpqdev = v;
	428
e174961c	429	seq_printf(seq, "%-5s %-10s %pM ",
1da177e4	430	bpqdev->axdev->name, bpqdev->ethdev->name,
e174961c	431	bpqdev->dest_addr);
1da177e4	432
0795af57 JP	433	if (is_multicast_ether_addr(bpqdev->acpt_addr))
	434	seq_printf(seq, "*\n");
	435	else
e174961c	436	seq_printf(seq, "%pM\n", bpqdev->acpt_addr);
1da177e4 LT	437
	438	}
	439	return 0;
	440	}
	441
4101dec9	442	static const struct seq_operations bpq_seqops = {
1da177e4 LT	443	.start = bpq_seq_start,
	444	.next = bpq_seq_next,
	445	.stop = bpq_seq_stop,
	446	.show = bpq_seq_show,
	447	};
	448
	449	static int bpq_info_open(struct inode inode, struct file file)
	450	{
	451	return seq_open(file, &bpq_seqops);
	452	}
	453
d54b1fdb	454	static const struct file_operations bpq_info_fops = {
1da177e4 LT	455	.owner = THIS_MODULE,
	456	.open = bpq_info_open,
	457	.read = seq_read,
	458	.llseek = seq_lseek,
	459	.release = seq_release,
	460	};
	461
	462
	463	/* ------------------------------------------------------------------------ */
	464
283767e7 SH	465	static const struct net_device_ops bpq_netdev_ops = {
	466	.ndo_open = bpq_open,
	467	.ndo_stop = bpq_close,
	468	.ndo_start_xmit = bpq_xmit,
	469	.ndo_set_mac_address = bpq_set_mac_address,
	470	.ndo_do_ioctl = bpq_ioctl,
	471	};
1da177e4 LT	472
	473	static void bpq_setup(struct net_device *dev)
	474	{
283767e7	475	dev->netdev_ops = &bpq_netdev_ops;
1da177e4 LT	476	dev->destructor = free_netdev;
1da177e4 LT	477
15b1c0e8 RB	478	memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
15b1c0e8 RB	479	memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
1da177e4 LT	480
	481	dev->flags = 0;
	482
	483	#if defined(CONFIG_AX25) \|\| defined(CONFIG_AX25_MODULE)
3b04ddde	484	dev->header_ops = &ax25_header_ops;
1da177e4 LT	485	#endif
	486
	487	dev->type = ARPHRD_AX25;
	488	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
	489	dev->mtu = AX25_DEF_PACLEN;
	490	dev->addr_len = AX25_ADDR_LEN;
	491
	492	}
	493
	494	/*
	495	* Setup a new device.
	496	*/
	497	static int bpq_new_device(struct net_device *edev)
	498	{
	499	int err;
	500	struct net_device *ndev;
	501	struct bpqdev *bpq;
	502
	503	ndev = alloc_netdev(sizeof(struct bpqdev), "bpq%d",
	504	bpq_setup);
	505	if (!ndev)
	506	return -ENOMEM;
	507
	508
	509	bpq = netdev_priv(ndev);
	510	dev_hold(edev);
	511	bpq->ethdev = edev;
	512	bpq->axdev = ndev;
	513
	514	memcpy(bpq->dest_addr, bcast_addr, sizeof(bpq_eth_addr));
	515	memcpy(bpq->acpt_addr, bcast_addr, sizeof(bpq_eth_addr));
	516
	517	err = dev_alloc_name(ndev, ndev->name);
	518	if (err < 0)
	519	goto error;
	520
	521	err = register_netdevice(ndev);
	522	if (err)
	523	goto error;
c773e847	524	bpq_set_lockdep_class(ndev);
1da177e4 LT	525
	526	/* List protected by RTNL */
	527	list_add_rcu(&bpq->bpq_list, &bpq_devices);
	528	return 0;
	529
	530	error:
	531	dev_put(edev);
	532	free_netdev(ndev);
	533	return err;
	534
	535	}
	536
	537	static void bpq_free_device(struct net_device *ndev)
	538	{
	539	struct bpqdev *bpq = netdev_priv(ndev);
	540
	541	dev_put(bpq->ethdev);
	542	list_del_rcu(&bpq->bpq_list);
	543
	544	unregister_netdevice(ndev);
	545	}
	546
	547	/*
	548	* Handle device status changes.
	549	*/
	550	static int bpq_device_event(struct notifier_block this,unsigned long event, void ptr)
	551	{
	552	struct net_device dev = (struct net_device )ptr;
	553
09ad9bc7	554	if (!net_eq(dev_net(dev), &init_net))
e9dc8653 EB	555	return NOTIFY_DONE;
e9dc8653 EB	556
1da177e4 LT	557	if (!dev_is_ethdev(dev))
	558	return NOTIFY_DONE;
	559
1da177e4 LT	560	switch (event) {
	561	case NETDEV_UP: /* new ethernet device -> new BPQ interface */
	562	if (bpq_get_ax25_dev(dev) == NULL)
	563	bpq_new_device(dev);
	564	break;
	565
	566	case NETDEV_DOWN: /* ethernet device closed -> close BPQ interface */
	567	if ((dev = bpq_get_ax25_dev(dev)) != NULL)
	568	dev_close(dev);
	569	break;
	570
	571	case NETDEV_UNREGISTER: /* ethernet device removed -> free BPQ interface */
	572	if ((dev = bpq_get_ax25_dev(dev)) != NULL)
	573	bpq_free_device(dev);
	574	break;
	575	default:
	576	break;
	577	}
1da177e4 LT	578
	579	return NOTIFY_DONE;
	580	}
	581
	582
	583	/* ------------------------------------------------------------------------ */
	584
	585	/*
	586	* Initialize driver. To be called from af_ax25 if not compiled as a
	587	* module
	588	*/
	589	static int __init bpq_init_driver(void)
	590	{
	591	#ifdef CONFIG_PROC_FS
457c4cbc	592	if (!proc_net_fops_create(&init_net, "bpqether", S_IRUGO, &bpq_info_fops)) {
1da177e4 LT	593	printk(KERN_ERR
	594	"bpq: cannot create /proc/net/bpqether entry.\n");
	595	return -ENOENT;
	596	}
	597	#endif /* CONFIG_PROC_FS */
	598
	599	dev_add_pack(&bpq_packet_type);
	600
	601	register_netdevice_notifier(&bpq_dev_notifier);
	602
	603	printk(banner);
	604
	605	return 0;
	606	}
	607
	608	static void __exit bpq_cleanup_driver(void)
	609	{
	610	struct bpqdev *bpq;
	611
	612	dev_remove_pack(&bpq_packet_type);
	613
	614	unregister_netdevice_notifier(&bpq_dev_notifier);
	615
457c4cbc	616	proc_net_remove(&init_net, "bpqether");
1da177e4 LT	617
	618	rtnl_lock();
	619	while (!list_empty(&bpq_devices)) {
	620	bpq = list_entry(bpq_devices.next, struct bpqdev, bpq_list);
	621	bpq_free_device(bpq->axdev);
	622	}
	623	rtnl_unlock();
	624	}
	625
	626	MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>");
	627	MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet");
	628	MODULE_LICENSE("GPL");
	629	module_init(bpq_init_driver);
	630	module_exit(bpq_cleanup_driver);