[deliverable/linux.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 <linux/slab.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/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/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[] __initconst = 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) &&
	    !ether_addr_equal(eth->h_source, bpq->acpt_addr))
		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;

	if (skb->protocol == htons(ETH_P_IP))
		return ax25_ip_xmit(skb);

	/*
	 * 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;
	struct bpqdev *bpqdev = v;

	++*pos;

	if (v == SEQ_START_TOKEN)
		p = rcu_dereference(list_next_rcu(&bpq_devices));
	else
		p = rcu_dereference(list_next_rcu(&bpqdev->bpq_list));

	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;
	dev->features	= NETIF_F_LLTX;	/* Allow recursion */

#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", NET_NAME_UNKNOWN,
			    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 = 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 = netdev_notifier_info_to_dev(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_create("bpqether", S_IRUGO, init_net.proc_net,
			 &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);

	remove_proc_entry("bpqether", init_net.proc_net);

	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>
5a0e3ad6	64	#include <linux/slab.h>
1da177e4 LT	65	#include <net/ax25.h>
	66	#include <linux/inet.h>
	67	#include <linux/netdevice.h>
0795af57	68	#include <linux/etherdevice.h>
1da177e4 LT	69	#include <linux/if_arp.h>
	70	#include <linux/skbuff.h>
	71	#include <net/sock.h>
1da177e4 LT	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>
1da177e4 LT	79	#include <linux/module.h>
	80	#include <linux/init.h>
	81	#include <linux/rtnetlink.h>
	82
	83	#include <net/ip.h>
	84	#include <net/arp.h>
457c4cbc	85	#include <net/net_namespace.h>
1da177e4 LT	86
	87	#include <linux/bpqether.h>
	88
afa8c78b	89	static const char banner[] __initconst = KERN_INFO \
eb33ae24	90	"AX.25: bpqether driver version 004\n";
1da177e4	91
1da177e4 LT	92	static char bcast_addr[6]={0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
	93
	94	static char bpq_eth_addr[6];
	95
f2ccd8fa	96	static int bpq_rcv(struct sk_buff , struct net_device , struct packet_type , struct net_device );
1da177e4	97	static int bpq_device_event(struct notifier_block , unsigned long, void );
1da177e4	98
7546dd97	99	static struct packet_type bpq_packet_type __read_mostly = {
09640e63	100	.type = cpu_to_be16(ETH_P_BPQ),
1da177e4 LT	101	.func = bpq_rcv,
	102	};
	103
	104	static struct notifier_block bpq_dev_notifier = {
351638e7	105	.notifier_call = bpq_device_event,
1da177e4 LT	106	};
	107
	108
	109	struct bpqdev {
	110	struct list_head bpq_list; /* list of bpq devices chain */
	111	struct net_device ethdev; / link to ethernet device */
	112	struct net_device axdev; / bpq device (bpq#) */
1da177e4 LT	113	char dest_addr[6]; /* ether destination address */
	114	char acpt_addr[6]; /* accept ether frames from this address only */
	115	};
	116
	117	static LIST_HEAD(bpq_devices);
	118
1eeb7e42 RB	119	/*
	120	* bpqether network devices are paired with ethernet devices below them, so
	121	* form a special "super class" of normal ethernet devices; split their locks
	122	* off into a separate class since they always nest.
	123	*/
	124	static struct lock_class_key bpq_netdev_xmit_lock_key;
cf508b12	125	static struct lock_class_key bpq_netdev_addr_lock_key;
1da177e4	126
e8a0464c DM	127	static void bpq_set_lockdep_class_one(struct net_device *dev,
	128	struct netdev_queue *txq,
	129	void *_unused)
c773e847 DM	130	{
	131	lockdep_set_class(&txq->_xmit_lock, &bpq_netdev_xmit_lock_key);
	132	}
	133
	134	static void bpq_set_lockdep_class(struct net_device *dev)
	135	{
cf508b12	136	lockdep_set_class(&dev->addr_list_lock, &bpq_netdev_addr_lock_key);
e8a0464c	137	netdev_for_each_tx_queue(dev, bpq_set_lockdep_class_one, NULL);
c773e847 DM	138	}
c773e847 DM	139
1da177e4 LT	140	/* ------------------------------------------------------------------------ */
	141
	142
	143	/*
	144	* Get the ethernet device for a BPQ device
	145	*/
	146	static inline struct net_device bpq_get_ether_dev(struct net_device dev)
	147	{
	148	struct bpqdev *bpq = netdev_priv(dev);
	149
	150	return bpq ? bpq->ethdev : NULL;
	151	}
	152
	153	/*
	154	* Get the BPQ device for the ethernet device
	155	*/
	156	static inline struct net_device bpq_get_ax25_dev(struct net_device dev)
	157	{
	158	struct bpqdev *bpq;
	159
bc0a7438	160	list_for_each_entry_rcu(bpq, &bpq_devices, bpq_list) {
1da177e4 LT	161	if (bpq->ethdev == dev)
	162	return bpq->axdev;
	163	}
	164	return NULL;
	165	}
	166
	167	static inline int dev_is_ethdev(struct net_device *dev)
	168	{
807540ba	169	return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
1da177e4 LT	170	}
	171
	172	/* ------------------------------------------------------------------------ */
	173
	174
	175	/*
	176	* Receive an AX.25 frame via an ethernet interface.
	177	*/
f2ccd8fa	178	static int bpq_rcv(struct sk_buff skb, struct net_device dev, struct packet_type ptype, struct net_device orig_dev)
1da177e4 LT	179	{
	180	int len;
	181	char * ptr;
	182	struct ethhdr *eth;
	183	struct bpqdev *bpq;
	184
09ad9bc7	185	if (!net_eq(dev_net(dev), &init_net))
e730c155 EB	186	goto drop;
e730c155 EB	187
1da177e4 LT	188	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
	189	return NET_RX_DROP;
	190
	191	if (!pskb_may_pull(skb, sizeof(struct ethhdr)))
	192	goto drop;
	193
	194	rcu_read_lock();
	195	dev = bpq_get_ax25_dev(dev);
	196
	197	if (dev == NULL \|\| !netif_running(dev))
	198	goto drop_unlock;
	199
	200	/*
	201	* if we want to accept frames from just one ethernet device
	202	* we check the source address of the sender.
	203	*/
	204
	205	bpq = netdev_priv(dev);
	206
	207	eth = eth_hdr(skb);
	208
	209	if (!(bpq->acpt_addr[0] & 0x01) &&
dc050c9e	210	!ether_addr_equal(eth->h_source, bpq->acpt_addr))
1da177e4 LT	211	goto drop_unlock;
	212
	213	if (skb_cow(skb, sizeof(struct ethhdr)))
	214	goto drop_unlock;
	215
	216	len = skb->data[0] + skb->data[1] * 256 - 5;
	217
	218	skb_pull(skb, 2); /* Remove the length bytes */
	219	skb_trim(skb, len); /* Set the length of the data */
	220
f57505fd SH	221	dev->stats.rx_packets++;
f57505fd SH	222	dev->stats.rx_bytes += len;
1da177e4 LT	223
	224	ptr = skb_push(skb, 1);
	225	*ptr = 0;
	226
56cb5156	227	skb->protocol = ax25_type_trans(skb, dev);
1da177e4	228	netif_rx(skb);
1da177e4 LT	229	unlock:
	230
	231	rcu_read_unlock();
	232
	233	return 0;
	234	drop_unlock:
	235	kfree_skb(skb);
	236	goto unlock;
	237
	238	drop:
	239	kfree_skb(skb);
	240	return 0;
	241	}
	242
	243	/*
	244	* Send an AX.25 frame via an ethernet interface
	245	*/
36e4d64a	246	static netdev_tx_t bpq_xmit(struct sk_buff skb, struct net_device dev)
1da177e4	247	{
1da177e4 LT	248	unsigned char *ptr;
1da177e4 LT	249	struct bpqdev *bpq;
f65d1f08	250	struct net_device *orig_dev;
1da177e4 LT	251	int size;
1da177e4 LT	252
1d5da757 EB	253	if (skb->protocol == htons(ETH_P_IP))
	254	return ax25_ip_xmit(skb);
	255
1da177e4 LT	256	/*
	257	* Just to be really sure not to send anything if the interface
	258	* is down, the ethernet device may have gone.
	259	*/
	260	if (!netif_running(dev)) {
	261	kfree_skb(skb);
d77eeb70	262	return NETDEV_TX_OK;
1da177e4 LT	263	}
1da177e4 LT	264
3eb00275	265	skb_pull(skb, 1); /* Drop KISS byte */
1da177e4 LT	266	size = skb->len;
	267
	268	/*
3eb00275 RB	269	* We're about to mess with the skb which may still shared with the
	270	* generic networking code so unshare and ensure it's got enough
	271	* space for the BPQ headers.
1da177e4	272	*/
3eb00275 RB	273	if (skb_cow(skb, AX25_BPQ_HEADER_LEN)) {
	274	if (net_ratelimit())
	275	pr_err("bpqether: out of memory\n");
1da177e4	276	kfree_skb(skb);
3eb00275 RB	277
3eb00275 RB	278	return NETDEV_TX_OK;
1da177e4 LT	279	}
1da177e4 LT	280
3eb00275	281	ptr = skb_push(skb, 2); /* Make space for length */
1da177e4 LT	282
	283	*ptr++ = (size + 5) % 256;
	284	*ptr++ = (size + 5) / 256;
	285
	286	bpq = netdev_priv(dev);
	287
f65d1f08	288	orig_dev = dev;
1da177e4	289	if ((dev = bpq_get_ether_dev(dev)) == NULL) {
f65d1f08	290	orig_dev->stats.tx_dropped++;
1da177e4	291	kfree_skb(skb);
98ca4a46	292	return NETDEV_TX_OK;
1da177e4 LT	293	}
1da177e4 LT	294
56cb5156	295	skb->protocol = ax25_type_trans(skb, dev);
c1d2bbe1	296	skb_reset_network_header(skb);
0c4e8581	297	dev_hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
f57505fd SH	298	dev->stats.tx_packets++;
f57505fd SH	299	dev->stats.tx_bytes+=skb->len;
1da177e4 LT	300
	301	dev_queue_xmit(skb);
	302	netif_wake_queue(dev);
6ed10654	303	return NETDEV_TX_OK;
1da177e4 LT	304	}
1da177e4 LT	305
1da177e4 LT	306	/*
	307	* Set AX.25 callsign
	308	*/
	309	static int bpq_set_mac_address(struct net_device dev, void addr)
	310	{
	311	struct sockaddr sa = (struct sockaddr )addr;
	312
	313	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
	314
	315	return 0;
	316	}
	317
	318	/* Ioctl commands
	319	*
	320	* SIOCSBPQETHOPT reserved for enhancements
	321	* SIOCSBPQETHADDR set the destination and accepted
	322	* source ethernet address (broadcast
	323	* or multicast: accept all)
	324	*/
	325	static int bpq_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
	326	{
	327	struct bpq_ethaddr __user *ethaddr = ifr->ifr_data;
	328	struct bpqdev *bpq = netdev_priv(dev);
	329	struct bpq_req req;
	330
	331	if (!capable(CAP_NET_ADMIN))
	332	return -EPERM;
	333
	334	switch (cmd) {
	335	case SIOCSBPQETHOPT:
	336	if (copy_from_user(&req, ifr->ifr_data, sizeof(struct bpq_req)))
	337	return -EFAULT;
	338	switch (req.cmd) {
	339	case SIOCGBPQETHPARAM:
	340	case SIOCSBPQETHPARAM:
	341	default:
	342	return -EINVAL;
	343	}
	344
	345	break;
	346
	347	case SIOCSBPQETHADDR:
	348	if (copy_from_user(bpq->dest_addr, ethaddr->destination, ETH_ALEN))
	349	return -EFAULT;
	350	if (copy_from_user(bpq->acpt_addr, ethaddr->accept, ETH_ALEN))
	351	return -EFAULT;
	352	break;
	353
	354	default:
	355	return -EINVAL;
	356	}
	357
	358	return 0;
	359	}
	360
	361	/*
	362	* open/close a device
	363	*/
	364	static int bpq_open(struct net_device *dev)
	365	{
	366	netif_start_queue(dev);
	367	return 0;
	368	}
	369
370	static int bpq_close(struct net_device *dev)
371	{
372	netif_stop_queue(dev);
373	return 0;
374	}
375
376
377	/* ------------------------------------------------------------------------ */
378
379
380	/*
381	* Proc filesystem
382	*/
1da177e4	383	static void bpq_seq_start(struct seq_file seq, loff_t *pos)
e334f564	384	__acquires(RCU)
1da177e4 LT	385	{
	386	int i = 1;
	387	struct bpqdev *bpqdev;
	388
	389	rcu_read_lock();
	390
	391	if (*pos == 0)
	392	return SEQ_START_TOKEN;
	393
bc0a7438	394	list_for_each_entry_rcu(bpqdev, &bpq_devices, bpq_list) {
1da177e4 LT	395	if (i == *pos)
	396	return bpqdev;
	397	}
	398	return NULL;
	399	}
	400
	401	static void bpq_seq_next(struct seq_file seq, void v, loff_t pos)
	402	{
	403	struct list_head *p;
13707f9e	404	struct bpqdev *bpqdev = v;
1da177e4 LT	405
	406	++*pos;
	407
	408	if (v == SEQ_START_TOKEN)
13707f9e	409	p = rcu_dereference(list_next_rcu(&bpq_devices));
1da177e4	410	else
13707f9e	411	p = rcu_dereference(list_next_rcu(&bpqdev->bpq_list));
1da177e4 LT	412
1da177e4 LT	413	return (p == &bpq_devices) ? NULL
b34bd06e	414	: list_entry(p, struct bpqdev, bpq_list);
1da177e4 LT	415	}
	416
	417	static void bpq_seq_stop(struct seq_file seq, void v)
e334f564	418	__releases(RCU)
1da177e4 LT	419	{
	420	rcu_read_unlock();
	421	}
	422
	423
	424	static int bpq_seq_show(struct seq_file seq, void v)
	425	{
	426	if (v == SEQ_START_TOKEN)
	427	seq_puts(seq,
	428	"dev ether destination accept from\n");
	429	else {
	430	const struct bpqdev *bpqdev = v;
	431
e174961c	432	seq_printf(seq, "%-5s %-10s %pM ",
1da177e4	433	bpqdev->axdev->name, bpqdev->ethdev->name,
e174961c	434	bpqdev->dest_addr);
1da177e4	435
0795af57 JP	436	if (is_multicast_ether_addr(bpqdev->acpt_addr))
	437	seq_printf(seq, "*\n");
	438	else
e174961c	439	seq_printf(seq, "%pM\n", bpqdev->acpt_addr);
1da177e4 LT	440
	441	}
	442	return 0;
	443	}
	444
4101dec9	445	static const struct seq_operations bpq_seqops = {
1da177e4 LT	446	.start = bpq_seq_start,
	447	.next = bpq_seq_next,
	448	.stop = bpq_seq_stop,
	449	.show = bpq_seq_show,
	450	};
	451
	452	static int bpq_info_open(struct inode inode, struct file file)
	453	{
	454	return seq_open(file, &bpq_seqops);
	455	}
	456
d54b1fdb	457	static const struct file_operations bpq_info_fops = {
1da177e4 LT	458	.owner = THIS_MODULE,
	459	.open = bpq_info_open,
	460	.read = seq_read,
	461	.llseek = seq_lseek,
	462	.release = seq_release,
	463	};
	464
	465
	466	/* ------------------------------------------------------------------------ */
	467
283767e7 SH	468	static const struct net_device_ops bpq_netdev_ops = {
	469	.ndo_open = bpq_open,
	470	.ndo_stop = bpq_close,
	471	.ndo_start_xmit = bpq_xmit,
	472	.ndo_set_mac_address = bpq_set_mac_address,
	473	.ndo_do_ioctl = bpq_ioctl,
	474	};
1da177e4 LT	475
	476	static void bpq_setup(struct net_device *dev)
	477	{
283767e7	478	dev->netdev_ops = &bpq_netdev_ops;
1da177e4 LT	479	dev->destructor = free_netdev;
1da177e4 LT	480
15b1c0e8 RB	481	memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN);
15b1c0e8 RB	482	memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN);
1da177e4 LT	483
1da177e4 LT	484	dev->flags = 0;
aa43c5ff	485	dev->features = NETIF_F_LLTX; /* Allow recursion */
1da177e4 LT	486
1da177e4 LT	487	#if defined(CONFIG_AX25) \|\| defined(CONFIG_AX25_MODULE)
3b04ddde	488	dev->header_ops = &ax25_header_ops;
1da177e4 LT	489	#endif
	490
	491	dev->type = ARPHRD_AX25;
	492	dev->hard_header_len = AX25_MAX_HEADER_LEN + AX25_BPQ_HEADER_LEN;
	493	dev->mtu = AX25_DEF_PACLEN;
	494	dev->addr_len = AX25_ADDR_LEN;
	495
	496	}
	497
	498	/*
	499	* Setup a new device.
	500	*/
	501	static int bpq_new_device(struct net_device *edev)
	502	{
	503	int err;
	504	struct net_device *ndev;
	505	struct bpqdev *bpq;
	506
c835a677 TG	507	ndev = alloc_netdev(sizeof(struct bpqdev), "bpq%d", NET_NAME_UNKNOWN,
c835a677 TG	508	bpq_setup);
1da177e4 LT	509	if (!ndev)
	510	return -ENOMEM;
	511
	512
	513	bpq = netdev_priv(ndev);
	514	dev_hold(edev);
	515	bpq->ethdev = edev;
	516	bpq->axdev = ndev;
	517
	518	memcpy(bpq->dest_addr, bcast_addr, sizeof(bpq_eth_addr));
	519	memcpy(bpq->acpt_addr, bcast_addr, sizeof(bpq_eth_addr));
	520
1da177e4 LT	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	*/
351638e7 JP	550	static int bpq_device_event(struct notifier_block *this,
351638e7 JP	551	unsigned long event, void *ptr)
1da177e4	552	{
351638e7	553	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1da177e4	554
09ad9bc7	555	if (!net_eq(dev_net(dev), &init_net))
e9dc8653 EB	556	return NOTIFY_DONE;
e9dc8653 EB	557
1da177e4 LT	558	if (!dev_is_ethdev(dev))
	559	return NOTIFY_DONE;
	560
1da177e4 LT	561	switch (event) {
	562	case NETDEV_UP: /* new ethernet device -> new BPQ interface */
	563	if (bpq_get_ax25_dev(dev) == NULL)
	564	bpq_new_device(dev);
	565	break;
	566
	567	case NETDEV_DOWN: /* ethernet device closed -> close BPQ interface */
	568	if ((dev = bpq_get_ax25_dev(dev)) != NULL)
	569	dev_close(dev);
	570	break;
	571
	572	case NETDEV_UNREGISTER: /* ethernet device removed -> free BPQ interface */
	573	if ((dev = bpq_get_ax25_dev(dev)) != NULL)
	574	bpq_free_device(dev);
	575	break;
	576	default:
	577	break;
	578	}
1da177e4 LT	579
	580	return NOTIFY_DONE;
	581	}
	582
	583
	584	/* ------------------------------------------------------------------------ */
	585
	586	/*
	587	* Initialize driver. To be called from af_ax25 if not compiled as a
	588	* module
	589	*/
	590	static int __init bpq_init_driver(void)
	591	{
	592	#ifdef CONFIG_PROC_FS
d4beaa66 G	593	if (!proc_create("bpqether", S_IRUGO, init_net.proc_net,
d4beaa66 G	594	&bpq_info_fops)) {
1da177e4 LT	595	printk(KERN_ERR
	596	"bpq: cannot create /proc/net/bpqether entry.\n");
	597	return -ENOENT;
	598	}
	599	#endif /* CONFIG_PROC_FS */
	600
	601	dev_add_pack(&bpq_packet_type);
	602
	603	register_netdevice_notifier(&bpq_dev_notifier);
	604
	605	printk(banner);
	606
	607	return 0;
	608	}
	609
	610	static void __exit bpq_cleanup_driver(void)
	611	{
	612	struct bpqdev *bpq;
	613
	614	dev_remove_pack(&bpq_packet_type);
	615
	616	unregister_netdevice_notifier(&bpq_dev_notifier);
	617
ece31ffd	618	remove_proc_entry("bpqether", init_net.proc_net);
1da177e4 LT	619
	620	rtnl_lock();
	621	while (!list_empty(&bpq_devices)) {
	622	bpq = list_entry(bpq_devices.next, struct bpqdev, bpq_list);
	623	bpq_free_device(bpq->axdev);
	624	}
	625	rtnl_unlock();
	626	}
	627
	628	MODULE_AUTHOR("Joerg Reuter DL1BKE <jreuter@yaina.de>");
	629	MODULE_DESCRIPTION("Transmit and receive AX.25 packets over Ethernet");
	630	MODULE_LICENSE("GPL");
	631	module_init(bpq_init_driver);
	632	module_exit(bpq_cleanup_driver);