net/bridge/netfilter/ebt_ulog.c - kernel/prism - Git at Google

 /*
  * netfilter module for userspace bridged Ethernet frames logging daemons
  *
  *	Authors:
  *	Bart De Schuymer <bdschuym@pandora.be>
  *	Harald Welte <laforge@netfilter.org>
  *
  *  November, 2004
  *
  * Based on ipt_ULOG.c, which is
  * (C) 2000-2002 by Harald Welte <laforge@netfilter.org>
  *
  * This module accepts two parameters:
  *
  * nlbufsiz:
  *   The parameter specifies how big the buffer for each netlink multicast
  * group is. e.g. If you say nlbufsiz=8192, up to eight kb of packets will
  * get accumulated in the kernel until they are sent to userspace. It is
  * NOT possible to allocate more than 128kB, and it is strongly discouraged,
  * because atomically allocating 128kB inside the network rx softirq is not
  * reliable. Please also keep in mind that this buffer size is allocated for
  * each nlgroup you are using, so the total kernel memory usage increases
  * by that factor.
  *
  * flushtimeout:
  *   Specify, after how many hundredths of a second the queue should be
  *   flushed even if it is not full yet.
  *
  */

 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/socket.h>
 #include <linux/skbuff.h>
 #include <linux/kernel.h>
 #include <linux/timer.h>
 #include <linux/netlink.h>
 #include <linux/netdevice.h>
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter_bridge/ebtables.h>
 #include <linux/netfilter_bridge/ebt_ulog.h>
 #include <net/netfilter/nf_log.h>
 #include <net/sock.h>
 #include "../br_private.h"

 #define PRINTR(format, args...) do { if (net_ratelimit()) \
 				printk(format , ## args); } while (0)

 static unsigned int nlbufsiz = NLMSG_GOODSIZE;
 module_param(nlbufsiz, uint, 0600);
 MODULE_PARM_DESC(nlbufsiz, "netlink buffer size (number of bytes) "
 			   "(defaults to 4096)");

 static unsigned int flushtimeout = 10;
 module_param(flushtimeout, uint, 0600);
 MODULE_PARM_DESC(flushtimeout, "buffer flush timeout (hundredths ofa second) "
 			       "(defaults to 10)");

 typedef struct {
 	unsigned int qlen;		/* number of nlmsgs' in the skb */
 	struct nlmsghdr *lastnlh;	/* netlink header of last msg in skb */
 	struct sk_buff *skb;		/* the pre-allocated skb */
 	struct timer_list timer;	/* the timer function */
 	spinlock_t lock;		/* the per-queue lock */
 } ebt_ulog_buff_t;

 static ebt_ulog_buff_t ulog_buffers[EBT_ULOG_MAXNLGROUPS];
 static struct sock *ebtulognl;

 /* send one ulog_buff_t to userspace */
 static void ulog_send(unsigned int nlgroup)
 {
 	ebt_ulog_buff_t *ub = &ulog_buffers[nlgroup];

 	if (timer_pending(&ub->timer))
 		del_timer(&ub->timer);

 	if (!ub->skb)
 		return;

 	/* last nlmsg needs NLMSG_DONE */
 	if (ub->qlen > 1)
 		ub->lastnlh->nlmsg_type = NLMSG_DONE;

 	NETLINK_CB(ub->skb).dst_group = nlgroup + 1;
 	netlink_broadcast(ebtulognl, ub->skb, 0, nlgroup + 1, GFP_ATOMIC);

 	ub->qlen = 0;
 	ub->skb = NULL;
 }

 /* timer function to flush queue in flushtimeout time */
 static void ulog_timer(unsigned long data)
 {
 	spin_lock_bh(&ulog_buffers[data].lock);
 	if (ulog_buffers[data].skb)
 		ulog_send(data);
 	spin_unlock_bh(&ulog_buffers[data].lock);
 }

 static struct sk_buff *ulog_alloc_skb(unsigned int size)
 {
 	struct sk_buff *skb;
 	unsigned int n;

 	n = max(size, nlbufsiz);
 	skb = alloc_skb(n, GFP_ATOMIC);
 	if (!skb) {
 		PRINTR(KERN_ERR "ebt_ulog: can't alloc whole buffer "
 		       "of size %ub!\n", n);
 		if (n > size) {
 			/* try to allocate only as much as we need for
 			 * current packet */
 			skb = alloc_skb(size, GFP_ATOMIC);
 			if (!skb)
 				PRINTR(KERN_ERR "ebt_ulog: can't even allocate "
 				       "buffer of size %ub\n", size);
 		}
 	}

 	return skb;
 }

 static void ebt_ulog_packet(unsigned int hooknr, const struct sk_buff *skb,
    const struct net_device *in, const struct net_device *out,
    const struct ebt_ulog_info *uloginfo, const char *prefix)
 {
 	ebt_ulog_packet_msg_t *pm;
 	size_t size, copy_len;
 	struct nlmsghdr *nlh;
 	unsigned int group = uloginfo->nlgroup;
 	ebt_ulog_buff_t *ub = &ulog_buffers[group];
 	spinlock_t *lock = &ub->lock;
 	ktime_t kt;

 	if ((uloginfo->cprange == 0) ||
 	    (uloginfo->cprange > skb->len + ETH_HLEN))
 		copy_len = skb->len + ETH_HLEN;
 	else
 		copy_len = uloginfo->cprange;

 	size = NLMSG_SPACE(sizeof(*pm) + copy_len);
 	if (size > nlbufsiz) {
 		PRINTR("ebt_ulog: Size %Zd needed, but nlbufsiz=%d\n",
 		       size, nlbufsiz);
 		return;
 	}

 	spin_lock_bh(lock);

 	if (!ub->skb) {
 		if (!(ub->skb = ulog_alloc_skb(size)))
 			goto alloc_failure;
 	} else if (size > skb_tailroom(ub->skb)) {
 		ulog_send(group);

 		if (!(ub->skb = ulog_alloc_skb(size)))
 			goto alloc_failure;
 	}

 	nlh = NLMSG_PUT(ub->skb, 0, ub->qlen, 0,
 			size - NLMSG_ALIGN(sizeof(*nlh)));
 	ub->qlen++;

 	pm = NLMSG_DATA(nlh);

 	/* Fill in the ulog data */
 	pm->version = EBT_ULOG_VERSION;
 	kt = ktime_get_real();
 	pm->stamp = ktime_to_timeval(kt);
 	if (ub->qlen == 1)
 		ub->skb->tstamp = kt;
 	pm->data_len = copy_len;
 	pm->mark = skb->mark;
 	pm->hook = hooknr;
 	if (uloginfo->prefix != NULL)
 		strcpy(pm->prefix, uloginfo->prefix);
 	else
 		*(pm->prefix) = '\0';

 	if (in) {
 		strcpy(pm->physindev, in->name);
 		/* If in isn't a bridge, then physindev==indev */
 		if (in->br_port)
 			strcpy(pm->indev, in->br_port->br->dev->name);
 		else
 			strcpy(pm->indev, in->name);
 	} else
 		pm->indev[0] = pm->physindev[0] = '\0';

 	if (out) {
 		/* If out exists, then out is a bridge port */
 		strcpy(pm->physoutdev, out->name);
 		strcpy(pm->outdev, out->br_port->br->dev->name);
 	} else
 		pm->outdev[0] = pm->physoutdev[0] = '\0';

 	if (skb_copy_bits(skb, -ETH_HLEN, pm->data, copy_len) < 0)
 		BUG();

 	if (ub->qlen > 1)
 		ub->lastnlh->nlmsg_flags |= NLM_F_MULTI;

 	ub->lastnlh = nlh;

 	if (ub->qlen >= uloginfo->qthreshold)
 		ulog_send(group);
 	else if (!timer_pending(&ub->timer)) {
 		ub->timer.expires = jiffies + flushtimeout * HZ / 100;
 		add_timer(&ub->timer);
 	}

 unlock:
 	spin_unlock_bh(lock);

 	return;

 nlmsg_failure:
 	printk(KERN_CRIT "ebt_ulog: error during NLMSG_PUT. This should "
 	       "not happen, please report to author.\n");
 	goto unlock;
 alloc_failure:
 	goto unlock;
 }

 /* this function is registered with the netfilter core */
 static void ebt_log_packet(u_int8_t pf, unsigned int hooknum,
    const struct sk_buff *skb, const struct net_device *in,
    const struct net_device *out, const struct nf_loginfo *li,
    const char *prefix)
 {
 	struct ebt_ulog_info loginfo;

 	if (!li || li->type != NF_LOG_TYPE_ULOG) {
 		loginfo.nlgroup = EBT_ULOG_DEFAULT_NLGROUP;
 		loginfo.cprange = 0;
 		loginfo.qthreshold = EBT_ULOG_DEFAULT_QTHRESHOLD;
 		loginfo.prefix[0] = '\0';
 	} else {
 		loginfo.nlgroup = li->u.ulog.group;
 		loginfo.cprange = li->u.ulog.copy_len;
 		loginfo.qthreshold = li->u.ulog.qthreshold;
 		strlcpy(loginfo.prefix, prefix, sizeof(loginfo.prefix));
 	}

 	ebt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix);
 }

 static unsigned int
 ebt_ulog_tg(struct sk_buff *skb, const struct xt_target_param *par)
 {
 	ebt_ulog_packet(par->hooknum, skb, par->in, par->out,
 	                par->targinfo, NULL);
 	return EBT_CONTINUE;
 }

 static bool ebt_ulog_tg_check(const struct xt_tgchk_param *par)
 {
 	struct ebt_ulog_info *uloginfo = par->targinfo;

 	if (uloginfo->nlgroup > 31)
 		return false;

 	uloginfo->prefix[EBT_ULOG_PREFIX_LEN - 1] = '\0';

 	if (uloginfo->qthreshold > EBT_ULOG_MAX_QLEN)
 		uloginfo->qthreshold = EBT_ULOG_MAX_QLEN;

 	return true;
 }

 static struct xt_target ebt_ulog_tg_reg __read_mostly = {
 	.name		= "ulog",
 	.revision	= 0,
 	.family		= NFPROTO_BRIDGE,
 	.target		= ebt_ulog_tg,
 	.checkentry	= ebt_ulog_tg_check,
 	.targetsize	= XT_ALIGN(sizeof(struct ebt_ulog_info)),
 	.me		= THIS_MODULE,
 };

 static struct nf_logger ebt_ulog_logger __read_mostly = {
 	.name		= "ebt_ulog",
 	.logfn		= &ebt_log_packet,
 	.me		= THIS_MODULE,
 };

 static int __init ebt_ulog_init(void)
 {
 	int ret;
 	int i;

 	if (nlbufsiz >= 128*1024) {
 		printk(KERN_NOTICE "ebt_ulog: Netlink buffer has to be <= 128kB,"
 		       " please try a smaller nlbufsiz parameter.\n");
 		return -EINVAL;
 	}

 	/* initialize ulog_buffers */
 	for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) {
 		setup_timer(&ulog_buffers[i].timer, ulog_timer, i);
 		spin_lock_init(&ulog_buffers[i].lock);
 	}

 	ebtulognl = netlink_kernel_create(&init_net, NETLINK_NFLOG,
 					  EBT_ULOG_MAXNLGROUPS, NULL, NULL,
 					  THIS_MODULE);
 	if (!ebtulognl) {
 		printk(KERN_WARNING KBUILD_MODNAME ": out of memory trying to "
 		       "call netlink_kernel_create\n");
 		ret = -ENOMEM;
 	} else if ((ret = xt_register_target(&ebt_ulog_tg_reg)) != 0) {
 		netlink_kernel_release(ebtulognl);
 	}

 	if (ret == 0)
 		nf_log_register(NFPROTO_BRIDGE, &ebt_ulog_logger);

 	return ret;
 }

 static void __exit ebt_ulog_fini(void)
 {
 	ebt_ulog_buff_t *ub;
 	int i;

 	nf_log_unregister(&ebt_ulog_logger);
 	xt_unregister_target(&ebt_ulog_tg_reg);
 	for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) {
 		ub = &ulog_buffers[i];
 		if (timer_pending(&ub->timer))
 			del_timer(&ub->timer);
 		spin_lock_bh(&ub->lock);
 		if (ub->skb) {
 			kfree_skb(ub->skb);
 			ub->skb = NULL;
 		}
 		spin_unlock_bh(&ub->lock);
 	}
 	netlink_kernel_release(ebtulognl);
 }

 module_init(ebt_ulog_init);
 module_exit(ebt_ulog_fini);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
 MODULE_DESCRIPTION("Ebtables: Packet logging to netlink using ULOG");
	/*
	* netfilter module for userspace bridged Ethernet frames logging daemons
	*
	* Authors:
	* Bart De Schuymer <bdschuym@pandora.be>
	* Harald Welte <laforge@netfilter.org>
	*
	* November, 2004
	*
	* Based on ipt_ULOG.c, which is
	* (C) 2000-2002 by Harald Welte <laforge@netfilter.org>
	*
	* This module accepts two parameters:
	*
	* nlbufsiz:
	* The parameter specifies how big the buffer for each netlink multicast
	* group is. e.g. If you say nlbufsiz=8192, up to eight kb of packets will
	* get accumulated in the kernel until they are sent to userspace. It is
	* NOT possible to allocate more than 128kB, and it is strongly discouraged,
	* because atomically allocating 128kB inside the network rx softirq is not
	* reliable. Please also keep in mind that this buffer size is allocated for
	* each nlgroup you are using, so the total kernel memory usage increases
	* by that factor.
	*
	* flushtimeout:
	* Specify, after how many hundredths of a second the queue should be
	* flushed even if it is not full yet.
	*
	*/

	#include <linux/module.h>
	#include <linux/spinlock.h>
	#include <linux/socket.h>
	#include <linux/skbuff.h>
	#include <linux/kernel.h>
	#include <linux/timer.h>
	#include <linux/netlink.h>
	#include <linux/netdevice.h>
	#include <linux/netfilter/x_tables.h>
	#include <linux/netfilter_bridge/ebtables.h>
	#include <linux/netfilter_bridge/ebt_ulog.h>
	#include <net/netfilter/nf_log.h>
	#include <net/sock.h>
	#include "../br_private.h"

	#define PRINTR(format, args...) do { if (net_ratelimit()) \
	printk(format , ## args); } while (0)

	static unsigned int nlbufsiz = NLMSG_GOODSIZE;
	module_param(nlbufsiz, uint, 0600);
	MODULE_PARM_DESC(nlbufsiz, "netlink buffer size (number of bytes) "
	"(defaults to 4096)");

	static unsigned int flushtimeout = 10;
	module_param(flushtimeout, uint, 0600);
	MODULE_PARM_DESC(flushtimeout, "buffer flush timeout (hundredths ofa second) "
	"(defaults to 10)");

	typedef struct {
	unsigned int qlen; /* number of nlmsgs' in the skb */
	struct nlmsghdr lastnlh; / netlink header of last msg in skb */
	struct sk_buff skb; / the pre-allocated skb */
	struct timer_list timer; /* the timer function */
	spinlock_t lock; /* the per-queue lock */
	} ebt_ulog_buff_t;

	static ebt_ulog_buff_t ulog_buffers[EBT_ULOG_MAXNLGROUPS];
	static struct sock *ebtulognl;

	/* send one ulog_buff_t to userspace */
	static void ulog_send(unsigned int nlgroup)
	{
	ebt_ulog_buff_t *ub = &ulog_buffers[nlgroup];

	if (timer_pending(&ub->timer))
	del_timer(&ub->timer);

	if (!ub->skb)
	return;

	/* last nlmsg needs NLMSG_DONE */
	if (ub->qlen > 1)
	ub->lastnlh->nlmsg_type = NLMSG_DONE;

	NETLINK_CB(ub->skb).dst_group = nlgroup + 1;
	netlink_broadcast(ebtulognl, ub->skb, 0, nlgroup + 1, GFP_ATOMIC);

	ub->qlen = 0;
	ub->skb = NULL;
	}

	/* timer function to flush queue in flushtimeout time */
	static void ulog_timer(unsigned long data)
	{
	spin_lock_bh(&ulog_buffers[data].lock);
	if (ulog_buffers[data].skb)
	ulog_send(data);
	spin_unlock_bh(&ulog_buffers[data].lock);
	}

	static struct sk_buff *ulog_alloc_skb(unsigned int size)
	{
	struct sk_buff *skb;
	unsigned int n;

	n = max(size, nlbufsiz);
	skb = alloc_skb(n, GFP_ATOMIC);
	if (!skb) {
	PRINTR(KERN_ERR "ebt_ulog: can't alloc whole buffer "
	"of size %ub!\n", n);
	if (n > size) {
	/* try to allocate only as much as we need for
	* current packet */
	skb = alloc_skb(size, GFP_ATOMIC);
	if (!skb)
	PRINTR(KERN_ERR "ebt_ulog: can't even allocate "
	"buffer of size %ub\n", size);
	}
	}

	return skb;
	}

	static void ebt_ulog_packet(unsigned int hooknr, const struct sk_buff *skb,
	const struct net_device in, const struct net_device out,
	const struct ebt_ulog_info uloginfo, const char prefix)
	{
	ebt_ulog_packet_msg_t *pm;
	size_t size, copy_len;
	struct nlmsghdr *nlh;
	unsigned int group = uloginfo->nlgroup;
	ebt_ulog_buff_t *ub = &ulog_buffers[group];
	spinlock_t *lock = &ub->lock;
	ktime_t kt;

	if ((uloginfo->cprange == 0) \|\|
	(uloginfo->cprange > skb->len + ETH_HLEN))
	copy_len = skb->len + ETH_HLEN;
	else
	copy_len = uloginfo->cprange;

	size = NLMSG_SPACE(sizeof(*pm) + copy_len);
	if (size > nlbufsiz) {
	PRINTR("ebt_ulog: Size %Zd needed, but nlbufsiz=%d\n",
	size, nlbufsiz);
	return;
	}

	spin_lock_bh(lock);

	if (!ub->skb) {
	if (!(ub->skb = ulog_alloc_skb(size)))
	goto alloc_failure;
	} else if (size > skb_tailroom(ub->skb)) {
	ulog_send(group);

	if (!(ub->skb = ulog_alloc_skb(size)))
	goto alloc_failure;
	}

	nlh = NLMSG_PUT(ub->skb, 0, ub->qlen, 0,
	size - NLMSG_ALIGN(sizeof(*nlh)));
	ub->qlen++;

	pm = NLMSG_DATA(nlh);

	/* Fill in the ulog data */
	pm->version = EBT_ULOG_VERSION;
	kt = ktime_get_real();
	pm->stamp = ktime_to_timeval(kt);
	if (ub->qlen == 1)
	ub->skb->tstamp = kt;
	pm->data_len = copy_len;
	pm->mark = skb->mark;
	pm->hook = hooknr;
	if (uloginfo->prefix != NULL)
	strcpy(pm->prefix, uloginfo->prefix);
	else
	*(pm->prefix) = '\0';

	if (in) {
	strcpy(pm->physindev, in->name);
	/* If in isn't a bridge, then physindev==indev */
	if (in->br_port)
	strcpy(pm->indev, in->br_port->br->dev->name);
	else
	strcpy(pm->indev, in->name);
	} else
	pm->indev[0] = pm->physindev[0] = '\0';

	if (out) {
	/* If out exists, then out is a bridge port */
	strcpy(pm->physoutdev, out->name);
	strcpy(pm->outdev, out->br_port->br->dev->name);
	} else
	pm->outdev[0] = pm->physoutdev[0] = '\0';

	if (skb_copy_bits(skb, -ETH_HLEN, pm->data, copy_len) < 0)
	BUG();

	if (ub->qlen > 1)
	ub->lastnlh->nlmsg_flags \|= NLM_F_MULTI;

	ub->lastnlh = nlh;

	if (ub->qlen >= uloginfo->qthreshold)
	ulog_send(group);
	else if (!timer_pending(&ub->timer)) {
	ub->timer.expires = jiffies + flushtimeout * HZ / 100;
	add_timer(&ub->timer);
	}

	unlock:
	spin_unlock_bh(lock);

	return;

	nlmsg_failure:
	printk(KERN_CRIT "ebt_ulog: error during NLMSG_PUT. This should "
	"not happen, please report to author.\n");
	goto unlock;
	alloc_failure:
	goto unlock;
	}

	/* this function is registered with the netfilter core */
	static void ebt_log_packet(u_int8_t pf, unsigned int hooknum,
	const struct sk_buff skb, const struct net_device in,
	const struct net_device out, const struct nf_loginfo li,
	const char *prefix)
	{
	struct ebt_ulog_info loginfo;

	if (!li \|\| li->type != NF_LOG_TYPE_ULOG) {
	loginfo.nlgroup = EBT_ULOG_DEFAULT_NLGROUP;
	loginfo.cprange = 0;
	loginfo.qthreshold = EBT_ULOG_DEFAULT_QTHRESHOLD;
	loginfo.prefix[0] = '\0';
	} else {
	loginfo.nlgroup = li->u.ulog.group;
	loginfo.cprange = li->u.ulog.copy_len;
	loginfo.qthreshold = li->u.ulog.qthreshold;
	strlcpy(loginfo.prefix, prefix, sizeof(loginfo.prefix));
	}

	ebt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix);
	}

	static unsigned int
	ebt_ulog_tg(struct sk_buff skb, const struct xt_target_param par)
	{
	ebt_ulog_packet(par->hooknum, skb, par->in, par->out,
	par->targinfo, NULL);
	return EBT_CONTINUE;
	}

	static bool ebt_ulog_tg_check(const struct xt_tgchk_param *par)
	{
	struct ebt_ulog_info *uloginfo = par->targinfo;

	if (uloginfo->nlgroup > 31)
	return false;

	uloginfo->prefix[EBT_ULOG_PREFIX_LEN - 1] = '\0';

	if (uloginfo->qthreshold > EBT_ULOG_MAX_QLEN)
	uloginfo->qthreshold = EBT_ULOG_MAX_QLEN;

	return true;
	}

	static struct xt_target ebt_ulog_tg_reg __read_mostly = {
	.name = "ulog",
	.revision = 0,
	.family = NFPROTO_BRIDGE,
	.target = ebt_ulog_tg,
	.checkentry = ebt_ulog_tg_check,
	.targetsize = XT_ALIGN(sizeof(struct ebt_ulog_info)),
	.me = THIS_MODULE,
	};

	static struct nf_logger ebt_ulog_logger __read_mostly = {
	.name = "ebt_ulog",
	.logfn = &ebt_log_packet,
	.me = THIS_MODULE,
	};

	static int __init ebt_ulog_init(void)
	{
	int ret;
	int i;

	if (nlbufsiz >= 128*1024) {
	printk(KERN_NOTICE "ebt_ulog: Netlink buffer has to be <= 128kB,"
	" please try a smaller nlbufsiz parameter.\n");
	return -EINVAL;
	}

	/* initialize ulog_buffers */
	for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) {
	setup_timer(&ulog_buffers[i].timer, ulog_timer, i);
	spin_lock_init(&ulog_buffers[i].lock);
	}

	ebtulognl = netlink_kernel_create(&init_net, NETLINK_NFLOG,
	EBT_ULOG_MAXNLGROUPS, NULL, NULL,
	THIS_MODULE);
	if (!ebtulognl) {
	printk(KERN_WARNING KBUILD_MODNAME ": out of memory trying to "
	"call netlink_kernel_create\n");
	ret = -ENOMEM;
	} else if ((ret = xt_register_target(&ebt_ulog_tg_reg)) != 0) {
	netlink_kernel_release(ebtulognl);
	}

	if (ret == 0)
	nf_log_register(NFPROTO_BRIDGE, &ebt_ulog_logger);

	return ret;
	}

	static void __exit ebt_ulog_fini(void)
	{
	ebt_ulog_buff_t *ub;
	int i;

	nf_log_unregister(&ebt_ulog_logger);
	xt_unregister_target(&ebt_ulog_tg_reg);
	for (i = 0; i < EBT_ULOG_MAXNLGROUPS; i++) {
	ub = &ulog_buffers[i];
	if (timer_pending(&ub->timer))
	del_timer(&ub->timer);
	spin_lock_bh(&ub->lock);
	if (ub->skb) {
	kfree_skb(ub->skb);
	ub->skb = NULL;
	}
	spin_unlock_bh(&ub->lock);
	}
	netlink_kernel_release(ebtulognl);
	}

	module_init(ebt_ulog_init);
	module_exit(ebt_ulog_fini);
	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
	MODULE_DESCRIPTION("Ebtables: Packet logging to netlink using ULOG");