net/netfilter/nfnetlink.c - maze/linux - Git at Google

 /* Netfilter messages via netlink socket. Allows for user space
  * protocol helpers and general trouble making from userspace.
  *
  * (C) 2001 by Jay Schulist <jschlst@samba.org>,
  * (C) 2002-2005 by Harald Welte <laforge@gnumonks.org>
  * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
  *
  * Initial netfilter messages via netlink development funded and
  * generally made possible by Network Robots, Inc. (www.networkrobots.com)
  *
  * Further development of this code funded by Astaro AG (http://www.astaro.com)
  *
  * This software may be used and distributed according to the terms
  * of the GNU General Public License, incorporated herein by reference.
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/socket.h>
 #include <linux/kernel.h>
 #include <linux/major.h>
 #include <linux/sched.h>
 #include <linux/timer.h>
 #include <linux/string.h>
 #include <linux/sockios.h>
 #include <linux/net.h>
 #include <linux/fcntl.h>
 #include <linux/skbuff.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
 #include <net/sock.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>

 #include <linux/netfilter.h>
 #include <linux/netlink.h>
 #include <linux/netfilter/nfnetlink.h>

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER);

 static char __initdata nfversion[] = "0.30";

 #if 0
 #define DEBUGP(format, args...)	\
 		printk(KERN_DEBUG "%s(%d):%s(): " format, __FILE__, \
 			__LINE__, __FUNCTION__, ## args)
 #else
 #define DEBUGP(format, args...)
 #endif

 static struct sock *nfnl = NULL;
 static struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT];
 DECLARE_MUTEX(nfnl_sem);

 void nfnl_lock(void)
 {
 	nfnl_shlock();
 }

 void nfnl_unlock(void)
 {
 	nfnl_shunlock();
 }

 int nfnetlink_subsys_register(struct nfnetlink_subsystem *n)
 {
 	DEBUGP("registering subsystem ID %u\n", n->subsys_id);

 	nfnl_lock();
 	if (subsys_table[n->subsys_id]) {
 		nfnl_unlock();
 		return -EBUSY;
 	}
 	subsys_table[n->subsys_id] = n;
 	nfnl_unlock();

 	return 0;
 }

 int nfnetlink_subsys_unregister(struct nfnetlink_subsystem *n)
 {
 	DEBUGP("unregistering subsystem ID %u\n", n->subsys_id);

 	nfnl_lock();
 	subsys_table[n->subsys_id] = NULL;
 	nfnl_unlock();

 	return 0;
 }

 static inline struct nfnetlink_subsystem *nfnetlink_get_subsys(u_int16_t type)
 {
 	u_int8_t subsys_id = NFNL_SUBSYS_ID(type);

 	if (subsys_id >= NFNL_SUBSYS_COUNT
 	    || subsys_table[subsys_id] == NULL)
 		return NULL;

 	return subsys_table[subsys_id];
 }

 static inline struct nfnl_callback *
 nfnetlink_find_client(u_int16_t type, struct nfnetlink_subsystem *ss)
 {
 	u_int8_t cb_id = NFNL_MSG_TYPE(type);

 	if (cb_id >= ss->cb_count) {
 		DEBUGP("msgtype %u >= %u, returning\n", type, ss->cb_count);
 		return NULL;
 	}

 	return &ss->cb[cb_id];
 }

 void __nfa_fill(struct sk_buff *skb, int attrtype, int attrlen,
 		const void *data)
 {
 	struct nfattr *nfa;
 	int size = NFA_LENGTH(attrlen);

 	nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size));
 	nfa->nfa_type = attrtype;
 	nfa->nfa_len  = size;
 	memcpy(NFA_DATA(nfa), data, attrlen);
 	memset(NFA_DATA(nfa) + attrlen, 0, NFA_ALIGN(size) - size);
 }

 void nfattr_parse(struct nfattr *tb[], int maxattr, struct nfattr *nfa, int len)
 {
 	memset(tb, 0, sizeof(struct nfattr *) * maxattr);

 	while (NFA_OK(nfa, len)) {
 		unsigned flavor = NFA_TYPE(nfa);
 		if (flavor && flavor <= maxattr)
 			tb[flavor-1] = nfa;
 		nfa = NFA_NEXT(nfa, len);
 	}
 }

 /**
  * nfnetlink_check_attributes - check and parse nfnetlink attributes
  *
  * subsys: nfnl subsystem for which this message is to be parsed
  * nlmsghdr: netlink message to be checked/parsed
  * cda: array of pointers, needs to be at least subsys->attr_count big
  *
  */
 static int
 nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys,
 			   struct nlmsghdr *nlh, struct nfattr *cda[])
 {
 	int min_len;
 	u_int16_t attr_count;
 	u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);

 	if (unlikely(cb_id >= subsys->cb_count)) {
 		DEBUGP("msgtype %u >= %u, returning\n",
 			cb_id, subsys->cb_count);
 		return -EINVAL;
 	}

 	min_len = NLMSG_SPACE(sizeof(struct nfgenmsg));
 	if (unlikely(nlh->nlmsg_len < min_len))
 		return -EINVAL;

 	attr_count = subsys->cb[cb_id].attr_count;
 	memset(cda, 0, sizeof(struct nfattr *) * attr_count);

 	/* check attribute lengths. */
 	if (likely(nlh->nlmsg_len > min_len)) {
 		struct nfattr *attr = NFM_NFA(NLMSG_DATA(nlh));
 		int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);

 		while (NFA_OK(attr, attrlen)) {
 			unsigned flavor = NFA_TYPE(attr);
 			if (flavor) {
 				if (flavor > attr_count)
 					return -EINVAL;
 				cda[flavor - 1] = attr;
 			}
 			attr = NFA_NEXT(attr, attrlen);
 		}
 	}

 	/* implicit: if nlmsg_len == min_len, we return 0, and an empty
 	 * (zeroed) cda[] array. The message is valid, but empty. */

         return 0;
 }

 int nfnetlink_has_listeners(unsigned int group)
 {
 	return netlink_has_listeners(nfnl, group);
 }
 EXPORT_SYMBOL_GPL(nfnetlink_has_listeners);

 int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
 {
 	gfp_t allocation = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;
 	int err = 0;

 	NETLINK_CB(skb).dst_group = group;
 	if (echo)
 		atomic_inc(&skb->users);
 	netlink_broadcast(nfnl, skb, pid, group, allocation);
 	if (echo)
 		err = netlink_unicast(nfnl, skb, pid, MSG_DONTWAIT);

 	return err;
 }

 int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags)
 {
 	return netlink_unicast(nfnl, skb, pid, flags);
 }

 /* Process one complete nfnetlink message. */
 static int nfnetlink_rcv_msg(struct sk_buff *skb,
 				    struct nlmsghdr *nlh, int *errp)
 {
 	struct nfnl_callback *nc;
 	struct nfnetlink_subsystem *ss;
 	int type, err = 0;

 	DEBUGP("entered; subsys=%u, msgtype=%u\n",
 		 NFNL_SUBSYS_ID(nlh->nlmsg_type),
 		 NFNL_MSG_TYPE(nlh->nlmsg_type));

 	if (security_netlink_recv(skb, CAP_NET_ADMIN)) {
 		DEBUGP("missing CAP_NET_ADMIN\n");
 		*errp = -EPERM;
 		return -1;
 	}

 	/* Only requests are handled by kernel now. */
 	if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) {
 		DEBUGP("received non-request message\n");
 		return 0;
 	}

 	/* All the messages must at least contain nfgenmsg */
 	if (nlh->nlmsg_len < NLMSG_SPACE(sizeof(struct nfgenmsg))) {
 		DEBUGP("received message was too short\n");
 		return 0;
 	}

 	type = nlh->nlmsg_type;
 	ss = nfnetlink_get_subsys(type);
 	if (!ss) {
 #ifdef CONFIG_KMOD
 		/* don't call nfnl_shunlock, since it would reenter
 		 * with further packet processing */
 		up(&nfnl_sem);
 		request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type));
 		nfnl_shlock();
 		ss = nfnetlink_get_subsys(type);
 		if (!ss)
 #endif
 			goto err_inval;
 	}

 	nc = nfnetlink_find_client(type, ss);
 	if (!nc) {
 		DEBUGP("unable to find client for type %d\n", type);
 		goto err_inval;
 	}

 	{
 		u_int16_t attr_count =
 			ss->cb[NFNL_MSG_TYPE(nlh->nlmsg_type)].attr_count;
 		struct nfattr *cda[attr_count];

 		memset(cda, 0, sizeof(struct nfattr *) * attr_count);

 		err = nfnetlink_check_attributes(ss, nlh, cda);
 		if (err < 0)
 			goto err_inval;

 		DEBUGP("calling handler\n");
 		err = nc->call(nfnl, skb, nlh, cda, errp);
 		*errp = err;
 		return err;
 	}

 err_inval:
 	DEBUGP("returning -EINVAL\n");
 	*errp = -EINVAL;
 	return -1;
 }

 /* Process one packet of messages. */
 static inline int nfnetlink_rcv_skb(struct sk_buff *skb)
 {
 	int err;
 	struct nlmsghdr *nlh;

 	while (skb->len >= NLMSG_SPACE(0)) {
 		u32 rlen;

 		nlh = (struct nlmsghdr *)skb->data;
 		if (nlh->nlmsg_len < sizeof(struct nlmsghdr)
 		    || skb->len < nlh->nlmsg_len)
 			return 0;
 		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
 		if (rlen > skb->len)
 			rlen = skb->len;
 		if (nfnetlink_rcv_msg(skb, nlh, &err)) {
 			if (!err)
 				return -1;
 			netlink_ack(skb, nlh, err);
 		} else
 			if (nlh->nlmsg_flags & NLM_F_ACK)
 				netlink_ack(skb, nlh, 0);
 		skb_pull(skb, rlen);
 	}

 	return 0;
 }

 static void nfnetlink_rcv(struct sock *sk, int len)
 {
 	do {
 		struct sk_buff *skb;

 		if (nfnl_shlock_nowait())
 			return;

 		while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 			if (nfnetlink_rcv_skb(skb)) {
 				if (skb->len)
 					skb_queue_head(&sk->sk_receive_queue,
 						       skb);
 				else
 					kfree_skb(skb);
 				break;
 			}
 			kfree_skb(skb);
 		}

 		/* don't call nfnl_shunlock, since it would reenter
 		 * with further packet processing */
 		up(&nfnl_sem);
 	} while(nfnl && nfnl->sk_receive_queue.qlen);
 }

 static void __exit nfnetlink_exit(void)
 {
 	printk("Removing netfilter NETLINK layer.\n");
 	sock_release(nfnl->sk_socket);
 	return;
 }

 static int __init nfnetlink_init(void)
 {
 	printk("Netfilter messages via NETLINK v%s.\n", nfversion);

 	nfnl = netlink_kernel_create(NETLINK_NETFILTER, NFNLGRP_MAX,
 	                             nfnetlink_rcv, THIS_MODULE);
 	if (!nfnl) {
 		printk(KERN_ERR "cannot initialize nfnetlink!\n");
 		return -1;
 	}

 	return 0;
 }

 module_init(nfnetlink_init);
 module_exit(nfnetlink_exit);

 EXPORT_SYMBOL_GPL(nfnetlink_subsys_register);
 EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister);
 EXPORT_SYMBOL_GPL(nfnetlink_send);
 EXPORT_SYMBOL_GPL(nfnetlink_unicast);
 EXPORT_SYMBOL_GPL(nfattr_parse);
 EXPORT_SYMBOL_GPL(__nfa_fill);
	/* Netfilter messages via netlink socket. Allows for user space
	* protocol helpers and general trouble making from userspace.
	*
	* (C) 2001 by Jay Schulist <jschlst@samba.org>,
	* (C) 2002-2005 by Harald Welte <laforge@gnumonks.org>
	* (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
	*
	* Initial netfilter messages via netlink development funded and
	* generally made possible by Network Robots, Inc. (www.networkrobots.com)
	*
	* Further development of this code funded by Astaro AG (http://www.astaro.com)
	*
	* This software may be used and distributed according to the terms
	* of the GNU General Public License, incorporated herein by reference.
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/socket.h>
	#include <linux/kernel.h>
	#include <linux/major.h>
	#include <linux/sched.h>
	#include <linux/timer.h>
	#include <linux/string.h>
	#include <linux/sockios.h>
	#include <linux/net.h>
	#include <linux/fcntl.h>
	#include <linux/skbuff.h>
	#include <asm/uaccess.h>
	#include <asm/system.h>
	#include <net/sock.h>
	#include <linux/init.h>
	#include <linux/spinlock.h>

	#include <linux/netfilter.h>
	#include <linux/netlink.h>
	#include <linux/netfilter/nfnetlink.h>

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
	MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER);

	static char __initdata nfversion[] = "0.30";

	#if 0
	#define DEBUGP(format, args...) \
	printk(KERN_DEBUG "%s(%d):%s(): " format, __FILE__, \
	__LINE__, __FUNCTION__, ## args)
	#else
	#define DEBUGP(format, args...)
	#endif

	static struct sock *nfnl = NULL;
	static struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT];
	DECLARE_MUTEX(nfnl_sem);

	void nfnl_lock(void)
	{
	nfnl_shlock();
	}

	void nfnl_unlock(void)
	{
	nfnl_shunlock();
	}

	int nfnetlink_subsys_register(struct nfnetlink_subsystem *n)
	{
	DEBUGP("registering subsystem ID %u\n", n->subsys_id);

	nfnl_lock();
	if (subsys_table[n->subsys_id]) {
	nfnl_unlock();
	return -EBUSY;
	}
	subsys_table[n->subsys_id] = n;
	nfnl_unlock();

	return 0;
	}

	int nfnetlink_subsys_unregister(struct nfnetlink_subsystem *n)
	{
	DEBUGP("unregistering subsystem ID %u\n", n->subsys_id);

	nfnl_lock();
	subsys_table[n->subsys_id] = NULL;
	nfnl_unlock();

	return 0;
	}

	static inline struct nfnetlink_subsystem *nfnetlink_get_subsys(u_int16_t type)
	{
	u_int8_t subsys_id = NFNL_SUBSYS_ID(type);

	if (subsys_id >= NFNL_SUBSYS_COUNT
	\|\| subsys_table[subsys_id] == NULL)
	return NULL;

	return subsys_table[subsys_id];
	}

	static inline struct nfnl_callback *
	nfnetlink_find_client(u_int16_t type, struct nfnetlink_subsystem *ss)
	{
	u_int8_t cb_id = NFNL_MSG_TYPE(type);

	if (cb_id >= ss->cb_count) {
	DEBUGP("msgtype %u >= %u, returning\n", type, ss->cb_count);
	return NULL;
	}

	return &ss->cb[cb_id];
	}

	void __nfa_fill(struct sk_buff *skb, int attrtype, int attrlen,
	const void *data)
	{
	struct nfattr *nfa;
	int size = NFA_LENGTH(attrlen);

	nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size));
	nfa->nfa_type = attrtype;
	nfa->nfa_len = size;
	memcpy(NFA_DATA(nfa), data, attrlen);
	memset(NFA_DATA(nfa) + attrlen, 0, NFA_ALIGN(size) - size);
	}

	void nfattr_parse(struct nfattr tb[], int maxattr, struct nfattr nfa, int len)
	{
	memset(tb, 0, sizeof(struct nfattr ) maxattr);

	while (NFA_OK(nfa, len)) {
	unsigned flavor = NFA_TYPE(nfa);
	if (flavor && flavor <= maxattr)
	tb[flavor-1] = nfa;
	nfa = NFA_NEXT(nfa, len);
	}
	}

	/**
	* nfnetlink_check_attributes - check and parse nfnetlink attributes
	*
	* subsys: nfnl subsystem for which this message is to be parsed
	* nlmsghdr: netlink message to be checked/parsed
	* cda: array of pointers, needs to be at least subsys->attr_count big
	*
	*/
	static int
	nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys,
	struct nlmsghdr nlh, struct nfattr cda[])
	{
	int min_len;
	u_int16_t attr_count;
	u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);

	if (unlikely(cb_id >= subsys->cb_count)) {
	DEBUGP("msgtype %u >= %u, returning\n",
	cb_id, subsys->cb_count);
	return -EINVAL;
	}

	min_len = NLMSG_SPACE(sizeof(struct nfgenmsg));
	if (unlikely(nlh->nlmsg_len < min_len))
	return -EINVAL;

	attr_count = subsys->cb[cb_id].attr_count;
	memset(cda, 0, sizeof(struct nfattr ) attr_count);

	/* check attribute lengths. */
	if (likely(nlh->nlmsg_len > min_len)) {
	struct nfattr *attr = NFM_NFA(NLMSG_DATA(nlh));
	int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);

	while (NFA_OK(attr, attrlen)) {
	unsigned flavor = NFA_TYPE(attr);
	if (flavor) {
	if (flavor > attr_count)
	return -EINVAL;
	cda[flavor - 1] = attr;
	}
	attr = NFA_NEXT(attr, attrlen);
	}
	}

	/* implicit: if nlmsg_len == min_len, we return 0, and an empty
	* (zeroed) cda[] array. The message is valid, but empty. */

	return 0;
	}

	int nfnetlink_has_listeners(unsigned int group)
	{
	return netlink_has_listeners(nfnl, group);
	}
	EXPORT_SYMBOL_GPL(nfnetlink_has_listeners);

	int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
	{
	gfp_t allocation = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;
	int err = 0;

	NETLINK_CB(skb).dst_group = group;
	if (echo)
	atomic_inc(&skb->users);
	netlink_broadcast(nfnl, skb, pid, group, allocation);
	if (echo)
	err = netlink_unicast(nfnl, skb, pid, MSG_DONTWAIT);

	return err;
	}

	int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags)
	{
	return netlink_unicast(nfnl, skb, pid, flags);
	}

	/* Process one complete nfnetlink message. */
	static int nfnetlink_rcv_msg(struct sk_buff *skb,
	struct nlmsghdr nlh, int errp)
	{
	struct nfnl_callback *nc;
	struct nfnetlink_subsystem *ss;
	int type, err = 0;

	DEBUGP("entered; subsys=%u, msgtype=%u\n",
	NFNL_SUBSYS_ID(nlh->nlmsg_type),
	NFNL_MSG_TYPE(nlh->nlmsg_type));

	if (security_netlink_recv(skb, CAP_NET_ADMIN)) {
	DEBUGP("missing CAP_NET_ADMIN\n");
	*errp = -EPERM;
	return -1;
	}

	/* Only requests are handled by kernel now. */
	if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) {
	DEBUGP("received non-request message\n");
	return 0;
	}

	/* All the messages must at least contain nfgenmsg */
	if (nlh->nlmsg_len < NLMSG_SPACE(sizeof(struct nfgenmsg))) {
	DEBUGP("received message was too short\n");
	return 0;
	}

	type = nlh->nlmsg_type;
	ss = nfnetlink_get_subsys(type);
	if (!ss) {
	#ifdef CONFIG_KMOD
	/* don't call nfnl_shunlock, since it would reenter
	* with further packet processing */
	up(&nfnl_sem);
	request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type));
	nfnl_shlock();
	ss = nfnetlink_get_subsys(type);
	if (!ss)
	#endif
	goto err_inval;
	}

	nc = nfnetlink_find_client(type, ss);
	if (!nc) {
	DEBUGP("unable to find client for type %d\n", type);
	goto err_inval;
	}

	{
	u_int16_t attr_count =
	ss->cb[NFNL_MSG_TYPE(nlh->nlmsg_type)].attr_count;
	struct nfattr *cda[attr_count];

	memset(cda, 0, sizeof(struct nfattr ) attr_count);

	err = nfnetlink_check_attributes(ss, nlh, cda);
	if (err < 0)
	goto err_inval;

	DEBUGP("calling handler\n");
	err = nc->call(nfnl, skb, nlh, cda, errp);
	*errp = err;
	return err;
	}

	err_inval:
	DEBUGP("returning -EINVAL\n");
	*errp = -EINVAL;
	return -1;
	}

	/* Process one packet of messages. */
	static inline int nfnetlink_rcv_skb(struct sk_buff *skb)
	{
	int err;
	struct nlmsghdr *nlh;

	while (skb->len >= NLMSG_SPACE(0)) {
	u32 rlen;

	nlh = (struct nlmsghdr *)skb->data;
	if (nlh->nlmsg_len < sizeof(struct nlmsghdr)
	\|\| skb->len < nlh->nlmsg_len)
	return 0;
	rlen = NLMSG_ALIGN(nlh->nlmsg_len);
	if (rlen > skb->len)
	rlen = skb->len;
	if (nfnetlink_rcv_msg(skb, nlh, &err)) {
	if (!err)
	return -1;
	netlink_ack(skb, nlh, err);
	} else
	if (nlh->nlmsg_flags & NLM_F_ACK)
	netlink_ack(skb, nlh, 0);
	skb_pull(skb, rlen);
	}

	return 0;
	}

	static void nfnetlink_rcv(struct sock *sk, int len)
	{
	do {
	struct sk_buff *skb;

	if (nfnl_shlock_nowait())
	return;

	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
	if (nfnetlink_rcv_skb(skb)) {
	if (skb->len)
	skb_queue_head(&sk->sk_receive_queue,
	skb);
	else
	kfree_skb(skb);
	break;
	}
	kfree_skb(skb);
	}

	/* don't call nfnl_shunlock, since it would reenter
	* with further packet processing */
	up(&nfnl_sem);
	} while(nfnl && nfnl->sk_receive_queue.qlen);
	}

	static void __exit nfnetlink_exit(void)
	{
	printk("Removing netfilter NETLINK layer.\n");
	sock_release(nfnl->sk_socket);
	return;
	}

	static int __init nfnetlink_init(void)
	{
	printk("Netfilter messages via NETLINK v%s.\n", nfversion);

	nfnl = netlink_kernel_create(NETLINK_NETFILTER, NFNLGRP_MAX,
	nfnetlink_rcv, THIS_MODULE);
	if (!nfnl) {
	printk(KERN_ERR "cannot initialize nfnetlink!\n");
	return -1;
	}

	return 0;
	}

	module_init(nfnetlink_init);
	module_exit(nfnetlink_exit);

	EXPORT_SYMBOL_GPL(nfnetlink_subsys_register);
	EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister);
	EXPORT_SYMBOL_GPL(nfnetlink_send);
	EXPORT_SYMBOL_GPL(nfnetlink_unicast);
	EXPORT_SYMBOL_GPL(nfattr_parse);
	EXPORT_SYMBOL_GPL(__nfa_fill);