[net-next-2.6.git] / security / selinux / netlabel.c

/*
 * SELinux NetLabel Support
 *
 * This file provides the necessary glue to tie NetLabel into the SELinux
 * subsystem.
 *
 * Author: Paul Moore <paul.moore@hp.com>
 *
 */

/*
 * (c) Copyright Hewlett-Packard Development Company, L.P., 2007
 *
 * This program 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 program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY;  without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program;  if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <net/sock.h>
#include <net/netlabel.h>

#include "objsec.h"
#include "security.h"

/**
 * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism
 * @sk: the socket to label
 * @sid: the SID to use
 *
 * Description:
 * Attempt to label a socket using the NetLabel mechanism using the given
 * SID.  Returns zero values on success, negative values on failure.  The
 * caller is responsibile for calling rcu_read_lock() before calling this
 * this function and rcu_read_unlock() after this function returns.
 *
 */
static int selinux_netlbl_sock_setsid(struct sock *sk, u32 sid)
{
	int rc;
	struct sk_security_struct *sksec = sk->sk_security;
	struct netlbl_lsm_secattr secattr;

	rc = security_netlbl_sid_to_secattr(sid, &secattr);
	if (rc != 0)
		return rc;

	rc = netlbl_sock_setattr(sk, &secattr);
	if (rc == 0) {
		spin_lock_bh(&sksec->nlbl_lock);
		sksec->nlbl_state = NLBL_LABELED;
		spin_unlock_bh(&sksec->nlbl_lock);
	}

	return rc;
}

/**
 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
 *
 * Description:
 * Invalidate the NetLabel security attribute mapping cache.
 *
 */
void selinux_netlbl_cache_invalidate(void)
{
	netlbl_cache_invalidate();
}

/**
 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
 * @ssec: the sk_security_struct
 * @family: the socket family
 *
 * Description:
 * Called when the NetLabel state of a sk_security_struct needs to be reset.
 * The caller is responsibile for all the NetLabel sk_security_struct locking.
 *
 */
void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
				      int family)
{
        if (family == PF_INET)
		ssec->nlbl_state = NLBL_REQUIRE;
	else
		ssec->nlbl_state = NLBL_UNSET;
}

/**
 * selinux_netlbl_sk_security_init - Setup the NetLabel fields
 * @ssec: the sk_security_struct
 * @family: the socket family
 *
 * Description:
 * Called when a new sk_security_struct is allocated to initialize the NetLabel
 * fields.
 *
 */
void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
				     int family)
{
	/* No locking needed, we are the only one who has access to ssec */
	selinux_netlbl_sk_security_reset(ssec, family);
	spin_lock_init(&ssec->nlbl_lock);
}

/**
 * selinux_netlbl_sk_security_clone - Copy the NetLabel fields
 * @ssec: the original sk_security_struct
 * @newssec: the cloned sk_security_struct
 *
 * Description:
 * Clone the NetLabel specific sk_security_struct fields from @ssec to
 * @newssec.
 *
 */
void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
				      struct sk_security_struct *newssec)
{
	/* We don't need to take newssec->nlbl_lock because we are the only
	 * thread with access to newssec, but we do need to take the RCU read
	 * lock as other threads could have access to ssec */
	rcu_read_lock();
	selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
	newssec->sclass = ssec->sclass;
	rcu_read_unlock();
}

/**
 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
 * @skb: the packet
 * @base_sid: the SELinux SID to use as a context for MLS only attributes
 * @sid: the SID
 *
 * Description:
 * Call the NetLabel mechanism to get the security attributes of the given
 * packet and use those attributes to determine the correct context/SID to
 * assign to the packet.  Returns zero on success, negative values on failure.
 *
 */
int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid)
{
	int rc;
	struct netlbl_lsm_secattr secattr;

	netlbl_secattr_init(&secattr);
	rc = netlbl_skbuff_getattr(skb, &secattr);
	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
		rc = security_netlbl_secattr_to_sid(&secattr, base_sid, sid);
	else
		*sid = SECSID_NULL;
	netlbl_secattr_destroy(&secattr);

	return rc;
}

/**
 * selinux_netlbl_sock_graft - Netlabel the new socket
 * @sk: the new connection
 * @sock: the new socket
 *
 * Description:
 * The connection represented by @sk is being grafted onto @sock so set the
 * socket's NetLabel to match the SID of @sk.
 *
 */
void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
{
	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
	struct sk_security_struct *sksec = sk->sk_security;
	struct netlbl_lsm_secattr secattr;
	u32 nlbl_peer_sid;

	sksec->sclass = isec->sclass;

	rcu_read_lock();

	if (sksec->nlbl_state != NLBL_REQUIRE) {
		rcu_read_unlock();
		return;
	}

	netlbl_secattr_init(&secattr);
	if (netlbl_sock_getattr(sk, &secattr) == 0 &&
	    secattr.flags != NETLBL_SECATTR_NONE &&
	    security_netlbl_secattr_to_sid(&secattr,
					   SECINITSID_NETMSG,
					   &nlbl_peer_sid) == 0)
		sksec->peer_sid = nlbl_peer_sid;
	netlbl_secattr_destroy(&secattr);

	/* Try to set the NetLabel on the socket to save time later, if we fail
	 * here we will pick up the pieces in later calls to
	 * selinux_netlbl_inode_permission(). */
	selinux_netlbl_sock_setsid(sk, sksec->sid);

	rcu_read_unlock();
}

/**
 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
 * @sock: the socket to label
 *
 * Description:
 * Attempt to label a socket using the NetLabel mechanism using the given
 * SID.  Returns zero values on success, negative values on failure.
 *
 */
int selinux_netlbl_socket_post_create(struct socket *sock)
{
	int rc = 0;
	struct sock *sk = sock->sk;
	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
	struct sk_security_struct *sksec = sk->sk_security;

	sksec->sclass = isec->sclass;

	rcu_read_lock();
	if (sksec->nlbl_state == NLBL_REQUIRE)
		rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
	rcu_read_unlock();

	return rc;
}

/**
 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
 * @inode: the file descriptor's inode
 * @mask: the permission mask
 *
 * Description:
 * Looks at a file's inode and if it is marked as a socket protected by
 * NetLabel then verify that the socket has been labeled, if not try to label
 * the socket now with the inode's SID.  Returns zero on success, negative
 * values on failure.
 *
 */
int selinux_netlbl_inode_permission(struct inode *inode, int mask)
{
	int rc;
	struct sock *sk;
	struct socket *sock;
	struct sk_security_struct *sksec;

	if (!S_ISSOCK(inode->i_mode) ||
	    ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
		return 0;
	sock = SOCKET_I(inode);
	sk = sock->sk;
	sksec = sk->sk_security;

	rcu_read_lock();
	if (sksec->nlbl_state != NLBL_REQUIRE) {
		rcu_read_unlock();
		return 0;
	}
	local_bh_disable();
	bh_lock_sock_nested(sk);
	rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
	bh_unlock_sock(sk);
	local_bh_enable();
	rcu_read_unlock();

	return rc;
}

/**
 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
 * @sksec: the sock's sk_security_struct
 * @skb: the packet
 * @ad: the audit data
 *
 * Description:
 * Fetch the NetLabel security attributes from @skb and perform an access check
 * against the receiving socket.  Returns zero on success, negative values on
 * error.
 *
 */
int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
				struct sk_buff *skb,
				struct avc_audit_data *ad)
{
	int rc;
	u32 nlbl_sid;
	u32 perm;

	rc = selinux_netlbl_skbuff_getsid(skb, SECINITSID_NETMSG, &nlbl_sid);
	if (rc != 0)
		return rc;
	if (nlbl_sid == SECSID_NULL)
		nlbl_sid = SECINITSID_UNLABELED;

	switch (sksec->sclass) {
	case SECCLASS_UDP_SOCKET:
		perm = UDP_SOCKET__RECVFROM;
		break;
	case SECCLASS_TCP_SOCKET:
		perm = TCP_SOCKET__RECVFROM;
		break;
	default:
		perm = RAWIP_SOCKET__RECVFROM;
	}

	rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
	if (rc == 0)
		return 0;

	if (nlbl_sid != SECINITSID_UNLABELED)
		netlbl_skbuff_err(skb, rc);
	return rc;
}

/**
 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
 * @sock: the socket
 * @level: the socket level or protocol
 * @optname: the socket option name
 *
 * Description:
 * Check the setsockopt() call and if the user is trying to replace the IP
 * options on a socket and a NetLabel is in place for the socket deny the
 * access; otherwise allow the access.  Returns zero when the access is
 * allowed, -EACCES when denied, and other negative values on error.
 *
 */
int selinux_netlbl_socket_setsockopt(struct socket *sock,
				     int level,
				     int optname)
{
	int rc = 0;
	struct sock *sk = sock->sk;
	struct sk_security_struct *sksec = sk->sk_security;
	struct netlbl_lsm_secattr secattr;

	rcu_read_lock();
	if (level == IPPROTO_IP && optname == IP_OPTIONS &&
	    sksec->nlbl_state == NLBL_LABELED) {
		netlbl_secattr_init(&secattr);
		lock_sock(sk);
		rc = netlbl_sock_getattr(sk, &secattr);
		release_sock(sk);
		if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
			rc = -EACCES;
		netlbl_secattr_destroy(&secattr);
	}
	rcu_read_unlock();

	return rc;
}
Commit	Line	Data
5778eabd PM	1	/*
	2	* SELinux NetLabel Support
	3	*
	4	* This file provides the necessary glue to tie NetLabel into the SELinux
	5	* subsystem.
	6	*
	7	* Author: Paul Moore <paul.moore@hp.com>
	8	*
	9	*/
	10
	11	/*
	12	* (c) Copyright Hewlett-Packard Development Company, L.P., 2007
	13	*
	14	* This program is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License as published by
	16	* the Free Software Foundation; either version 2 of the License, or
	17	* (at your option) any later version.
	18	*
	19	* This program is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
	22	* the GNU General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU General Public License
	25	* along with this program; if not, write to the Free Software
	26	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	27	*
	28	*/
	29
	30	#include <linux/spinlock.h>
	31	#include <linux/rcupdate.h>
	32	#include <net/sock.h>
	33	#include <net/netlabel.h>
	34
	35	#include "objsec.h"
	36	#include "security.h"
	37
	38	/**
ba6ff9f2 PM	39	* selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism
ba6ff9f2 PM	40	* @sk: the socket to label
5778eabd PM	41	* @sid: the SID to use
	42	*
	43	* Description:
	44	* Attempt to label a socket using the NetLabel mechanism using the given
	45	* SID. Returns zero values on success, negative values on failure. The
	46	* caller is responsibile for calling rcu_read_lock() before calling this
	47	* this function and rcu_read_unlock() after this function returns.
	48	*
	49	*/
ba6ff9f2	50	static int selinux_netlbl_sock_setsid(struct sock *sk, u32 sid)
5778eabd PM	51	{
5778eabd PM	52	int rc;
ba6ff9f2	53	struct sk_security_struct *sksec = sk->sk_security;
5778eabd PM	54	struct netlbl_lsm_secattr secattr;
	55
	56	rc = security_netlbl_sid_to_secattr(sid, &secattr);
	57	if (rc != 0)
	58	return rc;
	59
ba6ff9f2	60	rc = netlbl_sock_setattr(sk, &secattr);
5778eabd PM	61	if (rc == 0) {
	62	spin_lock_bh(&sksec->nlbl_lock);
	63	sksec->nlbl_state = NLBL_LABELED;
	64	spin_unlock_bh(&sksec->nlbl_lock);
	65	}
	66
	67	return rc;
	68	}
	69
	70	/**
	71	* selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
	72	*
	73	* Description:
	74	* Invalidate the NetLabel security attribute mapping cache.
	75	*
	76	*/
	77	void selinux_netlbl_cache_invalidate(void)
	78	{
	79	netlbl_cache_invalidate();
	80	}
	81
	82	/**
	83	* selinux_netlbl_sk_security_reset - Reset the NetLabel fields
	84	* @ssec: the sk_security_struct
	85	* @family: the socket family
	86	*
	87	* Description:
	88	* Called when the NetLabel state of a sk_security_struct needs to be reset.
	89	* The caller is responsibile for all the NetLabel sk_security_struct locking.
	90	*
	91	*/
	92	void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
	93	int family)
	94	{
	95	if (family == PF_INET)
	96	ssec->nlbl_state = NLBL_REQUIRE;
	97	else
	98	ssec->nlbl_state = NLBL_UNSET;
	99	}
	100
	101	/**
	102	* selinux_netlbl_sk_security_init - Setup the NetLabel fields
	103	* @ssec: the sk_security_struct
	104	* @family: the socket family
	105	*
	106	* Description:
	107	* Called when a new sk_security_struct is allocated to initialize the NetLabel
	108	* fields.
	109	*
	110	*/
	111	void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
	112	int family)
	113	{
	114	/* No locking needed, we are the only one who has access to ssec */
	115	selinux_netlbl_sk_security_reset(ssec, family);
	116	spin_lock_init(&ssec->nlbl_lock);
	117	}
	118
	119	/**
	120	* selinux_netlbl_sk_security_clone - Copy the NetLabel fields
	121	* @ssec: the original sk_security_struct
	122	* @newssec: the cloned sk_security_struct
	123	*
	124	* Description:
125	* Clone the NetLabel specific sk_security_struct fields from @ssec to
126	* @newssec.
127	*
128	*/
129	void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
130	struct sk_security_struct *newssec)
131	{
132	/* We don't need to take newssec->nlbl_lock because we are the only
133	* thread with access to newssec, but we do need to take the RCU read
134	* lock as other threads could have access to ssec */
135	rcu_read_lock();
136	selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
137	newssec->sclass = ssec->sclass;
138	rcu_read_unlock();
139	}
140
141	/**
142	* selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
143	* @skb: the packet
144	* @base_sid: the SELinux SID to use as a context for MLS only attributes
145	* @sid: the SID
146	*
147	* Description:
148	* Call the NetLabel mechanism to get the security attributes of the given
149	* packet and use those attributes to determine the correct context/SID to
150	* assign to the packet. Returns zero on success, negative values on failure.
151	*
152	*/
153	int selinux_netlbl_skbuff_getsid(struct sk_buff skb, u32 base_sid, u32 sid)
154	{
155	int rc;
156	struct netlbl_lsm_secattr secattr;
157
158	netlbl_secattr_init(&secattr);
159	rc = netlbl_skbuff_getattr(skb, &secattr);
160	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
9faf65fb	161	rc = security_netlbl_secattr_to_sid(&secattr, base_sid, sid);
5778eabd PM	162	else
	163	*sid = SECSID_NULL;
	164	netlbl_secattr_destroy(&secattr);
	165
	166	return rc;
	167	}
	168
	169	/**
	170	* selinux_netlbl_sock_graft - Netlabel the new socket
	171	* @sk: the new connection
	172	* @sock: the new socket
	173	*
	174	* Description:
	175	* The connection represented by @sk is being grafted onto @sock so set the
	176	* socket's NetLabel to match the SID of @sk.
	177	*
	178	*/
	179	void selinux_netlbl_sock_graft(struct sock sk, struct socket sock)
	180	{
	181	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
	182	struct sk_security_struct *sksec = sk->sk_security;
	183	struct netlbl_lsm_secattr secattr;
	184	u32 nlbl_peer_sid;
	185
	186	sksec->sclass = isec->sclass;
	187
	188	rcu_read_lock();
	189
	190	if (sksec->nlbl_state != NLBL_REQUIRE) {
	191	rcu_read_unlock();
	192	return;
	193	}
	194
	195	netlbl_secattr_init(&secattr);
	196	if (netlbl_sock_getattr(sk, &secattr) == 0 &&
	197	secattr.flags != NETLBL_SECATTR_NONE &&
	198	security_netlbl_secattr_to_sid(&secattr,
9faf65fb	199	SECINITSID_NETMSG,
5778eabd PM	200	&nlbl_peer_sid) == 0)
	201	sksec->peer_sid = nlbl_peer_sid;
	202	netlbl_secattr_destroy(&secattr);
	203
	204	/* Try to set the NetLabel on the socket to save time later, if we fail
	205	* here we will pick up the pieces in later calls to
	206	* selinux_netlbl_inode_permission(). */
ba6ff9f2	207	selinux_netlbl_sock_setsid(sk, sksec->sid);
5778eabd PM	208
	209	rcu_read_unlock();
	210	}
	211
	212	/**
	213	* selinux_netlbl_socket_post_create - Label a socket using NetLabel
	214	* @sock: the socket to label
	215	*
	216	* Description:
	217	* Attempt to label a socket using the NetLabel mechanism using the given
	218	* SID. Returns zero values on success, negative values on failure.
	219	*
	220	*/
	221	int selinux_netlbl_socket_post_create(struct socket *sock)
	222	{
	223	int rc = 0;
ba6ff9f2	224	struct sock *sk = sock->sk;
5778eabd	225	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
ba6ff9f2	226	struct sk_security_struct *sksec = sk->sk_security;
5778eabd PM	227
	228	sksec->sclass = isec->sclass;
	229
	230	rcu_read_lock();
	231	if (sksec->nlbl_state == NLBL_REQUIRE)
ba6ff9f2	232	rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
5778eabd PM	233	rcu_read_unlock();
	234
	235	return rc;
	236	}
	237
	238	/**
	239	* selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
	240	* @inode: the file descriptor's inode
	241	* @mask: the permission mask
	242	*
	243	* Description:
	244	* Looks at a file's inode and if it is marked as a socket protected by
	245	* NetLabel then verify that the socket has been labeled, if not try to label
	246	* the socket now with the inode's SID. Returns zero on success, negative
	247	* values on failure.
	248	*
	249	*/
	250	int selinux_netlbl_inode_permission(struct inode *inode, int mask)
	251	{
	252	int rc;
ba6ff9f2	253	struct sock *sk;
5778eabd	254	struct socket *sock;
ba6ff9f2	255	struct sk_security_struct *sksec;
5778eabd PM	256
	257	if (!S_ISSOCK(inode->i_mode) \|\|
	258	((mask & (MAY_WRITE \| MAY_APPEND)) == 0))
	259	return 0;
	260	sock = SOCKET_I(inode);
ba6ff9f2 PM	261	sk = sock->sk;
ba6ff9f2 PM	262	sksec = sk->sk_security;
5778eabd PM	263
	264	rcu_read_lock();
	265	if (sksec->nlbl_state != NLBL_REQUIRE) {
	266	rcu_read_unlock();
	267	return 0;
	268	}
	269	local_bh_disable();
ba6ff9f2 PM	270	bh_lock_sock_nested(sk);
	271	rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
	272	bh_unlock_sock(sk);
5778eabd PM	273	local_bh_enable();
	274	rcu_read_unlock();
	275
	276	return rc;
	277	}
	278
	279	/**
	280	* selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
	281	* @sksec: the sock's sk_security_struct
	282	* @skb: the packet
	283	* @ad: the audit data
	284	*
	285	* Description:
	286	* Fetch the NetLabel security attributes from @skb and perform an access check
	287	* against the receiving socket. Returns zero on success, negative values on
	288	* error.
	289	*
	290	*/
	291	int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
	292	struct sk_buff *skb,
	293	struct avc_audit_data *ad)
	294	{
	295	int rc;
9faf65fb PM	296	u32 nlbl_sid;
9faf65fb PM	297	u32 perm;
5778eabd	298
9faf65fb	299	rc = selinux_netlbl_skbuff_getsid(skb, SECINITSID_NETMSG, &nlbl_sid);
5778eabd PM	300	if (rc != 0)
5778eabd PM	301	return rc;
9faf65fb PM	302	if (nlbl_sid == SECSID_NULL)
9faf65fb PM	303	nlbl_sid = SECINITSID_UNLABELED;
5778eabd PM	304
	305	switch (sksec->sclass) {
	306	case SECCLASS_UDP_SOCKET:
9faf65fb	307	perm = UDP_SOCKET__RECVFROM;
5778eabd PM	308	break;
5778eabd PM	309	case SECCLASS_TCP_SOCKET:
9faf65fb	310	perm = TCP_SOCKET__RECVFROM;
5778eabd PM	311	break;
5778eabd PM	312	default:
9faf65fb	313	perm = RAWIP_SOCKET__RECVFROM;
5778eabd PM	314	}
5778eabd PM	315
9faf65fb	316	rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
5778eabd PM	317	if (rc == 0)
	318	return 0;
	319
9faf65fb PM	320	if (nlbl_sid != SECINITSID_UNLABELED)
9faf65fb PM	321	netlbl_skbuff_err(skb, rc);
5778eabd PM	322	return rc;
	323	}
	324
	325	/**
	326	* selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
	327	* @sock: the socket
	328	* @level: the socket level or protocol
	329	* @optname: the socket option name
	330	*
	331	* Description:
	332	* Check the setsockopt() call and if the user is trying to replace the IP
	333	* options on a socket and a NetLabel is in place for the socket deny the
	334	* access; otherwise allow the access. Returns zero when the access is
	335	* allowed, -EACCES when denied, and other negative values on error.
	336	*
	337	*/
	338	int selinux_netlbl_socket_setsockopt(struct socket *sock,
	339	int level,
	340	int optname)
	341	{
	342	int rc = 0;
ba6ff9f2 PM	343	struct sock *sk = sock->sk;
ba6ff9f2 PM	344	struct sk_security_struct *sksec = sk->sk_security;
5778eabd PM	345	struct netlbl_lsm_secattr secattr;
	346
	347	rcu_read_lock();
	348	if (level == IPPROTO_IP && optname == IP_OPTIONS &&
	349	sksec->nlbl_state == NLBL_LABELED) {
	350	netlbl_secattr_init(&secattr);
ba6ff9f2 PM	351	lock_sock(sk);
	352	rc = netlbl_sock_getattr(sk, &secattr);
	353	release_sock(sk);
5778eabd PM	354	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
	355	rc = -EACCES;
	356	netlbl_secattr_destroy(&secattr);
	357	}
	358	rcu_read_unlock();
	359
	360	return rc;
	361	}