[linux-2.6-block.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;

	if (!netlbl_enabled()) {
		*sid = SECSID_NULL;
		return 0;
	}

	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_UNLABELED,
					   &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 netlbl_sid;
	u32 recv_perm;

	if (!netlbl_enabled())
		return 0;

	rc = selinux_netlbl_skbuff_getsid(skb,
					  SECINITSID_UNLABELED,
					  &netlbl_sid);
	if (rc != 0)
		return rc;

	if (netlbl_sid == SECSID_NULL)
		return 0;

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

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

	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
23bcdc1a PM	158	if (!netlbl_enabled()) {
	159	*sid = SECSID_NULL;
	160	return 0;
	161	}
	162
5778eabd PM	163	netlbl_secattr_init(&secattr);
	164	rc = netlbl_skbuff_getattr(skb, &secattr);
	165	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
8d9107e8 LT	166	rc = security_netlbl_secattr_to_sid(&secattr,
	167	base_sid,
	168	sid);
5778eabd PM	169	else
	170	*sid = SECSID_NULL;
	171	netlbl_secattr_destroy(&secattr);
	172
	173	return rc;
	174	}
	175
	176	/**
	177	* selinux_netlbl_sock_graft - Netlabel the new socket
	178	* @sk: the new connection
	179	* @sock: the new socket
	180	*
	181	* Description:
	182	* The connection represented by @sk is being grafted onto @sock so set the
	183	* socket's NetLabel to match the SID of @sk.
	184	*
	185	*/
	186	void selinux_netlbl_sock_graft(struct sock sk, struct socket sock)
	187	{
	188	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
	189	struct sk_security_struct *sksec = sk->sk_security;
	190	struct netlbl_lsm_secattr secattr;
	191	u32 nlbl_peer_sid;
	192
	193	sksec->sclass = isec->sclass;
	194
	195	rcu_read_lock();
	196
	197	if (sksec->nlbl_state != NLBL_REQUIRE) {
	198	rcu_read_unlock();
	199	return;
	200	}
	201
	202	netlbl_secattr_init(&secattr);
	203	if (netlbl_sock_getattr(sk, &secattr) == 0 &&
	204	secattr.flags != NETLBL_SECATTR_NONE &&
	205	security_netlbl_secattr_to_sid(&secattr,
8d9107e8	206	SECINITSID_UNLABELED,
5778eabd PM	207	&nlbl_peer_sid) == 0)
	208	sksec->peer_sid = nlbl_peer_sid;
	209	netlbl_secattr_destroy(&secattr);
	210
	211	/* Try to set the NetLabel on the socket to save time later, if we fail
	212	* here we will pick up the pieces in later calls to
	213	* selinux_netlbl_inode_permission(). */
ba6ff9f2	214	selinux_netlbl_sock_setsid(sk, sksec->sid);
5778eabd PM	215
	216	rcu_read_unlock();
	217	}
	218
	219	/**
	220	* selinux_netlbl_socket_post_create - Label a socket using NetLabel
	221	* @sock: the socket to label
	222	*
	223	* Description:
	224	* Attempt to label a socket using the NetLabel mechanism using the given
	225	* SID. Returns zero values on success, negative values on failure.
	226	*
	227	*/
	228	int selinux_netlbl_socket_post_create(struct socket *sock)
	229	{
	230	int rc = 0;
ba6ff9f2	231	struct sock *sk = sock->sk;
5778eabd	232	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
ba6ff9f2	233	struct sk_security_struct *sksec = sk->sk_security;
5778eabd PM	234
	235	sksec->sclass = isec->sclass;
	236
	237	rcu_read_lock();
	238	if (sksec->nlbl_state == NLBL_REQUIRE)
ba6ff9f2	239	rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
5778eabd PM	240	rcu_read_unlock();
	241
	242	return rc;
	243	}
	244
	245	/**
	246	* selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
	247	* @inode: the file descriptor's inode
	248	* @mask: the permission mask
	249	*
	250	* Description:
	251	* Looks at a file's inode and if it is marked as a socket protected by
	252	* NetLabel then verify that the socket has been labeled, if not try to label
	253	* the socket now with the inode's SID. Returns zero on success, negative
	254	* values on failure.
	255	*
	256	*/
	257	int selinux_netlbl_inode_permission(struct inode *inode, int mask)
	258	{
	259	int rc;
ba6ff9f2	260	struct sock *sk;
5778eabd	261	struct socket *sock;
ba6ff9f2	262	struct sk_security_struct *sksec;
5778eabd PM	263
	264	if (!S_ISSOCK(inode->i_mode) \|\|
	265	((mask & (MAY_WRITE \| MAY_APPEND)) == 0))
	266	return 0;
	267	sock = SOCKET_I(inode);
ba6ff9f2 PM	268	sk = sock->sk;
ba6ff9f2 PM	269	sksec = sk->sk_security;
5778eabd PM	270
	271	rcu_read_lock();
	272	if (sksec->nlbl_state != NLBL_REQUIRE) {
	273	rcu_read_unlock();
	274	return 0;
	275	}
	276	local_bh_disable();
ba6ff9f2 PM	277	bh_lock_sock_nested(sk);
	278	rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
	279	bh_unlock_sock(sk);
5778eabd PM	280	local_bh_enable();
	281	rcu_read_unlock();
	282
	283	return rc;
	284	}
	285
	286	/**
	287	* selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
	288	* @sksec: the sock's sk_security_struct
	289	* @skb: the packet
	290	* @ad: the audit data
	291	*
	292	* Description:
	293	* Fetch the NetLabel security attributes from @skb and perform an access check
	294	* against the receiving socket. Returns zero on success, negative values on
	295	* error.
	296	*
	297	*/
	298	int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
	299	struct sk_buff *skb,
	300	struct avc_audit_data *ad)
	301	{
	302	int rc;
8d9107e8 LT	303	u32 netlbl_sid;
8d9107e8 LT	304	u32 recv_perm;
5778eabd	305
23bcdc1a PM	306	if (!netlbl_enabled())
	307	return 0;
	308
8d9107e8 LT	309	rc = selinux_netlbl_skbuff_getsid(skb,
	310	SECINITSID_UNLABELED,
	311	&netlbl_sid);
5778eabd PM	312	if (rc != 0)
5778eabd PM	313	return rc;
8d9107e8 LT	314
	315	if (netlbl_sid == SECSID_NULL)
	316	return 0;
5778eabd PM	317
	318	switch (sksec->sclass) {
	319	case SECCLASS_UDP_SOCKET:
8d9107e8	320	recv_perm = UDP_SOCKET__RECVFROM;
5778eabd PM	321	break;
5778eabd PM	322	case SECCLASS_TCP_SOCKET:
8d9107e8	323	recv_perm = TCP_SOCKET__RECVFROM;
5778eabd PM	324	break;
5778eabd PM	325	default:
8d9107e8	326	recv_perm = RAWIP_SOCKET__RECVFROM;
5778eabd PM	327	}
5778eabd PM	328
8d9107e8 LT	329	rc = avc_has_perm(sksec->sid,
	330	netlbl_sid,
	331	sksec->sclass,
	332	recv_perm,
	333	ad);
5778eabd PM	334	if (rc == 0)
	335	return 0;
	336
8d9107e8	337	netlbl_skbuff_err(skb, rc);
5778eabd PM	338	return rc;
	339	}
	340
	341	/**
	342	* selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
	343	* @sock: the socket
	344	* @level: the socket level or protocol
	345	* @optname: the socket option name
	346	*
	347	* Description:
	348	* Check the setsockopt() call and if the user is trying to replace the IP
	349	* options on a socket and a NetLabel is in place for the socket deny the
	350	* access; otherwise allow the access. Returns zero when the access is
	351	* allowed, -EACCES when denied, and other negative values on error.
	352	*
	353	*/
	354	int selinux_netlbl_socket_setsockopt(struct socket *sock,
	355	int level,
	356	int optname)
	357	{
	358	int rc = 0;
ba6ff9f2 PM	359	struct sock *sk = sock->sk;
ba6ff9f2 PM	360	struct sk_security_struct *sksec = sk->sk_security;
5778eabd PM	361	struct netlbl_lsm_secattr secattr;
	362
	363	rcu_read_lock();
	364	if (level == IPPROTO_IP && optname == IP_OPTIONS &&
	365	sksec->nlbl_state == NLBL_LABELED) {
	366	netlbl_secattr_init(&secattr);
ba6ff9f2 PM	367	lock_sock(sk);
	368	rc = netlbl_sock_getattr(sk, &secattr);
	369	release_sock(sk);
5778eabd PM	370	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
	371	rc = -EACCES;
	372	netlbl_secattr_destroy(&secattr);
	373	}
	374	rcu_read_unlock();
	375
	376	return rc;
	377	}