[deliverable/linux.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;

	netlbl_secattr_init(&secattr);

	rc = security_netlbl_sid_to_secattr(sid, &secattr);
	if (rc != 0)
		goto sock_setsid_return;
	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);
	}

sock_setsid_return:
	netlbl_secattr_destroy(&secattr);
	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);
		if (rc == 0 &&
		    (secattr.flags & NETLBL_SECATTR_CACHEABLE) &&
		    (secattr.flags & NETLBL_SECATTR_CACHE))
			netlbl_cache_add(skb, &secattr);
	} 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;
	struct netlbl_lsm_secattr secattr;

	if (!netlbl_enabled())
		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,
						    SECINITSID_NETMSG,
						    &nlbl_sid);
		if (rc == 0 &&
		    (secattr.flags & NETLBL_SECATTR_CACHEABLE) &&
		    (secattr.flags & NETLBL_SECATTR_CACHE))
			netlbl_cache_add(skb, &secattr);
	} else
		nlbl_sid = SECINITSID_UNLABELED;
	netlbl_secattr_destroy(&secattr);
	if (rc != 0)
		return rc;

	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;
5778eabd PM	55
45c950e0 PM	56	netlbl_secattr_init(&secattr);
45c950e0 PM	57
5778eabd PM	58	rc = security_netlbl_sid_to_secattr(sid, &secattr);
5778eabd PM	59	if (rc != 0)
45c950e0	60	goto sock_setsid_return;
ba6ff9f2	61	rc = netlbl_sock_setattr(sk, &secattr);
5778eabd PM	62	if (rc == 0) {
	63	spin_lock_bh(&sksec->nlbl_lock);
	64	sksec->nlbl_state = NLBL_LABELED;
	65	spin_unlock_bh(&sksec->nlbl_lock);
	66	}
	67
45c950e0 PM	68	sock_setsid_return:
45c950e0 PM	69	netlbl_secattr_destroy(&secattr);
5778eabd PM	70	return rc;
	71	}
	72
	73	/**
	74	* selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
	75	*
	76	* Description:
	77	* Invalidate the NetLabel security attribute mapping cache.
	78	*
	79	*/
	80	void selinux_netlbl_cache_invalidate(void)
	81	{
	82	netlbl_cache_invalidate();
	83	}
	84
	85	/**
	86	* selinux_netlbl_sk_security_reset - Reset the NetLabel fields
	87	* @ssec: the sk_security_struct
	88	* @family: the socket family
	89	*
	90	* Description:
	91	* Called when the NetLabel state of a sk_security_struct needs to be reset.
	92	* The caller is responsibile for all the NetLabel sk_security_struct locking.
	93	*
	94	*/
	95	void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
	96	int family)
	97	{
	98	if (family == PF_INET)
	99	ssec->nlbl_state = NLBL_REQUIRE;
	100	else
	101	ssec->nlbl_state = NLBL_UNSET;
	102	}
	103
	104	/**
	105	* selinux_netlbl_sk_security_init - Setup the NetLabel fields
	106	* @ssec: the sk_security_struct
	107	* @family: the socket family
	108	*
	109	* Description:
	110	* Called when a new sk_security_struct is allocated to initialize the NetLabel
	111	* fields.
	112	*
	113	*/
	114	void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
	115	int family)
	116	{
	117	/* No locking needed, we are the only one who has access to ssec */
	118	selinux_netlbl_sk_security_reset(ssec, family);
	119	spin_lock_init(&ssec->nlbl_lock);
	120	}
	121
	122	/**
	123	* selinux_netlbl_sk_security_clone - Copy the NetLabel fields
	124	* @ssec: the original sk_security_struct
	125	* @newssec: the cloned sk_security_struct
	126	*
	127	* Description:
	128	* Clone the NetLabel specific sk_security_struct fields from @ssec to
	129	* @newssec.
	130	*
	131	*/
	132	void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
	133	struct sk_security_struct *newssec)
134	{
135	/* We don't need to take newssec->nlbl_lock because we are the only
136	* thread with access to newssec, but we do need to take the RCU read
137	* lock as other threads could have access to ssec */
138	rcu_read_lock();
139	selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
140	newssec->sclass = ssec->sclass;
141	rcu_read_unlock();
142	}
143
144	/**
145	* selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
146	* @skb: the packet
147	* @base_sid: the SELinux SID to use as a context for MLS only attributes
148	* @sid: the SID
149	*
150	* Description:
151	* Call the NetLabel mechanism to get the security attributes of the given
152	* packet and use those attributes to determine the correct context/SID to
153	* assign to the packet. Returns zero on success, negative values on failure.
154	*
155	*/
156	int selinux_netlbl_skbuff_getsid(struct sk_buff skb, u32 base_sid, u32 sid)
157	{
158	int rc;
159	struct netlbl_lsm_secattr secattr;
160
23bcdc1a PM	161	if (!netlbl_enabled()) {
	162	*sid = SECSID_NULL;
	163	return 0;
	164	}
	165
5778eabd PM	166	netlbl_secattr_init(&secattr);
5778eabd PM	167	rc = netlbl_skbuff_getattr(skb, &secattr);
9534f71c	168	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) {
f36158c4	169	rc = security_netlbl_secattr_to_sid(&secattr, base_sid, sid);
9534f71c PM	170	if (rc == 0 &&
	171	(secattr.flags & NETLBL_SECATTR_CACHEABLE) &&
	172	(secattr.flags & NETLBL_SECATTR_CACHE))
	173	netlbl_cache_add(skb, &secattr);
	174	} else
5778eabd PM	175	*sid = SECSID_NULL;
	176	netlbl_secattr_destroy(&secattr);
	177
	178	return rc;
	179	}
	180
	181	/**
	182	* selinux_netlbl_sock_graft - Netlabel the new socket
	183	* @sk: the new connection
	184	* @sock: the new socket
	185	*
	186	* Description:
	187	* The connection represented by @sk is being grafted onto @sock so set the
	188	* socket's NetLabel to match the SID of @sk.
	189	*
	190	*/
	191	void selinux_netlbl_sock_graft(struct sock sk, struct socket sock)
	192	{
	193	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
	194	struct sk_security_struct *sksec = sk->sk_security;
	195	struct netlbl_lsm_secattr secattr;
	196	u32 nlbl_peer_sid;
	197
	198	sksec->sclass = isec->sclass;
	199
	200	rcu_read_lock();
	201
	202	if (sksec->nlbl_state != NLBL_REQUIRE) {
	203	rcu_read_unlock();
	204	return;
	205	}
	206
	207	netlbl_secattr_init(&secattr);
	208	if (netlbl_sock_getattr(sk, &secattr) == 0 &&
	209	secattr.flags != NETLBL_SECATTR_NONE &&
	210	security_netlbl_secattr_to_sid(&secattr,
f36158c4	211	SECINITSID_NETMSG,
5778eabd PM	212	&nlbl_peer_sid) == 0)
	213	sksec->peer_sid = nlbl_peer_sid;
	214	netlbl_secattr_destroy(&secattr);
	215
	216	/* Try to set the NetLabel on the socket to save time later, if we fail
	217	* here we will pick up the pieces in later calls to
	218	* selinux_netlbl_inode_permission(). */
ba6ff9f2	219	selinux_netlbl_sock_setsid(sk, sksec->sid);
5778eabd PM	220
	221	rcu_read_unlock();
	222	}
	223
	224	/**
	225	* selinux_netlbl_socket_post_create - Label a socket using NetLabel
	226	* @sock: the socket to label
	227	*
	228	* Description:
	229	* Attempt to label a socket using the NetLabel mechanism using the given
	230	* SID. Returns zero values on success, negative values on failure.
	231	*
	232	*/
	233	int selinux_netlbl_socket_post_create(struct socket *sock)
	234	{
	235	int rc = 0;
ba6ff9f2	236	struct sock *sk = sock->sk;
5778eabd	237	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
ba6ff9f2	238	struct sk_security_struct *sksec = sk->sk_security;
5778eabd PM	239
	240	sksec->sclass = isec->sclass;
	241
	242	rcu_read_lock();
	243	if (sksec->nlbl_state == NLBL_REQUIRE)
ba6ff9f2	244	rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
5778eabd PM	245	rcu_read_unlock();
	246
	247	return rc;
	248	}
	249
	250	/**
	251	* selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
	252	* @inode: the file descriptor's inode
	253	* @mask: the permission mask
	254	*
	255	* Description:
	256	* Looks at a file's inode and if it is marked as a socket protected by
	257	* NetLabel then verify that the socket has been labeled, if not try to label
	258	* the socket now with the inode's SID. Returns zero on success, negative
	259	* values on failure.
	260	*
	261	*/
	262	int selinux_netlbl_inode_permission(struct inode *inode, int mask)
	263	{
	264	int rc;
ba6ff9f2	265	struct sock *sk;
5778eabd	266	struct socket *sock;
ba6ff9f2	267	struct sk_security_struct *sksec;
5778eabd PM	268
	269	if (!S_ISSOCK(inode->i_mode) \|\|
	270	((mask & (MAY_WRITE \| MAY_APPEND)) == 0))
	271	return 0;
	272	sock = SOCKET_I(inode);
ba6ff9f2 PM	273	sk = sock->sk;
ba6ff9f2 PM	274	sksec = sk->sk_security;
5778eabd PM	275
	276	rcu_read_lock();
	277	if (sksec->nlbl_state != NLBL_REQUIRE) {
	278	rcu_read_unlock();
	279	return 0;
	280	}
	281	local_bh_disable();
ba6ff9f2 PM	282	bh_lock_sock_nested(sk);
	283	rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
	284	bh_unlock_sock(sk);
5778eabd PM	285	local_bh_enable();
	286	rcu_read_unlock();
	287
	288	return rc;
	289	}
	290
	291	/**
	292	* selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
	293	* @sksec: the sock's sk_security_struct
	294	* @skb: the packet
	295	* @ad: the audit data
	296	*
	297	* Description:
	298	* Fetch the NetLabel security attributes from @skb and perform an access check
	299	* against the receiving socket. Returns zero on success, negative values on
	300	* error.
	301	*
	302	*/
	303	int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
	304	struct sk_buff *skb,
	305	struct avc_audit_data *ad)
	306	{
	307	int rc;
f36158c4 PM	308	u32 nlbl_sid;
	309	u32 perm;
	310	struct netlbl_lsm_secattr secattr;
5778eabd	311
23bcdc1a PM	312	if (!netlbl_enabled())
	313	return 0;
	314
f36158c4 PM	315	netlbl_secattr_init(&secattr);
f36158c4 PM	316	rc = netlbl_skbuff_getattr(skb, &secattr);
9534f71c	317	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) {
f36158c4 PM	318	rc = security_netlbl_secattr_to_sid(&secattr,
	319	SECINITSID_NETMSG,
	320	&nlbl_sid);
9534f71c PM	321	if (rc == 0 &&
	322	(secattr.flags & NETLBL_SECATTR_CACHEABLE) &&
	323	(secattr.flags & NETLBL_SECATTR_CACHE))
	324	netlbl_cache_add(skb, &secattr);
	325	} else
f36158c4 PM	326	nlbl_sid = SECINITSID_UNLABELED;
f36158c4 PM	327	netlbl_secattr_destroy(&secattr);
5778eabd PM	328	if (rc != 0)
5778eabd PM	329	return rc;
8d9107e8	330
5778eabd PM	331	switch (sksec->sclass) {
5778eabd PM	332	case SECCLASS_UDP_SOCKET:
f36158c4	333	perm = UDP_SOCKET__RECVFROM;
5778eabd PM	334	break;
5778eabd PM	335	case SECCLASS_TCP_SOCKET:
f36158c4	336	perm = TCP_SOCKET__RECVFROM;
5778eabd PM	337	break;
5778eabd PM	338	default:
f36158c4	339	perm = RAWIP_SOCKET__RECVFROM;
5778eabd PM	340	}
5778eabd PM	341
f36158c4	342	rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
5778eabd PM	343	if (rc == 0)
	344	return 0;
	345
f36158c4 PM	346	if (nlbl_sid != SECINITSID_UNLABELED)
f36158c4 PM	347	netlbl_skbuff_err(skb, rc);
5778eabd PM	348	return rc;
	349	}
	350
	351	/**
	352	* selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
	353	* @sock: the socket
	354	* @level: the socket level or protocol
	355	* @optname: the socket option name
	356	*
	357	* Description:
	358	* Check the setsockopt() call and if the user is trying to replace the IP
	359	* options on a socket and a NetLabel is in place for the socket deny the
	360	* access; otherwise allow the access. Returns zero when the access is
	361	* allowed, -EACCES when denied, and other negative values on error.
	362	*
	363	*/
	364	int selinux_netlbl_socket_setsockopt(struct socket *sock,
	365	int level,
	366	int optname)
	367	{
	368	int rc = 0;
ba6ff9f2 PM	369	struct sock *sk = sock->sk;
ba6ff9f2 PM	370	struct sk_security_struct *sksec = sk->sk_security;
5778eabd PM	371	struct netlbl_lsm_secattr secattr;
	372
	373	rcu_read_lock();
	374	if (level == IPPROTO_IP && optname == IP_OPTIONS &&
	375	sksec->nlbl_state == NLBL_LABELED) {
	376	netlbl_secattr_init(&secattr);
ba6ff9f2 PM	377	lock_sock(sk);
	378	rc = netlbl_sock_getattr(sk, &secattr);
	379	release_sock(sk);
5778eabd PM	380	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
	381	rc = -EACCES;
	382	netlbl_secattr_destroy(&secattr);
	383	}
	384	rcu_read_unlock();
	385
	386	return rc;
	387	}