[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 <[email protected]>
 *
 */

/*
 * (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);
		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 <[email protected]>
	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);
5778eabd PM	164	rc = netlbl_skbuff_getattr(skb, &secattr);
9534f71c	165	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) {
f36158c4	166	rc = security_netlbl_secattr_to_sid(&secattr, base_sid, sid);
9534f71c PM	167	if (rc == 0 &&
	168	(secattr.flags & NETLBL_SECATTR_CACHEABLE) &&
	169	(secattr.flags & NETLBL_SECATTR_CACHE))
	170	netlbl_cache_add(skb, &secattr);
	171	} else
5778eabd PM	172	*sid = SECSID_NULL;
	173	netlbl_secattr_destroy(&secattr);
	174
	175	return rc;
	176	}
	177
	178	/**
	179	* selinux_netlbl_sock_graft - Netlabel the new socket
	180	* @sk: the new connection
	181	* @sock: the new socket
	182	*
	183	* Description:
	184	* The connection represented by @sk is being grafted onto @sock so set the
	185	* socket's NetLabel to match the SID of @sk.
	186	*
	187	*/
	188	void selinux_netlbl_sock_graft(struct sock sk, struct socket sock)
	189	{
	190	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
	191	struct sk_security_struct *sksec = sk->sk_security;
	192	struct netlbl_lsm_secattr secattr;
	193	u32 nlbl_peer_sid;
	194
	195	sksec->sclass = isec->sclass;
	196
	197	rcu_read_lock();
	198
	199	if (sksec->nlbl_state != NLBL_REQUIRE) {
	200	rcu_read_unlock();
	201	return;
	202	}
	203
	204	netlbl_secattr_init(&secattr);
	205	if (netlbl_sock_getattr(sk, &secattr) == 0 &&
	206	secattr.flags != NETLBL_SECATTR_NONE &&
	207	security_netlbl_secattr_to_sid(&secattr,
f36158c4	208	SECINITSID_NETMSG,
5778eabd PM	209	&nlbl_peer_sid) == 0)
	210	sksec->peer_sid = nlbl_peer_sid;
	211	netlbl_secattr_destroy(&secattr);
	212
	213	/* Try to set the NetLabel on the socket to save time later, if we fail
	214	* here we will pick up the pieces in later calls to
	215	* selinux_netlbl_inode_permission(). */
ba6ff9f2	216	selinux_netlbl_sock_setsid(sk, sksec->sid);
5778eabd PM	217
	218	rcu_read_unlock();
	219	}
	220
	221	/**
	222	* selinux_netlbl_socket_post_create - Label a socket using NetLabel
	223	* @sock: the socket to label
	224	*
	225	* Description:
	226	* Attempt to label a socket using the NetLabel mechanism using the given
	227	* SID. Returns zero values on success, negative values on failure.
	228	*
	229	*/
	230	int selinux_netlbl_socket_post_create(struct socket *sock)
	231	{
	232	int rc = 0;
ba6ff9f2	233	struct sock *sk = sock->sk;
5778eabd	234	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
ba6ff9f2	235	struct sk_security_struct *sksec = sk->sk_security;
5778eabd PM	236
	237	sksec->sclass = isec->sclass;
	238
	239	rcu_read_lock();
	240	if (sksec->nlbl_state == NLBL_REQUIRE)
ba6ff9f2	241	rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
5778eabd PM	242	rcu_read_unlock();
	243
	244	return rc;
	245	}
	246
	247	/**
	248	* selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
	249	* @inode: the file descriptor's inode
	250	* @mask: the permission mask
	251	*
	252	* Description:
	253	* Looks at a file's inode and if it is marked as a socket protected by
	254	* NetLabel then verify that the socket has been labeled, if not try to label
	255	* the socket now with the inode's SID. Returns zero on success, negative
	256	* values on failure.
	257	*
	258	*/
	259	int selinux_netlbl_inode_permission(struct inode *inode, int mask)
	260	{
	261	int rc;
ba6ff9f2	262	struct sock *sk;
5778eabd	263	struct socket *sock;
ba6ff9f2	264	struct sk_security_struct *sksec;
5778eabd PM	265
	266	if (!S_ISSOCK(inode->i_mode) \|\|
	267	((mask & (MAY_WRITE \| MAY_APPEND)) == 0))
	268	return 0;
	269	sock = SOCKET_I(inode);
ba6ff9f2 PM	270	sk = sock->sk;
ba6ff9f2 PM	271	sksec = sk->sk_security;
5778eabd PM	272
	273	rcu_read_lock();
	274	if (sksec->nlbl_state != NLBL_REQUIRE) {
	275	rcu_read_unlock();
	276	return 0;
	277	}
	278	local_bh_disable();
ba6ff9f2 PM	279	bh_lock_sock_nested(sk);
	280	rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
	281	bh_unlock_sock(sk);
5778eabd PM	282	local_bh_enable();
	283	rcu_read_unlock();
	284
	285	return rc;
	286	}
	287
	288	/**
	289	* selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
	290	* @sksec: the sock's sk_security_struct
	291	* @skb: the packet
	292	* @ad: the audit data
	293	*
	294	* Description:
	295	* Fetch the NetLabel security attributes from @skb and perform an access check
	296	* against the receiving socket. Returns zero on success, negative values on
	297	* error.
	298	*
	299	*/
	300	int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
	301	struct sk_buff *skb,
	302	struct avc_audit_data *ad)
	303	{
	304	int rc;
f36158c4 PM	305	u32 nlbl_sid;
	306	u32 perm;
	307	struct netlbl_lsm_secattr secattr;
5778eabd	308
23bcdc1a PM	309	if (!netlbl_enabled())
	310	return 0;
	311
f36158c4 PM	312	netlbl_secattr_init(&secattr);
f36158c4 PM	313	rc = netlbl_skbuff_getattr(skb, &secattr);
9534f71c	314	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) {
f36158c4 PM	315	rc = security_netlbl_secattr_to_sid(&secattr,
	316	SECINITSID_NETMSG,
	317	&nlbl_sid);
9534f71c PM	318	if (rc == 0 &&
	319	(secattr.flags & NETLBL_SECATTR_CACHEABLE) &&
	320	(secattr.flags & NETLBL_SECATTR_CACHE))
	321	netlbl_cache_add(skb, &secattr);
	322	} else
f36158c4 PM	323	nlbl_sid = SECINITSID_UNLABELED;
f36158c4 PM	324	netlbl_secattr_destroy(&secattr);
5778eabd PM	325	if (rc != 0)
5778eabd PM	326	return rc;
8d9107e8	327
5778eabd PM	328	switch (sksec->sclass) {
5778eabd PM	329	case SECCLASS_UDP_SOCKET:
f36158c4	330	perm = UDP_SOCKET__RECVFROM;
5778eabd PM	331	break;
5778eabd PM	332	case SECCLASS_TCP_SOCKET:
f36158c4	333	perm = TCP_SOCKET__RECVFROM;
5778eabd PM	334	break;
5778eabd PM	335	default:
f36158c4	336	perm = RAWIP_SOCKET__RECVFROM;
5778eabd PM	337	}
5778eabd PM	338
f36158c4	339	rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
5778eabd PM	340	if (rc == 0)
	341	return 0;
	342
f36158c4 PM	343	if (nlbl_sid != SECINITSID_UNLABELED)
f36158c4 PM	344	netlbl_skbuff_err(skb, rc);
5778eabd PM	345	return rc;
	346	}
	347
	348	/**
	349	* selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
	350	* @sock: the socket
	351	* @level: the socket level or protocol
	352	* @optname: the socket option name
	353	*
	354	* Description:
	355	* Check the setsockopt() call and if the user is trying to replace the IP
	356	* options on a socket and a NetLabel is in place for the socket deny the
	357	* access; otherwise allow the access. Returns zero when the access is
	358	* allowed, -EACCES when denied, and other negative values on error.
	359	*
	360	*/
	361	int selinux_netlbl_socket_setsockopt(struct socket *sock,
	362	int level,
	363	int optname)
	364	{
	365	int rc = 0;
ba6ff9f2 PM	366	struct sock *sk = sock->sk;
ba6ff9f2 PM	367	struct sk_security_struct *sksec = sk->sk_security;
5778eabd PM	368	struct netlbl_lsm_secattr secattr;
	369
	370	rcu_read_lock();
	371	if (level == IPPROTO_IP && optname == IP_OPTIONS &&
	372	sksec->nlbl_state == NLBL_LABELED) {
	373	netlbl_secattr_init(&secattr);
ba6ff9f2 PM	374	lock_sock(sk);
	375	rc = netlbl_sock_getattr(sk, &secattr);
	376	release_sock(sk);
5778eabd PM	377	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
	378	rc = -EACCES;
	379	netlbl_secattr_destroy(&secattr);
	380	}
	381	rcu_read_unlock();
	382
	383	return rc;
	384	}