1 files changed, 363 insertions, 0 deletions
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
new file mode 100644
index 000000000000..bf8750791dd1
--- /dev/null
+++ b/security/selinux/netlabel.c
@@ -0,0 +1,363 @@
+/*
+ * 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_socket_setsid - Label a socket using the NetLabel mechanism
+ * @sock: 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_socket_setsid(struct socket *sock, u32 sid)
+{
+	int rc;
+	struct sk_security_struct *sksec = sock->sk->sk_security;
+	struct netlbl_lsm_secattr secattr;
+
+	rc = security_netlbl_sid_to_secattr(sid, &secattr);
+	if (rc != 0)
+		return rc;
+
+	rc = netlbl_socket_setattr(sock, &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_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_socket_setsid(sock, 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 inode_security_struct *isec = SOCK_INODE(sock)->i_security;
+	struct sk_security_struct *sksec = sock->sk->sk_security;
+
+	sksec->sclass = isec->sclass;
+
+	rcu_read_lock();
+	if (sksec->nlbl_state == NLBL_REQUIRE)
+		rc = selinux_netlbl_socket_setsid(sock, 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 sk_security_struct *sksec;
+	struct socket *sock;
+
+	if (!S_ISSOCK(inode->i_mode) ||
+	    ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
+		return 0;
+	sock = SOCKET_I(inode);
+	sksec = sock->sk->sk_security;
+
+	rcu_read_lock();
+	if (sksec->nlbl_state != NLBL_REQUIRE) {
+		rcu_read_unlock();
+		return 0;
+	}
+	local_bh_disable();
+	bh_lock_sock_nested(sock->sk);
+	rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
+	bh_unlock_sock(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;
+
+	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 sk_security_struct *sksec = sock->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);
+		rc = netlbl_socket_getattr(sock, &secattr);
+		if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
+			rc = -EACCES;
+		netlbl_secattr_destroy(&secattr);
+	}
+	rcu_read_unlock();
+
+	return rc;
+}