[NetLabel]: SELinux support

Add NetLabel support to the SELinux LSM and modify the socket_post_create() LSM hook to return an error code. The most significant part of this patch is the addition of NetLabel hooks into the following SELinux LSM hooks: * selinux_file_permission() * selinux_socket_sendmsg() * selinux_socket_post_create() * selinux_socket_sock_rcv_skb() * selinux_socket_getpeersec_stream() * selinux_socket_getpeersec_dgram() * selinux_sock_graft() * selinux_inet_conn_request() The basic reasoning behind this patch is that outgoing packets are "NetLabel'd" by labeling their socket and the NetLabel security attributes are checked via the additional hook in selinux_socket_sock_rcv_skb(). NetLabel itself is only a labeling mechanism, similar to filesystem extended attributes, it is up to the SELinux enforcement mechanism to perform the actual access checks. In addition to the changes outlined above this patch also includes some changes to the extended bitmap (ebitmap) and multi-level security (mls) code to import and export SELinux TE/MLS attributes into and out of NetLabel. Signed-off-by: Paul Moore <[email protected]> Signed-off-by: David S. Miller <[email protected]>
adimgong · Sep 22, 2006 · 7420ed2 · 7420ed2
1 parent 96cb8e3
commit 7420ed2
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Showing 11 changed files with 1,020 additions and 28 deletions.
diff --git a/include/linux/security.h b/include/linux/security.h
@@ -1341,8 +1341,8 @@ struct security_operations {
 	int (*unix_may_send) (struct socket * sock, struct socket * other);
 
 	int (*socket_create) (int family, int type, int protocol, int kern);
-	void (*socket_post_create) (struct socket * sock, int family,
-				    int type, int protocol, int kern);
+	int (*socket_post_create) (struct socket * sock, int family,
+				   int type, int protocol, int kern);
 	int (*socket_bind) (struct socket * sock,
 			    struct sockaddr * address, int addrlen);
 	int (*socket_connect) (struct socket * sock,
@@ -2824,13 +2824,13 @@ static inline int security_socket_create (int family, int type,
 	return security_ops->socket_create(family, type, protocol, kern);
 }
 
-static inline void security_socket_post_create(struct socket * sock, 
-					       int family,
-					       int type, 
-					       int protocol, int kern)
+static inline int security_socket_post_create(struct socket * sock,
+					      int family,
+					      int type,
+					      int protocol, int kern)
 {
-	security_ops->socket_post_create(sock, family, type,
-					 protocol, kern);
+	return security_ops->socket_post_create(sock, family, type,
+						protocol, kern);
 }
 
 static inline int security_socket_bind(struct socket * sock, 
@@ -2982,11 +2982,12 @@ static inline int security_socket_create (int family, int type,
 	return 0;
 }
 
-static inline void security_socket_post_create(struct socket * sock, 
-					       int family,
-					       int type, 
-					       int protocol, int kern)
+static inline int security_socket_post_create(struct socket * sock,
+					      int family,
+					      int type,
+					      int protocol, int kern)
 {
+	return 0;
 }
 
 static inline int security_socket_bind(struct socket * sock, 

diff --git a/net/socket.c b/net/socket.c
@@ -973,11 +973,18 @@ int sock_create_lite(int family, int type, int protocol, struct socket **res)
 		goto out;
 	}
 
-	security_socket_post_create(sock, family, type, protocol, 1);
 	sock->type = type;
+	err = security_socket_post_create(sock, family, type, protocol, 1);
+	if (err)
+		goto out_release;
+
 out:
 	*res = sock;
 	return err;
+out_release:
+	sock_release(sock);
+	sock = NULL;
+	goto out;
 }
 
 /* No kernel lock held - perfect */
@@ -1214,7 +1221,9 @@ static int __sock_create(int family, int type, int protocol, struct socket **res
 	 */
 	module_put(net_families[family]->owner);
 	*res = sock;
-	security_socket_post_create(sock, family, type, protocol, kern);
+	err = security_socket_post_create(sock, family, type, protocol, kern);
+	if (err)
+		goto out_release;
 
 out:
 	net_family_read_unlock();

diff --git a/security/dummy.c b/security/dummy.c
@@ -709,10 +709,10 @@ static int dummy_socket_create (int family, int type,
 	return 0;
 }
 
-static void dummy_socket_post_create (struct socket *sock, int family, int type,
-				      int protocol, int kern)
+static int dummy_socket_post_create (struct socket *sock, int family, int type,
+				     int protocol, int kern)
 {
-	return;
+	return 0;
 }
 
 static int dummy_socket_bind (struct socket *sock, struct sockaddr *address,

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
@@ -12,6 +12,8 @@
  *  Copyright (C) 2003 Red Hat, Inc., James Morris <[email protected]>
  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  *                          <[email protected]>
+ *  Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
+ *                     Paul Moore, <[email protected]>
  *
  *	This program is free software; you can redistribute it and/or modify
  *	it under the terms of the GNU General Public License version 2,
@@ -74,6 +76,7 @@
 #include "objsec.h"
 #include "netif.h"
 #include "xfrm.h"
+#include "selinux_netlabel.h"
 
 #define XATTR_SELINUX_SUFFIX "selinux"
 #define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
@@ -2395,6 +2398,7 @@ static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t
 
 static int selinux_file_permission(struct file *file, int mask)
 {
+	int rc;
 	struct inode *inode = file->f_dentry->d_inode;
 
 	if (!mask) {
@@ -2406,8 +2410,12 @@ static int selinux_file_permission(struct file *file, int mask)
 	if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
 		mask |= MAY_APPEND;
 
-	return file_has_perm(current, file,
-			     file_mask_to_av(inode->i_mode, mask));
+	rc = file_has_perm(current, file,
+			   file_mask_to_av(inode->i_mode, mask));
+	if (rc)
+		return rc;
+
+	return selinux_netlbl_inode_permission(inode, mask);
 }
 
 static int selinux_file_alloc_security(struct file *file)
@@ -3058,9 +3066,10 @@ static int selinux_socket_create(int family, int type,
 	return err;
 }
 
-static void selinux_socket_post_create(struct socket *sock, int family,
-				       int type, int protocol, int kern)
+static int selinux_socket_post_create(struct socket *sock, int family,
+				      int type, int protocol, int kern)
 {
+	int err = 0;
 	struct inode_security_struct *isec;
 	struct task_security_struct *tsec;
 	struct sk_security_struct *sksec;
@@ -3077,9 +3086,12 @@ static void selinux_socket_post_create(struct socket *sock, int family,
 	if (sock->sk) {
 		sksec = sock->sk->sk_security;
 		sksec->sid = isec->sid;
+		err = selinux_netlbl_socket_post_create(sock,
+							family,
+							isec->sid);
 	}
 
-	return;
+	return err;
 }
 
 /* Range of port numbers used to automatically bind.
@@ -3260,7 +3272,13 @@ static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
  				  int size)
 {
-	return socket_has_perm(current, sock, SOCKET__WRITE);
+	int rc;
+
+	rc = socket_has_perm(current, sock, SOCKET__WRITE);
+	if (rc)
+		return rc;
+
+	return selinux_netlbl_inode_permission(SOCK_INODE(sock), MAY_WRITE);
 }
 
 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
@@ -3468,6 +3486,10 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	if (err)
 		goto out;
 
+	err = selinux_netlbl_sock_rcv_skb(sksec, skb, &ad);
+	if (err)
+		goto out;
+
 	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
 out:	
 	return err;
@@ -3491,8 +3513,9 @@ static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *op
 		peer_sid = ssec->peer_sid;
 	}
 	else if (isec->sclass == SECCLASS_TCP_SOCKET) {
-		peer_sid = selinux_socket_getpeer_stream(sock->sk);
-
+		peer_sid = selinux_netlbl_socket_getpeersec_stream(sock);
+		if (peer_sid == SECSID_NULL)
+			peer_sid = selinux_socket_getpeer_stream(sock->sk);
 		if (peer_sid == SECSID_NULL) {
 			err = -ENOPROTOOPT;
 			goto out;
@@ -3532,8 +3555,11 @@ static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *
 
 	if (sock && (sock->sk->sk_family == PF_UNIX))
 		selinux_get_inode_sid(SOCK_INODE(sock), &peer_secid);
-	else if (skb)
-		peer_secid = selinux_socket_getpeer_dgram(skb);
+	else if (skb) {
+		peer_secid = selinux_netlbl_socket_getpeersec_dgram(skb);
+		if (peer_secid == SECSID_NULL)
+			peer_secid = selinux_socket_getpeer_dgram(skb);
+	}
 
 	if (peer_secid == SECSID_NULL)
 		err = -EINVAL;
@@ -3578,16 +3604,24 @@ void selinux_sock_graft(struct sock* sk, struct socket *parent)
 	struct sk_security_struct *sksec = sk->sk_security;
 
 	isec->sid = sksec->sid;
+
+	selinux_netlbl_sock_graft(sk, parent);
 }
 
 int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 					   struct request_sock *req)
 {
 	struct sk_security_struct *sksec = sk->sk_security;
 	int err;
-	u32 newsid = 0;
+	u32 newsid;
 	u32 peersid;
 
+	newsid = selinux_netlbl_inet_conn_request(skb, sksec->sid);
+	if (newsid != SECSID_NULL) {
+		req->secid = newsid;
+		return 0;
+	}
+
 	err = selinux_xfrm_decode_session(skb, &peersid, 0);
 	BUG_ON(err);
 

diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
@@ -101,6 +101,14 @@ struct sk_security_struct {
 	struct sock *sk;		/* back pointer to sk object */
 	u32 sid;			/* SID of this object */
 	u32 peer_sid;			/* SID of peer */
+#ifdef CONFIG_NETLABEL
+	u16 sclass;			/* sock security class */
+	enum {				/* NetLabel state */
+		NLBL_UNSET = 0,
+		NLBL_REQUIRE,
+		NLBL_LABELED,
+	} nlbl_state;
+#endif
 };
 
 struct key_security_struct {

diff --git a/security/selinux/include/selinux_netlabel.h b/security/selinux/include/selinux_netlabel.h
@@ -0,0 +1,125 @@
+/*
+ * SELinux interface to the NetLabel subsystem
+ *
+ * Author : Paul Moore <[email protected]>
+ *
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
+ *
+ * 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
+ *
+ */
+
+#ifndef _SELINUX_NETLABEL_H_
+#define _SELINUX_NETLABEL_H_
+
+#ifdef CONFIG_NETLABEL
+void selinux_netlbl_cache_invalidate(void);
+int selinux_netlbl_socket_post_create(struct socket *sock,
+				      int sock_family,
+				      u32 sid);
+void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock);
+u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid);
+int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
+				struct sk_buff *skb,
+				struct avc_audit_data *ad);
+u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock);
+u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb);
+
+int __selinux_netlbl_inode_permission(struct inode *inode, int mask);
+/**
+ * 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.
+ *
+ */
+static inline int selinux_netlbl_inode_permission(struct inode *inode,
+						  int mask)
+{
+	int rc = 0;
+	struct inode_security_struct *isec;
+	struct sk_security_struct *sksec;
+
+	if (!S_ISSOCK(inode->i_mode))
+		return 0;
+
+	isec = inode->i_security;
+	sksec = SOCKET_I(inode)->sk->sk_security;
+	down(&isec->sem);
+	if (unlikely(sksec->nlbl_state == NLBL_REQUIRE &&
+		     (mask & (MAY_WRITE | MAY_APPEND))))
+		rc = __selinux_netlbl_inode_permission(inode, mask);
+	up(&isec->sem);
+
+	return rc;
+}
+#else
+static inline void selinux_netlbl_cache_invalidate(void)
+{
+	return;
+}
+
+static inline int selinux_netlbl_socket_post_create(struct socket *sock,
+						    int sock_family,
+						    u32 sid)
+{
+	return 0;
+}
+
+static inline void selinux_netlbl_sock_graft(struct sock *sk,
+					     struct socket *sock)
+{
+	return;
+}
+
+static inline u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb,
+						   u32 sock_sid)
+{
+	return SECSID_NULL;
+}
+
+static inline int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
+					      struct sk_buff *skb,
+					      struct avc_audit_data *ad)
+{
+	return 0;
+}
+
+static inline u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock)
+{
+	return SECSID_NULL;
+}
+
+static inline u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb)
+{
+	return SECSID_NULL;
+}
+
+static inline int selinux_netlbl_inode_permission(struct inode *inode,
+						  int mask)
+{
+	return 0;
+}
+#endif /* CONFIG_NETLABEL */
+
+#endif