+static int selinux_tun_dev_create(void)
+{
+ u32 sid = current_sid();
+
+ /* we aren't taking into account the "sockcreate" SID since the socket
+ * that is being created here is not a socket in the traditional sense,
+ * instead it is a private sock, accessible only to the kernel, and
+ * representing a wide range of network traffic spanning multiple
+ * connections unlike traditional sockets - check the TUN driver to
+ * get a better understanding of why this socket is special */
+
+ return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
+ NULL);
+}
+
+static void selinux_tun_dev_post_create(struct sock *sk)
+{
+ struct sk_security_struct *sksec = sk->sk_security;
+
+ /* we don't currently perform any NetLabel based labeling here and it
+ * isn't clear that we would want to do so anyway; while we could apply
+ * labeling without the support of the TUN user the resulting labeled
+ * traffic from the other end of the connection would almost certainly
+ * cause confusion to the TUN user that had no idea network labeling
+ * protocols were being used */
+
+ /* see the comments in selinux_tun_dev_create() about why we don't use
+ * the sockcreate SID here */
+
+ sksec->sid = current_sid();
+ sksec->sclass = SECCLASS_TUN_SOCKET;
+}
+
+static int selinux_tun_dev_attach(struct sock *sk)
+{
+ struct sk_security_struct *sksec = sk->sk_security;
+ u32 sid = current_sid();
+ int err;
+
+ err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
+ TUN_SOCKET__RELABELFROM, NULL);
+ if (err)
+ return err;
+ err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
+ TUN_SOCKET__RELABELTO, NULL);
+ if (err)
+ return err;
+
+ sksec->sid = sid;
+
+ return 0;
+}
+