oce: Disallow the passthrough ioctl for unprivileged users.

A missing check meant that unprivileged users could send passthrough
commands to the device firmware.

Reported by:	Ilja Van Sprundel <ivansprundel@ioactive.com>
MFC after:	3 days
Sponsored by:	The FreeBSD Foundation

sys/dev/oce/oce_if.c

@@ -620,6 +620,9 @@ oce_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 		break;
 
 	case SIOCGPRIVATE_0:
+		rc = priv_check(curthread, PRIV_DRIVER);
+		if (rc != 0)
+			break;
 		rc = oce_handle_passthrough(ifp, data);
 		break;
 	default:

sys/dev/oce/oce_if.h

@@ -48,6 +48,7 @@
 #include <sys/kernel.h>
 #include <sys/bus.h>
 #include <sys/mbuf.h>
+#include <sys/priv.h>
 #include <sys/rman.h>
 #include <sys/socket.h>
 #include <sys/sockio.h>