int ib_attach_mcast(struct ib_qp *qp, union ib_gid *gid, u16 lid)
 {
-       return qp->device->attach_mcast ?
-               qp->device->attach_mcast(qp, gid, lid) :
-               -ENOSYS;
+       if (!qp->device->attach_mcast)
+               return -ENOSYS;
+       if (gid->raw[0] != 0xff || qp->qp_type != IB_QPT_UD)
+               return -EINVAL;
+
+       return qp->device->attach_mcast(qp, gid, lid);
 }
 EXPORT_SYMBOL(ib_attach_mcast);
 
 int ib_detach_mcast(struct ib_qp *qp, union ib_gid *gid, u16 lid)
 {
-       return qp->device->detach_mcast ?
-               qp->device->detach_mcast(qp, gid, lid) :
-               -ENOSYS;
+       if (!qp->device->detach_mcast)
+               return -ENOSYS;
+       if (gid->raw[0] != 0xff || qp->qp_type != IB_QPT_UD)
+               return -EINVAL;
+
+       return qp->device->detach_mcast(qp, gid, lid);
 }
 EXPORT_SYMBOL(ib_detach_mcast);