igm_oflags
ogp->igm_oflags |= MSG_DONTROUTE;
if ((ogp->igm_oflags & MSG_DONTROUTE) == 0 &&
datagram.igm_oflags |= MSG_DONTROUTE;
if (((datagram.igm_oflags & MSG_DONTROUTE) == 0) &&
ogp->igm_oflags |= MSG_DONTROUTE;
oc.igm_oflags = flags;