PCAP_IF_LOOPBACK
curdev->flags |= PCAP_IF_LOOPBACK;
if (!(curdev->flags & PCAP_IF_LOOPBACK) &&
(nextdev->flags & PCAP_IF_LOOPBACK)) {
(!(curdev->flags & PCAP_IF_LOOPBACK) ||
(nextdev->flags & PCAP_IF_LOOPBACK))) {