pcap_can_set_rfmon(3) on FreeBSD
The text 78f56c1ac6c0, as FreeBSD 10.4-RELEASE, FreeBSD 10.3-RELEASE, FreeBSD 10.2-RELEASE, FreeBSD 10.1-RELEASE, FreeBSD 10.0-RELEASE, FreeBSD 9.3-RELEASE, FreeBSD 9.2-RELEASE, FreeBSD 9.1-RELEASE shipped it.
check whether monitor mode can be set for a not-yet-activated capture handle