pcap_set_datalink(3) on FreeBSD
The text c8ed8a921113, 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.
set the link-layer header type to be used by a capture device