pcap_datalink(3pcap) on macOS
The text ff469f9ac18a, as macOS 12.5, macOS 12.4, macOS 12.3, macOS 12.2, macOS 12.1, macOS 12.0.1, macOS 11.5, macOS 11.4, macOS 11.3, macOS 11.2, macOS 11.1, macOS 11.0.1, macOS 10.15.6, macOS 10.15.5, macOS 10.15.4, macOS 10.15.3, macOS 10.15.2 shipped it.
get the link-layer header type