pcap_breakloop(3) on FreeBSD
The text 7456b5a405f7, 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 shipped it.
force a pcap_dispatch() or pcap_loop() call to return