While lurking on the #netbsd IRC channel, a discussion happened about the need of a publish/subscribe mechanism for power events. powerd(8), a daemon that monitors sysmon(4) events (via /dev/power) and responds by spawning user specified shell scripts against those events could be a potential candidate to plug it in. Any userland subscribers interested in power events could subscribe, get notified and respond directly.

Here is a more useful filter, filter_rspamd. It's inspired by gilles@ Python implementation, however, handles concurrent requests.

Filters support for smtpd(8) landed in OpenBSD tree. gilles@ published a Python bridge and a case study using it with rspamd. Don't miss updates and other interesting entries from his blog.

An excerpt from ftp(1)…

"-A Force active mode FTP.  By default, ftp will try to use passive
mode FTP and fall back to active mode if passive is not supported
by the server.  This option causes ftp to always use an active
connection."

The modes and commands that start them…

Active: PORT, LPRT, EPRT
Passive: PASV, LPSV, EPSV