OpenVPN provides systemd service files: https://github.com/OpenVPN/openvpn/tree/master/distro/systemd Gentoo should be using upstream's definitions rather than providing its own. In addition to the lower maintenance requirements due to using upstream resources, the upstream definitions are more secure as they use "CapabilityBoundingSet" "DeviceAllow" and "LimitNPROC" which the current Gentoo definition does not. The existence of the upstream definition was noticed and reported at https://bugs.gentoo.org/show_bug.cgi?id=527614#c8 Reproducible: Always
Note that the tarball is missing these files. I have sent a patch upstream. http://sourceforge.net/p/openvpn/mailman/message/33102588/
Fixed in openvpn-2.3.7.