strongswan has a whitelisting feature: https://wiki.strongswan.org/projects/strongswan/wiki/Whitelist need to configure with --enable-whitelist feature request to be able to use this feature One possibility is a new "whitelist" USE flag.. However strongswan has a lot of plugins: https://wiki.strongswan.org/projects/strongswan/wiki/PluginList perhaps with a USE=plugins compile all the plugins, in that case "--enable-all"
Fixed in 5.2.0-r1 - we have added use flags for quite a few more modules now. whitelist is enabled with this use flag: "strongswan_plugins_whitelist"