swan-updown-0.2.0 is not a library.
swan-updown
see updown plugin.
First, it parses PLUTO_* and cli args.
Then it helps create ipsec interfaces on-demand and log to syslog.
usage
To utilize swan-updown, specify
connections.<conn>.children.<child>.updown = swan-updown [OPTIONS]
in swanctl.conf
For its arguments, see swan-updown -h.
modules
interface
It [creates / destroys] XFRM interface when an SA is [established / deleted].
The name of the interface is based on the --prefix argument and the PLUTO_IF_ID_IN environment variable.
Additionally, if --netns is specified, the interface will be moved into the given netns.
babeld
It makes babeld daemon [operate / stop operating] on the interface mentioned above.
To make it work, specify the path of the babeld socket with --babeld-ctl.