csu3_am335x/EVSE/GPL/openvpn-2.4.9/doc

OpenVPN Plugins
---------------

Starting with OpenVPN 2.0-beta17, compiled plugin modules are
supported on any *nix OS which includes libdl or on Windows.
One or more modules may be loaded into OpenVPN using
the --plugin directive, and each plugin module is capable of
intercepting any of the script callbacks which OpenVPN supports:

(1) up
(2) down
(3) route-up
(4) ipchange
(5) tls-verify
(6) auth-user-pass-verify
(7) client-connect
(8) client-disconnect
(9) learn-address

See the openvpn-plugin.h file in the top-level directory of the
OpenVPN source distribution for more detailed information
on the plugin interface.

Included Plugins
----------------

auth-pam -- Authenticate using PAM and a split privilege
execution model which functions even if
root privileges or the execution environment
have been altered with --user/--group/--chroot.
Tested on Linux only.

down-root -- Enable the running of down scripts with root privileges
even if --user/--group/--chroot have been used
to drop root privileges or change the execution
environment. Not applicable on Windows.

examples -- A simple example that demonstrates a portable
plugin, i.e. one which can be built for *nix
or Windows from the same source.

Building Plugins
----------------

cd to the top-level directory of a plugin, and use the
"make" command to build it. The examples plugin is
built using a build script, not a makefile.