The openconnect client expects to be configured using the uci interface.
To setup a VPN connection, add the following to /etc/config/network:
config interface 'MYVPN'
option _orig_ifname 'vpnc'
option _orig_bridge 'false'
option proto 'openconnect'
option server 'vpn.example.com'
option port '4443'
option username 'test'
option password 'secret'
option serverhash 'AE7FF6A0426F0A0CD0A02EB9EC3C5066FAEB0B25'
The additional files are also used:
/etc/openconnect/user-cert-vpn-MYVPN.pem: The user certificate
/etc/openconnect/user-key-vpn-MYVPN.pem: The user private key
/etc/openconnect/ca-cert-vpn-MYVPN.pem: The CA certificate (instead of serverhash)
After these are setup you can initiate the VPN using "ifup MYVPN", and
deinitialize it using ifdown. You may also use the luci web interface
(Network -> Interfaces -> AVPN Connect).
Note that you need to configure the firewall to allow communication between
the MYVPN interface and lan.
There is a luci plugin to allow configuring an openconnect interface from
the web environment, available as patch over luci at
https://github.com/nmav/luci-openconnect/tree/openconnect