OpenVPN: o dhclient falha

Question

Se eu iniciar o cliente openvpn e, em seguida, executar dhclient tap0 para obter um endereço IP, tudo funcionará bem.

Quando o mesmo comando é chamado por openvpn de um script ( up option):

#!/bin/sh
/sbin/dhclient tap0 || exit 1
exit 0

Falha:

dhclient[30524]: Sending on   LPF/tap0/aa:aa:aa:12:23:e9
dhclient[30524]: Can't bind to dhcp address: Permission denied
dhclient[30524]: Please make sure there is no other dhcp server
dhclient[30524]: running and that there's no entry for dhcp or
dhclient[30524]: bootp in /etc/inetd.conf.   Also make sure you
dhclient[30524]: are not running HP JetAdmin software, which
openvpn[30517]: WARNING: Failed running command (--up/--down): external program exited with error status: 1
openvpn[30517]: Exiting due to fatal error
dhclient[30524]: includes a bootp server.
dhclient[30524]: 
dhclient[30524]: If you think you have received this message due to a bug rather
dhclient[30524]: than a configuration issue please read the section on submitting
dhclient[30524]: bugs on either our web page at www.isc.org or in the README file
dhclient[30524]: before submitting a bug.  These pages explain the proper
dhclient[30524]: process and the information we find helpful for debugging..
dhclient[30524]: 
dhclient[30524]: exiting.
systemd[1]: openvpn-client.service: Main process exited, code=exited, status=1/FAILURE

Tudo é executado como root, por isso não deve ser um problema de permissão.

    

Answer 1

Tente colocar "sudo" no seu script ... e permitir que o dhclient de sudoers sem uma senha para o usuário que o openvpn esteja executando como.

Além disso, você especificou 'script-security 2' no seu conf?

--script-security level [method]
          This  directive offers policy-level control over OpenVPN’s usage
          of external programs and scripts.  Lower level values  are  more
          restrictive,  higher  values  are more permissive.  Settings for
          level:

          0 -- Strictly no calling of external programs.
          1 -- (Default) Only call built-in executables such as  ifconfig,
          ip, route, or netsh.
          2  --  Allow  calling  of  built-in executables and user-defined
          scripts.
          3 -- Allow passwords to be passed to scripts  via  environmental
          variables (potentially unsafe).'