T3214: Fixed ovpn config incompatibilities for IPv4+IPv6 and IPv6-onl…

[leonkramer]

Change Summary

T3214: Fixed ovpn config incompatibilities for IPv4+IPv6 and IPv6-only use. "nopool" option not necessary. net30 "ifconfig-pool" statement handled by OpenVPN if "nopool" is omitted. IPv6 route push was nested inside IPv4 if block, now in IPv6 block. Removed mandatory IPv4 subnet for IPv6-only use.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes)
• [ ] Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• [ ] Other (please describe):

Related Task(s)

• https://phabricator.vyos.net/T3214

Component(s) name

openvpn

Proposed changes

1. Fixed OpenVPN config incompatibilities for IPv4+IPv6 and IPv6-only use. "nopool" option not necessary in generated openvpn Configs because net30 "ifconfig-pool" statements are handled by OpenVPN if "nopool" is omitted.
2. The generated config would allow a IPv6 only usage of the OpenVPN, but a commit error appears which prevent that saying that an IPv4 subnet is required. I have removed that check.
3. Another incompatibility after change of 2) is that if only IPv6 "push-route" statement is defined, the IPv6 route is not being pushed because it is nested inside an IPv4 if block. I have moved the code into the IPv6 block.

How to test

• Configure OpenVPN interface with mode=server.
• Configure IPv4-only Subnet @ [interfaces openvpn vtunN server] = PrePatch: OK - PostPatch: OK
• Configure IPv6-only Subnet @ [interfaces openvpn vtunN server] = PrePatch: FAIL - PostPatch: OK
• • Commit Error: IPv6 server requires an IPv4 server subnet
• Configure IPv6+IPv4 Subnet @ [interfaces openvpn vtunN server] = PrePatch: FAIL - PostPatch: OK
• • OpenVPN Startup Error1: Options error: --server-ipv6 is incompatible with 'nopool' option
• • OpenVPN Startup Error2: Options error: --server already defines an ifconfig-pool, so you can't also specify --ifconfig-pool explicitly

Checklist:

• [x] I have read the CONTRIBUTING document
• [x] I have linked this PR to one or more Phabricator Task(s)
• [ ] I have run the components SMOKETESTS if applicable
• [x] My commit headlines contain a valid Task id
• [ ] My change requires a change to the documentation
• [ ] I have updated the documentation accordingly

[c-po]

HI @leonkramer,

sorry for the late reply, can you share a VyOS configuration that you used to get it up and running? I am courious in also adding it to our documentation.

[dmbaturin]

We'll merge it once 1.4/sagitta is branched off.

[dmbaturin]

It seems to be the same functionality as in https://github.com/vyos/vyos-1x/pull/1637 which is merged now.