Up and down scripts need to be informed of tun-ipv6 setting

[zackw]

If the client config file doesn't have ' tun-ipv6 ' in it, but the server sends IPv6 addressing options anyway, the automatic network configuration will ignore them:

Wed Jul 29 16:22:46 2015 PUSH: Received control message: 'PUSH_REPLY,topology subnet,route-gateway REDACTED,dhcp-option DNS REDACTED,ping 10,ping-restart 90,redirect-gateway def1,ifconfig-ipv6 2001:REDACTED::2/64 2001:REDACTED::1,route-ipv6 2000::/3 2001:REDACTED::1,explicit-exit-notify 2,ifconfig REDACTED 255.255.255.0'
Wed Jul 29 16:22:46 2015 OPTIONS IMPORT: timers and/or timeouts modified
Wed Jul 29 16:22:46 2015 OPTIONS IMPORT: explicit notify parm(s) modified
Wed Jul 29 16:22:46 2015 OPTIONS IMPORT: --ifconfig/up options modified
Wed Jul 29 16:22:46 2015 OPTIONS IMPORT: route options modified
Wed Jul 29 16:22:46 2015 OPTIONS IMPORT: route-related options modified
Wed Jul 29 16:22:46 2015 OPTIONS IMPORT: --ip-win32 and/or --dhcp-option options modified
Wed Jul 29 16:22:46 2015 ROUTE_GATEWAY REDACTED/255.255.255.0 IFACE=eth1 HWADDR=REDACTED
Wed Jul 29 16:22:46 2015 ROUTE6: default_gateway=UNDEF
Wed Jul 29 16:22:46 2015 TUN/TAP device tun0 opened
Wed Jul 29 16:22:46 2015 TUN/TAP TX queue length set to 100
Wed Jul 29 16:22:46 2015 do_ifconfig, tt->ipv6=0, tt->did_ifconfig_ipv6_setup=1
Wed Jul 29 16:22:46 2015 /sbin/ip link set dev tun0 up mtu 1500
Wed Jul 29 16:22:46 2015 /sbin/ip addr add dev tun0 REDACTED/24 broadcast REDACTED
Wed Jul 29 16:22:46 2015 /sbin/ip route add REDACTED/32 via REDACTED
Wed Jul 29 16:22:46 2015 /sbin/ip route add 0.0.0.0/1 via REDACTED
Wed Jul 29 16:22:46 2015 /sbin/ip route add 128.0.0.0/1 via REDACTED
Wed Jul 29 16:22:46 2015 add_route_ipv6(): not adding 2000::/3, no IPv6 on if tun0
Wed Jul 29 16:22:46 2015 Initialization Sequence Completed

This is the Right Thing -- in my case, anyway, the server is advertising IPv6 but it doesn't actually work , and the proxy service's customer support is all 'yeah, when it works we'll set the config file to say so'. However, for unrelated reasons I have to use an --up script and --ifconfig-noexec , and the environment passed to the script includes all the IPv6 addressing information but does not report whether tun-ipv6 has been set: either way I get something like

X509_...=REDACTED
common_name=server
config=REDACTED
daemon=0
daemon_log_redirect=0
daemon_pid=29128
daemon_start_time=1438202090
dev=tun0
dev_type=tun
foreign_option_1=dhcp-option DNS REDACTED
ifconfig_broadcast=REDACTED
ifconfig_ipv6_local=REDACTED::2
ifconfig_ipv6_netbits=64
ifconfig_ipv6_remote=REDACTED::1
ifconfig_local=REDACTED
ifconfig_netmask=255.255.255.0
link_mtu=1541
local_port_1=0
proto_1=udp
remote_1=REDACTED
remote_port_1=53
route_ipv6_gateway_1=REDACTED::1
route_ipv6_network_1=2000::/3
route_net_gateway=10.0.0.1
route_vpn_gateway=10.200.4.1
script_context=init
script_type=up
tls_...=REDACTED
trusted_ip=REDACTED
trusted_port=53
tun_mtu=1500
untrusted_ip=REDACTED
untrusted_port=53
verb=3

Please add an environment variable that indicates whether {{{tun-ipv6}} is set.

[JJK]

We've discussed this ticket at the OpenVPN Hackathon and would like to use a different solution:

if the client does not have "tun-ipv6" set then none of the *_ipv6_* env vars will be set.

Please let us know if this solution also solves your problem :)

[tct]

I'm guessing a lot has change regarding ipv6 since 2016(ish)

Can this be closed ?

[Gert Döring]

This can be closed, as tun-ipv6 is a no-op these days. There is nothing it will do.

IPv6 will be configured when there is IPv6 config in the client config or pushed from the server, and the tun/tap interface will always be in "multiprotocol" mode.

This was changed in 2016...

commit 86e2fa5597fd1ad8e0102f134c63d6bc8cb7c291
Author: Arne Schwabe <arne@…>
Date: Thu Oct 13 18:54:16 2016 +0200

Remove tun-ipv6 Option. Instead assume that IPv6 is always supported.

and went into 2.4.0