[iOS] IPv4 -> IPv6 transition

[Kristof Mattei]

Hi,
 
I’ve had a bug for the longest while when using Wireguard on T-Mobile USA (IPv6 only).
 
I have a VPN server listening to both IPv4 & IPv6. I have a DNS A and AAAA set on the same domain.
 
When making a connection from an IPv4-only WiFi network with Wireguard enabled and then walking away from the Wifi where we transition to a IPv6 network with 464XLAT we have the issue that Wireguard does not select the AAAA on the domain. 
 
It prefers IPv4, as shown here: https://git.zx2c4.com/wireguard-apple/tree/Sources/WireGuardKit/DNSResolver.swift#n46 and here: https://git.zx2c4.com/wireguard-apple/tree/Sources/WireGuardKit/DNSResolver.swift#n73
 
 
Would it be possible to get this change to prefer to use IPv6?
 
 
That said, if Wireguard has iOS development licenses, I’d be happy to submit a patch (my personal license doesn’t allow me to test VPNs…)

KM