SwiftNIO Local Proxy DNS settings

Related Projects SwiftNIO
1

I make local proxy with swiftnio(and NEPacketTunnelProvider) successfully. and I have a question about DNS settings.

In this way, the local proxy server connects to the host.

ClientBootstrap(group: context.eventLoop)
            .channelInitializer { channel in
                channel.pipeline.addHandler(MyClientHandler())
            }
            .connect(host: String(host), port: port)

I would like to configure DNS settings (like 1.1.1.1) here. Is there a way to do this?

2

NIO uses the system resolver, so today you can't easily override it on a per-process basis. Can you set the system resolver?

3

Thanks for reply.

I don't know much yet, so this is my first time hearing the system resolver.

But does that mean I just need to set up the system resolver?

and note that local proxy is in ios platform.(not mac)

4

Yes, so you just need to set 1.1.1.1 as the DNS resolver on iOS.

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5

I searched on google "DNS resolver on IOS", but im not sure.

Are you talking about this?

settings.dnsSettings = NEDNSSettings(servers: ["1.1.1.1", "8.8.8.8", "8.8.4.4"])
settings.dnsSettings?.matchDomains = [""]

However, it is the original code and the DNS has not been changed.

If you don't mind, could you tell me in detail?

6

That won’t work for code running inside the Network Extension provider, because NECP means that the extension ignores its own network. I talk about this more in A Peek Behind the NECP Curtain. Admittedly, that’s focused on interfaces, but the same applies for DNS resolvers.

There are two parts to this question. The first is: How does SwiftNIO use DNS? Cory answered this to confirm that it relies on the system resolver.

That leads to a second question: How can you change the behaviour of the system resolver on iOS? That’s very specific to Apple platforms, and so off-topic for Swift Forums. If you bounce over to Apple Developer Forums, I can help you out there.

Make sure to tag your thread with Network Extension so that I see it.

Share and Enjoy

Quinn “The Eskimo!” @ DTS @ Apple

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7

I post the question to Apple Developer Forum!

https://developer.apple.com/forums/thread/750548

reply please..!

1 Like