fix: permission denied appears on Android11+

[wlynxg]

fix:

• BasicHost: permission denied appears on Android11+ libp2p/go-libp2p#2986
• netlinkrib: permission denied ipfs/kubo#9513

related:

• x/mobile: Calling net.InterfaceAddrs() fails on Android SDK 30 golang/go#40569
• x/mobile: fix net.Interface() and net.InterfaceAddrs() in Android11 version golang/go#61089

[marten-seemann]

Pulling in a fork of the net package seems like the worst way possible to solve the problem.

[wlynxg]

If go can merge pr, it would be the best way. However, due to the variability of Android versions, merging into the main branch seems very difficult.
Therefore, although using a third-party library to obtain the list of network card interfaces is not the best way, it has been the solution on the Android side for a long time.

[homier]

@marten-seemann for now it's the only way. Go maintainers do not really do anything about the issue, the PR is stuck for several months in a row without any progress, while a lot of folks can't use anything related to multiaddr on Android without compiling Go toolchain with patch.

fyi: pion-webrtc also took this approach with anet (pion/transport@3ba6182)

[gbraad]

I understand the sentiment of not wanting an abstraction layer to fix the issue, but without putting pressure on the upstream Golang issue, this will remain in this limbo.

[MarcoPolo]

I don't love the solutions here.

Here's another solution I don't love, but maybe less bad than the others:

1. Fork net ourselves (or vendor it with patches)
2. Add a build tag to only include the fork on android builds.

[marten-seemann]

InterfaceMultiaddrs is a helper function, which one could argue doesn't belong in this package in the first place, or at least take a []net.Addr as input. It should be absolutely trivial for users to copy-paste it. I don't see any reason whatsoever to pull in a 3rd-party dependency.

[Stebalien]

IMO, the right solution is a package that exposes just a fixed InterfaceAddrs function. Overriding the entire net package is asking for trouble. That's also something that can be easily vendor.