NetworkInterface.list not implemented on Android

[abarth]

This API is not implemented in Dart for Android. See Socket::ListInterfaces in dart/runtime/bin/socket_android.cc.

Socket::ListInterfaces is also not setting the OSError. CObject::NewOSError then consumes the null OSError, resulting in a segfault.

See flutter/flutter#205

[johnmccutchan]

@zanderso FYI

[sethladd]

cc @iposva-google

[zanderso]

https://codereview.chromium.org/1916223003/

ifaddrs.h still does not exist in the NDK, so to support this API, we'll have to implement as suggested in the comment in socket_android.cc. In the meantime, I've fixed the crash, and added NetworkInterface.listSupported.

[sethladd]

It looks like we landed @zanderso 's patch. Can we close this issue?

[sortie]

Reopening since it appears ifaddrs.h is available as of Android API level 24 (August 2016). If we can take advantage of that API level, then we can implement this feature.

[dnfield]

It would be ideal if we could do this in a way that supports <API24 as well. WebRTC has an implementation that does this, for example.

[sortie]

Can you link to that implementation? I guess that would require making a raw system call.

[dnfield]

https://chromium.googlesource.com/external/webrtc/stable/talk/+/master/base/ifaddrs-android.cc

[dnfield]

My preference would be to see something like

#ifdef API_24 // or whatever the right name is?
// Use NDK implementation
#else
// Use system calls
#endif // API_24

Flutter, for example, currently supports down to API 16. I'd like to use this call in Flutter, but wouldn't be able to if it requires API 24 (which for Dart VM and the Engine, is a compile time flag).

[dnfield]

The #if should probably be more like this:

#if __ANDROID_API__ >= 24
  // use NDK
#else
  // use system calls, e.g. the way that WebRTC does it
#endif // __ANDROID_API__