Invalid integers used in networking code

[hrj]

While trying to use the websocket code as per #258, I encountered this assertion failure:

Uncaught Error: Assertion failed: Int value is out of bounds: 4026531841

Tracing this backwards, the number comes from src/natives/java_net.ts -> java_net_Inet4AddressImpl:lookupAllHostAddr -> host_allocate_address -> next_address. According to the comment at the beginning of the file:

Doppio returns an unused private IP in the range of 240.0.0.0 to 250.0.0.0 for each unique DNS lookup. Doppio uses this IP as a token for that particular DNS lookup....

These addresses as unsigned integers begin from 0xF0000000. However, Java has only signed integers.

My hunch is that the native code should use signed integers starting from -2^28. Does that make sense?

[jvilk]

I'm working on a fix in this branch in my spare time: https://github.com/plasma-umass/doppio/tree/sockets_fixed

Currently held up by Websockify nastiness for browser sockets, but the sockets now work in Node.

[jvilk]

#462 fixes this. Waiting on merge...