Support DOOR32.SYS style socket descriptor sharing

[NuSkooler]

Modern Win32 and Linux doors often support only DOOR32.SYS and a shared socket descriptor for I/O. This is currently an issue in the Node.js world as socket descriptors cannot be shared. On Windows, a socket is required to be duplicated before being sent to a process as well.

To support this, some native support will need built in most likely. Something like:

• Create socket
• DuplicateHandle() on Windows to dupe socket FD (WSAXXX API requires PID to share to first, which we don't have)
• Expose the duplicate handle FD to JavaScript side (e.g. to pass into DOOR32.SYS dropfile)
• Read data from socket handle is emitted to JS side via data event
• JS side can call write

Interesting resources:

• https://github.com/cubiclesoft/createprocess-windows
• https://github.com/vrcsix/synchronet/blob/93b01c55b3102ebc3c4f4793c3a45b8c13d0dc2a/src/sbbs3/main.cpp

[NuSkooler]

Would love any sort of help on this

[tracker1]

Looks like you already referenced the thread[0] I found this[1] in...

[0] nodejs/node#7627
[1] https://github.com/clshortfuse/node-getsockethandleaddress

[NuSkooler]

@tracker1 Yeah, I think that's a dead end. Even if we have the descriptor, we can't just start doing I/O on the thing as it would throw the event system out of wack.

Perhaps a shim:
enig(stdio) <> shim.exe <> {shim.exe's shared fd} <> door

Where shim.exe would create a dropfile using enig's as a template or something.

[NuSkooler]

Finally got around to coding a solution to this. Introducing bivrost!. This utility will allow "bridging" between ENiGMA½'s shared socket server and a DOOR32.SYS style shared socket / file descriptor.

Added initial docs @ https://github.com/NuSkooler/enigma-bbs/blob/0.0.9-alpha/docs/modding/local-doors.md#shared-socket-descriptors

See bivrost! and ArakNet hooked up boards for releases. This is intended to work under Linux as well.

Closing this issue -- this and #163 should be good to go. If this doesn't work for you please log a new ticket here or in the bivrost! repo if it's a bug around that specifically.