Xref: utzoo unix-pc.general:2541 comp.sys.att:5933
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!umbc3!alex
From: alex@umbc3.UMBC.EDU (Alex S. Crain)
Newsgroups: unix-pc.general,comp.sys.att
Subject: Re: sockets for SYSV (UNIXPC)
Message-ID: <1834@umbc3.UMBC.EDU>
Date: 25 Mar 89 17:41:08 GMT
References: <612@ivucsb.UUCP> <10667@stb.UUCP>
Reply-To: alex@umbc3.umbc.edu.UMBC.EDU (Alex S. Crain)
Organization: University of Maryland, Baltimore County
Lines: 61

In article <10667@stb.UUCP> michael@stb.UUCP (Michael) writes:
>As for a socket device driver, I'm currently writting a stream socket
>emulation library--but it needs to be in a known process context
>(hence a library, not a device).

	I was going to avoid saying anything, but more then that I want to
avoid duplication of effort, so here I am.

	For the last 6 weeks, I've been busy porting the BSD4.3 layered
socket code to the unix pc. Berkeley released the code awhile back, so it's
all free, and theres alot of it. So far, I've got about 3000 lines of code
that is nearly complete for

	socket()
	bind ()
	listen ()
	accept ()
	connect ()

within the AF_UNIX domain. socketpair () and pipe () have been working for 
over a week without problems, and I expect the other 5 to be debugged real 
soon (figure 30 working hours from now, I had a setback).

	Note the absence of select(). Also missing is out-of-band data and
an interface to fcntl(), although the hooks are there.

	What does this mean? It means that in June I expect to release code
to completely support AF_UNIX sockets, including select(), SOCK_STREAM,
SOCK_DGRAM, out-of-band, and all the options that make sence. I am also
preserving the layered interface, so that I can add AF_INET sockets via
a SLIP connection, and possibly AF_AT (appletalk).

	The code is huge, and is taking along time, but is moving along on
schedule, but it's still vaporware. I'm only making this announcement to
avoid duplication of effort, and I'll inform the net with a call for beta
sites when its complete and reasonably sound.

>			 How do file descriptors work inside
>the kernel, andways?

	I suggest a book called _The Design of the Unix Operating System_ by
Maurice Bach as a guide to the internals of unix (mostly system 5). Also
look for _UNIX PC Version 3.0 Device Driver Development Guide_, a free 40
page document from AT&T that comes with a kernal debugger on disk. I have
no idea who to talk to at AT&T, I started (a long time ago) with AT&T
information (1-800-???-????) and asked about unix-pc's and drivers until I
found someone who would send me something.

>			Michael
>p.s. Don't ask for the code right now. Is there a word for "pre-alpha" software?

	The word is Vaporware. Don't give up on your code, it likely that
a non-kernal socket library will come in real handy for people with smaller
machines (who don't need an extra 75K of kernal size). And, of course, I could
always get hit by a bus.

-- 
					:alex
Alex Crain
Systems Programmer			alex@umbc3.umbc.edu
Univ Md Baltimore County		nerwin!alex@umbc3.umbc.edu (NEW DOMAIN)