Re: [TUHS] Code bloat (was: How Unix brings people together, or it'sa small...)

I love SLiRP, it’s insanely easy to integrate into other programs/emulators to get that fun TCP/IP networking with no device drivers... I’ve put it into all kinds of fun things. My latest one was integrating with a cisco router via IPIP tunnelling. Just slap on a MAC frame from the encapsulated packet, and feed it into SLiRP, and likewise, strip the MAC frame, and feed it back to IPIP. Where I live I get throttled across international links all the time, SSH/PPTP/IPSEC/OpenVPN all seem to be detected and throttled down to 64kb/sec or less which is really disappointing, meanwhile I can pull files via HTTP for a good 10Mb/sec. So eventually Im going to try to mix it in with .net remoting so I can host SLiRP on Windows/IIS and have a Windows machine on my LAN grab the IPIP tunnel from my cisco and send it off via HTTP... That way the packet inspectors see proper HTTP traffic.. Then add in some compression and encryption and I’ve made yet another VPN, although one that’ll interface a router to SLiRP. But I’ve plugged it into SIMH, although they use a much more involved, and newer one now, PCem, Previous, Basilisk II, and I got the ball rolling on WinUAE. I may have left a few off, but yes, it’s an incredibly versatile library. From: Nick Downing Sent: Thursday, 9 February 2017 7:35 PM To: Jason Stevens Cc: TUHS main list; Greg 'groggy' Lehey Subject: Re: [TUHS] Code bloat (was: How Unix brings people together, or it'sa small...) Yes, NetBSD and 386BSD are interesting. They could well form a good basis for a minimal but fully functional OS for a modern platform. One reservation I have though, is as follows: When 386BSD and its derivatives like OpenBSD, NetBSD, FreeBSD came out, Unix was still encumbered and thus they had to be based on 4.4BSD Lite (not even NET/2 was safe). Nobody made an unencumbered version of say 4.3BSD or even NET/2, even though it was theoretically possible, by examining what had to be taken out/added to produce 4.4BSD Lite. Given that Unix is now unencumbered I believe there is no point adopting 4.4, or even 4.3Reno, because the main thing done in those releases as far as I know, is to add partial POSIX compliance. But if you want POSIX compliance you will not achieve minimality. As an example consider the BSD sigvec() routine. POSIX calls this sigaction(), the old SV_ONSTACK flag becomes SA_ONSTACK, the old integer mask becomes a sigset_t and so on... and in any reasonable POSIX compliant BSD the two calls are gonna have to coexist, etc. As to 32V, I appreciate your idea, as I was having some similar thoughts myself. However I personally wouldn't use 32V as a basis for any serious porting work, because I would assume V7 and 4.3 are much more stable and well tested, since they ran in a lot of installations over a long time. That's not to denigrate the huge achievement in porting V7 to the VAX and producing 32V, but it probably has some rough edges that were smoothed out over time to produce the 4BSDs. The situation is a bit different for kernel/toolchain/other userspace. As to the kernel I have been trying to make a detailed comparison between 32V and the BSDs, but have been a bit put off by the fact that all files moved around and may have been renamed, I will figure it all out eventually though. As to the toolchain I have compared it quite carefully with 4.3BSD, and I conclude you should use the later toolchain as there is no disadvantage and some advantages to doing so. As to the rest of the userspace, I BELIEVE that it's stock V7 with any 32-bit issues fixed, but I suspect somewhat hastily and superficially. Producing a 32V-like kernel from 4.3BSD sources would probably be quite difficult, it would be relatively easy to disable added system calls, but harder to disable things like setpgrp() or the associated support in the TTY drivers. More seriously the memory management would have to change, I am planning however to make virtual memory optional in the 4.3BSD kernel, by maybe putting the 32V code back in, protected by #ifndef VM or some such (somewhat like Steven Schultz has done in porting 4.3BSD to PDP-11 to produce 2.11BSD). On the other hand producing a 32V-like userland from the 4.3BSD sources would be pretty easy, I think just delete the sources for any executables that weren't distributed with 32V and possibly, if any of the tools seem particularly bloated, comment out any command line switches or features that weren't in 32V. Going to this level of effort would likely be pointless though. Another option would be taking V7 and re-porting it (except the toolchain) over to a 32-bit environment and kernel. I have developed over the past months, tools that make this relatively straightforward, and in the process would rediscover any 32-bit issues that were fixed in creating 32V. So I wouldn't use 32V. On a slightly different tack, I also have been for some time investigating the idea of an Apple II port of Unix, there are massive technical issues to be solved, but I think I got a bit closer the other night when I decided to collect all information and resources I could find about Mini-Unix and LSX (LSI Unix). Both are self-supporting V6-based environments, the compiler can only compile small programs but it is nonetheless possible for each Unix to recomple itself. LSX I believe could run from floppies (dunno about 140K floppies) in less than 64K. So, you know, true minimality is a relative term. We want something LSX-like for an Apple II, something 2.11BSD-like for an IBM PC/XT or 286 (as Peter Jeremy noted, it's a good fit, and I'd be interested to know more), something 4.3BSD-like for a VAX or 386... something a bit more fully featured for a modern 64-bit multi-gigabyte system... but just not as bloated as what we currently rely on. Hmm well it's hard. What I do know, is that I have a lot of old hardware with <16M RAM and Linux won't run on it anymore, and this annoys me very greatly. In talking about FreeBSD/Linux bloat I forgot to mention the packet filter, iptables (Linux) or pf (FreeBSD). I have a bit of experience with this, since I regularly used to put 2 Ethernet cards in my home server and make it Internet facing through one of them and share the connection using NAT through the other card. But I've come to the conclusion this is stupid, and moreover, that putting a complete mini-language into the kernel just for this purpose is utterly stupid. Programming the thing from userspace is incredibly intricate, and all this complexity serves no purpose. I recently found out about SLIRP (userspace packet rewriting) and I think this would be a good way to implement NAT on servers or routers that actually need to do NAT -- just make a userspace process that runs something SLIRP-like and has a raw socket to the second Ethernet card, and Bob's your uncle. But this got me thinking along pretty productive lines in terms of the tiny Apple II port -- I have been wanting to put the 2.11BSD network stack into an Apple II for a long time, but I've now realized this is not necessary. A much better approach for those Mini-Unix or LSX or even V7 systems, would be to have a userspace library that does SLIP and contains its own TCP, UDP, IP drivers, resolver and so on. Then if you run a userspace program like say, ftp, which is linked to the userspace TCP library, it would basically just open /dev/ttyXX, bring up the SLIP link itself, do any necessary downloads etc, then close the TTY and stop responding to any IP stuff coming over the SLIP link whilst you quit to the prompt, until another program reopens it. cheers, Nick On Wed, Feb 8, 2017 at 2:56 PM, Jason Stevens &lt;jsteve(a)superglobalmegacorp.com&gt; wrote: > > > > > > >> On Wed, Feb 8, 2017 at 1:55 PM, Greg 'groggy' Lehey &lt;grog(a)lemis.com >> >>> >> >> >>