[TUHS] looking for 4.1a BSD full kernel source

[TUHS] looking for 4.1a BSD full kernel source

[Paul Ruizendaal]

Hi,

I'm trying to find out exactly what was in the 4.1a BSD distribution, as far as the kernel is concerned. The image in the CSRG archive comes from a tape that had a hard read error and does not include any kernel sources. Some of the kernel files were already covered by SCCS around that time, but not everything. My main focus is to understand tcp/ip networking in 4.1a and whether the kernel could be built with either the Berkeley or the BBN network stack.

Does anybody know where I could find a full set of kernel sources for the 4.1a BSD kernel?

Many thanks in advance!

Paul

[TUHS] looking for 4.1a BSD full kernel source

[Paul Ruizendaal]

Hi Diomidis,

Thanks for that link. This is exactly what I'm trying to ascertain, and I'm finding conflicting evidence.
- The socket API was in a state of flux between October '81 and March '82 (when 4.1a was supposedly cut). By March '82 it was mostly there, but not until later in the year did it fully stabilize.
- The BBN stack did not use the sockets API as late as January '82
- What I currently fathom from the SCCS files is that the socket API implementation was hard coded to use the nascent Berkeley stack.
- But the BBN code was likely in the 4.x BSD source tree, outside of SCCS (Berkeley started out with the BBN code, but it morphed quite quickly and drastically)
- In 1985 the BBN code finally enters SCCS (marked 'deprecated'); this code was integrated with the sockets API, and much developed from its 1982 form

Either the below link is correct (and I think I may have contributed to its view in a private mail to Kirk), or there were two different distributions (4.1a BSD with Berkeley network code and 4BSD with BBN network code). The two may have merged into one in peoples' memories: 35 years is a long time. Finding the actual kernel source for the 4.1a distribution could provide clarity on this point.

Perhaps Bill Joy could shed some light on the issue, but I don't have contact details. Having actual source removes all doubt.

Paul


On 1 Dec 2016, at 10:51 , Diomidis Spinellis wrote:

> The best description I could find is the following:
> 
> http://minnie.tuhs.org/pipermail/tuhs/2016-September/007417.html
> 
> > The 4.1a distribution had the initial socket interface with a
> > prerelease of the BBN TCP/IP under it. There was wide distribution
> > of 4.1a. The 4.1b distribution had the fast filesystem added and
> > a more mature socket interface (notably the listen/accept model
> > added by Sam Leffler).
> 
> Diomidis
> 
> On 01/12/2016 10:30, Paul Ruizendaal wrote:
>> 
>> Hi,
>> 
>> I'm trying to find out exactly what was in the 4.1a BSD distribution, as far as the kernel is concerned. The image in the CSRG archive comes from a tape that had a hard read error and does not include any kernel sources. Some of the kernel files were already covered by SCCS around that time, but not everything. My main focus is to understand tcp/ip networking in 4.1a and whether the kernel could be built with either the Berkeley or the BBN network stack.
>> 
>> Does anybody know where I could find a full set of kernel sources for the 4.1a BSD kernel?
>> 
>> Many thanks in advance!
>> 
>> Paul
>> 
> 

[TUHS] looking for 4.1a BSD full kernel source

[Clem Cole]

Assuming I can read the tape, I know I do have a copy of 4.1a distribution
on 9-track.

Diomidis is correct, 4.1a use Joy/Cooper/Leffler reimplementation of of the
BBN stack, not the original BBN stack.

The BBN stack (Gurwitz et al) was for 4.1 (and other UNIX and non-Unix
systems).   I do not believe I have a copy of that tape.  Rob or maybe Eric
Cooper might.

How Sam added the code into the UCB SCCS, I never knew (you can ask him
directly, he is still findable these days).   Eric Cooper took the basic
BBN distribution and put it on the UCB 4.1 systems around campus >>before<<
Joy started the sockets work.   i.e. the installation was done by
installing 4.1, then taking the BBN tape and installing it as is. Cooper
helped me put it on the CAD machines in Cory Hall circa '81.   I then
helped Eric Allmen put it on the Ingres systems (again Cory Hall) shortly
thereafter [Please, remember, this was the "official" IP/TCP implementation
for UNIX.   Joy's work was an "underground" effort in response to CMU's
Accent].



BTW: about 3 years later, the BBN2 stack comes out from Rob and team and it
is actually even more interesting; because it now uses the sockets
interface (not the Chaosnet/UofI nami trick), and adds a number of both
performance enhancements (Van Jacobson's work, etc.) as well as a more
complete implementation of the IP stack.   I >>might<< have a copy of that
tape squirreled away; but I'll have to look.

On Thu, Dec 1, 2016 at 5:40 AM, Paul Ruizendaal <pnr at planet.nl> wrote:

> Hi Diomidis,
>
> Thanks for that link. This is exactly what I'm trying to ascertain, and
> I'm finding conflicting evidence.
> - The socket API was in a state of flux between October '81 and March '82
> (when 4.1a was supposedly cut). By March '82 it was mostly there, but not
> until later in the year did it fully stabilize.
> - The BBN stack did not use the sockets API as late as January '82
> - What I currently fathom from the SCCS files is that the socket API
> implementation was hard coded to use the nascent Berkeley stack.
> - But the BBN code was likely in the 4.x BSD source tree, outside of SCCS
> (Berkeley started out with the BBN code, but it morphed quite quickly and
> drastically)
> - In 1985 the BBN code finally enters SCCS (marked 'deprecated'); this
> code was integrated with the sockets API, and much developed from its 1982
> form
>
> Either the below link is correct (and I think I may have contributed to
> its view in a private mail to Kirk), or there were two different
> distributions (4.1a BSD with Berkeley network code and 4BSD with BBN
> network code). The two may have merged into one in peoples' memories: 35
> years is a long time. Finding the actual kernel source for the 4.1a
> distribution could provide clarity on this point.
>
> Perhaps Bill Joy could shed some light on the issue, but I don't have
> contact details. Having actual source removes all doubt.
>
> Paul
>
>
> On 1 Dec 2016, at 10:51 , Diomidis Spinellis wrote:
>
> > The best description I could find is the following:
> >
> > http://minnie.tuhs.org/pipermail/tuhs/2016-September/007417.html
> >
> > > The 4.1a distribution had the initial socket interface with a
> > > prerelease of the BBN TCP/IP under it. There was wide distribution
> > > of 4.1a. The 4.1b distribution had the fast filesystem added and
> > > a more mature socket interface (notably the listen/accept model
> > > added by Sam Leffler).
> >
> > Diomidis
> >
> > On 01/12/2016 10:30, Paul Ruizendaal wrote:
> >>
> >> Hi,
> >>
> >> I'm trying to find out exactly what was in the 4.1a BSD distribution,
> as far as the kernel is concerned. The image in the CSRG archive comes from
> a tape that had a hard read error and does not include any kernel sources.
> Some of the kernel files were already covered by SCCS around that time, but
> not everything. My main focus is to understand tcp/ip networking in 4.1a
> and whether the kernel could be built with either the Berkeley or the BBN
> network stack.
> >>
> >> Does anybody know where I could find a full set of kernel sources for
> the 4.1a BSD kernel?
> >>
> >> Many thanks in advance!
> >>
> >> Paul
> >>
> >
>
>
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[TUHS] Masscomp sources? was looking for 4.1a BSD full kernel source

[Larry McVoy]

By the way, the "getting started with sockets" document that came with 
the 4.1a BSD based Masscomp version of the OS is by far the nicest 
introduction to sockets that I've ever seen.  I used to have a copy
but lost it.  Any chance of finding that?  Are the Masscomp sources
around?

--lm

[TUHS] Masscomp sources? was looking for 4.1a BSD full kernel source

[Clem Cole]

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below...

On Thu, Dec 1, 2016 at 10:30 AM, Larry McVoy <lm at mcvoy.com> wrote:

> By the way, the "getting started with sockets" document that came with
> the 4.1a BSD based Masscomp version of the OS is by far the nicest
> introduction to sockets that I've ever seen.

​Thank you. You made my day.  I lead the coms group when that was done and
while I did not write the document, the doc writer that did, worked under
my direction..​





> I used to have a copy
> but lost it.  Any chance of finding that?

​Maybe - I'll ask her if she kept it.  I don't think I ever had the master.
  FYI: its troff of course ;-)​



>   Are the Masscomp sources
> ​ ​
> around?

​Maybe, I my knowledge they were never put on-line and Concurrent owns the
IP (little know fact - Masscomp is actually the legal entity that still
stands year later - I'll fill you in offline).  As for the sources need to
do some hunting.

Clem
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[TUHS] looking for 4.1a BSD full kernel source

[Paul Ruizendaal]

Clem,

Many thanks for your informative post!

> Assuming I can read the tape, I know I do have a copy of 4.1a distribution on 9-track.
That is great news. Let me know once you had a chance to look at it. I am in no hurry, so whenever you have time, even if that is months from now.

> Diomidis is correct, 4.1a use Joy/Cooper/Leffler reimplementation of of the BBN stack, not the original BBN stack.
I suspected as much, but I am happy to hear it confirmed. I've been told on several occasions that 4.1a contained the original BBN stack.

> The BBN stack (Gurwitz et al) was for 4.1 (and other UNIX and non-Unix systems).   I do not believe I have a copy of that tape.  Rob or maybe Eric Cooper might.
> 
> How Sam added the code into the UCB SCCS, I never knew (you can ask him directly, he is still findable these days).   Eric Cooper took the basic BBN distribution and put it on the UCB 4.1 systems around campus >>before<< Joy started the sockets work i.e. the installation was done by installing 4.1, then taking the BBN tape and installing it as is. 

I can confirm all this. I do have several copies of the BBN tapes from '81 and '82, they survived in Kirk McKusick's archive. They indeed contain material that is 'copied over' a clean 4 or 4.1 build tree. The first complete BBN beta is from May 1981 and Joy started on his network code in October 1981.

> BTW: about 3 years later, the BBN2 stack comes out from Rob and team and it is actually even more interesting; because it now uses the sockets interface (not the Chaosnet/UofI nami trick), and adds a number of both performance enhancements (Van Jacobson's work, etc.) as well as a more complete implementation of the IP stack.   I >>might<< have a copy of that tape squirreled away; but I'll have to look.

I think this might be the material that appears in the BSD source tree in 1985, right? Van Jacobson's work is ~1988, I think, but I could well be mistaken. I think the main performance improvement between the 1982 and the 1985 version was a switch from a kernel thread model to a software interrupt model, but as yet I haven't grasped why this is better and my assumption may be incorrect.

Paul

[TUHS] looking for 4.1a BSD full kernel source

[Clem Cole]

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below...

On Thu, Dec 1, 2016 at 3:13 PM, Paul Ruizendaal <pnr at planet.nl> wrote:

> Clem,
>
> Many thanks for your informative post!

​Most welcome.​


>
>
> > Assuming I can read the tape, I know I do have a copy of 4.1a
> distribution on 9-track.
> That is great news. Let me know once you had a chance to look at it. I am
> in no hurry, so whenever you have time, even if that is months from now.

​My queue keeps getting bigger.  I need to retire so I have time for my
home projects ;-)​



>
>
> > Diomidis is correct, 4.1a use Joy/Cooper/Leffler reimplementation of of
> the BBN stack, not the original BBN stack.
> I suspected as much, but I am happy to hear it confirmed. I've been told
> on several occasions that 4.1a contained the original BBN stack.

​Truth is the basic stuff will be pretty similar.   The big thing they
share is mbuf code and how basic IP/TCP state machines.   The primary
changes will be that it's not using open/nami and started to get rid of the
ioctl hacks IIRC.​  It's been a long time since I looked at those stacks.

The original BBN release was >>tuned<< for 4.1BSD but was based on their
"portable" IP/TCP release.  So it's what was used for the HP3000 and few
other systems that DARPA wanted IP stacks.    Again this is more obvious
when you look at the mbuf stuff.  Rob needed a specific OS kernel
independent way of handling memory, so he wrote his own handler and then
spliced the few things it needed into the local kernel.

Joy kept that code for a long time, although in later and later versions of
the BSD stack (i.e. by NET2) the mbuf code has been rehashed by many and
deviated from Rob's stuff in many ways.




>
>
> > The BBN stack (Gurwitz et al) was for 4.1 (and other UNIX and non-Unix
> systems).   I do not believe I have a copy of that tape.  Rob or maybe Eric
> Cooper might.
> >
> > How Sam added the code into the UCB SCCS, I never knew (you can ask him
> directly, he is still findable these days).   Eric Cooper took the basic
> BBN distribution and put it on the UCB 4.1 systems around campus >>before<<
> Joy started the sockets work i.e. the installation was done by installing
> 4.1, then taking the BBN tape and installing it as is.
>
> I can confirm all this. I do have several copies of the BBN tapes from '81
> and '82, they survived in Kirk McKusick's archive.

​You mean on his CD's - if so can you send me a path.  I'll try to peak at
them.  I have the CD's at home, although not online.​




> They indeed contain material that is 'copied over' a clean 4 or 4.1 build
> tree. The first complete BBN beta is from May 1981 and Joy started on his
> network code in October 1981.

​FYI:  I don't remember it as a beta, but you might be right.  I thought it
was the official distribution.   BTW it supported the BBN 1822 interface
and the Xerox 3Mbit boards with the Xerox taps on the Vax.  I wrote a 3Com
driver for it and Sam and I hacked up an InterLan and DEC drivers when we
finally got 10M cable.     We had had a single (3Mbit) Xerox cable that
went through Cory and over to the 5th floor of Evan and then hit its limit.
  But at 3Mbit, it was a huge step of from the Berk-Net (9600 baud serial
over DZ-11 ports).​

3Com, DEC and InterLan all were working on Unibus ethernet board at
different stages of readiness.   3Com must have been shipping for about
18-24 mons by then, because I had used them on Tektronix (I was their first
customer) but UCB was using the Xerox gear when we started.   DEC had
donated some of their gear to the CAD team, so we had those board before
Joy/Sam did in Evans.   Since I had one "pure DEC" system of our 3 780s in
the CAD group (most of the Vaxen at UCB had non-DEC gear), I was often an
early "test system" for Sam.




>
>
> > BTW: about 3 years later, the BBN2 stack comes out from Rob and team and
> it is actually even more interesting; because it now uses the sockets
> interface (not the Chaosnet/UofI nami trick), and adds a number of both
> performance enhancements (Van Jacobson's work, etc.) as well as a more
> complete implementation of the IP stack.   I >>might<< have a copy of that
> tape squirreled away; but I'll have to look.
>
> I think this might be the material that appears in the BSD source tree in
> 1985, right?

​I don't remember/know if it ever got put directly into the BSD tree.   Rob
released it independent of the BSD kit and you needed and BBN license to
get it.   It was what we used at Stellar​, because it was easier to make
parallel and we were adding it into a more System V then BSD-ish kernel
(the Stellar box was a 4 "core" system in its CPU).

There was definitely some bad blood at the time.  BBN had the contract to
support IP/TCP not UCB.  So the stacks did diverge.   Most (commercial)
people used the BSD 4.2 ( and later NET2) implementation because they got
it from UCB and did not get the separate BBN license.  Arpanet contractors
got the BBN2 code automatically, but I don't think many of folks installed
it unless they needed some feature that BBN had that UCB did not.  The
National Labs are likely to have picked it up; but not all of the
Universities.




> Van Jacobson's work is ~1988, I think, but I could well be mistaken.

​Van was at LBL (up the hill as we used to say).    He started with the BSD
4.2 code, but he was talking with Rob pretty regularly.   I know by the
time we did Stellar,  IIRC:  both Van and Rob​ were part of the DARPA
advisors committee (predecessor to the IETF).  I do remember when we were
at Stellar, Van and Rob were talking because we were doing the
threading/parallel lock stuff and I'm pretty sure Rob traded some of our
work for something Van was doing at the time.



> I think the main performance improvement between the 1982 and the 1985
> version was a switch from a kernel thread model to a software interrupt
> model, but as yet I haven't grasped why this is better and my assumption
> may be incorrect.

​I should know, but frankly do not remember.   I suspect if I started to
stare at the code, some of those bits will refill the cache in my brain.
IIRC it was related to the amount of state that needed to be
saved/switched.  In the thread model, I believe you need the complete
context, but in the Interrupt model and are sharing whatever context the
kernel has at the time of the interrupt.​


​Clem​
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