[comp.bugs.4bsd] 'Talk' command and protocol

eckert@faui10.UUCP (Toerless Eckert) (12/21/88)

From article <1468@cseg.uucp>, by dws@cseg.uucp (David W. Summers):
..
>    My main question is:  Is there a standard yet for this 'talk' protocol?  If
> so, where could I find it?  If not, then why not, and what would it take to
> produce one?  What is strange is that on each of our different types of
> computers, there was a 'talk   517/udp' entry in the /etc/services file which
> led me to believe that everyone knew about it.  However, I could find NOTHING
> that even referenced it during my search of the RFC's.

I do not think that talk was ever meant to be a _standard_. From my 
experiences with it i must conclude that it is a hack. While it is really
nice in its user interface, it has severe problems with its way to
exchange data. Talk uses the above mentioned structures CTL_MSG and
CTL_RESPONSE to exchange information about the partners through the net.
Talk does not use XDR or some other means of encapsulation when sending
this C structures. This causes problems when you want to run
talk between machines of different architectures. The 4.2BSD talk code
was written to run VAXen and on SUNs, and maybe on machines with similar
architecture. When receiving a CTL_MSG packet from the net, this code
does a plausiblity check about what type of machine this packet came from.
If swapping some bytes in the packet will result in a valid
IP address, then it will swap all bytes in the packet, because the program
has concluded that the remote machine must have a byte swapped architecture.
Another problem that this version of talk cannot handle at all is
the compiler alignement of structure elements. I once tried to compile talk
on a little endian machine that had an alignement to 4 byte boundaries.
Talk choked on this, and could not talk to Suns nor VAXen, because
those machines have a different alignement policy. This is what i call a
hack.
The talk supplied with 4.3BSD tries to solve this problem by
inserting some dummy char elements into this structures. But 4.3 talk
has also changed the overall structures, so it is truely incompatible
with 4.2 talk ( they use a different port for 4.3 talk though).

I have tried talk between a couple of machines ( Suns, Vaxen, Sequent,
Apollo), and there are couple of compinations that do not work. Its not
so easy to declare which version is broken, but in general it does
not work correctly.

Many other Manufacturers (HP, PCS, CRAY, ..) were so wise to leave 
talk out of their unix ports ;-)

I have previosly posted a request for a replacement for talk, but that
was only to comp.sources.wanted. Maybe that was the wrong audience.
Does someone on this lists knows if there is a suitable replacement for
talk, that does not suffer from the above mentioned problems ?

andrew@stl.stc.co.uk (Andrew Macpherson) (01/07/89)

In article <786@faui10.informatik.uni-erlangen.de> eckert@faui10.UUCP (Toerless Eckert) writes:
| I have previosly posted a request for a replacement for talk, but that
| was only to comp.sources.wanted. Maybe that was the wrong audience.
| Does someone on this lists knows if there is a suitable replacement for
| talk, that does not suffer from the above mentioned problems ?

Look out for "Phone" which has a nicer user interface, and gets round your
complaints.  let's see:

Ah yes, written by: J. Broome  UCB 1985.

I think I got it from the news network, but there must be somewhere nearer
you to get it.
-- 
Andrew Macpherson                          PSI%234237100122::andrew
andrew@stl.stc.co.uk        - or -         ...!mcvax!ukc!stl!andrew
"It is always a great mistake to treat the individual on the chance
that he may become a crowd" -- Mr Justice Codd: (A.P.Herbert)

yee@ames.arc.nasa.gov (Peter E. Yee) (01/08/89)

In article <924@acer.stl.stc.co.uk> "Andrew Macpherson" <andrew@stl.stc.co.uk> writes:
>In article <786@faui10.informatik.uni-erlangen.de> eckert@faui10.UUCP (Toerless Eckert) writes:
>| ... Does someone on this lists knows if there is a suitable replacement for
>| talk, that does not suffer from the above mentioned problems ?
>
>Look out for "Phone" which has a nicer user interface, and gets round your
>complaints.  let's see:

I have the sources to phone (obtained from Jonathan back whenever).  If there
is enough interest, I could make them available for anonymous ftp or mail them
to some people (if the number of interested folks is few).   If it came out
in 1985, and was posted to the net, it's probably in an archive somewhere,
but I never can seem to find archives for mod and comp.sources.

							-Peter Yee
							yee@ames.arc.nasa.gov
							ames!yee

wisner@killer.DALLAS.TX.US (Bill Wisner) (01/10/89)

The sources to phone are already available for anonymous FTP. I put them
up on EDDIE.MIT.EDU earlier this year. I think they're /pub/phone.tar.Z
or something similar.

hanst@htsa.uucp (Hans Trompert) (01/10/89)

In article <20431@ames.arc.nasa.gov> yee@ames.arc.nasa.gov.UUCP (Peter E. Yee) writes:
>I have the sources to phone (obtained from Jonathan back whenever).  If there
>is enough interest, I could make them available for anonymous ftp or mail them
>to some people (if the number of interested folks is few).   If it came out
>in 1985, and was posted to the net, it's probably in an archive somewhere,
>but I never can seem to find archives for mod and comp.sources.

We sure are interested, and I think many others are interested as well.
But we have no access to anonymous ftp, so why dont you post it on the net
if many people are interested.

-- 
                       Hans Trompert
                       Algemene Hogeschool Amsterdam
                       Technische en Maritieme Faculteit
                       hanst@htsa.uucp.nl

rhealey@umn-d-ub.D.UMN.EDU (Rob Healey) (01/11/89)

In article <704@htsa.uucp> hanst@htsa.uucp (Hans Trompert) writes:
>In article <20431@ames.arc.nasa.gov> yee@ames.arc.nasa.gov.UUCP (Peter E. Yee) writes:
>>I have the sources to phone (obtained from Jonathan back whenever).  If there
>>is enough interest, I could make them available for anonymous ftp or mail them
>>to some people (if the number of interested folks is few).   If it came out
>>in 1985, and was posted to the net, it's probably in an archive somewhere,
>>but I never can seem to find archives for mod and comp.sources.
>
>We sure are interested, and I think many others are interested as well.
>But we have no access to anonymous ftp, so why dont you post it on the net
>if many people are interested.
	
	Have you people had any problems with the code? I snarfed a copy
	off of eddie.mit.edu. It looks like it was written in the
	"WHAT! There's other computers besides a VAX!" era. It bombs on
	Sun's and an Encore Multimax, both 4.2 machines. The Sun works OK
	some of the time but try holding a 3 or more conversation across the
	network and ka-blewy... The user interface seems to be the main
	culprit. Anyone hacked on this code that could give me pointer's on
	what to do to get it to work on the Encore and not to crash on the
	Sun? I couldn't get it to run under bind/-lresolv on either machine.
	I had hoped the days of crudy Vax programs had gone forever... This
	program looks to be worth saving though, to bad Berkeley couldn't have
	made it a working replacement for talk. Even more amazing is it runs
	in user mode so no nasty SUID surprises.

		Thanks for any help,

		     -Rob Healey

		     rhealey@ub.d.umn.edu

trn@aplcomm.jhuapl.edu (Tony Nardo) (01/12/89)

In article <651@umn-d-ub.D.UMN.EDU> rhealey@ub.d.umn.edu.UUCP (Rob Healey) writes:
>>In article <20431@ames.arc.nasa.gov> yee@ames.arc.nasa.gov.UUCP (Peter E. Yee) writes:
>>>I have the sources to phone (obtained from Jonathan back whenever)....
>	Have you people had any problems with the code? I snarfed a copy
>	off of eddie.mit.edu. It looks like it was written in the
>	"WHAT! There's other computers besides a VAX!" era. It bombs on
>	Sun's and an Encore Multimax, both 4.2 machines. The Sun works OK
>	some of the time but try holding a 3 or more conversation across the
>	network and ka-blewy...

Your version survived longer than either of mine did.  I'm using a Sun 4/110.
As soon as I typed in the word "phone" on each, I found myself looking at a
"watchdog reset" prompt.  Not a pretty sight.

Does anyone have a version of "phone" that WORKS for the Sun?
-------				----------------			-------
ARPA,	trn@aplcomm.jhuapl.edu,		UUCP:	{backbone!}mimsy!aplcomm!trn
BITNET:	trn@warper.jhuapl.edu

	    "Thank God I'm only watching the game, controlling it."
				"One Night In Bangkok" (_Chess_)