[HECnet] Tops-20 Disk Quotas (was Anonymous FAL (Tops-20))

Fri Jul 5 11:57:45 PDT 2019

Oh, it's something beyond annoying, but it's not the accounting system 
confounding you; that can be completely disabled (I have it off on my 
systems).  The policy is actually built into the Tops-20 file system itself.

Directories under Tops-20 are vastly different--both in concept and 
implementation--from anything else that I've seen (and I did a lot of 
research into file system design at one particular job). Directory 
creation is cumbersome, typically requiring expert level intervention or 
significant programming.  However, it's whaay better than what Tops-10 
had at the time (nothing), ITS (don't ask), WAITS (nothing) or MVS 
(partitioned data sets, a true hack).

Create a directory under Unix? mkdir.  Easyn  peasy. Windows? md, unless 
you are running quotas.  Also no heavy lift.

Tops-20 got more and more complex.  In addition to having to take quota 
away from the superior and hand it over to the sub-directory, unless you 
are running PANDA modifications, you have to create an access group and 
allocate it or the poor user can't see his own sub-directory.   Group 
management can be confusing if you are running super-domestic structures 
and downright tedious for regular structures, otherwise.  There was 
more; Yeesh...   Instead of trying to check for every possible problem 
beforehand, it was sometimes easier to catch errors from the CRDIR%, go 
recursive and modify the superior (and on up).

You can defeat some of this.  Setting CD%NSQ will cause CRDIR% to no 
update the the superior, but you need rights to do it.  I always thought 
that there was a better way to do this, perhaps with an IPCF% based 
client/server application, coupled with some changes to the access 
control job.

Why all this hair?  Directories were considered precious resources.  Why 
would that be?  Consider what happens when you try to fit (or cram) a 
user population of over 25,000 students onto the triple 180 MB disk 
structures of the time (the maximum you could do in 1980's).  You get 
measly user permanent quotas of 100 pages (250KB), working of 1,000.  
Not much.

It's a vastly different world now.  So Tops-20 needs a mkdir, but that 
would need to talk to a privileged backend with policy and directory 
creation smarts.  I think that would be pretty friendly; definitely 
easier than trying to suss out BUILD or ^ECREATE.
> ------------------------------------------------------------------------
> On 7/4/2019 2:48 PM, Johnny Billquist wrote:
>
> The one annoying detail of the account system in TOPS-20 is that user 
> disk quotas are on a per directory basis. So you have to manually move 
> your disk quota around for your subdirectories.
>> ------------------------------------------------------------------------
>> On 2019-07-04 04:01, Thomas DeBellis wrote:
>>
>> Tops-20 is vastly different from Unix (and I believe also VMS) as to 
>> how it manages user ids and accounts.  Parts of the authentication 
>> paradigm are very tightly woven into the the file system.  Briefly,
>>
>>   * A user id is a login-able directory (I.E., one that doesn't have
>>     apassword and is not set FILES-ONLY).  In addition to basic OS
>>     restrictions which prevent you from viewing file system meta-data
>>     unless you have appropriate authorization, an access control job
>>     (ACJ) is layered on top of this which can even restrict
>>     privileged users.
>>   * Accounts are either validated out of a binary accounting file in
>>     monitor space (which is compiled from ASCII source) or via the
>>     ACJ.     Accounts can have multiple users or systems processes
>>     (such as spoolers) creating billing records. Users can switch
>>     between accounts on a per-job, per-fork and intra-program basis
>>     (a program can decide to bill certain portions of its activity to
>>     different accounts).
>>   * The obvious benefit is that there is no password file to attack
>>     or steal and you can't even tell that there is an accounting
>>     file; probing passwords is monitored and a certain amount of
>>     intervention is done.  It is /extremely/ fast. No /etc/passwd to
>>     grovel.
>>
>> However, a deleterious side-effect is that once an id is created, it 
>> can be used for _anything_, including online interactive login.
>>
>> On a PANDA monitor, is possible to specify a user id as FTP-ONLY, but 
>> neither the supplied 5 series ACJ nor the EXEC do anything with it.  
>> Historically, the Tops-20 FTP server implemented ANONYMOUS usage by 
>> parsing for the login user atom ANONYMOUS and then swallowing 
>> anything for the password (what was typically supplied was an email 
>> addresses). This was then hardwired into a local id.
>>
>> Artifacts of this still exist in certain browers.  Guess who supplies 
>> IEUSER@ as the email address password for ANONYOUS usage?
>>
>> I recall that this is the approach that we had to use with Tops-20 
>> FAL.  The Extended  Mode FTP server that I wrote is configurable via 
>> a file to specify the underlying id and password.  More 
>> productization would probably including having the ACJ enforce 
>> FTP-ONLY on LOGIN% or CRJOB% and having the EXEC parse for and 
>> display FTP-ONLY.  Probably about two weeks' part time work as I 
>> recall.  Might have to consider Batch policy.
>>
>> One approach here could be to lift the ANONYMOUS code out of EFTPSR 
>> and drop it into FAL and then do the changes to the ACJ and EXEC. I'm 
>> just surprised none of the HECnet Tops-10 or Tops-20 nerds have done 
>> it (there is some commonality in some of the sources).
>>
>> Since Tops-20 has a BLISS compiler which implements BLISS COMMON (my 
>> first training at DEC as an employee was to write code that would 
>> cross compile under VMS, RSX, Tops-10 and Tops-20).  I think it might 
>> be useful to review some of the VMS DECnet source, if any of that is 
>> available.  It might be possible to lift some functionality, which 
>> could be fun.
>>
>> Does the VMS hobbiest license get you source code?
>>> ------------------------------------------------------------------------
>>> On 7/3/2019 7:21 PM, Johnny Billquist wrote:
>>>
>>> VMS, as someone else mentioned, have a default account for FAL.
>>>
>>> RSX does not have that.  However, you can use proxy access in RSX to 
>>> achieve something similar.  Enable incoming and outgoing proxy, and 
>>> define a default account that incoming requests should be using that 
>>> way.
>>>
>>> If TOPS-20 can do this I don't know.  But it's a suggestion for 
>>> something else/more to check.
>>>
>>>   Johnny
>>>> ------------------------------------------------------------------------
>>>> On 2019-07-03 14:15, Thomas DeBellis wrote:
>>>>
>>>> I have some software that I'd like to post, but don't recall how to 
>>>> configure FAL to allow for an anonymous connection; to download 
>>>> from a restricted directory.
>>>>
>>>> I know how to do it for the FTP server (seeing as I wrote it), but 
>>>> ... different code base.
>>>>
>>>> I can only vaguely remember what we did for CCnet at Columbia 
>>>> University in the 1980's, but I think it was kind of a hack.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sonic.net/pipermail/hecnet-list/attachments/20190705/ad980a6a/attachment-0001.html>