[Info-vax] Reverse telnet to a terminal emulator?

[Jan-Erik Soderholm]

Snowshoe wrote 2011-07-20 20:49:
> On 7/20/2011 7:21 AM, VAXman- @SendSpamHere.ORG wrote:
>> In article<j05a2a$2k6$1 at speranza.aioe.org>, Snowshoe<no at spam.please> writes:
>>> On 7/19/2011 8:05 PM, VAXman- @SendSpamHere.ORG wrote:
>>>> In article<j050dd$fh5$1 at speranza.aioe.org>, Snowshoe<no at spam.please>
>>>> writes:
>>>>> I/O to a device that doesn't use $QIO. That's kind of weird for VMS.
>>>>
>>>> Your code will issue $QIOs to the FTAx device. That's not that weird
>>>> for VMS.
>>>
>>> I meant for the non-terminal end. If you'll recall with the TW/PY pair,
>>> the TW end was a normal terminal which used normal terminal driver
>>> $QIOs, and you issued $QIOs to get the data to/from the emulator end
>>> (PYxx: ). The program writes to its TW terminal, you do a $QIO read
>>> from the corresponding PYxx: to get the data.
>>> With the FT driver, you have this odd set of parallel services to do the
>>> emulator.
>>
>> What's so odd? PTD$READ/PTD$WRITE
>
> Which is not QIO.
>
>>>> The PTD$READ is really simple. You get handed the data that was seen
>>>> at the FTAx device in an AST. Read the buffer. Simple.
>>>
>>> As simple as $QIO READVBLK on PYxx:, except the funky buffer.
>>
>> Funky buffer?
>
> The one which you have to allocate memory for. Also IIRC the status return
> has to be just before the data in the same buffer, instead of an IOSB
> whereever.
>
>> This is getting as silly as the argument which ensued recently in one of
>> the "Linked-In" forums wherein a former VMS engineer claimed that VMS is
>> not VMS unless it runs solely/wholly on VAX. The stuff running on Alpha
>> and Itanium is not VMS! :rolleyes:
>
> Yes it is silly, and you're right, going nowhere. I just grumble a bit
> about a slightly odd interface and you act almost like I said VMS was
> inferior to Windows. :-)
>
>> Do you code in C? Do you complain about printf()s with null-terminated
>> strings? That's most definitely NOT VMS-like.
>
> No, it's not, and it's not from VMS. It's from the Unix world. I have a
> slight dislike to null-terminated strings in that they're a hole for buffer
> overflow attacks, a couple of which leaked into UCX TCPIP (ported from one
> of the DEC Unixes.
>
>> In the time it's taken you to complain about this, you could have had a
>> prototype coded.
> ...
>
> Same with sockets, from the Unix world.
>
>> If I keep replying to this thread, I'll have done all your work! ;)
>
> How does this pseudoterminal stuff help me find a PC client terminal that I
> can connect to? (I know of TELNET> CREATE_SESSION, I just need something
> for it to talk _to_)

Now. A few questions. Your application, does it connect using an
IPaddress/port ? Or does it talk to some TNAnnnn: port created
using TELNET CREATE ?

Obviously you do not have anything on the PC to CONNECT to.

I would try with the following setup.

Start your client terminal emulator using a startup script that does
a logon to a user where a simple DCL script is runed that does more
or less the following :

$ my_term = f$trnlnm("sys$command")
$ def/sys app_consol 'my_term'  ! Or some /table=app_lnmtab or something...

Now your have a local pointing to your dynamic TNA port :

$ sh log app_consol
    "APP_CONSOL" = "_TNA33:" (LNM$SYSTEM_TABLE)

Then from your app :

$ open/write my_consol app_consol
$ write my_consol "Hey there!"
Hey there!
$
$ close my_consol

But from your code of course, in whatever language it is written.

KISS.

Jan-Erik.



  My pseudoterminal stuff which started this subthread
> was written/swiped from SYS$EXAMPLES a few weeks ago, it works fine. I have
> to go back and look to see how pseudoterminals even got involved in this
> topic.
>