Ada program needs to ping another machine.

Ada program needs to ping another machine.

[Preben Randhol]

I'm making a small Ada program (on my spare time) that I want to be able
to run from both Linux and Windows. The problem is it need to check if
another machine is on or off and display this in a small GUI interface.
I can do this by using the ping command on Linux, but I would rather
learn how to do this from Ada. I'm not asking for a solution (of course
if somebody has something they want to share it would be nice), but some
hints on what I should read up on to find out how to do this. Can I use
sockets for instance? I'm developing on Linux and I don't have much clue
about Windows programming so I would like to make this as portable as
possible (that is, just recompiling in windows would be nice).

Eventually it would be nice to evolve the program into a talk program (a
program where one write simultaneously on a split screen) as the wintalk
program is rather unstable and I would hope Ada could increase
security.

Preben
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Re: Ada program needs to ping another machine.

[Gerhard Häring]

Preben Randhol wrote in <slrna4bc3i.2cl.randhol+abuse@kiuk0156.chembio.ntnu.no>:
> I'm making a small Ada program (on my spare time) that I want to be able
> to run from both Linux and Windows. The problem is it need to check if
> another machine is on or off and display this in a small GUI interface.
> I can do this by using the ping command on Linux, but I would rather
> learn how to do this from Ada. [...]

What about trying to connect to the echo port using AdaSockets?
Perhaps AdaSockets even supports ICMP? I haven't checked (never used
it myself).

Gerhard
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Re: Ada program needs to ping another machine.

[Stephen Leake]

Preben Randhol <randhol+abuse@pvv.org> writes:

> I'm making a small Ada program (on my spare time) that I want to be able
> to run from both Linux and Windows. The problem is it need to check if
> another machine is on or off and display this in a small GUI interface.
> I can do this by using the ping command on Linux, but I would rather
> learn how to do this from Ada. I'm not asking for a solution (of course
> if somebody has something they want to share it would be nice), but some
> hints on what I should read up on to find out how to do this. Can I use
> sockets for instance? I'm developing on Linux and I don't have much clue
> about Windows programming so I would like to make this as portable as
> possible (that is, just recompiling in windows would be nice).

Get the C source for ping from the Linux distribution, and either
pragma Import some of it, or translate it all to Ada.

> Eventually it would be nice to evolve the program into a talk
> program (a program where one write simultaneously on a split screen)
> as the wintalk program is rather unstable and I would hope Ada could
> increase security.

There are other talk programs out there; I doubt an Ada one would add
much. It would, of course, be fun to do :).

-- 
-- Stephe

Re: Ada program needs to ping another machine.

[Preben Randhol]

On 16 Jan 2002 15:55:56 -0500, Stephen Leake wrote:
> 
> Get the C source for ping from the Linux distribution, and either
> pragma Import some of it, or translate it all to Ada.

Yes I can do that, though I would perfer not to have anything in C (I
don't have a C compiler for windows among other things). But if it is
difficult then i could also just have a deamon running and try to
connect to the deamon on the other machine. Would need to do that
anyway.

>> Eventually it would be nice to evolve the program into a talk
>> program (a program where one write simultaneously on a split screen)
>> as the wintalk program is rather unstable and I would hope Ada could
>> increase security.
> 
> There are other talk programs out there; I doubt an Ada one would add
> much. It would, of course, be fun to do :).

Buffer overflow should hopefully be fixed.

But which other programs? I'm not talking about the chat programs where
you send one line and then have to wait for the other to answer. What
I'm talking about is that the users can simoultaneously write and you
see every keystroke as they are typed on the other side. Other featured
that would be nice is adding ssl and using Pango when GtkAda 2.0 is out.

http://www.pvv.org/~randhol/Ada95/talk.png shows how talk works on Linux
now running talk in a terminal. The first window is what user 1 on
machine 1 sees, the second is user 2 on machine 2. When you type you
will see what the other types as she/he types.

Preben
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Re: Ada program needs to ping another machine.

[Jim Rogers]

Preben Randhol wrote:

> On 16 Jan 2002 15:55:56 -0500, Stephen Leake wrote:
> 
>>Get the C source for ping from the Linux distribution, and either
>>pragma Import some of it, or translate it all to Ada.
>>
> 
> Yes I can do that, though I would perfer not to have anything in C (I
> don't have a C compiler for windows among other things). 


If you have GNAT for windows, you also have the gcc compiler for
windows. Even without the C compiler, you can link existing C
libraries to Ada using pragma Import and pragma Linker_Options.

Jim Rogers

Re: Ada program needs to ping another machine.

[Jeffrey Carter]

Preben Randhol wrote:
> 
> Yes I can do that, though I would perfer not to have anything in C (I
> don't have a C compiler for windows among other things). But if it is
> difficult then i could also just have a deamon running and try to
> connect to the deamon on the other machine. Would need to do that
> anyway.

If you have GNAT for Windows then you have a C compiler for Windows.
Since you're talking about a portable program with a GUI, I'd guess
you're using GtkAda, which relies on the GNAT compiler, so you have or
intend to get GNAT for Windows (I guess).

-- 
Jeffrey Carter

Re: Ada program needs to ping another machine.

[R. Srinivasan]

I have such an animal (sort of). I used AdaSockets with some modifications.
Unfortunately the version of AdaSockets on Linux available at that time was
not identical to the Windows version at least in the specifications. Perhaps
such issues have been ironed out now. I will be happy to send my copy of
"netmon" which can ping a list of host names in the same invocation if you
like.

I dont have it here but will have it tomorrow night. If anybody would like
to receive it please email me at r.srinivasan@cox.net (Remember however it
compiles/runs on Windows only).


"Preben Randhol" <randhol+abuse@pvv.org> wrote in message
news:slrna4bc3i.2cl.randhol+abuse@kiuk0156.chembio.ntnu.no...
> I'm making a small Ada program (on my spare time) that I want to be able
> to run from both Linux and Windows. The problem is it need to check if
> another machine is on or off and display this in a small GUI interface.
> I can do this by using the ping command on Linux, but I would rather
> learn how to do this from Ada. I'm not asking for a solution (of course
> if somebody has something they want to share it would be nice), but some
> hints on what I should read up on to find out how to do this. Can I use
> sockets for instance? I'm developing on Linux and I don't have much clue
> about Windows programming so I would like to make this as portable as
> possible (that is, just recompiling in windows would be nice).
>
> Eventually it would be nice to evolve the program into a talk program (a
> program where one write simultaneously on a split screen) as the wintalk
> program is rather unstable and I would hope Ada could increase
> security.
>
> Preben
> --
>  ()   Join the worldwide campaign to protect fundamental human rights.
> '||}
> {||'                                           http://www.amnesty.org/

Re: Ada program needs to ping another machine.

[Preben Randhol]

On Wed, 16 Jan 2002 22:43:11 GMT, Jeffrey Carter wrote:
> If you have GNAT for Windows then you have a C compiler for Windows.
> Since you're talking about a portable program with a GUI, I'd guess
> you're using GtkAda, which relies on the GNAT compiler, so you have or
> intend to get GNAT for Windows (I guess).

Yes, but I would be surprised if it was only to recompile the ping
source from linux on windows and it worked.

Preben
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Re: Ada program needs to ping another machine.

[Peter Hermann]

Preben Randhol <randhol+abuse@pvv.org> wrote:
[snip]
> sockets for instance? I'm developing on Linux and I don't have much clue
> about Windows programming so I would like to make this as portable as
> possible (that is, just recompiling in windows would be nice).

> Eventually it would be nice to evolve the program into a talk program (a
> program where one write simultaneously on a split screen) as the wintalk
> program is rather unstable and I would hope Ada could increase security.

Such a tool would be a first choice in an Ada contest.

-- 
--Peter Hermann(49)0711-685-3611 fax3758 ica2ph@csv.ica.uni-stuttgart.de
--Pfaffenwaldring 27 Raum 114, D-70569 Stuttgart Uni Computeranwendungen
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--Team Ada: "C'mon people let the world begin" (Paul McCartney)

Re: Ada program needs to ping another machine.

[Jerry van Dijk]

"R. Srinivasan" <rajasrinivasan@cox.net> writes:

> I have such an animal (sort of). I used AdaSockets with some modifications.
> Unfortunately the version of AdaSockets on Linux available at that time was
> not identical to the Windows version at least in the specifications. Perhaps
> such issues have been ironed out now.

AdaSockets now fully supports Windows natively. You can download a Win32
compiled copy from my homepage.

-- 
--  Jerry van Dijk   | email: jvandyk@attglobal.net
--  Leiden, Holland  | web:   users.ncrvnet.nl/gmvdijk

Re: Ada program needs to ping another machine.

[Frank]

>
> There are other talk programs out there; I doubt an Ada one would add
> much. It would, of course, be fun to do :).
>

Im not using chat-programs alot. But are there anyone that offers
encryption?
If not - could that be an idea?

Frank

Re: Ada program needs to ping another machine.

[Darren New]

Frank wrote:
> Im not using chat-programs alot. But are there anyone that offers
> encryption?
> If not - could that be an idea?

Yes, several. 

-- 
Darren New 
San Diego, CA, USA (PST). Cryptokeys on demand.
  The opposite of always is sometimes.
   The opposite of never is sometimes.

Re: Ada program needs to ping another machine.

[Preben Randhol]

On Thu, 17 Jan 2002 16:36:04 GMT, Frank wrote:
> Im not using chat-programs alot. But are there anyone that offers
> encryption?
> If not - could that be an idea?

Yes, but as I said before it is not a chat program where one send one
line of text at a time, but rather a stream of characters that are
continously read. I don't know if it makes sense trying to encrypt one
character, but I haven't read much about encryption so I do not know.
But if it is possible it would be nice.

One problem I thought of now is that on a multi-user environment I have
to be able pass the connection to the correct user. The daemonn need to
be connected to a standard port so that the other machine can connect to
it I would think. I'm unsure how to do this. I think I should check the
source code of talk and the talkd daemon. On Windows (or Mac) it is
easier as then the environment is single user so the program that the
user run can connect directly to the port.

Preben
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Re: Ada program needs to ping another machine.

[Johannes Grødem]

* Preben Randhol <randhol+abuse@pvv.org>:

> I don't know if it makes sense trying to encrypt one
> character, but I haven't read much about encryption so I do not know.

It makes perfect sense.  SSH does it, for example.  (Check out Applied
Cryptography by Bruce Schneier.)

-- 
johs

Re: Ada program needs to ping another machine.

[Gisle Sælensminde]

Preben Randhol wrote:
> On Thu, 17 Jan 2002 16:36:04 GMT, Frank wrote:
>> Im not using chat-programs alot. But are there anyone that offers
>> encryption?
>> If not - could that be an idea?
> 
> Yes, but as I said before it is not a chat program where one send one
> line of text at a time, but rather a stream of characters that are
> continously read. I don't know if it makes sense trying to encrypt one
> character, but I haven't read much about encryption so I do not know.
> But if it is possible it would be nice.

Cryptography is very difficult to get right, and you should not try to
design it yourself but rely on existing. Even using existing technology
is not without potential problems, and without understanding of how and
why the system is secure you may make the system unsecure. 

I can think of several strategies for doing this

You could use the SSL/TLS protocol and flush the socket for each byte
you type. The TLS protocol should be secure in this case as well. 
Even though the TLS protocol is tcp-based, you should be able to use
the protocol. This also make it possible to authenticate the peers
at startup of the protocol. In practice you can use the openssl library
to do the cryptography. The AWS web server use the openssl library to
implement the TLS/SSL layer of the https protocol. You could use 
the AWS source as an example. Another example is the kerberos protocol.
I would recomend this strategy. 

If you insist to use a packet based protocol (udp-style), then things
become harder. Several protocols that have been applied have proven to
be weak. On example is the encryption protocol for 803.11 wireless 
networks. Even though this was designed by aperently competent people.
Also the packet-bases extension to TLS used in WAP phones have similar
problems. One protocol that is belived to be secure is the IPSEC 
protocol, and the design could be reused. The protocol is quite 
complex however (800 pages of RFC documents I have heard, but I have
not counted myself). Also, to apply a protocol to a diffent usage than
intended can introduce problems as well.

OK - since NSA probably never will care about what you write in 
a chat session, you can ignore some of the arguments above.
One protocol thst is quite simple to implement is the CIPE protocol.
This is used for making VPNs. The protocol is not secure against
reply-attacks, but that's probably not a problem in chat application.
The protocol require that the peers shares a secret key, and that 
may be inpractical.

> One problem I thought of now is that on a multi-user environment I have
> to be able pass the connection to the correct user. The daemonn need to
> be connected to a standard port so that the other machine can connect to
> it I would think. I'm unsure how to do this. I think I should check the
> source code of talk and the talkd daemon. On Windows (or Mac) it is
> easier as then the environment is single user so the program that the
> user run can connect directly to the port.
> 
> Preben


--
Gisle S�lensminde ( gisle@ii.uib.no )   

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going
to land, and it could be dangerous sitting under them as they fly
overhead. (from RFC 1925)

Re: Ada program needs to ping another machine.

[Florian Weimer]

"Johannes Grï¿œdem" <st@kopkillah.com> writes:

> * Preben Randhol <randhol+abuse@pvv.org>:
>
>> I don't know if it makes sense trying to encrypt one
>> character, but I haven't read much about encryption so I do not know.
>
> It makes perfect sense.  SSH does it, for example.

No, it doesn't.  It adds a substantial amount of padding.

Re: Ada program needs to ping another machine.

[Johannes Grødem]

* Florian Weimer <fw@deneb.enyo.de>:

>>> I don't know if it makes sense trying to encrypt one
>>> character, but I haven't read much about encryption so I do not know.
>> It makes perfect sense.  SSH does it, for example.
> No, it doesn't.  It adds a substantial amount of padding.

I didn't say it sent only one character at a time.  But it encrypts
one character at a time, right?  (Well, with the default mode,
anyway.  CFB? OFB?)

-- 
johs

Re: Ada program needs to ping another machine.

[Preben Randhol]

On 17 Jan 2002 20:56:14 GMT, Gisle S�lensminde wrote:
> 
> Cryptography is very difficult to get right, and you should not try to
> design it yourself but rely on existing. Even using existing technology
> is not without potential problems, and without understanding of how and
> why the system is secure you may make the system unsecure. 

Yes.

> I can think of several strategies for doing this
> 
> You could use the SSL/TLS protocol and flush the socket for each byte
> you type. The TLS protocol should be secure in this case as well. 
> Even though the TLS protocol is tcp-based, you should be able to use
> the protocol. This also make it possible to authenticate the peers
> at startup of the protocol. In practice you can use the openssl library
> to do the cryptography. The AWS web server use the openssl library to
> implement the TLS/SSL layer of the https protocol. You could use 
> the AWS source as an example. Another example is the kerberos protocol.
> I would recomend this strategy. 

I think so too. SSL is usually also installed on different systems so it
would be easier to use. 

Preben
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Re: Ada program needs to ping another machine.

[Adrian Knoth]

Preben Randhol <randhol+abuse@pvv.org> wrote:

> But which other programs? I'm not talking about the chat programs where
> you send one line and then have to wait for the other to answer. What
> I'm talking about is that the users can simoultaneously write and you
> see every keystroke as they are typed on the other side. 

This is already implemented in 'talk'.

From the manpage:

     his login-name is the same.  Once communication is established, the two
     parties may type simultaneously, with their output appearing in separate
     windows.


So that you're getting lines instead of keystrokes surely points to a very
overloaded connection :)

> Other featured that would be nice is adding ssl 

ssl could be added to talk through stunnel on a different socket, directly
connecting to the local existing non-ssl-talk-daemon. I agree that for
clients real ssl-support would be port-saving (of 1).


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Re: Ada program needs to ping another machine.

[Preben Randhol]

On 18 Jan 2002 12:21:29 GMT, Adrian Knoth wrote:
> Preben Randhol <randhol+abuse@pvv.org> wrote:
> 
>> But which other programs? I'm not talking about the chat programs where
>> you send one line and then have to wait for the other to answer. What
>> I'm talking about is that the users can simoultaneously write and you
>> see every keystroke as they are typed on the other side. 
> 
> This is already implemented in 'talk'.

Yes and if you look back in the thread you will see that I have
mentioned talk several times.

> So that you're getting lines instead of keystrokes surely points to a very
> overloaded connection :)

What? Please read the whole thread.

Preben
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Re: Ada program needs to ping another machine.

[Pascal Obry]

Preben Randhol <randhol+abuse@pvv.org> writes:

> One problem I thought of now is that on a multi-user environment I have
> to be able pass the connection to the correct user. The daemonn need to
> be connected to a standard port so that the other machine can connect to
> it I would think. I'm unsure how to do this. I think I should check the
> source code of talk and the talkd daemon. On Windows (or Mac) it is
> easier as then the environment is single user so the program that the
> user run can connect directly to the port.

Well a chat program is quite trivial to do with GLADE. For encryption just use
one of the crypto filter (DES, SHA...). I have a small demo chat program that
I could share if it can help (just plain Ada, no GUI).

Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|         http://perso.wanadoo.fr/pascal.obry
--|
--| "The best way to travel is by means of imagination"

Re: Ada program needs to ping another machine.

[Preben Randhol]

On 18 Jan 2002 18:37:06 +0100, Pascal Obry wrote:
> Well a chat program is quite trivial to do with GLADE. For encryption just use
> one of the crypto filter (DES, SHA...). I have a small demo chat program that
> I could share if it can help (just plain Ada, no GUI).

Yes I would be interested in looking at it.

Preben
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Re: Ada program needs to ping another machine.

[Pascal Obry]

Preben Randhol <randhol+abuse@pvv.org> writes:

> On 18 Jan 2002 18:37:06 +0100, Pascal Obry wrote:
> > Well a chat program is quite trivial to do with GLADE. For encryption just use
> > one of the crypto filter (DES, SHA...). I have a small demo chat program that
> > I could share if it can help (just plain Ada, no GUI).
> 
> Yes I would be interested in looking at it.

Of, please give me your e-mail I'll send this to you. Note that in the code I
do not use filters (DES, or SHA) but this is a one line change in the GLADE
configuration file.

Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|         http://perso.wanadoo.fr/pascal.obry
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Re: Ada program needs to ping another machine.

[Adrian Knoth]

Preben Randhol <randhol+abuse@pvv.org> wrote:

>>> But which other programs? I'm not talking about the chat programs where
>>> you send one line and then have to wait for the other to answer. What
>>> I'm talking about is that the users can simoultaneously write and you
>>> see every keystroke as they are typed on the other side. 
>> This is already implemented in 'talk'.
> Yes and if you look back in the thread you will see that I have
> mentioned talk several times.

And? talk fits best.

>> So that you're getting lines instead of keystrokes surely points to a very
>> overloaded connection :)
> What? Please read the whole thread.

I did it again. You mentioned several times that your tool wouldn't be
line-orientated, but realtime (single keystrokes). This is _exactly_
what my talk does, and every other talk I've ever seen.

If I need encryption, I can connect through stunnel. Already posted this.

Again, I cannot see any profit.

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