home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Columbia Kermit
/
kermit.zip
/
newsgroups
/
misc.20000824-20010305
/
000093_news@columbia.edu _Wed Oct 25 10:09:57 2000.msg
< prev
next >
Wrap
Internet Message Format
|
2020-01-01
|
6KB
Return-Path: <news@columbia.edu>
Received: from watsun.cc.columbia.edu (watsun.cc.columbia.edu [128.59.39.2])
by uhaligani.cc.columbia.edu (8.9.3/8.9.3) with ESMTP id KAA05445
for <kermit.misc@cpunix.cc.columbia.edu>; Wed, 25 Oct 2000 10:09:56 -0400 (EDT)
Received: from newsmaster.cc.columbia.edu (newsmaster.cc.columbia.edu [128.59.59.30])
by watsun.cc.columbia.edu (8.8.5/8.8.5) with ESMTP id KAA28245
for <kermit.misc@watsun.cc.columbia.edu>; Wed, 25 Oct 2000 10:09:56 -0400 (EDT)
Received: (from news@localhost)
by newsmaster.cc.columbia.edu (8.9.3/8.9.3) id JAA00278
for kermit.misc@watsun.cc.columbia.edu; Wed, 25 Oct 2000 09:50:22 -0400 (EDT)
X-Authentication-Warning: newsmaster.cc.columbia.edu: news set sender to <news> using -f
From: fdc@columbia.edu (Frank da Cruz)
Subject: Re: log of a kermit comunication
Date: 25 Oct 2000 13:50:20 GMT
Organization: Columbia University
Message-ID: <8t6oes$8j$1@newsmaster.cc.columbia.edu>
To: kermit.misc@columbia.edu
In article <Pine.LNX.3.96.1001024185713.5485B-100000@atlanta.i2.com.br>,
Luiz Geraldo Silva Braz <braz@i2.com.br> wrote:
:
: This is a log of kermit comunication that I need to decode.
: The big questions are:
:
: 1) What king of command could generate the first string
: sent to the kermit server?
:
: #A& D#C"@%<ENTER> (see the log above)
:
: 2) Would this entire comunication be the result of just
: one c-kermit command or a lot of commands?
: What would be this (these) commands?
:
: I intend to create a script (using expect) to interact
: with c-kermit and automate this kind of comunication.
:
: I have inserted some coments (***) inside the log.
:
: Each set of packets has the sender ID ( "1>" to client and "0>"
: to the server) and two representations of the data sent in 2
: columns.
:
: Some non-printbles caracteres are represented by "." at the
: rigth column. In the left column appears the Hex code of each
: char and the simbol of the non-printblesi char.
:
: Thanks in advance.
:
: Luiz Braz
: braz@i2.com.br
: PS: Sorry about the errors. This is the first message I have
: wroten in English. :-)
:
: >-------------------------------------------------------------------------
: *** Estabilishing the connection. 817371001 is just the phone number. :-)
: 1> 0000: 41 54 44 54 30 77 30 33 31 38 31 37 33 37 31 30 ATDT0318173710
: A T D T 0 w 0 3 1 8 1 7 3 7 1 0
: 0010: 30 31 0D 01.
: 0 1 ^M
:
: 0> 0000: 0D 0A 43 4F 4E 4E 45 43 54 20 39 36 30 30 2F 41 ..CONNECT 9600/A
: ^M ^J C O N N E C T bs 9 6 0 0 / A
: 0010: 52 51 2F 56 33 32 2F 4C 41 50 4D 2F 56 34 32 42 RQ/V32/LAPM/V42B
: R Q / V 3 2 / L A P M / V 4 2 B
: 0020: 49 53 0D 0A IS..
: I S ^M ^J
:
This is the CONNECT message from the modem.
: 1> 0013: 23 41 26 20 20 44 23 43 22 40 25 0D #A& D#C"@%.
: # A & bs bs D # C " @ % ^M
:
The format of a Kermit packet is:
MARK LEN SEQ TYPE DATA CHECK
Where:
MARK is a control character, Ctrl-A by default.
LEN is a one-byte excess-32 length field.
SEQ is a one-byte excess-32 sequence number.
TYPE is a one-byte packet type.
DATA is 0 or more bytes of data.
CHECK is the block check.
Let's assume that your protocol dump is printing Ctrl-A as "#A". In
that case:
LEN = '&' = ASCII 38 - 32 = 6.
SEQ = ' ' = ASCII 32 = 32 = 0.
TYPE = ' ' which is not a valid Kermit packet type.
DATA = D#C"@
CHECK = %
So the MARK is wrong, the LEN is wrong, and the TYPE is wrong. No Kermit
program would recognize this as a valid packet.
If, however, the two spaces are a mistake of your recording tool, and really
there is only one space, then we have:
LEN = '&' = ASCII 38 - 32 = 6.
SEQ = ' ' = ASCII 32 = 32 = 0.
TYPE = 'D' (Data)
DATA = #C"@
CHECK = %
It's closer, but still the length is wrong (6 instead of 7). But if we
assume that #A is really Ctrl-A, then maybe #C really is Ctrl-C, in which
case the length would be correct. But the block check is still wrong.
: *** The server answers with an ack packet (Y) and a unknown M-package.
: What kind of package is it? I did't see it at the kermit
: protocol description I have?
: 0> 0024: 23 41 25 20 20 59 2A 24 33 0D 23 41 53 20 5F 4D #A% Y*$3.#AS _M
: # A % bs bs Y * $ 3 ^M # A S bs _ M
:
This too has a superficial resemblence to a Kermit packet, if we assume that
#A really is Ctrl-A and the two blanks are really one blank:
LEN = '%' = ASCII 37 - 32 = 5.
SEQ = ' ' = ASCII 32 = 32 = 0.
TYPE = 'Y' (ACK)
DATA+CHECK = *$#
But the block check isn't right, no matter how you interpret it.
[ ... and so on ... ]
: and the result of the command continues to come in sequences
: of three packages... (see the big questions I have made at the
: begining of this mesage.)
:
There is some resemblence to Kermit protocol, but it isn't really Kermit
protocol. The proper sequence of messages is not there, the packets are not
in the right format, the block checks are not correct. And this is even
allowing for some aftereffects of your recording tools.
- Frank