Device::SerialPort handshake detection 1

[svar]

I need to use the modem to connect to another one
and particularly pay attention to errors. Many errors are possible, but here I want to focus on the case where the other side is not a modem(i.e. has unplugged the PC and plugged in the normal phone)
Here is an

use Device::SerialPort;
#

http://search.cpan.org/dist/Win32-SerialPort/lib/Win32/SerialPort.pm

my $dialled_no='......';


&start_dialing($dialled_no);


sub start_dialing
{my $number=shift;
my $modem=new Device::SerialPort('/dev/cuad0') or die
"Unable to pen /dev/cuad0\n";

### Question no 1: What do I use instead of /dev/cuad0 if
### this will be used from a Windows machine?

# $modem->baudrate(115200);
$modem->baudrate(9600);
$modem->parity("none");
$modem->databits(8);
$modem->stopbits(1);
$modem->write("ATH;\n");

$modem->write("ATDT $number;\n");

### here I am unsure as to how you actually make the call and grab the other modem responses.

}

 

[PaulTEG]

For windows you should be using Win32::SerialPort, rather than Device::SerialPort

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)

 

[svar]

Ok,
so
$PortObj = new Win32::SerialPort ($PortName, $quiet)
|| die "Can't open $PortName: $^E\n"; # $quiet is option

what would be an example of $portName? 'COM1' ?

It is also unclear to me how I could check the answer from the modem, at the other end, or its absence

With Unix, I guess the simplest way to do this would be
"system wvdial $dialled_number | grep ...." or something similar, i.e. I don't really need that fine control of
the connection, all I need is to be able to specify a number to call and check the response from the other side.
But I need to do this in Windows and I cannot find how to call dialer.exe from the command line with the dialled number(and possibly other parameters) as an argument.

 

[PaulTEG]

COM1 or whatever port the modem is connected to in the control panel

The docs for Win32::SerialPort should have a simple example of communication between two modems

What are you using this for, if you don't mind me asking, there may be other ways?

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)

 

[svar]

The idea is a security scan for nonauthorized modems on a network(policy is that users should not have modems, so
scanning all numbers in the corporate network should trigger an alert if a modem answers on the other end).
So basically
-call all numbers sequentially
-raise an alert if a modem answers.

That's basically all there is to it

 

[PaulTEG]

You can determine if there's modems just by scanning the registry of pcs on the network, which would be quieter, no? If it's a security thing, and there's modems, and all of a sudden they start dialling, if there's a perp in the vicinity, they's well tipped off now, no?

Anyhoo, how's it going?

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)

 

[svar]

True, assuming one has access to the other PC's registry. As you can see from the other thread

http://www.tek-tips.com/viewthread.cfm?qid=1429253&page=1

I am trying both approaches.

Back to the question in hand, the idea is to call
using the modem and see if a modem answers(meaning getting a 'CONNECT'). I tested what would happen if I dial a non-modem and I usually get 'NO CARRIER', which I think is correct, but I also got sometimes 'NO ANSWER', which looks strange(note in all test, the same number was dialled -which is behind a PBX though).
I have not tested the code yet(I do not have a windows machine with a modem-it's only now that I am forced to use Windows and check windows), but if I understand it correctly, it should run something like this:

# First, define the Portname Object
use Win32::SerialPort ;
my $PortObj= new Win32::SerialPort('COM1') or die "cannot open COM1: $^E\n";
# Next, configure( as I understand this is compulsory)
$PortObj->baudrate(9600);
$PortObj->parity("odd");
$PortObj->databits(8);
$PortObj->stopbits(1);
#Next, do the call
my $phone=1234567;

## This I have not found the command for!!!!
#Next, capture response and look for connect
my ($match,$after,'CONNECT',$instead)=$PortObj->lastlook;

if($match){#found a CONNECT
print "found a modem for phone $phone\n";
}


Any ideas?

 

[PaulTEG]

$PortObj->write("ATDT$phone\r") || die "Could Not Dial\n";

from

http://members.aol.com/Bbirthisel/alpha.html

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)

 

[svar]

Thanks, glad to see it's the same as the call in the corresponding Unix module(Device::SerialPort). Shouldn't there be a space between ATDT and $phone?

 

[PaulTEG]

it's been a while since I wrote directly to modems, but I seem to remember a space, try it and see

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)

 

[svar]

Ok, the question now is how does one grab the input?

my ($match,$after,'CONNECT',$instead)=$ob->lastlook;

? because this does not seem to work

 

[PaulTEG]

show us what you got to date, there's some good examples on the link above ...

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)

 

[svar]

Here is the script with a Tk-interface, the main routine lifted from the examples, but... it does not work(it does dial, but does not capture what comes back)

#!/usr/bin/perl -w
# cross-platform example7, use LF-only on Un*x
###TODO: Can we autodetect port?
use strict;
use Tk;
require('dumpvar.pl');
use vars qw( $OS_win $ob $file $port);
my $min; my $max;
$file = 'MODEM_CONFIG_PARAMS';

BEGIN {
$OS_win = ($^O eq "MSWin32") ? 1 : 0;
if ($OS_win) {
eval "use Win32::SerialPort 0.13";
die "$@\n" if ($@);
$port = 'COM2';
$ob = Win32::SerialPort->new ($port);
}
else {
eval "use Device::SerialPort";
die "$@\n" if ($@);
$port = '/dev/modem';
$ob = Device::SerialPort->new ($port);
}
} # End BEGIN
my $top= MainWindow->new();
$top->title("Modem checker Configuration Menu");
my $menubar = $top->Frame;
$menubar ->pack(-side =>'top', -fill =>'x');
$menubar ->configure (-fg =>'red', -bg =>'blue', -relief =>'raised');
my $filemenu =$menubar->Menubutton(-text =>'File', -underline =>0);
$filemenu ->command(-label => 'Quit', -underline =>0, -command =>sub{$top->destroy()});
$filemenu->pack(-side =>'left');
$filemenu->configure(-fg =>'red', -bg =>'blue', -relief =>'raised');
my $frame=$top->Frame(-bg=>'aquamarine',-relief=>'sunken')->pack();
my $label0=$frame->Label(-text=>'Enter Phone Number Ranges to scan')->grid(-row=>0, -column=>0); ;
my $label=$frame->Label(-text=>'Starting number:')->grid(-row=>1,-column=>0);
my $entry=$frame->Entry(-textvariable=>\$min)->grid(-row=>1,-column=>1);
my $label2=$frame->Label(-text=>'Ending number:')->grid(-row=>2,-column=>0);
my $entry2=$frame->Entry(-textvariable=>\$max)->grid(-row=>2,-column=>1);

my $label3=$frame->Label(-text=>'Port for modem of the computer used to perform the scan(present computer)')->grid(-row=>3,-column=>0);
my $entry3=$frame->Entry(-textvariable=>\$port)->grid(-row=>3,-column=>1);

my $button=$frame->Button(-bg=>'firebrick1',-text=>'Start the scan',
-command=>sub{
#first, error handler
if ($min=~/\D/ or $max=~/\D/){
my $TOP=MainWindow->new();
$TOP->title('Error Message in range specification');
$TOP->Label(-text=>"Invalid(nondigit) input $min and $max",-bg=>'firebrick1')->pack();
my $buttoner=$TOP->Button(-bg=>'salmon1',-text=>'Ok',
-command=>sub{$TOP->destroy();});
&MainLoop();
}#if min or max=~/D

if (-e $file){

if ($OS_win){$ob = Win32::SerialPort->start ($file);}
else {$ob = Device::SerialPort->start ($file);}
die "Can't open serial port from $file: $^E\n" unless ($ob);
}#file exists
else {# file does not exist, create it!

if ($OS_win) {
$port = 'COM2';
$ob = Win32::SerialPort->new ($port);
}
else {
$port = '/dev/modem';
$ob = Device::SerialPort->new ($port);
}
unless($ob){
my $TOPob=MainWindow->new();
$TOPob->title("cannot open Serial Port $port");
$TOPob->Label(-text=>"cannot open Serial Port $port",-bg=>'firebrick1')->pack();
my $buttonob=$TOPob->Button(-bg=>'salmon1',-text=>'Ok',
-command=>sub{$TOPob->destroy();});
&MainLoop();
}#unless $ob

$ob->user_msg(1); # misc. warnings
$ob->error_msg(1); # hardware and data errors

$ob->baudrate(38400);
$ob->parity("none");
## $ob->parity_enable(1); # for any parity except "none"
$ob->databits(8);
$ob->stopbits(1);
$ob->handshake('rts');

$ob->write_settings;
$ob->save("$file");

print "wrote configuration file $file\n";

}#create it!
$ob->are_match("BUSY","CONNECT","OK","NO DIALTONE","ERROR","RING",
"NO CARRIER","NO ANSWER");
open(OUT,">DETECTED_MODEMS") or die "cannot open file DETECTED_MODEMS for writing\n";
if($min>$max){my $tmp=$min; $min=$max; $max=$tmp;
print "min and max entered in wrong order, revered them...\n";}
my $dialled_no;
for ($dialled_no=$min; $dialled_no<=$max; $dialled_no++ ){
&dial($dialled_no,$ob); }
close(OUT);
})->grid(-row=>4,-column=>1);

my $quitbut= $frame->Button(-bg=>'blue',-text=>'Stop the scan', -command=>sub{
$top->destroy();
})->grid(-row=>5,-column=>1);

&MainLoop();


sub waitfor {
my $ob=shift; my $timeout=$ob->get_tick_count + (1000 * shift);
$ob->lookclear; # clear buffers
my $gotit = "";

for (; {
return unless (defined ($gotit = $ob->lookfor));
if ($gotit ne "") {
my ($found, $end) = $ob->lastlook;
return $gotit.$found;
}
return if ($ob->reset_error);
return if ($ob->get_tick_count > $timeout);
}
}

# =============== execution begins here =======================



#print "\n5 seconds to failure..\n";
#waitfor(5) || print "Timed Out\n";

#undef $ob;
#------ get parameters


sub dial{my $phone=shift; my $ob=shift;
$ob->write("ATE0X4\r");
printf "%s\n", waitfor($ob,1); # 1 second
print "\nStarting Dial\n";
$ob->write("ATDT$phone\r") || die "Could Not Dial\n";
print "%s\n", waitfor($ob,20);
&main::dumpValue($ob);
printf "%s\n", waitfor($ob,20);
print "\n5 seconds to failure..\n";
waitfor($ob,5) || print "Timed Out\n";
my $match; my $after; my $instead;
my $result = $ob->input;
print "result = $result\n";
print "Starting 500 character background read\n";
my $in; print "oswin=$OS_win\n";
$in = $ob->read_bg(500) if ($OS_win);
print "in=$in\n" if ($OS_win);
#Next, capture response and look for connect
my $waiter=0;
while($waiter<20){
my $con1='CONNECT';
($match,$after,$con1,$instead)=$ob->lastlook;

if($match){#found a CONNECT
print OUT "found a modem for phone $phone match=$match\n";
}
sleep(2); $waiter++;}

$ob->write("ATZ\r") || die "Could Not reset \n";

}

 

[PaulTEG]

isolate what doesn't work into a smaller script without the interface and then work on that

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)