#!/usr/bin/perl -w

# 5/6/02

# David Aslanian

# nightelf@cableone.net



use Getopt::Long;

use IO::Socket::INET;

use strict;



## options config

my($port,$host,$proto,$help) = ('', '', 'tcp','');  ## proto defaults 
+to tcp

GetOptions('ports|port=s' => \$port, 'host=s' => \$host, 

       'proto=s' => \$proto, 'help' => \$help) or die $!;

die usage() if($help);



## validate and expand the port listing(s) in the --port option

my @ports = expand_ports($port);



## validate options

validate_opts($host, $proto);



#########################################

## main

#########################################

my $sock;

my @openports = ();

my $i = -1;



print "Scanning $host for open ports.....\n\n";

foreach my $cport (@ports) {

    $sock = IO::Socket::INET->new(PeerAddr => $host,

                                PeerPort => $cport,

                                Proto => $proto);

    if($sock) {

        $i++;

        $openports[$i] = $cport;

    }

}



print "Open ports on $host (using $proto):\n\t", join("\n\t", @openpor
+ts), "\n";







#########################################

## subs

#########################################



sub validate_opts {

    my($host, $proto) = (shift, shift);



    ## validate $host

    ## no ports, proto spec, or file path in the hostname allowed

    ## below: this is not right 

 #if(($host =~ /^(\w+\.)?\w+\.\w+$/i) || ($host =~ /^(\d{1,3}\.){3}(\d
+{1,3})$/) || ($host =~ /^[a-z-]+$/) {

 #        ## we're fine

 #} else {

 #        die usage("Bad host specification.");

 #}

     ## validate protocol

     die usage("Bad protocol specification.") unless($proto =~ /^tcp$|
+^udp$/);



}



sub expand_ports {     ## input: string containing port information, c
+ommas and ranges (1-10) can be used.

            ## output: a expanded, unique list of sorted ports ready t
+o be used for scanning.

    my $port = shift;

    my @ports = ();

    my($from, $to);  ## used for ranges (1-10)

    

    if($port =~ /^(\d+)$/) {  ## just a plain port number alone

        $ports[0] = $1;

        return(@ports);    

    }

    

    if($port =~ /^(\d+)-(\d+)$/) {  ## a range of ports alone (not in 
+a comma-seperated list)

        return(@ports = ($1 .. $2));

    }

    

    if($port =~ /^([\d-]+,)+([\d-]+),?$/) {  ## a list possibly contai
+ning ranges of ports

        my @splitted = split(',', $port);

        

        foreach my $splitted (@splitted) {

            if($splitted =~ /^(\d+)-(\d+)$/) {  ## if it is a range of
+ ports

                push(@ports, ($1 .. $2));

                next;

            }



            if($splitted =~ /^(\d+)$/) {

                push(@ports, $1);

                next;

            }

            

            ## if we get to this point in the iteration something went
+ wrong...

            die "bad port spec.\n";

        }



        ### take out duplicate values from @ports

        my %seen = ();

        my @uniq = ();



        foreach my $item (@ports) {

            unless($seen{$item}) {

                ##if we get here we haven't seen it before

                $seen{$item} = 1;

                push(@uniq, $item);

            }

        }

        @ports = @uniq;



        ### sort the ports

        @ports = sort { $a <=> $b } @ports;

        

        ### .. and finally return the expanded, unique, sorted ports t
+o the caller

        return @ports;

    }

    die usage("Bad or no port specification.\n");



    

}



sub usage {

    my $message = shift;



    print "Fatal error: $message\n\n" if($message);  ## only print an 
+error if there was one

print <<ENDUSAGE;

    Usage:    perlscan --host=<host> --ports=<ports> [--proto=tcp|udp]

        

      Options:



        --host, -h (ie --host=localhost)

            The hostname or ip adress to be scanned.



        --port, --ports, -po (ie --ports=1,2,3-30)

            The ports to be scanned. 

            A single port can be specified (ie --port=1), or a single 
+range

            of ports can be specified (ie --ports=1-1024), or a list o
+f ports

            and/or ranges can be specified (ie --ports=1,2,3-30).



        --proto, -pr (ie --proto=tcp)

            The protocol to use for the scan. This can be either tcp o
+r udp,

            this option is optionable and can be omitted, in which cas
+e the 

            default protocol will be used (tcp).



        --help, -h (ie --help)

            Display this usage information.

ENDUSAGE

}
[download]

Edit kudra, 2002-05-07 Changed title