#====================================================================
# USER DEFINES

 # global defaults

my $def_proto = "icmp"; # default protocol to use
my $pattern = 153;  # default data pattern to send.                    
my $num_bytes = 40;  # default number number of bytes to send in data section.
my $children = 20;  # default number of child processes to spawn
my $requests = 50;  # default number of requests that each child sends


 # protocol specific defaults

my $prot_ip = { tos => '0',
                ttl => '30',
                saddr => '172.16.0.1',
               };

my $prot_tcp = {source => "33333",
                dest => "80",
                urg => "0",
                ack => "0",
                psh => "0",
                rst => "0",
                syn => "1",
                fin => "0",
               };

my $prot_udp = {source => "53",
                dest => "33333",
               };

my $prot_icmp = {type => "8",
                 code => "0",
                };

#=======================================

#======================================================================
# MAIN

#-------------------
 # get data info from user
print "number of bytes in data field? [$num_bytes] : ";
$input = <STDIN>;
chomp ($input);
if (($input) && ($input<1501) && ($input>0)) {$num_bytes = $input;}

#---------


#-------------------
 # make data portion of packet
my $data = $pattern x $num_bytes;
$data = pack("C", $data);

#---------


#-------------------
 # get protocol info from user 

 # get ip info
set_ip();

 # get upper layer protocol type and info
print "tcp, udp, or icmp? [$def_proto] : ";
$input = <STDIN>;
chomp ($input);
if ($input ne "") {
    if ($input eq "tcp") {
        $def_proto = "tcp";
        set_tcp(); # set prefs for tcp datagram
        $prot_tcp->{data} = $data;
        $packet{tcp} = $prot_tcp;
    }
    elsif ($input eq "udp") {
        $def_proto = "udp";
        set_udp(); # set prefs for udp datagram
        $prot_udp->{data} = $data;
        $packet{udp} = $prot_udp;
    }
    else {
        $def_proto = "icmp";
        set_icmp(); # set prefs for icmp datagram
        $prot_icmp->{data} = $data;
        $packet{icmp} = $prot_icmp;
    }
}

$packet{ip} = $prot_ip;

#---------


#-------------------
 # fork off children and x-mit data
my $pm = new Parallel::ForkManager($children);

ReadMode 4; # Turn off controls keys

print "press any key to quit...\n";

while (not defined (my $key = ReadKey(-1))) {

     # Forks and returns the pid for the child:
    my $pid = $pm->start and next; 

        my $pkt_h = new Net::RawIP;       
        $pkt_h->set(\%packet);
        $pkt_h->send(.25,$requests);

    $pm->finish; # Terminates the child process

}

ReadMode 0; # Reset tty mode before exiting

print "\n\nwaiting on child processes to stop...";

$pm->wait_all_children;

print "...all done...quitting.\n";

#---------


#=======================================