#!/usr/bin/perl
#Server Script
use warnings;
use strict;
use IO::Socket;
use IO::Select;
use Net::Ping;

my $serverport = 23;
# create a socket to listen on SOMAXCONN = 512
my $server = new IO::Socket(
	Domain => PF_INET,
	Proto => 'tcp',
	LocalPort => $serverport,
	Listen => SOMAXCONN,
);
die "Cannot bind: $!\n" unless $server;

# create a 'select' object and add server fh to it
my $selector = new IO::Select($server);
# stop closing connections from aborting the server
$SIG{PIPE} = 'IGNORE';

# loop and handle connections
print "Multiplex server started on port $serverport...\n";

while (my @clients = $selector->can_read) {

# input has arrived, find out which handles(s)
foreach my $client (@clients) {
    if ($client == $server) {
        # it's a new connection, accept it
        my $newclient = $server->accept;
        my $port = $newclient->peerport;
        syswrite $newclient, "Welcome!\n";
        my $name = $newclient->peerhost;
        $selector->add($newclient);
    }else{
        # it's a message from an existing client
        my $port = $client->peerport;
        my $name = $client->peerhost;
        my ($message, $buf, $host);
        my $newclient = $client->accept;
        my $reach = Net::Ping->new($ > ? "tcp": "icmp");
        (defined $reach) or die "Couldn't create Net::Ping object: $!\n";
        if (sysread $client, $message, 1024) {
            print "Client $name:$port sent: $message";
            while (defined ($buf = <"$message">)) {
                $host = (split(/:/,$buf))[1];
                chomp($host);
                print "Remote IP to be pinged $host\n";
                if($reach->ping("$host")) {
                    print "$host is reachable\n";
                    print $client "reachable $host\n";
                }else{
                    print "$host is unreachable\n";
                    print $client "unreachable $host\n";
                }
            }
            print $client "\n Message received OK\n";
        }else{
            $selector->remove($client);
            $client->shutdown(SHUT_RDWR);
            print "\nClient disconnected\n"; # port, name not defined
        }
    }
}
}