#!/usr/bin/perl -w

use strict;
use diagnostics;

# cliserver.pl - UDP based CLI server: Sends to and receives from the CLI prompt
use POSIX;
use IO::Socket;
use Net::Telnet;

#my $time_to_die = 0;

#sub signal_handler {
#    $time_to_die = 1;
#}

#If we get INT,TERM,or HUP signals we will call signal handler and die;
#$SIG{HUP} = $SIG{INT} = $SIG{TERM} = \&signal_handler;

#Fork a new process
#my $pid = fork;

#Let the parent exit
#if ($pid) {
#    exit;
#}
#die "Couldn't fork: $!" unless defined($pid);

#Dissociate from the controlling terminal that started us and stop
#being part of whatever process group we had been a member of
#POSIX::setsid()
#    or die "Can't start a new session: $!";

#Loop until the signal handler changes the value of $time_to_die to 1
#until ($time_to_die) {

my($sock, $oldmsg, $newmsg, $hisaddr, $hishost, $MAXLEN, $PORTNO);
$MAXLEN = 1024;
$PORTNO = shift or die "usage: cliserver.pl <portno>";
$sock = IO::Socket::INET->new(LocalPort => $PORTNO, Proto => 'udp')
    or die "socket: $@";

my $debug = 1;
my $TIMEOUT = 9999;
my $t;
my $prematch;
my $CLISERVER = '10.89.224.199';
my @results = ();
&TelnetToCli(\$t,'optiuser','optiuser',$CLISERVER);

print "Awaiting UDP messages on port $PORTNO\n" if ($debug);
#$oldmsg = "This is the starting message.";

$hishost = 'unknown_host';

DATALOOP: while ($sock->recv($newmsg, $MAXLEN)) {
    my($port, $ipaddr) = sockaddr_in($sock->peername);
    $hishost = gethostbyaddr($ipaddr, AF_INET);
    print "Client $hishost said ``$newmsg''\n"  if ($debug);

    if ($newmsg) {
        #print "newmsg:$newmsg\n"  if ($debug);

        my $rc = &PerformCli(\$t,$newmsg);
        my $errormsg = $t->errmsg;

        if ($errormsg) {
            if ($errormsg !~ /pattern match timed-out/i) {          
				#We had some kind of error message so lets try to reinit the object
				#and try the cli command one more time
				print "\n\ntelnet object is being reinitialized\n\n";
				print "errormsg:$errormsg\n";
				$t->close();
				&TelnetToCli(\$t,'optiuser','optiuser',$CLISERVER);
				my $rc = &PerformCli(\$t,$newmsg);
				$errormsg = $t->errmsg;
            }
        }

		if ($rc) {
		    #A syntax error was encountered. Tell the client
                    $sock->send("Unsupported command ''$newmsg''\n");
		}
		elsif ($errormsg) {
		    #there was no match so send the log back
		    #Send the response     
		    my $line = $t->lastline;
		    $sock->send("$errormsg\n$line");
		}
		else {
                    my $line;
                    my $append;
                    foreach $line (@results) {
                        $append .= $line;
                }
                $sock->send($append);
        }
  
    }
    #Kind of a catch all... if we have an error message from the $t object we will try to reinitialize it
    my $errormsg = $t->errmsg;
    if ($errormsg) {
        print "Unknown error with telnet object...will try to reinitialize it\n" if ($debug);
        $t->close();
        &TelnetToCli(\$t,'optiuser','optiuser',$CLISERVER);
    }
            

} 
print "recv: $!\n" if ($debug);

#If we have not exhasted our retries then we go back to the while loop above
if ($TIMEOUT > 0) {
    $TIMEOUT--;
    print "Retrying MAINLOOP:$TIMEOUT\n" if ($debug);
    goto DATALOOP;
}
else {
    print "Number of retries exceeded TIMEOUT value\nExiting now" if ($debug);
}

#close telnet and exit the program
$t->close;
exit;


sub TelnetToCli {
    my ($t,$username,$password,$destination) = @_;

    $username = 'optiuser' if ($username eq '');
    $password = 'optiuser' if ($password eq '');
    $destination = 'priems05' if ($destination eq '');

    $$t = Net::Telnet->new( Timeout => 30,
                        Prompt  => '/[\$%#>]/',
                        Host    => $destination);

    $$t->errmode("return");

    $$t->login($username, $password);

    print "Telnet connection established with $destination\n"  if ($debug);

    #set the errormode for CLI Timeout
    #$$t->errmode(\&CliTimeout);

    print "CLI session started\n" if ($debug);

    $$t->errmode("return");

} #End of TelnetToCli

sub PerformCli {
    my ($t,$msgtoprocess) = @_;
 
    @results = ();
 
    #set the errormode
    $$t->errmode("return");

    #my $newfile = 'inputlog.txt';
    #my $fh = $$t->input_log($newfile);

    #Let's send our command to CLI and see if we get a match
    print "command:$msgtoprocess\n" if ($debug);
	#$$t->print($cmd);
    my $prompt = 'CLI>';
    eval {
    @results = $$t->cmd(String  => $msgtoprocess, 
                         Prompt => '/CLI>/');
    };

    return 0;
} #End of PerlformCli

sub Log {
    @results = ();
    $results[0] = shift;
}

sub CliTimeout {

    print "Problem starting CLI session\n";
} #End of CliTimeout

#}