#!/usr/bin/perl
#
# 20020404 Nereu - versao para ePN
#
use strict;
use Socket;
use Crypt::TripleDES;
use vars qw($line $hostname $command $command_name $timeout $key $answer $x $port $iaddr $paddr $proto $response $commandoutput $errorcode $crypt_on $debug $code $msg $s $M $H $d $m $y $wd $yd $isd);


$SIG{'ALRM'} = 'handler';

&GetArgv;
&Connect;
&Execute;

###

sub handler {
   &MyExit(3,"timeout(${timeout}s)!");
}

###

sub write_trace {
  $msg = shift;
  ($s,$M,$H,$d,$m,$y,$wd,$yd,$isd)=localtime(time);
  $y+=1900; $m+=1;
  printf(TRACE "%04d-%02d-%02d:%02d:%02d:%02d | %05d | %s\n",$y,$m,$d,$H,$M,$s,$$,$msg);
}

###

sub MyExit {
  $code = shift;
  $msg  = shift;
  if ( $debug ) { write_trace($msg); }
  print "check_nclient: $msg\n";
  exit($code);
}

###

sub GetArgv {

 my $i;
 my $j;

 $hostname="";
 $command="";
 $timeout = 80;
 $port = 999;
 $crypt_on = 1;
 $debug = 0;
 $key = "Eh segredo! Shhh!";

 for($i=0;$i<=$#ARGV;$i++) {
   if ( $ARGV[$i] eq "-h" ) {
     $hostname=$ARGV[++$i]; 
   } elsif ( $ARGV[$i] eq "-C" ) {
     if ( $ARGV[++$i] eq "off" ) { $crypt_on=0; }
   } elsif ( $ARGV[$i] eq "-t" ) {
     $timeout=$ARGV[++$i];
   } elsif ( $ARGV[$i] eq "-p" ) {
     $port=$ARGV[++$i];
   } elsif ( $ARGV[$i] eq "-d" ) {
     $debug=1;
   } elsif ( $ARGV[$i] eq "-c" ) {
     $command_name = $ARGV[++$i];
     $command_name =~ s/ //g;
     for($j=$i;$j<=$#ARGV;$j++) { 
       $command .= "$ARGV[$j] "; 
     }
     last;
   }
 }

 if ( $debug ) { 
   open(TRACE,">>/usr/local/netsaint/plugins/trace/${hostname}_${command_name}.trc") ||
                    &MyExit(3,"I canīt write trace file(${hostname}_${command_name}.trc)!");
   write_trace("-- BEGIN -- check_nclient");
 }

 if ( $hostname eq "" || $command eq "" ) {
    &MyExit(3,"Sintaxe error: check_nclient <-h hostname> [-p <port>] [-t <timeout>] [-C[rypt] <on|off>] <-c command>");
    exit(3);
  }

}

###

sub Connect {

  if ( $debug ) { write_trace("Connect begin"); }

  if ( $debug ) { write_trace("getservbyname"); }
  if ($port =~ /\D/) { $port = getservbyname($port, 'tcp'); }
  &MyExit(3,"Cannot get port($port)") unless $port;

  if ( $debug ) { write_trace("inet_atom(gethostbyname etc) sockaddr_in"); }
  $iaddr = inet_aton($hostname) or &MyExit(3,"No Host \"$hostname\"");
  $paddr = sockaddr_in($port, $iaddr);
  $proto = getprotobyname('tcp');
  socket(SOCK, PF_INET, SOCK_STREAM, $proto) or &MyExit(3,"Socket failed: \"$!\"");

  if ( $debug ) { write_trace("connect"); }
  connect(SOCK, $paddr) or &MyExit(3,"Connect failed: \"$!\"");
  select(SOCK);
  $| = 1;
  select(STDOUT);
  $| = 1;
  if ( $debug ) { write_trace("Connect end"); }
}

###

sub Execute {
  my $cipher;

  $response="";

  if ( $debug ) { write_trace("Execute begin"); }

  if ( $crypt_on ) {
    $cipher = new Crypt::TripleDES;
  }

  alarm($timeout);

  for ($x = 0; $answer = <SOCK>; $x++) {
    if ($x == 0) {
      if ( $debug ) { write_trace("get banner"); }
      unless ($answer =~ /nclient/) {
	die("This is not a nclient! (Banner was wrong)\r\n");
      } 

      if ( $debug ) { write_trace("send command"); }
      if ( $crypt_on ) {
        $command = unpack("H*", $cipher->encrypt3($command, $key));
      }
      print(SOCK $command . "\r\n");

    } elsif ($x == 1) {
      if ( $debug ) { write_trace("reading answer"); }
      $answer =~ s/\r\n$//;
      if ( $crypt_on ) {
        $response = $cipher->decrypt3(pack("H*", $answer), $key);
        print SOCK unpack("H*", $cipher->encrypt3("exit", $key)) ."\r\n";
      } else { 
        if ( $debug ) { write_trace("send exit"); }
        $response=$answer;
        print(SOCK "exit\r\n");
      }
    }
  }

  if ( $response ne "" ) {
    ($commandoutput, $errorcode) = split(/ \| /, $response);
    $commandoutput =~ s/^OP: //;
    $errorcode =~ s/^RC: //;
    $errorcode = $errorcode >> 8;
    if ( $debug ) { 
      write_trace("Execute end msg=[$commandoutput] code=[$errorcode]"); 
     write_trace("-- END   -- check_nclient");
    }
    print "$commandoutput\n";
    exit ( ( $errorcode < 0 || $errorcode > 4 ) ? 3 : $errorcode );
  } else {
    print "no answer from client!\n" ; exit(3);
  }
}

### End