lcontrol

#!/usr/bin/perl -w
use strict;
use Data::Dumper;
# This script can be used to start|stop the socat listening processes for every port listed in monitored_tcp or monitored_udp
# Please edit the arrays below to configure the monitored ports, ranges are acceptable e.g. 20-24 will expand to 20 21 22 23 24
# port 22 exluded in testing
my @monitored_tcp = qw (21 80 110);
my @monitored_udp = qw (1194 7000-7007);
my @protocols = qw (tcp udp);
my $socat_timeout = 60;
#my @monitored_tcp = qw (21 80 110 143 220 389 406 443 465 587 636 993 995 1194 1494 3128 3389 5900 8080);
#my @monitored_udp = qw (1194 4500 5000-5110 7000-7007);

# run with either 'start' or 'stop' as a parameter 
my $updown=shift;
my %monitored_all;

if (($updown) and ($updown eq 'start')) {
  &start;
} elsif (($updown) and ($updown eq 'stop')) {
  &stop;
} else {
  print "Usage: 'lcontrol start' starts the eduprobe listening processes, 'lcontrol stop' kills them\n";
  exit 0;
}


sub get_ports {
  my $arr;
  foreach (@protocols) {
  my $proto;
    if ($_ eq 'tcp') {
      $arr = \@monitored_tcp;
      $proto = 'tcp';
    } elsif ($_ eq 'udp') {
      $arr = \@monitored_udp;
      $proto = 'udp';
    }
    for my $p (@{$arr}) {
      if (($p =~ /^(\d+)-(\d+)$/) and ($1 < $2)) {
        my $low = $1;
         my $high = $2;
        while ($low <= $high) {
	  $monitored_all{$proto}{$low}++;
  	  $low++;
        }
      } elsif ($p =~ /^\d+$/) {
        $monitored_all{$proto}{$p}++;
      } else {
        die "failed to parse configured port array at port $_";
      }
    }
  }
}
  
sub start { 
  my $i = 0;
  &get_ports;
  &check_used_ports;
  foreach my $proto (keys %monitored_all) {
    P: foreach my $port (keys %{$monitored_all{$proto}}) {
      if (system ("/usr/bin/socat -T${socat_timeout} ${proto}4-LISTEN:$port,fork EXEC:\"/srv/script/eduprobe/responder $proto $port\" &") == 0) {
	$i++;
        print "started listener for v4 $proto/$port\n";
      } else {
        print "$proto/$port is in use - continue? y/n\n";
	while (<>) {
	  if ($_ =~ /^[y\n]$/) {
	    next P;
	  } else {
	    exit 1;
	  }
	}
      }
    }
  }
  if ($i > 0) {
    print "started $i processes\n";
  }
}

sub check_used_ports {
  my %inuse;
  my @openports = `/bin/netstat -nlp`;
  my $clash = 0;
  foreach (@openports) {
    if ($_ =~ /^(tcp|udp)\s+\d+\s+\d+\s+[\d\.]+:(\d+)/) {
      $inuse{$1}{$2}++;
    }
  }
  for my $upr (keys %inuse) {				# for Used PRotocols
    for my $cpr (keys %monitored_all) {			# and for Configured PRototcols
      if ($upr eq $cpr) {				# if current selection matches (e.g. bot 'tcp')
	for my $upt (keys %{$inuse{$upr}}) {		# loop through Used PorTs
	  for my $cpt (keys %{$monitored_all{$cpr}}) {	# and Configured PorTs
	    if ($upt eq $cpt) {				# if one is found that is configured to be monitored but is already used
	      print "Port in use: $upr/$upt\n";		# print error and die
	      $clash = 1;
	    }
	  }
	}
      }
    }
  }
  if ($clash == 1) {
    print "\nOne or more ports are configured for monitoring but are already in use, aborting.\nRun lcontrol down to kill any preexisting instances of the eduprobe listener.\n";
    exit 1;
  }
}

sub stop {
  system("pkill socat");
#  my @ps = `/bin/ps ax`;
#  my $i = 0;
#  foreach (@ps) {
#    if ($_ =~ /^([0-9]+).+?\/usr\/bin\/socat\s/) {
#      my $pid = $1;
#      $i++;
#      #print "killing listener $pid\n";
#      system ("kill $pid");
#    } elsif ($_ =~ /^([0-9]+).+?nc\s\-l.+?\.\/responder$/) {
#      my $pid = $1;
#      #print "killing netcat $pid\n";
#      system ("kill $pid");
#    }
#  }
#  if ($i > 0) {
#    print "killed $i processes\n";
#  }
}