gosa-si/modules/ArpWatch.pm

   1 #!/usr/bin/perl
   2 package POE::Component::ArpWatch;
   3
   4 use strict;
   5 use warnings;
   6
   7 BEGIN{
   8         eval('use POE');
   9         eval('use POE::Component::Pcap');
  10         eval('use NetPacket::Ethernet qw( :types )');
  11         eval('use NetPacket::ARP qw( :opcodes )');
  12 }
  13
  14 END{
  15 }
  16
  17 ## Map arp opcode #'s to strings
  18 my %arp_opcodes = (
  19                    NetPacket::ARP::ARP_OPCODE_REQUEST, 'ARP Request',
  20                    NetPacket::ARP::ARP_OPCODE_REPLY, 'ARP Reply',
  21                    NetPacket::ARP::RARP_OPCODE_REQUEST, 'RARP Request',
  22                    NetPacket::ARP::RARP_OPCODE_REPLY, 'RARP Reply',
  23                   );
  24
  25 ##
  26 ## POE::Component::ArpWatch->spawn(
  27 ##                                 [ Alias => 'arp_watch' ],
  28 ##                                 [ Device => 'eth0' ],
  29 ##                                 [ Dispatch => dispatch_state ],
  30 ##                                 [ Session => dispatch_session ],
  31 ##                                )
  32 ##
  33 sub spawn {
  34   my $class = shift;
  35   my %args = @_;
  36
  37   $args{ Alias } ||= 'arp_watch';
  38
  39   POE::Session->create(
  40                        inline_states => {
  41                                          _start => \&_start,
  42 #                                        _signal => \&_signal,
  43                                          _stop => \&_stop,,
  44                                          _dispatch => \&_dispatch,
  45                                          set_dispatch => \&set_dispatch,
  46                                          run => \&run,
  47                                          pause => \&pause,
  48                                          shutdown => \&shutdown,
  49                                         },
  50                        args => [
  51                                 $args{ Alias },   # ARG0
  52                                 $args{ Device },  # ARG1
  53                                 $args{ Dispatch },# ARG2
  54                                 $args{ Session }, # ARG3
  55                                ],
  56                       );
  57
  58   return $args{ Alias };
  59 }
  60
  61 sub _start {
  62   my ($kernel, $heap, $session,
  63       $alias, $device, $target_state, $target_session )
  64     = @_[ KERNEL, HEAP, SESSION, ARG0..ARG3 ];
  65
  66   POE::Component::Pcap->spawn(
  67                               Alias => $alias . '_pcap',
  68                               Device => $device,
  69                               Filter => 'arp',
  70                               Dispatch => '_dispatch',
  71                               Session => $session,
  72                              );
  73
  74   $heap->{'pcap_session'} = $kernel->alias_resolve( $alias . '_pcap' );
  75
  76   ## Set alias for ourselves and remember it
  77   $kernel->alias_set( $alias );
  78   $heap->{Alias} = $alias;
  79
  80   ## Set dispatch target session and state if it was given
  81   if( defined( $target_session ) ) {
  82     $heap->{'target_session'} = $target_session;
  83     $heap->{'target_state'} = $target_state;
  84   }
  85 }
  86
  87 sub set_dispatch {
  88   my( $heap, $sender, $target ) = @_[ HEAP, SENDER, ARG0 ];
  89
  90   if( defined $target ) {
  91     ## Remember whome to forward results to
  92     $heap->{'target_session'} = $sender;
  93     $heap->{'target_state'} = $target;
  94   } else {
  95     ## Clear target
  96     delete $heap->{'target_session'};
  97     delete $heap->{'target_state'};
  98   }
  99 }
 100
 101 sub run {
 102   $_[KERNEL]->post( $_[HEAP]->{'pcap_session'} => 'run' );
 103 }
 104
 105 sub pause {
 106   $_[KERNEL]->post( $_[HEAP]->{'pcap_session'} => 'pause' );
 107 }
 108
 109 sub _dispatch {
 110   my( $kernel, $heap, $packets ) =
 111     @_[ KERNEL, HEAP, ARG0 ];
 112
 113   if( exists $heap->{'target_session'} ) {
 114     $kernel->post( $heap->{'target_session'},
 115                    $heap->{'target_state'},
 116                    _process_packet( @{ $_ } ) ) foreach( @{$packets} );
 117   }
 118 }
 119
 120 sub _signal {
 121   # print "Got signal ", $_[ARG0], "\n";
 122
 123   $_[KERNEL]->post( pcap => 'shutdown' );
 124
 125   return 1
 126 }
 127
 128 sub shutdown {
 129   my ( $kernel, $heap, $session, $sender )
 130     = @_[ KERNEL, HEAP, SESSION, SENDER ];
 131   my $alias = $heap->{Alias};
 132
 133 #  print "In shutdown for sid ", $session->ID, ", alias $alias\n";
 134 #  print "shutdown by ", $sender->ID, "\n";
 135
 136   $kernel->post( $heap->{'pcap_session'} => 'shutdown' );
 137
 138   $kernel->alias_remove( $alias );
 139
 140 #  print "Out shutdown for sid ", $session->ID, ", alias $alias\n";
 141 }
 142
 143 sub _stop {
 144   my ( $kernel, $heap, $session ) = @_[ KERNEL, HEAP, SESSION ];
 145   my $alias = $heap->{Alias};
 146
 147 #  print "In state_stop for sid ", $session->ID, ", alias $alias\n";
 148
 149 #  print "Out state_stop for sid ", $session->ID, ", alias $alias\n";
 150 }
 151
 152 sub _process_packet {
 153   my( $hdr, $pkt ) = @_;
 154
 155   my $arp =
 156     NetPacket::ARP->decode( NetPacket::Ethernet->decode($pkt)->{data} );
 157
 158   ## Return hashref with apropriate fields
 159   return {
 160           type => $arp_opcodes{ $arp->{opcode} },
 161           tv_sec => $hdr->{tv_sec},
 162           tv_usec => $hdr->{tv_usec},
 163           source_haddr => _phys( $arp->{sha} ),
 164           source_ipaddr => _ipaddr( $arp->{spa} ),
 165           target_haddr => _phys( $arp->{tha} ),
 166           target_ipaddr => _ipaddr( $arp->{tpa} ),
 167          }
 168 }
 169
 170 ## Pretty printing subs for addresses
 171 sub _ipaddr { join( ".", unpack( "C4", pack( "N", oct( "0x". shift ) ) ) ) }
 172 sub _phys { join( ":", grep {length} split( /(..)/, shift ) ) }
 173
 174 # vim:ts=4:shiftwidth:expandtab
 175 1;
 176
 177 __END__