# # Shorewall version 5 - Drop Action # # /usr/share/shorewall/action.Drop # # The default DROP common rules # # This action is invoked before a DROP policy is enforced. The purpose # of the action is: # # a) Avoid logging lots of useless cruft. # b) Ensure that certain ICMP packets that are necessary for successful # internet operation are always ACCEPTed. # # The action accepts five optional parameters: # # 1 - 'audit' or '-'. Default is '-' which means don't audit in builtin # actions. # 2 - Action to take with Auth requests. Default is to do nothing special # with them. # 3 - Action to take with SMB requests. Default is DROP or A_DROP, # depending on the setting of the first parameter. # 4 - Action to take with required ICMP packets. Default is ACCEPT or # A_ACCEPT depending on the first parameter. # 5 - Action to take with late UDP replies (UDP source port 53). Default # is DROP or A_DROP depending on the first parameter. # # IF YOU ARE HAVING CONNECTION PROBLEMS, CHANGING THIS FILE WON'T HELP!!!!!!!!! # ############################################################################### # # The following magic provides different defaults for @2 thru @5, when @1 is # 'audit'. # ?begin perl; use Shorewall::Config; my ( $p1, $p2, $p3 , $p4, $p5 ) = get_action_params( 5 ); if ( defined $p1 ) { if ( $p1 eq 'audit' ) { set_action_param( 3, 'A_DROP') unless supplied $p3; set_action_param( 4, 'A_ACCEPT' ) unless supplied $p4; set_action_param( 5, 'A_DROP' ) unless supplied $p5; } else { fatal_error "Invalid value ($p1) for first Drop parameter" if supplied $p1; } } 1; ?end perl; DEFAULTS -,-,DROP,ACCEPT,DROP #TARGET SOURCE DEST PROTO DPORT SPORT # # Count packets that come through here # COUNT # # Special Handling for Auth # ?if @2 ne '-' Auth(@2) ?endif # # Don't log broadcasts # Broadcast(DROP,@1) # # ACCEPT critical ICMP types # AllowICMPs(@4) - - icmp # # Drop packets that are in the INVALID state -- these are usually ICMP packets # and just confuse people when they appear in the log. # Invalid(DROP,@1) # # Drop Microsoft noise so that it doesn't clutter up the log. # SMB(@3) DropUPnP(@5) # # Drop 'newnotsyn' traffic so that it doesn't get logged. # NotSyn(DROP,@1) - - tcp # # Drop late-arriving DNS replies. These are just a nuisance and clutter up # the log. # DropDNSrep(@5)