shorewall_code/Shorewall6/action.Drop

#
# Shorewall6 version 5 - Drop Action
#
# /usr/share/shorewall6/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 'auth' requests are rejected, even if the policy is
#	   DROP. Otherwise, you may experience problems establishing
#	   connections with servers that use auth.
#	c) 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 REJECT or A_REJECT,
#           depending on the setting of the first parameter.
#	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!!!!!!!!!
#
###############################################################################

?if passed($1)
    ?if $1 eq 'audit'
DEFAULTS -,A_REJECT,A_DROP,A_ACCEPT,A_DROP
    ?else
        ?error The first parameter to Drop must be 'audit' or '-'
    ?endif
?else
DEFAULTS -,REJECT,DROP,ACCEPT,DROP
?endif

#TARGET		SOURCE	DEST	PROTO	DPORT	SPORT
#
# Reject 'auth'
#
?if passed($2)
Auth($2)
?endif
#
# ACCEPT critical ICMP types
#
AllowICMPs($4)	-	-	ipv6-icmp
#
# Drop Broadcasts so they don't clutter up the log
# (broadcasts must *not* be rejected).
#
Broadcast(DROP,$1)
#
# 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)
#
# 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)