shorewall_code/Shorewall/action.Drop

#
# Shorewall -- /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 six 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.
# 6 - Action to take with UPnP packets. 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_DROP,A_ACCEPT,A_DROP,A_DROP
    ?else
        ?error The first parameter to Drop must be 'audit' or '-'
    ?endif
?else
DEFAULTS -,-,DROP,ACCEPT,DROP,DROP
?endif

#ACTION		SOURCE	DEST	PROTO	DPORT	SPORT
#
# Count packets that come through here
#
COUNT
#
# Special Handling for Auth
#
?if passed(@2)
Auth(@2)
?endif
#
# ACCEPT critical ICMP types
#
# For IPv6 connectivity ipv6-icmp broadcasting is required so
# AllowICMPs must be before silent broadcast Drop.
#
AllowICMPs(@4)	-	-	icmp
#
# Don't log broadcasts
#
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)
DropUPnP(@6)
#
# 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)