fail2ban/config/action.d/osx-ipfw.conf

# Fail2Ban configuration file
#
# Author: Nick Munger
# Modified by: Andy Fragen and Daniel Black
#
# Mod for OS X, using random rulenum as OSX ipfw doesn't include tables
#

[Definition]

# Option:  actionstart
# Notes.:  command executed on demand at the first ban (or at the start of Fail2Ban if actionstart_on_demand is set to false).
# Values:  CMD
#
actionstart = 


# Option:  actionstop
# Notes.:  command executed at the stop of jail (or at the end of Fail2Ban)
# Values:  CMD
#
actionstop = 


# Option:  actioncheck
# Notes.:  command executed once before each actionban command
# Values:  CMD
#
actioncheck = 


# Option:  actionban
# Notes.:  command executed when banning an IP. Take care that the
#          command is executed with Fail2Ban user rights.
# Tags:    <ip>  IP address
# Values:  CMD
#
actionban = ipfw add <rulenum> set <setnum> <blocktype> log <block> from <ip> to <dst> <port>


# Option:  actionunban
# Notes.:  command executed when unbanning an IP. Take care that the
#          command is executed with Fail2Ban user rights.
# Tags:    <ip>  IP address
# Values:  CMD
#
actionunban = ipfw delete `ipfw -S list | grep -i 'set <setnum> <blocktype> log <block> from <ip> to <dst>' | awk '{print $1;}'`

[Init]

# Option:  port
# Notes.:  specifies port to block. Can be blank however may require block="ip"
# Values:  [ NUM | STRING ]
#
port = ssh

# Option:  dst
# Notes.:  the local IP address of the network interface
# Values:  IP, any, me or anything support by ipfw as a dst
#
dst = me

# Option: block
# Notes:  This is how much to block.
#         Can be "ip", "tcp", "udp" or various other options.
# Values: STRING
block = tcp

# Option:  blocktype
# Notes.:  How to block the traffic. Use a action from man 8 ipfw
#          Common values: deny, unreach port, reset
# Values:  STRING
#
blocktype = unreach port

# Option:  set number
# Notes.:  The ipset number this is added to.
# Values:  0-31
setnum = 10

# Option:  number for ipfw rule
# Notes:   This is meant to be automatically generated and not overwritten
# Values:  Random value between 10000 and 12000
rulenum="`echo $((RANDOM%%2000+10000))`"

# Duplicate prevention mechanism
#rulenum = "`a=$((RANDOM%%2000+10000)); while ipfw show | grep -q ^$a\ ; do a=$((RANDOM%%2000+10000)); done; echo $a`"