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fuss:iptables [2020/02/17 19:43] – [Block Attacks with FireHOL Level 1 IP Abuse List] officefuss:iptables [2025/02/04 05:23] (current) – [Block GreenSnow Attacks] office
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-====== Packet Flow ====== +====== Packet Flow  ======
- +
-{{fuss_iptables_flow_through_netfilter.svg?512}} +
- +
-===== Abridged Version =====+
  
 {{fuss_iptables_flow_through_netfilter_abridged.png?512}} {{fuss_iptables_flow_through_netfilter_abridged.png?512}}
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                                                                                   Packet                                                                                   Packet
 </ditaa> </ditaa>
 +
 +===== ASCII (Simplified) =====
 +
 +From the Advanced Routing Howto.
 +
 +<ditaa>
 +       +------------+       +---------+       +-------------+
 +------>| PREROUTING +------>| FORWARD +------>| POSTROUTING +------>
 +       +------+-----+       +---------+       +-------+-----+
 +              |                                       ^
 +              |     +-------+  local  +--------+      |
 +              +---->| INPUT +-------->| OUTPUT +------+
 +                    +-------+         +--------+
 +</ditaa>
 +
 ====== Flush Tables ====== ====== Flush Tables ======
  
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 all of which should be available to install via the distribution's package manager. all of which should be available to install via the distribution's package manager.
  
-<file bash emerging-threats>+<file bash create-emerging-threats-ipset>
 #!/usr/bin/env bash #!/usr/bin/env bash
 ########################################################################### ###########################################################################
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   * ''awk''   * ''awk''
  
-<file bash firehol-level1>+<file bash create-level1-ipset>
 #!/usr/bin/env bash #!/usr/bin/env bash
 ########################################################################### ###########################################################################
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 To use, simply copy the script to ''/etc/cron.hourly'' and then insert the ''iptables'' rules at the top into the existing firewall. To use, simply copy the script to ''/etc/cron.hourly'' and then insert the ''iptables'' rules at the top into the existing firewall.
 +
 +====== Block GreenSnow Attacks ======
 +
 +[[https://greensnow.co/|Greensnow]] is a service that monitors attacks on various services across the internet and updates a list of offenders in real time. The script provided generates an ipset from the IP addresses provided by GreenSnow. The script can be saved to ''/etc/cron.hourly'' in order to update the list of offending IP addresses every hour.
 +
 +<file bash create-greensnow-ipset>
 +#!/usr/bin/env bash
 +###########################################################################
 +##  Copyright (C) Wizardry and Steamworks 2024 - License: GNU GPLv3      ##
 +###########################################################################
 +# Downloads GreenSnow attack IP list and adds all the networks to ipset. ##
 +###########################################################################
 +## Possible firewall configuration:
 +## Delete all the old rules.
 +#I=`/sbin/iptables-save | grep -- "-A INPUT -j GREENSNOW"`
 +#O=`/sbin/iptables-save | grep -- "-A OUTPUT -j GREENSNOW"`
 +#if [ ! -z "$I" ] || [ ! -z "$O" ]; then
 +#    /sbin/iptables -F GREENSNOW
 +#    /sbin/iptables -X GREENSNOW
 +#fi
 +#if [ ! -z "$I" ]; then
 +#    /sbin/iptables -D INPUT -j GREENSNOW
 +#fi
 +#if [ ! -z "$O" ]; then
 +#    /sbin/iptables -D OUTPUT -j GREENSNOW
 +#fi
 +## Create the chain again and add all the new rules.
 +#/sbin/iptables -N GREENSNOW
 +#/sbin/iptables -I INPUT 1 -j GREENSNOW
 +#/sbin/iptables -I OUTPUT 1 -j GREENSNOW
 +#/sbin/iptables -A GREENSNOW -p all -m set --match-set GREENSNOW src,dst -j DROP
 +## Continue with the rest.
 +#/sbin/iptables -A GREENSNOW -j RETURN
 +###########################################################################
 +
 +`ipset list GREENSNOW 2>/dev/null >/dev/null`
 +if [ $? = 1 ]; then
 +    ipset create GREENSNOW hash:net maxelem 262144 family inet
 +fi
 +ipset flush GREENSNOW
 +
 +while read LINE; do
 +    grep -E -vq "^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4}$" <<< "${LINE}"
 +    if [ $? -eq 0 ]; then
 +        continue
 +    fi
 +    printf %s "add GREENSNOW ${LINE}" | ipset restore -exist
 +done <<< $(curl -s -L https://blocklist.greensnow.co/greensnow.txt)
 +
 +</file>
 +
 +====== Block BotScout Bots ======
 +
 +[[https://botscout.com/|BotScout]] is an online service that tracks bots that automatically register accounts on various websites or post spam messages. The script below can be copied to ''/etc/cron.hourly'' in order to generate an ipset of all the IP addresses reported by BotScout.
 +
 +<file bash create-botscout-ipset>
 +#!/usr/bin/env bash
 +###########################################################################
 +##  Copyright (C) Wizardry and Steamworks 2024 - License: GNU GPLv3      ##
 +###########################################################################
 +# Downloads botscout IP list and adds all the networks to ipset.         ##
 +###########################################################################
 +## Possible firewall configuration:
 +## Delete all the old rules.
 +#I=`/sbin/iptables-save | grep -- "-A INPUT -j BOTSCOUT"`
 +#O=`/sbin/iptables-save | grep -- "-A OUTPUT -j BOTSCOUT"`
 +#if [ ! -z "$I" ] || [ ! -z "$O" ]; then
 +#    /sbin/iptables -F BOTSCOUT
 +#    /sbin/iptables -X BOTSCOUT
 +#fi
 +#if [ ! -z "$I" ]; then
 +#    /sbin/iptables -D INPUT -j BOTSCOUT
 +#fi
 +#if [ ! -z "$O" ]; then
 +#    /sbin/iptables -D OUTPUT -j BOTSCOUT
 +#fi
 +## Create the chain again and add all the new rules.
 +#/sbin/iptables -N BOTSCOUT
 +#/sbin/iptables -I INPUT 1 -j BOTSCOUT
 +#/sbin/iptables -I OUTPUT 1 -j BOTSCOUT
 +#/sbin/iptables -A BOTSCOUT -p all -m set --match-set BOTSCOUT src,dst -j DROP
 +## Continue with the rest.
 +#/sbin/iptables -A BOTSCOUT -j RETURN
 +###########################################################################
 +
 +`ipset list BOTSCOUT 2>/dev/null >/dev/null`
 +if [ $? = 1 ]; then
 +    ipset create BOTSCOUT hash:net maxelem 262144 family inet
 +fi
 +ipset flush BOTSCOUT
 +
 +while read LINE; do
 +    grep -E -vq "^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4}$" <<< "${LINE}"
 +    if [ $? -eq 0 ]; then
 +        continue
 +    fi
 +    printf %s "add BOTSCOUT ${LINE}" | ipset restore -exist
 +done <<< $(curl -s -L https://iplists.firehol.org/files/botscout.ipset)
 +
 +</file>
  
 ====== Delete a Single Rule ====== ====== Delete a Single Rule ======
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 The ''generate-country-ip-sets.sh'' script presented above will create 8 separate lists, 2 lists per country for both IPv4 and IPv6 using a list of countries ''COUNTRY_CODES'' adjustable in the configuration section of the script. The ''generate-country-ip-sets.sh'' script presented above will create 8 separate lists, 2 lists per country for both IPv4 and IPv6 using a list of countries ''COUNTRY_CODES'' adjustable in the configuration section of the script.
 +
 +====== PeerBlock Level 1 ======
 +
 +PeerBlock is a list of agencies dealing with copyright protection. The following script can be used to create an IP set and batch-block all of them.
 +
 +<code bash>
 +#!/usr/bin/env bash
 +###########################################################################
 +##  Copyright (C) Wizardry and Steamworks 2023 - License: GNU GPLv3      ##
 +###########################################################################
 +# Downloads peerblock level 1 and adds all the networks to ipset.        ##
 +###########################################################################
 +## Possible firewall configuration:
 +## Delete all the old rules.
 +#I=`/sbin/iptables-save | grep -- "-A INPUT -j PEERBLOCK-LEVEL1"`
 +#O=`/sbin/iptables-save | grep -- "-A OUTPUT -j PEERBLOCK-LEVEL1"`
 +#if [ ! -z "$I" ] || [ ! -z "$O" ]; then
 +#    /sbin/iptables -F PEERBLOCK-LEVEL1
 +#    /sbin/iptables -X PEERBLOCK-LEVEL1
 +#fi
 +#if [ ! -z "$I" ]; then
 +#    /sbin/iptables -D INPUT -j PEERBLOCK-LEVEL1
 +#fi
 +#if [ ! -z "$O" ]; then
 +#    /sbin/iptables -D OUTPUT -j PEERBLOCK-LEVEL1
 +#fi
 +## Create the chain again and add all the new rules.
 +#/sbin/iptables -N PEERBLOCK-LEVEL1
 +#/sbin/iptables -I INPUT 1 -j PEERBLOCK-LEVEL1
 +#/sbin/iptables -I OUTPUT 1 -j PEERBLOCK-LEVEL1
 +#/sbin/iptables -A PEERBLOCK-LEVEL1 -p all -m set --match-set PEERBLOCK-LEVEL1 src,dst -j DROP
 +## Continue with the rest.
 +#/sbin/iptables -A PEERBLOCK-LEVEL1 -j RETURN
 +###########################################################################
 +    
 +`ipset list PEERBLOCK-LEVEL1 2>/dev/null >/dev/null`
 +if [ $? = 1 ]; then
 +    ipset create PEERBLOCK-LEVEL1 hash:net maxelem 262144 family inet
 +fi
 +ipset flush PEERBLOCK-LEVEL1
 +curl -s -L "http://list.iblocklist.com/?list=bt_level1&amp;fileformat=p2p&amp;archiveformat=gz" -o - |
 +    gunzip |
 +    cut -d: -f2 |
 +    grep -E "^[-0-9.]+$" |
 +    awk '{print "add PEERBLOCK-LEVEL1 "$1}' |
 +    ipset restore -exist
 +
 +</code>
 +
 +Ideally, this script could be placed in ''/etc/cron.daily'' in order to daily refresh the set of IPs.
 +
 +====== Banning Countries on Debian ======
 +
 +On Debian, the procedure to obtain the ''geoip'' ''iptables'' module is to install the packages:
 +  * ''xtables-addons-dkms'',
 +  * ''xtables-addons-common'',
 +  * ''libtext-csv-xs-perl''
 +
 +With the packages installed, there are some tools under ''/usr/lib/exec/xtables-addons'' that can be used to both download a geoip database as well as create the necessary mappings in order to be able to block countries. The tools are the following:
 +  * ''xt_geoip_dl'',
 +  * ''xt_geoip_build''
 +
 +and:
 +  * ''xt_geoip_dl_maxmind'',
 +  * ''xt_geoip_build_maxmind''
 +
 +and can be used in pairs in order to generate a database for ''iptables''. The procedure is to first issue:
 +<code bash>
 +xt_geoip_dl
 +</code>
 +in order to download a database, followed by:
 +<code bash>
 +xt_geoip_build
 +</code>
 +in order to build the lookup table for the ''iptables'' ''geoip'' module.
 +
 +Note that ''xt_geoip_dl_maxmind'' will require a license file to be supplies as the first parameter in order to download the MaxMind database.
 +
 +The last command, ''xt_geoip_build'' will generate ''iv4'' and ''iv6'' files in the current directory and they will have to be moved into ''/usr/share/xt_geoip/'':
 +<code bash>
 +mkdir -p /usr/share/xt_geoip/
 +mv *.iv4 *.iv6 /usr/share/xt_geoip
 +</code>
 +
 +
 +
 +
fuss/iptables.1581968586.txt.gz · Last modified: 2020/02/17 19:43 by office
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