################################################################### # unbound-adblock 0.5 OpenBSD Installation Instructions # Copyright 2018-2021 Jordan Geoghegan ################################################################### ################################################################### # Table of Contents: ################################################################### * Unbound Configuration Notes * Upgrade Instructions (upgrade from 0.4) * Fresh Install Instructions * Post Install Notes ################################################################### # Notes: ################################################################### 1) This guide assumes you know how to setup Unbound. If not, there are plenty of online guides to setting up Unbound. An easy introductory guide to setting up unbound can be found here: https://www.openbsd.org/faq/pf/example1.html#dns OpenBSD Unbound Quick Start: -- Fetch and install example unbound config: $ ftp https://www.geoghegan.ca/pub/unbound-adblock/0.5/unbound.conf.example # install -m 644 -o root -g wheel unbound.conf.example /var/unbound/etc/unbound.conf -- Configure and enable 'unbound-control': # unbound-control-setup -- (Optional) Configure and enable DNSSEC # doas -u _unbound unbound-anchor -a "/var/unbound/db/root.key" -- Modify unbound.conf to suit your needs: # vi /var/unbound/etc/unbound.conf -- Enable and Start # rcctl enable unbound # rcctl start unbound ################################################################### # Upgrade from unbound-adblock 0.4 ################################################################### 1) Download updated script: $ ftp https://geoghegan.ca/pub/unbound-adblock/0.5/unbound-adblock.sh 2) Install script with appropriate permissions and remove old install location: # install -m 755 -o root -g bin unbound-adblock.sh /usr/local/bin/unbound-adblock # rm /usr/local/bin/unbound-adblock.sh 3) Update _adblock users home folder: Previous unbound-adblock releases incorrectly set the users home folder # usermod -d /var/empty _adblock 4) Update adblock file locations: unbound-adblock now uses the standard RPZ blocklist format # install -m 644 -o _adblock -g wheel /dev/null /var/unbound/db/adblock.rpz # rm /var/unbound/etc/adblock.conf 5) Update doas.conf permissions: $ cat /etc/doas.conf ... permit root permit nopass _adblock cmd /usr/sbin/unbound-control args -q status permit nopass _adblock cmd /usr/sbin/unbound-control args -q flush_zone unbound-adblock permit nopass _adblock cmd /usr/sbin/unbound-control args -q auth_zone_reload unbound-adblock # Only needed if using old unbound specific 'local-data' backend with '-o unbound' permit nopass _adblock cmd /usr/sbin/rcctl args reload unbound ... 6) Configure unbound-control if it isn't already: # unbound-control-setup 7) Update unbound.conf to remove reference to old 'adblock.conf' file and add newly required RPZ syntax: (Also add 'unbound-control' bits to your config if it's not there already) # cat /var/unbound/etc/unbound.conf ... # Required modules for RPZ module-config: "respip validator iterator" rpz: name: "unbound-adblock" zonefile: "/var/unbound/db/adblock.rpz" rpz-log: yes rpz-log-name: "unbound-adblock" remote-control: control-enable: yes control-interface: 127.0.0.1 ... Note: unbound will need to be restarted for the changes to take effect. 8) Create unbound-adblock log directory: # install -d -o root -g wheel -m 755 /var/log/unbound-adblock # install -o _adblock -g wheel -m 640 /dev/null /var/log/unbound-adblock/unbound-adblock.log # install -o _adblock -g wheel -m 640 /dev/null /var/log/unbound-adblock/unbound-adblock.log.0.gz 9) Update cron job (must be running OpenBSD 6.7 or newer - See note about cron in the 'Post Install Notes'): NOTE: unbound-adblock now requires specifying host OS type as an argument (See release notes) # crontab -u _adblock -e ... ~ 0~1 * * * -s unbound-adblock -O openbsd ... Note: unbound-adblock now automagically detects if mawk, gawk (GNU awk), ripgrep or GNU grep is present. This can improve performance on low powered devices significantly. Please read the man page for information on how to configure unbound-adblock. The manpage can be found here: https://www.geoghegan.ca/pub/unbound-adblock/0.5/man/man.txt To receive notification of new unbound-adblock releases and updates please send an email to 'announce@geoghegan.ca' with a subject line and body of "subscribe unbound-adblock" ################################################################### # Fresh Installation Guide ################################################################### 1) Configure Unbound as a local recursive DNS server See "Unbound Quick Start" above An example unbound.conf can be found here: https://www.geoghegan.ca/pub/unbound-adblock/0.5/unbound.conf.example 2) Download script: $ ftp https://geoghegan.ca/pub/unbound-adblock/0.5/unbound-adblock.sh 3) Create a new user (we'll call ours "_adblock"): The user should be created with a default shell of "nologin", home folder set to /var/empty/ with no password specified (disables password logins) # useradd -s /sbin/nologin -d /var/empty _adblock 4) Install script with appropriate permissions: # install -m 755 -o root -g bin unbound-adblock.sh /usr/local/bin/unbound-adblock 4.b) OPTIONAL: Install RipGrep and/or mawk for greatly improved performance: Note: RipGrep is not available on all CPU architectures, use ggrep if affected. # pkg_add ripgrep mawk 5) Create required files: # install -m 644 -o _adblock -g wheel /dev/null /var/unbound/db/adblock.rpz # install -d -o root -g wheel -m 755 /var/log/unbound-adblock # install -o _adblock -g wheel -m 640 /dev/null /var/log/unbound-adblock/unbound-adblock.log # install -o _adblock -g wheel -m 640 /dev/null /var/log/unbound-adblock/unbound-adblock.log.0.gz 6) Give user '_adblock' strict doas permission for the exact commands the script needs run as superuser. NOTE: Unlike 'sudo', _ALL_ users must be explicitly granted permission to use doas, even the root user. $ cat /etc/doas.conf ... permit root permit nopass _adblock cmd /usr/sbin/unbound-control args -q status permit nopass _adblock cmd /usr/sbin/unbound-control args -q flush_zone unbound-adblock permit nopass _adblock cmd /usr/sbin/unbound-control args -q auth_zone_reload unbound-adblock # Only needed if using old unbound specific 'local-data' backend with '-o unbound' permit nopass _adblock cmd /usr/sbin/rcctl args reload unbound ... 7) Configure unbound-control if it isn't already: # unbound-control-setup 8) Add a few lines to your unbound.conf located BEFORE the forwarders section: (Also add 'unbound-control' bits to your config if it's not there already) ... # Required modules for RPZ module-config: "respip validator iterator" rpz: name: "unbound-adblock" zonefile: "/var/unbound/db/adblock.rpz" rpz-log: yes rpz-log-name: "unbound-adblock" remote-control: control-enable: yes control-interface: 127.0.0.1 ... 9) Restart unbound to reload configuration changes: # rcctl restart unbound 10) Run script manually to parse and load the ruleset: # doas -u _adblock unbound-adblock -O openbsd 11) Edit _adblock users crontab to run unbound-adblock every night: # crontab -u _adblock -e ... ~ 0~1 * * * -s unbound-adblock -O openbsd ... NOTE: If you're running an OpenBSD release older than 6.7, you'll have to use a workaround: ... @daily sleep $(echo $((RANDOM\%7200+1))) ; unbound-adblock -O openbsd ... --- Please see the crontab(5) man page for further info Yay! unbound-adblock is now installed! With the nightly cron job, the list will be regularly updated with the latest known bad hosts. Please read the man page for information on how to configure unbound-adblock. The manpage can be found here: https://www.geoghegan.ca/pub/unbound-adblock/0.5/man/man.txt To receive notification of new unbound-adblock releases and updates please send an email to 'announce@geoghegan.ca' with a subject line and body of "subscribe unbound-adblock" ################################################################### # Post Install Notes: ################################################################### X) To add custom rules or enable features, or add alternate blocklists, See the "User Configuration Area" located at the top of the script. This area serves as a built in config file, so please feel free to edit it and experiment with all the features available within. --- Note: Most options can also be configured from the command line X) Regarding Cron Jobs: Over the past year I've noticed a number of list host servers going down at midnight in populated timezones (ie West Coast, East Coast and Western Europe). To be respectful (and to avoid overloading list providers servers) we have cron jobs scheduled to run at a random time within a defined interval. --- With the new default cron job, unbound-adblock will be run every night at some point between midnight and 2AM, and thus distributing the load of thousands of queries from numerous users over a 2 hour period rather than a matter of seconds. X) If you are trying to use very large blocklists, you may need to increase the users limits in /etc/login.conf. You may also need to increase the number of available file descriptors. X) If you would like to update unbound-adblock blocklists at a more frequent interval you can use a modified cron job: --- It is essential that you make use of the crontab randomization feature to ensure use of unbound-adblock remains respecful of blocklist provider resources. --- The following example runs unbound-adblock every 3 hours at a random minute (this avoids flooding the server with traffic at exactly XX:00) --- Run unbound-adblock every 3 hours Example: (you can change '/3' to '/4' to run every 4 hours) Note: Use of the '-s' switch prevents 2 instances of unbound-adblock from being run at the same time - which is a good thing. # crontab -u _adblock -e ... ~ */3 * * * -s unbound-adblock -O openbsd ... X) OPTIONAL -- Add the following line to your pf.conf: NOTE: This rule intercepts DNS traffic bound for Google DNS servers. Google mandates the use of their DNS servers in many apps and services. Many devices also use hardcoded Google DNS that cannot be changed. This is both a privacy and freedom concern. This should help rectify the issue: (This rule should be run on your router/gateway) # Replace '$adblock' with the IP address of the Unbound machine ... table {8.8.8.8 8.8.4.4} table {2001:4860:4860::8888 2001:4860:4860::8844} pass in quick to rdr-to $adblock pass in quick to rdr-to $adblock6 ... -- Reload your pf rule set: # pfctl -f /etc/pf.conf