untitled-document-1 / openwrt-adblock

hosts file based ad blocking for OpenWRT

openwrt-adblock

Hosts file based ad blocking for OpenWRT / LEDE

Prerequisites

• Make sure you have the necessary SSL root certificates. This will prevent a possible wget: can't execute 'openssl': No such file or directory error when the script attempts to download the hosts-file.net list.

opkg update
opkg install wget ca-certificates

To use it

• Download the ad block script, save it to /etc, and make it executable:

wget --no-check-certificate https://raw.githubusercontent.com/Untitled-Document-1/openwrt-adblock/master/adblock.sh -O /etc/adblock.sh
chmod +x /etc/adblock.sh

• Tell dnsmasq to use the blocked hosts file that adblock.sh generates:

  • If you have LuCI, navigate to Network > DHCP and DNS > Resolv and Hosts Files tab > Additional Hosts files field. Add the following:

  /tmp/block.hosts
  

  • If you don't have LuCI, add the following to /etc/config/dhcp under config dnsmasq:

  list addnhosts '/tmp/block.hosts'
  

• Run the adblock script:

/etc/adblock.sh

Note: you can now skip the age and lines threshold checks with the --force option.

Run on boot

• Add the following to /etc/rc.local (In LuCI, it's System > Startup)
  [the sleep is to make sure that your connection is fully up - the sleep period may need to be increased for slower routers and connections]

sleep 60 && /etc/adblock.sh &

Alternatively: add a cron job

• If your router is not restarted very often then a cron job may more suitable for keeping the blocked hosts file up-to-date. The following example shows a cron job that runs the script at 4am every day:

0 4 * * * /etc/adblock.sh

Please note: even though the script may be scheduled to run every day, the script contains a conditional that checks the Last modified date of the pre-existing blocked hosts file. Only if the file is older than 14 days will the file be re-created from the up-to-date lists. If you feel 14 days is too long and you want the file updated more frequently, then edit the script, changing the STALE_DAYS variable value to e.g. 7.

Optional - serve a 1 pixel transparent .gif for all of the newly un-routable things

wget --no-check-certificate -O /www/1.gif http://upload.wikimedia.org/wikipedia/commons/c/ce/Transparent.gif
uci set uhttpd.main.error_page="/1.gif" && uci commit
/etc/init.d/uhttpd restart