Add script to generate adblock / tracking block list

Until nextdns.io quota is reached, use script for blocking
tracking sites.

openwrt-unbound-block.sh

@@ -0,0 +1,28 @@
+#!/bin/sh
+
+# Set custom domain filtering in unbound.
+# It is temporary workaround until nextdns request quota is not reset.
+
+# NextDNS rules:
+#   NoTrack Tracker Blocklist
+#   EasyPrivacy
+#   AdGuard Tracking Protection filter
+
+TMP_FILE=/tmp/adblock
+if [ -f $TMP_FILE ]; then rm $TMP_FILE; fi
+touch $TMP_FILE
+
+# NoTrack Tracker Blocklist
+curl -SL https://gitlab.com/quidsup/notrack-blocklists/-/raw/master/notrack-blocklist.txt | sed 's/\#.*//g' | grep -v '^\s*$' >> "$TMP_FILE"
+curl -SL https://gitlab.com/quidsup/notrack-blocklists/-/raw/master/notrack-malware.txt | sed 's/\#.*//g' | grep -v '^\s*$' >> "$TMP_FILE"
+
+# EasyPrivacy
+curl -SL https://easylist.to/easylist/easyprivacy.txt |  grep -E '^||' | grep -vE '@|---|!' | sed 's/||//g' >> "$TMP_FILE"
+
+echo "server:" > /etc/unbound/unbound_ext.conf
+# consider: grep -E '^[a-zA-Z0-9.]'
+sort -u "$TMP_FILE" | grep -E '^[a-zA-Z0-9]' | grep -vE '/|!|\^|\(|\)|#|\.\.' | while read -r domain; do
+    echo -e "\tlocal-zone: \"$domain.\" refuse" >> /etc/unbound/unbound_ext.conf
+done
+
+/etc/init.d/unbound restart