DoH with Dnsmasq and https-dns-proxy

• This how-to describes the method for setting up DNS over HTTPS on OpenWrt.
• It relies on Dnsmasq and https-dns-proxy for masking DNS traffic as HTTPS traffic.
• Follow DNS hijacking to intercept DNS traffic or use VPN to protect all traffic.

Install the required packages. DNS encryption should be enabled automatically.

# Install packages
opkg update
opkg install https-dns-proxy

LAN clients should use Dnsmasq as a primary resolver. Dnsmasq forwards DNS queries to https-dns-proxy which encrypts DNS traffic.

Collect and analyze the following information.

# Restart services
service log restart; service dnsmasq restart; service https-dns-proxy restart
 
# Log and status
logread -e dnsmasq; netstat -l -n -p | grep -e dnsmasq
logread -e https-dns; netstat -l -n -p | grep -e https-dns
 
# Runtime configuration
pgrep -f -a dnsmasq; pgrep -f -a https-dns
head -v -n -0 /etc/resolv.* /tmp/resolv.* /tmp/resolv.*/*
 
# Persistent configuration
uci show dhcp; uci show https-dns-proxy

If you want to manage the settings using web interface. Install the necessary packages.

# Install packages
opkg update
opkg install luci-app-https-dns-proxy
service rpcd restart

• Navigate to LuCI → Network → DHCP and DNS to configure Dnsmasq.
• Navigate to LuCI → Services → HTTPS DNS Proxy to configure https-dns-proxy.

https-dns-proxy is configured with Google DNS and Cloudflare DNS by default. You can change it to Google DNS or any other DoH provider. Use resolvers supporting DNSSEC validation if necessary. Specify several resolvers to improve fault tolerance.

# Configure DoH provider
while uci -q delete https-dns-proxy.@https-dns-proxy[0]; do :; done
uci set https-dns-proxy.dns="https-dns-proxy"
uci set https-dns-proxy.dns.bootstrap_dns="8.8.8.8,8.8.4.4"
uci set https-dns-proxy.dns.resolver_url="https://dns.google/dns-query"
uci set https-dns-proxy.dns.listen_addr="127.0.0.1"
uci set https-dns-proxy.dns.listen_port="5053"
uci commit https-dns-proxy
service https-dns-proxy restart

If you are using the configurable NextDNS.io (paid subscription), that currently cannot be configured in LuCI.

Put your private DNS-over-HTTPS resolver endpoint (found in “Setup” in your NextDNS configuration page) into option resolver_url which is in /etc/config/https-dns-proxy.

LuCI will now erroneously show the wrong resolver in Instances because it doesn't recognize your private resolver.

If you make any changes for https-dns-proxy in LuCI it will overwrite your private resolver so you will need to manually enter it again.