dows (DNS over WebSocket proxy)

dows accepts DNS over WebSocket connections and proxies them to DNS servers over TCP.

Protocol

DNS over WebSocket is a transport for DNS messages. The proxy uses the last segment (as in RFC 3986) of the WebSocket path as the upstream endpoint. The upstream endpoint is encoded like an authority without userinfo (as in RFC 3986, Section 3). Each DNS message (as in RFC 1035, Section 4.1) is the payload of a WebSocket binary data message (as in RFC 6455).

Usage

The only command line argument is the optional listener address. To restrict the allowed upstreams and origins, DOWS_ALLOWED_UPSTREAMS and DOWS_ALLOWED_ORIGINS must be set to comma-separated lists of allowed values. Alternatively, setting a variable exactly to * (allow any) disables the respective check.