DNS Query Proxy

dnsqproxy is a simple DNS query proxy that may be used to execute DNS queries from remote servers. Queries and responses are communicated using JSON as described in RFC 4627.

N.B.: This software is not indended to be used for public facing services such as a DNS Looking Glass (e.g., https://github.com/bortzmeyer/dns-lg).

Proxy Protocol

• Queries are submitted as JSON, one query per line.
• Responses are emitted as JSON, one response per line
• Multiple queries may be submitted in a single session.
• Session is terminated by an empty command or by end-of-file.

Query Elements

Mandatory Query Elements

The following query elements must be specified and has no defaults.

• address -- IPv4/IPv6 address of the destination DNS server
• qname -- domain name to query
• qtype -- DNS resource record (RR) type

Optional Query Elements

• tag -- query/response tag (no default)
• port -- destination port (default 53)
• tcp_timeout -- TCP timeout in seconds (default 60)
• udp_timeout -- UDP timeout in seconds (no default, retrans/retry used for retransmission)
• retrans -- retransmission interval (default 5)
• retry -- number of times to retry to query (default 2)
• transport -- TCP or UDP (default "UDP")
• qclass -- query class (default "IN")
• bufsize -- EDNS0 buffer size (default 512)
• flags -- query flags
  • do -- DNSSEC OK (default 0)
  • cd -- Checking Disabled (default 0)
  • rd -- Recursion Desired (default 0)
  • ad -- Authenticated Data (default 0)

Response Elements

• tag -- query/response tag (if set in query)
• address -- IPv4/IPv6 address of destination DNS server
• port -- destination port
• transport -- TCP or UDP
• time -- query time in seconds
• version -- proxy version
• query -- full DNS query in Base64 format
• response -- full DNS response in Base64 format
• error -- error message (in case of error)

Examples

{"qtype":"SOA","qname":"github.com","address":"8.8.8.8","flags":{"rd":1}}

Dependencies

The following perl modules are required:

• Data::Dumper
• IO::Socket::INET6
• JSON
• MIME::Base64
• Net::DNS
• Net::DNS::SEC
• Net::IP
• Time::HiRes

Required Debian/Ubuntu Packages

• perl
• perl-base
• perl-modules
• libio-socket-inet6-perl
• libjson-perl
• libnet-dns-perl
• libnet-dns-sec-perl
• libnet-ip-perl