rip

RIP

A simple DNS server that extracts IP address (or cname) from the requested domain name and sends it back in the response.

Encoding rules

DNS server parses requested name to extract the requested mode, IP or CNAME by the following rules:

    <optional-prefix>.<IPv4>.4.<zone>  -> returns A record with <IPv4> address
    <optional-prefix>.<IPv6>.6.<zone>  -> returns AAAA record with <IPv6> address
    <proxy-name>.p.<zone>  -> resolve proxy name and returns it
    <ip1>.<ip2>.r.<zone>  -> pick random <ip1> or <ip2>
    <ip1>.<ip2>.l.<zone>  -> loop over <ip1> and <ip2>
    <ip1>.<ip2>.s.<zone>  -> "sticky" - <ip1> for first request, then <ip2> in sticky TTL (30 sec by default)
    <cname>.c.<zone>  -> return CNAME record with <cname>
    <any-name>.<zone>  -> returns default address
    [(<IPv4>.4|<IPv6>.6)...(<IPv4>.4|<IPv6>.6)].m.<zone>  -> returns multiple address according to order and type

IP address format

IP address can be presented in two variants - dash-delimited and base16-form. For example, ips 0a000001 and 10-0-0-1 are equal and points to 10.0.0.1 You can also use the built-in converter to encode IP address:

$ rip ip2hex fe80::fa94:c2ff:fee5:3cf6 127.0.0.1
fe80000000000000fa94c2fffee53cf6	7f000001

Cname/ProxyName format

cname and proxy modes support two name resolution logic - prefixed and dash-delimited: Eg:

    something.victim.com.c.evil.com -> CNAME to something.victim.com
    something.victim-com.c.evil.com -> CNAME to victim.com

Usage

Run NS server for zone example.com with default IP 77.88.55.70 and 2a02:6b8: a:: a:

$ rip ns --zone=example.com --ipv4=77.88.55.70 --ipv6=2a02:6b8:a::a

When requesting it, we should get the following responses:

# IPv4
    1-1-1-1.4.example.com ->  1.1.1.1 
    foo.1-1-1-1.4.example.com ->  1.1.1.1
    bar.foo.1-1-1-1.4.example.com ->  1.1.1.1

# IPv6
    2a01-7e01--f03c-91ff-fe3b-c9ba.6.example.com    ->  2a01:7e01::f03c:91ff:fe3b:c9ba
    foo.2a01-7e01--f03c-91ff-fe3b-c9ba.6.example.com    -> 2a01:7e01::f03c:91ff:fe3b:c9ba
    foo.--1.6.example.com   ->  ::1

# Random
    0a000002.0a000001.r.example.com ->  random between 10.0.0.1 and 10.0.0.2

# Loop
    8ba299a7.8ba299a8.l.example.com ->  loop over 139.162.153.167 and 139.162.153.168

# Sticky
    8ba299a7.8ba299a8.s.example.com ->  139.162.153.167 then 139.162.153.168, then 139.162.153.168 and so on

# Cname
    ya.ru.c.example.com ->  canonical name ya.ru
    google.com.c.example.com ->  canonical name google.com

# Proxy
    ya.ru.p.example.com ->  87.250.250.242 and 2a02:6b8::2:242
    google.com.p.example.com  ->  64.233.164.102 and 2a00:1450:4010:c07::64

# Multi
    1-1-1-1.4.8ba299a7.4.2a017e0100000000f03c91fffe3bc9ba.6.m.example.com   ->  1.1.1.1, 139.162.153.167, 2a01:7e01::f03c:91ff:fe3b:c9ba