Module: Tor::DNSEL

Defined in:
lib/tor/dnsel.rb

Constant Summary collapse

RESOLVER = 
Resolv::DefaultResolver
DNS_SUFFIX = 
'dnsel.torproject.org'.freeze

Class Method Summary collapse

Class Method Details

.dnsname(host) ⇒ String Also known as: hostname

Returns the DNS name used for Tor DNSEL queries of ‘host`.

Examples:

Tor::DNSEL.dnsname("1.2.3.4")           #=> "4.3.2.1.dnsel.torproject.org"

Parameters:

  • host (String, #to_s)

Returns:

  • (String) 


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# File 'lib/tor/dnsel.rb', line 58

def self.dnsname(host)
  source_addr = getaddress(host, true)
  "#{source_addr}.#{DNS_SUFFIX}"
end

.include?(host) ⇒ Boolean

Returns ‘true` if `host` is a Tor Exit Node, `false` otherwise.

If the DNS server is unreachable or the DNS query times out, returns ‘nil` to indicate that we don’t have a definitive answer one way or another.

Examples:

Tor::DNSEL.include?("185.220.101.21")    #=> true
Tor::DNSEL.include?("1.2.3.4")          #=> false

Parameters:

  • host (String, #to_s)

Returns:

  • (Boolean) 


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# File 'lib/tor/dnsel.rb', line 21

def self.include?(host)
  begin
    query(host) == '127.0.0.2'
  rescue Resolv::ResolvError # NXDOMAIN
    false
  rescue Resolv::ResolvTimeout
    nil
  rescue Errno::EHOSTUNREACH
    nil
  rescue Errno::EADDRNOTAVAIL
    nil
  end
end

.query(host) ⇒ String

Queries the Tor DNSEL for ‘host`, returning “172.0.0.2” if it is an exit node and raising a `Resolv::ResolvError` if it isn’t.

Examples:

Tor::DNSEL.query("185.220.101.21")       #=> "127.0.0.2"
Tor::DNSEL.query("1.2.3.4")             #=> Resolv::ResolvError

Parameters:

  • host (String, #to_s)

Returns:

  • (String)

Raises:

  • (Resolv::ResolvError) —

    for an NXDOMAIN response



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# File 'lib/tor/dnsel.rb', line 46

def self.query(host)
  getaddress(dnsname(host))
end