class Dnsruby::DNS

Dnsruby::DNS class

Resolv::DNS performs DNS queries.

class methods

methods

The searchlist and other Config info is applied to the domain name if appropriate. All the nameservers are tried (if there is no timely answer from the first).

This class uses Resolver to perform the queries.

Information taken from the following places :

Attributes

config[R]
do_caching[RW]

Public Class Methods

new(config_info=nil) click to toggle source

Creates a new DNS resolver

config_info can be:

  • nil

    Uses platform default (e.g. /etc/resolv.conf)

  • String

    Path to a file using /etc/resolv.conf's format

  • Hash

    Must contain :nameserver, :search and :ndots keys

    example :
    
     Dnsruby::DNS.new({:nameserver => ['210.251.121.21'],
                       :search => ['ruby-lang.org'],
                       :ndots => 1})
# File lib/dnsruby/DNS.rb, line 118
    def initialize(config_info=nil)
      @do_caching = true
      @config = Config.new()
      @config.set_config_info(config_info)
      @resolver = Resolver.new(@config)
#      if (@resolver.single_resolvers.length == 0)
#        raise ArgumentError.new("Must pass at least one valid resolver address")
#      end
    end
open(*args) { |dns| ... } click to toggle source

Creates a new DNS resolver. See Resolv::DNS.new for argument details.

Yields the created DNS resolver to the block, if given, otherwise returns it.

# File lib/dnsruby/DNS.rb, line 86
def self.open(*args)
  dns = new(*args)
  return dns unless block_given?
  begin
    yield dns
  ensure
    dns.close
  end
end

Public Instance Methods

close() click to toggle source

Closes the resolver

# File lib/dnsruby/DNS.rb, line 97
def close
  @resolver.close
end
each_address(name) { |address| ... } click to toggle source

Iterates over all IP addresses of name retrieved from the DNS resolver

name can be a Dnsruby::Name or a String. Retrieved address will be a Dnsruby::IPv4 or a Dnsruby::IPv6

# File lib/dnsruby/DNS.rb, line 153
def each_address(name)
  each_resource(name) {|resource| yield resource.address}
end
each_name(address) { |domainname| ... } click to toggle source

Iterates over all hostnames for address retrieved from the DNS resolver

address must be a Dnsruby::IPv4, Dnsruby::IPv6 or a String. Retrieved name will be a Dnsruby::Name.

# File lib/dnsruby/DNS.rb, line 180
def each_name(address)
  case address
  when Name
    ptr = address
  when  IPv4, IPv6
    ptr = address.to_name
  when IPv4::Regex
    ptr = IPv4.create(address).to_name
  when IPv6::Regex
    ptr = IPv6.create(address).to_name
  else
    raise ResolvError.new("cannot interpret as address: #{address}")
  end
  each_resource(ptr, Types.PTR, Classes.IN) {|resource| yield resource.domainname}
end
each_resource(name, type=Types.A, klass=Classes.IN, &proc) click to toggle source

Iterates over all type, klass resources for name

type defaults to Dnsruby::Types.A klass defaults to Dnsruby::Classes.IN

Yielded resource is represented as a Dnsruby::RR instance, e.g. Dnsruby::RR::IN::A

# File lib/dnsruby/DNS.rb, line 228
def each_resource(name, type=Types.A, klass=Classes.IN, &proc)
  type = Types.new(type)
  klass = Classes.new(klass)
  reply, reply_name = send_query(name, type, klass)
  case reply.rcode.code
  when RCode::NOERROR
    extract_resources(reply, reply_name, type, klass, &proc)
    return
    #       when RCode::NXDomain
    #         Dnsruby.log.debug("RCode::NXDomain returned - raising error")
    #         raise Config::NXDomain.new(reply_name.to_s)
  else
    Dnsruby.log.error{"Unexpected rcode : #{reply.rcode.string}"}
    raise Config::OtherResolvError.new(reply_name.to_s)
  end
end
getaddress(name) click to toggle source

Gets the first IP address of name from the DNS resolver

name can be a Dnsruby::Name or a String. Retrieved address will be a Dnsruby::IPv4 or a Dnsruby::IPv6

# File lib/dnsruby/DNS.rb, line 134
def getaddress(name)
  each_address(name) {|address| return address}
  raise ResolvError.new("DNS result has no information for #{name}")
end
getaddresses(name) click to toggle source

Gets all IP addresses of name from the DNS resolver

name can be a Dnsruby::Name or a String. Retrieved address will be a Dnsruby::IPv4 or a Dnsruby::IPv6

# File lib/dnsruby/DNS.rb, line 143
def getaddresses(name)
  ret = []
  each_address(name) {|address| ret << address}
  return ret
end
getname(address) click to toggle source

Gets the first hostname for address from the DNS resolver

address must be a Dnsruby::IPv4, Dnsruby::IPv6 or a String. Retrieved name will be a Dnsruby::Name.

# File lib/dnsruby/DNS.rb, line 161
def getname(address)
  each_name(address) {|name| return name}
  raise ResolvError.new("DNS result has no information for #{address}")
end
getnames(address) click to toggle source

Gets all hostnames for address from the DNS resolver

address must be a Dnsruby::IPv4, Dnsruby::IPv6 or a String. Retrieved name will be a Dnsruby::Name.

# File lib/dnsruby/DNS.rb, line 170
def getnames(address)
  ret = []
  each_name(address) {|name| ret << name}
  return ret
end
getresource(name, type=Types.A, klass=Classes.IN) click to toggle source

Look up the first type, klass resource for name

type defaults to Dnsruby::Types.A klass defaults to Dnsruby::Classes.IN

Returned resource is represented as a Dnsruby::RR instance, e.g. Dnsruby::RR::IN::A

# File lib/dnsruby/DNS.rb, line 203
def getresource(name, type=Types.A, klass=Classes.IN)
  each_resource(name, type, klass) {|resource| return resource}
  raise ResolvError.new("DNS result has no information for #{name}")
end
getresources(name, type=Types.A, klass=Classes.IN) click to toggle source

Look up all type, klass resources for name

type defaults to Dnsruby::Types.A klass defaults to Dnsruby::Classes.IN

Returned resource is represented as a Dnsruby::RR instance, e.g. Dnsruby::RR::IN::A

# File lib/dnsruby/DNS.rb, line 215
def getresources(name, type=Types.A, klass=Classes.IN)
  ret = []
  each_resource(name, type, klass) {|resource| ret << resource}
  return ret
end
to_s() click to toggle source
# File lib/dnsruby/DNS.rb, line 102
def to_s
  return "DNS : " + @config.to_s
end