class Dnsruby::DNS
Dnsruby::DNS
class¶ ↑
Resolv::DNS performs DNS
queries.
class methods¶ ↑
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Dnsruby::DNS.new(config_info=nil)
((|config_info|)) should be nil, a string or a hash. If nil is given, /etc/resolv.conf and platform specific information is used. If a string is given, it should be a filename which format is same as /etc/resolv.conf. If a hash is given, it may contains information for nameserver, search and ndots as follows. Dnsruby::DNS.new({:nameserver=>["210.251.121.21"], :search=>["ruby-lang.org"], :ndots=>1})
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Dnsruby::Resolv::DNS.open(config_info=nil) {|dns| …}
methods¶ ↑
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Dnsruby::DNS#each_address(name)
{|address| …}address lookup methods. ((|name|)) must be an instance of Dnsruby::Name or String. Resultant address is represented as an instance of Dnsruby::IPv4 or Dnsruby::IPv6.
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Dnsruby::DNS#each_name(address)
{|name| …}These methods lookup hostnames . ((|address|)) must be an instance of Dnsruby::IPv4, Dnsruby::IPv6 or String. Resultant name is represented as an instance of Dnsruby::Name.
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Dnsruby::DNS#getresource
(name, type, class) -
Dnsruby::DNS#getresources
(name, type, class) -
Dnsruby::DNS#each_resource
(name, type, class) {|resource| …}These methods lookup DNS resources of ((|name|)). ((|name|)) must be a instance of Dnsruby::Name or String. ((|type|)) must be a member of Dnsruby::Types ((|class|)) must be a member of Dnsruby::Classes Resultant resource is represented as an instance of (a subclass of) Dnsruby::RR. (Dnsruby::RR::IN::A, etc.)
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 :
-
STD0013
-
RFC 1035, etc.
-
etc.
Attributes
Public Class Methods
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
Public Instance Methods
Closes the resolver
# File lib/dnsruby/DNS.rb, line 97 def close @resolver.close end
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
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
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
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
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
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
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
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
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
# File lib/dnsruby/DNS.rb, line 102 def to_s return "DNS : " + @config.to_s end