Class: Dnsruby::DNS

Dnsruby::DNS class

class methods

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})

Dnsruby::DNS.open(config_info=nil)
Dnsruby::Resolv::DNS.open(config_info=nil) {|dns| …}

methods

Dnsruby::DNS#close
Dnsruby::DNS#getaddress(name)
Dnsruby::DNS#getaddresses(name)

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.

Dnsruby::DNS#getname(address)
Dnsruby::DNS#getnames(address)

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.

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.
ftp.isi.edu/in-notes/iana/assignments/dns-parameters
etc.

Methods

close each_address each_name each_resource getaddress getaddresses getname getnames getresource getresources new open to_s

Attributes

config [R]

Public Class methods

new(config_info=nil)

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})

[Source]

     # File lib/Dnsruby/DNS.rb, line 116
116:     def initialize(config_info=nil)
117:       @config = Config.new()
118:       @config.set_config_info(config_info)
119:       @resolver = Resolver.new(@config)
120: #      if (@resolver.single_resolvers.length == 0)

121: #        raise ArgumentError.new("Must pass at least one valid resolver address")

122: #      end

123:     end

open(*args) {|dns| ...}

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.

[Source]

    # File lib/Dnsruby/DNS.rb, line 84
84:     def self.open(*args)
85:       dns = new(*args)
86:       return dns unless block_given?
87:       begin
88:         yield dns
89:       ensure
90:         dns.close
91:       end
92:     end

Public Instance methods

close()

Closes the resolver

[Source]

    # File lib/Dnsruby/DNS.rb, line 95
95:     def close
96:       @resolver.close
97:     end

each_address(name) {|resource.address| ...}

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

[Source]

     # File lib/Dnsruby/DNS.rb, line 150
150:     def each_address(name)
151:       each_resource(name) {|resource| yield resource.address}
152:     end

each_name(address) {|resource.domainname| ...}

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.

[Source]

     # File lib/Dnsruby/DNS.rb, line 177
177:     def each_name(address)
178:       case address
179:       when Name
180:         ptr = address
181:       when  IPv4, IPv6
182:         ptr = address.to_name
183:       when IPv4::Regex
184:         ptr = IPv4.create(address).to_name
185:       when IPv6::Regex
186:         ptr = IPv6.create(address).to_name
187:       else
188:         raise ResolvError.new("cannot interpret as address: #{address}")
189:       end
190:       each_resource(ptr, Types.PTR, Classes.IN) {|resource| yield resource.domainname}
191:     end

each_resource(name, type=Types.A, klass=Classes.IN, &proc)

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

[Source]

     # File lib/Dnsruby/DNS.rb, line 225
225:     def each_resource(name, type=Types.A, klass=Classes.IN, &proc)
226:       type = Types.new(type)
227:       klass = Classes.new(klass)
228:       reply, reply_name = send_query(name, type, klass)
229:       case reply.rcode.code
230:       when RCode::NOERROR
231:         extract_resources(reply, reply_name, type, klass, &proc)
232:         return
233:         #      when RCode::NXDomain

234:         #        Dnsruby.log.debug("RCode::NXDomain returned - raising error")

235:         #        raise Config::NXDomain.new(reply_name.to_s)

236:       else
237:         Dnsruby.log.error{"Unexpected rcode : #{reply.rcode.string}"}
238:         raise Config::OtherResolvError.new(reply_name.to_s)
239:       end      
240:     end

getaddress(name)

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

[Source]

     # File lib/Dnsruby/DNS.rb, line 131
131:     def getaddress(name)
132:       each_address(name) {|address| return address}
133:       raise ResolvError.new("DNS result has no information for #{name}")
134:     end

getaddresses(name)

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

[Source]

     # File lib/Dnsruby/DNS.rb, line 140
140:     def getaddresses(name)
141:       ret = []
142:       each_address(name) {|address| ret << address}
143:       return ret
144:     end

getname(address)

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.

[Source]

     # File lib/Dnsruby/DNS.rb, line 158
158:     def getname(address)
159:       each_name(address) {|name| return name}
160:       raise ResolvError.new("DNS result has no information for #{address}")
161:     end

getnames(address)

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.

[Source]

     # File lib/Dnsruby/DNS.rb, line 167
167:     def getnames(address)
168:       ret = []
169:       each_name(address) {|name| ret << name}
170:       return ret
171:     end

getresource(name, type=Types.A, klass=Classes.IN)

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

[Source]

     # File lib/Dnsruby/DNS.rb, line 200
200:     def getresource(name, type=Types.A, klass=Classes.IN)
201:       each_resource(name, type, klass) {|resource| return resource}
202:       raise ResolvError.new("DNS result has no information for #{name}")
203:     end

getresources(name, type=Types.A, klass=Classes.IN)

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

[Source]

     # File lib/Dnsruby/DNS.rb, line 212
212:     def getresources(name, type=Types.A, klass=Classes.IN)
213:       ret = []
214:       each_resource(name, type, klass) {|resource| ret << resource}
215:       return ret
216:     end

to_s()

[Source]

     # File lib/Dnsruby/DNS.rb, line 100
100:     def to_s
101:       return "DNS : " + @config.to_s
102:     end