| Class | Resolv::DNS |
| In: |
lib/resolv.rb
|
| Parent: | Object |
Resolv::DNS is a DNS stub resolver.
Information taken from the following places:
config_info can be:
| nil: | Uses /etc/resolv.conf. |
| String: | Path to a file using /etc/resolv.conf‘s format. |
| Hash: | Must contain :nameserver, :search and :ndots keys. |
Example:
Resolv::DNS.new(:nameserver => ['210.251.121.21'],
:search => ['ruby-lang.org'],
:ndots => 1)
# File lib/resolv.rb, line 328
328: def initialize(config_info=nil)
329: @mutex = Mutex.new
330: @config = Config.new(config_info)
331: @initialized = nil
332: end
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/resolv.rb, line 303
303: def self.open(*args)
304: dns = new(*args)
305: return dns unless block_given?
306: begin
307: yield dns
308: ensure
309: dns.close
310: end
311: end
Iterates over all IP addresses for name retrieved from the DNS resolver.
name can be a Resolv::DNS::Name or a String. Retrieved addresses will be a Resolv::IPv4 or Resolv::IPv6
# File lib/resolv.rb, line 385
385: def each_address(name)
386: each_resource(name, Resource::IN::A) {|resource| yield resource.address}
387: each_resource(name, Resource::IN::AAAA) {|resource| yield resource.address}
388: end
Iterates over all hostnames for address retrieved from the DNS resolver.
address must be a Resolv::IPv4, Resolv::IPv6 or a String. Retrieved names will be Resolv::DNS::Name instances.
# File lib/resolv.rb, line 420
420: def each_name(address)
421: case address
422: when Name
423: ptr = address
424: when IPv4::Regex
425: ptr = IPv4.create(address).to_name
426: when IPv6::Regex
427: ptr = IPv6.create(address).to_name
428: else
429: raise ResolvError.new("cannot interpret as address: #{address}")
430: end
431: each_resource(ptr, Resource::IN::PTR) {|resource| yield resource.name}
432: end
Iterates over all typeclass DNS resources for name. See getresource for argument details.
# File lib/resolv.rb, line 476
476: def each_resource(name, typeclass, &proc)
477: lazy_initialize
478: requester = make_requester
479: senders = {}
480: begin
481: @config.resolv(name) {|candidate, tout, nameserver|
482: msg = Message.new
483: msg.rd = 1
484: msg.add_question(candidate, typeclass)
485: unless sender = senders[[candidate, nameserver]]
486: sender = senders[[candidate, nameserver]] =
487: requester.sender(msg, candidate, nameserver)
488: end
489: reply, reply_name = requester.request(sender, tout)
490: case reply.rcode
491: when RCode::NoError
492: extract_resources(reply, reply_name, typeclass, &proc)
493: return
494: when RCode::NXDomain
495: raise Config::NXDomain.new(reply_name.to_s)
496: else
497: raise Config::OtherResolvError.new(reply_name.to_s)
498: end
499: }
500: ensure
501: requester.close
502: end
503: end
Gets the IP address of name from the DNS resolver.
name can be a Resolv::DNS::Name or a String. Retrieved address will be a Resolv::IPv4 or Resolv::IPv6
# File lib/resolv.rb, line 361
361: def getaddress(name)
362: each_address(name) {|address| return address}
363: raise ResolvError.new("DNS result has no information for #{name}")
364: end
Gets all IP addresses for name from the DNS resolver.
name can be a Resolv::DNS::Name or a String. Retrieved addresses will be a Resolv::IPv4 or Resolv::IPv6
# File lib/resolv.rb, line 372
372: def getaddresses(name)
373: ret = []
374: each_address(name) {|address| ret << address}
375: return ret
376: end
Gets the hostname for address from the DNS resolver.
address must be a Resolv::IPv4, Resolv::IPv6 or a String. Retrieved name will be a Resolv::DNS::Name.
# File lib/resolv.rb, line 396
396: def getname(address)
397: each_name(address) {|name| return name}
398: raise ResolvError.new("DNS result has no information for #{address}")
399: end
Gets all hostnames for address from the DNS resolver.
address must be a Resolv::IPv4, Resolv::IPv6 or a String. Retrieved names will be Resolv::DNS::Name instances.
# File lib/resolv.rb, line 407
407: def getnames(address)
408: ret = []
409: each_name(address) {|name| ret << name}
410: return ret
411: end
Look up the typeclass DNS resource of name.
name must be a Resolv::DNS::Name or a String.
typeclass should be one of the following:
Returned resource is represented as a Resolv::DNS::Resource instance, i.e. Resolv::DNS::Resource::IN::A.
# File lib/resolv.rb, line 457
457: def getresource(name, typeclass)
458: each_resource(name, typeclass) {|resource| return resource}
459: raise ResolvError.new("DNS result has no information for #{name}")
460: end
Looks up all typeclass DNS resources for name. See getresource for argument details.
# File lib/resolv.rb, line 466
466: def getresources(name, typeclass)
467: ret = []
468: each_resource(name, typeclass) {|resource| ret << resource}
469: return ret
470: end