Object
Resolv::DNS is a DNS stub resolver.
Information taken from the following places:
STD0013
RFC 1035
etc.
Creates a new DNS resolver.
config_info
can be:
Uses /etc/resolv.conf.
Path to a file using /etc/resolv.conf's format.
Must contain :nameserver, :search and :ndots keys.
Example:
Resolv::DNS.new(:nameserver => ['210.251.121.21'], :search => ['ruby-lang.org'], :ndots => 1)
# File resolv.rb, line 323 def initialize(config_info=nil) @mutex = Mutex.new @config = Config.new(config_info) @initialized = nil end
Closes the DNS resolver.
# File resolv.rb, line 342 def close @mutex.synchronize { if @initialized @initialized = false end } 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 resolv.rb, line 380 def each_address(name) each_resource(name, Resource::IN::A) {|resource| yield resource.address} each_resource(name, Resource::IN::AAAA) {|resource| yield resource.address} 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 resolv.rb, line 415 def each_name(address) case address when Name ptr = address 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, Resource::IN::PTR) {|resource| yield resource.name} end
Iterates over all typeclass
DNS
resources for name
. See getresource for argument details.
# File resolv.rb, line 471 def each_resource(name, typeclass, &proc) lazy_initialize requester = make_requester senders = {} begin @config.resolv(name) {|candidate, tout, nameserver| msg = Message.new msg.rd = 1 msg.add_question(candidate, typeclass) unless sender = senders[[candidate, nameserver]] sender = senders[[candidate, nameserver]] = requester.sender(msg, candidate, nameserver) end reply, reply_name = requester.request(sender, tout) case reply.rcode when RCode::NoError extract_resources(reply, reply_name, typeclass, &proc) return when RCode::NXDomain raise Config::NXDomain.new(reply_name.to_s) else raise Config::OtherResolvError.new(reply_name.to_s) end } ensure requester.close end 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 resolv.rb, line 356 def getaddress(name) each_address(name) {|address| return address} raise ResolvError.new("DNS result has no information for #{name}") 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 resolv.rb, line 367 def getaddresses(name) ret = [] each_address(name) {|address| ret << address} return ret 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 resolv.rb, line 391 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 Resolv::IPv4, Resolv::IPv6 or a String. Retrieved names will be Resolv::DNS::Name instances.
# File resolv.rb, line 402 def getnames(address) ret = [] each_name(address) {|name| ret << name} return ret 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:
Resolv::DNS::Resource::IN::ANY
Resolv::DNS::Resource::IN::CNAME
Resolv::DNS::Resource::IN::HINFO
Resolv::DNS::Resource::IN::MINFO
Resolv::DNS::Resource::IN::MX
Resolv::DNS::Resource::IN::NS
Resolv::DNS::Resource::IN::PTR
Resolv::DNS::Resource::IN::SOA
Resolv::DNS::Resource::IN::TXT
Returned resource is represented as a Resolv::DNS::Resource instance, i.e. Resolv::DNS::Resource::IN::A.
# File resolv.rb, line 452 def getresource(name, typeclass) each_resource(name, typeclass) {|resource| return resource} raise ResolvError.new("DNS result has no information for #{name}") end
Looks up all typeclass
DNS resources
for name
. See getresource for argument details.
# File resolv.rb, line 461 def getresources(name, typeclass) ret = [] each_resource(name, typeclass) {|resource| ret << resource} return ret end