| Current File : //proc/thread-self/root/opt/alt/ruby20/lib64/ruby/2.0.0/resolv.rb |
require 'socket'
require 'fcntl'
require 'timeout'
require 'thread'
begin
require 'securerandom'
rescue LoadError
end
# Resolv is a thread-aware DNS resolver library written in Ruby. Resolv can
# handle multiple DNS requests concurrently without blocking the entire ruby
# interpreter.
#
# See also resolv-replace.rb to replace the libc resolver with Resolv.
#
# Resolv can look up various DNS resources using the DNS module directly.
#
# Examples:
#
# p Resolv.getaddress "www.ruby-lang.org"
# p Resolv.getname "210.251.121.214"
#
# Resolv::DNS.open do |dns|
# ress = dns.getresources "www.ruby-lang.org", Resolv::DNS::Resource::IN::A
# p ress.map { |r| r.address }
# ress = dns.getresources "ruby-lang.org", Resolv::DNS::Resource::IN::MX
# p ress.map { |r| [r.exchange.to_s, r.preference] }
# end
#
#
# == Bugs
#
# * NIS is not supported.
# * /etc/nsswitch.conf is not supported.
class Resolv
##
# Looks up the first IP address for +name+.
def self.getaddress(name)
DefaultResolver.getaddress(name)
end
##
# Looks up all IP address for +name+.
def self.getaddresses(name)
DefaultResolver.getaddresses(name)
end
##
# Iterates over all IP addresses for +name+.
def self.each_address(name, &block)
DefaultResolver.each_address(name, &block)
end
##
# Looks up the hostname of +address+.
def self.getname(address)
DefaultResolver.getname(address)
end
##
# Looks up all hostnames for +address+.
def self.getnames(address)
DefaultResolver.getnames(address)
end
##
# Iterates over all hostnames for +address+.
def self.each_name(address, &proc)
DefaultResolver.each_name(address, &proc)
end
##
# Creates a new Resolv using +resolvers+.
def initialize(resolvers=[Hosts.new, DNS.new])
@resolvers = resolvers
end
##
# Looks up the first IP address for +name+.
def getaddress(name)
each_address(name) {|address| return address}
raise ResolvError.new("no address for #{name}")
end
##
# Looks up all IP address for +name+.
def getaddresses(name)
ret = []
each_address(name) {|address| ret << address}
return ret
end
##
# Iterates over all IP addresses for +name+.
def each_address(name)
if AddressRegex =~ name
yield name
return
end
yielded = false
@resolvers.each {|r|
r.each_address(name) {|address|
yield address.to_s
yielded = true
}
return if yielded
}
end
##
# Looks up the hostname of +address+.
def getname(address)
each_name(address) {|name| return name}
raise ResolvError.new("no name for #{address}")
end
##
# Looks up all hostnames for +address+.
def getnames(address)
ret = []
each_name(address) {|name| ret << name}
return ret
end
##
# Iterates over all hostnames for +address+.
def each_name(address)
yielded = false
@resolvers.each {|r|
r.each_name(address) {|name|
yield name.to_s
yielded = true
}
return if yielded
}
end
##
# Indicates a failure to resolve a name or address.
class ResolvError < StandardError; end
##
# Indicates a timeout resolving a name or address.
class ResolvTimeout < TimeoutError; end
##
# Resolv::Hosts is a hostname resolver that uses the system hosts file.
class Hosts
if /mswin|mingw|bccwin/ =~ RUBY_PLATFORM
require 'win32/resolv'
DefaultFileName = Win32::Resolv.get_hosts_path
else
DefaultFileName = '/etc/hosts'
end
##
# Creates a new Resolv::Hosts, using +filename+ for its data source.
def initialize(filename = DefaultFileName)
@filename = filename
@mutex = Mutex.new
@initialized = nil
end
def lazy_initialize # :nodoc:
@mutex.synchronize {
unless @initialized
@name2addr = {}
@addr2name = {}
open(@filename, 'rb') {|f|
f.each {|line|
line.sub!(/#.*/, '')
addr, hostname, *aliases = line.split(/\s+/)
next unless addr
addr.untaint
hostname.untaint
@addr2name[addr] = [] unless @addr2name.include? addr
@addr2name[addr] << hostname
@addr2name[addr] += aliases
@name2addr[hostname] = [] unless @name2addr.include? hostname
@name2addr[hostname] << addr
aliases.each {|n|
n.untaint
@name2addr[n] = [] unless @name2addr.include? n
@name2addr[n] << addr
}
}
}
@name2addr.each {|name, arr| arr.reverse!}
@initialized = true
end
}
self
end
##
# Gets the IP address of +name+ from the hosts file.
def getaddress(name)
each_address(name) {|address| return address}
raise ResolvError.new("#{@filename} has no name: #{name}")
end
##
# Gets all IP addresses for +name+ from the hosts file.
def getaddresses(name)
ret = []
each_address(name) {|address| ret << address}
return ret
end
##
# Iterates over all IP addresses for +name+ retrieved from the hosts file.
def each_address(name, &proc)
lazy_initialize
if @name2addr.include?(name)
@name2addr[name].each(&proc)
end
end
##
# Gets the hostname of +address+ from the hosts file.
def getname(address)
each_name(address) {|name| return name}
raise ResolvError.new("#{@filename} has no address: #{address}")
end
##
# Gets all hostnames for +address+ from the hosts file.
def getnames(address)
ret = []
each_name(address) {|name| ret << name}
return ret
end
##
# Iterates over all hostnames for +address+ retrieved from the hosts file.
def each_name(address, &proc)
lazy_initialize
if @addr2name.include?(address)
@addr2name[address].each(&proc)
end
end
end
##
# Resolv::DNS is a DNS stub resolver.
#
# Information taken from the following places:
#
# * STD0013
# * RFC 1035
# * ftp://ftp.isi.edu/in-notes/iana/assignments/dns-parameters
# * etc.
class DNS
##
# Default DNS Port
Port = 53
##
# Default DNS UDP packet size
UDPSize = 512
##
# 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.
def self.open(*args)
dns = new(*args)
return dns unless block_given?
begin
yield dns
ensure
dns.close
end
end
##
# Creates a new DNS resolver.
#
# +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.
# :nameserver_port can be used to specify port number of nameserver address.
#
# The value of :nameserver should be an address string or
# an array of address strings.
# - :nameserver => '8.8.8.8'
# - :nameserver => ['8.8.8.8', '8.8.4.4']
#
# The value of :nameserver_port should be an array of
# pair of nameserver address and port number.
# - :nameserver_port => [['8.8.8.8', 53], ['8.8.4.4', 53]]
#
# Example:
#
# Resolv::DNS.new(:nameserver => ['210.251.121.21'],
# :search => ['ruby-lang.org'],
# :ndots => 1)
def initialize(config_info=nil)
@mutex = Mutex.new
@config = Config.new(config_info)
@initialized = nil
end
# Sets the resolver timeouts. This may be a single positive number
# or an array of positive numbers representing timeouts in seconds.
# If an array is specified, a DNS request will retry and wait for
# each successive interval in the array until a successful response
# is received. Specifying +nil+ reverts to the default timeouts:
# [ 5, second = 5 * 2 / nameserver_count, 2 * second, 4 * second ]
#
# Example:
#
# dns.timeouts = 3
#
def timeouts=(values)
@config.timeouts = values
end
def lazy_initialize # :nodoc:
@mutex.synchronize {
unless @initialized
@config.lazy_initialize
@initialized = true
end
}
self
end
##
# Closes the DNS resolver.
def close
@mutex.synchronize {
if @initialized
@initialized = false
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
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
def getaddresses(name)
ret = []
each_address(name) {|address| ret << address}
return ret
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
def each_address(name)
each_resource(name, Resource::IN::A) {|resource| yield resource.address}
if use_ipv6?
each_resource(name, Resource::IN::AAAA) {|resource| yield resource.address}
end
end
def use_ipv6? # :nodoc:
begin
list = Socket.ip_address_list
rescue NotImplementedError
return true
end
list.any? {|a| a.ipv6? && !a.ipv6_loopback? && !a.ipv6_linklocal? }
end
private :use_ipv6?
##
# 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.
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.
def getnames(address)
ret = []
each_name(address) {|name| ret << name}
return ret
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.
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
##
# 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::A
# * Resolv::DNS::Resource::IN::AAAA
# * 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
# * Resolv::DNS::Resource::IN::WKS
#
# Returned resource is represented as a Resolv::DNS::Resource instance,
# i.e. Resolv::DNS::Resource::IN::A.
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.
def getresources(name, typeclass)
ret = []
each_resource(name, typeclass) {|resource| ret << resource}
return ret
end
##
# Iterates over all +typeclass+ DNS resources for +name+. See
# #getresource for argument details.
def each_resource(name, typeclass, &proc)
lazy_initialize
requester = make_udp_requester
senders = {}
begin
@config.resolv(name) {|candidate, tout, nameserver, port|
msg = Message.new
msg.rd = 1
msg.add_question(candidate, typeclass)
unless sender = senders[[candidate, nameserver, port]]
sender = requester.sender(msg, candidate, nameserver, port)
next if !sender
senders[[candidate, nameserver, port]] = sender
end
reply, reply_name = requester.request(sender, tout)
case reply.rcode
when RCode::NoError
if reply.tc == 1 and not Requester::TCP === requester
requester.close
# Retry via TCP:
requester = make_tcp_requester(nameserver, port)
senders = {}
# This will use TCP for all remaining candidates (assuming the
# current candidate does not already respond successfully via
# TCP). This makes sense because we already know the full
# response will not fit in an untruncated UDP packet.
redo
else
extract_resources(reply, reply_name, typeclass, &proc)
end
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
def make_udp_requester # :nodoc:
nameserver_port = @config.nameserver_port
if nameserver_port.length == 1
Requester::ConnectedUDP.new(*nameserver_port[0])
else
Requester::UnconnectedUDP.new(*nameserver_port)
end
end
def make_tcp_requester(host, port) # :nodoc:
return Requester::TCP.new(host, port)
end
def extract_resources(msg, name, typeclass) # :nodoc:
if typeclass < Resource::ANY
n0 = Name.create(name)
msg.each_answer {|n, ttl, data|
yield data if n0 == n
}
end
yielded = false
n0 = Name.create(name)
msg.each_answer {|n, ttl, data|
if n0 == n
case data
when typeclass
yield data
yielded = true
when Resource::CNAME
n0 = data.name
end
end
}
return if yielded
msg.each_answer {|n, ttl, data|
if n0 == n
case data
when typeclass
yield data
end
end
}
end
if defined? SecureRandom
def self.random(arg) # :nodoc:
begin
SecureRandom.random_number(arg)
rescue NotImplementedError
rand(arg)
end
end
else
def self.random(arg) # :nodoc:
rand(arg)
end
end
def self.rangerand(range) # :nodoc:
base = range.begin
len = range.end - range.begin
if !range.exclude_end?
len += 1
end
base + random(len)
end
RequestID = {} # :nodoc:
RequestIDMutex = Mutex.new # :nodoc:
def self.allocate_request_id(host, port) # :nodoc:
id = nil
RequestIDMutex.synchronize {
h = (RequestID[[host, port]] ||= {})
begin
id = rangerand(0x0000..0xffff)
end while h[id]
h[id] = true
}
id
end
def self.free_request_id(host, port, id) # :nodoc:
RequestIDMutex.synchronize {
key = [host, port]
if h = RequestID[key]
h.delete id
if h.empty?
RequestID.delete key
end
end
}
end
def self.bind_random_port(udpsock, bind_host="0.0.0.0") # :nodoc:
begin
port = rangerand(1024..65535)
udpsock.bind(bind_host, port)
rescue Errno::EADDRINUSE, # POSIX
Errno::EACCES, # SunOS: See PRIV_SYS_NFS in privileges(5)
Errno::EPERM # FreeBSD: security.mac.portacl.port_high is configurable. See mac_portacl(4).
retry
end
end
class Requester # :nodoc:
def initialize
@senders = {}
@socks = nil
end
def request(sender, tout)
start = Time.now
timelimit = start + tout
begin
sender.send
rescue Errno::EHOSTUNREACH, # multi-homed IPv6 may generate this
Errno::ENETUNREACH
raise ResolvTimeout
end
while true
before_select = Time.now
timeout = timelimit - before_select
if timeout <= 0
raise ResolvTimeout
end
select_result = IO.select(@socks, nil, nil, timeout)
if !select_result
after_select = Time.now
next if after_select < timelimit
raise ResolvTimeout
end
begin
reply, from = recv_reply(select_result[0])
rescue Errno::ECONNREFUSED, # GNU/Linux, FreeBSD
Errno::ECONNRESET # Windows
# No name server running on the server?
# Don't wait anymore.
raise ResolvTimeout
end
begin
msg = Message.decode(reply)
rescue DecodeError
next # broken DNS message ignored
end
if s = @senders[[from,msg.id]]
break
else
# unexpected DNS message ignored
end
end
return msg, s.data
end
def close
socks = @socks
@socks = nil
if socks
socks.each {|sock| sock.close }
end
end
class Sender # :nodoc:
def initialize(msg, data, sock)
@msg = msg
@data = data
@sock = sock
end
end
class UnconnectedUDP < Requester # :nodoc:
def initialize(*nameserver_port)
super()
@nameserver_port = nameserver_port
@socks_hash = {}
@socks = []
nameserver_port.each {|host, port|
if host.index(':')
bind_host = "::"
af = Socket::AF_INET6
else
bind_host = "0.0.0.0"
af = Socket::AF_INET
end
next if @socks_hash[bind_host]
begin
sock = UDPSocket.new(af)
rescue Errno::EAFNOSUPPORT
next # The kernel doesn't support the address family.
end
sock.do_not_reverse_lookup = true
sock.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) if defined? Fcntl::F_SETFD
DNS.bind_random_port(sock, bind_host)
@socks << sock
@socks_hash[bind_host] = sock
}
end
def recv_reply(readable_socks)
reply, from = readable_socks[0].recvfrom(UDPSize)
return reply, [from[3],from[1]]
end
def sender(msg, data, host, port=Port)
sock = @socks_hash[host.index(':') ? "::" : "0.0.0.0"]
return nil if !sock
service = [host, port]
id = DNS.allocate_request_id(host, port)
request = msg.encode
request[0,2] = [id].pack('n')
return @senders[[service, id]] =
Sender.new(request, data, sock, host, port)
end
def close
super
@senders.each_key {|service, id|
DNS.free_request_id(service[0], service[1], id)
}
end
class Sender < Requester::Sender # :nodoc:
def initialize(msg, data, sock, host, port)
super(msg, data, sock)
@host = host
@port = port
end
attr_reader :data
def send
raise "@sock is nil." if @sock.nil?
@sock.send(@msg, 0, @host, @port)
end
end
end
class ConnectedUDP < Requester # :nodoc:
def initialize(host, port=Port)
super()
@host = host
@port = port
is_ipv6 = host.index(':')
sock = UDPSocket.new(is_ipv6 ? Socket::AF_INET6 : Socket::AF_INET)
@socks = [sock]
sock.do_not_reverse_lookup = true
sock.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) if defined? Fcntl::F_SETFD
DNS.bind_random_port(sock, is_ipv6 ? "::" : "0.0.0.0")
sock.connect(host, port)
end
def recv_reply(readable_socks)
reply = readable_socks[0].recv(UDPSize)
return reply, nil
end
def sender(msg, data, host=@host, port=@port)
unless host == @host && port == @port
raise RequestError.new("host/port don't match: #{host}:#{port}")
end
id = DNS.allocate_request_id(@host, @port)
request = msg.encode
request[0,2] = [id].pack('n')
return @senders[[nil,id]] = Sender.new(request, data, @socks[0])
end
def close
super
@senders.each_key {|from, id|
DNS.free_request_id(@host, @port, id)
}
end
class Sender < Requester::Sender # :nodoc:
def send
raise "@sock is nil." if @sock.nil?
@sock.send(@msg, 0)
end
attr_reader :data
end
end
class TCP < Requester # :nodoc:
def initialize(host, port=Port)
super()
@host = host
@port = port
sock = TCPSocket.new(@host, @port)
@socks = [sock]
sock.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) if defined? Fcntl::F_SETFD
@senders = {}
end
def recv_reply(readable_socks)
len = readable_socks[0].read(2).unpack('n')[0]
reply = @socks[0].read(len)
return reply, nil
end
def sender(msg, data, host=@host, port=@port)
unless host == @host && port == @port
raise RequestError.new("host/port don't match: #{host}:#{port}")
end
id = DNS.allocate_request_id(@host, @port)
request = msg.encode
request[0,2] = [request.length, id].pack('nn')
return @senders[[nil,id]] = Sender.new(request, data, @socks[0])
end
class Sender < Requester::Sender # :nodoc:
def send
@sock.print(@msg)
@sock.flush
end
attr_reader :data
end
def close
super
@senders.each_key {|from,id|
DNS.free_request_id(@host, @port, id)
}
end
end
##
# Indicates a problem with the DNS request.
class RequestError < StandardError
end
end
class Config # :nodoc:
def initialize(config_info=nil)
@mutex = Mutex.new
@config_info = config_info
@initialized = nil
@timeouts = nil
end
def timeouts=(values)
if values
values = Array(values)
values.each do |t|
Numeric === t or raise ArgumentError, "#{t.inspect} is not numeric"
t > 0.0 or raise ArgumentError, "timeout=#{t} must be postive"
end
@timeouts = values
else
@timeouts = nil
end
end
def Config.parse_resolv_conf(filename)
nameserver = []
search = nil
ndots = 1
open(filename, 'rb') {|f|
f.each {|line|
line.sub!(/[#;].*/, '')
keyword, *args = line.split(/\s+/)
args.each { |arg|
arg.untaint
}
next unless keyword
case keyword
when 'nameserver'
nameserver += args
when 'domain'
next if args.empty?
search = [args[0]]
when 'search'
next if args.empty?
search = args
when 'options'
args.each {|arg|
case arg
when /\Andots:(\d+)\z/
ndots = $1.to_i
end
}
end
}
}
return { :nameserver => nameserver, :search => search, :ndots => ndots }
end
def Config.default_config_hash(filename="/etc/resolv.conf")
if File.exist? filename
config_hash = Config.parse_resolv_conf(filename)
else
if /mswin|cygwin|mingw|bccwin/ =~ RUBY_PLATFORM
require 'win32/resolv'
search, nameserver = Win32::Resolv.get_resolv_info
config_hash = {}
config_hash[:nameserver] = nameserver if nameserver
config_hash[:search] = [search].flatten if search
end
end
config_hash || {}
end
def lazy_initialize
@mutex.synchronize {
unless @initialized
@nameserver_port = []
@search = nil
@ndots = 1
case @config_info
when nil
config_hash = Config.default_config_hash
when String
config_hash = Config.parse_resolv_conf(@config_info)
when Hash
config_hash = @config_info.dup
if String === config_hash[:nameserver]
config_hash[:nameserver] = [config_hash[:nameserver]]
end
if String === config_hash[:search]
config_hash[:search] = [config_hash[:search]]
end
else
raise ArgumentError.new("invalid resolv configuration: #{@config_info.inspect}")
end
if config_hash.include? :nameserver
@nameserver_port = config_hash[:nameserver].map {|ns| [ns, Port] }
end
if config_hash.include? :nameserver_port
@nameserver_port = config_hash[:nameserver_port].map {|ns, port| [ns, (port || Port)] }
end
@search = config_hash[:search] if config_hash.include? :search
@ndots = config_hash[:ndots] if config_hash.include? :ndots
if @nameserver_port.empty?
@nameserver_port << ['0.0.0.0', Port]
end
if @search
@search = @search.map {|arg| Label.split(arg) }
else
hostname = Socket.gethostname
if /\./ =~ hostname
@search = [Label.split($')]
else
@search = [[]]
end
end
if !@nameserver_port.kind_of?(Array) ||
@nameserver_port.any? {|ns_port|
!(Array === ns_port) ||
ns_port.length != 2
!(String === ns_port[0]) ||
!(Integer === ns_port[1])
}
raise ArgumentError.new("invalid nameserver config: #{@nameserver_port.inspect}")
end
if !@search.kind_of?(Array) ||
!@search.all? {|ls| ls.all? {|l| Label::Str === l } }
raise ArgumentError.new("invalid search config: #{@search.inspect}")
end
if !@ndots.kind_of?(Integer)
raise ArgumentError.new("invalid ndots config: #{@ndots.inspect}")
end
@initialized = true
end
}
self
end
def single?
lazy_initialize
if @nameserver_port.length == 1
return @nameserver_port[0]
else
return nil
end
end
def nameserver_port
@nameserver_port
end
def generate_candidates(name)
candidates = nil
name = Name.create(name)
if name.absolute?
candidates = [name]
else
if @ndots <= name.length - 1
candidates = [Name.new(name.to_a)]
else
candidates = []
end
candidates.concat(@search.map {|domain| Name.new(name.to_a + domain)})
fname = Name.create("#{name}.")
if !candidates.include?(fname)
candidates << fname
end
end
return candidates
end
InitialTimeout = 5
def generate_timeouts
ts = [InitialTimeout]
ts << ts[-1] * 2 / @nameserver_port.length
ts << ts[-1] * 2
ts << ts[-1] * 2
return ts
end
def resolv(name)
candidates = generate_candidates(name)
timeouts = @timeouts || generate_timeouts
begin
candidates.each {|candidate|
begin
timeouts.each {|tout|
@nameserver_port.each {|nameserver, port|
begin
yield candidate, tout, nameserver, port
rescue ResolvTimeout
end
}
}
raise ResolvError.new("DNS resolv timeout: #{name}")
rescue NXDomain
end
}
rescue ResolvError
end
end
##
# Indicates no such domain was found.
class NXDomain < ResolvError
end
##
# Indicates some other unhandled resolver error was encountered.
class OtherResolvError < ResolvError
end
end
module OpCode # :nodoc:
Query = 0
IQuery = 1
Status = 2
Notify = 4
Update = 5
end
module RCode # :nodoc:
NoError = 0
FormErr = 1
ServFail = 2
NXDomain = 3
NotImp = 4
Refused = 5
YXDomain = 6
YXRRSet = 7
NXRRSet = 8
NotAuth = 9
NotZone = 10
BADVERS = 16
BADSIG = 16
BADKEY = 17
BADTIME = 18
BADMODE = 19
BADNAME = 20
BADALG = 21
end
##
# Indicates that the DNS response was unable to be decoded.
class DecodeError < StandardError
end
##
# Indicates that the DNS request was unable to be encoded.
class EncodeError < StandardError
end
module Label # :nodoc:
def self.split(arg)
labels = []
arg.scan(/[^\.]+/) {labels << Str.new($&)}
return labels
end
class Str # :nodoc:
def initialize(string)
@string = string
@downcase = string.downcase
end
attr_reader :string, :downcase
def to_s
return @string
end
def inspect
return "#<#{self.class} #{self.to_s}>"
end
def ==(other)
return @downcase == other.downcase
end
def eql?(other)
return self == other
end
def hash
return @downcase.hash
end
end
end
##
# A representation of a DNS name.
class Name
##
# Creates a new DNS name from +arg+. +arg+ can be:
#
# Name:: returns +arg+.
# String:: Creates a new Name.
def self.create(arg)
case arg
when Name
return arg
when String
return Name.new(Label.split(arg), /\.\z/ =~ arg ? true : false)
else
raise ArgumentError.new("cannot interpret as DNS name: #{arg.inspect}")
end
end
def initialize(labels, absolute=true) # :nodoc:
@labels = labels
@absolute = absolute
end
def inspect # :nodoc:
"#<#{self.class}: #{self.to_s}#{@absolute ? '.' : ''}>"
end
##
# True if this name is absolute.
def absolute?
return @absolute
end
def ==(other) # :nodoc:
return false unless Name === other
return false unless @absolute == other.absolute?
return @labels == other.to_a
end
alias eql? == # :nodoc:
##
# Returns true if +other+ is a subdomain.
#
# Example:
#
# domain = Resolv::DNS::Name.create("y.z")
# p Resolv::DNS::Name.create("w.x.y.z").subdomain_of?(domain) #=> true
# p Resolv::DNS::Name.create("x.y.z").subdomain_of?(domain) #=> true
# p Resolv::DNS::Name.create("y.z").subdomain_of?(domain) #=> false
# p Resolv::DNS::Name.create("z").subdomain_of?(domain) #=> false
# p Resolv::DNS::Name.create("x.y.z.").subdomain_of?(domain) #=> false
# p Resolv::DNS::Name.create("w.z").subdomain_of?(domain) #=> false
#
def subdomain_of?(other)
raise ArgumentError, "not a domain name: #{other.inspect}" unless Name === other
return false if @absolute != other.absolute?
other_len = other.length
return false if @labels.length <= other_len
return @labels[-other_len, other_len] == other.to_a
end
def hash # :nodoc:
return @labels.hash ^ @absolute.hash
end
def to_a # :nodoc:
return @labels
end
def length # :nodoc:
return @labels.length
end
def [](i) # :nodoc:
return @labels[i]
end
##
# returns the domain name as a string.
#
# The domain name doesn't have a trailing dot even if the name object is
# absolute.
#
# Example:
#
# p Resolv::DNS::Name.create("x.y.z.").to_s #=> "x.y.z"
# p Resolv::DNS::Name.create("x.y.z").to_s #=> "x.y.z"
def to_s
return @labels.join('.')
end
end
class Message # :nodoc:
@@identifier = -1
def initialize(id = (@@identifier += 1) & 0xffff)
@id = id
@qr = 0
@opcode = 0
@aa = 0
@tc = 0
@rd = 0 # recursion desired
@ra = 0 # recursion available
@rcode = 0
@question = []
@answer = []
@authority = []
@additional = []
end
attr_accessor :id, :qr, :opcode, :aa, :tc, :rd, :ra, :rcode
attr_reader :question, :answer, :authority, :additional
def ==(other)
return @id == other.id &&
@qr == other.qr &&
@opcode == other.opcode &&
@aa == other.aa &&
@tc == other.tc &&
@rd == other.rd &&
@ra == other.ra &&
@rcode == other.rcode &&
@question == other.question &&
@answer == other.answer &&
@authority == other.authority &&
@additional == other.additional
end
def add_question(name, typeclass)
@question << [Name.create(name), typeclass]
end
def each_question
@question.each {|name, typeclass|
yield name, typeclass
}
end
def add_answer(name, ttl, data)
@answer << [Name.create(name), ttl, data]
end
def each_answer
@answer.each {|name, ttl, data|
yield name, ttl, data
}
end
def add_authority(name, ttl, data)
@authority << [Name.create(name), ttl, data]
end
def each_authority
@authority.each {|name, ttl, data|
yield name, ttl, data
}
end
def add_additional(name, ttl, data)
@additional << [Name.create(name), ttl, data]
end
def each_additional
@additional.each {|name, ttl, data|
yield name, ttl, data
}
end
def each_resource
each_answer {|name, ttl, data| yield name, ttl, data}
each_authority {|name, ttl, data| yield name, ttl, data}
each_additional {|name, ttl, data| yield name, ttl, data}
end
def encode
return MessageEncoder.new {|msg|
msg.put_pack('nnnnnn',
@id,
(@qr & 1) << 15 |
(@opcode & 15) << 11 |
(@aa & 1) << 10 |
(@tc & 1) << 9 |
(@rd & 1) << 8 |
(@ra & 1) << 7 |
(@rcode & 15),
@question.length,
@answer.length,
@authority.length,
@additional.length)
@question.each {|q|
name, typeclass = q
msg.put_name(name)
msg.put_pack('nn', typeclass::TypeValue, typeclass::ClassValue)
}
[@answer, @authority, @additional].each {|rr|
rr.each {|r|
name, ttl, data = r
msg.put_name(name)
msg.put_pack('nnN', data.class::TypeValue, data.class::ClassValue, ttl)
msg.put_length16 {data.encode_rdata(msg)}
}
}
}.to_s
end
class MessageEncoder # :nodoc:
def initialize
@data = ''
@names = {}
yield self
end
def to_s
return @data
end
def put_bytes(d)
@data << d
end
def put_pack(template, *d)
@data << d.pack(template)
end
def put_length16
length_index = @data.length
@data << "\0\0"
data_start = @data.length
yield
data_end = @data.length
@data[length_index, 2] = [data_end - data_start].pack("n")
end
def put_string(d)
self.put_pack("C", d.length)
@data << d
end
def put_string_list(ds)
ds.each {|d|
self.put_string(d)
}
end
def put_name(d)
put_labels(d.to_a)
end
def put_labels(d)
d.each_index {|i|
domain = d[i..-1]
if idx = @names[domain]
self.put_pack("n", 0xc000 | idx)
return
else
@names[domain] = @data.length
self.put_label(d[i])
end
}
@data << "\0"
end
def put_label(d)
self.put_string(d.to_s)
end
end
def Message.decode(m)
o = Message.new(0)
MessageDecoder.new(m) {|msg|
id, flag, qdcount, ancount, nscount, arcount =
msg.get_unpack('nnnnnn')
o.id = id
o.qr = (flag >> 15) & 1
o.opcode = (flag >> 11) & 15
o.aa = (flag >> 10) & 1
o.tc = (flag >> 9) & 1
o.rd = (flag >> 8) & 1
o.ra = (flag >> 7) & 1
o.rcode = flag & 15
(1..qdcount).each {
name, typeclass = msg.get_question
o.add_question(name, typeclass)
}
(1..ancount).each {
name, ttl, data = msg.get_rr
o.add_answer(name, ttl, data)
}
(1..nscount).each {
name, ttl, data = msg.get_rr
o.add_authority(name, ttl, data)
}
(1..arcount).each {
name, ttl, data = msg.get_rr
o.add_additional(name, ttl, data)
}
}
return o
end
class MessageDecoder # :nodoc:
def initialize(data)
@data = data
@index = 0
@limit = data.length
yield self
end
def inspect
"\#<#{self.class}: #{@data[0, @index].inspect} #{@data[@index..-1].inspect}>"
end
def get_length16
len, = self.get_unpack('n')
save_limit = @limit
@limit = @index + len
d = yield(len)
if @index < @limit
raise DecodeError.new("junk exists")
elsif @limit < @index
raise DecodeError.new("limit exceeded")
end
@limit = save_limit
return d
end
def get_bytes(len = @limit - @index)
raise DecodeError.new("limit exceeded") if @limit < @index + len
d = @data[@index, len]
@index += len
return d
end
def get_unpack(template)
len = 0
template.each_byte {|byte|
byte = "%c" % byte
case byte
when ?c, ?C
len += 1
when ?n
len += 2
when ?N
len += 4
else
raise StandardError.new("unsupported template: '#{byte.chr}' in '#{template}'")
end
}
raise DecodeError.new("limit exceeded") if @limit < @index + len
arr = @data.unpack("@#{@index}#{template}")
@index += len
return arr
end
def get_string
raise DecodeError.new("limit exceeded") if @limit <= @index
len = @data[@index].ord
raise DecodeError.new("limit exceeded") if @limit < @index + 1 + len
d = @data[@index + 1, len]
@index += 1 + len
return d
end
def get_string_list
strings = []
while @index < @limit
strings << self.get_string
end
strings
end
def get_name
return Name.new(self.get_labels)
end
def get_labels(limit=nil)
limit = @index if !limit || @index < limit
d = []
while true
raise DecodeError.new("limit exceeded") if @limit <= @index
case @data[@index].ord
when 0
@index += 1
return d
when 192..255
idx = self.get_unpack('n')[0] & 0x3fff
if limit <= idx
raise DecodeError.new("non-backward name pointer")
end
save_index = @index
@index = idx
d += self.get_labels(limit)
@index = save_index
return d
else
d << self.get_label
end
end
return d
end
def get_label
return Label::Str.new(self.get_string)
end
def get_question
name = self.get_name
type, klass = self.get_unpack("nn")
return name, Resource.get_class(type, klass)
end
def get_rr
name = self.get_name
type, klass, ttl = self.get_unpack('nnN')
typeclass = Resource.get_class(type, klass)
res = self.get_length16 { typeclass.decode_rdata self }
res.instance_variable_set :@ttl, ttl
return name, ttl, res
end
end
end
##
# A DNS query abstract class.
class Query
def encode_rdata(msg) # :nodoc:
raise EncodeError.new("#{self.class} is query.")
end
def self.decode_rdata(msg) # :nodoc:
raise DecodeError.new("#{self.class} is query.")
end
end
##
# A DNS resource abstract class.
class Resource < Query
##
# Remaining Time To Live for this Resource.
attr_reader :ttl
ClassHash = {} # :nodoc:
def encode_rdata(msg) # :nodoc:
raise NotImplementedError.new
end
def self.decode_rdata(msg) # :nodoc:
raise NotImplementedError.new
end
def ==(other) # :nodoc:
return false unless self.class == other.class
s_ivars = self.instance_variables
s_ivars.sort!
s_ivars.delete :@ttl
o_ivars = other.instance_variables
o_ivars.sort!
o_ivars.delete :@ttl
return s_ivars == o_ivars &&
s_ivars.collect {|name| self.instance_variable_get name} ==
o_ivars.collect {|name| other.instance_variable_get name}
end
def eql?(other) # :nodoc:
return self == other
end
def hash # :nodoc:
h = 0
vars = self.instance_variables
vars.delete :@ttl
vars.each {|name|
h ^= self.instance_variable_get(name).hash
}
return h
end
def self.get_class(type_value, class_value) # :nodoc:
return ClassHash[[type_value, class_value]] ||
Generic.create(type_value, class_value)
end
##
# A generic resource abstract class.
class Generic < Resource
##
# Creates a new generic resource.
def initialize(data)
@data = data
end
##
# Data for this generic resource.
attr_reader :data
def encode_rdata(msg) # :nodoc:
msg.put_bytes(data)
end
def self.decode_rdata(msg) # :nodoc:
return self.new(msg.get_bytes)
end
def self.create(type_value, class_value) # :nodoc:
c = Class.new(Generic)
c.const_set(:TypeValue, type_value)
c.const_set(:ClassValue, class_value)
Generic.const_set("Type#{type_value}_Class#{class_value}", c)
ClassHash[[type_value, class_value]] = c
return c
end
end
##
# Domain Name resource abstract class.
class DomainName < Resource
##
# Creates a new DomainName from +name+.
def initialize(name)
@name = name
end
##
# The name of this DomainName.
attr_reader :name
def encode_rdata(msg) # :nodoc:
msg.put_name(@name)
end
def self.decode_rdata(msg) # :nodoc:
return self.new(msg.get_name)
end
end
# Standard (class generic) RRs
ClassValue = nil # :nodoc:
##
# An authoritative name server.
class NS < DomainName
TypeValue = 2 # :nodoc:
end
##
# The canonical name for an alias.
class CNAME < DomainName
TypeValue = 5 # :nodoc:
end
##
# Start Of Authority resource.
class SOA < Resource
TypeValue = 6 # :nodoc:
##
# Creates a new SOA record. See the attr documentation for the
# details of each argument.
def initialize(mname, rname, serial, refresh, retry_, expire, minimum)
@mname = mname
@rname = rname
@serial = serial
@refresh = refresh
@retry = retry_
@expire = expire
@minimum = minimum
end
##
# Name of the host where the master zone file for this zone resides.
attr_reader :mname
##
# The person responsible for this domain name.
attr_reader :rname
##
# The version number of the zone file.
attr_reader :serial
##
# How often, in seconds, a secondary name server is to check for
# updates from the primary name server.
attr_reader :refresh
##
# How often, in seconds, a secondary name server is to retry after a
# failure to check for a refresh.
attr_reader :retry
##
# Time in seconds that a secondary name server is to use the data
# before refreshing from the primary name server.
attr_reader :expire
##
# The minimum number of seconds to be used for TTL values in RRs.
attr_reader :minimum
def encode_rdata(msg) # :nodoc:
msg.put_name(@mname)
msg.put_name(@rname)
msg.put_pack('NNNNN', @serial, @refresh, @retry, @expire, @minimum)
end
def self.decode_rdata(msg) # :nodoc:
mname = msg.get_name
rname = msg.get_name
serial, refresh, retry_, expire, minimum = msg.get_unpack('NNNNN')
return self.new(
mname, rname, serial, refresh, retry_, expire, minimum)
end
end
##
# A Pointer to another DNS name.
class PTR < DomainName
TypeValue = 12 # :nodoc:
end
##
# Host Information resource.
class HINFO < Resource
TypeValue = 13 # :nodoc:
##
# Creates a new HINFO running +os+ on +cpu+.
def initialize(cpu, os)
@cpu = cpu
@os = os
end
##
# CPU architecture for this resource.
attr_reader :cpu
##
# Operating system for this resource.
attr_reader :os
def encode_rdata(msg) # :nodoc:
msg.put_string(@cpu)
msg.put_string(@os)
end
def self.decode_rdata(msg) # :nodoc:
cpu = msg.get_string
os = msg.get_string
return self.new(cpu, os)
end
end
##
# Mailing list or mailbox information.
class MINFO < Resource
TypeValue = 14 # :nodoc:
def initialize(rmailbx, emailbx)
@rmailbx = rmailbx
@emailbx = emailbx
end
##
# Domain name responsible for this mail list or mailbox.
attr_reader :rmailbx
##
# Mailbox to use for error messages related to the mail list or mailbox.
attr_reader :emailbx
def encode_rdata(msg) # :nodoc:
msg.put_name(@rmailbx)
msg.put_name(@emailbx)
end
def self.decode_rdata(msg) # :nodoc:
rmailbx = msg.get_string
emailbx = msg.get_string
return self.new(rmailbx, emailbx)
end
end
##
# Mail Exchanger resource.
class MX < Resource
TypeValue= 15 # :nodoc:
##
# Creates a new MX record with +preference+, accepting mail at
# +exchange+.
def initialize(preference, exchange)
@preference = preference
@exchange = exchange
end
##
# The preference for this MX.
attr_reader :preference
##
# The host of this MX.
attr_reader :exchange
def encode_rdata(msg) # :nodoc:
msg.put_pack('n', @preference)
msg.put_name(@exchange)
end
def self.decode_rdata(msg) # :nodoc:
preference, = msg.get_unpack('n')
exchange = msg.get_name
return self.new(preference, exchange)
end
end
##
# Unstructured text resource.
class TXT < Resource
TypeValue = 16 # :nodoc:
def initialize(first_string, *rest_strings)
@strings = [first_string, *rest_strings]
end
##
# Returns an Array of Strings for this TXT record.
attr_reader :strings
##
# Returns the concatenated string from +strings+.
def data
@strings.join("")
end
def encode_rdata(msg) # :nodoc:
msg.put_string_list(@strings)
end
def self.decode_rdata(msg) # :nodoc:
strings = msg.get_string_list
return self.new(*strings)
end
end
##
# A Query type requesting any RR.
class ANY < Query
TypeValue = 255 # :nodoc:
end
ClassInsensitiveTypes = [ # :nodoc:
NS, CNAME, SOA, PTR, HINFO, MINFO, MX, TXT, ANY
]
##
# module IN contains ARPA Internet specific RRs.
module IN
ClassValue = 1 # :nodoc:
ClassInsensitiveTypes.each {|s|
c = Class.new(s)
c.const_set(:TypeValue, s::TypeValue)
c.const_set(:ClassValue, ClassValue)
ClassHash[[s::TypeValue, ClassValue]] = c
self.const_set(s.name.sub(/.*::/, ''), c)
}
##
# IPv4 Address resource
class A < Resource
TypeValue = 1
ClassValue = IN::ClassValue
ClassHash[[TypeValue, ClassValue]] = self # :nodoc:
##
# Creates a new A for +address+.
def initialize(address)
@address = IPv4.create(address)
end
##
# The Resolv::IPv4 address for this A.
attr_reader :address
def encode_rdata(msg) # :nodoc:
msg.put_bytes(@address.address)
end
def self.decode_rdata(msg) # :nodoc:
return self.new(IPv4.new(msg.get_bytes(4)))
end
end
##
# Well Known Service resource.
class WKS < Resource
TypeValue = 11
ClassValue = IN::ClassValue
ClassHash[[TypeValue, ClassValue]] = self # :nodoc:
def initialize(address, protocol, bitmap)
@address = IPv4.create(address)
@protocol = protocol
@bitmap = bitmap
end
##
# The host these services run on.
attr_reader :address
##
# IP protocol number for these services.
attr_reader :protocol
##
# A bit map of enabled services on this host.
#
# If protocol is 6 (TCP) then the 26th bit corresponds to the SMTP
# service (port 25). If this bit is set, then an SMTP server should
# be listening on TCP port 25; if zero, SMTP service is not
# supported.
attr_reader :bitmap
def encode_rdata(msg) # :nodoc:
msg.put_bytes(@address.address)
msg.put_pack("n", @protocol)
msg.put_bytes(@bitmap)
end
def self.decode_rdata(msg) # :nodoc:
address = IPv4.new(msg.get_bytes(4))
protocol, = msg.get_unpack("n")
bitmap = msg.get_bytes
return self.new(address, protocol, bitmap)
end
end
##
# An IPv6 address record.
class AAAA < Resource
TypeValue = 28
ClassValue = IN::ClassValue
ClassHash[[TypeValue, ClassValue]] = self # :nodoc:
##
# Creates a new AAAA for +address+.
def initialize(address)
@address = IPv6.create(address)
end
##
# The Resolv::IPv6 address for this AAAA.
attr_reader :address
def encode_rdata(msg) # :nodoc:
msg.put_bytes(@address.address)
end
def self.decode_rdata(msg) # :nodoc:
return self.new(IPv6.new(msg.get_bytes(16)))
end
end
##
# SRV resource record defined in RFC 2782
#
# These records identify the hostname and port that a service is
# available at.
class SRV < Resource
TypeValue = 33
ClassValue = IN::ClassValue
ClassHash[[TypeValue, ClassValue]] = self # :nodoc:
# Create a SRV resource record.
#
# See the documentation for #priority, #weight, #port and #target
# for +priority+, +weight+, +port and +target+ respectively.
def initialize(priority, weight, port, target)
@priority = priority.to_int
@weight = weight.to_int
@port = port.to_int
@target = Name.create(target)
end
# The priority of this target host.
#
# A client MUST attempt to contact the target host with the
# lowest-numbered priority it can reach; target hosts with the same
# priority SHOULD be tried in an order defined by the weight field.
# The range is 0-65535. Note that it is not widely implemented and
# should be set to zero.
attr_reader :priority
# A server selection mechanism.
#
# The weight field specifies a relative weight for entries with the
# same priority. Larger weights SHOULD be given a proportionately
# higher probability of being selected. The range of this number is
# 0-65535. Domain administrators SHOULD use Weight 0 when there
# isn't any server selection to do, to make the RR easier to read
# for humans (less noisy). Note that it is not widely implemented
# and should be set to zero.
attr_reader :weight
# The port on this target host of this service.
#
# The range is 0-65535.
attr_reader :port
# The domain name of the target host.
#
# A target of "." means that the service is decidedly not available
# at this domain.
attr_reader :target
def encode_rdata(msg) # :nodoc:
msg.put_pack("n", @priority)
msg.put_pack("n", @weight)
msg.put_pack("n", @port)
msg.put_name(@target)
end
def self.decode_rdata(msg) # :nodoc:
priority, = msg.get_unpack("n")
weight, = msg.get_unpack("n")
port, = msg.get_unpack("n")
target = msg.get_name
return self.new(priority, weight, port, target)
end
end
end
end
end
##
# A Resolv::DNS IPv4 address.
class IPv4
##
# Regular expression IPv4 addresses must match.
Regex256 = /0
|1(?:[0-9][0-9]?)?
|2(?:[0-4][0-9]?|5[0-5]?|[6-9])?
|[3-9][0-9]?/x
Regex = /\A(#{Regex256})\.(#{Regex256})\.(#{Regex256})\.(#{Regex256})\z/
def self.create(arg)
case arg
when IPv4
return arg
when Regex
if (0..255) === (a = $1.to_i) &&
(0..255) === (b = $2.to_i) &&
(0..255) === (c = $3.to_i) &&
(0..255) === (d = $4.to_i)
return self.new([a, b, c, d].pack("CCCC"))
else
raise ArgumentError.new("IPv4 address with invalid value: " + arg)
end
else
raise ArgumentError.new("cannot interpret as IPv4 address: #{arg.inspect}")
end
end
def initialize(address) # :nodoc:
unless address.kind_of?(String)
raise ArgumentError, 'IPv4 address must be a string'
end
unless address.length == 4
raise ArgumentError, "IPv4 address expects 4 bytes but #{address.length} bytes"
end
@address = address
end
##
# A String representation of this IPv4 address.
##
# The raw IPv4 address as a String.
attr_reader :address
def to_s # :nodoc:
return sprintf("%d.%d.%d.%d", *@address.unpack("CCCC"))
end
def inspect # :nodoc:
return "#<#{self.class} #{self.to_s}>"
end
##
# Turns this IPv4 address into a Resolv::DNS::Name.
def to_name
return DNS::Name.create(
'%d.%d.%d.%d.in-addr.arpa.' % @address.unpack('CCCC').reverse)
end
def ==(other) # :nodoc:
return @address == other.address
end
def eql?(other) # :nodoc:
return self == other
end
def hash # :nodoc:
return @address.hash
end
end
##
# A Resolv::DNS IPv6 address.
class IPv6
##
# IPv6 address format a:b:c:d:e:f:g:h
Regex_8Hex = /\A
(?:[0-9A-Fa-f]{1,4}:){7}
[0-9A-Fa-f]{1,4}
\z/x
##
# Compressed IPv6 address format a::b
Regex_CompressedHex = /\A
((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?) ::
((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)
\z/x
##
# IPv4 mapped IPv6 address format a:b:c:d:e:f:w.x.y.z
Regex_6Hex4Dec = /\A
((?:[0-9A-Fa-f]{1,4}:){6,6})
(\d+)\.(\d+)\.(\d+)\.(\d+)
\z/x
##
# Compressed IPv4 mapped IPv6 address format a::b:w.x.y.z
Regex_CompressedHex4Dec = /\A
((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?) ::
((?:[0-9A-Fa-f]{1,4}:)*)
(\d+)\.(\d+)\.(\d+)\.(\d+)
\z/x
##
# A composite IPv6 address Regexp.
Regex = /
(?:#{Regex_8Hex}) |
(?:#{Regex_CompressedHex}) |
(?:#{Regex_6Hex4Dec}) |
(?:#{Regex_CompressedHex4Dec})/x
##
# Creates a new IPv6 address from +arg+ which may be:
#
# IPv6:: returns +arg+.
# String:: +arg+ must match one of the IPv6::Regex* constants
def self.create(arg)
case arg
when IPv6
return arg
when String
address = ''
if Regex_8Hex =~ arg
arg.scan(/[0-9A-Fa-f]+/) {|hex| address << [hex.hex].pack('n')}
elsif Regex_CompressedHex =~ arg
prefix = $1
suffix = $2
a1 = ''
a2 = ''
prefix.scan(/[0-9A-Fa-f]+/) {|hex| a1 << [hex.hex].pack('n')}
suffix.scan(/[0-9A-Fa-f]+/) {|hex| a2 << [hex.hex].pack('n')}
omitlen = 16 - a1.length - a2.length
address << a1 << "\0" * omitlen << a2
elsif Regex_6Hex4Dec =~ arg
prefix, a, b, c, d = $1, $2.to_i, $3.to_i, $4.to_i, $5.to_i
if (0..255) === a && (0..255) === b && (0..255) === c && (0..255) === d
prefix.scan(/[0-9A-Fa-f]+/) {|hex| address << [hex.hex].pack('n')}
address << [a, b, c, d].pack('CCCC')
else
raise ArgumentError.new("not numeric IPv6 address: " + arg)
end
elsif Regex_CompressedHex4Dec =~ arg
prefix, suffix, a, b, c, d = $1, $2, $3.to_i, $4.to_i, $5.to_i, $6.to_i
if (0..255) === a && (0..255) === b && (0..255) === c && (0..255) === d
a1 = ''
a2 = ''
prefix.scan(/[0-9A-Fa-f]+/) {|hex| a1 << [hex.hex].pack('n')}
suffix.scan(/[0-9A-Fa-f]+/) {|hex| a2 << [hex.hex].pack('n')}
omitlen = 12 - a1.length - a2.length
address << a1 << "\0" * omitlen << a2 << [a, b, c, d].pack('CCCC')
else
raise ArgumentError.new("not numeric IPv6 address: " + arg)
end
else
raise ArgumentError.new("not numeric IPv6 address: " + arg)
end
return IPv6.new(address)
else
raise ArgumentError.new("cannot interpret as IPv6 address: #{arg.inspect}")
end
end
def initialize(address) # :nodoc:
unless address.kind_of?(String) && address.length == 16
raise ArgumentError.new('IPv6 address must be 16 bytes')
end
@address = address
end
##
# The raw IPv6 address as a String.
attr_reader :address
def to_s # :nodoc:
address = sprintf("%X:%X:%X:%X:%X:%X:%X:%X", *@address.unpack("nnnnnnnn"))
unless address.sub!(/(^|:)0(:0)+(:|$)/, '::')
address.sub!(/(^|:)0(:|$)/, '::')
end
return address
end
def inspect # :nodoc:
return "#<#{self.class} #{self.to_s}>"
end
##
# Turns this IPv6 address into a Resolv::DNS::Name.
#--
# ip6.arpa should be searched too. [RFC3152]
def to_name
return DNS::Name.new(
@address.unpack("H32")[0].split(//).reverse + ['ip6', 'arpa'])
end
def ==(other) # :nodoc:
return @address == other.address
end
def eql?(other) # :nodoc:
return self == other
end
def hash # :nodoc:
return @address.hash
end
end
##
# Default resolver to use for Resolv class methods.
DefaultResolver = self.new
##
# Address Regexp to use for matching IP addresses.
AddressRegex = /(?:#{IPv4::Regex})|(?:#{IPv6::Regex})/
end