ruby · k0kubun · Jul 8, 2025 · Jul 8, 2025
@@ -4,13 +4,8 @@
 
 =end
 
-require 'win32/registry'
-
 module Win32
   module Resolv
-    API = Registry::API
-    Error = Registry::Error
-
     def self.get_hosts_path
       path = get_hosts_dir
       path = File.expand_path('hosts', path)
@@ -47,89 +42,103 @@ module Win32
 # Windows NT
 #====================================================================
   module Resolv
-    module SZ
-      refine Registry do
-        # ad hoc workaround for broken registry
-        def read_s(key)
-          type, str = read(key)
-          unless type == Registry::REG_SZ
-            warn "Broken registry, #{name}\\#{key} was #{Registry.type2name(type)}, ignored"
-            return String.new
+    begin
+      require 'win32/registry'
+      module SZ
+        refine Registry do
+          # ad hoc workaround for broken registry
+          def read_s(key)
+            type, str = read(key)
+            unless type == Registry::REG_SZ
+              warn "Broken registry, #{name}\\#{key} was #{Registry.type2name(type)}, ignored"
+              return String.new
+            end
+            str
           end
-          str
         end
       end
+      using SZ
+    rescue LoadError
+      require "open3"
     end
-    using SZ
 
     TCPIP_NT = 'SYSTEM\CurrentControlSet\Services\Tcpip\Parameters'
 
     class << self
       private
       def get_hosts_dir
-        Registry::HKEY_LOCAL_MACHINE.open(TCPIP_NT) do |reg|
-          reg.read_s_expand('DataBasePath')
-        end
+        get_item_property(TCPIP_NT, 'DataBasePath', expand: true)
       end
 
       def get_info
         search = nil
         nameserver = get_dns_server_list
-        Registry::HKEY_LOCAL_MACHINE.open(TCPIP_NT) do |reg|
-          begin
-            slist = reg.read_s('SearchList')
-            search = slist.split(/,\s*/) unless slist.empty?
-          rescue Registry::Error
-          end
 
-          if add_search = search.nil?
-            search = []
-            begin
-              nvdom = reg.read_s('NV Domain')
-              unless nvdom.empty?
-                @search = [ nvdom ]
-                if reg.read_i('UseDomainNameDevolution') != 0
-                  if /^\w+\./ =~ nvdom
-                    devo = $'
-                  end
-                end
+        slist = get_item_property(TCPIP_NT, 'SearchList')
+        search = slist.split(/,\s*/) unless slist.empty?
+
+        if add_search = search.nil?
+          search = []
+          nvdom = get_item_property(TCPIP_NT, 'NV Domain')
+
+          unless nvdom.empty?
+            @search = [ nvdom ]
+            udmnd = get_item_property(TCPIP_NT, 'UseDomainNameDevolution').to_i
+            if udmnd != 0
+              if /^\w+\./ =~ nvdom
+                devo = $'
               end
-            rescue Registry::Error
             end
           end
+        end
 
-          reg.open('Interfaces') do |h|
-            h.each_key do |iface, |
-              h.open(iface) do |regif|
-                next unless ns = %w[NameServer DhcpNameServer].find do |key|
-                  begin
-                    ns = regif.read_s(key)
-                  rescue Registry::Error
-                  else
-                    break ns.split(/[,\s]\s*/) unless ns.empty?
-                  end
-                end
-                next if (nameserver & ns).empty?
-
-                if add_search
-                  begin
-                    [ 'Domain', 'DhcpDomain' ].each do |key|
-                      dom = regif.read_s(key)
-                      unless dom.empty?
-                        search.concat(dom.split(/,\s*/))
-                        break
-                      end
-                    end
-                  rescue Registry::Error
-                  end
+        ifs = if defined?(Win32::Registry)
+                Registry::HKEY_LOCAL_MACHINE.open(TCPIP_NT + '\Interfaces') do |reg|
+                  reg.keys
+                rescue Registry::Error
+                  []
                 end
+              else
+                cmd = "Get-ChildItem 'HKLM:\\#{TCPIP_NT}\\Interfaces' | ForEach-Object { $_.PSChildName }"
+                output, _ = Open3.capture2('powershell', '-Command', cmd)
+                output.split(/\n+/)
+              end
+
+        ifs.each do |iface|
+          next unless ns = %w[NameServer DhcpNameServer].find do |key|
+            ns = get_item_property(TCPIP_NT + '\Interfaces' + "\\#{iface}", key)
+            break ns.split(/[,\s]\s*/) unless ns.empty?
+          end
+
+          next if (nameserver & ns).empty?
+
+          if add_search
+            [ 'Domain', 'DhcpDomain' ].each do |key|
+              dom = get_item_property(TCPIP_NT + '\Interfaces' + "\\#{iface}", key)
+              unless dom.empty?
+                search.concat(dom.split(/,\s*/))
+                break
               end
             end
           end
-          search << devo if add_search and devo
         end
+        search << devo if add_search and devo
         [ search.uniq, nameserver.uniq ]
       end
+
+      def get_item_property(path, name, expand: false)
+        if defined?(Win32::Registry)
+          Registry::HKEY_LOCAL_MACHINE.open(path) do |reg|
+            expand ? reg.read_s_expand(name) : reg.read_s(name)
+          rescue Registry::Error
+            ""
+          end
+        else
+          cmd = "Get-ItemProperty -Path 'HKLM:\\#{path}' -Name '#{name}' -ErrorAction SilentlyContinue | Select-Object -ExpandProperty '#{name}'"
+          output, _ = Open3.capture2('powershell', '-Command', cmd)
+          output.strip
+        end
+      end
     end
   end
 end
@@ -13,6 +13,8 @@ w32error_make_error(DWORD e)
     return rb_class_new_instance(1, &code, rb_path2class("Win32::Resolv::Error"));
 }
 
+NORETURN(static void w32error_raise(DWORD e));
+
 static void
 w32error_raise(DWORD e)
 {

@@ -33,7 +33,7 @@
 
 class Resolv
 
-  VERSION = "0.6.0"
+  VERSION = "0.6.2"
 
   ##
   # Looks up the first IP address for +name+.
@@ -173,13 +173,16 @@ class ResolvError < StandardError; end
 
   class ResolvTimeout < Timeout::Error; end
 
+  WINDOWS = /mswin|cygwin|mingw|bccwin/ =~ RUBY_PLATFORM || ::RbConfig::CONFIG['host_os'] =~ /mswin/
+  private_constant :WINDOWS
+
   ##
   # Resolv::Hosts is a hostname resolver that uses the system hosts file.
 
   class Hosts
-    if /mswin|mingw|cygwin/ =~ RUBY_PLATFORM and
+    if WINDOWS
       begin
-        require 'win32/resolv'
+        require 'win32/resolv' unless defined?(Win32::Resolv)
         DefaultFileName = Win32::Resolv.get_hosts_path || IO::NULL
       rescue LoadError
       end
@@ -659,8 +662,20 @@ def self.free_request_id(host, port, id) # :nodoc:
       }
     end
 
-    def self.bind_random_port(udpsock, bind_host="0.0.0.0") # :nodoc:
-      begin
+    case RUBY_PLATFORM
+    when *[
+      # https://www.rfc-editor.org/rfc/rfc6056.txt
+      # Appendix A. Survey of the Algorithms in Use by Some Popular Implementations
+      /freebsd/, /linux/, /netbsd/, /openbsd/, /solaris/,
+      /darwin/, # the same as FreeBSD
+    ] then
+      def self.bind_random_port(udpsock, bind_host="0.0.0.0") # :nodoc:
+        udpsock.bind(bind_host, 0)
+      end
+    else
+      # Sequential port assignment
+      def self.bind_random_port(udpsock, bind_host="0.0.0.0") # :nodoc:
+        # Ephemeral port number range recommended by RFC 6056
         port = random(1024..65535)
         udpsock.bind(bind_host, port)
       rescue Errno::EADDRINUSE, # POSIX
@@ -983,13 +998,13 @@ def Config.parse_resolv_conf(filename)
             next unless keyword
             case keyword
             when 'nameserver'
-              nameserver.concat(args)
+              nameserver.concat(args.each(&:freeze))
             when 'domain'
               next if args.empty?
-              search = [args[0]]
+              search = [args[0].freeze]
             when 'search'
               next if args.empty?
-              search = args
+              search = args.each(&:freeze)
             when 'options'
               args.each {|arg|
                 case arg
@@ -1000,22 +1015,22 @@ def Config.parse_resolv_conf(filename)
             end
           }
         }
-        return { :nameserver => nameserver, :search => search, :ndots => ndots }
+        return { :nameserver => nameserver.freeze, :search => search.freeze, :ndots => ndots.freeze }.freeze
       end
 
       def Config.default_config_hash(filename="/etc/resolv.conf")
         if File.exist? filename
-          config_hash = Config.parse_resolv_conf(filename)
+          Config.parse_resolv_conf(filename)
+        elsif WINDOWS
+          require 'win32/resolv' unless defined?(Win32::Resolv)
+          search, nameserver = Win32::Resolv.get_resolv_info
+          config_hash = {}
+          config_hash[:nameserver] = nameserver if nameserver
+          config_hash[:search] = [search].flatten if search
+          config_hash
         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
@@ -1664,6 +1679,7 @@ def get_labels
           prev_index = @index
           save_index = nil
           d = []
+          size = -1
           while true
             raise DecodeError.new("limit exceeded") if @limit <= @index
             case @data.getbyte(@index)
@@ -1684,7 +1700,10 @@ def get_labels
               end
               @index = idx
             else
-              d << self.get_label
+              l = self.get_label
+              d << l
+              size += 1 + l.string.bytesize
+              raise DecodeError.new("name label data exceed 255 octets") if size > 255
             end
           end
         end
@@ -2110,7 +2129,14 @@ class Resource < Query
 
       attr_reader :ttl
 
-      ClassHash = {} # :nodoc:
+      ClassHash = Module.new do
+        module_function
+
+        def []=(type_class_value, klass)
+          type_value, class_value = type_class_value
+          Resource.const_set(:"Type#{type_value}_Class#{class_value}", klass)
+        end
+      end
 
       def encode_rdata(msg) # :nodoc:
         raise NotImplementedError.new
@@ -2148,7 +2174,9 @@ def hash # :nodoc:
       end
 
       def self.get_class(type_value, class_value) # :nodoc:
-        return ClassHash[[type_value, class_value]] ||
+        cache = :"Type#{type_value}_Class#{class_value}"
+
+        return (const_defined?(cache) && const_get(cache)) ||
                Generic.create(type_value, class_value)
       end
 
@@ -2577,7 +2605,7 @@ def initialize(flags, tag, value)
         end
 
         ##
-        # Flags for this proprty:
+        # Flags for this property:
         # - Bit 0 : 0 = not critical, 1 = critical
 
         attr_reader :flags

@@ -627,6 +627,13 @@ def test_too_big_label_address
     assert_operator(2**14, :<, m.to_s.length)
   end
 
+  def test_too_long_address
+    too_long_address_message = [0, 0, 1, 0, 0, 0].pack("n*") + "\x01x" * 129 + [0, 0, 0].pack("cnn")
+    assert_raise_with_message(Resolv::DNS::DecodeError, /name label data exceed 255 octets/) do
+      Resolv::DNS::Message.decode too_long_address_message
+    end
+  end
+
   def assert_no_fd_leak
     socket = assert_throw(self) do |tag|
       Resolv::DNS.stub(:bind_random_port, ->(s, *) {throw(tag, s)}) do