wip: Reline behind a feature flag

lib/metasploit/framework/command/console.rb

@@ -92,7 +92,6 @@ def driver_options
       driver_options['ModulePath'] = options.modules.path
       driver_options['Plugins'] = options.console.plugins
       driver_options['Readline'] = options.console.readline
-      driver_options['RealReadline'] = options.console.real_readline
       driver_options['Resource'] = options.console.resources
       driver_options['XCommands'] = options.console.commands
 

lib/metasploit/framework/parsed_options/console.rb

@@ -16,7 +16,6 @@ def options
         options.console.plugins = []
         options.console.quiet = false
         options.console.readline = true
-        options.console.real_readline = false
         options.console.resources = []
         options.console.subcommand = :run
       }
@@ -54,7 +53,11 @@ def option_parser
         end
 
         option_parser.on('-L', '--real-readline', 'Use the system Readline library instead of RbReadline') do
-          options.console.real_readline = true
+          message = "The RealReadline option has been marked as deprecated, and is currently a noop.\n"
+          message << "Metasploit Framework now uses Reline exclusively as the input handling library.\n"
+          message << "If you require this functionality, please use the following link to tell us:\n"
+          message << '  https://github.com/rapid7/metasploit-framework/issues/19399'
+          warn message
         end
 
         option_parser.on('-o', '--output FILE', 'Output to the specified file') do |file|

lib/metasploit/framework/parsed_options/remote_db.rb

@@ -13,7 +13,6 @@ def options
         options.console.local_output = nil
         options.console.plugins = []
         options.console.quiet = false
-        options.console.real_readline = false
         options.console.resources = []
         options.console.subcommand = :run
       }

lib/msf/core/feature_manager.rb

@@ -28,6 +28,7 @@ class FeatureManager
     MSSQL_SESSION_TYPE = 'mssql_session_type'
     LDAP_SESSION_TYPE = 'ldap_session_type'
     SHOW_SUCCESSFUL_LOGINS = 'show_successful_logins'
+    USE_RELINE = 'use_reline'
 
     DEFAULTS = [
       {
@@ -124,6 +125,13 @@ class FeatureManager
         requires_restart: false,
         default_value: true,
         developer_notes: 'Enabled in Metasploit 6.4.x'
+      }.freeze,
+      {
+        name: USE_RELINE,
+        description: 'When enabled, the new Reline library will be used instead of the legacy Readline library for input/output. New UI sessions will be using Reline, but sessions that existed before this feature has been set will continue to be Readline-based.',
+        requires_restart: false,
+        default_value: false,
+        developer_notes: 'To be enabled by default after sufficient testing and Reline fixes the issues raised here: https://github.com/ruby/reline/issues/created_by/sjanusz-r7'
       }.freeze
     ].freeze
 

lib/msf/ui/console/command_dispatcher/core.rb

@@ -760,7 +760,8 @@ def cmd_features_tabs(_str, words)
   end
 
   def cmd_history(*args)
-    length = Readline::HISTORY.length
+    history = Msf::Ui::Console::Driver.input_lib::HISTORY
+    length = history.length
 
     if length < @history_limit
       limit = length
@@ -780,10 +781,12 @@ def cmd_history(*args)
           limit = val.to_i
         end
       when '-c'
-        if Readline::HISTORY.respond_to?(:clear)
-          Readline::HISTORY.clear
-        elsif defined?(RbReadline)
-          RbReadline.clear_history
+        if history.respond_to?(:clear)
+          history.clear
+        elsif history.respond_to?(:clear_history)
+          history.clear_history
+        elsif history.respond_to?(:pop) && history.respond_to?(:length)
+          history.length.times { |_i| history.pop }
         else
           print_error('Could not clear history, skipping file')
           return false
@@ -808,7 +811,7 @@ def cmd_history(*args)
 
     (start..length-1).each do |pos|
       cmd_num = (pos + 1).to_s
-      print_line "#{cmd_num.ljust(pad_len)}  #{Readline::HISTORY[pos]}"
+      print_line "#{cmd_num.ljust(pad_len)}  #{history[pos]}"
     end
   end
 

lib/msf/ui/console/command_dispatcher/developer.rb

@@ -131,6 +131,7 @@ def cmd_irb(*args)
 
       framework.history_manager.with_context(name: :irb) do
         begin
+          reline_autocomplete = Reline.autocompletion if defined?(Reline)
           if active_module
             print_status("You are in #{active_module.fullname}\n")
             Rex::Ui::Text::IrbShell.new(active_module).run
@@ -140,6 +141,8 @@ def cmd_irb(*args)
           end
         rescue
           print_error("Error during IRB: #{$!}\n\n#{$@.join("\n")}")
+        ensure
+          Reline.autocompletion = reline_autocomplete if defined?(Reline)
         end
       end
 
@@ -515,6 +518,10 @@ def cmd_time_help
   private
 
   def modified_files
+    # Temporary work-around until Open3 gets fixed on Windows 11:
+    # https://github.com/ruby/open3/issues/9
+    return [] if Rex::Compat.is_cygwin || Rex::Compat.is_windows
+
     # Using an array avoids shelling out, so we avoid escaping/quoting
     changed_files = %w[git diff --name-only]
     begin

lib/msf/ui/console/driver.rb

@@ -53,8 +53,6 @@ class Driver < Msf::Ui::Driver
   # @option opts [Boolean] 'AllowCommandPassthru' (true) Whether to allow
   #   unrecognized commands to be executed by the system shell
   # @option opts [Boolean] 'Readline' (true) Whether to use the readline or not
-  # @option opts [Boolean] 'RealReadline' (false) Whether to use the system's
-  #   readline library instead of RBReadline
   # @option opts [String] 'HistFile' (Msf::Config.history_file) Path to a file
   #   where we can store command history
   # @option opts [Array<String>] 'Resources' ([]) A list of resource files to
@@ -64,8 +62,6 @@ class Driver < Msf::Ui::Driver
   # @option opts [Boolean] 'SkipDatabaseInit' (false) Whether to skip
   #   connecting to the database and running migrations
   def initialize(prompt = DefaultPrompt, prompt_char = DefaultPromptChar, opts = {})
-    choose_readline(opts)
-
     histfile = opts['HistFile'] || Msf::Config.history_file
 
     begin
@@ -132,14 +128,6 @@ def initialize(prompt = DefaultPrompt, prompt_char = DefaultPromptChar, opts = {
     # stack
     enstack_dispatcher(CommandDispatcher::Core)
 
-    # Report readline error if there was one..
-    if !@rl_err.nil?
-      print_error("***")
-      print_error("* Unable to load readline: #{@rl_err}")
-      print_error("* Falling back to RbReadLine")
-      print_error("***")
-    end
-
     # Load the other "core" command dispatchers
     CommandDispatchers.each do |dispatcher_class|
       dispatcher = enstack_dispatcher(dispatcher_class)
@@ -234,6 +222,49 @@ def initialize(prompt = DefaultPrompt, prompt_char = DefaultPromptChar, opts = {
     end
   end
 
+  def self.windows_legacy_console_deprecated?
+    # We can't need a Windows-specific workaround if we're not on Windows.
+    return false unless Rex::Compat::is_windows || Rex::Compat::is_cygwin
+
+    kernel32_path = Pathname.new(File.join('C:', 'Windows', 'System32', 'Kernel32.dll')).expand_path
+    # This should never really happen. If it does, we have a bigger problem than legacy console support.
+    return false unless kernel32_path.exist?
+
+    @@windows_calls_mutex ||= Mutex.new
+    @@windows_calls_mutex.synchronize do
+      # Windows 11 has deprecated legacy console support.
+      # Check if some relevant functions return an error, or an invalid value.
+      @@kernel32_handle ||= Fiddle.dlopen(kernel32_path)
+      @@get_std_handle ||= Fiddle::Function.new(@@kernel32_handle['GetStdHandle'], [Fiddle::TYPE_LONG], Fiddle::TYPE_LONG)
+      std_input_handle = -10
+      # It is not required to call CloseHandle on this handle: https://learn.microsoft.com/en-us/windows/console/getstdhandle
+      @@console_input_handle = @@get_std_handle.Call(std_input_handle)
+      @@get_console_mode ||= Fiddle::Function.new(@@kernel32_handle['GetConsoleMode'], [Fiddle::TYPE_LONG, Fiddle::TYPE_INTPTR_T], Fiddle::TYPE_LONG)
+
+      # The Fiddle::Pointer object will be freed at the end of this block, so we don't leak memory.
+      Fiddle::Pointer.malloc(4) do |console_mode_ptr|
+        console_mode_result = @@get_console_mode.Call(@@console_input_handle, console_mode_ptr)
+
+        # The function returns 0 on error, non-zero on success: https://learn.microsoft.com/en-us/windows/console/getconsolemode
+        # We know that if this fails, the legacy console support is not available, e.g. Windows 11, so use Reline.
+        return true if console_mode_result == 0 || console_mode_ptr.to_s(2) == "\x00\x00"
+      end
+
+      false
+    end
+  end
+
+  def self.using_reline?
+    return true if Msf::FeatureManager.instance.enabled?(Msf::FeatureManager::USE_RELINE)
+    return true if self.windows_legacy_console_deprecated?
+
+    false
+  end
+
+  def self.input_lib
+    self.using_reline? ? ::Reline : ::Readline
+  end
+
   #
   # Loads configuration that needs to be analyzed before the framework
   # instance is created.
@@ -323,11 +354,12 @@ def save_config
   # Saves the recent history to the specified file
   #
   def save_recent_history(path)
-    num = Readline::HISTORY.length - hist_last_saved - 1
+    history = self.input_lib::HISTORY
+    num = history.length - hist_last_saved - 1
 
     tmprc = ""
     num.times { |x|
-      tmprc << Readline::HISTORY[hist_last_saved + x] + "\n"
+      tmprc << history[hist_last_saved + x] + "\n"
     }
 
     if tmprc.length > 0
@@ -339,7 +371,7 @@ def save_recent_history(path)
 
     # Always update this, even if we didn't save anything. We do this
     # so that we don't end up saving the "makerc" command itself.
-    self.hist_last_saved = Readline::HISTORY.length
+    self.hist_last_saved = history.length
   end
 
   #
@@ -702,44 +734,6 @@ def handle_session_tlv_logging(val)
 
     false
   end
-
-  # Require the appropriate readline library based on the user's preference.
-  #
-  # @return [void]
-  def choose_readline(opts)
-    # Choose a readline library before calling the parent
-    @rl_err = nil
-    if opts['RealReadline']
-      # Remove the gem version from load path to be sure we're getting the
-      # stdlib readline.
-      gem_dir = Gem::Specification.find_all_by_name('rb-readline').first.gem_dir
-      rb_readline_path = File.join(gem_dir, "lib")
-      index = $LOAD_PATH.index(rb_readline_path)
-      # Bundler guarantees that the gem will be there, so it should be safe to
-      # assume we found it in the load path, but check to be on the safe side.
-      if index
-        $LOAD_PATH.delete_at(index)
-      end
-    end
-
-    begin
-      require 'readline'
-    rescue ::LoadError => e
-      if @rl_err.nil? && index
-        # Then this is the first time the require failed and we have an index
-        # for the gem version as a fallback.
-        @rl_err = e
-        # Put the gem back and see if that works
-        $LOAD_PATH.insert(index, rb_readline_path)
-        index = rb_readline_path = nil
-        retry
-      else
-        # Either we didn't have the gem to fall back on, or we failed twice.
-        # Nothing more we can do here.
-        raise e
-      end
-    end
-  end
 end
 
 end

lib/msf/ui/console/module_option_tab_completion.rb

@@ -49,22 +49,23 @@ def tab_complete_module_datastore_names(mod, str, words)
         # Tab completion options values
         #
         def tab_complete_option(mod, str, words)
+          lib = Msf::Ui::Console::Driver.input_lib
           if str.end_with?('=')
             option_name = str.chop
             option_value = ''
 
-            ::Readline.completion_append_character = ' '
+            lib.completion_append_character = ' '
             return tab_complete_option_values(mod, option_value, words, opt: option_name).map { |value| "#{str}#{value}" }
           elsif str.include?('=')
             str_split = str.split('=')
             option_name = str_split[0].strip
             option_value = str_split[1].strip
 
-            ::Readline.completion_append_character = ' '
+            lib.completion_append_character = ' '
             return tab_complete_option_values(mod, option_value, words, opt: option_name).map { |value| "#{option_name}=#{value}" }
           end
 
-          ::Readline.completion_append_character = ''
+          lib.completion_append_character = ''
           tab_complete_option_names(mod, str, words).map { |name| "#{name}=" }
         end
 

lib/msf/ui/debug.rb

@@ -220,13 +220,14 @@ def self.framework_config(framework)
       end
 
       def self.history(driver)
-        end_pos = Readline::HISTORY.length - 1
+        lib = Msf::Ui::Console::Driver.input_lib
+        end_pos = lib::HISTORY.length - 1
         start_pos = end_pos - COMMAND_HISTORY_TOTAL > driver.hist_last_saved ? end_pos - (COMMAND_HISTORY_TOTAL - 1) : driver.hist_last_saved
 
         commands = ''
         while start_pos <= end_pos
           # Formats command position in history to 6 characters in length
-          commands += "#{'%-6.6s' % start_pos.to_s} #{Readline::HISTORY[start_pos]}\n"
+          commands += "#{'%-6.6s' % start_pos.to_s} #{lib::HISTORY[start_pos]}\n"
           start_pos += 1
         end
 

lib/rex/post/meterpreter/ui/console/command_dispatcher/stdapi/fs.rb

@@ -901,8 +901,9 @@ def tab_complete_cdirectory(str, words)
   end
 
   def tab_complete_path(str, words, dir_only)
+    lib = Msf::Ui::Console::Driver.input_lib
     if client.platform == 'windows'
-        ::Readline.completion_case_fold = true
+      lib.completion_case_fold = true
     end
     if client.commands.include?(COMMAND_ID_STDAPI_FS_LS)
       expanded = str
@@ -915,7 +916,7 @@ def tab_complete_path(str, words, dir_only)
         # This is annoying if we're recursively tab-traversing our way through subdirectories -
         # we may want to continue traversing, but MSF will add a space, requiring us to back up to continue
         # tab-completing our way through successive subdirectories.
-        ::Readline.completion_append_character = nil
+        lib.completion_append_character = nil
       end
       results
     else

lib/rex/ui/text/dispatcher_shell.rb

@@ -311,7 +311,8 @@ def tab_complete_directory(str, words)
         # This is annoying if we're recursively tab-traversing our way through subdirectories -
         # we may want to continue traversing, but MSF will add a space, requiring us to back up to continue
         # tab-completing our way through successive subdirectories.
-        ::Readline.completion_append_character = nil
+        lib = Msf::Ui::Console::Driver.input_lib
+        lib.completion_append_character = nil
       end
 
       if dirs.length == 0 && File.directory?(str)
@@ -408,9 +409,14 @@ def initialize(prompt, prompt_char = '>', histfile = nil, framework = nil, name
   # a design problem in the Readline module and depends on the
   # Readline.basic_word_break_characters variable being set to \x00
   #
-  def tab_complete(str)
-    ::Readline.completion_append_character = ' '
-    ::Readline.completion_case_fold = false
+  def tab_complete(str, opts: {})
+    lib = Msf::Ui::Console::Driver.input_lib
+    lib.completion_append_character = ' '
+    lib.completion_case_fold = false
+
+    if opts[:preposing] && Msf::Ui::Console::Driver.using_reline?
+      str = "#{opts[:preposing]}#{str}"
+    end
 
     # Check trailing whitespace so we can tell 'x' from 'x '
     str_match = str.match(/[^\\]([\\]{2})*\s+$/)
@@ -424,11 +430,7 @@ def tab_complete(str)
 
     # Pop the last word and pass it to the real method
     result = tab_complete_stub(str, split_str)
-    if result
-      result.uniq
-    else
-      result
-    end
+    result&.uniq
   end
 
   # Performs tab completion of a command, if supported