Place Reline behind a feature flag

Gemfile.lock

@@ -405,7 +405,7 @@ GEM
       nokogiri
     redcarpet (3.6.0)
     regexp_parser (2.9.2)
-    reline (0.5.10)
+    reline (0.5.11)
       io-console (~> 0.5)
     require_all (3.0.0)
     rex-arch (0.1.16)

lib/msf/core/feature_manager.rb

@@ -29,6 +29,7 @@ class FeatureManager
     LDAP_SESSION_TYPE = 'ldap_session_type'
     SHOW_SUCCESSFUL_LOGINS = 'show_successful_logins'
     DISPLAY_MODULE_ACTION = 'display_module_action'
+    USE_RELINE = 'use_reline'
 
     DEFAULTS = [
       {
@@ -132,6 +133,13 @@ class FeatureManager
         requires_restart: false,
         default_value: true,
         developer_notes: 'Added as a feature so users can turn it off if they wish to reduce clutter in their terminal'
+      }.freeze,
+      {
+        name: USE_RELINE,
+        description: 'When enabled, the new Reline library will be used instead of the legacy Readline library for input/output.',
+        requires_restart: true,
+        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::MsfReadline.instance.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

@@ -313,12 +313,9 @@ def save_config
   # Saves the recent history to the specified file
   #
   def save_recent_history(path)
-    num = Readline::HISTORY.length - hist_last_saved - 1
-
-    tmprc = ""
-    num.times { |x|
-      tmprc << Readline::HISTORY[hist_last_saved + x] + "\n"
-    }
+    history = Msf::Ui::Console::MsfReadline.instance.history
+    num = history.length - hist_last_saved - 1
+    tmprc = history.entries[hist_last_saved..].join("\n")
 
     if tmprc.length > 0
       print_status("Saving last #{num} commands to #{path} ...")
@@ -329,7 +326,7 @@ 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
 
   #

lib/msf/ui/console/module_option_tab_completion.rb

@@ -53,18 +53,18 @@ def tab_complete_option(mod, str, words)
             option_name = str.chop
             option_value = ''
 
-            ::Readline.completion_append_character = ' '
+            Msf::Ui::Console::MsfReadline.instance.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 = ' '
+            Msf::Ui::Console::MsfReadline.instance.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 = ''
+          Msf::Ui::Console::MsfReadline.instance.completion_append_character = ''
           tab_complete_option_names(mod, str, words).map { |name| "#{name}=" }
         end
 

lib/msf/ui/console/msf_readline.rb

@@ -0,0 +1,106 @@
+#
+# This class is responsible for handling Readline/Reline-agnostic user input.
+#
+class Msf::Ui::Console::MsfReadline
+  require 'singleton'
+  # Required to check the Reline flag.
+  require 'msf/core/feature_manager'
+  require 'readline'
+  require 'reline'
+
+  include Singleton
+
+  attr_accessor :history
+
+  def initialize
+    @backend = using_reline? ? ::Reline : ::Readline
+    @history = @backend::HISTORY
+  end
+
+  def method_missing(sym, *args, &block)
+    if @backend.respond_to?(sym)
+      @backend.send(sym, *args, &block)
+    else
+      msg = "Method '#{sym}' not found in #{@backend.class}"
+      elog(msg)
+      raise NoMethodError, msg
+    end
+  end
+
+  # Read a line from the user, and return it.
+  # @param prompt [String] The prompt to show to the user.
+  # @param add_history [Boolean] True if the user's input should be saved to the history.
+  # @param opts [Hash] Options
+  # @return String The line that the user has entered.
+  def readline(prompt, add_history = false, opts: {})
+    input(prompt, add_history, opts: opts)
+  end
+
+  def using_reline?
+    Msf::FeatureManager.instance.enabled?(Msf::FeatureManager::USE_RELINE)
+  end
+
+  private
+
+  attr_accessor :backend
+
+  def input(*args, opts: {})
+    using_reline? ? input_reline(*args, opts: opts) : input_rbreadline(*args, opts: opts)
+  end
+
+  def input_rbreadline(prompt, add_history = false, opts: {})
+    # rb-readlines's Readline.readline hardcodes the input and output to
+    # $stdin and $stdout, which means setting `Readline.input` or
+    # `Readline.output` has no effect when running `Readline.readline` with
+    # rb-readline, so need to reimplement
+    # []`Readline.readline`](https://github.com/luislavena/rb-readline/blob/ce4908dae45dbcae90a6e42e3710b8c3a1f2cd64/lib/readline.rb#L36-L58)
+    # for rb-readline to support setting input and output.  Output needs to
+    # be set so that colorization works for the prompt on Windows.
+
+    input_on_entry = RbReadline.rl_instream
+    output_on_entry = RbReadline.rl_outstream
+
+    begin
+      RbReadline.rl_instream = opts[:fd]
+      RbReadline.rl_outstream = opts[:output]
+      line = RbReadline.readline(prompt.to_s)
+    rescue ::StandardError => e
+      RbReadline.rl_instream = input_on_entry
+      RbReadline.rl_outstream = output_on_entry
+      RbReadline.rl_cleanup_after_signal
+      RbReadline.rl_deprep_terminal
+
+      raise e
+    end
+
+    if add_history && line && !line.start_with?(' ')
+      # Don't add duplicate lines to history
+      if ::Readline::HISTORY.empty? || line.strip != ::Readline::HISTORY[-1]
+        RbReadline.add_history(line.strip)
+      end
+    end
+
+    line.dup
+  end
+
+  def input_reline(prompt, add_history = false, opts: {})
+    input_on_entry = Reline::IOGate.instance_variable_get(:@input)
+    output_on_entry = Reline::IOGate.instance_variable_get(:@output)
+
+    begin
+      Reline.input = opts[:fd]
+      Reline.output = opts[:output]
+      line = Reline.readline(prompt.to_s, add_history)
+    ensure
+      Reline.input = input_on_entry
+      Reline.output = output_on_entry
+    end
+
+    # Don't add duplicate lines to history
+    if Reline::HISTORY.length > 1 && line == Reline::HISTORY[-2]
+      Reline::HISTORY.pop
+    end
+
+    line.dup
+  end
+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
+        history = Msf::Ui::Console::MsfReadline.instance.history
+        end_pos = 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} #{history[start_pos]}\n"
           start_pos += 1
         end
 

lib/msf_autoload.rb

@@ -347,3 +347,17 @@ def finalize_loader(loader)
 
 # XXX: Should be removed once the `lib/metasploit` folder is loaded by Zeitwerk
 require 'metasploit/framework/hashes'
+
+# TODO: Remove this monkey-patch once the following issue is addressed over on Reline's repository here:
+# https://github.com/ruby/reline/issues/756
+require 'reline'
+class ::Reline::Core
+  alias old_completion_append_character= completion_append_character=
+  alias old_completion_append_character completion_append_character
+
+  def completion_append_character=(v)
+    self.old_completion_append_character = v
+    # Additionally keep the line_editor in sync
+    line_editor.completion_append_character = self.old_completion_append_character
+  end
+end

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

@@ -902,7 +902,7 @@ def tab_complete_cdirectory(str, words)
 
   def tab_complete_path(str, words, dir_only)
     if client.platform == 'windows'
-        ::Readline.completion_case_fold = true
+      Msf::Ui::Console::MsfReadline.instance.completion_case_fold = true
     end
     if client.commands.include?(COMMAND_ID_STDAPI_FS_LS)
       expanded = str
@@ -915,7 +915,7 @@ 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
+        Msf::Ui::Console::MsfReadline.instance.completion_append_character = nil
       end
       results
     else

lib/rex/ui/text/dispatcher_shell.rb

@@ -311,7 +311,7 @@ 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
+        Msf::Ui::Console::MsfReadline.instance.completion_append_character = nil
       end
 
       if dirs.length == 0 && File.directory?(str)
@@ -408,9 +408,13 @@ 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: {})
+    Msf::Ui::Console::MsfReadline.instance.completion_append_character = ' '
+    Msf::Ui::Console::MsfReadline.instance.completion_case_fold = false
+
+    if opts[:preposing] && Msf::Ui::Console::MsfReadline.instance.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 +428,7 @@ 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