Merge pull request rapid7#19526 from rapid7/revert-19397-replace-readline-with-reline

Revert "Replace Readline with Reline"

Author: adfoster-r7

lib/metasploit/framework/command/console.rb

@@ -92,6 +92,7 @@ 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

@@ -16,6 +16,7 @@ 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
       }
@@ -53,11 +54,7 @@ def option_parser
         end
 
         option_parser.on('-L', '--real-readline', 'Use the system Readline library instead of RbReadline') do
-          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
+          options.console.real_readline = true
         end
 
         option_parser.on('-o', '--output FILE', 'Output to the specified file') do |file|

lib/metasploit/framework/parsed_options/remote_db.rb

@@ -13,6 +13,7 @@ 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/ui/console/command_dispatcher/core.rb

@@ -760,7 +760,7 @@ def cmd_features_tabs(_str, words)
   end
 
   def cmd_history(*args)
-    length = ::Reline::HISTORY.length
+    length = Readline::HISTORY.length
 
     if length < @history_limit
       limit = length
@@ -780,7 +780,14 @@ def cmd_history(*args)
           limit = val.to_i
         end
       when '-c'
-        ::Reline::HISTORY.clear
+        if Readline::HISTORY.respond_to?(:clear)
+          Readline::HISTORY.clear
+        elsif defined?(RbReadline)
+          RbReadline.clear_history
+        else
+          print_error('Could not clear history, skipping file')
+          return false
+        end
 
         # Portable file truncation?
         if File.writable?(Msf::Config.history_file)
@@ -801,7 +808,7 @@ def cmd_history(*args)
 
     (start..length-1).each do |pos|
       cmd_num = (pos + 1).to_s
-      print_line "#{cmd_num.ljust(pad_len)}  #{::Reline::HISTORY[pos]}"
+      print_line "#{cmd_num.ljust(pad_len)}  #{Readline::HISTORY[pos]}"
     end
   end
 

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

@@ -131,7 +131,6 @@ def cmd_irb(*args)
 
       framework.history_manager.with_context(name: :irb) do
         begin
-          reline_autocomplete = Reline.autocompletion
           if active_module
             print_status("You are in #{active_module.fullname}\n")
             Rex::Ui::Text::IrbShell.new(active_module).run
@@ -141,8 +140,6 @@ def cmd_irb(*args)
           end
         rescue
           print_error("Error during IRB: #{$!}\n\n#{$@.join("\n")}")
-        ensure
-          Reline.autocompletion = reline_autocomplete if defined? reline_autocomplete
         end
       end
 
@@ -518,10 +515,6 @@ 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

@@ -53,6 +53,8 @@ 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
@@ -62,6 +64,8 @@ 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
@@ -128,6 +132,14 @@ 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)
@@ -311,11 +323,11 @@ def save_config
   # Saves the recent history to the specified file
   #
   def save_recent_history(path)
-    num = ::Reline::HISTORY.length - hist_last_saved - 1
+    num = Readline::HISTORY.length - hist_last_saved - 1
 
     tmprc = ""
     num.times { |x|
-      tmprc << ::Reline::HISTORY[hist_last_saved + x] + "\n"
+      tmprc << Readline::HISTORY[hist_last_saved + x] + "\n"
     }
 
     if tmprc.length > 0
@@ -327,7 +339,7 @@ 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 = ::Reline::HISTORY.length
+    self.hist_last_saved = Readline::HISTORY.length
   end
 
   #
@@ -690,6 +702,44 @@ 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

@@ -53,18 +53,18 @@ def tab_complete_option(mod, str, words)
             option_name = str.chop
             option_value = ''
 
-            ::Reline.completion_append_character = ' '
+            ::Readline.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
 
-            ::Reline.completion_append_character = ' '
+            ::Readline.completion_append_character = ' '
             return tab_complete_option_values(mod, option_value, words, opt: option_name).map { |value| "#{option_name}=#{value}" }
           end
 
-          ::Reline.completion_append_character = ''
+          ::Readline.completion_append_character = ''
           tab_complete_option_names(mod, str, words).map { |name| "#{name}=" }
         end
 

lib/msf/ui/debug.rb

@@ -220,13 +220,13 @@ def self.framework_config(framework)
       end
 
       def self.history(driver)
-        end_pos = ::Reline::HISTORY.length - 1
+        end_pos = Readline::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} #{::Reline::HISTORY[start_pos]}\n"
+          commands += "#{'%-6.6s' % start_pos.to_s} #{Readline::HISTORY[start_pos]}\n"
           start_pos += 1
         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'
-      ::Reline.completion_case_fold = true
+        ::Readline.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.
-        ::Reline.completion_append_character = nil
+        ::Readline.completion_append_character = nil
       end
       results
     else
@@ -939,6 +939,7 @@ def unexpand_path_for_suggestions(original_path, expanded_path, suggestions)
       result
     end
   end
+
 end
 
 end

lib/rex/post/sql/ui/console/interactive_sql_client.rb

@@ -20,7 +20,7 @@ module InteractiveSqlClient
   #
   def _interact
     while self.interacting
-      sql_input = reline_multiline
+      sql_input = _multiline_with_fallback
       self.interacting = (sql_input[:status] != :exit)
 
       if sql_input[:status] == :help
@@ -65,21 +65,35 @@ def _winch
     # noop
   end
 
-  # Get multi-line input support provided by Reline.
-  def reline_multiline
+  # Try getting multi-line input support provided by Reline, fall back to Readline.
+  def _multiline_with_fallback
     name = session.type
     query = {}
     history_file = Msf::Config.history_file_for_session_type(session_type: name, interactive: true)
     return { status: :fail, errors: ["Unable to get history file for session type: #{name}"] } if history_file.nil?
 
-    framework.history_manager.with_context(history_file: history_file , name: name) do
+    # Multiline (Reline) and fallback (Readline) have separate history contexts as they are two different libraries.
+    framework.history_manager.with_context(history_file: history_file , name: name, input_library: :reline) do
       query = _multiline
     end
 
+    if query[:status] == :fail
+      framework.history_manager.with_context(history_file: history_file, name: name, input_library: :readline) do
+        query = _fallback
+      end
+    end
+
     query
   end
 
   def _multiline
+    begin
+      require 'reline' unless defined?(::Reline)
+    rescue ::LoadError => e
+      elog('Failed to load Reline', e)
+      return { status: :fail, errors: [e] }
+    end
+
     stop_words = %w[stop s exit e end quit q].freeze
     help_words = %w[help h].freeze
 
@@ -138,6 +152,28 @@ def _multiline
     { status: :success, result: raw_query }
   end
 
+  def _fallback
+    stop_words = %w[stop s exit e end quit q].freeze
+    line_buffer = []
+    while (line = ::Readline.readline(prompt = line_buffer.empty? ? 'SQL >> ' : 'SQL *> ', add_history = true))
+      return { status: :exit, result: nil } unless self.interacting
+
+      if stop_words.include? line.chomp.downcase
+        self.interacting = false
+        print_status 'Exiting Interactive mode.'
+        return { status: :exit, result: nil }
+      end
+
+      next if line.empty?
+
+      line_buffer.append line
+
+      break if line.end_with? ';'
+    end
+
+    { status: :success, result: line_buffer.join(' ') }
+  end
+
   attr_accessor :on_log_proc, :client_dispatcher
 
   private