support upgrading a powershell session to meterpreter

Author: Brent Cook

lib/msf/base/sessions/powershell.rb

@@ -27,6 +27,13 @@ def self.type
     "powershell"
   end
 
+  #
+  # Returns the session platform.
+  #
+  def platform
+    "win"
+  end
+
   #
   # Returns the session description.
   #

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

@@ -1917,12 +1917,12 @@ def cmd_sessions(*args)
             session.response_timeout = response_timeout
           end
           begin
-            if session.type == 'shell'
+            if session.type.include? 'shell'
               session.init_ui(driver.input, driver.output)
               session.execute_script('post/multi/manage/shell_to_meterpreter')
               session.reset_ui
             else
-              print_error("Session #{sess_id} is not a command shell session, skipping...")
+              print_error("Session #{sess_id} is not a command shell session, it is #{session.type}, skipping...")
               next
             end
           ensure