Module: Msf::Sessions::WinrmStreamAdapterCommon

Included in:
Msf::Sessions::WinrmCommandShell::WinRMStreamAdapter, Msf::Sessions::WinrmPowerShell::WinRMPowerShellStreamAdapter
Defined in:
lib/msf/base/sessions/winrm_stream_adapter_common.rb

Overview

Shared output-buffering and polling logic for the WinRM stream adapters (Msf::Sessions::WinrmCommandShell::WinRMStreamAdapter and Msf::Sessions::WinrmPowerShell::WinRMPowerShellStreamAdapter). Both adapters receive output on a background thread and buffer it for Msf::Session::Provider::SingleCommandShell to read via #get_once.

Instance Method Summary collapse

Instance Method Details

#_get_once(length) ⇒ Object 



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# File 'lib/msf/base/sessions/winrm_stream_adapter_common.rb', line 64

def _get_once(length)
  result = ''
  @buffer_mutex.synchronize do
    result = @buffer.join('')
    @buffer = []
    if (length > -1) && (result.length > length)
      # Return up to length, and keep the rest in the buffer.
      extra = result[length..]
      result = result[0, length]
      @buffer << extra
    end
  end
  result
end

#get_once(length = -1,, timeout = 1) ⇒ Object

:category: Msf::Session::Provider::SingleCommandShell implementors

Read buffered output received from the background thread. Yields (if a block is given) each time we’re about to loop back and wait again, so includers can nudge their background thread along.



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# File 'lib/msf/base/sessions/winrm_stream_adapter_common.rb', line 42

def get_once(length = -1, timeout = 1)
  start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  result = ''
  loop do
    result = _get_once(length)
    elapsed = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start_time
    time_remaining = timeout - elapsed
    break if result != '' || time_remaining <= 0

    # rubocop:disable Lint/SuppressedException
    begin
      @received_stdout_event.wait(time_remaining)
    rescue ::Timeout::Error
    ensure
      @received_stdout_event.reset
    end
    # rubocop:enable Lint/SuppressedException
    yield if block_given?
  end
  result
end

#init_stream_buffer ⇒ Object

Includers must call this from #initialize before using #get_once, #_get_once, or #append_output.



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# File 'lib/msf/base/sessions/winrm_stream_adapter_common.rb', line 15

def init_stream_buffer
  @buffer_mutex = Mutex.new
  @buffer = []
  # auto_reset is false: #get_once resets the event itself after every
  # wake-up, immediately before it re-checks the buffer. If the event
  # auto-reset on #set instead, a #set landing between that buffer check
  # and the call to #wait would be missed (a classic lost wakeup),
  # leaving the reader blocked for the full timeout even though output
  # was already sitting in the buffer.
  @received_stdout_event = Rex::Sync::Event.new(false, false)
end

#localinfo ⇒ Object 



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# File 'lib/msf/base/sessions/winrm_stream_adapter_common.rb', line 31

def localinfo
  shell.transport.localinfo
end

#peerinfo ⇒ Object 



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# File 'lib/msf/base/sessions/winrm_stream_adapter_common.rb', line 27

def peerinfo
  shell.transport.peerinfo
end