Class: Rex::Post::Meterpreter::Channels::Pool

Inherits:
Rex::Post::Meterpreter::Channel show all
Defined in:
lib/rex/post/meterpreter/channels/pool.rb

Overview

This class acts as a base class for all channels that are classified as ‘pools’. This means that only one side of the channel, typically the client half, acts on the other half of the channel. Examples of pools come in the form of files where the remote side never sends any unrequested data.

Another key distinction of Pools is that they, in general, support the DIO mode ‘seek’ which allows for changing the position, or offset, into the channel.

Instance Attribute Summary

Attributes inherited from Rex::Post::Meterpreter::Channel

#cid, #client, #cls, #flags, #params, #type

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Rex::Post::Meterpreter::Channel

#_close, _close, #_read, #_write, #close, #close_read, #close_write, create, #dio_close_handler, #dio_handler, #dio_map, #dio_read_handler, #dio_write_handler, finalize, #flag?, #interactive, request_handler, #synchronous?, #write

Methods included from InboundPacketHandler

#request_handler, #response_handler

Constructor Details

#initialize(client, cid, type, flags) ⇒ Pool

Passes the initialization information up to the base class



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# File 'lib/rex/post/meterpreter/channels/pool.rb', line 41

def initialize(client, cid, type, flags)
  super(client, cid, type, flags)
end

Class Method Details

.cls ⇒ Object 



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# File 'lib/rex/post/meterpreter/channels/pool.rb', line 27

def cls
  return CHANNEL_CLASS_POOL
end

Instance Method Details

#eof ⇒ Object

Checks to see if the EOF flag has been set on the pool.



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# File 'lib/rex/post/meterpreter/channels/pool.rb', line 54

def eof
  request = Packet.create_request('core_channel_eof')

  request.add_tlv(TLV_TYPE_CHANNEL_ID, self.cid)

  begin
    response = self.client.send_request(request)
  rescue
    return true
  end

  if (response.has_tlv?(TLV_TYPE_BOOL))
    return response.get_tlv_value(TLV_TYPE_BOOL)
  end

  return false
end

#pos ⇒ Object

Synonym for tell.



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# File 'lib/rex/post/meterpreter/channels/pool.rb', line 128

def pos
  return tell
end

#read(length = nil) ⇒ Object

Reads data from the remote side of the pool and raises EOFError if the pool has been reached EOF.



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# File 'lib/rex/post/meterpreter/channels/pool.rb', line 76

def read(length = nil)
  begin
    data = super(length)
  rescue
    data = nil
  end

  if (((data == nil) || (data.length == 0)) &&
      (self.eof))
    raise EOFError
  end

  return data
end

#seek(offset, whence = SEEK_SET) ⇒ Object

This method seeks to an offset within the remote side of the pool using the standard seek whence clauses.



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# File 'lib/rex/post/meterpreter/channels/pool.rb', line 95

def seek(offset, whence = SEEK_SET)
  sane = 0

  # Just in case...
  case whence
    when ::IO::SEEK_SET
      sane = 0
    when ::IO::SEEK_CUR
      sane = 1
    when ::IO::SEEK_END
      sane = 2
    else
      raise RuntimeError, "Invalid seek whence #{whence}.", caller
  end

  request = Packet.create_request('core_channel_seek')

  request.add_tlv(TLV_TYPE_CHANNEL_ID, self.cid)
  request.add_tlv(TLV_TYPE_SEEK_OFFSET, offset)
  request.add_tlv(TLV_TYPE_SEEK_WHENCE, sane)

  begin
    response = self.client.send_request(request)
  rescue
    return -1
  end

  return tell
end

#tell ⇒ Object

This method returns the current file pointer position to the caller.



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# File 'lib/rex/post/meterpreter/channels/pool.rb', line 135

def tell
  request = Packet.create_request('core_channel_tell')
  pos     = -1

  request.add_tlv(TLV_TYPE_CHANNEL_ID, self.cid)

  begin
    response = self.client.send_request(request)
  rescue
    return pos
  end

  # Set the return value to the position that we're at
  if (response.has_tlv?(TLV_TYPE_SEEK_POS))
    pos = response.get_tlv_value(TLV_TYPE_SEEK_POS)
  end

  return pos
end