Class: Rex::Post::Meterpreter::GroupTlv

Inherits:
Tlv
  • Object
show all
Defined in:
lib/rex/post/meterpreter/packet.rb

Overview

Group TLVs contain zero or more TLVs

Direct Known Subclasses

Packet

Instance Attribute Summary collapse

Attributes inherited from Tlv

#compress, #type, #value

Instance Method Summary collapse

Methods inherited from Tlv

#inspect, #meta_type?, #type?, #value?

Constructor Details

#initialize(type) ⇒ GroupTlv

Initializes the group TLV container to the supplied type and creates an empty TLV array.



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# File 'lib/rex/post/meterpreter/packet.rb', line 366

def initialize(type)
	super(type)

	self.tlvs = [ ]
end

Instance Attribute Details

#tlvs ⇒ Object

Returns the value of attribute tlvs.



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# File 'lib/rex/post/meterpreter/packet.rb', line 354

def tlvs
  @tlvs
end

Instance Method Details

#add_tlv(type, value = nil, replace = false, compress = false) ⇒ Object

Adds a TLV of a given type and value.



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# File 'lib/rex/post/meterpreter/packet.rb', line 434

def add_tlv(type, value = nil, replace = false, compress=false)

	# If we should replace any TLVs with the same type...remove them first
	if (replace)
		each(type) { |tlv|
			if (tlv.type == type)
				self.tlvs.delete(tlv)
			end
		}
	end

	if (type & TLV_META_TYPE_GROUP == TLV_META_TYPE_GROUP)
		tlv = GroupTlv.new(type)
	else
		tlv = Tlv.new(type, value, compress)
	end

	self.tlvs << tlv

	return tlv
end

#add_tlvs(tlvs) ⇒ Object

Adds zero or more TLVs to the packet.



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# File 'lib/rex/post/meterpreter/packet.rb', line 459

def add_tlvs(tlvs)
	if (tlvs != nil)
		tlvs.each { |tlv|
			add_tlv(tlv['type'], tlv['value'])
		}
	end
end

#each(type = TLV_TYPE_ANY, &block) ⇒ Object

Enumerates TLVs of the supplied type.



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# File 'lib/rex/post/meterpreter/packet.rb', line 381

def each(type = TLV_TYPE_ANY, &block)
	get_tlvs(type).each(&block)
end

#each_tlv(type = TLV_TYPE_ANY, &block) ⇒ Object

Synonym for each.



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# File 'lib/rex/post/meterpreter/packet.rb', line 388

def each_tlv(type = TLV_TYPE_ANY, &block)
	each(type, &block)
end

#each_tlv_with_index(type = TLV_TYPE_ANY, &block) ⇒ Object

Synonym for each_with_index.



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# File 'lib/rex/post/meterpreter/packet.rb', line 402

def each_tlv_with_index(type = TLV_TYPE_ANY, &block)
	each_with_index(type, block)
end

#each_with_index(type = TLV_TYPE_ANY, &block) ⇒ Object

Enumerates TLVs of a supplied type with indexes.



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# File 'lib/rex/post/meterpreter/packet.rb', line 395

def each_with_index(type = TLV_TYPE_ANY, &block)
	get_tlvs(type).each_with_index(&block)
end

#from_r(raw) ⇒ Object

Converts the TLV group container from raw to all of the individual TLVs.



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# File 'lib/rex/post/meterpreter/packet.rb', line 534

def from_r(raw)
	offset = 8

	# Reset the TLVs array
	self.tlvs = []
	self.type = raw.unpack("NN")[1]

	# Enumerate all of the TLVs
	while (offset < raw.length-1)

		tlv = nil

		# Get the length and type
		length, type = raw[offset..offset+8].unpack("NN")

		if (type & TLV_META_TYPE_GROUP == TLV_META_TYPE_GROUP)
			tlv = GroupTlv.new(type)
		else
			tlv = Tlv.new(type)
		end

		tlv.from_r(raw[offset..offset+length])

		# Insert it into the list of TLVs
		tlvs << tlv

		# Move up
		offset += length
	end
end

#get_tlv(type, index = 0) ⇒ Object

Gets the first TLV of a given type.



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# File 'lib/rex/post/meterpreter/packet.rb', line 470

def get_tlv(type, index = 0)
	type_tlvs = get_tlvs(type)

	if (type_tlvs.length > index)
		return type_tlvs[index]
	end

	return nil
end

#get_tlv_value(type, index = 0) ⇒ Object

Returns the value of a TLV if it exists, otherwise nil.



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# File 'lib/rex/post/meterpreter/packet.rb', line 483

def get_tlv_value(type, index = 0)
	tlv = get_tlv(type, index)

	return (tlv != nil) ? tlv.value : nil
end

#get_tlv_values(type) ⇒ Object

Returns an array of values for all tlvs of type type.



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# File 'lib/rex/post/meterpreter/packet.rb', line 492

def get_tlv_values(type)
	get_tlvs(type).collect { |a| a.value }
end

#get_tlvs(type) ⇒ Object

Returns an array of TLVs for the given type.



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# File 'lib/rex/post/meterpreter/packet.rb', line 409

def get_tlvs(type)
	if (type == TLV_TYPE_ANY)
		return self.tlvs
	else
		type_tlvs = []

		self.tlvs.each() { |tlv|
			if (tlv.type?(type))
				type_tlvs << tlv
			end
		}

		return type_tlvs
	end
end

#has_tlv?(type) ⇒ Boolean

Checks to see if the container has a TLV of a given type.

Returns:

  • (Boolean) 


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# File 'lib/rex/post/meterpreter/packet.rb', line 499

def has_tlv?(type)
	return get_tlv(type) != nil
end

#reset ⇒ Object

Zeros out the array of TLVs.



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# File 'lib/rex/post/meterpreter/packet.rb', line 506

def reset
	self.tlvs = []
end

#to_r ⇒ Object

Converts all of the TLVs in the TLV array to raw and prefixes them with a container TLV of this instance’s TLV type.



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# File 'lib/rex/post/meterpreter/packet.rb', line 520

def to_r
	raw = ''

	self.each() { |tlv|
		raw << tlv.to_r
	}

	return [raw.length + 8, self.type].pack("NN") + raw
end