75 lines
1.4 KiB
Ruby
75 lines
1.4 KiB
Ruby
#!/usr/bin/env ruby
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# -*- coding: binary -*-
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# Rex::Struct2
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module Rex
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module Struct2
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class Generic
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require 'rex/struct2/element'
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include Rex::Struct2::Element
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attr_reader :default
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attr_writer :default
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attr_accessor :mask, :check_mask
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def initialize(packspec, signed=false, default=nil)
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@packspec = packspec
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@default = default
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bytelen = [ -1 ].pack(@packspec).length
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self.mask = (1 << (8 * bytelen)) - 1
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if signed
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self.check_mask = 1 << (8 * bytelen - 1)
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else
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self.check_mask = 0
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end
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reset()
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end
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def reset
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self.value = @default
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end
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def to_s
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# I realize this will bomb out if this isn't an integer, for
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# example if it is nil. That should only happen for a user
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# error so that's what I want it to do...
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string = [ @value ].pack(@packspec)
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if restraint && restraint.max
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return string.slice(0, restraint.max)
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else
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return string
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end
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# what to do for restraint.min?!?
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end
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def from_s(bytes)
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value = bytes.unpack(@packspec)[0]
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# return nil on unpack error
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return if !value
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len = slength()
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# error on any restraint issues
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return if restraint && restraint.max && len > restraint.max
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return if restraint && restraint.min && len < restraint.min
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# else set our value and return length used for this element
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if (value & check_mask) != 0
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value = -((~value & mask) + 1)
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end
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self.value = value
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return(len)
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end
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end
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# end Rex::Struct2
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end
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end
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