62 lines
1.2 KiB
Ruby
62 lines
1.2 KiB
Ruby
require 'fiddle'
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require 'fiddle/import'
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class NS
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extend Fiddle::Importer
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dlload Fiddle.dlopen( nil)
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SetNS_Function = Fiddle::Function.new handler['setns'], [Fiddle::TYPE_VOIDP, Fiddle::TYPE_VOIDP], Fiddle::TYPE_INT
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class <<self
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def setns fd, t
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r = SetNS_Function.call fd.to_i, t.to_i
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SystemCallError.new "setns(#{fd.to_i})", Fiddle.last_error if -1 == r
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r
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end
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def _open_nsfd pid, type
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File.open "/proc/%d/ns/%s" % [pid, type]
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end
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def open pid, *types, &exe
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ns = new pid, *types
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if block_given?
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begin yield ns
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ensure ns.close
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end
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else ns
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end
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end
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def change pid, *types, &exe
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open pid, *types do |ns|
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ns.change &exe
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end
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end
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end
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attr_reader :pid, :fds, :types
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def initialize pid, *types
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@pid, @fds = pid, {}
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types.map {|t| @fds[t] = self.class._open_nsfd pid, t }
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end
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def close
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@fds.each {|t, fd| fd.close }
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end
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def change &block
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@owns = @fds.map {|t, _f| Own[t] }
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begin
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@fds.each {|type, fd| self.class.setns fd, 0 }
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yield
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ensure
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@owns.each {|fd| self.class.setns fd, 0 }
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end
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end
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Own = Hash.new {|h, ns| h[ns] = _open_nsfd $$, ns }
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end
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