193 lines
8.1 KiB
Elixir
193 lines
8.1 KiB
Elixir
defmodule Openflow.Match do
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@match_size 8
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@header_size 4
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defstruct([
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type: :oxm,
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fields: []
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])
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alias __MODULE__
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def new(fields \\ []) do
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oxm_fields =
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fields
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|> keyword_to_oxm_fields([])
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%Match{type: :oxm, fields: oxm_fields}
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end
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def read(binary) do
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<<1::16, no_pad_len::16, binary1::binary>> = binary
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padding_length = Openflow.Utils.pad_length(no_pad_len, 8)
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match_field_len = no_pad_len - @header_size
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<<match_fields::size(match_field_len)-binary, _::size(padding_length)-unit(8), rest::bitstring>> = binary1
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{decode_fields(match_fields, []), rest}
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end
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def to_binary(%Match{fields: fields}) do
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fields_bin = encode_fields(fields, <<>>)
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length = byte_size(fields_bin) + @match_size - @header_size
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type_int = Openflow.Enums.to_int(:oxm, :match_type)
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padding = Openflow.Utils.padding(length, 8)
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<<type_int::16, length::16, fields_bin::bytes, 0::size(padding)-unit(8)>>
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end
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def codec_header(oxm_field) when is_atom(oxm_field) do
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oxm_field = case has_mask(oxm_field) do
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1 ->
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string = to_string(oxm_field)
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"masked_" <> field = string
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String.to_atom(field)
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0 ->
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oxm_field
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end
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case Openflow.Match.Field.vendor_of(oxm_field) do
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oxm_class when oxm_class in [:nxm_0, :nxm_1, :openflow_basic, :packet_register] ->
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oxm_class_int = Openflow.Enums.to_int(oxm_class, :oxm_class)
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oxm_field_int = Openflow.Enums.to_int(oxm_field, oxm_class)
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oxm_length = div(Openflow.Match.Field.n_bits_of(oxm_field), 8)
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has_mask = has_mask(oxm_field)
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<<oxm_class_int::16, oxm_field_int::7, has_mask::1, oxm_length::8>>
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experimenter when experimenter in [:nicira_ext_match, :onf_ext_match, :hp_ext_match] ->
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oxm_class_int = 0xffff
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experimenter_int = Openflow.Enums.to_int(experimenter, :experimenter_oxm_vendors)
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oxm_field_int = Openflow.Enums.to_int(oxm_field, experimenter)
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oxm_length = div(Openflow.Match.Field.n_bits_of(oxm_field) + 4, 8)
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has_mask = has_mask(oxm_field)
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<<oxm_class_int::16, oxm_field_int::7, has_mask::1, oxm_length::8, experimenter_int::32>>
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end
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end
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def codec_header(<<oxm_class_int::16, oxm_field_int::7, oxm_has_mask::1, _oxm_length::8>>) do
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oxm_class = Openflow.Enums.to_atom(oxm_class_int, :oxm_class)
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case oxm_has_mask do
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0 -> Openflow.Enums.to_atom(oxm_field_int, oxm_class)
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1 ->
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field_str =
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oxm_field_int
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|> Openflow.Enums.to_atom(oxm_class)
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|> to_string
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String.to_atom("masked_" <> field_str)
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end
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end
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def codec_header(<<0xffff::16, oxm_field_int::7, oxm_has_mask::1, _oxm_length::8, experimenter_int::32>>) do
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experimenter = Openflow.Enums.to_atom(experimenter_int, :experimenter_oxm_vendors)
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Openflow.Enums.to_atom(oxm_field_int, experimenter)
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case oxm_has_mask do
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0 -> Openflow.Enums.to_atom(oxm_field_int, experimenter)
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1 ->
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field_str =
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oxm_field_int
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|> Openflow.Enums.to_atom(experimenter)
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|> to_string
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String.to_atom("masked_" <> field_str)
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end
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end
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def header_size(<<_oxm_class_int::16, _oxm_field_int::7, _oxm_has_mask::1, _oxm_length::8, _::bytes>>),
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do: 4
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def header_size(<<0xffff::16, _oxm_field_int::7, _oxm_has_mask::1, _oxm_length::8, _exp_int::32, _::bytes>>),
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do: 8
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# private functions
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defp decode_fields(<<>>, acc), do: Enum.reverse(acc)
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defp decode_fields(<<0xffff::16, _::7, 1::1, length::8, vendor_int::32, field_int::16, binary::bytes>>, acc) do
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length = length - 6
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field_len = div(length, 2)
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<<value_bin::size(field_len)-bytes, mask_bin::size(field_len)-bytes, rest::bytes>> = binary
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experimenter = Openflow.Enums.to_atom(vendor_int, :experimenter_oxm_vendors)
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field_name = Openflow.Enums.to_atom(field_int, experimenter)
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value = Openflow.Match.Field.codec(value_bin, field_name)
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mask = Openflow.Match.Field.codec(mask_bin, field_name)
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decode_fields(rest, [{field_name, {value, mask}}|acc])
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end
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defp decode_fields(<<0xffff::16, _::7, 0::1, length::8, vendor_int::32, field_int::16, binary::bytes>>, acc) do
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length = length - 6
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<<value_bin::size(length)-bytes, rest::bytes>> = binary
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experimenter = Openflow.Enums.to_atom(vendor_int, :experimenter_oxm_vendors)
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field_name = Openflow.Enums.to_atom(field_int, experimenter)
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value = Openflow.Match.Field.codec(value_bin, field_name)
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decode_fields(rest, [{field_name, value}|acc])
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end
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defp decode_fields(<<class_int::16, field_int::7, 1::1, length::8, binary::bytes>>, acc) do
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field_len = div(length, 2)
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<<value_bin::size(field_len)-bytes, mask_bin::size(field_len)-bytes, rest::bytes>> = binary
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class = Openflow.Enums.to_atom(class_int, :oxm_class)
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field_name = Openflow.Enums.to_atom(field_int, class)
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value = Openflow.Match.Field.codec(value_bin, field_name)
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mask = Openflow.Match.Field.codec(mask_bin, field_name)
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decode_fields(rest, [{field_name, {value, mask}}|acc])
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end
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defp decode_fields(<<class_int::16, field_int::7, 0::1, length::8, binary::bytes>>, acc) do
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<<value_bin::size(length)-bytes, rest::bytes>> = binary
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class = Openflow.Enums.to_atom(class_int, :oxm_class)
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field_name = Openflow.Enums.to_atom(field_int, class)
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value = Openflow.Match.Field.codec(value_bin, field_name)
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decode_fields(rest, [{field_name, value}|acc])
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end
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defp encode_fields([], acc), do: acc
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defp encode_fields([field|fields], acc) do
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encode_fields(fields, <<acc::bytes, (encode_field(field))::bytes>>)
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end
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defp encode_field(%{class: class, field: field, has_mask: true, value: value, mask: mask})
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when class == :nicira_ext_match or class == :onf_ext_match do
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vendor_int = Openflow.Enums.to_int(class, :experimenter_oxm_vendors)
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field_int = Openflow.Enums.to_int(field, class)
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has_mask_int = 1
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length = (byte_size(value) * 2) + 6
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<<0xffff::16, 0::7, has_mask_int::1, length::8, vendor_int::32, field_int::16, value::bytes, mask::bytes>>
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end
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defp encode_field(%{class: class, field: field, has_mask: false, value: value})
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when class == :nicira_ext_match or class == :onf_ext_match do
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vendor_int = Openflow.Enums.to_int(class, :experimenter_oxm_vendors)
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field_int = Openflow.Enums.to_int(field, class)
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has_mask_int = 0
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length = byte_size(value) + 6
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<<0xffff::16, 0::7, has_mask_int::1, length::8, vendor_int::32, field_int::16, value::bytes>>
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end
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defp encode_field(%{class: class, field: field, has_mask: true, value: value, mask: mask}) do
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class_int = Openflow.Enums.to_int(class, :oxm_class)
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field_int = Openflow.Enums.to_int(field, class)
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has_mask_int = 1
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length = byte_size(value) * 2
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<<class_int::16, field_int::7, has_mask_int::1, length::8, value::bytes, mask::bytes>>
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end
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defp encode_field(%{class: class, field: field, has_mask: false, value: value}) do
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class_int = Openflow.Enums.to_int(class, :oxm_class)
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field_int = Openflow.Enums.to_int(field, class)
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has_mask_int = 0
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length = byte_size(value)
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<<class_int::16, field_int::7, has_mask_int::1, length::8, value::bytes>>
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end
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defp keyword_to_oxm_fields([], acc), do: Enum.reverse(acc)
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defp keyword_to_oxm_fields([{field_name, field_value}|fields], acc) do
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keyword_to_oxm_fields(fields, [oxm_field(field_name, field_value)|acc])
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end
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defp oxm_field(field_name, {value, mask}) do
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value_bin = Openflow.Match.Field.codec(value, field_name)
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mask_bin = Openflow.Match.Field.codec(mask, field_name)
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match_class = Openflow.Match.Field.vendor_of(field_name)
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%{class: match_class, field: field_name, has_mask: true, value: value_bin, mask: mask_bin}
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end
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defp oxm_field(field_name, value) do
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value_bin = Openflow.Match.Field.codec(value, field_name)
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match_class = Openflow.Match.Field.vendor_of(field_name)
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%{class: match_class, field: field_name, has_mask: false, value: value_bin}
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end
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defp has_mask(oxm_field) when is_atom(oxm_field) do
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has_mask? =
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oxm_field
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|> to_string
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|> String.match?(~r/^masked_/)
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if has_mask? do
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1
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else
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0
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end
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end
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end
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