tres/lib/openflow/actions/nx_nat.ex
2019-05-05 23:39:45 +09:00

146 lines
4.1 KiB
Elixir

defmodule Openflow.Action.NxNat do
defstruct(
flags: [],
ipv4_min: nil,
ipv4_max: nil,
ipv6_min: nil,
ipv6_max: nil,
proto_min: nil,
proto_max: nil
)
@experimenter 0x00002320
@nxast 36
alias __MODULE__
alias Openflow.Action.Experimenter
def new(options \\ []) do
flags = Keyword.get(options, :flags, [])
ipv4_min = Keyword.get(options, :ipv4_min)
ipv4_max = Keyword.get(options, :ipv4_max)
ipv6_min = Keyword.get(options, :ipv6_min)
ipv6_max = Keyword.get(options, :ipv6_max)
proto_min = Keyword.get(options, :proto_min)
proto_max = Keyword.get(options, :proto_max)
%NxNat{
flags: flags,
ipv4_min: ipv4_min,
ipv4_max: ipv4_max,
ipv6_min: ipv6_min,
ipv6_max: ipv6_max,
proto_min: proto_min,
proto_max: proto_max
}
end
def to_binary(%NxNat{flags: flags} = nat) do
flags_int = Openflow.Enums.flags_to_int(flags, :nx_nat_flags)
range_flags =
nat
|> get_ranges
|> Openflow.Enums.flags_to_int(:nx_nat_range)
|> Openflow.Enums.int_to_flags(:nx_nat_range)
ranges_bin = encode_ranges("", range_flags, nat)
range_flags_int = Openflow.Enums.flags_to_int(range_flags, :nx_nat_range)
Experimenter.pack_exp_header(<<
@experimenter::32,
@nxast::16,
0::size(2)-unit(8),
flags_int::16,
range_flags_int::16,
ranges_bin::bytes
>>)
end
def read(<<@experimenter::32, @nxast::16, body::bytes>>) do
<<0::size(2)-unit(8), flags_int::16, range_flags_int::16, ranges_bin::bytes>> = body
flags = Openflow.Enums.int_to_flags(flags_int, :nx_nat_flags)
range_flags = Openflow.Enums.int_to_flags(range_flags_int, :nx_nat_range)
decode_ranges(%NxNat{flags: flags}, range_flags, ranges_bin)
end
# private functions
defp get_ranges(nat) do
nat
|> Map.from_struct()
|> Map.delete(:flags)
|> Enum.map(fn {k, v} -> if(not is_nil(v), do: k, else: nil) end)
|> Enum.filter(fn v -> not is_nil(v) end)
end
defp encode_ranges(acc, [], _nat), do: acc
defp encode_ranges(acc, [range | rest], nat) do
cond do
range == :ipv4_min or range == :ipv4_max ->
case Map.get(nat, range) do
{a1, a2, a3, a4} ->
encode_ranges(<<acc::bytes, a1, a2, a3, a4>>, rest, nat)
"" ->
encode_ranges(<<acc::bytes>>, rest, nat)
end
range == :ipv6_min or range == :ipv6_max ->
case Map.get(nat, range) do
{a1, a2, a3, a4, a5, a6, a7, a8} ->
encode_ranges(
<<acc::bytes, a1::16, a2::16, a3::16, a4::16, a5::16, a6::16, a7::16, a8::16>>,
rest,
nat
)
"" ->
encode_ranges(<<acc::bytes>>, rest, nat)
end
range == :proto_min or range == :proto_max ->
case Map.get(nat, range) do
proto when is_integer(proto) and proto in 1..0xFFFF ->
encode_ranges(<<acc::bytes, proto::16>>, rest, nat)
_ ->
encode_ranges(<<acc::bytes>>, rest, nat)
end
end
end
defp decode_ranges(nat, [], _), do: nat
defp decode_ranges(nat, [range | ranges], bin) do
cond do
range == :ipv4_min or range == :ipv4_max ->
case bin do
<<a1, a2, a3, a4, rest::bytes>> ->
decode_ranges(struct(nat, %{range => {a1, a2, a3, a4}}), ranges, rest)
rest ->
decode_ranges(struct(nat, %{range => ""}), ranges, rest)
end
range == :ipv6_min or range == :ipv6_max ->
case bin do
<<a1::16, a2::16, a3::16, a4::16, a5::16, a6::16, a7::16, a8::16, rest::bytes>> ->
decode_ranges(struct(nat, %{range => {a1, a2, a3, a4, a5, a6, a7, a8}}), ranges, rest)
rest ->
decode_ranges(struct(nat, %{range => ""}), ranges, rest)
end
range == :proto_min or range == :proto_max ->
case bin do
<<proto::16, rest::bytes>> when proto in 1..0xFFFF ->
decode_ranges(struct(nat, %{range => proto}), ranges, rest)
rest ->
decode_ranges(struct(nat, %{range => ""}), ranges, rest)
end
end
end
end