%%% Copyright (c) 2011-2023 Michael Santos <michael.santos@gmail.com>. All
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%%% Copyright (c) 2013, YAMAMOTO Takashi
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%% @doc tunctl behaviour for NetBSD.
%%
%% NOTE: On NetBSD, tap(4) and tun(4) are separate drivers.
%% The former, which this module deals with, is always `no_pi'.
%%
%% References:
%%
%% * https://man.netbsd.org/tap.4
%%
%% * https://man.netbsd.org/tun.4
-module(tunctl_netbsd).
-behaviour(tunctl).

-include("tuntap.hrl").

-include_lib("procket/include/ioctl.hrl").
-include_lib("procket/include/procket.hrl").

-export([
    create/2,
    persist/2,
    owner/2,
    group/2,

    header/1
]).

%%--------------------------------------------------------------------
%%% Exports
%%--------------------------------------------------------------------
create(<<>>, Opt) ->
    create(<<"tap0">>, Opt);
create(Ifname, Opt) when byte_size(Ifname) < ?IFNAMSIZ, is_list(Opt) ->
    case proplists:get_bool(no_pi, Opt) of
        true ->
            case procket:dev(binary_to_list(Ifname)) of
                {ok, FD} ->
                    {ok, FD, Ifname};
                Error ->
                    Error
            end;
        false ->
            {error, unsupported}
    end.

%% N/A
persist(_FD, _Status) ->
    ok.

owner(_FD, _Owner) ->
    ok.

group(_FD, _Group) ->
    ok.

header(<<?UINT16(Flags), ?UINT16(Proto), Buf/binary>>) ->
    {tun_pi, Flags, Proto, Buf}.

%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------