%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2004-2017. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%
-module(ssh_options).
-include("ssh.hrl").
-include_lib("kernel/include/file.hrl").
-export([default/1,
get_value/5, get_value/6,
put_value/5,
delete_key/5,
handle_options/2
]).
-export_type([options/0
]).
%%%================================================================
%%% Types
-type option_in() :: proplists:property() | proplists:proplist() .
-type option_class() :: internal_options | socket_options | user_options .
-type option_declaration() :: #{class := user_options,
chk := fun((any) -> boolean() | {true,any()}),
default => any()
}.
-type option_declarations() :: #{ {option_key(),def} := option_declaration() }.
-type error() :: {error,{eoptions,any()}} .
%%%================================================================
%%%
%%% Get an option
%%%
-spec get_value(option_class(), option_key(), options(),
atom(), non_neg_integer()) -> any() | no_return().
get_value(Class, Key, Opts, _CallerMod, _CallerLine) when is_map(Opts) ->
case Class of
internal_options -> maps:get(Key, maps:get(internal_options,Opts));
socket_options -> proplists:get_value(Key, maps:get(socket_options,Opts));
user_options -> maps:get(Key, Opts)
end;
get_value(Class, Key, Opts, _CallerMod, _CallerLine) ->
error({bad_options,Class, Key, Opts, _CallerMod, _CallerLine}).
-spec get_value(option_class(), option_key(), options(), fun(() -> any()),
atom(), non_neg_integer()) -> any() | no_return().
get_value(socket_options, Key, Opts, DefFun, _CallerMod, _CallerLine) when is_map(Opts) ->
proplists:get_value(Key, maps:get(socket_options,Opts), DefFun);
get_value(Class, Key, Opts, DefFun, CallerMod, CallerLine) when is_map(Opts) ->
try get_value(Class, Key, Opts, CallerMod, CallerLine)
of
undefined -> DefFun();
Value -> Value
catch
error:{badkey,Key} -> DefFun()
end;
get_value(Class, Key, Opts, _DefFun, _CallerMod, _CallerLine) ->
error({bad_options,Class, Key, Opts, _CallerMod, _CallerLine}).
%%%================================================================
%%%
%%% Put an option
%%%
-spec put_value(option_class(), option_in(), options(),
atom(), non_neg_integer()) -> options().
put_value(user_options, KeyVal, Opts, _CallerMod, _CallerLine) when is_map(Opts) ->
put_user_value(KeyVal, Opts);
put_value(internal_options, KeyVal, Opts, _CallerMod, _CallerLine) when is_map(Opts) ->
InternalOpts = maps:get(internal_options,Opts),
Opts#{internal_options := put_internal_value(KeyVal, InternalOpts)};
put_value(socket_options, KeyVal, Opts, _CallerMod, _CallerLine) when is_map(Opts) ->
SocketOpts = maps:get(socket_options,Opts),
Opts#{socket_options := put_socket_value(KeyVal, SocketOpts)}.
%%%----------------
put_user_value(L, Opts) when is_list(L) ->
lists:foldl(fun put_user_value/2, Opts, L);
put_user_value({Key,Value}, Opts) ->
Opts#{Key := Value}.
%%%----------------
put_internal_value(L, IntOpts) when is_list(L) ->
lists:foldl(fun put_internal_value/2, IntOpts, L);
put_internal_value({Key,Value}, IntOpts) ->
IntOpts#{Key => Value}.
%%%----------------
put_socket_value(L, SockOpts) when is_list(L) ->
L ++ SockOpts;
put_socket_value({Key,Value}, SockOpts) ->
[{Key,Value} | SockOpts];
put_socket_value(A, SockOpts) when is_atom(A) ->
[A | SockOpts].
%%%================================================================
%%%
%%% Delete an option
%%%
-spec delete_key(option_class(), option_key(), options(),
atom(), non_neg_integer()) -> options().
delete_key(internal_options, Key, Opts, _CallerMod, _CallerLine) when is_map(Opts) ->
InternalOpts = maps:get(internal_options,Opts),
Opts#{internal_options := maps:remove(Key, InternalOpts)}.
%%%================================================================
%%%
%%% Initialize the options
%%%
-spec handle_options(role(), proplists:proplist()) -> options() | error() .
-spec handle_options(role(), proplists:proplist(), options()) -> options() | error() .
handle_options(Role, PropList0) ->
handle_options(Role, PropList0, #{socket_options => [],
internal_options => #{},
user_options => []
}).
handle_options(Role, PropList0, Opts0) when is_map(Opts0),
is_list(PropList0) ->
PropList1 = proplists:unfold(PropList0),
try
OptionDefinitions = default(Role),
InitialMap =
maps:fold(
fun({K,def}, #{default:=V}, M) -> M#{K=>V};
(_,_,M) -> M
end,
Opts0#{user_options =>
maps:get(user_options,Opts0) ++ PropList1
},
OptionDefinitions),
%% Enter the user's values into the map; unknown keys are
%% treated as socket options
lists:foldl(fun(KV, Vals) ->
save(KV, OptionDefinitions, Vals)
end, InitialMap, PropList1)
catch
error:{eoptions, KV, undefined} ->
{error, {eoptions,KV}};
error:{eoptions, KV, Txt} when is_list(Txt) ->
{error, {eoptions,{KV,lists:flatten(Txt)}}};
error:{eoptions, KV, Extra} ->
{error, {eoptions,{KV,Extra}}}
end.
check_fun(Key, Defs) ->
#{chk := Fun} = maps:get({Key,def}, Defs),
Fun.
%%%================================================================
%%%
%%% Check and save one option
%%%
%%% First some prohibited inet options:
save({K,V}, _, _) when K == reuseaddr ;
K == active
->
forbidden_option(K, V);
%%% then compatibility conversions:
save({allow_user_interaction,V}, Opts, Vals) ->
save({user_interaction,V}, Opts, Vals);
%% Special case for socket options 'inet' and 'inet6'
save(Inet, Defs, OptMap) when Inet==inet ; Inet==inet6 ->
save({inet,Inet}, Defs, OptMap);
%% Two clauses to prepare for a proplists:unfold
save({Inet,true}, Defs, OptMap) when Inet==inet ; Inet==inet6 -> save({inet,Inet}, Defs, OptMap);
save({Inet,false}, _Defs, OptMap) when Inet==inet ; Inet==inet6 -> OptMap;
%% and finaly the 'real stuff':
save({Key,Value}, Defs, OptMap) when is_map(OptMap) ->
try (check_fun(Key,Defs))(Value)
of
true ->
OptMap#{Key := Value};
{true, ModifiedValue} ->
OptMap#{Key := ModifiedValue};
false ->
error({eoptions, {Key,Value}, "Bad value"})
catch
%% An unknown Key (= not in the definition map) is
%% regarded as an inet option:
error:{badkey,{inet,def}} ->
%% atomic (= non-tuple) options 'inet' and 'inet6':
OptMap#{socket_options := [Value | maps:get(socket_options,OptMap)]};
error:{badkey,{Key,def}} ->
OptMap#{socket_options := [{Key,Value} | maps:get(socket_options,OptMap)]};
%% But a Key that is known but the value does not validate
%% by the check fun will give an error exception:
error:{check,{BadValue,Extra}} ->
error({eoptions, {Key,BadValue}, Extra})
end;
save(Opt, _Defs, OptMap) when is_map(OptMap) ->
OptMap#{socket_options := [Opt | maps:get(socket_options,OptMap)]}.
%%%================================================================
%%%
%%% Default options
%%%
-spec default(role() | common) -> option_declarations() .
default(server) ->
(default(common))
#{
{subsystems, def} =>
#{default => [ssh_sftpd:subsystem_spec([])],
chk => fun(L) ->
is_list(L) andalso
lists:all(fun({Name,{CB,Args}}) ->
check_string(Name) andalso
is_atom(CB) andalso
is_list(Args);
(_) ->
false
end, L)
end,
class => user_options
},
{shell, def} =>
#{default => {shell, start, []},
chk => fun({M,F,A}) -> is_atom(M) andalso is_atom(F) andalso is_list(A);
(V) -> check_function1(V) orelse check_function2(V)
end,
class => user_options
},
{exec, def} => % FIXME: need some archeology....
#{default => undefined,
chk => fun({M,F,_}) -> is_atom(M) andalso is_atom(F);
(V) -> is_function(V)
end,
class => user_options
},
{ssh_cli, def} =>
#{default => undefined,
chk => fun({Cb, As}) -> is_atom(Cb) andalso is_list(As);
(V) -> V == no_cli
end,
class => user_options
},
{system_dir, def} =>
#{default => "/etc/ssh",
chk => fun(V) -> check_string(V) andalso check_dir(V) end,
class => user_options
},
{auth_method_kb_interactive_data, def} =>
#{default => undefined, % Default value can be constructed when User is known
chk => fun({S1,S2,S3,B}) ->
check_string(S1) andalso
check_string(S2) andalso
check_string(S3) andalso
is_boolean(B);
(F) ->
check_function3(F)
end,
class => user_options
},
{user_passwords, def} =>
#{default => [],
chk => fun(V) ->
is_list(V) andalso
lists:all(fun({S1,S2}) ->
check_string(S1) andalso
check_string(S2)
end, V)
end,
class => user_options
},
{password, def} =>
#{default => undefined,
chk => fun check_string/1,
class => user_options
},
{dh_gex_groups, def} =>
#{default => undefined,
chk => fun check_dh_gex_groups/1,
class => user_options
},
{dh_gex_limits, def} =>
#{default => {0, infinity},
chk => fun({I1,I2}) ->
check_pos_integer(I1) andalso
check_pos_integer(I2) andalso
I1 < I2;
(_) ->
false
end,
class => user_options
},
{pwdfun, def} =>
#{default => undefined,
chk => fun(V) -> check_function4(V) orelse check_function2(V) end,
class => user_options
},
{negotiation_timeout, def} =>
#{default => 2*60*1000,
chk => fun check_timeout/1,
class => user_options
},
{max_sessions, def} =>
#{default => infinity,
chk => fun check_pos_integer/1,
class => user_options
},
{max_channels, def} =>
#{default => infinity,
chk => fun check_pos_integer/1,
class => user_options
},
{parallel_login, def} =>
#{default => false,
chk => fun erlang:is_boolean/1,
class => user_options
},
{minimal_remote_max_packet_size, def} =>
#{default => 0,
chk => fun check_pos_integer/1,
class => user_options
},
{failfun, def} =>
#{default => fun(_,_,_) -> void end,
chk => fun(V) -> check_function3(V) orelse
check_function2(V) % Backwards compatibility
end,
class => user_options
},
{connectfun, def} =>
#{default => fun(_,_,_) -> void end,
chk => fun check_function3/1,
class => user_options
},
%%%%% Undocumented
{infofun, def} =>
#{default => fun(_,_,_) -> void end,
chk => fun(V) -> check_function3(V) orelse
check_function2(V) % Backwards compatibility
end,
class => user_options
}
};
default(client) ->
(default(common))
#{
{dsa_pass_phrase, def} =>
#{default => undefined,
chk => fun check_string/1,
class => user_options
},
{rsa_pass_phrase, def} =>
#{default => undefined,
chk => fun check_string/1,
class => user_options
},
{silently_accept_hosts, def} =>
#{default => false,
chk => fun check_silently_accept_hosts/1,
class => user_options
},
{user_interaction, def} =>
#{default => true,
chk => fun erlang:is_boolean/1,
class => user_options
},
{pref_public_key_algs, def} =>
#{default => ssh_transport:default_algorithms(public_key),
chk => fun check_pref_public_key_algs/1,
class => user_options
},
{dh_gex_limits, def} =>
#{default => {1024, 6144, 8192}, % FIXME: Is this true nowadays?
chk => fun({Min,I,Max}) ->
lists:all(fun check_pos_integer/1,
[Min,I,Max]);
(_) -> false
end,
class => user_options
},
{connect_timeout, def} =>
#{default => infinity,
chk => fun check_timeout/1,
class => user_options
},
{user, def} =>
#{default =>
begin
Env = case os:type() of
{win32, _} -> "USERNAME";
{unix, _} -> "LOGNAME"
end,
case os:getenv(Env) of
false ->
case os:getenv("USER") of
false -> undefined;
User -> User
end;
User ->
User
end
end,
chk => fun check_string/1,
class => user_options
},
{password, def} =>
#{default => undefined,
chk => fun check_string/1,
class => user_options
},
{quiet_mode, def} =>
#{default => false,
chk => fun erlang:is_boolean/1,
class => user_options
},
%%%%% Undocumented
{keyboard_interact_fun, def} =>
#{default => undefined,
chk => fun check_function3/1,
class => user_options
}
};
default(common) ->
#{
{user_dir, def} =>
#{default => false, % FIXME: TBD ~/.ssh at time of call when user is known
chk => fun(V) -> check_string(V) andalso check_dir(V) end,
class => user_options
},
{preferred_algorithms, def} =>
#{default => ssh:default_algorithms(),
chk => fun check_preferred_algorithms/1,
class => user_options
},
{id_string, def} =>
#{default => undefined, % FIXME: see ssh_transport:ssh_vsn/0
chk => fun(random) ->
{true, {random,2,5}}; % 2 - 5 random characters
({random,I1,I2}) ->
%% Undocumented
check_pos_integer(I1) andalso
check_pos_integer(I2) andalso
I1=<I2;
(V) ->
check_string(V)
end,
class => user_options
},
{key_cb, def} =>
#{default => {ssh_file, []},
chk => fun({Mod,Opts}) -> is_atom(Mod) andalso is_list(Opts);
(Mod) when is_atom(Mod) -> {true, {Mod,[]}};
(_) -> false
end,
class => user_options
},
{profile, def} =>
#{default => ?DEFAULT_PROFILE,
chk => fun erlang:is_atom/1,
class => user_options
},
{idle_time, def} =>
#{default => infinity,
chk => fun check_timeout/1,
class => user_options
},
%% This is a "SocketOption"...
%% {fd, def} =>
%% #{default => undefined,
%% chk => fun erlang:is_integer/1,
%% class => user_options
%% },
{disconnectfun, def} =>
#{default => fun(_) -> void end,
chk => fun check_function1/1,
class => user_options
},
{unexpectedfun, def} =>
#{default => fun(_,_) -> report end,
chk => fun check_function2/1,
class => user_options
},
{ssh_msg_debug_fun, def} =>
#{default => fun(_,_,_,_) -> void end,
chk => fun check_function4/1,
class => user_options
},
{rekey_limit, def} => % FIXME: Why not common?
#{default => 1024000000,
chk => fun check_non_neg_integer/1,
class => user_options
},
{auth_methods, def} =>
#{default => ?SUPPORTED_AUTH_METHODS,
chk => fun(As) ->
try
Sup = string:tokens(?SUPPORTED_AUTH_METHODS, ","),
New = string:tokens(As, ","),
[] == [X || X <- New,
not lists:member(X,Sup)]
catch
_:_ -> false
end
end,
class => user_options
},
%%%%% Undocumented
{transport, def} =>
#{default => ?DEFAULT_TRANSPORT,
chk => fun({A,B,C}) ->
is_atom(A) andalso is_atom(B) andalso is_atom(C)
end,
class => user_options
},
{vsn, def} =>
#{default => {2,0},
chk => fun({Maj,Min}) -> check_non_neg_integer(Maj) andalso check_non_neg_integer(Min);
(_) -> false
end,
class => user_options
},
{tstflg, def} =>
#{default => [],
chk => fun erlang:is_list/1,
class => user_options
},
{user_dir_fun, def} =>
#{default => undefined,
chk => fun check_function1/1,
class => user_options
},
{max_random_length_padding, def} =>
#{default => ?MAX_RND_PADDING_LEN,
chk => fun check_non_neg_integer/1,
class => user_options
},
{send_ext_info, def} =>
#{default => true,
chk => fun erlang:is_boolean/1,
class => user_options
},
{recv_ext_info, def} =>
#{default => true,
chk => fun erlang:is_boolean/1,
class => user_options
}
}.
%%%================================================================
%%%================================================================
%%%================================================================
%%%
%%% check_*/1 -> true | false | error({check,Spec})
%%% See error_in_check/2,3
%%%
%%% error_in_check(BadValue) -> error_in_check(BadValue, undefined).
error_in_check(BadValue, Extra) -> error({check,{BadValue,Extra}}).
%%%----------------------------------------------------------------
check_timeout(infinity) -> true;
check_timeout(I) -> check_pos_integer(I).
%%%----------------------------------------------------------------
check_pos_integer(I) -> is_integer(I) andalso I>0.
%%%----------------------------------------------------------------
check_non_neg_integer(I) -> is_integer(I) andalso I>=0.
%%%----------------------------------------------------------------
check_function1(F) -> is_function(F,1).
check_function2(F) -> is_function(F,2).
check_function3(F) -> is_function(F,3).
check_function4(F) -> is_function(F,4).
%%%----------------------------------------------------------------
check_pref_public_key_algs(V) ->
%% Get the dynamically supported keys, that is, thoose
%% that are stored
PKs = ssh_transport:supported_algorithms(public_key),
CHK = fun(A, Ack) ->
case lists:member(A, PKs) of
true ->
case lists:member(A,Ack) of
false -> [A|Ack];
true -> Ack % Remove duplicates
end;
false -> error_in_check(A, "Not supported public key")
end
end,
case lists:foldr(
fun(ssh_dsa, Ack) -> CHK('ssh-dss', Ack); % compatibility
(ssh_rsa, Ack) -> CHK('ssh-rsa', Ack); % compatibility
(X, Ack) -> CHK(X, Ack)
end, [], V)
of
V -> true;
[] -> false;
V1 -> {true,V1}
end.
%%%----------------------------------------------------------------
%% Check that it is a directory and is readable
check_dir(Dir) ->
case file:read_file_info(Dir) of
{ok, #file_info{type = directory,
access = Access}} ->
case Access of
read -> true;
read_write -> true;
_ -> error_in_check(Dir, eacces)
end;
{ok, #file_info{}}->
error_in_check(Dir, enotdir);
{error, Error} ->
error_in_check(Dir, Error)
end.
%%%----------------------------------------------------------------
check_string(S) -> is_list(S). % FIXME: stub
%%%----------------------------------------------------------------
check_dh_gex_groups({file,File}) when is_list(File) ->
case file:consult(File) of
{ok, GroupDefs} ->
check_dh_gex_groups(GroupDefs);
{error, Error} ->
error_in_check({file,File},Error)
end;
check_dh_gex_groups({ssh_moduli_file,File}) when is_list(File) ->
case file:open(File,[read]) of
{ok,D} ->
try
read_moduli_file(D, 1, [])
of
{ok,Moduli} ->
check_dh_gex_groups(Moduli);
{error,Error} ->
error_in_check({ssh_moduli_file,File}, Error)
catch
_:_ ->
error_in_check({ssh_moduli_file,File}, "Bad format in file "++File)
after
file:close(D)
end;
{error, Error} ->
error_in_check({ssh_moduli_file,File}, Error)
end;
check_dh_gex_groups(L0) when is_list(L0), is_tuple(hd(L0)) ->
{true,
collect_per_size(
lists:foldl(
fun({N,G,P}, Acc) when is_integer(N),N>0,
is_integer(G),G>0,
is_integer(P),P>0 ->
[{N,{G,P}} | Acc];
({N,{G,P}}, Acc) when is_integer(N),N>0,
is_integer(G),G>0,
is_integer(P),P>0 ->
[{N,{G,P}} | Acc];
({N,GPs}, Acc) when is_list(GPs) ->
lists:foldr(fun({Gi,Pi}, Acci) when is_integer(Gi),Gi>0,
is_integer(Pi),Pi>0 ->
[{N,{Gi,Pi}} | Acci]
end, Acc, GPs)
end, [], L0))};
check_dh_gex_groups(_) ->
false.
collect_per_size(L) ->
lists:foldr(
fun({Sz,GP}, [{Sz,GPs}|Acc]) -> [{Sz,[GP|GPs]}|Acc];
({Sz,GP}, Acc) -> [{Sz,[GP]}|Acc]
end, [], lists:sort(L)).
read_moduli_file(D, I, Acc) ->
case io:get_line(D,"") of
{error,Error} ->
{error,Error};
eof ->
{ok, Acc};
"#" ++ _ -> read_moduli_file(D, I+1, Acc);
<<"#",_/binary>> -> read_moduli_file(D, I+1, Acc);
Data ->
Line = if is_binary(Data) -> binary_to_list(Data);
is_list(Data) -> Data
end,
try
[_Time,_Class,_Tests,_Tries,Size,G,P] = string:tokens(Line," \r\n"),
M = {list_to_integer(Size),
{list_to_integer(G), list_to_integer(P,16)}
},
read_moduli_file(D, I+1, [M|Acc])
catch
_:_ ->
read_moduli_file(D, I+1, Acc)
end
end.
%%%----------------------------------------------------------------
-define(SHAs, [md5, sha, sha224, sha256, sha384, sha512]).
check_silently_accept_hosts(B) when is_boolean(B) -> true;
check_silently_accept_hosts(F) when is_function(F,2) -> true;
check_silently_accept_hosts({false,S}) when is_atom(S) -> valid_hash(S);
check_silently_accept_hosts({S,F}) when is_function(F,2) -> valid_hash(S);
check_silently_accept_hosts(_) -> false.
valid_hash(S) -> valid_hash(S, proplists:get_value(hashs,crypto:supports())).
valid_hash(S, Ss) when is_atom(S) -> lists:member(S, ?SHAs) andalso lists:member(S, Ss);
valid_hash(L, Ss) when is_list(L) -> lists:all(fun(S) -> valid_hash(S,Ss) end, L);
valid_hash(X, _) -> error_in_check(X, "Expect atom or list in fingerprint spec").
%%%----------------------------------------------------------------
check_preferred_algorithms(Algs) ->
[error_in_check(K,"Bad preferred_algorithms key")
|| {K,_} <- Algs,
not lists:keymember(K,1,ssh:default_algorithms())],
try alg_duplicates(Algs, [], [])
of
[] ->
{true,
[case proplists:get_value(Key, Algs) of
undefined ->
{Key,DefAlgs};
Vals ->
handle_pref_alg(Key,Vals,SupAlgs)
end
|| {{Key,DefAlgs}, {Key,SupAlgs}} <- lists:zip(ssh:default_algorithms(),
ssh_transport:supported_algorithms())
]
};
Dups ->
error_in_check(Dups, "Duplicates")
catch
_:_ ->
false
end.
alg_duplicates([{K,V}|KVs], Ks, Dups0) ->
Dups =
case lists:member(K,Ks) of
true -> [K|Dups0];
false -> Dups0
end,
case V--lists:usort(V) of
[] -> alg_duplicates(KVs, [K|Ks], Dups);
Ds -> alg_duplicates(KVs, [K|Ks], Dups++Ds)
end;
alg_duplicates([], _Ks, Dups) ->
Dups.
handle_pref_alg(Key,
Vs=[{client2server,C2Ss=[_|_]},{server2client,S2Cs=[_|_]}],
[{client2server,Sup_C2Ss},{server2client,Sup_S2Cs}]
) ->
chk_alg_vs(Key, C2Ss, Sup_C2Ss),
chk_alg_vs(Key, S2Cs, Sup_S2Cs),
{Key, Vs};
handle_pref_alg(Key,
Vs=[{server2client,[_|_]},{client2server,[_|_]}],
Sup=[{client2server,_},{server2client,_}]
) ->
handle_pref_alg(Key, lists:reverse(Vs), Sup);
handle_pref_alg(Key,
Vs=[V|_],
Sup=[{client2server,_},{server2client,_}]
) when is_atom(V) ->
handle_pref_alg(Key, [{client2server,Vs},{server2client,Vs}], Sup);
handle_pref_alg(Key,
Vs=[V|_],
Sup=[S|_]
) when is_atom(V), is_atom(S) ->
chk_alg_vs(Key, Vs, Sup),
{Key, Vs};
handle_pref_alg(Key, Vs, _) ->
error_in_check({Key,Vs}, "Badly formed list").
chk_alg_vs(OptKey, Values, SupportedValues) ->
case (Values -- SupportedValues) of
[] -> Values;
[none] -> [none]; % for testing only
Bad -> error_in_check({OptKey,Bad}, "Unsupported value(s) found")
end.
%%%----------------------------------------------------------------
forbidden_option(K,V) ->
Txt = io_lib:format("The option '~s' is used internally. The "
"user is not allowed to specify this option.",
[K]),
error({eoptions, {K,V}, Txt}).
%%%----------------------------------------------------------------
