%%%----------------------------------------------------------------------
%%% File : mod_http_api.erl
%%% Author : Christophe romain <christophe.romain@process-one.net>
%%% Purpose : Implements REST API for ejabberd using JSON data
%%% Created : 15 Sep 2014 by Christophe Romain <christophe.romain@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2020 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License along
%%% with this program; if not, write to the Free Software Foundation, Inc.,
%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
%%%
%%%----------------------------------------------------------------------
-module(mod_http_api).
-author('cromain@process-one.net').
-behaviour(gen_mod).
-export([start/2, stop/1, reload/3, process/2, depends/2,
mod_options/1, mod_doc/0]).
-include_lib("xmpp/include/xmpp.hrl").
-include("logger.hrl").
-include("ejabberd_http.hrl").
-include("ejabberd_stacktrace.hrl").
-include("translate.hrl").
-define(DEFAULT_API_VERSION, 0).
-define(CT_PLAIN,
{<<"Content-Type">>, <<"text/plain">>}).
-define(CT_XML,
{<<"Content-Type">>, <<"text/xml; charset=utf-8">>}).
-define(CT_JSON,
{<<"Content-Type">>, <<"application/json">>}).
-define(AC_ALLOW_ORIGIN,
{<<"Access-Control-Allow-Origin">>, <<"*">>}).
-define(AC_ALLOW_METHODS,
{<<"Access-Control-Allow-Methods">>,
<<"GET, POST, OPTIONS">>}).
-define(AC_ALLOW_HEADERS,
{<<"Access-Control-Allow-Headers">>,
<<"Content-Type, Authorization, X-Admin">>}).
-define(AC_MAX_AGE,
{<<"Access-Control-Max-Age">>, <<"86400">>}).
-define(OPTIONS_HEADER,
[?CT_PLAIN, ?AC_ALLOW_ORIGIN, ?AC_ALLOW_METHODS,
?AC_ALLOW_HEADERS, ?AC_MAX_AGE]).
-define(HEADER(CType),
[CType, ?AC_ALLOW_ORIGIN, ?AC_ALLOW_HEADERS]).
%% -------------------
%% Module control
%% -------------------
start(_Host, _Opts) ->
ok.
stop(_Host) ->
ok.
reload(_Host, _NewOpts, _OldOpts) ->
ok.
depends(_Host, _Opts) ->
[].
%% ----------
%% basic auth
%% ----------
extract_auth(#request{auth = HTTPAuth, ip = {IP, _}, opts = Opts}) ->
Info = case HTTPAuth of
{SJID, Pass} ->
try jid:decode(SJID) of
#jid{luser = User, lserver = Server} ->
case ejabberd_auth:check_password(User, <<"">>, Server, Pass) of
true ->
#{usr => {User, Server, <<"">>}, caller_server => Server};
false ->
{error, invalid_auth}
end
catch _:{bad_jid, _} ->
{error, invalid_auth}
end;
{oauth, Token, _} ->
case ejabberd_oauth:check_token(Token) of
{ok, {U, S}, Scope} ->
#{usr => {U, S, <<"">>}, oauth_scope => Scope, caller_server => S};
{false, Reason} ->
{error, Reason}
end;
invalid ->
{error, invalid_auth};
_ ->
#{}
end,
case Info of
Map when is_map(Map) ->
Tag = proplists:get_value(tag, Opts, <<>>),
Map#{caller_module => ?MODULE, ip => IP, tag => Tag};
_ ->
?DEBUG("Invalid auth data: ~p", [Info]),
Info
end.
%% ------------------
%% command processing
%% ------------------
%process(Call, Request) ->
% ?DEBUG("~p~n~p", [Call, Request]), ok;
process(_, #request{method = 'POST', data = <<>>}) ->
?DEBUG("Bad Request: no data", []),
badrequest_response(<<"Missing POST data">>);
process([Call], #request{method = 'POST', data = Data, ip = IPPort} = Req) ->
Version = get_api_version(Req),
try
Args = extract_args(Data),
log(Call, Args, IPPort),
perform_call(Call, Args, Req, Version)
catch
%% TODO We need to refactor to remove redundant error return formatting
throw:{error, unknown_command} ->
json_format({404, 44, <<"Command not found.">>});
_:{error,{_,invalid_json}} = _Err ->
?DEBUG("Bad Request: ~p", [_Err]),
badrequest_response(<<"Invalid JSON input">>);
?EX_RULE(_Class, _Error, Stack) ->
StackTrace = ?EX_STACK(Stack),
?DEBUG("Bad Request: ~p ~p", [_Error, StackTrace]),
badrequest_response()
end;
process([Call], #request{method = 'GET', q = Data, ip = {IP, _}} = Req) ->
Version = get_api_version(Req),
try
Args = case Data of
[{nokey, <<>>}] -> [];
_ -> Data
end,
log(Call, Args, IP),
perform_call(Call, Args, Req, Version)
catch
%% TODO We need to refactor to remove redundant error return formatting
throw:{error, unknown_command} ->
json_format({404, 44, <<"Command not found.">>});
?EX_RULE(_, _Error, Stack) ->
StackTrace = ?EX_STACK(Stack),
?DEBUG("Bad Request: ~p ~p", [_Error, StackTrace]),
badrequest_response()
end;
process([_Call], #request{method = 'OPTIONS', data = <<>>}) ->
{200, ?OPTIONS_HEADER, []};
process(_, #request{method = 'OPTIONS'}) ->
{400, ?OPTIONS_HEADER, []};
process(_Path, Request) ->
?DEBUG("Bad Request: no handler ~p", [Request]),
json_error(400, 40, <<"Missing command name.">>).
perform_call(Command, Args, Req, Version) ->
case catch binary_to_existing_atom(Command, utf8) of
Call when is_atom(Call) ->
case extract_auth(Req) of
{error, expired} -> invalid_token_response();
{error, not_found} -> invalid_token_response();
{error, invalid_auth} -> unauthorized_response();
Auth when is_map(Auth) ->
Result = handle(Call, Auth, Args, Version),
json_format(Result)
end;
_ ->
json_error(404, 40, <<"Endpoint not found.">>)
end.
%% Be tolerant to make API more easily usable from command-line pipe.
extract_args(<<"\n">>) -> [];
extract_args(Data) ->
case jiffy:decode(Data) of
List when is_list(List) -> List;
{List} when is_list(List) -> List;
Other -> [Other]
end.
% get API version N from last "vN" element in URL path
get_api_version(#request{path = Path}) ->
get_api_version(lists:reverse(Path));
get_api_version([<<"v", String/binary>> | Tail]) ->
case catch binary_to_integer(String) of
N when is_integer(N) ->
N;
_ ->
get_api_version(Tail)
end;
get_api_version([_Head | Tail]) ->
get_api_version(Tail);
get_api_version([]) ->
?DEFAULT_API_VERSION.
%% ----------------
%% command handlers
%% ----------------
%% TODO Check accept types of request before decided format of reply.
% generic ejabberd command handler
handle(Call, Auth, Args, Version) when is_atom(Call), is_list(Args) ->
Args2 = [{misc:binary_to_atom(Key), Value} || {Key, Value} <- Args],
try handle2(Call, Auth, Args2, Version)
catch throw:not_found ->
{404, <<"not_found">>};
throw:{not_found, Why} when is_atom(Why) ->
{404, misc:atom_to_binary(Why)};
throw:{not_found, Msg} ->
{404, iolist_to_binary(Msg)};
throw:not_allowed ->
{401, <<"not_allowed">>};
throw:{not_allowed, Why} when is_atom(Why) ->
{401, misc:atom_to_binary(Why)};
throw:{not_allowed, Msg} ->
{401, iolist_to_binary(Msg)};
throw:{error, account_unprivileged} ->
{403, 31, <<"Command need to be run with admin privilege.">>};
throw:{error, access_rules_unauthorized} ->
{403, 32, <<"AccessRules: Account does not have the right to perform the operation.">>};
throw:{invalid_parameter, Msg} ->
{400, iolist_to_binary(Msg)};
throw:{error, Why} when is_atom(Why) ->
{400, misc:atom_to_binary(Why)};
throw:{error, Msg} ->
{400, iolist_to_binary(Msg)};
throw:Error when is_atom(Error) ->
{400, misc:atom_to_binary(Error)};
throw:Msg when is_list(Msg); is_binary(Msg) ->
{400, iolist_to_binary(Msg)};
?EX_RULE(Class, Error, Stack) ->
StackTrace = ?EX_STACK(Stack),
?ERROR_MSG("REST API Error: "
"~ts(~p) -> ~p:~p ~p",
[Call, hide_sensitive_args(Args),
Class, Error, StackTrace]),
{500, <<"internal_error">>}
end.
handle2(Call, Auth, Args, Version) when is_atom(Call), is_list(Args) ->
{ArgsF, ArgsR, _ResultF} = ejabberd_commands:get_command_format(Call, Auth, Version),
ArgsFormatted = format_args(Call, rename_old_args(Args, ArgsR), ArgsF),
case ejabberd_commands:execute_command2(Call, ArgsFormatted, Auth, Version) of
{error, Error} ->
throw(Error);
Res ->
format_command_result(Call, Auth, Res, Version)
end.
rename_old_args(Args, []) ->
Args;
rename_old_args(Args, [{OldName, NewName} | ArgsR]) ->
Args2 = case lists:keytake(OldName, 1, Args) of
{value, {OldName, Value}, ArgsTail} ->
[{NewName, Value} | ArgsTail];
false ->
Args
end,
rename_old_args(Args2, ArgsR).
get_elem_delete(Call, A, L, F) ->
case proplists:get_all_values(A, L) of
[Value] -> {Value, proplists:delete(A, L)};
[_, _ | _] ->
?INFO_MSG("Command ~ts call rejected, it has duplicate attribute ~w",
[Call, A]),
throw({invalid_parameter,
io_lib:format("Request have duplicate argument: ~w", [A])});
[] ->
case F of
{list, _} ->
{[], L};
_ ->
?INFO_MSG("Command ~ts call rejected, missing attribute ~w",
[Call, A]),
throw({invalid_parameter,
io_lib:format("Request have missing argument: ~w", [A])})
end
end.
format_args(Call, Args, ArgsFormat) ->
{ArgsRemaining, R} = lists:foldl(fun ({ArgName,
ArgFormat},
{Args1, Res}) ->
{ArgValue, Args2} =
get_elem_delete(Call, ArgName,
Args1, ArgFormat),
Formatted = format_arg(ArgValue,
ArgFormat),
{Args2, Res ++ [Formatted]}
end,
{Args, []}, ArgsFormat),
case ArgsRemaining of
[] -> R;
L when is_list(L) ->
ExtraArgs = [N || {N, _} <- L],
?INFO_MSG("Command ~ts call rejected, it has unknown arguments ~w",
[Call, ExtraArgs]),
throw({invalid_parameter,
io_lib:format("Request have unknown arguments: ~w", [ExtraArgs])})
end.
format_arg({Elements},
{list, {_ElementDefName, {tuple, [{_Tuple1N, Tuple1S}, {_Tuple2N, Tuple2S}]} = Tuple}})
when is_list(Elements) andalso
(Tuple1S == binary orelse Tuple1S == string) ->
lists:map(fun({F1, F2}) ->
{format_arg(F1, Tuple1S), format_arg(F2, Tuple2S)};
({Val}) when is_list(Val) ->
format_arg({Val}, Tuple)
end, Elements);
format_arg(Elements,
{list, {_ElementDefName, {list, _} = ElementDefFormat}})
when is_list(Elements) ->
[{format_arg(Element, ElementDefFormat)}
|| Element <- Elements];
format_arg(Elements,
{list, {_ElementDefName, ElementDefFormat}})
when is_list(Elements) ->
[format_arg(Element, ElementDefFormat)
|| Element <- Elements];
format_arg({[{Name, Value}]},
{tuple, [{_Tuple1N, Tuple1S}, {_Tuple2N, Tuple2S}]})
when Tuple1S == binary;
Tuple1S == string ->
{format_arg(Name, Tuple1S), format_arg(Value, Tuple2S)};
format_arg({Elements},
{tuple, ElementsDef})
when is_list(Elements) ->
F = lists:map(fun({TElName, TElDef}) ->
case lists:keyfind(atom_to_binary(TElName, latin1), 1, Elements) of
{_, Value} ->
format_arg(Value, TElDef);
_ when TElDef == binary; TElDef == string ->
<<"">>;
_ ->
?ERROR_MSG("Missing field ~p in tuple ~p", [TElName, Elements]),
throw({invalid_parameter,
io_lib:format("Missing field ~w in tuple ~w", [TElName, Elements])})
end
end, ElementsDef),
list_to_tuple(F);
format_arg(Elements, {list, ElementsDef})
when is_list(Elements) and is_atom(ElementsDef) ->
[format_arg(Element, ElementsDef)
|| Element <- Elements];
format_arg(Arg, integer) when is_integer(Arg) -> Arg;
format_arg(Arg, binary) when is_list(Arg) -> process_unicode_codepoints(Arg);
format_arg(Arg, binary) when is_binary(Arg) -> Arg;
format_arg(Arg, string) when is_list(Arg) -> Arg;
format_arg(Arg, string) when is_binary(Arg) -> binary_to_list(Arg);
format_arg(undefined, binary) -> <<>>;
format_arg(undefined, string) -> "";
format_arg(Arg, Format) ->
?ERROR_MSG("Don't know how to format Arg ~p for format ~p", [Arg, Format]),
throw({invalid_parameter,
io_lib:format("Arg ~w is not in format ~w",
[Arg, Format])}).
process_unicode_codepoints(Str) ->
iolist_to_binary(lists:map(fun(X) when X > 255 -> unicode:characters_to_binary([X]);
(Y) -> Y
end, Str)).
%% ----------------
%% internal helpers
%% ----------------
format_command_result(Cmd, Auth, Result, Version) ->
{_, _, ResultFormat} = ejabberd_commands:get_command_format(Cmd, Auth, Version),
case {ResultFormat, Result} of
{{_, rescode}, V} when V == true; V == ok ->
{200, 0};
{{_, rescode}, _} ->
{200, 1};
{_, {error, ErrorAtom, Code, Msg}} ->
format_error_result(ErrorAtom, Code, Msg);
{{_, restuple}, {V, Text}} when V == true; V == ok ->
{200, iolist_to_binary(Text)};
{{_, restuple}, {ErrorAtom, Msg}} ->
format_error_result(ErrorAtom, 0, Msg);
{{_, {list, _}}, _V} ->
{_, L} = format_result(Result, ResultFormat),
{200, L};
{{_, {tuple, _}}, _V} ->
{_, T} = format_result(Result, ResultFormat),
{200, T};
_ ->
{200, {[format_result(Result, ResultFormat)]}}
end.
format_result(Atom, {Name, atom}) ->
{misc:atom_to_binary(Name), misc:atom_to_binary(Atom)};
format_result(Int, {Name, integer}) ->
{misc:atom_to_binary(Name), Int};
format_result([String | _] = StringList, {Name, string}) when is_list(String) ->
Binarized = iolist_to_binary(string:join(StringList, "\n")),
{misc:atom_to_binary(Name), Binarized};
format_result(String, {Name, string}) ->
{misc:atom_to_binary(Name), iolist_to_binary(String)};
format_result(Code, {Name, rescode}) ->
{misc:atom_to_binary(Name), Code == true orelse Code == ok};
format_result({Code, Text}, {Name, restuple}) ->
{misc:atom_to_binary(Name),
{[{<<"res">>, Code == true orelse Code == ok},
{<<"text">>, iolist_to_binary(Text)}]}};
format_result(Code, {Name, restuple}) ->
{misc:atom_to_binary(Name),
{[{<<"res">>, Code == true orelse Code == ok},
{<<"text">>, <<"">>}]}};
format_result(Els, {Name, {list, {_, {tuple, [{_, atom}, _]}} = Fmt}}) ->
{misc:atom_to_binary(Name), {[format_result(El, Fmt) || El <- Els]}};
format_result(Els, {Name, {list, {_, {tuple, [{name, string}, {value, _}]}} = Fmt}}) ->
{misc:atom_to_binary(Name), {[format_result(El, Fmt) || El <- Els]}};
format_result(Els, {Name, {list, Def}}) ->
{misc:atom_to_binary(Name), [element(2, format_result(El, Def)) || El <- Els]};
format_result(Tuple, {_Name, {tuple, [{_, atom}, ValFmt]}}) ->
{Name2, Val} = Tuple,
{_, Val2} = format_result(Val, ValFmt),
{misc:atom_to_binary(Name2), Val2};
format_result(Tuple, {_Name, {tuple, [{name, string}, {value, _} = ValFmt]}}) ->
{Name2, Val} = Tuple,
{_, Val2} = format_result(Val, ValFmt),
{iolist_to_binary(Name2), Val2};
format_result(Tuple, {Name, {tuple, Def}}) ->
Els = lists:zip(tuple_to_list(Tuple), Def),
{misc:atom_to_binary(Name), {[format_result(El, ElDef) || {El, ElDef} <- Els]}};
format_result(404, {_Name, _}) ->
"not_found".
format_error_result(conflict, Code, Msg) ->
{409, Code, iolist_to_binary(Msg)};
format_error_result(not_exists, Code, Msg) ->
{404, Code, iolist_to_binary(Msg)};
format_error_result(_ErrorAtom, Code, Msg) ->
{500, Code, iolist_to_binary(Msg)}.
unauthorized_response() ->
json_error(401, 10, <<"You are not authorized to call this command.">>).
invalid_token_response() ->
json_error(401, 10, <<"Oauth Token is invalid or expired.">>).
%% outofscope_response() ->
%% json_error(401, 11, <<"Token does not grant usage to command required scope.">>).
badrequest_response() ->
badrequest_response(<<"400 Bad Request">>).
badrequest_response(Body) ->
json_response(400, jiffy:encode(Body)).
json_format({Code, Result}) ->
json_response(Code, jiffy:encode(Result));
json_format({HTMLCode, JSONErrorCode, Message}) ->
json_error(HTMLCode, JSONErrorCode, Message).
json_response(Code, Body) when is_integer(Code) ->
{Code, ?HEADER(?CT_JSON), Body}.
%% HTTPCode, JSONCode = integers
%% message is binary
json_error(HTTPCode, JSONCode, Message) ->
{HTTPCode, ?HEADER(?CT_JSON),
jiffy:encode({[{<<"status">>, <<"error">>},
{<<"code">>, JSONCode},
{<<"message">>, Message}]})
}.
log(Call, Args, {Addr, Port}) ->
AddrS = misc:ip_to_list({Addr, Port}),
?INFO_MSG("API call ~ts ~p from ~ts:~p", [Call, hide_sensitive_args(Args), AddrS, Port]);
log(Call, Args, IP) ->
?INFO_MSG("API call ~ts ~p (~p)", [Call, hide_sensitive_args(Args), IP]).
hide_sensitive_args(Args=[_H|_T]) ->
lists:map( fun({<<"password">>, Password}) -> {<<"password">>, ejabberd_config:may_hide_data(Password)};
({<<"newpass">>,NewPassword}) -> {<<"newpass">>, ejabberd_config:may_hide_data(NewPassword)};
(E) -> E end,
Args);
hide_sensitive_args(NonListArgs) ->
NonListArgs.
mod_options(_) ->
[].
mod_doc() ->
#{desc =>
[?T("This module provides a ReST API to call ejabberd commands "
"using JSON data."), "",
?T("To use this module, in addition to adding it to the 'modules' "
"section, you must also add it to 'request_handlers' of some "
"listener."), "",
?T("To use a specific API version N, when defining the URL path "
"in the request_handlers, add a 'vN'. "
"For example: '/api/v2: mod_http_api'"), "",
?T("To run a command, send a POST request to the corresponding "
"URL: 'http://localhost:5280/api/<command_name>'")]}.
