%%%---------------------------------------------------------------------- %%% File : ejabberd_commands.erl %%% Author : Badlop %%% Purpose : Management of ejabberd commands %%% Created : 20 May 2008 by Badlop %%% %%% %%% ejabberd, Copyright (C) 2002-2019 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. %%% %%%---------------------------------------------------------------------- %%% @headerfile "ejabberd_commands.hrl" %%% @doc Management of ejabberd commands. %%% %%% An ejabberd command is an abstract function identified by a name, %%% with a defined number and type of calling arguments and type of %%% result, that can be defined in any Erlang module and executed %%% using any valid frontend. %%% %%% %%% == Define a new ejabberd command == %%% %%% ejabberd commands can be defined and registered in %%% any Erlang module. %%% %%% Some commands are procedures; and their purpose is to perform an %%% action in the server, so the command result is only some result %%% code or result tuple. Other commands are inspectors, and their %%% purpose is to gather some information about the server and return %%% a detailed response: it can be integer, string, atom, tuple, list %%% or a mix of those ones. %%% %%% The arguments and result of an ejabberd command are strictly %%% defined. The number and format of the arguments provided when %%% calling an ejabberd command must match the definition of that %%% command. The format of the result provided by an ejabberd command %%% must be exactly its definition. For example, if a command is said %%% to return an integer, it must always return an integer (except in %%% case of a crash). %%% %%% If you are developing an Erlang module that will run inside %%% ejabberd and you want to provide a new ejabberd command to %%% administer some task related to your module, you only need to: %%% implement a function, define the command, and register it. %%% %%% %%% === Define a new ejabberd command === %%% %%% An ejabberd command is defined using the Erlang record %%% 'ejabberd_commands'. This record has several elements that you %%% must define. Note that 'tags', 'desc' and 'longdesc' are optional. %%% %%% For example let's define an ejabberd command 'pow' that gets the %%% integers 'base' and 'exponent'. Its result will be an integer %%% 'power': %%% %%% 
#ejabberd_commands{name = pow, tags = [test],
%%%                 desc = "Return the power of base for exponent",
%%%                 longdesc = "This is an example command. The formula is:\n"
%%%                 "  power = base ^ exponent",
%%%                 module = ?MODULE, function = pow,
%%%                 args = [{base, integer}, {exponent, integer}],
%%%                 result = {power, integer}}
%%% %%% %%% === Implement the function associated to the command === %%% %%% Now implement a function in your module that matches the arguments %%% and result of the ejabberd command. %%% %%% For example the function calc_power gets two integers Base and %%% Exponent. It calculates the power and rounds to an integer: %%% %%% 
calc_power(Base, Exponent) ->
%%%    PowFloat = math:pow(Base, Exponent),
%%%    round(PowFloat).
%%% %%% Since this function will be called by ejabberd_commands, it must %%% be exported. %%% Add to your module: %%% 
-export([calc_power/2]).
%%% %%% Only some types of result formats are allowed. %%% If the format is defined as 'rescode', then your function must return: %%% ok | true | atom() %%% where the atoms ok and true as considered positive answers, %%% and any other response atom is considered negative. %%% %%% If the format is defined as 'restuple', then the command must return: %%% {rescode(), string()} %%% %%% If the format is defined as '{list, something()}', then the command %%% must return a list of something(). %%% %%% %%% === Register the command === %%% %%% Define this function and put inside the #ejabberd_command you %%% defined in the beginning: %%% %%% 
commands() ->
%%%    [
%%%
%%%    ].
%%% %%% You need to include this header file in order to use the record: %%% %%% 
-include("ejabberd_commands.hrl").
%%% %%% When your module is initialized or started, register your commands: %%% %%% 
ejabberd_commands:register_commands(commands()),
%%% %%% And when your module is stopped, unregister your commands: %%% %%% 
ejabberd_commands:unregister_commands(commands()),
%%% %%% That's all! Now when your module is started, the command will be %%% registered and any frontend can access it. For example: %%% %%% 
$ ejabberdctl help pow
%%%
%%%   Command Name: pow
%%%
%%%   Arguments: base::integer
%%%              exponent::integer
%%%
%%%   Returns: power::integer
%%%
%%%   Tags: test
%%%
%%%   Description: Return the power of base for exponent
%%%
%%% This is an example command. The formula is:
%%%  power = base ^ exponent
%%%
%%% $ ejabberdctl pow 3 4
%%% 81
%%%
%%% %%% %%% == Execute an ejabberd command == %%% %%% ejabberd commands are mean to be executed using any valid %%% frontend. An ejabberd commands is implemented in a regular Erlang %%% function, so it is also possible to execute this function in any %%% Erlang module, without dealing with the associated ejabberd %%% commands. %%% %%% %%% == Frontend to ejabberd commands == %%% %%% Currently there are two frontends to ejabberd commands: the shell %%% script {@link ejabberd_ctl. ejabberdctl}, and the XML-RPC server %%% ejabberd_xmlrpc. %%% %%% %%% === ejabberdctl as a frontend to ejabberd commands === %%% %%% It is possible to use ejabberdctl to get documentation of any %%% command. But ejabberdctl does not support all the argument types %%% allowed in ejabberd commands, so there are some ejabberd commands %%% that cannot be executed using ejabberdctl. %%% %%% Also note that the ejabberdctl shell administration script also %%% manages ejabberdctl commands, which are unrelated to ejabberd %%% commands and can only be executed using ejabberdctl. %%% %%% %%% === ejabberd_xmlrpc as a frontend to ejabberd commands === %%% %%% ejabberd_xmlrpc provides an XML-RPC server to execute ejabberd commands. %%% ejabberd_xmlrpc is a contributed module published in ejabberd-modules SVN. %%% %%% Since ejabberd_xmlrpc does not provide any method to get documentation %%% of the ejabberd commands, please use ejabberdctl to know which %%% commands are available, and their usage. %%% %%% The number and format of the arguments provided when calling an %%% ejabberd command must match the definition of that command. Please %%% make sure the XML-RPC call provides the required arguments, with %%% the specified format. The order of the arguments in an XML-RPC %%% call is not important, because all the data is tagged and will be %%% correctly prepared by ejabberd_xmlrpc before executing the ejabberd %%% command. %%% TODO: consider this feature: %%% All commands are catched. If an error happens, return the restuple: %%% {error, flattened error string} %%% This means that ecomm call APIs (ejabberd_ctl, ejabberd_xmlrpc) %%% need to allows this. And ejabberd_xmlrpc must be prepared to %%% handle such an unexpected response. -module(ejabberd_commands). -author('badlop@process-one.net'). -behaviour(gen_server). -define(DEFAULT_VERSION, 1000000). -export([start_link/0, list_commands/0, list_commands/1, get_command_format/1, get_command_format/2, get_command_format/3, get_command_definition/1, get_command_definition/2, get_tags_commands/0, get_tags_commands/1, register_commands/1, unregister_commands/1, get_commands_spec/0, get_commands_definition/0, get_commands_definition/1, execute_command2/3, execute_command2/4]). %% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -include("ejabberd_commands.hrl"). -include("logger.hrl"). -include_lib("stdlib/include/ms_transform.hrl"). -define(POLICY_ACCESS, '$policy'). -type auth() :: {binary(), binary(), binary() | {oauth, binary()}, boolean()} | map(). -record(state, {}). get_commands_spec() -> [ #ejabberd_commands{name = gen_html_doc_for_commands, tags = [documentation], desc = "Generates html documentation for ejabberd_commands", module = ejabberd_commands_doc, function = generate_html_output, args = [{file, binary}, {regexp, binary}, {examples, binary}], result = {res, rescode}, args_desc = ["Path to file where generated " "documentation should be stored", "Regexp matching names of commands or modules " "that will be included inside generated document", "Comma separated list of languages (chosen from java, perl, xmlrpc, json)" "that will have example invocation include in markdown document"], result_desc = "0 if command failed, 1 when succeeded", args_example = ["/home/me/docs/api.html", "mod_admin", "java,json"], result_example = ok}, #ejabberd_commands{name = gen_markdown_doc_for_commands, tags = [documentation], desc = "Generates markdown documentation for ejabberd_commands", module = ejabberd_commands_doc, function = generate_md_output, args = [{file, binary}, {regexp, binary}, {examples, binary}], result = {res, rescode}, args_desc = ["Path to file where generated " "documentation should be stored", "Regexp matching names of commands or modules " "that will be included inside generated document", "Comma separated list of languages (chosen from java, perl, xmlrpc, json)" "that will have example invocation include in markdown document"], result_desc = "0 if command failed, 1 when succeeded", args_example = ["/home/me/docs/api.html", "mod_admin", "java,json"], result_example = ok}]. start_link() -> gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). init([]) -> try mnesia:transform_table(ejabberd_commands, ignore, record_info(fields, ejabberd_commands)) catch exit:{aborted, {no_exists, _}} -> ok end, ejabberd_mnesia:create(?MODULE, ejabberd_commands, [{ram_copies, [node()]}, {local_content, true}, {attributes, record_info(fields, ejabberd_commands)}, {type, bag}]), register_commands(get_commands_spec()), {ok, #state{}}. handle_call(_Request, _From, State) -> Reply = ok, {reply, Reply, State}. handle_cast(_Msg, State) -> {noreply, State}. handle_info(_Info, State) -> {noreply, State}. terminate(_Reason, _State) -> ok. code_change(_OldVsn, State, _Extra) -> {ok, State}. -spec register_commands([ejabberd_commands()]) -> ok. %% @doc Register ejabberd commands. %% If a command is already registered, a warning is printed and the %% old command is preserved. %% A registered command is not directly available to be called through %% ejabberd ReST API. It need to be exposed to be available through API. register_commands(Commands) -> lists:foreach( fun(Command) -> %% XXX check if command exists mnesia:dirty_write(Command) %% ?DEBUG("This command is already defined:~n~p", [Command]) end, Commands), ejabberd_access_permissions:invalidate(), ok. -spec unregister_commands([ejabberd_commands()]) -> ok. %% @doc Unregister ejabberd commands. unregister_commands(Commands) -> lists:foreach( fun(Command) -> mnesia:dirty_delete_object(Command) end, Commands), ejabberd_access_permissions:invalidate(). -spec list_commands() -> [{atom(), [aterm()], string()}]. %% @doc Get a list of all the available commands, arguments and description. list_commands() -> list_commands(?DEFAULT_VERSION). -spec list_commands(integer()) -> [{atom(), [aterm()], string()}]. %% @doc Get a list of all the available commands, arguments and %% description in a given API verion. list_commands(Version) -> Commands = get_commands_definition(Version), [{Name, Args, Desc} || #ejabberd_commands{name = Name, args = Args, desc = Desc} <- Commands]. -spec get_command_format(atom()) -> {[aterm()], [{atom(),atom()}], rterm()}. %% @doc Get the format of arguments and result of a command. get_command_format(Name) -> get_command_format(Name, noauth, ?DEFAULT_VERSION). get_command_format(Name, Version) when is_integer(Version) -> get_command_format(Name, noauth, Version); get_command_format(Name, Auth) -> get_command_format(Name, Auth, ?DEFAULT_VERSION). -spec get_command_format(atom(), noauth | admin | auth(), integer()) -> {[aterm()], [{atom(),atom()}], rterm()}. get_command_format(Name, Auth, Version) -> Admin = is_admin(Name, Auth, #{}), #ejabberd_commands{args = Args, result = Result, args_rename = Rename, policy = Policy} = get_command_definition(Name, Version), case Policy of user when Admin; Auth == noauth -> {[{user, binary}, {host, binary} | Args], Rename, Result}; _ -> {Args, Rename, Result} end. -spec get_command_definition(atom()) -> ejabberd_commands(). %% @doc Get the definition record of a command. get_command_definition(Name) -> get_command_definition(Name, ?DEFAULT_VERSION). -spec get_command_definition(atom(), integer()) -> ejabberd_commands(). %% @doc Get the definition record of a command in a given API version. get_command_definition(Name, Version) -> case lists:reverse( lists:sort( mnesia:dirty_select( ejabberd_commands, ets:fun2ms( fun(#ejabberd_commands{name = N, version = V} = C) when N == Name, V =< Version -> {V, C} end)))) of [{_, Command} | _ ] -> Command; _E -> throw({error, unknown_command}) end. get_commands_definition() -> get_commands_definition(?DEFAULT_VERSION). -spec get_commands_definition(integer()) -> [ejabberd_commands()]. % @doc Returns all commands for a given API version get_commands_definition(Version) -> L = lists:reverse( lists:sort( mnesia:dirty_select( ejabberd_commands, ets:fun2ms( fun(#ejabberd_commands{name = Name, version = V} = C) when V =< Version -> {Name, V, C} end)))), F = fun({_Name, _V, Command}, []) -> [Command]; ({Name, _V, _Command}, [#ejabberd_commands{name=Name}|_T] = Acc) -> Acc; ({_Name, _V, Command}, Acc) -> [Command | Acc] end, lists:foldl(F, [], L). execute_command2(Name, Arguments, CallerInfo) -> execute_command2(Name, Arguments, CallerInfo, ?DEFAULT_VERSION). execute_command2(Name, Arguments, CallerInfo, Version) -> Command = get_command_definition(Name, Version), case ejabberd_access_permissions:can_access(Name, CallerInfo) of allow -> do_execute_command(Command, Arguments); _ -> throw({error, access_rules_unauthorized}) end. do_execute_command(Command, Arguments) -> Module = Command#ejabberd_commands.module, Function = Command#ejabberd_commands.function, ?DEBUG("Executing command ~p:~p with Args=~p", [Module, Function, Arguments]), ejabberd_hooks:run(api_call, [Module, Function, Arguments]), apply(Module, Function, Arguments). -spec get_tags_commands() -> [{string(), [string()]}]. %% @spec () -> [{Tag::string(), [CommandName::string()]}] %% @doc Get all the tags and associated commands. get_tags_commands() -> get_tags_commands(?DEFAULT_VERSION). -spec get_tags_commands(integer()) -> [{string(), [string()]}]. %% @spec (integer) -> [{Tag::string(), [CommandName::string()]}] %% @doc Get all the tags and associated commands in a given API version get_tags_commands(Version) -> CommandTags = [{Name, Tags} || #ejabberd_commands{name = Name, tags = Tags} <- get_commands_definition(Version)], Dict = lists:foldl( fun({CommandNameAtom, CTags}, D) -> CommandName = atom_to_list(CommandNameAtom), case CTags of [] -> orddict:append("untagged", CommandName, D); _ -> lists:foldl( fun(TagAtom, DD) -> Tag = atom_to_list(TagAtom), orddict:append(Tag, CommandName, DD) end, D, CTags) end end, orddict:new(), CommandTags), orddict:to_list(Dict). %% ----------------------------- %% Access verification %% ----------------------------- -spec is_admin(atom(), admin | noauth | auth(), map()) -> boolean(). is_admin(_Name, admin, _Extra) -> true; is_admin(_Name, {_User, _Server, _, false}, _Extra) -> false; is_admin(_Name, Map, _extra) when is_map(Map) -> true; is_admin(_Name, _Auth, _Extra) -> false.