%%%----------------------------------------------------------------------
%%% File : mod_caps.erl
%%% Author : Magnus Henoch <henoch@dtek.chalmers.se>
%%% Purpose : Request and cache Entity Capabilities (XEP-0115)
%%% Created : 7 Oct 2006 by Magnus Henoch <henoch@dtek.chalmers.se>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2022 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.
%%%
%%% 2009, improvements from ProcessOne to support correct PEP handling
%%% through s2s, use less memory, and speedup global caps handling
%%%----------------------------------------------------------------------
-module(mod_caps).
-author('henoch@dtek.chalmers.se').
-protocol({xep, 115, '1.5'}).
-behaviour(gen_server).
-behaviour(gen_mod).
-export([read_caps/1, list_features/1, caps_stream_features/2,
disco_features/5, disco_identity/5, disco_info/5,
get_features/2, export/1, import_info/0, import/5,
get_user_caps/2, import_start/2, import_stop/2,
compute_disco_hash/2, is_valid_node/1]).
%% gen_mod callbacks
-export([start/2, stop/1, reload/3, depends/2]).
%% gen_server callbacks
-export([init/1, handle_info/2, handle_call/3,
handle_cast/2, terminate/2, code_change/3]).
-export([user_send_packet/1, user_receive_packet/1,
c2s_presence_in/2, c2s_copy_session/2,
mod_opt_type/1, mod_options/1, mod_doc/0]).
-include("logger.hrl").
-include_lib("xmpp/include/xmpp.hrl").
-include("mod_caps.hrl").
-include("translate.hrl").
-define(BAD_HASH_LIFETIME, 600).
-record(state, {host = <<"">> :: binary()}).
-type digest_type() :: md5 | sha | sha224 | sha256 | sha384 | sha512.
-callback init(binary(), gen_mod:opts()) -> any().
-callback import(binary(), {binary(), binary()}, [binary() | pos_integer()]) -> ok.
-callback caps_read(binary(), {binary(), binary()}) ->
{ok, non_neg_integer() | [binary()]} | error.
-callback caps_write(binary(), {binary(), binary()},
non_neg_integer() | [binary()]) -> any().
-callback use_cache(binary()) -> boolean().
-optional_callbacks([use_cache/1]).
start(Host, Opts) ->
gen_mod:start_child(?MODULE, Host, Opts).
stop(Host) ->
gen_mod:stop_child(?MODULE, Host).
-spec get_features(binary(), nothing | caps()) -> [binary()].
get_features(_Host, nothing) -> [];
get_features(Host, #caps{node = Node, version = Version,
exts = Exts}) ->
SubNodes = [Version | Exts],
Mod = gen_mod:db_mod(Host, ?MODULE),
lists:foldl(
fun(SubNode, Acc) ->
NodePair = {Node, SubNode},
Res = case use_cache(Mod, Host) of
true ->
ets_cache:lookup(caps_features_cache, NodePair,
caps_read_fun(Host, NodePair));
false ->
Mod:caps_read(Host, NodePair)
end,
case Res of
{ok, Features} when is_list(Features) ->
Features ++ Acc;
_ -> Acc
end
end, [], SubNodes).
-spec list_features(ejabberd_c2s:state()) -> [{ljid(), caps()}].
list_features(C2SState) ->
Rs = maps:get(caps_resources, C2SState, gb_trees:empty()),
gb_trees:to_list(Rs).
-spec get_user_caps(jid() | ljid(), ejabberd_c2s:state()) -> {ok, caps()} | error.
get_user_caps(JID, C2SState) ->
Rs = maps:get(caps_resources, C2SState, gb_trees:empty()),
LJID = jid:tolower(JID),
case gb_trees:lookup(LJID, Rs) of
{value, Caps} ->
{ok, Caps};
none ->
error
end.
-spec read_caps(#presence{}) -> nothing | caps().
read_caps(Presence) ->
case xmpp:get_subtag(Presence, #caps{}) of
false -> nothing;
Caps -> Caps
end.
-spec user_send_packet({stanza(), ejabberd_c2s:state()}) -> {stanza(), ejabberd_c2s:state()}.
user_send_packet({#presence{type = available,
from = #jid{luser = U, lserver = LServer} = From,
to = #jid{luser = U, lserver = LServer,
lresource = <<"">>}} = Pkt,
#{jid := To} = State}) ->
case read_caps(Pkt) of
nothing -> ok;
#caps{version = Version, exts = Exts} = Caps ->
feature_request(LServer, From, To, Caps, [Version | Exts])
end,
{Pkt, State};
user_send_packet(Acc) ->
Acc.
-spec user_receive_packet({stanza(), ejabberd_c2s:state()}) -> {stanza(), ejabberd_c2s:state()}.
user_receive_packet({#presence{from = From, type = available} = Pkt,
#{lserver := LServer, jid := To} = State}) ->
IsRemote = case From#jid.lresource of
% Don't store caps for presences sent by our muc rooms
<<>> ->
try ejabberd_router:host_of_route(From#jid.lserver) of
MaybeMuc ->
not lists:member(From#jid.lserver,
gen_mod:get_module_opt_hosts(MaybeMuc, mod_muc))
catch error:{unregistered_route, _} ->
true
end;
_ ->
not ejabberd_router:is_my_host(From#jid.lserver)
end,
if IsRemote ->
case read_caps(Pkt) of
nothing -> ok;
#caps{version = Version, exts = Exts} = Caps ->
feature_request(LServer, To, From, Caps, [Version | Exts])
end;
true -> ok
end,
{Pkt, State};
user_receive_packet(Acc) ->
Acc.
-spec caps_stream_features([xmpp_element()], binary()) -> [xmpp_element()].
caps_stream_features(Acc, MyHost) ->
case gen_mod:is_loaded(MyHost, ?MODULE) of
true ->
case make_my_disco_hash(MyHost) of
<<"">> ->
Acc;
Hash ->
[#caps{hash = <<"sha-1">>, node = ejabberd_config:get_uri(),
version = Hash} | Acc]
end;
false ->
Acc
end.
-spec disco_features({error, stanza_error()} | {result, [binary()]} | empty,
jid(), jid(),
binary(), binary()) ->
{error, stanza_error()} | {result, [binary()]} | empty.
disco_features(Acc, From, To, Node, Lang) ->
case is_valid_node(Node) of
true ->
ejabberd_hooks:run_fold(disco_local_features,
To#jid.lserver, empty,
[From, To, <<"">>, Lang]);
false ->
Acc
end.
-spec disco_identity([identity()], jid(), jid(),
binary(), binary()) ->
[identity()].
disco_identity(Acc, From, To, Node, Lang) ->
case is_valid_node(Node) of
true ->
ejabberd_hooks:run_fold(disco_local_identity,
To#jid.lserver, [],
[From, To, <<"">>, Lang]);
false ->
Acc
end.
-spec disco_info([xdata()], binary(), module(), binary(), binary()) -> [xdata()];
([xdata()], jid(), jid(), binary(), binary()) -> [xdata()].
disco_info(Acc, Host, Module, Node, Lang) when is_atom(Module) ->
case is_valid_node(Node) of
true ->
ejabberd_hooks:run_fold(disco_info, Host, [],
[Host, Module, <<"">>, Lang]);
false ->
Acc
end;
disco_info(Acc, _, _, _Node, _Lang) ->
Acc.
-spec c2s_presence_in(ejabberd_c2s:state(), presence()) -> ejabberd_c2s:state().
c2s_presence_in(C2SState,
#presence{from = From, to = To, type = Type} = Presence) ->
ToSelf = (From#jid.luser == To#jid.luser)
andalso (From#jid.lserver == To#jid.lserver),
Caps = read_caps(Presence),
Operation =
case {Type, ToSelf, Caps} of
{unavailable, _, _} -> delete;
{error, _, _} -> delete;
{available, _, nothing} -> skip;
{available, true, _} -> insert;
{available, _, _} ->
{Subscription, _, _} = ejabberd_hooks:run_fold(
roster_get_jid_info, To#jid.lserver,
{none, none, []},
[To#jid.luser, To#jid.lserver, From]),
case Subscription of
from -> insert;
both -> insert;
_ -> skip
end;
_ ->
skip
end,
case Operation of
skip ->
C2SState;
delete ->
LFrom = jid:tolower(From),
Rs = maps:get(caps_resources, C2SState, gb_trees:empty()),
C2SState#{caps_resources => gb_trees:delete_any(LFrom, Rs)};
insert ->
LFrom = jid:tolower(From),
Rs = maps:get(caps_resources, C2SState, gb_trees:empty()),
NewRs = case gb_trees:lookup(LFrom, Rs) of
{value, Caps} -> Rs;
none ->
ejabberd_hooks:run(caps_add, To#jid.lserver,
[From, To,
get_features(To#jid.lserver, Caps)]),
gb_trees:insert(LFrom, Caps, Rs);
_ ->
ejabberd_hooks:run(caps_update, To#jid.lserver,
[From, To,
get_features(To#jid.lserver, Caps)]),
gb_trees:update(LFrom, Caps, Rs)
end,
C2SState#{caps_resources => NewRs}
end.
-spec c2s_copy_session(ejabberd_c2s:state(), ejabberd_c2s:state())
-> ejabberd_c2s:state().
c2s_copy_session(C2SState, #{caps_resources := Rs}) ->
C2SState#{caps_resources => Rs};
c2s_copy_session(C2SState, _) ->
C2SState.
-spec depends(binary(), gen_mod:opts()) -> [{module(), hard | soft}].
depends(_Host, _Opts) ->
[].
reload(Host, NewOpts, OldOpts) ->
NewMod = gen_mod:db_mod(NewOpts, ?MODULE),
OldMod = gen_mod:db_mod(OldOpts, ?MODULE),
if OldMod /= NewMod ->
NewMod:init(Host, NewOpts);
true ->
ok
end,
init_cache(NewMod, Host, NewOpts).
init([Host|_]) ->
process_flag(trap_exit, true),
Opts = gen_mod:get_module_opts(Host, ?MODULE),
Mod = gen_mod:db_mod(Opts, ?MODULE),
init_cache(Mod, Host, Opts),
Mod:init(Host, Opts),
ejabberd_hooks:add(c2s_presence_in, Host, ?MODULE,
c2s_presence_in, 75),
ejabberd_hooks:add(user_send_packet, Host, ?MODULE,
user_send_packet, 75),
ejabberd_hooks:add(user_receive_packet, Host, ?MODULE,
user_receive_packet, 75),
ejabberd_hooks:add(c2s_post_auth_features, Host, ?MODULE,
caps_stream_features, 75),
ejabberd_hooks:add(s2s_in_post_auth_features, Host, ?MODULE,
caps_stream_features, 75),
ejabberd_hooks:add(c2s_copy_session, Host, ?MODULE,
c2s_copy_session, 75),
ejabberd_hooks:add(disco_local_features, Host, ?MODULE,
disco_features, 75),
ejabberd_hooks:add(disco_local_identity, Host, ?MODULE,
disco_identity, 75),
ejabberd_hooks:add(disco_info, Host, ?MODULE,
disco_info, 75),
{ok, #state{host = Host}}.
handle_call(stop, _From, State) ->
{stop, normal, ok, State};
handle_call(Request, From, State) ->
?WARNING_MSG("Unexpected call from ~p: ~p", [From, Request]),
{noreply, State}.
handle_cast(Msg, State) ->
?WARNING_MSG("Unexpected cast: ~p", [Msg]),
{noreply, State}.
handle_info({iq_reply, IQReply, {Host, From, To, Caps, SubNodes}}, State) ->
feature_response(IQReply, Host, From, To, Caps, SubNodes),
{noreply, State};
handle_info(Info, State) ->
?WARNING_MSG("Unexpected info: ~p", [Info]),
{noreply, State}.
terminate(_Reason, State) ->
Host = State#state.host,
ejabberd_hooks:delete(c2s_presence_in, Host, ?MODULE,
c2s_presence_in, 75),
ejabberd_hooks:delete(user_send_packet, Host, ?MODULE,
user_send_packet, 75),
ejabberd_hooks:delete(user_receive_packet, Host,
?MODULE, user_receive_packet, 75),
ejabberd_hooks:delete(c2s_post_auth_features, Host,
?MODULE, caps_stream_features, 75),
ejabberd_hooks:delete(s2s_in_post_auth_features, Host,
?MODULE, caps_stream_features, 75),
ejabberd_hooks:delete(c2s_copy_session, Host, ?MODULE,
c2s_copy_session, 75),
ejabberd_hooks:delete(disco_local_features, Host,
?MODULE, disco_features, 75),
ejabberd_hooks:delete(disco_local_identity, Host,
?MODULE, disco_identity, 75),
ejabberd_hooks:delete(disco_info, Host, ?MODULE,
disco_info, 75),
ok.
code_change(_OldVsn, State, _Extra) -> {ok, State}.
-spec feature_request(binary(), jid(), jid(), caps(), [binary()]) -> any().
feature_request(Host, From, To, Caps,
[SubNode | Tail] = SubNodes) ->
Node = Caps#caps.node,
NodePair = {Node, SubNode},
Mod = gen_mod:db_mod(Host, ?MODULE),
Res = case use_cache(Mod, Host) of
true ->
ets_cache:lookup(caps_features_cache, NodePair,
caps_read_fun(Host, NodePair));
false ->
Mod:caps_read(Host, NodePair)
end,
case Res of
{ok, Fs} when is_list(Fs) ->
feature_request(Host, From, To, Caps, Tail);
_ ->
LTo = jid:tolower(To),
case ets_cache:insert_new(caps_requests_cache, {LTo, NodePair}, ok) of
true ->
IQ = #iq{type = get,
from = From,
to = To,
sub_els = [#disco_info{node = <<Node/binary, "#",
SubNode/binary>>}]},
ejabberd_router:route_iq(
IQ, {Host, From, To, Caps, SubNodes},
gen_mod:get_module_proc(Host, ?MODULE));
false ->
ok
end,
feature_request(Host, From, To, Caps, Tail)
end;
feature_request(_Host, _From, _To, _Caps, []) -> ok.
-spec feature_response(iq(), binary(), jid(), jid(), caps(), [binary()]) -> any().
feature_response(#iq{type = result, sub_els = [El]},
Host, From, To, Caps, [SubNode | SubNodes]) ->
NodePair = {Caps#caps.node, SubNode},
try
DiscoInfo = xmpp:decode(El),
case check_hash(Caps, DiscoInfo) of
true ->
Features = DiscoInfo#disco_info.features,
LServer = jid:nameprep(Host),
Mod = gen_mod:db_mod(LServer, ?MODULE),
case Mod:caps_write(LServer, NodePair, Features) of
ok ->
case use_cache(Mod, LServer) of
true ->
ets_cache:delete(caps_features_cache, NodePair);
false ->
ok
end;
{error, _} ->
ok
end;
false -> ok
end
catch _:{xmpp_codec, _Why} ->
ok
end,
feature_request(Host, From, To, Caps, SubNodes);
feature_response(_IQResult, Host, From, To, Caps,
[_SubNode | SubNodes]) ->
feature_request(Host, From, To, Caps, SubNodes).
-spec caps_read_fun(binary(), {binary(), binary()})
-> fun(() -> {ok, [binary()] | non_neg_integer()} | error).
caps_read_fun(Host, Node) ->
LServer = jid:nameprep(Host),
Mod = gen_mod:db_mod(LServer, ?MODULE),
fun() -> Mod:caps_read(LServer, Node) end.
-spec make_my_disco_hash(binary()) -> binary().
make_my_disco_hash(Host) ->
JID = jid:make(Host),
case {ejabberd_hooks:run_fold(disco_local_features,
Host, empty, [JID, JID, <<"">>, <<"">>]),
ejabberd_hooks:run_fold(disco_local_identity, Host, [],
[JID, JID, <<"">>, <<"">>]),
ejabberd_hooks:run_fold(disco_info, Host, [],
[Host, undefined, <<"">>, <<"">>])}
of
{{result, Features}, Identities, Info} ->
Feats = lists:map(fun ({{Feat, _Host}}) -> Feat;
(Feat) -> Feat
end,
Features),
DiscoInfo = #disco_info{identities = Identities,
features = Feats,
xdata = Info},
compute_disco_hash(DiscoInfo, sha);
_Err -> <<"">>
end.
-spec compute_disco_hash(disco_info(), digest_type()) -> binary().
compute_disco_hash(DiscoInfo, Algo) ->
Concat = list_to_binary([concat_identities(DiscoInfo),
concat_features(DiscoInfo), concat_info(DiscoInfo)]),
base64:encode(case Algo of
md5 -> erlang:md5(Concat);
sha -> crypto:hash(sha, Concat);
sha224 -> crypto:hash(sha224, Concat);
sha256 -> crypto:hash(sha256, Concat);
sha384 -> crypto:hash(sha384, Concat);
sha512 -> crypto:hash(sha512, Concat)
end).
-spec check_hash(caps(), disco_info()) -> boolean().
check_hash(Caps, DiscoInfo) ->
case Caps#caps.hash of
<<"md5">> ->
Caps#caps.version == compute_disco_hash(DiscoInfo, md5);
<<"sha-1">> ->
Caps#caps.version == compute_disco_hash(DiscoInfo, sha);
<<"sha-224">> ->
Caps#caps.version == compute_disco_hash(DiscoInfo, sha224);
<<"sha-256">> ->
Caps#caps.version == compute_disco_hash(DiscoInfo, sha256);
<<"sha-384">> ->
Caps#caps.version == compute_disco_hash(DiscoInfo, sha384);
<<"sha-512">> ->
Caps#caps.version == compute_disco_hash(DiscoInfo, sha512);
_ -> true
end.
-spec concat_features(disco_info()) -> iolist().
concat_features(#disco_info{features = Features}) ->
lists:usort([[Feat, $<] || Feat <- Features]).
-spec concat_identities(disco_info()) -> iolist().
concat_identities(#disco_info{identities = Identities}) ->
lists:sort(
[[Cat, $/, T, $/, Lang, $/, Name, $<] ||
#identity{category = Cat, type = T,
lang = Lang, name = Name} <- Identities]).
-spec concat_info(disco_info()) -> iolist().
concat_info(#disco_info{xdata = Xs}) ->
lists:sort(
[concat_xdata_fields(X) || #xdata{type = result} = X <- Xs]).
-spec concat_xdata_fields(xdata()) -> iolist().
concat_xdata_fields(#xdata{fields = Fields} = X) ->
Form = xmpp_util:get_xdata_values(<<"FORM_TYPE">>, X),
Res = [[Var, $<, lists:sort([[Val, $<] || Val <- Values])]
|| #xdata_field{var = Var, values = Values} <- Fields,
is_binary(Var), Var /= <<"FORM_TYPE">>],
[Form, $<, lists:sort(Res)].
-spec is_valid_node(binary()) -> boolean().
is_valid_node(Node) ->
case str:tokens(Node, <<"#">>) of
[H|_] ->
H == ejabberd_config:get_uri();
[] ->
false
end.
init_cache(Mod, Host, Opts) ->
CacheOpts = cache_opts(Opts),
case use_cache(Mod, Host) of
true ->
ets_cache:new(caps_features_cache, CacheOpts);
false ->
ets_cache:delete(caps_features_cache)
end,
CacheSize = proplists:get_value(max_size, CacheOpts),
ets_cache:new(caps_requests_cache,
[{max_size, CacheSize},
{life_time, timer:seconds(?BAD_HASH_LIFETIME)}]).
use_cache(Mod, Host) ->
case erlang:function_exported(Mod, use_cache, 1) of
true -> Mod:use_cache(Host);
false -> mod_caps_opt:use_cache(Host)
end.
cache_opts(Opts) ->
MaxSize = mod_caps_opt:cache_size(Opts),
CacheMissed = mod_caps_opt:cache_missed(Opts),
LifeTime = mod_caps_opt:cache_life_time(Opts),
[{max_size, MaxSize}, {cache_missed, CacheMissed}, {life_time, LifeTime}].
export(LServer) ->
Mod = gen_mod:db_mod(LServer, ?MODULE),
Mod:export(LServer).
import_info() ->
[{<<"caps_features">>, 4}].
import_start(LServer, DBType) ->
ets:new(caps_features_tmp, [private, named_table, bag]),
Mod = gen_mod:db_mod(DBType, ?MODULE),
Mod:init(LServer, []),
ok.
import(_LServer, {sql, _}, _DBType, <<"caps_features">>,
[Node, SubNode, Feature, _TimeStamp]) ->
Feature1 = case catch binary_to_integer(Feature) of
I when is_integer(I), I>0 -> I;
_ -> Feature
end,
ets:insert(caps_features_tmp, {{Node, SubNode}, Feature1}),
ok.
import_stop(LServer, DBType) ->
import_next(LServer, DBType, ets:first(caps_features_tmp)),
ets:delete(caps_features_tmp),
ok.
import_next(_LServer, _DBType, '$end_of_table') ->
ok;
import_next(LServer, DBType, NodePair) ->
Features = [F || {_, F} <- ets:lookup(caps_features_tmp, NodePair)],
Mod = gen_mod:db_mod(DBType, ?MODULE),
Mod:import(LServer, NodePair, Features),
import_next(LServer, DBType, ets:next(caps_features_tmp, NodePair)).
mod_opt_type(db_type) ->
econf:db_type(?MODULE);
mod_opt_type(use_cache) ->
econf:bool();
mod_opt_type(cache_size) ->
econf:pos_int(infinity);
mod_opt_type(cache_missed) ->
econf:bool();
mod_opt_type(cache_life_time) ->
econf:timeout(second, infinity).
mod_options(Host) ->
[{db_type, ejabberd_config:default_db(Host, ?MODULE)},
{use_cache, ejabberd_option:use_cache(Host)},
{cache_size, ejabberd_option:cache_size(Host)},
{cache_missed, ejabberd_option:cache_missed(Host)},
{cache_life_time, ejabberd_option:cache_life_time(Host)}].
mod_doc() ->
#{desc =>
[?T("This module implements "
"https://xmpp.org/extensions/xep-0115.html"
"[XEP-0115: Entity Capabilities]."),
?T("The main purpose of the module is to provide "
"PEP functionality (see _`mod_pubsub`_).")],
opts =>
[{db_type,
#{value => "mnesia | sql",
desc =>
?T("Same as top-level _`default_db`_ option, but applied to this module only.")}},
{use_cache,
#{value => "true | false",
desc =>
?T("Same as top-level _`use_cache`_ option, but applied to this module only.")}},
{cache_size,
#{value => "pos_integer() | infinity",
desc =>
?T("Same as top-level _`cache_size`_ option, but applied to this module only.")}},
{cache_missed,
#{value => "true | false",
desc =>
?T("Same as top-level _`cache_missed`_ option, but applied to this module only.")}},
{cache_life_time,
#{value => "timeout()",
desc =>
?T("Same as top-level _`cache_life_time`_ option, but applied to this module only.")}}]}.
