mod_antispam: initial import from ejabberd-contrib/mod_spam_filter

src/mod_antispam_rtbl.erl

@@ -0,0 +1,132 @@
+%%%----------------------------------------------------------------------
+%%% File    : mod_antispam_rtbl.erl
+%%% Author  : Stefan Strigler <stefan@strigler.de>
+%%% Purpose : Collection of RTBL specific functionality
+%%% Created : 20 Mar 2025 by Stefan Strigler <stefan@strigler.de>
+%%%
+%%%
+%%% ejabberd, Copyright (C) 2025 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_antispam_rtbl).
+-author('stefan@strigler.de').
+
+-include_lib("xmpp/include/xmpp.hrl").
+-include("logger.hrl").
+
+-define(SERVICE_MODULE, mod_antispam).
+-define(SERVICE_JID_PREFIX, "rtbl-").
+
+-export([parse_blocked_domains/1,
+	 parse_pubsub_event/1,
+	 pubsub_event_handler/1,
+	 request_blocked_domains/3,
+	 subscribe/3,
+	 unsubscribe/3]).
+
+subscribe(RTBLHost, RTBLDomainsNode, From) ->
+    FromJID = service_jid(From),
+    SubIQ = #iq{type = set, to = jid:make(RTBLHost), from = FromJID,
+		sub_els = [
+			   #pubsub{subscribe = #ps_subscribe{jid = FromJID, node = RTBLDomainsNode}}]},
+    ?DEBUG("Sending subscription request:~n~p", [xmpp:encode(SubIQ)]),
+    ejabberd_router:route_iq(SubIQ, subscribe_result, self()).
+
+-spec unsubscribe(binary() | none, binary(), binary()) -> ok.
+unsubscribe(none, _PSNode, _From) ->
+    ok;
+unsubscribe(RTBLHost, RTBLDomainsNode, From) ->
+    FromJID = jid:make(From),
+    SubIQ = #iq{type = set, to = jid:make(RTBLHost), from = FromJID,
+		sub_els = [
+			   #pubsub{unsubscribe = #ps_unsubscribe{jid = FromJID, node = RTBLDomainsNode}}]},
+    ejabberd_router:route_iq(SubIQ, unsubscribe_result, self()).
+
+-spec request_blocked_domains(binary() | none, binary(), binary()) -> ok.
+request_blocked_domains(none, _PSNode, _From) ->
+    ok;
+request_blocked_domains(RTBLHost, RTBLDomainsNode, From) ->
+    IQ = #iq{type = get, from = jid:make(From),
+	     to = jid:make(RTBLHost),
+	     sub_els = [
+			#pubsub{items = #ps_items{node = RTBLDomainsNode}}]},
+    ?DEBUG("Requesting RTBL blocked domains from ~s:~n~p", [RTBLHost, xmpp:encode(IQ)]),
+    ejabberd_router:route_iq(IQ, blocked_domains, self()).
+
+-spec parse_blocked_domains(stanza()) -> #{binary() => any()} | undefined.
+parse_blocked_domains(#iq{to = #jid{lserver = LServer}, type = result} = IQ) ->
+    ?DEBUG("parsing iq-result items: ~p", [IQ]),
+    RTBLDomainsNode = gen_mod:get_module_opt(LServer, ?SERVICE_MODULE, rtbl_domains_node),
+    case xmpp:get_subtag(IQ, #pubsub{}) of
+	#pubsub{items = #ps_items{node = RTBLDomainsNode, items = Items}} ->
+	    ?DEBUG("Got items:~n~p", [Items]),
+	    parse_items(Items);
+	_ ->
+	    undefined
+    end.
+
+-spec parse_pubsub_event(stanza()) -> #{binary() => any()}.
+parse_pubsub_event(#message{to = #jid{lserver = LServer}} = Msg) ->
+    RTBLDomainsNode = gen_mod:get_module_opt(LServer, ?SERVICE_MODULE, rtbl_domains_node),
+    case xmpp:get_subtag(Msg, #ps_event{}) of
+	#ps_event{items = #ps_items{node = RTBLDomainsNode, retract = ID}} when ID /= undefined ->
+	    ?DEBUG("Got item to retract:~n~p", [ID]),
+	    #{ID => false};
+	#ps_event{items = #ps_items{node = RTBLDomainsNode, items = Items}} ->
+	    ?DEBUG("Got items:~n~p", [Items]),
+	    parse_items(Items);
+	Other ->
+	    ?WARNING_MSG("Couldn't extract items: ~p", [Other]),
+	    #{}
+    end.
+
+-spec parse_items([ps_item()]) -> #{binary() => any()}.
+parse_items(Items) ->
+    lists:foldl(
+      fun(#ps_item{id = ID}, Acc) ->
+	      %% TODO extract meta/extra instructions
+	      maps:put(ID, true, Acc)
+      end, #{}, Items).
+
+-spec service_jid(binary()) -> jid().
+service_jid(Host) ->
+    jid:make(<<>>, Host, <<?SERVICE_JID_PREFIX, (ejabberd_cluster:node_id())/binary>>).
+
+%%--------------------------------------------------------------------
+%% Hook callbacks.
+%%--------------------------------------------------------------------
+
+-spec pubsub_event_handler(stanza()) -> drop | stanza().
+pubsub_event_handler(#message{from = FromJid,
+			      to = #jid{lserver = LServer,
+					lresource = <<?SERVICE_JID_PREFIX, _/binary>>}} = Msg) ->
+    ?DEBUG("Got RTBL message:~n~p", [Msg]),
+    From = jid:encode(FromJid),
+    case gen_mod:get_module_opt(LServer, ?SERVICE_MODULE, rtbl_host) of
+	From ->
+	    ParsedItems = parse_pubsub_event(Msg),
+	    Proc = gen_mod:get_module_proc(LServer, ?SERVICE_MODULE),
+	    gen_server:cast(Proc, {update_blocked_domains, ParsedItems}),
+	    %% FIXME what's the difference between `{drop, ...}` and `{stop, {drop, ...}}`?
+	    drop;
+	_Other ->
+	    ?INFO_MSG("Got unexpected message from ~s to rtbl resource:~n~p", [From, Msg]),
+	    Msg
+    end;
+pubsub_event_handler(Acc) ->
+    ?DEBUG("unexpected something on pubsub_event_handler: ~p", [Acc]),
+    Acc.