mod_mam: Make sure a stanza ID is always added

Let mod_mam store incoming messages from a new hook in ejabberd_sm.
This makes sure all messages are tagged with a stanza ID, including
those that are forked to multiple resources in ejabberd_sm.

Closes #1344.

src/ejabberd_sm.erl

@@ -137,10 +137,17 @@ route(To, Term) ->
 
 -spec route(stanza()) -> ok.
 route(Packet) ->
-    try do_route(Packet), ok
+    #jid{lserver = LServer} = xmpp:get_to(Packet),
+    case ejabberd_hooks:run_fold(sm_receive_packet, LServer, Packet, []) of
+	drop ->
+	    ?DEBUG("hook dropped stanza:~n~s", [xmpp:pp(Packet)]);
+	Packet1 ->
+	    try do_route(Packet1), ok
 	    catch E:R ->
 		    ?ERROR_MSG("failed to route packet:~n~s~nReason = ~p",
-                       [xmpp:pp(Packet), {E, {R, erlang:get_stacktrace()}}])
+			       [xmpp:pp(Packet1),
+				{E, {R, erlang:get_stacktrace()}}])
+	    end
     end.
 
 -spec open_session(sid(), binary(), binary(), binary(), prio(), info()) -> ok.

src/mod_mam.erl

@@ -32,12 +32,12 @@
 %% API
 -export([start/2, stop/1, reload/3, depends/2]).
 
--export([user_send_packet/1, user_send_packet_strip_tag/1, user_receive_packet/1,
+-export([user_send_packet/1, user_send_packet_strip_tag/1, sm_receive_packet/1,
 	 process_iq_v0_2/1, process_iq_v0_3/1, disco_sm_features/5,
 	 remove_user/2, remove_room/3, mod_opt_type/1, muc_process_iq/2,
 	 muc_filter_message/3, message_is_archived/3, delete_old_messages/2,
 	 get_commands_spec/0, msg_to_el/4, get_room_config/4, set_room_option/3,
-	 offline_message/1, export/1]).
+	 export/1]).
 
 -include("xmpp.hrl").
 -include("logger.hrl").
@@ -77,14 +77,12 @@ start(Host, Opts) ->
     Mod:init(Host, Opts),
     init_cache(Host, Opts),
     register_iq_handlers(Host, IQDisc),
-    ejabberd_hooks:add(user_receive_packet, Host, ?MODULE,
-		       user_receive_packet, 88),
+    ejabberd_hooks:add(sm_receive_packet, Host, ?MODULE,
+		       sm_receive_packet, 50),
     ejabberd_hooks:add(user_send_packet, Host, ?MODULE,
 		       user_send_packet, 88),
     ejabberd_hooks:add(user_send_packet, Host, ?MODULE,
                user_send_packet_strip_tag, 500),
-    ejabberd_hooks:add(offline_message_hook, Host, ?MODULE,
-		       offline_message, 40),
     ejabberd_hooks:add(muc_filter_message, Host, ?MODULE,
 		       muc_filter_message, 50),
     ejabberd_hooks:add(muc_process_iq, Host, ?MODULE,
@@ -140,14 +138,12 @@ cache_opts(Host, Opts) ->
 
 stop(Host) ->
     unregister_iq_handlers(Host),
+    ejabberd_hooks:delete(sm_receive_packet, Host, ?MODULE,
+			  sm_receive_packet, 50),
     ejabberd_hooks:delete(user_send_packet, Host, ?MODULE,
 			  user_send_packet, 88),
-    ejabberd_hooks:delete(user_receive_packet, Host, ?MODULE,
-			  user_receive_packet, 88),
     ejabberd_hooks:delete(user_send_packet, Host, ?MODULE,
 			  user_send_packet_strip_tag, 500),
-    ejabberd_hooks:delete(offline_message_hook, Host, ?MODULE,
-			  offline_message, 40),
     ejabberd_hooks:delete(muc_filter_message, Host, ?MODULE,
 			  muc_filter_message, 50),
     ejabberd_hooks:delete(muc_process_iq, Host, ?MODULE,
@@ -265,12 +261,11 @@ set_room_option(_Acc, {mam, Val}, _Lang) ->
 set_room_option(Acc, _Property, _Lang) ->
     Acc.
 
--spec user_receive_packet({stanza(), c2s_state()}) -> {stanza(), c2s_state()}.
-user_receive_packet({Pkt, #{jid := JID} = C2SState}) ->
-    Peer = xmpp:get_from(Pkt),
+-spec sm_receive_packet(stanza()) -> stanza().
+sm_receive_packet(#message{from = Peer, to = JID} = Pkt) ->
     LUser = JID#jid.luser,
     LServer = JID#jid.lserver,
-    Pkt2 = case should_archive(Pkt, LServer) of
+    case should_archive(Pkt, LServer) of
 	true ->
 		   Pkt1 = strip_my_archived_tag(Pkt, LServer),
 		   case store_msg(Pkt1, LUser, LServer, Peer, recv) of
@@ -281,8 +276,9 @@ user_receive_packet({Pkt, #{jid := JID} = C2SState}) ->
 	    end;
 	_ ->
 	    Pkt
-	   end,
-    {Pkt2, C2SState}.
+    end;
+sm_receive_packet(Acc) ->
+    Acc.
 
 -spec user_send_packet({stanza(), c2s_state()}) -> {stanza(), c2s_state()}.
 user_send_packet({Pkt, #{jid := JID} = C2SState}) ->
@@ -304,23 +300,6 @@ user_send_packet({Pkt, #{jid := JID} = C2SState}) ->
 	   end,
     {Pkt2, C2SState}.
 
--spec offline_message({any(), message()}) -> {any(), message()}.
-offline_message({_Action, #message{from = Peer, to = To} = Pkt} = Acc) ->
-    LUser = To#jid.luser,
-    LServer = To#jid.lserver,
-    case should_archive(Pkt, LServer) of
-	true ->
-	    Pkt1 = strip_my_archived_tag(Pkt, LServer),
-	    case store_msg(Pkt1, LUser, LServer, Peer, recv) of
-		{ok, ID} ->
-		    {archived, set_stanza_id(Pkt1, To, ID)};
-		_ ->
-		    Acc
-	    end;
-	false ->
-	    Acc
-    end.
-
 -spec user_send_packet_strip_tag({stanza(), c2s_state()}) ->
 					{stanza(), c2s_state()}.
 user_send_packet_strip_tag({Pkt, #{jid := JID} = C2SState}) ->
@@ -547,8 +526,6 @@ process_iq(LServer, #iq{from = #jid{luser = LUser}, lang = Lang,
 
 should_archive(#message{type = error}, _LServer) ->
     false;
-should_archive(#message{meta = #{sm_copy := true}}, _LServer) ->
-    false;
 should_archive(#message{meta = #{from_offline := true}}, _LServer) ->
     false;
 should_archive(#message{body = Body, subject = Subject,