fix(visitors): Fixes s2s multiple connections.

We cannot use filters with s2s as not sending a stanza will result skipping existing connection and creating a new one.
This also clears some of the "No hosts[from_host] (please report)" errors, but there is still one (easy to repro is we disable the jicofo locking) on join we see a presence trying to be routed using the wrong from (virtual  tenant jid).

resources/prosody-plugins/mod_fmuc.lua

@@ -20,6 +20,7 @@ local room_jid_match_rewrite = util.room_jid_match_rewrite;
 local get_room_from_jid = util.get_room_from_jid;
 local get_focus_occupant = util.get_focus_occupant;
 local internal_room_jid_match_rewrite = util.internal_room_jid_match_rewrite;
+local presence_check_status = util.presence_check_status;
 
 -- this is the main virtual host of this vnode
 local local_domain = module:get_option_string('muc_mapper_domain_base');
@@ -325,6 +326,8 @@ module:hook('muc-occupant-groupchat', function(event)
     if occupant and occupant_host ~= main_domain then
         local main_message = st.clone(stanza);
         main_message.attr.to = jid.join(jid.node(room.jid), muc_domain_prefix..'.'..main_domain);
+        -- make sure we fix the from to be the real jid
+        main_message.attr.from = room_jid_match_rewrite(stanza.attr.from);
         module:send(main_message);
     end
     stanza.attr.from = from; -- something prosody does internally
@@ -461,15 +464,24 @@ end
 module:hook('iq/host', iq_from_main_handler, 10);
 
 -- Filters presences (if detected) that are with destination the main prosody
-function filter_stanza(stanza)
-    if not stanza.attr or not stanza.attr.to or stanza.name ~= 'presence' then
-        return stanza;
-    end
+function filter_stanza(stanza, session)
+    if (stanza.name == 'presence' or stanza.name == 'message') and session.type ~= 'c2s' then
+        -- we clone it so we do not affect broadcast using same stanza, sending it to clients
+        local f_st = st.clone(stanza);
+        f_st.skipMapping = true;
+        return f_st;
+    elseif stanza.name == 'presence' and session.type == 'c2s' and jid.node(stanza.attr.to) == 'focus' then
+        local x = stanza:get_child('x', 'http://jabber.org/protocol/muc#user');
+        if presence_check_status(x, '110') then
+            return stanza; -- no filter
+        end
 
-    if jid.host(stanza.attr.to) == main_domain then
+        -- we want to filter presences to jicofo for the main participants
+        -- no point of having them, but if it is the one of the first to be sent
+        -- when first visitor is joining can produce the 'No hosts[from_host]' error as we
+        -- rewrite the from, but we need to not do it to be able to filter it later for the s2s
         return nil; -- returning nil filters the stanza
     end
-
     return stanza; -- no filter
 end
 function filter_session(session)
@@ -478,3 +490,34 @@ function filter_session(session)
 end
 
 filters.add_filter_hook(filter_session);
+
+
+function route_s2s_stanza(event)
+    local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza;
+
+    if to_host ~= main_domain then
+        return; -- continue with hook listeners
+    end
+
+     if stanza.name == 'message' then
+        if jid.resource(stanza.to) then
+            -- there is no point of delivering messages to main participants individually
+            return true; -- drop it
+        end
+        return;
+     end
+
+     if stanza.name == 'presence' then
+        -- we want to leave only unavailable presences to go to main node
+        -- all other presences from jicofo or the main participants there is no point to go to the main node
+        -- they are anyway not handled
+        if stanza.attr.type ~= 'unavailable' then
+            return true; -- drop it
+        end
+        return;
+     end
+end
+
+-- routing to sessions in mod_s2s is -1 and -10, we want to hook before that to make sure to is correct
+-- or if we want to filter that stanza
+module:hook("route/remote", route_s2s_stanza, 10);

resources/prosody-plugins/mod_muc_domain_mapper.lua

@@ -17,6 +17,10 @@ local internal_room_jid_match_rewrite = util.internal_room_jid_match_rewrite;
 
 -- We must filter stanzas in order to hook in to all incoming and outgoing messaging which skips the stanza routers
 function filter_stanza(stanza)
+    if stanza.skipMapping then
+        return stanza;
+    end
+
     if stanza.name == "message" or stanza.name == "iq" or stanza.name == "presence" then
         -- module:log("debug", "Filtering stanza type %s  to %s from %s",stanza.name,stanza.attr.to,stanza.attr.from);
         if stanza.name == "iq" then

resources/prosody-plugins/mod_muc_meeting_id.lua

@@ -115,8 +115,6 @@ function handle_jicofo_unlock(event)
 
     -- and now let's handle all pre_join_queue events
     for _, ev in room.pre_join_queue:items() do
-        -- we see wrong from on some stanzas when using tenants with visitor nodes
-        ev.stanza.attr.from = internal_room_jid_match_rewrite(ev.stanza.attr.from, ev.stanza)
         module:log('info', 'Occupant processed from queue %s', ev.occupant.nick);
         room:handle_normal_presence(ev.origin, ev.stanza);
     end

resources/prosody-plugins/mod_visitors.lua

@@ -129,7 +129,8 @@ local function stanza_handler(event)
         return;
     end
 
-    if stanza.attr.type == 'result' and sent_iq_cache:get(stanza.attr.id) then
+    -- we receive error from vnode for our disconnect message as the room was already destroyed (all visitors left)
+    if (stanza.attr.type == 'result' or stanza.attr.type == 'error') and sent_iq_cache:get(stanza.attr.id) then
         sent_iq_cache:set(stanza.attr.id, nil);
         return true;
     end