prosody: Prevent federation for users with prosody:restricted role (#37)

ansible/files/prosody.cfg.lua

@@ -75,6 +75,7 @@ modules_enabled = {
 		"update_notify";
 		"turncredentials";
 		"admin_shell";
+		"isolate_host";
 		"snikket_client_id";
 		"snikket_ios_preserve_push";
 
@@ -203,6 +204,9 @@ if ENV_SNIKKET_TWEAK_TURNSERVER ~= "0" or ENV_SNIKKET_TWEAK_TURNSERVER_DOMAIN th
 	turncredentials_secret = ENV_SNIKKET_TWEAK_TURNSERVER_SECRET or assert(io.open("/snikket/prosody/turn-auth-secret-v2")):read("*l");
 end
 
+-- Allow restricted users access to push notification servers
+isolate_except_domains = { "push.snikket.net", "push-ios.snikket.net" }
+
 VirtualHost (DOMAIN)
 	authentication = "internal_hashed"
 

ansible/tasks/prosody.yml

@@ -122,6 +122,7 @@
     - mod_prometheus
     - mod_spam_reporting
     - mod_watch_spam_reports
+    - mod_isolate_host
 
 - name: Enable wanted modules (snikket-modules)
   file:
@@ -135,6 +136,7 @@
     - mod_invites_bootstrap
     - mod_snikket_client_id
     - mod_snikket_ios_preserve_push
+    - mod_snikket_restricted_users
 
 - name: "Install lua-ossl for encrypted push notifications"
   apt:

snikket-modules/mod_snikket_restricted_users/mod_snikket_restricted_users.lua

@@ -0,0 +1,16 @@
+local jid_bare = require "util.jid".bare;
+local um_get_roles = require "core.usermanager".get_roles;
+
+local function check_user_isolated(event)
+	local session = event.session;
+	if not session.no_host_isolation then
+		local bare_jid = jid_bare(session.full_jid);
+		local roles = um_get_roles(bare_jid, module.host);
+		if roles and not roles["prosody:restricted"] then
+			-- Bypass isolation for all unrestricted users
+			session.no_host_isolation = true;
+		end
+	end
+end
+
+module:hook("resource-bind", check_user_isolated, -0.5);