--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_alias/README.markdown	Sat Nov 21 00:10:08 2015 -0500
@@ -0,0 +1,57 @@
+---
+summary: Point alias accounts or domains to correct XMPP user
+...
+
+Introduction
+============
+
+This module allows you to set up aliases that alert people who try to
+contact them or add them to their roster what your actual JID is.  This
+is useful for changing JIDs, or just in the case where you own both
+example.com and example.net, and want people who contact you@example.com
+to be alerted to contact you at you@example.net instead.
+
+This type of aliasing is well supported in the email world, but very hard
+to handle with XMPP, this module sidesteps all the hard problems by just
+sending the user a helpful message, requiring humans to decide what they
+actually want to do.
+
+This doesn't require any special support on other clients or servers,
+just the ability to recieve messages.
+
+Configuration
+=============
+
+Add the module to the `modules_enabled` list.
+
+    modules_enabled = {
+        ...
+        "alias";
+    }
+
+Then set up your list of aliases, aliases can be full or bare JIDs,
+or hosts:
+
+    aliases = {
+        ["old@example.net"] = "new@example.net";
+        ["you@example.com"] = "you@example.net";
+        ["conference.example.com"] = "conference.example.net";
+    }
+
+You can also set up a custom response, by default it is:
+
+    alias_response = "User $alias can be contacted at $target";
+
+A script named mod_alias_postfixadmin.sh is included in this directory to
+generate the aliases array directly from a postfixadmin MySQL database.
+Instructions for use are included in the script.
+
+Compatibility
+=============
+
+  ------- --------------
+  trunk   Works
+  0.10    Works
+  0.9     Unknown
+  0.8     Unknown
+  ------- --------------

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_alias/mod_alias.lua	Sat Nov 21 00:10:08 2015 -0500
@@ -0,0 +1,43 @@
+-- Copyright (C) 2015 Travis Burtrum
+-- This file is MIT/X11 licensed.
+
+-- set like so in prosody config, works on full or bare jids, or hosts:
+--aliases = {
+--		["old@example.net"] = "new@example.net";
+--		["you@example.com"] = "you@example.net";
+--		["conference.example.com"] = "conference.example.net";
+--}
+
+local aliases = module:get_option("aliases", {});
+local alias_response = module:get_option("alias_response", "User $alias can be contacted at $target");
+
+local st = require "util.stanza";
+
+function handle_alias(event)
+
+	if event.stanza.attr.type ~= "error" then
+		local alias = event.stanza.attr.to;
+		local target = aliases[alias];
+		if target then
+			local replacements = {
+				alias = alias,
+				target = target
+			};
+			local error_message = alias_response:gsub("%$([%w_]+)", function (v)
+					return replacements[v] or nil;
+				end);
+			local message = st.message{ type = "chat", from = alias, to = event.stanza.attr.from }:tag("body"):text(error_message);
+			module:send(message);
+			return event.origin.send(st.error_reply(event.stanza, "cancel", "gone", error_message));
+		end
+	end
+
+end
+
+module:hook("message/bare", handle_alias, 300);
+module:hook("message/full", handle_alias, 300);
+module:hook("message/host", handle_alias, 300);
+
+module:hook("presence/bare", handle_alias, 300);
+module:hook("presence/full", handle_alias, 300);
+module:hook("presence/host", handle_alias, 300);

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_alias/mod_alias_postfixadmin.sh	Sat Nov 21 00:10:08 2015 -0500
@@ -0,0 +1,20 @@
+#!/bin/sh
+# Copyright (C) 2015 Travis Burtrum
+# This file is MIT/X11 licensed.
+
+# run like ./mod_alias_postfixadmin.sh "mysql -N -upostfixadmin -ppostfixadmin postfixadmin" > /etc/prosody/aliases.cfg.lua
+# then put:
+# Include "aliases.cfg.lua"
+# in prosody.cfg.lua
+
+mysql="$1"
+
+echo "-- alias plugin, generated by mod_alias_postfixadmin.sh"
+echo "aliases = {"
+
+echo "SELECT concat('["'"'"', address, '"'"'"] = "'"'"', goto, '"'"'";') FROM alias WHERE address != goto;
+SELECT concat('["'"'"', address, '"'"'"] = "'"'"', goto, '"'"'";') FROM (
+	select replace(address, concat('@', target_domain), concat('@', alias_domain)) as address, goto FROM alias JOIN alias_domain ON alias_domain.target_domain = SUBSTRING(alias.address, locate('@',alias.address) + 1, length(alias.address))
+) a WHERE a.address != a.goto;" | $mysql | sort | uniq
+
+echo "}"