mod_mix: Various changes

- Refactor and clean code
- Implement lots of MIX-ADMIN
- Beginning of MIX-ANON

mod_mix/anon.lib.lua

@@ -0,0 +1,14 @@
+local dataforms = require("util.dataforms");
+local namespaces = module:require("mix/namespaces");
+
+local mix_anon_form = dataforms.new({
+    { name = "FORM_TYPE", type = "hidden", value = namespaces.anon },
+    { name = "JID Visibility", type = "text-single" },
+    { name = "Private Messages", type = "text-single" },
+    { name = "Presence", type = "text-single" },
+    { name = "vCard", type = "text-single" },
+});
+
+return {
+    form = mix_anon_form;
+};

mod_mix/helpers.lib.lua

@@ -13,11 +13,18 @@ end
 
 local function find_str(array, str)
     -- Returns the index of str in array. -1 if array does not contain str
-    local i, _ = find(array, function(v) return v == str end);
+    local i, _ = find(array, function(v) return v == str; end);
     return i;
 end
 
+local function in_array(array, element)
+    -- Returns true if element is in array. False otherwise.
+    local i, _ = find(array, function(v) return v == element; end);
+    return i ~= -1;
+end
+
 return {
     find_str = find_str,
     find = find,
+    in_array = in_array,
 };

mod_mix/mix.lib.lua

@@ -1,12 +1,20 @@
 local st = require("util.stanza");
+local array = require("util.array");
+local jid_lib = require("util.jid");
+local uuid = require("util.uuid");
+local time = require("util.time");
 local helpers = module:require("mix/helpers");
+local namespaces = module:require("mix/namespaces");
+local pep = module:depends("pep");
 
-Participant = {};
+
+local Participant = {};
 Participant.__index = Participant;
-function Participant:new(jid, nick)
+function Participant:new(jid, nick, config)
     return setmetatable({
         jid = jid,
         nick = nick,
+        config = config,
     }, Participant);
 end
 
@@ -14,9 +22,9 @@ function Participant:from(config)
     return setmetatable(config, Participant);
 end
 
-Channel = {}
+local Channel = {};
 Channel.__index = Channel;
-function Channel:new(jid, name, description, participants, subscriptions, spid, contacts, adhoc)
+function Channel:new(jid, name, description, participants, administrators, owners, subscriptions, spid, contacts, adhoc, allowed, banned, config, nodes)
     return setmetatable({
         jid = jid,
         name = name,
@@ -26,6 +34,12 @@ function Channel:new(jid, name, description, participants, subscriptions, spid,
         spid = spid,
         contacts = contacts,
         adhoc = adhoc,
+        administrators = administrators,
+        owners = owners,
+        config = config,
+        nodes = nodes,
+        allowed = allowed,
+        banned = banned,
     }, Channel);
 end
 function Channel:from(config)
@@ -88,7 +102,322 @@ function Channel:debug_print()
     end
 end
 
+function Channel:allow_jid(jid)
+    local srv = pep.get_pep_service(jid_lib.node(self.jid));
+    array.push(self.allowed, jid);
+    srv:set_node_config(namespaces.allowed,
+                        true,
+                        { ["max_items"] = #self.allowed + 1 });
+    srv:publish(namespaces.allowed, true, jid, nil);
+end
+
+function Channel:ban_jid(jid)
+    local srv = pep.get_pep_service(jid_lib.node(self.jid));
+    self.banned:push(jid);
+    srv:set_node_config(namespaces.banned,
+                        true,
+                        { ["max_items"] = #self.banned + 1 });
+    srv:publish(namespaces.banned, true, jid, nil);
+
+    local i = helpers.find_str(jid, "@");
+    if i ~= nil then
+        -- "@" in JID => We're banning a real JID
+        if self:is_participant(jid) then
+            self:remove_participant(jid);
+        end
+    else
+        -- No "@" in JID => We're banning a host
+        for _, participant in self.participants do
+            if jid_lib.host(participant.jid) == jid then
+                self:remove_participant(participant.jid);
+            end
+        end
+    end
+end
+
+function Channel:remove_participant(jid)
+    -- Removes a user form the channel. May be a kick, may be a leave.
+    local srv = pep.get_pep_service(jid_lib.node(self.jid));
+
+    -- Step 1: Unsubscribe from all subscribed nodes
+    for _, node in ipairs(self.subscriptions[jid]) do
+        srv:remove_subscription(node, true, jid);
+    end
+    self.subscriptions[jid] = nil;
+
+    -- Step 2: Remove affiliations to all nodes
+    for _, node in ipairs(self.nodes) do
+        srv:set_affiliation(node, true, jid, "outcast");
+    end
+
+    -- Step 3: Remove jid as participant
+    local i, _ = self:find_participant(jid);
+    table.remove(self.participants, i);
+
+    -- Step 4: Retract jid from participants node
+    local spid = self:get_spid(jid);
+    local notifier = st.stanza("retract", { id = spid });
+    srv:retract(namespaces.participants, true, jid, notifier);
+    self:save_state();
+end
+
+function Channel:is_allowed(jid)
+    local i, _ = helpers.find(self.allowed, jid);
+    local j, _ = helpers.find(self.allowed, jid_lib.host(jid));
+
+    return i ~= -1 and j ~= -1;
+end
+
+function Channel:is_admin(jid)
+    return helpers.in_array(self.administrators, jid);
+end
+
+function Channel:is_owner(jid)
+    return helpers.in_array(self.owners, jid);
+end
+
+function Channel:may_subscribe(jid, node, joining)
+    -- Returns true when a JID is allowed to subscribe to a node.
+    -- If joining is true and the node is set to "participants", then
+    -- true will be returned as the user will be a participant.
+    -- NOTE: When using this function directly, be careful to
+    --       check first whether the JID is allowed to join.
+    -- TODO: Presence
+    local group = "";
+    if node == namespaces.info then
+        group = self.config["Information Node Subscription"];
+    elseif node == namespaces.participants then
+        group = self.config["Participants Node Subscription"];
+    elseif node == namespaces.messages then
+        group = self.config["Messages Node Subscription"];
+    elseif node == namespaces.allowed then
+        group = self.config["Allowed Node Subscription"];
+    elseif node == namespaces.banned then
+        group = self.config["Banned Node Subscription"];
+    elseif node == namespaces.config then
+        group = "admins";
+    elseif node == namespaces.avatar or node == namespaces.avatar_metadata then
+        group = "participants";
+    end
+
+    module:log("debug", "may_subscribe: Group: %s", group);
+    module:log("debug", "Is Owner: %s", self:is_owner(jid));
+    module:log("debug", "Is Admin: %s", self:is_admin(jid));
+    module:log("debug", "Is Participant: %s", self:is_participant(jid));
+    module:log("debug", "Is allowed: %s", self:is_allowed(jid));
+
+    if group == "anyone" then
+        return true;
+    elseif group == "allowed" then
+        return self:is_allowed(jid);
+    elseif group == "nobody" then
+        return false;
+    elseif group == "admins" then
+        return self:is_admin(jid) or self:is_owner(jid);
+    elseif group == "owners" then
+        return self:is_owner(jid);
+    elseif group == "participants" then
+        return self:is_participant(jid) or self:is_admin(jid) or self:is_owner(jid) or joining;
+    end
+
+    return false;
+end
+
+function Channel:may_access(jid, node)
+    -- Access means read and subscribe
+    local group = "";
+    if node == namespaces.config then
+        -- TODO: For some reason, this is failing
+        --group = self.config["Configuration Node Access"];
+        group = "owners";
+    end
+
+    if group == "nobody" then
+        return false;
+    elseif group == "allowed" then
+        return self:is_allowed(jid);
+    elseif group == "admins" then
+        return self:is_admin(jid) or self:is_owner(jid);
+    elseif group == "owners" then
+        return self:is_owner(jid);
+    elseif group == "participants" then
+        return self:is_participant(jid) or self:is_admin(jid) or self:is_owner(jid);
+    end
+
+    return false;
+end
+
+function Channel:may_update(jid, node)
+    module:log("debug", "Update node %s", node);
+    local group = "";
+    -- TODO: Deal with avatars
+    if node == namespaces.info then
+        group = self.config["Information Node Update Rights"];
+    elseif node == namespaces.config then
+        -- TODO: Make this configurable
+        group = "admins";
+    elseif node == namespaces.avatar or node == namespaces.avatar_metadata then
+        group = self.config["Avatar Nodes Update Rights"];
+    end
+
+    if group == "admins" then
+        return self:is_admin(jid) or self:is_owner(jid);
+    elseif group == "owners" then
+        return self:is_owner(jid);
+    elseif group == "participants" then
+        return self:is_participant(jid) or self:is_admin(jid) or self:is_owner(jid);
+    elseif group == "allowed" then
+        return self:is_allowed(jid);
+    end
+
+    return false;
+end
+
+function Channel:may_join(jid)
+    -- Does the banned node exist?
+    if helpers.in_array(self.nodes, namespaces.banned) then
+        local host = jid_lib.host(jid);
+        if helpers.in_array(self.banned, host) or helpers.in_array(self.banned, jid) then
+            -- User or host is banned
+            return false;
+        end
+    end
+
+    -- Does the allowed node exist?
+    if helpers.in_array(self.nodes, namespaces.allowed) then
+        local host = jid_lib.host(jid);
+        if helpers.in_array(self.allowed, host) or helpers.in_array(self.allowed, jid) then
+            -- User or host is allowed
+            return true;
+        else
+            -- "Whitelist" is on but user or host is not on it.
+            return false;
+        end
+    end
+
+    return true;
+end
+
+function Channel:may(jid, action, data)
+    if action == "subscribe" then
+        return self:may_subscribe(jid, data, false);
+    elseif action == "access" then
+        return self:may_access(jid, data);
+    elseif action == "update" then
+        return self:may_update(jid, data);
+    elseif action == "pm" then
+        return self.config["Private Messages"];
+    elseif action == "join" then
+        return self:may_join(jid);
+    elseif action == "invite" then
+        if not (self:is_admin(jid) or self:is_owner(jid)) then
+            return self.config["Participation Addition by Invitation from Participant"];
+        else
+            return true;
+        end
+    elseif action == "retract" then
+        -- Is this the same user
+        -- TODO: jid == data may not work when using SPIDs
+        if jid == data then
+            return self.config["User Message Retraction"];
+        else
+            local group = self.config["Administrator Message Retraction Rights"];
+            if group == "nobody" then
+                return false;
+            elseif group == "admins" then
+                return self:is_admin(jid) or self:is_owner(jid);
+            elseif group == "owners" then
+                return self:is_owner(jid);
+            end
+
+            return false;
+        end
+    end
+end
+
+function Channel:broadcast_message(message, participant, archive)
+    -- Broadcast a message stanza according to rules layed out by
+    -- XEP-0369
+    local msg = st.clone(message);
+    msg:add_child(st.stanza("mix", { xmlns = namespaces.mix_core })
+                    :tag("nick"):text(participant.nick):up()
+                    :tag("jid"):text(participant.jid):up());
+
+    -- Put the message into the archive
+    local mam_id = uuid.generate();
+    msg.attr.id = mam_id;
+    -- NOTE: The spec says to do so
+    msg.attr.from = self.jid;
+    archive:append(message.attr.to, mam_id, msg, time.now());
+    msg.attr.from = self.jid.."/"..self:get_spid(participant.jid);
+
+    if module:fire_event("mix-broadcast-message", { message = msg, channel = self }) then
+        return;
+    end
+
+    for _, p in pairs(self.participants) do
+        -- Only users who subscribed to the messages node should receive
+        -- messages
+        if self:is_subscribed(p.jid, namespaces.messages) then
+            local tmp = st.clone(msg);
+            tmp.attr.to = p.jid;
+            module:send(tmp);
+        end
+    end
+end
+
+function Channel:publish_participant(spid, participant)
+    -- Publish a new participant on the service
+    local srv = pep.get_pep_service(jid_lib.node(self.jid));
+
+    -- NOTE: This function has be to called *after* the new participant
+    --       has been added to the channel.participants array
+    srv:set_node_config(namespaces.participants,
+                        true,
+                        { ["max_items"] = #self.participants });
+    srv:publish(namespaces.participants,
+                true,
+                spid,
+                st.stanza("item", { id = spid, xmlns = "http://jabber.org/protocol/pubsub" })
+                    :tag("participant", { xmlns = namespaces.mix_core })
+                        :tag("nick"):text(participant["nick"]):up()
+                        :tag("jid"):text(participant["jid"]));
+end
+
+local default_channel_configuration = {
+    ["Last Change Made By"] = "";
+    ["Owner"] = {};               -- Filled in during creation
+    ["Administrator"] = {};
+    ["End of Life"] = "";
+    ["Nodes Present"] = {};       -- Filled in during creation
+    ["Messages Node Subscription"] = "participants";
+    ["Presence Node Subscription"] = "participants";
+    ["Participants Node Subscription"] = "participants";
+    ["Information Node Subscription"] = "participants";
+    ["Allowed Node Subscription"] = "admins";
+    ["Banned Node Subscription"] = "admins";
+    ["Configuration Node Access"] = "owners";
+    ["Information Node Update Rights"] = "admins";
+    ["Avatar Node Update Rights"] = "admins";
+    ["Open Presence"] = false;
+    ["Participants Must Provide Presence"] = false;
+    ["User Message Retraction"] = false;
+    ["Administrator Message Retraction Rights"] = "owners";
+    ["Participation Addition by Invitation from Participant"] = false;
+    ["Private Messages"] = true;
+    ["Mandatory Nicks"] = true;
+};
+
+local default_participant_configuration = {
+    ["JID Visibility"] = "never";
+    ["Private Messages"] = "allow";
+    ["Presence"] = "share";
+    ["vCard"] = "block";
+};
+
 return {
     Channel = Channel,
-    Participant = Participant
+    Participant = Participant,
+    default_channel_configuration = default_channel_configuration,
+    default_participant_configuration = default_participant_configuration,
 };

mod_mix/mod_mix.lua

@@ -1,5 +1,6 @@
--- Big TODOlist
+-- TODO: Channel info's Contacts is empty
--- TODO: Channel:is_subscribed could be replaced by get_pep_service(...):get_subscription
+-- TODO: Maybe reset affiliations to none instead of outcast
+-- TODO: Handle creation and deletion of avatar nodes when publishing to :config
 
 local host = module:get_host();
 if module:get_host_type() ~= "component" then
@@ -12,27 +13,18 @@ local uuid = require("util.uuid");
 local id = require("util.id");
 local datetime = require("util.datetime");
 local time = require("util.time");
-local serialization = require("util.serialization");
 local dataforms = require("util.dataforms");
+local array = require("util.array");
+local set = require("util.set");
 local pep = module:depends("pep");
+
 local helpers = module:require("mix/helpers");
+local namespaces = module:require("mix/namespaces");
+local anon = module:require("mix/anon");
 
 local mixlib = module:require("mix/mix");
-Channel = mixlib.Channel;
+local Channel = mixlib.Channel;
-Participant = mixlib.Participant;
+local Participant = mixlib.Participant;
-
--- XML namespaces
-local mix_core_xmlns = "urn:xmpp:mix:core:1";
-local mix_anon_xmlns = "urn:xmpp:mix:anon:0";
---local mix_admin_xmlns = "urn:xmpp:mix:admin:0";
-local mix_node_messages = "urn:xmpp:mix:nodes:messages";
-local mix_node_participants = "urn:xmpp:mix:nodes:participants";
-local mix_node_info = "urn:xmpp:mix:nodes:info";
---local mix_node_allowed = "urn:xmpp:mix:nodes:allowed";
---local mix_node_banned = "urn:xmpp:mix:nodes:banned";
---local mix_node_config = "urn:xmpp:mix:nodes:config";
-
-local mam_xmlns = "urn:xmpp:mam:2";
 
 -- Persistent data
 local persistent_channels = module:open_store("mix_channels", "keyval");
@@ -43,29 +35,29 @@ local message_archive = module:open_store("mix_log", "archive");
 local default_channel_description = module:get_option("default_description", "A MIX channel for chatting");
 local default_channel_name = module:get_option("default_name", "MIX channel");
 local restrict_channel_creation = module:get_option("restrict_local_channels", "local");
+local service_name = module:get_option("service_name", "Prosody MIX service");
+
+-- MIX configuration
+local default_mix_nodes = array { namespaces.info, namespaces.participants, namespaces.messages, namespaces.config };
 
 -- Dataforms
 -- MAM
 local mam_query_form = dataforms.new({
-    { name = "FORM_TYPE", type = "hidden", value = mam_xmlns },
+    { name = "FORM_TYPE", type = "hidden", value = namespaces.mam },
     { name = "with", type = "jid-single" },
     { name = "start", type = "text-single" },
     { name = "end", type = "text-single" },
 });
--- MIX Anon
+-- MIX Core
-local mix_anon_form = dataforms.new({
+local mix_info_form = dataforms.new({
-    { name = "FORM_TYPE", type = "hidden", value = mix_anon_xmlns },
+    { name = "FORM_TYPE", type = "hidden", value = namespaces.mix_core },
-    { name = "JID Visibility", type = "text-single" },
+    { name = "Name", type = "text-single" },
-    { name = "Private Messages", type = "text-single" },
+    { name = "Description", type = "text-single" },
-    { name = "Presence", type = "text-single" },
+    { name = "Contact", type = "jid-multi" }
-    { name = "vCard", type = "text-single" },
 });
-
-
 -- MIX-ADMIN stuff
---[[
 local mix_config_form = dataforms.new({
-    { name = "FORM_TYPE", type = "hidden", value = mix_admin_xmlns },
+    { name = "FORM_TYPE", type = "hidden", value = namespaces.mix_admin },
     { name = "Last Change Made By", type = "jid-single" },
     { name = "Owner", type = "jid-multi" },
     { name = "Administrator", type = "jid-multi" },
@@ -78,13 +70,45 @@ local mix_config_form = dataforms.new({
     { name = "Allowed Node Subscription", type = "list-single" },
     { name = "Banned Node Subscription", type = "list-single" },
     { name = "Configuration Node Access", type = "list-single" },
+    { name = "Information Node Update Rights", type = "list-single" },
+    { name = "Avatar Node Update Rights", type = "list-single" },
+    { name = "Open Presence", type = "boolean" },
+    { name = "Participants Must Provide Presence", type = "boolean" },
+    { name = "User Message Retraction", type = "boolean" },
+    { name = "Administrator Message Retraction Rights", type = "list-single" },
+    { name = "Participation Addition by Invitation from Participant", type = "boolean" },
+    { name = "Private Messages", type = "boolean" },
+    { name = "Mandatory Nicks", type = "boolean "},
 });
-]]--
+
+local function mix_admin_node_to_value(node)
+    local map = {
+        [namespaces.messages] = "messages";
+        [namespaces.participants] = "participants";
+        [namespaces.info] = "info";
+        [namespaces.allowed] = "allowed";
+        [namespaces.banned] = "banned";
+    };
+
+    return "'"..map[node].."'";
+end
+
+local function mix_admin_value_to_node(value)
+    local map = {
+        ["'messages'"] = namespaces.messages;
+        ["'participants'"] = namespaces.participants;
+        ["'info'"] = namespaces.info;
+        ["'allowed'"] = namespaces.allowed;
+        ["'banned'"] = namespaces.banned;
+    };
+
+    return map[value]
+end
 
 module:depends("disco");
-module:add_identity("conference", "mix", module:get_option("name", "Prosody MIX service"));
+module:add_identity("conference", "mix", service_name);
 module:add_feature("http://jabber.org/protocol/disco#info");
-module:add_feature(mix_core_xmlns);
+module:add_feature(namespaces.mix_core);
 
 local channels = {};
 
@@ -108,27 +132,10 @@ local function save_channels()
 end
 
 function Channel:save_state()
-    -- Saving the entire state everything one channel seems stupid,
+    -- Store the channel in the persistent channel store
-    -- so we just save the changed channel
+    module:log("debug", "Saving channel %s...", self.jid);
-    module:log("debug", "Saving state of channel %s...", self.jid);
     persistent_channel_data:set(self.jid, self);
-    module:log("debug", "Saving state done.", self.jid);
+    module:log("debug", "Saving done.", self.jid);
-end
-
-local function publish_participant(service, channel, spid, participant)
-    -- Publish a new participant on the service
-    -- NOTE: This function has be to called *after* the new participant
-    --       has been added to the channel.participants attay
-    service:set_node_config(mix_node_participants,
-                            true,
-                            { ["max_items"] = #channel.participants });
-    service:publish(mix_node_participants,
-                    true,
-                    spid,
-                    st.stanza("item", { id = spid, xmlns = "http://jabber.org/protocol/pubsub" })
-                        :tag("participant", { xmlns = mix_core_xmlns })
-                            :tag("nick"):text(participant["nick"]):up()
-                            :tag("jid"):text(participant["jid"]));
 end
 
 function module.load()
@@ -190,7 +197,7 @@ module:hook("iq/bare/http://jabber.org/protocol/disco#items:query", function(eve
     end
 
     local reply = st.reply(stanza):tag("query", { xmlns = "http://jabber.org/protocol/disco#items", node = "mix" });
-    for _, node in pairs({mix_node_messages, mix_node_participants, mix_node_info}) do
+    for _, node in pairs(channel.nodes) do
         reply:tag("item", { jid = channel.jid, node = node }):up();
     end
 
@@ -233,14 +240,13 @@ module:hook("iq-get/host/http://jabber.org/protocol/disco#info:query", function(
     local origin, stanza = event.origin, event.stanza;
     local reply = st.reply(stanza)
                     :tag("query", { xmlns = "http://jabber.org/protocol/disco#info" })
-                        -- TODO: Name
+                        :tag("identity", { category = "conference", type = "mix", name = service_name }):up()
-                        :tag("identity", { category = "conference", type = "mix", name = "" }):up()
                         :tag("feature", { var = "http://jabber.org/protocol/disco#info" }):up()
                         :tag("feature", { var = "http://jabber.org/protocol/disco#items" }):up()
-                        :tag("feature", { var = mix_core_xmlns }):up();
+                        :tag("feature", { var = namespaces.mix_core }):up();
 
     if can_create_channels(stanza.attr.from) then
-        reply:tag("feature", { var = mix_core_xmlns.."#create-channel" }):up();
+        reply:tag("feature", { var = namespaces.mix_core.."#create-channel" }):up();
     end
     origin.send(reply);
     return true;
@@ -259,14 +265,14 @@ module:hook("iq-get/bare/http://jabber.org/protocol/disco#info:query", function(
     reply:tag("feature", { var = "http://jabber.org/protocol/disco#info" }):up();
     reply:tag("identity", { category = "conference", name = channel.name, type = "mix" }):up();
 
-    reply:tag("feature", { var = mix_core_xmlns }):up();
+    reply:tag("feature", { var = namespaces.mix_core }):up();
     reply:tag("feature", { var = "urn:xmpp:mam:2" }):up();
 
     origin.send(reply);
     return true;
 end);
 
-module:hook("iq-set/bare/"..mam_xmlns..":query", function(event)
+module:hook("iq-set/bare/"..namespaces.mam..":query", function(event)
     local stanza, origin = event.stanza, event.origin;
     local channel_jid = stanza.attr.to;
     local j, channel = get_channel(channel_jid);
@@ -277,12 +283,12 @@ module:hook("iq-set/bare/"..mam_xmlns..":query", function(event)
     end
 
     -- Check if the user is subscribed to the messages node
-    if not channel:is_subscribed(stanza.attr.from, mix_node_messages) then
+    if not channel:is_subscribed(stanza.attr.from, namespaces.messages) then
         origin.send(st.error_reply(stanza, "cancel", "forbidden"));
         return true;
     end
 
-    local query = stanza:get_child("query", mam_xmlns);
+    local query = stanza:get_child("query", namespaces.mam);
     local filter = {};
     local query_id = query.attr.queryid;
     local x = query:get_child("x", "jabber:x:data");
@@ -314,7 +320,7 @@ module:hook("iq-set/bare/"..mam_xmlns..":query", function(event)
     end
     for message_id, item, when in data do
         local msg = st.stanza("message", { from = channel_jid, to = stanza.attr.from, type = "groupchat" })
-                        :tag("result", { xmlns = mam_xmlns, queryid = query_id, id = message_id })
+                        :tag("result", { xmlns = namespaces.mam, queryid = query_id, id = message_id })
                             :tag("forwarded", { xmlns = "urn:xmpp:forward:0" })
                                 :tag("delay", { xmlns = "urn:xmpp:delay", stamp = datetime.datetime(when) }):up();
         msg:add_child(item);
@@ -323,16 +329,17 @@ module:hook("iq-set/bare/"..mam_xmlns..":query", function(event)
     return true;
 end);
 
-module:hook("iq-get/bare/"..mam_xmlns..":query", function(event)
+module:hook("iq-get/bare/"..namespaces.mam..":query", function(event)
     if event.stanza.attr.id ~= "form1" then return; end
 
     module:log("debug", "Got a MAM query for supported fields");
 
+    -- TODO: Use dataforms:...
     local ret = st.reply(event.stanza)
-                    :tag("query", { xmlns = mam_xmlns })
+                    :tag("query", { xmlns = namespaces.mam })
                         :tag("x", { xmlns = "jabber:x:data", type = "form"})
                             :tag("field", { type = "hidden", var = "FORM_TYPE" })
-                                :tag("value"):text(mam_xmlns):up():up()
+                                :tag("value"):text(namespaces.mam):up():up()
                             :tag("field", { type = "jid-single", var = "with" }):up()
                             :tag("field", { type = "text-single", var = "start" }):up()
                             :tag("field", { type = "text-single", var = "end" });
@@ -340,7 +347,7 @@ module:hook("iq-get/bare/"..mam_xmlns..":query", function(event)
     return true;
 end);
 
-module:hook("iq-set/bare/"..mix_core_xmlns..":leave", function(event)
+module:hook("iq-set/bare/"..namespaces.mix_core..":leave", function(event)
     module:log("debug", "MIX leave received");
     local origin, stanza = event.origin, event.stanza;
     local from = jid.bare(stanza.attr.from);
@@ -361,38 +368,22 @@ module:hook("iq-set/bare/"..mix_core_xmlns..":leave", function(event)
         return true;
     end
 
-    -- Remove the user as a participant by...
+    channel:remove_participant(from);
-    -- Unsubscribing
-    local srv = pep.get_pep_service(jid.node(channel.jid));
-    for _, node in pairs(channel.subscriptions[from]) do
-        srv:set_affiliation(node, true, from, "outcast");
-        srv:remove_subscription(node, true, from);
-        module:log("debug", "Unsubscribed %s from %s on %s", from, node, channel.jid);
-    end
-    channel.subscriptions[from] = nil;
-    -- Retracting the participation
-    local spid = channel:get_spid(from);
-    local notifier = st.stanza("retract", { id = spid });
-    -- TODO: Maybe error handling
-    srv:retract(mix_node_participants, true, spid, notifier);
-    -- Removing the user
-    table.remove(channel.participants, j);
-    channel:save_state();
 
     module:fire_event("mix-channel-leave", { channel = channel, participant = participant });
 
-    origin.send(st.reply(stanza):tag("leave", { xmlns = mix_core_xmlns }));
+    origin.send(st.reply(stanza):tag("leave", { xmlns = namespaces.mix_core }));
     return true;
 end);
 
-module:hook("iq-set/bare/"..mix_core_xmlns..":join", function(event)
+module:hook("iq-set/bare/"..namespaces.mix_core..":join", function(event)
     module:log("debug", "MIX join received");
 
     local origin, stanza = event.origin, event.stanza;
     local from = jid.bare(stanza.attr.from);
     local _, channel = get_channel(stanza.attr.to);
     if not channel then
-        origin.send(channel_not_found(stanza));
+        origin:send(channel_not_found(stanza));
         return true;
     end
 
@@ -403,12 +394,24 @@ module:hook("iq-set/bare/"..mix_core_xmlns..":join", function(event)
         return true;
     end
 
+    -- Is the user allowed to join?
+    if not channel:may(from, "join", nil) then
+        origin:send(st.error_reply(stanza, "cancel", "forbidden", "User or host is banned"));
+        return true;
+    end
+
     local spid = channel:get_spid(from) or uuid.generate(); -- Stable Participant ID
     local reply = st.reply(stanza)
-                    :tag("join", { xmlns = mix_core_xmlns, id = spid });
+                    :tag("join", { xmlns = namespaces.mix_core, id = spid });
-    local srv = pep.get_pep_service(jid.node(stanza.attr.to));
+    local join = stanza:get_child("join", namespaces.mix_core);
-    local join = stanza:get_child("join", mix_core_xmlns);
     local nick_tag = join:get_child("nick");
+
+    -- Check if the channel has mandatory nicks
+    if channel.config["Mandatory Nicks"] and not nick_tag then
+        origin:send(st.error_reply(stanza, "modify", "forbidden", "Nicks are mandatory"));
+        return true;
+    end
+
     local nick;
     if not nick_tag then
         nick = jid.node(from);
@@ -417,14 +420,24 @@ module:hook("iq-set/bare/"..mix_core_xmlns..":join", function(event)
     end
     module:log("debug", "User joining as nick %s", nick);
 
+    local srv = pep.get_pep_service(jid.node(channel.jid));
     local nodes = {};
     local has_subscribed_once = false;
     local first_error = nil;
+    local owner_or_admin = channel:is_admin(from) or channel:is_owner(from);
     for subscribe in join:childtags("subscribe") do
+        -- May the user subscribe to the node?
         module:log("debug", "Subscribing user to node %s", subscribe.attr.node);
-        -- TODO: Once MIX-ADMIN is implemented, we should check here what
+        if channel:may_subscribe(from, subscribe.attr.node, true) then
-        -- affiliation we set, e.g. if the JID is the owner, then set owner.
+            -- Set the correct affiliation
-        srv:set_affiliation(subscribe.attr.node, true, from, "member");
+            local affiliation = "";
+            if owner_or_admin then
+                affiliation = "publisher";
+            else
+                affiliation = "member";
+            end
+            srv:set_affiliation(subscribe.attr.node, true, from, affiliation);
+
             local ok, err = srv:add_subscription(subscribe.attr.node, true, from);
             if not ok then
                 module:log("debug", "Error during subscription: %s", err);
@@ -434,69 +447,66 @@ module:hook("iq-set/bare/"..mix_core_xmlns..":join", function(event)
                 if first_error ~= nil then
                     first_error = err;
                 end
+
+                -- Reset affiliation
+                srv:set_affiliation(subscribe.attr.node, true, from, "outcast");
+
             else
                 table.insert(nodes, subscribe.attr.node);
                 reply:tag("subscribe", { node = subscribe.attr.node }):up();
                 has_subscribed_once = true;
             end
+        else
+            module:log("debug", "Error during subscription: may_subscribe returned false");
+            if first_error ~= nil then
+                first_error = "Channel does not allow subscribing";
+            end
+        end
     end
 
     if not has_subscribed_once then
-        origin.send(st.error_reply(stanza, "cancel", first_error));
+        -- TODO: This does not work
+        origin:send(st.error_reply(stanza, "cancel", first_error));
         return true;
     end
 
     -- TODO: Make the default configurable
-    local jid_visibility = "never"; -- default
+    local config = mixlib.default_participant_configuration;
-    local allow_pms = "allow";
+    local x = join:get_child("x");
-    local allow_vcards = "block";
-    local share_presence = "share";
-    local x = join:get_child("x", "jabber:x:data");
     if x ~= nil then
-        -- TODO: Rethink naming
         -- TODO: Error handling?
-        local form, err = mix_anon_form:data(x);
+        local form, err = anon.form:data(x);
         if form["JID Visibility"] then
-            jid_visibility = form["JID Visibility"];
+            config["JID Visibility"] = form["JID Visibility"];
         end
         if form["Private Messages"] then
-            allow_pms = form["Private Messages"];
+            config["Private Messages"] = form["Private Messages"];
         end
         if form["Presence"] then
-            share_presence = form["Presence"];
+            config["Presence"] = form["Presence"];
         end
         if form["vCard"] then
-            allow_vcards = form["vCard"];
+            config["vCard"] = form["vCard"];
         end
     end
 
-    local participant = Participant:new(jid.bare(from), nick, jid_visibility, allow_pms, share_presence, allow_vcards);
+    local participant = Participant:new(jid.bare(from), nick, config);
     channel.subscriptions[from] = nodes;
     table.insert(channel.participants, participant)
     channel:set_spid(jid.bare(stanza.attr.from), spid);
-    publish_participant(srv, channel, spid, participant);
+    channel:publish_participant(spid, participant);
     channel:save_state();
 
     module:fire_event("mix-channel-join", { channel = channel, participant = participant });
 
-    reply:add_child(nick_tag);
+    -- We do not reuse nick_tag as it might be nil
-    reply:tag("x", { xmlns = "jabber:x:data", type = "result" })
+    reply:tag("nick"):text(nick):up();
-        :tag("field", { var = "FORM_TYPE", type = "hidden" })
+    reply:add_child(anon.form:form(config, "result"));
-            :tag("value"):text(mix_anon_xmlns):up():up()
-        :tag("field", { var = "JID Visibility"})
-            :tag("value"):text(jid_visibility):up():up()
-        :tag("field", { var = "Private Messages"})
-            :tag("value"):text(allow_pms):up():up()
-        :tag("field", { var = "Presence"})
-            :tag("value"):text(share_presence):up():up()
-        :tag("field", { var = "vCard"})
-            :tag("value"):text(allow_vcards):up():up();
-
     origin.send(reply);
     return true
 end);
 
-module:hook("iq-set/bare/"..mix_core_xmlns..":setnick", function(event)
+module:hook("iq-set/bare/"..namespaces.mix_core..":setnick", function(event)
     module:log("debug", "MIX setnick received");
     local origin, stanza = event.origin, event.stanza;
     local from = jid.bare(stanza.attr.from);
@@ -514,7 +524,7 @@ module:hook("iq-set/bare/"..mix_core_xmlns..":setnick", function(event)
     end
 
     -- NOTE: Prosody should guarantee us that the setnick stanza exists
-    local setnick = stanza:get_child("setnick", mix_core_xmlns);
+    local setnick = stanza:get_child("setnick", namespaces.mix_core);
     local nick = setnick:get_child("nick");
     if nick == nil then
         origin.send(st.error_reply(stanza, "cancel", "bad-request", "Missing <nick>"));
@@ -524,14 +534,12 @@ module:hook("iq-set/bare/"..mix_core_xmlns..":setnick", function(event)
     -- Change the nick
     channel.participants[j].nick = nick:get_text();
     -- Inform all other members
-    local srv = pep.get_pep_service(jid.node(channel.jid));
+    channel:publish_participant(channel:get_spid(participant.jid), participant);
-    --local participant = channel.participants[participant_index];
-    publish_participant(srv, channel, channel:get_spid(participant.jid), participant);
 
     module:fire_event("mix-change-nick", { channel = channel, participant = participant });
 
     origin.send(st.reply(stanza)
-                    :tag("setnick", { xmlns = mix_core_xmlns })
+                    :tag("setnick", { xmlns = namespaces.mix_core })
                         :tag("nick"):text(nick:get_text()));
     channel:save_state();
     return true;
@@ -539,32 +547,38 @@ end);
 
 function Channel:publish_info(srv)
     local timestamp = datetime.datetime(time.now());
+    -- TODO: Check if this is correct
     local info = st.stanza("item", { id = timestamp, xmlns = "http://jabber.org/protocol/pubsub" })
-                    :tag("x", { xmlns = "jabber:x:data", type = "result" })
+                    :add_child(mix_info_form:form({
-                        :tag("field", { var = "FORM_TYPE", type = "hidden" })
+                        ["FORM_TYPE"] = "hidden",
-                            :tag("value"):text(mix_core_xmlns):up():up()
+                        ["Name"] = self.name,
-                        :tag("field", { var = "Name" })
+                        ["Description"] = self.description,
-                            :tag("value"):text(self.name):up()
+                        ["Contacts"] = self.contacts
-                        :tag("field", { var = "Contact" });
+                    }, "result"));
-    for _, contact in pairs(self.contacts) do
+    srv:publish(namespaces.info, true, timestamp, info);
-        info:add_child(st.stanza("value"):text(contact));
-    end
-    srv:publish(mix_node_info, true, timestamp, info);
 end
 
 local function create_channel(node, creator, adhoc)
-    local channel = Channel:new(string.format("%s@%s", node, host),
+    -- TODO: Now all properties from the admin dataform are covered
+    local channel = Channel:new(string.format("%s@%s", node, host), -- Channel JID
                                 default_channel_name,
                                 default_channel_description,
-                                {},
+                                {},             -- Participants
-                                {},
+                                {},             -- Administrators
-                                {},
+                                { creator },    -- Owners
-                                { creator },
+                                {},             -- Subscriptions
-                                adhoc);
+                                {},             -- SPID mapping
+                                { creator },    -- Contacts
+                                adhoc,          -- Is channel an AdHoc channel
+                                {},             -- Allowed
+                                {},             -- Banned
+                                mixlib.default_channel_configuration, -- Channel config
+                                {});            -- Present nodes
+
     -- Create the PEP nodes
     local srv = pep.get_pep_service(node);
     -- MIX-CORE
-    for _, psnode in pairs({ mix_node_info, mix_node_participants, mix_node_messages }) do
+    for _, psnode in ipairs(default_mix_nodes) do
         srv:create(psnode, true, {
             ["access_model"] = "whitelist",
             ["persist_items"] = true,
@@ -572,28 +586,44 @@ local function create_channel(node, creator, adhoc)
     end
     channel:publish_info(srv);
 
-    --[[
     -- MIX-ADMIN
-    local admin_nodes = { mix_node_banned, mix_node_config };
+    local admin_nodes = array { namespaces.banned };
     if adhoc then
-        table.insert(admin_nodes, mix_node_allowed);
+        admin_nodes:push(namespaces.allowed);
     end
     for _, psnode in pairs(admin_nodes) do
-        srv:create(mix_node_allowed, true, { ["access_model"] = "whitelist" });
+        srv:create(psnode, true, {
-        srv:set_affiliation(mix_node_allowed, true, creator, "owner");
+            ["access_model"] = "whitelist",
+            ["persist_items"] = true,
+        });
+        srv:set_affiliation(namespaces.allowed, true, creator, "publish");
     end
     if adhoc then
         -- Allow the creator to join
-        srv:publish(mix_node_allowed,
+        channel:allow_jid(creator);
-                    true,
-                    nil,
-                    st.stanza("item", { id = creator }));
     end
-    ]]--
+
+    -- Some bookkeeping
+    local nodes = default_mix_nodes + admin_nodes;
+    local node_names = array(nodes):filter(function (element)
+        return element ~= namespaces.config;
+    end):map(mix_admin_node_to_value):push("'avatar'");
+    -- NOTE: This is to prevent cycles during serialization (apparently)
+    channel.nodes = {table.unpack(nodes)};
+
+    local config = mixlib.default_channel_configuration;
+    config["Owner"] = { creator };
+    config["Nodes Present"] = node_names;
+    channel.config = config;
+    srv:publish(namespaces.config,
+                true,
+                "",
+                st.stanza("item", { xmlns = "http://jabber.org/protocol/pubsub" })
+                    :add_child(mix_config_form:form(config, "result")));
     table.insert(channels, channel);
 end
 
-module:hook("iq-set/host/"..mix_core_xmlns..":create", function(event)
+module:hook("iq-set/host/"..namespaces.mix_core..":create", function(event)
     module:log("debug", "MIX create received");
     local origin, stanza = event.origin, event.stanza;
     local from = jid.bare(stanza.attr.from);
@@ -604,7 +634,7 @@ module:hook("iq-set/host/"..mix_core_xmlns..":create", function(event)
         return true;
     end
 
-    local create = stanza:get_child("create", mix_core_xmlns);
+    local create = stanza:get_child("create", namespaces.mix_core);
     local node;
     if create.attr.channel ~= nil then
         -- Create non-adhoc channel
@@ -637,17 +667,17 @@ module:hook("iq-set/host/"..mix_core_xmlns..":create", function(event)
     -- TODO: Add an event
 
     origin.send(st.reply(stanza)
-                :tag("create", { xmlns = mix_core_xmlns, channel = node }));
+                :tag("create", { xmlns = namespaces.mix_core, channel = node }));
     save_channels();
     return true;
 end);
 
-module:hook("iq-set/host/"..mix_core_xmlns..":destroy", function(event)
+module:hook("iq-set/host/"..namespaces.mix_core..":destroy", function(event)
     module:log("debug", "MIX destroy received");
     local origin, stanza = event.origin, event.stanza;
     local from = jid.bare(stanza.attr.from);
 
-    local destroy = stanza:get_child("destroy", mix_core_xmlns);
+    local destroy = stanza:get_child("destroy", namespaces.mix_core);
     local node = destroy.attr.channel;
     local node_jid = string.format("%s@%s", node, host);
     local i, channel = get_channel(node_jid);
@@ -656,15 +686,14 @@ module:hook("iq-set/host/"..mix_core_xmlns..":destroy", function(event)
         return true;
     end
 
-    -- TODO: Permission checks
+    if not channel:is_owner(from) then
-    -- TODO: Maybe make this configurable
-    if helpers.find_str(channel.contacts, from) == -1 then
         origin.send(st.error_reply(stanza, "cancel", "forbidden"));
         return true;
     end
+
     -- Remove all registered nodes
     local srv = pep.get_pep_service(node);
-    for _, pep_node in pairs({ mix_node_participants, mix_node_info, mix_node_messages }) do
+    for _, pep_node in pairs(channel.nodes) do
         srv:delete(pep_node, true);
     end
     table.remove(channels, i);
@@ -698,31 +727,280 @@ module:hook("message/bare", function(event)
         return true;
     end
 
-    local msg = st.clone(stanza);
+    -- Handles sending the message accordingly, firing an event and
-    msg:add_child(st.stanza("mix", { xmlns = mix_core_xmlns })
+    -- even doing nothing if an event handler for "mix-broadcast-message"
-                    :tag("nick"):text(participant.nick):up()
+    -- returns true.
-                    :tag("jid"):text(participant.jid):up());
+    channel:broadcast_message(stanza, participant, message_archive);
-
-    -- Put the message into the archive
-    local mam_id = uuid.generate();
-    msg.attr.id = mam_id;
-    -- NOTE: The spec says to do so
-    msg.attr.from = channel.jid;
-    message_archive:append(stanza.attr.to, mam_id, msg, time.now());
-    msg.attr.from = channel.jid.."/"..channel:get_spid(from);
-
-    if module:fire_event("mix-broadcast-message", { message = msg, channel = channel }) then
-        return true;
-    end
-
-    for _, p in pairs(channel.participants) do
-        -- Only users who subscribed to the messages node should receive
-        -- messages
-        if channel:is_subscribed(p.jid, mix_node_messages) then
-            local tmp = st.clone(msg);
-            tmp.attr.to = p.jid;
-            module:send(tmp);
-        end
-    end
     return true;
 end);
+
+local function handle_new_node(srv, channel, node)
+    if node == namespaces.allowed then
+        -- If the allowed node is created, make sure to add the owners
+        -- as allowed
+
+        channel.allowed = {};
+        for _, owner in pairs(channel.owners) do
+            array.push(channel.allowed, owner)
+            srv:publish(namespaces.allowed, true, owner, nil);
+        end
+
+        -- Remove all non-allowed participants
+        for _, participant in channel.participants do
+            if not channel:is_allowed(participant.jid) then
+                channel:remove_participant(participant.jid);
+            end
+        end
+    end
+end
+
+-- MIX Admin events
+local function handle_pubsub_publish(event, publish, channel)
+    local node = publish.attr.node;
+    local from = jid.bare(event.stanza.attr.from);
+    local item = publish:get_child("item");
+
+    -- TODO: Deal with avatars
+    -- TODO: Should we trust the clients to behave?
+    -- local srv = pep.get_pep_service(jid.node(channel.jid));
+    if node == namespaces.config then
+        if not channel:may(from, "update", namespaces.config) then
+            -- TODO: This does not work
+            event.origin:send(st.error_reply(publish, "auth", "forbidden"));
+            return true;
+        end
+
+        local config, err = mix_config_form:data(item);
+        -- TODO: Error handling?
+
+        local srv = pep.get_pep_service(jid.node(channel.jid));
+        -- TODO: Check this over
+        local removed_admins = set.new(channel.administrators):difference(set.new(config["Administrator"]));
+        local removed_owners = set.new(channel.owners):difference(set.new(config["Owner"]));
+        local new_node_names = set.new(config["Nodes Present"]):difference(set.new(channel.nodes));
+        local removed_node_names = set.new(channel.nodes):difference(set.new(config["Nodes Present"]));
+        local new_nodes = array.map(new_node_names, mix_admin_value_to_node); -- TODO
+        local removed_nodes = array.map(removed_node_names, mix_admin_value_to_node); -- TODO
+
+        -- TODO: Verify that this is actually safe
+        for _, jid_ in pairs(array.append(removed_admins, removed_owners)) do
+            for _, psnode in pairs(channel.nodes) do
+                srv:set_affiliation(psnode, true, jid_, "member");
+            end
+        end
+
+        -- TODO: Apply this to the PubSub publish
+        config["Last Change Made By"] = jid.bare(event.stanza.attr.from);
+        channel.owners = config["Owner"];
+        channel.administrators = config["Administrator"];
+        channel.config = config;
+        channel.nodes = config["Nodes Present"]
+
+        -- Remove all nodes that are not existant anymore...
+        for _, removed_node in pairs(removed_nodes) do
+            for participant, subscriptions in channel.participants do
+                local j, _ = helpers.find(subscriptions, removed_node);
+                if j ~= -1 then
+                    srv:remove_subscription(removed_node, true, from);
+                    table.remove(participant.subscriptions, j);
+                end
+            end
+
+            if removed_node == namespaces.allowed then
+                channel.allowed = nil;
+            elseif removed_node == namespaces.banned then
+                channel.banned = nil;
+            end
+        end
+        -- ... and create all new ones.
+        for _, new_node in pairs(new_nodes) do
+            srv:create(new_node, true, {
+                ["access_model"] = "whitelist",
+                ["persist_items"] = true,
+            });
+            for participant, _ in channel.participants do
+                local affiliation = "";
+                if channel:is_admin(participant.jid) or channel:is_owner(participant.jid) then
+                    affiliation = "publisher";
+                else
+                    affiliation = "member";
+                end
+
+                srv:set_affiliation(new_node, true, affiliation);
+            end
+
+            handle_new_node(srv, channel, new_node);
+          end
+
+        for _, jid_ in pairs(array.append(channel.owners, channel.administrators)) do
+            for _, psnode in pairs(channel.nodes) do
+                srv:set_affiliation(psnode, true, jid_, "publisher");
+            end
+        end
+    elseif node == namespaces.info then
+        if not channel:may(from, "update", namespaces.info) then
+            -- TODO: This does not work
+            event.origin:send(st.error_reply(publish, "auth", "forbidden"));
+            return true;
+        end
+
+        local info, err = mix_info_form:data(item);
+        -- TODO: Error handling
+        if info["Name"] then
+            channel.name = info["Name"];
+        end
+        if info["Description"] then
+            channel.description = info["Description"];
+        end
+        if info["Contact"] then
+            channel.contacts = info["Contact"];
+        end
+
+        module:log("debug", "Channel info updated");
+    elseif node == namespaces.banned then
+        channel:ban_jid(publish:get_child("item").attr.id);
+    elseif node == namespaces.allowed then
+        channel:allow_jid(publish:get_child("item").attr.id);
+    elseif node == namespaces.participants or node == namespaces.messages then
+        -- We don't want admins or owners to publish to these nodes as they
+        -- are managed by the module
+        local reply = st.error_reply(event.stanza, "cancel", "feature-not-implemented");
+        reply:tag("unsupported", {
+            xmlns = "http://jabber.org/protocol/pubsub#errors",
+            feature = "publish",
+        });
+        event.origin:send(reply);
+        return true;
+    end
+
+    -- Let the actual PubSub implementation handle the rest
+    channel:save_state();
+end
+
+local function handle_pubsub_retract(event, retract, channel)
+    local node = retract.attr.node;
+    local item = retract:get_child("item");
+    if node == namespaces.banned then
+        channel.banned = array.filter(channel.banned, function (element)
+            return element ~= item.attr.id;
+        end);
+    elseif node == namespaces.allowed then
+        channel.allowed = array.filter(channel.allowed, function (element)
+            return element ~= item.attr.id;
+        end);
+    elseif node == namespaces.participants then
+        local reply = st.error_reply(event.stanza, "cancel", "feature-not-implemented");
+        reply:tag("unsupported", {
+            xmlns = "http://jabber.org/protocol/pubsub#errors",
+            feature = "delete-items"
+        });
+        event.origin:send(reply);
+        return true;
+    end
+
+    channel:save_state();
+end
+
+local function handle_pubsub_subscribe(event, subscribe, channel)
+    local from = jid.bare(event.stanza.attr.from);
+    local origin = event.origin;
+    local node = subscribe.attr.node;
+
+    -- Check for node existance
+    local i, _ = helpers.find(channel.nodes, node);
+    if i == -1 then
+        -- Let the actual PubSub implementation handle it
+        return;
+    end
+
+    if not channel:may(from, "subscribe", node) then
+        origin:send(st.error_reply(event.stanza, "auth", "forbidden"));
+        return true;
+    end
+
+    table.insert(channel.subscriptions[from], node);
+    channel:save_state();
+    -- The rest is handled by the actual PubSub implementation
+end
+
+local function handle_pubsub_unsubscribe(event, subscribe, channel)
+    local from = jid.bare(event.stanza.attr.from);
+    local origin = event.origin;
+    local node = subscribe.attr.node;
+
+    -- Check for node existance
+    local i, _ = helpers.find(channel.nodes, node);
+    if i == -1 then
+        -- Let the actual PubSub implementation handle it
+        return;
+    end
+
+    if not channel:may(from, "subscribe", node) then
+        origin:send(st.error_reply(event.stanza, "auth", "forbidden"));
+        return true;
+    end
+
+    local j, _ = helpers.find(channel.subscriptions[from], node);
+    if j == -1 then
+        local errstanza = st.error_reply(event.stanza, "cancel", "unexpected-request");
+        errstanza:tag("not-subscribed", { xmlns = "http://jabber.org/protocol/pubsub#errors" });
+        origin:send(errstanza);
+        return true;
+    end
+    table.remove(channel.subscriptions[from], j);
+    channel:save_state();
+    -- The rest is handled by the actual PubSub implementation
+end
+
+local function handle_pubsub_items(event, items, channel)
+    local node = items.attr.node;
+    local from = jid.bare(event.stanza.attr.from);
+    if node == namespaces.config then
+        if not channel:may(from, "access", node) then
+            return true;
+        end
+    end
+end
+
+module:hook("iq-get/bare/http://jabber.org/protocol/pubsub:pubsub", function(event)
+    local stanza = event.stanza;
+    local _, channel = get_channel(stanza.attr.to);
+    if not channel then
+        return;
+    end
+
+    local pubsub = stanza:get_child("pubsub", "http://jabber.org/protocol/pubsub");
+    local items = pubsub:get_child("items");
+    if items then
+        return handle_pubsub_items(event, items, channel);
+    end
+end, 1000);
+
+module:hook("iq-set/bare/http://jabber.org/protocol/pubsub:pubsub", function(event)
+    local stanza = event.stanza;
+    local _, channel = get_channel(stanza.attr.to);
+    if not channel then
+        return;
+    end
+
+    local pubsub = stanza:get_child("pubsub", "http://jabber.org/protocol/pubsub");
+    local publish = pubsub:get_child("publish");
+    if publish then
+        return handle_pubsub_publish(event, publish, channel);
+    end
+
+    local subscribe = pubsub:get_child("subscribe");
+    if subscribe then
+        return handle_pubsub_subscribe(event, subscribe, channel);
+    end
+
+    local unsubscribe = pubsub:get_child("unsubscribe");
+    if unsubscribe then
+        return handle_pubsub_unsubscribe(event, subscribe, channel);
+    end
+
+    local retract = pubsub:get_child("retract");
+    if retract then
+        return handle_pubsub_retract(event, retract, channel);
+    end
+end, 1000);

mod_mix/namespaces.lib.lua

@@ -0,0 +1,19 @@
+return {
+    -- XMLNS
+    -- MIX
+    mix_core = "urn:xmpp:mix:core:1";
+    mix_anon = "urn:xmpp:mix:anon:0";
+    mix_admin = "urn:xmpp:mix:admin:0";
+    -- MAM
+    mam = "urn:xmpp:mam:2";
+    -- User Avatar
+    avatar = "urn:xmpp:avatar:data";
+    avatar_metadata = "urn:xmpp:avatar:metadata";
+    -- MIX PubSub nodes
+    messages = "urn:xmpp:mix:nodes:messages";
+    participants = "urn:xmpp:mix:nodes:participants";
+    info = "urn:xmpp:mix:nodes:info";
+    allowed = "urn:xmpp:mix:nodes:allowed";
+    banned = "urn:xmpp:mix:nodes:banned";
+    config = "urn:xmpp:mix:nodes:config";
+};