--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/mod_blocklist.lua	Sun Aug 10 10:27:00 2014 +0200
@@ -0,0 +1,273 @@
+-- Prosody IM
+-- Copyright (C) 2009-2010 Matthew Wild
+-- Copyright (C) 2009-2010 Waqas Hussain
+-- Copyright (C) 2014 Kim Alvefur
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+-- This module implements XEP-0191: Blocking Command
+--
+
+local user_exists = require"core.usermanager".user_exists;
+local is_contact_subscribed = require"core.rostermanager".is_contact_subscribed;
+local st = require"util.stanza";
+local st_error_reply = st.error_reply;
+local jid_prep, jid_split = import("jid", "prep", "split");
+
+local host = module.host;
+local storage = module:open_store();
+local sessions = prosody.hosts[host].sessions;
+
+-- Cache of blocklists used since module was loaded
+local cache = {};
+if module:get_option_boolean("blocklist_weak_cache") then
+	-- Lower memory usage, more IO and latency
+	setmetatable(cache, { __mode = "v" });
+end
+
+local null_blocklist = {};
+
+module:add_feature("urn:xmpp:blocking");
+
+local function set_blocklist(username, blocklist)
+	local ok, err = storage:set(username, blocklist);
+	if not ok then
+		return ok, err;
+	end
+	-- Successful save, update the cache
+	cache[username] = blocklist;
+	return true;
+end
+
+-- Migrates from the old mod_privacy storage
+local function migrate_privacy_list(username)
+	local migrated_data = { [false] = "not empty" };
+	module:log("info", "Migrating blocklist from mod_privacy storage for user '%s'", username);
+	local legacy_data = module:open_store("privacy"):get(username);
+	if legacy_data and legacy_data.lists and legacy_data.default then
+		legacy_data = legacy_data.lists[legacy_data.default];
+		legacy_data = legacy_data and legacy_data.items;
+	else
+		return migrated_data;
+	end
+	if legacy_data then
+		local item, jid;
+		for i = 1, #legacy_data do
+			item = legacy_data[i];
+			if item.type == "jid" and item.action == "deny" then
+				jid = jid_prep(item.value);
+				if not jid then
+					module:log("warn", "Invalid JID in privacy store for user '%s' not migrated: %s", username, tostring(item.value));
+				else
+					migrated_data[jid] = true;
+				end
+			end
+		end
+	end
+	set_blocklist(username, migrated_data);
+	return migrated_data;
+end
+
+local function get_blocklist(username)
+	local blocklist = cache[username];
+	if not blocklist then
+		if not user_exists(username, host) then
+			return null_blocklist;
+		end
+		blocklist = storage:get(username);
+		if not blocklist then
+			blocklist = migrate_privacy_list(username);
+		end
+		cache[username] = blocklist;
+	end
+	return blocklist;
+end
+
+module:hook("iq-get/self/urn:xmpp:blocking:blocklist", function (event)
+	local origin, stanza = event.origin, event.stanza;
+	local username = origin.username;
+	local reply = st.reply(stanza):tag("blocklist", { xmlns = "urn:xmpp:blocking" });
+	local blocklist = get_blocklist(username);
+	for jid in pairs(blocklist) do
+		if jid then
+			reply:tag("item", { jid = jid }):up();
+		end
+	end
+	origin.interested_blocklist = true; -- Gets notified about changes
+	return origin.send(reply);
+end);
+
+-- Add or remove a bare jid from the blocklist
+-- We want this to be atomic and not do a partial update
+local function edit_blocklist(event)
+	local origin, stanza = event.origin, event.stanza;
+	local username = origin.username;
+	local act = stanza.tags[1];
+	local new = {};
+
+	local jid;
+	for item in act:childtags("item") do
+		jid = jid_prep(item.attr.jid);
+		if not jid then
+			return origin.send(st_error_reply(stanza, "modify", "jid-malformed"));
+		end
+		item.attr.jid = jid; -- echo back prepped
+		new[jid] = is_contact_subscribed(username, host, jid) or false;
+	end
+
+	local mode = act.name == "block" or nil;
+
+	if mode and not next(new) then
+		-- <block/> element does not contain at least one <item/> child element
+		return origin.send(st_error_reply(stanza, "modify", "bad-request"));
+	end
+
+	local blocklist = get_blocklist(username);
+
+	local new_blocklist = {};
+
+	if mode and next(new) then
+		for jid in pairs(blocklist) do
+			new_blocklist[jid] = true;
+		end
+		for jid in pairs(new) do
+			new_blocklist[jid] = mode;
+		end
+		-- else empty the blocklist
+	end
+	new_blocklist[false] = "not empty"; -- In order to avoid doing the migration thing twice
+
+	local ok, err = set_blocklist(username, new_blocklist);
+	if ok then
+		origin.send(st.reply(stanza));
+	else
+		return origin.send(st_error_reply(stanza, "wait", "internal-server-error", err));
+	end
+
+	if mode then
+		for jid, in_roster in pairs(new) do
+			if not blocklist[jid] and in_roster and sessions[username] then
+				for _, session in pairs(sessions[username].sessions) do
+					module:send(st.presence({ type = "unavailable", to = jid, from = session.full_jid }));
+				end
+			end
+		end
+	end
+	if sessions[username] then
+		local blocklist_push = st.iq({ type = "set", id = "blocklist-push" })
+			:add_child(act); -- I am lazy
+
+		for _, session in pairs(sessions[username].sessions) do
+			if session.interested_blocklist then
+				blocklist_push.attr.to = session.full_jid;
+				session.send(blocklist_push);
+			end
+		end
+	end
+
+	return true;
+end
+
+module:hook("iq-set/self/urn:xmpp:blocking:block", edit_blocklist);
+module:hook("iq-set/self/urn:xmpp:blocking:unblock", edit_blocklist);
+
+-- Cache invalidation, solved!
+module:hook_global("user-deleted", function (event)
+	if event.host == host then
+		cache[event.username] = nil;
+	end
+end);
+
+-- Buggy clients
+module:hook("iq-error/self/blocklist-push", function (event)
+	local type, condition, text = event.stanza:get_error();
+	(event.origin.log or module._log)("warn", "client returned an error in response to notification from mod_%s: %s%s%s", module.name, condition, text and ": " or "", text or "");
+	return true;
+end);
+
+local function is_blocked(user, jid)
+	local blocklist = cache[user] or get_blocklist(user);
+	if blocklist[jid] then return true; end
+	local node, host = jid_split(jid);
+	return blocklist[host] or node and blocklist[node..'@'..host];
+end
+
+-- Event handlers for bouncing or dropping stanzas
+local function drop_stanza(event)
+	local stanza = event.stanza;
+	local attr = stanza.attr;
+	local to, from = attr.to, attr.from;
+	to = to and jid_split(to);
+	if to and from then
+		return is_blocked(to, from);
+	end
+end
+
+local function bounce_stanza(event)
+	local origin, stanza = event.origin, event.stanza;
+	if drop_stanza(event) then
+		return origin.send(st_error_reply(stanza, "cancel", "service-unavailable"));
+	end
+end
+
+local function bounce_iq(event)
+	local type = event.stanza.attr.type;
+	if type == "set" or type == "get" then
+		return bounce_stanza(event);
+	end
+	return drop_stanza(event); -- result or error
+end
+
+local function bounce_message(event)
+	local type = event.stanza.attr.type;
+	if type == "chat" or not type or type == "normal" then
+		return bounce_stanza(event);
+	end
+	return drop_stanza(event); -- drop headlines, groupchats etc
+end
+
+local function drop_outgoing(event)
+	local origin, stanza = event.origin, event.stanza;
+	local username = origin.username or jid_split(stanza.attr.from);
+	if not username then return end
+	local to = stanza.attr.to;
+	if to then return is_blocked(username, to); end
+	-- nil 'to' means a self event, don't bock those
+end
+
+local function bounce_outgoing(event)
+	local origin, stanza = event.origin, event.stanza;
+	local type = stanza.attr.type;
+	if type == "error" or stanza.name == "iq" and type == "result" then
+		return drop_outgoing(event);
+	end
+	if drop_outgoing(event) then
+		return origin.send(st_error_reply(stanza, "cancel", "not-acceptable", "You have blocked this JID")
+			:tag("blocked", { xmlns = "urn:xmpp:blocking:errors" }));
+	end
+end
+
+-- Hook all the events!
+local prio_in, prio_out = 100, 100;
+module:hook("presence/bare", drop_stanza, prio_in);
+module:hook("presence/full", drop_stanza, prio_in);
+
+module:hook("message/bare", bounce_message, prio_in);
+module:hook("message/full", bounce_message, prio_in);
+
+module:hook("iq/bare", bounce_iq, prio_in);
+module:hook("iq/full", bounce_iq, prio_in);
+
+module:hook("pre-message/bare", bounce_outgoing, prio_out);
+module:hook("pre-message/full", bounce_outgoing, prio_out);
+module:hook("pre-message/host", bounce_outgoing, prio_out);
+
+module:hook("pre-presence/bare", drop_outgoing, prio_out);
+module:hook("pre-presence/full", drop_outgoing, prio_out);
+module:hook("pre-presence/host", drop_outgoing, prio_out);
+
+module:hook("pre-iq/bare", bounce_outgoing, prio_out);
+module:hook("pre-iq/full", bounce_outgoing, prio_out);
+module:hook("pre-iq/host", bounce_outgoing, prio_out);
+