plugins/mod_privacy.lua

-- Prosody IM

-- Copyright (C) 2009-2010 Matthew Wild

-- Copyright (C) 2009-2010 Waqas Hussain

-- Copyright (C) 2009 Thilo Cestonaro

-- 

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

module:add_feature("jabber:iq:privacy");

local prosody = prosody;

local st = require "util.stanza";

local datamanager = require "util.datamanager";

local bare_sessions, full_sessions = bare_sessions, full_sessions;

local util_Jid = require "util.jid";

local jid_bare = util_Jid.bare;

local jid_split, jid_join = util_Jid.split, util_Jid.join;

local load_roster = require "core.rostermanager".load_roster;

local to_number = tonumber;

function isListUsed(origin, name, privacy_lists)

	local user = bare_sessions[origin.username.."@"..origin.host];

	if user then

		for resource, session in pairs(user.sessions) do

			if resource ~= origin.resource then

				if session.activePrivacyList == name then

					return true;

				elseif session.activePrivacyList == nil and privacy_lists.default == name then

					return true;

				end

			end

		end

	end

end

function isAnotherSessionUsingDefaultList(origin)

	local user = bare_sessions[origin.username.."@"..origin.host];

	if user then

		for resource, session in pairs(user.sessions) do

			if resource ~= origin.resource and session.activePrivacyList == nil then

				return true;

			end

		end

	end

end

function sendUnavailable(origin, to, from)

--[[ example unavailable presence stanza

<presence from="node@host/resource" type="unavailable" to="node@host" >

	<status>Logged out</status>

</presence>

]]--

	local presence = st.presence({from=from, type="unavailable"});

	presence:tag("status"):text("Logged out");

	local node, host = jid_bare(to);

	local bare = node .. "@" .. host;

	local user = bare_sessions[bare];

	if user then

		for resource, session in pairs(user.sessions) do

			presence.attr.to = session.full_jid;

			module:log("debug", "send unavailable to: %s; from: %s", tostring(presence.attr.to), tostring(presence.attr.from));

			origin.send(presence);

		end

	end

end

function declineList(privacy_lists, origin, stanza, which)

	if which == "default" then

		if isAnotherSessionUsingDefaultList(origin) then

			return { "cancel", "conflict", "Another session is online and using the default list."};

		end

		privacy_lists.default = nil;

		origin.send(st.reply(stanza));

	elseif which == "active" then

		origin.activePrivacyList = nil;

		origin.send(st.reply(stanza));

	else

		return {"modify", "bad-request", "Neither default nor active list specifed to decline."};

	end

	return true;

end

function activateList(privacy_lists, origin, stanza, which, name)

	local list = privacy_lists.lists[name];

	if which == "default" and list then

		if isAnotherSessionUsingDefaultList(origin) then

			return {"cancel", "conflict", "Another session is online and using the default list."};

		end

		privacy_lists.default = name;

		origin.send(st.reply(stanza));

	elseif which == "active" and list then

		origin.activePrivacyList = name;

		origin.send(st.reply(stanza));

	elseif not list then

		return {"cancel", "item-not-found", "No such list: "..name};

	else

		return {"modify", "bad-request", "No list chosen to be active or default."};

	end

	return true;

end

function deleteList(privacy_lists, origin, stanza, name)

	local list = privacy_lists.lists[name];

	if list then

		if isListUsed(origin, name, privacy_lists) then

			return {"cancel", "conflict", "Another session is online and using the list which should be deleted."};

		end

		if privacy_lists.default == name then

			privacy_lists.default = nil;

		end

		if origin.activePrivacyList == name then

			origin.activePrivacyList = nil;

		end

		privacy_lists.lists[name] = nil;

		origin.send(st.reply(stanza));

		return true;

	end

	return {"modify", "bad-request", "Not existing list specifed to be deleted."};

end

function createOrReplaceList (privacy_lists, origin, stanza, name, entries, roster)

	local bare_jid = origin.username.."@"..origin.host;

	if privacy_lists.lists == nil then

		privacy_lists.lists = {};

	end

	local list = {};

	privacy_lists.lists[name] = list;

	local orderCheck = {};

	list.name = name;

	list.items = {};

	for _,item in ipairs(entries) do

		if to_number(item.attr.order) == nil or to_number(item.attr.order) < 0 or orderCheck[item.attr.order] ~= nil then

			return {"modify", "bad-request", "Order attribute not valid."};

		end

		if item.attr.type ~= nil and item.attr.type ~= "jid" and item.attr.type ~= "subscription" and item.attr.type ~= "group" then

			return {"modify", "bad-request", "Type attribute not valid."};

		end

		local tmp = {};

		orderCheck[item.attr.order] = true;

		tmp["type"] = item.attr.type;

		tmp["value"] = item.attr.value;

		tmp["action"] = item.attr.action;

		tmp["order"] = to_number(item.attr.order);

		tmp["presence-in"] = false;

		tmp["presence-out"] = false;

		tmp["message"] = false;

		tmp["iq"] = false;

		if #item.tags > 0 then

			for _,tag in ipairs(item.tags) do

				tmp[tag.name] = true;

			end

		end

		if tmp.type == "subscription" then

			if	tmp.value ~= "both" and

				tmp.value ~= "to" and

				tmp.value ~= "from" and

				tmp.value ~= "none" then

				return {"cancel", "bad-request", "Subscription value must be both, to, from or none."};

			end

		end

		if tmp.action ~= "deny" and tmp.action ~= "allow" then

			return {"cancel", "bad-request", "Action must be either deny or allow."};

		end

		list.items[#list.items + 1] = tmp;

	end

	table.sort(list, function(a, b) return a.order < b.order; end);

	origin.send(st.reply(stanza));

	if bare_sessions[bare_jid] ~= nil then

		local iq = st.iq ( { type = "set", id="push1" } );

		iq:tag ("query", { xmlns = "jabber:iq:privacy" } );

		iq:tag ("list", { name = list.name } ):up();

		iq:up();

		for resource, session in pairs(bare_sessions[bare_jid].sessions) do

			iq.attr.to = bare_jid.."/"..resource

			session.send(iq);

		end

	else

		return {"cancel", "bad-request", "internal error."};

	end

	return true;

end

function getList(privacy_lists, origin, stanza, name)

	local reply = st.reply(stanza);

	reply:tag("query", {xmlns="jabber:iq:privacy"});

	if name == nil then

		if privacy_lists.lists then

			if origin.activePrivacyList then

				reply:tag("active", {name=origin.activePrivacyList}):up();

			end

			if privacy_lists.default then

				reply:tag("default", {name=privacy_lists.default}):up();

			end

			for name,list in pairs(privacy_lists.lists) do

				reply:tag("list", {name=name}):up();

			end

		end

	else

		local list = privacy_lists.lists[name];

		if list then

			reply = reply:tag("list", {name=list.name});

			for _,item in ipairs(list.items) do

				reply:tag("item", {type=item.type, value=item.value, action=item.action, order=item.order});

				if item["message"] then reply:tag("message"):up(); end

				if item["iq"] then reply:tag("iq"):up(); end

				if item["presence-in"] then reply:tag("presence-in"):up(); end

				if item["presence-out"] then reply:tag("presence-out"):up(); end

				reply:up();

			end

		else

			return {"cancel", "item-not-found", "Unknown list specified."};

		end

	end

	origin.send(reply);

	return true;

end

module:hook("iq/bare/jabber:iq:privacy:query", function(data)

	local origin, stanza = data.origin, data.stanza;

	if stanza.attr.to == nil then -- only service requests to own bare JID

		local query = stanza.tags[1]; -- the query element

		local valid = false;

		local privacy_lists = datamanager.load(origin.username, origin.host, "privacy") or { lists = {} };

		if privacy_lists.lists[1] then -- Code to migrate from old privacy lists format, remove in 0.8

			module:log("info", "Upgrading format of stored privacy lists for %s@%s", origin.username, origin.host);

			local lists = privacy_lists.lists;

			for idx, list in ipairs(lists) do

				lists[list.name] = list;

				lists[idx] = nil;

			end

		end

		if stanza.attr.type == "set" then

			if #query.tags == 1 then --  the <query/> element MUST NOT include more than one child element

				for _,tag in ipairs(query.tags) do

					if tag.name == "active" or tag.name == "default" then

						if tag.attr.name == nil then -- Client declines the use of active / default list

							valid = declineList(privacy_lists, origin, stanza, tag.name);

						else -- Client requests change of active / default list

							valid = activateList(privacy_lists, origin, stanza, tag.name, tag.attr.name);

						end

					elseif tag.name == "list" and tag.attr.name then -- Client adds / edits a privacy list

						if #tag.tags == 0 then -- Client removes a privacy list

							valid = deleteList(privacy_lists, origin, stanza, tag.attr.name);

						else -- Client edits a privacy list

							valid = createOrReplaceList(privacy_lists, origin, stanza, tag.attr.name, tag.tags);

						end

					end

				end

			end

		elseif stanza.attr.type == "get" then

			local name = nil;

			local listsToRetrieve = 0;

			if #query.tags >= 1 then

				for _,tag in ipairs(query.tags) do

					if tag.name == "list" then -- Client requests a privacy list from server

						name = tag.attr.name;

						listsToRetrieve = listsToRetrieve + 1;

					end

				end

			end

			if listsToRetrieve == 0 or listsToRetrieve == 1 then

				valid = getList(privacy_lists, origin, stanza, name);

			end

		end

		if valid ~= true then

			valid = valid or { "cancel", "bad-request", "Couldn't understand request" };

			if valid[1] == nil then

				valid[1] = "cancel";

			end

			if valid[2] == nil then

				valid[2] = "bad-request";

			end

			origin.send(st.error_reply(stanza, valid[1], valid[2], valid[3]));

		else

			datamanager.store(origin.username, origin.host, "privacy", privacy_lists);

		end

		return true;

	end

end);

function checkIfNeedToBeBlocked(e, session)

	local origin, stanza = e.origin, e.stanza;

	local privacy_lists = datamanager.load(session.username, session.host, "privacy") or {};

	local bare_jid = session.username.."@"..session.host;

	local to = stanza.attr.to or bare_jid;

	local from = stanza.attr.from;

	local is_to_user = bare_jid == jid_bare(to);

	local is_from_user = bare_jid == jid_bare(from);

	--module:log("debug", "stanza: %s, to: %s, from: %s", tostring(stanza.name), tostring(to), tostring(from));

	if privacy_lists.lists == nil or

		not (session.activePrivacyList or privacy_lists.default)

	then

		return; -- Nothing to block, default is Allow all

	end

	if is_from_user and is_to_user then

		--module:log("debug", "Not blocking communications between user's resources");

		return; -- from one of a user's resource to another => HANDS OFF!

	end

	local item;

	local listname = session.activePrivacyList;

	if listname == nil then

		listname = privacy_lists.default; -- no active list selected, use default list

	end

	local list = privacy_lists.lists[listname];

	if not list then -- should never happen

		module:log("warn", "given privacy list not found. name: %s for user %s", listname, bare_jid);

		return;

	end

	for _,item in ipairs(list.items) do

		local apply = false;

		local block = false;

		if (

			(stanza.name == "message" and item.message) or

			(stanza.name == "iq" and item.iq) or

			(stanza.name == "presence" and is_to_user and item["presence-in"]) or

			(stanza.name == "presence" and is_from_user and item["presence-out"]) or

			(item.message == false and item.iq == false and item["presence-in"] == false and item["presence-out"] == false)

		) then

			apply = true;

		end

		if apply then

			local evilJid = {};

			apply = false;

			if is_to_user then

				--module:log("debug", "evil jid is (from): %s", from);

				evilJid.node, evilJid.host, evilJid.resource = jid_split(from);

			else

				--module:log("debug", "evil jid is (to): %s", to);

				evilJid.node, evilJid.host, evilJid.resource = jid_split(to);

			end

			if	item.type == "jid" and

				(evilJid.node and evilJid.host and evilJid.resource and item.value == evilJid.node.."@"..evilJid.host.."/"..evilJid.resource) or

				(evilJid.node and evilJid.host and item.value == evilJid.node.."@"..evilJid.host) or

				(evilJid.host and evilJid.resource and item.value == evilJid.host.."/"..evilJid.resource) or

				(evilJid.host and item.value == evilJid.host) then

				apply = true;

				block = (item.action == "deny");

			elseif item.type == "group" then

				local roster = load_roster(session.username, session.host);

				local roster_entry = roster[jid_join(evilJid.node, evilJid.host)];

				if roster_entry then

					local groups = roster_entry.groups;

					for group in pairs(groups) do

						if group == item.value then

							apply = true;

							block = (item.action == "deny");

							break;

						end

					end

				end

			elseif item.type == "subscription" then -- we need a valid bare evil jid

				local roster = load_roster(session.username, session.host);

				local roster_entry = roster[jid_join(evilJid.node, evilJid.host)];

				if (not(roster_entry) and item.value == "none")

				   or (roster_entry and roster_entry.subscription == item.value) then

					apply = true;

					block = (item.action == "deny");

				end

			elseif item.type == nil then

				apply = true;

				block = (item.action == "deny");

			end

		end

		if apply then

			if block then

				module:log("debug", "stanza blocked: %s, to: %s, from: %s", tostring(stanza.name), tostring(to), tostring(from));

				if stanza.name == "message" then

					origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));

				elseif stanza.name == "iq" and (stanza.attr.type == "get" or stanza.attr.type == "set") then

					origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));

				end

				return true; -- stanza blocked !

			else

				--module:log("debug", "stanza explicitly allowed!")

				return;

			end

		end

	end

end

function preCheckIncoming(e)

	local session;

	if e.stanza.attr.to ~= nil then

		local node, host, resource = jid_split(e.stanza.attr.to);

		if node == nil or host == nil then

			return;

		end

		if resource == nil then

			local prio = 0;

			local session_;

			if bare_sessions[node.."@"..host] ~= nil then

				for resource, session_ in pairs(bare_sessions[node.."@"..host].sessions) do

					if session_.priority ~= nil and session_.priority > prio then

						session = session_;

						prio = session_.priority;

					end

				end

			end

		else

			session = full_sessions[node.."@"..host.."/"..resource];

		end

		if session ~= nil then

			return checkIfNeedToBeBlocked(e, session);

		else

			--module:log("debug", "preCheckIncoming: Couldn't get session for jid: %s@%s/%s", tostring(node), tostring(host), tostring(resource));

		end

	end

end

function preCheckOutgoing(e)

	local session = e.origin;

	if e.stanza.attr.from == nil then

		e.stanza.attr.from = session.username .. "@" .. session.host;

		if session.resource ~= nil then

		 	e.stanza.attr.from = e.stanza.attr.from .. "/" .. session.resource;

		end

	end

	if session.username then -- FIXME do properly

		return checkIfNeedToBeBlocked(e, session);

	end

end

module:hook("pre-message/full", preCheckOutgoing, 500);

module:hook("pre-message/bare", preCheckOutgoing, 500);

module:hook("pre-message/host", preCheckOutgoing, 500);

module:hook("pre-iq/full", preCheckOutgoing, 500);

module:hook("pre-iq/bare", preCheckOutgoing, 500);

module:hook("pre-iq/host", preCheckOutgoing, 500);

module:hook("pre-presence/full", preCheckOutgoing, 500);

module:hook("pre-presence/bare", preCheckOutgoing, 500);

module:hook("pre-presence/host", preCheckOutgoing, 500);

module:hook("message/full", preCheckIncoming, 500);

module:hook("message/bare", preCheckIncoming, 500);

module:hook("message/host", preCheckIncoming, 500);

module:hook("iq/full", preCheckIncoming, 500);

module:hook("iq/bare", preCheckIncoming, 500);

module:hook("iq/host", preCheckIncoming, 500);

module:hook("presence/full", preCheckIncoming, 500);

module:hook("presence/bare", preCheckIncoming, 500);

module:hook("presence/host", preCheckIncoming, 500);