view mod_privacy_lists/mod_privacy_lists.lua @ 5296:0f5657db1cfc

mod_isolate_host: handle server-generated stanzas The hook for setting the no_host_isolation is only called for c2s sessions. This does not work for stanzas generated by the server, such as PEP notifications or presence probe answers. To handle that, we do per-stanza checks for the case that the origin is local.
author Jonas Schäfer <jonas@wielicki.name>
date Sat, 01 Apr 2023 12:03:08 +0200
parents a6fa44eeb818
children
line wrap: on
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-- Prosody IM
-- Copyright (C) 2009-2014 Matthew Wild
-- Copyright (C) 2009-2014 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 st = require "util.stanza";
local bare_sessions, full_sessions = prosody.bare_sessions, prosody.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;

local privacy_storage = module:open_store("privacy");
local user_sessions = hosts[module.host].sessions;

local function get_lists(username)
	return user_sessions[username].privacy_lists;
end

local function save_lists(username)
	local privacy_lists = user_sessions[username].privacy_lists;
	if privacy_lists.default == nil and next(privacy_lists.lists) == nil then
		privacy_lists = nil;
	end
	return privacy_storage:set(username, privacy_lists);
end

module:hook("resource-bind", function (event)
	local username = event.session.username;
	user_sessions[username].privacy_lists = privacy_storage:get(username) or { lists = {} };
end);

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 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)
	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.items, 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=("%d"):format(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 = get_lists(origin.username);

		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
			save_lists(origin.username);
		end
		return true;
	end
end);

function checkIfNeedToBeBlocked(e, session)
	local origin, stanza = e.origin, e.stanza;
	local user = user_sessions[session.username];
	local privacy_lists = user and user.privacy_lists;
	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 not privacy_lists or 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 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
				-- drop and not bounce groupchat messages, otherwise users will get kicked
				if stanza.attr.type == "groupchat" then
					return true;
				end
				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;
			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);