File

plugins/mod_blocklist.lua @ 10682:62ef68f95b6f 0.11

mod_mam,mod_muc_mam: Allow other work to be performed during archive cleanup (fixes #1504) This lets Prosody handle socket related work between each step in the cleanup in order to prevent the server from being completely blocked during this. An async storage backend would not need this but those are currently rare.
author Kim Alvefur <zash@zash.se>
date Wed, 11 Mar 2020 21:15:01 +0100
parent 10052:0c35f353db68
child 10053:4b2cc8a60449
line wrap: on
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-- Prosody IM
-- Copyright (C) 2009-2010 Matthew Wild
-- Copyright (C) 2009-2010 Waqas Hussain
-- Copyright (C) 2014-2015 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 rostermanager = require"core.rostermanager";
local is_contact_subscribed = rostermanager.is_contact_subscribed;
local is_contact_pending_in = rostermanager.is_contact_pending_in;
local load_roster = rostermanager.load_roster;
local save_roster = rostermanager.save_roster;
local st = require"util.stanza";
local st_error_reply = st.error_reply;
local jid_prep = require"util.jid".prep;
local jid_split = require"util.jid".split;

local storage = module:open_store();
local sessions = prosody.hosts[module.host].sessions;
local full_sessions = prosody.full_sessions;

-- First level cache of blocklists by username.
-- Weak table so may randomly expire at any time.
local cache = setmetatable({}, { __mode = "v" });

-- Second level of caching, keeps a fixed number of items, also anchors
-- items in the above cache.
--
-- The size of this affects how often we will need to load a blocklist from
-- disk, which we want to avoid during routing. On the other hand, we don't
-- want to use too much memory either, so this can be tuned by advanced
-- users. TODO use science to figure out a better default, 64 is just a guess.
local cache_size = module:get_option_number("blocklist_cache_size", 64);
local cache2 = require"util.cache".new(cache_size);

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
	cache2:set(username, blocklist);
	cache[username] = blocklist;
	return true;
end

-- Migrates from the old mod_privacy storage
local function migrate_privacy_list(username)
	local legacy_data = module:open_store("privacy"):get(username);
	if not legacy_data or not legacy_data.lists or not legacy_data.default then return; end
	local default_list = legacy_data.lists[legacy_data.default];
	if not default_list or not default_list.items then return; end

	local migrated_data = { [false] = { created = os.time(); migrated = "privacy" }};

	module:log("info", "Migrating blocklist from mod_privacy storage for user '%s'", username);
	for _, item in ipairs(default_list.items) do
		if item.type == "jid" and item.action == "deny" then
			local 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
	set_blocklist(username, migrated_data);
	return migrated_data;
end

local function get_blocklist(username)
	local blocklist = cache2:get(username);
	if not blocklist then
		if not user_exists(username, module.host) then
			return null_blocklist;
		end
		blocklist = storage:get(username);
		if not blocklist then
			blocklist = migrate_privacy_list(username);
		end
		if not blocklist then
			blocklist = { [false] = { created = os.time(); }; };
		end
		cache2:set(username, blocklist);
	end
	cache[username] = blocklist;
	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 = cache[username] or 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
	origin.send(reply);
	return true;
end, -1);

-- Add or remove some jid(s) from the blocklist
-- We want this to be atomic and not do a partial update
local function edit_blocklist(event)
	local now = os.time();
	local origin, stanza = event.origin, event.stanza;
	local username = origin.username;
	local action = stanza.tags[1]; -- "block" or "unblock"
	local is_blocking = action.name == "block" and now or nil; -- nil if unblocking
	local new = {}; -- JIDs to block depending or unblock on action


	-- XEP-0191 sayeth:
	-- > When the user blocks communications with the contact, the user's
	-- > server MUST send unavailable presence information to the contact (but
	-- > only if the contact is allowed to receive presence notifications [...]
	-- So contacts we need to do that for are added to the set below.
	local send_unavailable = is_blocking and {};
	local send_available = not is_blocking and {};

	-- Because blocking someone currently also blocks the ability to reject
	-- subscription requests, we'll preemptively reject such
	local remove_pending = is_blocking and {};

	for item in action:childtags("item") do
		local jid = jid_prep(item.attr.jid);
		if not jid then
			origin.send(st_error_reply(stanza, "modify", "jid-malformed"));
			return true;
		end
		item.attr.jid = jid; -- echo back prepped
		new[jid] = true;
		if is_blocking then
			if is_contact_subscribed(username, module.host, jid) then
				send_unavailable[jid] = true;
			elseif is_contact_pending_in(username, module.host, jid) then
				remove_pending[jid] = true;
			end
		elseif is_contact_subscribed(username, module.host, jid) then
			send_available[jid] = true;
		end
	end

	if is_blocking and not next(new) then
		-- <block/> element does not contain at least one <item/> child element
		origin.send(st_error_reply(stanza, "modify", "bad-request"));
		return true;
	end

	local blocklist = cache[username] or get_blocklist(username);

	local new_blocklist = {
		-- We set the [false] key to someting as a signal not to migrate privacy lists
		[false] = blocklist[false] or { created = now; };
	};
	if type(blocklist[false]) == "table" then
		new_blocklist[false].modified = now;
	end

	if is_blocking or next(new) then
		for jid, t in pairs(blocklist) do
			if jid then new_blocklist[jid] = t; end
		end
		for jid in pairs(new) do
			new_blocklist[jid] = is_blocking;
		end
		-- else empty the blocklist
	end

	local ok, err = set_blocklist(username, new_blocklist);
	if ok then
		origin.send(st.reply(stanza));
	else
		origin.send(st_error_reply(stanza, "wait", "internal-server-error", err));
		return true;
	end

	if is_blocking then
		for jid in pairs(send_unavailable) do
			if not blocklist[jid] then
				for _, session in pairs(sessions[username].sessions) do
					if session.presence then
						module:send(st.presence({ type = "unavailable", to = jid, from = session.full_jid }));
					end
				end
			end
		end

		if next(remove_pending) then
			local roster = load_roster(username, module.host);
			for jid in pairs(remove_pending) do
				roster[false].pending[jid] = nil;
			end
			save_roster(username, module.host, roster);
			-- Not much we can do about save failing here
		end
	else
		local user_bare = username .. "@" .. module.host;
		for jid in pairs(send_available) do
			module:send(st.presence({ type = "probe", to = user_bare, from = jid }));
		end
	end

	local blocklist_push = st.iq({ type = "set", id = "blocklist-push" })
		:add_child(action); -- 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

	return true;
end

module:hook("iq-set/self/urn:xmpp:blocking:block", edit_blocklist, -1);
module:hook("iq-set/self/urn:xmpp:blocking:unblock", edit_blocklist, -1);

-- Cache invalidation, solved!
module:hook_global("user-deleted", function (event)
	if event.host == module.host then
		cache2:set(event.username, nil);
		cache[event.username] = nil;
	end
end);

-- Buggy clients
module:hook("iq-error/self/blocklist-push", function (event)
	local origin, stanza = event.origin, event.stanza;
	local _, condition, text = stanza:get_error();
	local log = (origin.log or module._log);
	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
		origin.send(st_error_reply(stanza, "cancel", "service-unavailable"));
		return true;
	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 stanza = event.stanza;
	local type = stanza.attr.type;
	if type == "chat" or not type or type == "normal" then
		if full_sessions[stanza.attr.to] then
			-- See #690
			return drop_stanza(event);
		end
		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
		origin.send(st_error_reply(stanza, "cancel", "not-acceptable", "You have blocked this JID")
			:tag("blocked", { xmlns = "urn:xmpp:blocking:errors" }));
		return true;
	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", bounce_outgoing, -1);
module:hook("pre-presence/host", bounce_outgoing, -1);
module:hook("pre-presence/full", bounce_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);