-- XEP-XXXX: Web Push (aka: My mobile OS vendor won't let me have persistent TCP connections, take two) -- Copyright (C) 2019 Maxime “pep” Buquet -- -- Heavily based on mod_cloud_notify. -- Copyright (C) 2015-2016 Kim Alvefur -- Copyright (C) 2017-2018 Thilo Molitor local st = require"util.stanza"; local dataform = require "util.dataforms"; local http = require "net.http"; local os_time = os.time; local next = next; local jid = require"util.jid"; local filters = require"util.filters"; local xmlns_webpush = "urn:xmpp:webpush:0"; local max_push_devices = module:get_option_number("push_max_devices", 5); local dummy_body = module:get_option_string("push_notification_important_body", "New Message!"); local host_sessions = prosody.hosts[module.host].sessions; -- TODO: Generate it at setup time. Obviously not to be used other than for -- testing purposes, or at all. -- ECDH keypair local server_pubkey = "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEhxZpb8yIVc/2hNesGLGAxEakyYy0MqEetjgL7BIOm8ybhVKxapKqNXjXJ+NOO5/b0Z0UuBg/HynGnf0xKKNhBQ=="; local server_privkey = "MHcCAQEEIPhZac9pQ8aVTx9a5JyRcqfk3nuQQUFy3PaDcSWleojzoAoGCCqGSM49AwEHoUQDQgAEhxZpb8yIVc/2hNesGLGAxEakyYy0MqEetjgL7BIOm8ybhVKxapKqNXjXJ+NOO5/b0Z0UuBg/HynGnf0xKKNhBQ=="; -- Advertize disco feature local function account_disco_info(event) local form = dataform.new { { name = "FORM_TYPE", type = "hidden", value = "http://jabber.org/protocol/webpush#public-key" }; { name = "webpush#public-key", value = server_pubkey }; }; (event.reply or event.stanza):tag("feature", {var=xmlns_webpush}):up() :add_child(form:form({}, "result")); end module:hook("account-disco-info", account_disco_info); -- ordered table iterator, allow to iterate on the natural order of the keys of a table, -- see http://lua-users.org/wiki/SortedIteration local function __genOrderedIndex( t ) local orderedIndex = {} for key in pairs(t) do table.insert( orderedIndex, key ) end -- sort in reverse order (newest one first) table.sort( orderedIndex, function(a, b) if a == nil or t[a] == nil or b == nil or t[b] == nil then return false end -- only one timestamp given, this is the newer one if t[a].timestamp ~= nil and t[b].timestamp == nil then return true end if t[a].timestamp == nil and t[b].timestamp ~= nil then return false end -- both timestamps given, sort normally if t[a].timestamp ~= nil and t[b].timestamp ~= nil then return t[a].timestamp > t[b].timestamp end return false -- normally not reached end) return orderedIndex end local function orderedNext(t, state) -- Equivalent of the next function, but returns the keys in timestamp -- order. We use a temporary ordered key table that is stored in the -- table being iterated. local key = nil --print("orderedNext: state = "..tostring(state) ) if state == nil then -- the first time, generate the index t.__orderedIndex = __genOrderedIndex( t ) key = t.__orderedIndex[1] else -- fetch the next value for i = 1, #t.__orderedIndex do if t.__orderedIndex[i] == state then key = t.__orderedIndex[i+1] end end end if key then return key, t[key] end -- no more value to return, cleanup t.__orderedIndex = nil return end local function orderedPairs(t) -- Equivalent of the pairs() function on tables. Allows to iterate -- in order return orderedNext, t, nil end -- small helper function to return new table with only "maximum" elements containing only the newest entries local function reduce_table(table, maximum) local count = 0; local result = {}; for key, value in orderedPairs(table) do count = count + 1; if count > maximum then break end result[key] = value; end return result; end local push_store = (function() local store = module:open_store(); local push_services = {}; local api = {}; function api:get(user) if not push_services[user] then local err; push_services[user], err = store:get(user); if not push_services[user] and err then module:log("warn", "Error reading web push notification storage for user '%s': %s", user, tostring(err)); push_services[user] = {}; return push_services[user], false; end end if not push_services[user] then push_services[user] = {} end return push_services[user], true; end function api:set(user, data) push_services[user] = reduce_table(data, max_push_devices); local ok, err = store:set(user, push_services[user]); if not ok then module:log("error", "Error writing web push notification storage for user '%s': %s", user, tostring(err)); return false; end return true; end function api:set_identifier(user, push_identifier, data) local services = self:get(user); services[push_identifier] = data; return self:set(user, services); end return api; end)(); local function push_enable(event) local origin, stanza = event.origin, event.stanza; local enable = stanza.tags[1]; origin.log("debug", "Attempting to enable web push notifications"); -- MUST contain a 'href' attribute of the XMPP Push Service being enabled local push_endpoint = nil; local push_auth = nil; local push_p256dh = nil; local endpoint_tag = enable:get_child('endpoint'); if endpoint_tag ~= nil then push_endpoint = endpoint_tag:get_text(); end local auth_tag = enable:get_child('auth'); if auth_tag ~= nil then push_auth = auth_tag:get_text(); end local p256dh_tag = enable:get_child('p256dh'); if p256dh_tag ~= nil then push_p256dh = p256dh_tag:get_text(); end if not push_endpoint or not push_auth or not push_p256dh then origin.log("debug", "Web Push notification enable request missing 'endpoint', 'auth', or 'p256dh' tags"); origin.send(st.error_reply(stanza, "modify", "bad-request", "Missing enable child tag")); return true; end local push_identifier = "foo"; local push_service = push_endpoint; local ok = push_store:set_identifier(origin.username, push_identifier, push_service); if not ok then origin.send(st.error_reply(stanza, "wait", "internal-server-error")); else origin.push_identifier = push_identifier; origin.push_settings = push_service; origin.log("info", "Web Push notifications enabled for %s (%s)", tostring(stanza.attr.from), tostring(origin.push_identifier)); origin.send(st.reply(stanza)); end return true; end module:hook("iq-set/self/"..xmlns_webpush..":enable", push_enable); -- module:hook("iq-set/self/"..xmlns_webpush..":disable", push_disable); -- small helper function to extract relevant push settings local function get_push_settings(stanza, session) local to = stanza.attr.to; local node = to and jid.split(to) or session.username; local user_push_services = push_store:get(node); return node, user_push_services; end local function log_http_req(response_body, response_code, response) module:log("debug", "FOO: response_body: %s; response_code: %s; response: %s", response_body, tostring(response_code), tostring(response)); end local function handle_notify_request(stanza, node, user_push_services, log_push_decline) local pushes = 0; if not user_push_services or next(user_push_services) == nil then return pushes end for push_identifier, push_info in pairs(user_push_services) do local send_push = true; -- only send push to this node when not already done for this stanza or if no stanza is given at all if stanza then if not stanza._push_notify then stanza._push_notify = {}; end if stanza._push_notify[push_identifier] then if log_push_decline then module:log("debug", "Already sent push notification for %s@%s to %s", node, module.host, tostring(push_info)); end send_push = false; end stanza._push_notify[push_identifier] = true; end if send_push then local headers = { TTL = "60" }; http.request(push_info, { method = "POST", headers = headers }, log_http_req); pushes = pushes + 1; end end return pushes; end -- publish on offline message module:hook("message/offline/handle", function(event) local node, user_push_services = get_push_settings(event.stanza, event.origin); module:log("debug", "Invoking web push handle_notify_request() for offline stanza"); handle_notify_request(event.stanza, node, user_push_services, true); end, 1); -- is this push a high priority one (this is needed for ios apps not using voip pushes) local function is_important(stanza) local st_name = stanza and stanza.name or nil; if not st_name then return false; end -- nonzas are never important here if st_name == "presence" then return false; -- same for presences elseif st_name == "message" then -- unpack carbon copies local stanza_direction = "in"; local carbon; local st_type; -- support carbon copied message stanzas having an arbitrary message-namespace or no message-namespace at all if not carbon then carbon = find(stanza, "{urn:xmpp:carbons:2}/forwarded/message"); end if not carbon then carbon = find(stanza, "{urn:xmpp:carbons:1}/forwarded/message"); end stanza_direction = carbon and stanza:child_with_name("sent") and "out" or "in"; if carbon then stanza = carbon; end st_type = stanza.attr.type; -- headline message are always not important if st_type == "headline" then return false; end -- carbon copied outgoing messages are not important if carbon and stanza_direction == "out" then return false; end -- We can't check for body contents in encrypted messages, so let's treat them as important -- Some clients don't even set a body or an empty body for encrypted messages -- check omemo https://xmpp.org/extensions/inbox/omemo.html if stanza:get_child("encrypted", "eu.siacs.conversations.axolotl") or stanza:get_child("encrypted", "urn:xmpp:omemo:0") then return true; end -- check xep27 pgp https://xmpp.org/extensions/xep-0027.html if stanza:get_child("x", "jabber:x:encrypted") then return true; end -- check xep373 pgp (OX) https://xmpp.org/extensions/xep-0373.html if stanza:get_child("openpgp", "urn:xmpp:openpgp:0") then return true; end local body = stanza:get_child_text("body"); if st_type == "groupchat" and stanza:get_child_text("subject") then return false; end -- groupchat subjects are not important here return body ~= nil and body ~= ""; -- empty bodies are not important end return false; -- this stanza wasn't one of the above cases --> it is not important, too end -- publish on unacked smacks message local function process_smacks_stanza(stanza, session) if session.push_identifier then session.log("debug", "Invoking web push handle_notify_request() for smacks queued stanza"); local user_push_services = {[session.push_identifier] = session.push_settings}; local node = get_push_settings(stanza, session); if handle_notify_request(stanza, node, user_push_services, true) ~= 0 then if session.hibernating and not session.first_hibernated_push then -- if important stanzas are treated differently (pushed with last-message-body field set to dummy string) -- and the message was important (e.g. had a last-message-body field) OR if we treat all pushes equally, -- then record the time of first push in the session for the smack module which will extend its hibernation -- timeout based on the value of session.first_hibernated_push if not dummy_body or (dummy_body and is_important(stanza)) then session.first_hibernated_push = os_time(); end end end end return stanza; end local function process_smacks_queue(queue, session) if not session.push_identifier then return; end local user_push_services = {[session.push_identifier] = session.push_settings}; local notified = { unimportant = false; important = false } for i=1, #queue do local stanza = queue[i]; local node = get_push_settings(stanza, session); local stanza_type = "unimportant" if dummy_body and is_important(stanza) then stanza_type = "important"; end if not notified[stanza_type] then -- only notify if we didn't try to push for this stanza type already -- session.log("debug", "Invoking cloud handle_notify_request() for smacks queued stanza: %d", i); if handle_notify_request(stanza, node, user_push_services, false) ~= 0 then if session.hibernating and not session.first_hibernated_push then -- if important stanzas are treated differently (pushed with last-message-body field set to dummy string) -- and the message was important (e.g. had a last-message-body field) OR if we treat all pushes equally, -- then record the time of first push in the session for the smack module which will extend its hibernation -- timeout based on the value of session.first_hibernated_push if not dummy_body or (dummy_body and is_important(stanza)) then session.first_hibernated_push = os_time(); end end session.log("debug", "Web Push handle_notify_request() > 0, not notifying for other queued stanzas of type %s", stanza_type); notified[stanza_type] = true end end end end -- smacks hibernation is started local function hibernate_session(event) local session = event.origin; local queue = event.queue; session.first_hibernated_push = nil; -- process unacked stanzas process_smacks_queue(queue, session); -- process future unacked (hibernated) stanzas filters.add_filter(session, "stanzas/out", process_smacks_stanza, -990); end -- smacks hibernation is ended local function restore_session(event) local session = event.resumed; if session then -- older smacks module versions send only the "intermediate" session in event.session and no session.resumed one filters.remove_filter(session, "stanzas/out", process_smacks_stanza); session.first_hibernated_push = nil; end end -- smacks ack is delayed local function ack_delayed(event) local session = event.origin; local queue = event.queue; -- process unacked stanzas (handle_notify_request() will only send push requests for new stanzas) process_smacks_queue(queue, session); end -- archive message added local function archive_message_added(event) -- event is: { origin = origin, stanza = stanza, for_user = store_user, id = id } -- only notify for new mam messages when at least one device is online if not event.for_user or not host_sessions[event.for_user] then return; end local stanza = event.stanza; local user_session = host_sessions[event.for_user].sessions; local to = stanza.attr.to; to = to and jid.split(to) or event.origin.username; -- only notify if the stanza destination is the mam user we store it for if event.for_user == to then local user_push_services = push_store:get(to); if next(user_push_services) == nil then return end -- only notify nodes with no active sessions (smacks is counted as active and handled separate) local notify_push_services = {}; for identifier, push_info in pairs(user_push_services) do local identifier_found = nil; for _, session in pairs(user_session) do -- module:log("debug", "searching for '%s': identifier '%s' for session %s", tostring(identifier), tostring(session.push_identifier), tostring(session.full_jid)); if session.push_identifier == identifier then identifier_found = session; break; end end if identifier_found then identifier_found.log("debug", "Not web push notifying '%s' of new MAM stanza (session still alive)", identifier); else notify_push_services[identifier] = push_info; end end handle_notify_request(event.stanza, to, notify_push_services, true); end end module:hook("smacks-hibernation-start", hibernate_session); module:hook("smacks-hibernation-end", restore_session); module:hook("smacks-ack-delayed", ack_delayed); module:hook("archive-message-added", archive_message_added); function module.command(arg) print("TODO: Generate server keypair") end module:log("info", "Module loaded"); function module.unload() if module.unhook then module:unhook("account-disco-info", account_disco_info); module:unhook("iq-set/self/"..xmlns_webpush..":enable", push_enable); -- module:unhook("iq-set/self/"..xmlns_webpush..":disable", push_disable); end module:log("info", "Module unloaded"); end