Initial version of mod_web_push. WARNING: Do not use.
-- 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