mod_websocket: Fire pre-session-close event (fixes #1800)
This event was added in a7c183bb4e64 and is required to make mod_smacks know
that a session was intentionally closed and shouldn't be hibernated (see
fcea4d9e7502).
Because this was missing from mod_websocket's session.close(), mod_smacks
would always attempt to hibernate websocket sessions even if they closed
cleanly.
That mod_websocket has its own copy of session.close() is something to fix
another day (probably not in the stable branch). So for now this commit makes
the minimal change to get things working again.
Thanks to Damian and the Jitsi team for reporting.
-- TODO warn when trying to create an user before the tombstone expires
-- e.g. via telnet or other admin interface
local datetime = require "util.datetime";
local errors = require "util.error";
local jid_node = require"util.jid".node;
local st = require "util.stanza";
-- Using a map store as key-value store so that removal of all user data
-- does not also remove the tombstone, which would defeat the point
local graveyard = module:open_store(nil, "map");
local graveyard_cache = require "util.cache".new(module:get_option_number("tombstone_cache_size", 1024));
local ttl = module:get_option_number("user_tombstone_expiry", nil);
-- Keep tombstones forever by default
--
-- Rationale:
-- There is no way to be completely sure when remote services have
-- forgotten and revoked all memberships.
-- TODO If the user left a JID they moved to, return a gone+redirect error
-- TODO Attempt to deregister from MUCs based on bookmarks
-- TODO Unsubscribe from pubsub services if a notification is received
module:hook_global("user-deleted", function(event)
if event.host == module.host then
local ok, err = graveyard:set(nil, event.username, os.time());
if not ok then module:log("error", "Could store tombstone for %s: %s", event.username, err); end
end
end);
-- Public API
function has_tombstone(username)
local tombstone;
-- Check cache
local cached_result = graveyard_cache:get(username);
if cached_result == false then
-- We cached that there is no tombstone for this user
return false;
elseif cached_result then
tombstone = cached_result;
else
local stored_result, err = graveyard:get(nil, username);
if not stored_result and not err then
-- Cache that there is no tombstone for this user
graveyard_cache:set(username, false);
return false;
elseif err then
-- Failed to check tombstone status
return nil, err;
end
-- We have a tombstone stored, so let's continue with that
tombstone = stored_result;
end
-- Check expiry
if ttl and tombstone + ttl < os.time() then
module:log("debug", "Tombstone for %s created at %s has expired", username, datetime.datetime(tombstone));
graveyard:set(nil, username, nil);
graveyard_cache:set(username, nil); -- clear cache entry (if any)
return nil;
end
-- Cache for the future
graveyard_cache:set(username, tombstone);
return tombstone;
end
module:hook("user-registering", function(event)
local tombstone, err = has_tombstone(event.username);
if err then
event.allowed, event.error = errors.coerce(false, err);
return true;
elseif not tombstone then
-- Feel free
return;
end
module:log("debug", "Tombstone for %s created at %s", event.username, datetime.datetime(tombstone));
event.allowed = false;
return true;
end);
module:hook("presence/bare", function(event)
local origin, presence = event.origin, event.stanza;
local local_username = jid_node(presence.attr.to);
if not local_username then return; end
-- We want to undo any left-over presence subscriptions and notify the former
-- contact that they're gone.
--
-- FIXME This leaks that the user once existed. Hard to avoid without keeping
-- the contact list in some form, which we don't want to do for privacy
-- reasons. Bloom filter perhaps?
local pres_type = presence.attr.type;
local is_probe = pres_type == "probe";
local is_normal = pres_type == nil or pres_type == "unavailable";
if is_probe and has_tombstone(local_username) then
origin.send(st.error_reply(presence, "cancel", "gone", "User deleted"));
origin.send(st.presence({ type = "unsubscribed"; to = presence.attr.from; from = presence.attr.to }));
return true;
elseif is_normal and has_tombstone(local_username) then
origin.send(st.error_reply(presence, "cancel", "gone", "User deleted"));
origin.send(st.presence({ type = "unsubscribe"; to = presence.attr.from; from = presence.attr.to }));
return true;
end
end, 1);