Software / code / prosody
File
plugins/mod_invites_register.lua @ 13652:a08065207ef0
net.server_epoll: Call :shutdown() on TLS sockets when supported
Comment from Matthew:
This fixes a potential issue where the Prosody process gets blocked on sockets
waiting for them to close. Unlike non-TLS sockets, closing a TLS socket sends
layer 7 data, and this can cause problems for sockets which are in the process
of being cleaned up.
This depends on LuaSec changes which are not yet upstream.
From Martijn's original email:
So first my analysis of luasec. in ssl.c the socket is put into blocking
mode right before calling SSL_shutdown() inside meth_destroy(). My best
guess to why this is is because meth_destroy is linked to the __close
and __gc methods, which can't exactly be called multiple times and
luasec does want to make sure that a tls session is shutdown as clean
as possible.
I can't say I disagree with this reasoning and don't want to change this
behaviour. My solution to this without changing the current behaviour is
to introduce a shutdown() method. I am aware that this overlaps in a
conflicting way with tcp's shutdown method, but it stays close to the
OpenSSL name. This method calls SSL_shutdown() in the current
(non)blocking mode of the underlying socket and returns a boolean
whether or not the shutdown is completed (matching SSL_shutdown()'s 0
or 1 return values), and returns the familiar ssl_ioerror() strings on
error with a false for completion. This error can then be used to
determine if we have wantread/wantwrite to finalize things. Once
meth_shutdown() has been called once a shutdown flag will be set, which
indicates to meth_destroy() that the SSL_shutdown() has been handled
by the application and it shouldn't be needed to set the socket to
blocking mode. I've left the SSL_shutdown() call in the
LSEC_STATE_CONNECTED to prevent TOCTOU if the application reaches a
timeout for the shutdown code, which might allow SSL_shutdown() to
clean up anyway at the last possible moment.
Another thing I've changed to luasec is the call to socket_setblocking()
right before calling close(2) in socket_destroy() in usocket.c.
According to the latest POSIX[0]:
Note that the requirement for close() on a socket to block for up to
the current linger interval is not conditional on the O_NONBLOCK
setting.
Which I read to mean that removing O_NONBLOCK on the socket before close
doesn't impact the behaviour and only causes noise in system call
tracers. I didn't touch the windows bits of this, since I don't do
windows.
For the prosody side of things I've made the TLS shutdown bits resemble
interface:onwritable(), and put it under a combined guard of self._tls
and self.conn.shutdown. The self._tls bit is there to prevent getting
stuck on this condition, and self.conn.shutdown is there to prevent the
code being called by instances where the patched luasec isn't deployed.
The destroy() method can be called from various places and is read by
me as the "we give up" error path. To accommodate for these unexpected
entrypoints I've added a single call to self.conn:shutdown() to prevent
the socket being put into blocking mode. I have no expectations that
there is any other use here. Same as previous, the self.conn.shutdown
check is there to make sure it's not called on unpatched luasec
deployments and self._tls is there to make sure we don't call shutdown()
on tcp sockets.
I wouldn't recommend logging of the conn:shutdown() error inside
close(), since a lot of clients simply close the connection before
SSL_shutdown() is done.
| author | Martijn van Duren <martijn@openbsd.org> |
|---|---|
| date | Thu, 06 Feb 2025 15:04:38 +0000 |
| parent | 13011:16b47c3b44f3 |
| child | 13843:87dd8639f08f |
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local st = require "prosody.util.stanza"; local jid_split = require "prosody.util.jid".split; local jid_bare = require "prosody.util.jid".bare; local rostermanager = require "prosody.core.rostermanager"; local require_encryption = module:get_option_boolean("c2s_require_encryption", module:get_option_boolean("require_encryption", true)); local invite_only = module:get_option_boolean("registration_invite_only", true); local invites; if prosody.process_type == "prosody" then invites = module:depends("invites"); if invite_only then module:depends("register_ibr"); end end local legacy_invite_stream_feature = st.stanza("register", { xmlns = "urn:xmpp:invite" }):up(); local invite_stream_feature = st.stanza("register", { xmlns = "urn:xmpp:ibr-token:0" }):up(); module:hook("stream-features", function(event) local session, features = event.origin, event.features; -- Advertise to unauthorized clients only. if session.type ~= "c2s_unauthed" or (require_encryption and not session.secure) then return end features:add_child(legacy_invite_stream_feature); features:add_child(invite_stream_feature); end); -- XEP-0379: Pre-Authenticated Roster Subscription module:hook("presence/bare", function (event) local stanza = event.stanza; if stanza.attr.type ~= "subscribe" then return end local preauth = stanza:get_child("preauth", "urn:xmpp:pars:0"); if not preauth then return end local token = preauth.attr.token; if not token then return end local username, host = jid_split(stanza.attr.to); local invite, err = invites.get(token, username); if not invite then module:log("debug", "Got invalid token, error: %s", err); return; end local contact = jid_bare(stanza.attr.from); module:log("debug", "Approving inbound subscription to %s from %s", username, contact); if rostermanager.set_contact_pending_in(username, host, contact, stanza) then if rostermanager.subscribed(username, host, contact) then invite:use(); rostermanager.roster_push(username, host, contact); -- Send back a subscription request (goal is mutual subscription) if not rostermanager.is_user_subscribed(username, host, contact) and not rostermanager.is_contact_pending_out(username, host, contact) then module:log("debug", "Sending automatic subscription request to %s from %s", contact, username); if rostermanager.set_contact_pending_out(username, host, contact) then rostermanager.roster_push(username, host, contact); module:send(st.presence({type = "subscribe", from = username.."@"..host, to = contact })); else module:log("warn", "Failed to set contact pending out for %s", username); end end end end end, 1); -- Client is submitting a preauth token to allow registration module:hook("stanza/iq/urn:xmpp:pars:0:preauth", function(event) local preauth = event.stanza.tags[1]; local token = preauth.attr.token; local validated_invite = invites.get(token); if not validated_invite then local reply = st.error_reply(event.stanza, "cancel", "forbidden", "The invite token is invalid or expired"); event.origin.send(reply); return true; end event.origin.validated_invite = validated_invite; local reply = st.reply(event.stanza); event.origin.send(reply); return true; end); -- Registration attempt - ensure a valid preauth token has been supplied module:hook("user-registering", function (event) local validated_invite = event.validated_invite or (event.session and event.session.validated_invite); if invite_only and not validated_invite then event.allowed = false; event.reason = "Registration on this server is through invitation only"; return; elseif not validated_invite then -- This registration is not using an invite, but -- the server is not in invite-only mode, so nothing -- for this module to do... return; end if validated_invite and validated_invite.additional_data and validated_invite.additional_data.allow_reset then event.allow_reset = validated_invite.additional_data.allow_reset; end end); -- Make a *one-way* subscription. User will see when contact is online, -- contact will not see when user is online. function subscribe(host, user_username, contact_username) local user_jid = user_username.."@"..host; local contact_jid = contact_username.."@"..host; -- Update user's roster to say subscription request is pending... rostermanager.set_contact_pending_out(user_username, host, contact_jid); -- Update contact's roster to say subscription request is pending... rostermanager.set_contact_pending_in(contact_username, host, user_jid); -- Update contact's roster to say subscription request approved... rostermanager.subscribed(contact_username, host, user_jid); -- Update user's roster to say subscription request approved... rostermanager.process_inbound_subscription_approval(user_username, host, contact_jid); end -- Make a mutual subscription between jid1 and jid2. Each JID will see -- when the other one is online. function subscribe_both(host, user1, user2) subscribe(host, user1, user2); subscribe(host, user2, user1); end -- Registration successful, if there was a preauth token, mark it as used module:hook("user-registered", function (event) local validated_invite = event.validated_invite or (event.session and event.session.validated_invite); if not validated_invite then return; end local inviter_username = validated_invite.inviter; local contact_username = event.username; validated_invite:use(); if inviter_username then module:log("debug", "Creating mutual subscription between %s and %s", inviter_username, contact_username); subscribe_both(module.host, inviter_username, contact_username); rostermanager.roster_push(inviter_username, module.host, contact_username.."@"..module.host); end if validated_invite.additional_data then module:log("debug", "Importing roles from invite"); local roles = validated_invite.additional_data.roles; if roles and roles[1] ~= nil then local um = require "prosody.core.usermanager"; local ok, err = um.set_user_role(event.username, module.host, roles[1]); if not ok then module:log("error", "Could not set role %s for newly registered user %s: %s", roles[1], event.username, err); end for i = 2, #roles do local ok, err = um.add_user_secondary_role(event.username, module.host, roles[i]); if not ok then module:log("warn", "Could not add secondary role %s for newly registered user %s: %s", roles[i], event.username, err); end end elseif roles and type(next(roles)) == "string" then module:log("warn", "Invite carries legacy, migration required for user '%s' for role set %q to take effect", event.username, roles); module:open_store("roles"):set(contact_username, roles); end end end); -- Equivalent of user-registered but for when the account already existed -- (i.e. password reset) module:hook("user-password-reset", function (event) local validated_invite = event.validated_invite or (event.session and event.session.validated_invite); if not validated_invite then return; end validated_invite:use(); end);