Commit 254b23ab authored by David Goulet's avatar David Goulet 🤘
Browse files

hs: Schedule mainloop event on dirinfo change



Due to a possible Guard subsystem recursion, when the HS client gets
notified that the directory information has changed, it must run it in a
seperate mainloop event to avoid such issue.

See the ticket for more information on the recursion. This also fixes a
fatal assert.

Fixes #40579
Signed-off-by: David Goulet's avatarDavid Goulet <dgoulet@torproject.org>
parent 9efb04bb
Pipeline #31376 passed with stage
in 24 minutes and 27 seconds
o Minor bugfixes (onion service, client):
- Fix a fatal assert due to a guard subsystem recursion triggered by the
onion service client. Fixes bug 40579; bugfix on 0.3.5.1-alpha.
......@@ -38,6 +38,7 @@
#include "lib/crypt_ops/crypto_format.h"
#include "lib/crypt_ops/crypto_rand.h"
#include "lib/crypt_ops/crypto_util.h"
#include "lib/evloop/compat_libevent.h"
#include "core/or/cpath_build_state_st.h"
#include "feature/dircommon/dir_connection_st.h"
......@@ -46,11 +47,30 @@
#include "core/or/origin_circuit_st.h"
#include "core/or/socks_request_st.h"
#include "trunnel/hs/cell_introduce1.h"
/** This event is activated when we are notified that directory information has
* changed. It must be done asynchronous from the call due to possible
* recursion from the caller of that notification. See #40579. */
static struct mainloop_event_t *dir_info_changed_ev = NULL;
/** Client-side authorizations for hidden services; map of service identity
* public key to hs_client_service_authorization_t *. */
static digest256map_t *client_auths = NULL;
#include "trunnel/hs/cell_introduce1.h"
/** Mainloop callback. Scheduled to run when we are notified of a directory
* info change. See hs_client_dir_info_changed(). */
static void
dir_info_changed_callback(mainloop_event_t *event, void *arg)
{
(void) event;
(void) arg;
/* We have possibly reached the minimum directory information or new
* consensus so retry all pending SOCKS connection in
* AP_CONN_STATE_RENDDESC_WAIT state in order to fetch the descriptor. */
retry_all_socks_conn_waiting_for_desc();
}
/** Return a human-readable string for the client fetch status code. */
static const char *
......@@ -2584,6 +2604,9 @@ hs_client_free_all(void)
/* Purge the hidden service request cache. */
hs_purge_last_hid_serv_requests();
client_service_authorization_free_all();
/* This is NULL safe. */
mainloop_event_free(dir_info_changed_ev);
}
/** Purge all potentially remotely-detectable state held in the hidden
......@@ -2609,14 +2632,27 @@ hs_client_purge_state(void)
log_info(LD_REND, "Hidden service client state has been purged.");
}
/** Called when our directory information has changed. */
/** Called when our directory information has changed.
*
* The work done in that function has to either be kept within the HS subsystem
* or else scheduled as a mainloop event. In other words, this function can't
* call outside to another subsystem to avoid risking recursion problems. */
void
hs_client_dir_info_changed(void)
{
/* We have possibly reached the minimum directory information or new
* consensus so retry all pending SOCKS connection in
* AP_CONN_STATE_RENDDESC_WAIT state in order to fetch the descriptor. */
retry_all_socks_conn_waiting_for_desc();
/* Make sure the mainloop has been initialized. Code path exist that reaches
* this before it is. */
if (!tor_libevent_is_initialized()) {
return;
}
/* Lazily create the event. HS Client subsystem doesn't have an init function
* and so we do it here before activating it. */
if (!dir_info_changed_ev) {
dir_info_changed_ev = mainloop_event_new(dir_info_changed_callback, NULL);
}
/* Activate it to run immediately. */
mainloop_event_activate(dir_info_changed_ev);
}
#ifdef TOR_UNIT_TESTS
......
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