commit 36b5ca2c8b07f4cbdb1b76e9fb0c10fff3d540ac Author: David Goulet dgoulet@torproject.org Date: Wed Dec 21 13:35:22 2016 -0500
hs: Move and improve the service pruning code
First, this commit moves the code used to prune the service list when reloading Tor (HUP signal for instance) to a function from rend_config_services().
Second, fix bug #21054, improve the code by using the newly added circuit_get_next_service_intro_circ() function instead of poking at the global list directly and add _many_ more comments.
Fixes #21054.
Signed-off-by: David Goulet dgoulet@torproject.org --- changes/bug21054 | 5 ++ src/or/rendservice.c | 172 ++++++++++++++++++++++++++++----------------------- 2 files changed, 99 insertions(+), 78 deletions(-)
diff --git a/changes/bug21054 b/changes/bug21054 new file mode 100644 index 0000000..bc49949 --- /dev/null +++ b/changes/bug21054 @@ -0,0 +1,5 @@ + o Minor bugfixes (hidden service): + - Fix the config reload pruning of old vs new services so it actually + works when both ephemeral and non ephemeral services were configured + which lead to a BUG() stacktrace. Close #21054; Bugfix on + tor-0.3.0.1-alpha. diff --git a/src/or/rendservice.c b/src/or/rendservice.c index 1713a84..a4e6452 100644 --- a/src/or/rendservice.c +++ b/src/or/rendservice.c @@ -542,6 +542,95 @@ rend_service_check_dir_and_add(smartlist_t *service_list, return rend_add_service(s_list, service); }
+/* If this is a reload and there were hidden services configured before, + * keep the introduction points that are still needed and close the + * other ones. */ +static void +prune_services_on_reload(smartlist_t *old_service_list, + smartlist_t *new_service_list) +{ + origin_circuit_t *ocirc = NULL; + smartlist_t *surviving_services = NULL; + + tor_assert(old_service_list); + tor_assert(new_service_list); + + /* This contains all _existing_ services that survives the relaod that is + * that haven't been removed from the configuration. The difference between + * this list and the new service list is that the new list can possibly + * contain newly configured service that have no introduction points opened + * yet nor key material loaded or generated. */ + surviving_services = smartlist_new(); + + /* Preserve the existing ephemeral services. + * + * This is the ephemeral service equivalent of the "Copy introduction + * points to new services" block, except there's no copy required since + * the service structure isn't regenerated. + * + * After this is done, all ephemeral services will be: + * * Removed from old_service_list, so the equivalent non-ephemeral code + * will not attempt to preserve them. + * * Added to the new_service_list (that previously only had the + * services listed in the configuration). + * * Added to surviving_services, which is the list of services that + * will NOT have their intro point closed. + */ + SMARTLIST_FOREACH_BEGIN(old_service_list, rend_service_t *, old) { + if (rend_service_is_ephemeral(old)) { + SMARTLIST_DEL_CURRENT(old_service_list, old); + smartlist_add(surviving_services, old); + smartlist_add(new_service_list, old); + } + } SMARTLIST_FOREACH_END(old); + + /* Copy introduction points to new services. This is O(n^2), but it's only + * called on reconfigure, so it's ok performance wise. */ + SMARTLIST_FOREACH_BEGIN(new_service_list, rend_service_t *, new) { + SMARTLIST_FOREACH_BEGIN(old_service_list, rend_service_t *, old) { + /* Skip ephemeral services as we only want to copy introduction points + * from current services to newly configured one that already exists. + * The same directory means it's the same service. */ + if (rend_service_is_ephemeral(new) || rend_service_is_ephemeral(old) || + strcmp(old->directory, new->directory)) { + continue; + } + smartlist_add_all(new->intro_nodes, old->intro_nodes); + smartlist_clear(old->intro_nodes); + smartlist_add_all(new->expiring_nodes, old->expiring_nodes); + smartlist_clear(old->expiring_nodes); + /* This regular service will survive the closing IPs step after. */ + smartlist_add(surviving_services, old); + break; + } SMARTLIST_FOREACH_END(old); + } SMARTLIST_FOREACH_END(new); + + /* For every service introduction circuit we can find, see if we have a + * matching surviving configured service. If not, close the circuit. */ + while ((ocirc = circuit_get_next_service_intro_circ(ocirc))) { + int keep_it = 0; + tor_assert(ocirc->rend_data); + SMARTLIST_FOREACH_BEGIN(surviving_services, const rend_service_t *, s) { + if (rend_circuit_pk_digest_eq(ocirc, (uint8_t *) s->pk_digest)) { + /* Keep this circuit as we have a matching configured service. */ + keep_it = 1; + break; + } + } SMARTLIST_FOREACH_END(s); + if (keep_it) { + continue; + } + log_info(LD_REND, "Closing intro point %s for service %s.", + safe_str_client(extend_info_describe( + ocirc->build_state->chosen_exit)), + safe_str_client(rend_data_get_address(ocirc->rend_data))); + /* Reason is FINISHED because service has been removed and thus the + * circuit is considered old/uneeded. */ + circuit_mark_for_close(TO_CIRCUIT(ocirc), END_CIRC_REASON_FINISHED); + } + smartlist_free(surviving_services); +} + /** Set up rend_service_list, based on the values of HiddenServiceDir and * HiddenServicePort in <b>options</b>. Return 0 on success and -1 on * failure. (If <b>validate_only</b> is set, parse, warn and return as @@ -807,84 +896,11 @@ rend_config_services(const or_options_t *options, int validate_only) * keep the introduction points that are still needed and close the * other ones. */ if (old_service_list && !validate_only) { - smartlist_t *surviving_services = smartlist_new(); - - /* Preserve the existing ephemeral services. - * - * This is the ephemeral service equivalent of the "Copy introduction - * points to new services" block, except there's no copy required since - * the service structure isn't regenerated. - * - * After this is done, all ephemeral services will be: - * * Removed from old_service_list, so the equivalent non-ephemeral code - * will not attempt to preserve them. - * * Added to the new rend_service_list (that previously only had the - * services listed in the configuration). - * * Added to surviving_services, which is the list of services that - * will NOT have their intro point closed. - */ - SMARTLIST_FOREACH(old_service_list, rend_service_t *, old, { - if (rend_service_is_ephemeral(old)) { - SMARTLIST_DEL_CURRENT(old_service_list, old); - smartlist_add(surviving_services, old); - smartlist_add(rend_service_list, old); - } - }); - - /* Copy introduction points to new services. */ - /* XXXX This is O(n^2), but it's only called on reconfigure, so it's - * probably ok? */ - SMARTLIST_FOREACH_BEGIN(rend_service_list, rend_service_t *, new) { - SMARTLIST_FOREACH_BEGIN(old_service_list, rend_service_t *, old) { - if (BUG(rend_service_is_ephemeral(new)) || - BUG(rend_service_is_ephemeral(old))) { - continue; - } - if (BUG(!new->directory) || BUG(!old->directory) || - strcmp(old->directory, new->directory)) { - continue; - } - smartlist_add_all(new->intro_nodes, old->intro_nodes); - smartlist_clear(old->intro_nodes); - smartlist_add_all(new->expiring_nodes, old->expiring_nodes); - smartlist_clear(old->expiring_nodes); - smartlist_add(surviving_services, old); - break; - } SMARTLIST_FOREACH_END(old); - } SMARTLIST_FOREACH_END(new); - - /* Close introduction circuits of services we don't serve anymore. */ - /* XXXX it would be nicer if we had a nicer abstraction to use here, - * so we could just iterate over the list of services to close, but - * once again, this isn't critical-path code. */ - SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { - if (!circ->marked_for_close && - circ->state == CIRCUIT_STATE_OPEN && - (circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO || - circ->purpose == CIRCUIT_PURPOSE_S_INTRO)) { - origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(circ); - int keep_it = 0; - tor_assert(oc->rend_data); - SMARTLIST_FOREACH(surviving_services, rend_service_t *, ptr, { - if (rend_circuit_pk_digest_eq(oc, (uint8_t *) ptr->pk_digest)) { - keep_it = 1; - break; - } - }); - if (keep_it) - continue; - log_info(LD_REND, "Closing intro point %s for service %s.", - safe_str_client(extend_info_describe( - oc->build_state->chosen_exit)), - rend_data_get_address(oc->rend_data)); - circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED); - /* XXXX Is there another reason we should use here? */ - } - } - SMARTLIST_FOREACH_END(circ); - smartlist_free(surviving_services); - SMARTLIST_FOREACH(old_service_list, rend_service_t *, ptr, - rend_service_free(ptr)); + prune_services_on_reload(old_service_list, rend_service_list); + /* Every remaining service in the old list have been removed from the + * configuration so clean them up safely. */ + SMARTLIST_FOREACH(old_service_list, rend_service_t *, s, + rend_service_free(s)); smartlist_free(old_service_list); }