diff options
Diffstat (limited to 'src/or/directory.c')
| -rw-r--r-- | src/or/directory.c | 262 |
1 files changed, 29 insertions, 233 deletions
diff --git a/src/or/directory.c b/src/or/directory.c index c9c07f336d..a5fee5d5a1 100644 --- a/src/or/directory.c +++ b/src/or/directory.c @@ -96,6 +96,9 @@ static void directory_initiate_command_rend( time_t if_modified_since, const rend_data_t *rend_query); +static void connection_dir_close_consensus_fetches( + dir_connection_t *except_this_one, const char *resource); + /********* START VARIABLES **********/ /** How far in the future do we allow a directory server to tell us it is @@ -1170,12 +1173,6 @@ directory_initiate_command_rend(const tor_addr_port_t *or_addr_port, return; } - /* ensure we don't make excess connections when we're already downloading - * a consensus during bootstrap */ - if (connection_dir_avoid_extra_connection_for_purpose(dir_purpose)) { - return; - } - conn = dir_connection_new(tor_addr_family(&addr)); /* set up conn so it's got all the data we need to remember */ @@ -1216,11 +1213,6 @@ directory_initiate_command_rend(const tor_addr_port_t *or_addr_port, conn->base_.state = DIR_CONN_STATE_CLIENT_SENDING; /* fall through */ case 0: - /* Close this connection if there's another consensus connection - * downloading (during bootstrap), or connecting (after bootstrap). */ - if (connection_dir_close_consensus_conn_if_extra(conn)) { - return; - } /* queue the command on the outbuf */ directory_send_command(conn, dir_purpose, 1, resource, payload, payload_len, @@ -1268,11 +1260,6 @@ directory_initiate_command_rend(const tor_addr_port_t *or_addr_port, connection_mark_for_close(TO_CONN(conn)); return; } - /* Close this connection if there's another consensus connection - * downloading (during bootstrap), or connecting (after bootstrap). */ - if (connection_dir_close_consensus_conn_if_extra(conn)) { - return; - } conn->base_.state = DIR_CONN_STATE_CLIENT_SENDING; /* queue the command on the outbuf */ directory_send_command(conn, dir_purpose, 0, resource, @@ -2029,6 +2016,10 @@ connection_dir_client_reached_eof(dir_connection_t *conn) networkstatus_consensus_download_failed(0, flavname); return -1; } + + /* If we launched other fetches for this consensus, cancel them. */ + connection_dir_close_consensus_fetches(conn, flavname); + /* launches router downloads as needed */ routers_update_all_from_networkstatus(now, 3); update_microdescs_from_networkstatus(now); @@ -3826,226 +3817,37 @@ connection_dir_finished_flushing(dir_connection_t *conn) return 0; } -/* A helper function for connection_dir_close_consensus_conn_if_extra() - * and connection_dir_close_extra_consensus_conns() that returns 0 if - * we can't have, or don't want to close, excess consensus connections. */ -STATIC int -connection_dir_would_close_consensus_conn_helper(void) -{ - const or_options_t *options = get_options(); - - /* we're only interested in closing excess connections if we could - * have created any in the first place */ - if (!networkstatus_consensus_can_use_multiple_directories(options)) { - return 0; - } - - /* We want to close excess connections downloading a consensus. - * If there aren't any excess, we don't have anything to close. */ - if (!networkstatus_consensus_has_excess_connections()) { - return 0; - } - - /* If we have excess connections, but none of them are downloading a - * consensus, and we are still bootstrapping (that is, we have no usable - * consensus), we don't want to close any until one starts downloading. */ - if (!networkstatus_consensus_is_downloading_usable_flavor() - && networkstatus_consensus_is_bootstrapping(time(NULL))) { - return 0; - } - - /* If we have just stopped bootstrapping (that is, just parsed a consensus), - * we might still have some excess connections hanging around. So we still - * have to check if we want to close any, even if we've stopped - * bootstrapping. */ - return 1; -} - -/* Check if we would close excess consensus connections. If we would, any - * new consensus connection would become excess immediately, so return 1. - * Otherwise, return 0. */ -int -connection_dir_avoid_extra_connection_for_purpose(unsigned int purpose) -{ - const or_options_t *options = get_options(); - - /* We're not interested in connections that aren't fetching a consensus. */ - if (purpose != DIR_PURPOSE_FETCH_CONSENSUS) { - return 0; - } - - /* we're only interested in avoiding excess connections if we could - * have created any in the first place */ - if (!networkstatus_consensus_can_use_multiple_directories(options)) { - return 0; - } - - /* If there are connections downloading a consensus, and we are still - * bootstrapping (that is, we have no usable consensus), we can be sure that - * any further connections would be excess. */ - if (networkstatus_consensus_is_downloading_usable_flavor() - && networkstatus_consensus_is_bootstrapping(time(NULL))) { - return 1; - } - - return 0; -} - -/* Check if we have more than one consensus download connection attempt, and - * close conn: - * - if we don't have a consensus, and we're downloading a consensus, and conn - * is not downloading a consensus yet; - * - if we do have a consensus, and there's more than one consensus connection. +/* We just got a new consensus! If there are other in-progress requests + * for this consensus flavor (for example because we launched several in + * parallel), cancel them. * - * Post-bootstrap consensus connection attempts are initiated one at a time. - * So this function won't close any consensus connection attempts that - * are initiated after bootstrap. - */ -int -connection_dir_close_consensus_conn_if_extra(dir_connection_t *conn) -{ - tor_assert(conn); - tor_assert(conn->base_.type == CONN_TYPE_DIR); - - /* We're not interested in connections that aren't fetching a consensus. */ - if (conn->base_.purpose != DIR_PURPOSE_FETCH_CONSENSUS) { - return 0; - } - - /* The connection has already been closed */ - if (conn->base_.marked_for_close) { - return 0; - } - - /* Only close this connection if there's another consensus connection - * downloading (during bootstrap), or connecting (after bootstrap). - * Post-bootstrap consensus connection attempts won't be closed, because - * they only occur one at a time. */ - if (!connection_dir_would_close_consensus_conn_helper()) { - return 0; - } - - const int we_are_bootstrapping = networkstatus_consensus_is_bootstrapping( - time(NULL)); - - /* We don't want to check other connections to see if they are downloading, - * as this is prone to race-conditions. So leave it for - * connection_dir_close_extra_consensus_conns(() to clean up. - * - * But if conn has just started connecting, or we have a consensus already, - * we can be sure it's not needed any more. */ - if (!we_are_bootstrapping - || conn->base_.state == DIR_CONN_STATE_CONNECTING) { - connection_close_immediate(&conn->base_); - connection_mark_for_close(&conn->base_); - return -1; - } - - return 0; -} - -/* Clean up excess consensus download connection attempts. - * During bootstrap, or when the bootstrap consensus has just been downloaded, - * if we have more than one active consensus connection: - * - if we don't have a consensus, and we're downloading a consensus, keep an - * earlier connection, or a connection to a fallback directory, and close - * all other connections; - * - if we have just downloaded the bootstrap consensus, and have other - * consensus connections left over, close all of them. + * We do this check here (not just in + * connection_ap_handshake_attach_circuit()) to handle the edge case where + * a consensus fetch begins and ends before some other one tries to attach to + * a circuit, in which case the other one won't know that we're all happy now. * - * Post-bootstrap consensus connection attempts are initiated one at a time. - * So this function won't close any consensus connection attempts that - * are initiated after bootstrap. + * Don't mark the conn that just gave us the consensus -- otherwise we + * would end up double-marking it when it cleans itself up. */ -void -connection_dir_close_extra_consensus_conns(void) +static void +connection_dir_close_consensus_fetches(dir_connection_t *except_this_one, + const char *resource) { - /* Only cleanup connections if there is more than one consensus connection, - * and at least one of those connections is already downloading - * (during bootstrap), or connecting (just after the bootstrap consensus is - * downloaded). - * Post-bootstrap consensus connection attempts won't be cleaned up, because - * they only occur one at a time. */ - if (!connection_dir_would_close_consensus_conn_helper()) { - return; - } - - int we_are_bootstrapping = networkstatus_consensus_is_bootstrapping( - time(NULL)); - - const char *usable_resource = networkstatus_get_flavor_name( - usable_consensus_flavor()); - smartlist_t *consens_usable_conns = - connection_dir_list_by_purpose_and_resource( - DIR_PURPOSE_FETCH_CONSENSUS, - usable_resource); - - /* If we want to keep a connection that's downloading, find a connection to - * keep, favouring: - * - connections opened earlier (they are likely to have progressed further) - * - connections to fallbacks (to reduce the load on authorities) */ - dir_connection_t *kept_download_conn = NULL; - int kept_is_authority = 0; - if (we_are_bootstrapping) { - SMARTLIST_FOREACH_BEGIN(consens_usable_conns, - dir_connection_t *, d) { - tor_assert(d); - int d_is_authority = router_digest_is_trusted_dir(d->identity_digest); - /* keep the first connection that is past the connecting state, but - * prefer fallbacks. */ - if (d->base_.state != DIR_CONN_STATE_CONNECTING) { - if (!kept_download_conn || (kept_is_authority && !d_is_authority)) { - kept_download_conn = d; - kept_is_authority = d_is_authority; - /* we've found the earliest fallback, and want to keep it regardless - * of any other connections */ - if (!kept_is_authority) - break; - } - } - } SMARTLIST_FOREACH_END(d); - } - - SMARTLIST_FOREACH_BEGIN(consens_usable_conns, - dir_connection_t *, d) { - tor_assert(d); - /* don't close this connection if it's the one we want to keep */ - if (kept_download_conn && d == kept_download_conn) + smartlist_t *conns_to_close = + connection_dir_list_by_purpose_and_resource(DIR_PURPOSE_FETCH_CONSENSUS, + resource); + SMARTLIST_FOREACH_BEGIN(conns_to_close, dir_connection_t *, d) { + if (d == except_this_one) continue; - /* mark all other connections for close */ - if (!d->base_.marked_for_close) { - connection_close_immediate(&d->base_); - connection_mark_for_close(&d->base_); - } + log_info(LD_DIR, "Closing consensus fetch (to %s) since one " + "has just arrived.", TO_CONN(d)->address); + connection_mark_for_close(TO_CONN(d)); } SMARTLIST_FOREACH_END(d); - - smartlist_free(consens_usable_conns); - consens_usable_conns = NULL; - - /* make sure we've closed all excess connections */ - const int final_connecting_conn_count = - connection_dir_count_by_purpose_resource_and_state( - DIR_PURPOSE_FETCH_CONSENSUS, - usable_resource, - DIR_CONN_STATE_CONNECTING); - if (final_connecting_conn_count > 0) { - log_warn(LD_BUG, "Expected 0 consensus connections connecting after " - "cleanup, got %d.", final_connecting_conn_count); - } - const int expected_final_conn_count = (we_are_bootstrapping ? 1 : 0); - const int final_conn_count = - connection_dir_count_by_purpose_and_resource( - DIR_PURPOSE_FETCH_CONSENSUS, - usable_resource); - if (final_conn_count > expected_final_conn_count) { - log_warn(LD_BUG, "Expected %d consensus connections after cleanup, got " - "%d.", expected_final_conn_count, final_connecting_conn_count); - } + smartlist_free(conns_to_close); } /** Connected handler for directory connections: begin sending data to the - * server, and return 0, or, if the connection is an excess bootstrap - * connection, close all excess bootstrap connections. + * server, and return 0. * Only used when connections don't immediately connect. */ int connection_dir_finished_connecting(dir_connection_t *conn) @@ -4057,12 +3859,6 @@ connection_dir_finished_connecting(dir_connection_t *conn) log_debug(LD_HTTP,"Dir connection to router %s:%u established.", conn->base_.address,conn->base_.port); - /* Close this connection if there's another consensus connection - * downloading (during bootstrap), or connecting (after bootstrap). */ - if (connection_dir_close_consensus_conn_if_extra(conn)) { - return -1; - } - /* start flushing conn */ conn->base_.state = DIR_CONN_STATE_CLIENT_SENDING; return 0; |