/* Copyright (c) 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. * Copyright (c) 2007-2017, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file circuituse.c * \brief Launch the right sort of circuits and attach the right streams to * them. * * As distinct from circuitlist.c, which manages lookups to find circuits, and * circuitbuild.c, which handles the logistics of circuit construction, this * module keeps track of which streams can be attached to which circuits (in * circuit_get_best()), and attaches streams to circuits (with * circuit_try_attaching_streams(), connection_ap_handshake_attach_circuit(), * and connection_ap_handshake_attach_chosen_circuit() ). * * This module also makes sure that we are building circuits for all of the * predicted ports, using circuit_remove_handled_ports(), * circuit_stream_is_being_handled(), and circuit_build_needed_cirs(). It * handles launching circuits for specific targets using * circuit_launch_by_extend_info(). * * This is also where we handle expiring circuits that have been around for * too long without actually completing, along with the circuit_build_timeout * logic in circuitstats.c. **/ #include "or.h" #include "addressmap.h" #include "bridges.h" #include "channel.h" #include "circpathbias.h" #include "circuitbuild.h" #include "circuitlist.h" #include "circuitstats.h" #include "circuituse.h" #include "config.h" #include "connection.h" #include "connection_edge.h" #include "control.h" #include "entrynodes.h" #include "hs_common.h" #include "hs_client.h" #include "hs_ident.h" #include "nodelist.h" #include "networkstatus.h" #include "policies.h" #include "rendclient.h" #include "rendcommon.h" #include "rendservice.h" #include "rephist.h" #include "router.h" #include "routerlist.h" static void circuit_expire_old_circuits_clientside(void); static void circuit_increment_failure_count(void); /** Check whether the hidden service destination of the stream at * edge_conn is the same as the destination of the circuit at * origin_circ. */ static int circuit_matches_with_rend_stream(const edge_connection_t *edge_conn, const origin_circuit_t *origin_circ) { /* Check if this is a v2 rendezvous circ/stream */ if ((edge_conn->rend_data && !origin_circ->rend_data) || (!edge_conn->rend_data && origin_circ->rend_data) || (edge_conn->rend_data && origin_circ->rend_data && rend_cmp_service_ids(rend_data_get_address(edge_conn->rend_data), rend_data_get_address(origin_circ->rend_data)))) { /* this circ is not for this conn */ return 0; } /* Check if this is a v3 rendezvous circ/stream */ if ((edge_conn->hs_ident && !origin_circ->hs_ident) || (!edge_conn->hs_ident && origin_circ->hs_ident) || (edge_conn->hs_ident && origin_circ->hs_ident && !ed25519_pubkey_eq(&edge_conn->hs_ident->identity_pk, &origin_circ->hs_ident->identity_pk))) { /* this circ is not for this conn */ return 0; } return 1; } /** Return 1 if circ could be returned by circuit_get_best(). * Else return 0. */ static int circuit_is_acceptable(const origin_circuit_t *origin_circ, const entry_connection_t *conn, int must_be_open, uint8_t purpose, int need_uptime, int need_internal, time_t now) { const circuit_t *circ = TO_CIRCUIT(origin_circ); const node_t *exitnode; cpath_build_state_t *build_state; tor_assert(circ); tor_assert(conn); tor_assert(conn->socks_request); if (must_be_open && (circ->state != CIRCUIT_STATE_OPEN || !circ->n_chan)) return 0; /* ignore non-open circs */ if (circ->marked_for_close) return 0; /* if this circ isn't our purpose, skip. */ if (purpose == CIRCUIT_PURPOSE_C_REND_JOINED && !must_be_open) { if (circ->purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND && circ->purpose != CIRCUIT_PURPOSE_C_REND_READY && circ->purpose != CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED && circ->purpose != CIRCUIT_PURPOSE_C_REND_JOINED) return 0; } else if (purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT && !must_be_open) { if (circ->purpose != CIRCUIT_PURPOSE_C_INTRODUCING && circ->purpose != CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) return 0; } else { if (purpose != circ->purpose) return 0; } /* If this is a timed-out hidden service circuit, skip it. */ if (origin_circ->hs_circ_has_timed_out) { return 0; } if (purpose == CIRCUIT_PURPOSE_C_GENERAL || purpose == CIRCUIT_PURPOSE_C_REND_JOINED) { if (circ->timestamp_dirty && circ->timestamp_dirty+get_options()->MaxCircuitDirtiness <= now) return 0; } if (origin_circ->unusable_for_new_conns) return 0; /* decide if this circ is suitable for this conn */ /* for rend circs, circ->cpath->prev is not the last router in the * circuit, it's the magical extra service hop. so just check the nickname * of the one we meant to finish at. */ build_state = origin_circ->build_state; exitnode = build_state_get_exit_node(build_state); if (need_uptime && !build_state->need_uptime) return 0; if (need_internal != build_state->is_internal) return 0; if (purpose == CIRCUIT_PURPOSE_C_GENERAL) { tor_addr_t addr; const int family = tor_addr_parse(&addr, conn->socks_request->address); if (!exitnode && !build_state->onehop_tunnel) { log_debug(LD_CIRC,"Not considering circuit with unknown router."); return 0; /* this circuit is screwed and doesn't know it yet, * or is a rendezvous circuit. */ } if (build_state->onehop_tunnel) { if (!conn->want_onehop) { log_debug(LD_CIRC,"Skipping one-hop circuit."); return 0; } tor_assert(conn->chosen_exit_name); if (build_state->chosen_exit) { char digest[DIGEST_LEN]; if (hexdigest_to_digest(conn->chosen_exit_name, digest) < 0) return 0; /* broken digest, we don't want it */ if (tor_memneq(digest, build_state->chosen_exit->identity_digest, DIGEST_LEN)) return 0; /* this is a circuit to somewhere else */ if (tor_digest_is_zero(digest)) { /* we don't know the digest; have to compare addr:port */ if (family < 0 || !tor_addr_eq(&build_state->chosen_exit->addr, &addr) || build_state->chosen_exit->port != conn->socks_request->port) return 0; } } } else { if (conn->want_onehop) { /* don't use three-hop circuits -- that could hurt our anonymity. */ return 0; } } if (origin_circ->prepend_policy && family != -1) { int r = compare_tor_addr_to_addr_policy(&addr, conn->socks_request->port, origin_circ->prepend_policy); if (r == ADDR_POLICY_REJECTED) return 0; } if (exitnode && !connection_ap_can_use_exit(conn, exitnode)) { /* can't exit from this router */ return 0; } } else { /* not general: this might be a rend circuit */ const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn); if (!circuit_matches_with_rend_stream(edge_conn, origin_circ)) { return 0; } } if (!connection_edge_compatible_with_circuit(conn, origin_circ)) { /* conn needs to be isolated from other conns that have already used * origin_circ */ return 0; } return 1; } /** Return 1 if circuit a is better than circuit b for * conn, and return 0 otherwise. Used by circuit_get_best. */ static int circuit_is_better(const origin_circuit_t *oa, const origin_circuit_t *ob, const entry_connection_t *conn) { const circuit_t *a = TO_CIRCUIT(oa); const circuit_t *b = TO_CIRCUIT(ob); const uint8_t purpose = ENTRY_TO_CONN(conn)->purpose; int a_bits, b_bits; /* If one of the circuits was allowed to live due to relaxing its timeout, * it is definitely worse (it's probably a much slower path). */ if (oa->relaxed_timeout && !ob->relaxed_timeout) return 0; /* ob is better. It's not relaxed. */ if (!oa->relaxed_timeout && ob->relaxed_timeout) return 1; /* oa is better. It's not relaxed. */ switch (purpose) { case CIRCUIT_PURPOSE_C_GENERAL: /* if it's used but less dirty it's best; * else if it's more recently created it's best */ if (b->timestamp_dirty) { if (a->timestamp_dirty && a->timestamp_dirty > b->timestamp_dirty) return 1; } else { if (a->timestamp_dirty || timercmp(&a->timestamp_began, &b->timestamp_began, OP_GT)) return 1; if (ob->build_state->is_internal) /* XXXX++ what the heck is this internal thing doing here. I * think we can get rid of it. circuit_is_acceptable() already * makes sure that is_internal is exactly what we need it to * be. -RD */ return 1; } break; case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT: /* the closer it is to ack_wait the better it is */ if (a->purpose > b->purpose) return 1; break; case CIRCUIT_PURPOSE_C_REND_JOINED: /* the closer it is to rend_joined the better it is */ if (a->purpose > b->purpose) return 1; break; } /* XXXX Maybe this check should get a higher priority to avoid * using up circuits too rapidly. */ a_bits = connection_edge_update_circuit_isolation(conn, (origin_circuit_t*)oa, 1); b_bits = connection_edge_update_circuit_isolation(conn, (origin_circuit_t*)ob, 1); /* if x_bits < 0, then we have not used x for anything; better not to dirty * a connection if we can help it. */ if (a_bits < 0) { return 0; } else if (b_bits < 0) { return 1; } a_bits &= ~ oa->isolation_flags_mixed; a_bits &= ~ ob->isolation_flags_mixed; if (n_bits_set_u8(a_bits) < n_bits_set_u8(b_bits)) { /* The fewer new restrictions we need to make on a circuit for stream * isolation, the better. */ return 1; } return 0; } /** Find the best circ that conn can use, preferably one which is * dirty. Circ must not be too old. * * Conn must be defined. * * If must_be_open, ignore circs not in CIRCUIT_STATE_OPEN. * * circ_purpose specifies what sort of circuit we must have. * It can be C_GENERAL, C_INTRODUCE_ACK_WAIT, or C_REND_JOINED. * * If it's REND_JOINED and must_be_open==0, then return the closest * rendezvous-purposed circuit that you can find. * * If it's INTRODUCE_ACK_WAIT and must_be_open==0, then return the * closest introduce-purposed circuit that you can find. */ static origin_circuit_t * circuit_get_best(const entry_connection_t *conn, int must_be_open, uint8_t purpose, int need_uptime, int need_internal) { origin_circuit_t *best=NULL; struct timeval now; int intro_going_on_but_too_old = 0; tor_assert(conn); tor_assert(purpose == CIRCUIT_PURPOSE_C_GENERAL || purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT || purpose == CIRCUIT_PURPOSE_C_REND_JOINED); tor_gettimeofday(&now); SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { origin_circuit_t *origin_circ; if (!CIRCUIT_IS_ORIGIN(circ)) continue; origin_circ = TO_ORIGIN_CIRCUIT(circ); /* Log an info message if we're going to launch a new intro circ in * parallel */ if (purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT && !must_be_open && origin_circ->hs_circ_has_timed_out) { intro_going_on_but_too_old = 1; continue; } if (!circuit_is_acceptable(origin_circ,conn,must_be_open,purpose, need_uptime,need_internal, (time_t)now.tv_sec)) continue; /* now this is an acceptable circ to hand back. but that doesn't * mean it's the *best* circ to hand back. try to decide. */ if (!best || circuit_is_better(origin_circ,best,conn)) best = origin_circ; } SMARTLIST_FOREACH_END(circ); if (!best && intro_going_on_but_too_old) log_info(LD_REND|LD_CIRC, "There is an intro circuit being created " "right now, but it has already taken quite a while. Starting " "one in parallel."); return best; } /** Return the number of not-yet-open general-purpose origin circuits. */ static int count_pending_general_client_circuits(void) { int count = 0; SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { if (circ->marked_for_close || circ->state == CIRCUIT_STATE_OPEN || circ->purpose != CIRCUIT_PURPOSE_C_GENERAL || !CIRCUIT_IS_ORIGIN(circ)) continue; ++count; } SMARTLIST_FOREACH_END(circ); return count; } #if 0 /** Check whether, according to the policies in options, the * circuit circ makes sense. */ /* XXXX currently only checks Exclude{Exit}Nodes; it should check more. * Also, it doesn't have the right definition of an exit circuit. Also, * it's never called. */ int circuit_conforms_to_options(const origin_circuit_t *circ, const or_options_t *options) { const crypt_path_t *cpath, *cpath_next = NULL; /* first check if it includes any excluded nodes */ for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) { cpath_next = cpath->next; if (routerset_contains_extendinfo(options->ExcludeNodes, cpath->extend_info)) return 0; } /* then consider the final hop */ if (routerset_contains_extendinfo(options->ExcludeExitNodes, circ->cpath->prev->extend_info)) return 0; return 1; } #endif /** Close all circuits that start at us, aren't open, and were born * at least CircuitBuildTimeout seconds ago. */ void circuit_expire_building(void) { /* circ_times.timeout_ms and circ_times.close_ms are from * circuit_build_times_get_initial_timeout() if we haven't computed * custom timeouts yet */ struct timeval general_cutoff, begindir_cutoff, fourhop_cutoff, close_cutoff, extremely_old_cutoff, hs_extremely_old_cutoff, cannibalized_cutoff, c_intro_cutoff, s_intro_cutoff, stream_cutoff; const or_options_t *options = get_options(); struct timeval now; cpath_build_state_t *build_state; int any_opened_circs = 0; tor_gettimeofday(&now); /* Check to see if we have any opened circuits. If we don't, * we want to be more lenient with timeouts, in case the * user has relocated and/or changed network connections. * See bug #3443. */ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, next_circ) { if (!CIRCUIT_IS_ORIGIN(next_circ) || /* didn't originate here */ next_circ->marked_for_close) { /* don't mess with marked circs */ continue; } if (TO_ORIGIN_CIRCUIT(next_circ)->has_opened && next_circ->state == CIRCUIT_STATE_OPEN && TO_ORIGIN_CIRCUIT(next_circ)->build_state && TO_ORIGIN_CIRCUIT(next_circ)->build_state->desired_path_len == DEFAULT_ROUTE_LEN) { any_opened_circs = 1; break; } } SMARTLIST_FOREACH_END(next_circ); #define SET_CUTOFF(target, msec) do { \ long ms = tor_lround(msec); \ struct timeval diff; \ diff.tv_sec = ms / 1000; \ diff.tv_usec = (int)((ms % 1000) * 1000); \ timersub(&now, &diff, &target); \ } while (0) /** * Because circuit build timeout is calculated only based on 3 hop * general purpose circuit construction, we need to scale the timeout * to make it properly apply to longer circuits, and circuits of * certain usage types. The following diagram illustrates how we * derive the scaling below. In short, we calculate the number * of times our telescoping-based circuit construction causes cells * to traverse each link for the circuit purpose types in question, * and then assume each link is equivalent. * * OP --a--> A --b--> B --c--> C * OP --a--> A --b--> B --c--> C --d--> D * * Let h = a = b = c = d * * Three hops (general_cutoff) * RTTs = 3a + 2b + c * RTTs = 6h * Cannibalized: * RTTs = a+b+c+d * RTTs = 4h * Four hops: * RTTs = 4a + 3b + 2c + d * RTTs = 10h * Client INTRODUCE1+ACK: // XXX: correct? * RTTs = 5a + 4b + 3c + 2d * RTTs = 14h * Server intro: * RTTs = 4a + 3b + 2c * RTTs = 9h */ SET_CUTOFF(general_cutoff, get_circuit_build_timeout_ms()); SET_CUTOFF(begindir_cutoff, get_circuit_build_timeout_ms()); /* > 3hop circs seem to have a 1.0 second delay on their cannibalized * 4th hop. */ SET_CUTOFF(fourhop_cutoff, get_circuit_build_timeout_ms() * (10/6.0) + 1000); /* CIRCUIT_PURPOSE_C_ESTABLISH_REND behaves more like a RELAY cell. * Use the stream cutoff (more or less). */ SET_CUTOFF(stream_cutoff, MAX(options->CircuitStreamTimeout,15)*1000 + 1000); /* Be lenient with cannibalized circs. They already survived the official * CBT, and they're usually not performance-critical. */ SET_CUTOFF(cannibalized_cutoff, MAX(get_circuit_build_close_time_ms()*(4/6.0), options->CircuitStreamTimeout * 1000) + 1000); /* Intro circs have an extra round trip (and are also 4 hops long) */ SET_CUTOFF(c_intro_cutoff, get_circuit_build_timeout_ms() * (14/6.0) + 1000); /* Server intro circs have an extra round trip */ SET_CUTOFF(s_intro_cutoff, get_circuit_build_timeout_ms() * (9/6.0) + 1000); SET_CUTOFF(close_cutoff, get_circuit_build_close_time_ms()); SET_CUTOFF(extremely_old_cutoff, get_circuit_build_close_time_ms()*2 + 1000); SET_CUTOFF(hs_extremely_old_cutoff, MAX(get_circuit_build_close_time_ms()*2 + 1000, options->SocksTimeout * 1000)); SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *,victim) { struct timeval cutoff; if (!CIRCUIT_IS_ORIGIN(victim) || /* didn't originate here */ victim->marked_for_close) /* don't mess with marked circs */ continue; /* If we haven't yet started the first hop, it means we don't have * any orconns available, and thus have not started counting time yet * for this circuit. See circuit_deliver_create_cell() and uses of * timestamp_began. * * Continue to wait in this case. The ORConn should timeout * independently and kill us then. */ if (TO_ORIGIN_CIRCUIT(victim)->cpath->state == CPATH_STATE_CLOSED) { continue; } build_state = TO_ORIGIN_CIRCUIT(victim)->build_state; if (build_state && build_state->onehop_tunnel) cutoff = begindir_cutoff; else if (victim->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) cutoff = close_cutoff; else if (victim->purpose == CIRCUIT_PURPOSE_C_INTRODUCING || victim->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) cutoff = c_intro_cutoff; else if (victim->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) cutoff = s_intro_cutoff; else if (victim->purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND) cutoff = stream_cutoff; else if (victim->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING) cutoff = close_cutoff; else if (TO_ORIGIN_CIRCUIT(victim)->has_opened && victim->state != CIRCUIT_STATE_OPEN) cutoff = cannibalized_cutoff; else if (build_state && build_state->desired_path_len >= 4) cutoff = fourhop_cutoff; else cutoff = general_cutoff; if (TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out) cutoff = hs_extremely_old_cutoff; if (timercmp(&victim->timestamp_began, &cutoff, OP_GT)) continue; /* it's still young, leave it alone */ /* We need to double-check the opened state here because * we don't want to consider opened 1-hop dircon circuits for * deciding when to relax the timeout, but we *do* want to relax * those circuits too if nothing else is opened *and* they still * aren't either. */ if (!any_opened_circs && victim->state != CIRCUIT_STATE_OPEN) { /* It's still young enough that we wouldn't close it, right? */ if (timercmp(&victim->timestamp_began, &close_cutoff, OP_GT)) { if (!TO_ORIGIN_CIRCUIT(victim)->relaxed_timeout) { int first_hop_succeeded = TO_ORIGIN_CIRCUIT(victim)->cpath->state == CPATH_STATE_OPEN; log_info(LD_CIRC, "No circuits are opened. Relaxing timeout for circuit %d " "(a %s %d-hop circuit in state %s with channel state %s).", TO_ORIGIN_CIRCUIT(victim)->global_identifier, circuit_purpose_to_string(victim->purpose), TO_ORIGIN_CIRCUIT(victim)->build_state ? TO_ORIGIN_CIRCUIT(victim)->build_state->desired_path_len : -1, circuit_state_to_string(victim->state), channel_state_to_string(victim->n_chan->state)); /* We count the timeout here for CBT, because technically this * was a timeout, and the timeout value needs to reset if we * see enough of them. Note this means we also need to avoid * double-counting below, too. */ circuit_build_times_count_timeout(get_circuit_build_times_mutable(), first_hop_succeeded); TO_ORIGIN_CIRCUIT(victim)->relaxed_timeout = 1; } continue; } else { static ratelim_t relax_timeout_limit = RATELIM_INIT(3600); const double build_close_ms = get_circuit_build_close_time_ms(); log_fn_ratelim(&relax_timeout_limit, LOG_NOTICE, LD_CIRC, "No circuits are opened. Relaxed timeout for circuit %d " "(a %s %d-hop circuit in state %s with channel state %s) to " "%ldms. However, it appears the circuit has timed out " "anyway.", TO_ORIGIN_CIRCUIT(victim)->global_identifier, circuit_purpose_to_string(victim->purpose), TO_ORIGIN_CIRCUIT(victim)->build_state ? TO_ORIGIN_CIRCUIT(victim)->build_state->desired_path_len : -1, circuit_state_to_string(victim->state), channel_state_to_string(victim->n_chan->state), (long)build_close_ms); } } #if 0 /* some debug logs, to help track bugs */ if (victim->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING && victim->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) { if (!victim->timestamp_dirty) log_fn(LOG_DEBUG,"Considering %sopen purpose %d to %s (circid %d)." "(clean).", victim->state == CIRCUIT_STATE_OPEN ? "" : "non", victim->purpose, victim->build_state->chosen_exit_name, victim->n_circ_id); else log_fn(LOG_DEBUG,"Considering %sopen purpose %d to %s (circid %d). " "%d secs since dirty.", victim->state == CIRCUIT_STATE_OPEN ? "" : "non", victim->purpose, victim->build_state->chosen_exit_name, victim->n_circ_id, (int)(now - victim->timestamp_dirty)); } #endif /* if circ is !open, or if it's open but purpose is a non-finished * intro or rend, then mark it for close */ if (victim->state == CIRCUIT_STATE_OPEN) { switch (victim->purpose) { default: /* most open circuits can be left alone. */ continue; /* yes, continue inside a switch refers to the nearest * enclosing loop. C is smart. */ case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO: break; /* too old, need to die */ case CIRCUIT_PURPOSE_C_REND_READY: /* it's a rend_ready circ -- has it already picked a query? */ /* c_rend_ready circs measure age since timestamp_dirty, * because that's set when they switch purposes */ if (TO_ORIGIN_CIRCUIT(victim)->rend_data || victim->timestamp_dirty > cutoff.tv_sec) continue; break; case CIRCUIT_PURPOSE_PATH_BIAS_TESTING: /* Open path bias testing circuits are given a long * time to complete the test, but not forever */ TO_ORIGIN_CIRCUIT(victim)->path_state = PATH_STATE_USE_FAILED; break; case CIRCUIT_PURPOSE_C_INTRODUCING: /* We keep old introducing circuits around for * a while in parallel, and they can end up "opened". * We decide below if we're going to mark them timed * out and eventually close them. */ break; case CIRCUIT_PURPOSE_C_ESTABLISH_REND: case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED: case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT: /* rend and intro circs become dirty each time they * make an introduction attempt. so timestamp_dirty * will reflect the time since the last attempt. */ if (victim->timestamp_dirty > cutoff.tv_sec) continue; break; } } else { /* circuit not open, consider recording failure as timeout */ int first_hop_succeeded = TO_ORIGIN_CIRCUIT(victim)->cpath && TO_ORIGIN_CIRCUIT(victim)->cpath->state == CPATH_STATE_OPEN; if (TO_ORIGIN_CIRCUIT(victim)->p_streams != NULL) { log_warn(LD_BUG, "Circuit %d (purpose %d, %s) has timed out, " "yet has attached streams!", TO_ORIGIN_CIRCUIT(victim)->global_identifier, victim->purpose, circuit_purpose_to_string(victim->purpose)); tor_fragile_assert(); continue; } if (circuit_timeout_want_to_count_circ(TO_ORIGIN_CIRCUIT(victim)) && circuit_build_times_enough_to_compute(get_circuit_build_times())) { /* Circuits are allowed to last longer for measurement. * Switch their purpose and wait. */ if (victim->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) { control_event_circuit_status(TO_ORIGIN_CIRCUIT(victim), CIRC_EVENT_FAILED, END_CIRC_REASON_TIMEOUT); circuit_change_purpose(victim, CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT); /* Record this failure to check for too many timeouts * in a row. This function does not record a time value yet * (we do that later); it only counts the fact that we did * have a timeout. We also want to avoid double-counting * already "relaxed" circuits, which are counted above. */ if (!TO_ORIGIN_CIRCUIT(victim)->relaxed_timeout) { circuit_build_times_count_timeout( get_circuit_build_times_mutable(), first_hop_succeeded); } continue; } /* * If the circuit build time is much greater than we would have cut * it off at, we probably had a suspend event along this codepath, * and we should discard the value. */ if (timercmp(&victim->timestamp_began, &extremely_old_cutoff, OP_LT)) { log_notice(LD_CIRC, "Extremely large value for circuit build timeout: %lds. " "Assuming clock jump. Purpose %d (%s)", (long)(now.tv_sec - victim->timestamp_began.tv_sec), victim->purpose, circuit_purpose_to_string(victim->purpose)); } else if (circuit_build_times_count_close( get_circuit_build_times_mutable(), first_hop_succeeded, (time_t)victim->timestamp_created.tv_sec)) { circuit_build_times_set_timeout(get_circuit_build_times_mutable()); } } } /* If this is a hidden service client circuit which is far enough along in * connecting to its destination, and we haven't already flagged it as * 'timed out', flag it so we'll launch another intro or rend circ, but * don't mark it for close yet. * * (Circs flagged as 'timed out' are given a much longer timeout * period above, so we won't close them in the next call to * circuit_expire_building.) */ if (!(TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out)) { switch (victim->purpose) { case CIRCUIT_PURPOSE_C_REND_READY: /* We only want to spare a rend circ if it has been specified in * an INTRODUCE1 cell sent to a hidden service. A circ's * pending_final_cpath field is non-NULL iff it is a rend circ * and we have tried to send an INTRODUCE1 cell specifying it. * Thus, if the pending_final_cpath field *is* NULL, then we * want to not spare it. */ if (TO_ORIGIN_CIRCUIT(victim)->build_state && TO_ORIGIN_CIRCUIT(victim)->build_state->pending_final_cpath == NULL) break; /* fallthrough! */ case CIRCUIT_PURPOSE_C_INTRODUCING: /* connection_ap_handshake_attach_circuit() will relaunch for us */ case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT: case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED: /* If we have reached this line, we want to spare the circ for now. */ log_info(LD_CIRC,"Marking circ %u (state %d:%s, purpose %d) " "as timed-out HS circ", (unsigned)victim->n_circ_id, victim->state, circuit_state_to_string(victim->state), victim->purpose); TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out = 1; continue; default: break; } } /* If this is a service-side rendezvous circuit which is far * enough along in connecting to its destination, consider sparing * it. */ if (!(TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out) && victim->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) { log_info(LD_CIRC,"Marking circ %u (state %d:%s, purpose %d) " "as timed-out HS circ; relaunching rendezvous attempt.", (unsigned)victim->n_circ_id, victim->state, circuit_state_to_string(victim->state), victim->purpose); TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out = 1; rend_service_relaunch_rendezvous(TO_ORIGIN_CIRCUIT(victim)); continue; } if (victim->n_chan) log_info(LD_CIRC, "Abandoning circ %u %s:%u (state %d,%d:%s, purpose %d, " "len %d)", TO_ORIGIN_CIRCUIT(victim)->global_identifier, channel_get_canonical_remote_descr(victim->n_chan), (unsigned)victim->n_circ_id, TO_ORIGIN_CIRCUIT(victim)->has_opened, victim->state, circuit_state_to_string(victim->state), victim->purpose, TO_ORIGIN_CIRCUIT(victim)->build_state ? TO_ORIGIN_CIRCUIT(victim)->build_state->desired_path_len : -1); else log_info(LD_CIRC, "Abandoning circ %u %u (state %d,%d:%s, purpose %d, len %d)", TO_ORIGIN_CIRCUIT(victim)->global_identifier, (unsigned)victim->n_circ_id, TO_ORIGIN_CIRCUIT(victim)->has_opened, victim->state, circuit_state_to_string(victim->state), victim->purpose, TO_ORIGIN_CIRCUIT(victim)->build_state ? TO_ORIGIN_CIRCUIT(victim)->build_state->desired_path_len : -1); circuit_log_path(LOG_INFO,LD_CIRC,TO_ORIGIN_CIRCUIT(victim)); if (victim->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) circuit_mark_for_close(victim, END_CIRC_REASON_MEASUREMENT_EXPIRED); else circuit_mark_for_close(victim, END_CIRC_REASON_TIMEOUT); pathbias_count_timeout(TO_ORIGIN_CIRCUIT(victim)); } SMARTLIST_FOREACH_END(victim); } /** * Mark for close all circuits that start here, that were built through a * guard we weren't sure if we wanted to use, and that have been waiting * around for way too long. */ void circuit_expire_waiting_for_better_guard(void) { SMARTLIST_FOREACH_BEGIN(circuit_get_global_origin_circuit_list(), origin_circuit_t *, circ) { if (TO_CIRCUIT(circ)->marked_for_close) continue; if (circ->guard_state == NULL) continue; if (entry_guard_state_should_expire(circ->guard_state)) circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_NONE); } SMARTLIST_FOREACH_END(circ); } /** For debugging #8387: track when we last called * circuit_expire_old_circuits_clientside. */ static time_t last_expired_clientside_circuits = 0; /** * As a diagnostic for bug 8387, log information about how many one-hop * circuits we have around that have been there for at least age * seconds. Log a few of them. * Ignores Single Onion Service intro and Tor2web redezvous circuits, they are * expected to be long-term one-hop circuits. */ void circuit_log_ancient_one_hop_circuits(int age) { #define MAX_ANCIENT_ONEHOP_CIRCUITS_TO_LOG 10 time_t now = time(NULL); time_t cutoff = now - age; int n_found = 0; smartlist_t *log_these = smartlist_new(); const or_options_t *options = get_options(); SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { const origin_circuit_t *ocirc; if (! CIRCUIT_IS_ORIGIN(circ)) continue; if (circ->timestamp_created.tv_sec >= cutoff) continue; /* Single Onion Services deliberately make long term one-hop intro * connections. We only ignore active intro point connections, if we take * a long time establishing, that's worth logging. */ if (rend_service_allow_non_anonymous_connection(options) && circ->purpose == CIRCUIT_PURPOSE_S_INTRO) continue; /* Tor2web deliberately makes long term one-hop rend connections, * particularly when Tor2webRendezvousPoints is used. We only ignore * active rend point connections, if we take a long time to rendezvous, * that's worth logging. */ if (rend_client_allow_non_anonymous_connection(options) && circ->purpose == CIRCUIT_PURPOSE_C_REND_JOINED) continue; ocirc = CONST_TO_ORIGIN_CIRCUIT(circ); if (ocirc->build_state && ocirc->build_state->onehop_tunnel) { ++n_found; if (smartlist_len(log_these) < MAX_ANCIENT_ONEHOP_CIRCUITS_TO_LOG) smartlist_add(log_these, (origin_circuit_t*) ocirc); } } SMARTLIST_FOREACH_END(circ); if (n_found == 0) goto done; log_notice(LD_HEARTBEAT, "Diagnostic for issue 8387: Found %d one-hop circuits more " "than %d seconds old! Logging %d...", n_found, age, smartlist_len(log_these)); SMARTLIST_FOREACH_BEGIN(log_these, const origin_circuit_t *, ocirc) { char created[ISO_TIME_LEN+1]; int stream_num; const edge_connection_t *conn; char *dirty = NULL; const circuit_t *circ = TO_CIRCUIT(ocirc); format_local_iso_time(created, (time_t)circ->timestamp_created.tv_sec); if (circ->timestamp_dirty) { char dirty_since[ISO_TIME_LEN+1]; format_local_iso_time(dirty_since, circ->timestamp_dirty); tor_asprintf(&dirty, "Dirty since %s (%ld seconds vs %ld-second cutoff)", dirty_since, (long)(now - circ->timestamp_dirty), (long) options->MaxCircuitDirtiness); } else { dirty = tor_strdup("Not marked dirty"); } log_notice(LD_HEARTBEAT, " #%d created at %s. %s, %s. %s for close. " "Package window: %d. " "%s for new conns. %s.", ocirc_sl_idx, created, circuit_state_to_string(circ->state), circuit_purpose_to_string(circ->purpose), circ->marked_for_close ? "Marked" : "Not marked", circ->package_window, ocirc->unusable_for_new_conns ? "Not usable" : "usable", dirty); tor_free(dirty); stream_num = 0; for (conn = ocirc->p_streams; conn; conn = conn->next_stream) { const connection_t *c = TO_CONN(conn); char stream_created[ISO_TIME_LEN+1]; if (++stream_num >= 5) break; format_local_iso_time(stream_created, c->timestamp_created); log_notice(LD_HEARTBEAT, " Stream#%d created at %s. " "%s conn in state %s. " "It is %slinked and %sreading from a linked connection %p. " "Package window %d. " "%s for close (%s:%d). Hold-open is %sset. " "Has %ssent RELAY_END. %s on circuit.", stream_num, stream_created, conn_type_to_string(c->type), conn_state_to_string(c->type, c->state), c->linked ? "" : "not ", c->reading_from_linked_conn ? "": "not", c->linked_conn, conn->package_window, c->marked_for_close ? "Marked" : "Not marked", c->marked_for_close_file ? c->marked_for_close_file : "--", c->marked_for_close, c->hold_open_until_flushed ? "" : "not ", conn->edge_has_sent_end ? "" : "not ", conn->edge_blocked_on_circ ? "Blocked" : "Not blocked"); if (! c->linked_conn) continue; c = c->linked_conn; log_notice(LD_HEARTBEAT, " Linked to %s connection in state %s " "(Purpose %d). %s for close (%s:%d). Hold-open is %sset. ", conn_type_to_string(c->type), conn_state_to_string(c->type, c->state), c->purpose, c->marked_for_close ? "Marked" : "Not marked", c->marked_for_close_file ? c->marked_for_close_file : "--", c->marked_for_close, c->hold_open_until_flushed ? "" : "not "); } } SMARTLIST_FOREACH_END(ocirc); log_notice(LD_HEARTBEAT, "It has been %ld seconds since I last called " "circuit_expire_old_circuits_clientside().", (long)(now - last_expired_clientside_circuits)); done: smartlist_free(log_these); } /** Remove any elements in needed_ports that are handled by an * open or in-progress circuit. */ void circuit_remove_handled_ports(smartlist_t *needed_ports) { int i; uint16_t *port; for (i = 0; i < smartlist_len(needed_ports); ++i) { port = smartlist_get(needed_ports, i); tor_assert(*port); if (circuit_stream_is_being_handled(NULL, *port, MIN_CIRCUITS_HANDLING_STREAM)) { // log_debug(LD_CIRC,"Port %d is already being handled; removing.", port); smartlist_del(needed_ports, i--); tor_free(port); } else { log_debug(LD_CIRC,"Port %d is not handled.", *port); } } } /** Return 1 if at least min general-purpose non-internal circuits * will have an acceptable exit node for exit stream conn if it * is defined, else for "*:port". * Else return 0. */ int circuit_stream_is_being_handled(entry_connection_t *conn, uint16_t port, int min) { const node_t *exitnode; int num=0; time_t now = time(NULL); int need_uptime = smartlist_contains_int_as_string( get_options()->LongLivedPorts, conn ? conn->socks_request->port : port); SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { if (CIRCUIT_IS_ORIGIN(circ) && !circ->marked_for_close && circ->purpose == CIRCUIT_PURPOSE_C_GENERAL && (!circ->timestamp_dirty || circ->timestamp_dirty + get_options()->MaxCircuitDirtiness > now)) { origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ); cpath_build_state_t *build_state = origin_circ->build_state; if (build_state->is_internal || build_state->onehop_tunnel) continue; if (origin_circ->unusable_for_new_conns) continue; exitnode = build_state_get_exit_node(build_state); if (exitnode && (!need_uptime || build_state->need_uptime)) { int ok; if (conn) { ok = connection_ap_can_use_exit(conn, exitnode); } else { addr_policy_result_t r; r = compare_tor_addr_to_node_policy(NULL, port, exitnode); ok = r != ADDR_POLICY_REJECTED && r != ADDR_POLICY_PROBABLY_REJECTED; } if (ok) { if (++num >= min) return 1; } } } } SMARTLIST_FOREACH_END(circ); return 0; } /** Don't keep more than this many unused open circuits around. */ #define MAX_UNUSED_OPEN_CIRCUITS 14 /* Return true if a circuit is available for use, meaning that it is open, * clean, usable for new multi-hop connections, and a general purpose origin * circuit. * Accept any kind of circuit, return false if the above conditions are not * met. */ STATIC int circuit_is_available_for_use(const circuit_t *circ) { const origin_circuit_t *origin_circ; cpath_build_state_t *build_state; if (!CIRCUIT_IS_ORIGIN(circ)) return 0; /* We first filter out only origin circuits before doing the following checks. */ if (circ->marked_for_close) return 0; /* Don't mess with marked circs */ if (circ->timestamp_dirty) return 0; /* Only count clean circs */ if (circ->purpose != CIRCUIT_PURPOSE_C_GENERAL) return 0; /* We only pay attention to general purpose circuits. General purpose circuits are always origin circuits. */ origin_circ = CONST_TO_ORIGIN_CIRCUIT(circ); if (origin_circ->unusable_for_new_conns) return 0; build_state = origin_circ->build_state; if (build_state->onehop_tunnel) return 0; return 1; } /* Return true if we need any more exit circuits. * needs_uptime and needs_capacity are set only if we need more exit circuits. * Check if we know of a port that's been requested recently and no circuit * is currently available that can handle it. */ STATIC int needs_exit_circuits(time_t now, int *needs_uptime, int *needs_capacity) { return (!circuit_all_predicted_ports_handled(now, needs_uptime, needs_capacity) && router_have_consensus_path() == CONSENSUS_PATH_EXIT); } /* Hidden services need at least this many internal circuits */ #define SUFFICIENT_UPTIME_INTERNAL_HS_SERVERS 3 /* Return true if we need any more hidden service server circuits. * HS servers only need an internal circuit. */ STATIC int needs_hs_server_circuits(int num_uptime_internal) { return (rend_num_services() && num_uptime_internal < SUFFICIENT_UPTIME_INTERNAL_HS_SERVERS && router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN); } /* We need at least this many internal circuits for hidden service clients */ #define SUFFICIENT_INTERNAL_HS_CLIENTS 3 /* We need at least this much uptime for internal circuits for hidden service * clients */ #define SUFFICIENT_UPTIME_INTERNAL_HS_CLIENTS 2 /* Return true if we need any more hidden service client circuits. * HS clients only need an internal circuit. */ STATIC int needs_hs_client_circuits(time_t now, int *needs_uptime, int *needs_capacity, int num_internal, int num_uptime_internal) { int used_internal_recently = rep_hist_get_predicted_internal(now, needs_uptime, needs_capacity); int requires_uptime = num_uptime_internal < SUFFICIENT_UPTIME_INTERNAL_HS_CLIENTS && needs_uptime; return (used_internal_recently && (requires_uptime || num_internal < SUFFICIENT_INTERNAL_HS_CLIENTS) && router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN); } /* The minimum number of open slots we should keep in order to preemptively * build circuits. */ #define CBT_MIN_REMAINING_PREEMPTIVE_CIRCUITS 2 /* Check to see if we need more circuits to have a good build timeout. However, * leave a couple slots open so that we can still build circuits preemptively * as needed. */ #define CBT_MAX_UNUSED_OPEN_CIRCUITS (MAX_UNUSED_OPEN_CIRCUITS - \ CBT_MIN_REMAINING_PREEMPTIVE_CIRCUITS) /* Return true if we need more circuits for a good build timeout. * XXXX make the assumption that build timeout streams should be * created whenever we can build internal circuits. */ STATIC int needs_circuits_for_build(int num) { if (router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN) { if (num < CBT_MAX_UNUSED_OPEN_CIRCUITS && !circuit_build_times_disabled(get_options()) && circuit_build_times_needs_circuits_now(get_circuit_build_times())) { return 1; } } return 0; } /** Determine how many circuits we have open that are clean, * Make sure it's enough for all the upcoming behaviors we predict we'll have. * But put an upper bound on the total number of circuits. */ static void circuit_predict_and_launch_new(void) { int num=0, num_internal=0, num_uptime_internal=0; int hidserv_needs_uptime=0, hidserv_needs_capacity=1; int port_needs_uptime=0, port_needs_capacity=1; time_t now = time(NULL); int flags = 0; /* Count how many of each type of circuit we currently have. */ SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { if (!circuit_is_available_for_use(circ)) continue; num++; cpath_build_state_t *build_state = TO_ORIGIN_CIRCUIT(circ)->build_state; if (build_state->is_internal) num_internal++; if (build_state->need_uptime && build_state->is_internal) num_uptime_internal++; } SMARTLIST_FOREACH_END(circ); /* If that's enough, then stop now. */ if (num >= MAX_UNUSED_OPEN_CIRCUITS) return; if (needs_exit_circuits(now, &port_needs_uptime, &port_needs_capacity)) { if (port_needs_uptime) flags |= CIRCLAUNCH_NEED_UPTIME; if (port_needs_capacity) flags |= CIRCLAUNCH_NEED_CAPACITY; log_info(LD_CIRC, "Have %d clean circs (%d internal), need another exit circ.", num, num_internal); circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags); return; } if (needs_hs_server_circuits(num_uptime_internal)) { flags = (CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_NEED_UPTIME | CIRCLAUNCH_IS_INTERNAL); log_info(LD_CIRC, "Have %d clean circs (%d internal), need another internal " "circ for my hidden service.", num, num_internal); circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags); return; } if (needs_hs_client_circuits(now, &hidserv_needs_uptime, &hidserv_needs_capacity, num_internal, num_uptime_internal)) { if (hidserv_needs_uptime) flags |= CIRCLAUNCH_NEED_UPTIME; if (hidserv_needs_capacity) flags |= CIRCLAUNCH_NEED_CAPACITY; flags |= CIRCLAUNCH_IS_INTERNAL; log_info(LD_CIRC, "Have %d clean circs (%d uptime-internal, %d internal), need" " another hidden service circ.", num, num_uptime_internal, num_internal); circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags); return; } if (needs_circuits_for_build(num)) { flags = CIRCLAUNCH_NEED_CAPACITY; /* if there are no exits in the consensus, make timeout * circuits internal */ if (router_have_consensus_path() == CONSENSUS_PATH_INTERNAL) flags |= CIRCLAUNCH_IS_INTERNAL; log_info(LD_CIRC, "Have %d clean circs need another buildtime test circ.", num); circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags); return; } } /** Build a new test circuit every 5 minutes */ #define TESTING_CIRCUIT_INTERVAL 300 /** This function is called once a second, if router_have_minimum_dir_info() * is true. Its job is to make sure all services we offer have enough circuits * available. Some services just want enough circuits for current tasks, * whereas others want a minimum set of idle circuits hanging around. */ void circuit_build_needed_circs(time_t now) { const or_options_t *options = get_options(); /* launch a new circ for any pending streams that need one * XXXX make the assumption that (some) AP streams (i.e. HS clients) * don't require an exit circuit, review in #13814. * This allows HSs to function in a consensus without exits. */ if (router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN) connection_ap_rescan_and_attach_pending(); circuit_expire_old_circs_as_needed(now); if (!options->DisablePredictedCircuits) circuit_predict_and_launch_new(); } /** * Called once a second either directly or from * circuit_build_needed_circs(). As appropriate (once per NewCircuitPeriod) * resets failure counts and expires old circuits. */ void circuit_expire_old_circs_as_needed(time_t now) { static time_t time_to_expire_and_reset = 0; if (time_to_expire_and_reset < now) { circuit_reset_failure_count(1); time_to_expire_and_reset = now + get_options()->NewCircuitPeriod; if (proxy_mode(get_options())) addressmap_clean(now); circuit_expire_old_circuits_clientside(); #if 0 /* disable for now, until predict-and-launch-new can cull leftovers */ /* If we ever re-enable, this has to move into * circuit_build_needed_circs */ circ = circuit_get_youngest_clean_open(CIRCUIT_PURPOSE_C_GENERAL); if (get_options()->RunTesting && circ && circ->timestamp_began.tv_sec + TESTING_CIRCUIT_INTERVAL < now) { log_fn(LOG_INFO,"Creating a new testing circuit."); circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, 0); } #endif } } /** If the stream conn is a member of any of the linked * lists of circ, then remove it from the list. */ void circuit_detach_stream(circuit_t *circ, edge_connection_t *conn) { edge_connection_t *prevconn; tor_assert(circ); tor_assert(conn); if (conn->base_.type == CONN_TYPE_AP) { entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn); entry_conn->may_use_optimistic_data = 0; } conn->cpath_layer = NULL; /* don't keep a stale pointer */ conn->on_circuit = NULL; if (CIRCUIT_IS_ORIGIN(circ)) { origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ); int removed = 0; if (conn == origin_circ->p_streams) { origin_circ->p_streams = conn->next_stream; removed = 1; } else { for (prevconn = origin_circ->p_streams; prevconn && prevconn->next_stream && prevconn->next_stream != conn; prevconn = prevconn->next_stream) ; if (prevconn && prevconn->next_stream) { prevconn->next_stream = conn->next_stream; removed = 1; } } if (removed) { log_debug(LD_APP, "Removing stream %d from circ %u", conn->stream_id, (unsigned)circ->n_circ_id); /* If the stream was removed, and it was a rend stream, decrement the * number of streams on the circuit associated with the rend service. */ if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED) { tor_assert(origin_circ->rend_data); origin_circ->rend_data->nr_streams--; } return; } } else { or_circuit_t *or_circ = TO_OR_CIRCUIT(circ); if (conn == or_circ->n_streams) { or_circ->n_streams = conn->next_stream; return; } if (conn == or_circ->resolving_streams) { or_circ->resolving_streams = conn->next_stream; return; } for (prevconn = or_circ->n_streams; prevconn && prevconn->next_stream && prevconn->next_stream != conn; prevconn = prevconn->next_stream) ; if (prevconn && prevconn->next_stream) { prevconn->next_stream = conn->next_stream; return; } for (prevconn = or_circ->resolving_streams; prevconn && prevconn->next_stream && prevconn->next_stream != conn; prevconn = prevconn->next_stream) ; if (prevconn && prevconn->next_stream) { prevconn->next_stream = conn->next_stream; return; } } log_warn(LD_BUG,"Edge connection not in circuit's list."); /* Don't give an error here; it's harmless. */ tor_fragile_assert(); } /** Find each circuit that has been unused for too long, or dirty * for too long and has no streams on it: mark it for close. */ static void circuit_expire_old_circuits_clientside(void) { struct timeval cutoff, now; tor_gettimeofday(&now); last_expired_clientside_circuits = now.tv_sec; SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { if (circ->marked_for_close || !CIRCUIT_IS_ORIGIN(circ)) continue; cutoff = now; cutoff.tv_sec -= TO_ORIGIN_CIRCUIT(circ)->circuit_idle_timeout; /* If the circuit has been dirty for too long, and there are no streams * on it, mark it for close. */ if (circ->timestamp_dirty && circ->timestamp_dirty + get_options()->MaxCircuitDirtiness < now.tv_sec && !TO_ORIGIN_CIRCUIT(circ)->p_streams /* nothing attached */ ) { log_debug(LD_CIRC, "Closing n_circ_id %u (dirty %ld sec ago, " "purpose %d)", (unsigned)circ->n_circ_id, (long)(now.tv_sec - circ->timestamp_dirty), circ->purpose); /* Don't do this magic for testing circuits. Their death is governed * by circuit_expire_building */ if (circ->purpose != CIRCUIT_PURPOSE_PATH_BIAS_TESTING) circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED); } else if (!circ->timestamp_dirty && circ->state == CIRCUIT_STATE_OPEN) { if (timercmp(&circ->timestamp_began, &cutoff, OP_LT)) { if (circ->purpose == CIRCUIT_PURPOSE_C_GENERAL || circ->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT || circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO || circ->purpose == CIRCUIT_PURPOSE_TESTING || (circ->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING && circ->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) || circ->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) { log_info(LD_CIRC, "Closing circuit "U64_FORMAT " that has been unused for %ld msec.", U64_PRINTF_ARG(TO_ORIGIN_CIRCUIT(circ)->global_identifier), tv_mdiff(&circ->timestamp_began, &now)); circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED); } else if (!TO_ORIGIN_CIRCUIT(circ)->is_ancient) { /* Server-side rend joined circuits can end up really old, because * they are reused by clients for longer than normal. The client * controls their lifespan. (They never become dirty, because * connection_exit_begin_conn() never marks anything as dirty.) * Similarly, server-side intro circuits last a long time. */ if (circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED && circ->purpose != CIRCUIT_PURPOSE_S_INTRO) { log_notice(LD_CIRC, "Ancient non-dirty circuit %d is still around after " "%ld milliseconds. Purpose: %d (%s)", TO_ORIGIN_CIRCUIT(circ)->global_identifier, tv_mdiff(&circ->timestamp_began, &now), circ->purpose, circuit_purpose_to_string(circ->purpose)); TO_ORIGIN_CIRCUIT(circ)->is_ancient = 1; } } } } } SMARTLIST_FOREACH_END(circ); } /** How long do we wait before killing circuits with the properties * described below? * * Probably we could choose a number here as low as 5 to 10 seconds, * since these circs are used for begindir, and a) generally you either * ask another begindir question right after or you don't for a long time, * b) clients at least through 0.2.1.x choose from the whole set of * directory mirrors at each choice, and c) re-establishing a one-hop * circuit via create-fast is a light operation assuming the TLS conn is * still there. * * I expect "b" to go away one day when we move to using directory * guards, but I think "a" and "c" are good enough reasons that a low * number is safe even then. */ #define IDLE_ONE_HOP_CIRC_TIMEOUT 60 /** Find each non-origin circuit that has been unused for too long, * has no streams on it, used a create_fast, and ends here: mark it * for close. */ void circuit_expire_old_circuits_serverside(time_t now) { or_circuit_t *or_circ; time_t cutoff = now - IDLE_ONE_HOP_CIRC_TIMEOUT; SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { if (circ->marked_for_close || CIRCUIT_IS_ORIGIN(circ)) continue; or_circ = TO_OR_CIRCUIT(circ); /* If the circuit has been idle for too long, and there are no streams * on it, and it ends here, and it used a create_fast, mark it for close. */ if (or_circ->is_first_hop && !circ->n_chan && !or_circ->n_streams && !or_circ->resolving_streams && or_circ->p_chan && channel_when_last_xmit(or_circ->p_chan) <= cutoff) { log_info(LD_CIRC, "Closing circ_id %u (empty %d secs ago)", (unsigned)or_circ->p_circ_id, (int)(now - channel_when_last_xmit(or_circ->p_chan))); circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED); } } SMARTLIST_FOREACH_END(circ); } /** Number of testing circuits we want open before testing our bandwidth. */ #define NUM_PARALLEL_TESTING_CIRCS 4 /** True iff we've ever had enough testing circuits open to test our * bandwidth. */ static int have_performed_bandwidth_test = 0; /** Reset have_performed_bandwidth_test, so we'll start building * testing circuits again so we can exercise our bandwidth. */ void reset_bandwidth_test(void) { have_performed_bandwidth_test = 0; } /** Return 1 if we've already exercised our bandwidth, or if we * have fewer than NUM_PARALLEL_TESTING_CIRCS testing circuits * established or on the way. Else return 0. */ int circuit_enough_testing_circs(void) { int num = 0; if (have_performed_bandwidth_test) return 1; SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { if (!circ->marked_for_close && CIRCUIT_IS_ORIGIN(circ) && circ->purpose == CIRCUIT_PURPOSE_TESTING && circ->state == CIRCUIT_STATE_OPEN) num++; } SMARTLIST_FOREACH_END(circ); return num >= NUM_PARALLEL_TESTING_CIRCS; } /** A testing circuit has completed. Take whatever stats we want. * Noticing reachability is taken care of in onionskin_answer(), * so there's no need to record anything here. But if we still want * to do the bandwidth test, and we now have enough testing circuits * open, do it. */ static void circuit_testing_opened(origin_circuit_t *circ) { if (have_performed_bandwidth_test || !check_whether_orport_reachable(get_options())) { /* either we've already done everything we want with testing circuits, * or this testing circuit became open due to a fluke, e.g. we picked * a last hop where we already had the connection open due to an * outgoing local circuit. */ circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_AT_ORIGIN); } else if (circuit_enough_testing_circs()) { router_perform_bandwidth_test(NUM_PARALLEL_TESTING_CIRCS, time(NULL)); have_performed_bandwidth_test = 1; } else consider_testing_reachability(1, 0); } /** A testing circuit has failed to build. Take whatever stats we want. */ static void circuit_testing_failed(origin_circuit_t *circ, int at_last_hop) { const or_options_t *options = get_options(); if (server_mode(options) && check_whether_orport_reachable(options)) return; log_info(LD_GENERAL, "Our testing circuit (to see if your ORPort is reachable) " "has failed. I'll try again later."); /* These aren't used yet. */ (void)circ; (void)at_last_hop; } /** The circuit circ has just become open. Take the next * step: for rendezvous circuits, we pass circ to the appropriate * function in rendclient or rendservice. For general circuits, we * call connection_ap_attach_pending, which looks for pending streams * that could use circ. */ void circuit_has_opened(origin_circuit_t *circ) { control_event_circuit_status(circ, CIRC_EVENT_BUILT, 0); /* Remember that this circuit has finished building. Now if we start * it building again later (e.g. by extending it), we will know not * to consider its build time. */ circ->has_opened = 1; switch (TO_CIRCUIT(circ)->purpose) { case CIRCUIT_PURPOSE_C_ESTABLISH_REND: rend_client_rendcirc_has_opened(circ); /* Start building an intro circ if we don't have one yet. */ connection_ap_attach_pending(1); /* This isn't a call to circuit_try_attaching_streams because a * circuit in _C_ESTABLISH_REND state isn't connected to its * hidden service yet, thus we can't attach streams to it yet, * thus circuit_try_attaching_streams would always clear the * circuit's isolation state. circuit_try_attaching_streams is * called later, when the rend circ enters _C_REND_JOINED * state. */ break; case CIRCUIT_PURPOSE_C_INTRODUCING: rend_client_introcirc_has_opened(circ); break; case CIRCUIT_PURPOSE_C_GENERAL: /* Tell any AP connections that have been waiting for a new * circuit that one is ready. */ circuit_try_attaching_streams(circ); break; case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO: /* at the service, waiting for introductions */ hs_service_circuit_has_opened(circ); break; case CIRCUIT_PURPOSE_S_CONNECT_REND: /* at the service, connecting to rend point */ hs_service_circuit_has_opened(circ); break; case CIRCUIT_PURPOSE_TESTING: circuit_testing_opened(circ); break; /* default: * This won't happen in normal operation, but might happen if the * controller did it. Just let it slide. */ } } /** If the stream-isolation state of circ can be cleared, clear * it. Return non-zero iff circ's isolation state was cleared. */ static int circuit_try_clearing_isolation_state(origin_circuit_t *circ) { if (/* The circuit may have become non-open if it was cannibalized.*/ circ->base_.state == CIRCUIT_STATE_OPEN && /* If !isolation_values_set, there is nothing to clear. */ circ->isolation_values_set && /* It's not legal to clear a circuit's isolation info if it's ever had * streams attached */ !circ->isolation_any_streams_attached) { /* If we have any isolation information set on this circuit, and * we didn't manage to attach any streams to it, then we can * and should clear it and try again. */ circuit_clear_isolation(circ); return 1; } else { return 0; } } /** Called when a circuit becomes ready for streams to be attached to * it. */ void circuit_try_attaching_streams(origin_circuit_t *circ) { /* Attach streams to this circuit if we can. */ connection_ap_attach_pending(1); /* The call to circuit_try_clearing_isolation_state here will do * nothing and return 0 if we didn't attach any streams to circ * above. */ if (circuit_try_clearing_isolation_state(circ)) { /* Maybe *now* we can attach some streams to this circuit. */ connection_ap_attach_pending(1); } } /** Called whenever a circuit could not be successfully built. */ void circuit_build_failed(origin_circuit_t *circ) { channel_t *n_chan = NULL; /* we should examine circ and see if it failed because of * the last hop or an earlier hop. then use this info below. */ int failed_at_last_hop = 0; /* If the last hop isn't open, and the second-to-last is, we failed * at the last hop. */ if (circ->cpath && circ->cpath->prev->state != CPATH_STATE_OPEN && circ->cpath->prev->prev->state == CPATH_STATE_OPEN) { failed_at_last_hop = 1; } if (circ->cpath && circ->cpath->state != CPATH_STATE_OPEN && ! circ->base_.received_destroy) { /* We failed at the first hop for some reason other than a DESTROY cell. * If there's an OR connection to blame, blame it. Also, avoid this relay * for a while, and fail any one-hop directory fetches destined for it. */ const char *n_chan_id = circ->cpath->extend_info->identity_digest; int already_marked = 0; if (circ->base_.n_chan) { n_chan = circ->base_.n_chan; if (n_chan->is_bad_for_new_circs) { /* We only want to blame this router when a fresh healthy * connection fails. So don't mark this router as newly failed, * since maybe this was just an old circuit attempt that's * finally timing out now. Also, there's no need to blow away * circuits/streams/etc, since the failure of an unhealthy conn * doesn't tell us much about whether a healthy conn would * succeed. */ already_marked = 1; } log_info(LD_OR, "Our circuit failed to get a response from the first hop " "(%s). I'm going to try to rotate to a better connection.", channel_get_canonical_remote_descr(n_chan)); n_chan->is_bad_for_new_circs = 1; } else { log_info(LD_OR, "Our circuit died before the first hop with no connection"); } if (n_chan_id && !already_marked) { /* New guard API: we failed. */ if (circ->guard_state) entry_guard_failed(&circ->guard_state); /* if there are any one-hop streams waiting on this circuit, fail * them now so they can retry elsewhere. */ connection_ap_fail_onehop(n_chan_id, circ->build_state); } } switch (circ->base_.purpose) { case CIRCUIT_PURPOSE_C_GENERAL: /* If we never built the circuit, note it as a failure. */ circuit_increment_failure_count(); if (failed_at_last_hop) { /* Make sure any streams that demand our last hop as their exit * know that it's unlikely to happen. */ circuit_discard_optional_exit_enclaves(circ->cpath->prev->extend_info); } break; case CIRCUIT_PURPOSE_TESTING: circuit_testing_failed(circ, failed_at_last_hop); break; case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO: /* at the service, waiting for introductions */ if (circ->base_.state != CIRCUIT_STATE_OPEN) { circuit_increment_failure_count(); } /* no need to care here, because the service will rebuild intro * points periodically. */ break; case CIRCUIT_PURPOSE_C_INTRODUCING: /* at the client, connecting to intro point */ /* Don't increment failure count, since the service may have picked * the introduction point maliciously */ /* The client will pick a new intro point when this one dies, if * the stream in question still cares. No need to act here. */ break; case CIRCUIT_PURPOSE_C_ESTABLISH_REND: /* at the client, waiting for the service */ circuit_increment_failure_count(); /* the client will pick a new rend point when this one dies, if * the stream in question still cares. No need to act here. */ break; case CIRCUIT_PURPOSE_S_CONNECT_REND: /* at the service, connecting to rend point */ /* Don't increment failure count, since the client may have picked * the rendezvous point maliciously */ log_info(LD_REND, "Couldn't connect to the client's chosen rend point %s " "(%s hop failed).", escaped(build_state_get_exit_nickname(circ->build_state)), failed_at_last_hop?"last":"non-last"); rend_service_relaunch_rendezvous(circ); break; /* default: * This won't happen in normal operation, but might happen if the * controller did it. Just let it slide. */ } } /** Number of consecutive failures so far; should only be touched by * circuit_launch_new and circuit_*_failure_count. */ static int n_circuit_failures = 0; /** Before the last time we called circuit_reset_failure_count(), were * there a lot of failures? */ static int did_circs_fail_last_period = 0; /** Don't retry launching a new circuit if we try this many times with no * success. */ #define MAX_CIRCUIT_FAILURES 5 /** Launch a new circuit; see circuit_launch_by_extend_info() for * details on arguments. */ origin_circuit_t * circuit_launch(uint8_t purpose, int flags) { return circuit_launch_by_extend_info(purpose, NULL, flags); } /* Do we have enough descriptors to build paths? * If need_exit is true, return 1 if we can build exit paths. * (We need at least one Exit in the consensus to build exit paths.) * If need_exit is false, return 1 if we can build internal paths. */ static int have_enough_path_info(int need_exit) { if (need_exit) return router_have_consensus_path() == CONSENSUS_PATH_EXIT; else return router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN; } /** Launch a new circuit with purpose purpose and exit node * extend_info (or NULL to select a random exit node). If flags * contains CIRCLAUNCH_NEED_UPTIME, choose among routers with high uptime. If * CIRCLAUNCH_NEED_CAPACITY is set, choose among routers with high bandwidth. * If CIRCLAUNCH_IS_INTERNAL is true, the last hop need not be an exit node. * If CIRCLAUNCH_ONEHOP_TUNNEL is set, the circuit will have only one hop. * Return the newly allocated circuit on success, or NULL on failure. */ origin_circuit_t * circuit_launch_by_extend_info(uint8_t purpose, extend_info_t *extend_info, int flags) { origin_circuit_t *circ; int onehop_tunnel = (flags & CIRCLAUNCH_ONEHOP_TUNNEL) != 0; int have_path = have_enough_path_info(! (flags & CIRCLAUNCH_IS_INTERNAL) ); int need_specific_rp = 0; if (!onehop_tunnel && (!router_have_minimum_dir_info() || !have_path)) { log_debug(LD_CIRC,"Haven't %s yet; canceling " "circuit launch.", !router_have_minimum_dir_info() ? "fetched enough directory info" : "received a consensus with exits"); return NULL; } /* If Tor2webRendezvousPoints is enabled and we are dealing with an RP circuit, we want a specific RP node so we shouldn't canibalize an already existing circuit. */ if (get_options()->Tor2webRendezvousPoints && purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND) { need_specific_rp = 1; } if ((extend_info || purpose != CIRCUIT_PURPOSE_C_GENERAL) && purpose != CIRCUIT_PURPOSE_TESTING && !onehop_tunnel && !need_specific_rp) { /* see if there are appropriate circs available to cannibalize. */ /* XXX if we're planning to add a hop, perhaps we want to look for * internal circs rather than exit circs? -RD */ circ = circuit_find_to_cannibalize(purpose, extend_info, flags); if (circ) { uint8_t old_purpose = circ->base_.purpose; struct timeval old_timestamp_began = circ->base_.timestamp_began; log_info(LD_CIRC,"Cannibalizing circ '%s' for purpose %d (%s)", build_state_get_exit_nickname(circ->build_state), purpose, circuit_purpose_to_string(purpose)); if ((purpose == CIRCUIT_PURPOSE_S_CONNECT_REND || purpose == CIRCUIT_PURPOSE_C_INTRODUCING) && circ->path_state == PATH_STATE_BUILD_SUCCEEDED) { /* Path bias: Cannibalized rends pre-emptively count as a * successfully built but unused closed circuit. We don't * wait until the extend (or the close) because the rend * point could be malicious. * * Same deal goes for client side introductions. Clients * can be manipulated to connect repeatedly to them * (especially web clients). * * If we decide to probe the initial portion of these circs, * (up to the adversary's final hop), we need to remove this, * or somehow mark the circuit with a special path state. */ /* This must be called before the purpose change */ pathbias_check_close(circ, END_CIRC_REASON_FINISHED); } circuit_change_purpose(TO_CIRCUIT(circ), purpose); /* Reset the start date of this circ, else expire_building * will see it and think it's been trying to build since it * began. * * Technically, the code should reset this when the * create cell is finally sent, but we're close enough * here. */ tor_gettimeofday(&circ->base_.timestamp_began); control_event_circuit_cannibalized(circ, old_purpose, &old_timestamp_began); switch (purpose) { case CIRCUIT_PURPOSE_C_ESTABLISH_REND: /* it's ready right now */ break; case CIRCUIT_PURPOSE_C_INTRODUCING: case CIRCUIT_PURPOSE_S_CONNECT_REND: case CIRCUIT_PURPOSE_C_GENERAL: case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO: /* need to add a new hop */ tor_assert(extend_info); if (circuit_extend_to_new_exit(circ, extend_info) < 0) return NULL; break; default: log_warn(LD_BUG, "unexpected purpose %d when cannibalizing a circ.", purpose); tor_fragile_assert(); return NULL; } return circ; } } if (did_circs_fail_last_period && n_circuit_failures > MAX_CIRCUIT_FAILURES) { /* too many failed circs in a row. don't try. */ // log_fn(LOG_INFO,"%d failures so far, not trying.",n_circuit_failures); return NULL; } /* try a circ. if it fails, circuit_mark_for_close will increment * n_circuit_failures */ return circuit_establish_circuit(purpose, extend_info, flags); } /** Record another failure at opening a general circuit. When we have * too many, we'll stop trying for the remainder of this minute. */ static void circuit_increment_failure_count(void) { ++n_circuit_failures; log_debug(LD_CIRC,"n_circuit_failures now %d.",n_circuit_failures); } /** Reset the failure count for opening general circuits. This means * we will try MAX_CIRCUIT_FAILURES times more (if necessary) before * stopping again. */ void circuit_reset_failure_count(int timeout) { if (timeout && n_circuit_failures > MAX_CIRCUIT_FAILURES) did_circs_fail_last_period = 1; else did_circs_fail_last_period = 0; n_circuit_failures = 0; } /** Find an open circ that we're happy to use for conn and return 1. If * there isn't one, and there isn't one on the way, launch one and return * 0. If it will never work, return -1. * * Write the found or in-progress or launched circ into *circp. */ static int circuit_get_open_circ_or_launch(entry_connection_t *conn, uint8_t desired_circuit_purpose, origin_circuit_t **circp) { origin_circuit_t *circ; int check_exit_policy; int need_uptime, need_internal; int want_onehop; const or_options_t *options = get_options(); tor_assert(conn); tor_assert(circp); if (ENTRY_TO_CONN(conn)->state != AP_CONN_STATE_CIRCUIT_WAIT) { connection_t *c = ENTRY_TO_CONN(conn); log_err(LD_BUG, "Connection state mismatch: wanted " "AP_CONN_STATE_CIRCUIT_WAIT, but got %d (%s)", c->state, conn_state_to_string(c->type, c->state)); } tor_assert(ENTRY_TO_CONN(conn)->state == AP_CONN_STATE_CIRCUIT_WAIT); /* Will the exit policy of the exit node apply to this stream? */ check_exit_policy = conn->socks_request->command == SOCKS_COMMAND_CONNECT && !conn->use_begindir && !connection_edge_is_rendezvous_stream(ENTRY_TO_EDGE_CONN(conn)); /* Does this connection want a one-hop circuit? */ want_onehop = conn->want_onehop; /* Do we need a high-uptime circuit? */ need_uptime = !conn->want_onehop && !conn->use_begindir && smartlist_contains_int_as_string(options->LongLivedPorts, conn->socks_request->port); /* Do we need an "internal" circuit? */ if (desired_circuit_purpose != CIRCUIT_PURPOSE_C_GENERAL) need_internal = 1; else if (conn->use_begindir || conn->want_onehop) need_internal = 1; else need_internal = 0; /* We now know what kind of circuit we need. See if there is an * open circuit that we can use for this stream */ circ = circuit_get_best(conn, 1 /* Insist on open circuits */, desired_circuit_purpose, need_uptime, need_internal); if (circ) { /* We got a circuit that will work for this stream! We can return it. */ *circp = circ; return 1; /* we're happy */ } /* Okay, there's no circuit open that will work for this stream. Let's * see if there's an in-progress circuit or if we have to launch one */ /* Do we know enough directory info to build circuits at all? */ int have_path = have_enough_path_info(!need_internal); if (!want_onehop && (!router_have_minimum_dir_info() || !have_path)) { /* If we don't have enough directory information, we can't build * multihop circuits. */ if (!connection_get_by_type(CONN_TYPE_DIR)) { int severity = LOG_NOTICE; /* Retry some stuff that might help the connection work. */ if (entry_list_is_constrained(options) && guards_retry_optimistic(options)) { log_fn(severity, LD_APP|LD_DIR, "Application request when we haven't %s. " "Optimistically trying known %s again.", !router_have_minimum_dir_info() ? "used client functionality lately" : "received a consensus with exits", options->UseBridges ? "bridges" : "entrynodes"); } else if (!options->UseBridges || any_bridge_descriptors_known()) { log_fn(severity, LD_APP|LD_DIR, "Application request when we haven't %s. " "Optimistically trying directory fetches again.", !router_have_minimum_dir_info() ? "used client functionality lately" : "received a consensus with exits"); routerlist_retry_directory_downloads(time(NULL)); } } /* Since we didn't have enough directory info, we can't attach now. The * stream will be dealt with when router_have_minimum_dir_info becomes 1, * or when all directory attempts fail and directory_all_unreachable() * kills it. */ return 0; } /* Check whether the exit policy of the chosen exit, or the exit policies * of _all_ nodes, would forbid this node. */ if (check_exit_policy) { if (!conn->chosen_exit_name) { struct in_addr in; tor_addr_t addr, *addrp=NULL; if (tor_inet_aton(conn->socks_request->address, &in)) { tor_addr_from_in(&addr, &in); addrp = &addr; } if (router_exit_policy_all_nodes_reject(addrp, conn->socks_request->port, need_uptime)) { log_notice(LD_APP, "No Tor server allows exit to %s:%d. Rejecting.", safe_str_client(conn->socks_request->address), conn->socks_request->port); return -1; } } else { /* XXXX Duplicates checks in connection_ap_handshake_attach_circuit: * refactor into a single function. */ const node_t *node = node_get_by_nickname(conn->chosen_exit_name, 1); int opt = conn->chosen_exit_optional; if (node && !connection_ap_can_use_exit(conn, node)) { log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP, "Requested exit point '%s' is excluded or " "would refuse request. %s.", conn->chosen_exit_name, opt ? "Trying others" : "Closing"); if (opt) { conn->chosen_exit_optional = 0; tor_free(conn->chosen_exit_name); /* Try again. */ return circuit_get_open_circ_or_launch(conn, desired_circuit_purpose, circp); } return -1; } } } /* Now, check whether there already a circuit on the way that could handle * this stream. This check matches the one above, but this time we * do not require that the circuit will work. */ circ = circuit_get_best(conn, 0 /* don't insist on open circuits */, desired_circuit_purpose, need_uptime, need_internal); if (circ) log_debug(LD_CIRC, "one on the way!"); if (!circ) { /* No open or in-progress circuit could handle this stream! We * will have to launch one! */ /* The chosen exit node, if there is one. */ extend_info_t *extend_info=NULL; const int n_pending = count_pending_general_client_circuits(); /* Do we have too many pending circuits? */ if (n_pending >= options->MaxClientCircuitsPending) { static ratelim_t delay_limit = RATELIM_INIT(10*60); char *m; if ((m = rate_limit_log(&delay_limit, approx_time()))) { log_notice(LD_APP, "We'd like to launch a circuit to handle a " "connection, but we already have %d general-purpose client " "circuits pending. Waiting until some finish.%s", n_pending, m); tor_free(m); } return 0; } /* If this is a hidden service trying to start an introduction point, * handle that case. */ if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) { /* need to pick an intro point */ rend_data_t *rend_data = ENTRY_TO_EDGE_CONN(conn)->rend_data; tor_assert(rend_data); extend_info = rend_client_get_random_intro(rend_data); if (!extend_info) { log_info(LD_REND, "No intro points for '%s': re-fetching service descriptor.", safe_str_client(rend_data_get_address(rend_data))); rend_client_refetch_v2_renddesc(rend_data); connection_ap_mark_as_non_pending_circuit(conn); ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_RENDDESC_WAIT; return 0; } log_info(LD_REND,"Chose %s as intro point for '%s'.", extend_info_describe(extend_info), safe_str_client(rend_data_get_address(rend_data))); } /* If we have specified a particular exit node for our * connection, then be sure to open a circuit to that exit node. */ if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL) { if (conn->chosen_exit_name) { const node_t *r; int opt = conn->chosen_exit_optional; r = node_get_by_nickname(conn->chosen_exit_name, 1); if (r && node_has_descriptor(r)) { /* We might want to connect to an IPv6 bridge for loading descriptors so we use the preferred address rather than the primary. */ extend_info = extend_info_from_node(r, conn->want_onehop ? 1 : 0); if (!extend_info) { log_warn(LD_CIRC,"Could not make a one-hop connection to %s. " "Discarding this circuit.", conn->chosen_exit_name); return -1; } } else { /* ! (r && node_has_descriptor(r)) */ log_debug(LD_DIR, "considering %d, %s", want_onehop, conn->chosen_exit_name); if (want_onehop && conn->chosen_exit_name[0] == '$') { /* We're asking for a one-hop circuit to a router that * we don't have a routerinfo about. Make up an extend_info. */ /* XXX prop220: we need to make chosen_exit_name able to * encode both key formats. This is not absolutely critical * since this is just for one-hop circuits, but we should * still get it done */ char digest[DIGEST_LEN]; char *hexdigest = conn->chosen_exit_name+1; tor_addr_t addr; if (strlen(hexdigest) < HEX_DIGEST_LEN || base16_decode(digest,DIGEST_LEN, hexdigest,HEX_DIGEST_LEN) != DIGEST_LEN) { log_info(LD_DIR, "Broken exit digest on tunnel conn. Closing."); return -1; } if (tor_addr_parse(&addr, conn->socks_request->address) < 0) { log_info(LD_DIR, "Broken address %s on tunnel conn. Closing.", escaped_safe_str_client(conn->socks_request->address)); return -1; } /* XXXX prop220 add a workaround for ed25519 ID below*/ extend_info = extend_info_new(conn->chosen_exit_name+1, digest, NULL, /* Ed25519 ID */ NULL, NULL, /* onion keys */ &addr, conn->socks_request->port); } else { /* ! (want_onehop && conn->chosen_exit_name[0] == '$') */ /* We will need an onion key for the router, and we * don't have one. Refuse or relax requirements. */ log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP, "Requested exit point '%s' is not known. %s.", conn->chosen_exit_name, opt ? "Trying others" : "Closing"); if (opt) { conn->chosen_exit_optional = 0; tor_free(conn->chosen_exit_name); /* Try again with no requested exit */ return circuit_get_open_circ_or_launch(conn, desired_circuit_purpose, circp); } return -1; } } } } /* Done checking for general circutis with chosen exits. */ /* What purpose do we need to launch this circuit with? */ uint8_t new_circ_purpose; if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_REND_JOINED) new_circ_purpose = CIRCUIT_PURPOSE_C_ESTABLISH_REND; else if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) new_circ_purpose = CIRCUIT_PURPOSE_C_INTRODUCING; else new_circ_purpose = desired_circuit_purpose; #ifdef ENABLE_TOR2WEB_MODE /* If tor2Web is on, then hidden service requests should be one-hop. */ if (options->Tor2webMode && (new_circ_purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND || new_circ_purpose == CIRCUIT_PURPOSE_C_INTRODUCING)) { want_onehop = 1; } #endif /* Determine what kind of a circuit to launch, and actually launch it. */ { int flags = CIRCLAUNCH_NEED_CAPACITY; if (want_onehop) flags |= CIRCLAUNCH_ONEHOP_TUNNEL; if (need_uptime) flags |= CIRCLAUNCH_NEED_UPTIME; if (need_internal) flags |= CIRCLAUNCH_IS_INTERNAL; circ = circuit_launch_by_extend_info(new_circ_purpose, extend_info, flags); } extend_info_free(extend_info); /* Now trigger things that need to happen when we launch circuits */ if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL) { /* We just caused a circuit to get built because of this stream. * If this stream has caused a _lot_ of circuits to be built, that's * a bad sign: we should tell the user. */ if (conn->num_circuits_launched < NUM_CIRCUITS_LAUNCHED_THRESHOLD && ++conn->num_circuits_launched == NUM_CIRCUITS_LAUNCHED_THRESHOLD) log_info(LD_CIRC, "The application request to %s:%d has launched " "%d circuits without finding one it likes.", escaped_safe_str_client(conn->socks_request->address), conn->socks_request->port, conn->num_circuits_launched); } else { /* help predict this next time */ rep_hist_note_used_internal(time(NULL), need_uptime, 1); if (circ) { /* write the service_id into circ */ circ->rend_data = rend_data_dup(ENTRY_TO_EDGE_CONN(conn)->rend_data); if (circ->base_.purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND && circ->base_.state == CIRCUIT_STATE_OPEN) circuit_has_opened(circ); } } } /* endif (!circ) */ /* We either found a good circuit, or launched a new circuit, or failed to * do so. Report success, and delay. */ if (circ) { /* Mark the circuit with the isolation fields for this connection. * When the circuit arrives, we'll clear these flags: this is * just some internal bookkeeping to make sure that we have * launched enough circuits. */ connection_edge_update_circuit_isolation(conn, circ, 0); } else { log_info(LD_APP, "No safe circuit (purpose %d) ready for edge " "connection; delaying.", desired_circuit_purpose); } *circp = circ; return 0; } /** Return true iff crypt_path is one of the crypt_paths for * circ. */ static int cpath_is_on_circuit(origin_circuit_t *circ, crypt_path_t *crypt_path) { crypt_path_t *cpath, *cpath_next = NULL; for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) { cpath_next = cpath->next; if (crypt_path == cpath) return 1; } return 0; } /** Return true iff client-side optimistic data is supported. */ static int optimistic_data_enabled(void) { const or_options_t *options = get_options(); if (options->OptimisticData < 0) { /* Note: this default was 0 before #18815 was merged. We can't take the * parameter out of the consensus until versions before that are all * obsolete. */ const int32_t enabled = networkstatus_get_param(NULL, "UseOptimisticData", /*default*/ 1, 0, 1); return (int)enabled; } return options->OptimisticData; } /** Attach the AP stream apconn to circ's linked list of * p_streams. Also set apconn's cpath_layer to cpath, or to the last * hop in circ's cpath if cpath is NULL. */ static void link_apconn_to_circ(entry_connection_t *apconn, origin_circuit_t *circ, crypt_path_t *cpath) { const node_t *exitnode = NULL; /* add it into the linked list of streams on this circuit */ log_debug(LD_APP|LD_CIRC, "attaching new conn to circ. n_circ_id %u.", (unsigned)circ->base_.n_circ_id); /* reset it, so we can measure circ timeouts */ ENTRY_TO_CONN(apconn)->timestamp_lastread = time(NULL); ENTRY_TO_EDGE_CONN(apconn)->next_stream = circ->p_streams; ENTRY_TO_EDGE_CONN(apconn)->on_circuit = TO_CIRCUIT(circ); /* assert_connection_ok(conn, time(NULL)); */ circ->p_streams = ENTRY_TO_EDGE_CONN(apconn); if (connection_edge_is_rendezvous_stream(ENTRY_TO_EDGE_CONN(apconn))) { /* We are attaching a stream to a rendezvous circuit. That means * that an attempt to connect to a hidden service just * succeeded. Tell rendclient.c. */ hs_client_note_connection_attempt_succeeded(ENTRY_TO_EDGE_CONN(apconn)); } if (cpath) { /* we were given one; use it */ tor_assert(cpath_is_on_circuit(circ, cpath)); } else { /* use the last hop in the circuit */ tor_assert(circ->cpath); tor_assert(circ->cpath->prev); tor_assert(circ->cpath->prev->state == CPATH_STATE_OPEN); cpath = circ->cpath->prev; } ENTRY_TO_EDGE_CONN(apconn)->cpath_layer = cpath; circ->isolation_any_streams_attached = 1; connection_edge_update_circuit_isolation(apconn, circ, 0); /* Compute the exitnode if possible, for logging below */ if (cpath->extend_info) exitnode = node_get_by_id(cpath->extend_info->identity_digest); /* See if we can use optimistic data on this circuit */ if (optimistic_data_enabled() && (circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL || circ->base_.purpose == CIRCUIT_PURPOSE_C_REND_JOINED)) apconn->may_use_optimistic_data = 1; else apconn->may_use_optimistic_data = 0; log_info(LD_APP, "Looks like completed circuit to %s %s allow " "optimistic data for connection to %s", circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL ? /* node_describe() does the right thing if exitnode is NULL */ safe_str_client(node_describe(exitnode)) : "hidden service", apconn->may_use_optimistic_data ? "does" : "doesn't", safe_str_client(apconn->socks_request->address)); } /** Return true iff address is matched by one of the entries in * TrackHostExits. */ int hostname_in_track_host_exits(const or_options_t *options, const char *address) { if (!options->TrackHostExits) return 0; SMARTLIST_FOREACH_BEGIN(options->TrackHostExits, const char *, cp) { if (cp[0] == '.') { /* match end */ if (cp[1] == '\0' || !strcasecmpend(address, cp) || !strcasecmp(address, &cp[1])) return 1; } else if (strcasecmp(cp, address) == 0) { return 1; } } SMARTLIST_FOREACH_END(cp); return 0; } /** If an exit wasn't explicitly specified for conn, consider saving * the exit that we *did* choose for use by future connections to * conn's destination. */ static void consider_recording_trackhost(const entry_connection_t *conn, const origin_circuit_t *circ) { const or_options_t *options = get_options(); char *new_address = NULL; char fp[HEX_DIGEST_LEN+1]; /* Search the addressmap for this conn's destination. */ /* If they're not in the address map.. */ if (!options->TrackHostExits || addressmap_have_mapping(conn->socks_request->address, options->TrackHostExitsExpire)) return; /* nothing to track, or already mapped */ if (!hostname_in_track_host_exits(options, conn->socks_request->address) || !circ->build_state->chosen_exit) return; /* write down the fingerprint of the chosen exit, not the nickname, * because the chosen exit might not be named. */ base16_encode(fp, sizeof(fp), circ->build_state->chosen_exit->identity_digest, DIGEST_LEN); /* Add this exit/hostname pair to the addressmap. */ tor_asprintf(&new_address, "%s.%s.exit", conn->socks_request->address, fp); addressmap_register(conn->socks_request->address, new_address, time(NULL) + options->TrackHostExitsExpire, ADDRMAPSRC_TRACKEXIT, 0, 0); } /** Attempt to attach the connection conn to circ, and send a * begin or resolve cell as appropriate. Return values are as for * connection_ap_handshake_attach_circuit. The stream will exit from the hop * indicated by cpath, or from the last hop in circ's cpath if * cpath is NULL. */ int connection_ap_handshake_attach_chosen_circuit(entry_connection_t *conn, origin_circuit_t *circ, crypt_path_t *cpath) { connection_t *base_conn = ENTRY_TO_CONN(conn); tor_assert(conn); tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT || base_conn->state == AP_CONN_STATE_CONTROLLER_WAIT); tor_assert(conn->socks_request); tor_assert(circ); tor_assert(circ->base_.state == CIRCUIT_STATE_OPEN); base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT; if (!circ->base_.timestamp_dirty || ((conn->entry_cfg.isolation_flags & ISO_SOCKSAUTH) && (conn->entry_cfg.socks_iso_keep_alive) && (conn->socks_request->usernamelen || conn->socks_request->passwordlen))) { /* When stream isolation is in use and controlled by an application * we are willing to keep using the stream. */ circ->base_.timestamp_dirty = approx_time(); } pathbias_count_use_attempt(circ); /* Now, actually link the connection. */ link_apconn_to_circ(conn, circ, cpath); tor_assert(conn->socks_request); if (conn->socks_request->command == SOCKS_COMMAND_CONNECT) { if (!conn->use_begindir) consider_recording_trackhost(conn, circ); if (connection_ap_handshake_send_begin(conn) < 0) return -1; } else { if (connection_ap_handshake_send_resolve(conn) < 0) return -1; } return 1; } /** Try to find a safe live circuit for stream conn. If we find one, * attach the stream, send appropriate cells, and return 1. Otherwise, * try to launch new circuit(s) for the stream. If we can launch * circuits, return 0. Otherwise, if we simply can't proceed with * this stream, return -1. (conn needs to die, and is maybe already marked). */ /* XXXX this function should mark for close whenever it returns -1; * its callers shouldn't have to worry about that. */ int connection_ap_handshake_attach_circuit(entry_connection_t *conn) { connection_t *base_conn = ENTRY_TO_CONN(conn); int retval; int conn_age; int want_onehop; tor_assert(conn); tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT); tor_assert(conn->socks_request); want_onehop = conn->want_onehop; conn_age = (int)(time(NULL) - base_conn->timestamp_created); /* Is this connection so old that we should give up on it? */ if (conn_age >= get_options()->SocksTimeout) { int severity = (tor_addr_is_null(&base_conn->addr) && !base_conn->port) ? LOG_INFO : LOG_NOTICE; log_fn(severity, LD_APP, "Tried for %d seconds to get a connection to %s:%d. Giving up.", conn_age, safe_str_client(conn->socks_request->address), conn->socks_request->port); return -1; } /* We handle "general" (non-onion) connections much more straightforwardly. */ if (!connection_edge_is_rendezvous_stream(ENTRY_TO_EDGE_CONN(conn))) { /* we're a general conn */ origin_circuit_t *circ=NULL; /* Are we linked to a dir conn that aims to fetch a consensus? * We check here because the conn might no longer be needed. */ if (base_conn->linked_conn && base_conn->linked_conn->type == CONN_TYPE_DIR && base_conn->linked_conn->purpose == DIR_PURPOSE_FETCH_CONSENSUS) { /* Yes we are. Is there a consensus fetch farther along than us? */ if (networkstatus_consensus_is_already_downloading( TO_DIR_CONN(base_conn->linked_conn)->requested_resource)) { /* We're doing the "multiple consensus fetch attempts" game from * proposal 210, and we're late to the party. Just close this conn. * The circuit and TLS conn that we made will time out after a while * if nothing else wants to use them. */ log_info(LD_DIR, "Closing extra consensus fetch (to %s) since one " "is already downloading.", base_conn->linked_conn->address); return -1; } } /* If we have a chosen exit, we need to use a circuit that's * open to that exit. See what exit we meant, and whether we can use it. */ if (conn->chosen_exit_name) { const node_t *node = node_get_by_nickname(conn->chosen_exit_name, 1); int opt = conn->chosen_exit_optional; if (!node && !want_onehop) { /* We ran into this warning when trying to extend a circuit to a * hidden service directory for which we didn't have a router * descriptor. See flyspray task 767 for more details. We should * keep this in mind when deciding to use BEGIN_DIR cells for other * directory requests as well. -KL*/ log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP, "Requested exit point '%s' is not known. %s.", conn->chosen_exit_name, opt ? "Trying others" : "Closing"); if (opt) { /* If we are allowed to ignore the .exit request, do so */ conn->chosen_exit_optional = 0; tor_free(conn->chosen_exit_name); return 0; } return -1; } if (node && !connection_ap_can_use_exit(conn, node)) { log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP, "Requested exit point '%s' is excluded or " "would refuse request. %s.", conn->chosen_exit_name, opt ? "Trying others" : "Closing"); if (opt) { /* If we are allowed to ignore the .exit request, do so */ conn->chosen_exit_optional = 0; tor_free(conn->chosen_exit_name); return 0; } return -1; } } /* Find the circuit that we should use, if there is one. Otherwise * launch it. */ retval = circuit_get_open_circ_or_launch( conn, CIRCUIT_PURPOSE_C_GENERAL, &circ); if (retval < 1) { /* We were either told "-1" (complete failure) or 0 (circuit in * progress); we can't attach this stream yet. */ return retval; } log_debug(LD_APP|LD_CIRC, "Attaching apconn to circ %u (stream %d sec old).", (unsigned)circ->base_.n_circ_id, conn_age); /* print the circ's path, so clients can figure out which circs are * sucking. */ circuit_log_path(LOG_INFO,LD_APP|LD_CIRC,circ); /* We have found a suitable circuit for our conn. Hurray. Do * the attachment. */ return connection_ap_handshake_attach_chosen_circuit(conn, circ, NULL); } else { /* we're a rendezvous conn */ origin_circuit_t *rendcirc=NULL, *introcirc=NULL; tor_assert(!ENTRY_TO_EDGE_CONN(conn)->cpath_layer); /* start by finding a rendezvous circuit for us */ retval = circuit_get_open_circ_or_launch( conn, CIRCUIT_PURPOSE_C_REND_JOINED, &rendcirc); if (retval < 0) return -1; /* failed */ if (retval > 0) { tor_assert(rendcirc); /* one is already established, attach */ log_info(LD_REND, "rend joined circ %u already here. attaching. " "(stream %d sec old)", (unsigned)rendcirc->base_.n_circ_id, conn_age); /* Mark rendezvous circuits as 'newly dirty' every time you use * them, since the process of rebuilding a rendezvous circ is so * expensive. There is a tradeoff between linkability and * feasibility, at this point. */ rendcirc->base_.timestamp_dirty = time(NULL); /* We've also attempted to use them. If they fail, we need to * probe them for path bias */ pathbias_count_use_attempt(rendcirc); link_apconn_to_circ(conn, rendcirc, NULL); if (connection_ap_handshake_send_begin(conn) < 0) return 0; /* already marked, let them fade away */ return 1; } /* At this point we need to re-check the state, since it's possible that * our call to circuit_get_open_circ_or_launch() changed the connection's * state from "CIRCUIT_WAIT" to "RENDDESC_WAIT" because we decided to * re-fetch the descriptor. */ if (ENTRY_TO_CONN(conn)->state != AP_CONN_STATE_CIRCUIT_WAIT) { log_info(LD_REND, "This connection is no longer ready to attach; its " "state changed." "(We probably have to re-fetch its descriptor.)"); return 0; } if (rendcirc && (rendcirc->base_.purpose == CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED)) { log_info(LD_REND, "pending-join circ %u already here, with intro ack. " "Stalling. (stream %d sec old)", (unsigned)rendcirc->base_.n_circ_id, conn_age); return 0; } /* it's on its way. find an intro circ. */ retval = circuit_get_open_circ_or_launch( conn, CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT, &introcirc); if (retval < 0) return -1; /* failed */ if (retval > 0) { /* one has already sent the intro. keep waiting. */ tor_assert(introcirc); log_info(LD_REND, "Intro circ %u present and awaiting ack (rend %u). " "Stalling. (stream %d sec old)", (unsigned)introcirc->base_.n_circ_id, rendcirc ? (unsigned)rendcirc->base_.n_circ_id : 0, conn_age); return 0; } /* now rendcirc and introcirc are each either undefined or not finished */ if (rendcirc && introcirc && rendcirc->base_.purpose == CIRCUIT_PURPOSE_C_REND_READY) { log_info(LD_REND, "ready rend circ %u already here (no intro-ack yet on " "intro %u). (stream %d sec old)", (unsigned)rendcirc->base_.n_circ_id, (unsigned)introcirc->base_.n_circ_id, conn_age); tor_assert(introcirc->base_.purpose == CIRCUIT_PURPOSE_C_INTRODUCING); if (introcirc->base_.state == CIRCUIT_STATE_OPEN) { log_info(LD_REND,"found open intro circ %u (rend %u); sending " "introduction. (stream %d sec old)", (unsigned)introcirc->base_.n_circ_id, (unsigned)rendcirc->base_.n_circ_id, conn_age); switch (rend_client_send_introduction(introcirc, rendcirc)) { case 0: /* success */ rendcirc->base_.timestamp_dirty = time(NULL); introcirc->base_.timestamp_dirty = time(NULL); pathbias_count_use_attempt(introcirc); pathbias_count_use_attempt(rendcirc); assert_circuit_ok(TO_CIRCUIT(rendcirc)); assert_circuit_ok(TO_CIRCUIT(introcirc)); return 0; case -1: /* transient error */ return 0; case -2: /* permanent error */ return -1; default: /* oops */ tor_fragile_assert(); return -1; } } } log_info(LD_REND, "Intro (%u) and rend (%u) circs are not both ready. " "Stalling conn. (%d sec old)", introcirc ? (unsigned)introcirc->base_.n_circ_id : 0, rendcirc ? (unsigned)rendcirc->base_.n_circ_id : 0, conn_age); return 0; } } /** Change circ's purpose to new_purpose. */ void circuit_change_purpose(circuit_t *circ, uint8_t new_purpose) { uint8_t old_purpose; /* Don't allow an OR circ to become an origin circ or vice versa. */ tor_assert(!!(CIRCUIT_IS_ORIGIN(circ)) == !!(CIRCUIT_PURPOSE_IS_ORIGIN(new_purpose))); if (circ->purpose == new_purpose) return; if (CIRCUIT_IS_ORIGIN(circ)) { char old_purpose_desc[80] = ""; strncpy(old_purpose_desc, circuit_purpose_to_string(circ->purpose), 80-1); old_purpose_desc[80-1] = '\0'; log_debug(LD_CIRC, "changing purpose of origin circ %d " "from \"%s\" (%d) to \"%s\" (%d)", TO_ORIGIN_CIRCUIT(circ)->global_identifier, old_purpose_desc, circ->purpose, circuit_purpose_to_string(new_purpose), new_purpose); } old_purpose = circ->purpose; circ->purpose = new_purpose; if (CIRCUIT_IS_ORIGIN(circ)) { control_event_circuit_purpose_changed(TO_ORIGIN_CIRCUIT(circ), old_purpose); } } /** Mark circ so that no more connections can be attached to it. */ void mark_circuit_unusable_for_new_conns(origin_circuit_t *circ) { const or_options_t *options = get_options(); tor_assert(circ); /* XXXX This is a kludge; we're only keeping it around in case there's * something that doesn't check unusable_for_new_conns, and to avoid * deeper refactoring of our expiration logic. */ if (! circ->base_.timestamp_dirty) circ->base_.timestamp_dirty = approx_time(); if (options->MaxCircuitDirtiness >= circ->base_.timestamp_dirty) circ->base_.timestamp_dirty = 1; /* prevent underflow */ else circ->base_.timestamp_dirty -= options->MaxCircuitDirtiness; circ->unusable_for_new_conns = 1; }