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- /* Copyright (c) 2001 Matej Pfajfar.
- * Copyright (c) 2001-2004, Roger Dingledine.
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2016, 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 "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);
- /** Return 1 if <b>circ</b> 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 */
- const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
- 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;
- }
- }
- 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 <b>a</b> is better than circuit <b>b</b> for
- * <b>conn</b>, 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 <b>options</b>, the
- * circuit <b>circ</b> 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', and the user has not told us to
- * close such circs immediately on timeout, flag it as 'timed out'
- * 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 (!(options->CloseHSClientCircuitsImmediatelyOnTimeout) &&
- !(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 (!(options->CloseHSServiceRendCircuitsImmediatelyOnTimeout) &&
- !(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 <b>age</b>
- * 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 <b>needed_ports</b> 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 <b>min</b> general-purpose non-internal circuits
- * will have an acceptable exit node for exit stream <b>conn</b> 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
- /** Figure out 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;
- /* First, count how many of each type of circuit we have already. */
- SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
- cpath_build_state_t *build_state;
- origin_circuit_t *origin_circ;
- if (!CIRCUIT_IS_ORIGIN(circ))
- continue;
- if (circ->marked_for_close)
- continue; /* don't mess with marked circs */
- if (circ->timestamp_dirty)
- continue; /* only count clean circs */
- if (circ->purpose != CIRCUIT_PURPOSE_C_GENERAL)
- continue; /* only pay attention to general-purpose circs */
- origin_circ = TO_ORIGIN_CIRCUIT(circ);
- if (origin_circ->unusable_for_new_conns)
- continue;
- build_state = origin_circ->build_state;
- if (build_state->onehop_tunnel)
- continue;
- num++;
- 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; /* we already have many, making more probably will hurt */
- /* Second, see if we need any 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.
- * Exits (obviously) require an exit circuit. */
- if (!circuit_all_predicted_ports_handled(now, &port_needs_uptime,
- &port_needs_capacity)
- && router_have_consensus_path() == CONSENSUS_PATH_EXIT) {
- 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;
- }
- /* Third, see if we need any more hidden service (server) circuits.
- * HS servers only need an internal circuit. */
- if (num_rend_services() && num_uptime_internal < 3
- && router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN) {
- 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;
- }
- /* Fourth, see if we need any more hidden service (client) circuits.
- * HS clients only need an internal circuit. */
- if (rep_hist_get_predicted_internal(now, &hidserv_needs_uptime,
- &hidserv_needs_capacity) &&
- ((num_uptime_internal<2 && hidserv_needs_uptime) ||
- num_internal<3)
- && router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN) {
- 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;
- }
- /* Finally, check to see if we still need more circuits to learn
- * a good build timeout. But if we're close to our max number we
- * want, don't do another -- we want to leave a few slots open so
- * we can still build circuits preemptively as needed.
- * XXXX make the assumption that build timeout streams should be
- * created whenever we can build internal circuits. */
- if (router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN) {
- if (num < MAX_UNUSED_OPEN_CIRCUITS-2 &&
- ! circuit_build_times_disabled() &&
- circuit_build_times_needs_circuits_now(get_circuit_build_times())) {
- 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_min_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();
- /* make sure any hidden services have enough intro points
- * HS intro point streams only require an internal circuit */
- if (router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN)
- rend_consider_services_intro_points();
- 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 <b>conn</b> is a member of any of the linked
- * lists of <b>circ</b>, 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();
- }
- /** If we haven't yet decided on a good timeout value for circuit
- * building, we close idles circuits aggressively so we can get more
- * data points. */
- #define IDLE_TIMEOUT_WHILE_LEARNING (10*60)
- /** 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);
- cutoff = now;
- last_expired_clientside_circuits = now.tv_sec;
- if (! circuit_build_times_disabled() &&
- circuit_build_times_needs_circuits(get_circuit_build_times())) {
- /* Circuits should be shorter lived if we need more of them
- * for learning a good build timeout */
- cutoff.tv_sec -= IDLE_TIMEOUT_WHILE_LEARNING;
- } else {
- cutoff.tv_sec -= get_options()->CircuitIdleTimeout;
- }
- SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) {
- if (circ->marked_for_close || !CIRCUIT_IS_ORIGIN(circ))
- continue;
- /* 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_debug(LD_CIRC,
- "Closing circuit that has been unused for %ld msec.",
- 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 <b>circ</b> 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 */
- rend_service_intro_has_opened(circ);
- break;
- case CIRCUIT_PURPOSE_S_CONNECT_REND:
- /* at the service, connecting to rend point */
- rend_service_rendezvous_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 <b>circ</b> can be cleared, clear
- * it. Return non-zero iff <b>circ</b>'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);
- #ifdef ENABLE_LEGACY_GUARD_ALGORITHM
- /* Old guard API: we failed. */
- entry_guard_register_connect_status(n_chan_id, 0, 1, time(NULL));
- #endif
- /* 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 <b>purpose</b> and exit node
- * <b>extend_info</b> (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 <b>conn</b> 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] == '$') {
- /* We're asking for a one-hop circuit to a router that
- * we don't have a routerinfo about. Make up an extend_info. */
- char digest[DIGEST_LEN];
- char *hexdigest = conn->chosen_exit_name+1;
- tor_addr_t addr;
- if (strlen(hexdigest) < HEX_DIGEST_LEN ||
- base16_decode(digest,DIGEST_LEN,
- hexdigest,HEX_DIGEST_LEN) != DIGEST_LEN) {
- log_info(LD_DIR, "Broken exit digest on tunnel conn. Closing.");
- return -1;
- }
- if (tor_addr_parse(&addr, conn->socks_request->address) < 0) {
- log_info(LD_DIR, "Broken address %s on tunnel conn. Closing.",
- escaped_safe_str_client(conn->socks_request->address));
- return -1;
- }
- extend_info = extend_info_new(conn->chosen_exit_name+1,
- digest, NULL, NULL, &addr,
- conn->socks_request->port);
- } else { /* ! (want_onehop && conn->chosen_exit_name[0] == '$') */
- /* 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 <b>crypt_path</b> is one of the crypt_paths for
- * <b>circ</b>. */
- 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 <b>apconn</b> to circ's linked list of
- * p_streams. Also set apconn's cpath_layer to <b>cpath</b>, or to the last
- * hop in circ's cpath if <b>cpath</b> 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. */
- rend_client_note_connection_attempt_ended(
- ENTRY_TO_EDGE_CONN(apconn)->rend_data);
- }
- 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 <b>address</b> 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 <b>conn</b>, consider saving
- * the exit that we *did* choose for use by future connections to
- * <b>conn</b>'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 <b>conn</b> to <b>circ</b>, 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 <b>cpath</b>, or from the last hop in circ's cpath if
- * <b>cpath</b> 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 <b>conn</b>. 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 people 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 <b>circ</b>'s purpose to <b>new_purpose</b>. */
- 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 <b>circ</b> 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;
- }
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