commit 94523bffdc3c06a9645d8e1d81fd9e3b6b3a0551 Merge: feb7253df a3bc950e4 Author: Nick Mathewson nickm@torproject.org Date: Fri Mar 15 08:52:50 2019 -0400

Merge remote-tracking branch 'tor-github/pr/791' into maint-0.4.0

changes/bug29665 | 7 +++++++ src/core/or/circuituse.c | 4 ++++ 2 files changed, 11 insertions(+)

diff --cc src/core/or/circuituse.c index 2fdf6f7e8,000000000..fd782c0cd mode 100644,000000..100644 --- a/src/core/or/circuituse.c +++ b/src/core/or/circuituse.c @@@ -1,3146 -1,0 +1,3150 @@@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, 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 "core/or/or.h" +#include "app/config/config.h" +#include "core/mainloop/connection.h" +#include "core/or/channel.h" +#include "core/or/circuitbuild.h" +#include "core/or/circuitlist.h" +#include "core/or/circuitstats.h" +#include "core/or/circuituse.h" +#include "core/or/circuitpadding.h" +#include "core/or/connection_edge.h" +#include "core/or/policies.h" +#include "feature/client/addressmap.h" +#include "feature/client/bridges.h" +#include "feature/client/circpathbias.h" +#include "feature/client/entrynodes.h" +#include "feature/control/control.h" +#include "feature/dircommon/directory.h" +#include "feature/hs/hs_circuit.h" +#include "feature/hs/hs_client.h" +#include "feature/hs/hs_common.h" +#include "feature/hs/hs_ident.h" +#include "feature/hs/hs_stats.h" +#include "feature/nodelist/describe.h" +#include "feature/nodelist/networkstatus.h" +#include "feature/nodelist/nodelist.h" +#include "feature/nodelist/routerlist.h" +#include "feature/relay/routermode.h" +#include "feature/relay/selftest.h" +#include "feature/rend/rendclient.h" +#include "feature/rend/rendcommon.h" +#include "feature/rend/rendservice.h" +#include "feature/stats/predict_ports.h" +#include "lib/math/fp.h" +#include "lib/time/tvdiff.h" + +#include "core/or/cpath_build_state_st.h" +#include "feature/dircommon/dir_connection_st.h" +#include "core/or/entry_connection_st.h" +#include "core/or/extend_info_st.h" +#include "core/or/or_circuit_st.h" +#include "core/or/origin_circuit_st.h" +#include "core/or/socks_request_st.h" + +static void circuit_expire_old_circuits_clientside(void); +static void circuit_increment_failure_count(void); + +/** Check whether the hidden service destination of the stream at + * <b>edge_conn</b> is the same as the destination of the circuit at + * <b>origin_circ</b>. */ +static int +circuit_matches_with_rend_stream(const edge_connection_t *edge_conn, + const origin_circuit_t *origin_circ) +{ + /* Check if this is a v2 rendezvous circ/stream */ + if ((edge_conn->rend_data && !origin_circ->rend_data) || + (!edge_conn->rend_data && origin_circ->rend_data) || + (edge_conn->rend_data && origin_circ->rend_data && + rend_cmp_service_ids(rend_data_get_address(edge_conn->rend_data), + rend_data_get_address(origin_circ->rend_data)))) { + /* this circ is not for this conn */ + return 0; + } + + /* Check if this is a v3 rendezvous circ/stream */ + if ((edge_conn->hs_ident && !origin_circ->hs_ident) || + (!edge_conn->hs_ident && origin_circ->hs_ident) || + (edge_conn->hs_ident && origin_circ->hs_ident && + !ed25519_pubkey_eq(&edge_conn->hs_ident->identity_pk, + &origin_circ->hs_ident->identity_pk))) { + /* this circ is not for this conn */ + return 0; + } + + return 1; +} + +/** Return 1 if <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_HSDIR_GET || + purpose == CIRCUIT_PURPOSE_S_HSDIR_POST || + purpose == CIRCUIT_PURPOSE_HS_VANGUARDS || + 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 || + purpose == CIRCUIT_PURPOSE_S_HSDIR_POST || + purpose == CIRCUIT_PURPOSE_C_HSDIR_GET) { + tor_addr_t addr; + const int family = tor_addr_parse(&addr, conn->socks_request->address); + if (!exitnode && !build_state->onehop_tunnel) { + log_debug(LD_CIRC,"Not considering circuit with unknown router."); + return 0; /* this circuit is screwed and doesn't know it yet, + * or is a rendezvous circuit. */ + } + if (build_state->onehop_tunnel) { + if (!conn->want_onehop) { + log_debug(LD_CIRC,"Skipping one-hop circuit."); + return 0; + } + tor_assert(conn->chosen_exit_name); + if (build_state->chosen_exit) { + char digest[DIGEST_LEN]; + if (hexdigest_to_digest(conn->chosen_exit_name, digest) < 0) + return 0; /* broken digest, we don't want it */ + if (tor_memneq(digest, build_state->chosen_exit->identity_digest, + DIGEST_LEN)) + return 0; /* this is a circuit to somewhere else */ + if (tor_digest_is_zero(digest)) { + /* we don't know the digest; have to compare addr:port */ + if (family < 0 || + !tor_addr_eq(&build_state->chosen_exit->addr, &addr) || + build_state->chosen_exit->port != conn->socks_request->port) + return 0; + } + } + } else { + if (conn->want_onehop) { + /* don't use three-hop circuits -- that could hurt our anonymity. */ + return 0; + } + } + if (origin_circ->prepend_policy && family != -1) { + int r = compare_tor_addr_to_addr_policy(&addr, + conn->socks_request->port, + origin_circ->prepend_policy); + if (r == ADDR_POLICY_REJECTED) + return 0; + } + if (exitnode && !connection_ap_can_use_exit(conn, exitnode)) { + /* can't exit from this router */ + return 0; + } + } else { /* not general: this might be a rend circuit */ + const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn); + if (!circuit_matches_with_rend_stream(edge_conn, origin_circ)) { + return 0; + } + } + + if (!connection_edge_compatible_with_circuit(conn, origin_circ)) { + /* conn needs to be isolated from other conns that have already used + * origin_circ */ + return 0; + } + + return 1; +} + +/** Return 1 if circuit <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_S_HSDIR_POST: + case CIRCUIT_PURPOSE_C_HSDIR_GET: + 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_HS_VANGUARDS || + purpose == CIRCUIT_PURPOSE_C_HSDIR_GET || + purpose == CIRCUIT_PURPOSE_S_HSDIR_POST || + 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 && + !circ->marked_for_close) { + 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 || + !CIRCUIT_PURPOSE_COUNTS_TOWARDS_MAXPENDING(circ->purpose) || + !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 /* 0 */ + +/** + * Close all circuits that start at us, aren't open, and were born + * at least CircuitBuildTimeout seconds ago. + * + * TODO: This function is now partially redundant to + * circuit_build_times_handle_completed_hop(), but that function only + * covers circuits up to and including 3 hops that are still actually + * completing hops. However, circuit_expire_building() also handles longer + * circuits, as well as circuits that are completely stalled. + * In the future (after prop247/other path selection revamping), we probably + * want to eliminate this rats nest in favor of a simpler approach. + */ +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. */ + any_opened_circs = circuit_any_opened_circuits(); + +#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()); + + // TODO: We should probably use route_len_for_purpose() here instead, + // except that does not count the extra round trip for things like server + // intros and rends. + + /* > 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; + bool fixed_time = circuit_build_times_disabled(get_options()); + + 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_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; + if (!fixed_time) { + 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), + victim->n_chan ? + channel_state_to_string(victim->n_chan->state) : "none"); + } + + /* 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(); + if (!fixed_time) { + 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), + victim->n_chan ? + channel_state_to_string(victim->n_chan->state) : "none", + (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 /* 0 */ + + /* 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 || + TO_ORIGIN_CIRCUIT(victim)->hs_ident || + 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: + /* That purpose means that the intro point circuit has been opened + * successfully but the INTRODUCE1 cell hasn't been sent yet because + * the client is waiting for the rendezvous point circuit to open. + * Keep this circuit open while waiting for the rendezvous circuit. + * We let the circuit idle timeout take care of cleaning this + * circuit if it never used. */ + continue; + 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())) { + + log_info(LD_CIRC, + "Deciding to count the timeout for circuit %"PRIu32"\n", + TO_ORIGIN_CIRCUIT(victim)->global_identifier); + + /* Circuits are allowed to last longer for measurement. + * Switch their purpose and wait. */ + if (victim->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) { + circuit_build_times_mark_circ_as_measurement_only(TO_ORIGIN_CIRCUIT( + victim)); + continue; + } + + /* + * If the circuit build time is much greater than we would have cut + * it off at, we probably had a suspend event along this codepath, + * and we should discard the value. + */ + if (timercmp(&victim->timestamp_began, &extremely_old_cutoff, OP_LT)) { + log_notice(LD_CIRC, + "Extremely large value for circuit build timeout: %lds. " + "Assuming clock jump. Purpose %d (%s)", + (long)(now.tv_sec - victim->timestamp_began.tv_sec), + victim->purpose, + circuit_purpose_to_string(victim->purpose)); + } else if (circuit_build_times_count_close( + get_circuit_build_times_mutable(), + first_hop_succeeded, + (time_t)victim->timestamp_created.tv_sec)) { + circuit_build_times_set_timeout(get_circuit_build_times_mutable()); + } + } + } + + /* If this is a hidden service client circuit which is far enough along in + * connecting to its destination, and we haven't already flagged it as + * 'timed out', flag it so we'll launch another intro or rend circ, but + * don't mark it for close yet. + * + * (Circs flagged as 'timed out' are given a much longer timeout + * period above, so we won't close them in the next call to + * circuit_expire_building.) */ + if (!(TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out)) { + switch (victim->purpose) { + case CIRCUIT_PURPOSE_C_REND_READY: + /* We only want to spare a rend circ if it has been specified in + * an INTRODUCE1 cell sent to a hidden service. A circ's + * pending_final_cpath field is non-NULL iff it is a rend circ + * and we have tried to send an INTRODUCE1 cell specifying it. + * Thus, if the pending_final_cpath field *is* NULL, then we + * want to not spare it. */ + if (TO_ORIGIN_CIRCUIT(victim)->build_state && + TO_ORIGIN_CIRCUIT(victim)->build_state->pending_final_cpath == + NULL) + break; + /* fallthrough! */ + case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT: + case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED: + /* If we have reached this line, we want to spare the circ for now. */ + log_info(LD_CIRC,"Marking circ %u (state %d:%s, purpose %d) " + "as timed-out HS circ", + (unsigned)victim->n_circ_id, + victim->state, circuit_state_to_string(victim->state), + victim->purpose); + TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out = 1; + continue; + default: + break; + } + } + + /* If this is a service-side rendezvous circuit which is far + * enough along in connecting to its destination, consider sparing + * it. */ + if (!(TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out) && + victim->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) { + log_info(LD_CIRC,"Marking circ %u (state %d:%s, purpose %d) " + "as timed-out HS circ; relaunching rendezvous attempt.", + (unsigned)victim->n_circ_id, + victim->state, circuit_state_to_string(victim->state), + victim->purpose); + TO_ORIGIN_CIRCUIT(victim)->hs_circ_has_timed_out = 1; + hs_circ_retry_service_rendezvous_point(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, it is + * 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 + * and rendezvous connections. Don't log the established ones. */ + if (rend_service_allow_non_anonymous_connection(options) && + (circ->purpose == CIRCUIT_PURPOSE_S_INTRO || + circ->purpose == CIRCUIT_PURPOSE_S_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; + if (origin_circ->isolation_values_set && + (conn == NULL || + !connection_edge_compatible_with_circuit(conn, origin_circ))) + continue; + + exitnode = build_state_get_exit_node(build_state); + if (exitnode && (!need_uptime || build_state->need_uptime)) { + int ok; + if (conn) { + ok = connection_ap_can_use_exit(conn, exitnode); + } else { + addr_policy_result_t r; + r = compare_tor_addr_to_node_policy(NULL, port, exitnode); + ok = r != ADDR_POLICY_REJECTED && r != ADDR_POLICY_PROBABLY_REJECTED; + } + if (ok) { + if (++num >= min) + return 1; + } + } + } + } + SMARTLIST_FOREACH_END(circ); + return 0; +} + +/** Don't keep more than this many unused open circuits around. */ +#define MAX_UNUSED_OPEN_CIRCUITS 14 + +/* Return true if a circuit is available for use, meaning that it is open, + * clean, usable for new multi-hop connections, and a general purpose origin + * circuit. + * Accept any kind of circuit, return false if the above conditions are not + * met. */ +STATIC int +circuit_is_available_for_use(const circuit_t *circ) +{ + const origin_circuit_t *origin_circ; + cpath_build_state_t *build_state; + + if (!CIRCUIT_IS_ORIGIN(circ)) + return 0; /* We first filter out only origin circuits before doing the + following checks. */ + if (circ->marked_for_close) + return 0; /* Don't mess with marked circs */ + if (circ->timestamp_dirty) + return 0; /* Only count clean circs */ + if (circ->purpose != CIRCUIT_PURPOSE_C_GENERAL && + circ->purpose != CIRCUIT_PURPOSE_HS_VANGUARDS) + return 0; /* We only pay attention to general purpose circuits. + General purpose circuits are always origin circuits. */ + + origin_circ = CONST_TO_ORIGIN_CIRCUIT(circ); + if (origin_circ->unusable_for_new_conns) + return 0; + + build_state = origin_circ->build_state; + if (build_state->onehop_tunnel) + return 0; + + return 1; +} + +/* Return true if we need any more exit circuits. + * needs_uptime and needs_capacity are set only if we need more exit circuits. + * Check if we know of a port that's been requested recently and no circuit + * is currently available that can handle it. */ +STATIC int +needs_exit_circuits(time_t now, int *needs_uptime, int *needs_capacity) +{ + return (!circuit_all_predicted_ports_handled(now, needs_uptime, + needs_capacity) && + router_have_consensus_path() == CONSENSUS_PATH_EXIT); +} + +/* Hidden services need at least this many internal circuits */ +#define SUFFICIENT_UPTIME_INTERNAL_HS_SERVERS 3 + +/* Return true if we need any more hidden service server circuits. + * HS servers only need an internal circuit. */ +STATIC int +needs_hs_server_circuits(time_t now, int num_uptime_internal) +{ + if (!rend_num_services() && !hs_service_get_num_services()) { + /* No services, we don't need anything. */ + goto no_need; + } + + if (num_uptime_internal >= SUFFICIENT_UPTIME_INTERNAL_HS_SERVERS) { + /* We have sufficient amount of internal circuit. */ + goto no_need; + } + + if (router_have_consensus_path() == CONSENSUS_PATH_UNKNOWN) { + /* Consensus hasn't been checked or might be invalid so requesting + * internal circuits is not wise. */ + goto no_need; + } + + /* At this point, we need a certain amount of circuits and we will most + * likely use them for rendezvous so we note down the use of internal + * circuit for our prediction for circuit needing uptime and capacity. */ + rep_hist_note_used_internal(now, 1, 1); + + return 1; + no_need: + return 0; +} + +/* We need at least this many internal circuits for hidden service clients */ +#define SUFFICIENT_INTERNAL_HS_CLIENTS 3 + +/* We need at least this much uptime for internal circuits for hidden service + * clients */ +#define SUFFICIENT_UPTIME_INTERNAL_HS_CLIENTS 2 + +/* Return true if we need any more hidden service client circuits. + * HS clients only need an internal circuit. */ +STATIC int +needs_hs_client_circuits(time_t now, int *needs_uptime, int *needs_capacity, + int num_internal, int num_uptime_internal) +{ + int used_internal_recently = rep_hist_get_predicted_internal(now, + needs_uptime, + needs_capacity); + int requires_uptime = num_uptime_internal < + SUFFICIENT_UPTIME_INTERNAL_HS_CLIENTS && + needs_uptime; + + return (used_internal_recently && + (requires_uptime || num_internal < SUFFICIENT_INTERNAL_HS_CLIENTS) && + router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN); +} + +/* This is how many circuits can be opened concurrently during the cbt learning + * phase. This number cannot exceed the tor-wide MAX_UNUSED_OPEN_CIRCUITS. */ +#define DFLT_CBT_UNUSED_OPEN_CIRCS (10) +#define MIN_CBT_UNUSED_OPEN_CIRCS 0 +#define MAX_CBT_UNUSED_OPEN_CIRCS MAX_UNUSED_OPEN_CIRCUITS + +/* Return true if we need more circuits for a good build timeout. + * XXXX make the assumption that build timeout streams should be + * created whenever we can build internal circuits. */ +STATIC int +needs_circuits_for_build(int num) +{ + if (router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN) { + if (num < networkstatus_get_param(NULL, "cbtmaxopencircs", + DFLT_CBT_UNUSED_OPEN_CIRCS, + MIN_CBT_UNUSED_OPEN_CIRCS, + MAX_CBT_UNUSED_OPEN_CIRCS) && + !circuit_build_times_disabled(get_options()) && + circuit_build_times_needs_circuits_now(get_circuit_build_times())) { + return 1; + } + } + return 0; +} + +/** + * Launch the appropriate type of predicted circuit for hidden + * services, depending on our options. + */ +static void +circuit_launch_predicted_hs_circ(int flags) +{ + /* K.I.S.S. implementation of bug #23101: If we are using + * vanguards or pinned middles, pre-build a specific purpose + * for HS circs. */ + if (circuit_should_use_vanguards(CIRCUIT_PURPOSE_HS_VANGUARDS)) { + circuit_launch(CIRCUIT_PURPOSE_HS_VANGUARDS, flags); + } else { + /* If no vanguards, then no HS-specific prebuilt circuits are needed. + * Normal GENERAL circs are fine */ + circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags); + } +} + +/** Determine how many circuits we have open that are clean, + * Make sure it's enough for all the upcoming behaviors we predict we'll have. + * But put an upper bound on the total number of circuits. + */ +static void +circuit_predict_and_launch_new(void) +{ + int num=0, num_internal=0, num_uptime_internal=0; + int hidserv_needs_uptime=0, hidserv_needs_capacity=1; + int port_needs_uptime=0, port_needs_capacity=1; + time_t now = time(NULL); + int flags = 0; + + /* Count how many of each type of circuit we currently have. */ + SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { + if (!circuit_is_available_for_use(circ)) + continue; + + num++; + + cpath_build_state_t *build_state = TO_ORIGIN_CIRCUIT(circ)->build_state; + if (build_state->is_internal) + num_internal++; + if (build_state->need_uptime && build_state->is_internal) + num_uptime_internal++; + } + SMARTLIST_FOREACH_END(circ); + + /* If that's enough, then stop now. */ + if (num >= MAX_UNUSED_OPEN_CIRCUITS) + return; + + if (needs_exit_circuits(now, &port_needs_uptime, &port_needs_capacity)) { + if (port_needs_uptime) + flags |= CIRCLAUNCH_NEED_UPTIME; + if (port_needs_capacity) + flags |= CIRCLAUNCH_NEED_CAPACITY; + + log_info(LD_CIRC, + "Have %d clean circs (%d internal), need another exit circ.", + num, num_internal); + circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags); + return; + } + + if (needs_hs_server_circuits(now, num_uptime_internal)) { + flags = (CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_NEED_UPTIME | + CIRCLAUNCH_IS_INTERNAL); + + log_info(LD_CIRC, + "Have %d clean circs (%d internal), need another internal " + "circ for my hidden service.", + num, num_internal); + circuit_launch_predicted_hs_circ(flags); + return; + } + + if (needs_hs_client_circuits(now, &hidserv_needs_uptime, + &hidserv_needs_capacity, + num_internal, num_uptime_internal)) + { + if (hidserv_needs_uptime) + flags |= CIRCLAUNCH_NEED_UPTIME; + if (hidserv_needs_capacity) + flags |= CIRCLAUNCH_NEED_CAPACITY; + flags |= CIRCLAUNCH_IS_INTERNAL; + + log_info(LD_CIRC, + "Have %d clean circs (%d uptime-internal, %d internal), need" + " another hidden service circ.", + num, num_uptime_internal, num_internal); + + circuit_launch_predicted_hs_circ(flags); + return; + } + + if (needs_circuits_for_build(num)) { + flags = CIRCLAUNCH_NEED_CAPACITY; + /* if there are no exits in the consensus, make timeout + * circuits internal */ + if (router_have_consensus_path() == CONSENSUS_PATH_INTERNAL) + flags |= CIRCLAUNCH_IS_INTERNAL; + + log_info(LD_CIRC, + "Have %d clean circs need another buildtime test circ.", num); + circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, flags); + return; + } +} + +/** Build a new test circuit every 5 minutes */ +#define TESTING_CIRCUIT_INTERVAL 300 + +/** This function is called once a second, if router_have_minimum_dir_info() + * is true. Its job is to make sure all services we offer have enough circuits + * available. Some services just want enough circuits for current tasks, + * whereas others want a minimum set of idle circuits hanging around. + */ +void +circuit_build_needed_circs(time_t now) +{ + const or_options_t *options = get_options(); + + /* launch a new circ for any pending streams that need one + * XXXX make the assumption that (some) AP streams (i.e. HS clients) + * don't require an exit circuit, review in #13814. + * This allows HSs to function in a consensus without exits. */ + if (router_have_consensus_path() != CONSENSUS_PATH_UNKNOWN) + connection_ap_rescan_and_attach_pending(); + + circuit_expire_old_circs_as_needed(now); + + if (!options->DisablePredictedCircuits) + circuit_predict_and_launch_new(); +} + +/** + * Called once a second either directly or from + * circuit_build_needed_circs(). As appropriate (once per NewCircuitPeriod) + * resets failure counts and expires old circuits. + */ +void +circuit_expire_old_circs_as_needed(time_t now) +{ + static time_t time_to_expire_and_reset = 0; + + if (time_to_expire_and_reset < now) { + circuit_reset_failure_count(1); + time_to_expire_and_reset = now + get_options()->NewCircuitPeriod; + if (proxy_mode(get_options())) + addressmap_clean(now); + circuit_expire_old_circuits_clientside(); + +#if 0 /* disable for now, until predict-and-launch-new can cull leftovers */ + + /* If we ever re-enable, this has to move into + * circuit_build_needed_circs */ + + circ = circuit_get_youngest_clean_open(CIRCUIT_PURPOSE_C_GENERAL); + if (get_options()->RunTesting && + circ && + circ->timestamp_began.tv_sec + TESTING_CIRCUIT_INTERVAL < now) { + log_fn(LOG_INFO,"Creating a new testing circuit."); + circuit_launch(CIRCUIT_PURPOSE_C_GENERAL, 0); + } +#endif /* 0 */ + } +} + +/** 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) { + hs_dec_rdv_stream_counter(origin_circ); + } + + /* If there are no more streams on this circ, tell circpad */ + if (!origin_circ->p_streams) + circpad_machine_event_circ_has_no_streams(origin_circ); + + return; + } + } else { + or_circuit_t *or_circ = TO_OR_CIRCUIT(circ); + if (conn == or_circ->n_streams) { + or_circ->n_streams = conn->next_stream; + return; + } + if (conn == or_circ->resolving_streams) { + or_circ->resolving_streams = conn->next_stream; + return; + } + + for (prevconn = or_circ->n_streams; + prevconn && prevconn->next_stream && prevconn->next_stream != conn; + prevconn = prevconn->next_stream) + ; + if (prevconn && prevconn->next_stream) { + prevconn->next_stream = conn->next_stream; + return; + } + + for (prevconn = or_circ->resolving_streams; + prevconn && prevconn->next_stream && prevconn->next_stream != conn; + prevconn = prevconn->next_stream) + ; + if (prevconn && prevconn->next_stream) { + prevconn->next_stream = conn->next_stream; + return; + } + } + + log_warn(LD_BUG,"Edge connection not in circuit's list."); + /* Don't give an error here; it's harmless. */ + tor_fragile_assert(); +} + +/** Find each circuit that has been unused for too long, or dirty + * for too long and has no streams on it: mark it for close. + */ +static void +circuit_expire_old_circuits_clientside(void) +{ + struct timeval cutoff, now; + + tor_gettimeofday(&now); + last_expired_clientside_circuits = now.tv_sec; + + SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, circ) { + if (circ->marked_for_close || !CIRCUIT_IS_ORIGIN(circ)) + continue; + + cutoff = now; + cutoff.tv_sec -= TO_ORIGIN_CIRCUIT(circ)->circuit_idle_timeout; + + /* If the circuit has been dirty for too long, and there are no streams + * on it, mark it for close. + */ + if (circ->timestamp_dirty && + circ->timestamp_dirty + get_options()->MaxCircuitDirtiness < + now.tv_sec && + !TO_ORIGIN_CIRCUIT(circ)->p_streams /* nothing attached */ ) { + log_debug(LD_CIRC, "Closing n_circ_id %u (dirty %ld sec ago, " + "purpose %d)", + (unsigned)circ->n_circ_id, + (long)(now.tv_sec - circ->timestamp_dirty), + circ->purpose); + /* Don't do this magic for testing circuits. Their death is governed + * by circuit_expire_building */ + if (circ->purpose != CIRCUIT_PURPOSE_PATH_BIAS_TESTING) + circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED); + } else if (!circ->timestamp_dirty && circ->state == CIRCUIT_STATE_OPEN) { + if (timercmp(&circ->timestamp_began, &cutoff, OP_LT)) { + if (circ->purpose == CIRCUIT_PURPOSE_C_GENERAL || + circ->purpose == CIRCUIT_PURPOSE_C_HSDIR_GET || + circ->purpose == CIRCUIT_PURPOSE_S_HSDIR_POST || + circ->purpose == CIRCUIT_PURPOSE_HS_VANGUARDS || + circ->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT || + circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO || + circ->purpose == CIRCUIT_PURPOSE_TESTING || + (circ->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING && + circ->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) || + circ->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) { + log_info(LD_CIRC, + "Closing circuit %"PRIu32 + " that has been unused for %ld msec.", + TO_ORIGIN_CIRCUIT(circ)->global_identifier, + tv_mdiff(&circ->timestamp_began, &now)); + circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED); + } else if (!TO_ORIGIN_CIRCUIT(circ)->is_ancient) { + /* Server-side rend joined circuits can end up really old, because + * they are reused by clients for longer than normal. The client + * controls their lifespan. (They never become dirty, because + * connection_exit_begin_conn() never marks anything as dirty.) + * Similarly, server-side intro circuits last a long time. */ + if (circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED && + circ->purpose != CIRCUIT_PURPOSE_S_INTRO) { + log_notice(LD_CIRC, + "Ancient non-dirty circuit %d is still around after " + "%ld milliseconds. Purpose: %d (%s)", + TO_ORIGIN_CIRCUIT(circ)->global_identifier, + tv_mdiff(&circ->timestamp_began, &now), + circ->purpose, + circuit_purpose_to_string(circ->purpose)); + TO_ORIGIN_CIRCUIT(circ)->is_ancient = 1; + } + } + } + } + } SMARTLIST_FOREACH_END(circ); +} + +/** How long do we wait before killing circuits with the properties + * described below? + * + * Probably we could choose a number here as low as 5 to 10 seconds, + * since these circs are used for begindir, and a) generally you either + * ask another begindir question right after or you don't for a long time, + * b) clients at least through 0.2.1.x choose from the whole set of + * directory mirrors at each choice, and c) re-establishing a one-hop + * circuit via create-fast is a light operation assuming the TLS conn is + * still there. + * + * I expect "b" to go away one day when we move to using directory + * guards, but I think "a" and "c" are good enough reasons that a low + * number is safe even then. + */ +#define IDLE_ONE_HOP_CIRC_TIMEOUT 60 + +/** Find each non-origin circuit that has been unused for too long, + * has no streams on it, came from a client, 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. ++ * ++ * Also if there is a rend_splice on it, it's a single onion service ++ * circuit and we should not close it. + */ + if (or_circ->p_chan && channel_is_client(or_circ->p_chan) && + !circ->n_chan && + !or_circ->n_streams && !or_circ->resolving_streams && ++ !or_circ->rend_splice && + 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 + router_do_reachability_checks(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) +{ + circuit_event_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: + hs_client_circuit_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: + hs_client_circuit_has_opened(circ); + break; + case CIRCUIT_PURPOSE_C_GENERAL: + case CIRCUIT_PURPOSE_C_HSDIR_GET: + case CIRCUIT_PURPOSE_S_HSDIR_POST: + /* Tell any AP connections that have been waiting for a new + * circuit that one is ready. */ + circuit_try_attaching_streams(circ); + break; + case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO: + /* at the service, waiting for introductions */ + hs_service_circuit_has_opened(circ); + break; + case CIRCUIT_PURPOSE_S_CONNECT_REND: + /* at the service, connecting to rend point */ + hs_service_circuit_has_opened(circ); + break; + case CIRCUIT_PURPOSE_TESTING: + circuit_testing_opened(circ); + break; + /* default: + * This won't happen in normal operation, but might happen if the + * controller did it. Just let it slide. */ + } +} + +/** If the stream-isolation state of <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; + + /* First, check to see if this was a path failure, rather than build + * failure. + * + * Note that we deliberately use circuit_get_cpath_len() (and not + * circuit_get_cpath_opened_len()) because we only want to ensure + * that a full path is *chosen*. This is different than a full path + * being *built*. We only want to count *build* failures below. + * + * Path selection failures can happen spuriously for a number + * of reasons (such as aggressive/invalid user-specified path + * restrictions in the torrc, insufficient microdescriptors, and + * non-user reasons like exitpolicy issues), and so should not be + * counted as failures below. + */ + if (circuit_get_cpath_len(circ) < circ->build_state->desired_path_len) { + static ratelim_t pathfail_limit = RATELIM_INIT(3600); + log_fn_ratelim(&pathfail_limit, LOG_NOTICE, LD_CIRC, + "Our circuit %u (id: %" PRIu32 ") died due to an invalid " + "selected path, purpose %s. This may be a torrc " + "configuration issue, or a bug.", + TO_CIRCUIT(circ)->n_circ_id, circ->global_identifier, + circuit_purpose_to_string(TO_CIRCUIT(circ)->purpose)); + + /* If the path failed on an RP, retry it. */ + if (TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) + hs_circ_retry_service_rendezvous_point(circ); + + /* In all other cases, just bail. The rest is just failure accounting + * that we don't want to do */ + return; + } + + /* 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; + } + + /* Check if we failed at first hop */ + 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_ident = circ->cpath->extend_info->identity_digest; + tor_assert(n_chan_ident); + 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 %u (id: %" PRIu32 ") failed to get a response " + "from the first hop (%s). I'm going to try to rotate to a " + "better connection.", + TO_CIRCUIT(circ)->n_circ_id, circ->global_identifier, + channel_get_canonical_remote_descr(n_chan)); + n_chan->is_bad_for_new_circs = 1; + } else { + log_info(LD_OR, + "Our circuit %u (id: %" PRIu32 ") died before the first hop " + "with no connection", + TO_CIRCUIT(circ)->n_circ_id, circ->global_identifier); + } + if (!already_marked) { + /* + * If we have guard state (new guard API) and our path selection + * code actually chose a full path, then blame the failure of this + * circuit on the guard. + */ + if (circ->guard_state) + entry_guard_failed(&circ->guard_state); + /* if there are any one-hop streams waiting on this circuit, fail + * them now so they can retry elsewhere. */ + connection_ap_fail_onehop(n_chan_ident, circ->build_state); + } + } + + switch (circ->base_.purpose) { + case CIRCUIT_PURPOSE_C_HSDIR_GET: + case CIRCUIT_PURPOSE_S_HSDIR_POST: + 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"); + hs_circ_retry_service_rendezvous_point(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; +} + +/** + * Tell us if a circuit is a hidden service circuit. + */ +int +circuit_purpose_is_hidden_service(uint8_t purpose) +{ + if (purpose == CIRCUIT_PURPOSE_HS_VANGUARDS) { + return 1; + } + + /* Client-side purpose */ + if (purpose >= CIRCUIT_PURPOSE_C_HS_MIN_ && + purpose <= CIRCUIT_PURPOSE_C_HS_MAX_) { + return 1; + } + + /* Service-side purpose */ + if (purpose >= CIRCUIT_PURPOSE_S_HS_MIN_ && + purpose <= CIRCUIT_PURPOSE_S_HS_MAX_) { + return 1; + } + + return 0; +} + +/** + * Return true if this circuit purpose should use vanguards + * or pinned Layer2 or Layer3 guards. + * + * This function takes both the circuit purpose and the + * torrc options for pinned middles/vanguards into account + * (ie: the circuit must be a hidden service circuit and + * vanguards/pinned middles must be enabled for it to return + * true). + */ +int +circuit_should_use_vanguards(uint8_t purpose) +{ + const or_options_t *options = get_options(); + + /* Only hidden service circuits use vanguards */ + if (!circuit_purpose_is_hidden_service(purpose)) + return 0; + + /* Pinned middles are effectively vanguards */ + if (options->HSLayer2Nodes || options->HSLayer3Nodes) + return 1; + + return 0; +} + +/** + * Return true for the set of conditions for which it is OK to use + * a cannibalized circuit. + * + * Don't cannibalize for onehops, or certain purposes. + */ +static int +circuit_should_cannibalize_to_build(uint8_t purpose_to_build, + int has_extend_info, + int onehop_tunnel) +{ + + /* Do not try to cannibalize if this is a one hop circuit. */ + if (onehop_tunnel) { + return 0; + } + + /* Don't try to cannibalize for general purpose circuits that do not + * specify a custom exit. */ + if (purpose_to_build == CIRCUIT_PURPOSE_C_GENERAL && !has_extend_info) { + return 0; + } + + /* Don't cannibalize for testing circuits. We want to see if they + * complete normally. Also don't cannibalize for vanguard-purpose + * circuits, since those are specially pre-built for later + * cannibalization by the actual specific circuit types that need + * vanguards. + */ + if (purpose_to_build == CIRCUIT_PURPOSE_TESTING || + purpose_to_build == CIRCUIT_PURPOSE_HS_VANGUARDS) { + return 0; + } + + /* For vanguards, the server-side intro circ is not cannibalized + * because we pre-build 4 hop HS circuits, and it only needs a 3 hop + * circuit. It is also long-lived, so it is more important that + * it have lower latency than get built fast. + */ + if (circuit_should_use_vanguards(purpose_to_build) && + purpose_to_build == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) { + return 0; + } + + return 1; +} + +/** 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) ); + + /* Keep some stats about our attempts to launch HS rendezvous circuits */ + if (purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) { + hs_stats_note_service_rendezvous_launch(); + } + + 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 we can/should cannibalize another circuit to build this one, + * then do so. */ + if (circuit_should_cannibalize_to_build(purpose, + extend_info != NULL, + onehop_tunnel)) { + /* 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 %u (id: %" PRIu32 ") for " + "purpose %d (%s)", + TO_CIRCUIT(circ)->n_circ_id, circ->global_identifier, 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_HSDIR_POST: + case CIRCUIT_PURPOSE_C_HSDIR_GET: + 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 we are configured with EntryNodes or UseBridges */ + if (entry_list_is_constrained(options)) { + /* Retry all our guards / bridges. + * guards_retry_optimistic() always returns true here. */ + int rv = guards_retry_optimistic(options); + tor_assert_nonfatal_once(rv); + 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 { + /* Getting directory documents doesn't help much if we have a limited + * number of guards */ + tor_assert_nonfatal(!options->UseBridges); + tor_assert_nonfatal(!options->EntryNodes); + /* Retry our directory fetches, so we have a fresh set of guard info */ + 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, 0); + 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) { + const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn); + /* need to pick an intro point */ + extend_info = hs_client_get_random_intro_from_edge(edge_conn); + if (!extend_info) { + log_info(LD_REND, "No intro points: re-fetching service descriptor."); + if (edge_conn->rend_data) { + rend_client_refetch_v2_renddesc(edge_conn->rend_data); + } else { + hs_client_refetch_hsdesc(&edge_conn->hs_ident->identity_pk); + } + connection_ap_mark_as_waiting_for_renddesc(conn); + return 0; + } + log_info(LD_REND,"Chose %s as intro point for '%s'.", + extend_info_describe(extend_info), + (edge_conn->rend_data) ? + safe_str_client(rend_data_get_address(edge_conn->rend_data)) : + "service"); + } + + /* 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 || + desired_circuit_purpose == CIRCUIT_PURPOSE_S_HSDIR_POST || + desired_circuit_purpose == CIRCUIT_PURPOSE_C_HSDIR_GET) { + if (conn->chosen_exit_name) { + const node_t *r; + int opt = conn->chosen_exit_optional; + r = node_get_by_nickname(conn->chosen_exit_name, 0); + if (r && node_has_preferred_descriptor(r, conn->want_onehop ? 1 : 0)) { + /* 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_preferred_descriptor(...)) */ + log_debug(LD_DIR, "considering %d, %s", + want_onehop, conn->chosen_exit_name); + if (want_onehop && conn->chosen_exit_name[0] == '$') { + /* We're asking for a one-hop circuit to a router that + * we don't have a routerinfo about. Make up an extend_info. */ + /* XXX prop220: we need to make chosen_exit_name able to + * encode both key formats. This is not absolutely critical + * since this is just for one-hop circuits, but we should + * still get it done */ + char digest[DIGEST_LEN]; + char *hexdigest = conn->chosen_exit_name+1; + tor_addr_t addr; + if (strlen(hexdigest) < HEX_DIGEST_LEN || + base16_decode(digest,DIGEST_LEN, + hexdigest,HEX_DIGEST_LEN) != DIGEST_LEN) { + log_info(LD_DIR, "Broken exit digest on tunnel conn. Closing."); + return -1; + } + if (tor_addr_parse(&addr, conn->socks_request->address) < 0) { + log_info(LD_DIR, "Broken address %s on tunnel conn. Closing.", + escaped_safe_str_client(conn->socks_request->address)); + return -1; + } + /* XXXX prop220 add a workaround for ed25519 ID below*/ + extend_info = extend_info_new(conn->chosen_exit_name+1, + digest, + NULL, /* Ed25519 ID */ + NULL, NULL, /* onion keys */ + &addr, conn->socks_request->port); + } else { /* ! (want_onehop && conn->chosen_exit_name[0] == '$') */ + /* We will need an onion key for the router, and we + * don't have one. Refuse or relax requirements. */ + log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP, + "Requested exit point '%s' is not known. %s.", + conn->chosen_exit_name, opt ? "Trying others" : "Closing"); + if (opt) { + conn->chosen_exit_optional = 0; + tor_free(conn->chosen_exit_name); + /* Try again with no requested exit */ + return circuit_get_open_circ_or_launch(conn, + desired_circuit_purpose, + circp); + } + return -1; + } + } + } + } /* Done checking for general circutis with chosen exits. */ + + /* What purpose do we need to launch this circuit with? */ + uint8_t new_circ_purpose; + if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_REND_JOINED) + new_circ_purpose = CIRCUIT_PURPOSE_C_ESTABLISH_REND; + else if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) + new_circ_purpose = CIRCUIT_PURPOSE_C_INTRODUCING; + else + new_circ_purpose = desired_circuit_purpose; + + /* 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; + + /* If we are about to pick a v3 RP right now, make sure we pick a + * rendezvous point that supports the v3 protocol! */ + if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_REND_JOINED && + new_circ_purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND && + ENTRY_TO_EDGE_CONN(conn)->hs_ident) { + flags |= CIRCLAUNCH_IS_V3_RP; + log_info(LD_GENERAL, "Getting rendezvous circuit to v3 service!"); + } + + 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 || + desired_circuit_purpose == CIRCUIT_PURPOSE_C_HSDIR_GET || + desired_circuit_purpose == CIRCUIT_PURPOSE_S_HSDIR_POST) { + /* 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) { + const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn); + if (edge_conn->rend_data) { + /* write the service_id into circ */ + circ->rend_data = rend_data_dup(edge_conn->rend_data); + } else if (edge_conn->hs_ident) { + circ->hs_ident = + hs_ident_circuit_new(&edge_conn->hs_ident->identity_pk, + HS_IDENT_CIRCUIT_INTRO); + } + 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); + + /* If this is the first stream on this circuit, tell circpad + * that streams are attached */ + if (!circ->p_streams) + circpad_machine_event_circ_has_streams(circ); + + /* reset it, so we can measure circ timeouts */ + ENTRY_TO_CONN(apconn)->timestamp_last_read_allowed = time(NULL); + ENTRY_TO_EDGE_CONN(apconn)->next_stream = circ->p_streams; + ENTRY_TO_EDGE_CONN(apconn)->on_circuit = TO_CIRCUIT(circ); + /* assert_connection_ok(conn, time(NULL)); */ + circ->p_streams = ENTRY_TO_EDGE_CONN(apconn); + + if (connection_edge_is_rendezvous_stream(ENTRY_TO_EDGE_CONN(apconn))) { + /* We are attaching a stream to a rendezvous circuit. That means + * that an attempt to connect to a hidden service just + * succeeded. Tell rendclient.c. */ + hs_client_note_connection_attempt_succeeded(ENTRY_TO_EDGE_CONN(apconn)); + } + + if (cpath) { /* we were given one; use it */ + tor_assert(cpath_is_on_circuit(circ, cpath)); + } else { + /* use the last hop in the circuit */ + tor_assert(circ->cpath); + tor_assert(circ->cpath->prev); + tor_assert(circ->cpath->prev->state == CPATH_STATE_OPEN); + cpath = circ->cpath->prev; + } + ENTRY_TO_EDGE_CONN(apconn)->cpath_layer = cpath; + + circ->isolation_any_streams_attached = 1; + connection_edge_update_circuit_isolation(apconn, circ, 0); + + /* Compute the exitnode if possible, for logging below */ + if (cpath->extend_info) + exitnode = node_get_by_id(cpath->extend_info->identity_digest); + + /* See if we can use optimistic data on this circuit */ + if (optimistic_data_enabled() && + (circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL || + circ->base_.purpose == CIRCUIT_PURPOSE_C_HSDIR_GET || + circ->base_.purpose == CIRCUIT_PURPOSE_S_HSDIR_POST || + 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; +} + +/** + * Return an appropriate circuit purpose for non-rend streams. + * We don't handle rends here because a rend stream triggers two + * circuit builds with different purposes, so it is handled elsewhere. + * + * This function just figures out what type of hsdir activity this is, + * and tells us. Everything else is general. + */ +static int +connection_ap_get_nonrend_circ_purpose(const entry_connection_t *conn) +{ + const connection_t *base_conn = ENTRY_TO_CONN(conn); + tor_assert_nonfatal(!connection_edge_is_rendezvous_stream( + ENTRY_TO_EDGE_CONN(conn))); + + if (base_conn->linked_conn && + base_conn->linked_conn->type == CONN_TYPE_DIR) { + /* Set a custom purpose for hsdir activity */ + if (base_conn->linked_conn->purpose == DIR_PURPOSE_UPLOAD_RENDDESC_V2 || + base_conn->linked_conn->purpose == DIR_PURPOSE_UPLOAD_HSDESC) { + return CIRCUIT_PURPOSE_S_HSDIR_POST; + } else if (base_conn->linked_conn->purpose + == DIR_PURPOSE_FETCH_RENDDESC_V2 || + base_conn->linked_conn->purpose + == DIR_PURPOSE_FETCH_HSDESC) { + return CIRCUIT_PURPOSE_C_HSDIR_GET; + } + } + + /* All other purposes are general for now */ + return CIRCUIT_PURPOSE_C_GENERAL; +} + +/** 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, 0); + 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, + connection_ap_get_nonrend_circ_purpose(conn), + &circ); + + if (retval < 1) { + /* We were either told "-1" (complete failure) or 0 (circuit in + * progress); we can't attach this stream yet. */ + return retval; + } + + log_debug(LD_APP|LD_CIRC, + "Attaching apconn to circ %u (stream %d sec old).", + (unsigned)circ->base_.n_circ_id, conn_age); + /* print the circ's path, so clients can figure out which circs are + * sucking. */ + circuit_log_path(LOG_INFO,LD_APP|LD_CIRC,circ); + + /* We have found a suitable circuit for our conn. Hurray. Do + * the attachment. */ + return connection_ap_handshake_attach_chosen_circuit(conn, circ, NULL); + + } else { /* we're a rendezvous conn */ + origin_circuit_t *rendcirc=NULL, *introcirc=NULL; + + tor_assert(!ENTRY_TO_EDGE_CONN(conn)->cpath_layer); + + /* start by finding a rendezvous circuit for us */ + + retval = circuit_get_open_circ_or_launch( + conn, CIRCUIT_PURPOSE_C_REND_JOINED, &rendcirc); + if (retval < 0) return -1; /* failed */ + + if (retval > 0) { + tor_assert(rendcirc); + /* one is already established, attach */ + log_info(LD_REND, + "rend joined circ %u (id: %" PRIu32 ") already here. " + "Attaching. (stream %d sec old)", + (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id, + rendcirc->global_identifier, 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 (id: %" PRIu32 ") already here, with " + "intro ack. Stalling. (stream %d sec old)", + (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id, + rendcirc->global_identifier, 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 (id: %" PRIu32 ") present and " + "awaiting ACK. Rend circuit %u (id: %" PRIu32 "). " + "Stalling. (stream %d sec old)", + (unsigned) TO_CIRCUIT(introcirc)->n_circ_id, + introcirc->global_identifier, + rendcirc ? (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id : 0, + rendcirc ? rendcirc->global_identifier : 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 (id: %" PRIu32 ") already here. No" + "intro-ack yet on intro %u (id: %" PRIu32 "). " + "(stream %d sec old)", + (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id, + rendcirc->global_identifier, + (unsigned) TO_CIRCUIT(introcirc)->n_circ_id, + introcirc->global_identifier, conn_age); + + tor_assert(introcirc->base_.purpose == CIRCUIT_PURPOSE_C_INTRODUCING); + if (introcirc->base_.state == CIRCUIT_STATE_OPEN) { + int ret; + log_info(LD_REND, "Found open intro circ %u (id: %" PRIu32 "). " + "Rend circuit %u (id: %" PRIu32 "); Sending " + "introduction. (stream %d sec old)", + (unsigned) TO_CIRCUIT(introcirc)->n_circ_id, + introcirc->global_identifier, + (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id, + rendcirc->global_identifier, conn_age); + ret = hs_client_send_introduce1(introcirc, rendcirc); + switch (ret) { + 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 (id: %" PRIu32 ") and rend circuit %u " + "(id: %" PRIu32 ") circuits are not both ready. " + "Stalling conn. (%d sec old)", + introcirc ? (unsigned) TO_CIRCUIT(introcirc)->n_circ_id : 0, + introcirc ? introcirc->global_identifier : 0, + rendcirc ? (unsigned) TO_CIRCUIT(rendcirc)->n_circ_id : 0, + rendcirc ? rendcirc->global_identifier : 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); + + circpad_machine_event_circ_purpose_changed(TO_ORIGIN_CIRCUIT(circ)); + } +} + +/** 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; +} + +/** + * Add relay_body_len and RELAY_PAYLOAD_SIZE-relay_body_len to + * the valid delivered written fields and the overhead field, + * respectively. + */ +void +circuit_sent_valid_data(origin_circuit_t *circ, uint16_t relay_body_len) +{ + if (!circ) return; + + tor_assert_nonfatal(relay_body_len <= RELAY_PAYLOAD_SIZE); + + circ->n_delivered_written_circ_bw = + tor_add_u32_nowrap(circ->n_delivered_written_circ_bw, relay_body_len); + circ->n_overhead_written_circ_bw = + tor_add_u32_nowrap(circ->n_overhead_written_circ_bw, + RELAY_PAYLOAD_SIZE-relay_body_len); +} + +/** + * Add relay_body_len and RELAY_PAYLOAD_SIZE-relay_body_len to + * the valid delivered read field and the overhead field, + * respectively. + */ +void +circuit_read_valid_data(origin_circuit_t *circ, uint16_t relay_body_len) +{ + if (!circ) return; + + tor_assert_nonfatal(relay_body_len <= RELAY_PAYLOAD_SIZE); + + circ->n_delivered_read_circ_bw = + tor_add_u32_nowrap(circ->n_delivered_read_circ_bw, relay_body_len); + circ->n_overhead_read_circ_bw = + tor_add_u32_nowrap(circ->n_overhead_read_circ_bw, + RELAY_PAYLOAD_SIZE-relay_body_len); +}