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- /* Copyright (c) 2001 Matej Pfajfar.
- * Copyright (c) 2001-2004, Roger Dingledine.
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2010, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * \file circuituse.c
- * \brief Launch the right sort of circuits and attach streams to them.
- **/
- #include "or.h"
- #include "circuitbuild.h"
- #include "circuitlist.h"
- #include "circuituse.h"
- #include "config.h"
- #include "connection.h"
- #include "connection_edge.h"
- #include "control.h"
- #include "policies.h"
- #include "rendclient.h"
- #include "rendcommon.h"
- #include "rendservice.h"
- #include "rephist.h"
- #include "router.h"
- #include "routerlist.h"
- /********* START VARIABLES **********/
- extern circuit_t *global_circuitlist; /* from circuitlist.c */
- /********* END VARIABLES ************/
- static void circuit_expire_old_circuits_clientside(time_t now);
- static void circuit_increment_failure_count(void);
- /** Return 1 if <b>circ</b> could be returned by circuit_get_best().
- * Else return 0.
- */
- static int
- circuit_is_acceptable(circuit_t *circ, edge_connection_t *conn,
- int must_be_open, uint8_t purpose,
- int need_uptime, int need_internal,
- time_t now)
- {
- routerinfo_t *exitrouter;
- cpath_build_state_t *build_state;
- tor_assert(circ);
- tor_assert(conn);
- tor_assert(conn->socks_request);
- if (!CIRCUIT_IS_ORIGIN(circ))
- return 0; /* this circ doesn't start at us */
- if (must_be_open && (circ->state != CIRCUIT_STATE_OPEN || !circ->n_conn))
- 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 (purpose == CIRCUIT_PURPOSE_C_GENERAL)
- if (circ->timestamp_dirty &&
- circ->timestamp_dirty+get_options()->MaxCircuitDirtiness <= now)
- 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 bob hop. so just check the nickname
- * of the one we meant to finish at.
- */
- build_state = TO_ORIGIN_CIRCUIT(circ)->build_state;
- exitrouter = build_state_get_exit_router(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) {
- if (!exitrouter && !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 (memcmp(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 */
- tor_addr_t addr;
- int r = tor_addr_from_str(&addr, conn->socks_request->address);
- if (r < 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 (exitrouter && !connection_ap_can_use_exit(conn, exitrouter, 0)) {
- /* can't exit from this router */
- return 0;
- }
- } else { /* not general */
- origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
- if ((conn->rend_data && !ocirc->rend_data) ||
- (!conn->rend_data && ocirc->rend_data) ||
- (conn->rend_data && ocirc->rend_data &&
- rend_cmp_service_ids(conn->rend_data->onion_address,
- ocirc->rend_data->onion_address))) {
- /* this circ is not for this conn */
- return 0;
- }
- }
- return 1;
- }
- /** Return 1 if circuit <b>a</b> is better than circuit <b>b</b> for
- * <b>purpose</b>, and return 0 otherwise. Used by circuit_get_best.
- */
- static int
- circuit_is_better(circuit_t *a, circuit_t *b, uint8_t purpose)
- {
- switch (purpose) {
- case CIRCUIT_PURPOSE_C_GENERAL:
- /* if it's used but less dirty it's best;
- * else if it's more recently created it's best
- */
- if (b->timestamp_dirty) {
- if (a->timestamp_dirty &&
- a->timestamp_dirty > b->timestamp_dirty)
- return 1;
- } else {
- if (a->timestamp_dirty ||
- a->timestamp_created > b->timestamp_created)
- return 1;
- if (CIRCUIT_IS_ORIGIN(b) &&
- TO_ORIGIN_CIRCUIT(b)->build_state->is_internal)
- 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;
- }
- 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(edge_connection_t *conn, int must_be_open, uint8_t purpose,
- int need_uptime, int need_internal)
- {
- circuit_t *circ, *best=NULL;
- time_t now = time(NULL);
- int intro_going_on_but_too_old = 0;
- tor_assert(conn);
- tor_assert(purpose == CIRCUIT_PURPOSE_C_GENERAL ||
- purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT ||
- purpose == CIRCUIT_PURPOSE_C_REND_JOINED);
- for (circ=global_circuitlist;circ;circ = circ->next) {
- if (!circuit_is_acceptable(circ,conn,must_be_open,purpose,
- need_uptime,need_internal,now))
- continue;
- /* XXX022 make this 15 be a function of circuit finishing times we've
- * seen lately, a la Fallon Chen's GSoC work -RD */
- #define REND_PARALLEL_INTRO_DELAY 15
- if (purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT &&
- !must_be_open && circ->state != CIRCUIT_STATE_OPEN &&
- circ->timestamp_created + REND_PARALLEL_INTRO_DELAY < now) {
- intro_going_on_but_too_old = 1;
- 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(circ,best,purpose))
- best = 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 ? TO_ORIGIN_CIRCUIT(best) : NULL;
- }
- /** 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. */
- int
- circuit_conforms_to_options(const origin_circuit_t *circ,
- const or_options_t *options)
- {
- const crypt_path_t *cpath, *cpath_next = NULL;
- for (cpath = circ->cpath; cpath && cpath_next != circ->cpath;
- cpath = cpath_next) {
- cpath_next = cpath->next;
- if (routerset_contains_extendinfo(options->ExcludeNodes,
- cpath->extend_info))
- return 0;
- if (cpath->next == circ->cpath) {
- /* This is apparently the exit node. */
- if (routerset_contains_extendinfo(options->ExcludeExitNodes,
- cpath->extend_info))
- return 0;
- }
- }
- return 1;
- }
- /** Close all circuits that start at us, aren't open, and were born
- * at least CircuitBuildTimeout seconds ago.
- */
- void
- circuit_expire_building(time_t now)
- {
- circuit_t *victim, *next_circ = global_circuitlist;
- /* 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 */
- time_t general_cutoff = now - tor_lround(circ_times.timeout_ms/1000);
- time_t begindir_cutoff = now - tor_lround(circ_times.timeout_ms/2000);
- time_t fourhop_cutoff = now - tor_lround(4*circ_times.timeout_ms/3000);
- time_t cannibalize_cutoff = now - tor_lround(circ_times.timeout_ms/2000);
- time_t close_cutoff = now - tor_lround(circ_times.close_ms/1000);
- time_t introcirc_cutoff = begindir_cutoff;
- cpath_build_state_t *build_state;
- while (next_circ) {
- time_t cutoff;
- victim = next_circ;
- next_circ = next_circ->next;
- if (!CIRCUIT_IS_ORIGIN(victim) || /* didn't originate here */
- victim->marked_for_close) /* don't mess with marked circs */
- continue;
- build_state = TO_ORIGIN_CIRCUIT(victim)->build_state;
- if (build_state && build_state->onehop_tunnel)
- cutoff = begindir_cutoff;
- else if (build_state && build_state->desired_path_len == 4
- && !TO_ORIGIN_CIRCUIT(victim)->has_opened)
- cutoff = fourhop_cutoff;
- else if (TO_ORIGIN_CIRCUIT(victim)->has_opened)
- cutoff = cannibalize_cutoff;
- else if (victim->purpose == CIRCUIT_PURPOSE_C_INTRODUCING)
- cutoff = introcirc_cutoff;
- else if (victim->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT)
- cutoff = close_cutoff;
- else
- cutoff = general_cutoff;
- if (victim->timestamp_created > cutoff)
- continue; /* it's still young, leave it alone */
- #if 0
- /* some debug logs, to help track bugs */
- if (victim->purpose == CIRCUIT_PURPOSE_C_INTRODUCING &&
- victim->timestamp_created <= introcirc_cutoff &&
- victim->timestamp_created > general_cutoff)
- log_info(LD_REND|LD_CIRC, "Timing out introduction circuit which we "
- "would not have done if it had been a general circuit.");
- if (victim->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING &&
- victim->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) {
- if (!victim->timestamp_dirty)
- log_fn(LOG_DEBUG,"Considering %sopen purpose %d to %s (circid %d)."
- "(clean).",
- victim->state == CIRCUIT_STATE_OPEN ? "" : "non",
- victim->purpose, victim->build_state->chosen_exit_name,
- victim->n_circ_id);
- else
- log_fn(LOG_DEBUG,"Considering %sopen purpose %d to %s (circid %d). "
- "%d secs since dirty.",
- victim->state == CIRCUIT_STATE_OPEN ? "" : "non",
- victim->purpose, victim->build_state->chosen_exit_name,
- victim->n_circ_id,
- (int)(now - victim->timestamp_dirty));
- }
- #endif
- /* if circ is !open, or if it's open but purpose is a non-finished
- * intro or rend, then mark it for close */
- if (victim->state == CIRCUIT_STATE_OPEN) {
- switch (victim->purpose) {
- default: /* most open circuits can be left alone. */
- continue; /* yes, continue inside a switch refers to the nearest
- * enclosing loop. C is smart. */
- case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
- case CIRCUIT_PURPOSE_C_INTRODUCING:
- case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
- break; /* too old, need to die */
- case CIRCUIT_PURPOSE_C_REND_READY:
- /* it's a rend_ready circ -- has it already picked a query? */
- /* c_rend_ready circs measure age since timestamp_dirty,
- * because that's set when they switch purposes
- */
- if (TO_ORIGIN_CIRCUIT(victim)->rend_data ||
- victim->timestamp_dirty > cutoff)
- continue;
- break;
- 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)
- 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) has timed out, "
- "yet has attached streams!",
- TO_ORIGIN_CIRCUIT(victim)->global_identifier,
- victim->purpose);
- tor_fragile_assert();
- continue;
- }
- if (circuit_timeout_want_to_count_circ(TO_ORIGIN_CIRCUIT(victim)) &&
- circuit_build_times_enough_to_compute(&circ_times)) {
- /* Circuits are allowed to last longer for measurement.
- * Switch their purpose and wait. */
- if (victim->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
- control_event_circuit_status(TO_ORIGIN_CIRCUIT(victim),
- CIRC_EVENT_FAILED,
- END_CIRC_REASON_TIMEOUT);
- victim->purpose = CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT;
- /* Record this failure to check for too many timeouts
- * in a row. This function does not record a time value yet
- * (we do that later); it only counts the fact that we did
- * have a timeout. */
- circuit_build_times_count_timeout(&circ_times,
- first_hop_succeeded);
- continue;
- }
- /*
- * If the circuit build time is much greater than we would have cut
- * it off at, we probably had a suspend event along this codepath,
- * and we should discard the value.
- */
- if (now - victim->timestamp_created > 2*circ_times.close_ms/1000+1) {
- log_notice(LD_CIRC,
- "Extremely large value for circuit build timeout: %lds. "
- "Assuming clock jump. Purpose %d",
- (long)(now - victim->timestamp_created),
- victim->purpose);
- } else if (circuit_build_times_count_close(&circ_times,
- first_hop_succeeded,
- victim->timestamp_created)) {
- circuit_build_times_set_timeout(&circ_times);
- }
- }
- }
- if (victim->n_conn)
- log_info(LD_CIRC,"Abandoning circ %s:%d:%d (state %d:%s, purpose %d)",
- victim->n_conn->_base.address, victim->n_conn->_base.port,
- victim->n_circ_id,
- victim->state, circuit_state_to_string(victim->state),
- victim->purpose);
- else
- log_info(LD_CIRC,"Abandoning circ %d (state %d:%s, purpose %d)",
- victim->n_circ_id, victim->state,
- circuit_state_to_string(victim->state), victim->purpose);
- 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);
- }
- }
- /** 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(edge_connection_t *conn,
- uint16_t port, int min)
- {
- circuit_t *circ;
- routerinfo_t *exitrouter;
- int num=0;
- time_t now = time(NULL);
- int need_uptime = smartlist_string_num_isin(get_options()->LongLivedPorts,
- conn ? conn->socks_request->port : port);
- for (circ=global_circuitlist;circ;circ = circ->next) {
- 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)) {
- cpath_build_state_t *build_state = TO_ORIGIN_CIRCUIT(circ)->build_state;
- if (build_state->is_internal || build_state->onehop_tunnel)
- continue;
- exitrouter = build_state_get_exit_router(build_state);
- if (exitrouter && (!need_uptime || build_state->need_uptime)) {
- int ok;
- if (conn) {
- ok = connection_ap_can_use_exit(conn, exitrouter, 0);
- } else {
- addr_policy_result_t r = compare_addr_to_addr_policy(
- 0, port, exitrouter->exit_policy);
- ok = r != ADDR_POLICY_REJECTED && r != ADDR_POLICY_PROBABLY_REJECTED;
- }
- if (ok) {
- if (++num >= min)
- return 1;
- }
- }
- }
- }
- return 0;
- }
- /** Don't keep more than this many unused open circuits around. */
- #define MAX_UNUSED_OPEN_CIRCUITS 14
- /** Figure out how many circuits we have open that are clean. Make
- * sure it's enough for all the upcoming behaviors we predict we'll have.
- * But put an upper bound on the total number of circuits.
- */
- static void
- circuit_predict_and_launch_new(void)
- {
- circuit_t *circ;
- int num=0, num_internal=0, num_uptime_internal=0;
- int hidserv_needs_uptime=0, hidserv_needs_capacity=1;
- int port_needs_uptime=0, port_needs_capacity=1;
- time_t now = time(NULL);
- int flags = 0;
- /* First, count how many of each type of circuit we have already. */
- for (circ=global_circuitlist;circ;circ = circ->next) {
- cpath_build_state_t *build_state;
- if (!CIRCUIT_IS_ORIGIN(circ))
- continue;
- if (circ->marked_for_close)
- continue; /* don't mess with marked circs */
- if (circ->timestamp_dirty)
- continue; /* only count clean circs */
- if (circ->purpose != CIRCUIT_PURPOSE_C_GENERAL)
- continue; /* only pay attention to general-purpose circs */
- build_state = TO_ORIGIN_CIRCUIT(circ)->build_state;
- if (build_state->onehop_tunnel)
- continue;
- num++;
- if (build_state->is_internal)
- num_internal++;
- if (build_state->need_uptime && build_state->is_internal)
- num_uptime_internal++;
- }
- /* If that's enough, then stop now. */
- if (num >= MAX_UNUSED_OPEN_CIRCUITS)
- return; /* we already have many, making more probably will hurt */
- /* Second, see if we need any more exit circuits. */
- /* check if we know of a port that's been requested recently
- * and no circuit is currently available that can handle it. */
- if (!circuit_all_predicted_ports_handled(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_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
- return;
- }
- /* Third, see if we need any more hidden service (server) circuits. */
- if (num_rend_services() && num_uptime_internal < 3) {
- 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_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
- return;
- }
- /* Fourth, see if we need any more hidden service (client) circuits. */
- if (rep_hist_get_predicted_internal(now, &hidserv_needs_uptime,
- &hidserv_needs_capacity) &&
- ((num_uptime_internal<2 && hidserv_needs_uptime) ||
- num_internal<2)) {
- 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_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
- return;
- }
- /* Finally, check to see if we still need more circuits to learn
- * a good build timeout. But if we're close to our max number we
- * want, don't do another -- we want to leave a few slots open so
- * we can still build circuits preemptively as needed. */
- if (num < MAX_UNUSED_OPEN_CIRCUITS-2 &&
- circuit_build_times_needs_circuits_now(&circ_times)) {
- flags = CIRCLAUNCH_NEED_CAPACITY;
- log_info(LD_CIRC,
- "Have %d clean circs need another buildtime test circ.", num);
- circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
- return;
- }
- }
- /** Build a new test circuit every 5 minutes */
- #define TESTING_CIRCUIT_INTERVAL 300
- /** This function is called once a second, if router_have_min_dir_info() is
- * true. Its job is to make sure all services we offer have enough circuits
- * available. Some services just want enough circuits for current tasks,
- * whereas others want a minimum set of idle circuits hanging around.
- */
- void
- circuit_build_needed_circs(time_t now)
- {
- static time_t time_to_new_circuit = 0;
- or_options_t *options = get_options();
- /* launch a new circ for any pending streams that need one */
- connection_ap_attach_pending();
- /* make sure any hidden services have enough intro points */
- rend_services_introduce();
- if (time_to_new_circuit < now) {
- circuit_reset_failure_count(1);
- time_to_new_circuit = now + options->NewCircuitPeriod;
- if (proxy_mode(get_options()))
- addressmap_clean(now);
- circuit_expire_old_circuits_clientside(now);
- #if 0 /* disable for now, until predict-and-launch-new can cull leftovers */
- circ = circuit_get_youngest_clean_open(CIRCUIT_PURPOSE_C_GENERAL);
- if (get_options()->RunTesting &&
- circ &&
- circ->timestamp_created + TESTING_CIRCUIT_INTERVAL < now) {
- log_fn(LOG_INFO,"Creating a new testing circuit.");
- circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, 0);
- }
- #endif
- }
- if (!options->DisablePredictedCircuits)
- circuit_predict_and_launch_new();
- }
- /** 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);
- conn->cpath_layer = NULL; /* make sure we don't keep a stale pointer */
- conn->on_circuit = NULL;
- if (CIRCUIT_IS_ORIGIN(circ)) {
- origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
- if (conn == origin_circ->p_streams) {
- origin_circ->p_streams = conn->next_stream;
- return;
- }
- 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;
- return;
- }
- } else {
- or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
- if (conn == or_circ->n_streams) {
- or_circ->n_streams = conn->next_stream;
- return;
- }
- if (conn == or_circ->resolving_streams) {
- or_circ->resolving_streams = conn->next_stream;
- return;
- }
- for (prevconn = or_circ->n_streams;
- prevconn && prevconn->next_stream && prevconn->next_stream != conn;
- prevconn = prevconn->next_stream)
- ;
- if (prevconn && prevconn->next_stream) {
- prevconn->next_stream = conn->next_stream;
- return;
- }
- for (prevconn = or_circ->resolving_streams;
- prevconn && prevconn->next_stream && prevconn->next_stream != conn;
- prevconn = prevconn->next_stream)
- ;
- if (prevconn && prevconn->next_stream) {
- prevconn->next_stream = conn->next_stream;
- return;
- }
- }
- log_warn(LD_BUG,"Edge connection not in circuit's list.");
- /* Don't give an error here; it's harmless. */
- tor_fragile_assert();
- }
- /** If we haven't yet decided on a good timeout value for circuit
- * building, we close idles circuits aggressively so we can get more
- * data points. */
- #define IDLE_TIMEOUT_WHILE_LEARNING (10*60)
- /** Find each circuit that has been unused for too long, or dirty
- * for too long and has no streams on it: mark it for close.
- */
- static void
- circuit_expire_old_circuits_clientside(time_t now)
- {
- circuit_t *circ;
- time_t cutoff;
- if (circuit_build_times_needs_circuits(&circ_times)) {
- /* Circuits should be shorter lived if we need more of them
- * for learning a good build timeout */
- cutoff = now - IDLE_TIMEOUT_WHILE_LEARNING;
- } else {
- cutoff = now - get_options()->CircuitIdleTimeout;
- }
- for (circ = global_circuitlist; circ; circ = circ->next) {
- if (circ->marked_for_close || !CIRCUIT_IS_ORIGIN(circ))
- continue;
- /* If the circuit has been dirty for too long, and there are no streams
- * on it, mark it for close.
- */
- if (circ->timestamp_dirty &&
- circ->timestamp_dirty + get_options()->MaxCircuitDirtiness < now &&
- !TO_ORIGIN_CIRCUIT(circ)->p_streams /* nothing attached */ ) {
- log_debug(LD_CIRC, "Closing n_circ_id %d (dirty %d secs ago, "
- "purpose %d)",
- circ->n_circ_id, (int)(now - circ->timestamp_dirty),
- circ->purpose);
- circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
- } else if (!circ->timestamp_dirty && circ->state == CIRCUIT_STATE_OPEN) {
- if (circ->timestamp_created < cutoff) {
- if (circ->purpose == CIRCUIT_PURPOSE_C_GENERAL ||
- circ->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT ||
- circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
- circ->purpose == CIRCUIT_PURPOSE_TESTING ||
- (circ->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING &&
- circ->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) ||
- circ->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) {
- log_debug(LD_CIRC,
- "Closing circuit that has been unused for %ld seconds.",
- (long)(now - circ->timestamp_created));
- 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 seconds. Purpose: %d",
- TO_ORIGIN_CIRCUIT(circ)->global_identifier,
- (long)(now - circ->timestamp_created),
- circ->purpose);
- /* FFFF implement a new circuit_purpose_to_string() so we don't
- * just print out a number for circ->purpose */
- TO_ORIGIN_CIRCUIT(circ)->is_ancient = 1;
- }
- }
- }
- }
- }
- }
- /** How long do we wait before killing circuits with the properties
- * described below?
- *
- * Probably we could choose a number here as low as 5 to 10 seconds,
- * since these circs are used for begindir, and a) generally you either
- * ask another begindir question right after or you don't for a long time,
- * b) clients at least through 0.2.1.x choose from the whole set of
- * directory mirrors at each choice, and c) re-establishing a one-hop
- * circuit via create-fast is a light operation assuming the TLS conn is
- * still there.
- *
- * I expect "b" to go away one day when we move to using directory
- * guards, but I think "a" and "c" are good enough reasons that a low
- * number is safe even then.
- */
- #define IDLE_ONE_HOP_CIRC_TIMEOUT 60
- /** Find each non-origin circuit that has been unused for too long,
- * has no streams on it, used a create_fast, and ends here: mark it
- * for close.
- */
- void
- circuit_expire_old_circuits_serverside(time_t now)
- {
- circuit_t *circ;
- or_circuit_t *or_circ;
- time_t cutoff = now - IDLE_ONE_HOP_CIRC_TIMEOUT;
- for (circ = global_circuitlist; circ; circ = circ->next) {
- if (circ->marked_for_close || CIRCUIT_IS_ORIGIN(circ))
- continue;
- or_circ = TO_OR_CIRCUIT(circ);
- /* If the circuit has been idle for too long, and there are no streams
- * on it, and it ends here, and it used a create_fast, mark it for close.
- */
- if (or_circ->is_first_hop && !circ->n_conn &&
- !or_circ->n_streams && !or_circ->resolving_streams &&
- or_circ->p_conn &&
- or_circ->p_conn->timestamp_last_added_nonpadding <= cutoff) {
- log_info(LD_CIRC, "Closing circ_id %d (empty %d secs ago)",
- or_circ->p_circ_id,
- (int)(now - or_circ->p_conn->timestamp_last_added_nonpadding));
- circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
- }
- }
- }
- /** 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)
- {
- circuit_t *circ;
- int num = 0;
- if (have_performed_bandwidth_test)
- return 1;
- for (circ = global_circuitlist; circ; circ = circ->next) {
- if (!circ->marked_for_close && CIRCUIT_IS_ORIGIN(circ) &&
- circ->purpose == CIRCUIT_PURPOSE_TESTING &&
- circ->state == CIRCUIT_STATE_OPEN)
- num++;
- }
- 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()) {
- /* either we've already done everything we want with testing circuits,
- * or this testing circuit became open due to a fluke, e.g. we picked
- * a last hop where we already had the connection open due to an
- * outgoing local circuit. */
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_AT_ORIGIN);
- } else if (circuit_enough_testing_circs()) {
- router_perform_bandwidth_test(NUM_PARALLEL_TESTING_CIRCS, time(NULL));
- have_performed_bandwidth_test = 1;
- } else
- consider_testing_reachability(1, 0);
- }
- /** A testing circuit has failed to build. Take whatever stats we want. */
- static void
- circuit_testing_failed(origin_circuit_t *circ, int at_last_hop)
- {
- if (server_mode(get_options()) && check_whether_orport_reachable())
- return;
- log_info(LD_GENERAL,
- "Our testing circuit (to see if your ORPort is reachable) "
- "has failed. I'll try again later.");
- /* These aren't used yet. */
- (void)circ;
- (void)at_last_hop;
- }
- /** The circuit <b>circ</b> has just become open. Take the next
- * step: for rendezvous circuits, we pass circ to the appropriate
- * function in rendclient or rendservice. For general circuits, we
- * call connection_ap_attach_pending, which looks for pending streams
- * that could use circ.
- */
- void
- circuit_has_opened(origin_circuit_t *circ)
- {
- control_event_circuit_status(circ, CIRC_EVENT_BUILT, 0);
- /* Remember that this circuit has finished building. Now if we start
- * it building again later (e.g. by extending it), we will know not
- * to consider its build time. */
- circ->has_opened = 1;
- switch (TO_CIRCUIT(circ)->purpose) {
- case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
- rend_client_rendcirc_has_opened(circ);
- connection_ap_attach_pending();
- break;
- case CIRCUIT_PURPOSE_C_INTRODUCING:
- rend_client_introcirc_has_opened(circ);
- break;
- case CIRCUIT_PURPOSE_C_GENERAL:
- /* Tell any AP connections that have been waiting for a new
- * circuit that one is ready. */
- connection_ap_attach_pending();
- break;
- case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
- /* at Bob, waiting for introductions */
- rend_service_intro_has_opened(circ);
- break;
- case CIRCUIT_PURPOSE_S_CONNECT_REND:
- /* at Bob, connecting to rend point */
- rend_service_rendezvous_has_opened(circ);
- break;
- case CIRCUIT_PURPOSE_TESTING:
- circuit_testing_opened(circ);
- break;
- /* default:
- * This won't happen in normal operation, but might happen if the
- * controller did it. Just let it slide. */
- }
- }
- /** Called whenever a circuit could not be successfully built.
- */
- void
- circuit_build_failed(origin_circuit_t *circ)
- {
- /* we should examine circ and see if it failed because of
- * the last hop or an earlier hop. then use this info below.
- */
- int failed_at_last_hop = 0;
- /* If the last hop isn't open, and the second-to-last is, we failed
- * at the last hop. */
- if (circ->cpath &&
- circ->cpath->prev->state != CPATH_STATE_OPEN &&
- circ->cpath->prev->prev->state == CPATH_STATE_OPEN) {
- failed_at_last_hop = 1;
- }
- if (circ->cpath &&
- circ->cpath->state != CPATH_STATE_OPEN) {
- /* We failed at the first hop. 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_conn_id = circ->cpath->extend_info->identity_digest;
- int already_marked = 0;
- if (circ->_base.n_conn) {
- or_connection_t *n_conn = circ->_base.n_conn;
- if (n_conn->is_bad_for_new_circs) {
- /* We only want to blame this router when a fresh healthy
- * connection fails. So don't mark this router as newly failed,
- * since maybe this was just an old circuit attempt that's
- * finally timing out now. Also, there's no need to blow away
- * circuits/streams/etc, since the failure of an unhealthy conn
- * doesn't tell us much about whether a healthy conn would
- * succeed. */
- already_marked = 1;
- }
- log_info(LD_OR,
- "Our circuit failed to get a response from the first hop "
- "(%s:%d). I'm going to try to rotate to a better connection.",
- n_conn->_base.address, n_conn->_base.port);
- n_conn->is_bad_for_new_circs = 1;
- } else {
- log_info(LD_OR,
- "Our circuit died before the first hop with no connection");
- }
- if (n_conn_id && !already_marked) {
- entry_guard_register_connect_status(n_conn_id, 0, 1, time(NULL));
- /* if there are any one-hop streams waiting on this circuit, fail
- * them now so they can retry elsewhere. */
- connection_ap_fail_onehop(n_conn_id, circ->build_state);
- }
- }
- switch (circ->_base.purpose) {
- case CIRCUIT_PURPOSE_C_GENERAL:
- /* If we never built the circuit, note it as a failure. */
- circuit_increment_failure_count();
- if (failed_at_last_hop) {
- /* Make sure any streams that demand our last hop as their exit
- * know that it's unlikely to happen. */
- circuit_discard_optional_exit_enclaves(circ->cpath->prev->extend_info);
- }
- break;
- case CIRCUIT_PURPOSE_TESTING:
- circuit_testing_failed(circ, failed_at_last_hop);
- break;
- case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
- /* at Bob, waiting for introductions */
- if (circ->_base.state != CIRCUIT_STATE_OPEN) {
- circuit_increment_failure_count();
- }
- /* no need to care here, because bob will rebuild intro
- * points periodically. */
- break;
- case CIRCUIT_PURPOSE_C_INTRODUCING:
- /* at Alice, connecting to intro point */
- /* Don't increment failure count, since Bob may have picked
- * the introduction point maliciously */
- /* Alice 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 Alice, waiting for Bob */
- circuit_increment_failure_count();
- /* Alice 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 Bob, connecting to rend point */
- /* Don't increment failure count, since Alice may have picked
- * the rendezvous point maliciously */
- log_info(LD_REND,
- "Couldn't connect to Alice's chosen rend point %s "
- "(%s hop failed).",
- escaped(build_state_get_exit_nickname(circ->build_state)),
- failed_at_last_hop?"last":"non-last");
- rend_service_relaunch_rendezvous(circ);
- break;
- /* default:
- * This won't happen in normal operation, but might happen if the
- * controller did it. Just let it slide. */
- }
- }
- /** Number of consecutive failures so far; should only be touched by
- * circuit_launch_new and circuit_*_failure_count.
- */
- static int n_circuit_failures = 0;
- /** Before the last time we called circuit_reset_failure_count(), were
- * there a lot of failures? */
- static int did_circs_fail_last_period = 0;
- /** Don't retry launching a new circuit if we try this many times with no
- * success. */
- #define MAX_CIRCUIT_FAILURES 5
- /** Launch a new circuit; see circuit_launch_by_extend_info() for
- * details on arguments. */
- origin_circuit_t *
- circuit_launch_by_router(uint8_t purpose,
- routerinfo_t *exit, int flags)
- {
- origin_circuit_t *circ;
- extend_info_t *info = NULL;
- if (exit)
- info = extend_info_from_router(exit);
- circ = circuit_launch_by_extend_info(purpose, info, flags);
- extend_info_free(info);
- return circ;
- }
- /** 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;
- if (!onehop_tunnel && !router_have_minimum_dir_info()) {
- log_debug(LD_CIRC,"Haven't fetched enough directory info yet; canceling "
- "circuit launch.");
- return NULL;
- }
- if ((extend_info || purpose != CIRCUIT_PURPOSE_C_GENERAL) &&
- purpose != CIRCUIT_PURPOSE_TESTING && !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) {
- log_info(LD_CIRC,"Cannibalizing circ '%s' for purpose %d",
- build_state_get_exit_nickname(circ->build_state), purpose);
- circ->_base.purpose = purpose;
- /* reset the birth date of this circ, else expire_building
- * will see it and think it's been trying to build since it
- * began. */
- circ->_base.timestamp_created = time(NULL);
- switch (purpose) {
- case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
- case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
- /* it's ready right now */
- break;
- case CIRCUIT_PURPOSE_C_INTRODUCING:
- case CIRCUIT_PURPOSE_S_CONNECT_REND:
- case CIRCUIT_PURPOSE_C_GENERAL:
- /* 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(edge_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;
- or_options_t *options = get_options();
- tor_assert(conn);
- tor_assert(circp);
- tor_assert(conn->_base.state == AP_CONN_STATE_CIRCUIT_WAIT);
- check_exit_policy =
- conn->socks_request->command == SOCKS_COMMAND_CONNECT &&
- !conn->use_begindir &&
- !connection_edge_is_rendezvous_stream(conn);
- want_onehop = conn->want_onehop;
- need_uptime = !conn->want_onehop && !conn->use_begindir &&
- smartlist_string_num_isin(options->LongLivedPorts,
- conn->socks_request->port);
- need_internal = desired_circuit_purpose != CIRCUIT_PURPOSE_C_GENERAL;
- circ = circuit_get_best(conn, 1, desired_circuit_purpose,
- need_uptime, need_internal);
- if (circ) {
- *circp = circ;
- return 1; /* we're happy */
- }
- if (!want_onehop && !router_have_minimum_dir_info()) {
- if (!connection_get_by_type(CONN_TYPE_DIR)) {
- int severity = LOG_NOTICE;
- /* FFFF if this is a tunneled directory fetch, don't yell
- * as loudly. the user doesn't even know it's happening. */
- if (entry_list_is_constrained(options) &&
- entries_known_but_down(options)) {
- log_fn(severity, LD_APP|LD_DIR,
- "Application request when we haven't used client functionality "
- "lately. Optimistically trying known %s again.",
- options->UseBridges ? "bridges" : "entrynodes");
- entries_retry_all(options);
- } else if (!options->UseBridges || any_bridge_descriptors_known()) {
- log_fn(severity, LD_APP|LD_DIR,
- "Application request when we haven't used client functionality "
- "lately. Optimistically trying directory fetches again.");
- routerlist_retry_directory_downloads(time(NULL));
- }
- }
- /* 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;
- }
- /* Do we need to check exit policy? */
- if (check_exit_policy) {
- if (!conn->chosen_exit_name) {
- struct in_addr in;
- uint32_t addr = 0;
- if (tor_inet_aton(conn->socks_request->address, &in))
- addr = ntohl(in.s_addr);
- if (router_exit_policy_all_routers_reject(addr,
- 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 {
- /* XXXX022 Duplicates checks in connection_ap_handshake_attach_circuit */
- routerinfo_t *router = router_get_by_nickname(conn->chosen_exit_name, 1);
- int opt = conn->chosen_exit_optional;
- if (router && !connection_ap_can_use_exit(conn, router, 0)) {
- log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
- "Requested exit point '%s' 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;
- }
- }
- }
- /* is one already on the way? */
- circ = circuit_get_best(conn, 0, desired_circuit_purpose,
- need_uptime, need_internal);
- if (circ)
- log_debug(LD_CIRC, "one on the way!");
- if (!circ) {
- extend_info_t *extend_info=NULL;
- uint8_t new_circ_purpose;
- if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) {
- /* need to pick an intro point */
- tor_assert(conn->rend_data);
- extend_info = rend_client_get_random_intro(conn->rend_data);
- if (!extend_info) {
- log_info(LD_REND,
- "No intro points for '%s': re-fetching service descriptor.",
- safe_str_client(conn->rend_data->onion_address));
- rend_client_refetch_v2_renddesc(conn->rend_data);
- conn->_base.state = AP_CONN_STATE_RENDDESC_WAIT;
- return 0;
- }
- log_info(LD_REND,"Chose '%s' as intro point for '%s'.",
- extend_info->nickname,
- safe_str_client(conn->rend_data->onion_address));
- }
- /* If we have specified a particular exit node for our
- * connection, then be sure to open a circuit to that exit node.
- */
- if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL) {
- if (conn->chosen_exit_name) {
- routerinfo_t *r;
- int opt = conn->chosen_exit_optional;
- r = router_get_by_nickname(conn->chosen_exit_name, 1);
- if (r) {
- extend_info = extend_info_from_router(r);
- } else {
- log_debug(LD_DIR, "considering %d, %s",
- want_onehop, conn->chosen_exit_name);
- if (want_onehop && conn->chosen_exit_name[0] == '$') {
- /* We're asking for a one-hop circuit to a router that
- * we don't have a routerinfo about. Make up an extend_info. */
- char digest[DIGEST_LEN];
- char *hexdigest = conn->chosen_exit_name+1;
- tor_addr_t addr;
- if (strlen(hexdigest) < HEX_DIGEST_LEN ||
- base16_decode(digest,DIGEST_LEN,hexdigest,HEX_DIGEST_LEN)<0) {
- log_info(LD_DIR, "Broken exit digest on tunnel conn. Closing.");
- return -1;
- }
- if (tor_addr_from_str(&addr, conn->socks_request->address) < 0) {
- log_info(LD_DIR, "Broken address %s on tunnel conn. Closing.",
- escaped_safe_str_client(conn->socks_request->address));
- return -1;
- }
- extend_info = extend_info_alloc(conn->chosen_exit_name+1,
- digest, NULL, &addr,
- conn->socks_request->port);
- } else {
- /* 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;
- }
- }
- }
- }
- 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;
- {
- int flags = CIRCLAUNCH_NEED_CAPACITY;
- if (want_onehop) flags |= CIRCLAUNCH_ONEHOP_TUNNEL;
- if (need_uptime) flags |= CIRCLAUNCH_NEED_UPTIME;
- if (need_internal) flags |= CIRCLAUNCH_IS_INTERNAL;
- circ = circuit_launch_by_extend_info(new_circ_purpose, extend_info,
- flags);
- }
- extend_info_free(extend_info);
- if (desired_circuit_purpose != CIRCUIT_PURPOSE_C_GENERAL) {
- /* help predict this next time */
- rep_hist_note_used_internal(time(NULL), need_uptime, 1);
- if (circ) {
- /* write the service_id into circ */
- circ->rend_data = rend_data_dup(conn->rend_data);
- if (circ->_base.purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND &&
- circ->_base.state == CIRCUIT_STATE_OPEN)
- rend_client_rendcirc_has_opened(circ);
- }
- }
- }
- if (!circ)
- 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;
- }
- /** 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(edge_connection_t *apconn, origin_circuit_t *circ,
- crypt_path_t *cpath)
- {
- /* 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 %d.",
- circ->_base.n_circ_id);
- /* reset it, so we can measure circ timeouts */
- apconn->_base.timestamp_lastread = time(NULL);
- apconn->next_stream = circ->p_streams;
- apconn->on_circuit = TO_CIRCUIT(circ);
- /* assert_connection_ok(conn, time(NULL)); */
- circ->p_streams = apconn;
- if (cpath) { /* we were given one; use it */
- tor_assert(cpath_is_on_circuit(circ, cpath));
- apconn->cpath_layer = 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);
- apconn->cpath_layer = circ->cpath->prev;
- }
- }
- /** If an exit wasn't specifically chosen, save the history for future
- * use. */
- static void
- consider_recording_trackhost(edge_connection_t *conn, origin_circuit_t *circ)
- {
- int found_needle = 0;
- or_options_t *options = get_options();
- size_t len;
- char *new_address;
- char fp[HEX_DIGEST_LEN+1];
- /* Search the addressmap for this conn's destination. */
- /* If he's not in the address map.. */
- if (!options->TrackHostExits ||
- addressmap_have_mapping(conn->socks_request->address,
- options->TrackHostExitsExpire))
- return; /* nothing to track, or already mapped */
- SMARTLIST_FOREACH(options->TrackHostExits, const char *, cp, {
- if (cp[0] == '.') { /* match end */
- if (cp[1] == '\0' ||
- !strcasecmpend(conn->socks_request->address, cp) ||
- !strcasecmp(conn->socks_request->address, &cp[1]))
- found_needle = 1;
- } else if (strcasecmp(cp, conn->socks_request->address) == 0) {
- found_needle = 1;
- }
- });
- if (!found_needle || !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. */
- len = strlen(conn->socks_request->address) + 1 /* '.' */ +
- strlen(fp) + 1 /* '.' */ +
- strlen("exit") + 1 /* '\0' */;
- new_address = tor_malloc(len);
- tor_snprintf(new_address, len, "%s.%s.exit",
- conn->socks_request->address, fp);
- addressmap_register(conn->socks_request->address, new_address,
- time(NULL) + options->TrackHostExitsExpire,
- ADDRMAPSRC_TRACKEXIT);
- }
- /** 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(edge_connection_t *conn,
- origin_circuit_t *circ,
- crypt_path_t *cpath)
- {
- tor_assert(conn);
- tor_assert(conn->_base.state == AP_CONN_STATE_CIRCUIT_WAIT ||
- conn->_base.state == AP_CONN_STATE_CONTROLLER_WAIT);
- tor_assert(conn->socks_request);
- tor_assert(circ);
- tor_assert(circ->_base.state == CIRCUIT_STATE_OPEN);
- conn->_base.state = AP_CONN_STATE_CIRCUIT_WAIT;
- if (!circ->_base.timestamp_dirty)
- circ->_base.timestamp_dirty = time(NULL);
- link_apconn_to_circ(conn, circ, cpath);
- tor_assert(conn->socks_request);
- if (conn->socks_request->command == SOCKS_COMMAND_CONNECT) {
- if (!conn->use_begindir)
- consider_recording_trackhost(conn, circ);
- if (connection_ap_handshake_send_begin(conn) < 0)
- return -1;
- } else {
- if (connection_ap_handshake_send_resolve(conn) < 0)
- return -1;
- }
- return 1;
- }
- /** Try to find a safe live circuit for CONN_TYPE_AP connection conn. If
- * we don't find one: if conn cannot be handled by any known nodes,
- * warn and return -1 (conn needs to die, and is maybe already marked);
- * else launch new circuit (if necessary) and return 0.
- * Otherwise, associate conn with a safe live circuit, do the
- * right next step, and return 1.
- */
- /* 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(edge_connection_t *conn)
- {
- int retval;
- int conn_age;
- int want_onehop;
- tor_assert(conn);
- tor_assert(conn->_base.state == AP_CONN_STATE_CIRCUIT_WAIT);
- tor_assert(conn->socks_request);
- want_onehop = conn->want_onehop;
- conn_age = (int)(time(NULL) - conn->_base.timestamp_created);
- if (conn_age >= get_options()->SocksTimeout) {
- int severity = (tor_addr_is_null(&conn->_base.addr) && !conn->_base.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;
- }
- if (!connection_edge_is_rendezvous_stream(conn)) { /* we're a general conn */
- origin_circuit_t *circ=NULL;
- if (conn->chosen_exit_name) {
- routerinfo_t *router = router_get_by_nickname(conn->chosen_exit_name, 1);
- int opt = conn->chosen_exit_optional;
- if (!router && !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) {
- conn->chosen_exit_optional = 0;
- tor_free(conn->chosen_exit_name);
- return 0;
- }
- return -1;
- }
- if (router && !connection_ap_can_use_exit(conn, router, 0)) {
- log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
- "Requested exit point '%s' 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);
- return 0;
- }
- return -1;
- }
- }
- /* find the circuit that we should use, if there is one. */
- retval = circuit_get_open_circ_or_launch(
- conn, CIRCUIT_PURPOSE_C_GENERAL, &circ);
- if (retval < 1) // XXX021 if we totally fail, this still returns 0 -RD
- return retval;
- log_debug(LD_APP|LD_CIRC,
- "Attaching apconn to circ %d (stream %d sec old).",
- circ->_base.n_circ_id, conn_age);
- /* print the circ's path, so people can figure out which circs are
- * sucking. */
- circuit_log_path(LOG_INFO,LD_APP|LD_CIRC,circ);
- /* We have found a suitable circuit for our conn. Hurray. */
- 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(!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 %d already here. attaching. "
- "(stream %d sec old)",
- rendcirc->_base.n_circ_id, conn_age);
- /* Mark rendezvous circuits as 'newly dirty' every time you use
- * them, since the process of rebuilding a rendezvous circ is so
- * expensive. There is a tradeoff between linkability and
- * feasibility, at this point.
- */
- rendcirc->_base.timestamp_dirty = time(NULL);
- 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;
- }
- if (rendcirc && (rendcirc->_base.purpose ==
- CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED)) {
- log_info(LD_REND,
- "pending-join circ %d already here, with intro ack. "
- "Stalling. (stream %d sec old)",
- rendcirc->_base.n_circ_id, conn_age);
- return 0;
- }
- /* it's on its way. find an intro circ. */
- retval = circuit_get_open_circ_or_launch(
- conn, CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT, &introcirc);
- if (retval < 0) return -1; /* failed */
- if (retval > 0) {
- /* one has already sent the intro. keep waiting. */
- circuit_t *c = NULL;
- tor_assert(introcirc);
- log_info(LD_REND, "Intro circ %d present and awaiting ack (rend %d). "
- "Stalling. (stream %d sec old)",
- introcirc->_base.n_circ_id,
- rendcirc ? rendcirc->_base.n_circ_id : 0,
- conn_age);
- /* abort parallel intro circs, if any */
- for (c = global_circuitlist; c; c = c->next) {
- if (c->purpose == CIRCUIT_PURPOSE_C_INTRODUCING &&
- !c->marked_for_close && CIRCUIT_IS_ORIGIN(c)) {
- origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(c);
- if (oc->rend_data &&
- !rend_cmp_service_ids(conn->rend_data->onion_address,
- oc->rend_data->onion_address)) {
- log_info(LD_REND|LD_CIRC, "Closing introduction circuit that we "
- "built in parallel.");
- circuit_mark_for_close(c, END_CIRC_REASON_TIMEOUT);
- }
- }
- }
- 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 %d already here (no intro-ack yet on "
- "intro %d). (stream %d sec old)",
- rendcirc->_base.n_circ_id,
- introcirc->_base.n_circ_id, conn_age);
- tor_assert(introcirc->_base.purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
- if (introcirc->_base.state == CIRCUIT_STATE_OPEN) {
- log_info(LD_REND,"found open intro circ %d (rend %d); sending "
- "introduction. (stream %d sec old)",
- introcirc->_base.n_circ_id, rendcirc->_base.n_circ_id,
- conn_age);
- if (rend_client_send_introduction(introcirc, rendcirc) < 0) {
- return -1;
- }
- rendcirc->_base.timestamp_dirty = time(NULL);
- introcirc->_base.timestamp_dirty = time(NULL);
- assert_circuit_ok(TO_CIRCUIT(rendcirc));
- assert_circuit_ok(TO_CIRCUIT(introcirc));
- return 0;
- }
- }
- log_info(LD_REND, "Intro (%d) and rend (%d) circs are not both ready. "
- "Stalling conn. (%d sec old)",
- introcirc ? introcirc->_base.n_circ_id : 0,
- rendcirc ? rendcirc->_base.n_circ_id : 0, conn_age);
- return 0;
- }
- }
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