Merge commit 'mikeperry/bug1740' into maint-0.2.2
[tor/rransom.git] / src / or / circuituse.c
blob36dc1c1643b21da9adf90c4ee846fc632eb10673
1 /* Copyright (c) 2001 Matej Pfajfar.
2 * Copyright (c) 2001-2004, Roger Dingledine.
3 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
4 * Copyright (c) 2007-2010, The Tor Project, Inc. */
5 /* See LICENSE for licensing information */
7 /**
8 * \file circuituse.c
9 * \brief Launch the right sort of circuits and attach streams to them.
10 **/
12 #include "or.h"
13 #include "circuitbuild.h"
14 #include "circuitlist.h"
15 #include "circuituse.h"
16 #include "config.h"
17 #include "connection.h"
18 #include "connection_edge.h"
19 #include "control.h"
20 #include "policies.h"
21 #include "rendclient.h"
22 #include "rendcommon.h"
23 #include "rendservice.h"
24 #include "rephist.h"
25 #include "router.h"
26 #include "routerlist.h"
28 /********* START VARIABLES **********/
30 extern circuit_t *global_circuitlist; /* from circuitlist.c */
32 /********* END VARIABLES ************/
34 static void circuit_expire_old_circuits_clientside(time_t now);
35 static void circuit_increment_failure_count(void);
37 long int lround(double x);
39 /** Return 1 if <b>circ</b> could be returned by circuit_get_best().
40 * Else return 0.
42 static int
43 circuit_is_acceptable(circuit_t *circ, edge_connection_t *conn,
44 int must_be_open, uint8_t purpose,
45 int need_uptime, int need_internal,
46 time_t now)
48 routerinfo_t *exitrouter;
49 cpath_build_state_t *build_state;
50 tor_assert(circ);
51 tor_assert(conn);
52 tor_assert(conn->socks_request);
54 if (!CIRCUIT_IS_ORIGIN(circ))
55 return 0; /* this circ doesn't start at us */
56 if (must_be_open && (circ->state != CIRCUIT_STATE_OPEN || !circ->n_conn))
57 return 0; /* ignore non-open circs */
58 if (circ->marked_for_close)
59 return 0;
61 /* if this circ isn't our purpose, skip. */
62 if (purpose == CIRCUIT_PURPOSE_C_REND_JOINED && !must_be_open) {
63 if (circ->purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND &&
64 circ->purpose != CIRCUIT_PURPOSE_C_REND_READY &&
65 circ->purpose != CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED &&
66 circ->purpose != CIRCUIT_PURPOSE_C_REND_JOINED)
67 return 0;
68 } else if (purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT &&
69 !must_be_open) {
70 if (circ->purpose != CIRCUIT_PURPOSE_C_INTRODUCING &&
71 circ->purpose != CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT)
72 return 0;
73 } else {
74 if (purpose != circ->purpose)
75 return 0;
78 if (purpose == CIRCUIT_PURPOSE_C_GENERAL)
79 if (circ->timestamp_dirty &&
80 circ->timestamp_dirty+get_options()->MaxCircuitDirtiness <= now)
81 return 0;
83 /* decide if this circ is suitable for this conn */
85 /* for rend circs, circ->cpath->prev is not the last router in the
86 * circuit, it's the magical extra bob hop. so just check the nickname
87 * of the one we meant to finish at.
89 build_state = TO_ORIGIN_CIRCUIT(circ)->build_state;
90 exitrouter = build_state_get_exit_router(build_state);
92 if (need_uptime && !build_state->need_uptime)
93 return 0;
94 if (need_internal != build_state->is_internal)
95 return 0;
97 if (purpose == CIRCUIT_PURPOSE_C_GENERAL) {
98 if (!exitrouter && !build_state->onehop_tunnel) {
99 log_debug(LD_CIRC,"Not considering circuit with unknown router.");
100 return 0; /* this circuit is screwed and doesn't know it yet,
101 * or is a rendezvous circuit. */
103 if (build_state->onehop_tunnel) {
104 if (!conn->want_onehop) {
105 log_debug(LD_CIRC,"Skipping one-hop circuit.");
106 return 0;
108 tor_assert(conn->chosen_exit_name);
109 if (build_state->chosen_exit) {
110 char digest[DIGEST_LEN];
111 if (hexdigest_to_digest(conn->chosen_exit_name, digest) < 0)
112 return 0; /* broken digest, we don't want it */
113 if (memcmp(digest, build_state->chosen_exit->identity_digest,
114 DIGEST_LEN))
115 return 0; /* this is a circuit to somewhere else */
116 if (tor_digest_is_zero(digest)) {
117 /* we don't know the digest; have to compare addr:port */
118 tor_addr_t addr;
119 int r = tor_addr_from_str(&addr, conn->socks_request->address);
120 if (r < 0 ||
121 !tor_addr_eq(&build_state->chosen_exit->addr, &addr) ||
122 build_state->chosen_exit->port != conn->socks_request->port)
123 return 0;
126 } else {
127 if (conn->want_onehop) {
128 /* don't use three-hop circuits -- that could hurt our anonymity. */
129 return 0;
132 if (exitrouter && !connection_ap_can_use_exit(conn, exitrouter, 0)) {
133 /* can't exit from this router */
134 return 0;
136 } else { /* not general */
137 origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
138 if ((conn->rend_data && !ocirc->rend_data) ||
139 (!conn->rend_data && ocirc->rend_data) ||
140 (conn->rend_data && ocirc->rend_data &&
141 rend_cmp_service_ids(conn->rend_data->onion_address,
142 ocirc->rend_data->onion_address))) {
143 /* this circ is not for this conn */
144 return 0;
147 return 1;
150 /** Return 1 if circuit <b>a</b> is better than circuit <b>b</b> for
151 * <b>purpose</b>, and return 0 otherwise. Used by circuit_get_best.
153 static int
154 circuit_is_better(circuit_t *a, circuit_t *b, uint8_t purpose)
156 switch (purpose) {
157 case CIRCUIT_PURPOSE_C_GENERAL:
158 /* if it's used but less dirty it's best;
159 * else if it's more recently created it's best
161 if (b->timestamp_dirty) {
162 if (a->timestamp_dirty &&
163 a->timestamp_dirty > b->timestamp_dirty)
164 return 1;
165 } else {
166 if (a->timestamp_dirty ||
167 a->timestamp_created > b->timestamp_created)
168 return 1;
169 if (CIRCUIT_IS_ORIGIN(b) &&
170 TO_ORIGIN_CIRCUIT(b)->build_state->is_internal)
171 return 1;
173 break;
174 case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
175 /* the closer it is to ack_wait the better it is */
176 if (a->purpose > b->purpose)
177 return 1;
178 break;
179 case CIRCUIT_PURPOSE_C_REND_JOINED:
180 /* the closer it is to rend_joined the better it is */
181 if (a->purpose > b->purpose)
182 return 1;
183 break;
185 return 0;
188 /** Find the best circ that conn can use, preferably one which is
189 * dirty. Circ must not be too old.
191 * Conn must be defined.
193 * If must_be_open, ignore circs not in CIRCUIT_STATE_OPEN.
195 * circ_purpose specifies what sort of circuit we must have.
196 * It can be C_GENERAL, C_INTRODUCE_ACK_WAIT, or C_REND_JOINED.
198 * If it's REND_JOINED and must_be_open==0, then return the closest
199 * rendezvous-purposed circuit that you can find.
201 * If it's INTRODUCE_ACK_WAIT and must_be_open==0, then return the
202 * closest introduce-purposed circuit that you can find.
204 static origin_circuit_t *
205 circuit_get_best(edge_connection_t *conn, int must_be_open, uint8_t purpose,
206 int need_uptime, int need_internal)
208 circuit_t *circ, *best=NULL;
209 time_t now = time(NULL);
210 int intro_going_on_but_too_old = 0;
212 tor_assert(conn);
214 tor_assert(purpose == CIRCUIT_PURPOSE_C_GENERAL ||
215 purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT ||
216 purpose == CIRCUIT_PURPOSE_C_REND_JOINED);
218 for (circ=global_circuitlist;circ;circ = circ->next) {
219 if (!circuit_is_acceptable(circ,conn,must_be_open,purpose,
220 need_uptime,need_internal,now))
221 continue;
223 /* XXX022 make this 15 be a function of circuit finishing times we've
224 * seen lately, a la Fallon Chen's GSoC work -RD */
225 #define REND_PARALLEL_INTRO_DELAY 15
226 if (purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT &&
227 !must_be_open && circ->state != CIRCUIT_STATE_OPEN &&
228 circ->timestamp_created + REND_PARALLEL_INTRO_DELAY < now) {
229 intro_going_on_but_too_old = 1;
230 continue;
233 /* now this is an acceptable circ to hand back. but that doesn't
234 * mean it's the *best* circ to hand back. try to decide.
236 if (!best || circuit_is_better(circ,best,purpose))
237 best = circ;
240 if (!best && intro_going_on_but_too_old)
241 log_info(LD_REND|LD_CIRC, "There is an intro circuit being created "
242 "right now, but it has already taken quite a while. Starting "
243 "one in parallel.");
245 return best ? TO_ORIGIN_CIRCUIT(best) : NULL;
248 /** Check whether, according to the policies in <b>options</b>, the
249 * circuit <b>circ</b> makes sense. */
250 /* XXXX currently only checks Exclude{Exit}Nodes. It should check more. */
252 circuit_conforms_to_options(const origin_circuit_t *circ,
253 const or_options_t *options)
255 const crypt_path_t *cpath, *cpath_next = NULL;
257 for (cpath = circ->cpath; cpath && cpath_next != circ->cpath;
258 cpath = cpath_next) {
259 cpath_next = cpath->next;
261 if (routerset_contains_extendinfo(options->ExcludeNodes,
262 cpath->extend_info))
263 return 0;
265 if (cpath->next == circ->cpath) {
266 /* This is apparently the exit node. */
268 if (routerset_contains_extendinfo(options->ExcludeExitNodes,
269 cpath->extend_info))
270 return 0;
273 return 1;
276 /** Close all circuits that start at us, aren't open, and were born
277 * at least CircuitBuildTimeout seconds ago.
279 void
280 circuit_expire_building(time_t now)
282 circuit_t *victim, *next_circ = global_circuitlist;
283 /* circ_times.timeout is BUILD_TIMEOUT_INITIAL_VALUE if we haven't
284 * decided on a customized one yet */
285 time_t general_cutoff = now - lround(circ_times.timeout_ms/1000);
286 time_t begindir_cutoff = now - lround(circ_times.timeout_ms/2000);
287 time_t fourhop_cutoff = now - lround(4*circ_times.timeout_ms/3000);
288 time_t cannibalize_cutoff = now - lround(circ_times.timeout_ms/2000);
289 time_t close_cutoff = now - lround(circ_times.close_ms/1000);
290 time_t introcirc_cutoff = begindir_cutoff;
291 cpath_build_state_t *build_state;
293 while (next_circ) {
294 time_t cutoff;
295 victim = next_circ;
296 next_circ = next_circ->next;
297 if (!CIRCUIT_IS_ORIGIN(victim) || /* didn't originate here */
298 victim->marked_for_close) /* don't mess with marked circs */
299 continue;
301 build_state = TO_ORIGIN_CIRCUIT(victim)->build_state;
302 if (build_state && build_state->onehop_tunnel)
303 cutoff = begindir_cutoff;
304 else if (build_state && build_state->desired_path_len == 4
305 && !TO_ORIGIN_CIRCUIT(victim)->has_opened)
306 cutoff = fourhop_cutoff;
307 else if (TO_ORIGIN_CIRCUIT(victim)->has_opened)
308 cutoff = cannibalize_cutoff;
309 else if (victim->purpose == CIRCUIT_PURPOSE_C_INTRODUCING)
310 cutoff = introcirc_cutoff;
311 else if (victim->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT)
312 cutoff = close_cutoff;
313 else
314 cutoff = general_cutoff;
316 if (victim->timestamp_created > cutoff)
317 continue; /* it's still young, leave it alone */
319 #if 0
320 /* some debug logs, to help track bugs */
321 if (victim->purpose == CIRCUIT_PURPOSE_C_INTRODUCING &&
322 victim->timestamp_created <= introcirc_cutoff &&
323 victim->timestamp_created > general_cutoff)
324 log_info(LD_REND|LD_CIRC, "Timing out introduction circuit which we "
325 "would not have done if it had been a general circuit.");
327 if (victim->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING &&
328 victim->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) {
329 if (!victim->timestamp_dirty)
330 log_fn(LOG_DEBUG,"Considering %sopen purpose %d to %s (circid %d)."
331 "(clean).",
332 victim->state == CIRCUIT_STATE_OPEN ? "" : "non",
333 victim->purpose, victim->build_state->chosen_exit_name,
334 victim->n_circ_id);
335 else
336 log_fn(LOG_DEBUG,"Considering %sopen purpose %d to %s (circid %d). "
337 "%d secs since dirty.",
338 victim->state == CIRCUIT_STATE_OPEN ? "" : "non",
339 victim->purpose, victim->build_state->chosen_exit_name,
340 victim->n_circ_id,
341 (int)(now - victim->timestamp_dirty));
343 #endif
345 /* if circ is !open, or if it's open but purpose is a non-finished
346 * intro or rend, then mark it for close */
347 if (victim->state == CIRCUIT_STATE_OPEN) {
348 switch (victim->purpose) {
349 default: /* most open circuits can be left alone. */
350 continue; /* yes, continue inside a switch refers to the nearest
351 * enclosing loop. C is smart. */
352 case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
353 case CIRCUIT_PURPOSE_C_INTRODUCING:
354 case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
355 break; /* too old, need to die */
356 case CIRCUIT_PURPOSE_C_REND_READY:
357 /* it's a rend_ready circ -- has it already picked a query? */
358 /* c_rend_ready circs measure age since timestamp_dirty,
359 * because that's set when they switch purposes
361 if (TO_ORIGIN_CIRCUIT(victim)->rend_data ||
362 victim->timestamp_dirty > cutoff)
363 continue;
364 break;
365 case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
366 case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
367 /* rend and intro circs become dirty each time they
368 * make an introduction attempt. so timestamp_dirty
369 * will reflect the time since the last attempt.
371 if (victim->timestamp_dirty > cutoff)
372 continue;
373 break;
375 } else { /* circuit not open, consider recording failure as timeout */
376 int first_hop_succeeded = TO_ORIGIN_CIRCUIT(victim)->cpath &&
377 TO_ORIGIN_CIRCUIT(victim)->cpath->state == CPATH_STATE_OPEN;
379 if (TO_ORIGIN_CIRCUIT(victim)->p_streams != NULL) {
380 log_warn(LD_BUG, "Circuit %d (purpose %d) has timed out, "
381 "yet has attached streams!",
382 TO_ORIGIN_CIRCUIT(victim)->global_identifier,
383 victim->purpose);
384 tor_fragile_assert();
385 continue;
388 if (circuit_timeout_want_to_count_circ(TO_ORIGIN_CIRCUIT(victim))) {
389 /* Circuits are allowed to last longer for measurement.
390 * Switch their purpose and wait. */
391 if (victim->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
392 victim->purpose = CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT;
393 /* Record this failure to check for too many timeouts
394 * in a row. This function does not record a time value yet
395 * (we do that later); it only counts the fact that we did
396 * have a timeout. */
397 circuit_build_times_count_timeout(&circ_times,
398 first_hop_succeeded);
399 continue;
403 * If the circuit build time is much greater than we would have cut
404 * it off at, we probably had a suspend event along this codepath,
405 * and we should discard the value.
407 if (now - victim->timestamp_created > 2*circ_times.close_ms/1000+1) {
408 log_notice(LD_CIRC,
409 "Extremely large value for circuit build timeout: %lds. "
410 "Assuming clock jump. Purpose %d",
411 (long)(now - victim->timestamp_created),
412 victim->purpose);
413 } else if (circuit_build_times_count_close(&circ_times,
414 first_hop_succeeded,
415 victim->timestamp_created)) {
416 circuit_build_times_set_timeout(&circ_times);
421 if (victim->n_conn)
422 log_info(LD_CIRC,"Abandoning circ %s:%d:%d (state %d:%s, purpose %d)",
423 victim->n_conn->_base.address, victim->n_conn->_base.port,
424 victim->n_circ_id,
425 victim->state, circuit_state_to_string(victim->state),
426 victim->purpose);
427 else
428 log_info(LD_CIRC,"Abandoning circ %d (state %d:%s, purpose %d)",
429 victim->n_circ_id, victim->state,
430 circuit_state_to_string(victim->state), victim->purpose);
432 circuit_log_path(LOG_INFO,LD_CIRC,TO_ORIGIN_CIRCUIT(victim));
433 circuit_mark_for_close(victim, END_CIRC_REASON_TIMEOUT);
437 /** Remove any elements in <b>needed_ports</b> that are handled by an
438 * open or in-progress circuit.
440 void
441 circuit_remove_handled_ports(smartlist_t *needed_ports)
443 int i;
444 uint16_t *port;
446 for (i = 0; i < smartlist_len(needed_ports); ++i) {
447 port = smartlist_get(needed_ports, i);
448 tor_assert(*port);
449 if (circuit_stream_is_being_handled(NULL, *port,
450 MIN_CIRCUITS_HANDLING_STREAM)) {
451 // log_debug(LD_CIRC,"Port %d is already being handled; removing.", port);
452 smartlist_del(needed_ports, i--);
453 tor_free(port);
454 } else {
455 log_debug(LD_CIRC,"Port %d is not handled.", *port);
460 /** Return 1 if at least <b>min</b> general-purpose non-internal circuits
461 * will have an acceptable exit node for exit stream <b>conn</b> if it
462 * is defined, else for "*:port".
463 * Else return 0.
466 circuit_stream_is_being_handled(edge_connection_t *conn,
467 uint16_t port, int min)
469 circuit_t *circ;
470 routerinfo_t *exitrouter;
471 int num=0;
472 time_t now = time(NULL);
473 int need_uptime = smartlist_string_num_isin(get_options()->LongLivedPorts,
474 conn ? conn->socks_request->port : port);
476 for (circ=global_circuitlist;circ;circ = circ->next) {
477 if (CIRCUIT_IS_ORIGIN(circ) &&
478 !circ->marked_for_close &&
479 circ->purpose == CIRCUIT_PURPOSE_C_GENERAL &&
480 (!circ->timestamp_dirty ||
481 circ->timestamp_dirty + get_options()->MaxCircuitDirtiness > now)) {
482 cpath_build_state_t *build_state = TO_ORIGIN_CIRCUIT(circ)->build_state;
483 if (build_state->is_internal || build_state->onehop_tunnel)
484 continue;
486 exitrouter = build_state_get_exit_router(build_state);
487 if (exitrouter && (!need_uptime || build_state->need_uptime)) {
488 int ok;
489 if (conn) {
490 ok = connection_ap_can_use_exit(conn, exitrouter, 0);
491 } else {
492 addr_policy_result_t r = compare_addr_to_addr_policy(
493 0, port, exitrouter->exit_policy);
494 ok = r != ADDR_POLICY_REJECTED && r != ADDR_POLICY_PROBABLY_REJECTED;
496 if (ok) {
497 if (++num >= min)
498 return 1;
503 return 0;
506 /** Don't keep more than this many unused open circuits around. */
507 #define MAX_UNUSED_OPEN_CIRCUITS 14
509 /** Figure out how many circuits we have open that are clean. Make
510 * sure it's enough for all the upcoming behaviors we predict we'll have.
511 * But put an upper bound on the total number of circuits.
513 static void
514 circuit_predict_and_launch_new(void)
516 circuit_t *circ;
517 int num=0, num_internal=0, num_uptime_internal=0;
518 int hidserv_needs_uptime=0, hidserv_needs_capacity=1;
519 int port_needs_uptime=0, port_needs_capacity=1;
520 time_t now = time(NULL);
521 int flags = 0;
523 /* First, count how many of each type of circuit we have already. */
524 for (circ=global_circuitlist;circ;circ = circ->next) {
525 cpath_build_state_t *build_state;
526 if (!CIRCUIT_IS_ORIGIN(circ))
527 continue;
528 if (circ->marked_for_close)
529 continue; /* don't mess with marked circs */
530 if (circ->timestamp_dirty)
531 continue; /* only count clean circs */
532 if (circ->purpose != CIRCUIT_PURPOSE_C_GENERAL)
533 continue; /* only pay attention to general-purpose circs */
534 build_state = TO_ORIGIN_CIRCUIT(circ)->build_state;
535 if (build_state->onehop_tunnel)
536 continue;
537 num++;
538 if (build_state->is_internal)
539 num_internal++;
540 if (build_state->need_uptime && build_state->is_internal)
541 num_uptime_internal++;
544 /* If that's enough, then stop now. */
545 if (num >= MAX_UNUSED_OPEN_CIRCUITS)
546 return; /* we already have many, making more probably will hurt */
548 /* Second, see if we need any more exit circuits. */
549 /* check if we know of a port that's been requested recently
550 * and no circuit is currently available that can handle it. */
551 if (!circuit_all_predicted_ports_handled(now, &port_needs_uptime,
552 &port_needs_capacity)) {
553 if (port_needs_uptime)
554 flags |= CIRCLAUNCH_NEED_UPTIME;
555 if (port_needs_capacity)
556 flags |= CIRCLAUNCH_NEED_CAPACITY;
557 log_info(LD_CIRC,
558 "Have %d clean circs (%d internal), need another exit circ.",
559 num, num_internal);
560 circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
561 return;
564 /* Third, see if we need any more hidden service (server) circuits. */
565 if (num_rend_services() && num_uptime_internal < 3) {
566 flags = (CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_NEED_UPTIME |
567 CIRCLAUNCH_IS_INTERNAL);
568 log_info(LD_CIRC,
569 "Have %d clean circs (%d internal), need another internal "
570 "circ for my hidden service.",
571 num, num_internal);
572 circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
573 return;
576 /* Fourth, see if we need any more hidden service (client) circuits. */
577 if (rep_hist_get_predicted_internal(now, &hidserv_needs_uptime,
578 &hidserv_needs_capacity) &&
579 ((num_uptime_internal<2 && hidserv_needs_uptime) ||
580 num_internal<2)) {
581 if (hidserv_needs_uptime)
582 flags |= CIRCLAUNCH_NEED_UPTIME;
583 if (hidserv_needs_capacity)
584 flags |= CIRCLAUNCH_NEED_CAPACITY;
585 flags |= CIRCLAUNCH_IS_INTERNAL;
586 log_info(LD_CIRC,
587 "Have %d clean circs (%d uptime-internal, %d internal), need"
588 " another hidden service circ.",
589 num, num_uptime_internal, num_internal);
590 circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
591 return;
594 /* Finally, check to see if we still need more circuits to learn
595 * a good build timeout. But if we're close to our max number we
596 * want, don't do another -- we want to leave a few slots open so
597 * we can still build circuits preemptively as needed. */
598 if (num < MAX_UNUSED_OPEN_CIRCUITS-2 &&
599 circuit_build_times_needs_circuits_now(&circ_times)) {
600 flags = CIRCLAUNCH_NEED_CAPACITY;
601 log_info(LD_CIRC,
602 "Have %d clean circs need another buildtime test circ.", num);
603 circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
604 return;
608 /** Build a new test circuit every 5 minutes */
609 #define TESTING_CIRCUIT_INTERVAL 300
611 /** This function is called once a second, if router_have_min_dir_info() is
612 * true. Its job is to make sure all services we offer have enough circuits
613 * available. Some services just want enough circuits for current tasks,
614 * whereas others want a minimum set of idle circuits hanging around.
616 void
617 circuit_build_needed_circs(time_t now)
619 static time_t time_to_new_circuit = 0;
620 or_options_t *options = get_options();
622 /* launch a new circ for any pending streams that need one */
623 connection_ap_attach_pending();
625 /* make sure any hidden services have enough intro points */
626 rend_services_introduce();
628 if (time_to_new_circuit < now) {
629 circuit_reset_failure_count(1);
630 time_to_new_circuit = now + options->NewCircuitPeriod;
631 if (proxy_mode(get_options()))
632 addressmap_clean(now);
633 circuit_expire_old_circuits_clientside(now);
635 #if 0 /* disable for now, until predict-and-launch-new can cull leftovers */
636 circ = circuit_get_youngest_clean_open(CIRCUIT_PURPOSE_C_GENERAL);
637 if (get_options()->RunTesting &&
638 circ &&
639 circ->timestamp_created + TESTING_CIRCUIT_INTERVAL < now) {
640 log_fn(LOG_INFO,"Creating a new testing circuit.");
641 circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, 0);
643 #endif
645 if (!options->DisablePredictedCircuits)
646 circuit_predict_and_launch_new();
649 /** If the stream <b>conn</b> is a member of any of the linked
650 * lists of <b>circ</b>, then remove it from the list.
652 void
653 circuit_detach_stream(circuit_t *circ, edge_connection_t *conn)
655 edge_connection_t *prevconn;
657 tor_assert(circ);
658 tor_assert(conn);
660 conn->cpath_layer = NULL; /* make sure we don't keep a stale pointer */
661 conn->on_circuit = NULL;
663 if (CIRCUIT_IS_ORIGIN(circ)) {
664 origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
665 if (conn == origin_circ->p_streams) {
666 origin_circ->p_streams = conn->next_stream;
667 return;
670 for (prevconn = origin_circ->p_streams;
671 prevconn && prevconn->next_stream && prevconn->next_stream != conn;
672 prevconn = prevconn->next_stream)
674 if (prevconn && prevconn->next_stream) {
675 prevconn->next_stream = conn->next_stream;
676 return;
678 } else {
679 or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
680 if (conn == or_circ->n_streams) {
681 or_circ->n_streams = conn->next_stream;
682 return;
684 if (conn == or_circ->resolving_streams) {
685 or_circ->resolving_streams = conn->next_stream;
686 return;
689 for (prevconn = or_circ->n_streams;
690 prevconn && prevconn->next_stream && prevconn->next_stream != conn;
691 prevconn = prevconn->next_stream)
693 if (prevconn && prevconn->next_stream) {
694 prevconn->next_stream = conn->next_stream;
695 return;
698 for (prevconn = or_circ->resolving_streams;
699 prevconn && prevconn->next_stream && prevconn->next_stream != conn;
700 prevconn = prevconn->next_stream)
702 if (prevconn && prevconn->next_stream) {
703 prevconn->next_stream = conn->next_stream;
704 return;
708 log_warn(LD_BUG,"Edge connection not in circuit's list.");
709 /* Don't give an error here; it's harmless. */
710 tor_fragile_assert();
713 /** If we haven't yet decided on a good timeout value for circuit
714 * building, we close idles circuits aggressively so we can get more
715 * data points. */
716 #define IDLE_TIMEOUT_WHILE_LEARNING (10*60)
718 /** Find each circuit that has been unused for too long, or dirty
719 * for too long and has no streams on it: mark it for close.
721 static void
722 circuit_expire_old_circuits_clientside(time_t now)
724 circuit_t *circ;
725 time_t cutoff;
727 if (circuit_build_times_needs_circuits(&circ_times)) {
728 /* Circuits should be shorter lived if we need more of them
729 * for learning a good build timeout */
730 cutoff = now - IDLE_TIMEOUT_WHILE_LEARNING;
731 } else {
732 cutoff = now - get_options()->CircuitIdleTimeout;
735 for (circ = global_circuitlist; circ; circ = circ->next) {
736 if (circ->marked_for_close || !CIRCUIT_IS_ORIGIN(circ))
737 continue;
738 /* If the circuit has been dirty for too long, and there are no streams
739 * on it, mark it for close.
741 if (circ->timestamp_dirty &&
742 circ->timestamp_dirty + get_options()->MaxCircuitDirtiness < now &&
743 !TO_ORIGIN_CIRCUIT(circ)->p_streams /* nothing attached */ ) {
744 log_debug(LD_CIRC, "Closing n_circ_id %d (dirty %d secs ago, "
745 "purpose %d)",
746 circ->n_circ_id, (int)(now - circ->timestamp_dirty),
747 circ->purpose);
748 circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
749 } else if (!circ->timestamp_dirty && circ->state == CIRCUIT_STATE_OPEN) {
750 if (circ->timestamp_created < cutoff) {
751 if (circ->purpose == CIRCUIT_PURPOSE_C_GENERAL ||
752 circ->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT ||
753 circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
754 circ->purpose == CIRCUIT_PURPOSE_TESTING ||
755 (circ->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING &&
756 circ->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) ||
757 circ->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) {
758 log_debug(LD_CIRC,
759 "Closing circuit that has been unused for %ld seconds.",
760 (long)(now - circ->timestamp_created));
761 circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
762 } else if (!TO_ORIGIN_CIRCUIT(circ)->is_ancient) {
763 /* Server-side rend joined circuits can end up really old, because
764 * they are reused by clients for longer than normal. The client
765 * controls their lifespan. (They never become dirty, because
766 * connection_exit_begin_conn() never marks anything as dirty.)
767 * Similarly, server-side intro circuits last a long time. */
768 if (circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED &&
769 circ->purpose != CIRCUIT_PURPOSE_S_INTRO) {
770 log_notice(LD_CIRC,
771 "Ancient non-dirty circuit %d is still around after "
772 "%ld seconds. Purpose: %d",
773 TO_ORIGIN_CIRCUIT(circ)->global_identifier,
774 (long)(now - circ->timestamp_created),
775 circ->purpose);
776 /* FFFF implement a new circuit_purpose_to_string() so we don't
777 * just print out a number for circ->purpose */
778 TO_ORIGIN_CIRCUIT(circ)->is_ancient = 1;
786 /** How long do we wait before killing circuits with the properties
787 * described below?
789 * Probably we could choose a number here as low as 5 to 10 seconds,
790 * since these circs are used for begindir, and a) generally you either
791 * ask another begindir question right after or you don't for a long time,
792 * b) clients at least through 0.2.1.x choose from the whole set of
793 * directory mirrors at each choice, and c) re-establishing a one-hop
794 * circuit via create-fast is a light operation assuming the TLS conn is
795 * still there.
797 * I expect "b" to go away one day when we move to using directory
798 * guards, but I think "a" and "c" are good enough reasons that a low
799 * number is safe even then.
801 #define IDLE_ONE_HOP_CIRC_TIMEOUT 60
803 /** Find each non-origin circuit that has been unused for too long,
804 * has no streams on it, used a create_fast, and ends here: mark it
805 * for close.
807 void
808 circuit_expire_old_circuits_serverside(time_t now)
810 circuit_t *circ;
811 or_circuit_t *or_circ;
812 time_t cutoff = now - IDLE_ONE_HOP_CIRC_TIMEOUT;
814 for (circ = global_circuitlist; circ; circ = circ->next) {
815 if (circ->marked_for_close || CIRCUIT_IS_ORIGIN(circ))
816 continue;
817 or_circ = TO_OR_CIRCUIT(circ);
818 /* If the circuit has been idle for too long, and there are no streams
819 * on it, and it ends here, and it used a create_fast, mark it for close.
821 if (or_circ->is_first_hop && !circ->n_conn &&
822 !or_circ->n_streams && !or_circ->resolving_streams &&
823 or_circ->p_conn &&
824 or_circ->p_conn->timestamp_last_added_nonpadding <= cutoff) {
825 log_info(LD_CIRC, "Closing circ_id %d (empty %d secs ago)",
826 or_circ->p_circ_id,
827 (int)(now - or_circ->p_conn->timestamp_last_added_nonpadding));
828 circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
833 /** Number of testing circuits we want open before testing our bandwidth. */
834 #define NUM_PARALLEL_TESTING_CIRCS 4
836 /** True iff we've ever had enough testing circuits open to test our
837 * bandwidth. */
838 static int have_performed_bandwidth_test = 0;
840 /** Reset have_performed_bandwidth_test, so we'll start building
841 * testing circuits again so we can exercise our bandwidth. */
842 void
843 reset_bandwidth_test(void)
845 have_performed_bandwidth_test = 0;
848 /** Return 1 if we've already exercised our bandwidth, or if we
849 * have fewer than NUM_PARALLEL_TESTING_CIRCS testing circuits
850 * established or on the way. Else return 0.
853 circuit_enough_testing_circs(void)
855 circuit_t *circ;
856 int num = 0;
858 if (have_performed_bandwidth_test)
859 return 1;
861 for (circ = global_circuitlist; circ; circ = circ->next) {
862 if (!circ->marked_for_close && CIRCUIT_IS_ORIGIN(circ) &&
863 circ->purpose == CIRCUIT_PURPOSE_TESTING &&
864 circ->state == CIRCUIT_STATE_OPEN)
865 num++;
867 return num >= NUM_PARALLEL_TESTING_CIRCS;
870 /** A testing circuit has completed. Take whatever stats we want.
871 * Noticing reachability is taken care of in onionskin_answer(),
872 * so there's no need to record anything here. But if we still want
873 * to do the bandwidth test, and we now have enough testing circuits
874 * open, do it.
876 static void
877 circuit_testing_opened(origin_circuit_t *circ)
879 if (have_performed_bandwidth_test ||
880 !check_whether_orport_reachable()) {
881 /* either we've already done everything we want with testing circuits,
882 * or this testing circuit became open due to a fluke, e.g. we picked
883 * a last hop where we already had the connection open due to an
884 * outgoing local circuit. */
885 circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_AT_ORIGIN);
886 } else if (circuit_enough_testing_circs()) {
887 router_perform_bandwidth_test(NUM_PARALLEL_TESTING_CIRCS, time(NULL));
888 have_performed_bandwidth_test = 1;
889 } else
890 consider_testing_reachability(1, 0);
893 /** A testing circuit has failed to build. Take whatever stats we want. */
894 static void
895 circuit_testing_failed(origin_circuit_t *circ, int at_last_hop)
897 if (server_mode(get_options()) && check_whether_orport_reachable())
898 return;
900 log_info(LD_GENERAL,
901 "Our testing circuit (to see if your ORPort is reachable) "
902 "has failed. I'll try again later.");
904 /* These aren't used yet. */
905 (void)circ;
906 (void)at_last_hop;
909 /** The circuit <b>circ</b> has just become open. Take the next
910 * step: for rendezvous circuits, we pass circ to the appropriate
911 * function in rendclient or rendservice. For general circuits, we
912 * call connection_ap_attach_pending, which looks for pending streams
913 * that could use circ.
915 void
916 circuit_has_opened(origin_circuit_t *circ)
918 control_event_circuit_status(circ, CIRC_EVENT_BUILT, 0);
920 /* Remember that this circuit has finished building. Now if we start
921 * it building again later (e.g. by extending it), we will know not
922 * to consider its build time. */
923 circ->has_opened = 1;
925 switch (TO_CIRCUIT(circ)->purpose) {
926 case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
927 rend_client_rendcirc_has_opened(circ);
928 connection_ap_attach_pending();
929 break;
930 case CIRCUIT_PURPOSE_C_INTRODUCING:
931 rend_client_introcirc_has_opened(circ);
932 break;
933 case CIRCUIT_PURPOSE_C_GENERAL:
934 /* Tell any AP connections that have been waiting for a new
935 * circuit that one is ready. */
936 connection_ap_attach_pending();
937 break;
938 case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
939 /* at Bob, waiting for introductions */
940 rend_service_intro_has_opened(circ);
941 break;
942 case CIRCUIT_PURPOSE_S_CONNECT_REND:
943 /* at Bob, connecting to rend point */
944 rend_service_rendezvous_has_opened(circ);
945 break;
946 case CIRCUIT_PURPOSE_TESTING:
947 circuit_testing_opened(circ);
948 break;
949 /* default:
950 * This won't happen in normal operation, but might happen if the
951 * controller did it. Just let it slide. */
955 /** Called whenever a circuit could not be successfully built.
957 void
958 circuit_build_failed(origin_circuit_t *circ)
960 /* we should examine circ and see if it failed because of
961 * the last hop or an earlier hop. then use this info below.
963 int failed_at_last_hop = 0;
964 /* If the last hop isn't open, and the second-to-last is, we failed
965 * at the last hop. */
966 if (circ->cpath &&
967 circ->cpath->prev->state != CPATH_STATE_OPEN &&
968 circ->cpath->prev->prev->state == CPATH_STATE_OPEN) {
969 failed_at_last_hop = 1;
971 if (circ->cpath &&
972 circ->cpath->state != CPATH_STATE_OPEN) {
973 /* We failed at the first hop. If there's an OR connection
974 * to blame, blame it. Also, avoid this relay for a while, and
975 * fail any one-hop directory fetches destined for it. */
976 const char *n_conn_id = circ->cpath->extend_info->identity_digest;
977 int already_marked = 0;
978 if (circ->_base.n_conn) {
979 or_connection_t *n_conn = circ->_base.n_conn;
980 if (n_conn->is_bad_for_new_circs) {
981 /* We only want to blame this router when a fresh healthy
982 * connection fails. So don't mark this router as newly failed,
983 * since maybe this was just an old circuit attempt that's
984 * finally timing out now. Also, there's no need to blow away
985 * circuits/streams/etc, since the failure of an unhealthy conn
986 * doesn't tell us much about whether a healthy conn would
987 * succeed. */
988 already_marked = 1;
990 log_info(LD_OR,
991 "Our circuit failed to get a response from the first hop "
992 "(%s:%d). I'm going to try to rotate to a better connection.",
993 n_conn->_base.address, n_conn->_base.port);
994 n_conn->is_bad_for_new_circs = 1;
995 } else {
996 log_info(LD_OR,
997 "Our circuit died before the first hop with no connection");
999 if (n_conn_id && !already_marked) {
1000 entry_guard_register_connect_status(n_conn_id, 0, 1, time(NULL));
1001 /* if there are any one-hop streams waiting on this circuit, fail
1002 * them now so they can retry elsewhere. */
1003 connection_ap_fail_onehop(n_conn_id, circ->build_state);
1007 switch (circ->_base.purpose) {
1008 case CIRCUIT_PURPOSE_C_GENERAL:
1009 /* If we never built the circuit, note it as a failure. */
1010 circuit_increment_failure_count();
1011 if (failed_at_last_hop) {
1012 /* Make sure any streams that demand our last hop as their exit
1013 * know that it's unlikely to happen. */
1014 circuit_discard_optional_exit_enclaves(circ->cpath->prev->extend_info);
1016 break;
1017 case CIRCUIT_PURPOSE_TESTING:
1018 circuit_testing_failed(circ, failed_at_last_hop);
1019 break;
1020 case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
1021 /* at Bob, waiting for introductions */
1022 if (circ->_base.state != CIRCUIT_STATE_OPEN) {
1023 circuit_increment_failure_count();
1025 /* no need to care here, because bob will rebuild intro
1026 * points periodically. */
1027 break;
1028 case CIRCUIT_PURPOSE_C_INTRODUCING:
1029 /* at Alice, connecting to intro point */
1030 /* Don't increment failure count, since Bob may have picked
1031 * the introduction point maliciously */
1032 /* Alice will pick a new intro point when this one dies, if
1033 * the stream in question still cares. No need to act here. */
1034 break;
1035 case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
1036 /* at Alice, waiting for Bob */
1037 circuit_increment_failure_count();
1038 /* Alice will pick a new rend point when this one dies, if
1039 * the stream in question still cares. No need to act here. */
1040 break;
1041 case CIRCUIT_PURPOSE_S_CONNECT_REND:
1042 /* at Bob, connecting to rend point */
1043 /* Don't increment failure count, since Alice may have picked
1044 * the rendezvous point maliciously */
1045 log_info(LD_REND,
1046 "Couldn't connect to Alice's chosen rend point %s "
1047 "(%s hop failed).",
1048 escaped(build_state_get_exit_nickname(circ->build_state)),
1049 failed_at_last_hop?"last":"non-last");
1050 rend_service_relaunch_rendezvous(circ);
1051 break;
1052 /* default:
1053 * This won't happen in normal operation, but might happen if the
1054 * controller did it. Just let it slide. */
1058 /** Number of consecutive failures so far; should only be touched by
1059 * circuit_launch_new and circuit_*_failure_count.
1061 static int n_circuit_failures = 0;
1062 /** Before the last time we called circuit_reset_failure_count(), were
1063 * there a lot of failures? */
1064 static int did_circs_fail_last_period = 0;
1066 /** Don't retry launching a new circuit if we try this many times with no
1067 * success. */
1068 #define MAX_CIRCUIT_FAILURES 5
1070 /** Launch a new circuit; see circuit_launch_by_extend_info() for
1071 * details on arguments. */
1072 origin_circuit_t *
1073 circuit_launch_by_router(uint8_t purpose,
1074 routerinfo_t *exit, int flags)
1076 origin_circuit_t *circ;
1077 extend_info_t *info = NULL;
1078 if (exit)
1079 info = extend_info_from_router(exit);
1080 circ = circuit_launch_by_extend_info(purpose, info, flags);
1082 extend_info_free(info);
1083 return circ;
1086 /** Launch a new circuit with purpose <b>purpose</b> and exit node
1087 * <b>extend_info</b> (or NULL to select a random exit node). If flags
1088 * contains CIRCLAUNCH_NEED_UPTIME, choose among routers with high uptime. If
1089 * CIRCLAUNCH_NEED_CAPACITY is set, choose among routers with high bandwidth.
1090 * If CIRCLAUNCH_IS_INTERNAL is true, the last hop need not be an exit node.
1091 * If CIRCLAUNCH_ONEHOP_TUNNEL is set, the circuit will have only one hop.
1092 * Return the newly allocated circuit on success, or NULL on failure. */
1093 origin_circuit_t *
1094 circuit_launch_by_extend_info(uint8_t purpose,
1095 extend_info_t *extend_info,
1096 int flags)
1098 origin_circuit_t *circ;
1099 int onehop_tunnel = (flags & CIRCLAUNCH_ONEHOP_TUNNEL) != 0;
1101 if (!onehop_tunnel && !router_have_minimum_dir_info()) {
1102 log_debug(LD_CIRC,"Haven't fetched enough directory info yet; canceling "
1103 "circuit launch.");
1104 return NULL;
1107 if ((extend_info || purpose != CIRCUIT_PURPOSE_C_GENERAL) &&
1108 purpose != CIRCUIT_PURPOSE_TESTING && !onehop_tunnel) {
1109 /* see if there are appropriate circs available to cannibalize. */
1110 /* XXX if we're planning to add a hop, perhaps we want to look for
1111 * internal circs rather than exit circs? -RD */
1112 circ = circuit_find_to_cannibalize(purpose, extend_info, flags);
1113 if (circ) {
1114 log_info(LD_CIRC,"Cannibalizing circ '%s' for purpose %d",
1115 build_state_get_exit_nickname(circ->build_state), purpose);
1116 circ->_base.purpose = purpose;
1117 /* reset the birth date of this circ, else expire_building
1118 * will see it and think it's been trying to build since it
1119 * began. */
1120 circ->_base.timestamp_created = time(NULL);
1121 switch (purpose) {
1122 case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
1123 case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
1124 /* it's ready right now */
1125 break;
1126 case CIRCUIT_PURPOSE_C_INTRODUCING:
1127 case CIRCUIT_PURPOSE_S_CONNECT_REND:
1128 case CIRCUIT_PURPOSE_C_GENERAL:
1129 /* need to add a new hop */
1130 tor_assert(extend_info);
1131 if (circuit_extend_to_new_exit(circ, extend_info) < 0)
1132 return NULL;
1133 break;
1134 default:
1135 log_warn(LD_BUG,
1136 "unexpected purpose %d when cannibalizing a circ.",
1137 purpose);
1138 tor_fragile_assert();
1139 return NULL;
1141 return circ;
1145 if (did_circs_fail_last_period &&
1146 n_circuit_failures > MAX_CIRCUIT_FAILURES) {
1147 /* too many failed circs in a row. don't try. */
1148 // log_fn(LOG_INFO,"%d failures so far, not trying.",n_circuit_failures);
1149 return NULL;
1152 /* try a circ. if it fails, circuit_mark_for_close will increment
1153 * n_circuit_failures */
1154 return circuit_establish_circuit(purpose, extend_info, flags);
1157 /** Record another failure at opening a general circuit. When we have
1158 * too many, we'll stop trying for the remainder of this minute.
1160 static void
1161 circuit_increment_failure_count(void)
1163 ++n_circuit_failures;
1164 log_debug(LD_CIRC,"n_circuit_failures now %d.",n_circuit_failures);
1167 /** Reset the failure count for opening general circuits. This means
1168 * we will try MAX_CIRCUIT_FAILURES times more (if necessary) before
1169 * stopping again.
1171 void
1172 circuit_reset_failure_count(int timeout)
1174 if (timeout && n_circuit_failures > MAX_CIRCUIT_FAILURES)
1175 did_circs_fail_last_period = 1;
1176 else
1177 did_circs_fail_last_period = 0;
1178 n_circuit_failures = 0;
1181 /** Find an open circ that we're happy to use for <b>conn</b> and return 1. If
1182 * there isn't one, and there isn't one on the way, launch one and return
1183 * 0. If it will never work, return -1.
1185 * Write the found or in-progress or launched circ into *circp.
1187 static int
1188 circuit_get_open_circ_or_launch(edge_connection_t *conn,
1189 uint8_t desired_circuit_purpose,
1190 origin_circuit_t **circp)
1192 origin_circuit_t *circ;
1193 int check_exit_policy;
1194 int need_uptime, need_internal;
1195 int want_onehop;
1196 or_options_t *options = get_options();
1198 tor_assert(conn);
1199 tor_assert(circp);
1200 tor_assert(conn->_base.state == AP_CONN_STATE_CIRCUIT_WAIT);
1201 check_exit_policy =
1202 conn->socks_request->command == SOCKS_COMMAND_CONNECT &&
1203 !conn->use_begindir &&
1204 !connection_edge_is_rendezvous_stream(conn);
1205 want_onehop = conn->want_onehop;
1207 need_uptime = !conn->want_onehop && !conn->use_begindir &&
1208 smartlist_string_num_isin(options->LongLivedPorts,
1209 conn->socks_request->port);
1210 need_internal = desired_circuit_purpose != CIRCUIT_PURPOSE_C_GENERAL;
1212 circ = circuit_get_best(conn, 1, desired_circuit_purpose,
1213 need_uptime, need_internal);
1215 if (circ) {
1216 *circp = circ;
1217 return 1; /* we're happy */
1220 if (!want_onehop && !router_have_minimum_dir_info()) {
1221 if (!connection_get_by_type(CONN_TYPE_DIR)) {
1222 int severity = LOG_NOTICE;
1223 /* FFFF if this is a tunneled directory fetch, don't yell
1224 * as loudly. the user doesn't even know it's happening. */
1225 if (entry_list_is_constrained(options) &&
1226 entries_known_but_down(options)) {
1227 log_fn(severity, LD_APP|LD_DIR,
1228 "Application request when we haven't used client functionality "
1229 "lately. Optimistically trying known %s again.",
1230 options->UseBridges ? "bridges" : "entrynodes");
1231 entries_retry_all(options);
1232 } else if (!options->UseBridges || any_bridge_descriptors_known()) {
1233 log_fn(severity, LD_APP|LD_DIR,
1234 "Application request when we haven't used client functionality "
1235 "lately. Optimistically trying directory fetches again.");
1236 routerlist_retry_directory_downloads(time(NULL));
1239 /* the stream will be dealt with when router_have_minimum_dir_info becomes
1240 * 1, or when all directory attempts fail and directory_all_unreachable()
1241 * kills it.
1243 return 0;
1246 /* Do we need to check exit policy? */
1247 if (check_exit_policy) {
1248 if (!conn->chosen_exit_name) {
1249 struct in_addr in;
1250 uint32_t addr = 0;
1251 if (tor_inet_aton(conn->socks_request->address, &in))
1252 addr = ntohl(in.s_addr);
1253 if (router_exit_policy_all_routers_reject(addr,
1254 conn->socks_request->port,
1255 need_uptime)) {
1256 log_notice(LD_APP,
1257 "No Tor server allows exit to %s:%d. Rejecting.",
1258 safe_str_client(conn->socks_request->address),
1259 conn->socks_request->port);
1260 return -1;
1262 } else {
1263 /* XXXX022 Duplicates checks in connection_ap_handshake_attach_circuit */
1264 routerinfo_t *router = router_get_by_nickname(conn->chosen_exit_name, 1);
1265 int opt = conn->chosen_exit_optional;
1266 if (router && !connection_ap_can_use_exit(conn, router, 0)) {
1267 log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
1268 "Requested exit point '%s' would refuse request. %s.",
1269 conn->chosen_exit_name, opt ? "Trying others" : "Closing");
1270 if (opt) {
1271 conn->chosen_exit_optional = 0;
1272 tor_free(conn->chosen_exit_name);
1273 /* Try again. */
1274 return circuit_get_open_circ_or_launch(conn,
1275 desired_circuit_purpose,
1276 circp);
1278 return -1;
1283 /* is one already on the way? */
1284 circ = circuit_get_best(conn, 0, desired_circuit_purpose,
1285 need_uptime, need_internal);
1286 if (circ)
1287 log_debug(LD_CIRC, "one on the way!");
1288 if (!circ) {
1289 extend_info_t *extend_info=NULL;
1290 uint8_t new_circ_purpose;
1292 if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) {
1293 /* need to pick an intro point */
1294 tor_assert(conn->rend_data);
1295 extend_info = rend_client_get_random_intro(conn->rend_data);
1296 if (!extend_info) {
1297 log_info(LD_REND,
1298 "No intro points for '%s': re-fetching service descriptor.",
1299 safe_str_client(conn->rend_data->onion_address));
1300 rend_client_refetch_v2_renddesc(conn->rend_data);
1301 conn->_base.state = AP_CONN_STATE_RENDDESC_WAIT;
1302 return 0;
1304 log_info(LD_REND,"Chose '%s' as intro point for '%s'.",
1305 extend_info->nickname,
1306 safe_str_client(conn->rend_data->onion_address));
1309 /* If we have specified a particular exit node for our
1310 * connection, then be sure to open a circuit to that exit node.
1312 if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL) {
1313 if (conn->chosen_exit_name) {
1314 routerinfo_t *r;
1315 int opt = conn->chosen_exit_optional;
1316 r = router_get_by_nickname(conn->chosen_exit_name, 1);
1317 if (r) {
1318 extend_info = extend_info_from_router(r);
1319 } else {
1320 log_debug(LD_DIR, "considering %d, %s",
1321 want_onehop, conn->chosen_exit_name);
1322 if (want_onehop && conn->chosen_exit_name[0] == '$') {
1323 /* We're asking for a one-hop circuit to a router that
1324 * we don't have a routerinfo about. Make up an extend_info. */
1325 char digest[DIGEST_LEN];
1326 char *hexdigest = conn->chosen_exit_name+1;
1327 tor_addr_t addr;
1328 if (strlen(hexdigest) < HEX_DIGEST_LEN ||
1329 base16_decode(digest,DIGEST_LEN,hexdigest,HEX_DIGEST_LEN)<0) {
1330 log_info(LD_DIR, "Broken exit digest on tunnel conn. Closing.");
1331 return -1;
1333 if (tor_addr_from_str(&addr, conn->socks_request->address) < 0) {
1334 log_info(LD_DIR, "Broken address %s on tunnel conn. Closing.",
1335 escaped_safe_str_client(conn->socks_request->address));
1336 return -1;
1338 extend_info = extend_info_alloc(conn->chosen_exit_name+1,
1339 digest, NULL, &addr,
1340 conn->socks_request->port);
1341 } else {
1342 /* We will need an onion key for the router, and we
1343 * don't have one. Refuse or relax requirements. */
1344 log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
1345 "Requested exit point '%s' is not known. %s.",
1346 conn->chosen_exit_name, opt ? "Trying others" : "Closing");
1347 if (opt) {
1348 conn->chosen_exit_optional = 0;
1349 tor_free(conn->chosen_exit_name);
1350 /* Try again with no requested exit */
1351 return circuit_get_open_circ_or_launch(conn,
1352 desired_circuit_purpose,
1353 circp);
1355 return -1;
1361 if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_REND_JOINED)
1362 new_circ_purpose = CIRCUIT_PURPOSE_C_ESTABLISH_REND;
1363 else if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT)
1364 new_circ_purpose = CIRCUIT_PURPOSE_C_INTRODUCING;
1365 else
1366 new_circ_purpose = desired_circuit_purpose;
1369 int flags = CIRCLAUNCH_NEED_CAPACITY;
1370 if (want_onehop) flags |= CIRCLAUNCH_ONEHOP_TUNNEL;
1371 if (need_uptime) flags |= CIRCLAUNCH_NEED_UPTIME;
1372 if (need_internal) flags |= CIRCLAUNCH_IS_INTERNAL;
1373 circ = circuit_launch_by_extend_info(new_circ_purpose, extend_info,
1374 flags);
1377 extend_info_free(extend_info);
1379 if (desired_circuit_purpose != CIRCUIT_PURPOSE_C_GENERAL) {
1380 /* help predict this next time */
1381 rep_hist_note_used_internal(time(NULL), need_uptime, 1);
1382 if (circ) {
1383 /* write the service_id into circ */
1384 circ->rend_data = rend_data_dup(conn->rend_data);
1385 if (circ->_base.purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND &&
1386 circ->_base.state == CIRCUIT_STATE_OPEN)
1387 rend_client_rendcirc_has_opened(circ);
1391 if (!circ)
1392 log_info(LD_APP,
1393 "No safe circuit (purpose %d) ready for edge "
1394 "connection; delaying.",
1395 desired_circuit_purpose);
1396 *circp = circ;
1397 return 0;
1400 /** Return true iff <b>crypt_path</b> is one of the crypt_paths for
1401 * <b>circ</b>. */
1402 static int
1403 cpath_is_on_circuit(origin_circuit_t *circ, crypt_path_t *crypt_path)
1405 crypt_path_t *cpath, *cpath_next = NULL;
1406 for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) {
1407 cpath_next = cpath->next;
1408 if (crypt_path == cpath)
1409 return 1;
1411 return 0;
1414 /** Attach the AP stream <b>apconn</b> to circ's linked list of
1415 * p_streams. Also set apconn's cpath_layer to <b>cpath</b>, or to the last
1416 * hop in circ's cpath if <b>cpath</b> is NULL.
1418 static void
1419 link_apconn_to_circ(edge_connection_t *apconn, origin_circuit_t *circ,
1420 crypt_path_t *cpath)
1422 /* add it into the linked list of streams on this circuit */
1423 log_debug(LD_APP|LD_CIRC, "attaching new conn to circ. n_circ_id %d.",
1424 circ->_base.n_circ_id);
1425 /* reset it, so we can measure circ timeouts */
1426 apconn->_base.timestamp_lastread = time(NULL);
1427 apconn->next_stream = circ->p_streams;
1428 apconn->on_circuit = TO_CIRCUIT(circ);
1429 /* assert_connection_ok(conn, time(NULL)); */
1430 circ->p_streams = apconn;
1432 if (cpath) { /* we were given one; use it */
1433 tor_assert(cpath_is_on_circuit(circ, cpath));
1434 apconn->cpath_layer = cpath;
1435 } else { /* use the last hop in the circuit */
1436 tor_assert(circ->cpath);
1437 tor_assert(circ->cpath->prev);
1438 tor_assert(circ->cpath->prev->state == CPATH_STATE_OPEN);
1439 apconn->cpath_layer = circ->cpath->prev;
1443 /** If an exit wasn't specifically chosen, save the history for future
1444 * use. */
1445 static void
1446 consider_recording_trackhost(edge_connection_t *conn, origin_circuit_t *circ)
1448 int found_needle = 0;
1449 or_options_t *options = get_options();
1450 size_t len;
1451 char *new_address;
1452 char fp[HEX_DIGEST_LEN+1];
1454 /* Search the addressmap for this conn's destination. */
1455 /* If he's not in the address map.. */
1456 if (!options->TrackHostExits ||
1457 addressmap_have_mapping(conn->socks_request->address,
1458 options->TrackHostExitsExpire))
1459 return; /* nothing to track, or already mapped */
1461 SMARTLIST_FOREACH(options->TrackHostExits, const char *, cp, {
1462 if (cp[0] == '.') { /* match end */
1463 if (cp[1] == '\0' ||
1464 !strcasecmpend(conn->socks_request->address, cp) ||
1465 !strcasecmp(conn->socks_request->address, &cp[1]))
1466 found_needle = 1;
1467 } else if (strcasecmp(cp, conn->socks_request->address) == 0) {
1468 found_needle = 1;
1472 if (!found_needle || !circ->build_state->chosen_exit)
1473 return;
1475 /* write down the fingerprint of the chosen exit, not the nickname,
1476 * because the chosen exit might not be named. */
1477 base16_encode(fp, sizeof(fp),
1478 circ->build_state->chosen_exit->identity_digest, DIGEST_LEN);
1480 /* Add this exit/hostname pair to the addressmap. */
1481 len = strlen(conn->socks_request->address) + 1 /* '.' */ +
1482 strlen(fp) + 1 /* '.' */ +
1483 strlen("exit") + 1 /* '\0' */;
1484 new_address = tor_malloc(len);
1486 tor_snprintf(new_address, len, "%s.%s.exit",
1487 conn->socks_request->address, fp);
1489 addressmap_register(conn->socks_request->address, new_address,
1490 time(NULL) + options->TrackHostExitsExpire,
1491 ADDRMAPSRC_TRACKEXIT);
1494 /** Attempt to attach the connection <b>conn</b> to <b>circ</b>, and send a
1495 * begin or resolve cell as appropriate. Return values are as for
1496 * connection_ap_handshake_attach_circuit. The stream will exit from the hop
1497 * indicated by <b>cpath</b>, or from the last hop in circ's cpath if
1498 * <b>cpath</b> is NULL. */
1500 connection_ap_handshake_attach_chosen_circuit(edge_connection_t *conn,
1501 origin_circuit_t *circ,
1502 crypt_path_t *cpath)
1504 tor_assert(conn);
1505 tor_assert(conn->_base.state == AP_CONN_STATE_CIRCUIT_WAIT ||
1506 conn->_base.state == AP_CONN_STATE_CONTROLLER_WAIT);
1507 tor_assert(conn->socks_request);
1508 tor_assert(circ);
1509 tor_assert(circ->_base.state == CIRCUIT_STATE_OPEN);
1511 conn->_base.state = AP_CONN_STATE_CIRCUIT_WAIT;
1513 if (!circ->_base.timestamp_dirty)
1514 circ->_base.timestamp_dirty = time(NULL);
1516 link_apconn_to_circ(conn, circ, cpath);
1517 tor_assert(conn->socks_request);
1518 if (conn->socks_request->command == SOCKS_COMMAND_CONNECT) {
1519 if (!conn->use_begindir)
1520 consider_recording_trackhost(conn, circ);
1521 if (connection_ap_handshake_send_begin(conn) < 0)
1522 return -1;
1523 } else {
1524 if (connection_ap_handshake_send_resolve(conn) < 0)
1525 return -1;
1528 return 1;
1531 /** Try to find a safe live circuit for CONN_TYPE_AP connection conn. If
1532 * we don't find one: if conn cannot be handled by any known nodes,
1533 * warn and return -1 (conn needs to die, and is maybe already marked);
1534 * else launch new circuit (if necessary) and return 0.
1535 * Otherwise, associate conn with a safe live circuit, do the
1536 * right next step, and return 1.
1538 /* XXXX this function should mark for close whenever it returns -1;
1539 * its callers shouldn't have to worry about that. */
1541 connection_ap_handshake_attach_circuit(edge_connection_t *conn)
1543 int retval;
1544 int conn_age;
1545 int want_onehop;
1547 tor_assert(conn);
1548 tor_assert(conn->_base.state == AP_CONN_STATE_CIRCUIT_WAIT);
1549 tor_assert(conn->socks_request);
1550 want_onehop = conn->want_onehop;
1552 conn_age = (int)(time(NULL) - conn->_base.timestamp_created);
1554 if (conn_age >= get_options()->SocksTimeout) {
1555 int severity = (tor_addr_is_null(&conn->_base.addr) && !conn->_base.port) ?
1556 LOG_INFO : LOG_NOTICE;
1557 log_fn(severity, LD_APP,
1558 "Tried for %d seconds to get a connection to %s:%d. Giving up.",
1559 conn_age, safe_str_client(conn->socks_request->address),
1560 conn->socks_request->port);
1561 return -1;
1564 if (!connection_edge_is_rendezvous_stream(conn)) { /* we're a general conn */
1565 origin_circuit_t *circ=NULL;
1567 if (conn->chosen_exit_name) {
1568 routerinfo_t *router = router_get_by_nickname(conn->chosen_exit_name, 1);
1569 int opt = conn->chosen_exit_optional;
1570 if (!router && !want_onehop) {
1571 /* We ran into this warning when trying to extend a circuit to a
1572 * hidden service directory for which we didn't have a router
1573 * descriptor. See flyspray task 767 for more details. We should
1574 * keep this in mind when deciding to use BEGIN_DIR cells for other
1575 * directory requests as well. -KL*/
1576 log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
1577 "Requested exit point '%s' is not known. %s.",
1578 conn->chosen_exit_name, opt ? "Trying others" : "Closing");
1579 if (opt) {
1580 conn->chosen_exit_optional = 0;
1581 tor_free(conn->chosen_exit_name);
1582 return 0;
1584 return -1;
1586 if (router && !connection_ap_can_use_exit(conn, router, 0)) {
1587 log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
1588 "Requested exit point '%s' would refuse request. %s.",
1589 conn->chosen_exit_name, opt ? "Trying others" : "Closing");
1590 if (opt) {
1591 conn->chosen_exit_optional = 0;
1592 tor_free(conn->chosen_exit_name);
1593 return 0;
1595 return -1;
1599 /* find the circuit that we should use, if there is one. */
1600 retval = circuit_get_open_circ_or_launch(
1601 conn, CIRCUIT_PURPOSE_C_GENERAL, &circ);
1602 if (retval < 1) // XXX021 if we totally fail, this still returns 0 -RD
1603 return retval;
1605 log_debug(LD_APP|LD_CIRC,
1606 "Attaching apconn to circ %d (stream %d sec old).",
1607 circ->_base.n_circ_id, conn_age);
1608 /* print the circ's path, so people can figure out which circs are
1609 * sucking. */
1610 circuit_log_path(LOG_INFO,LD_APP|LD_CIRC,circ);
1612 /* We have found a suitable circuit for our conn. Hurray. */
1613 return connection_ap_handshake_attach_chosen_circuit(conn, circ, NULL);
1615 } else { /* we're a rendezvous conn */
1616 origin_circuit_t *rendcirc=NULL, *introcirc=NULL;
1618 tor_assert(!conn->cpath_layer);
1620 /* start by finding a rendezvous circuit for us */
1622 retval = circuit_get_open_circ_or_launch(
1623 conn, CIRCUIT_PURPOSE_C_REND_JOINED, &rendcirc);
1624 if (retval < 0) return -1; /* failed */
1626 if (retval > 0) {
1627 tor_assert(rendcirc);
1628 /* one is already established, attach */
1629 log_info(LD_REND,
1630 "rend joined circ %d already here. attaching. "
1631 "(stream %d sec old)",
1632 rendcirc->_base.n_circ_id, conn_age);
1633 /* Mark rendezvous circuits as 'newly dirty' every time you use
1634 * them, since the process of rebuilding a rendezvous circ is so
1635 * expensive. There is a tradeoff between linkability and
1636 * feasibility, at this point.
1638 rendcirc->_base.timestamp_dirty = time(NULL);
1639 link_apconn_to_circ(conn, rendcirc, NULL);
1640 if (connection_ap_handshake_send_begin(conn) < 0)
1641 return 0; /* already marked, let them fade away */
1642 return 1;
1645 if (rendcirc && (rendcirc->_base.purpose ==
1646 CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED)) {
1647 log_info(LD_REND,
1648 "pending-join circ %d already here, with intro ack. "
1649 "Stalling. (stream %d sec old)",
1650 rendcirc->_base.n_circ_id, conn_age);
1651 return 0;
1654 /* it's on its way. find an intro circ. */
1655 retval = circuit_get_open_circ_or_launch(
1656 conn, CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT, &introcirc);
1657 if (retval < 0) return -1; /* failed */
1659 if (retval > 0) {
1660 /* one has already sent the intro. keep waiting. */
1661 circuit_t *c = NULL;
1662 tor_assert(introcirc);
1663 log_info(LD_REND, "Intro circ %d present and awaiting ack (rend %d). "
1664 "Stalling. (stream %d sec old)",
1665 introcirc->_base.n_circ_id,
1666 rendcirc ? rendcirc->_base.n_circ_id : 0,
1667 conn_age);
1668 /* abort parallel intro circs, if any */
1669 for (c = global_circuitlist; c; c = c->next) {
1670 if (c->purpose == CIRCUIT_PURPOSE_C_INTRODUCING &&
1671 !c->marked_for_close && CIRCUIT_IS_ORIGIN(c)) {
1672 origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(c);
1673 if (oc->rend_data &&
1674 !rend_cmp_service_ids(conn->rend_data->onion_address,
1675 oc->rend_data->onion_address)) {
1676 log_info(LD_REND|LD_CIRC, "Closing introduction circuit that we "
1677 "built in parallel.");
1678 circuit_mark_for_close(c, END_CIRC_REASON_TIMEOUT);
1682 return 0;
1685 /* now rendcirc and introcirc are each either undefined or not finished */
1687 if (rendcirc && introcirc &&
1688 rendcirc->_base.purpose == CIRCUIT_PURPOSE_C_REND_READY) {
1689 log_info(LD_REND,
1690 "ready rend circ %d already here (no intro-ack yet on "
1691 "intro %d). (stream %d sec old)",
1692 rendcirc->_base.n_circ_id,
1693 introcirc->_base.n_circ_id, conn_age);
1695 tor_assert(introcirc->_base.purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
1696 if (introcirc->_base.state == CIRCUIT_STATE_OPEN) {
1697 log_info(LD_REND,"found open intro circ %d (rend %d); sending "
1698 "introduction. (stream %d sec old)",
1699 introcirc->_base.n_circ_id, rendcirc->_base.n_circ_id,
1700 conn_age);
1701 if (rend_client_send_introduction(introcirc, rendcirc) < 0) {
1702 return -1;
1704 rendcirc->_base.timestamp_dirty = time(NULL);
1705 introcirc->_base.timestamp_dirty = time(NULL);
1706 assert_circuit_ok(TO_CIRCUIT(rendcirc));
1707 assert_circuit_ok(TO_CIRCUIT(introcirc));
1708 return 0;
1712 log_info(LD_REND, "Intro (%d) and rend (%d) circs are not both ready. "
1713 "Stalling conn. (%d sec old)",
1714 introcirc ? introcirc->_base.n_circ_id : 0,
1715 rendcirc ? rendcirc->_base.n_circ_id : 0, conn_age);
1716 return 0;