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) 2007-2008, The Tor Project, Inc. */
5 /* See LICENSE for licensing information */
7 const char circuitbuild_c_id
[] =
11 * \file circuitbuild.c
12 * \brief The actual details of building circuits.
17 /********* START VARIABLES **********/
19 /** A global list of all circuits at this hop. */
20 extern circuit_t
*global_circuitlist
;
22 /** An entry_guard_t represents our information about a chosen long-term
23 * first hop, known as a "helper" node in the literature. We can't just
24 * use a routerinfo_t, since we want to remember these even when we
25 * don't have a directory. */
27 char nickname
[MAX_NICKNAME_LEN
+1];
28 char identity
[DIGEST_LEN
];
29 time_t chosen_on_date
; /**< Approximately when was this guard added?
30 * "0" if we don't know. */
31 char *chosen_by_version
; /**< What tor version added this guard? NULL
32 * if we don't know. */
33 unsigned int made_contact
: 1; /**< 0 if we have never connected to this
34 * router, 1 if we have. */
35 unsigned int can_retry
: 1; /**< Should we retry connecting to this entry,
36 * in spite of having it marked as unreachable?*/
37 time_t bad_since
; /**< 0 if this guard is currently usable, or the time at
38 * which it was observed to become (according to the
39 * directory or the user configuration) unusable. */
40 time_t unreachable_since
; /**< 0 if we can connect to this guard, or the
41 * time at which we first noticed we couldn't
43 time_t last_attempted
; /**< 0 if we can connect to this guard, or the time
44 * at which we last failed to connect to it. */
47 /** A list of our chosen entry guards. */
48 static smartlist_t
*entry_guards
= NULL
;
49 /** A value of 1 means that the entry_guards list has changed
50 * and those changes need to be flushed to disk. */
51 static int entry_guards_dirty
= 0;
53 /********* END VARIABLES ************/
55 static int circuit_deliver_create_cell(circuit_t
*circ
,
56 uint8_t cell_type
, const char *payload
);
57 static int onion_pick_cpath_exit(origin_circuit_t
*circ
, extend_info_t
*exit
);
58 static crypt_path_t
*onion_next_hop_in_cpath(crypt_path_t
*cpath
);
59 static int onion_extend_cpath(origin_circuit_t
*circ
);
60 static int count_acceptable_routers(smartlist_t
*routers
);
61 static int onion_append_hop(crypt_path_t
**head_ptr
, extend_info_t
*choice
);
63 static void entry_guards_changed(void);
64 static time_t start_of_month(time_t when
);
66 /** Iterate over values of circ_id, starting from conn-\>next_circ_id,
67 * and with the high bit specified by conn-\>circ_id_type, until we get
68 * a circ_id that is not in use by any other circuit on that conn.
70 * Return it, or 0 if can't get a unique circ_id.
73 get_unique_circ_id_by_conn(or_connection_t
*conn
)
75 circid_t test_circ_id
;
80 if (conn
->circ_id_type
== CIRC_ID_TYPE_NEITHER
) {
81 log_warn(LD_BUG
, "Trying to pick a circuit ID for a connection from "
82 "a client with no identity.");
85 high_bit
= (conn
->circ_id_type
== CIRC_ID_TYPE_HIGHER
) ? 1<<15 : 0;
87 /* Sequentially iterate over test_circ_id=1...1<<15-1 until we find a
88 * circID such that (high_bit|test_circ_id) is not already used. */
89 test_circ_id
= conn
->next_circ_id
++;
90 if (test_circ_id
== 0 || test_circ_id
>= 1<<15) {
92 conn
->next_circ_id
= 2;
94 if (++attempts
> 1<<15) {
95 /* Make sure we don't loop forever if all circ_id's are used. This
96 * matters because it's an external DoS opportunity.
98 log_warn(LD_CIRC
,"No unused circ IDs. Failing.");
101 test_circ_id
|= high_bit
;
102 } while (circuit_id_in_use_on_orconn(test_circ_id
, conn
));
106 /** If <b>verbose</b> is false, allocate and return a comma-separated list of
107 * the currently built elements of circuit_t. If <b>verbose</b> is true, also
108 * list information about link status in a more verbose format using spaces.
109 * If <b>verbose_names</b> is false, give nicknames for Named routers and hex
110 * digests for others; if <b>verbose_names</b> is true, use $DIGEST=Name style
114 circuit_list_path_impl(origin_circuit_t
*circ
, int verbose
, int verbose_names
)
117 smartlist_t
*elements
;
118 const char *states
[] = {"closed", "waiting for keys", "open"};
122 elements
= smartlist_create();
125 const char *nickname
= build_state_get_exit_nickname(circ
->build_state
);
126 tor_snprintf(buf
, sizeof(buf
), "%s%s circ (length %d%s%s):",
127 circ
->build_state
->is_internal
? "internal" : "exit",
128 circ
->build_state
->need_uptime
? " (high-uptime)" : "",
129 circ
->build_state
->desired_path_len
,
130 circ
->_base
.state
== CIRCUIT_STATE_OPEN
? "" : ", exit ",
131 circ
->_base
.state
== CIRCUIT_STATE_OPEN
? "" :
132 (nickname
?nickname
:"*unnamed*"));
133 smartlist_add(elements
, tor_strdup(buf
));
142 if (!verbose
&& hop
->state
!= CPATH_STATE_OPEN
)
144 if (!hop
->extend_info
)
147 elt
= tor_malloc(MAX_VERBOSE_NICKNAME_LEN
+1);
148 if ((ri
= router_get_by_digest(hop
->extend_info
->identity_digest
))) {
149 router_get_verbose_nickname(elt
, ri
);
150 } else if (hop
->extend_info
->nickname
&&
151 is_legal_nickname(hop
->extend_info
->nickname
)) {
153 base16_encode(elt
+1, HEX_DIGEST_LEN
+1,
154 hop
->extend_info
->identity_digest
, DIGEST_LEN
);
155 elt
[HEX_DIGEST_LEN
+1]= '~';
156 strlcpy(elt
+HEX_DIGEST_LEN
+2,
157 hop
->extend_info
->nickname
, MAX_NICKNAME_LEN
+1);
160 base16_encode(elt
+1, HEX_DIGEST_LEN
+1,
161 hop
->extend_info
->identity_digest
, DIGEST_LEN
);
163 } else { /* ! verbose_names */
164 if ((ri
= router_get_by_digest(hop
->extend_info
->identity_digest
)) &&
166 elt
= tor_strdup(hop
->extend_info
->nickname
);
168 elt
= tor_malloc(HEX_DIGEST_LEN
+2);
170 base16_encode(elt
+1, HEX_DIGEST_LEN
+1,
171 hop
->extend_info
->identity_digest
, DIGEST_LEN
);
176 size_t len
= strlen(elt
)+2+strlen(states
[hop
->state
])+1;
177 char *v
= tor_malloc(len
);
178 tor_assert(hop
->state
<= 2);
179 tor_snprintf(v
,len
,"%s(%s)",elt
,states
[hop
->state
]);
180 smartlist_add(elements
, v
);
183 smartlist_add(elements
, elt
);
186 } while (hop
!= circ
->cpath
);
188 s
= smartlist_join_strings(elements
, verbose
?" ":",", 0, NULL
);
189 SMARTLIST_FOREACH(elements
, char*, cp
, tor_free(cp
));
190 smartlist_free(elements
);
194 /** If <b>verbose</b> is false, allocate and return a comma-separated
195 * list of the currently built elements of circuit_t. If
196 * <b>verbose</b> is true, also list information about link status in
197 * a more verbose format using spaces.
200 circuit_list_path(origin_circuit_t
*circ
, int verbose
)
202 return circuit_list_path_impl(circ
, verbose
, 0);
205 /** Allocate and return a comma-separated list of the currently built elements
206 * of circuit_t, giving each as a verbose nickname.
209 circuit_list_path_for_controller(origin_circuit_t
*circ
)
211 return circuit_list_path_impl(circ
, 0, 1);
214 /** Log, at severity <b>severity</b>, the nicknames of each router in
215 * circ's cpath. Also log the length of the cpath, and the intended
219 circuit_log_path(int severity
, unsigned int domain
, origin_circuit_t
*circ
)
221 char *s
= circuit_list_path(circ
,1);
222 log(severity
,domain
,"%s",s
);
226 /** Tell the rep(utation)hist(ory) module about the status of the links
227 * in circ. Hops that have become OPEN are marked as successfully
228 * extended; the _first_ hop that isn't open (if any) is marked as
231 /* XXXX Someday we should learn from OR circuits too. */
233 circuit_rep_hist_note_result(origin_circuit_t
*circ
)
236 char *prev_digest
= NULL
;
237 routerinfo_t
*router
;
239 if (!hop
) /* circuit hasn't started building yet. */
241 if (server_mode(get_options())) {
242 routerinfo_t
*me
= router_get_my_routerinfo();
245 prev_digest
= me
->cache_info
.identity_digest
;
248 router
= router_get_by_digest(hop
->extend_info
->identity_digest
);
251 if (hop
->state
== CPATH_STATE_OPEN
)
252 rep_hist_note_extend_succeeded(prev_digest
,
253 router
->cache_info
.identity_digest
);
255 rep_hist_note_extend_failed(prev_digest
,
256 router
->cache_info
.identity_digest
);
260 prev_digest
= router
->cache_info
.identity_digest
;
265 } while (hop
!=circ
->cpath
);
268 /** Pick all the entries in our cpath. Stop and return 0 when we're
269 * happy, or return -1 if an error occurs. */
271 onion_populate_cpath(origin_circuit_t
*circ
)
275 r
= onion_extend_cpath(circ
);
277 log_info(LD_CIRC
,"Generating cpath hop failed.");
282 return 0; /* if r == 1 */
285 /** Create and return a new origin circuit. Initialize its purpose and
286 * build-state based on our arguments. The <b>flags</b> argument is a
287 * bitfield of CIRCLAUNCH_* flags. */
289 origin_circuit_init(uint8_t purpose
, int flags
)
291 /* sets circ->p_circ_id and circ->p_conn */
292 origin_circuit_t
*circ
= origin_circuit_new();
293 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_OR_WAIT
);
294 circ
->build_state
= tor_malloc_zero(sizeof(cpath_build_state_t
));
295 circ
->build_state
->onehop_tunnel
=
296 ((flags
& CIRCLAUNCH_ONEHOP_TUNNEL
) ? 1 : 0);
297 circ
->build_state
->need_uptime
=
298 ((flags
& CIRCLAUNCH_NEED_UPTIME
) ? 1 : 0);
299 circ
->build_state
->need_capacity
=
300 ((flags
& CIRCLAUNCH_NEED_CAPACITY
) ? 1 : 0);
301 circ
->build_state
->is_internal
=
302 ((flags
& CIRCLAUNCH_IS_INTERNAL
) ? 1 : 0);
303 circ
->_base
.purpose
= purpose
;
307 /** Build a new circuit for <b>purpose</b>. If <b>exit</b>
308 * is defined, then use that as your exit router, else choose a suitable
311 * Also launch a connection to the first OR in the chosen path, if
312 * it's not open already.
315 circuit_establish_circuit(uint8_t purpose
, extend_info_t
*exit
, int flags
)
317 origin_circuit_t
*circ
;
320 circ
= origin_circuit_init(purpose
, flags
);
322 if (onion_pick_cpath_exit(circ
, exit
) < 0 ||
323 onion_populate_cpath(circ
) < 0) {
324 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_NOPATH
);
328 control_event_circuit_status(circ
, CIRC_EVENT_LAUNCHED
, 0);
330 if ((err_reason
= circuit_handle_first_hop(circ
)) < 0) {
331 circuit_mark_for_close(TO_CIRCUIT(circ
), -err_reason
);
337 /** Start establishing the first hop of our circuit. Figure out what
338 * OR we should connect to, and if necessary start the connection to
339 * it. If we're already connected, then send the 'create' cell.
340 * Return 0 for ok, -reason if circ should be marked-for-close. */
342 circuit_handle_first_hop(origin_circuit_t
*circ
)
344 crypt_path_t
*firsthop
;
345 or_connection_t
*n_conn
;
346 char tmpbuf
[INET_NTOA_BUF_LEN
];
350 firsthop
= onion_next_hop_in_cpath(circ
->cpath
);
351 tor_assert(firsthop
);
352 tor_assert(firsthop
->extend_info
);
354 /* now see if we're already connected to the first OR in 'route' */
355 in
.s_addr
= htonl(firsthop
->extend_info
->addr
);
356 tor_inet_ntoa(&in
, tmpbuf
, sizeof(tmpbuf
));
357 log_debug(LD_CIRC
,"Looking for firsthop '%s:%u'",tmpbuf
,
358 firsthop
->extend_info
->port
);
360 n_conn
= connection_or_get_by_identity_digest(
361 firsthop
->extend_info
->identity_digest
);
362 /* If we don't have an open conn, or the conn we have is obsolete
363 * (i.e. old or broken) and the other side will let us make a second
364 * connection without dropping it immediately... */
365 if (!n_conn
|| n_conn
->_base
.state
!= OR_CONN_STATE_OPEN
||
366 (n_conn
->_base
.or_is_obsolete
)) {
367 /* not currently connected */
368 circ
->_base
.n_hop
= extend_info_dup(firsthop
->extend_info
);
370 if (!n_conn
|| n_conn
->_base
.or_is_obsolete
) { /* launch the connection */
371 if (circ
->build_state
->onehop_tunnel
)
372 control_event_bootstrap(BOOTSTRAP_STATUS_CONN_DIR
, 0);
373 n_conn
= connection_or_connect(firsthop
->extend_info
->addr
,
374 firsthop
->extend_info
->port
,
375 firsthop
->extend_info
->identity_digest
);
376 if (!n_conn
) { /* connect failed, forget the whole thing */
377 log_info(LD_CIRC
,"connect to firsthop failed. Closing.");
378 return -END_CIRC_REASON_CONNECTFAILED
;
382 log_debug(LD_CIRC
,"connecting in progress (or finished). Good.");
383 /* return success. The onion/circuit/etc will be taken care of
384 * automatically (may already have been) whenever n_conn reaches
385 * OR_CONN_STATE_OPEN.
388 } else { /* it's already open. use it. */
389 tor_assert(!circ
->_base
.n_hop
);
390 circ
->_base
.n_conn
= n_conn
;
391 log_debug(LD_CIRC
,"Conn open. Delivering first onion skin.");
392 if ((err_reason
= circuit_send_next_onion_skin(circ
)) < 0) {
393 log_info(LD_CIRC
,"circuit_send_next_onion_skin failed.");
400 /** Find any circuits that are waiting on <b>or_conn</b> to become
401 * open and get them to send their create cells forward.
403 * Status is 1 if connect succeeded, or 0 if connect failed.
406 circuit_n_conn_done(or_connection_t
*or_conn
, int status
)
408 smartlist_t
*pending_circs
;
411 log_debug(LD_CIRC
,"or_conn to %s/%s, status=%d",
412 or_conn
->nickname
? or_conn
->nickname
: "NULL",
413 or_conn
->_base
.address
, status
);
415 pending_circs
= smartlist_create();
416 circuit_get_all_pending_on_or_conn(pending_circs
, or_conn
);
418 SMARTLIST_FOREACH_BEGIN(pending_circs
, circuit_t
*, circ
)
420 /* These checks are redundant wrt get_all_pending_on_or_conn, but I'm
421 * leaving them in in case it's possible for the status of a circuit to
422 * change as we're going down the list. */
423 if (circ
->marked_for_close
|| circ
->n_conn
|| !circ
->n_hop
||
424 circ
->state
!= CIRCUIT_STATE_OR_WAIT
)
427 if (tor_digest_is_zero(circ
->n_hop
->identity_digest
)) {
428 /* Look at addr/port. This is an unkeyed connection. */
429 if (circ
->n_hop
->addr
!= or_conn
->_base
.addr
||
430 circ
->n_hop
->port
!= or_conn
->_base
.port
)
433 /* We expected a key. See if it's the right one. */
434 if (memcmp(or_conn
->identity_digest
,
435 circ
->n_hop
->identity_digest
, DIGEST_LEN
))
438 if (!status
) { /* or_conn failed; close circ */
439 log_info(LD_CIRC
,"or_conn failed. Closing circ.");
440 circuit_mark_for_close(circ
, END_CIRC_REASON_OR_CONN_CLOSED
);
443 log_debug(LD_CIRC
, "Found circ, sending create cell.");
444 /* circuit_deliver_create_cell will set n_circ_id and add us to
445 * orconn_circuid_circuit_map, so we don't need to call
446 * set_circid_orconn here. */
447 circ
->n_conn
= or_conn
;
448 extend_info_free(circ
->n_hop
);
451 if (CIRCUIT_IS_ORIGIN(circ
)) {
453 circuit_send_next_onion_skin(TO_ORIGIN_CIRCUIT(circ
))) < 0) {
455 "send_next_onion_skin failed; circuit marked for closing.");
456 circuit_mark_for_close(circ
, -err_reason
);
458 /* XXX could this be bad, eg if next_onion_skin failed because conn
462 /* pull the create cell out of circ->onionskin, and send it */
463 tor_assert(circ
->n_conn_onionskin
);
464 if (circuit_deliver_create_cell(circ
,CELL_CREATE
,
465 circ
->n_conn_onionskin
)<0) {
466 circuit_mark_for_close(circ
, END_CIRC_REASON_RESOURCELIMIT
);
469 tor_free(circ
->n_conn_onionskin
);
470 circuit_set_state(circ
, CIRCUIT_STATE_OPEN
);
473 SMARTLIST_FOREACH_END(circ
);
475 smartlist_free(pending_circs
);
478 /** Find a new circid that isn't currently in use on the circ->n_conn
480 * circuit <b>circ</b>, and deliver a cell of type <b>cell_type</b>
481 * (either CELL_CREATE or CELL_CREATE_FAST) with payload <b>payload</b>
483 * Return -1 if we failed to find a suitable circid, else return 0.
486 circuit_deliver_create_cell(circuit_t
*circ
, uint8_t cell_type
,
493 tor_assert(circ
->n_conn
);
495 tor_assert(cell_type
== CELL_CREATE
|| cell_type
== CELL_CREATE_FAST
);
497 id
= get_unique_circ_id_by_conn(circ
->n_conn
);
499 log_warn(LD_CIRC
,"failed to get unique circID.");
502 log_debug(LD_CIRC
,"Chosen circID %u.", id
);
503 circuit_set_n_circid_orconn(circ
, id
, circ
->n_conn
);
505 memset(&cell
, 0, sizeof(cell_t
));
506 cell
.command
= cell_type
;
507 cell
.circ_id
= circ
->n_circ_id
;
509 memcpy(cell
.payload
, payload
, ONIONSKIN_CHALLENGE_LEN
);
510 append_cell_to_circuit_queue(circ
, circ
->n_conn
, &cell
, CELL_DIRECTION_OUT
);
512 if (CIRCUIT_IS_ORIGIN(circ
)) {
513 /* mark it so it gets better rate limiting treatment. */
514 circ
->n_conn
->client_used
= time(NULL
);
520 /** We've decided to start our reachability testing. If all
521 * is set, log this to the user. Return 1 if we did, or 0 if
522 * we chose not to log anything. */
524 inform_testing_reachability(void)
527 routerinfo_t
*me
= router_get_my_routerinfo();
531 tor_snprintf(dirbuf
, sizeof(dirbuf
), " and DirPort %s:%d",
532 me
->address
, me
->dir_port
);
533 log(LOG_NOTICE
, LD_OR
, "Now checking whether ORPort %s:%d%s %s reachable... "
534 "(this may take up to %d minutes -- look for log "
535 "messages indicating success)",
536 me
->address
, me
->or_port
,
537 me
->dir_port
? dirbuf
: "",
538 me
->dir_port
? "are" : "is",
539 TIMEOUT_UNTIL_UNREACHABILITY_COMPLAINT
/60);
543 /** Return true iff we should send a create_fast cell to build a circuit
544 * starting at <b>router</b>. (If <b>router</b> is NULL, we don't have
545 * information on the router, so assume true.) */
547 should_use_create_fast_for_router(routerinfo_t
*router
,
548 origin_circuit_t
*circ
)
550 or_options_t
*options
= get_options();
551 (void) router
; /* ignore the router's version. */
553 if (!options
->FastFirstHopPK
) /* create_fast is disabled */
555 if (server_mode(options
) && circ
->cpath
->extend_info
->onion_key
) {
556 /* We're a server, and we know an onion key. We can choose.
557 * Prefer to blend in. */
564 /** This is the backbone function for building circuits.
566 * If circ's first hop is closed, then we need to build a create
567 * cell and send it forward.
569 * Otherwise, we need to build a relay extend cell and send it
572 * Return -reason if we want to tear down circ, else return 0.
575 circuit_send_next_onion_skin(origin_circuit_t
*circ
)
578 routerinfo_t
*router
;
579 char payload
[2+4+DIGEST_LEN
+ONIONSKIN_CHALLENGE_LEN
];
585 if (circ
->cpath
->state
== CPATH_STATE_CLOSED
) {
588 log_debug(LD_CIRC
,"First skin; sending create cell.");
589 if (circ
->build_state
->onehop_tunnel
)
590 control_event_bootstrap(BOOTSTRAP_STATUS_ONEHOP_CREATE
, 0);
592 control_event_bootstrap(BOOTSTRAP_STATUS_CIRCUIT_CREATE
, 0);
594 router
= router_get_by_digest(circ
->_base
.n_conn
->identity_digest
);
595 fast
= should_use_create_fast_for_router(router
, circ
);
596 if (!fast
&& !circ
->cpath
->extend_info
->onion_key
) {
598 "Can't send create_fast, but have no onion key. Failing.");
599 return - END_CIRC_REASON_INTERNAL
;
602 /* We are an OR, or we are connecting to an old Tor: we should
603 * send an old slow create cell.
605 cell_type
= CELL_CREATE
;
606 if (onion_skin_create(circ
->cpath
->extend_info
->onion_key
,
607 &(circ
->cpath
->dh_handshake_state
),
609 log_warn(LD_CIRC
,"onion_skin_create (first hop) failed.");
610 return - END_CIRC_REASON_INTERNAL
;
612 note_request("cell: create", 1);
614 /* We are not an OR, and we're building the first hop of a circuit to a
615 * new OR: we can be speedy and use CREATE_FAST to save an RSA operation
616 * and a DH operation. */
617 cell_type
= CELL_CREATE_FAST
;
618 memset(payload
, 0, sizeof(payload
));
619 crypto_rand(circ
->cpath
->fast_handshake_state
,
620 sizeof(circ
->cpath
->fast_handshake_state
));
621 memcpy(payload
, circ
->cpath
->fast_handshake_state
,
622 sizeof(circ
->cpath
->fast_handshake_state
));
623 note_request("cell: create fast", 1);
626 if (circuit_deliver_create_cell(TO_CIRCUIT(circ
), cell_type
, payload
) < 0)
627 return - END_CIRC_REASON_RESOURCELIMIT
;
629 circ
->cpath
->state
= CPATH_STATE_AWAITING_KEYS
;
630 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_BUILDING
);
631 log_info(LD_CIRC
,"First hop: finished sending %s cell to '%s'",
632 fast
? "CREATE_FAST" : "CREATE",
633 router
? router
->nickname
: "<unnamed>");
635 tor_assert(circ
->cpath
->state
== CPATH_STATE_OPEN
);
636 tor_assert(circ
->_base
.state
== CIRCUIT_STATE_BUILDING
);
637 log_debug(LD_CIRC
,"starting to send subsequent skin.");
638 hop
= onion_next_hop_in_cpath(circ
->cpath
);
640 /* done building the circuit. whew. */
641 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_OPEN
);
642 log_info(LD_CIRC
,"circuit built!");
643 circuit_reset_failure_count(0);
644 if (circ
->build_state
->onehop_tunnel
)
645 control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_STATUS
, 0);
646 if (!has_completed_circuit
&& !circ
->build_state
->onehop_tunnel
) {
647 or_options_t
*options
= get_options();
648 has_completed_circuit
=1;
649 /* FFFF Log a count of known routers here */
650 log(LOG_NOTICE
, LD_GENERAL
,
651 "Tor has successfully opened a circuit. "
652 "Looks like client functionality is working.");
653 control_event_bootstrap(BOOTSTRAP_STATUS_DONE
, 0);
654 control_event_client_status(LOG_NOTICE
, "CIRCUIT_ESTABLISHED");
655 if (server_mode(options
) && !check_whether_orport_reachable()) {
656 inform_testing_reachability();
657 consider_testing_reachability(1, 1);
660 circuit_rep_hist_note_result(circ
);
661 circuit_has_opened(circ
); /* do other actions as necessary */
665 set_uint32(payload
, htonl(hop
->extend_info
->addr
));
666 set_uint16(payload
+4, htons(hop
->extend_info
->port
));
668 onionskin
= payload
+2+4;
669 memcpy(payload
+2+4+ONIONSKIN_CHALLENGE_LEN
,
670 hop
->extend_info
->identity_digest
, DIGEST_LEN
);
671 payload_len
= 2+4+ONIONSKIN_CHALLENGE_LEN
+DIGEST_LEN
;
673 if (onion_skin_create(hop
->extend_info
->onion_key
,
674 &(hop
->dh_handshake_state
), onionskin
) < 0) {
675 log_warn(LD_CIRC
,"onion_skin_create failed.");
676 return - END_CIRC_REASON_INTERNAL
;
679 log_info(LD_CIRC
,"Sending extend relay cell.");
680 note_request("cell: extend", 1);
681 /* send it to hop->prev, because it will transfer
682 * it to a create cell and then send to hop */
683 if (relay_send_command_from_edge(0, TO_CIRCUIT(circ
),
684 RELAY_COMMAND_EXTEND
,
685 payload
, payload_len
, hop
->prev
) < 0)
686 return 0; /* circuit is closed */
688 hop
->state
= CPATH_STATE_AWAITING_KEYS
;
693 /** Our clock just jumped by <b>seconds_elapsed</b>. Assume
694 * something has also gone wrong with our network: notify the user,
695 * and abandon all not-yet-used circuits. */
697 circuit_note_clock_jumped(int seconds_elapsed
)
699 int severity
= server_mode(get_options()) ? LOG_WARN
: LOG_NOTICE
;
700 log(severity
, LD_GENERAL
, "Your system clock just jumped %d seconds %s; "
701 "assuming established circuits no longer work.",
702 seconds_elapsed
>=0 ? seconds_elapsed
: -seconds_elapsed
,
703 seconds_elapsed
>=0 ? "forward" : "backward");
704 control_event_general_status(LOG_WARN
, "CLOCK_JUMPED TIME=%d",
706 has_completed_circuit
=0; /* so it'll log when it works again */
707 control_event_client_status(severity
, "CIRCUIT_NOT_ESTABLISHED REASON=%s",
709 circuit_mark_all_unused_circs();
710 circuit_expire_all_dirty_circs();
713 /** Take the 'extend' cell, pull out addr/port plus the onion skin. Make
714 * sure we're connected to the next hop, and pass it the onion skin using
715 * a create cell. Return -1 if we want to warn and tear down the circuit,
719 circuit_extend(cell_t
*cell
, circuit_t
*circ
)
721 or_connection_t
*n_conn
;
724 char *id_digest
=NULL
;
729 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
730 "n_conn already set. Bug/attack. Closing.");
734 if (!server_mode(get_options())) {
735 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
736 "Got an extend cell, but running as a client. Closing.");
740 relay_header_unpack(&rh
, cell
->payload
);
742 if (rh
.length
< 4+2+ONIONSKIN_CHALLENGE_LEN
+DIGEST_LEN
) {
743 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
744 "Wrong length %d on extend cell. Closing circuit.",
749 n_addr
= ntohl(get_uint32(cell
->payload
+RELAY_HEADER_SIZE
));
750 n_port
= ntohs(get_uint16(cell
->payload
+RELAY_HEADER_SIZE
+4));
751 onionskin
= cell
->payload
+RELAY_HEADER_SIZE
+4+2;
752 id_digest
= cell
->payload
+RELAY_HEADER_SIZE
+4+2+ONIONSKIN_CHALLENGE_LEN
;
754 n_conn
= connection_or_get_by_identity_digest(id_digest
);
756 /* If we don't have an open conn, or the conn we have is obsolete
757 * (i.e. old or broken) and the other side will let us make a second
758 * connection without dropping it immediately... */
759 if (!n_conn
|| n_conn
->_base
.state
!= OR_CONN_STATE_OPEN
||
760 n_conn
->_base
.or_is_obsolete
) {
762 char tmpbuf
[INET_NTOA_BUF_LEN
];
763 in
.s_addr
= htonl(n_addr
);
764 tor_inet_ntoa(&in
,tmpbuf
,sizeof(tmpbuf
));
765 log_debug(LD_CIRC
|LD_OR
,"Next router (%s:%d) not connected. Connecting.",
766 tmpbuf
, (int)n_port
);
768 circ
->n_hop
= extend_info_alloc(NULL
/*nickname*/,
773 circ
->n_conn_onionskin
= tor_malloc(ONIONSKIN_CHALLENGE_LEN
);
774 memcpy(circ
->n_conn_onionskin
, onionskin
, ONIONSKIN_CHALLENGE_LEN
);
775 circuit_set_state(circ
, CIRCUIT_STATE_OR_WAIT
);
777 if (! (n_conn
&& !n_conn
->_base
.or_is_obsolete
)) {
778 /* we should try to open a connection */
779 n_conn
= connection_or_connect(n_addr
, n_port
, id_digest
);
781 log_info(LD_CIRC
,"Launching n_conn failed. Closing circuit.");
782 circuit_mark_for_close(circ
, END_CIRC_REASON_CONNECTFAILED
);
785 log_debug(LD_CIRC
,"connecting in progress (or finished). Good.");
787 /* return success. The onion/circuit/etc will be taken care of
788 * automatically (may already have been) whenever n_conn reaches
789 * OR_CONN_STATE_OPEN.
794 tor_assert(!circ
->n_hop
); /* Connection is already established. */
795 circ
->n_conn
= n_conn
;
796 log_debug(LD_CIRC
,"n_conn is %s:%u",
797 n_conn
->_base
.address
,n_conn
->_base
.port
);
799 if (circuit_deliver_create_cell(circ
, CELL_CREATE
, onionskin
) < 0)
804 /** Initialize cpath-\>{f|b}_{crypto|digest} from the key material in
805 * key_data. key_data must contain CPATH_KEY_MATERIAL bytes, which are
807 * - 20 to initialize f_digest
808 * - 20 to initialize b_digest
809 * - 16 to key f_crypto
810 * - 16 to key b_crypto
812 * (If 'reverse' is true, then f_XX and b_XX are swapped.)
815 circuit_init_cpath_crypto(crypt_path_t
*cpath
, const char *key_data
,
818 crypto_digest_env_t
*tmp_digest
;
819 crypto_cipher_env_t
*tmp_crypto
;
822 tor_assert(key_data
);
823 tor_assert(!(cpath
->f_crypto
|| cpath
->b_crypto
||
824 cpath
->f_digest
|| cpath
->b_digest
));
826 cpath
->f_digest
= crypto_new_digest_env();
827 crypto_digest_add_bytes(cpath
->f_digest
, key_data
, DIGEST_LEN
);
828 cpath
->b_digest
= crypto_new_digest_env();
829 crypto_digest_add_bytes(cpath
->b_digest
, key_data
+DIGEST_LEN
, DIGEST_LEN
);
831 if (!(cpath
->f_crypto
=
832 crypto_create_init_cipher(key_data
+(2*DIGEST_LEN
),1))) {
833 log_warn(LD_BUG
,"Forward cipher initialization failed.");
836 if (!(cpath
->b_crypto
=
837 crypto_create_init_cipher(key_data
+(2*DIGEST_LEN
)+CIPHER_KEY_LEN
,0))) {
838 log_warn(LD_BUG
,"Backward cipher initialization failed.");
843 tmp_digest
= cpath
->f_digest
;
844 cpath
->f_digest
= cpath
->b_digest
;
845 cpath
->b_digest
= tmp_digest
;
846 tmp_crypto
= cpath
->f_crypto
;
847 cpath
->f_crypto
= cpath
->b_crypto
;
848 cpath
->b_crypto
= tmp_crypto
;
854 /** A created or extended cell came back to us on the circuit, and it included
855 * <b>reply</b> as its body. (If <b>reply_type</b> is CELL_CREATED, the body
856 * contains (the second DH key, plus KH). If <b>reply_type</b> is
857 * CELL_CREATED_FAST, the body contains a secret y and a hash H(x|y).)
859 * Calculate the appropriate keys and digests, make sure KH is
860 * correct, and initialize this hop of the cpath.
862 * Return - reason if we want to mark circ for close, else return 0.
865 circuit_finish_handshake(origin_circuit_t
*circ
, uint8_t reply_type
,
868 char keys
[CPATH_KEY_MATERIAL_LEN
];
871 if (circ
->cpath
->state
== CPATH_STATE_AWAITING_KEYS
)
874 hop
= onion_next_hop_in_cpath(circ
->cpath
);
875 if (!hop
) { /* got an extended when we're all done? */
876 log_warn(LD_PROTOCOL
,"got extended when circ already built? Closing.");
877 return - END_CIRC_REASON_TORPROTOCOL
;
880 tor_assert(hop
->state
== CPATH_STATE_AWAITING_KEYS
);
882 if (reply_type
== CELL_CREATED
&& hop
->dh_handshake_state
) {
883 if (onion_skin_client_handshake(hop
->dh_handshake_state
, reply
, keys
,
884 DIGEST_LEN
*2+CIPHER_KEY_LEN
*2) < 0) {
885 log_warn(LD_CIRC
,"onion_skin_client_handshake failed.");
886 return -END_CIRC_REASON_TORPROTOCOL
;
888 /* Remember hash of g^xy */
889 memcpy(hop
->handshake_digest
, reply
+DH_KEY_LEN
, DIGEST_LEN
);
890 } else if (reply_type
== CELL_CREATED_FAST
&& !hop
->dh_handshake_state
) {
891 if (fast_client_handshake(hop
->fast_handshake_state
, reply
, keys
,
892 DIGEST_LEN
*2+CIPHER_KEY_LEN
*2) < 0) {
893 log_warn(LD_CIRC
,"fast_client_handshake failed.");
894 return -END_CIRC_REASON_TORPROTOCOL
;
896 memcpy(hop
->handshake_digest
, reply
+DIGEST_LEN
, DIGEST_LEN
);
898 log_warn(LD_PROTOCOL
,"CREATED cell type did not match CREATE cell type.");
899 return -END_CIRC_REASON_TORPROTOCOL
;
902 if (hop
->dh_handshake_state
) {
903 crypto_dh_free(hop
->dh_handshake_state
); /* don't need it anymore */
904 hop
->dh_handshake_state
= NULL
;
906 memset(hop
->fast_handshake_state
, 0, sizeof(hop
->fast_handshake_state
));
908 if (circuit_init_cpath_crypto(hop
, keys
, 0)<0) {
909 return -END_CIRC_REASON_TORPROTOCOL
;
912 hop
->state
= CPATH_STATE_OPEN
;
913 log_info(LD_CIRC
,"Finished building %scircuit hop:",
914 (reply_type
== CELL_CREATED_FAST
) ? "fast " : "");
915 circuit_log_path(LOG_INFO
,LD_CIRC
,circ
);
916 control_event_circuit_status(circ
, CIRC_EVENT_EXTENDED
, 0);
921 /** We received a relay truncated cell on circ.
923 * Since we don't ask for truncates currently, getting a truncated
924 * means that a connection broke or an extend failed. For now,
925 * just give up: for circ to close, and return 0.
928 circuit_truncated(origin_circuit_t
*circ
, crypt_path_t
*layer
)
930 // crypt_path_t *victim;
931 // connection_t *stream;
936 /* XXX Since we don't ask for truncates currently, getting a truncated
937 * means that a connection broke or an extend failed. For now,
940 circuit_mark_for_close(TO_CIRCUIT(circ
),
941 END_CIRC_REASON_FLAG_REMOTE
|END_CIRC_REASON_OR_CONN_CLOSED
);
945 while (layer
->next
!= circ
->cpath
) {
946 /* we need to clear out layer->next */
947 victim
= layer
->next
;
948 log_debug(LD_CIRC
, "Killing a layer of the cpath.");
950 for (stream
= circ
->p_streams
; stream
; stream
=stream
->next_stream
) {
951 if (stream
->cpath_layer
== victim
) {
952 log_info(LD_APP
, "Marking stream %d for close because of truncate.",
954 /* no need to send 'end' relay cells,
955 * because the other side's already dead
957 connection_mark_unattached_ap(stream
, END_STREAM_REASON_DESTROY
);
961 layer
->next
= victim
->next
;
962 circuit_free_cpath_node(victim
);
965 log_info(LD_CIRC
, "finished");
970 /** Given a response payload and keys, initialize, then send a created
974 onionskin_answer(or_circuit_t
*circ
, uint8_t cell_type
, const char *payload
,
978 crypt_path_t
*tmp_cpath
;
980 tmp_cpath
= tor_malloc_zero(sizeof(crypt_path_t
));
981 tmp_cpath
->magic
= CRYPT_PATH_MAGIC
;
983 memset(&cell
, 0, sizeof(cell_t
));
984 cell
.command
= cell_type
;
985 cell
.circ_id
= circ
->p_circ_id
;
987 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_OPEN
);
989 memcpy(cell
.payload
, payload
,
990 cell_type
== CELL_CREATED
? ONIONSKIN_REPLY_LEN
: DIGEST_LEN
*2);
992 log_debug(LD_CIRC
,"init digest forward 0x%.8x, backward 0x%.8x.",
993 (unsigned int)*(uint32_t*)(keys
),
994 (unsigned int)*(uint32_t*)(keys
+20));
995 if (circuit_init_cpath_crypto(tmp_cpath
, keys
, 0)<0) {
996 log_warn(LD_BUG
,"Circuit initialization failed");
1000 circ
->n_digest
= tmp_cpath
->f_digest
;
1001 circ
->n_crypto
= tmp_cpath
->f_crypto
;
1002 circ
->p_digest
= tmp_cpath
->b_digest
;
1003 circ
->p_crypto
= tmp_cpath
->b_crypto
;
1004 tmp_cpath
->magic
= 0;
1005 tor_free(tmp_cpath
);
1007 if (cell_type
== CELL_CREATED
)
1008 memcpy(circ
->handshake_digest
, cell
.payload
+DH_KEY_LEN
, DIGEST_LEN
);
1010 memcpy(circ
->handshake_digest
, cell
.payload
+DIGEST_LEN
, DIGEST_LEN
);
1012 circ
->is_first_hop
= (cell_type
== CELL_CREATED_FAST
);
1014 append_cell_to_circuit_queue(TO_CIRCUIT(circ
),
1015 circ
->p_conn
, &cell
, CELL_DIRECTION_IN
);
1016 log_debug(LD_CIRC
,"Finished sending 'created' cell.");
1018 if (!is_local_IP(circ
->p_conn
->_base
.addr
) &&
1019 !connection_or_nonopen_was_started_here(circ
->p_conn
)) {
1020 /* record that we could process create cells from a non-local conn
1021 * that we didn't initiate; presumably this means that create cells
1022 * can reach us too. */
1023 router_orport_found_reachable();
1029 /** Choose a length for a circuit of purpose <b>purpose</b>.
1030 * Default length is 3 + the number of endpoints that would give something
1031 * away. If the routerlist <b>routers</b> doesn't have enough routers
1032 * to handle the desired path length, return as large a path length as
1033 * is feasible, except if it's less than 2, in which case return -1.
1036 new_route_len(uint8_t purpose
, extend_info_t
*exit
,
1037 smartlist_t
*routers
)
1039 int num_acceptable_routers
;
1042 tor_assert(routers
);
1046 purpose
!= CIRCUIT_PURPOSE_TESTING
&&
1047 purpose
!= CIRCUIT_PURPOSE_S_ESTABLISH_INTRO
)
1050 num_acceptable_routers
= count_acceptable_routers(routers
);
1052 log_debug(LD_CIRC
,"Chosen route length %d (%d/%d routers suitable).",
1053 routelen
, num_acceptable_routers
, smartlist_len(routers
));
1055 if (num_acceptable_routers
< 2) {
1057 "Not enough acceptable routers (%d). Discarding this circuit.",
1058 num_acceptable_routers
);
1062 if (num_acceptable_routers
< routelen
) {
1063 log_info(LD_CIRC
,"Not enough routers: cutting routelen from %d to %d.",
1064 routelen
, num_acceptable_routers
);
1065 routelen
= num_acceptable_routers
;
1071 /** Fetch the list of predicted ports, dup it into a smartlist of
1072 * uint16_t's, remove the ones that are already handled by an
1073 * existing circuit, and return it.
1075 static smartlist_t
*
1076 circuit_get_unhandled_ports(time_t now
)
1078 smartlist_t
*source
= rep_hist_get_predicted_ports(now
);
1079 smartlist_t
*dest
= smartlist_create();
1083 for (i
= 0; i
< smartlist_len(source
); ++i
) {
1084 tmp
= tor_malloc(sizeof(uint16_t));
1085 memcpy(tmp
, smartlist_get(source
, i
), sizeof(uint16_t));
1086 smartlist_add(dest
, tmp
);
1089 circuit_remove_handled_ports(dest
);
1093 /** Return 1 if we already have circuits present or on the way for
1094 * all anticipated ports. Return 0 if we should make more.
1096 * If we're returning 0, set need_uptime and need_capacity to
1097 * indicate any requirements that the unhandled ports have.
1100 circuit_all_predicted_ports_handled(time_t now
, int *need_uptime
,
1105 smartlist_t
*sl
= circuit_get_unhandled_ports(now
);
1106 smartlist_t
*LongLivedServices
= get_options()->LongLivedPorts
;
1107 tor_assert(need_uptime
);
1108 tor_assert(need_capacity
);
1109 enough
= (smartlist_len(sl
) == 0);
1110 for (i
= 0; i
< smartlist_len(sl
); ++i
) {
1111 port
= smartlist_get(sl
, i
);
1112 if (smartlist_string_num_isin(LongLivedServices
, *port
))
1120 /** Return 1 if <b>router</b> can handle one or more of the ports in
1121 * <b>needed_ports</b>, else return 0.
1124 router_handles_some_port(routerinfo_t
*router
, smartlist_t
*needed_ports
)
1129 for (i
= 0; i
< smartlist_len(needed_ports
); ++i
) {
1130 addr_policy_result_t r
;
1131 port
= *(uint16_t *)smartlist_get(needed_ports
, i
);
1133 r
= compare_addr_to_addr_policy(0, port
, router
->exit_policy
);
1134 if (r
!= ADDR_POLICY_REJECTED
&& r
!= ADDR_POLICY_PROBABLY_REJECTED
)
1140 /** Return true iff <b>conn</b> needs another general circuit to be
1143 ap_stream_wants_exit_attention(connection_t
*conn
)
1145 if (conn
->type
== CONN_TYPE_AP
&&
1146 conn
->state
== AP_CONN_STATE_CIRCUIT_WAIT
&&
1147 !conn
->marked_for_close
&&
1148 !connection_edge_is_rendezvous_stream(TO_EDGE_CONN(conn
)) &&
1149 !circuit_stream_is_being_handled(TO_EDGE_CONN(conn
), 0,
1150 MIN_CIRCUITS_HANDLING_STREAM
))
1155 /** Return a pointer to a suitable router to be the exit node for the
1156 * general-purpose circuit we're about to build.
1158 * Look through the connection array, and choose a router that maximizes
1159 * the number of pending streams that can exit from this router.
1161 * Return NULL if we can't find any suitable routers.
1163 static routerinfo_t
*
1164 choose_good_exit_server_general(routerlist_t
*dir
, int need_uptime
,
1169 int n_pending_connections
= 0;
1170 smartlist_t
*connections
;
1171 int best_support
= -1;
1172 int n_best_support
=0;
1173 smartlist_t
*sl
, *preferredexits
;
1174 routerinfo_t
*router
;
1175 or_options_t
*options
= get_options();
1177 connections
= get_connection_array();
1179 /* Count how many connections are waiting for a circuit to be built.
1180 * We use this for log messages now, but in the future we may depend on it.
1182 SMARTLIST_FOREACH(connections
, connection_t
*, conn
,
1184 if (ap_stream_wants_exit_attention(conn
))
1185 ++n_pending_connections
;
1187 // log_fn(LOG_DEBUG, "Choosing exit node; %d connections are pending",
1188 // n_pending_connections);
1189 /* Now we count, for each of the routers in the directory, how many
1190 * of the pending connections could possibly exit from that
1191 * router (n_supported[i]). (We can't be sure about cases where we
1192 * don't know the IP address of the pending connection.)
1194 n_supported
= tor_malloc(sizeof(int)*smartlist_len(dir
->routers
));
1195 for (i
= 0; i
< smartlist_len(dir
->routers
); ++i
) {/* iterate over routers */
1196 router
= smartlist_get(dir
->routers
, i
);
1197 if (router_is_me(router
)) {
1198 n_supported
[i
] = -1;
1199 // log_fn(LOG_DEBUG,"Skipping node %s -- it's me.", router->nickname);
1200 /* XXX there's probably a reverse predecessor attack here, but
1201 * it's slow. should we take this out? -RD
1205 if (!router
->is_running
|| router
->is_bad_exit
) {
1206 n_supported
[i
] = -1;
1207 continue; /* skip routers that are known to be down or bad exits */
1209 if (router_is_unreliable(router
, need_uptime
, need_capacity
, 0)) {
1210 n_supported
[i
] = -1;
1211 continue; /* skip routers that are not suitable */
1213 if (!(router
->is_valid
|| options
->_AllowInvalid
& ALLOW_INVALID_EXIT
)) {
1214 /* if it's invalid and we don't want it */
1215 n_supported
[i
] = -1;
1216 // log_fn(LOG_DEBUG,"Skipping node %s (index %d) -- invalid router.",
1217 // router->nickname, i);
1218 continue; /* skip invalid routers */
1220 if (router_exit_policy_rejects_all(router
)) {
1221 n_supported
[i
] = -1;
1222 // log_fn(LOG_DEBUG,"Skipping node %s (index %d) -- it rejects all.",
1223 // router->nickname, i);
1224 continue; /* skip routers that reject all */
1227 /* iterate over connections */
1228 SMARTLIST_FOREACH(connections
, connection_t
*, conn
,
1230 if (!ap_stream_wants_exit_attention(conn
))
1231 continue; /* Skip everything but APs in CIRCUIT_WAIT */
1232 if (connection_ap_can_use_exit(TO_EDGE_CONN(conn
), router
)) {
1234 // log_fn(LOG_DEBUG,"%s is supported. n_supported[%d] now %d.",
1235 // router->nickname, i, n_supported[i]);
1237 // log_fn(LOG_DEBUG,"%s (index %d) would reject this stream.",
1238 // router->nickname, i);
1240 }); /* End looping over connections. */
1241 if (n_supported
[i
] > best_support
) {
1242 /* If this router is better than previous ones, remember its index
1243 * and goodness, and start counting how many routers are this good. */
1244 best_support
= n_supported
[i
]; n_best_support
=1;
1245 // log_fn(LOG_DEBUG,"%s is new best supported option so far.",
1246 // router->nickname);
1247 } else if (n_supported
[i
] == best_support
) {
1248 /* If this router is _as good_ as the best one, just increment the
1249 * count of equally good routers.*/
1254 "Found %d servers that might support %d/%d pending connections.",
1255 n_best_support
, best_support
>= 0 ? best_support
: 0,
1256 n_pending_connections
);
1258 preferredexits
= smartlist_create();
1259 add_nickname_list_to_smartlist(preferredexits
,options
->ExitNodes
,1);
1261 sl
= smartlist_create();
1263 /* If any routers definitely support any pending connections, choose one
1265 if (best_support
> 0) {
1266 for (i
= 0; i
< smartlist_len(dir
->routers
); i
++)
1267 if (n_supported
[i
] == best_support
)
1268 smartlist_add(sl
, smartlist_get(dir
->routers
, i
));
1270 routerset_subtract_routers(sl
,options
->_ExcludeExitNodesUnion
);
1271 if (options
->StrictExitNodes
|| smartlist_overlap(sl
,preferredexits
))
1272 smartlist_intersect(sl
,preferredexits
);
1273 router
= routerlist_sl_choose_by_bandwidth(sl
, WEIGHT_FOR_EXIT
);
1275 /* Either there are no pending connections, or no routers even seem to
1276 * possibly support any of them. Choose a router at random that satisfies
1277 * at least one predicted exit port. */
1280 smartlist_t
*needed_ports
;
1282 if (best_support
== -1) {
1283 if (need_uptime
|| need_capacity
) {
1285 "We couldn't find any live%s%s routers; falling back "
1286 "to list of all routers.",
1287 need_capacity
?", fast":"",
1288 need_uptime
?", stable":"");
1289 smartlist_free(preferredexits
);
1291 tor_free(n_supported
);
1292 return choose_good_exit_server_general(dir
, 0, 0);
1294 log_notice(LD_CIRC
, "All routers are down or won't exit -- choosing a "
1295 "doomed exit at random.");
1297 needed_ports
= circuit_get_unhandled_ports(time(NULL
));
1298 for (try = 0; try < 2; try++) {
1299 /* try once to pick only from routers that satisfy a needed port,
1300 * then if there are none, pick from any that support exiting. */
1301 for (i
= 0; i
< smartlist_len(dir
->routers
); i
++) {
1302 router
= smartlist_get(dir
->routers
, i
);
1303 if (n_supported
[i
] != -1 &&
1304 (try || router_handles_some_port(router
, needed_ports
))) {
1305 // log_fn(LOG_DEBUG,"Try %d: '%s' is a possibility.",
1306 // try, router->nickname);
1307 smartlist_add(sl
, router
);
1311 routerset_subtract_routers(sl
,options
->_ExcludeExitNodesUnion
);
1312 if (options
->StrictExitNodes
|| smartlist_overlap(sl
,preferredexits
))
1313 smartlist_intersect(sl
,preferredexits
);
1314 /* XXX sometimes the above results in null, when the requested
1315 * exit node is down. we should pick it anyway. */
1316 router
= routerlist_sl_choose_by_bandwidth(sl
, WEIGHT_FOR_EXIT
);
1320 SMARTLIST_FOREACH(needed_ports
, uint16_t *, cp
, tor_free(cp
));
1321 smartlist_free(needed_ports
);
1324 smartlist_free(preferredexits
);
1326 tor_free(n_supported
);
1328 log_info(LD_CIRC
, "Chose exit server '%s'", router
->nickname
);
1331 if (options
->StrictExitNodes
) {
1333 "No specified exit routers seem to be running, and "
1334 "StrictExitNodes is set: can't choose an exit.");
1339 /** Return a pointer to a suitable router to be the exit node for the
1340 * circuit of purpose <b>purpose</b> that we're about to build (or NULL
1341 * if no router is suitable).
1343 * For general-purpose circuits, pass it off to
1344 * choose_good_exit_server_general()
1346 * For client-side rendezvous circuits, choose a random node, weighted
1347 * toward the preferences in 'options'.
1349 static routerinfo_t
*
1350 choose_good_exit_server(uint8_t purpose
, routerlist_t
*dir
,
1351 int need_uptime
, int need_capacity
, int is_internal
)
1353 or_options_t
*options
= get_options();
1354 router_crn_flags_t flags
= 0;
1356 flags
|= CRN_NEED_UPTIME
;
1358 flags
|= CRN_NEED_CAPACITY
;
1361 case CIRCUIT_PURPOSE_C_GENERAL
:
1362 if (options
->_AllowInvalid
& ALLOW_INVALID_MIDDLE
)
1363 flags
|= CRN_ALLOW_INVALID
;
1364 if (is_internal
) /* pick it like a middle hop */
1365 return router_choose_random_node(NULL
, NULL
,
1366 options
->ExcludeNodes
, flags
);
1368 return choose_good_exit_server_general(dir
,need_uptime
,need_capacity
);
1369 case CIRCUIT_PURPOSE_C_ESTABLISH_REND
:
1370 if (options
->_AllowInvalid
& ALLOW_INVALID_RENDEZVOUS
)
1371 flags
|= CRN_ALLOW_INVALID
;
1372 return router_choose_random_node(NULL
, NULL
,
1373 options
->ExcludeNodes
, flags
);
1375 log_warn(LD_BUG
,"Unhandled purpose %d", purpose
);
1376 tor_fragile_assert();
1380 /** Decide a suitable length for circ's cpath, and pick an exit
1381 * router (or use <b>exit</b> if provided). Store these in the
1382 * cpath. Return 0 if ok, -1 if circuit should be closed. */
1384 onion_pick_cpath_exit(origin_circuit_t
*circ
, extend_info_t
*exit
)
1386 cpath_build_state_t
*state
= circ
->build_state
;
1387 routerlist_t
*rl
= router_get_routerlist();
1389 if (state
->onehop_tunnel
) {
1390 log_debug(LD_CIRC
, "Launching a one-hop circuit for dir tunnel.");
1391 state
->desired_path_len
= 1;
1393 int r
= new_route_len(circ
->_base
.purpose
, exit
, rl
->routers
);
1394 if (r
< 1) /* must be at least 1 */
1396 state
->desired_path_len
= r
;
1399 if (exit
) { /* the circuit-builder pre-requested one */
1400 log_info(LD_CIRC
,"Using requested exit node '%s'", exit
->nickname
);
1401 exit
= extend_info_dup(exit
);
1402 } else { /* we have to decide one */
1403 routerinfo_t
*router
=
1404 choose_good_exit_server(circ
->_base
.purpose
, rl
, state
->need_uptime
,
1405 state
->need_capacity
, state
->is_internal
);
1407 log_warn(LD_CIRC
,"failed to choose an exit server");
1410 exit
= extend_info_from_router(router
);
1412 state
->chosen_exit
= exit
;
1416 /** Give <b>circ</b> a new exit destination to <b>exit</b>, and add a
1417 * hop to the cpath reflecting this. Don't send the next extend cell --
1418 * the caller will do this if it wants to.
1421 circuit_append_new_exit(origin_circuit_t
*circ
, extend_info_t
*exit
)
1423 cpath_build_state_t
*state
;
1427 state
= circ
->build_state
;
1429 if (state
->chosen_exit
)
1430 extend_info_free(state
->chosen_exit
);
1431 state
->chosen_exit
= extend_info_dup(exit
);
1433 ++circ
->build_state
->desired_path_len
;
1434 onion_append_hop(&circ
->cpath
, exit
);
1438 /** Take an open <b>circ</b>, and add a new hop at the end, based on
1439 * <b>info</b>. Set its state back to CIRCUIT_STATE_BUILDING, and then
1440 * send the next extend cell to begin connecting to that hop.
1443 circuit_extend_to_new_exit(origin_circuit_t
*circ
, extend_info_t
*exit
)
1446 circuit_append_new_exit(circ
, exit
);
1447 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_BUILDING
);
1448 if ((err_reason
= circuit_send_next_onion_skin(circ
))<0) {
1449 log_warn(LD_CIRC
, "Couldn't extend circuit to new point '%s'.",
1451 circuit_mark_for_close(TO_CIRCUIT(circ
), -err_reason
);
1457 /** Return the number of routers in <b>routers</b> that are currently up
1458 * and available for building circuits through.
1461 count_acceptable_routers(smartlist_t
*routers
)
1467 n
= smartlist_len(routers
);
1469 r
= smartlist_get(routers
, i
);
1470 // log_debug(LD_CIRC,
1471 // "Contemplating whether router %d (%s) is a new option.",
1473 if (r
->is_running
== 0) {
1474 // log_debug(LD_CIRC,"Nope, the directory says %d is not running.",i);
1477 if (r
->is_valid
== 0) {
1478 // log_debug(LD_CIRC,"Nope, the directory says %d is not valid.",i);
1480 /* XXX This clause makes us count incorrectly: if AllowInvalidRouters
1481 * allows this node in some places, then we're getting an inaccurate
1482 * count. For now, be conservative and don't count it. But later we
1483 * should try to be smarter. */
1486 // log_debug(LD_CIRC,"I like %d. num_acceptable_routers now %d.",i, num);
1488 ; /* C requires an explicit statement after the label */
1494 /** Add <b>new_hop</b> to the end of the doubly-linked-list <b>head_ptr</b>.
1495 * This function is used to extend cpath by another hop.
1498 onion_append_to_cpath(crypt_path_t
**head_ptr
, crypt_path_t
*new_hop
)
1501 new_hop
->next
= (*head_ptr
);
1502 new_hop
->prev
= (*head_ptr
)->prev
;
1503 (*head_ptr
)->prev
->next
= new_hop
;
1504 (*head_ptr
)->prev
= new_hop
;
1506 *head_ptr
= new_hop
;
1507 new_hop
->prev
= new_hop
->next
= new_hop
;
1511 /** A helper function used by onion_extend_cpath(). Use <b>purpose</b>
1512 * and <b>state</b> and the cpath <b>head</b> (currently populated only
1513 * to length <b>cur_len</b> to decide a suitable middle hop for a
1514 * circuit. In particular, make sure we don't pick the exit node or its
1515 * family, and make sure we don't duplicate any previous nodes or their
1517 static routerinfo_t
*
1518 choose_good_middle_server(uint8_t purpose
,
1519 cpath_build_state_t
*state
,
1524 routerinfo_t
*r
, *choice
;
1525 crypt_path_t
*cpath
;
1526 smartlist_t
*excluded
;
1527 or_options_t
*options
= get_options();
1528 router_crn_flags_t flags
= 0;
1529 tor_assert(_CIRCUIT_PURPOSE_MIN
<= purpose
&&
1530 purpose
<= _CIRCUIT_PURPOSE_MAX
);
1532 log_debug(LD_CIRC
, "Contemplating intermediate hop: random choice.");
1533 excluded
= smartlist_create();
1534 if ((r
= build_state_get_exit_router(state
))) {
1535 smartlist_add(excluded
, r
);
1536 routerlist_add_family(excluded
, r
);
1538 for (i
= 0, cpath
= head
; i
< cur_len
; ++i
, cpath
=cpath
->next
) {
1539 if ((r
= router_get_by_digest(cpath
->extend_info
->identity_digest
))) {
1540 smartlist_add(excluded
, r
);
1541 routerlist_add_family(excluded
, r
);
1545 if (state
->need_uptime
)
1546 flags
|= CRN_NEED_UPTIME
;
1547 if (state
->need_capacity
)
1548 flags
|= CRN_NEED_CAPACITY
;
1549 if (options
->_AllowInvalid
& ALLOW_INVALID_MIDDLE
)
1550 flags
|= CRN_ALLOW_INVALID
;
1551 choice
= router_choose_random_node(NULL
,
1552 excluded
, options
->ExcludeNodes
, flags
);
1553 smartlist_free(excluded
);
1557 /** Pick a good entry server for the circuit to be built according to
1558 * <b>state</b>. Don't reuse a chosen exit (if any), don't use this
1559 * router (if we're an OR), and respect firewall settings; if we're
1560 * configured to use entry guards, return one.
1562 * If <b>state</b> is NULL, we're choosing a router to serve as an entry
1563 * guard, not for any particular circuit.
1565 static routerinfo_t
*
1566 choose_good_entry_server(uint8_t purpose
, cpath_build_state_t
*state
)
1568 routerinfo_t
*r
, *choice
;
1569 smartlist_t
*excluded
;
1570 or_options_t
*options
= get_options();
1571 router_crn_flags_t flags
= 0;
1573 if (state
&& options
->UseEntryGuards
&&
1574 (purpose
!= CIRCUIT_PURPOSE_TESTING
|| options
->BridgeRelay
)) {
1575 return choose_random_entry(state
);
1578 excluded
= smartlist_create();
1580 if (state
&& (r
= build_state_get_exit_router(state
))) {
1581 smartlist_add(excluded
, r
);
1582 routerlist_add_family(excluded
, r
);
1584 if (firewall_is_fascist_or()) {
1585 /*XXXX021 This can slow things down a lot; use a smarter implementation */
1586 /* exclude all ORs that listen on the wrong port */
1587 routerlist_t
*rl
= router_get_routerlist();
1590 for (i
=0; i
< smartlist_len(rl
->routers
); i
++) {
1591 r
= smartlist_get(rl
->routers
, i
);
1592 if (!fascist_firewall_allows_address_or(r
->addr
,r
->or_port
))
1593 smartlist_add(excluded
, r
);
1596 /* and exclude current entry guards, if applicable */
1597 if (options
->UseEntryGuards
&& entry_guards
) {
1598 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
1600 if ((r
= router_get_by_digest(entry
->identity
)))
1601 smartlist_add(excluded
, r
);
1606 flags
|= CRN_NEED_GUARD
;
1607 if (state
->need_uptime
)
1608 flags
|= CRN_NEED_UPTIME
;
1609 if (state
->need_capacity
)
1610 flags
|= CRN_NEED_CAPACITY
;
1612 if (options
->_AllowInvalid
& ALLOW_INVALID_ENTRY
)
1613 flags
|= CRN_ALLOW_INVALID
;
1615 choice
= router_choose_random_node(
1618 options
->ExcludeNodes
,
1620 smartlist_free(excluded
);
1624 /** Return the first non-open hop in cpath, or return NULL if all
1626 static crypt_path_t
*
1627 onion_next_hop_in_cpath(crypt_path_t
*cpath
)
1629 crypt_path_t
*hop
= cpath
;
1631 if (hop
->state
!= CPATH_STATE_OPEN
)
1634 } while (hop
!= cpath
);
1638 /** Choose a suitable next hop in the cpath <b>head_ptr</b>,
1639 * based on <b>state</b>. Append the hop info to head_ptr.
1642 onion_extend_cpath(origin_circuit_t
*circ
)
1644 uint8_t purpose
= circ
->_base
.purpose
;
1645 cpath_build_state_t
*state
= circ
->build_state
;
1646 int cur_len
= circuit_get_cpath_len(circ
);
1647 extend_info_t
*info
= NULL
;
1649 if (cur_len
>= state
->desired_path_len
) {
1650 log_debug(LD_CIRC
, "Path is complete: %d steps long",
1651 state
->desired_path_len
);
1655 log_debug(LD_CIRC
, "Path is %d long; we want %d", cur_len
,
1656 state
->desired_path_len
);
1658 if (cur_len
== state
->desired_path_len
- 1) { /* Picking last node */
1659 info
= extend_info_dup(state
->chosen_exit
);
1660 } else if (cur_len
== 0) { /* picking first node */
1661 routerinfo_t
*r
= choose_good_entry_server(purpose
, state
);
1663 info
= extend_info_from_router(r
);
1666 choose_good_middle_server(purpose
, state
, circ
->cpath
, cur_len
);
1668 info
= extend_info_from_router(r
);
1672 log_warn(LD_CIRC
,"Failed to find node for hop %d of our path. Discarding "
1673 "this circuit.", cur_len
);
1677 log_debug(LD_CIRC
,"Chose router %s for hop %d (exit is %s)",
1678 info
->nickname
, cur_len
+1, build_state_get_exit_nickname(state
));
1680 onion_append_hop(&circ
->cpath
, info
);
1681 extend_info_free(info
);
1685 /** Create a new hop, annotate it with information about its
1686 * corresponding router <b>choice</b>, and append it to the
1687 * end of the cpath <b>head_ptr</b>. */
1689 onion_append_hop(crypt_path_t
**head_ptr
, extend_info_t
*choice
)
1691 crypt_path_t
*hop
= tor_malloc_zero(sizeof(crypt_path_t
));
1693 /* link hop into the cpath, at the end. */
1694 onion_append_to_cpath(head_ptr
, hop
);
1696 hop
->magic
= CRYPT_PATH_MAGIC
;
1697 hop
->state
= CPATH_STATE_CLOSED
;
1699 hop
->extend_info
= extend_info_dup(choice
);
1701 hop
->package_window
= CIRCWINDOW_START
;
1702 hop
->deliver_window
= CIRCWINDOW_START
;
1707 /** Allocate a new extend_info object based on the various arguments. */
1709 extend_info_alloc(const char *nickname
, const char *digest
,
1710 crypto_pk_env_t
*onion_key
,
1711 uint32_t addr
, uint16_t port
)
1713 extend_info_t
*info
= tor_malloc_zero(sizeof(extend_info_t
));
1714 memcpy(info
->identity_digest
, digest
, DIGEST_LEN
);
1716 strlcpy(info
->nickname
, nickname
, sizeof(info
->nickname
));
1718 info
->onion_key
= crypto_pk_dup_key(onion_key
);
1724 /** Allocate and return a new extend_info_t that can be used to build a
1725 * circuit to or through the router <b>r</b>. */
1727 extend_info_from_router(routerinfo_t
*r
)
1730 return extend_info_alloc(r
->nickname
, r
->cache_info
.identity_digest
,
1731 r
->onion_pkey
, r
->addr
, r
->or_port
);
1734 /** Release storage held by an extend_info_t struct. */
1736 extend_info_free(extend_info_t
*info
)
1739 if (info
->onion_key
)
1740 crypto_free_pk_env(info
->onion_key
);
1744 /** Allocate and return a new extend_info_t with the same contents as
1747 extend_info_dup(extend_info_t
*info
)
1749 extend_info_t
*newinfo
;
1751 newinfo
= tor_malloc(sizeof(extend_info_t
));
1752 memcpy(newinfo
, info
, sizeof(extend_info_t
));
1753 if (info
->onion_key
)
1754 newinfo
->onion_key
= crypto_pk_dup_key(info
->onion_key
);
1756 newinfo
->onion_key
= NULL
;
1760 /** Return the routerinfo_t for the chosen exit router in <b>state</b>.
1761 * If there is no chosen exit, or if we don't know the routerinfo_t for
1762 * the chosen exit, return NULL.
1765 build_state_get_exit_router(cpath_build_state_t
*state
)
1767 if (!state
|| !state
->chosen_exit
)
1769 return router_get_by_digest(state
->chosen_exit
->identity_digest
);
1772 /** Return the nickname for the chosen exit router in <b>state</b>. If
1773 * there is no chosen exit, or if we don't know the routerinfo_t for the
1774 * chosen exit, return NULL.
1777 build_state_get_exit_nickname(cpath_build_state_t
*state
)
1779 if (!state
|| !state
->chosen_exit
)
1781 return state
->chosen_exit
->nickname
;
1784 /** Check whether the entry guard <b>e</b> is usable, given the directory
1785 * authorities' opinion about the router (stored in <b>ri</b>) and the user's
1786 * configuration (in <b>options</b>). Set <b>e</b>->bad_since
1787 * accordingly. Return true iff the entry guard's status changes.
1789 * If it's not usable, set *<b>reason</b> to a static string explaining why.
1791 /*XXXX021 take a routerstatus, not a routerinfo. */
1793 entry_guard_set_status(entry_guard_t
*e
, routerinfo_t
*ri
,
1794 time_t now
, or_options_t
*options
, const char **reason
)
1796 char buf
[HEX_DIGEST_LEN
+1];
1799 tor_assert(options
);
1803 /* Do we want to mark this guard as bad? */
1805 *reason
= "unlisted";
1806 else if (!ri
->is_running
)
1808 else if (options
->UseBridges
&& ri
->purpose
!= ROUTER_PURPOSE_BRIDGE
)
1809 *reason
= "not a bridge";
1810 else if (!options
->UseBridges
&& !ri
->is_possible_guard
&&
1811 !router_nickname_is_in_list(ri
, options
->EntryNodes
))
1812 *reason
= "not recommended as a guard";
1813 else if (routerset_contains_router(options
->ExcludeNodes
, ri
))
1814 *reason
= "excluded";
1816 if (*reason
&& ! e
->bad_since
) {
1817 /* Router is newly bad. */
1818 base16_encode(buf
, sizeof(buf
), e
->identity
, DIGEST_LEN
);
1819 log_info(LD_CIRC
, "Entry guard %s (%s) is %s: marking as unusable.",
1820 e
->nickname
, buf
, *reason
);
1823 control_event_guard(e
->nickname
, e
->identity
, "BAD");
1825 } else if (!*reason
&& e
->bad_since
) {
1826 /* There's nothing wrong with the router any more. */
1827 base16_encode(buf
, sizeof(buf
), e
->identity
, DIGEST_LEN
);
1828 log_info(LD_CIRC
, "Entry guard %s (%s) is no longer unusable: "
1829 "marking as ok.", e
->nickname
, buf
);
1832 control_event_guard(e
->nickname
, e
->identity
, "GOOD");
1839 /** Return true iff enough time has passed since we last tried to connect
1840 * to the unreachable guard <b>e</b> that we're willing to try again. */
1842 entry_is_time_to_retry(entry_guard_t
*e
, time_t now
)
1845 if (e
->last_attempted
< e
->unreachable_since
)
1847 diff
= now
- e
->unreachable_since
;
1849 return now
> (e
->last_attempted
+ 60*60);
1850 else if (diff
< 3*24*60*60)
1851 return now
> (e
->last_attempted
+ 4*60*60);
1852 else if (diff
< 7*24*60*60)
1853 return now
> (e
->last_attempted
+ 18*60*60);
1855 return now
> (e
->last_attempted
+ 36*60*60);
1858 /** Return the router corresponding to <b>e</b>, if <b>e</b> is
1859 * working well enough that we are willing to use it as an entry
1860 * right now. (Else return NULL.) In particular, it must be
1861 * - Listed as either up or never yet contacted;
1862 * - Present in the routerlist;
1863 * - Listed as 'stable' or 'fast' by the current dirserver concensus,
1864 * if demanded by <b>need_uptime</b> or <b>need_capacity</b>;
1865 * (This check is currently redundant with the Guard flag, but in
1866 * the future that might change. Best to leave it in for now.)
1867 * - Allowed by our current ReachableORAddresses config option; and
1868 * - Currently thought to be reachable by us (unless assume_reachable
1871 static INLINE routerinfo_t
*
1872 entry_is_live(entry_guard_t
*e
, int need_uptime
, int need_capacity
,
1873 int assume_reachable
)
1878 /* no good if it's unreachable, unless assume_unreachable or can_retry. */
1879 if (!assume_reachable
&& !e
->can_retry
&&
1880 e
->unreachable_since
&& !entry_is_time_to_retry(e
, time(NULL
)))
1882 r
= router_get_by_digest(e
->identity
);
1885 if (get_options()->UseBridges
&& r
->purpose
!= ROUTER_PURPOSE_BRIDGE
)
1887 if (!get_options()->UseBridges
&& r
->purpose
!= ROUTER_PURPOSE_GENERAL
)
1889 if (router_is_unreliable(r
, need_uptime
, need_capacity
, 0))
1891 if (!fascist_firewall_allows_address_or(r
->addr
,r
->or_port
))
1896 /** Return the number of entry guards that we think are usable. */
1898 num_live_entry_guards(void)
1903 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
1905 if (entry_is_live(entry
, 0, 1, 0))
1911 /** If <b>digest</b> matches the identity of any node in the
1912 * entry_guards list, return that node. Else return NULL. */
1913 static INLINE entry_guard_t
*
1914 is_an_entry_guard(const char *digest
)
1916 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
1917 if (!memcmp(digest
, entry
->identity
, DIGEST_LEN
))
1923 /** Dump a description of our list of entry guards to the log at level
1924 * <b>severity</b>. */
1926 log_entry_guards(int severity
)
1928 smartlist_t
*elements
= smartlist_create();
1932 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
1934 tor_snprintf(buf
, sizeof(buf
), "%s (%s%s)",
1936 entry_is_live(e
, 0, 1, 0) ? "up " : "down ",
1937 e
->made_contact
? "made-contact" : "never-contacted");
1938 smartlist_add(elements
, tor_strdup(buf
));
1941 s
= smartlist_join_strings(elements
, ",", 0, NULL
);
1942 SMARTLIST_FOREACH(elements
, char*, cp
, tor_free(cp
));
1943 smartlist_free(elements
);
1944 log_fn(severity
,LD_CIRC
,"%s",s
);
1948 /** Called when one or more guards that we would previously have used for some
1949 * purpose are no longer in use because a higher-priority guard has become
1952 control_event_guard_deferred(void)
1954 /* XXXX We don't actually have a good way to figure out _how many_ entries
1955 * are live for some purpose. We need an entry_is_even_slightly_live()
1956 * function for this to work right. NumEntryGuards isn't reliable: if we
1957 * need guards with weird properties, we can have more than that number
1962 or_options_t
*options
= get_options();
1965 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
1967 if (entry_is_live(entry
, 0, 1, 0)) {
1968 if (n
++ == options
->NumEntryGuards
) {
1969 control_event_guard(entry
->nickname
, entry
->identity
, "DEFERRED");
1977 /** Add a new (preferably stable and fast) router to our
1978 * entry_guards list. Return a pointer to the router if we succeed,
1979 * or NULL if we can't find any more suitable entries.
1981 * If <b>chosen</b> is defined, use that one, and if it's not
1982 * already in our entry_guards list, put it at the *beginning*.
1983 * Else, put the one we pick at the end of the list. */
1984 static routerinfo_t
*
1985 add_an_entry_guard(routerinfo_t
*chosen
, int reset_status
)
1987 routerinfo_t
*router
;
1988 entry_guard_t
*entry
;
1992 entry
= is_an_entry_guard(router
->cache_info
.identity_digest
);
1995 entry
->bad_since
= 0;
1996 entry
->can_retry
= 1;
2001 router
= choose_good_entry_server(CIRCUIT_PURPOSE_C_GENERAL
, NULL
);
2005 entry
= tor_malloc_zero(sizeof(entry_guard_t
));
2006 log_info(LD_CIRC
, "Chose '%s' as new entry guard.", router
->nickname
);
2007 strlcpy(entry
->nickname
, router
->nickname
, sizeof(entry
->nickname
));
2008 memcpy(entry
->identity
, router
->cache_info
.identity_digest
, DIGEST_LEN
);
2009 entry
->chosen_on_date
= start_of_month(time(NULL
));
2010 entry
->chosen_by_version
= tor_strdup(VERSION
);
2011 if (chosen
) /* prepend */
2012 smartlist_insert(entry_guards
, 0, entry
);
2014 smartlist_add(entry_guards
, entry
);
2015 control_event_guard(entry
->nickname
, entry
->identity
, "NEW");
2016 control_event_guard_deferred();
2017 log_entry_guards(LOG_INFO
);
2021 /** If the use of entry guards is configured, choose more entry guards
2022 * until we have enough in the list. */
2024 pick_entry_guards(void)
2026 or_options_t
*options
= get_options();
2029 tor_assert(entry_guards
);
2031 while (num_live_entry_guards() < options
->NumEntryGuards
) {
2032 if (!add_an_entry_guard(NULL
, 0))
2037 entry_guards_changed();
2040 /** How long (in seconds) do we allow an entry guard to be nonfunctional,
2041 * unlisted, excluded, or otherwise nonusable before we give up on it? */
2042 #define ENTRY_GUARD_REMOVE_AFTER (30*24*60*60)
2044 /** Release all storage held by <b>e</b>. */
2046 entry_guard_free(entry_guard_t
*e
)
2049 tor_free(e
->chosen_by_version
);
2053 /** Remove any entry guard which was selected by an unknown version of Tor,
2054 * or which was selected by a version of Tor that's known to select
2055 * entry guards badly. */
2057 remove_obsolete_entry_guards(void)
2060 for (i
= 0; i
< smartlist_len(entry_guards
); ++i
) {
2061 entry_guard_t
*entry
= smartlist_get(entry_guards
, i
);
2062 const char *ver
= entry
->chosen_by_version
;
2063 const char *msg
= NULL
;
2065 int version_is_bad
= 0;
2067 msg
= "does not say what version of Tor it was selected by";
2069 } else if (tor_version_parse(ver
, &v
)) {
2070 msg
= "does not seem to be from any recognized version of Tor";
2072 } else if ((tor_version_as_new_as(ver
, "0.1.0.10-alpha") &&
2073 !tor_version_as_new_as(ver
, "0.1.2.16-dev")) ||
2074 (tor_version_as_new_as(ver
, "0.2.0.0-alpha") &&
2075 !tor_version_as_new_as(ver
, "0.2.0.6-alpha"))) {
2076 msg
= "was selected without regard for guard bandwidth";
2079 if (version_is_bad
) {
2080 char dbuf
[HEX_DIGEST_LEN
+1];
2082 base16_encode(dbuf
, sizeof(dbuf
), entry
->identity
, DIGEST_LEN
);
2083 log_notice(LD_CIRC
, "Entry guard '%s' (%s) %s. (Version=%s.) "
2085 entry
->nickname
, dbuf
, msg
, ver
?escaped(ver
):"none");
2086 control_event_guard(entry
->nickname
, entry
->identity
, "DROPPED");
2087 entry_guard_free(entry
);
2088 smartlist_del_keeporder(entry_guards
, i
--);
2089 log_entry_guards(LOG_INFO
);
2094 return changed
? 1 : 0;
2097 /** Remove all entry guards that have been down or unlisted for so
2098 * long that we don't think they'll come up again. Return 1 if we
2099 * removed any, or 0 if we did nothing. */
2101 remove_dead_entry_guards(void)
2103 char dbuf
[HEX_DIGEST_LEN
+1];
2104 char tbuf
[ISO_TIME_LEN
+1];
2105 time_t now
= time(NULL
);
2109 for (i
= 0; i
< smartlist_len(entry_guards
); ) {
2110 entry_guard_t
*entry
= smartlist_get(entry_guards
, i
);
2111 if (entry
->bad_since
&&
2112 entry
->bad_since
+ ENTRY_GUARD_REMOVE_AFTER
< now
) {
2114 base16_encode(dbuf
, sizeof(dbuf
), entry
->identity
, DIGEST_LEN
);
2115 format_local_iso_time(tbuf
, entry
->bad_since
);
2116 log_info(LD_CIRC
, "Entry guard '%s' (%s) has been down or unlisted "
2117 "since %s local time; removing.",
2118 entry
->nickname
, dbuf
, tbuf
);
2119 control_event_guard(entry
->nickname
, entry
->identity
, "DROPPED");
2120 entry_guard_free(entry
);
2121 smartlist_del_keeporder(entry_guards
, i
);
2122 log_entry_guards(LOG_INFO
);
2127 return changed
? 1 : 0;
2130 /** A new directory or router-status has arrived; update the down/listed
2131 * status of the entry guards.
2133 * An entry is 'down' if the directory lists it as nonrunning.
2134 * An entry is 'unlisted' if the directory doesn't include it.
2136 * Don't call this on startup; only on a fresh download. Otherwise we'll
2137 * think that things are unlisted.
2140 entry_guards_compute_status(void)
2144 int severity
= LOG_DEBUG
;
2145 or_options_t
*options
;
2149 options
= get_options();
2153 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
2155 routerinfo_t
*r
= router_get_by_digest(entry
->identity
);
2156 const char *reason
= NULL
;
2157 /*XXX021 log reason again. */
2158 if (entry_guard_set_status(entry
, r
, now
, options
, &reason
))
2161 if (entry
->bad_since
)
2165 if (remove_dead_entry_guards())
2168 severity
= changed
? LOG_DEBUG
: LOG_INFO
;
2171 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
2172 log_info(LD_CIRC
, "Summary: Entry '%s' is %s, %s, and %s.",
2174 entry
->unreachable_since
? "unreachable" : "reachable",
2175 entry
->bad_since
? "unusable" : "usable",
2176 entry_is_live(entry
, 0, 1, 0) ? "live" : "not live"));
2177 log_info(LD_CIRC
, " (%d/%d entry guards are usable/new)",
2178 num_live_entry_guards(), smartlist_len(entry_guards
));
2179 log_entry_guards(LOG_INFO
);
2180 entry_guards_changed();
2184 /** Called when a connection to an OR with the identity digest <b>digest</b>
2185 * is established (<b>succeeded</b>==1) or has failed (<b>succeeded</b>==0).
2186 * If the OR is an entry, change that entry's up/down status.
2187 * Return 0 normally, or -1 if we want to tear down the new connection.
2190 entry_guard_register_connect_status(const char *digest
, int succeeded
,
2194 int refuse_conn
= 0;
2195 int first_contact
= 0;
2196 entry_guard_t
*entry
= NULL
;
2198 char buf
[HEX_DIGEST_LEN
+1];
2203 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
2205 if (!memcmp(e
->identity
, digest
, DIGEST_LEN
)) {
2215 base16_encode(buf
, sizeof(buf
), entry
->identity
, DIGEST_LEN
);
2218 if (entry
->unreachable_since
) {
2219 log_info(LD_CIRC
, "Entry guard '%s' (%s) is now reachable again. Good.",
2220 entry
->nickname
, buf
);
2221 entry
->can_retry
= 0;
2222 entry
->unreachable_since
= 0;
2223 entry
->last_attempted
= now
;
2224 control_event_guard(entry
->nickname
, entry
->identity
, "UP");
2227 if (!entry
->made_contact
) {
2228 entry
->made_contact
= 1;
2229 first_contact
= changed
= 1;
2231 } else { /* ! succeeded */
2232 if (!entry
->made_contact
) {
2233 /* We've never connected to this one. */
2235 "Connection to never-contacted entry guard '%s' (%s) failed. "
2236 "Removing from the list. %d/%d entry guards usable/new.",
2237 entry
->nickname
, buf
,
2238 num_live_entry_guards()-1, smartlist_len(entry_guards
)-1);
2239 entry_guard_free(entry
);
2240 smartlist_del_keeporder(entry_guards
, idx
);
2241 log_entry_guards(LOG_INFO
);
2243 } else if (!entry
->unreachable_since
) {
2244 log_info(LD_CIRC
, "Unable to connect to entry guard '%s' (%s). "
2245 "Marking as unreachable.", entry
->nickname
, buf
);
2246 entry
->unreachable_since
= entry
->last_attempted
= now
;
2247 control_event_guard(entry
->nickname
, entry
->identity
, "DOWN");
2249 entry
->can_retry
= 0; /* We gave it an early chance; no good. */
2251 char tbuf
[ISO_TIME_LEN
+1];
2252 format_iso_time(tbuf
, entry
->unreachable_since
);
2253 log_debug(LD_CIRC
, "Failed to connect to unreachable entry guard "
2254 "'%s' (%s). It has been unreachable since %s.",
2255 entry
->nickname
, buf
, tbuf
);
2256 entry
->last_attempted
= now
;
2257 entry
->can_retry
= 0; /* We gave it an early chance; no good. */
2261 if (first_contact
) {
2262 /* We've just added a new long-term entry guard. Perhaps the network just
2263 * came back? We should give our earlier entries another try too,
2264 * and close this connection so we don't use it before we've given
2265 * the others a shot. */
2266 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
, {
2269 if (e
->made_contact
) {
2270 routerinfo_t
*r
= entry_is_live(e
, 0, 1, 1);
2271 if (r
&& e
->unreachable_since
) {
2279 "Connected to new entry guard '%s' (%s). Marking earlier "
2280 "entry guards up. %d/%d entry guards usable/new.",
2281 entry
->nickname
, buf
,
2282 num_live_entry_guards(), smartlist_len(entry_guards
));
2283 log_entry_guards(LOG_INFO
);
2289 entry_guards_changed();
2290 return refuse_conn
? -1 : 0;
2293 /** When we try to choose an entry guard, should we parse and add
2294 * config's EntryNodes first? */
2295 static int should_add_entry_nodes
= 0;
2297 /** Called when the value of EntryNodes changes in our configuration. */
2299 entry_nodes_should_be_added(void)
2301 log_info(LD_CIRC
, "New EntryNodes config option detected. Will use.");
2302 should_add_entry_nodes
= 1;
2305 /** Add all nodes in EntryNodes that aren't currently guard nodes to the list
2306 * of guard nodes, at the front. */
2308 entry_guards_prepend_from_config(void)
2310 or_options_t
*options
= get_options();
2311 smartlist_t
*entry_routers
, *entry_fps
;
2312 smartlist_t
*old_entry_guards_on_list
, *old_entry_guards_not_on_list
;
2313 tor_assert(entry_guards
);
2315 should_add_entry_nodes
= 0;
2317 if (!options
->EntryNodes
) {
2318 /* It's possible that a controller set EntryNodes, thus making
2319 * should_add_entry_nodes set, then cleared it again, all before the
2320 * call to choose_random_entry() that triggered us. If so, just return.
2325 log_info(LD_CIRC
,"Adding configured EntryNodes '%s'.",
2326 options
->EntryNodes
);
2328 entry_routers
= smartlist_create();
2329 entry_fps
= smartlist_create();
2330 old_entry_guards_on_list
= smartlist_create();
2331 old_entry_guards_not_on_list
= smartlist_create();
2333 /* Split entry guards into those on the list and those not. */
2334 add_nickname_list_to_smartlist(entry_routers
, options
->EntryNodes
, 0);
2335 SMARTLIST_FOREACH(entry_routers
, routerinfo_t
*, ri
,
2336 smartlist_add(entry_fps
,ri
->cache_info
.identity_digest
));
2337 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
, {
2338 if (smartlist_digest_isin(entry_fps
, e
->identity
))
2339 smartlist_add(old_entry_guards_on_list
, e
);
2341 smartlist_add(old_entry_guards_not_on_list
, e
);
2344 /* Remove all currently configured entry guards from entry_routers. */
2345 SMARTLIST_FOREACH(entry_routers
, routerinfo_t
*, ri
, {
2346 if (is_an_entry_guard(ri
->cache_info
.identity_digest
)) {
2347 SMARTLIST_DEL_CURRENT(entry_routers
, ri
);
2351 /* Now build the new entry_guards list. */
2352 smartlist_clear(entry_guards
);
2353 /* First, the previously configured guards that are in EntryNodes. */
2354 smartlist_add_all(entry_guards
, old_entry_guards_on_list
);
2355 /* Next, the rest of EntryNodes */
2356 SMARTLIST_FOREACH(entry_routers
, routerinfo_t
*, ri
, {
2357 add_an_entry_guard(ri
, 0);
2359 /* Finally, the remaining EntryNodes, unless we're strict */
2360 if (options
->StrictEntryNodes
) {
2361 SMARTLIST_FOREACH(old_entry_guards_not_on_list
, entry_guard_t
*, e
,
2362 entry_guard_free(e
));
2364 smartlist_add_all(entry_guards
, old_entry_guards_not_on_list
);
2367 smartlist_free(entry_routers
);
2368 smartlist_free(entry_fps
);
2369 smartlist_free(old_entry_guards_on_list
);
2370 smartlist_free(old_entry_guards_not_on_list
);
2371 entry_guards_changed();
2374 /** Return 1 if we're fine adding arbitrary routers out of the
2375 * directory to our entry guard list. Else return 0. */
2377 entry_list_can_grow(or_options_t
*options
)
2379 if (options
->StrictEntryNodes
)
2381 if (options
->UseBridges
)
2386 /** Pick a live (up and listed) entry guard from entry_guards. If
2387 * <b>state</b> is non-NULL, this is for a specific circuit --
2388 * make sure not to pick this circuit's exit or any node in the
2389 * exit's family. If <b>state</b> is NULL, we're looking for a random
2390 * guard (likely a bridge). */
2392 choose_random_entry(cpath_build_state_t
*state
)
2394 or_options_t
*options
= get_options();
2395 smartlist_t
*live_entry_guards
= smartlist_create();
2396 smartlist_t
*exit_family
= smartlist_create();
2397 routerinfo_t
*chosen_exit
= state
?build_state_get_exit_router(state
) : NULL
;
2398 routerinfo_t
*r
= NULL
;
2399 int need_uptime
= state
? state
->need_uptime
: 0;
2400 int need_capacity
= state
? state
->need_capacity
: 0;
2401 int consider_exit_family
= 0;
2404 smartlist_add(exit_family
, chosen_exit
);
2405 routerlist_add_family(exit_family
, chosen_exit
);
2406 consider_exit_family
= 1;
2410 entry_guards
= smartlist_create();
2412 if (should_add_entry_nodes
)
2413 entry_guards_prepend_from_config();
2415 if (entry_list_can_grow(options
) &&
2417 smartlist_len(entry_guards
) < options
->NumEntryGuards
))
2418 pick_entry_guards();
2421 smartlist_clear(live_entry_guards
);
2422 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
2424 r
= entry_is_live(entry
, need_uptime
, need_capacity
, 0);
2425 if (r
&& (!consider_exit_family
|| !smartlist_isin(exit_family
, r
))) {
2426 smartlist_add(live_entry_guards
, r
);
2427 if (!entry
->made_contact
) {
2428 /* Always start with the first not-yet-contacted entry
2429 * guard. Otherwise we might add several new ones, pick
2430 * the second new one, and now we've expanded our entry
2431 * guard list without needing to. */
2432 goto choose_and_finish
;
2434 if (smartlist_len(live_entry_guards
) >= options
->NumEntryGuards
)
2435 break; /* we have enough */
2439 /* Try to have at least 2 choices available. This way we don't
2440 * get stuck with a single live-but-crummy entry and just keep
2442 * (We might get 2 live-but-crummy entry guards, but so be it.) */
2443 if (smartlist_len(live_entry_guards
) < 2) {
2444 if (entry_list_can_grow(options
)) {
2445 /* still no? try adding a new entry then */
2446 /* XXX if guard doesn't imply fast and stable, then we need
2447 * to tell add_an_entry_guard below what we want, or it might
2448 * be a long time til we get it. -RD */
2449 r
= add_an_entry_guard(NULL
, 0);
2451 smartlist_add(live_entry_guards
, r
);
2452 entry_guards_changed();
2455 if (!r
&& need_uptime
) {
2456 need_uptime
= 0; /* try without that requirement */
2459 if (!r
&& need_capacity
) {
2460 /* still no? last attempt, try without requiring capacity */
2464 if (!r
&& !entry_list_can_grow(options
) && consider_exit_family
) {
2465 /* still no? if we're using bridges or have strictentrynodes
2466 * set, and our chosen exit is in the same family as all our
2467 * bridges/entry guards, then be flexible about families. */
2468 consider_exit_family
= 0;
2471 /* live_entry_guards may be empty below. Oh well, we tried. */
2475 if (entry_list_can_grow(options
)) {
2476 /* We choose uniformly at random here, because choose_good_entry_server()
2477 * already weights its choices by bandwidth, so we don't want to
2478 * *double*-weight our guard selection. */
2479 r
= smartlist_choose(live_entry_guards
);
2481 /* We need to weight by bandwidth, because our bridges or entryguards
2482 * were not already selected proportional to their bandwidth. */
2483 r
= routerlist_sl_choose_by_bandwidth(live_entry_guards
, WEIGHT_FOR_GUARD
);
2485 smartlist_free(live_entry_guards
);
2486 smartlist_free(exit_family
);
2490 /** Helper: Return the start of the month containing <b>time</b>. */
2492 start_of_month(time_t now
)
2495 tor_gmtime_r(&now
, &tm
);
2500 return tor_timegm(&tm
);
2503 /** Parse <b>state</b> and learn about the entry guards it describes.
2504 * If <b>set</b> is true, and there are no errors, replace the global
2505 * entry_list with what we find.
2506 * On success, return 0. On failure, alloc into *<b>msg</b> a string
2507 * describing the error, and return -1.
2510 entry_guards_parse_state(or_state_t
*state
, int set
, char **msg
)
2512 entry_guard_t
*node
= NULL
;
2513 smartlist_t
*new_entry_guards
= smartlist_create();
2514 config_line_t
*line
;
2515 time_t now
= time(NULL
);
2516 const char *state_version
= state
->TorVersion
;
2517 digestmap_t
*added_by
= digestmap_new();
2520 for (line
= state
->EntryGuards
; line
; line
= line
->next
) {
2521 if (!strcasecmp(line
->key
, "EntryGuard")) {
2522 smartlist_t
*args
= smartlist_create();
2523 node
= tor_malloc_zero(sizeof(entry_guard_t
));
2524 /* all entry guards on disk have been contacted */
2525 node
->made_contact
= 1;
2526 smartlist_add(new_entry_guards
, node
);
2527 smartlist_split_string(args
, line
->value
, " ",
2528 SPLIT_SKIP_SPACE
|SPLIT_IGNORE_BLANK
, 0);
2529 if (smartlist_len(args
)<2) {
2530 *msg
= tor_strdup("Unable to parse entry nodes: "
2531 "Too few arguments to EntryGuard");
2532 } else if (!is_legal_nickname(smartlist_get(args
,0))) {
2533 *msg
= tor_strdup("Unable to parse entry nodes: "
2534 "Bad nickname for EntryGuard");
2536 strlcpy(node
->nickname
, smartlist_get(args
,0), MAX_NICKNAME_LEN
+1);
2537 if (base16_decode(node
->identity
, DIGEST_LEN
, smartlist_get(args
,1),
2538 strlen(smartlist_get(args
,1)))<0) {
2539 *msg
= tor_strdup("Unable to parse entry nodes: "
2540 "Bad hex digest for EntryGuard");
2543 SMARTLIST_FOREACH(args
, char*, cp
, tor_free(cp
));
2544 smartlist_free(args
);
2547 } else if (!strcasecmp(line
->key
, "EntryGuardDownSince") ||
2548 !strcasecmp(line
->key
, "EntryGuardUnlistedSince")) {
2550 time_t last_try
= 0;
2552 *msg
= tor_strdup("Unable to parse entry nodes: "
2553 "EntryGuardDownSince/UnlistedSince without EntryGuard");
2556 if (parse_iso_time(line
->value
, &when
)<0) {
2557 *msg
= tor_strdup("Unable to parse entry nodes: "
2558 "Bad time in EntryGuardDownSince/UnlistedSince");
2562 /* It's a bad idea to believe info in the future: you can wind
2563 * up with timeouts that aren't allowed to happen for years. */
2566 if (strlen(line
->value
) >= ISO_TIME_LEN
+ISO_TIME_LEN
+1) {
2567 /* ignore failure */
2568 (void) parse_iso_time(line
->value
+ISO_TIME_LEN
+1, &last_try
);
2570 if (!strcasecmp(line
->key
, "EntryGuardDownSince")) {
2571 node
->unreachable_since
= when
;
2572 node
->last_attempted
= last_try
;
2574 node
->bad_since
= when
;
2576 } else if (!strcasecmp(line
->key
, "EntryGuardAddedBy")) {
2578 /* format is digest version date */
2579 if (strlen(line
->value
) < HEX_DIGEST_LEN
+1+1+1+ISO_TIME_LEN
) {
2580 log_warn(LD_BUG
, "EntryGuardAddedBy line is not long enough.");
2583 if (base16_decode(d
, sizeof(d
), line
->value
, HEX_DIGEST_LEN
)<0 ||
2584 line
->value
[HEX_DIGEST_LEN
] != ' ') {
2585 log_warn(LD_BUG
, "EntryGuardAddedBy line %s does not begin with "
2586 "hex digest", escaped(line
->value
));
2589 digestmap_set(added_by
, d
, tor_strdup(line
->value
+HEX_DIGEST_LEN
+1));
2591 log_warn(LD_BUG
, "Unexpected key %s", line
->key
);
2595 SMARTLIST_FOREACH(new_entry_guards
, entry_guard_t
*, e
,
2598 char *val
= digestmap_get(added_by
, e
->identity
);
2599 if (val
&& (sp
= strchr(val
, ' '))) {
2602 if (parse_iso_time(sp
, &when
)<0) {
2603 log_warn(LD_BUG
, "Can't read time %s in EntryGuardAddedBy", sp
);
2605 e
->chosen_by_version
= tor_strdup(val
);
2606 e
->chosen_on_date
= when
;
2609 if (state_version
) {
2610 e
->chosen_by_version
= tor_strdup(state_version
);
2611 e
->chosen_on_date
= start_of_month(time(NULL
));
2617 SMARTLIST_FOREACH(new_entry_guards
, entry_guard_t
*, e
,
2618 entry_guard_free(e
));
2619 smartlist_free(new_entry_guards
);
2620 } else { /* !*err && set */
2622 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
2623 entry_guard_free(e
));
2624 smartlist_free(entry_guards
);
2626 entry_guards
= new_entry_guards
;
2627 entry_guards_dirty
= 0;
2628 if (remove_obsolete_entry_guards())
2629 entry_guards_dirty
= 1;
2631 digestmap_free(added_by
, _tor_free
);
2632 return *msg
? -1 : 0;
2635 /** Our list of entry guards has changed, or some element of one
2636 * of our entry guards has changed. Write the changes to disk within
2637 * the next few minutes.
2640 entry_guards_changed(void)
2643 entry_guards_dirty
= 1;
2645 /* or_state_save() will call entry_guards_update_state(). */
2646 when
= get_options()->AvoidDiskWrites
? time(NULL
) + 3600 : time(NULL
)+600;
2647 or_state_mark_dirty(get_or_state(), when
);
2650 /** If the entry guard info has not changed, do nothing and return.
2651 * Otherwise, free the EntryGuards piece of <b>state</b> and create
2652 * a new one out of the global entry_guards list, and then mark
2653 * <b>state</b> dirty so it will get saved to disk.
2656 entry_guards_update_state(or_state_t
*state
)
2658 config_line_t
**next
, *line
;
2659 if (! entry_guards_dirty
)
2662 config_free_lines(state
->EntryGuards
);
2663 next
= &state
->EntryGuards
;
2666 entry_guards
= smartlist_create();
2667 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
2669 char dbuf
[HEX_DIGEST_LEN
+1];
2670 if (!e
->made_contact
)
2671 continue; /* don't write this one to disk */
2672 *next
= line
= tor_malloc_zero(sizeof(config_line_t
));
2673 line
->key
= tor_strdup("EntryGuard");
2674 line
->value
= tor_malloc(HEX_DIGEST_LEN
+MAX_NICKNAME_LEN
+2);
2675 base16_encode(dbuf
, sizeof(dbuf
), e
->identity
, DIGEST_LEN
);
2676 tor_snprintf(line
->value
,HEX_DIGEST_LEN
+MAX_NICKNAME_LEN
+2,
2677 "%s %s", e
->nickname
, dbuf
);
2678 next
= &(line
->next
);
2679 if (e
->unreachable_since
) {
2680 *next
= line
= tor_malloc_zero(sizeof(config_line_t
));
2681 line
->key
= tor_strdup("EntryGuardDownSince");
2682 line
->value
= tor_malloc(ISO_TIME_LEN
+1+ISO_TIME_LEN
+1);
2683 format_iso_time(line
->value
, e
->unreachable_since
);
2684 if (e
->last_attempted
) {
2685 line
->value
[ISO_TIME_LEN
] = ' ';
2686 format_iso_time(line
->value
+ISO_TIME_LEN
+1, e
->last_attempted
);
2688 next
= &(line
->next
);
2691 *next
= line
= tor_malloc_zero(sizeof(config_line_t
));
2692 line
->key
= tor_strdup("EntryGuardUnlistedSince");
2693 line
->value
= tor_malloc(ISO_TIME_LEN
+1);
2694 format_iso_time(line
->value
, e
->bad_since
);
2695 next
= &(line
->next
);
2697 if (e
->chosen_on_date
&& e
->chosen_by_version
&&
2698 !strchr(e
->chosen_by_version
, ' ')) {
2699 char d
[HEX_DIGEST_LEN
+1];
2700 char t
[ISO_TIME_LEN
+1];
2702 *next
= line
= tor_malloc_zero(sizeof(config_line_t
));
2703 line
->key
= tor_strdup("EntryGuardAddedBy");
2704 val_len
= (HEX_DIGEST_LEN
+1+strlen(e
->chosen_by_version
)
2706 line
->value
= tor_malloc(val_len
);
2707 base16_encode(d
, sizeof(d
), e
->identity
, DIGEST_LEN
);
2708 format_iso_time(t
, e
->chosen_on_date
);
2709 tor_snprintf(line
->value
, val_len
, "%s %s %s",
2710 d
, e
->chosen_by_version
, t
);
2711 next
= &(line
->next
);
2714 if (!get_options()->AvoidDiskWrites
)
2715 or_state_mark_dirty(get_or_state(), 0);
2716 entry_guards_dirty
= 0;
2719 /** If <b>question</b> is the string "entry-guards", then dump
2720 * to *<b>answer</b> a newly allocated string describing all of
2721 * the nodes in the global entry_guards list. See control-spec.txt
2723 * For backward compatibility, we also handle the string "helper-nodes".
2726 getinfo_helper_entry_guards(control_connection_t
*conn
,
2727 const char *question
, char **answer
)
2729 int use_long_names
= conn
->use_long_names
;
2731 if (!strcmp(question
,"entry-guards") ||
2732 !strcmp(question
,"helper-nodes")) {
2733 smartlist_t
*sl
= smartlist_create();
2734 char tbuf
[ISO_TIME_LEN
+1];
2735 char nbuf
[MAX_VERBOSE_NICKNAME_LEN
+1];
2737 entry_guards
= smartlist_create();
2738 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
2740 size_t len
= MAX_VERBOSE_NICKNAME_LEN
+ISO_TIME_LEN
+32;
2741 char *c
= tor_malloc(len
);
2742 const char *status
= NULL
;
2744 if (!e
->made_contact
) {
2745 status
= "never-connected";
2746 } else if (e
->bad_since
) {
2747 when
= e
->bad_since
;
2748 status
= "unusable";
2752 if (use_long_names
) {
2753 routerinfo_t
*ri
= router_get_by_digest(e
->identity
);
2755 router_get_verbose_nickname(nbuf
, ri
);
2758 base16_encode(nbuf
+1, sizeof(nbuf
)-1, e
->identity
, DIGEST_LEN
);
2759 /* e->nickname field is not very reliable if we don't know about
2760 * this router any longer; don't include it. */
2763 base16_encode(nbuf
, sizeof(nbuf
), e
->identity
, DIGEST_LEN
);
2766 format_iso_time(tbuf
, when
);
2767 tor_snprintf(c
, len
, "%s %s %s\n", nbuf
, status
, tbuf
);
2769 tor_snprintf(c
, len
, "%s %s\n", nbuf
, status
);
2771 smartlist_add(sl
, c
);
2773 *answer
= smartlist_join_strings(sl
, "", 0, NULL
);
2774 SMARTLIST_FOREACH(sl
, char *, c
, tor_free(c
));
2780 /** Information about a configured bridge. Currently this just matches the
2781 * ones in the torrc file, but one day we may be able to learn about new
2782 * bridges on our own, and remember them in the state file. */
2784 /** IPv4 address of the bridge. */
2786 /** TLS port for the bridge. */
2788 /** Expected identity digest, or all \0's if we don't know what the
2789 * digest should be. */
2790 char identity
[DIGEST_LEN
];
2791 /** When should we next try to fetch a descriptor for this bridge? */
2792 download_status_t fetch_status
;
2795 /** A list of configured bridges. Whenever we actually get a descriptor
2796 * for one, we add it as an entry guard. */
2797 static smartlist_t
*bridge_list
= NULL
;
2799 /** Initialize the bridge list to empty, creating it if needed. */
2801 clear_bridge_list(void)
2804 bridge_list
= smartlist_create();
2805 SMARTLIST_FOREACH(bridge_list
, bridge_info_t
*, b
, tor_free(b
));
2806 smartlist_clear(bridge_list
);
2809 /** Return a bridge pointer if <b>ri</b> is one of our known bridges
2810 * (either by comparing keys if possible, else by comparing addr/port).
2811 * Else return NULL. */
2812 static bridge_info_t
*
2813 routerinfo_get_configured_bridge(routerinfo_t
*ri
)
2817 SMARTLIST_FOREACH(bridge_list
, bridge_info_t
*, bridge
,
2819 if (tor_digest_is_zero(bridge
->identity
) &&
2820 bridge
->addr
== ri
->addr
&& bridge
->port
== ri
->or_port
)
2822 if (!memcmp(bridge
->identity
, ri
->cache_info
.identity_digest
,
2829 /** Return 1 if <b>ri</b> is one of our known bridges, else 0. */
2831 routerinfo_is_a_configured_bridge(routerinfo_t
*ri
)
2833 return routerinfo_get_configured_bridge(ri
) ? 1 : 0;
2836 /** Remember a new bridge at <b>addr</b>:<b>port</b>. If <b>digest</b>
2837 * is set, it tells us the identity key too. */
2839 bridge_add_from_config(uint32_t addr
, uint16_t port
, char *digest
)
2841 bridge_info_t
*b
= tor_malloc_zero(sizeof(bridge_info_t
));
2845 memcpy(b
->identity
, digest
, DIGEST_LEN
);
2847 bridge_list
= smartlist_create();
2848 smartlist_add(bridge_list
, b
);
2851 /** Schedule the next fetch for <b>bridge</b>, based on
2852 * some retry schedule. */
2854 bridge_fetch_status_increment(bridge_info_t
*bridge
, time_t now
)
2856 switch (bridge
->fetch_status
.n_download_failures
) {
2857 case 0: bridge
->fetch_status
.next_attempt_at
= now
+60*15; break;
2858 case 1: bridge
->fetch_status
.next_attempt_at
= now
+60*15; break;
2859 default: bridge
->fetch_status
.next_attempt_at
= now
+60*60; break;
2861 if (bridge
->fetch_status
.n_download_failures
< 10)
2862 bridge
->fetch_status
.n_download_failures
++;
2865 /** We just got a new descriptor for <b>bridge</b>. Reschedule the
2866 * next fetch for a long time from <b>now</b>. */
2868 bridge_fetch_status_arrived(bridge_info_t
*bridge
, time_t now
)
2871 bridge
->fetch_status
.next_attempt_at
= now
+60*60;
2872 bridge
->fetch_status
.n_download_failures
= 0;
2875 /** If <b>digest</b> is one of our known bridges, return it. */
2876 static bridge_info_t
*
2877 find_bridge_by_digest(char *digest
)
2879 SMARTLIST_FOREACH(bridge_list
, bridge_info_t
*, bridge
,
2881 if (!memcmp(bridge
->identity
, digest
, DIGEST_LEN
))
2887 /** We need to ask <b>bridge</b> for its server descriptor. <b>address</b>
2888 * is a helpful string describing this bridge. */
2890 launch_direct_bridge_descriptor_fetch(char *address
, bridge_info_t
*bridge
)
2892 if (connection_get_by_type_addr_port_purpose(
2893 CONN_TYPE_DIR
, bridge
->addr
, bridge
->port
,
2894 DIR_PURPOSE_FETCH_SERVERDESC
))
2895 return; /* it's already on the way */
2896 directory_initiate_command(address
, bridge
->addr
,
2898 0, /* does not matter */
2899 1, bridge
->identity
,
2900 DIR_PURPOSE_FETCH_SERVERDESC
,
2901 ROUTER_PURPOSE_BRIDGE
,
2902 0, "authority.z", NULL
, 0, 0);
2905 /** Fetching the bridge descriptor from the bridge authority returned a
2906 * "not found". Fall back to trying a direct fetch. */
2908 retry_bridge_descriptor_fetch_directly(char *digest
)
2910 bridge_info_t
*bridge
= find_bridge_by_digest(digest
);
2911 char address_buf
[INET_NTOA_BUF_LEN
+1];
2915 return; /* not found? oh well. */
2917 in
.s_addr
= htonl(bridge
->addr
);
2918 tor_inet_ntoa(&in
, address_buf
, sizeof(address_buf
));
2919 launch_direct_bridge_descriptor_fetch(address_buf
, bridge
);
2922 /** For each bridge in our list for which we don't currently have a
2923 * descriptor, fetch a new copy of its descriptor -- either directly
2924 * from the bridge or via a bridge authority. */
2926 fetch_bridge_descriptors(time_t now
)
2928 char address_buf
[INET_NTOA_BUF_LEN
+1];
2930 or_options_t
*options
= get_options();
2931 int num_bridge_auths
= get_n_authorities(BRIDGE_AUTHORITY
);
2932 int ask_bridge_directly
;
2933 int can_use_bridge_authority
;
2938 SMARTLIST_FOREACH(bridge_list
, bridge_info_t
*, bridge
,
2940 if (bridge
->fetch_status
.next_attempt_at
> now
)
2941 continue; /* don't bother, no need to retry yet */
2943 /* schedule another fetch as if this one will fail, in case it does */
2944 bridge_fetch_status_increment(bridge
, now
);
2946 in
.s_addr
= htonl(bridge
->addr
);
2947 tor_inet_ntoa(&in
, address_buf
, sizeof(address_buf
));
2949 can_use_bridge_authority
= !tor_digest_is_zero(bridge
->identity
) &&
2951 ask_bridge_directly
= !can_use_bridge_authority
||
2952 !options
->UpdateBridgesFromAuthority
;
2953 log_debug(LD_DIR
, "ask_bridge_directly=%d (%d, %d, %d)",
2954 ask_bridge_directly
, tor_digest_is_zero(bridge
->identity
),
2955 !options
->UpdateBridgesFromAuthority
, !num_bridge_auths
);
2957 if (ask_bridge_directly
&&
2958 !fascist_firewall_allows_address_or(bridge
->addr
, bridge
->port
)) {
2959 log_notice(LD_DIR
, "Bridge at '%s:%d' isn't reachable by our "
2960 "firewall policy. %s.", address_buf
, bridge
->port
,
2961 can_use_bridge_authority
?
2962 "Asking bridge authority instead" : "Skipping");
2963 if (can_use_bridge_authority
)
2964 ask_bridge_directly
= 0;
2969 if (ask_bridge_directly
) {
2970 /* we need to ask the bridge itself for its descriptor. */
2971 launch_direct_bridge_descriptor_fetch(address_buf
, bridge
);
2973 /* We have a digest and we want to ask an authority. We could
2974 * combine all the requests into one, but that may give more
2975 * hints to the bridge authority than we want to give. */
2976 char resource
[10 + HEX_DIGEST_LEN
];
2977 memcpy(resource
, "fp/", 3);
2978 base16_encode(resource
+3, HEX_DIGEST_LEN
+1,
2979 bridge
->identity
, DIGEST_LEN
);
2980 memcpy(resource
+3+HEX_DIGEST_LEN
, ".z", 3);
2981 log_info(LD_DIR
, "Fetching bridge info '%s' from bridge authority.",
2983 directory_get_from_dirserver(DIR_PURPOSE_FETCH_SERVERDESC
,
2984 ROUTER_PURPOSE_BRIDGE
, resource
, 0);
2989 /** We just learned a descriptor for a bridge. See if that
2990 * digest is in our entry guard list, and add it if not. */
2992 learned_bridge_descriptor(routerinfo_t
*ri
, int from_cache
)
2995 tor_assert(ri
->purpose
== ROUTER_PURPOSE_BRIDGE
);
2996 if (get_options()->UseBridges
) {
2997 int first
= !any_bridge_descriptors_known();
2998 bridge_info_t
*bridge
= routerinfo_get_configured_bridge(ri
);
2999 time_t now
= time(NULL
);
3002 if (bridge
) { /* if we actually want to use this one */
3003 /* it's here; schedule its re-fetch for a long time from now. */
3005 bridge_fetch_status_arrived(bridge
, now
);
3007 add_an_entry_guard(ri
, 1);
3008 log_notice(LD_DIR
, "new bridge descriptor '%s' (%s)", ri
->nickname
,
3009 from_cache
? "cached" : "fresh");
3011 routerlist_retry_directory_downloads(now
);
3016 /** Return 1 if any of our entry guards have descriptors that
3017 * are marked with purpose 'bridge' and are running. Else return 0.
3019 * We use this function to decide if we're ready to start building
3020 * circuits through our bridges, or if we need to wait until the
3021 * directory "server/authority" requests finish. */
3023 any_bridge_descriptors_known(void)
3025 tor_assert(get_options()->UseBridges
);
3026 return choose_random_entry(NULL
)!=NULL
? 1 : 0;
3029 /** Return 1 if there are any directory conns fetching bridge descriptors
3030 * that aren't marked for close. We use this to guess if we should tell
3031 * the controller that we have a problem. */
3033 any_pending_bridge_descriptor_fetches(void)
3035 smartlist_t
*conns
= get_connection_array();
3036 SMARTLIST_FOREACH(conns
, connection_t
*, conn
,
3038 if (conn
->type
== CONN_TYPE_DIR
&&
3039 conn
->purpose
== DIR_PURPOSE_FETCH_SERVERDESC
&&
3040 TO_DIR_CONN(conn
)->router_purpose
== ROUTER_PURPOSE_BRIDGE
&&
3041 !conn
->marked_for_close
&&
3042 conn
->linked
&& !conn
->linked_conn
->marked_for_close
) {
3043 log_debug(LD_DIR
, "found one: %s", conn
->address
);
3050 /** Return 1 if we have at least one descriptor for a bridge and
3051 * all descriptors we know are down. Else return 0. If <b>act</b> is
3052 * 1, then mark the down bridges up; else just observe and report. */
3054 bridges_retry_helper(int act
)
3058 int any_running
= 0;
3060 entry_guards
= smartlist_create();
3061 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
3063 ri
= router_get_by_digest(e
->identity
);
3064 if (ri
&& ri
->purpose
== ROUTER_PURPOSE_BRIDGE
) {
3067 any_running
= 1; /* some bridge is both known and running */
3068 else if (act
) { /* mark it for retry */
3075 return any_known
&& !any_running
;
3078 /** Do we know any descriptors for our bridges, and are they all
3081 bridges_known_but_down(void)
3083 return bridges_retry_helper(0);
3086 /** Mark all down known bridges up. */
3088 bridges_retry_all(void)
3090 bridges_retry_helper(1);
3093 /** Release all storage held by the list of entry guards and related
3094 * memory structs. */
3096 entry_guards_free_all(void)
3099 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
3100 entry_guard_free(e
));
3101 smartlist_free(entry_guards
);
3102 entry_guards
= NULL
;
3104 clear_bridge_list();
3105 smartlist_free(bridge_list
);