1 /* Copyright (c) 2001 Matej Pfajfar.
2 * Copyright (c) 2001-2004, Roger Dingledine.
3 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
4 * Copyright (c) 2007-2010, The Tor Project, Inc. */
5 /* See LICENSE for licensing information */
9 * \brief The actual details of building circuits.
12 #define CIRCUIT_PRIVATE
20 #define MIN(a,b) ((a)<(b)?(a):(b))
23 #define CBT_BIN_TO_MS(bin) ((bin)*CBT_BIN_WIDTH + (CBT_BIN_WIDTH/2))
25 /********* START VARIABLES **********/
26 /** Global list of circuit build times */
27 // FIXME: Add this as a member for entry_guard_t instead of global?
28 // Then we could do per-guard statistics, as guards are likely to
29 // vary in their own latency. The downside of this is that guards
30 // can change frequently, so we'd be building a lot more circuits
32 circuit_build_times_t circ_times
;
34 /** A global list of all circuits at this hop. */
35 extern circuit_t
*global_circuitlist
;
37 /** An entry_guard_t represents our information about a chosen long-term
38 * first hop, known as a "helper" node in the literature. We can't just
39 * use a routerinfo_t, since we want to remember these even when we
40 * don't have a directory. */
42 char nickname
[MAX_NICKNAME_LEN
+1];
43 char identity
[DIGEST_LEN
];
44 time_t chosen_on_date
; /**< Approximately when was this guard added?
45 * "0" if we don't know. */
46 char *chosen_by_version
; /**< What tor version added this guard? NULL
47 * if we don't know. */
48 unsigned int made_contact
: 1; /**< 0 if we have never connected to this
49 * router, 1 if we have. */
50 unsigned int can_retry
: 1; /**< Should we retry connecting to this entry,
51 * in spite of having it marked as unreachable?*/
52 time_t bad_since
; /**< 0 if this guard is currently usable, or the time at
53 * which it was observed to become (according to the
54 * directory or the user configuration) unusable. */
55 time_t unreachable_since
; /**< 0 if we can connect to this guard, or the
56 * time at which we first noticed we couldn't
58 time_t last_attempted
; /**< 0 if we can connect to this guard, or the time
59 * at which we last failed to connect to it. */
62 /** A list of our chosen entry guards. */
63 static smartlist_t
*entry_guards
= NULL
;
64 /** A value of 1 means that the entry_guards list has changed
65 * and those changes need to be flushed to disk. */
66 static int entry_guards_dirty
= 0;
68 /** If set, we're running the unit tests: we should avoid clobbering
69 * our state file or accessing get_options() or get_or_state() */
70 static int unit_tests
= 0;
72 /********* END VARIABLES ************/
74 static int circuit_deliver_create_cell(circuit_t
*circ
,
75 uint8_t cell_type
, const char *payload
);
76 static int onion_pick_cpath_exit(origin_circuit_t
*circ
, extend_info_t
*exit
);
77 static crypt_path_t
*onion_next_hop_in_cpath(crypt_path_t
*cpath
);
78 static int onion_extend_cpath(origin_circuit_t
*circ
);
79 static int count_acceptable_routers(smartlist_t
*routers
);
80 static int onion_append_hop(crypt_path_t
**head_ptr
, extend_info_t
*choice
);
82 static void entry_guards_changed(void);
85 circuit_build_times_disabled(void)
90 int consensus_disabled
= networkstatus_get_param(NULL
, "cbtdisabled",
92 int config_disabled
= !get_options()->LearnCircuitBuildTimeout
;
93 int dirauth_disabled
= get_options()->AuthoritativeDir
;
94 int state_disabled
= (get_or_state()->LastWritten
== -1);
96 if (consensus_disabled
|| config_disabled
|| dirauth_disabled
||
99 "CircuitBuildTime learning is disabled. "
100 "Consensus=%d, Config=%d, AuthDir=%d, StateFile=%d",
101 consensus_disabled
, config_disabled
, dirauth_disabled
,
111 circuit_build_times_max_timeouts(void)
113 int32_t num
= networkstatus_get_param(NULL
, "cbtmaxtimeouts",
114 CBT_DEFAULT_MAX_RECENT_TIMEOUT_COUNT
);
119 circuit_build_times_default_num_xm_modes(void)
121 int32_t num
= networkstatus_get_param(NULL
, "cbtnummodes",
122 CBT_DEFAULT_NUM_XM_MODES
);
127 circuit_build_times_min_circs_to_observe(void)
129 int32_t num
= networkstatus_get_param(NULL
, "cbtmincircs",
130 CBT_DEFAULT_MIN_CIRCUITS_TO_OBSERVE
);
135 circuit_build_times_quantile_cutoff(void)
137 int32_t num
= networkstatus_get_param(NULL
, "cbtquantile",
138 CBT_DEFAULT_QUANTILE_CUTOFF
);
143 circuit_build_times_close_quantile(void)
145 int32_t num
= networkstatus_get_param(NULL
, "cbtclosequantile",
146 CBT_DEFAULT_CLOSE_QUANTILE
);
152 circuit_build_times_test_frequency(void)
154 int32_t num
= networkstatus_get_param(NULL
, "cbttestfreq",
155 CBT_DEFAULT_TEST_FREQUENCY
);
160 circuit_build_times_min_timeout(void)
162 int32_t num
= networkstatus_get_param(NULL
, "cbtmintimeout",
163 CBT_DEFAULT_TIMEOUT_MIN_VALUE
);
168 circuit_build_times_initial_timeout(void)
170 int32_t num
= networkstatus_get_param(NULL
, "cbtinitialtimeout",
171 CBT_DEFAULT_TIMEOUT_INITIAL_VALUE
);
176 circuit_build_times_recent_circuit_count(void)
178 int32_t num
= networkstatus_get_param(NULL
, "cbtrecentcount",
179 CBT_DEFAULT_RECENT_CIRCUITS
);
184 * This function is called when we get a consensus update.
186 * It checks to see if we have changed any consensus parameters
187 * that require reallocation or discard of previous stats.
190 circuit_build_times_new_consensus_params(circuit_build_times_t
*cbt
,
193 int32_t num
= networkstatus_get_param(ns
, "cbtrecentcount",
194 CBT_DEFAULT_RECENT_CIRCUITS
);
196 if (num
!= cbt
->liveness
.num_recent_circs
) {
197 int8_t *recent_circs
;
198 log_notice(LD_CIRC
, "Changing recent timeout size from %d to %d",
199 cbt
->liveness
.num_recent_circs
, num
);
202 tor_assert(cbt
->liveness
.timeouts_after_firsthop
);
205 * Technically this is a circular array that we are reallocating
206 * and memcopying. However, since it only consists of either 1s
207 * or 0s, and is only used in a statistical test to determine when
208 * we should discard our history after a sufficient number of 1's
209 * have been reached, it is fine if order is not preserved or
212 * cbtrecentcount should only be changing in cases of severe network
213 * distress anyway, so memory correctness here is paramount over
214 * doing acrobatics to preserve the array.
216 recent_circs
= tor_malloc_zero(sizeof(int8_t)*num
);
217 memcpy(recent_circs
, cbt
->liveness
.timeouts_after_firsthop
,
218 sizeof(int8_t)*MIN(num
, cbt
->liveness
.num_recent_circs
));
220 // Adjust the index if it needs it.
221 if (num
< cbt
->liveness
.num_recent_circs
) {
222 cbt
->liveness
.after_firsthop_idx
= MIN(num
-1,
223 cbt
->liveness
.after_firsthop_idx
);
226 tor_free(cbt
->liveness
.timeouts_after_firsthop
);
227 cbt
->liveness
.timeouts_after_firsthop
= recent_circs
;
228 cbt
->liveness
.num_recent_circs
= num
;
232 /** Make a note that we're running unit tests (rather than running Tor
233 * itself), so we avoid clobbering our state file. */
235 circuitbuild_running_unit_tests(void)
241 * Return the initial default or configured timeout in milliseconds
244 circuit_build_times_get_initial_timeout(void)
247 if (!unit_tests
&& get_options()->CircuitBuildTimeout
) {
248 timeout
= get_options()->CircuitBuildTimeout
*1000;
249 if (timeout
< circuit_build_times_min_timeout()) {
250 log_warn(LD_CIRC
, "Config CircuitBuildTimeout too low. Setting to %ds",
251 circuit_build_times_min_timeout()/1000);
252 timeout
= circuit_build_times_min_timeout();
255 timeout
= circuit_build_times_initial_timeout();
261 * Reset the build time state.
263 * Leave estimated parameters, timeout and network liveness intact
267 circuit_build_times_reset(circuit_build_times_t
*cbt
)
269 memset(cbt
->circuit_build_times
, 0, sizeof(cbt
->circuit_build_times
));
270 cbt
->total_build_times
= 0;
271 cbt
->build_times_idx
= 0;
272 cbt
->have_computed_timeout
= 0;
276 * Initialize the buildtimes structure for first use.
278 * Sets the initial timeout value based to either the
279 * config setting or BUILD_TIMEOUT_INITIAL_VALUE.
282 circuit_build_times_init(circuit_build_times_t
*cbt
)
284 memset(cbt
, 0, sizeof(*cbt
));
285 cbt
->liveness
.num_recent_circs
= circuit_build_times_recent_circuit_count();
286 cbt
->liveness
.timeouts_after_firsthop
= tor_malloc_zero(sizeof(int8_t)*
287 cbt
->liveness
.num_recent_circs
);
288 cbt
->close_ms
= cbt
->timeout_ms
= circuit_build_times_get_initial_timeout();
289 control_event_buildtimeout_set(cbt
, BUILDTIMEOUT_SET_EVENT_RESET
);
293 * Rewind our build time history by n positions.
296 circuit_build_times_rewind_history(circuit_build_times_t
*cbt
, int n
)
300 cbt
->build_times_idx
-= n
;
301 cbt
->build_times_idx
%= CBT_NCIRCUITS_TO_OBSERVE
;
303 for (i
= 0; i
< n
; i
++) {
304 cbt
->circuit_build_times
[(i
+cbt
->build_times_idx
)
305 %CBT_NCIRCUITS_TO_OBSERVE
]=0;
308 if (cbt
->total_build_times
> n
) {
309 cbt
->total_build_times
-= n
;
311 cbt
->total_build_times
= 0;
315 "Rewound history by %d places. Current index: %d. "
316 "Total: %d", n
, cbt
->build_times_idx
, cbt
->total_build_times
);
320 * Add a new build time value <b>time</b> to the set of build times. Time
321 * units are milliseconds.
323 * circuit_build_times <b>cbt</a> is a circular array, so loop around when
327 circuit_build_times_add_time(circuit_build_times_t
*cbt
, build_time_t time
)
329 if (time
<= 0 || time
> CBT_BUILD_TIME_MAX
) {
330 log_warn(LD_BUG
, "Circuit build time is too large (%u)."
331 "This is probably a bug.", time
);
332 tor_fragile_assert();
336 log_debug(LD_CIRC
, "Adding circuit build time %u", time
);
338 cbt
->circuit_build_times
[cbt
->build_times_idx
] = time
;
339 cbt
->build_times_idx
= (cbt
->build_times_idx
+ 1) % CBT_NCIRCUITS_TO_OBSERVE
;
340 if (cbt
->total_build_times
< CBT_NCIRCUITS_TO_OBSERVE
)
341 cbt
->total_build_times
++;
343 if ((cbt
->total_build_times
% CBT_SAVE_STATE_EVERY
) == 0) {
344 /* Save state every n circuit builds */
345 if (!unit_tests
&& !get_options()->AvoidDiskWrites
)
346 or_state_mark_dirty(get_or_state(), 0);
353 * Return maximum circuit build time
356 circuit_build_times_max(circuit_build_times_t
*cbt
)
359 build_time_t max_build_time
= 0;
360 for (i
= 0; i
< CBT_NCIRCUITS_TO_OBSERVE
; i
++) {
361 if (cbt
->circuit_build_times
[i
] > max_build_time
362 && cbt
->circuit_build_times
[i
] != CBT_BUILD_ABANDONED
)
363 max_build_time
= cbt
->circuit_build_times
[i
];
365 return max_build_time
;
369 /** Return minimum circuit build time */
371 circuit_build_times_min(circuit_build_times_t
*cbt
)
374 build_time_t min_build_time
= CBT_BUILD_TIME_MAX
;
375 for (i
= 0; i
< CBT_NCIRCUITS_TO_OBSERVE
; i
++) {
376 if (cbt
->circuit_build_times
[i
] && /* 0 <-> uninitialized */
377 cbt
->circuit_build_times
[i
] < min_build_time
)
378 min_build_time
= cbt
->circuit_build_times
[i
];
380 if (min_build_time
== CBT_BUILD_TIME_MAX
) {
381 log_warn(LD_CIRC
, "No build times less than CBT_BUILD_TIME_MAX!");
383 return min_build_time
;
388 * Calculate and return a histogram for the set of build times.
390 * Returns an allocated array of histrogram bins representing
391 * the frequency of index*CBT_BIN_WIDTH millisecond
392 * build times. Also outputs the number of bins in nbins.
394 * The return value must be freed by the caller.
397 circuit_build_times_create_histogram(circuit_build_times_t
*cbt
,
401 build_time_t max_build_time
= circuit_build_times_max(cbt
);
404 *nbins
= 1 + (max_build_time
/ CBT_BIN_WIDTH
);
405 histogram
= tor_malloc_zero(*nbins
* sizeof(build_time_t
));
407 // calculate histogram
408 for (i
= 0; i
< CBT_NCIRCUITS_TO_OBSERVE
; i
++) {
409 if (cbt
->circuit_build_times
[i
] == 0
410 || cbt
->circuit_build_times
[i
] == CBT_BUILD_ABANDONED
)
411 continue; /* 0 <-> uninitialized */
413 c
= (cbt
->circuit_build_times
[i
] / CBT_BIN_WIDTH
);
421 * Return the Pareto start-of-curve parameter Xm.
423 * Because we are not a true Pareto curve, we compute this as the
424 * weighted average of the N=3 most frequent build time bins.
427 circuit_build_times_get_xm(circuit_build_times_t
*cbt
)
429 build_time_t i
, nbins
;
430 build_time_t
*nth_max_bin
;
431 int32_t bin_counts
=0;
432 build_time_t ret
= 0;
433 uint32_t *histogram
= circuit_build_times_create_histogram(cbt
, &nbins
);
435 int num_modes
= circuit_build_times_default_num_xm_modes();
437 // Only use one mode if < 1000 buildtimes. Not enough data
439 if (cbt
->total_build_times
< CBT_NCIRCUITS_TO_OBSERVE
)
442 nth_max_bin
= (build_time_t
*)tor_malloc_zero(num_modes
*sizeof(build_time_t
));
444 for (i
= 0; i
< nbins
; i
++) {
445 if (histogram
[i
] >= histogram
[nth_max_bin
[0]]) {
449 for (n
= 1; n
< num_modes
; n
++) {
450 if (histogram
[i
] >= histogram
[nth_max_bin
[n
]] &&
451 (!histogram
[nth_max_bin
[n
-1]]
452 || histogram
[i
] < histogram
[nth_max_bin
[n
-1]])) {
458 for (n
= 0; n
< num_modes
; n
++) {
459 bin_counts
+= histogram
[nth_max_bin
[n
]];
460 ret
+= CBT_BIN_TO_MS(nth_max_bin
[n
])*histogram
[nth_max_bin
[n
]];
461 log_info(LD_CIRC
, "Xm mode #%d: %u %u", n
, CBT_BIN_TO_MS(nth_max_bin
[n
]),
462 histogram
[nth_max_bin
[n
]]);
467 tor_free(nth_max_bin
);
473 * Output a histogram of current circuit build times to
474 * the or_state_t state structure.
477 circuit_build_times_update_state(circuit_build_times_t
*cbt
,
482 build_time_t nbins
= 0;
483 config_line_t
**next
, *line
;
485 histogram
= circuit_build_times_create_histogram(cbt
, &nbins
);
487 config_free_lines(state
->BuildtimeHistogram
);
488 next
= &state
->BuildtimeHistogram
;
491 state
->TotalBuildTimes
= cbt
->total_build_times
;
492 state
->CircuitBuildAbandonedCount
= 0;
494 for (i
= 0; i
< CBT_NCIRCUITS_TO_OBSERVE
; i
++) {
495 if (cbt
->circuit_build_times
[i
] == CBT_BUILD_ABANDONED
)
496 state
->CircuitBuildAbandonedCount
++;
499 for (i
= 0; i
< nbins
; i
++) {
500 // compress the histogram by skipping the blanks
501 if (histogram
[i
] == 0) continue;
502 *next
= line
= tor_malloc_zero(sizeof(config_line_t
));
503 line
->key
= tor_strdup("CircuitBuildTimeBin");
504 line
->value
= tor_malloc(25);
505 tor_snprintf(line
->value
, 25, "%d %d",
506 CBT_BIN_TO_MS(i
), histogram
[i
]);
507 next
= &(line
->next
);
511 if (!get_options()->AvoidDiskWrites
)
512 or_state_mark_dirty(get_or_state(), 0);
519 * Shuffle the build times array.
521 * Stolen from http://en.wikipedia.org/wiki/Fisher\u2013Yates_shuffle
524 circuit_build_times_shuffle_and_store_array(circuit_build_times_t
*cbt
,
525 build_time_t
*raw_times
,
529 if (num_times
> CBT_NCIRCUITS_TO_OBSERVE
) {
530 log_notice(LD_CIRC
, "Decreasing circuit_build_times size from %d to %d",
531 num_times
, CBT_NCIRCUITS_TO_OBSERVE
);
534 /* This code can only be run on a compact array */
536 int k
= crypto_rand_int(n
+ 1); /* 0 <= k <= n. */
537 build_time_t tmp
= raw_times
[k
];
538 raw_times
[k
] = raw_times
[n
];
542 /* Since the times are now shuffled, take a random CBT_NCIRCUITS_TO_OBSERVE
543 * subset (ie the first CBT_NCIRCUITS_TO_OBSERVE values) */
544 for (n
= 0; n
< MIN(num_times
, CBT_NCIRCUITS_TO_OBSERVE
); n
++) {
545 circuit_build_times_add_time(cbt
, raw_times
[n
]);
550 * Filter old synthetic timeouts that were created before the
551 * new right-censored Pareto calculation was deployed.
553 * Once all clients before 0.2.1.13-alpha are gone, this code
557 circuit_build_times_filter_timeouts(circuit_build_times_t
*cbt
)
559 int num_filtered
=0, i
=0;
560 double timeout_rate
= 0;
561 build_time_t max_timeout
= 0;
563 timeout_rate
= circuit_build_times_timeout_rate(cbt
);
564 max_timeout
= (build_time_t
)cbt
->close_ms
;
566 for (i
= 0; i
< CBT_NCIRCUITS_TO_OBSERVE
; i
++) {
567 if (cbt
->circuit_build_times
[i
] > max_timeout
) {
568 build_time_t replaced
= cbt
->circuit_build_times
[i
];
570 cbt
->circuit_build_times
[i
] = CBT_BUILD_ABANDONED
;
572 log_debug(LD_CIRC
, "Replaced timeout %d with %d", replaced
,
573 cbt
->circuit_build_times
[i
]);
578 "We had %d timeouts out of %d build times, "
579 "and filtered %d above the max of %u",
580 (int)(cbt
->total_build_times
*timeout_rate
),
581 cbt
->total_build_times
, num_filtered
, max_timeout
);
587 * Load histogram from <b>state</b>, shuffling the resulting array
588 * after we do so. Use this result to estimate parameters and
589 * calculate the timeout.
591 * Returns -1 and sets msg on error. Msg must be freed by the caller.
594 circuit_build_times_parse_state(circuit_build_times_t
*cbt
,
595 or_state_t
*state
, char **msg
)
598 uint32_t loaded_cnt
= 0, N
= 0;
601 build_time_t
*loaded_times
;
602 circuit_build_times_init(cbt
);
605 if (circuit_build_times_disabled()) {
609 /* build_time_t 0 means uninitialized */
610 loaded_times
= tor_malloc_zero(sizeof(build_time_t
)*state
->TotalBuildTimes
);
612 for (line
= state
->BuildtimeHistogram
; line
; line
= line
->next
) {
613 smartlist_t
*args
= smartlist_create();
614 smartlist_split_string(args
, line
->value
, " ",
615 SPLIT_SKIP_SPACE
|SPLIT_IGNORE_BLANK
, 0);
616 if (smartlist_len(args
) < 2) {
617 *msg
= tor_strdup("Unable to parse circuit build times: "
618 "Too few arguments to CircuitBuildTime");
619 SMARTLIST_FOREACH(args
, char*, cp
, tor_free(cp
));
620 smartlist_free(args
);
623 const char *ms_str
= smartlist_get(args
,0);
624 const char *count_str
= smartlist_get(args
,1);
628 ms
= (build_time_t
)tor_parse_ulong(ms_str
, 0, 0,
629 CBT_BUILD_TIME_MAX
, &ok
, NULL
);
631 *msg
= tor_strdup("Unable to parse circuit build times: "
632 "Unparsable bin number");
633 SMARTLIST_FOREACH(args
, char*, cp
, tor_free(cp
));
634 smartlist_free(args
);
637 count
= (uint32_t)tor_parse_ulong(count_str
, 0, 0,
638 UINT32_MAX
, &ok
, NULL
);
640 *msg
= tor_strdup("Unable to parse circuit build times: "
641 "Unparsable bin count");
642 SMARTLIST_FOREACH(args
, char*, cp
, tor_free(cp
));
643 smartlist_free(args
);
647 if (loaded_cnt
+count
+state
->CircuitBuildAbandonedCount
648 > state
->TotalBuildTimes
) {
650 "Too many build times in state file. "
651 "Stopping short before %d",
653 SMARTLIST_FOREACH(args
, char*, cp
, tor_free(cp
));
654 smartlist_free(args
);
658 for (k
= 0; k
< count
; k
++) {
659 loaded_times
[loaded_cnt
++] = ms
;
662 SMARTLIST_FOREACH(args
, char*, cp
, tor_free(cp
));
663 smartlist_free(args
);
668 "Adding %d timeouts.", state
->CircuitBuildAbandonedCount
);
669 for (i
=0; i
< state
->CircuitBuildAbandonedCount
; i
++) {
670 loaded_times
[loaded_cnt
++] = CBT_BUILD_ABANDONED
;
673 if (loaded_cnt
!= state
->TotalBuildTimes
) {
675 "Corrupt state file? Build times count mismatch. "
676 "Read %d times, but file says %d", loaded_cnt
,
677 state
->TotalBuildTimes
);
680 circuit_build_times_shuffle_and_store_array(cbt
, loaded_times
, loaded_cnt
);
682 /* Verify that we didn't overwrite any indexes */
683 for (i
=0; i
< CBT_NCIRCUITS_TO_OBSERVE
; i
++) {
684 if (!cbt
->circuit_build_times
[i
])
689 "Loaded %d/%d values from %d lines in circuit time histogram",
690 tot_values
, cbt
->total_build_times
, N
);
691 tor_assert(cbt
->total_build_times
== tot_values
);
692 tor_assert(cbt
->total_build_times
<= CBT_NCIRCUITS_TO_OBSERVE
);
694 circuit_build_times_set_timeout(cbt
);
696 if (!state
->CircuitBuildAbandonedCount
&& cbt
->total_build_times
) {
697 circuit_build_times_filter_timeouts(cbt
);
700 tor_free(loaded_times
);
701 return *msg
? -1 : 0;
705 * Estimates the Xm and Alpha parameters using
706 * http://en.wikipedia.org/wiki/Pareto_distribution#Parameter_estimation
708 * The notable difference is that we use mode instead of min to estimate Xm.
709 * This is because our distribution is frechet-like. We claim this is
710 * an acceptable approximation because we are only concerned with the
711 * accuracy of the CDF of the tail.
714 circuit_build_times_update_alpha(circuit_build_times_t
*cbt
)
716 build_time_t
*x
=cbt
->circuit_build_times
;
718 int n
=0,i
=0,abandoned_count
=0;
719 build_time_t max_time
=0;
721 /* http://en.wikipedia.org/wiki/Pareto_distribution#Parameter_estimation */
722 /* We sort of cheat here and make our samples slightly more pareto-like
723 * and less frechet-like. */
724 cbt
->Xm
= circuit_build_times_get_xm(cbt
);
726 tor_assert(cbt
->Xm
> 0);
728 for (i
=0; i
< CBT_NCIRCUITS_TO_OBSERVE
; i
++) {
733 if (x
[i
] < cbt
->Xm
) {
734 a
+= tor_mathlog(cbt
->Xm
);
735 } else if (x
[i
] == CBT_BUILD_ABANDONED
) {
738 a
+= tor_mathlog(x
[i
]);
745 if (n
!=cbt
->total_build_times
) {
746 log_err(LD_CIRC
, "Discrepancy in build times count: %d vs %d", n
,
747 cbt
->total_build_times
);
749 tor_assert(n
==cbt
->total_build_times
);
751 tor_assert(max_time
> 0);
753 a
+= abandoned_count
*tor_mathlog(max_time
);
755 a
-= n
*tor_mathlog(cbt
->Xm
);
756 // Estimator comes from Eq #4 in:
757 // "Bayesian estimation based on trimmed samples from Pareto populations"
758 // by Arturo J. Fernández. We are right-censored only.
759 a
= (n
-abandoned_count
)/a
;
765 * This is the Pareto Quantile Function. It calculates the point x
766 * in the distribution such that F(x) = quantile (ie quantile*100%
767 * of the mass of the density function is below x on the curve).
769 * We use it to calculate the timeout and also to generate synthetic
770 * values of time for circuits that timeout before completion.
772 * See http://en.wikipedia.org/wiki/Quantile_function,
773 * http://en.wikipedia.org/wiki/Inverse_transform_sampling and
774 * http://en.wikipedia.org/wiki/Pareto_distribution#Generating_a_
775 * random_sample_from_Pareto_distribution
776 * That's right. I'll cite wikipedia all day long.
778 * Return value is in milliseconds.
781 circuit_build_times_calculate_timeout(circuit_build_times_t
*cbt
,
785 tor_assert(quantile
>= 0);
786 tor_assert(1.0-quantile
> 0);
787 tor_assert(cbt
->Xm
> 0);
789 ret
= cbt
->Xm
/pow(1.0-quantile
,1.0/cbt
->alpha
);
790 if (ret
> INT32_MAX
) {
799 circuit_build_times_cdf(circuit_build_times_t
*cbt
, double x
)
802 tor_assert(cbt
->Xm
> 0);
803 ret
= 1.0-pow(cbt
->Xm
/x
,cbt
->alpha
);
804 tor_assert(0 <= ret
&& ret
<= 1.0);
809 * Generate a synthetic time using our distribution parameters.
811 * The return value will be within the [q_lo, q_hi) quantile points
815 circuit_build_times_generate_sample(circuit_build_times_t
*cbt
,
816 double q_lo
, double q_hi
)
818 uint64_t r
= crypto_rand_uint64(UINT64_MAX
-1);
822 /* Generate between [q_lo, q_hi) */
823 q_hi
-= 1.0/(INT32_MAX
);
825 tor_assert(q_lo
>= 0);
826 tor_assert(q_hi
< 1);
827 tor_assert(q_lo
< q_hi
);
829 u
= q_lo
+ ((q_hi
-q_lo
)*r
)/(1.0*UINT64_MAX
);
831 tor_assert(0 <= u
&& u
< 1.0);
832 /* circuit_build_times_calculate_timeout returns <= INT32_MAX */
834 tor_lround(circuit_build_times_calculate_timeout(cbt
, u
));
840 * Estimate an initial alpha parameter by solving the quantile
841 * function with a quantile point and a specific timeout value.
844 circuit_build_times_initial_alpha(circuit_build_times_t
*cbt
,
845 double quantile
, double timeout_ms
)
847 // Q(u) = Xm/((1-u)^(1/a))
848 // Q(0.8) = Xm/((1-0.8))^(1/a)) = CircBuildTimeout
849 // CircBuildTimeout = Xm/((1-0.8))^(1/a))
850 // CircBuildTimeout = Xm*((1-0.8))^(-1/a))
851 // ln(CircBuildTimeout) = ln(Xm)+ln(((1-0.8)))*(-1/a)
852 // -ln(1-0.8)/(ln(CircBuildTimeout)-ln(Xm))=a
853 tor_assert(quantile
>= 0);
854 tor_assert(cbt
->Xm
> 0);
855 cbt
->alpha
= tor_mathlog(1.0-quantile
)/
856 (tor_mathlog(cbt
->Xm
)-tor_mathlog(timeout_ms
));
857 tor_assert(cbt
->alpha
> 0);
861 * Returns true if we need circuits to be built
864 circuit_build_times_needs_circuits(circuit_build_times_t
*cbt
)
866 /* Return true if < MIN_CIRCUITS_TO_OBSERVE */
867 if (cbt
->total_build_times
< circuit_build_times_min_circs_to_observe())
873 * Returns true if we should build a timeout test circuit
877 circuit_build_times_needs_circuits_now(circuit_build_times_t
*cbt
)
879 return circuit_build_times_needs_circuits(cbt
) &&
880 approx_time()-cbt
->last_circ_at
> circuit_build_times_test_frequency();
884 * Called to indicate that the network showed some signs of liveness.
886 * This function is called every time we receive a cell. Avoid
887 * syscalls, events, and other high-intensity work.
890 circuit_build_times_network_is_live(circuit_build_times_t
*cbt
)
892 cbt
->liveness
.network_last_live
= approx_time();
893 cbt
->liveness
.nonlive_discarded
= 0;
894 cbt
->liveness
.nonlive_timeouts
= 0;
898 * Called to indicate that we completed a circuit. Because this circuit
899 * succeeded, it doesn't count as a timeout-after-the-first-hop.
902 circuit_build_times_network_circ_success(circuit_build_times_t
*cbt
)
904 cbt
->liveness
.timeouts_after_firsthop
[cbt
->liveness
.after_firsthop_idx
] = 0;
905 cbt
->liveness
.after_firsthop_idx
++;
906 cbt
->liveness
.after_firsthop_idx
%= cbt
->liveness
.num_recent_circs
;
910 * A circuit just timed out. If it failed after the first hop, record it
911 * in our history for later deciding if the network speed has changed.
914 circuit_build_times_network_timeout(circuit_build_times_t
*cbt
,
918 cbt
->liveness
.timeouts_after_firsthop
[cbt
->liveness
.after_firsthop_idx
]=1;
919 cbt
->liveness
.after_firsthop_idx
++;
920 cbt
->liveness
.after_firsthop_idx
%= cbt
->liveness
.num_recent_circs
;
925 * A circuit was just forcibly closed. If there has been no recent network
926 * activity at all, but this circuit was launched back when we thought the
927 * network was live, increment the number of "nonlive" circuit timeouts.
930 circuit_build_times_network_close(circuit_build_times_t
*cbt
,
931 int did_onehop
, time_t start_time
)
933 time_t now
= time(NULL
);
935 * Check if this is a timeout that was for a circuit that spent its
936 * entire existence during a time where we have had no network activity.
938 * Also double check that it is a valid timeout after we have possibly
939 * just recently reset cbt->close_ms.
941 * We use close_ms here because timeouts aren't actually counted as timeouts
942 * until close_ms elapses.
944 if (cbt
->liveness
.network_last_live
<= start_time
&&
945 start_time
<= (now
- cbt
->close_ms
/1000.0)) {
948 "Circuit somehow completed a hop while the network was "
949 "not live. Network was last live at %ld, but circuit launched "
950 "at %ld. It's now %ld.", cbt
->liveness
.network_last_live
,
953 cbt
->liveness
.nonlive_timeouts
++;
958 * Returns false if the network has not received a cell or tls handshake
959 * in the past NETWORK_NOTLIVE_TIMEOUT_COUNT circuits.
961 * Also has the side effect of rewinding the circuit time history
962 * in the case of recent liveness changes.
965 circuit_build_times_network_check_live(circuit_build_times_t
*cbt
)
967 time_t now
= approx_time();
968 if (cbt
->liveness
.nonlive_timeouts
>= CBT_NETWORK_NONLIVE_DISCARD_COUNT
) {
969 if (!cbt
->liveness
.nonlive_discarded
) {
970 cbt
->liveness
.nonlive_discarded
= 1;
971 log_notice(LD_CIRC
, "Network is no longer live (too many recent "
972 "circuit timeouts). Dead for %ld seconds.",
973 (long int)(now
- cbt
->liveness
.network_last_live
));
974 /* Only discard NETWORK_NONLIVE_TIMEOUT_COUNT-1 because we stopped
975 * counting after that */
976 circuit_build_times_rewind_history(cbt
,
977 CBT_NETWORK_NONLIVE_TIMEOUT_COUNT
-1);
978 control_event_buildtimeout_set(cbt
, BUILDTIMEOUT_SET_EVENT_DISCARD
);
981 } else if (cbt
->liveness
.nonlive_timeouts
>=
982 CBT_NETWORK_NONLIVE_TIMEOUT_COUNT
) {
983 if (cbt
->timeout_ms
< circuit_build_times_get_initial_timeout()) {
985 "Network is flaky. No activity for %ld seconds. "
986 "Temporarily raising timeout to %lds.",
987 (long int)(now
- cbt
->liveness
.network_last_live
),
988 tor_lround(circuit_build_times_get_initial_timeout()/1000));
989 cbt
->liveness
.suspended_timeout
= cbt
->timeout_ms
;
990 cbt
->liveness
.suspended_close_timeout
= cbt
->close_ms
;
991 cbt
->close_ms
= cbt
->timeout_ms
992 = circuit_build_times_get_initial_timeout();
993 control_event_buildtimeout_set(cbt
, BUILDTIMEOUT_SET_EVENT_SUSPENDED
);
997 } else if (cbt
->liveness
.suspended_timeout
> 0) {
999 "Network activity has resumed. "
1000 "Resuming circuit timeout calculations.");
1001 cbt
->timeout_ms
= cbt
->liveness
.suspended_timeout
;
1002 cbt
->close_ms
= cbt
->liveness
.suspended_close_timeout
;
1003 cbt
->liveness
.suspended_timeout
= 0;
1004 cbt
->liveness
.suspended_close_timeout
= 0;
1005 control_event_buildtimeout_set(cbt
, BUILDTIMEOUT_SET_EVENT_RESUME
);
1012 * Returns true if we have seen more than MAX_RECENT_TIMEOUT_COUNT of
1013 * the past RECENT_CIRCUITS time out after the first hop. Used to detect
1014 * if the network connection has changed significantly.
1016 * Also resets the entire timeout history in this case and causes us
1017 * to restart the process of building test circuits and estimating a
1021 circuit_build_times_network_check_changed(circuit_build_times_t
*cbt
)
1023 int total_build_times
= cbt
->total_build_times
;
1024 int timeout_count
=0;
1027 /* how many of our recent circuits made it to the first hop but then
1029 for (i
= 0; i
< cbt
->liveness
.num_recent_circs
; i
++) {
1030 timeout_count
+= cbt
->liveness
.timeouts_after_firsthop
[i
];
1033 /* If 80% of our recent circuits are timing out after the first hop,
1034 * we need to re-estimate a new initial alpha and timeout. */
1035 if (timeout_count
< circuit_build_times_max_timeouts()) {
1039 circuit_build_times_reset(cbt
);
1040 memset(cbt
->liveness
.timeouts_after_firsthop
, 0,
1041 sizeof(*cbt
->liveness
.timeouts_after_firsthop
)*
1042 cbt
->liveness
.num_recent_circs
);
1043 cbt
->liveness
.after_firsthop_idx
= 0;
1045 /* Check to see if this has happened before. If so, double the timeout
1046 * to give people on abysmally bad network connections a shot at access */
1047 if (cbt
->timeout_ms
>= circuit_build_times_get_initial_timeout()) {
1048 if (cbt
->timeout_ms
> INT32_MAX
/2 || cbt
->close_ms
> INT32_MAX
/2) {
1049 log_warn(LD_CIRC
, "Insanely large circuit build timeout value. "
1050 "(timeout = %lfmsec, close = %lfmsec)",
1051 cbt
->timeout_ms
, cbt
->close_ms
);
1053 cbt
->timeout_ms
*= 2;
1057 cbt
->close_ms
= cbt
->timeout_ms
1058 = circuit_build_times_get_initial_timeout();
1061 control_event_buildtimeout_set(cbt
, BUILDTIMEOUT_SET_EVENT_RESET
);
1064 "Network connection speed appears to have changed. Resetting "
1065 "timeout to %lds after %d timeouts and %d buildtimes.",
1066 tor_lround(cbt
->timeout_ms
/1000), timeout_count
,
1073 * Count the number of timeouts in a set of cbt data.
1076 circuit_build_times_timeout_rate(const circuit_build_times_t
*cbt
)
1079 for (i
= 0; i
< CBT_NCIRCUITS_TO_OBSERVE
; i
++) {
1080 if (cbt
->circuit_build_times
[i
] >= cbt
->timeout_ms
) {
1085 if (!cbt
->total_build_times
)
1088 return ((double)timeouts
)/cbt
->total_build_times
;
1092 * Store a timeout as a synthetic value.
1094 * Returns true if the store was successful and we should possibly
1095 * update our timeout estimate.
1098 circuit_build_times_count_close(circuit_build_times_t
*cbt
,
1102 if (circuit_build_times_disabled()) {
1103 cbt
->close_ms
= cbt
->timeout_ms
1104 = circuit_build_times_get_initial_timeout();
1108 /* Record this force-close to help determine if the network is dead */
1109 circuit_build_times_network_close(cbt
, did_onehop
, start_time
);
1111 /* Only count timeouts if network is live.. */
1112 if (!circuit_build_times_network_check_live(cbt
)) {
1116 circuit_build_times_add_time(cbt
, CBT_BUILD_ABANDONED
);
1121 * Update timeout counts to determine if we need to expire
1122 * our build time history due to excessive timeouts.
1125 circuit_build_times_count_timeout(circuit_build_times_t
*cbt
,
1128 if (circuit_build_times_disabled()) {
1129 cbt
->close_ms
= cbt
->timeout_ms
1130 = circuit_build_times_get_initial_timeout();
1134 circuit_build_times_network_timeout(cbt
, did_onehop
);
1136 /* If there are a ton of timeouts, we should reset
1137 * the circuit build timeout.
1139 circuit_build_times_network_check_changed(cbt
);
1143 * Estimate a new timeout based on history and set our timeout
1144 * variable accordingly.
1147 circuit_build_times_set_timeout_worker(circuit_build_times_t
*cbt
)
1149 if (cbt
->total_build_times
< circuit_build_times_min_circs_to_observe()) {
1153 circuit_build_times_update_alpha(cbt
);
1155 cbt
->timeout_ms
= circuit_build_times_calculate_timeout(cbt
,
1156 circuit_build_times_quantile_cutoff());
1158 cbt
->close_ms
= circuit_build_times_calculate_timeout(cbt
,
1159 circuit_build_times_close_quantile());
1161 /* Sometimes really fast guard nodes give us such a steep curve
1162 * that this ends up being not that much greater than timeout_ms.
1163 * Make it be at least 1 min to handle this case. */
1164 cbt
->close_ms
= MAX(cbt
->close_ms
, circuit_build_times_initial_timeout());
1166 cbt
->have_computed_timeout
= 1;
1171 * Exposed function to compute a new timeout. Dispatches events and
1172 * also filters out extremely high timeout values.
1175 circuit_build_times_set_timeout(circuit_build_times_t
*cbt
)
1177 long prev_timeout
= tor_lround(cbt
->timeout_ms
/1000);
1178 double timeout_rate
;
1180 if (!circuit_build_times_set_timeout_worker(cbt
))
1183 if (cbt
->timeout_ms
< circuit_build_times_min_timeout()) {
1184 log_warn(LD_CIRC
, "Set buildtimeout to low value %lfms. Setting to %dms",
1185 cbt
->timeout_ms
, circuit_build_times_min_timeout());
1186 cbt
->timeout_ms
= circuit_build_times_min_timeout();
1187 if (cbt
->close_ms
< cbt
->timeout_ms
) {
1188 /* This shouldn't happen because of MAX() in timeout_worker above,
1189 * but doing it just in case */
1190 cbt
->close_ms
= circuit_build_times_initial_timeout();
1194 control_event_buildtimeout_set(cbt
, BUILDTIMEOUT_SET_EVENT_COMPUTED
);
1196 timeout_rate
= circuit_build_times_timeout_rate(cbt
);
1198 if (prev_timeout
> tor_lround(cbt
->timeout_ms
/1000)) {
1200 "Based on %d circuit times, it looks like we don't need to "
1201 "wait so long for circuits to finish. We will now assume a "
1202 "circuit is too slow to use after waiting %ld seconds.",
1203 cbt
->total_build_times
,
1204 tor_lround(cbt
->timeout_ms
/1000));
1206 "Circuit timeout data: %lfms, %lfms, Xm: %d, a: %lf, r: %lf",
1207 cbt
->timeout_ms
, cbt
->close_ms
, cbt
->Xm
, cbt
->alpha
,
1209 } else if (prev_timeout
< tor_lround(cbt
->timeout_ms
/1000)) {
1211 "Based on %d circuit times, it looks like we need to wait "
1212 "longer for circuits to finish. We will now assume a "
1213 "circuit is too slow to use after waiting %ld seconds.",
1214 cbt
->total_build_times
,
1215 tor_lround(cbt
->timeout_ms
/1000));
1217 "Circuit timeout data: %lfms, %lfms, Xm: %d, a: %lf, r: %lf",
1218 cbt
->timeout_ms
, cbt
->close_ms
, cbt
->Xm
, cbt
->alpha
,
1222 "Set circuit build timeout to %lds (%lfms, %lfms, Xm: %d, a: %lf,"
1223 " r: %lf) based on %d circuit times",
1224 tor_lround(cbt
->timeout_ms
/1000),
1225 cbt
->timeout_ms
, cbt
->close_ms
, cbt
->Xm
, cbt
->alpha
, timeout_rate
,
1226 cbt
->total_build_times
);
1230 /** Iterate over values of circ_id, starting from conn-\>next_circ_id,
1231 * and with the high bit specified by conn-\>circ_id_type, until we get
1232 * a circ_id that is not in use by any other circuit on that conn.
1234 * Return it, or 0 if can't get a unique circ_id.
1237 get_unique_circ_id_by_conn(or_connection_t
*conn
)
1239 circid_t test_circ_id
;
1240 circid_t attempts
=0;
1244 if (conn
->circ_id_type
== CIRC_ID_TYPE_NEITHER
) {
1245 log_warn(LD_BUG
, "Trying to pick a circuit ID for a connection from "
1246 "a client with no identity.");
1249 high_bit
= (conn
->circ_id_type
== CIRC_ID_TYPE_HIGHER
) ? 1<<15 : 0;
1251 /* Sequentially iterate over test_circ_id=1...1<<15-1 until we find a
1252 * circID such that (high_bit|test_circ_id) is not already used. */
1253 test_circ_id
= conn
->next_circ_id
++;
1254 if (test_circ_id
== 0 || test_circ_id
>= 1<<15) {
1256 conn
->next_circ_id
= 2;
1258 if (++attempts
> 1<<15) {
1259 /* Make sure we don't loop forever if all circ_id's are used. This
1260 * matters because it's an external DoS opportunity.
1262 log_warn(LD_CIRC
,"No unused circ IDs. Failing.");
1265 test_circ_id
|= high_bit
;
1266 } while (circuit_id_in_use_on_orconn(test_circ_id
, conn
));
1267 return test_circ_id
;
1270 /** If <b>verbose</b> is false, allocate and return a comma-separated list of
1271 * the currently built elements of circuit_t. If <b>verbose</b> is true, also
1272 * list information about link status in a more verbose format using spaces.
1273 * If <b>verbose_names</b> is false, give nicknames for Named routers and hex
1274 * digests for others; if <b>verbose_names</b> is true, use $DIGEST=Name style
1278 circuit_list_path_impl(origin_circuit_t
*circ
, int verbose
, int verbose_names
)
1281 smartlist_t
*elements
;
1282 const char *states
[] = {"closed", "waiting for keys", "open"};
1285 elements
= smartlist_create();
1288 const char *nickname
= build_state_get_exit_nickname(circ
->build_state
);
1290 tor_asprintf(&cp
, "%s%s circ (length %d%s%s):",
1291 circ
->build_state
->is_internal
? "internal" : "exit",
1292 circ
->build_state
->need_uptime
? " (high-uptime)" : "",
1293 circ
->build_state
->desired_path_len
,
1294 circ
->_base
.state
== CIRCUIT_STATE_OPEN
? "" : ", exit ",
1295 circ
->_base
.state
== CIRCUIT_STATE_OPEN
? "" :
1296 (nickname
?nickname
:"*unnamed*"));
1297 smartlist_add(elements
, cp
);
1308 if (!verbose
&& hop
->state
!= CPATH_STATE_OPEN
)
1310 if (!hop
->extend_info
)
1312 id
= hop
->extend_info
->identity_digest
;
1313 if (verbose_names
) {
1314 elt
= tor_malloc(MAX_VERBOSE_NICKNAME_LEN
+1);
1315 if ((ri
= router_get_by_digest(id
))) {
1316 router_get_verbose_nickname(elt
, ri
);
1317 } else if ((rs
= router_get_consensus_status_by_id(id
))) {
1318 routerstatus_get_verbose_nickname(elt
, rs
);
1319 } else if (is_legal_nickname(hop
->extend_info
->nickname
)) {
1321 base16_encode(elt
+1, HEX_DIGEST_LEN
+1, id
, DIGEST_LEN
);
1322 elt
[HEX_DIGEST_LEN
+1]= '~';
1323 strlcpy(elt
+HEX_DIGEST_LEN
+2,
1324 hop
->extend_info
->nickname
, MAX_NICKNAME_LEN
+1);
1327 base16_encode(elt
+1, HEX_DIGEST_LEN
+1, id
, DIGEST_LEN
);
1329 } else { /* ! verbose_names */
1330 if ((ri
= router_get_by_digest(id
)) &&
1332 elt
= tor_strdup(hop
->extend_info
->nickname
);
1334 elt
= tor_malloc(HEX_DIGEST_LEN
+2);
1336 base16_encode(elt
+1, HEX_DIGEST_LEN
+1, id
, DIGEST_LEN
);
1341 size_t len
= strlen(elt
)+2+strlen(states
[hop
->state
])+1;
1342 char *v
= tor_malloc(len
);
1343 tor_assert(hop
->state
<= 2);
1344 tor_snprintf(v
,len
,"%s(%s)",elt
,states
[hop
->state
]);
1345 smartlist_add(elements
, v
);
1348 smartlist_add(elements
, elt
);
1351 } while (hop
!= circ
->cpath
);
1353 s
= smartlist_join_strings(elements
, verbose
?" ":",", 0, NULL
);
1354 SMARTLIST_FOREACH(elements
, char*, cp
, tor_free(cp
));
1355 smartlist_free(elements
);
1359 /** If <b>verbose</b> is false, allocate and return a comma-separated
1360 * list of the currently built elements of circuit_t. If
1361 * <b>verbose</b> is true, also list information about link status in
1362 * a more verbose format using spaces.
1365 circuit_list_path(origin_circuit_t
*circ
, int verbose
)
1367 return circuit_list_path_impl(circ
, verbose
, 0);
1370 /** Allocate and return a comma-separated list of the currently built elements
1371 * of circuit_t, giving each as a verbose nickname.
1374 circuit_list_path_for_controller(origin_circuit_t
*circ
)
1376 return circuit_list_path_impl(circ
, 0, 1);
1379 /** Log, at severity <b>severity</b>, the nicknames of each router in
1380 * circ's cpath. Also log the length of the cpath, and the intended
1384 circuit_log_path(int severity
, unsigned int domain
, origin_circuit_t
*circ
)
1386 char *s
= circuit_list_path(circ
,1);
1387 tor_log(severity
,domain
,"%s",s
);
1391 /** Tell the rep(utation)hist(ory) module about the status of the links
1392 * in circ. Hops that have become OPEN are marked as successfully
1393 * extended; the _first_ hop that isn't open (if any) is marked as
1396 /* XXXX Someday we should learn from OR circuits too. */
1398 circuit_rep_hist_note_result(origin_circuit_t
*circ
)
1401 char *prev_digest
= NULL
;
1402 routerinfo_t
*router
;
1404 if (!hop
) /* circuit hasn't started building yet. */
1406 if (server_mode(get_options())) {
1407 routerinfo_t
*me
= router_get_my_routerinfo();
1410 prev_digest
= me
->cache_info
.identity_digest
;
1413 router
= router_get_by_digest(hop
->extend_info
->identity_digest
);
1416 if (hop
->state
== CPATH_STATE_OPEN
)
1417 rep_hist_note_extend_succeeded(prev_digest
,
1418 router
->cache_info
.identity_digest
);
1420 rep_hist_note_extend_failed(prev_digest
,
1421 router
->cache_info
.identity_digest
);
1425 prev_digest
= router
->cache_info
.identity_digest
;
1430 } while (hop
!=circ
->cpath
);
1433 /** Pick all the entries in our cpath. Stop and return 0 when we're
1434 * happy, or return -1 if an error occurs. */
1436 onion_populate_cpath(origin_circuit_t
*circ
)
1440 r
= onion_extend_cpath(circ
);
1442 log_info(LD_CIRC
,"Generating cpath hop failed.");
1447 return 0; /* if r == 1 */
1450 /** Create and return a new origin circuit. Initialize its purpose and
1451 * build-state based on our arguments. The <b>flags</b> argument is a
1452 * bitfield of CIRCLAUNCH_* flags. */
1454 origin_circuit_init(uint8_t purpose
, int flags
)
1456 /* sets circ->p_circ_id and circ->p_conn */
1457 origin_circuit_t
*circ
= origin_circuit_new();
1458 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_OR_WAIT
);
1459 circ
->build_state
= tor_malloc_zero(sizeof(cpath_build_state_t
));
1460 circ
->build_state
->onehop_tunnel
=
1461 ((flags
& CIRCLAUNCH_ONEHOP_TUNNEL
) ? 1 : 0);
1462 circ
->build_state
->need_uptime
=
1463 ((flags
& CIRCLAUNCH_NEED_UPTIME
) ? 1 : 0);
1464 circ
->build_state
->need_capacity
=
1465 ((flags
& CIRCLAUNCH_NEED_CAPACITY
) ? 1 : 0);
1466 circ
->build_state
->is_internal
=
1467 ((flags
& CIRCLAUNCH_IS_INTERNAL
) ? 1 : 0);
1468 circ
->_base
.purpose
= purpose
;
1472 /** Build a new circuit for <b>purpose</b>. If <b>exit</b>
1473 * is defined, then use that as your exit router, else choose a suitable
1476 * Also launch a connection to the first OR in the chosen path, if
1477 * it's not open already.
1480 circuit_establish_circuit(uint8_t purpose
, extend_info_t
*exit
, int flags
)
1482 origin_circuit_t
*circ
;
1485 circ
= origin_circuit_init(purpose
, flags
);
1487 if (onion_pick_cpath_exit(circ
, exit
) < 0 ||
1488 onion_populate_cpath(circ
) < 0) {
1489 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_NOPATH
);
1493 control_event_circuit_status(circ
, CIRC_EVENT_LAUNCHED
, 0);
1495 if ((err_reason
= circuit_handle_first_hop(circ
)) < 0) {
1496 circuit_mark_for_close(TO_CIRCUIT(circ
), -err_reason
);
1502 /** Start establishing the first hop of our circuit. Figure out what
1503 * OR we should connect to, and if necessary start the connection to
1504 * it. If we're already connected, then send the 'create' cell.
1505 * Return 0 for ok, -reason if circ should be marked-for-close. */
1507 circuit_handle_first_hop(origin_circuit_t
*circ
)
1509 crypt_path_t
*firsthop
;
1510 or_connection_t
*n_conn
;
1512 const char *msg
= NULL
;
1513 int should_launch
= 0;
1515 firsthop
= onion_next_hop_in_cpath(circ
->cpath
);
1516 tor_assert(firsthop
);
1517 tor_assert(firsthop
->extend_info
);
1519 /* now see if we're already connected to the first OR in 'route' */
1520 log_debug(LD_CIRC
,"Looking for firsthop '%s:%u'",
1521 fmt_addr(&firsthop
->extend_info
->addr
),
1522 firsthop
->extend_info
->port
);
1524 n_conn
= connection_or_get_for_extend(firsthop
->extend_info
->identity_digest
,
1525 &firsthop
->extend_info
->addr
,
1530 /* not currently connected in a useful way. */
1531 const char *name
= strlen(firsthop
->extend_info
->nickname
) ?
1532 firsthop
->extend_info
->nickname
: fmt_addr(&firsthop
->extend_info
->addr
);
1533 log_info(LD_CIRC
, "Next router is %s: %s ",
1534 safe_str_client(name
), msg
?msg
:"???");
1535 circ
->_base
.n_hop
= extend_info_dup(firsthop
->extend_info
);
1537 if (should_launch
) {
1538 if (circ
->build_state
->onehop_tunnel
)
1539 control_event_bootstrap(BOOTSTRAP_STATUS_CONN_DIR
, 0);
1540 n_conn
= connection_or_connect(&firsthop
->extend_info
->addr
,
1541 firsthop
->extend_info
->port
,
1542 firsthop
->extend_info
->identity_digest
);
1543 if (!n_conn
) { /* connect failed, forget the whole thing */
1544 log_info(LD_CIRC
,"connect to firsthop failed. Closing.");
1545 return -END_CIRC_REASON_CONNECTFAILED
;
1549 log_debug(LD_CIRC
,"connecting in progress (or finished). Good.");
1550 /* return success. The onion/circuit/etc will be taken care of
1551 * automatically (may already have been) whenever n_conn reaches
1552 * OR_CONN_STATE_OPEN.
1555 } else { /* it's already open. use it. */
1556 tor_assert(!circ
->_base
.n_hop
);
1557 circ
->_base
.n_conn
= n_conn
;
1558 log_debug(LD_CIRC
,"Conn open. Delivering first onion skin.");
1559 if ((err_reason
= circuit_send_next_onion_skin(circ
)) < 0) {
1560 log_info(LD_CIRC
,"circuit_send_next_onion_skin failed.");
1567 /** Find any circuits that are waiting on <b>or_conn</b> to become
1568 * open and get them to send their create cells forward.
1570 * Status is 1 if connect succeeded, or 0 if connect failed.
1573 circuit_n_conn_done(or_connection_t
*or_conn
, int status
)
1575 smartlist_t
*pending_circs
;
1578 log_debug(LD_CIRC
,"or_conn to %s/%s, status=%d",
1579 or_conn
->nickname
? or_conn
->nickname
: "NULL",
1580 or_conn
->_base
.address
, status
);
1582 pending_circs
= smartlist_create();
1583 circuit_get_all_pending_on_or_conn(pending_circs
, or_conn
);
1585 SMARTLIST_FOREACH_BEGIN(pending_circs
, circuit_t
*, circ
)
1587 /* These checks are redundant wrt get_all_pending_on_or_conn, but I'm
1588 * leaving them in in case it's possible for the status of a circuit to
1589 * change as we're going down the list. */
1590 if (circ
->marked_for_close
|| circ
->n_conn
|| !circ
->n_hop
||
1591 circ
->state
!= CIRCUIT_STATE_OR_WAIT
)
1594 if (tor_digest_is_zero(circ
->n_hop
->identity_digest
)) {
1595 /* Look at addr/port. This is an unkeyed connection. */
1596 if (!tor_addr_eq(&circ
->n_hop
->addr
, &or_conn
->_base
.addr
) ||
1597 circ
->n_hop
->port
!= or_conn
->_base
.port
)
1600 /* We expected a key. See if it's the right one. */
1601 if (memcmp(or_conn
->identity_digest
,
1602 circ
->n_hop
->identity_digest
, DIGEST_LEN
))
1605 if (!status
) { /* or_conn failed; close circ */
1606 log_info(LD_CIRC
,"or_conn failed. Closing circ.");
1607 circuit_mark_for_close(circ
, END_CIRC_REASON_OR_CONN_CLOSED
);
1610 log_debug(LD_CIRC
, "Found circ, sending create cell.");
1611 /* circuit_deliver_create_cell will set n_circ_id and add us to
1612 * orconn_circuid_circuit_map, so we don't need to call
1613 * set_circid_orconn here. */
1614 circ
->n_conn
= or_conn
;
1615 extend_info_free(circ
->n_hop
);
1618 if (CIRCUIT_IS_ORIGIN(circ
)) {
1620 circuit_send_next_onion_skin(TO_ORIGIN_CIRCUIT(circ
))) < 0) {
1622 "send_next_onion_skin failed; circuit marked for closing.");
1623 circuit_mark_for_close(circ
, -err_reason
);
1625 /* XXX could this be bad, eg if next_onion_skin failed because conn
1629 /* pull the create cell out of circ->onionskin, and send it */
1630 tor_assert(circ
->n_conn_onionskin
);
1631 if (circuit_deliver_create_cell(circ
,CELL_CREATE
,
1632 circ
->n_conn_onionskin
)<0) {
1633 circuit_mark_for_close(circ
, END_CIRC_REASON_RESOURCELIMIT
);
1636 tor_free(circ
->n_conn_onionskin
);
1637 circuit_set_state(circ
, CIRCUIT_STATE_OPEN
);
1640 SMARTLIST_FOREACH_END(circ
);
1642 smartlist_free(pending_circs
);
1645 /** Find a new circid that isn't currently in use on the circ->n_conn
1647 * circuit <b>circ</b>, and deliver a cell of type <b>cell_type</b>
1648 * (either CELL_CREATE or CELL_CREATE_FAST) with payload <b>payload</b>
1650 * Return -1 if we failed to find a suitable circid, else return 0.
1653 circuit_deliver_create_cell(circuit_t
*circ
, uint8_t cell_type
,
1654 const char *payload
)
1660 tor_assert(circ
->n_conn
);
1661 tor_assert(payload
);
1662 tor_assert(cell_type
== CELL_CREATE
|| cell_type
== CELL_CREATE_FAST
);
1664 id
= get_unique_circ_id_by_conn(circ
->n_conn
);
1666 log_warn(LD_CIRC
,"failed to get unique circID.");
1669 log_debug(LD_CIRC
,"Chosen circID %u.", id
);
1670 circuit_set_n_circid_orconn(circ
, id
, circ
->n_conn
);
1672 memset(&cell
, 0, sizeof(cell_t
));
1673 cell
.command
= cell_type
;
1674 cell
.circ_id
= circ
->n_circ_id
;
1676 memcpy(cell
.payload
, payload
, ONIONSKIN_CHALLENGE_LEN
);
1677 append_cell_to_circuit_queue(circ
, circ
->n_conn
, &cell
, CELL_DIRECTION_OUT
);
1679 if (CIRCUIT_IS_ORIGIN(circ
)) {
1680 /* mark it so it gets better rate limiting treatment. */
1681 circ
->n_conn
->client_used
= time(NULL
);
1687 /** We've decided to start our reachability testing. If all
1688 * is set, log this to the user. Return 1 if we did, or 0 if
1689 * we chose not to log anything. */
1691 inform_testing_reachability(void)
1694 routerinfo_t
*me
= router_get_my_routerinfo();
1697 control_event_server_status(LOG_NOTICE
,
1698 "CHECKING_REACHABILITY ORADDRESS=%s:%d",
1699 me
->address
, me
->or_port
);
1701 tor_snprintf(dirbuf
, sizeof(dirbuf
), " and DirPort %s:%d",
1702 me
->address
, me
->dir_port
);
1703 control_event_server_status(LOG_NOTICE
,
1704 "CHECKING_REACHABILITY DIRADDRESS=%s:%d",
1705 me
->address
, me
->dir_port
);
1707 log_notice(LD_OR
, "Now checking whether ORPort %s:%d%s %s reachable... "
1708 "(this may take up to %d minutes -- look for log "
1709 "messages indicating success)",
1710 me
->address
, me
->or_port
,
1711 me
->dir_port
? dirbuf
: "",
1712 me
->dir_port
? "are" : "is",
1713 TIMEOUT_UNTIL_UNREACHABILITY_COMPLAINT
/60);
1718 /** Return true iff we should send a create_fast cell to start building a given
1721 should_use_create_fast_for_circuit(origin_circuit_t
*circ
)
1723 or_options_t
*options
= get_options();
1724 tor_assert(circ
->cpath
);
1725 tor_assert(circ
->cpath
->extend_info
);
1727 if (!circ
->cpath
->extend_info
->onion_key
)
1728 return 1; /* our hand is forced: only a create_fast will work. */
1729 if (!options
->FastFirstHopPK
)
1730 return 0; /* we prefer to avoid create_fast */
1731 if (server_mode(options
)) {
1732 /* We're a server, and we know an onion key. We can choose.
1733 * Prefer to blend in. */
1740 /** This is the backbone function for building circuits.
1742 * If circ's first hop is closed, then we need to build a create
1743 * cell and send it forward.
1745 * Otherwise, we need to build a relay extend cell and send it
1748 * Return -reason if we want to tear down circ, else return 0.
1751 circuit_send_next_onion_skin(origin_circuit_t
*circ
)
1754 routerinfo_t
*router
;
1755 char payload
[2+4+DIGEST_LEN
+ONIONSKIN_CHALLENGE_LEN
];
1761 if (circ
->cpath
->state
== CPATH_STATE_CLOSED
) {
1764 log_debug(LD_CIRC
,"First skin; sending create cell.");
1765 if (circ
->build_state
->onehop_tunnel
)
1766 control_event_bootstrap(BOOTSTRAP_STATUS_ONEHOP_CREATE
, 0);
1768 control_event_bootstrap(BOOTSTRAP_STATUS_CIRCUIT_CREATE
, 0);
1770 router
= router_get_by_digest(circ
->_base
.n_conn
->identity_digest
);
1771 fast
= should_use_create_fast_for_circuit(circ
);
1773 /* We are an OR and we know the right onion key: we should
1774 * send an old slow create cell.
1776 cell_type
= CELL_CREATE
;
1777 if (onion_skin_create(circ
->cpath
->extend_info
->onion_key
,
1778 &(circ
->cpath
->dh_handshake_state
),
1780 log_warn(LD_CIRC
,"onion_skin_create (first hop) failed.");
1781 return - END_CIRC_REASON_INTERNAL
;
1783 note_request("cell: create", 1);
1785 /* We are not an OR, and we're building the first hop of a circuit to a
1786 * new OR: we can be speedy and use CREATE_FAST to save an RSA operation
1787 * and a DH operation. */
1788 cell_type
= CELL_CREATE_FAST
;
1789 memset(payload
, 0, sizeof(payload
));
1790 crypto_rand(circ
->cpath
->fast_handshake_state
,
1791 sizeof(circ
->cpath
->fast_handshake_state
));
1792 memcpy(payload
, circ
->cpath
->fast_handshake_state
,
1793 sizeof(circ
->cpath
->fast_handshake_state
));
1794 note_request("cell: create fast", 1);
1797 if (circuit_deliver_create_cell(TO_CIRCUIT(circ
), cell_type
, payload
) < 0)
1798 return - END_CIRC_REASON_RESOURCELIMIT
;
1800 circ
->cpath
->state
= CPATH_STATE_AWAITING_KEYS
;
1801 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_BUILDING
);
1802 log_info(LD_CIRC
,"First hop: finished sending %s cell to '%s'",
1803 fast
? "CREATE_FAST" : "CREATE",
1804 router
? router
->nickname
: "<unnamed>");
1806 tor_assert(circ
->cpath
->state
== CPATH_STATE_OPEN
);
1807 tor_assert(circ
->_base
.state
== CIRCUIT_STATE_BUILDING
);
1808 log_debug(LD_CIRC
,"starting to send subsequent skin.");
1809 hop
= onion_next_hop_in_cpath(circ
->cpath
);
1811 /* done building the circuit. whew. */
1812 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_OPEN
);
1813 if (!circ
->build_state
->onehop_tunnel
) {
1816 tor_gettimeofday(&end
);
1817 timediff
= tv_mdiff(&circ
->_base
.highres_created
, &end
);
1819 * If the circuit build time is much greater than we would have cut
1820 * it off at, we probably had a suspend event along this codepath,
1821 * and we should discard the value.
1823 if (timediff
< 0 || timediff
> 2*circ_times
.close_ms
+1000) {
1824 log_notice(LD_CIRC
, "Strange value for circuit build time: %ldmsec. "
1825 "Assuming clock jump.", timediff
);
1826 } else if (!circuit_build_times_disabled()) {
1827 /* Don't count circuit times if the network was not live */
1828 if (circuit_build_times_network_check_live(&circ_times
)) {
1829 circuit_build_times_add_time(&circ_times
, (build_time_t
)timediff
);
1830 circuit_build_times_set_timeout(&circ_times
);
1833 if (circ
->_base
.purpose
!= CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT
) {
1834 circuit_build_times_network_circ_success(&circ_times
);
1838 log_info(LD_CIRC
,"circuit built!");
1839 circuit_reset_failure_count(0);
1840 if (circ
->build_state
->onehop_tunnel
)
1841 control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_STATUS
, 0);
1842 if (!has_completed_circuit
&& !circ
->build_state
->onehop_tunnel
) {
1843 or_options_t
*options
= get_options();
1844 has_completed_circuit
=1;
1845 /* FFFF Log a count of known routers here */
1846 log_notice(LD_GENERAL
,
1847 "Tor has successfully opened a circuit. "
1848 "Looks like client functionality is working.");
1849 control_event_bootstrap(BOOTSTRAP_STATUS_DONE
, 0);
1850 control_event_client_status(LOG_NOTICE
, "CIRCUIT_ESTABLISHED");
1851 if (server_mode(options
) && !check_whether_orport_reachable()) {
1852 inform_testing_reachability();
1853 consider_testing_reachability(1, 1);
1856 circuit_rep_hist_note_result(circ
);
1857 circuit_has_opened(circ
); /* do other actions as necessary */
1859 /* We're done with measurement circuits here. Just close them */
1860 if (circ
->_base
.purpose
== CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT
)
1861 circuit_mark_for_close(TO_CIRCUIT(circ
), END_CIRC_REASON_FINISHED
);
1865 if (tor_addr_family(&hop
->extend_info
->addr
) != AF_INET
) {
1866 log_warn(LD_BUG
, "Trying to extend to a non-IPv4 address.");
1867 return - END_CIRC_REASON_INTERNAL
;
1870 set_uint32(payload
, tor_addr_to_ipv4n(&hop
->extend_info
->addr
));
1871 set_uint16(payload
+4, htons(hop
->extend_info
->port
));
1873 onionskin
= payload
+2+4;
1874 memcpy(payload
+2+4+ONIONSKIN_CHALLENGE_LEN
,
1875 hop
->extend_info
->identity_digest
, DIGEST_LEN
);
1876 payload_len
= 2+4+ONIONSKIN_CHALLENGE_LEN
+DIGEST_LEN
;
1878 if (onion_skin_create(hop
->extend_info
->onion_key
,
1879 &(hop
->dh_handshake_state
), onionskin
) < 0) {
1880 log_warn(LD_CIRC
,"onion_skin_create failed.");
1881 return - END_CIRC_REASON_INTERNAL
;
1884 log_info(LD_CIRC
,"Sending extend relay cell.");
1885 note_request("cell: extend", 1);
1886 /* send it to hop->prev, because it will transfer
1887 * it to a create cell and then send to hop */
1888 if (relay_send_command_from_edge(0, TO_CIRCUIT(circ
),
1889 RELAY_COMMAND_EXTEND
,
1890 payload
, payload_len
, hop
->prev
) < 0)
1891 return 0; /* circuit is closed */
1893 hop
->state
= CPATH_STATE_AWAITING_KEYS
;
1898 /** Our clock just jumped by <b>seconds_elapsed</b>. Assume
1899 * something has also gone wrong with our network: notify the user,
1900 * and abandon all not-yet-used circuits. */
1902 circuit_note_clock_jumped(int seconds_elapsed
)
1904 int severity
= server_mode(get_options()) ? LOG_WARN
: LOG_NOTICE
;
1905 tor_log(severity
, LD_GENERAL
, "Your system clock just jumped %d seconds %s; "
1906 "assuming established circuits no longer work.",
1907 seconds_elapsed
>=0 ? seconds_elapsed
: -seconds_elapsed
,
1908 seconds_elapsed
>=0 ? "forward" : "backward");
1909 control_event_general_status(LOG_WARN
, "CLOCK_JUMPED TIME=%d",
1911 has_completed_circuit
=0; /* so it'll log when it works again */
1912 control_event_client_status(severity
, "CIRCUIT_NOT_ESTABLISHED REASON=%s",
1914 circuit_mark_all_unused_circs();
1915 circuit_expire_all_dirty_circs();
1918 /** Take the 'extend' <b>cell</b>, pull out addr/port plus the onion
1919 * skin and identity digest for the next hop. If we're already connected,
1920 * pass the onion skin to the next hop using a create cell; otherwise
1921 * launch a new OR connection, and <b>circ</b> will notice when the
1922 * connection succeeds or fails.
1924 * Return -1 if we want to warn and tear down the circuit, else return 0.
1927 circuit_extend(cell_t
*cell
, circuit_t
*circ
)
1929 or_connection_t
*n_conn
;
1932 char *id_digest
=NULL
;
1936 const char *msg
= NULL
;
1937 int should_launch
= 0;
1940 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
1941 "n_conn already set. Bug/attack. Closing.");
1945 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
1946 "conn to next hop already launched. Bug/attack. Closing.");
1950 if (!server_mode(get_options())) {
1951 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
1952 "Got an extend cell, but running as a client. Closing.");
1956 relay_header_unpack(&rh
, cell
->payload
);
1958 if (rh
.length
< 4+2+ONIONSKIN_CHALLENGE_LEN
+DIGEST_LEN
) {
1959 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
1960 "Wrong length %d on extend cell. Closing circuit.",
1965 n_addr32
= ntohl(get_uint32(cell
->payload
+RELAY_HEADER_SIZE
));
1966 n_port
= ntohs(get_uint16(cell
->payload
+RELAY_HEADER_SIZE
+4));
1967 onionskin
= cell
->payload
+RELAY_HEADER_SIZE
+4+2;
1968 id_digest
= cell
->payload
+RELAY_HEADER_SIZE
+4+2+ONIONSKIN_CHALLENGE_LEN
;
1969 tor_addr_from_ipv4h(&n_addr
, n_addr32
);
1971 if (!n_port
|| !n_addr32
) {
1972 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
1973 "Client asked me to extend to zero destination port or addr.");
1977 /* Check if they asked us for 0000..0000. We support using
1978 * an empty fingerprint for the first hop (e.g. for a bridge relay),
1979 * but we don't want to let people send us extend cells for empty
1980 * fingerprints -- a) because it opens the user up to a mitm attack,
1981 * and b) because it lets an attacker force the relay to hold open a
1982 * new TLS connection for each extend request. */
1983 if (tor_digest_is_zero(id_digest
)) {
1984 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
1985 "Client asked me to extend without specifying an id_digest.");
1989 /* Next, check if we're being asked to connect to the hop that the
1990 * extend cell came from. There isn't any reason for that, and it can
1991 * assist circular-path attacks. */
1992 if (!memcmp(id_digest
, TO_OR_CIRCUIT(circ
)->p_conn
->identity_digest
,
1994 log_fn(LOG_PROTOCOL_WARN
, LD_PROTOCOL
,
1995 "Client asked me to extend back to the previous hop.");
1999 n_conn
= connection_or_get_for_extend(id_digest
,
2005 log_debug(LD_CIRC
|LD_OR
,"Next router (%s:%d): %s",
2006 fmt_addr(&n_addr
), (int)n_port
, msg
?msg
:"????");
2008 circ
->n_hop
= extend_info_alloc(NULL
/*nickname*/,
2013 circ
->n_conn_onionskin
= tor_malloc(ONIONSKIN_CHALLENGE_LEN
);
2014 memcpy(circ
->n_conn_onionskin
, onionskin
, ONIONSKIN_CHALLENGE_LEN
);
2015 circuit_set_state(circ
, CIRCUIT_STATE_OR_WAIT
);
2017 if (should_launch
) {
2018 /* we should try to open a connection */
2019 n_conn
= connection_or_connect(&n_addr
, n_port
, id_digest
);
2021 log_info(LD_CIRC
,"Launching n_conn failed. Closing circuit.");
2022 circuit_mark_for_close(circ
, END_CIRC_REASON_CONNECTFAILED
);
2025 log_debug(LD_CIRC
,"connecting in progress (or finished). Good.");
2027 /* return success. The onion/circuit/etc will be taken care of
2028 * automatically (may already have been) whenever n_conn reaches
2029 * OR_CONN_STATE_OPEN.
2034 tor_assert(!circ
->n_hop
); /* Connection is already established. */
2035 circ
->n_conn
= n_conn
;
2036 log_debug(LD_CIRC
,"n_conn is %s:%u",
2037 n_conn
->_base
.address
,n_conn
->_base
.port
);
2039 if (circuit_deliver_create_cell(circ
, CELL_CREATE
, onionskin
) < 0)
2044 /** Initialize cpath-\>{f|b}_{crypto|digest} from the key material in
2045 * key_data. key_data must contain CPATH_KEY_MATERIAL bytes, which are
2047 * - 20 to initialize f_digest
2048 * - 20 to initialize b_digest
2049 * - 16 to key f_crypto
2050 * - 16 to key b_crypto
2052 * (If 'reverse' is true, then f_XX and b_XX are swapped.)
2055 circuit_init_cpath_crypto(crypt_path_t
*cpath
, const char *key_data
,
2058 crypto_digest_env_t
*tmp_digest
;
2059 crypto_cipher_env_t
*tmp_crypto
;
2062 tor_assert(key_data
);
2063 tor_assert(!(cpath
->f_crypto
|| cpath
->b_crypto
||
2064 cpath
->f_digest
|| cpath
->b_digest
));
2066 cpath
->f_digest
= crypto_new_digest_env();
2067 crypto_digest_add_bytes(cpath
->f_digest
, key_data
, DIGEST_LEN
);
2068 cpath
->b_digest
= crypto_new_digest_env();
2069 crypto_digest_add_bytes(cpath
->b_digest
, key_data
+DIGEST_LEN
, DIGEST_LEN
);
2071 if (!(cpath
->f_crypto
=
2072 crypto_create_init_cipher(key_data
+(2*DIGEST_LEN
),1))) {
2073 log_warn(LD_BUG
,"Forward cipher initialization failed.");
2076 if (!(cpath
->b_crypto
=
2077 crypto_create_init_cipher(key_data
+(2*DIGEST_LEN
)+CIPHER_KEY_LEN
,0))) {
2078 log_warn(LD_BUG
,"Backward cipher initialization failed.");
2083 tmp_digest
= cpath
->f_digest
;
2084 cpath
->f_digest
= cpath
->b_digest
;
2085 cpath
->b_digest
= tmp_digest
;
2086 tmp_crypto
= cpath
->f_crypto
;
2087 cpath
->f_crypto
= cpath
->b_crypto
;
2088 cpath
->b_crypto
= tmp_crypto
;
2094 /** A created or extended cell came back to us on the circuit, and it included
2095 * <b>reply</b> as its body. (If <b>reply_type</b> is CELL_CREATED, the body
2096 * contains (the second DH key, plus KH). If <b>reply_type</b> is
2097 * CELL_CREATED_FAST, the body contains a secret y and a hash H(x|y).)
2099 * Calculate the appropriate keys and digests, make sure KH is
2100 * correct, and initialize this hop of the cpath.
2102 * Return - reason if we want to mark circ for close, else return 0.
2105 circuit_finish_handshake(origin_circuit_t
*circ
, uint8_t reply_type
,
2108 char keys
[CPATH_KEY_MATERIAL_LEN
];
2111 if (circ
->cpath
->state
== CPATH_STATE_AWAITING_KEYS
)
2114 hop
= onion_next_hop_in_cpath(circ
->cpath
);
2115 if (!hop
) { /* got an extended when we're all done? */
2116 log_warn(LD_PROTOCOL
,"got extended when circ already built? Closing.");
2117 return - END_CIRC_REASON_TORPROTOCOL
;
2120 tor_assert(hop
->state
== CPATH_STATE_AWAITING_KEYS
);
2122 if (reply_type
== CELL_CREATED
&& hop
->dh_handshake_state
) {
2123 if (onion_skin_client_handshake(hop
->dh_handshake_state
, reply
, keys
,
2124 DIGEST_LEN
*2+CIPHER_KEY_LEN
*2) < 0) {
2125 log_warn(LD_CIRC
,"onion_skin_client_handshake failed.");
2126 return -END_CIRC_REASON_TORPROTOCOL
;
2128 /* Remember hash of g^xy */
2129 memcpy(hop
->handshake_digest
, reply
+DH_KEY_LEN
, DIGEST_LEN
);
2130 } else if (reply_type
== CELL_CREATED_FAST
&& !hop
->dh_handshake_state
) {
2131 if (fast_client_handshake(hop
->fast_handshake_state
, reply
, keys
,
2132 DIGEST_LEN
*2+CIPHER_KEY_LEN
*2) < 0) {
2133 log_warn(LD_CIRC
,"fast_client_handshake failed.");
2134 return -END_CIRC_REASON_TORPROTOCOL
;
2136 memcpy(hop
->handshake_digest
, reply
+DIGEST_LEN
, DIGEST_LEN
);
2138 log_warn(LD_PROTOCOL
,"CREATED cell type did not match CREATE cell type.");
2139 return -END_CIRC_REASON_TORPROTOCOL
;
2142 crypto_dh_free(hop
->dh_handshake_state
); /* don't need it anymore */
2143 hop
->dh_handshake_state
= NULL
;
2145 memset(hop
->fast_handshake_state
, 0, sizeof(hop
->fast_handshake_state
));
2147 if (circuit_init_cpath_crypto(hop
, keys
, 0)<0) {
2148 return -END_CIRC_REASON_TORPROTOCOL
;
2151 hop
->state
= CPATH_STATE_OPEN
;
2152 log_info(LD_CIRC
,"Finished building %scircuit hop:",
2153 (reply_type
== CELL_CREATED_FAST
) ? "fast " : "");
2154 circuit_log_path(LOG_INFO
,LD_CIRC
,circ
);
2155 control_event_circuit_status(circ
, CIRC_EVENT_EXTENDED
, 0);
2160 /** We received a relay truncated cell on circ.
2162 * Since we don't ask for truncates currently, getting a truncated
2163 * means that a connection broke or an extend failed. For now,
2164 * just give up: for circ to close, and return 0.
2167 circuit_truncated(origin_circuit_t
*circ
, crypt_path_t
*layer
)
2169 // crypt_path_t *victim;
2170 // connection_t *stream;
2175 /* XXX Since we don't ask for truncates currently, getting a truncated
2176 * means that a connection broke or an extend failed. For now,
2179 circuit_mark_for_close(TO_CIRCUIT(circ
),
2180 END_CIRC_REASON_FLAG_REMOTE
|END_CIRC_REASON_OR_CONN_CLOSED
);
2184 while (layer
->next
!= circ
->cpath
) {
2185 /* we need to clear out layer->next */
2186 victim
= layer
->next
;
2187 log_debug(LD_CIRC
, "Killing a layer of the cpath.");
2189 for (stream
= circ
->p_streams
; stream
; stream
=stream
->next_stream
) {
2190 if (stream
->cpath_layer
== victim
) {
2191 log_info(LD_APP
, "Marking stream %d for close because of truncate.",
2193 /* no need to send 'end' relay cells,
2194 * because the other side's already dead
2196 connection_mark_unattached_ap(stream
, END_STREAM_REASON_DESTROY
);
2200 layer
->next
= victim
->next
;
2201 circuit_free_cpath_node(victim
);
2204 log_info(LD_CIRC
, "finished");
2209 /** Given a response payload and keys, initialize, then send a created
2213 onionskin_answer(or_circuit_t
*circ
, uint8_t cell_type
, const char *payload
,
2217 crypt_path_t
*tmp_cpath
;
2219 tmp_cpath
= tor_malloc_zero(sizeof(crypt_path_t
));
2220 tmp_cpath
->magic
= CRYPT_PATH_MAGIC
;
2222 memset(&cell
, 0, sizeof(cell_t
));
2223 cell
.command
= cell_type
;
2224 cell
.circ_id
= circ
->p_circ_id
;
2226 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_OPEN
);
2228 memcpy(cell
.payload
, payload
,
2229 cell_type
== CELL_CREATED
? ONIONSKIN_REPLY_LEN
: DIGEST_LEN
*2);
2231 log_debug(LD_CIRC
,"init digest forward 0x%.8x, backward 0x%.8x.",
2232 (unsigned int)*(uint32_t*)(keys
),
2233 (unsigned int)*(uint32_t*)(keys
+20));
2234 if (circuit_init_cpath_crypto(tmp_cpath
, keys
, 0)<0) {
2235 log_warn(LD_BUG
,"Circuit initialization failed");
2236 tor_free(tmp_cpath
);
2239 circ
->n_digest
= tmp_cpath
->f_digest
;
2240 circ
->n_crypto
= tmp_cpath
->f_crypto
;
2241 circ
->p_digest
= tmp_cpath
->b_digest
;
2242 circ
->p_crypto
= tmp_cpath
->b_crypto
;
2243 tmp_cpath
->magic
= 0;
2244 tor_free(tmp_cpath
);
2246 if (cell_type
== CELL_CREATED
)
2247 memcpy(circ
->handshake_digest
, cell
.payload
+DH_KEY_LEN
, DIGEST_LEN
);
2249 memcpy(circ
->handshake_digest
, cell
.payload
+DIGEST_LEN
, DIGEST_LEN
);
2251 circ
->is_first_hop
= (cell_type
== CELL_CREATED_FAST
);
2253 append_cell_to_circuit_queue(TO_CIRCUIT(circ
),
2254 circ
->p_conn
, &cell
, CELL_DIRECTION_IN
);
2255 log_debug(LD_CIRC
,"Finished sending 'created' cell.");
2257 if (!is_local_addr(&circ
->p_conn
->_base
.addr
) &&
2258 !connection_or_nonopen_was_started_here(circ
->p_conn
)) {
2259 /* record that we could process create cells from a non-local conn
2260 * that we didn't initiate; presumably this means that create cells
2261 * can reach us too. */
2262 router_orport_found_reachable();
2268 /** Choose a length for a circuit of purpose <b>purpose</b>.
2269 * Default length is 3 + the number of endpoints that would give something
2270 * away. If the routerlist <b>routers</b> doesn't have enough routers
2271 * to handle the desired path length, return as large a path length as
2272 * is feasible, except if it's less than 2, in which case return -1.
2275 new_route_len(uint8_t purpose
, extend_info_t
*exit
,
2276 smartlist_t
*routers
)
2278 int num_acceptable_routers
;
2281 tor_assert(routers
);
2285 purpose
!= CIRCUIT_PURPOSE_TESTING
&&
2286 purpose
!= CIRCUIT_PURPOSE_S_ESTABLISH_INTRO
)
2289 num_acceptable_routers
= count_acceptable_routers(routers
);
2291 log_debug(LD_CIRC
,"Chosen route length %d (%d/%d routers suitable).",
2292 routelen
, num_acceptable_routers
, smartlist_len(routers
));
2294 if (num_acceptable_routers
< 2) {
2296 "Not enough acceptable routers (%d). Discarding this circuit.",
2297 num_acceptable_routers
);
2301 if (num_acceptable_routers
< routelen
) {
2302 log_info(LD_CIRC
,"Not enough routers: cutting routelen from %d to %d.",
2303 routelen
, num_acceptable_routers
);
2304 routelen
= num_acceptable_routers
;
2310 /** Fetch the list of predicted ports, dup it into a smartlist of
2311 * uint16_t's, remove the ones that are already handled by an
2312 * existing circuit, and return it.
2314 static smartlist_t
*
2315 circuit_get_unhandled_ports(time_t now
)
2317 smartlist_t
*source
= rep_hist_get_predicted_ports(now
);
2318 smartlist_t
*dest
= smartlist_create();
2322 for (i
= 0; i
< smartlist_len(source
); ++i
) {
2323 tmp
= tor_malloc(sizeof(uint16_t));
2324 memcpy(tmp
, smartlist_get(source
, i
), sizeof(uint16_t));
2325 smartlist_add(dest
, tmp
);
2328 circuit_remove_handled_ports(dest
);
2332 /** Return 1 if we already have circuits present or on the way for
2333 * all anticipated ports. Return 0 if we should make more.
2335 * If we're returning 0, set need_uptime and need_capacity to
2336 * indicate any requirements that the unhandled ports have.
2339 circuit_all_predicted_ports_handled(time_t now
, int *need_uptime
,
2344 smartlist_t
*sl
= circuit_get_unhandled_ports(now
);
2345 smartlist_t
*LongLivedServices
= get_options()->LongLivedPorts
;
2346 tor_assert(need_uptime
);
2347 tor_assert(need_capacity
);
2348 // Always predict need_capacity
2350 enough
= (smartlist_len(sl
) == 0);
2351 for (i
= 0; i
< smartlist_len(sl
); ++i
) {
2352 port
= smartlist_get(sl
, i
);
2353 if (smartlist_string_num_isin(LongLivedServices
, *port
))
2361 /** Return 1 if <b>router</b> can handle one or more of the ports in
2362 * <b>needed_ports</b>, else return 0.
2365 router_handles_some_port(routerinfo_t
*router
, smartlist_t
*needed_ports
)
2370 for (i
= 0; i
< smartlist_len(needed_ports
); ++i
) {
2371 addr_policy_result_t r
;
2372 port
= *(uint16_t *)smartlist_get(needed_ports
, i
);
2374 r
= compare_addr_to_addr_policy(0, port
, router
->exit_policy
);
2375 if (r
!= ADDR_POLICY_REJECTED
&& r
!= ADDR_POLICY_PROBABLY_REJECTED
)
2381 /** Return true iff <b>conn</b> needs another general circuit to be
2384 ap_stream_wants_exit_attention(connection_t
*conn
)
2386 if (conn
->type
== CONN_TYPE_AP
&&
2387 conn
->state
== AP_CONN_STATE_CIRCUIT_WAIT
&&
2388 !conn
->marked_for_close
&&
2389 !(TO_EDGE_CONN(conn
)->want_onehop
) && /* ignore one-hop streams */
2390 !(TO_EDGE_CONN(conn
)->use_begindir
) && /* ignore targeted dir fetches */
2391 !(TO_EDGE_CONN(conn
)->chosen_exit_name
) && /* ignore defined streams */
2392 !connection_edge_is_rendezvous_stream(TO_EDGE_CONN(conn
)) &&
2393 !circuit_stream_is_being_handled(TO_EDGE_CONN(conn
), 0,
2394 MIN_CIRCUITS_HANDLING_STREAM
))
2399 /** Return a pointer to a suitable router to be the exit node for the
2400 * general-purpose circuit we're about to build.
2402 * Look through the connection array, and choose a router that maximizes
2403 * the number of pending streams that can exit from this router.
2405 * Return NULL if we can't find any suitable routers.
2407 static routerinfo_t
*
2408 choose_good_exit_server_general(routerlist_t
*dir
, int need_uptime
,
2413 int n_pending_connections
= 0;
2414 smartlist_t
*connections
;
2415 int best_support
= -1;
2416 int n_best_support
=0;
2417 routerinfo_t
*router
;
2418 or_options_t
*options
= get_options();
2420 connections
= get_connection_array();
2422 /* Count how many connections are waiting for a circuit to be built.
2423 * We use this for log messages now, but in the future we may depend on it.
2425 SMARTLIST_FOREACH(connections
, connection_t
*, conn
,
2427 if (ap_stream_wants_exit_attention(conn
))
2428 ++n_pending_connections
;
2430 // log_fn(LOG_DEBUG, "Choosing exit node; %d connections are pending",
2431 // n_pending_connections);
2432 /* Now we count, for each of the routers in the directory, how many
2433 * of the pending connections could possibly exit from that
2434 * router (n_supported[i]). (We can't be sure about cases where we
2435 * don't know the IP address of the pending connection.)
2437 * -1 means "Don't use this router at all."
2439 n_supported
= tor_malloc(sizeof(int)*smartlist_len(dir
->routers
));
2440 for (i
= 0; i
< smartlist_len(dir
->routers
); ++i
) {/* iterate over routers */
2441 router
= smartlist_get(dir
->routers
, i
);
2442 if (router_is_me(router
)) {
2443 n_supported
[i
] = -1;
2444 // log_fn(LOG_DEBUG,"Skipping node %s -- it's me.", router->nickname);
2445 /* XXX there's probably a reverse predecessor attack here, but
2446 * it's slow. should we take this out? -RD
2450 if (!router
->is_running
|| router
->is_bad_exit
) {
2451 n_supported
[i
] = -1;
2452 continue; /* skip routers that are known to be down or bad exits */
2454 if (router_is_unreliable(router
, need_uptime
, need_capacity
, 0) &&
2455 (!options
->ExitNodes
||
2456 !routerset_contains_router(options
->ExitNodes
, router
))) {
2457 /* FFFF Someday, differentiate between a routerset that names
2458 * routers, and a routerset that names countries, and only do this
2459 * check if they've asked for specific exit relays. Or if the country
2460 * they ask for is rare. Or something. */
2461 n_supported
[i
] = -1;
2462 continue; /* skip routers that are not suitable, unless we have
2463 * ExitNodes set, in which case we asked for it */
2465 if (!(router
->is_valid
|| options
->_AllowInvalid
& ALLOW_INVALID_EXIT
)) {
2466 /* if it's invalid and we don't want it */
2467 n_supported
[i
] = -1;
2468 // log_fn(LOG_DEBUG,"Skipping node %s (index %d) -- invalid router.",
2469 // router->nickname, i);
2470 continue; /* skip invalid routers */
2472 if (options
->ExcludeSingleHopRelays
&& router
->allow_single_hop_exits
) {
2473 n_supported
[i
] = -1;
2476 if (router_exit_policy_rejects_all(router
)) {
2477 n_supported
[i
] = -1;
2478 // log_fn(LOG_DEBUG,"Skipping node %s (index %d) -- it rejects all.",
2479 // router->nickname, i);
2480 continue; /* skip routers that reject all */
2483 /* iterate over connections */
2484 SMARTLIST_FOREACH(connections
, connection_t
*, conn
,
2486 if (!ap_stream_wants_exit_attention(conn
))
2487 continue; /* Skip everything but APs in CIRCUIT_WAIT */
2488 if (connection_ap_can_use_exit(TO_EDGE_CONN(conn
), router
, 1)) {
2490 // log_fn(LOG_DEBUG,"%s is supported. n_supported[%d] now %d.",
2491 // router->nickname, i, n_supported[i]);
2493 // log_fn(LOG_DEBUG,"%s (index %d) would reject this stream.",
2494 // router->nickname, i);
2496 }); /* End looping over connections. */
2497 if (n_pending_connections
> 0 && n_supported
[i
] == 0) {
2498 /* Leave best_support at -1 if that's where it is, so we can
2499 * distinguish it later. */
2502 if (n_supported
[i
] > best_support
) {
2503 /* If this router is better than previous ones, remember its index
2504 * and goodness, and start counting how many routers are this good. */
2505 best_support
= n_supported
[i
]; n_best_support
=1;
2506 // log_fn(LOG_DEBUG,"%s is new best supported option so far.",
2507 // router->nickname);
2508 } else if (n_supported
[i
] == best_support
) {
2509 /* If this router is _as good_ as the best one, just increment the
2510 * count of equally good routers.*/
2515 "Found %d servers that might support %d/%d pending connections.",
2516 n_best_support
, best_support
>= 0 ? best_support
: 0,
2517 n_pending_connections
);
2519 /* If any routers definitely support any pending connections, choose one
2521 if (best_support
> 0) {
2522 smartlist_t
*supporting
= smartlist_create(), *use
= smartlist_create();
2524 for (i
= 0; i
< smartlist_len(dir
->routers
); i
++)
2525 if (n_supported
[i
] == best_support
)
2526 smartlist_add(supporting
, smartlist_get(dir
->routers
, i
));
2528 routersets_get_disjunction(use
, supporting
, options
->ExitNodes
,
2529 options
->_ExcludeExitNodesUnion
, 1);
2530 if (smartlist_len(use
) == 0 && options
->ExitNodes
&&
2531 !options
->StrictNodes
) { /* give up on exitnodes and try again */
2532 routersets_get_disjunction(use
, supporting
, NULL
,
2533 options
->_ExcludeExitNodesUnion
, 1);
2535 router
= routerlist_sl_choose_by_bandwidth(use
, WEIGHT_FOR_EXIT
);
2536 smartlist_free(use
);
2537 smartlist_free(supporting
);
2539 /* Either there are no pending connections, or no routers even seem to
2540 * possibly support any of them. Choose a router at random that satisfies
2541 * at least one predicted exit port. */
2544 smartlist_t
*needed_ports
, *supporting
, *use
;
2546 if (best_support
== -1) {
2547 if (need_uptime
|| need_capacity
) {
2549 "We couldn't find any live%s%s routers; falling back "
2550 "to list of all routers.",
2551 need_capacity
?", fast":"",
2552 need_uptime
?", stable":"");
2553 tor_free(n_supported
);
2554 return choose_good_exit_server_general(dir
, 0, 0);
2556 log_notice(LD_CIRC
, "All routers are down or won't exit%s -- "
2557 "choosing a doomed exit at random.",
2558 options
->_ExcludeExitNodesUnion
? " or are Excluded" : "");
2560 supporting
= smartlist_create();
2561 use
= smartlist_create();
2562 needed_ports
= circuit_get_unhandled_ports(time(NULL
));
2563 for (try = 0; try < 2; try++) {
2564 /* try once to pick only from routers that satisfy a needed port,
2565 * then if there are none, pick from any that support exiting. */
2566 for (i
= 0; i
< smartlist_len(dir
->routers
); i
++) {
2567 router
= smartlist_get(dir
->routers
, i
);
2568 if (n_supported
[i
] != -1 &&
2569 (try || router_handles_some_port(router
, needed_ports
))) {
2570 // log_fn(LOG_DEBUG,"Try %d: '%s' is a possibility.",
2571 // try, router->nickname);
2572 smartlist_add(supporting
, router
);
2576 routersets_get_disjunction(use
, supporting
, options
->ExitNodes
,
2577 options
->_ExcludeExitNodesUnion
, 1);
2578 if (smartlist_len(use
) == 0 && options
->ExitNodes
&&
2579 !options
->StrictNodes
) { /* give up on exitnodes and try again */
2580 routersets_get_disjunction(use
, supporting
, NULL
,
2581 options
->_ExcludeExitNodesUnion
, 1);
2583 /* FFF sometimes the above results in null, when the requested
2584 * exit node is considered down by the consensus. we should pick
2585 * it anyway, since the user asked for it. */
2586 router
= routerlist_sl_choose_by_bandwidth(use
, WEIGHT_FOR_EXIT
);
2589 smartlist_clear(supporting
);
2590 smartlist_clear(use
);
2592 SMARTLIST_FOREACH(needed_ports
, uint16_t *, cp
, tor_free(cp
));
2593 smartlist_free(needed_ports
);
2594 smartlist_free(use
);
2595 smartlist_free(supporting
);
2598 tor_free(n_supported
);
2600 log_info(LD_CIRC
, "Chose exit server '%s'", router
->nickname
);
2603 if (options
->ExitNodes
&& options
->StrictNodes
) {
2605 "No specified exit routers seem to be running, and "
2606 "StrictNodes is set: can't choose an exit.");
2611 /** Return a pointer to a suitable router to be the exit node for the
2612 * circuit of purpose <b>purpose</b> that we're about to build (or NULL
2613 * if no router is suitable).
2615 * For general-purpose circuits, pass it off to
2616 * choose_good_exit_server_general()
2618 * For client-side rendezvous circuits, choose a random node, weighted
2619 * toward the preferences in 'options'.
2621 static routerinfo_t
*
2622 choose_good_exit_server(uint8_t purpose
, routerlist_t
*dir
,
2623 int need_uptime
, int need_capacity
, int is_internal
)
2625 or_options_t
*options
= get_options();
2626 router_crn_flags_t flags
= 0;
2628 flags
|= CRN_NEED_UPTIME
;
2630 flags
|= CRN_NEED_CAPACITY
;
2633 case CIRCUIT_PURPOSE_C_GENERAL
:
2634 if (options
->_AllowInvalid
& ALLOW_INVALID_MIDDLE
)
2635 flags
|= CRN_ALLOW_INVALID
;
2636 if (is_internal
) /* pick it like a middle hop */
2637 return router_choose_random_node(NULL
, options
->ExcludeNodes
, flags
);
2639 return choose_good_exit_server_general(dir
,need_uptime
,need_capacity
);
2640 case CIRCUIT_PURPOSE_C_ESTABLISH_REND
:
2641 if (options
->_AllowInvalid
& ALLOW_INVALID_RENDEZVOUS
)
2642 flags
|= CRN_ALLOW_INVALID
;
2643 return router_choose_random_node(NULL
, options
->ExcludeNodes
, flags
);
2645 log_warn(LD_BUG
,"Unhandled purpose %d", purpose
);
2646 tor_fragile_assert();
2650 /** Log a warning if the user specified an exit for the circuit that
2651 * has been excluded from use by ExcludeNodes or ExcludeExitNodes. */
2653 warn_if_last_router_excluded(origin_circuit_t
*circ
, const extend_info_t
*exit
)
2655 or_options_t
*options
= get_options();
2656 routerset_t
*rs
= options
->ExcludeNodes
;
2657 const char *description
;
2658 int domain
= LD_CIRC
;
2659 uint8_t purpose
= circ
->_base
.purpose
;
2661 if (circ
->build_state
->onehop_tunnel
)
2667 case CIRCUIT_PURPOSE_OR
:
2668 case CIRCUIT_PURPOSE_INTRO_POINT
:
2669 case CIRCUIT_PURPOSE_REND_POINT_WAITING
:
2670 case CIRCUIT_PURPOSE_REND_ESTABLISHED
:
2671 log_warn(LD_BUG
, "Called on non-origin circuit (purpose %d)",
2674 case CIRCUIT_PURPOSE_C_GENERAL
:
2675 if (circ
->build_state
->is_internal
)
2677 description
= "Requested exit node";
2678 rs
= options
->_ExcludeExitNodesUnion
;
2680 case CIRCUIT_PURPOSE_C_INTRODUCING
:
2681 case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT
:
2682 case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED
:
2683 case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO
:
2684 case CIRCUIT_PURPOSE_S_CONNECT_REND
:
2685 case CIRCUIT_PURPOSE_S_REND_JOINED
:
2686 case CIRCUIT_PURPOSE_TESTING
:
2688 case CIRCUIT_PURPOSE_C_ESTABLISH_REND
:
2689 case CIRCUIT_PURPOSE_C_REND_READY
:
2690 case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED
:
2691 case CIRCUIT_PURPOSE_C_REND_JOINED
:
2692 description
= "Chosen rendezvous point";
2695 case CIRCUIT_PURPOSE_CONTROLLER
:
2696 rs
= options
->_ExcludeExitNodesUnion
;
2697 description
= "Controller-selected circuit target";
2701 if (routerset_contains_extendinfo(rs
, exit
)) {
2702 log_fn(LOG_WARN
, domain
, "%s '%s' is in ExcludeNodes%s. Using anyway "
2703 "(circuit purpose %d).",
2704 description
,exit
->nickname
,
2705 rs
==options
->ExcludeNodes
?"":" or ExcludeExitNodes",
2707 circuit_log_path(LOG_WARN
, domain
, circ
);
2713 /** Decide a suitable length for circ's cpath, and pick an exit
2714 * router (or use <b>exit</b> if provided). Store these in the
2715 * cpath. Return 0 if ok, -1 if circuit should be closed. */
2717 onion_pick_cpath_exit(origin_circuit_t
*circ
, extend_info_t
*exit
)
2719 cpath_build_state_t
*state
= circ
->build_state
;
2720 routerlist_t
*rl
= router_get_routerlist();
2722 if (state
->onehop_tunnel
) {
2723 log_debug(LD_CIRC
, "Launching a one-hop circuit for dir tunnel.");
2724 state
->desired_path_len
= 1;
2726 int r
= new_route_len(circ
->_base
.purpose
, exit
, rl
->routers
);
2727 if (r
< 1) /* must be at least 1 */
2729 state
->desired_path_len
= r
;
2732 if (exit
) { /* the circuit-builder pre-requested one */
2733 warn_if_last_router_excluded(circ
, exit
);
2734 log_info(LD_CIRC
,"Using requested exit node '%s'", exit
->nickname
);
2735 exit
= extend_info_dup(exit
);
2736 } else { /* we have to decide one */
2737 routerinfo_t
*router
=
2738 choose_good_exit_server(circ
->_base
.purpose
, rl
, state
->need_uptime
,
2739 state
->need_capacity
, state
->is_internal
);
2741 log_warn(LD_CIRC
,"failed to choose an exit server");
2744 exit
= extend_info_from_router(router
);
2746 state
->chosen_exit
= exit
;
2750 /** Give <b>circ</b> a new exit destination to <b>exit</b>, and add a
2751 * hop to the cpath reflecting this. Don't send the next extend cell --
2752 * the caller will do this if it wants to.
2755 circuit_append_new_exit(origin_circuit_t
*circ
, extend_info_t
*exit
)
2757 cpath_build_state_t
*state
;
2761 state
= circ
->build_state
;
2763 extend_info_free(state
->chosen_exit
);
2764 state
->chosen_exit
= extend_info_dup(exit
);
2766 ++circ
->build_state
->desired_path_len
;
2767 onion_append_hop(&circ
->cpath
, exit
);
2771 /** Take an open <b>circ</b>, and add a new hop at the end, based on
2772 * <b>info</b>. Set its state back to CIRCUIT_STATE_BUILDING, and then
2773 * send the next extend cell to begin connecting to that hop.
2776 circuit_extend_to_new_exit(origin_circuit_t
*circ
, extend_info_t
*exit
)
2779 warn_if_last_router_excluded(circ
, exit
);
2780 circuit_append_new_exit(circ
, exit
);
2781 circuit_set_state(TO_CIRCUIT(circ
), CIRCUIT_STATE_BUILDING
);
2782 if ((err_reason
= circuit_send_next_onion_skin(circ
))<0) {
2783 log_warn(LD_CIRC
, "Couldn't extend circuit to new point '%s'.",
2785 circuit_mark_for_close(TO_CIRCUIT(circ
), -err_reason
);
2791 /** Return the number of routers in <b>routers</b> that are currently up
2792 * and available for building circuits through.
2795 count_acceptable_routers(smartlist_t
*routers
)
2801 n
= smartlist_len(routers
);
2803 r
= smartlist_get(routers
, i
);
2804 // log_debug(LD_CIRC,
2805 // "Contemplating whether router %d (%s) is a new option.",
2807 if (r
->is_running
== 0) {
2808 // log_debug(LD_CIRC,"Nope, the directory says %d is not running.",i);
2811 if (r
->is_valid
== 0) {
2812 // log_debug(LD_CIRC,"Nope, the directory says %d is not valid.",i);
2814 /* XXX This clause makes us count incorrectly: if AllowInvalidRouters
2815 * allows this node in some places, then we're getting an inaccurate
2816 * count. For now, be conservative and don't count it. But later we
2817 * should try to be smarter. */
2820 // log_debug(LD_CIRC,"I like %d. num_acceptable_routers now %d.",i, num);
2822 ; /* C requires an explicit statement after the label */
2828 /** Add <b>new_hop</b> to the end of the doubly-linked-list <b>head_ptr</b>.
2829 * This function is used to extend cpath by another hop.
2832 onion_append_to_cpath(crypt_path_t
**head_ptr
, crypt_path_t
*new_hop
)
2835 new_hop
->next
= (*head_ptr
);
2836 new_hop
->prev
= (*head_ptr
)->prev
;
2837 (*head_ptr
)->prev
->next
= new_hop
;
2838 (*head_ptr
)->prev
= new_hop
;
2840 *head_ptr
= new_hop
;
2841 new_hop
->prev
= new_hop
->next
= new_hop
;
2845 /** A helper function used by onion_extend_cpath(). Use <b>purpose</b>
2846 * and <b>state</b> and the cpath <b>head</b> (currently populated only
2847 * to length <b>cur_len</b> to decide a suitable middle hop for a
2848 * circuit. In particular, make sure we don't pick the exit node or its
2849 * family, and make sure we don't duplicate any previous nodes or their
2851 static routerinfo_t
*
2852 choose_good_middle_server(uint8_t purpose
,
2853 cpath_build_state_t
*state
,
2858 routerinfo_t
*r
, *choice
;
2859 crypt_path_t
*cpath
;
2860 smartlist_t
*excluded
;
2861 or_options_t
*options
= get_options();
2862 router_crn_flags_t flags
= 0;
2863 tor_assert(_CIRCUIT_PURPOSE_MIN
<= purpose
&&
2864 purpose
<= _CIRCUIT_PURPOSE_MAX
);
2866 log_debug(LD_CIRC
, "Contemplating intermediate hop: random choice.");
2867 excluded
= smartlist_create();
2868 if ((r
= build_state_get_exit_router(state
))) {
2869 smartlist_add(excluded
, r
);
2870 routerlist_add_family(excluded
, r
);
2872 for (i
= 0, cpath
= head
; i
< cur_len
; ++i
, cpath
=cpath
->next
) {
2873 if ((r
= router_get_by_digest(cpath
->extend_info
->identity_digest
))) {
2874 smartlist_add(excluded
, r
);
2875 routerlist_add_family(excluded
, r
);
2879 if (state
->need_uptime
)
2880 flags
|= CRN_NEED_UPTIME
;
2881 if (state
->need_capacity
)
2882 flags
|= CRN_NEED_CAPACITY
;
2883 if (options
->_AllowInvalid
& ALLOW_INVALID_MIDDLE
)
2884 flags
|= CRN_ALLOW_INVALID
;
2885 choice
= router_choose_random_node(excluded
, options
->ExcludeNodes
, flags
);
2886 smartlist_free(excluded
);
2890 /** Pick a good entry server for the circuit to be built according to
2891 * <b>state</b>. Don't reuse a chosen exit (if any), don't use this
2892 * router (if we're an OR), and respect firewall settings; if we're
2893 * configured to use entry guards, return one.
2895 * If <b>state</b> is NULL, we're choosing a router to serve as an entry
2896 * guard, not for any particular circuit.
2898 static routerinfo_t
*
2899 choose_good_entry_server(uint8_t purpose
, cpath_build_state_t
*state
)
2901 routerinfo_t
*r
, *choice
;
2902 smartlist_t
*excluded
;
2903 or_options_t
*options
= get_options();
2904 router_crn_flags_t flags
= CRN_NEED_GUARD
;
2906 if (state
&& options
->UseEntryGuards
&&
2907 (purpose
!= CIRCUIT_PURPOSE_TESTING
|| options
->BridgeRelay
)) {
2908 return choose_random_entry(state
);
2911 excluded
= smartlist_create();
2913 if (state
&& (r
= build_state_get_exit_router(state
))) {
2914 smartlist_add(excluded
, r
);
2915 routerlist_add_family(excluded
, r
);
2917 if (firewall_is_fascist_or()) {
2918 /*XXXX This could slow things down a lot; use a smarter implementation */
2919 /* exclude all ORs that listen on the wrong port, if anybody notices. */
2920 routerlist_t
*rl
= router_get_routerlist();
2923 for (i
=0; i
< smartlist_len(rl
->routers
); i
++) {
2924 r
= smartlist_get(rl
->routers
, i
);
2925 if (!fascist_firewall_allows_or(r
))
2926 smartlist_add(excluded
, r
);
2929 /* and exclude current entry guards, if applicable */
2930 if (options
->UseEntryGuards
&& entry_guards
) {
2931 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
2933 if ((r
= router_get_by_digest(entry
->identity
))) {
2934 smartlist_add(excluded
, r
);
2935 routerlist_add_family(excluded
, r
);
2941 if (state
->need_uptime
)
2942 flags
|= CRN_NEED_UPTIME
;
2943 if (state
->need_capacity
)
2944 flags
|= CRN_NEED_CAPACITY
;
2946 if (options
->_AllowInvalid
& ALLOW_INVALID_ENTRY
)
2947 flags
|= CRN_ALLOW_INVALID
;
2949 choice
= router_choose_random_node(excluded
, options
->ExcludeNodes
, flags
);
2950 smartlist_free(excluded
);
2954 /** Return the first non-open hop in cpath, or return NULL if all
2956 static crypt_path_t
*
2957 onion_next_hop_in_cpath(crypt_path_t
*cpath
)
2959 crypt_path_t
*hop
= cpath
;
2961 if (hop
->state
!= CPATH_STATE_OPEN
)
2964 } while (hop
!= cpath
);
2968 /** Choose a suitable next hop in the cpath <b>head_ptr</b>,
2969 * based on <b>state</b>. Append the hop info to head_ptr.
2972 onion_extend_cpath(origin_circuit_t
*circ
)
2974 uint8_t purpose
= circ
->_base
.purpose
;
2975 cpath_build_state_t
*state
= circ
->build_state
;
2976 int cur_len
= circuit_get_cpath_len(circ
);
2977 extend_info_t
*info
= NULL
;
2979 if (cur_len
>= state
->desired_path_len
) {
2980 log_debug(LD_CIRC
, "Path is complete: %d steps long",
2981 state
->desired_path_len
);
2985 log_debug(LD_CIRC
, "Path is %d long; we want %d", cur_len
,
2986 state
->desired_path_len
);
2988 if (cur_len
== state
->desired_path_len
- 1) { /* Picking last node */
2989 info
= extend_info_dup(state
->chosen_exit
);
2990 } else if (cur_len
== 0) { /* picking first node */
2991 routerinfo_t
*r
= choose_good_entry_server(purpose
, state
);
2993 info
= extend_info_from_router(r
);
2996 choose_good_middle_server(purpose
, state
, circ
->cpath
, cur_len
);
2998 info
= extend_info_from_router(r
);
3002 log_warn(LD_CIRC
,"Failed to find node for hop %d of our path. Discarding "
3003 "this circuit.", cur_len
);
3007 log_debug(LD_CIRC
,"Chose router %s for hop %d (exit is %s)",
3008 info
->nickname
, cur_len
+1, build_state_get_exit_nickname(state
));
3010 onion_append_hop(&circ
->cpath
, info
);
3011 extend_info_free(info
);
3015 /** Create a new hop, annotate it with information about its
3016 * corresponding router <b>choice</b>, and append it to the
3017 * end of the cpath <b>head_ptr</b>. */
3019 onion_append_hop(crypt_path_t
**head_ptr
, extend_info_t
*choice
)
3021 crypt_path_t
*hop
= tor_malloc_zero(sizeof(crypt_path_t
));
3023 /* link hop into the cpath, at the end. */
3024 onion_append_to_cpath(head_ptr
, hop
);
3026 hop
->magic
= CRYPT_PATH_MAGIC
;
3027 hop
->state
= CPATH_STATE_CLOSED
;
3029 hop
->extend_info
= extend_info_dup(choice
);
3031 hop
->package_window
= circuit_initial_package_window();
3032 hop
->deliver_window
= CIRCWINDOW_START
;
3037 /** Allocate a new extend_info object based on the various arguments. */
3039 extend_info_alloc(const char *nickname
, const char *digest
,
3040 crypto_pk_env_t
*onion_key
,
3041 const tor_addr_t
*addr
, uint16_t port
)
3043 extend_info_t
*info
= tor_malloc_zero(sizeof(extend_info_t
));
3044 memcpy(info
->identity_digest
, digest
, DIGEST_LEN
);
3046 strlcpy(info
->nickname
, nickname
, sizeof(info
->nickname
));
3048 info
->onion_key
= crypto_pk_dup_key(onion_key
);
3049 tor_addr_copy(&info
->addr
, addr
);
3054 /** Allocate and return a new extend_info_t that can be used to build a
3055 * circuit to or through the router <b>r</b>. */
3057 extend_info_from_router(routerinfo_t
*r
)
3061 tor_addr_from_ipv4h(&addr
, r
->addr
);
3062 return extend_info_alloc(r
->nickname
, r
->cache_info
.identity_digest
,
3063 r
->onion_pkey
, &addr
, r
->or_port
);
3066 /** Release storage held by an extend_info_t struct. */
3068 extend_info_free(extend_info_t
*info
)
3072 crypto_free_pk_env(info
->onion_key
);
3076 /** Allocate and return a new extend_info_t with the same contents as
3079 extend_info_dup(extend_info_t
*info
)
3081 extend_info_t
*newinfo
;
3083 newinfo
= tor_malloc(sizeof(extend_info_t
));
3084 memcpy(newinfo
, info
, sizeof(extend_info_t
));
3085 if (info
->onion_key
)
3086 newinfo
->onion_key
= crypto_pk_dup_key(info
->onion_key
);
3088 newinfo
->onion_key
= NULL
;
3092 /** Return the routerinfo_t for the chosen exit router in <b>state</b>.
3093 * If there is no chosen exit, or if we don't know the routerinfo_t for
3094 * the chosen exit, return NULL.
3097 build_state_get_exit_router(cpath_build_state_t
*state
)
3099 if (!state
|| !state
->chosen_exit
)
3101 return router_get_by_digest(state
->chosen_exit
->identity_digest
);
3104 /** Return the nickname for the chosen exit router in <b>state</b>. If
3105 * there is no chosen exit, or if we don't know the routerinfo_t for the
3106 * chosen exit, return NULL.
3109 build_state_get_exit_nickname(cpath_build_state_t
*state
)
3111 if (!state
|| !state
->chosen_exit
)
3113 return state
->chosen_exit
->nickname
;
3116 /** Check whether the entry guard <b>e</b> is usable, given the directory
3117 * authorities' opinion about the router (stored in <b>ri</b>) and the user's
3118 * configuration (in <b>options</b>). Set <b>e</b>->bad_since
3119 * accordingly. Return true iff the entry guard's status changes.
3121 * If it's not usable, set *<b>reason</b> to a static string explaining why.
3123 /*XXXX take a routerstatus, not a routerinfo. */
3125 entry_guard_set_status(entry_guard_t
*e
, routerinfo_t
*ri
,
3126 time_t now
, or_options_t
*options
, const char **reason
)
3128 char buf
[HEX_DIGEST_LEN
+1];
3131 tor_assert(options
);
3135 /* Do we want to mark this guard as bad? */
3137 *reason
= "unlisted";
3138 else if (!ri
->is_running
)
3140 else if (options
->UseBridges
&& ri
->purpose
!= ROUTER_PURPOSE_BRIDGE
)
3141 *reason
= "not a bridge";
3142 else if (!options
->UseBridges
&& !ri
->is_possible_guard
&&
3143 !routerset_contains_router(options
->EntryNodes
,ri
))
3144 *reason
= "not recommended as a guard";
3145 else if (routerset_contains_router(options
->ExcludeNodes
, ri
))
3146 *reason
= "excluded";
3148 if (*reason
&& ! e
->bad_since
) {
3149 /* Router is newly bad. */
3150 base16_encode(buf
, sizeof(buf
), e
->identity
, DIGEST_LEN
);
3151 log_info(LD_CIRC
, "Entry guard %s (%s) is %s: marking as unusable.",
3152 e
->nickname
, buf
, *reason
);
3155 control_event_guard(e
->nickname
, e
->identity
, "BAD");
3157 } else if (!*reason
&& e
->bad_since
) {
3158 /* There's nothing wrong with the router any more. */
3159 base16_encode(buf
, sizeof(buf
), e
->identity
, DIGEST_LEN
);
3160 log_info(LD_CIRC
, "Entry guard %s (%s) is no longer unusable: "
3161 "marking as ok.", e
->nickname
, buf
);
3164 control_event_guard(e
->nickname
, e
->identity
, "GOOD");
3170 /** Return true iff enough time has passed since we last tried to connect
3171 * to the unreachable guard <b>e</b> that we're willing to try again. */
3173 entry_is_time_to_retry(entry_guard_t
*e
, time_t now
)
3176 if (e
->last_attempted
< e
->unreachable_since
)
3178 diff
= now
- e
->unreachable_since
;
3180 return now
> (e
->last_attempted
+ 60*60);
3181 else if (diff
< 3*24*60*60)
3182 return now
> (e
->last_attempted
+ 4*60*60);
3183 else if (diff
< 7*24*60*60)
3184 return now
> (e
->last_attempted
+ 18*60*60);
3186 return now
> (e
->last_attempted
+ 36*60*60);
3189 /** Return the router corresponding to <b>e</b>, if <b>e</b> is
3190 * working well enough that we are willing to use it as an entry
3191 * right now. (Else return NULL.) In particular, it must be
3192 * - Listed as either up or never yet contacted;
3193 * - Present in the routerlist;
3194 * - Listed as 'stable' or 'fast' by the current dirserver consensus,
3195 * if demanded by <b>need_uptime</b> or <b>need_capacity</b>
3196 * (unless it's a configured EntryNode);
3197 * - Allowed by our current ReachableORAddresses config option; and
3198 * - Currently thought to be reachable by us (unless <b>assume_reachable</b>
3201 * If the answer is no, set *<b>msg</b> to an explanation of why.
3203 static INLINE routerinfo_t
*
3204 entry_is_live(entry_guard_t
*e
, int need_uptime
, int need_capacity
,
3205 int assume_reachable
, const char **msg
)
3208 or_options_t
*options
= get_options();
3215 /* no good if it's unreachable, unless assume_unreachable or can_retry. */
3216 if (!assume_reachable
&& !e
->can_retry
&&
3217 e
->unreachable_since
&& !entry_is_time_to_retry(e
, time(NULL
))) {
3218 *msg
= "unreachable";
3221 r
= router_get_by_digest(e
->identity
);
3223 *msg
= "no descriptor";
3226 if (get_options()->UseBridges
&& r
->purpose
!= ROUTER_PURPOSE_BRIDGE
) {
3227 *msg
= "not a bridge";
3230 if (!get_options()->UseBridges
&& r
->purpose
!= ROUTER_PURPOSE_GENERAL
) {
3231 *msg
= "not general-purpose";
3234 if (options
->EntryNodes
&&
3235 routerset_contains_router(options
->EntryNodes
, r
)) {
3236 /* they asked for it, they get it */
3237 need_uptime
= need_capacity
= 0;
3239 if (router_is_unreliable(r
, need_uptime
, need_capacity
, 0)) {
3240 *msg
= "not fast/stable";
3243 if (!fascist_firewall_allows_or(r
)) {
3244 *msg
= "unreachable by config";
3250 /** Return the number of entry guards that we think are usable. */
3252 num_live_entry_guards(void)
3258 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
3260 if (entry_is_live(entry
, 0, 1, 0, &msg
))
3266 /** If <b>digest</b> matches the identity of any node in the
3267 * entry_guards list, return that node. Else return NULL. */
3268 static INLINE entry_guard_t
*
3269 is_an_entry_guard(const char *digest
)
3271 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
3272 if (!memcmp(digest
, entry
->identity
, DIGEST_LEN
))
3278 /** Dump a description of our list of entry guards to the log at level
3279 * <b>severity</b>. */
3281 log_entry_guards(int severity
)
3283 smartlist_t
*elements
= smartlist_create();
3286 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
3288 const char *msg
= NULL
;
3290 if (entry_is_live(e
, 0, 1, 0, &msg
))
3291 tor_asprintf(&cp
, "%s (up %s)",
3293 e
->made_contact
? "made-contact" : "never-contacted");
3295 tor_asprintf(&cp
, "%s (%s, %s)",
3297 e
->made_contact
? "made-contact" : "never-contacted");
3298 smartlist_add(elements
, cp
);
3301 s
= smartlist_join_strings(elements
, ",", 0, NULL
);
3302 SMARTLIST_FOREACH(elements
, char*, cp
, tor_free(cp
));
3303 smartlist_free(elements
);
3304 log_fn(severity
,LD_CIRC
,"%s",s
);
3308 /** Called when one or more guards that we would previously have used for some
3309 * purpose are no longer in use because a higher-priority guard has become
3312 control_event_guard_deferred(void)
3314 /* XXXX We don't actually have a good way to figure out _how many_ entries
3315 * are live for some purpose. We need an entry_is_even_slightly_live()
3316 * function for this to work right. NumEntryGuards isn't reliable: if we
3317 * need guards with weird properties, we can have more than that number
3323 or_options_t
*options
= get_options();
3326 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
3328 if (entry_is_live(entry
, 0, 1, 0, &msg
)) {
3329 if (n
++ == options
->NumEntryGuards
) {
3330 control_event_guard(entry
->nickname
, entry
->identity
, "DEFERRED");
3338 /** Add a new (preferably stable and fast) router to our
3339 * entry_guards list. Return a pointer to the router if we succeed,
3340 * or NULL if we can't find any more suitable entries.
3342 * If <b>chosen</b> is defined, use that one, and if it's not
3343 * already in our entry_guards list, put it at the *beginning*.
3344 * Else, put the one we pick at the end of the list. */
3345 static routerinfo_t
*
3346 add_an_entry_guard(routerinfo_t
*chosen
, int reset_status
)
3348 routerinfo_t
*router
;
3349 entry_guard_t
*entry
;
3353 entry
= is_an_entry_guard(router
->cache_info
.identity_digest
);
3356 entry
->bad_since
= 0;
3357 entry
->can_retry
= 1;
3362 router
= choose_good_entry_server(CIRCUIT_PURPOSE_C_GENERAL
, NULL
);
3366 entry
= tor_malloc_zero(sizeof(entry_guard_t
));
3367 log_info(LD_CIRC
, "Chose '%s' as new entry guard.", router
->nickname
);
3368 strlcpy(entry
->nickname
, router
->nickname
, sizeof(entry
->nickname
));
3369 memcpy(entry
->identity
, router
->cache_info
.identity_digest
, DIGEST_LEN
);
3370 /* Choose expiry time smudged over the past month. The goal here
3371 * is to a) spread out when Tor clients rotate their guards, so they
3372 * don't all select them on the same day, and b) avoid leaving a
3373 * precise timestamp in the state file about when we first picked
3374 * this guard. For details, see the Jan 2010 or-dev thread. */
3375 entry
->chosen_on_date
= time(NULL
) - crypto_rand_int(3600*24*30);
3376 entry
->chosen_by_version
= tor_strdup(VERSION
);
3377 if (chosen
) /* prepend */
3378 smartlist_insert(entry_guards
, 0, entry
);
3380 smartlist_add(entry_guards
, entry
);
3381 control_event_guard(entry
->nickname
, entry
->identity
, "NEW");
3382 control_event_guard_deferred();
3383 log_entry_guards(LOG_INFO
);
3387 /** If the use of entry guards is configured, choose more entry guards
3388 * until we have enough in the list. */
3390 pick_entry_guards(void)
3392 or_options_t
*options
= get_options();
3395 tor_assert(entry_guards
);
3397 while (num_live_entry_guards() < options
->NumEntryGuards
) {
3398 if (!add_an_entry_guard(NULL
, 0))
3403 entry_guards_changed();
3406 /** How long (in seconds) do we allow an entry guard to be nonfunctional,
3407 * unlisted, excluded, or otherwise nonusable before we give up on it? */
3408 #define ENTRY_GUARD_REMOVE_AFTER (30*24*60*60)
3410 /** Release all storage held by <b>e</b>. */
3412 entry_guard_free(entry_guard_t
*e
)
3416 tor_free(e
->chosen_by_version
);
3420 /** Remove any entry guard which was selected by an unknown version of Tor,
3421 * or which was selected by a version of Tor that's known to select
3422 * entry guards badly. */
3424 remove_obsolete_entry_guards(void)
3427 time_t now
= time(NULL
);
3429 for (i
= 0; i
< smartlist_len(entry_guards
); ++i
) {
3430 entry_guard_t
*entry
= smartlist_get(entry_guards
, i
);
3431 const char *ver
= entry
->chosen_by_version
;
3432 const char *msg
= NULL
;
3434 int version_is_bad
= 0, date_is_bad
= 0;
3436 msg
= "does not say what version of Tor it was selected by";
3438 } else if (tor_version_parse(ver
, &v
)) {
3439 msg
= "does not seem to be from any recognized version of Tor";
3442 size_t len
= strlen(ver
)+5;
3443 char *tor_ver
= tor_malloc(len
);
3444 tor_snprintf(tor_ver
, len
, "Tor %s", ver
);
3445 if ((tor_version_as_new_as(tor_ver
, "0.1.0.10-alpha") &&
3446 !tor_version_as_new_as(tor_ver
, "0.1.2.16-dev")) ||
3447 (tor_version_as_new_as(tor_ver
, "0.2.0.0-alpha") &&
3448 !tor_version_as_new_as(tor_ver
, "0.2.0.6-alpha")) ||
3449 /* above are bug 440; below are bug 1217 */
3450 (tor_version_as_new_as(tor_ver
, "0.2.1.3-alpha") &&
3451 !tor_version_as_new_as(tor_ver
, "0.2.1.23")) ||
3452 (tor_version_as_new_as(tor_ver
, "0.2.2.0-alpha") &&
3453 !tor_version_as_new_as(tor_ver
, "0.2.2.7-alpha"))) {
3454 msg
= "was selected without regard for guard bandwidth";
3459 if (!version_is_bad
&& entry
->chosen_on_date
+ 3600*24*60 < now
) {
3460 /* It's been 2 months since the date listed in our state file. */
3461 msg
= "was selected several months ago";
3465 if (version_is_bad
|| date_is_bad
) { /* we need to drop it */
3466 char dbuf
[HEX_DIGEST_LEN
+1];
3468 base16_encode(dbuf
, sizeof(dbuf
), entry
->identity
, DIGEST_LEN
);
3469 log_fn(version_is_bad
? LOG_NOTICE
: LOG_INFO
, LD_CIRC
,
3470 "Entry guard '%s' (%s) %s. (Version=%s.) Replacing it.",
3471 entry
->nickname
, dbuf
, msg
, ver
?escaped(ver
):"none");
3472 control_event_guard(entry
->nickname
, entry
->identity
, "DROPPED");
3473 entry_guard_free(entry
);
3474 smartlist_del_keeporder(entry_guards
, i
--);
3475 log_entry_guards(LOG_INFO
);
3480 return changed
? 1 : 0;
3483 /** Remove all entry guards that have been down or unlisted for so
3484 * long that we don't think they'll come up again. Return 1 if we
3485 * removed any, or 0 if we did nothing. */
3487 remove_dead_entry_guards(void)
3489 char dbuf
[HEX_DIGEST_LEN
+1];
3490 char tbuf
[ISO_TIME_LEN
+1];
3491 time_t now
= time(NULL
);
3495 for (i
= 0; i
< smartlist_len(entry_guards
); ) {
3496 entry_guard_t
*entry
= smartlist_get(entry_guards
, i
);
3497 if (entry
->bad_since
&&
3498 entry
->bad_since
+ ENTRY_GUARD_REMOVE_AFTER
< now
) {
3500 base16_encode(dbuf
, sizeof(dbuf
), entry
->identity
, DIGEST_LEN
);
3501 format_local_iso_time(tbuf
, entry
->bad_since
);
3502 log_info(LD_CIRC
, "Entry guard '%s' (%s) has been down or unlisted "
3503 "since %s local time; removing.",
3504 entry
->nickname
, dbuf
, tbuf
);
3505 control_event_guard(entry
->nickname
, entry
->identity
, "DROPPED");
3506 entry_guard_free(entry
);
3507 smartlist_del_keeporder(entry_guards
, i
);
3508 log_entry_guards(LOG_INFO
);
3513 return changed
? 1 : 0;
3516 /** A new directory or router-status has arrived; update the down/listed
3517 * status of the entry guards.
3519 * An entry is 'down' if the directory lists it as nonrunning.
3520 * An entry is 'unlisted' if the directory doesn't include it.
3522 * Don't call this on startup; only on a fresh download. Otherwise we'll
3523 * think that things are unlisted.
3526 entry_guards_compute_status(void)
3530 int severity
= LOG_DEBUG
;
3531 or_options_t
*options
;
3532 digestmap_t
*reasons
;
3537 options
= get_options();
3538 if (options
->EntryNodes
) /* reshuffle the entry guard list if needed */
3539 entry_nodes_should_be_added();
3543 reasons
= digestmap_new();
3544 SMARTLIST_FOREACH_BEGIN(entry_guards
, entry_guard_t
*, entry
)
3546 routerinfo_t
*r
= router_get_by_digest(entry
->identity
);
3547 const char *reason
= NULL
;
3548 if (entry_guard_set_status(entry
, r
, now
, options
, &reason
))
3551 if (entry
->bad_since
)
3554 digestmap_set(reasons
, entry
->identity
, (char*)reason
);
3556 SMARTLIST_FOREACH_END(entry
);
3558 if (remove_dead_entry_guards())
3561 severity
= changed
? LOG_DEBUG
: LOG_INFO
;
3564 SMARTLIST_FOREACH_BEGIN(entry_guards
, entry_guard_t
*, entry
) {
3565 const char *reason
= digestmap_get(reasons
, entry
->identity
);
3566 const char *live_msg
= "";
3567 routerinfo_t
*r
= entry_is_live(entry
, 0, 1, 0, &live_msg
);
3568 log_info(LD_CIRC
, "Summary: Entry '%s' is %s, %s%s%s, and %s%s.",
3570 entry
->unreachable_since
? "unreachable" : "reachable",
3571 entry
->bad_since
? "unusable" : "usable",
3573 reason
? reason
: "",
3574 r
? "live" : "not live / ",
3576 } SMARTLIST_FOREACH_END(entry
);
3577 log_info(LD_CIRC
, " (%d/%d entry guards are usable/new)",
3578 num_live_entry_guards(), smartlist_len(entry_guards
));
3579 log_entry_guards(LOG_INFO
);
3580 entry_guards_changed();
3583 digestmap_free(reasons
, NULL
);
3586 /** Called when a connection to an OR with the identity digest <b>digest</b>
3587 * is established (<b>succeeded</b>==1) or has failed (<b>succeeded</b>==0).
3588 * If the OR is an entry, change that entry's up/down status.
3589 * Return 0 normally, or -1 if we want to tear down the new connection.
3591 * If <b>mark_relay_status</b>, also call router_set_status() on this
3594 * XXX022 change succeeded and mark_relay_status into 'int flags'.
3597 entry_guard_register_connect_status(const char *digest
, int succeeded
,
3598 int mark_relay_status
, time_t now
)
3601 int refuse_conn
= 0;
3602 int first_contact
= 0;
3603 entry_guard_t
*entry
= NULL
;
3605 char buf
[HEX_DIGEST_LEN
+1];
3610 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
3612 if (!memcmp(e
->identity
, digest
, DIGEST_LEN
)) {
3622 base16_encode(buf
, sizeof(buf
), entry
->identity
, DIGEST_LEN
);
3625 if (entry
->unreachable_since
) {
3626 log_info(LD_CIRC
, "Entry guard '%s' (%s) is now reachable again. Good.",
3627 entry
->nickname
, buf
);
3628 entry
->can_retry
= 0;
3629 entry
->unreachable_since
= 0;
3630 entry
->last_attempted
= now
;
3631 control_event_guard(entry
->nickname
, entry
->identity
, "UP");
3634 if (!entry
->made_contact
) {
3635 entry
->made_contact
= 1;
3636 first_contact
= changed
= 1;
3638 } else { /* ! succeeded */
3639 if (!entry
->made_contact
) {
3640 /* We've never connected to this one. */
3642 "Connection to never-contacted entry guard '%s' (%s) failed. "
3643 "Removing from the list. %d/%d entry guards usable/new.",
3644 entry
->nickname
, buf
,
3645 num_live_entry_guards()-1, smartlist_len(entry_guards
)-1);
3646 control_event_guard(entry
->nickname
, entry
->identity
, "DROPPED");
3647 entry_guard_free(entry
);
3648 smartlist_del_keeporder(entry_guards
, idx
);
3649 log_entry_guards(LOG_INFO
);
3651 } else if (!entry
->unreachable_since
) {
3652 log_info(LD_CIRC
, "Unable to connect to entry guard '%s' (%s). "
3653 "Marking as unreachable.", entry
->nickname
, buf
);
3654 entry
->unreachable_since
= entry
->last_attempted
= now
;
3655 control_event_guard(entry
->nickname
, entry
->identity
, "DOWN");
3657 entry
->can_retry
= 0; /* We gave it an early chance; no good. */
3659 char tbuf
[ISO_TIME_LEN
+1];
3660 format_iso_time(tbuf
, entry
->unreachable_since
);
3661 log_debug(LD_CIRC
, "Failed to connect to unreachable entry guard "
3662 "'%s' (%s). It has been unreachable since %s.",
3663 entry
->nickname
, buf
, tbuf
);
3664 entry
->last_attempted
= now
;
3665 entry
->can_retry
= 0; /* We gave it an early chance; no good. */
3669 /* if the caller asked us to, also update the is_running flags for this
3671 if (mark_relay_status
)
3672 router_set_status(digest
, succeeded
);
3674 if (first_contact
) {
3675 /* We've just added a new long-term entry guard. Perhaps the network just
3676 * came back? We should give our earlier entries another try too,
3677 * and close this connection so we don't use it before we've given
3678 * the others a shot. */
3679 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
, {
3682 if (e
->made_contact
) {
3684 routerinfo_t
*r
= entry_is_live(e
, 0, 1, 1, &msg
);
3685 if (r
&& e
->unreachable_since
) {
3693 "Connected to new entry guard '%s' (%s). Marking earlier "
3694 "entry guards up. %d/%d entry guards usable/new.",
3695 entry
->nickname
, buf
,
3696 num_live_entry_guards(), smartlist_len(entry_guards
));
3697 log_entry_guards(LOG_INFO
);
3703 entry_guards_changed();
3704 return refuse_conn
? -1 : 0;
3707 /** When we try to choose an entry guard, should we parse and add
3708 * config's EntryNodes first? */
3709 static int should_add_entry_nodes
= 0;
3711 /** Called when the value of EntryNodes changes in our configuration. */
3713 entry_nodes_should_be_added(void)
3715 log_info(LD_CIRC
, "EntryNodes config option set. Putting configured "
3716 "relays at the front of the entry guard list.");
3717 should_add_entry_nodes
= 1;
3720 /** Add all nodes in EntryNodes that aren't currently guard nodes to the list
3721 * of guard nodes, at the front. */
3723 entry_guards_prepend_from_config(void)
3725 or_options_t
*options
= get_options();
3726 smartlist_t
*entry_routers
, *entry_fps
;
3727 smartlist_t
*old_entry_guards_on_list
, *old_entry_guards_not_on_list
;
3728 tor_assert(entry_guards
);
3730 should_add_entry_nodes
= 0;
3732 if (!options
->EntryNodes
) {
3733 /* It's possible that a controller set EntryNodes, thus making
3734 * should_add_entry_nodes set, then cleared it again, all before the
3735 * call to choose_random_entry() that triggered us. If so, just return.
3741 char *string
= routerset_to_string(options
->EntryNodes
);
3742 log_info(LD_CIRC
,"Adding configured EntryNodes '%s'.", string
);
3746 entry_routers
= smartlist_create();
3747 entry_fps
= smartlist_create();
3748 old_entry_guards_on_list
= smartlist_create();
3749 old_entry_guards_not_on_list
= smartlist_create();
3751 /* Split entry guards into those on the list and those not. */
3753 /* XXXX022 Now that we allow countries and IP ranges in EntryNodes, this is
3754 * potentially an enormous list. For now, we disable such values for
3755 * EntryNodes in options_validate(); really, this wants a better solution.
3756 * Perhaps we should do this calculation once whenever the list of routers
3757 * changes or the entrynodes setting changes.
3759 routerset_get_all_routers(entry_routers
, options
->EntryNodes
, 0);
3760 SMARTLIST_FOREACH(entry_routers
, routerinfo_t
*, ri
,
3761 smartlist_add(entry_fps
,ri
->cache_info
.identity_digest
));
3762 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
, {
3763 if (smartlist_digest_isin(entry_fps
, e
->identity
))
3764 smartlist_add(old_entry_guards_on_list
, e
);
3766 smartlist_add(old_entry_guards_not_on_list
, e
);
3769 /* Remove all currently configured entry guards from entry_routers. */
3770 SMARTLIST_FOREACH(entry_routers
, routerinfo_t
*, ri
, {
3771 if (is_an_entry_guard(ri
->cache_info
.identity_digest
)) {
3772 SMARTLIST_DEL_CURRENT(entry_routers
, ri
);
3776 /* Now build the new entry_guards list. */
3777 smartlist_clear(entry_guards
);
3778 /* First, the previously configured guards that are in EntryNodes. */
3779 smartlist_add_all(entry_guards
, old_entry_guards_on_list
);
3780 /* Next, the rest of EntryNodes */
3781 SMARTLIST_FOREACH(entry_routers
, routerinfo_t
*, ri
, {
3782 add_an_entry_guard(ri
, 0);
3784 /* Finally, the remaining previously configured guards that are not in
3785 * EntryNodes, unless we're strict in which case we drop them */
3786 if (options
->StrictNodes
) {
3787 SMARTLIST_FOREACH(old_entry_guards_not_on_list
, entry_guard_t
*, e
,
3788 entry_guard_free(e
));
3790 smartlist_add_all(entry_guards
, old_entry_guards_not_on_list
);
3793 smartlist_free(entry_routers
);
3794 smartlist_free(entry_fps
);
3795 smartlist_free(old_entry_guards_on_list
);
3796 smartlist_free(old_entry_guards_not_on_list
);
3797 entry_guards_changed();
3800 /** Return 0 if we're fine adding arbitrary routers out of the
3801 * directory to our entry guard list, or return 1 if we have a
3802 * list already and we'd prefer to stick to it.
3805 entry_list_is_constrained(or_options_t
*options
)
3807 if (options
->EntryNodes
)
3809 if (options
->UseBridges
)
3814 /* Are we dead set against changing our entry guard list, or would we
3815 * change it if it means keeping Tor usable? */
3817 entry_list_is_totally_static(or_options_t
*options
)
3819 if (options
->EntryNodes
&& options
->StrictNodes
)
3821 if (options
->UseBridges
)
3826 /** Pick a live (up and listed) entry guard from entry_guards. If
3827 * <b>state</b> is non-NULL, this is for a specific circuit --
3828 * make sure not to pick this circuit's exit or any node in the
3829 * exit's family. If <b>state</b> is NULL, we're looking for a random
3830 * guard (likely a bridge). */
3832 choose_random_entry(cpath_build_state_t
*state
)
3834 or_options_t
*options
= get_options();
3835 smartlist_t
*live_entry_guards
= smartlist_create();
3836 smartlist_t
*exit_family
= smartlist_create();
3837 routerinfo_t
*chosen_exit
= state
?build_state_get_exit_router(state
) : NULL
;
3838 routerinfo_t
*r
= NULL
;
3839 int need_uptime
= state
? state
->need_uptime
: 0;
3840 int need_capacity
= state
? state
->need_capacity
: 0;
3841 int preferred_min
, consider_exit_family
= 0;
3844 smartlist_add(exit_family
, chosen_exit
);
3845 routerlist_add_family(exit_family
, chosen_exit
);
3846 consider_exit_family
= 1;
3850 entry_guards
= smartlist_create();
3852 if (should_add_entry_nodes
)
3853 entry_guards_prepend_from_config();
3855 if (!entry_list_is_constrained(options
) &&
3856 smartlist_len(entry_guards
) < options
->NumEntryGuards
)
3857 pick_entry_guards();
3860 smartlist_clear(live_entry_guards
);
3861 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, entry
,
3864 r
= entry_is_live(entry
, need_uptime
, need_capacity
, 0, &msg
);
3866 continue; /* down, no point */
3867 if (consider_exit_family
&& smartlist_isin(exit_family
, r
))
3868 continue; /* avoid relays that are family members of our exit */
3869 if (options
->EntryNodes
&&
3870 !routerset_contains_router(options
->EntryNodes
, r
)) {
3871 /* We've come to the end of our preferred entry nodes. */
3872 if (smartlist_len(live_entry_guards
))
3873 goto choose_and_finish
; /* only choose from the ones we like */
3874 if (options
->StrictNodes
) {
3875 /* in theory this case should never happen, since
3876 * entry_guards_prepend_from_config() drops unwanted relays */
3877 tor_fragile_assert();
3880 "No relays from EntryNodes available. Using others.");
3883 smartlist_add(live_entry_guards
, r
);
3884 if (!entry
->made_contact
) {
3885 /* Always start with the first not-yet-contacted entry
3886 * guard. Otherwise we might add several new ones, pick
3887 * the second new one, and now we've expanded our entry
3888 * guard list without needing to. */
3889 goto choose_and_finish
;
3891 if (smartlist_len(live_entry_guards
) >= options
->NumEntryGuards
)
3892 break; /* we have enough */
3895 if (entry_list_is_constrained(options
)) {
3896 /* If we prefer the entry nodes we've got, and we have at least
3897 * one choice, that's great. Use it. */
3900 /* Try to have at least 2 choices available. This way we don't
3901 * get stuck with a single live-but-crummy entry and just keep
3903 * (We might get 2 live-but-crummy entry guards, but so be it.) */
3907 if (smartlist_len(live_entry_guards
) < preferred_min
) {
3908 if (!entry_list_is_totally_static(options
)) {
3909 /* still no? try adding a new entry then */
3910 /* XXX if guard doesn't imply fast and stable, then we need
3911 * to tell add_an_entry_guard below what we want, or it might
3912 * be a long time til we get it. -RD */
3913 r
= add_an_entry_guard(NULL
, 0);
3915 entry_guards_changed();
3916 /* XXX we start over here in case the new node we added shares
3917 * a family with our exit node. There's a chance that we'll just
3918 * load up on entry guards here, if the network we're using is
3919 * one big family. Perhaps we should teach add_an_entry_guard()
3920 * to understand nodes-to-avoid-if-possible? -RD */
3924 if (!r
&& need_uptime
) {
3925 need_uptime
= 0; /* try without that requirement */
3928 if (!r
&& need_capacity
) {
3929 /* still no? last attempt, try without requiring capacity */
3933 if (!r
&& entry_list_is_constrained(options
) && consider_exit_family
) {
3934 /* still no? if we're using bridges or have strictentrynodes
3935 * set, and our chosen exit is in the same family as all our
3936 * bridges/entry guards, then be flexible about families. */
3937 consider_exit_family
= 0;
3940 /* live_entry_guards may be empty below. Oh well, we tried. */
3944 if (entry_list_is_constrained(options
)) {
3945 /* We need to weight by bandwidth, because our bridges or entryguards
3946 * were not already selected proportional to their bandwidth. */
3947 r
= routerlist_sl_choose_by_bandwidth(live_entry_guards
, WEIGHT_FOR_GUARD
);
3949 /* We choose uniformly at random here, because choose_good_entry_server()
3950 * already weights its choices by bandwidth, so we don't want to
3951 * *double*-weight our guard selection. */
3952 r
= smartlist_choose(live_entry_guards
);
3954 smartlist_free(live_entry_guards
);
3955 smartlist_free(exit_family
);
3959 /** Parse <b>state</b> and learn about the entry guards it describes.
3960 * If <b>set</b> is true, and there are no errors, replace the global
3961 * entry_list with what we find.
3962 * On success, return 0. On failure, alloc into *<b>msg</b> a string
3963 * describing the error, and return -1.
3966 entry_guards_parse_state(or_state_t
*state
, int set
, char **msg
)
3968 entry_guard_t
*node
= NULL
;
3969 smartlist_t
*new_entry_guards
= smartlist_create();
3970 config_line_t
*line
;
3971 time_t now
= time(NULL
);
3972 const char *state_version
= state
->TorVersion
;
3973 digestmap_t
*added_by
= digestmap_new();
3976 for (line
= state
->EntryGuards
; line
; line
= line
->next
) {
3977 if (!strcasecmp(line
->key
, "EntryGuard")) {
3978 smartlist_t
*args
= smartlist_create();
3979 node
= tor_malloc_zero(sizeof(entry_guard_t
));
3980 /* all entry guards on disk have been contacted */
3981 node
->made_contact
= 1;
3982 smartlist_add(new_entry_guards
, node
);
3983 smartlist_split_string(args
, line
->value
, " ",
3984 SPLIT_SKIP_SPACE
|SPLIT_IGNORE_BLANK
, 0);
3985 if (smartlist_len(args
)<2) {
3986 *msg
= tor_strdup("Unable to parse entry nodes: "
3987 "Too few arguments to EntryGuard");
3988 } else if (!is_legal_nickname(smartlist_get(args
,0))) {
3989 *msg
= tor_strdup("Unable to parse entry nodes: "
3990 "Bad nickname for EntryGuard");
3992 strlcpy(node
->nickname
, smartlist_get(args
,0), MAX_NICKNAME_LEN
+1);
3993 if (base16_decode(node
->identity
, DIGEST_LEN
, smartlist_get(args
,1),
3994 strlen(smartlist_get(args
,1)))<0) {
3995 *msg
= tor_strdup("Unable to parse entry nodes: "
3996 "Bad hex digest for EntryGuard");
3999 SMARTLIST_FOREACH(args
, char*, cp
, tor_free(cp
));
4000 smartlist_free(args
);
4003 } else if (!strcasecmp(line
->key
, "EntryGuardDownSince") ||
4004 !strcasecmp(line
->key
, "EntryGuardUnlistedSince")) {
4006 time_t last_try
= 0;
4008 *msg
= tor_strdup("Unable to parse entry nodes: "
4009 "EntryGuardDownSince/UnlistedSince without EntryGuard");
4012 if (parse_iso_time(line
->value
, &when
)<0) {
4013 *msg
= tor_strdup("Unable to parse entry nodes: "
4014 "Bad time in EntryGuardDownSince/UnlistedSince");
4018 /* It's a bad idea to believe info in the future: you can wind
4019 * up with timeouts that aren't allowed to happen for years. */
4022 if (strlen(line
->value
) >= ISO_TIME_LEN
+ISO_TIME_LEN
+1) {
4023 /* ignore failure */
4024 (void) parse_iso_time(line
->value
+ISO_TIME_LEN
+1, &last_try
);
4026 if (!strcasecmp(line
->key
, "EntryGuardDownSince")) {
4027 node
->unreachable_since
= when
;
4028 node
->last_attempted
= last_try
;
4030 node
->bad_since
= when
;
4032 } else if (!strcasecmp(line
->key
, "EntryGuardAddedBy")) {
4034 /* format is digest version date */
4035 if (strlen(line
->value
) < HEX_DIGEST_LEN
+1+1+1+ISO_TIME_LEN
) {
4036 log_warn(LD_BUG
, "EntryGuardAddedBy line is not long enough.");
4039 if (base16_decode(d
, sizeof(d
), line
->value
, HEX_DIGEST_LEN
)<0 ||
4040 line
->value
[HEX_DIGEST_LEN
] != ' ') {
4041 log_warn(LD_BUG
, "EntryGuardAddedBy line %s does not begin with "
4042 "hex digest", escaped(line
->value
));
4045 digestmap_set(added_by
, d
, tor_strdup(line
->value
+HEX_DIGEST_LEN
+1));
4047 log_warn(LD_BUG
, "Unexpected key %s", line
->key
);
4051 SMARTLIST_FOREACH(new_entry_guards
, entry_guard_t
*, e
,
4054 char *val
= digestmap_get(added_by
, e
->identity
);
4055 if (val
&& (sp
= strchr(val
, ' '))) {
4058 if (parse_iso_time(sp
, &when
)<0) {
4059 log_warn(LD_BUG
, "Can't read time %s in EntryGuardAddedBy", sp
);
4061 e
->chosen_by_version
= tor_strdup(val
);
4062 e
->chosen_on_date
= when
;
4065 if (state_version
) {
4066 e
->chosen_by_version
= tor_strdup(state_version
);
4067 e
->chosen_on_date
= time(NULL
) - crypto_rand_int(3600*24*30);
4073 SMARTLIST_FOREACH(new_entry_guards
, entry_guard_t
*, e
,
4074 entry_guard_free(e
));
4075 smartlist_free(new_entry_guards
);
4076 } else { /* !err && set */
4078 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
4079 entry_guard_free(e
));
4080 smartlist_free(entry_guards
);
4082 entry_guards
= new_entry_guards
;
4083 entry_guards_dirty
= 0;
4084 /* XXX022 hand new_entry_guards to this func, and move it up a
4085 * few lines, so we don't have to re-dirty it */
4086 if (remove_obsolete_entry_guards())
4087 entry_guards_dirty
= 1;
4089 digestmap_free(added_by
, _tor_free
);
4090 return *msg
? -1 : 0;
4093 /** Our list of entry guards has changed, or some element of one
4094 * of our entry guards has changed. Write the changes to disk within
4095 * the next few minutes.
4098 entry_guards_changed(void)
4101 entry_guards_dirty
= 1;
4103 /* or_state_save() will call entry_guards_update_state(). */
4104 when
= get_options()->AvoidDiskWrites
? time(NULL
) + 3600 : time(NULL
)+600;
4105 or_state_mark_dirty(get_or_state(), when
);
4108 /** If the entry guard info has not changed, do nothing and return.
4109 * Otherwise, free the EntryGuards piece of <b>state</b> and create
4110 * a new one out of the global entry_guards list, and then mark
4111 * <b>state</b> dirty so it will get saved to disk.
4114 entry_guards_update_state(or_state_t
*state
)
4116 config_line_t
**next
, *line
;
4117 if (! entry_guards_dirty
)
4120 config_free_lines(state
->EntryGuards
);
4121 next
= &state
->EntryGuards
;
4124 entry_guards
= smartlist_create();
4125 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
4127 char dbuf
[HEX_DIGEST_LEN
+1];
4128 if (!e
->made_contact
)
4129 continue; /* don't write this one to disk */
4130 *next
= line
= tor_malloc_zero(sizeof(config_line_t
));
4131 line
->key
= tor_strdup("EntryGuard");
4132 line
->value
= tor_malloc(HEX_DIGEST_LEN
+MAX_NICKNAME_LEN
+2);
4133 base16_encode(dbuf
, sizeof(dbuf
), e
->identity
, DIGEST_LEN
);
4134 tor_snprintf(line
->value
,HEX_DIGEST_LEN
+MAX_NICKNAME_LEN
+2,
4135 "%s %s", e
->nickname
, dbuf
);
4136 next
= &(line
->next
);
4137 if (e
->unreachable_since
) {
4138 *next
= line
= tor_malloc_zero(sizeof(config_line_t
));
4139 line
->key
= tor_strdup("EntryGuardDownSince");
4140 line
->value
= tor_malloc(ISO_TIME_LEN
+1+ISO_TIME_LEN
+1);
4141 format_iso_time(line
->value
, e
->unreachable_since
);
4142 if (e
->last_attempted
) {
4143 line
->value
[ISO_TIME_LEN
] = ' ';
4144 format_iso_time(line
->value
+ISO_TIME_LEN
+1, e
->last_attempted
);
4146 next
= &(line
->next
);
4149 *next
= line
= tor_malloc_zero(sizeof(config_line_t
));
4150 line
->key
= tor_strdup("EntryGuardUnlistedSince");
4151 line
->value
= tor_malloc(ISO_TIME_LEN
+1);
4152 format_iso_time(line
->value
, e
->bad_since
);
4153 next
= &(line
->next
);
4155 if (e
->chosen_on_date
&& e
->chosen_by_version
&&
4156 !strchr(e
->chosen_by_version
, ' ')) {
4157 char d
[HEX_DIGEST_LEN
+1];
4158 char t
[ISO_TIME_LEN
+1];
4160 *next
= line
= tor_malloc_zero(sizeof(config_line_t
));
4161 line
->key
= tor_strdup("EntryGuardAddedBy");
4162 val_len
= (HEX_DIGEST_LEN
+1+strlen(e
->chosen_by_version
)
4164 line
->value
= tor_malloc(val_len
);
4165 base16_encode(d
, sizeof(d
), e
->identity
, DIGEST_LEN
);
4166 format_iso_time(t
, e
->chosen_on_date
);
4167 tor_snprintf(line
->value
, val_len
, "%s %s %s",
4168 d
, e
->chosen_by_version
, t
);
4169 next
= &(line
->next
);
4172 if (!get_options()->AvoidDiskWrites
)
4173 or_state_mark_dirty(get_or_state(), 0);
4174 entry_guards_dirty
= 0;
4177 /** If <b>question</b> is the string "entry-guards", then dump
4178 * to *<b>answer</b> a newly allocated string describing all of
4179 * the nodes in the global entry_guards list. See control-spec.txt
4181 * For backward compatibility, we also handle the string "helper-nodes".
4184 getinfo_helper_entry_guards(control_connection_t
*conn
,
4185 const char *question
, char **answer
)
4188 if (!strcmp(question
,"entry-guards") ||
4189 !strcmp(question
,"helper-nodes")) {
4190 smartlist_t
*sl
= smartlist_create();
4191 char tbuf
[ISO_TIME_LEN
+1];
4192 char nbuf
[MAX_VERBOSE_NICKNAME_LEN
+1];
4194 entry_guards
= smartlist_create();
4195 SMARTLIST_FOREACH_BEGIN(entry_guards
, entry_guard_t
*, e
) {
4196 size_t len
= MAX_VERBOSE_NICKNAME_LEN
+ISO_TIME_LEN
+32;
4197 char *c
= tor_malloc(len
);
4198 const char *status
= NULL
;
4202 if (!e
->made_contact
) {
4203 status
= "never-connected";
4204 } else if (e
->bad_since
) {
4205 when
= e
->bad_since
;
4206 status
= "unusable";
4211 ri
= router_get_by_digest(e
->identity
);
4213 router_get_verbose_nickname(nbuf
, ri
);
4216 base16_encode(nbuf
+1, sizeof(nbuf
)-1, e
->identity
, DIGEST_LEN
);
4217 /* e->nickname field is not very reliable if we don't know about
4218 * this router any longer; don't include it. */
4222 format_iso_time(tbuf
, when
);
4223 tor_snprintf(c
, len
, "%s %s %s\n", nbuf
, status
, tbuf
);
4225 tor_snprintf(c
, len
, "%s %s\n", nbuf
, status
);
4227 smartlist_add(sl
, c
);
4228 } SMARTLIST_FOREACH_END(e
);
4229 *answer
= smartlist_join_strings(sl
, "", 0, NULL
);
4230 SMARTLIST_FOREACH(sl
, char *, c
, tor_free(c
));
4236 /** Information about a configured bridge. Currently this just matches the
4237 * ones in the torrc file, but one day we may be able to learn about new
4238 * bridges on our own, and remember them in the state file. */
4240 /** Address of the bridge. */
4242 /** TLS port for the bridge. */
4244 /** Expected identity digest, or all zero bytes if we don't know what the
4245 * digest should be. */
4246 char identity
[DIGEST_LEN
];
4247 /** When should we next try to fetch a descriptor for this bridge? */
4248 download_status_t fetch_status
;
4251 /** A list of configured bridges. Whenever we actually get a descriptor
4252 * for one, we add it as an entry guard. */
4253 static smartlist_t
*bridge_list
= NULL
;
4255 /** Initialize the bridge list to empty, creating it if needed. */
4257 clear_bridge_list(void)
4260 bridge_list
= smartlist_create();
4261 SMARTLIST_FOREACH(bridge_list
, bridge_info_t
*, b
, tor_free(b
));
4262 smartlist_clear(bridge_list
);
4265 /** Return a bridge pointer if <b>ri</b> is one of our known bridges
4266 * (either by comparing keys if possible, else by comparing addr/port).
4267 * Else return NULL. */
4268 static bridge_info_t
*
4269 routerinfo_get_configured_bridge(routerinfo_t
*ri
)
4273 SMARTLIST_FOREACH_BEGIN(bridge_list
, bridge_info_t
*, bridge
)
4275 if (tor_digest_is_zero(bridge
->identity
) &&
4276 tor_addr_eq_ipv4h(&bridge
->addr
, ri
->addr
) &&
4277 bridge
->port
== ri
->or_port
)
4279 if (!memcmp(bridge
->identity
, ri
->cache_info
.identity_digest
,
4283 SMARTLIST_FOREACH_END(bridge
);
4287 /** Return 1 if <b>ri</b> is one of our known bridges, else 0. */
4289 routerinfo_is_a_configured_bridge(routerinfo_t
*ri
)
4291 return routerinfo_get_configured_bridge(ri
) ? 1 : 0;
4294 /** Remember a new bridge at <b>addr</b>:<b>port</b>. If <b>digest</b>
4295 * is set, it tells us the identity key too. */
4297 bridge_add_from_config(const tor_addr_t
*addr
, uint16_t port
, char *digest
)
4299 bridge_info_t
*b
= tor_malloc_zero(sizeof(bridge_info_t
));
4300 tor_addr_copy(&b
->addr
, addr
);
4303 memcpy(b
->identity
, digest
, DIGEST_LEN
);
4304 b
->fetch_status
.schedule
= DL_SCHED_BRIDGE
;
4306 bridge_list
= smartlist_create();
4307 smartlist_add(bridge_list
, b
);
4310 /** If <b>digest</b> is one of our known bridges, return it. */
4311 static bridge_info_t
*
4312 find_bridge_by_digest(const char *digest
)
4314 SMARTLIST_FOREACH(bridge_list
, bridge_info_t
*, bridge
,
4316 if (!memcmp(bridge
->identity
, digest
, DIGEST_LEN
))
4322 /** We need to ask <b>bridge</b> for its server descriptor. <b>address</b>
4323 * is a helpful string describing this bridge. */
4325 launch_direct_bridge_descriptor_fetch(bridge_info_t
*bridge
)
4329 if (connection_get_by_type_addr_port_purpose(
4330 CONN_TYPE_DIR
, &bridge
->addr
, bridge
->port
,
4331 DIR_PURPOSE_FETCH_SERVERDESC
))
4332 return; /* it's already on the way */
4334 address
= tor_dup_addr(&bridge
->addr
);
4335 directory_initiate_command(address
, &bridge
->addr
,
4337 0, /* does not matter */
4338 1, bridge
->identity
,
4339 DIR_PURPOSE_FETCH_SERVERDESC
,
4340 ROUTER_PURPOSE_BRIDGE
,
4341 0, "authority.z", NULL
, 0, 0);
4345 /** Fetching the bridge descriptor from the bridge authority returned a
4346 * "not found". Fall back to trying a direct fetch. */
4348 retry_bridge_descriptor_fetch_directly(const char *digest
)
4350 bridge_info_t
*bridge
= find_bridge_by_digest(digest
);
4352 return; /* not found? oh well. */
4354 launch_direct_bridge_descriptor_fetch(bridge
);
4357 /** For each bridge in our list for which we don't currently have a
4358 * descriptor, fetch a new copy of its descriptor -- either directly
4359 * from the bridge or via a bridge authority. */
4361 fetch_bridge_descriptors(time_t now
)
4363 or_options_t
*options
= get_options();
4364 int num_bridge_auths
= get_n_authorities(BRIDGE_AUTHORITY
);
4365 int ask_bridge_directly
;
4366 int can_use_bridge_authority
;
4371 SMARTLIST_FOREACH_BEGIN(bridge_list
, bridge_info_t
*, bridge
)
4373 if (!download_status_is_ready(&bridge
->fetch_status
, now
,
4374 IMPOSSIBLE_TO_DOWNLOAD
))
4375 continue; /* don't bother, no need to retry yet */
4377 /* schedule another fetch as if this one will fail, in case it does */
4378 download_status_failed(&bridge
->fetch_status
, 0);
4380 can_use_bridge_authority
= !tor_digest_is_zero(bridge
->identity
) &&
4382 ask_bridge_directly
= !can_use_bridge_authority
||
4383 !options
->UpdateBridgesFromAuthority
;
4384 log_debug(LD_DIR
, "ask_bridge_directly=%d (%d, %d, %d)",
4385 ask_bridge_directly
, tor_digest_is_zero(bridge
->identity
),
4386 !options
->UpdateBridgesFromAuthority
, !num_bridge_auths
);
4388 if (ask_bridge_directly
&&
4389 !fascist_firewall_allows_address_or(&bridge
->addr
, bridge
->port
)) {
4390 log_notice(LD_DIR
, "Bridge at '%s:%d' isn't reachable by our "
4391 "firewall policy. %s.", fmt_addr(&bridge
->addr
),
4393 can_use_bridge_authority
?
4394 "Asking bridge authority instead" : "Skipping");
4395 if (can_use_bridge_authority
)
4396 ask_bridge_directly
= 0;
4401 if (ask_bridge_directly
) {
4402 /* we need to ask the bridge itself for its descriptor. */
4403 launch_direct_bridge_descriptor_fetch(bridge
);
4405 /* We have a digest and we want to ask an authority. We could
4406 * combine all the requests into one, but that may give more
4407 * hints to the bridge authority than we want to give. */
4408 char resource
[10 + HEX_DIGEST_LEN
];
4409 memcpy(resource
, "fp/", 3);
4410 base16_encode(resource
+3, HEX_DIGEST_LEN
+1,
4411 bridge
->identity
, DIGEST_LEN
);
4412 memcpy(resource
+3+HEX_DIGEST_LEN
, ".z", 3);
4413 log_info(LD_DIR
, "Fetching bridge info '%s' from bridge authority.",
4415 directory_get_from_dirserver(DIR_PURPOSE_FETCH_SERVERDESC
,
4416 ROUTER_PURPOSE_BRIDGE
, resource
, 0);
4419 SMARTLIST_FOREACH_END(bridge
);
4422 /** We just learned a descriptor for a bridge. See if that
4423 * digest is in our entry guard list, and add it if not. */
4425 learned_bridge_descriptor(routerinfo_t
*ri
, int from_cache
)
4428 tor_assert(ri
->purpose
== ROUTER_PURPOSE_BRIDGE
);
4429 if (get_options()->UseBridges
) {
4430 int first
= !any_bridge_descriptors_known();
4431 bridge_info_t
*bridge
= routerinfo_get_configured_bridge(ri
);
4432 time_t now
= time(NULL
);
4435 if (bridge
) { /* if we actually want to use this one */
4436 /* it's here; schedule its re-fetch for a long time from now. */
4438 download_status_reset(&bridge
->fetch_status
);
4440 add_an_entry_guard(ri
, 1);
4441 log_notice(LD_DIR
, "new bridge descriptor '%s' (%s)", ri
->nickname
,
4442 from_cache
? "cached" : "fresh");
4444 routerlist_retry_directory_downloads(now
);
4449 /** Return 1 if any of our entry guards have descriptors that
4450 * are marked with purpose 'bridge' and are running. Else return 0.
4452 * We use this function to decide if we're ready to start building
4453 * circuits through our bridges, or if we need to wait until the
4454 * directory "server/authority" requests finish. */
4456 any_bridge_descriptors_known(void)
4458 tor_assert(get_options()->UseBridges
);
4459 return choose_random_entry(NULL
)!=NULL
? 1 : 0;
4462 /** Return 1 if there are any directory conns fetching bridge descriptors
4463 * that aren't marked for close. We use this to guess if we should tell
4464 * the controller that we have a problem. */
4466 any_pending_bridge_descriptor_fetches(void)
4468 smartlist_t
*conns
= get_connection_array();
4469 SMARTLIST_FOREACH(conns
, connection_t
*, conn
,
4471 if (conn
->type
== CONN_TYPE_DIR
&&
4472 conn
->purpose
== DIR_PURPOSE_FETCH_SERVERDESC
&&
4473 TO_DIR_CONN(conn
)->router_purpose
== ROUTER_PURPOSE_BRIDGE
&&
4474 !conn
->marked_for_close
&&
4475 conn
->linked
&& !conn
->linked_conn
->marked_for_close
) {
4476 log_debug(LD_DIR
, "found one: %s", conn
->address
);
4483 /** Return 1 if we have at least one descriptor for a bridge and
4484 * all descriptors we know are down. Else return 0. If <b>act</b> is
4485 * 1, then mark the down bridges up; else just observe and report. */
4487 bridges_retry_helper(int act
)
4491 int any_running
= 0;
4493 entry_guards
= smartlist_create();
4494 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
4496 ri
= router_get_by_digest(e
->identity
);
4497 if (ri
&& ri
->purpose
== ROUTER_PURPOSE_BRIDGE
) {
4500 any_running
= 1; /* some bridge is both known and running */
4501 else if (act
) { /* mark it for retry */
4508 log_debug(LD_DIR
, "any_known %d, any_running %d", any_known
, any_running
);
4509 return any_known
&& !any_running
;
4512 /** Do we know any descriptors for our bridges, and are they all
4515 bridges_known_but_down(void)
4517 return bridges_retry_helper(0);
4520 /** Mark all down known bridges up. */
4522 bridges_retry_all(void)
4524 bridges_retry_helper(1);
4527 /** Release all storage held by the list of entry guards and related
4528 * memory structs. */
4530 entry_guards_free_all(void)
4533 SMARTLIST_FOREACH(entry_guards
, entry_guard_t
*, e
,
4534 entry_guard_free(e
));
4535 smartlist_free(entry_guards
);
4536 entry_guards
= NULL
;
4538 clear_bridge_list();
4539 smartlist_free(bridge_list
);