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diff --git a/src/transport/gnunet-service-transport_validation.c b/src/transport/gnunet-service-transport_validation.c
deleted file mode 100644
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1/*
2 This file is part of GNUnet.
3 Copyright (C) 2010-2015 GNUnet e.V.
4
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
9
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
14
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17
18 SPDX-License-Identifier: AGPL3.0-or-later
19 */
20
21/**
22 * @file transport/gnunet-service-transport_validation.c
23 * @brief address validation subsystem
24 * @author Christian Grothoff
25 */
26#include "platform.h"
27#include "gnunet-service-transport_ats.h"
28#include "gnunet-service-transport_hello.h"
29#include "gnunet-service-transport_neighbours.h"
30#include "gnunet-service-transport_plugins.h"
31#include "gnunet-service-transport_validation.h"
32#include "gnunet-service-transport.h"
33#include "gnunet_hello_lib.h"
34#include "gnunet_ats_service.h"
35#include "gnunet_peerinfo_service.h"
36#include "gnunet_signatures.h"
37
38/**
39 * Current state of a validation process.
40 *
41 * FIXME: what state is used to indicate that a validation
42 * was successful? If that is clarified/determined, "UGH" in
43 * ~gnunetpeerinfogtk.c:1103 should be resolved.
44 */
45enum GNUNET_TRANSPORT_ValidationState
46{
47 /**
48 * Undefined state
49 *
50 * Used for final callback indicating operation done
51 */
52 GNUNET_TRANSPORT_VS_NONE,
53
54 /**
55 * Fresh validation entry
56 *
57 * Entry was just created, no validation process was executed
58 */
59 GNUNET_TRANSPORT_VS_NEW,
60
61 /**
62 * Updated validation entry
63 *
64 * This is an update for an existing validation entry
65 */
66 GNUNET_TRANSPORT_VS_UPDATE,
67
68 /**
69 * Timeout for validation entry
70 *
71 * A timeout occurred during the validation process
72 */
73 GNUNET_TRANSPORT_VS_TIMEOUT,
74
75 /**
76 * Validation entry is removed
77 *
78 * The validation entry is getting removed due to a failed validation
79 */
80 GNUNET_TRANSPORT_VS_REMOVE
81};
82
83
84/**
85 * How long is a PONG signature valid? We'll recycle a signature until
86 * 1/4 of this time is remaining. PONGs should expire so that if our
87 * external addresses change an adversary cannot replay them indefinitely.
88 * OTOH, we don't want to spend too much time generating PONG signatures,
89 * so they must have some lifetime to reduce our CPU usage.
90 */
91#define PONG_SIGNATURE_LIFETIME GNUNET_TIME_relative_multiply ( \
92 GNUNET_TIME_UNIT_HOURS, 1)
93
94/**
95 * After how long do we expire an address in a HELLO that we just
96 * validated? This value is also used for our own addresses when we
97 * create a HELLO.
98 */
99#define HELLO_ADDRESS_EXPIRATION GNUNET_TIME_relative_multiply ( \
100 GNUNET_TIME_UNIT_HOURS, 12)
101
102/**
103 * How often do we allow PINGing an address that we have not yet
104 * validated? This also determines how long we track an address that
105 * we cannot validate (because after this time we can destroy the
106 * validation record).
107 */
108#define UNVALIDATED_PING_KEEPALIVE GNUNET_TIME_relative_multiply ( \
109 GNUNET_TIME_UNIT_MINUTES, 5)
110
111/**
112 * How often do we PING an address that we have successfully validated
113 * in the past but are not actively using? Should be (significantly)
114 * smaller than HELLO_ADDRESS_EXPIRATION.
115 */
116#define VALIDATED_PING_FREQUENCY GNUNET_TIME_relative_multiply ( \
117 GNUNET_TIME_UNIT_MINUTES, 15)
118
119/**
120 * How often do we PING an address that we are currently using?
121 */
122#define CONNECTED_PING_FREQUENCY GNUNET_TIME_relative_multiply ( \
123 GNUNET_TIME_UNIT_MINUTES, 2)
124
125/**
126 * How much delay is acceptable for sending the PING or PONG?
127 */
128#define ACCEPTABLE_PING_DELAY GNUNET_TIME_relative_multiply ( \
129 GNUNET_TIME_UNIT_SECONDS, 1)
130
131/**
132 * Size of the validation map hashmap.
133 */
134#define VALIDATION_MAP_SIZE 256
135
136/**
137 * Priority to use for PINGs
138 */
139#define PING_PRIORITY 2
140
141/**
142 * Priority to use for PONGs
143 */
144#define PONG_PRIORITY 4
145
146
147GNUNET_NETWORK_STRUCT_BEGIN
148
149/**
150 * Message used to ask a peer to validate receipt (to check an address
151 * from a HELLO). Followed by the address we are trying to validate,
152 * or an empty address if we are just sending a PING to confirm that a
153 * connection which the receiver (of the PING) initiated is still valid.
154 */
155struct TransportPingMessage
156{
157 /**
158 * Type will be #GNUNET_MESSAGE_TYPE_TRANSPORT_PING
159 */
160 struct GNUNET_MessageHeader header;
161
162 /**
163 * Challenge code (to ensure fresh reply).
164 */
165 uint32_t challenge GNUNET_PACKED;
166
167 /**
168 * Who is the intended recipient?
169 */
170 struct GNUNET_PeerIdentity target;
171};
172
173
174/**
175 * Message used to validate a HELLO. The challenge is included in the
176 * confirmation to make matching of replies to requests possible. The
177 * signature signs our public key, an expiration time and our address.<p>
178 *
179 * This message is followed by our transport address that the PING tried
180 * to confirm (if we liked it). The address can be empty (zero bytes)
181 * if the PING had not address either (and we received the request via
182 * a connection that we initiated).
183 */
184struct TransportPongMessage
185{
186 /**
187 * Type will be #GNUNET_MESSAGE_TYPE_TRANSPORT_PONG
188 */
189 struct GNUNET_MessageHeader header;
190
191 /**
192 * Challenge code from PING (showing freshness). Not part of what
193 * is signed so that we can re-use signatures.
194 */
195 uint32_t challenge GNUNET_PACKED;
196
197 /**
198 * Signature.
199 */
200 struct GNUNET_CRYPTO_EddsaSignature signature;
201
202 /**
203 * #GNUNET_SIGNATURE_PURPOSE_TRANSPORT_PONG_OWN to confirm that this is a
204 * plausible address for the signing peer.
205 */
206 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
207
208 /**
209 * When does this signature expire?
210 */
211 struct GNUNET_TIME_AbsoluteNBO expiration;
212
213 /**
214 * Size of address appended to this message (part of what is
215 * being signed, hence not redundant).
216 */
217 uint32_t addrlen GNUNET_PACKED;
218};
219GNUNET_NETWORK_STRUCT_END
220
221/**
222 * Information about an address under validation
223 */
224struct ValidationEntry
225{
226 /**
227 * The address.
228 */
229 struct GNUNET_HELLO_Address *address;
230
231 /**
232 * Handle to the blacklist check (if we're currently in it).
233 */
234 struct GST_BlacklistCheck *bc;
235
236 /**
237 * Cached PONG signature
238 */
239 struct GNUNET_CRYPTO_EddsaSignature pong_sig_cache;
240
241 /**
242 * ID of task that will clean up this entry if nothing happens.
243 */
244 struct GNUNET_SCHEDULER_Task *timeout_task;
245
246 /**
247 * ID of task that will trigger address revalidation.
248 */
249 struct GNUNET_SCHEDULER_Task *revalidation_task;
250
251 /**
252 * At what time did we send the latest validation request (PING)?
253 */
254 struct GNUNET_TIME_Absolute send_time;
255
256 /**
257 * At what time do we send the next validation request (PING)?
258 */
259 struct GNUNET_TIME_Absolute next_validation;
260
261 /**
262 * Until when is this address valid?
263 * ZERO if it is not currently considered valid.
264 */
265 struct GNUNET_TIME_Absolute valid_until;
266
267 /**
268 * Until when is the cached PONG signature valid?
269 * ZERO if it is not currently considered valid.
270 */
271 struct GNUNET_TIME_Absolute pong_sig_valid_until;
272
273 /**
274 * How long until we can try to validate this address again?
275 * FOREVER if the address is for an unsupported plugin (from PEERINFO)
276 * ZERO if the address is considered valid (no validation needed)
277 * otherwise a time in the future if we're currently denying re-validation
278 */
279 struct GNUNET_TIME_Absolute revalidation_block;
280
281 /**
282 * Last observed latency for this address (round-trip), delay between
283 * last PING sent and PONG received; FOREVER if we never got a PONG.
284 */
285 struct GNUNET_TIME_Relative latency;
286
287 /**
288 * Current state of this validation entry
289 */
290 enum GNUNET_TRANSPORT_ValidationState state;
291
292 /**
293 * Challenge number we used.
294 */
295 uint32_t challenge;
296
297 /**
298 * When passing the address in #add_valid_peer_address(), did we
299 * copy the address to the HELLO yet?
300 */
301 int copied;
302
303 /**
304 * Are we currently using this address for a connection?
305 */
306 int in_use;
307
308 /**
309 * Are we expecting a PONG message for this validation entry?
310 */
311 int expecting_pong;
312
313 /**
314 * Is this address known to ATS as valid right now?
315 */
316 int known_to_ats;
317
318 /**
319 * Which network type does our address belong to?
320 */
321 enum GNUNET_NetworkType network;
322};
323
324
325/**
326 * Map of PeerIdentities to 'struct ValidationEntry*'s (addresses
327 * of the given peer that we are currently validating, have validated
328 * or are blocked from re-validation for a while).
329 */
330static struct GNUNET_CONTAINER_MultiPeerMap *validation_map;
331
332/**
333 * Context for peerinfo iteration.
334 */
335static struct GNUNET_PEERINFO_NotifyContext *pnc;
336
337/**
338 * Minimum delay between to validations
339 */
340static struct GNUNET_TIME_Relative validation_delay;
341
342/**
343 * Number of validations running; any PING that was not yet
344 * matched by a PONG and for which we have not yet hit the
345 * timeout is considered a running 'validation'.
346 */
347static unsigned int validations_running;
348
349/**
350 * Validition fast start threshold
351 */
352static unsigned int validations_fast_start_threshold;
353
354/**
355 * When is next validation allowed
356 */
357static struct GNUNET_TIME_Absolute validation_next;
358
359
360/**
361 * Context for the validation entry match function.
362 */
363struct ValidationEntryMatchContext
364{
365 /**
366 * Where to store the result?
367 */
368 struct ValidationEntry *ve;
369
370 /**
371 * Address we're interested in.
372 */
373 const struct GNUNET_HELLO_Address *address;
374};
375
376
377/**
378 * Provide an update on the `validation_map` map size to statistics.
379 * This function should be called whenever the `validation_map`
380 * is changed.
381 */
382static void
383publish_ve_stat_update ()
384{
385 GNUNET_STATISTICS_set (GST_stats,
386 gettext_noop ("# Addresses in validation map"),
387 GNUNET_CONTAINER_multipeermap_size (validation_map),
388 GNUNET_NO);
389}
390
391
392/**
393 * Iterate over validation entries until a matching one is found.
394 *
395 * @param cls the `struct ValidationEntryMatchContext *`
396 * @param key peer identity (unused)
397 * @param value a `struct ValidationEntry *` to match
398 * @return #GNUNET_YES if the entry does not match,
399 * #GNUNET_NO if the entry does match
400 */
401static int
402validation_entry_match (void *cls,
403 const struct GNUNET_PeerIdentity *key,
404 void *value)
405{
406 struct ValidationEntryMatchContext *vemc = cls;
407 struct ValidationEntry *ve = value;
408
409 if (0 == GNUNET_HELLO_address_cmp (ve->address,
410 vemc->address))
411 {
412 vemc->ve = ve;
413 return GNUNET_NO;
414 }
415 return GNUNET_YES;
416}
417
418
419/**
420 * A validation entry changed. Update the state and notify
421 * monitors.
422 *
423 * @param ve validation entry that changed
424 * @param state new state
425 */
426static void
427validation_entry_changed (struct ValidationEntry *ve,
428 enum GNUNET_TRANSPORT_ValidationState state)
429{
430 ve->state = state;
431}
432
433
434/**
435 * Iterate over validation entries and free them.
436 *
437 * @param cls (unused)
438 * @param key peer identity (unused)
439 * @param value a `struct ValidationEntry *` to clean up
440 * @return #GNUNET_YES (continue to iterate)
441 */
442static int
443cleanup_validation_entry (void *cls,
444 const struct GNUNET_PeerIdentity *key,
445 void *value)
446{
447 struct ValidationEntry *ve = value;
448
449 ve->next_validation = GNUNET_TIME_UNIT_ZERO_ABS;
450 ve->valid_until = GNUNET_TIME_UNIT_ZERO_ABS;
451
452 /* Notify about deleted entry */
453 validation_entry_changed (ve,
454 GNUNET_TRANSPORT_VS_REMOVE);
455
456 if (NULL != ve->bc)
457 {
458 GST_blacklist_test_cancel (ve->bc);
459 ve->bc = NULL;
460 }
461 GNUNET_break (GNUNET_OK ==
462 GNUNET_CONTAINER_multipeermap_remove (validation_map,
463 &ve->address->peer,
464 ve));
465 publish_ve_stat_update ();
466 if (GNUNET_YES == ve->known_to_ats)
467 {
468 GST_ats_expire_address (ve->address);
469 GNUNET_assert (GNUNET_NO ==
470 GST_ats_is_known_no_session (ve->address));
471 ve->known_to_ats = GNUNET_NO;
472 }
473 GNUNET_HELLO_address_free (ve->address);
474 if (NULL != ve->timeout_task)
475 {
476 GNUNET_SCHEDULER_cancel (ve->timeout_task);
477 ve->timeout_task = NULL;
478 }
479 if (NULL != ve->revalidation_task)
480 {
481 GNUNET_SCHEDULER_cancel (ve->revalidation_task);
482 ve->revalidation_task = NULL;
483 }
484 if ((GNUNET_YES == ve->expecting_pong) &&
485 (validations_running > 0))
486 {
487 validations_running--;
488 GNUNET_STATISTICS_set (GST_stats,
489 gettext_noop ("# validations running"),
490 validations_running,
491 GNUNET_NO);
492 }
493 GNUNET_free (ve);
494 return GNUNET_OK;
495}
496
497
498/**
499 * Address validation cleanup task. Assesses if the record is no
500 * longer valid and then possibly triggers its removal.
501 *
502 * @param cls the `struct ValidationEntry`
503 */
504static void
505timeout_hello_validation (void *cls)
506{
507 struct ValidationEntry *ve = cls;
508 struct GNUNET_TIME_Absolute max;
509 struct GNUNET_TIME_Relative left;
510
511 ve->timeout_task = NULL;
512 /* For valid addresses, we want to wait until the expire;
513 for addresses under PING validation, we want to wait
514 until we give up on the PING */
515 max = GNUNET_TIME_absolute_max (ve->valid_until,
516 ve->revalidation_block);
517 left = GNUNET_TIME_absolute_get_remaining (max);
518 if (left.rel_value_us > 0)
519 {
520 /* We should wait a bit longer. This happens when
521 address lifetimes are extended due to successful
522 validations. */
523 ve->timeout_task =
524 GNUNET_SCHEDULER_add_delayed (left,
525 &timeout_hello_validation,
526 ve);
527 return;
528 }
529 GNUNET_STATISTICS_update (GST_stats,
530 gettext_noop (
531 "# address records discarded (timeout)"),
532 1,
533 GNUNET_NO);
534 cleanup_validation_entry (NULL,
535 &ve->address->peer,
536 ve);
537}
538
539
540/**
541 * Function called with the result from blacklisting.
542 * Send a PING to the other peer if a communication is allowed.
543 *
544 * @param cls our `struct ValidationEntry`
545 * @param pid identity of the other peer
546 * @param address_null address associated with the request, always NULL
547 * @param session_null session associated with the request, always NULL
548 * @param result #GNUNET_OK if the connection is allowed,
549 * #GNUNET_NO if not,
550 * #GNUNET_SYSERR if operation was aborted
551 */
552static void
553transmit_ping_if_allowed (void *cls,
554 const struct GNUNET_PeerIdentity *pid,
555 const struct GNUNET_HELLO_Address *address_null,
556 struct GNUNET_ATS_Session *session_null,
557 int result)
558{
559 struct ValidationEntry *ve = cls;
560 struct TransportPingMessage ping;
561 struct GNUNET_TRANSPORT_PluginFunctions *papi;
562 struct GNUNET_TIME_Absolute next;
563 const struct GNUNET_MessageHeader *hello;
564 ssize_t ret;
565 size_t tsize;
566 size_t slen;
567 uint16_t hsize;
568 struct GNUNET_ATS_Session *session;
569
570 ve->bc = NULL;
571 if (GNUNET_OK != result)
572 {
573 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
574 "Blacklist denies sending PING to `%s' `%s' `%s'\n",
575 GNUNET_i2s (pid),
576 GST_plugins_a2s (ve->address),
577 ve->address->transport_name);
578 GNUNET_STATISTICS_update (GST_stats,
579 gettext_noop (
580 "# address records discarded (blacklist)"),
581 1,
582 GNUNET_NO);
583 cleanup_validation_entry (NULL,
584 pid,
585 ve);
586 return;
587 }
588 hello = GST_hello_get ();
589 GNUNET_assert (NULL != hello);
590 slen = strlen (ve->address->transport_name) + 1;
591 hsize = ntohs (hello->size);
592 tsize = sizeof(struct TransportPingMessage)
593 + ve->address->address_length + slen + hsize;
594
595 ping.header.size =
596 htons (sizeof(struct TransportPingMessage)
597 + ve->address->address_length + slen);
598 ping.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_PING);
599 ping.challenge = htonl (ve->challenge);
600 ping.target = *pid;
601
602 if (tsize >= GNUNET_MAX_MESSAGE_SIZE)
603 {
604 GNUNET_break (0);
605 hsize = 0;
606 tsize =
607 sizeof(struct TransportPingMessage) + ve->address->address_length
608 + slen + hsize;
609 }
610 {
611 char message_buf[tsize] GNUNET_ALIGN;
612
613 GNUNET_memcpy (message_buf,
614 hello,
615 hsize);
616 GNUNET_memcpy (&message_buf[hsize],
617 &ping,
618 sizeof(struct TransportPingMessage));
619 GNUNET_memcpy (&message_buf[sizeof(struct TransportPingMessage) + hsize],
620 ve->address->transport_name,
621 slen);
622 GNUNET_memcpy (&message_buf[sizeof(struct TransportPingMessage) + slen
623 + hsize],
624 ve->address->address,
625 ve->address->address_length);
626 papi = GST_plugins_find (ve->address->transport_name);
627 GNUNET_assert (NULL != papi);
628 session = papi->get_session (papi->cls,
629 ve->address);
630 if (NULL == session)
631 {
632 /* Could not get a valid session */
633 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
634 "Failed to get session to send PING to `%s' at `%s'\n",
635 GNUNET_i2s (pid),
636 GST_plugins_a2s (ve->address));
637 return;
638 }
639
640 ret = papi->send (papi->cls, session,
641 message_buf, tsize,
642 PING_PRIORITY,
643 ACCEPTABLE_PING_DELAY,
644 NULL, NULL);
645 if (-1 == ret)
646 {
647 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
648 "Failed to send PING to `%s' at `%s'\n",
649 GNUNET_i2s (pid),
650 GST_plugins_a2s (ve->address));
651 return;
652 }
653 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
654 "Transmitted plain PING to `%s' `%s' `%s'\n",
655 GNUNET_i2s (pid),
656 GST_plugins_a2s (ve->address),
657 ve->address->transport_name);
658 ve->network = papi->get_network (papi->cls,
659 session);
660 GNUNET_break (GNUNET_NT_UNSPECIFIED != ve->network);
661 GST_neighbours_notify_data_sent (ve->address,
662 session,
663 tsize);
664 next = GNUNET_TIME_relative_to_absolute (validation_delay);
665 validation_next = GNUNET_TIME_absolute_max (next,
666 validation_next);
667 ve->send_time = GNUNET_TIME_absolute_get ();
668 GNUNET_STATISTICS_update (GST_stats,
669 gettext_noop (
670 "# PINGs for address validation sent"),
671 1,
672 GNUNET_NO);
673 ve->expecting_pong = GNUNET_YES;
674 validations_running++;
675 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
676 "Validation started, %u validation processes running\n",
677 validations_running);
678 GNUNET_STATISTICS_set (GST_stats,
679 gettext_noop ("# validations running"),
680 validations_running,
681 GNUNET_NO);
682 /* Notify about PING sent */
683 validation_entry_changed (ve,
684 GNUNET_TRANSPORT_VS_UPDATE);
685 }
686}
687
688
689/**
690 * Do address validation again to keep address valid.
691 *
692 * @param cls the `struct ValidationEntry`
693 */
694static void
695revalidate_address (void *cls)
696{
697 struct ValidationEntry *ve = cls;
698 struct GNUNET_TIME_Relative canonical_delay;
699 struct GNUNET_TIME_Relative delay;
700 struct GNUNET_TIME_Relative blocked_for;
701 struct GST_BlacklistCheck *bc;
702 uint32_t rdelay;
703
704 ve->revalidation_task = NULL;
705 delay = GNUNET_TIME_absolute_get_remaining (ve->revalidation_block);
706 /* Considering current connectivity situation, what is the maximum
707 block period permitted? */
708 if (GNUNET_YES == ve->in_use)
709 canonical_delay = CONNECTED_PING_FREQUENCY;
710 else if (GNUNET_TIME_absolute_get_remaining (ve->valid_until).rel_value_us >
711 0)
712 canonical_delay = VALIDATED_PING_FREQUENCY;
713 else
714 canonical_delay = UNVALIDATED_PING_KEEPALIVE;
715 /* Use delay that is MIN of original delay and possibly adjusted
716 new maximum delay (which may be lower); the real delay
717 is originally randomized between "canonical_delay" and "2 * canonical_delay",
718 so continue to permit that window for the operation. */
719 delay = GNUNET_TIME_relative_min (delay,
720 GNUNET_TIME_relative_multiply (
721 canonical_delay,
722 2));
723 ve->revalidation_block = GNUNET_TIME_relative_to_absolute (delay);
724 if (delay.rel_value_us > 0)
725 {
726 /* should wait a bit longer */
727 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
728 "Waiting for %s longer before (re)validating address `%s'\n",
729 GNUNET_STRINGS_relative_time_to_string (delay,
730 GNUNET_YES),
731 GST_plugins_a2s (ve->address));
732 ve->revalidation_task =
733 GNUNET_SCHEDULER_add_delayed (delay,
734 &revalidate_address, ve);
735 ve->next_validation = GNUNET_TIME_relative_to_absolute (delay);
736 return;
737 }
738 /* check if globally we have too many active validations at a
739 too high rate, if so, delay ours */
740 blocked_for = GNUNET_TIME_absolute_get_remaining (validation_next);
741 if ((validations_running > validations_fast_start_threshold) &&
742 (blocked_for.rel_value_us > 0))
743 {
744 /* Validations are blocked, have to wait for blocked_for time */
745 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
746 "Validations blocked for another %s, delaying validating address `%s'\n",
747 GNUNET_STRINGS_relative_time_to_string (blocked_for,
748 GNUNET_YES),
749 GST_plugins_a2s (ve->address));
750 GNUNET_STATISTICS_update (GST_stats,
751 gettext_noop (
752 "# validations delayed by global throttle"),
753 1,
754 GNUNET_NO);
755 ve->revalidation_task =
756 GNUNET_SCHEDULER_add_delayed (blocked_for,
757 &revalidate_address,
758 ve);
759 ve->next_validation = GNUNET_TIME_relative_to_absolute (blocked_for);
760 return;
761 }
762
763 /* We are good to go; remember to not go again for `canonical_delay` time;
764 add up to `canonical_delay` to randomize start time */
765 ve->revalidation_block = GNUNET_TIME_relative_to_absolute (canonical_delay);
766 /* schedule next PINGing with some extra random delay to avoid synchronous re-validations */
767 rdelay =
768 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
769 canonical_delay.rel_value_us);
770
771 delay = GNUNET_TIME_relative_add (canonical_delay,
772 GNUNET_TIME_relative_multiply
773 (GNUNET_TIME_UNIT_MICROSECONDS,
774 rdelay));
775
776 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
777 "Validating now, next scheduled for %s, now validating address `%s'\n",
778 GNUNET_STRINGS_relative_time_to_string (blocked_for,
779 GNUNET_YES),
780 GST_plugins_a2s (ve->address));
781 ve->revalidation_task =
782 GNUNET_SCHEDULER_add_delayed (delay,
783 &revalidate_address,
784 ve);
785 ve->next_validation = GNUNET_TIME_relative_to_absolute (delay);
786
787 /* start PINGing by checking blacklist */
788 GNUNET_STATISTICS_update (GST_stats,
789 gettext_noop ("# address revalidations started"), 1,
790 GNUNET_NO);
791 if (NULL != ve->bc)
792 {
793 GST_blacklist_test_cancel (ve->bc);
794 ve->bc = NULL;
795 }
796 bc = GST_blacklist_test_allowed (&ve->address->peer,
797 ve->address->transport_name,
798 &transmit_ping_if_allowed,
799 ve,
800 NULL,
801 NULL);
802 if (NULL != bc)
803 {
804 /* If transmit_ping_if_allowed was already called it may have freed ve,
805 * so only set ve->bc if it has not been called.
806 */
807 ve->bc = bc;
808 }
809}
810
811
812/**
813 * Find a ValidationEntry entry for the given neighbour that matches
814 * the given address and transport. If none exists, create one (but
815 * without starting any validation).
816 *
817 * @param address address to find
818 * @return validation entry matching the given specifications, NULL
819 * if we don't have an existing entry and no public key was given
820 */
821static struct ValidationEntry *
822find_validation_entry (const struct GNUNET_HELLO_Address *address)
823{
824 struct ValidationEntryMatchContext vemc;
825 struct ValidationEntry *ve;
826
827 vemc.ve = NULL;
828 vemc.address = address;
829 GNUNET_CONTAINER_multipeermap_get_multiple (validation_map,
830 &address->peer,
831 &validation_entry_match, &vemc);
832 if (NULL != (ve = vemc.ve))
833 return ve;
834 GNUNET_assert (GNUNET_NO ==
835 GST_ats_is_known_no_session (address));
836 ve = GNUNET_new (struct ValidationEntry);
837 ve->in_use = GNUNET_SYSERR; /* not defined */
838 ve->address = GNUNET_HELLO_address_copy (address);
839 ve->pong_sig_valid_until = GNUNET_TIME_UNIT_ZERO_ABS;
840 memset (&ve->pong_sig_cache,
841 '\0',
842 sizeof(struct GNUNET_CRYPTO_EddsaSignature));
843 ve->latency = GNUNET_TIME_UNIT_FOREVER_REL;
844 ve->challenge =
845 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
846 ve->timeout_task =
847 GNUNET_SCHEDULER_add_delayed (UNVALIDATED_PING_KEEPALIVE,
848 &timeout_hello_validation,
849 ve);
850 GNUNET_CONTAINER_multipeermap_put (validation_map,
851 &address->peer,
852 ve,
853 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
854 publish_ve_stat_update ();
855 validation_entry_changed (ve,
856 GNUNET_TRANSPORT_VS_NEW);
857 return ve;
858}
859
860
861/**
862 * Iterator which adds the given address to the set of validated
863 * addresses.
864 *
865 * @param cls original HELLO message
866 * @param address the address
867 * @param expiration expiration time
868 * @return #GNUNET_OK (keep the address), could return
869 * #GNUNET_NO (delete address, but this is ignored);
870 * #GNUNET_SYSERR would abort iteration (but we always iterate all)
871 */
872static int
873add_valid_address (void *cls,
874 const struct GNUNET_HELLO_Address *address,
875 struct GNUNET_TIME_Absolute expiration)
876{
877 const struct GNUNET_HELLO_Message *hello = cls;
878 struct ValidationEntry *ve;
879 struct GNUNET_PeerIdentity pid;
880 struct GNUNET_ATS_Properties prop;
881 struct GNUNET_TRANSPORT_PluginFunctions *papi;
882
883 if (0 == GNUNET_TIME_absolute_get_remaining (expiration).rel_value_us)
884 return GNUNET_OK; /* expired */
885 if (GNUNET_OK != GNUNET_HELLO_get_id (hello, &pid))
886 {
887 GNUNET_break (0);
888 return GNUNET_OK; /* invalid HELLO !? */
889 }
890 if (NULL == (papi = GST_plugins_find (address->transport_name)))
891 {
892 /* might have been valid in the past, but we don't have that
893 plugin loaded right now */
894 return GNUNET_OK;
895 }
896 if (NULL ==
897 papi->address_to_string (papi->cls,
898 address->address,
899 address->address_length))
900 {
901 /* Why do we try to add an ill-formed address? */
902 GNUNET_break (0);
903 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
904 "Address with %u bytes for plugin %s and peer %s is malformed\n",
905 (unsigned int) address->address_length,
906 address->transport_name,
907 GNUNET_i2s (&pid));
908 return GNUNET_OK;
909 }
910
911 ve = find_validation_entry (address);
912 ve->network = papi->get_network_for_address (papi->cls,
913 address);
914 GNUNET_break (GNUNET_NT_UNSPECIFIED != ve->network);
915 ve->valid_until = GNUNET_TIME_absolute_max (ve->valid_until,
916 expiration);
917 if (NULL == ve->revalidation_task)
918 {
919 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
920 "Starting revalidations for valid address `%s'\n",
921 GST_plugins_a2s (ve->address));
922 ve->next_validation = GNUNET_TIME_absolute_get ();
923 ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
924 }
925 validation_entry_changed (ve,
926 GNUNET_TRANSPORT_VS_UPDATE);
927 memset (&prop, 0, sizeof(prop));
928 prop.scope = ve->network;
929 prop.delay = GNUNET_TIME_relative_divide (ve->latency, 2);
930 if (GNUNET_YES != ve->known_to_ats)
931 {
932 ve->known_to_ats = GNUNET_YES;
933 GST_ats_add_address (address, &prop);
934 GNUNET_assert (GNUNET_YES ==
935 GST_ats_is_known_no_session (ve->address));
936 }
937 return GNUNET_OK;
938}
939
940
941/**
942 * Function called for any HELLO known to PEERINFO.
943 *
944 * @param cls unused (NULL)
945 * @param peer id of the peer, NULL for last call (during iteration,
946 * as we are monitoring, this should never happen)
947 * @param hello hello message for the peer (can be NULL)
948 * @param err_msg error message
949 */
950static void
951process_peerinfo_hello (void *cls,
952 const struct GNUNET_PeerIdentity *peer,
953 const struct GNUNET_HELLO_Message *hello,
954 const char *err_msg)
955{
956 GNUNET_assert (NULL != peer);
957 if (NULL == hello)
958 return;
959 if (0 == memcmp (&GST_my_identity,
960 peer,
961 sizeof(struct GNUNET_PeerIdentity)))
962 {
963 /* Peerinfo returned own identity, skip validation */
964 return;
965 }
966 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
967 "Handling HELLO for peer `%s'\n",
968 GNUNET_i2s (peer));
969 GNUNET_assert (NULL ==
970 GNUNET_HELLO_iterate_addresses (hello, GNUNET_NO,
971 &add_valid_address,
972 (void *) hello));
973}
974
975
976/**
977 * Start the validation subsystem.
978 *
979 * @param max_fds maximum number of fds to use
980 */
981void
982GST_validation_start (unsigned int max_fds)
983{
984 /**
985 * Initialization for validation throttling
986 *
987 * We have a maximum number max_fds of connections we can use for validation
988 * We monitor the number of validations in parallel and start to throttle it
989 * when doing to many validations in parallel:
990 * if (running validations < (max_fds / 2))
991 * - "fast start": run validation immediately
992 * - have delay of (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT.rel_value_us) / (max_fds / 2)
993 * (300 sec / ~150 == ~2 sec.) between two validations
994 */validation_next = GNUNET_TIME_absolute_get ();
995 validation_delay.rel_value_us =
996 (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT.rel_value_us) / (max_fds / 2);
997 validations_fast_start_threshold = (max_fds / 2);
998 validations_running = 0;
999 GNUNET_STATISTICS_set (GST_stats,
1000 gettext_noop ("# validations running"),
1001 validations_running,
1002 GNUNET_NO);
1003 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1004 "Validation uses a fast start threshold of %u connections and a delay of %s\n",
1005 validations_fast_start_threshold,
1006 GNUNET_STRINGS_relative_time_to_string (validation_delay,
1007 GNUNET_YES));
1008 validation_map = GNUNET_CONTAINER_multipeermap_create (VALIDATION_MAP_SIZE,
1009 GNUNET_NO);
1010 pnc = GNUNET_PEERINFO_notify (GST_cfg, GNUNET_YES,
1011 &process_peerinfo_hello, NULL);
1012}
1013
1014
1015/**
1016 * Stop the validation subsystem.
1017 */
1018void
1019GST_validation_stop ()
1020{
1021 GNUNET_CONTAINER_multipeermap_iterate (validation_map,
1022 &cleanup_validation_entry,
1023 NULL);
1024 GNUNET_CONTAINER_multipeermap_destroy (validation_map);
1025 validation_map = NULL;
1026 GNUNET_PEERINFO_notify_cancel (pnc);
1027}
1028
1029
1030/**
1031 * Send the given PONG to the given address.
1032 *
1033 * @param cls the PONG message
1034 * @param valid_until is ZERO if we never validated the address,
1035 * otherwise a time up to when we consider it (or was) valid
1036 * @param validation_block is FOREVER if the address is for an unsupported plugin (from PEERINFO)
1037 * is ZERO if the address is considered valid (no validation needed)
1038 * otherwise a time in the future if we're currently denying re-validation
1039 * @param address target address
1040 */
1041static void
1042multicast_pong (void *cls,
1043 struct GNUNET_TIME_Absolute valid_until,
1044 struct GNUNET_TIME_Absolute validation_block,
1045 const struct GNUNET_HELLO_Address *address)
1046{
1047 struct TransportPongMessage *pong = cls;
1048 struct GNUNET_TRANSPORT_PluginFunctions *papi;
1049 struct GNUNET_ATS_Session *session;
1050
1051 papi = GST_plugins_find (address->transport_name);
1052 if (NULL == papi)
1053 {
1054 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1055 "Plugin %s not supported, cannot send PONG\n",
1056 address->transport_name);
1057 return;
1058 }
1059 GNUNET_assert (NULL != papi->send);
1060 GNUNET_assert (NULL != papi->get_session);
1061 session = papi->get_session (papi->cls, address);
1062 if (NULL == session)
1063 {
1064 GNUNET_break (0);
1065 return;
1066 }
1067 GST_ats_new_session (address, session);
1068 papi->send (papi->cls, session,
1069 (const char *) pong,
1070 ntohs (pong->header.size),
1071 PONG_PRIORITY,
1072 ACCEPTABLE_PING_DELAY,
1073 NULL, NULL);
1074 GST_neighbours_notify_data_sent (address,
1075 session,
1076 pong->header.size);
1077}
1078
1079
1080/**
1081 * We've received a PING. If appropriate, generate a PONG.
1082 *
1083 * @param sender peer sending the PING
1084 * @param hdr the PING
1085 * @param sender_address the sender address as we got it
1086 * @param session session we got the PING from
1087 * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
1088 */
1089int
1090GST_validation_handle_ping (const struct GNUNET_PeerIdentity *sender,
1091 const struct GNUNET_MessageHeader *hdr,
1092 const struct GNUNET_HELLO_Address *sender_address,
1093 struct GNUNET_ATS_Session *session)
1094{
1095 const struct TransportPingMessage *ping;
1096 struct TransportPongMessage *pong;
1097 struct GNUNET_TRANSPORT_PluginFunctions *papi;
1098 struct GNUNET_CRYPTO_EddsaSignature *sig_cache;
1099 struct GNUNET_TIME_Absolute *sig_cache_exp;
1100 const char *addr;
1101 const char *addrend;
1102 char *plugin_name;
1103 char *pos;
1104 size_t len_address;
1105 size_t len_plugin;
1106 ssize_t ret;
1107 struct GNUNET_HELLO_Address address;
1108
1109 if (0 ==
1110 memcmp (&GST_my_identity,
1111 sender,
1112 sizeof(struct GNUNET_PeerIdentity)))
1113 return GNUNET_OK; /* our own, ignore! */
1114 if (ntohs (hdr->size) < sizeof(struct TransportPingMessage))
1115 {
1116 GNUNET_break_op (0);
1117 return GNUNET_SYSERR;
1118 }
1119 ping = (const struct TransportPingMessage *) hdr;
1120 if (0 !=
1121 memcmp (&ping->target,
1122 &GST_my_identity,
1123 sizeof(struct GNUNET_PeerIdentity)))
1124 {
1125 GNUNET_STATISTICS_update (GST_stats,
1126 gettext_noop
1127 ("# PING message for different peer received"),
1128 1,
1129 GNUNET_NO);
1130 return GNUNET_SYSERR;
1131 }
1132 GNUNET_STATISTICS_update (GST_stats,
1133 gettext_noop ("# PING messages received"), 1,
1134 GNUNET_NO);
1135 addr = (const char *) &ping[1];
1136 len_address = ntohs (hdr->size) - sizeof(struct TransportPingMessage);
1137 /* peer wants to confirm that this is one of our addresses, this is what is
1138 * used for address validation */
1139
1140 sig_cache = NULL;
1141 sig_cache_exp = NULL;
1142 papi = NULL;
1143 if (len_address > 0)
1144 {
1145 addrend = memchr (addr, '\0', len_address);
1146 if (NULL == addrend)
1147 {
1148 GNUNET_break_op (0);
1149 return GNUNET_SYSERR;
1150 }
1151 addrend++;
1152 len_plugin = strlen (addr) + 1;
1153 len_address -= len_plugin;
1154 address.local_info = GNUNET_HELLO_ADDRESS_INFO_NONE;
1155 address.address = addrend;
1156 address.address_length = len_address;
1157 address.transport_name = addr;
1158 address.peer = GST_my_identity;
1159
1160 if (NULL == address.transport_name)
1161 {
1162 GNUNET_break (0);
1163 }
1164
1165 if (0 != strstr (address.transport_name, "_client"))
1166 {
1167 plugin_name = GNUNET_strdup (address.transport_name);
1168 pos = strstr (plugin_name, "_client");
1169 GNUNET_assert (NULL != pos);
1170 GNUNET_snprintf (pos, strlen ("_server") + 1, "%s", "_server");
1171 }
1172 else
1173 plugin_name = GNUNET_strdup (address.transport_name);
1174
1175 if (NULL == (papi = GST_plugins_find (plugin_name)))
1176 {
1177 /* we don't have the plugin for this address */
1178 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1179 _ (
1180 "Plugin `%s' not available, cannot confirm having this address\n"),
1181 plugin_name);
1182 GNUNET_free (plugin_name);
1183 return GNUNET_SYSERR;
1184 }
1185 GNUNET_free (plugin_name);
1186 if (GNUNET_OK !=
1187 papi->check_address (papi->cls,
1188 addrend,
1189 len_address))
1190 {
1191 GNUNET_STATISTICS_update (GST_stats,
1192 gettext_noop
1193 ("# failed address checks during validation"),
1194 1,
1195 GNUNET_NO);
1196 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1197 _ (
1198 "Address `%s' is not one of my addresses, not confirming PING\n"),
1199 GST_plugins_a2s (&address));
1200 return GNUNET_SYSERR;
1201 }
1202 else
1203 {
1204 GNUNET_STATISTICS_update (GST_stats,
1205 gettext_noop
1206 (
1207 "# successful address checks during validation"),
1208 1,
1209 GNUNET_NO);
1210 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1211 "Address `%s' is one of my addresses, confirming PING\n",
1212 GST_plugins_a2s (&address));
1213 }
1214
1215 if (GNUNET_YES !=
1216 GST_hello_test_address (&address,
1217 &sig_cache,
1218 &sig_cache_exp))
1219 {
1220 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1221 _ (
1222 "Not confirming PING from peer `%s' with address `%s' since I cannot confirm having this address.\n"),
1223 GNUNET_i2s (sender),
1224 GST_plugins_a2s (&address));
1225 return GNUNET_SYSERR;
1226 }
1227 }
1228 else
1229 {
1230 addrend = NULL; /* make gcc happy */
1231 len_plugin = 0;
1232 static struct GNUNET_CRYPTO_EddsaSignature no_address_signature;
1233 static struct GNUNET_TIME_Absolute no_address_signature_expiration;
1234
1235 sig_cache = &no_address_signature;
1236 sig_cache_exp = &no_address_signature_expiration;
1237 }
1238
1239 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1240 "I am `%s', sending PONG to peer `%s'\n",
1241 GNUNET_i2s_full (&GST_my_identity),
1242 GNUNET_i2s (sender));
1243
1244 /* message with structure:
1245 * [TransportPongMessage][Transport name][Address] */
1246
1247 pong = GNUNET_malloc (sizeof(struct TransportPongMessage) + len_address
1248 + len_plugin);
1249 pong->header.size =
1250 htons (sizeof(struct TransportPongMessage) + len_address + len_plugin);
1251 pong->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_PONG);
1252 pong->purpose.size =
1253 htonl (sizeof(struct GNUNET_CRYPTO_EccSignaturePurpose)
1254 + sizeof(uint32_t) + sizeof(struct GNUNET_TIME_AbsoluteNBO)
1255 + len_address + len_plugin);
1256 pong->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_TRANSPORT_PONG_OWN);
1257 GNUNET_memcpy (&pong->challenge, &ping->challenge, sizeof(ping->challenge));
1258 pong->addrlen = htonl (len_address + len_plugin);
1259 GNUNET_memcpy (&pong[1], addr, len_plugin); /* Copy transport plugin */
1260 if (len_address > 0)
1261 {
1262 GNUNET_assert (NULL != addrend);
1263 GNUNET_memcpy (&((char *) &pong[1])[len_plugin], addrend, len_address);
1264 }
1265 if (GNUNET_TIME_absolute_get_remaining (*sig_cache_exp).rel_value_us <
1266 PONG_SIGNATURE_LIFETIME.rel_value_us / 4)
1267 {
1268 /* create / update cached sig */
1269 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1270 "Creating PONG signature to indicate ownership.\n");
1271 *sig_cache_exp = GNUNET_TIME_relative_to_absolute (PONG_SIGNATURE_LIFETIME);
1272 pong->expiration = GNUNET_TIME_absolute_hton (*sig_cache_exp);
1273 if (GNUNET_OK !=
1274 GNUNET_CRYPTO_eddsa_sign_ (&GST_my_private_key,
1275 &pong->purpose,
1276 sig_cache))
1277 {
1278 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1279 _ ("Failed to create PONG signature for peer `%s'\n"),
1280 GNUNET_i2s (sender));
1281 }
1282 }
1283 else
1284 {
1285 pong->expiration = GNUNET_TIME_absolute_hton (*sig_cache_exp);
1286 }
1287 pong->signature = *sig_cache;
1288
1289 GNUNET_assert (NULL != sender_address);
1290
1291 /* first see if the session we got this PING from can be used to transmit
1292 * a response reliably */
1293 if (NULL == papi)
1294 {
1295 ret = -1;
1296 }
1297 else
1298 {
1299 GNUNET_assert (NULL != papi->send);
1300 GNUNET_assert (NULL != papi->get_session);
1301 if (NULL == session)
1302 {
1303 session = papi->get_session (papi->cls, sender_address);
1304 }
1305 if (NULL == session)
1306 {
1307 GNUNET_break (0);
1308 ret = -1;
1309 }
1310 else
1311 {
1312 ret = papi->send (papi->cls, session,
1313 (const char *) pong,
1314 ntohs (pong->header.size),
1315 PONG_PRIORITY, ACCEPTABLE_PING_DELAY,
1316 NULL, NULL);
1317 if (-1 != ret)
1318 GST_neighbours_notify_data_sent (sender_address,
1319 session,
1320 pong->header.size);
1321 }
1322 }
1323 if (-1 != ret)
1324 {
1325 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1326 "Transmitted PONG to `%s' via reliable mechanism\n",
1327 GNUNET_i2s (sender));
1328 /* done! */
1329 GNUNET_STATISTICS_update (GST_stats,
1330 gettext_noop
1331 ("# PONGs unicast via reliable transport"), 1,
1332 GNUNET_NO);
1333 GNUNET_free (pong);
1334 return GNUNET_OK;
1335 }
1336
1337 /* no reliable method found, try transmission via all known addresses */
1338 GNUNET_STATISTICS_update (GST_stats,
1339 gettext_noop
1340 ("# PONGs multicast to all available addresses"),
1341 1,
1342 GNUNET_NO);
1343 GST_validation_get_addresses (sender,
1344 &multicast_pong, pong);
1345 GNUNET_free (pong);
1346 return GNUNET_OK;
1347}
1348
1349
1350/**
1351 * Validate an individual address.
1352 *
1353 * @param address address we should try to validate
1354 */
1355void
1356GST_validation_handle_address (const struct GNUNET_HELLO_Address *address)
1357{
1358 struct GNUNET_TRANSPORT_PluginFunctions *papi;
1359 struct ValidationEntry *ve;
1360
1361 papi = GST_plugins_find (address->transport_name);
1362 if (NULL == papi)
1363 {
1364 /* This plugin is currently unavailable ... ignore */
1365 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1366 "No plugin available for %s\n",
1367 address->transport_name);
1368 return;
1369 }
1370 ve = find_validation_entry (address);
1371 if (NULL == ve->revalidation_task)
1372 {
1373 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1374 "Validation process started for fresh address `%s' of %s\n",
1375 GST_plugins_a2s (ve->address),
1376 GNUNET_i2s (&ve->address->peer));
1377 ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
1378 }
1379 else
1380 {
1381 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1382 "Validation already running for address `%s' of %s\n",
1383 GST_plugins_a2s (ve->address),
1384 GNUNET_i2s (&ve->address->peer));
1385 }
1386}
1387
1388
1389/**
1390 * Iterator callback to go over all addresses and try to validate them
1391 * (unless blocked or already validated).
1392 *
1393 * @param cls NULL
1394 * @param address the address
1395 * @param expiration expiration time
1396 * @return #GNUNET_OK (keep the address)
1397 */
1398static int
1399validate_address_iterator (void *cls,
1400 const struct GNUNET_HELLO_Address *address,
1401 struct GNUNET_TIME_Absolute expiration)
1402{
1403 if (0 == GNUNET_TIME_absolute_get_remaining (expiration).rel_value_us)
1404 {
1405 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1406 "Skipping expired address from HELLO\n");
1407 return GNUNET_OK; /* expired */
1408 }
1409 GST_validation_handle_address (address);
1410 return GNUNET_OK;
1411}
1412
1413
1414/**
1415 * Add the validated peer address to the HELLO.
1416 *
1417 * @param cls the `struct ValidationEntry *` with the validated address
1418 * @param max space in @a buf
1419 * @param buf where to add the address
1420 * @return number of bytes written, #GNUNET_SYSERR to signal the
1421 * end of the iteration.
1422 */
1423static ssize_t
1424add_valid_peer_address (void *cls,
1425 size_t max,
1426 void *buf)
1427{
1428 struct ValidationEntry *ve = cls;
1429
1430 if (GNUNET_YES == ve->copied)
1431 return GNUNET_SYSERR; /* Done */
1432 ve->copied = GNUNET_YES;
1433 return GNUNET_HELLO_add_address (ve->address,
1434 ve->valid_until,
1435 buf,
1436 max);
1437}
1438
1439
1440/**
1441 * We've received a PONG. Check if it matches a pending PING and
1442 * mark the respective address as confirmed.
1443 *
1444 * @param sender peer sending the PONG
1445 * @param hdr the PONG
1446 * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
1447 */
1448int
1449GST_validation_handle_pong (const struct GNUNET_PeerIdentity *sender,
1450 const struct GNUNET_MessageHeader *hdr)
1451{
1452 const struct TransportPongMessage *pong;
1453 struct ValidationEntry *ve;
1454 const char *tname;
1455 const char *addr;
1456 size_t addrlen;
1457 size_t slen;
1458 size_t size;
1459 struct GNUNET_HELLO_Message *hello;
1460 struct GNUNET_HELLO_Address address;
1461 int sig_res;
1462 int do_verify;
1463
1464 if (0 ==
1465 memcmp (&GST_my_identity,
1466 sender,
1467 sizeof(struct GNUNET_PeerIdentity)))
1468 return GNUNET_OK; /* our own, ignore! */
1469
1470 if (ntohs (hdr->size) < sizeof(struct TransportPongMessage))
1471 {
1472 GNUNET_break_op (0);
1473 return GNUNET_SYSERR;
1474 }
1475 GNUNET_STATISTICS_update (GST_stats,
1476 gettext_noop ("# PONG messages received"), 1,
1477 GNUNET_NO);
1478
1479 /* message with structure:
1480 * [TransportPongMessage][Transport name][Address] */
1481
1482 pong = (const struct TransportPongMessage *) hdr;
1483 tname = (const char *) &pong[1];
1484 size = ntohs (hdr->size) - sizeof(struct TransportPongMessage);
1485 addr = memchr (tname, '\0', size);
1486 if (NULL == addr)
1487 {
1488 GNUNET_break_op (0);
1489 return GNUNET_SYSERR;
1490 }
1491 addr++;
1492 slen = strlen (tname) + 1;
1493 addrlen = size - slen;
1494
1495 if (NULL == GST_plugins_find (tname))
1496 {
1497 /* we got the PONG, but the transport plugin specified in it
1498 is not supported by this peer, so this cannot be a good
1499 PONG for us. */
1500 GNUNET_break_op (0);
1501 return GNUNET_OK;
1502 }
1503
1504 address.peer = *sender;
1505 address.address = addr;
1506 address.address_length = addrlen;
1507 address.transport_name = tname;
1508 address.local_info = GNUNET_HELLO_ADDRESS_INFO_NONE;
1509 ve = find_validation_entry (&address);
1510 if ((NULL == ve) || (GNUNET_NO == ve->expecting_pong))
1511 {
1512 GNUNET_STATISTICS_update (GST_stats,
1513 gettext_noop
1514 (
1515 "# PONGs dropped, no matching pending validation"),
1516 1, GNUNET_NO);
1517 return GNUNET_OK;
1518 }
1519 /* now check that PONG is well-formed */
1520 if (0 != memcmp (&ve->address->peer,
1521 sender,
1522 sizeof(struct GNUNET_PeerIdentity)))
1523 {
1524 GNUNET_break_op (0);
1525 return GNUNET_SYSERR;
1526 }
1527 if (0 ==
1528 GNUNET_TIME_absolute_get_remaining
1529 (GNUNET_TIME_absolute_ntoh (pong->expiration)).rel_value_us)
1530 {
1531 GNUNET_STATISTICS_update (GST_stats,
1532 gettext_noop
1533 ("# PONGs dropped, signature expired"), 1,
1534 GNUNET_NO);
1535 return GNUNET_SYSERR;
1536 }
1537
1538 sig_res = GNUNET_SYSERR;
1539 do_verify = GNUNET_YES;
1540 if (0 != GNUNET_TIME_absolute_get_remaining (
1541 ve->pong_sig_valid_until).rel_value_us)
1542 {
1543 /* We have a cached and valid signature for this peer,
1544 * try to compare instead of verify */
1545 if (0 == memcmp (&ve->pong_sig_cache,
1546 &pong->signature,
1547 sizeof(struct GNUNET_CRYPTO_EddsaSignature)))
1548 {
1549 /* signatures are identical, we can skip verification */
1550 sig_res = GNUNET_OK;
1551 do_verify = GNUNET_NO;
1552 }
1553 else
1554 {
1555 sig_res = GNUNET_SYSERR;
1556 /* signatures do not match, we have to verify */
1557 }
1558 }
1559
1560 if (GNUNET_YES == do_verify)
1561 {
1562 /* Do expensive verification */
1563 sig_res = GNUNET_CRYPTO_eddsa_verify_ (
1564 GNUNET_SIGNATURE_PURPOSE_TRANSPORT_PONG_OWN,
1565 &pong->purpose,
1566 &pong->signature,
1567 &ve->address->peer.public_key);
1568 if (sig_res == GNUNET_SYSERR)
1569 {
1570 GNUNET_break_op (0);
1571 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1572 "Failed to verify: invalid signature on address `%s':%s from peer `%s'\n",
1573 tname,
1574 GST_plugins_a2s (ve->address),
1575 GNUNET_i2s (sender));
1576 }
1577 }
1578 if (sig_res == GNUNET_SYSERR)
1579 {
1580 GNUNET_break_op (0);
1581 return GNUNET_SYSERR;
1582 }
1583
1584 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1585 "Validation process successful for peer `%s' with plugin `%s' address `%s'\n",
1586 GNUNET_i2s (sender),
1587 tname,
1588 GST_plugins_a2s (ve->address));
1589 GNUNET_STATISTICS_update (GST_stats,
1590 gettext_noop ("# validations succeeded"),
1591 1,
1592 GNUNET_NO);
1593 /* validity achieved, remember it! */
1594 ve->expecting_pong = GNUNET_NO;
1595 ve->valid_until = GNUNET_TIME_relative_to_absolute (HELLO_ADDRESS_EXPIRATION);
1596 ve->pong_sig_cache = pong->signature;
1597 ve->pong_sig_valid_until = GNUNET_TIME_absolute_ntoh (pong->expiration);
1598 ve->latency = GNUNET_TIME_absolute_get_duration (ve->send_time);
1599 {
1600 if (GNUNET_YES == ve->known_to_ats)
1601 {
1602 GNUNET_assert (GNUNET_YES ==
1603 GST_ats_is_known_no_session (ve->address));
1604 GST_ats_update_delay (ve->address,
1605 GNUNET_TIME_relative_divide (ve->latency, 2));
1606 }
1607 else
1608 {
1609 struct GNUNET_ATS_Properties prop;
1610
1611 memset (&prop, 0, sizeof(prop));
1612 GNUNET_break (GNUNET_NT_UNSPECIFIED != ve->network);
1613 prop.scope = ve->network;
1614 prop.delay = GNUNET_TIME_relative_divide (ve->latency, 2);
1615 GNUNET_assert (GNUNET_NO ==
1616 GST_ats_is_known_no_session (ve->address));
1617 ve->known_to_ats = GNUNET_YES;
1618 GST_ats_add_address (ve->address, &prop);
1619 GNUNET_assert (GNUNET_YES ==
1620 GST_ats_is_known_no_session (ve->address));
1621 }
1622 }
1623 if (validations_running > 0)
1624 {
1625 validations_running--;
1626 GNUNET_STATISTICS_set (GST_stats,
1627 gettext_noop ("# validations running"),
1628 validations_running,
1629 GNUNET_NO);
1630 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1631 "Validation finished, %u validation processes running\n",
1632 validations_running);
1633 }
1634 else
1635 {
1636 GNUNET_break (0);
1637 }
1638
1639 /* Notify about new validity */
1640 validation_entry_changed (ve,
1641 GNUNET_TRANSPORT_VS_UPDATE);
1642
1643 /* build HELLO to store in PEERINFO */
1644 GNUNET_STATISTICS_update (GST_stats,
1645 gettext_noop ("# HELLOs given to peerinfo"),
1646 1,
1647 GNUNET_NO);
1648 ve->copied = GNUNET_NO;
1649 hello = GNUNET_HELLO_create (&ve->address->peer.public_key,
1650 &add_valid_peer_address,
1651 ve,
1652 GNUNET_NO);
1653 GNUNET_break (NULL !=
1654 GNUNET_PEERINFO_add_peer (GST_peerinfo,
1655 hello,
1656 NULL,
1657 NULL));
1658 GNUNET_free (hello);
1659 return GNUNET_OK;
1660}
1661
1662
1663/**
1664 * We've received a HELLO, check which addresses are new and trigger
1665 * validation.
1666 *
1667 * @param hello the HELLO we received
1668 * @return #GNUNET_OK if the message was fine, #GNUNET_SYSERR on serious error
1669 */
1670int
1671GST_validation_handle_hello (const struct GNUNET_MessageHeader *hello)
1672{
1673 const struct GNUNET_HELLO_Message *hm =
1674 (const struct GNUNET_HELLO_Message *) hello;
1675 struct GNUNET_PeerIdentity pid;
1676 int friend;
1677
1678 friend = GNUNET_HELLO_is_friend_only (hm);
1679 if (((GNUNET_YES != friend) &&
1680 (GNUNET_NO != friend)) ||
1681 (GNUNET_OK != GNUNET_HELLO_get_id (hm, &pid)))
1682 {
1683 /* malformed HELLO */
1684 GNUNET_break_op (0);
1685 return GNUNET_SYSERR;
1686 }
1687 if (0 ==
1688 memcmp (&GST_my_identity,
1689 &pid,
1690 sizeof(struct GNUNET_PeerIdentity)))
1691 {
1692 /* got our own HELLO, how boring */
1693 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1694 "Validation received our own HELLO (%s), ignoring\n",
1695 GNUNET_i2s (&pid));
1696 return GNUNET_OK;
1697 }
1698 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1699 "Validation received HELLO message for peer `%s' with size %u, checking for new addresses\n",
1700 GNUNET_i2s (&pid),
1701 ntohs (hello->size));
1702 GNUNET_assert (NULL ==
1703 GNUNET_HELLO_iterate_addresses (hm,
1704 GNUNET_NO,
1705 &validate_address_iterator,
1706 NULL));
1707 return GNUNET_OK;
1708}
1709
1710
1711/**
1712 * Closure for #iterate_addresses().
1713 */
1714struct IteratorContext
1715{
1716 /**
1717 * Function to call on each address.
1718 */
1719 GST_ValidationAddressCallback cb;
1720
1721 /**
1722 * Closure for @e cb.
1723 */
1724 void *cb_cls;
1725};
1726
1727
1728/**
1729 * Call the callback in the closure for each validation entry.
1730 *
1731 * @param cls the `struct IteratorContext`
1732 * @param key the peer's identity
1733 * @param value the `struct ValidationEntry`
1734 * @return #GNUNET_OK (continue to iterate)
1735 */
1736static int
1737iterate_addresses (void *cls,
1738 const struct GNUNET_PeerIdentity *key,
1739 void *value)
1740{
1741 struct IteratorContext *ic = cls;
1742 struct ValidationEntry *ve = value;
1743
1744 ic->cb (ic->cb_cls,
1745 ve->valid_until,
1746 ve->revalidation_block,
1747 ve->address);
1748 return GNUNET_OK;
1749}
1750
1751
1752/**
1753 * Call the given function for each address for the given target.
1754 * Can either give a snapshot (synchronous API) or be continuous.
1755 *
1756 * @param target peer information is requested for
1757 * @param cb function to call; will not be called after this function returns
1758 * @param cb_cls closure for @a cb
1759 */
1760void
1761GST_validation_get_addresses (const struct GNUNET_PeerIdentity *target,
1762 GST_ValidationAddressCallback cb,
1763 void *cb_cls)
1764{
1765 struct IteratorContext ic;
1766
1767 ic.cb = cb;
1768 ic.cb_cls = cb_cls;
1769 GNUNET_CONTAINER_multipeermap_get_multiple (validation_map,
1770 target,
1771 &iterate_addresses, &ic);
1772}
1773
1774
1775/**
1776 * Update if we are using an address for a connection actively right now.
1777 * Based on this, the validation module will measure latency for the
1778 * address more or less often.
1779 *
1780 * @param address the address that we are now using (or not)
1781 * @param in_use #GNUNET_YES if we are now using the address for a connection,
1782 * #GNUNET_NO if we are no longer using the address for a connection
1783 */
1784void
1785GST_validation_set_address_use (const struct GNUNET_HELLO_Address *address,
1786 int in_use)
1787{
1788 struct ValidationEntry *ve;
1789
1790 if (GNUNET_HELLO_address_check_option (address,
1791 GNUNET_HELLO_ADDRESS_INFO_INBOUND))
1792 return; /* ignore inbound for validation */
1793 if (NULL == GST_plugins_find (address->transport_name))
1794 {
1795 /* How can we use an address for which we don't have the plugin? */
1796 GNUNET_break (0);
1797 return;
1798 }
1799 ve = find_validation_entry (address);
1800 if (NULL == ve)
1801 {
1802 GNUNET_break (0);
1803 return;
1804 }
1805 if (in_use == ve->in_use)
1806 return;
1807 ve->in_use = in_use;
1808 if (GNUNET_YES == in_use)
1809 {
1810 /* from now on, higher frequency, so reschedule now */
1811 if (NULL != ve->revalidation_task)
1812 GNUNET_SCHEDULER_cancel (ve->revalidation_task);
1813 ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address,
1814 ve);
1815 }
1816}
1817
1818
1819/* end of file gnunet-service-transport_validation.c */
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-30 19:47:52 +0000