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3 (C) 2010,2011 Christian Grothoff (and other contributing authors)
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22 * @file transport/gnunet-service-transport_validation.c
23 * @brief address validation subsystem
24 * @author Christian Grothoff
27 #include "gnunet-service-transport_validation.h"
28 #include "gnunet-service-transport_plugins.h"
29 #include "gnunet-service-transport_hello.h"
30 #include "gnunet-service-transport_blacklist.h"
31 #include "gnunet-service-transport.h"
32 #include "gnunet_hello_lib.h"
33 #include "gnunet_ats_service.h"
34 #include "gnunet_peerinfo_service.h"
35 #include "gnunet_signatures.h"
39 * How long is a PONG signature valid? We'll recycle a signature until
40 * 1/4 of this time is remaining. PONGs should expire so that if our
41 * external addresses change an adversary cannot replay them indefinitely.
42 * OTOH, we don't want to spend too much time generating PONG signatures,
43 * so they must have some lifetime to reduce our CPU usage.
45 #define PONG_SIGNATURE_LIFETIME GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 1)
48 * After how long do we expire an address in a HELLO that we just
49 * validated? This value is also used for our own addresses when we
52 #define HELLO_ADDRESS_EXPIRATION GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 12)
55 * How often do we allow PINGing an address that we have not yet
56 * validated? This also determines how long we track an address that
57 * we cannot validate (because after this time we can destroy the
60 #define UNVALIDATED_PING_KEEPALIVE GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
63 * How often do we PING an address that we have successfully validated
64 * in the past but are not actively using? Should be (significantly)
65 * smaller than HELLO_ADDRESS_EXPIRATION.
67 #define VALIDATED_PING_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
70 * How often do we PING an address that we are currently using?
72 #define CONNECTED_PING_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2)
75 * How much delay is acceptable for sending the PING or PONG?
77 #define ACCEPTABLE_PING_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)
80 * Size of the validation map hashmap.
82 #define VALIDATION_MAP_SIZE 256
85 * Priority to use for PINGs
87 #define PING_PRIORITY 2
90 * Priority to use for PONGs
92 #define PONG_PRIORITY 4
95 GNUNET_NETWORK_STRUCT_BEGIN
98 * Message used to ask a peer to validate receipt (to check an address
99 * from a HELLO). Followed by the address we are trying to validate,
100 * or an empty address if we are just sending a PING to confirm that a
101 * connection which the receiver (of the PING) initiated is still valid.
103 struct TransportPingMessage
107 * Type will be GNUNET_MESSAGE_TYPE_TRANSPORT_PING
109 struct GNUNET_MessageHeader header;
112 * Challenge code (to ensure fresh reply).
114 uint32_t challenge GNUNET_PACKED;
117 * Who is the intended recipient?
119 struct GNUNET_PeerIdentity target;
125 * Message used to validate a HELLO. The challenge is included in the
126 * confirmation to make matching of replies to requests possible. The
127 * signature signs our public key, an expiration time and our address.<p>
129 * This message is followed by our transport address that the PING tried
130 * to confirm (if we liked it). The address can be empty (zero bytes)
131 * if the PING had not address either (and we received the request via
132 * a connection that we initiated).
134 struct TransportPongMessage
138 * Type will be GNUNET_MESSAGE_TYPE_TRANSPORT_PONG
140 struct GNUNET_MessageHeader header;
143 * Challenge code from PING (showing freshness). Not part of what
144 * is signed so that we can re-use signatures.
146 uint32_t challenge GNUNET_PACKED;
151 struct GNUNET_CRYPTO_EccSignature signature;
154 * GNUNET_SIGNATURE_PURPOSE_TRANSPORT_PONG_OWN to confirm that this is a
155 * plausible address for the signing peer.
157 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
160 * When does this signature expire?
162 struct GNUNET_TIME_AbsoluteNBO expiration;
165 * Size of address appended to this message (part of what is
166 * being signed, hence not redundant).
168 uint32_t addrlen GNUNET_PACKED;
171 GNUNET_NETWORK_STRUCT_END
174 * Information about an address under validation
176 struct ValidationEntry
182 struct GNUNET_HELLO_Address *address;
185 * Handle to the blacklist check (if we're currently in it).
187 struct GST_BlacklistCheck *bc;
190 * Public key of the peer.
192 struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded public_key;
195 * The identity of the peer. FIXME: duplicated (also in 'address')
197 struct GNUNET_PeerIdentity pid;
200 * Cached PONG signature
202 struct GNUNET_CRYPTO_EccSignature pong_sig_cache;
205 * ID of task that will clean up this entry if nothing happens.
207 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
210 * ID of task that will trigger address revalidation.
212 GNUNET_SCHEDULER_TaskIdentifier revalidation_task;
215 * At what time did we send the latest validation request (PING)?
217 struct GNUNET_TIME_Absolute send_time;
220 * Until when is this address valid?
221 * ZERO if it is not currently considered valid.
223 struct GNUNET_TIME_Absolute valid_until;
226 * Until when is the cached PONG signature valid?
227 * ZERO if it is not currently considered valid.
229 struct GNUNET_TIME_Absolute pong_sig_valid_until;
232 * How long until we can try to validate this address again?
233 * FOREVER if the address is for an unsupported plugin (from PEERINFO)
234 * ZERO if the address is considered valid (no validation needed)
235 * otherwise a time in the future if we're currently denying re-validation
237 struct GNUNET_TIME_Absolute revalidation_block;
240 * Last observed latency for this address (round-trip), delay between
241 * last PING sent and PONG received; FOREVER if we never got a PONG.
243 struct GNUNET_TIME_Relative latency;
246 * Challenge number we used.
251 * When passing the address in 'add_valid_peer_address', did we
252 * copy the address to the HELLO yet?
257 * Are we currently using this address for a connection?
262 * Are we expecting a PONG message for this validation entry?
266 /* FIXME: DEBUGGING */
267 int last_line_set_to_no;
268 int last_line_set_to_yes;
270 enum GNUNET_ATS_Network_Type network;
275 * Context of currently active requests to peerinfo
276 * for validation of HELLOs.
278 struct CheckHelloValidatedContext
282 * This is a doubly-linked list.
284 struct CheckHelloValidatedContext *next;
287 * This is a doubly-linked list.
289 struct CheckHelloValidatedContext *prev;
292 * Hello that we are validating.
294 const struct GNUNET_HELLO_Message *hello;
300 * Head of linked list of HELLOs awaiting validation.
302 static struct CheckHelloValidatedContext *chvc_head;
305 * Tail of linked list of HELLOs awaiting validation
307 static struct CheckHelloValidatedContext *chvc_tail;
310 * Map of PeerIdentities to 'struct ValidationEntry*'s (addresses
311 * of the given peer that we are currently validating, have validated
312 * or are blocked from re-validation for a while).
314 static struct GNUNET_CONTAINER_MultiHashMap *validation_map;
317 * Context for peerinfo iteration.
319 static struct GNUNET_PEERINFO_NotifyContext *pnc;
323 * Minimum delay between to validations
325 static struct GNUNET_TIME_Relative validation_delay;
328 * Number of validations running
330 static unsigned int validations_running;
333 * Validition fast start threshold
335 static unsigned int validations_fast_start_threshold;
338 * When is next validation allowed
340 static struct GNUNET_TIME_Absolute validation_next;
343 * Context for the validation entry match function.
345 struct ValidationEntryMatchContext
348 * Where to store the result?
350 struct ValidationEntry *ve;
353 * Address we're interested in.
355 const struct GNUNET_HELLO_Address *address;
361 * Iterate over validation entries until a matching one is found.
363 * @param cls the 'struct ValidationEntryMatchContext'
364 * @param key peer identity (unused)
365 * @param value a 'struct ValidationEntry' to match
366 * @return GNUNET_YES if the entry does not match,
367 * GNUNET_NO if the entry does match
370 validation_entry_match (void *cls, const struct GNUNET_HashCode * key, void *value)
372 struct ValidationEntryMatchContext *vemc = cls;
373 struct ValidationEntry *ve = value;
375 if (0 == GNUNET_HELLO_address_cmp (ve->address, vemc->address))
385 * Iterate over validation entries and free them.
387 * @param cls (unused)
388 * @param key peer identity (unused)
389 * @param value a 'struct ValidationEntry' to clean up
390 * @return GNUNET_YES (continue to iterate)
393 cleanup_validation_entry (void *cls, const struct GNUNET_HashCode * key, void *value)
395 struct ValidationEntry *ve = value;
399 GST_blacklist_test_cancel (ve->bc);
402 GNUNET_break (GNUNET_OK ==
403 GNUNET_CONTAINER_multihashmap_remove (validation_map,
404 &ve->pid.hashPubKey, ve));
405 GNUNET_HELLO_address_free (ve->address);
406 if (GNUNET_SCHEDULER_NO_TASK != ve->timeout_task)
408 GNUNET_SCHEDULER_cancel (ve->timeout_task);
409 ve->timeout_task = GNUNET_SCHEDULER_NO_TASK;
411 if (GNUNET_SCHEDULER_NO_TASK != ve->revalidation_task)
413 GNUNET_SCHEDULER_cancel (ve->revalidation_task);
414 ve->revalidation_task = GNUNET_SCHEDULER_NO_TASK;
416 if ((GNUNET_YES == ve->expecting_pong) &&
417 (validations_running > 0))
419 validations_running --;
420 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
421 "Validation finished, %u validation processes running\n",
422 validations_running);
430 * Address validation cleanup task. Assesses if the record is no
431 * longer valid and then possibly triggers its removal.
433 * @param cls the 'struct ValidationEntry'
434 * @param tc scheduler context (unused)
437 timeout_hello_validation (void *cls,
438 const struct GNUNET_SCHEDULER_TaskContext *tc)
440 struct ValidationEntry *ve = cls;
441 struct GNUNET_TIME_Absolute max;
442 struct GNUNET_TIME_Relative left;
444 ve->timeout_task = GNUNET_SCHEDULER_NO_TASK;
445 max = GNUNET_TIME_absolute_max (ve->valid_until, ve->revalidation_block);
446 left = GNUNET_TIME_absolute_get_remaining (max);
447 if (left.rel_value > 0)
449 /* should wait a bit longer */
451 GNUNET_SCHEDULER_add_delayed (left, &timeout_hello_validation, ve);
454 GNUNET_STATISTICS_update (GST_stats,
455 gettext_noop ("# address records discarded"), 1,
457 cleanup_validation_entry (NULL, &ve->pid.hashPubKey, ve);
462 * Function called with the result from blacklisting.
463 * Send a PING to the other peer if a communication is allowed.
465 * @param cls our 'struct ValidationEntry'
466 * @param pid identity of the other peer
467 * @param result GNUNET_OK if the connection is allowed, GNUNET_NO if not
470 transmit_ping_if_allowed (void *cls, const struct GNUNET_PeerIdentity *pid,
473 struct ValidationEntry *ve = cls;
474 struct TransportPingMessage ping;
475 struct GNUNET_TRANSPORT_PluginFunctions *papi;
476 struct GNUNET_TIME_Absolute next;
477 const struct GNUNET_MessageHeader *hello;
478 enum GNUNET_ATS_Network_Type network;
486 if (GNUNET_NO == result)
488 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Blacklist denies to send PING to `%s' %s %s\n",
489 GNUNET_i2s (pid), GST_plugins_a2s (ve->address), ve->address->transport_name);
493 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitting plain PING to `%s' %s %s\n",
494 GNUNET_i2s (pid), GST_plugins_a2s (ve->address), ve->address->transport_name);
496 next = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), validation_delay);
497 if (next.abs_value > validation_next.abs_value)
498 validation_next = next; /* We're going to send a PING so delay next validation */
500 slen = strlen (ve->address->transport_name) + 1;
501 hello = GST_hello_get ();
502 hsize = ntohs (hello->size);
504 sizeof (struct TransportPingMessage) + ve->address->address_length +
508 htons (sizeof (struct TransportPingMessage) +
509 ve->address->address_length + slen);
510 ping.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_PING);
511 ping.challenge = htonl (ve->challenge);
514 if (tsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
516 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
518 ("Not transmitting `%s' with `%s', message too big (%u bytes!). This should not happen.\n"),
519 "HELLO", "PING", (unsigned int) tsize);
520 /* message too big (!?), get rid of HELLO */
523 sizeof (struct TransportPingMessage) + ve->address->address_length +
527 char message_buf[tsize];
529 /* build message with structure:
530 * [HELLO][TransportPingMessage][Transport name][Address] */
531 memcpy (message_buf, hello, hsize);
532 memcpy (&message_buf[hsize], &ping, sizeof (struct TransportPingMessage));
533 memcpy (&message_buf[sizeof (struct TransportPingMessage) + hsize],
534 ve->address->transport_name, slen);
535 memcpy (&message_buf[sizeof (struct TransportPingMessage) + slen + hsize],
536 ve->address->address, ve->address->address_length);
537 papi = GST_plugins_find (ve->address->transport_name);
542 GNUNET_assert (papi->send != NULL);
543 GNUNET_assert (papi->get_session != NULL);
544 struct Session * session = papi->get_session(papi->cls, ve->address);
548 ret = papi->send (papi->cls, session,
550 PING_PRIORITY, ACCEPTABLE_PING_DELAY,
552 network = papi->get_network (ve->address, session);
553 if (GNUNET_ATS_NET_UNSPECIFIED == network)
555 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
556 "Could not obtain a valid network for `%s' %s\n",
557 GNUNET_i2s (pid), GST_plugins_a2s (ve->address));
563 /* Could not get a valid session */
564 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Could not get a valid session for `%s' %s\n",
565 GNUNET_i2s (pid), GST_plugins_a2s (ve->address));
572 ve->send_time = GNUNET_TIME_absolute_get ();
573 GNUNET_STATISTICS_update (GST_stats,
575 ("# PING without HELLO messages sent"), 1,
578 ve->network = network;
579 ve->expecting_pong = GNUNET_YES;
580 validations_running ++;
581 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
582 "Validation started, %u validation processes running\n",
583 validations_running);
589 * Do address validation again to keep address valid.
591 * @param cls the 'struct ValidationEntry'
592 * @param tc scheduler context (unused)
595 revalidate_address (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
597 struct ValidationEntry *ve = cls;
598 struct GNUNET_TIME_Relative canonical_delay;
599 struct GNUNET_TIME_Relative delay;
600 struct GNUNET_TIME_Relative blocked_for;
601 struct GST_BlacklistCheck *bc;
604 ve->revalidation_task = GNUNET_SCHEDULER_NO_TASK;
605 delay = GNUNET_TIME_absolute_get_remaining (ve->revalidation_block);
606 /* How long until we can possibly permit the next PING? */
609 GNUNET_YES) ? CONNECTED_PING_FREQUENCY
610 : ((GNUNET_TIME_absolute_get_remaining (ve->valid_until).rel_value >
611 0) ? VALIDATED_PING_FREQUENCY : UNVALIDATED_PING_KEEPALIVE);
612 if (delay.rel_value > canonical_delay.rel_value * 2)
614 /* situation changed, recalculate delay */
615 delay = canonical_delay;
616 ve->revalidation_block = GNUNET_TIME_relative_to_absolute (delay);
618 if (delay.rel_value > 0)
620 /* should wait a bit longer */
621 ve->revalidation_task =
622 GNUNET_SCHEDULER_add_delayed (delay, &revalidate_address, ve);
625 blocked_for = GNUNET_TIME_absolute_get_remaining(validation_next);
626 if ((validations_running > validations_fast_start_threshold) &&
627 (blocked_for.rel_value > 0))
629 /* Validations are blocked, have to wait for blocked_for time */
630 ve->revalidation_task =
631 GNUNET_SCHEDULER_add_delayed (blocked_for, &revalidate_address, ve);
634 ve->revalidation_block = GNUNET_TIME_relative_to_absolute (canonical_delay);
636 /* schedule next PINGing with some extra random delay to avoid synchronous re-validations */
638 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
639 canonical_delay.rel_value);
641 /* Debug code for mantis 0002726*/
642 if (GNUNET_TIME_UNIT_FOREVER_REL.rel_value ==
643 GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, rdelay).rel_value)
645 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
646 "Revalidation interval for peer `%s' for is FOREVER (debug: rdelay: %llu, canonical delay %llu)\n",
647 GNUNET_i2s (&ve->pid),
648 (unsigned long long) delay.rel_value,
649 (unsigned long long) canonical_delay.rel_value);
650 delay = canonical_delay;
654 delay = GNUNET_TIME_relative_add (canonical_delay,
655 GNUNET_TIME_relative_multiply
656 (GNUNET_TIME_UNIT_MILLISECONDS, rdelay));
658 /* End debug code for mantis 0002726*/
659 ve->revalidation_task =
660 GNUNET_SCHEDULER_add_delayed (delay, &revalidate_address, ve);
662 /* start PINGing by checking blacklist */
663 GNUNET_STATISTICS_update (GST_stats,
664 gettext_noop ("# address revalidations started"), 1,
666 bc = GST_blacklist_test_allowed (&ve->pid, ve->address->transport_name,
667 &transmit_ping_if_allowed, ve);
669 ve->bc = bc; /* only set 'bc' if 'transmit_ping_if_allowed' was not already
675 * Find a ValidationEntry entry for the given neighbour that matches
676 * the given address and transport. If none exists, create one (but
677 * without starting any validation).
679 * @param public_key public key of the peer, NULL for unknown
680 * @param address address to find
681 * @return validation entry matching the given specifications, NULL
682 * if we don't have an existing entry and no public key was given
684 static struct ValidationEntry *
685 find_validation_entry (const struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded
686 *public_key, const struct GNUNET_HELLO_Address *address)
688 struct ValidationEntryMatchContext vemc;
689 struct ValidationEntry *ve;
692 vemc.address = address;
693 GNUNET_CONTAINER_multihashmap_get_multiple (validation_map,
694 &address->peer.hashPubKey,
695 &validation_entry_match, &vemc);
696 if (NULL != (ve = vemc.ve))
698 if (public_key == NULL)
700 ve = GNUNET_malloc (sizeof (struct ValidationEntry));
701 ve->in_use = GNUNET_SYSERR; /* not defined */
702 ve->last_line_set_to_no = 0;
703 ve->last_line_set_to_yes = 0;
704 ve->address = GNUNET_HELLO_address_copy (address);
705 ve->public_key = *public_key;
706 ve->pid = address->peer;
707 ve->pong_sig_valid_until = GNUNET_TIME_absolute_get_zero_();
708 memset (&ve->pong_sig_cache, '\0', sizeof (struct GNUNET_CRYPTO_EccSignature));
709 ve->latency = GNUNET_TIME_UNIT_FOREVER_REL;
711 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
713 GNUNET_SCHEDULER_add_delayed (UNVALIDATED_PING_KEEPALIVE,
714 &timeout_hello_validation, ve);
715 GNUNET_CONTAINER_multihashmap_put (validation_map, &address->peer.hashPubKey,
717 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
718 ve->expecting_pong = GNUNET_NO;
724 * Iterator which adds the given address to the set of validated
727 * @param cls original HELLO message
728 * @param address the address
729 * @param expiration expiration time
730 * @return GNUNET_OK (keep the address)
733 add_valid_address (void *cls, const struct GNUNET_HELLO_Address *address,
734 struct GNUNET_TIME_Absolute expiration)
736 const struct GNUNET_HELLO_Message *hello = cls;
737 struct ValidationEntry *ve;
738 struct GNUNET_PeerIdentity pid;
739 struct GNUNET_ATS_Information ats;
740 struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded public_key;
742 if (GNUNET_TIME_absolute_get_remaining (expiration).rel_value == 0)
743 return GNUNET_OK; /* expired */
744 if ((GNUNET_OK != GNUNET_HELLO_get_id (hello, &pid)) ||
745 (GNUNET_OK != GNUNET_HELLO_get_key (hello, &public_key)))
748 return GNUNET_OK; /* invalid HELLO !? */
750 if (0 == memcmp (&GST_my_identity, &pid, sizeof (struct GNUNET_PeerIdentity)))
752 /* Peerinfo returned own identity, skip validation */
756 ve = find_validation_entry (&public_key, address);
757 ve->valid_until = GNUNET_TIME_absolute_max (ve->valid_until, expiration);
759 if (GNUNET_SCHEDULER_NO_TASK == ve->revalidation_task)
760 ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
762 ats.type = htonl (GNUNET_ATS_NETWORK_TYPE);
763 ats.value = htonl (ve->network);
764 GNUNET_ATS_address_add (GST_ats, address, NULL, &ats, 1);
771 * Function called for any HELLO known to PEERINFO.
774 * @param peer id of the peer, NULL for last call
775 * @param hello hello message for the peer (can be NULL)
776 * @param err_msg error message
779 process_peerinfo_hello (void *cls, const struct GNUNET_PeerIdentity *peer,
780 const struct GNUNET_HELLO_Message *hello,
783 GNUNET_assert (NULL != peer);
786 GNUNET_assert (NULL ==
787 GNUNET_HELLO_iterate_addresses (hello, GNUNET_NO,
794 * Start the validation subsystem.
796 * @param max_fds maximum number of fds to use
799 GST_validation_start (unsigned int max_fds)
802 * Initialization for validation throttling
804 * We have a maximum number max_fds of connections we can use for validation
805 * We monitor the number of validations in parallel and start to throttle it
806 * when doing to many validations in parallel:
807 * if (running validations < (max_fds / 2))
808 * - "fast start": run validation immediately
809 * - have delay of (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT.rel_value) / (max_fds / 2)
810 * (300 sec / ~150 == ~2 sec.) between two validations
813 validation_next = GNUNET_TIME_absolute_get();
814 validation_delay.rel_value = (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT.rel_value) / (max_fds / 2);
815 validations_fast_start_threshold = (max_fds / 2);
816 validations_running = 0;
817 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Validation uses a fast start threshold of %u connections and a delay between of %u ms\n ",
818 validations_fast_start_threshold, validation_delay.rel_value);
819 validation_map = GNUNET_CONTAINER_multihashmap_create (VALIDATION_MAP_SIZE,
821 pnc = GNUNET_PEERINFO_notify (GST_cfg, GNUNET_YES, &process_peerinfo_hello, NULL);
826 * Stop the validation subsystem.
829 GST_validation_stop ()
831 struct CheckHelloValidatedContext *chvc;
833 GNUNET_CONTAINER_multihashmap_iterate (validation_map,
834 &cleanup_validation_entry, NULL);
835 GNUNET_CONTAINER_multihashmap_destroy (validation_map);
836 validation_map = NULL;
837 while (NULL != (chvc = chvc_head))
839 GNUNET_CONTAINER_DLL_remove (chvc_head, chvc_tail, chvc);
842 GNUNET_PEERINFO_notify_cancel (pnc);
847 * Send the given PONG to the given address.
849 * @param cls the PONG message
850 * @param public_key public key for the peer, never NULL
851 * @param valid_until is ZERO if we never validated the address,
852 * otherwise a time up to when we consider it (or was) valid
853 * @param validation_block is FOREVER if the address is for an unsupported plugin (from PEERINFO)
854 * is ZERO if the address is considered valid (no validation needed)
855 * otherwise a time in the future if we're currently denying re-validation
856 * @param address target address
859 multicast_pong (void *cls,
860 const struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded
861 *public_key, struct GNUNET_TIME_Absolute valid_until,
862 struct GNUNET_TIME_Absolute validation_block,
863 const struct GNUNET_HELLO_Address *address)
865 struct TransportPongMessage *pong = cls;
866 struct GNUNET_TRANSPORT_PluginFunctions *papi;
868 papi = GST_plugins_find (address->transport_name);
872 GNUNET_assert (papi->send != NULL);
873 GNUNET_assert (papi->get_session != NULL);
875 struct Session * session = papi->get_session(papi->cls, address);
882 papi->send (papi->cls, session,
883 (const char *) pong, ntohs (pong->header.size),
884 PONG_PRIORITY, ACCEPTABLE_PING_DELAY,
890 * We've received a PING. If appropriate, generate a PONG.
892 * @param sender peer sending the PING
893 * @param hdr the PING
894 * @param sender_address the sender address as we got it
895 * @param session session we got the PING from
898 GST_validation_handle_ping (const struct GNUNET_PeerIdentity *sender,
899 const struct GNUNET_MessageHeader *hdr,
900 const struct GNUNET_HELLO_Address *sender_address,
901 struct Session *session)
903 const struct TransportPingMessage *ping;
904 struct TransportPongMessage *pong;
905 struct GNUNET_TRANSPORT_PluginFunctions *papi;
906 struct GNUNET_TRANSPORT_PluginFunctions *server_papi;
907 struct GNUNET_CRYPTO_EccSignature *sig_cache;
908 struct GNUNET_TIME_Absolute *sig_cache_exp;
916 int buggy = GNUNET_NO;
917 struct GNUNET_HELLO_Address address;
919 if (ntohs (hdr->size) < sizeof (struct TransportPingMessage))
924 ping = (const struct TransportPingMessage *) hdr;
926 memcmp (&ping->target, &GST_my_identity,
927 sizeof (struct GNUNET_PeerIdentity)))
929 GNUNET_STATISTICS_update (GST_stats,
931 ("# PING message for different peer received"), 1,
935 GNUNET_STATISTICS_update (GST_stats,
936 gettext_noop ("# PING messages received"), 1,
938 addr = (const char *) &ping[1];
939 alen = ntohs (hdr->size) - sizeof (struct TransportPingMessage);
940 /* peer wants to confirm that this is one of our addresses, this is what is
941 * used for address validation */
944 sig_cache_exp = NULL;
948 addrend = memchr (addr, '\0', alen);
955 slen = strlen (addr) + 1;
957 address.address = addrend;
958 address.address_length = alen;
959 address.transport_name = addr;
960 address.peer = GST_my_identity;
962 if (NULL == address.transport_name)
967 if (0 != strstr (address.transport_name, "_client"))
969 plugin_name = GNUNET_strdup (address.transport_name);
970 pos = strstr (plugin_name, "_client");
971 GNUNET_assert (NULL != pos);
972 GNUNET_snprintf (pos, strlen ("_server") + 1, "%s", "_server");
975 plugin_name = GNUNET_strdup (address.transport_name);
977 if (NULL == (papi = GST_plugins_find (plugin_name)))
979 /* we don't have the plugin for this address */
980 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Plugin `%s' not available, cannot confirm having this address \n",
982 GNUNET_free (plugin_name);
985 GNUNET_free (plugin_name);
986 if (GNUNET_OK != papi->check_address (papi->cls, addrend, alen))
988 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Address `%s' is not one of my addresses, not confirming PING\n",
989 GST_plugins_a2s (&address));
993 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Address `%s' is one of my addresses, confirming PING\n",
994 GST_plugins_a2s (&address)); /* DEBUGGING*/
996 if (GNUNET_YES != GST_hello_test_address (&address, &sig_cache, &sig_cache_exp))
998 if (GNUNET_NO == buggy)
1000 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1001 "Not confirming PING from peer `%s' with address `%s' since I cannot confirm having this address.\n",
1002 GNUNET_i2s (sender),
1003 GST_plugins_a2s (&address));
1008 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1009 _("Received a PING message with validation bug from `%s'\n"),
1010 GNUNET_i2s (sender));
1016 addrend = NULL; /* make gcc happy */
1018 static struct GNUNET_CRYPTO_EccSignature no_address_signature;
1019 static struct GNUNET_TIME_Absolute no_address_signature_expiration;
1021 sig_cache = &no_address_signature;
1022 sig_cache_exp = &no_address_signature_expiration;
1025 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1026 "I am `%s', sending PONG to peer `%s'\n",
1027 GNUNET_h2s (&GST_my_identity.hashPubKey),
1028 GNUNET_i2s (sender));
1030 /* message with structure:
1031 * [TransportPongMessage][Transport name][Address] */
1033 pong = GNUNET_malloc (sizeof (struct TransportPongMessage) + alen + slen);
1035 htons (sizeof (struct TransportPongMessage) + alen + slen);
1036 pong->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_PONG);
1037 pong->purpose.size =
1038 htonl (sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
1039 sizeof (uint32_t) + sizeof (struct GNUNET_TIME_AbsoluteNBO) +
1041 pong->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_TRANSPORT_PONG_OWN);
1042 memcpy (&pong->challenge, &ping->challenge, sizeof (ping->challenge));
1043 pong->addrlen = htonl (alen + slen);
1044 memcpy (&pong[1], addr, slen); /* Copy transport plugin */
1047 GNUNET_assert (NULL != addrend);
1048 memcpy (&((char *) &pong[1])[slen], addrend, alen);
1050 if (GNUNET_TIME_absolute_get_remaining (*sig_cache_exp).rel_value <
1051 PONG_SIGNATURE_LIFETIME.rel_value / 4)
1053 /* create / update cached sig */
1054 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1055 "Creating PONG signature to indicate ownership.\n");
1056 *sig_cache_exp = GNUNET_TIME_relative_to_absolute (PONG_SIGNATURE_LIFETIME);
1057 pong->expiration = GNUNET_TIME_absolute_hton (*sig_cache_exp);
1058 GNUNET_assert (GNUNET_OK ==
1059 GNUNET_CRYPTO_ecc_sign (GST_my_private_key, &pong->purpose,
1064 pong->expiration = GNUNET_TIME_absolute_hton (*sig_cache_exp);
1066 pong->signature = *sig_cache;
1068 GNUNET_assert (sender_address != NULL);
1070 /* first see if the session we got this PING from can be used to transmit
1071 * a response reliably */
1076 GNUNET_assert (papi->send != NULL);
1077 GNUNET_assert (papi->get_session != NULL);
1079 if (session == NULL)
1081 session = papi->get_session (papi->cls, sender_address);
1083 if (session == NULL)
1090 ret = papi->send (papi->cls, session,
1091 (const char *) pong, ntohs (pong->header.size),
1092 PONG_PRIORITY, ACCEPTABLE_PING_DELAY,
1098 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1099 "Transmitted PONG to `%s' via reliable mechanism\n",
1100 GNUNET_i2s (sender));
1102 GNUNET_STATISTICS_update (GST_stats,
1104 ("# PONGs unicast via reliable transport"), 1,
1110 /* no reliable method found, try transmission via all known addresses */
1111 GNUNET_STATISTICS_update (GST_stats,
1113 ("# PONGs multicast to all available addresses"), 1,
1115 GST_validation_get_addresses (sender, &multicast_pong, pong);
1121 * Context for the 'validate_address' function
1123 struct ValidateAddressContext
1126 * Hash of the public key of the peer whose address is being validated.
1128 struct GNUNET_PeerIdentity pid;
1131 * Public key of the peer whose address is being validated.
1133 struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded public_key;
1138 * Iterator callback to go over all addresses and try to validate them
1139 * (unless blocked or already validated).
1141 * @param cls pointer to a 'struct ValidateAddressContext'
1142 * @param address the address
1143 * @param expiration expiration time
1144 * @return GNUNET_OK (keep the address)
1147 validate_address_iterator (void *cls,
1148 const struct GNUNET_HELLO_Address *address,
1149 struct GNUNET_TIME_Absolute expiration)
1151 const struct ValidateAddressContext *vac = cls;
1152 struct ValidationEntry *ve;
1154 if (GNUNET_TIME_absolute_get_remaining (expiration).rel_value == 0)
1155 return GNUNET_OK; /* expired */
1156 ve = find_validation_entry (&vac->public_key, address);
1157 if (GNUNET_SCHEDULER_NO_TASK == ve->revalidation_task)
1158 ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
1164 * Add the validated peer address to the HELLO.
1166 * @param cls the 'struct ValidationEntry' with the validated address
1167 * @param max space in buf
1168 * @param buf where to add the address
1169 * @return number of bytes written, 0 to signal the
1170 * end of the iteration.
1173 add_valid_peer_address (void *cls, size_t max, void *buf)
1175 struct ValidationEntry *ve = cls;
1177 if (GNUNET_YES == ve->copied)
1178 return 0; /* terminate */
1179 ve->copied = GNUNET_YES;
1180 return GNUNET_HELLO_add_address (ve->address, ve->valid_until, buf, max);
1185 * We've received a PONG. Check if it matches a pending PING and
1186 * mark the respective address as confirmed.
1188 * @param sender peer sending the PONG
1189 * @param hdr the PONG
1192 GST_validation_handle_pong (const struct GNUNET_PeerIdentity *sender,
1193 const struct GNUNET_MessageHeader *hdr)
1195 const struct TransportPongMessage *pong;
1196 struct ValidationEntry *ve;
1202 struct GNUNET_HELLO_Message *hello;
1203 struct GNUNET_HELLO_Address address;
1207 if (ntohs (hdr->size) < sizeof (struct TransportPongMessage))
1209 GNUNET_break_op (0);
1212 GNUNET_STATISTICS_update (GST_stats,
1213 gettext_noop ("# PONG messages received"), 1,
1216 /* message with structure:
1217 * [TransportPongMessage][Transport name][Address] */
1219 pong = (const struct TransportPongMessage *) hdr;
1220 tname = (const char *) &pong[1];
1221 size = ntohs (hdr->size) - sizeof (struct TransportPongMessage);
1222 addr = memchr (tname, '\0', size);
1225 GNUNET_break_op (0);
1229 slen = strlen (tname) + 1;
1230 addrlen = size - slen;
1231 address.peer = *sender;
1232 address.address = addr;
1233 address.address_length = addrlen;
1234 address.transport_name = tname;
1235 ve = find_validation_entry (NULL, &address);
1236 if ((NULL == ve) || (GNUNET_NO == ve->expecting_pong))
1238 GNUNET_STATISTICS_update (GST_stats,
1240 ("# PONGs dropped, no matching pending validation"),
1244 /* now check that PONG is well-formed */
1245 if (0 != memcmp (&ve->pid, sender, sizeof (struct GNUNET_PeerIdentity)))
1247 GNUNET_break_op (0);
1250 if (GNUNET_TIME_absolute_get_remaining
1251 (GNUNET_TIME_absolute_ntoh (pong->expiration)).rel_value == 0)
1253 GNUNET_STATISTICS_update (GST_stats,
1255 ("# PONGs dropped, signature expired"), 1,
1260 sig_res = GNUNET_SYSERR;
1261 do_verify = GNUNET_YES;
1262 if (0 != GNUNET_TIME_absolute_get_remaining(ve->pong_sig_valid_until).rel_value)
1264 /* We have a cached and valid signature for this peer,
1265 * try to compare instead of verify */
1266 if (0 == memcmp (&ve->pong_sig_cache, &pong->signature, sizeof (struct GNUNET_CRYPTO_EccSignature)))
1268 /* signatures are identical, we can skip verification */
1269 sig_res = GNUNET_OK;
1270 do_verify = GNUNET_NO;
1274 sig_res = GNUNET_SYSERR;
1275 /* signatures do not match, we have to verify */
1279 if (GNUNET_YES == do_verify)
1281 /* Do expensive verification */
1282 sig_res = GNUNET_CRYPTO_ecc_verify (GNUNET_SIGNATURE_PURPOSE_TRANSPORT_PONG_OWN,
1283 &pong->purpose, &pong->signature,
1285 if (sig_res == GNUNET_SYSERR)
1286 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1287 "Failed to verify: invalid signature on address %s:%s from peer `%s'\n",
1288 tname, GST_plugins_a2s (ve->address),GNUNET_i2s (sender));
1291 if (sig_res == GNUNET_SYSERR)
1294 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1295 "Address validated for peer `%s' with plugin `%s': `%s'\n",
1296 GNUNET_i2s (sender), tname, GST_plugins_a2s (ve->address));
1297 /* validity achieved, remember it! */
1298 ve->expecting_pong = GNUNET_NO;
1299 ve->valid_until = GNUNET_TIME_relative_to_absolute (HELLO_ADDRESS_EXPIRATION);
1300 ve->pong_sig_cache = pong->signature;
1301 ve->pong_sig_valid_until = GNUNET_TIME_absolute_ntoh (pong->expiration);
1302 ve->latency = GNUNET_TIME_absolute_get_duration (ve->send_time);
1304 struct GNUNET_ATS_Information ats[2];
1305 ats[0].type = htonl (GNUNET_ATS_QUALITY_NET_DELAY);
1306 ats[0].value = htonl ((uint32_t) ve->latency.rel_value);
1307 ats[1].type = htonl (GNUNET_ATS_NETWORK_TYPE);
1308 ats[1].value = htonl ((uint32_t) ve->network);
1309 GNUNET_ATS_address_add (GST_ats, ve->address, NULL, ats, 2);
1311 if (validations_running > 0)
1313 validations_running --;
1314 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1315 "Validation finished, %u validation processes running\n",
1316 validations_running);
1321 /* build HELLO to store in PEERINFO */
1322 ve->copied = GNUNET_NO;
1323 hello = GNUNET_HELLO_create (&ve->public_key, &add_valid_peer_address, ve, GNUNET_NO);
1324 GNUNET_PEERINFO_add_peer (GST_peerinfo, hello, NULL, NULL);
1325 GNUNET_free (hello);
1330 * We've received a HELLO, check which addresses are new and trigger
1333 * @param hello the HELLO we received
1336 GST_validation_handle_hello (const struct GNUNET_MessageHeader *hello)
1338 const struct GNUNET_HELLO_Message *hm =
1339 (const struct GNUNET_HELLO_Message *) hello;
1340 struct ValidateAddressContext vac;
1341 struct GNUNET_HELLO_Message *h;
1344 friend = GNUNET_HELLO_is_friend_only (hm);
1345 if (((GNUNET_YES != friend) && (GNUNET_NO != friend)) ||
1346 (GNUNET_OK != GNUNET_HELLO_get_id (hm, &vac.pid)) ||
1347 (GNUNET_OK != GNUNET_HELLO_get_key (hm, &vac.public_key)))
1349 /* malformed HELLO */
1354 memcmp (&GST_my_identity, &vac.pid, sizeof (struct GNUNET_PeerIdentity)))
1356 /* Add peer identity without addresses to peerinfo service */
1357 h = GNUNET_HELLO_create (&vac.public_key, NULL, NULL, friend);
1358 GNUNET_PEERINFO_add_peer (GST_peerinfo, h, NULL, NULL);
1360 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1361 _("Adding `%s' without addresses for peer `%s'\n"), "HELLO",
1362 GNUNET_i2s (&vac.pid));
1365 GNUNET_assert (NULL ==
1366 GNUNET_HELLO_iterate_addresses (hm, GNUNET_NO,
1367 &validate_address_iterator,
1373 * Closure for 'iterate_addresses'
1375 struct IteratorContext
1378 * Function to call on each address.
1380 GST_ValidationAddressCallback cb;
1391 * Call the callback in the closure for each validation entry.
1393 * @param cls the 'struct GST_ValidationIteratorContext'
1394 * @param key the peer's identity
1395 * @param value the 'struct ValidationEntry'
1396 * @return GNUNET_OK (continue to iterate)
1399 iterate_addresses (void *cls, const struct GNUNET_HashCode * key, void *value)
1401 struct IteratorContext *ic = cls;
1402 struct ValidationEntry *ve = value;
1404 ic->cb (ic->cb_cls, &ve->public_key, ve->valid_until, ve->revalidation_block,
1411 * Call the given function for each address for the given target.
1412 * Can either give a snapshot (synchronous API) or be continuous.
1414 * @param target peer information is requested for
1415 * @param cb function to call; will not be called after this function returns
1416 * @param cb_cls closure for 'cb'
1419 GST_validation_get_addresses (const struct GNUNET_PeerIdentity *target,
1420 GST_ValidationAddressCallback cb, void *cb_cls)
1422 struct IteratorContext ic;
1426 GNUNET_CONTAINER_multihashmap_get_multiple (validation_map,
1427 &target->hashPubKey,
1428 &iterate_addresses, &ic);
1433 * Update if we are using an address for a connection actively right now.
1434 * Based on this, the validation module will measure latency for the
1435 * address more or less often.
1437 * @param address the address
1438 * @param session the session
1439 * @param in_use GNUNET_YES if we are now using the address for a connection,
1440 * GNUNET_NO if we are no longer using the address for a connection
1441 * @param line line of caller just for DEBUGGING!
1444 GST_validation_set_address_use (const struct GNUNET_HELLO_Address *address,
1445 struct Session *session,
1449 struct ValidationEntry *ve;
1451 if (NULL != address)
1452 ve = find_validation_entry (NULL, address);
1454 ve = NULL; /* FIXME: lookup based on session... */
1457 /* this can happen for inbound connections (sender_address_len == 0); */
1460 if (ve->in_use == in_use)
1463 if (GNUNET_YES == in_use)
1465 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1466 "Error setting address in use for peer `%s' `%s' to USED: set last time by %i, called now by %i\n",
1467 GNUNET_i2s (&address->peer), GST_plugins_a2s (address),
1468 ve->last_line_set_to_yes, line);
1470 if (GNUNET_NO == in_use)
1472 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1473 "Error setting address in use for peer `%s' `%s' to NOT_USED: set last time by %i, called now by %i\n",
1474 GNUNET_i2s (&address->peer), GST_plugins_a2s (address),
1475 ve->last_line_set_to_no, line);
1479 if (GNUNET_YES == in_use)
1481 ve->last_line_set_to_yes = line;
1483 if (GNUNET_NO == in_use)
1485 ve->last_line_set_to_no = line;
1488 GNUNET_break (ve->in_use != in_use); /* should be different... */
1489 ve->in_use = in_use;
1490 if (in_use == GNUNET_YES)
1492 /* from now on, higher frequeny, so reschedule now */
1493 GNUNET_SCHEDULER_cancel (ve->revalidation_task);
1494 ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
1500 * Query validation about the latest observed latency on a given
1503 * @param sender peer
1504 * @param address the address
1505 * @param session session
1506 * @return observed latency of the address, FOREVER if the address was
1507 * never successfully validated
1509 struct GNUNET_TIME_Relative
1510 GST_validation_get_address_latency (const struct GNUNET_PeerIdentity *sender,
1511 const struct GNUNET_HELLO_Address *address,
1512 struct Session *session)
1514 struct ValidationEntry *ve;
1516 if (NULL == address)
1518 GNUNET_break (0); // FIXME: support having latency only with session...
1519 return GNUNET_TIME_UNIT_FOREVER_REL;
1521 ve = find_validation_entry (NULL, address);
1523 return GNUNET_TIME_UNIT_FOREVER_REL;
1528 /* end of file gnunet-service-transport_validation.c */