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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_RsaSignature 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_RsaSignaturePurpose 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_RsaPublicKeyBinaryEncoded public_key;
195 * The identity of the peer. FIXME: duplicated (also in 'address')
197 struct GNUNET_PeerIdentity pid;
200 * ID of task that will clean up this entry if nothing happens.
202 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
205 * ID of task that will trigger address revalidation.
207 GNUNET_SCHEDULER_TaskIdentifier revalidation_task;
210 * At what time did we send the latest validation request (PING)?
212 struct GNUNET_TIME_Absolute send_time;
215 * Until when is this address valid?
216 * ZERO if it is not currently considered valid.
218 struct GNUNET_TIME_Absolute valid_until;
221 * How long until we can try to validate this address again?
222 * FOREVER if the address is for an unsupported plugin (from PEERINFO)
223 * ZERO if the address is considered valid (no validation needed)
224 * otherwise a time in the future if we're currently denying re-validation
226 struct GNUNET_TIME_Absolute revalidation_block;
229 * Last observed latency for this address (round-trip), delay between
230 * last PING sent and PONG received; FOREVER if we never got a PONG.
232 struct GNUNET_TIME_Relative latency;
235 * Challenge number we used.
240 * When passing the address in 'add_valid_peer_address', did we
241 * copy the address to the HELLO yet?
246 * Are we currently using this address for a connection?
251 * Are we expecting a PONG message for this validation entry?
255 /* FIXME: DEBUGGING */
256 int last_line_set_to_no;
257 int last_line_set_to_yes;
262 * Context of currently active requests to peerinfo
263 * for validation of HELLOs.
265 struct CheckHelloValidatedContext
269 * This is a doubly-linked list.
271 struct CheckHelloValidatedContext *next;
274 * This is a doubly-linked list.
276 struct CheckHelloValidatedContext *prev;
279 * Hello that we are validating.
281 const struct GNUNET_HELLO_Message *hello;
287 * Head of linked list of HELLOs awaiting validation.
289 static struct CheckHelloValidatedContext *chvc_head;
292 * Tail of linked list of HELLOs awaiting validation
294 static struct CheckHelloValidatedContext *chvc_tail;
297 * Map of PeerIdentities to 'struct ValidationEntry*'s (addresses
298 * of the given peer that we are currently validating, have validated
299 * or are blocked from re-validation for a while).
301 static struct GNUNET_CONTAINER_MultiHashMap *validation_map;
304 * Context for peerinfo iteration.
306 static struct GNUNET_PEERINFO_NotifyContext *pnc;
310 * Context for the validation entry match function.
312 struct ValidationEntryMatchContext
315 * Where to store the result?
317 struct ValidationEntry *ve;
320 * Address we're interested in.
322 const struct GNUNET_HELLO_Address *address;
328 * Iterate over validation entries until a matching one is found.
330 * @param cls the 'struct ValidationEntryMatchContext'
331 * @param key peer identity (unused)
332 * @param value a 'struct ValidationEntry' to match
333 * @return GNUNET_YES if the entry does not match,
334 * GNUNET_NO if the entry does match
337 validation_entry_match (void *cls, const GNUNET_HashCode * key, void *value)
339 struct ValidationEntryMatchContext *vemc = cls;
340 struct ValidationEntry *ve = value;
342 if (0 == GNUNET_HELLO_address_cmp (ve->address, vemc->address))
352 * Iterate over validation entries and free them.
354 * @param cls (unused)
355 * @param key peer identity (unused)
356 * @param value a 'struct ValidationEntry' to clean up
357 * @return GNUNET_YES (continue to iterate)
360 cleanup_validation_entry (void *cls, const GNUNET_HashCode * key, void *value)
362 struct ValidationEntry *ve = value;
366 GST_blacklist_test_cancel (ve->bc);
369 GNUNET_break (GNUNET_OK ==
370 GNUNET_CONTAINER_multihashmap_remove (validation_map,
371 &ve->pid.hashPubKey, ve));
372 GNUNET_HELLO_address_free (ve->address);
373 if (GNUNET_SCHEDULER_NO_TASK != ve->timeout_task)
375 GNUNET_SCHEDULER_cancel (ve->timeout_task);
376 ve->timeout_task = GNUNET_SCHEDULER_NO_TASK;
378 if (GNUNET_SCHEDULER_NO_TASK != ve->revalidation_task)
380 GNUNET_SCHEDULER_cancel (ve->revalidation_task);
381 ve->revalidation_task = GNUNET_SCHEDULER_NO_TASK;
389 * Address validation cleanup task. Assesses if the record is no
390 * longer valid and then possibly triggers its removal.
392 * @param cls the 'struct ValidationEntry'
393 * @param tc scheduler context (unused)
396 timeout_hello_validation (void *cls,
397 const struct GNUNET_SCHEDULER_TaskContext *tc)
399 struct ValidationEntry *ve = cls;
400 struct GNUNET_TIME_Absolute max;
401 struct GNUNET_TIME_Relative left;
403 ve->timeout_task = GNUNET_SCHEDULER_NO_TASK;
404 max = GNUNET_TIME_absolute_max (ve->valid_until, ve->revalidation_block);
405 left = GNUNET_TIME_absolute_get_remaining (max);
406 if (left.rel_value > 0)
408 /* should wait a bit longer */
410 GNUNET_SCHEDULER_add_delayed (left, &timeout_hello_validation, ve);
413 GNUNET_STATISTICS_update (GST_stats,
414 gettext_noop ("# address records discarded"), 1,
416 cleanup_validation_entry (NULL, &ve->pid.hashPubKey, ve);
421 * Function called with the result from blacklisting.
422 * Send a PING to the other peer if a communication is allowed.
424 * @param cls our 'struct ValidationEntry'
425 * @param pid identity of the other peer
426 * @param result GNUNET_OK if the connection is allowed, GNUNET_NO if not
429 transmit_ping_if_allowed (void *cls, const struct GNUNET_PeerIdentity *pid,
432 struct ValidationEntry *ve = cls;
433 struct TransportPingMessage ping;
434 struct GNUNET_TRANSPORT_PluginFunctions *papi;
435 const struct GNUNET_MessageHeader *hello;
442 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitting plain PING to `%s' %s\n",
443 GNUNET_i2s (pid), GST_plugins_a2s (ve->address));
445 slen = strlen (ve->address->transport_name) + 1;
446 hello = GST_hello_get ();
447 hsize = ntohs (hello->size);
449 sizeof (struct TransportPingMessage) + ve->address->address_length +
453 htons (sizeof (struct TransportPingMessage) +
454 ve->address->address_length + slen);
455 ping.header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_PING);
456 ping.challenge = htonl (ve->challenge);
459 if (tsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
461 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
463 ("Not transmitting `%s' with `%s', message too big (%u bytes!). This should not happen.\n"),
464 "HELLO", "PING", (unsigned int) tsize);
465 /* message too big (!?), get rid of HELLO */
468 sizeof (struct TransportPingMessage) + ve->address->address_length +
472 char message_buf[tsize];
474 /* build message with structure:
475 * [HELLO][TransportPingMessage][Transport name][Address] */
476 memcpy (message_buf, hello, hsize);
477 memcpy (&message_buf[hsize], &ping, sizeof (struct TransportPingMessage));
478 memcpy (&message_buf[sizeof (struct TransportPingMessage) + hsize],
479 ve->address->transport_name, slen);
480 memcpy (&message_buf[sizeof (struct TransportPingMessage) + slen + hsize],
481 ve->address, ve->address->address_length);
482 papi = GST_plugins_find (ve->address->transport_name);
487 GNUNET_assert (papi->send != NULL);
488 GNUNET_assert (papi->get_session != NULL);
489 struct Session * session = papi->get_session(papi->cls, ve->address);
493 ret = papi->send (papi->cls, session,
495 PING_PRIORITY, ACCEPTABLE_PING_DELAY,
500 /* Could not get a valid session */
501 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Could not get a valid session for `%s' %s\n",
502 GNUNET_i2s (pid), GST_plugins_a2s (ve->address));
509 ve->send_time = GNUNET_TIME_absolute_get ();
510 GNUNET_STATISTICS_update (GST_stats,
512 ("# PING without HELLO messages sent"), 1,
514 ve->expecting_pong = GNUNET_YES;
520 * Do address validation again to keep address valid.
522 * @param cls the 'struct ValidationEntry'
523 * @param tc scheduler context (unused)
526 revalidate_address (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
528 struct ValidationEntry *ve = cls;
529 struct GNUNET_TIME_Relative canonical_delay;
530 struct GNUNET_TIME_Relative delay;
531 struct GST_BlacklistCheck *bc;
534 ve->revalidation_task = GNUNET_SCHEDULER_NO_TASK;
535 delay = GNUNET_TIME_absolute_get_remaining (ve->revalidation_block);
536 /* How long until we can possibly permit the next PING? */
539 GNUNET_YES) ? CONNECTED_PING_FREQUENCY
540 : ((GNUNET_TIME_absolute_get_remaining (ve->valid_until).rel_value >
541 0) ? VALIDATED_PING_FREQUENCY : UNVALIDATED_PING_KEEPALIVE);
542 if (delay.rel_value > canonical_delay.rel_value * 2)
544 /* situation changed, recalculate delay */
545 delay = canonical_delay;
546 ve->revalidation_block = GNUNET_TIME_relative_to_absolute (delay);
548 if (delay.rel_value > 0)
550 /* should wait a bit longer */
551 ve->revalidation_task =
552 GNUNET_SCHEDULER_add_delayed (delay, &revalidate_address, ve);
555 ve->revalidation_block = GNUNET_TIME_relative_to_absolute (canonical_delay);
557 /* schedule next PINGing with some extra random delay to avoid synchronous re-validations */
559 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
560 canonical_delay.rel_value);
562 GNUNET_TIME_relative_add (canonical_delay,
563 GNUNET_TIME_relative_multiply
564 (GNUNET_TIME_UNIT_MILLISECONDS, rdelay));
565 ve->revalidation_task =
566 GNUNET_SCHEDULER_add_delayed (delay, &revalidate_address, ve);
568 /* start PINGing by checking blacklist */
569 GNUNET_STATISTICS_update (GST_stats,
570 gettext_noop ("# address revalidations started"), 1,
572 bc = GST_blacklist_test_allowed (&ve->pid, ve->address->transport_name,
573 &transmit_ping_if_allowed, ve);
575 ve->bc = bc; /* only set 'bc' if 'transmit_ping_if_allowed' was not already
581 * Find a ValidationEntry entry for the given neighbour that matches
582 * the given address and transport. If none exists, create one (but
583 * without starting any validation).
585 * @param public_key public key of the peer, NULL for unknown
586 * @param address address to find
587 * @return validation entry matching the given specifications, NULL
588 * if we don't have an existing entry and no public key was given
590 static struct ValidationEntry *
591 find_validation_entry (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
592 *public_key, const struct GNUNET_HELLO_Address *address)
594 struct ValidationEntryMatchContext vemc;
595 struct ValidationEntry *ve;
598 vemc.address = address;
599 GNUNET_CONTAINER_multihashmap_get_multiple (validation_map,
600 &address->peer.hashPubKey,
601 &validation_entry_match, &vemc);
602 if (NULL != (ve = vemc.ve))
604 if (public_key == NULL)
606 ve = GNUNET_malloc (sizeof (struct ValidationEntry));
607 ve->in_use = GNUNET_SYSERR; /* not defined */
608 ve->last_line_set_to_no = 0;
609 ve->last_line_set_to_yes = 0;
610 ve->address = GNUNET_HELLO_address_copy (address);
611 ve->public_key = *public_key;
612 ve->pid = address->peer;
613 ve->latency = GNUNET_TIME_UNIT_FOREVER_REL;
615 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
617 GNUNET_SCHEDULER_add_delayed (UNVALIDATED_PING_KEEPALIVE,
618 &timeout_hello_validation, ve);
619 GNUNET_CONTAINER_multihashmap_put (validation_map, &address->peer.hashPubKey,
621 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
622 ve->expecting_pong = GNUNET_NO;
628 * Iterator which adds the given address to the set of validated
631 * @param cls original HELLO message
632 * @param address the address
633 * @param expiration expiration time
634 * @return GNUNET_OK (keep the address)
637 add_valid_address (void *cls, const struct GNUNET_HELLO_Address *address,
638 struct GNUNET_TIME_Absolute expiration)
640 const struct GNUNET_HELLO_Message *hello = cls;
641 struct ValidationEntry *ve;
642 struct GNUNET_PeerIdentity pid;
643 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded public_key;
645 if (GNUNET_TIME_absolute_get_remaining (expiration).rel_value == 0)
646 return GNUNET_OK; /* expired */
647 if ((GNUNET_OK != GNUNET_HELLO_get_id (hello, &pid)) ||
648 (GNUNET_OK != GNUNET_HELLO_get_key (hello, &public_key)))
651 return GNUNET_OK; /* invalid HELLO !? */
653 if (0 == memcmp (&GST_my_identity, &pid, sizeof (struct GNUNET_PeerIdentity)))
655 /* Peerinfo returned own identity, skip validation */
659 ve = find_validation_entry (&public_key, address);
660 ve->valid_until = GNUNET_TIME_absolute_max (ve->valid_until, expiration);
662 if (GNUNET_SCHEDULER_NO_TASK == ve->revalidation_task)
663 ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
664 GNUNET_ATS_address_update (GST_ats, address, NULL, NULL, 0);
670 * Function called for any HELLO known to PEERINFO.
673 * @param peer id of the peer, NULL for last call
674 * @param hello hello message for the peer (can be NULL)
675 * @param err_msg error message
678 process_peerinfo_hello (void *cls, const struct GNUNET_PeerIdentity *peer,
679 const struct GNUNET_HELLO_Message *hello,
682 GNUNET_assert (NULL != peer);
685 GNUNET_assert (NULL ==
686 GNUNET_HELLO_iterate_addresses (hello, GNUNET_NO,
693 * Start the validation subsystem.
696 GST_validation_start ()
698 validation_map = GNUNET_CONTAINER_multihashmap_create (VALIDATION_MAP_SIZE);
699 pnc = GNUNET_PEERINFO_notify (GST_cfg, &process_peerinfo_hello, NULL);
704 * Stop the validation subsystem.
707 GST_validation_stop ()
709 struct CheckHelloValidatedContext *chvc;
711 GNUNET_CONTAINER_multihashmap_iterate (validation_map,
712 &cleanup_validation_entry, NULL);
713 GNUNET_CONTAINER_multihashmap_destroy (validation_map);
714 validation_map = NULL;
715 while (NULL != (chvc = chvc_head))
717 GNUNET_CONTAINER_DLL_remove (chvc_head, chvc_tail, chvc);
720 GNUNET_PEERINFO_notify_cancel (pnc);
725 * Send the given PONG to the given address.
727 * @param cls the PONG message
728 * @param public_key public key for the peer, never NULL
729 * @param valid_until is ZERO if we never validated the address,
730 * otherwise a time up to when we consider it (or was) valid
731 * @param validation_block is FOREVER if the address is for an unsupported plugin (from PEERINFO)
732 * is ZERO if the address is considered valid (no validation needed)
733 * otherwise a time in the future if we're currently denying re-validation
734 * @param address target address
737 multicast_pong (void *cls,
738 const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
739 *public_key, struct GNUNET_TIME_Absolute valid_until,
740 struct GNUNET_TIME_Absolute validation_block,
741 const struct GNUNET_HELLO_Address *address)
743 struct TransportPongMessage *pong = cls;
744 struct GNUNET_TRANSPORT_PluginFunctions *papi;
746 papi = GST_plugins_find (address->transport_name);
750 GNUNET_assert (papi->send != NULL);
751 GNUNET_assert (papi->get_session != NULL);
753 struct Session * session = papi->get_session(papi->cls, address);
760 papi->send (papi->cls, session,
761 (const char *) pong, ntohs (pong->header.size),
762 PONG_PRIORITY, ACCEPTABLE_PING_DELAY,
768 * We've received a PING. If appropriate, generate a PONG.
770 * @param sender peer sending the PING
771 * @param hdr the PING
772 * @param sender_address the sender address as we got it
773 * @param session session we got the PING from
776 GST_validation_handle_ping (const struct GNUNET_PeerIdentity *sender,
777 const struct GNUNET_MessageHeader *hdr,
778 const struct GNUNET_HELLO_Address *sender_address,
779 struct Session *session)
781 const struct TransportPingMessage *ping;
782 struct TransportPongMessage *pong;
783 struct GNUNET_TRANSPORT_PluginFunctions *papi;
784 struct GNUNET_CRYPTO_RsaSignature *sig_cache;
785 struct GNUNET_TIME_Absolute *sig_cache_exp;
791 struct GNUNET_HELLO_Address address;
793 if (ntohs (hdr->size) < sizeof (struct TransportPingMessage))
798 ping = (const struct TransportPingMessage *) hdr;
800 memcmp (&ping->target, &GST_my_identity,
801 sizeof (struct GNUNET_PeerIdentity)))
803 GNUNET_STATISTICS_update (GST_stats,
805 ("# PING message for different peer received"), 1,
809 GNUNET_STATISTICS_update (GST_stats,
810 gettext_noop ("# PING messages received"), 1,
812 addr = (const char *) &ping[1];
813 alen = ntohs (hdr->size) - sizeof (struct TransportPingMessage);
814 /* peer wants to confirm that this is one of our addresses, this is what is
815 * used for address validation */
818 sig_cache_exp = NULL;
822 addrend = memchr (addr, '\0', alen);
829 slen = strlen (addr) + 1;
831 address.address = addrend;
832 address.address_length = alen;
833 address.transport_name = addr;
834 address.peer = *sender;
836 GST_hello_test_address (&address, &sig_cache, &sig_cache_exp))
838 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
840 ("Not confirming PING with address `%s' since I cannot confirm having this address.\n"),
841 GST_plugins_a2s (&address));
847 addrend = NULL; /* make gcc happy */
849 static struct GNUNET_CRYPTO_RsaSignature no_address_signature;
850 static struct GNUNET_TIME_Absolute no_address_signature_expiration;
852 sig_cache = &no_address_signature;
853 sig_cache_exp = &no_address_signature_expiration;
856 pong = GNUNET_malloc (sizeof (struct TransportPongMessage) + alen + slen);
858 htons (sizeof (struct TransportPongMessage) + alen + slen);
859 pong->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_PONG);
861 htonl (sizeof (struct GNUNET_CRYPTO_RsaSignaturePurpose) +
862 sizeof (uint32_t) + sizeof (struct GNUNET_TIME_AbsoluteNBO) +
864 pong->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_TRANSPORT_PONG_OWN);
865 pong->challenge = ping->challenge;
866 pong->addrlen = htonl (alen + slen);
867 memcpy (&pong[1], addr, slen);
868 memcpy (&((char *) &pong[1])[slen], addrend, alen);
869 if (GNUNET_TIME_absolute_get_remaining (*sig_cache_exp).rel_value <
870 PONG_SIGNATURE_LIFETIME.rel_value / 4)
872 /* create / update cached sig */
874 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
875 "Creating PONG signature to indicate ownership.\n");
877 *sig_cache_exp = GNUNET_TIME_relative_to_absolute (PONG_SIGNATURE_LIFETIME);
878 pong->expiration = GNUNET_TIME_absolute_hton (*sig_cache_exp);
879 GNUNET_assert (GNUNET_OK ==
880 GNUNET_CRYPTO_rsa_sign (GST_my_private_key, &pong->purpose,
885 pong->expiration = GNUNET_TIME_absolute_hton (*sig_cache_exp);
887 pong->signature = *sig_cache;
889 GNUNET_assert (sender_address != NULL);
891 /* first see if the session we got this PING from can be used to transmit
892 * a response reliably */
893 papi = GST_plugins_find (sender_address->transport_name);
898 GNUNET_assert (papi->send != NULL);
899 GNUNET_assert (papi->get_session != NULL);
903 session = papi->get_session (papi->cls, sender_address);
912 ret = papi->send (papi->cls, session,
913 (const char *) pong, ntohs (pong->header.size),
914 PONG_PRIORITY, ACCEPTABLE_PING_DELAY,
920 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
921 "Transmitted PONG to `%s' via reliable mechanism\n",
922 GNUNET_i2s (sender));
924 GNUNET_STATISTICS_update (GST_stats,
926 ("# PONGs unicast via reliable transport"), 1,
932 /* no reliable method found, try transmission via all known addresses */
933 GNUNET_STATISTICS_update (GST_stats,
935 ("# PONGs multicast to all available addresses"), 1,
937 GST_validation_get_addresses (sender, &multicast_pong, pong);
943 * Context for the 'validate_address' function
945 struct ValidateAddressContext
948 * Hash of the public key of the peer whose address is being validated.
950 struct GNUNET_PeerIdentity pid;
953 * Public key of the peer whose address is being validated.
955 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded public_key;
960 * Iterator callback to go over all addresses and try to validate them
961 * (unless blocked or already validated).
963 * @param cls pointer to a 'struct ValidateAddressContext'
964 * @param address the address
965 * @param expiration expiration time
966 * @return GNUNET_OK (keep the address)
969 validate_address_iterator (void *cls,
970 const struct GNUNET_HELLO_Address *address,
971 struct GNUNET_TIME_Absolute expiration)
973 const struct ValidateAddressContext *vac = cls;
974 struct ValidationEntry *ve;
976 if (GNUNET_TIME_absolute_get_remaining (expiration).rel_value == 0)
977 return GNUNET_OK; /* expired */
978 ve = find_validation_entry (&vac->public_key, address);
979 if (GNUNET_SCHEDULER_NO_TASK == ve->revalidation_task)
980 ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
986 * Add the validated peer address to the HELLO.
988 * @param cls the 'struct ValidationEntry' with the validated address
989 * @param max space in buf
990 * @param buf where to add the address
991 * @return number of bytes written, 0 to signal the
992 * end of the iteration.
995 add_valid_peer_address (void *cls, size_t max, void *buf)
997 struct ValidationEntry *ve = cls;
999 if (GNUNET_YES == ve->copied)
1000 return 0; /* terminate */
1001 ve->copied = GNUNET_YES;
1002 return GNUNET_HELLO_add_address (ve->address, ve->valid_until, buf, max);
1007 * We've received a PONG. Check if it matches a pending PING and
1008 * mark the respective address as confirmed.
1010 * @param sender peer sending the PONG
1011 * @param hdr the PONG
1014 GST_validation_handle_pong (const struct GNUNET_PeerIdentity *sender,
1015 const struct GNUNET_MessageHeader *hdr)
1017 const struct TransportPongMessage *pong;
1018 struct ValidationEntry *ve;
1024 struct GNUNET_HELLO_Message *hello;
1025 struct GNUNET_HELLO_Address address;
1027 if (ntohs (hdr->size) < sizeof (struct TransportPongMessage))
1029 GNUNET_break_op (0);
1032 GNUNET_STATISTICS_update (GST_stats,
1033 gettext_noop ("# PONG messages received"), 1,
1036 pong = (const struct TransportPongMessage *) hdr;
1037 tname = (const char *) &pong[1];
1038 size = ntohs (hdr->size) - sizeof (struct TransportPongMessage);
1039 addr = memchr (tname, '\0', size);
1042 GNUNET_break_op (0);
1046 slen = strlen (tname) + 1;
1047 addrlen = size - slen;
1048 address.peer = *sender;
1049 address.address = addr;
1050 address.address_length = addrlen;
1051 address.transport_name = tname;
1052 ve = find_validation_entry (NULL, &address);
1053 if ((NULL == ve) || (ve->expecting_pong == GNUNET_NO))
1055 GNUNET_STATISTICS_update (GST_stats,
1057 ("# PONGs dropped, no matching pending validation"),
1061 /* now check that PONG is well-formed */
1062 if (0 != memcmp (&ve->pid, sender, sizeof (struct GNUNET_PeerIdentity)))
1064 GNUNET_break_op (0);
1069 GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_TRANSPORT_PONG_OWN,
1070 &pong->purpose, &pong->signature,
1073 GNUNET_break_op (0);
1077 if (GNUNET_TIME_absolute_get_remaining
1078 (GNUNET_TIME_absolute_ntoh (pong->expiration)).rel_value == 0)
1080 GNUNET_STATISTICS_update (GST_stats,
1082 ("# PONGs dropped, signature expired"), 1,
1087 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1088 "Address validated for peer `%s' with plugin `%s': `%s'\n",
1089 GNUNET_i2s (sender), tname, GST_plugins_a2s (tname, addr,
1093 /* validity achieved, remember it! */
1094 ve->expecting_pong = GNUNET_NO;
1095 ve->valid_until = GNUNET_TIME_relative_to_absolute (HELLO_ADDRESS_EXPIRATION);
1096 ve->latency = GNUNET_TIME_absolute_get_duration (ve->send_time);
1098 struct GNUNET_ATS_Information ats;
1100 ats.type = htonl (GNUNET_ATS_QUALITY_NET_DELAY);
1101 ats.value = htonl ((uint32_t) ve->latency.rel_value);
1102 GNUNET_ATS_address_update (GST_ats, ve->address, NULL, &ats, 1);
1104 /* build HELLO to store in PEERINFO */
1105 ve->copied = GNUNET_NO;
1106 hello = GNUNET_HELLO_create (&ve->public_key, &add_valid_peer_address, ve);
1107 GNUNET_PEERINFO_add_peer (GST_peerinfo, hello);
1108 GNUNET_free (hello);
1113 * We've received a HELLO, check which addresses are new and trigger
1116 * @param hello the HELLO we received
1119 GST_validation_handle_hello (const struct GNUNET_MessageHeader *hello)
1121 const struct GNUNET_HELLO_Message *hm =
1122 (const struct GNUNET_HELLO_Message *) hello;
1123 struct ValidateAddressContext vac;
1124 struct GNUNET_HELLO_Message *h;
1126 if ((GNUNET_OK != GNUNET_HELLO_get_id (hm, &vac.pid)) ||
1127 (GNUNET_OK != GNUNET_HELLO_get_key (hm, &vac.public_key)))
1129 /* malformed HELLO */
1134 memcmp (&GST_my_identity, &vac.pid, sizeof (struct GNUNET_PeerIdentity)))
1136 /* Add peer identity without addresses to peerinfo service */
1137 h = GNUNET_HELLO_create (&vac.public_key, NULL, NULL);
1138 GNUNET_PEERINFO_add_peer (GST_peerinfo, h);
1139 #if VERBOSE_VALIDATION
1140 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1141 _("Adding `%s' without addresses for peer `%s'\n"), "HELLO",
1142 GNUNET_i2s (&vac.pid));
1145 GNUNET_assert (NULL ==
1146 GNUNET_HELLO_iterate_addresses (hm, GNUNET_NO,
1147 &validate_address_iterator,
1153 * Closure for 'iterate_addresses'
1155 struct IteratorContext
1158 * Function to call on each address.
1160 GST_ValidationAddressCallback cb;
1171 * Call the callback in the closure for each validation entry.
1173 * @param cls the 'struct GST_ValidationIteratorContext'
1174 * @param key the peer's identity
1175 * @param value the 'struct ValidationEntry'
1176 * @return GNUNET_OK (continue to iterate)
1179 iterate_addresses (void *cls, const GNUNET_HashCode * key, void *value)
1181 struct IteratorContext *ic = cls;
1182 struct ValidationEntry *ve = value;
1184 ic->cb (ic->cb_cls, &ve->public_key, ve->valid_until, ve->revalidation_block,
1191 * Call the given function for each address for the given target.
1192 * Can either give a snapshot (synchronous API) or be continuous.
1194 * @param target peer information is requested for
1195 * @param cb function to call; will not be called after this function returns
1196 * @param cb_cls closure for 'cb'
1199 GST_validation_get_addresses (const struct GNUNET_PeerIdentity *target,
1200 GST_ValidationAddressCallback cb, void *cb_cls)
1202 struct IteratorContext ic;
1206 GNUNET_CONTAINER_multihashmap_get_multiple (validation_map,
1207 &target->hashPubKey,
1208 &iterate_addresses, &ic);
1213 * Update if we are using an address for a connection actively right now.
1214 * Based on this, the validation module will measure latency for the
1215 * address more or less often.
1217 * @param address the address
1218 * @param session the session
1219 * @param in_use GNUNET_YES if we are now using the address for a connection,
1220 * GNUNET_NO if we are no longer using the address for a connection
1221 * @param line line of caller just for DEBUGGING!
1224 GST_validation_set_address_use (const struct GNUNET_HELLO_Address *address,
1225 struct Session *session,
1229 struct ValidationEntry *ve;
1231 if (NULL != address)
1232 ve = find_validation_entry (NULL, address);
1234 ve = NULL; /* FIXME: lookup based on session... */
1237 /* this can happen for inbound connections (sender_address_len == 0); */
1240 if (ve->in_use == in_use)
1243 if (GNUNET_YES == in_use)
1245 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1246 "Error setting address in use for peer `%s' `%s' to USED: set last time by %i, called now by %i\n",
1247 GNUNET_i2s (&address->peer), GST_plugins_a2s (address),
1248 ve->last_line_set_to_yes, line);
1250 if (GNUNET_NO == in_use)
1252 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1253 "Error setting address in use for peer `%s' `%s' to NOT_USED: set last time by %i, called now by %i\n",
1254 GNUNET_i2s (&address->peer), GST_plugins_a2s (address),
1255 ve->last_line_set_to_no, line);
1259 if (GNUNET_YES == in_use)
1261 ve->last_line_set_to_yes = line;
1263 if (GNUNET_NO == in_use)
1265 ve->last_line_set_to_no = line;
1268 GNUNET_break (ve->in_use != in_use); /* should be different... */
1269 ve->in_use = in_use;
1270 if (in_use == GNUNET_YES)
1272 /* from now on, higher frequeny, so reschedule now */
1273 GNUNET_SCHEDULER_cancel (ve->revalidation_task);
1274 ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
1280 * Query validation about the latest observed latency on a given
1283 * @param sender peer
1284 * @param address the address
1285 * @param session session
1286 * @return observed latency of the address, FOREVER if the address was
1287 * never successfully validated
1289 struct GNUNET_TIME_Relative
1290 GST_validation_get_address_latency (const struct GNUNET_PeerIdentity *sender,
1291 const struct GNUNET_HELLO_Address *address,
1292 struct Session *session)
1294 struct ValidationEntry *ve;
1296 if (NULL == address)
1298 GNUNET_break (0); // FIXME: support having latency only with session...
1299 return GNUNET_TIME_UNIT_FOREVER_REL;
1301 ve = find_validation_entry (NULL, address);
1303 return GNUNET_TIME_UNIT_FOREVER_REL;
1308 /* end of file gnunet-service-transport_validation.c */