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1/*
2 This file is part of GNUnet
3 Copyright (C) 2010-2014, 2018, 2019 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-communicator-udp.c
23 * @brief Transport plugin using UDP.
24 * @author Christian Grothoff
25 *
26 * TODO:
27 * - consider imposing transmission limits in the absence
28 * of ACKs; or: maybe this should be done at TNG service level?
29 * (at least the receiver might want to enforce limits on
30 * KX/DH operations per sender in here) (#5552)
31 * - overall, we should look more into flow control support
32 * (either in backchannel, or general solution in TNG service)
33 * - handle addresses discovered from broadcasts (#5551)
34 * (think: what was the story again on address validation?
35 * where is the API for that!?!)
36 * - support DNS names in BINDTO option (#5528)
37 * - support NAT connection reversal method (#5529)
38 * - support other UDP-specific NAT traversal methods (#)
39 */
40#include "platform.h"
41#include "gnunet_util_lib.h"
42#include "gnunet_protocols.h"
43#include "gnunet_signatures.h"
44#include "gnunet_constants.h"
45#include "gnunet_nt_lib.h"
46#include "gnunet_nat_service.h"
47#include "gnunet_statistics_service.h"
48#include "gnunet_transport_application_service.h"
49#include "gnunet_transport_communication_service.h"
50
51/**
52 * How often do we rekey based on time (at least)
53 */
54#define DEFAULT_REKEY_TIME_INTERVAL GNUNET_TIME_UNIT_DAYS
55
56/**
57 * How long do we wait until we must have received the initial KX?
58 */
59#define PROTO_QUEUE_TIMEOUT GNUNET_TIME_UNIT_MINUTES
60
61/**
62 * How often do we broadcast our presence on the LAN?
63 */
64#define BROADCAST_FREQUENCY GNUNET_TIME_UNIT_MINUTES
65
66/**
67 * How often do we scan for changes to our network interfaces?
68 */
69#define INTERFACE_SCAN_FREQUENCY \
70 GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
71
72/**
73 * How long do we believe our addresses to remain up (before
74 * the other peer should revalidate).
75 */
76#define ADDRESS_VALIDITY_PERIOD GNUNET_TIME_UNIT_HOURS
77
78#define WORKING_QUEUE_INTERVALL \
79 GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MICROSECONDS,1)
80
81/**
82 * AES key size.
83 */
84#define AES_KEY_SIZE (256 / 8)
85
86/**
87 * AES (GCM) IV size.
88 */
89#define AES_IV_SIZE (96 / 8)
90
91/**
92 * Size of the GCM tag.
93 */
94#define GCM_TAG_SIZE (128 / 8)
95
96#define GENERATE_AT_ONCE 2
97
98/**
99 * If we fall below this number of available KCNs,
100 * we generate additional ACKs until we reach
101 * #KCN_TARGET.
102 * Should be large enough that we don't generate ACKs all
103 * the time and still have enough time for the ACK to
104 * arrive before the sender runs out. So really this
105 * should ideally be based on the RTT.
106 */
107#define KCN_THRESHOLD 92
108
109/**
110 * How many KCNs do we keep around *after* we hit
111 * the #KCN_THRESHOLD? Should be larger than
112 * #KCN_THRESHOLD so we do not generate just one
113 * ACK at the time.
114 */
115#define KCN_TARGET 128
116
117/**
118 * What is the maximum delta between KCN sequence numbers
119 * that we allow. Used to expire 'ancient' KCNs that likely
120 * were dropped by the network. Must be larger than
121 * KCN_TARGET (otherwise we generate new KCNs all the time),
122 * but not too large (otherwise packet loss may cause
123 * sender to fall back to KX needlessly when sender runs
124 * out of ACK'ed KCNs due to losses).
125 */
126#define MAX_SQN_DELTA 160
127
128/**
129 * How many shared master secrets do we keep around
130 * at most per sender? Should be large enough so
131 * that we generally have a chance of sending an ACK
132 * before the sender already rotated out the master
133 * secret. Generally values around #KCN_TARGET make
134 * sense. Might make sense to adapt to RTT if we had
135 * a good measurement...
136 */
137#define MAX_SECRETS 128000
138
139/**
140 * Default value for how often we do rekey based on number of bytes transmitted?
141 * (additionally randomized).
142 */
143#define DEFAULT_REKEY_MAX_BYTES (1024LLU * 1024 * 1024 * 4LLU)
144
145/**
146 * Address prefix used by the communicator.
147 */
148
149#define COMMUNICATOR_ADDRESS_PREFIX "udp"
150
151/**
152 * Configuration section used by the communicator.
153 */
154#define COMMUNICATOR_CONFIG_SECTION "communicator-udp"
155
156GNUNET_NETWORK_STRUCT_BEGIN
157
158
159/**
160 * Signature we use to verify that the ephemeral key was really chosen by
161 * the specified sender. If possible, the receiver should respond with
162 * a `struct UDPAck` (possibly via backchannel).
163 */
164struct UdpHandshakeSignature
165{
166 /**
167 * Purpose must be #GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE
168 */
169 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
170
171 /**
172 * Identity of the inititor of the UDP connection (UDP client).
173 */
174 struct GNUNET_PeerIdentity sender;
175
176 /**
177 * Presumed identity of the target of the UDP connection (UDP server)
178 */
179 struct GNUNET_PeerIdentity receiver;
180
181 /**
182 * Ephemeral key used by the @e sender.
183 */
184 struct GNUNET_CRYPTO_EcdhePublicKey ephemeral;
185
186 /**
187 * Monotonic time of @e sender, to possibly help detect replay attacks
188 * (if receiver persists times by sender).
189 */
190 struct GNUNET_TIME_AbsoluteNBO monotonic_time;
191};
192
193
194/**
195 * "Plaintext" header at beginning of KX message. Followed
196 * by encrypted `struct UDPConfirmation`.
197 */
198struct InitialKX
199{
200 /**
201 * Ephemeral key for KX.
202 */
203 struct GNUNET_CRYPTO_EcdhePublicKey ephemeral;
204
205 /**
206 * HMAC for the following encrypted message, using GCM. HMAC uses
207 * key derived from the handshake with sequence number zero.
208 */
209 char gcm_tag[GCM_TAG_SIZE];
210
211 /**
212 * A flag indicating, if the sender is doing rekeying.
213 */
214 int rekeying;
215};
216
217
218/**
219 * Encrypted continuation of UDP initial handshake, followed
220 * by message header with payload.
221 */
222struct UDPConfirmation
223{
224 /**
225 * Sender's identity
226 */
227 struct GNUNET_PeerIdentity sender;
228
229 /**
230 * Sender's signature of type #GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE
231 */
232 struct GNUNET_CRYPTO_EddsaSignature sender_sig;
233
234 /**
235 * Monotonic time of @e sender, to possibly help detect replay attacks
236 * (if receiver persists times by sender).
237 */
238 struct GNUNET_TIME_AbsoluteNBO monotonic_time;
239
240 /* followed by messages */
241
242 /* padding may follow actual messages */
243};
244
245
246/**
247 * UDP key acknowledgement. May be sent via backchannel. Allows the
248 * sender to use `struct UDPBox` with the acknowledge key henceforth.
249 */
250struct UDPAck
251{
252 /**
253 * Type is #GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK.
254 */
255 struct GNUNET_MessageHeader header;
256
257 /**
258 * Sequence acknowledgement limit. Specifies current maximum sequence
259 * number supported by receiver.
260 */
261 uint32_t sequence_max GNUNET_PACKED;
262
263 /**
264 * Sequence acknowledgement limit. Specifies current maximum sequence
265 * number supported by receiver.
266 */
267 uint32_t acks_available GNUNET_PACKED;
268
269 /**
270 * CMAC of the base key being acknowledged.
271 */
272 struct GNUNET_HashCode cmac;
273};
274
275
276/**
277 * Signature we use to verify that the broadcast was really made by
278 * the peer that claims to have made it. Basically, affirms that the
279 * peer is really using this IP address (albeit possibly not in _our_
280 * LAN). Makes it difficult for peers in the LAN to claim to
281 * be just any global peer -- an attacker must have at least
282 * shared a LAN with the peer they're pretending to be here.
283 */
284struct UdpBroadcastSignature
285{
286 /**
287 * Purpose must be #GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST
288 */
289 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
290
291 /**
292 * Identity of the inititor of the UDP broadcast.
293 */
294 struct GNUNET_PeerIdentity sender;
295
296 /**
297 * Hash of the sender's UDP address.
298 */
299 struct GNUNET_HashCode h_address;
300};
301
302
303/**
304 * Broadcast by peer in LAN announcing its presence. Unusual in that
305 * we don't pad these to full MTU, as we cannot prevent being
306 * recognized in LAN as GNUnet peers if this feature is enabled
307 * anyway. Also, the entire message is in cleartext.
308 */
309struct UDPBroadcast
310{
311 /**
312 * Sender's peer identity.
313 */
314 struct GNUNET_PeerIdentity sender;
315
316 /**
317 * Sender's signature of type
318 * #GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST
319 */
320 struct GNUNET_CRYPTO_EddsaSignature sender_sig;
321};
322
323
324/**
325 * UDP message box. Always sent encrypted, only allowed after
326 * the receiver sent a `struct UDPAck` for the base key!
327 */
328struct UDPBox
329{
330 /**
331 * Key and IV identification code. KDF applied to an acknowledged
332 * base key and a sequence number. Sequence numbers must be used
333 * monotonically increasing up to the maximum specified in
334 * `struct UDPAck`. Without further `struct UDPAck`s, the sender
335 * must fall back to sending handshakes!
336 */
337 struct GNUNET_ShortHashCode kid;
338
339 /**
340 * 128-bit authentication tag for the following encrypted message,
341 * from GCM. MAC starts at the @e body_start that follows and
342 * extends until the end of the UDP payload. If the @e hmac is
343 * wrong, the receiver should check if the message might be a
344 * `struct UdpHandshakeSignature`.
345 */
346 char gcm_tag[GCM_TAG_SIZE];
347
348 /**
349 * A flag indicating, if the sender is doing rekeying.
350 */
351 int rekeying;
352};
353
354/**
355 * UDP message box. Always sent encrypted, only allowed after
356 * the receiver sent a `struct UDPAck` for the base key!
357 */
358struct UDPRekey
359{
360 /**
361 * Key and IV identification code. KDF applied to an acknowledged
362 * base key and a sequence number. Sequence numbers must be used
363 * monotonically increasing up to the maximum specified in
364 * `struct UDPAck`. Without further `struct UDPAck`s, the sender
365 * must fall back to sending handshakes!
366 */
367 struct GNUNET_ShortHashCode kid;
368
369 /**
370 * 128-bit authentication tag for the following encrypted message,
371 * from GCM. MAC starts at the @e body_start that follows and
372 * extends until the end of the UDP payload. If the @e hmac is
373 * wrong, the receiver should check if the message might be a
374 * `struct UdpHandshakeSignature`.
375 */
376 char gcm_tag[GCM_TAG_SIZE];
377
378 /**
379 * Sender's identity
380 */
381 struct GNUNET_PeerIdentity sender;
382};
383
384GNUNET_NETWORK_STRUCT_END
385
386/**
387 * Shared secret we generated for a particular sender or receiver.
388 */
389struct SharedSecret;
390
391
392/**
393 * Pre-generated "kid" code (key and IV identification code) to
394 * quickly derive master key for a `struct UDPBox`.
395 */
396struct KeyCacheEntry
397{
398 /**
399 * Kept in a DLL.
400 */
401 struct KeyCacheEntry *next;
402
403 /**
404 * Kept in a DLL.
405 */
406 struct KeyCacheEntry *prev;
407
408 /**
409 * Key and IV identification code. KDF applied to an acknowledged
410 * base key and a sequence number. Sequence numbers must be used
411 * monotonically increasing up to the maximum specified in
412 * `struct UDPAck`. Without further `struct UDPAck`s, the sender
413 * must fall back to sending handshakes!
414 */
415 struct GNUNET_ShortHashCode kid;
416
417 /**
418 * Corresponding shared secret.
419 */
420 struct SharedSecret *ss;
421
422 /**
423 * Sequence number used to derive this entry from master key.
424 */
425 uint32_t sequence_number;
426};
427
428
429/**
430 * Information we track per sender address we have recently been
431 * in contact with (decryption from sender).
432 */
433struct SenderAddress;
434
435/**
436 * Information we track per receiving address we have recently been
437 * in contact with (encryption to receiver).
438 */
439struct ReceiverAddress;
440
441/**
442 * Shared secret we generated for a particular sender or receiver.
443 */
444struct SharedSecret
445{
446 /**
447 * Kept in a DLL.
448 */
449 struct SharedSecret *next;
450
451 /**
452 * Kept in a DLL.
453 */
454 struct SharedSecret *prev;
455
456 /**
457 * Kept in a DLL, sorted by sequence number. Only if we are decrypting.
458 */
459 struct KeyCacheEntry *kce_head;
460
461 /**
462 * Kept in a DLL, sorted by sequence number. Only if we are decrypting.
463 */
464 struct KeyCacheEntry *kce_tail;
465
466 /**
467 * Sender we use this shared secret with, or NULL.
468 */
469 struct SenderAddress *sender;
470
471 /**
472 * Receiver we use this shared secret with, or NULL.
473 */
474 struct ReceiverAddress *receiver;
475
476 /**
477 * Master shared secret.
478 */
479 struct GNUNET_HashCode master;
480
481 /**
482 * CMAC is used to identify @e master in ACKs.
483 */
484 struct GNUNET_HashCode cmac;
485
486 /**
487 * Up to which sequence number did we use this @e master already?
488 * (for encrypting only)
489 */
490 uint32_t sequence_used;
491
492 /**
493 * Up to which sequence number did the other peer allow us to use
494 * this key, or up to which number did we allow the other peer to
495 * use this key?
496 */
497 uint32_t sequence_allowed;
498
499 /**
500 * Number of active KCN entries.
501 */
502 unsigned int active_kce_count;
503};
504
505
506/**
507 * Information we track per sender address we have recently been
508 * in contact with (we decrypt messages from the sender).
509 */
510struct SenderAddress
511{
512 /**
513 * Shared secret we use with @e target for rekeying.
514 */
515 struct SharedSecret *ss_rekey;
516
517 /**
518 * Flag indicating sender is initiated rekeying for this receiver.
519 */
520 int rekeying;
521
522 /**
523 * To whom are we talking to.
524 */
525 struct GNUNET_PeerIdentity target;
526
527 /**
528 * Entry in sender expiration heap.
529 */
530 struct GNUNET_CONTAINER_HeapNode *hn;
531
532 /**
533 * Shared secrets we used with @e target, first used is head.
534 */
535 struct SharedSecret *ss_head;
536
537 /**
538 * Shared secrets we used with @e target, last used is tail.
539 */
540 struct SharedSecret *ss_tail;
541
542 /**
543 * Address of the other peer.
544 */
545 struct sockaddr *address;
546
547 /**
548 * Length of the address.
549 */
550 socklen_t address_len;
551
552 /**
553 * Timeout for this sender.
554 */
555 struct GNUNET_TIME_Absolute timeout;
556
557 /**
558 * Length of the DLL at @a ss_head.
559 */
560 unsigned int num_secrets;
561
562 /**
563 * Number of BOX keys from ACKs we have currently
564 * available for this sender.
565 */
566 unsigned int acks_available;
567
568 /**
569 * Which network type does this queue use?
570 */
571 enum GNUNET_NetworkType nt;
572
573 /**
574 * sender_destroy already called on sender.
575 */
576 int sender_destroy_called;
577
578
579 /**
580 * ID of kce working queue task
581 */
582 struct GNUNET_SCHEDULER_Task *kce_task;
583
584 /**
585 * ID of kce rekey working queue task
586 */
587 struct GNUNET_SCHEDULER_Task *kce_task_rekey;
588
589 /**
590 * Is the kce_task finished?
591 */
592 int kce_task_finished;
593};
594
595
596/**
597 * Information we track per receiving address we have recently been
598 * in contact with (encryption to receiver).
599 */
600struct ReceiverAddress
601{
602
603 /**
604 * Shared secret we use with @e target for rekeying.
605 */
606 struct SharedSecret *ss_rekey;
607
608 /**
609 * Acks available when we started rekeying.
610 */
611 unsigned int rekey_acks_available;
612
613 /**
614 * Send bytes for this receiver address.
615 */
616 uint64_t rekey_send_bytes;
617
618 /**
619 * Timeout for this receiver address.
620 */
621 struct GNUNET_TIME_Absolute rekey_timeout;
622
623 /**
624 * Flag indicating sender is initiated rekeying for this receiver.
625 */
626 int rekeying;
627
628 /**
629 * Number of kce we retain for sending the rekeying shared secret.
630 */
631 int number_rekeying_kce;
632
633 /**
634 * To whom are we talking to.
635 */
636 struct GNUNET_PeerIdentity target;
637
638 /**
639 * Shared secrets we received from @e target, first used is head.
640 */
641 struct SharedSecret *ss_head;
642
643 /**
644 * Shared secrets we received with @e target, last used is tail.
645 */
646 struct SharedSecret *ss_tail;
647
648 /**
649 * Address of the receiver in the human-readable format
650 * with the #COMMUNICATOR_ADDRESS_PREFIX.
651 */
652 char *foreign_addr;
653
654 /**
655 * Address of the other peer.
656 */
657 struct sockaddr *address;
658
659 /**
660 * Length of the address.
661 */
662 socklen_t address_len;
663
664 /**
665 * Entry in sender expiration heap.
666 */
667 struct GNUNET_CONTAINER_HeapNode *hn;
668
669 /**
670 * KX message queue we are providing for the #ch.
671 */
672 struct GNUNET_MQ_Handle *kx_mq;
673
674 /**
675 * Default message queue we are providing for the #ch.
676 */
677 struct GNUNET_MQ_Handle *d_mq;
678
679 /**
680 * handle for KX queue with the #ch.
681 */
682 struct GNUNET_TRANSPORT_QueueHandle *kx_qh;
683
684 /**
685 * handle for default queue with the #ch.
686 */
687 struct GNUNET_TRANSPORT_QueueHandle *d_qh;
688
689 /**
690 * Timeout for this receiver address.
691 */
692 struct GNUNET_TIME_Absolute timeout;
693
694 /**
695 * MTU we allowed transport for this receiver's KX queue.
696 */
697 size_t kx_mtu;
698
699 /**
700 * MTU we allowed transport for this receiver's default queue.
701 */
702 size_t d_mtu;
703
704 /**
705 * Length of the DLL at @a ss_head.
706 */
707 unsigned int num_secrets;
708
709 /**
710 * Number of BOX keys from ACKs we have currently
711 * available for this receiver.
712 */
713 unsigned int acks_available;
714
715 /**
716 * Which network type does this queue use?
717 */
718 enum GNUNET_NetworkType nt;
719
720 /**
721 * receiver_destroy already called on receiver.
722 */
723 int receiver_destroy_called;
724};
725
726/**
727 * Interface we broadcast our presence on.
728 */
729struct BroadcastInterface
730{
731 /**
732 * Kept in a DLL.
733 */
734 struct BroadcastInterface *next;
735
736 /**
737 * Kept in a DLL.
738 */
739 struct BroadcastInterface *prev;
740
741 /**
742 * Task for this broadcast interface.
743 */
744 struct GNUNET_SCHEDULER_Task *broadcast_task;
745
746 /**
747 * Sender's address of the interface.
748 */
749 struct sockaddr *sa;
750
751 /**
752 * Broadcast address to use on the interface.
753 */
754 struct sockaddr *ba;
755
756 /**
757 * Message we broadcast on this interface.
758 */
759 struct UDPBroadcast bcm;
760
761 /**
762 * If this is an IPv6 interface, this is the request
763 * we use to join/leave the group.
764 */
765 struct ipv6_mreq mcreq;
766
767 /**
768 * Number of bytes in @e sa.
769 */
770 socklen_t salen;
771
772 /**
773 * Was this interface found in the last #iface_proc() scan?
774 */
775 int found;
776};
777
778/**
779 * The rekey interval
780 */
781static struct GNUNET_TIME_Relative rekey_interval;
782
783/**
784 * How often we do rekey based on number of bytes transmitted
785 */
786static unsigned long long rekey_max_bytes;
787/**
788 * Shared secret we finished the last kce working queue for.
789 */
790struct SharedSecret *ss_finished;
791
792/**
793 * Cache of pre-generated key IDs.
794 */
795static struct GNUNET_CONTAINER_MultiShortmap *key_cache;
796
797/**
798 * ID of read task
799 */
800static struct GNUNET_SCHEDULER_Task *read_task;
801
802/**
803 * ID of timeout task
804 */
805static struct GNUNET_SCHEDULER_Task *timeout_task;
806
807/**
808 * ID of master broadcast task
809 */
810static struct GNUNET_SCHEDULER_Task *broadcast_task;
811
812/**
813 * For logging statistics.
814 */
815static struct GNUNET_STATISTICS_Handle *stats;
816
817/**
818 * Our environment.
819 */
820static struct GNUNET_TRANSPORT_CommunicatorHandle *ch;
821
822/**
823 * Receivers (map from peer identity to `struct ReceiverAddress`)
824 */
825static struct GNUNET_CONTAINER_MultiPeerMap *receivers;
826
827/**
828 * Senders (map from peer identity to `struct SenderAddress`)
829 */
830static struct GNUNET_CONTAINER_MultiPeerMap *senders;
831
832/**
833 * Expiration heap for senders (contains `struct SenderAddress`)
834 */
835static struct GNUNET_CONTAINER_Heap *senders_heap;
836
837/**
838 * Expiration heap for receivers (contains `struct ReceiverAddress`)
839 */
840static struct GNUNET_CONTAINER_Heap *receivers_heap;
841
842/**
843 * Broadcast interface tasks. Kept in a DLL.
844 */
845static struct BroadcastInterface *bi_head;
846
847/**
848 * Broadcast interface tasks. Kept in a DLL.
849 */
850static struct BroadcastInterface *bi_tail;
851
852/**
853 * Our socket.
854 */
855static struct GNUNET_NETWORK_Handle *udp_sock;
856
857/**
858 * #GNUNET_YES if #udp_sock supports IPv6.
859 */
860static int have_v6_socket;
861
862/**
863 * Our public key.
864 */
865static struct GNUNET_PeerIdentity my_identity;
866
867/**
868 * Our private key.
869 */
870static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
871
872/**
873 * Our configuration.
874 */
875static const struct GNUNET_CONFIGURATION_Handle *cfg;
876
877/**
878 * Our handle to report addresses for validation to TRANSPORT.
879 */
880static struct GNUNET_TRANSPORT_ApplicationHandle *ah;
881
882/**
883 * Network scanner to determine network types.
884 */
885static struct GNUNET_NT_InterfaceScanner *is;
886
887/**
888 * Connection to NAT service.
889 */
890static struct GNUNET_NAT_Handle *nat;
891
892/**
893 * Port number to which we are actually bound.
894 */
895static uint16_t my_port;
896
897
898/**
899 * An interface went away, stop broadcasting on it.
900 *
901 * @param bi entity to close down
902 */
903static void
904bi_destroy (struct BroadcastInterface *bi)
905{
906 if (AF_INET6 == bi->sa->sa_family)
907 {
908 /* Leave the multicast group */
909 if (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (udp_sock,
910 IPPROTO_IPV6,
911 IPV6_LEAVE_GROUP,
912 &bi->mcreq,
913 sizeof(bi->mcreq)))
914 {
915 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "setsockopt");
916 }
917 }
918 GNUNET_CONTAINER_DLL_remove (bi_head, bi_tail, bi);
919 GNUNET_SCHEDULER_cancel (bi->broadcast_task);
920 GNUNET_free (bi->sa);
921 GNUNET_free (bi->ba);
922 GNUNET_free (bi);
923}
924
925
926/**
927 * Destroys a receiving state due to timeout or shutdown.
928 *
929 * @param receiver entity to close down
930 */
931static void
932receiver_destroy (struct ReceiverAddress *receiver)
933{
934
935 receiver->receiver_destroy_called = GNUNET_YES;
936
937 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
938 "Disconnecting receiver for peer `%s'\n",
939 GNUNET_i2s (&receiver->target));
940 /*if (NULL != (mq = receiver->kx_mq))
941 {
942 receiver->kx_mq = NULL;
943 GNUNET_MQ_destroy (mq);
944 }*/
945 if (NULL != receiver->kx_qh)
946 {
947 GNUNET_TRANSPORT_communicator_mq_del (receiver->kx_qh);
948 receiver->kx_qh = NULL;
949 receiver->kx_mq = NULL;
950 }
951 /*if (NULL != (mq = receiver->d_mq))
952 {
953 receiver->d_mq = NULL;
954 GNUNET_MQ_destroy (mq);
955 }*/
956 if (NULL != receiver->d_qh)
957 {
958 GNUNET_TRANSPORT_communicator_mq_del (receiver->d_qh);
959 receiver->d_qh = NULL;
960 }
961 GNUNET_assert (GNUNET_YES ==
962 GNUNET_CONTAINER_multipeermap_remove (receivers,
963 &receiver->target,
964 receiver));
965 GNUNET_assert (receiver == GNUNET_CONTAINER_heap_remove_node (receiver->hn));
966 GNUNET_STATISTICS_set (stats,
967 "# receivers active",
968 GNUNET_CONTAINER_multipeermap_size (receivers),
969 GNUNET_NO);
970 GNUNET_free (receiver->address);
971 GNUNET_free (receiver->foreign_addr);
972 GNUNET_free (receiver);
973}
974
975
976/**
977 * Free memory used by key cache entry.
978 *
979 * @param kce the key cache entry
980 */
981static void
982kce_destroy (struct KeyCacheEntry *kce)
983{
984 struct SharedSecret *ss = kce->ss;
985
986 ss->active_kce_count--;
987 ss->sender->acks_available--;
988 GNUNET_CONTAINER_DLL_remove (ss->kce_head, ss->kce_tail, kce);
989 GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multishortmap_remove (key_cache,
990 &kce->kid,
991 kce));
992 GNUNET_free (kce);
993}
994
995
996/**
997 * Compute @a kid.
998 *
999 * @param msec master secret for HMAC calculation
1000 * @param serial number for the @a smac calculation
1001 * @param kid[out] where to write the key ID
1002 */
1003static void
1004get_kid (const struct GNUNET_HashCode *msec,
1005 uint32_t serial,
1006 struct GNUNET_ShortHashCode *kid)
1007{
1008 uint32_t sid = htonl (serial);
1009
1010 GNUNET_CRYPTO_hkdf (kid,
1011 sizeof(*kid),
1012 GCRY_MD_SHA512,
1013 GCRY_MD_SHA256,
1014 &sid,
1015 sizeof(sid),
1016 msec,
1017 sizeof(*msec),
1018 "UDP-KID",
1019 strlen ("UDP-KID"),
1020 NULL,
1021 0);
1022}
1023
1024
1025/**
1026 * Setup key cache entry for sequence number @a seq and shared secret @a ss.
1027 *
1028 * @param ss shared secret
1029 * @param seq sequence number for the key cache entry
1030 */
1031static void
1032kce_generate (struct SharedSecret *ss, uint32_t seq)
1033{
1034 struct KeyCacheEntry *kce;
1035
1036 GNUNET_assert (0 < seq);
1037 kce = GNUNET_new (struct KeyCacheEntry);
1038 kce->ss = ss;
1039 kce->sequence_number = seq;
1040 get_kid (&ss->master, seq, &kce->kid);
1041 GNUNET_CONTAINER_DLL_insert (ss->kce_head, ss->kce_tail, kce);
1042 ss->active_kce_count++;
1043 ss->sender->acks_available++;
1044 (void) GNUNET_CONTAINER_multishortmap_put (
1045 key_cache,
1046 &kce->kid,
1047 kce,
1048 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
1049 GNUNET_STATISTICS_set (stats,
1050 "# KIDs active",
1051 GNUNET_CONTAINER_multishortmap_size (key_cache),
1052 GNUNET_NO);
1053}
1054
1055
1056/**
1057 * Destroy @a ss and associated key cache entries.
1058 *
1059 * @param ss shared secret to destroy
1060 * @param withoutKce If GNUNET_YES shared secrets with kce will not be destroyed.
1061 */
1062static int
1063secret_destroy (struct SharedSecret *ss, int withoutKce)
1064{
1065 struct SenderAddress *sender;
1066 struct ReceiverAddress *receiver;
1067 struct KeyCacheEntry *kce;
1068
1069 if (withoutKce && (ss->sequence_allowed > 0))
1070 return GNUNET_NO;
1071
1072 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1073 "secret %s destroy %u %u\n",
1074 GNUNET_h2s (&ss->master),
1075 withoutKce,
1076 ss->sequence_allowed);
1077 if (NULL != (sender = ss->sender))
1078 {
1079 GNUNET_CONTAINER_DLL_remove (sender->ss_head, sender->ss_tail, ss);
1080 sender->num_secrets--;
1081 }
1082 if (NULL != (receiver = ss->receiver))
1083 {
1084 GNUNET_CONTAINER_DLL_remove (receiver->ss_head, receiver->ss_tail, ss);
1085 receiver->num_secrets--;
1086 // Uncomment this for alternativ 1 of backchannel functionality
1087 receiver->acks_available -= (ss->sequence_allowed - ss->sequence_used);
1088 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1089 "%u receiver->acks_available 3\n",
1090 receiver->acks_available);
1091 // Until here for alternativ 1
1092 }
1093 while (NULL != (kce = ss->kce_head))
1094 kce_destroy (kce);
1095 GNUNET_STATISTICS_update (stats, "# Secrets active", -1, GNUNET_NO);
1096 GNUNET_STATISTICS_set (stats,
1097 "# KIDs active",
1098 GNUNET_CONTAINER_multishortmap_size (key_cache),
1099 GNUNET_NO);
1100 GNUNET_free (ss);
1101 return GNUNET_YES;
1102}
1103
1104
1105/**
1106 * Functions with this signature are called whenever we need
1107 * to close a sender's state due to timeout.
1108 *
1109 * @param sender entity to close down
1110 */
1111static void
1112sender_destroy (struct SenderAddress *sender)
1113{
1114 sender->sender_destroy_called = GNUNET_YES;
1115 GNUNET_assert (
1116 GNUNET_YES ==
1117 GNUNET_CONTAINER_multipeermap_remove (senders, &sender->target, sender));
1118 GNUNET_assert (sender == GNUNET_CONTAINER_heap_remove_node (sender->hn));
1119 GNUNET_STATISTICS_set (stats,
1120 "# senders active",
1121 GNUNET_CONTAINER_multipeermap_size (senders),
1122 GNUNET_NO);
1123 GNUNET_free (sender->address);
1124 GNUNET_free (sender);
1125}
1126
1127
1128/**
1129 * Compute @a key and @a iv.
1130 *
1131 * @param msec master secret for calculation
1132 * @param serial number for the @a smac calculation
1133 * @param key[out] where to write the decryption key
1134 * @param iv[out] where to write the IV
1135 */
1136static void
1137get_iv_key (const struct GNUNET_HashCode *msec,
1138 uint32_t serial,
1139 char key[AES_KEY_SIZE],
1140 char iv[AES_IV_SIZE])
1141{
1142 uint32_t sid = htonl (serial);
1143 char res[AES_KEY_SIZE + AES_IV_SIZE];
1144
1145 GNUNET_CRYPTO_hkdf (res,
1146 sizeof(res),
1147 GCRY_MD_SHA512,
1148 GCRY_MD_SHA256,
1149 &sid,
1150 sizeof(sid),
1151 msec,
1152 sizeof(*msec),
1153 "UDP-IV-KEY",
1154 strlen ("UDP-IV-KEY"),
1155 NULL,
1156 0);
1157 memcpy (key, res, AES_KEY_SIZE);
1158 memcpy (iv, &res[AES_KEY_SIZE], AES_IV_SIZE);
1159}
1160
1161
1162/**
1163 * Increment sender timeout due to activity.
1164 *
1165 * @param sender address for which the timeout should be rescheduled
1166 */
1167static void
1168reschedule_sender_timeout (struct SenderAddress *sender)
1169{
1170 sender->timeout =
1171 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
1172 GNUNET_CONTAINER_heap_update_cost (sender->hn, sender->timeout.abs_value_us);
1173}
1174
1175
1176/**
1177 * Increment receiver timeout due to activity.
1178 *
1179 * @param receiver address for which the timeout should be rescheduled
1180 */
1181static void
1182reschedule_receiver_timeout (struct ReceiverAddress *receiver)
1183{
1184 receiver->timeout =
1185 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
1186 GNUNET_CONTAINER_heap_update_cost (receiver->hn,
1187 receiver->timeout.abs_value_us);
1188}
1189
1190
1191/**
1192 * Task run to check #receiver_heap and #sender_heap for timeouts.
1193 *
1194 * @param cls unused, NULL
1195 */
1196static void
1197check_timeouts (void *cls)
1198{
1199 struct GNUNET_TIME_Relative st;
1200 struct GNUNET_TIME_Relative rt;
1201 struct GNUNET_TIME_Relative delay;
1202 struct ReceiverAddress *receiver;
1203 struct SenderAddress *sender;
1204
1205 (void) cls;
1206 timeout_task = NULL;
1207 rt = GNUNET_TIME_UNIT_FOREVER_REL;
1208 while (NULL != (receiver = GNUNET_CONTAINER_heap_peek (receivers_heap)))
1209 {
1210 /* if (GNUNET_YES != receiver->receiver_destroy_called) */
1211 /* { */
1212 rt = GNUNET_TIME_absolute_get_remaining (receiver->timeout);
1213 if (0 != rt.rel_value_us)
1214 break;
1215 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1216 "Receiver timed out\n");
1217 receiver_destroy (receiver);
1218 // }
1219 }
1220 st = GNUNET_TIME_UNIT_FOREVER_REL;
1221 while (NULL != (sender = GNUNET_CONTAINER_heap_peek (senders_heap)))
1222 {
1223 if (GNUNET_YES != sender->sender_destroy_called)
1224 {
1225 st = GNUNET_TIME_absolute_get_remaining (sender->timeout);
1226 if (0 != st.rel_value_us)
1227 break;
1228 sender_destroy (sender);
1229 }
1230 }
1231 delay = GNUNET_TIME_relative_min (rt, st);
1232 if (delay.rel_value_us < GNUNET_TIME_UNIT_FOREVER_REL.rel_value_us)
1233 timeout_task = GNUNET_SCHEDULER_add_delayed (delay, &check_timeouts, NULL);
1234}
1235
1236
1237/**
1238 * Calculate cmac from master in @a ss.
1239 *
1240 * @param ss[in,out] data structure to complete
1241 */
1242static void
1243calculate_cmac (struct SharedSecret *ss)
1244{
1245 GNUNET_CRYPTO_hkdf (&ss->cmac,
1246 sizeof(ss->cmac),
1247 GCRY_MD_SHA512,
1248 GCRY_MD_SHA256,
1249 "CMAC",
1250 strlen ("CMAC"),
1251 &ss->master,
1252 sizeof(ss->master),
1253 "UDP-CMAC",
1254 strlen ("UDP-CMAC"),
1255 NULL,
1256 0);
1257}
1258
1259
1260/**
1261 * We received @a plaintext_len bytes of @a plaintext from a @a sender.
1262 * Pass it on to CORE.
1263 *
1264 * @param queue the queue that received the plaintext
1265 * @param plaintext the plaintext that was received
1266 * @param plaintext_len number of bytes of plaintext received
1267 */
1268static void
1269pass_plaintext_to_core (struct SenderAddress *sender,
1270 const void *plaintext,
1271 size_t plaintext_len)
1272{
1273 const struct GNUNET_MessageHeader *hdr = plaintext;
1274 const char *pos = plaintext;
1275
1276 while (ntohs (hdr->size) < plaintext_len)
1277 {
1278 GNUNET_STATISTICS_update (stats,
1279 "# bytes given to core",
1280 ntohs (hdr->size),
1281 GNUNET_NO);
1282 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1283 "Giving %u bytes to TNG\n", ntohs (hdr->size));
1284 GNUNET_assert (GNUNET_SYSERR !=
1285 GNUNET_TRANSPORT_communicator_receive (ch,
1286 &sender->target,
1287 hdr,
1288 ADDRESS_VALIDITY_PERIOD,
1289 NULL /* no flow control possible */
1290 ,
1291 NULL));
1292 /* move on to next message, if any */
1293 plaintext_len -= ntohs (hdr->size);
1294 if (plaintext_len < sizeof(*hdr))
1295 break;
1296 pos += ntohs (hdr->size);
1297 hdr = (const struct GNUNET_MessageHeader *) pos;
1298 // TODO for now..., we do not actually sen >1msg or have a way of telling
1299 // if we are done
1300 break;
1301 }
1302 GNUNET_STATISTICS_update (stats,
1303 "# bytes padding discarded",
1304 plaintext_len,
1305 GNUNET_NO);
1306}
1307
1308
1309/**
1310 * Setup @a cipher based on shared secret @a msec and
1311 * serial number @a serial.
1312 *
1313 * @param msec master shared secret
1314 * @param serial serial number of cipher to set up
1315 * @param cipher[out] cipher to initialize
1316 */
1317static void
1318setup_cipher (const struct GNUNET_HashCode *msec,
1319 uint32_t serial,
1320 gcry_cipher_hd_t *cipher)
1321{
1322 char key[AES_KEY_SIZE];
1323 char iv[AES_IV_SIZE];
1324 int rc;
1325
1326 GNUNET_assert (0 ==
1327 gcry_cipher_open (cipher,
1328 GCRY_CIPHER_AES256 /* low level: go for speed */,
1329 GCRY_CIPHER_MODE_GCM,
1330 0 /* flags */));
1331 get_iv_key (msec, serial, key, iv);
1332 rc = gcry_cipher_setkey (*cipher, key, sizeof(key));
1333 GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
1334 rc = gcry_cipher_setiv (*cipher, iv, sizeof(iv));
1335 GNUNET_assert ((0 == rc) || ((char) rc == GPG_ERR_WEAK_KEY));
1336}
1337
1338
1339/**
1340 * Try to decrypt @a buf using shared secret @a ss and key/iv
1341 * derived using @a serial.
1342 *
1343 * @param ss shared secret
1344 * @param tag GCM authentication tag
1345 * @param serial serial number to use
1346 * @param in_buf input buffer to decrypt
1347 * @param in_buf_size number of bytes in @a in_buf and available in @a out_buf
1348 * @param out_buf where to write the result
1349 * @return #GNUNET_OK on success
1350 */
1351static int
1352try_decrypt (const struct SharedSecret *ss,
1353 const char tag[GCM_TAG_SIZE],
1354 uint32_t serial,
1355 const char *in_buf,
1356 size_t in_buf_size,
1357 char *out_buf)
1358{
1359 gcry_cipher_hd_t cipher;
1360
1361 setup_cipher (&ss->master, serial, &cipher);
1362 GNUNET_assert (
1363 0 ==
1364 gcry_cipher_decrypt (cipher, out_buf, in_buf_size, in_buf, in_buf_size));
1365 if (0 != gcry_cipher_checktag (cipher, tag, GCM_TAG_SIZE))
1366 {
1367 gcry_cipher_close (cipher);
1368 GNUNET_STATISTICS_update (stats,
1369 "# AEAD authentication failures",
1370 1,
1371 GNUNET_NO);
1372 return GNUNET_SYSERR;
1373 }
1374 gcry_cipher_close (cipher);
1375 return GNUNET_OK;
1376}
1377
1378
1379/**
1380 * Setup shared secret for decryption.
1381 *
1382 * @param ephemeral ephemeral key we received from the other peer
1383 * @return new shared secret
1384 */
1385static struct SharedSecret *
1386setup_shared_secret_dec (const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral)
1387{
1388 struct SharedSecret *ss;
1389
1390 ss = GNUNET_new (struct SharedSecret);
1391 GNUNET_CRYPTO_eddsa_ecdh (my_private_key, ephemeral, &ss->master);
1392 return ss;
1393}
1394
1395
1396/**
1397 * Setup shared secret for encryption.
1398 *
1399 * @param ephemeral ephemeral key we are sending to the other peer
1400 * @param receiver[in,out] queue to initialize encryption key for
1401 * @return new shared secret
1402 */
1403static struct SharedSecret *
1404setup_shared_secret_enc (const struct GNUNET_CRYPTO_EcdhePrivateKey *ephemeral,
1405 struct ReceiverAddress *receiver, int add_to_receiver)
1406{
1407 struct SharedSecret *ss;
1408
1409 ss = GNUNET_new (struct SharedSecret);
1410 GNUNET_CRYPTO_ecdh_eddsa (ephemeral,
1411 &receiver->target.public_key,
1412 &ss->master);
1413 calculate_cmac (ss);
1414 ss->receiver = receiver;
1415 GNUNET_CONTAINER_DLL_insert (receiver->ss_head, receiver->ss_tail, ss);
1416 receiver->num_secrets++;
1417 GNUNET_STATISTICS_update (stats, "# Secrets active", 1, GNUNET_NO);
1418 return ss;
1419}
1420
1421
1422/**
1423 * Setup the MQ for the @a receiver. If a queue exists,
1424 * the existing one is destroyed. Then the MTU is
1425 * recalculated and a fresh queue is initialized.
1426 *
1427 * @param receiver receiver to setup MQ for
1428 */
1429static void
1430setup_receiver_mq (struct ReceiverAddress *receiver);
1431
1432/**
1433 * Destroying all secrets. Depending on parameter we keep those secrets having a kce.
1434 *
1435 * @param ss The secret we will not destroy.
1436 * @param withoutKce If GNUNET_YES shared secrets with kce will not be destroyed.
1437 */
1438static void
1439destroy_all_secrets (struct SharedSecret *ss, int withoutKce)
1440{
1441 struct SenderAddress *sender;
1442 struct ReceiverAddress *receiver;
1443 struct SharedSecret *ss_to_destroy;
1444 struct SharedSecret *ss_start;
1445 struct SharedSecret *pos;
1446 int at_least_one_destroyed = GNUNET_NO;
1447
1448 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1449 "Starting destroy all withoutKce: %u.\n",
1450 withoutKce);
1451
1452 if (NULL != (sender = ss->sender))
1453 {
1454 ss_start = sender->ss_head;
1455 }
1456 else if (NULL != (receiver = ss->receiver))
1457 {
1458 ss_start = receiver->ss_head;
1459 }
1460 else
1461 {
1462 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1463 "Shared secret has no sender or receiver!\n");
1464 return;
1465 }
1466
1467 pos = ss_start;
1468 while (NULL != pos)
1469 {
1470 ss_to_destroy = pos;
1471 pos = pos->next;
1472
1473 if (ss != ss_to_destroy)
1474 at_least_one_destroyed = secret_destroy (ss_to_destroy, withoutKce);
1475 }
1476
1477 if ((ss != ss_start) && ! at_least_one_destroyed)
1478 {
1479 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1480 "Really destroying all.\n");
1481 destroy_all_secrets (ss_start, GNUNET_NO);
1482 }
1483
1484 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1485 "Finished destroy all.\n");
1486}
1487
1488
1489static void
1490add_acks (struct SharedSecret *ss, int acks_to_add)
1491{
1492
1493 struct ReceiverAddress *receiver = ss->receiver;
1494
1495 GNUNET_assert (NULL != ss);
1496 GNUNET_assert (NULL != receiver);
1497 GNUNET_assert (NULL != receiver->d_qh);
1498
1499 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1500 "Tell transport we have %u more acks!\n",
1501 acks_to_add);
1502 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1503 "%u kce for rekeying.\n",
1504 receiver->number_rekeying_kce);
1505 GNUNET_TRANSPORT_communicator_mq_update (ch,
1506 receiver->d_qh,
1507 acks_to_add,
1508 1);
1509 // Until here for alternativ 1
1510
1511 /* move ss to head to avoid discarding it anytime soon! */
1512
1513 GNUNET_CONTAINER_DLL_remove (receiver->ss_head, receiver->ss_tail, ss);
1514 GNUNET_CONTAINER_DLL_insert (receiver->ss_head, receiver->ss_tail, ss);
1515 destroy_all_secrets (ss, GNUNET_YES);
1516}
1517
1518
1519static uint32_t
1520reset_rekey_kces (struct ReceiverAddress *receiver,
1521 uint32_t acks_to_add)
1522{
1523 int needed_for_rekeying;
1524
1525 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1526 "%u kce for rekeying and %u acks_to_add\n",
1527 receiver->number_rekeying_kce,
1528 acks_to_add);
1529
1530 needed_for_rekeying = (3 - receiver->number_rekeying_kce);
1531 if (acks_to_add <= needed_for_rekeying)
1532 {
1533 receiver->number_rekeying_kce += acks_to_add;
1534 acks_to_add = 0;
1535 }
1536 else
1537 {
1538 acks_to_add -= (3 - receiver->number_rekeying_kce);
1539 receiver->number_rekeying_kce = 3;
1540 }
1541
1542 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1543 "%u kce for rekeying and %u acks_to_add\n",
1544 receiver->number_rekeying_kce,
1545 acks_to_add);
1546 return acks_to_add;
1547}
1548
1549
1550static void
1551add_acks_rekey (struct ReceiverAddress *receiver)
1552{
1553 uint32_t acks_to_add = receiver->ss_rekey->sequence_allowed;
1554
1555 if (receiver->number_rekeying_kce < 3)
1556 acks_to_add = reset_rekey_kces (receiver, acks_to_add);
1557 receiver->acks_available = receiver->ss_rekey->sequence_allowed;
1558 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1559 "%u receiver->acks_available 4\n",
1560 receiver->acks_available);
1561 /* add_acks (receiver->ss_rekey, acks_to_add - 3); */
1562 if (0 != acks_to_add)
1563 {
1564 add_acks (receiver->ss_rekey, acks_to_add);
1565 }
1566 receiver->ss_rekey = NULL;
1567 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1568 "# rekeying successful\n");
1569 GNUNET_STATISTICS_update (stats,
1570 "# rekeying successful",
1571 1,
1572 GNUNET_NO);
1573}
1574
1575
1576/**
1577 * We received an ACK for @a pid. Check if it is for
1578 * the receiver in @a value and if so, handle it and
1579 * return #GNUNET_NO. Otherwise, return #GNUNET_YES.
1580 *
1581 * @param cls a `const struct UDPAck`
1582 * @param pid peer the ACK is from
1583 * @param value a `struct ReceiverAddress`
1584 * @return #GNUNET_YES to continue to iterate
1585 */
1586static int
1587handle_ack (void *cls, const struct GNUNET_PeerIdentity *pid, void *value)
1588{
1589 const struct UDPAck *ack = cls;
1590 struct ReceiverAddress *receiver = value;
1591 uint32_t acks_to_add;
1592 uint32_t allowed;
1593 // int needed_for_rekeying;
1594
1595 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1596 "in handle ack with cmac %s\n",
1597 GNUNET_h2s (&ack->cmac));
1598
1599 if (NULL != receiver->ss_rekey)
1600 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1601 "We have rekey secret with cmac %s \n",
1602 GNUNET_h2s (&receiver->ss_rekey->cmac));
1603
1604 if ((NULL != receiver->ss_rekey) && (0 == memcmp (&ack->cmac,
1605 &receiver->ss_rekey->cmac,
1606 sizeof(struct
1607 GNUNET_HashCode))) )
1608 {
1609 allowed = ntohl (ack->sequence_max);
1610
1611 if (allowed > receiver->ss_rekey->sequence_allowed)
1612 {
1613 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1614 "%u > %u (%u %u) for rekey secrect %s\n", allowed,
1615 receiver->ss_rekey->sequence_allowed,
1616 receiver->acks_available,
1617 ack->acks_available,
1618 GNUNET_h2s (&receiver->ss_rekey->master));
1619
1620 receiver->ss_rekey->sequence_allowed = allowed;
1621
1622 if (GNUNET_NO == receiver->rekeying)
1623 add_acks_rekey (receiver);
1624
1625 return GNUNET_NO;
1626 }
1627 }
1628
1629 (void) pid;
1630 for (struct SharedSecret *ss = receiver->ss_head; NULL != ss; ss = ss->next)
1631 {
1632 if (0 == memcmp (&ack->cmac, &ss->cmac, sizeof(struct GNUNET_HashCode)))
1633 {
1634
1635 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1636 "Found matching mac\n");
1637
1638 allowed = ntohl (ack->sequence_max);
1639
1640 if (allowed > ss->sequence_allowed)
1641 {
1642 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1643 "%u > %u (%u %u) for secrect %s\n", allowed,
1644 ss->sequence_allowed,
1645 receiver->acks_available,
1646 ack->acks_available,
1647 GNUNET_h2s (&ss->master));
1648 // Uncomment this for alternativ 1 of backchannel functionality
1649 acks_to_add = (allowed - ss->sequence_allowed);
1650 if ((GNUNET_NO == receiver->rekeying) &&
1651 (receiver->number_rekeying_kce < 3) )
1652 acks_to_add = reset_rekey_kces (receiver, acks_to_add);
1653 /* if ((GNUNET_NO == receiver->rekeying) && */
1654 /* (receiver->number_rekeying_kce < */
1655 /* 3) ) */
1656 /* { */
1657 /* needed_for_rekeying = (3 - receiver->number_rekeying_kce); */
1658 /* if (acks_to_add <= needed_for_rekeying) */
1659 /* { */
1660 /* receiver->number_rekeying_kce += acks_to_add; */
1661 /* acks_to_add = 0; */
1662 /* } */
1663 /* else */
1664 /* { */
1665 /* acks_to_add -= (3 - receiver->number_rekeying_kce); */
1666 /* receiver->number_rekeying_kce = 3; */
1667 /* } */
1668 /* } */
1669 /* GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, */
1670 /* "%u kce for rekeying\n", */
1671 /* receiver->number_rekeying_kce); */
1672
1673 if ((0 != acks_to_add) && (GNUNET_NO == receiver->rekeying))
1674 {
1675 receiver->acks_available += (allowed - ss->sequence_allowed);
1676 ss->sequence_allowed = allowed;
1677 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1678 "%u receiver->acks_available 5\n",
1679 receiver->acks_available);
1680 add_acks (ss, acks_to_add);
1681 }
1682 }
1683 return GNUNET_NO;
1684 }
1685 }
1686 return GNUNET_YES;
1687}
1688
1689
1690/**
1691 * Test if we have received a valid message in plaintext.
1692 * If so, handle it.
1693 *
1694 * @param sender peer to process inbound plaintext for
1695 * @param buf buffer we received
1696 * @param buf_size number of bytes in @a buf
1697 */
1698static void
1699try_handle_plaintext (struct SenderAddress *sender,
1700 const void *buf,
1701 size_t buf_size)
1702{
1703 const struct GNUNET_MessageHeader *hdr =
1704 (const struct GNUNET_MessageHeader *) buf;
1705 const struct UDPAck *ack = (const struct UDPAck *) buf;
1706 uint16_t type;
1707
1708 if (sizeof(*hdr) > buf_size)
1709 return; /* not even a header */
1710 if (ntohs (hdr->size) > buf_size)
1711 return; /* not even a header */
1712 type = ntohs (hdr->type);
1713 switch (type)
1714 {
1715 case GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK:
1716 /* lookup master secret by 'cmac', then update sequence_max */
1717 GNUNET_CONTAINER_multipeermap_get_multiple (receivers,
1718 &sender->target,
1719 &handle_ack,
1720 (void *) ack);
1721 /* There could be more messages after the ACK, handle those as well */
1722 buf += ntohs (hdr->size);
1723 buf_size -= ntohs (hdr->size);
1724 pass_plaintext_to_core (sender, buf, buf_size);
1725 break;
1726
1727 case GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_PAD:
1728 /* skip padding */
1729 break;
1730
1731 default:
1732 pass_plaintext_to_core (sender, buf, buf_size);
1733 }
1734}
1735
1736
1737static void
1738kce_generate_cb (void *cls)
1739{
1740 struct SharedSecret *ss = cls;
1741
1742 ss->sender->kce_task = NULL;
1743
1744 if (((GNUNET_NO == ss->sender->rekeying) && (ss->sender->acks_available <
1745 KCN_TARGET) ) ||
1746 ((ss->sender->ss_rekey == ss) && (GNUNET_YES == ss->sender->rekeying) &&
1747 (ss->sender->acks_available < 128)))
1748 {
1749
1750 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1751 "Precomputing keys for master %s\n",
1752 GNUNET_h2s (&(ss->master)));
1753
1754 for (int i = 0; i < GENERATE_AT_ONCE; i++)
1755 kce_generate (ss, ++ss->sequence_allowed);
1756
1757 ss->sender->kce_task = GNUNET_SCHEDULER_add_delayed (
1758 WORKING_QUEUE_INTERVALL,
1759 kce_generate_cb,
1760 ss);
1761 }
1762 else
1763 {
1764 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1765 "We have enough keys.\n");
1766 ss_finished = ss;
1767 ss->sender->kce_task_finished = GNUNET_YES;
1768 }
1769
1770
1771}
1772
1773
1774static void
1775kce_generate_rekey_cb (void *cls)
1776{
1777 struct SharedSecret *ss = cls;
1778
1779 ss->sender->kce_task_rekey = NULL;
1780
1781 if (NULL == ss->sender->kce_task)
1782 {
1783
1784 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1785 "Precomputing keys for rekey master %s\n",
1786 GNUNET_h2s (&(ss->master)));
1787
1788 for (int i = 0; i < GENERATE_AT_ONCE; i++)
1789 kce_generate (ss, ++ss->sequence_allowed);
1790
1791 ss->sender->kce_task = GNUNET_SCHEDULER_add_delayed (
1792 WORKING_QUEUE_INTERVALL,
1793 kce_generate_cb,
1794 ss);
1795 ss->sender->kce_task_rekey = NULL;
1796 }
1797 else
1798 {
1799 ss->sender->kce_task_rekey = GNUNET_SCHEDULER_add_delayed (
1800 WORKING_QUEUE_INTERVALL,
1801 kce_generate_rekey_cb,
1802 ss);
1803 }
1804}
1805
1806
1807/**
1808 * We established a shared secret with a sender. We should try to send
1809 * the sender an `struct UDPAck` at the next opportunity to allow the
1810 * sender to use @a ss longer (assuming we did not yet already
1811 * recently).
1812 *
1813 * @param ss shared secret to generate ACKs for
1814 * @param initial The SharedSecret came with initial KX.
1815 */
1816static void
1817consider_ss_ack (struct SharedSecret *ss, int initial)
1818{
1819 struct GNUNET_SCHEDULER_Task *kce_task_rekey;
1820 struct GNUNET_SCHEDULER_Task *kce_task;
1821 int kce_task_finished;
1822
1823 kce_task_rekey = ss->sender->kce_task_rekey;
1824 kce_task_finished = ss->sender->kce_task_finished;
1825 kce_task = ss->sender->kce_task;
1826
1827 GNUNET_assert (NULL != ss->sender);
1828 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1829 "Considering SS UDPAck %s\n",
1830 GNUNET_i2s_full (&ss->sender->target));
1831
1832 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1833 "We have %u acks available.\n",
1834 ss->sender->acks_available);
1835 /* drop ancient KeyCacheEntries */
1836 while ((NULL != ss->kce_head) &&
1837 (MAX_SQN_DELTA <
1838 ss->kce_head->sequence_number - ss->kce_tail->sequence_number))
1839 kce_destroy (ss->kce_tail);
1840
1841
1842 if (GNUNET_NO == initial)
1843 kce_generate (ss, ++ss->sequence_allowed);
1844
1845 /*if (0 == ss->sender->acks_available)
1846 {
1847 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1848 "Generating keys\n");
1849 while (ss->active_kce_count < KCN_TARGET)
1850 kce_generate (ss, ++ss->sequence_allowed);
1851 }*/
1852
1853 if (((NULL != kce_task) && kce_task_finished) || (GNUNET_NO == initial))
1854 {
1855 struct UDPAck ack;
1856 struct SharedSecret *ss_tell;
1857
1858 if (GNUNET_NO != initial)
1859 ss_tell = ss_finished;
1860 else
1861 ss_tell = ss;
1862
1863 ack.header.type = htons (GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK);
1864 ack.header.size = htons (sizeof(ack));
1865 ack.sequence_max = htonl (ss_tell->sequence_allowed);
1866 ack.acks_available = ss->sender->acks_available;
1867 ack.cmac = ss_tell->cmac;
1868 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1869 "Notifying transport of UDPAck %s with initial %u and master %s\n",
1870 GNUNET_i2s_full (&ss_tell->sender->target),
1871 initial,
1872 GNUNET_h2s (&(ss_tell->master)));
1873 GNUNET_TRANSPORT_communicator_notify (ch,
1874 &ss_tell->sender->target,
1875 COMMUNICATOR_ADDRESS_PREFIX,
1876 &ack.header);
1877 if (GNUNET_NO != initial)
1878 {
1879 destroy_all_secrets (ss, GNUNET_YES);
1880 kce_task = NULL;
1881 kce_task_finished = GNUNET_NO;
1882 }
1883 }
1884 else if ((NULL == kce_task) && ((KCN_THRESHOLD >
1885 ss->sender->acks_available) ||
1886 (GNUNET_YES == ss->sender->rekeying) ||
1887 (ss->sender->num_secrets > MAX_SECRETS) ))
1888 {
1889
1890 // kce_generate (ss, ++ss->sequence_allowed);
1891 // kce_generate (ss, ++ss->sequence_allowed);
1892 // TODO This task must be per sender!
1893 kce_task = GNUNET_SCHEDULER_add_delayed (WORKING_QUEUE_INTERVALL,
1894 kce_generate_cb,
1895 ss);
1896 kce_task_finished = GNUNET_NO;
1897
1898 }
1899 else if ((NULL == kce_task_rekey) && (GNUNET_YES ==
1900 ss->sender->rekeying) )
1901 {
1902 kce_task_rekey = GNUNET_SCHEDULER_add_delayed (WORKING_QUEUE_INTERVALL,
1903 kce_generate_rekey_cb,
1904 ss);
1905 }
1906}
1907
1908
1909/**
1910 * We received a @a box with matching @a kce. Decrypt and process it.
1911 *
1912 * @param box the data we received
1913 * @param box_len number of bytes in @a box
1914 * @param kce key index to decrypt @a box
1915 */
1916static void
1917decrypt_box (const struct UDPBox *box,
1918 size_t box_len,
1919 struct KeyCacheEntry *kce)
1920{
1921 struct SharedSecret *ss = kce->ss;
1922 char out_buf[box_len - sizeof(*box)];
1923
1924 GNUNET_assert (NULL != ss->sender);
1925 if (GNUNET_OK != try_decrypt (ss,
1926 box->gcm_tag,
1927 kce->sequence_number,
1928 (const char *) &box[1],
1929 sizeof(out_buf),
1930 out_buf))
1931 {
1932 GNUNET_STATISTICS_update (stats,
1933 "# Decryption failures with valid KCE",
1934 1,
1935 GNUNET_NO);
1936 kce_destroy (kce);
1937 return;
1938 }
1939 kce_destroy (kce);
1940 GNUNET_STATISTICS_update (stats,
1941 "# bytes decrypted with BOX",
1942 sizeof(out_buf),
1943 GNUNET_NO);
1944 GNUNET_STATISTICS_update (stats,
1945 "# messages decrypted with BOX",
1946 1,
1947 GNUNET_NO);
1948 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1949 "decrypted UDPBox with kid %s\n",
1950 GNUNET_sh2s (&box->kid));
1951 try_handle_plaintext (ss->sender, out_buf, sizeof(out_buf));
1952 if ((GNUNET_NO == box->rekeying) && (GNUNET_YES == ss->sender->rekeying))
1953 {
1954 ss->sender->rekeying = GNUNET_NO;
1955 ss->sender->ss_rekey = NULL;
1956 // destroy_all_secrets (ss, GNUNET_NO);
1957 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1958 "Receiver stopped rekeying.\n");
1959 }
1960 else if (GNUNET_NO == box->rekeying)
1961 consider_ss_ack (ss, GNUNET_NO);
1962 else
1963 {
1964 ss->sender->rekeying = GNUNET_YES;
1965 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1966 "Got Box: Receiver doing rekeying.\n");
1967 }
1968}
1969
1970
1971/**
1972 * We received a @a rekey with matching @a kce. Decrypt and process it.
1973 *
1974 * @param rekey the data we received
1975 * @param rekey_len number of bytes in @a rekey
1976 * @param kce key index to decrypt @a rekey
1977 */
1978static void
1979decrypt_rekey (const struct UDPRekey *rekey,
1980 size_t rekey_len,
1981 struct KeyCacheEntry *kce,
1982 struct SenderAddress *sender)
1983{
1984 struct SharedSecret *ss = kce->ss;
1985 struct SharedSecret *ss_rekey;
1986 char out_buf[rekey_len - sizeof(*rekey)];
1987 struct GNUNET_HashCode *master;
1988
1989
1990 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1991 "decrypt_rekey.\n");
1992
1993 GNUNET_assert (NULL != ss->sender);
1994 if (GNUNET_OK != try_decrypt (ss,
1995 rekey->gcm_tag,
1996 kce->sequence_number,
1997 (const char *) &rekey[1],
1998 sizeof(out_buf),
1999 out_buf))
2000 {
2001 GNUNET_STATISTICS_update (stats,
2002 "# Decryption failures with valid KCE",
2003 1,
2004 GNUNET_NO);
2005 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2006 "Decryption with kid %s failed\n",
2007 GNUNET_sh2s (&rekey->kid));
2008 kce_destroy (kce);
2009 return;
2010 }
2011 kce_destroy (kce);
2012 GNUNET_STATISTICS_update (stats,
2013 "# bytes decrypted with Rekey",
2014 sizeof(out_buf),
2015 GNUNET_NO);
2016 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2017 "decrypted UDPRekey with kid %s\n",
2018 GNUNET_sh2s (&rekey->kid));
2019 /*cmac = (struct GNUNET_HashCode *) out_buf;
2020 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2021 "Received secret with cmac %s \n",
2022 GNUNET_h2s (&cmac));*/
2023 // ss_rekey = (struct SharedSecret *) out_buf;
2024 master = (struct GNUNET_HashCode *) out_buf;
2025 ss_rekey = GNUNET_new (struct SharedSecret);
2026 ss_rekey->master = *master;
2027 calculate_cmac (ss_rekey);
2028 ss_rekey->sender = sender;
2029 // ss_rekey->sequence_used = 0;
2030 // ss_rekey->sequence_allowed = 0;
2031 /* ss_rekey->active_kce_count = 0; */
2032 /* ss_rekey->prev = NULL; */
2033 /* ss_rekey->next = NULL; */
2034 /* GNUNET_assert (ss_rekey->prev == NULL && sender->ss_head != ss_rekey); */
2035 /* GNUNET_assert (ss_rekey->next == NULL && sender->ss_tail != ss_rekey); */
2036 GNUNET_CONTAINER_DLL_insert (sender->ss_head, sender->ss_tail, ss_rekey);
2037 sender->ss_rekey = ss_rekey;
2038 sender->num_secrets++;
2039 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2040 "Received secret with cmac %s\n",
2041 GNUNET_h2s (&(ss_rekey->cmac)));
2042 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2043 "Received secret with master %s.\n",
2044 GNUNET_h2s (&(ss_rekey->master)));
2045 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2046 "We have %u sequence_allowed.\n",
2047 ss_rekey->sequence_allowed);
2048 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2049 "We have a sender %p\n",
2050 ss_rekey->sender);
2051 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2052 "We have %u acks available.\n",
2053 ss_rekey->sender->acks_available);
2054 consider_ss_ack (ss_rekey, GNUNET_YES);
2055
2056}
2057
2058
2059/**
2060 * Closure for #find_sender_by_address()
2061 */
2062struct SearchContext
2063{
2064 /**
2065 * Address we are looking for.
2066 */
2067 const struct sockaddr *address;
2068
2069 /**
2070 * Number of bytes in @e address.
2071 */
2072 socklen_t address_len;
2073
2074 /**
2075 * Return value to set if we found a match.
2076 */
2077 struct SenderAddress *sender;
2078};
2079
2080
2081/**
2082 * Find existing `struct SenderAddress` by matching addresses.
2083 *
2084 * @param cls a `struct SearchContext`
2085 * @param key ignored, must match already
2086 * @param value a `struct SenderAddress`
2087 * @return #GNUNET_YES if not found (continue to search), #GNUNET_NO if found
2088 */
2089static int
2090find_sender_by_address (void *cls,
2091 const struct GNUNET_PeerIdentity *key,
2092 void *value)
2093{
2094 struct SearchContext *sc = cls;
2095 struct SenderAddress *sender = value;
2096
2097 if ((sender->address_len == sc->address_len) &&
2098 (0 == memcmp (sender->address, sc->address, sender->address_len)))
2099 {
2100 sc->sender = sender;
2101 return GNUNET_NO; /* stop iterating! */
2102 }
2103 return GNUNET_YES;
2104}
2105
2106
2107/**
2108 * Create sender address for @a target. Note that we
2109 * might already have one, so a fresh one is only allocated
2110 * if one does not yet exist for @a address.
2111 *
2112 * @param target peer to generate address for
2113 * @param address target address
2114 * @param address_len number of bytes in @a address
2115 * @return data structure to keep track of key material for
2116 * decrypting data from @a target
2117 */
2118static struct SenderAddress *
2119setup_sender (const struct GNUNET_PeerIdentity *target,
2120 const struct sockaddr *address,
2121 socklen_t address_len)
2122{
2123 struct SenderAddress *sender;
2124 struct SearchContext sc = { .address = address,
2125 .address_len = address_len,
2126 .sender = NULL };
2127
2128 GNUNET_CONTAINER_multipeermap_get_multiple (senders,
2129 target,
2130 &find_sender_by_address,
2131 &sc);
2132 if (NULL != sc.sender)
2133 {
2134 reschedule_sender_timeout (sc.sender);
2135 return sc.sender;
2136 }
2137 sender = GNUNET_new (struct SenderAddress);
2138 sender->target = *target;
2139 sender->address = GNUNET_memdup (address, address_len);
2140 sender->address_len = address_len;
2141 (void) GNUNET_CONTAINER_multipeermap_put (
2142 senders,
2143 &sender->target,
2144 sender,
2145 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
2146 GNUNET_STATISTICS_set (stats,
2147 "# senders active",
2148 GNUNET_CONTAINER_multipeermap_size (receivers),
2149 GNUNET_NO);
2150 sender->timeout =
2151 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
2152 sender->hn = GNUNET_CONTAINER_heap_insert (senders_heap,
2153 sender,
2154 sender->timeout.abs_value_us);
2155 sender->nt = GNUNET_NT_scanner_get_type (is, address, address_len);
2156 if (NULL == timeout_task)
2157 timeout_task = GNUNET_SCHEDULER_add_now (&check_timeouts, NULL);
2158 return sender;
2159}
2160
2161
2162/**
2163 * Check signature from @a uc against @a ephemeral.
2164 *
2165 * @param ephermal key that is signed
2166 * @param uc signature of claimant
2167 * @return #GNUNET_OK if signature is valid
2168 */
2169static int
2170verify_confirmation (const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral,
2171 const struct UDPConfirmation *uc)
2172{
2173 struct UdpHandshakeSignature uhs;
2174
2175 uhs.purpose.purpose = htonl (GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE);
2176 uhs.purpose.size = htonl (sizeof(uhs));
2177 uhs.sender = uc->sender;
2178 uhs.receiver = my_identity;
2179 uhs.ephemeral = *ephemeral;
2180 uhs.monotonic_time = uc->monotonic_time;
2181 return GNUNET_CRYPTO_eddsa_verify (
2182 GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE,
2183 &uhs,
2184 &uc->sender_sig,
2185 &uc->sender.public_key);
2186}
2187
2188
2189/**
2190 * Converts @a address to the address string format used by this
2191 * communicator in HELLOs.
2192 *
2193 * @param address the address to convert, must be AF_INET or AF_INET6.
2194 * @param address_len number of bytes in @a address
2195 * @return string representation of @a address
2196 */
2197static char *
2198sockaddr_to_udpaddr_string (const struct sockaddr *address,
2199 socklen_t address_len)
2200{
2201 char *ret;
2202
2203 switch (address->sa_family)
2204 {
2205 case AF_INET:
2206 GNUNET_asprintf (&ret,
2207 "%s-%s",
2208 COMMUNICATOR_ADDRESS_PREFIX,
2209 GNUNET_a2s (address, address_len));
2210 break;
2211
2212 case AF_INET6:
2213 GNUNET_asprintf (&ret,
2214 "%s-%s",
2215 COMMUNICATOR_ADDRESS_PREFIX,
2216 GNUNET_a2s (address, address_len));
2217 break;
2218
2219 default:
2220 GNUNET_assert (0);
2221 }
2222 return ret;
2223}
2224
2225
2226/**
2227 * Socket read task.
2228 *
2229 * @param cls NULL
2230 */
2231static void
2232sock_read (void *cls)
2233{
2234 struct sockaddr_storage sa;
2235 socklen_t salen = sizeof(sa);
2236 char buf[UINT16_MAX];
2237 ssize_t rcvd;
2238
2239 (void) cls;
2240 read_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
2241 udp_sock,
2242 &sock_read,
2243 NULL);
2244 rcvd = GNUNET_NETWORK_socket_recvfrom (udp_sock,
2245 buf,
2246 sizeof(buf),
2247 (struct sockaddr *) &sa,
2248 &salen);
2249 if (-1 == rcvd)
2250 {
2251 GNUNET_log_strerror (GNUNET_ERROR_TYPE_DEBUG, "recv");
2252 return;
2253 }
2254 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2255 "Read %lu bytes\n", rcvd);
2256
2257 if (rcvd > sizeof(struct UDPRekey))
2258 {
2259 const struct UDPRekey *rekey;
2260 const struct UDPBox *box;
2261 struct KeyCacheEntry *kce;
2262 struct SenderAddress *sender;
2263 int do_decrypt = GNUNET_NO;
2264
2265 rekey = (const struct UDPRekey *) buf;
2266 box = (const struct UDPBox *) buf;
2267 kce = GNUNET_CONTAINER_multishortmap_get (key_cache, &rekey->kid);
2268
2269 if ((GNUNET_YES == box->rekeying) || (GNUNET_NO == box->rekeying))
2270 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2271 "UDPRekey has rekeying %u\n",
2272 box->rekeying);
2273 else
2274 do_decrypt = GNUNET_YES;
2275
2276 if ((GNUNET_YES == do_decrypt) && (NULL != kce) && (GNUNET_YES ==
2277 kce->ss->sender->
2278 rekeying))
2279 {
2280 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2281 "UDPRekey with kid %s\n",
2282 GNUNET_sh2s (&rekey->kid));
2283 sender = setup_sender (&rekey->sender, (const struct sockaddr *) &sa,
2284 salen);
2285
2286 if (NULL != sender->ss_rekey)
2287 return;
2288
2289 decrypt_rekey (rekey, (size_t) rcvd, kce, sender);
2290 return;
2291 }
2292 }
2293
2294 /* first, see if it is a UDPBox */
2295 if (rcvd > sizeof(struct UDPBox))
2296 {
2297 const struct UDPBox *box;
2298 struct KeyCacheEntry *kce;
2299
2300 box = (const struct UDPBox *) buf;
2301 kce = GNUNET_CONTAINER_multishortmap_get (key_cache, &box->kid);
2302 if (NULL != kce)
2303 {
2304 decrypt_box (box, (size_t) rcvd, kce);
2305 return;
2306 }
2307 }
2308
2309 /* next, check if it is a broadcast */
2310 if (sizeof(struct UDPBroadcast) == rcvd)
2311 {
2312 const struct UDPBroadcast *ub;
2313 struct UdpBroadcastSignature uhs;
2314
2315 ub = (const struct UDPBroadcast *) buf;
2316 uhs.purpose.purpose = htonl (GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST);
2317 uhs.purpose.size = htonl (sizeof(uhs));
2318 uhs.sender = ub->sender;
2319 GNUNET_CRYPTO_hash (&sa, salen, &uhs.h_address);
2320 if (GNUNET_OK ==
2321 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST,
2322 &uhs,
2323 &ub->sender_sig,
2324 &ub->sender.public_key))
2325 {
2326 char *addr_s;
2327 enum GNUNET_NetworkType nt;
2328
2329 addr_s =
2330 sockaddr_to_udpaddr_string ((const struct sockaddr *) &sa, salen);
2331 GNUNET_STATISTICS_update (stats, "# broadcasts received", 1, GNUNET_NO);
2332 /* use our own mechanism to determine network type */
2333 nt =
2334 GNUNET_NT_scanner_get_type (is, (const struct sockaddr *) &sa, salen);
2335 GNUNET_TRANSPORT_application_validate (ah, &ub->sender, nt, addr_s);
2336 GNUNET_free (addr_s);
2337 return;
2338 }
2339 /* continue with KX, mostly for statistics... */
2340 }
2341
2342
2343 /* finally, test if it is a KX */
2344 if (rcvd < sizeof(struct UDPConfirmation) + sizeof(struct InitialKX))
2345 {
2346 GNUNET_STATISTICS_update (stats,
2347 "# messages dropped (no kid, too small for KX)",
2348 1,
2349 GNUNET_NO);
2350 return;
2351 }
2352 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2353 "Got KX\n");
2354 {
2355 const struct InitialKX *kx;
2356 struct SharedSecret *ss;
2357 char pbuf[rcvd - sizeof(struct InitialKX)];
2358 const struct UDPConfirmation *uc;
2359 struct SenderAddress *sender;
2360
2361 kx = (const struct InitialKX *) buf;
2362 ss = setup_shared_secret_dec (&kx->ephemeral);
2363 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2364 "Before DEC\n");
2365
2366 if (GNUNET_OK != try_decrypt (ss,
2367 kx->gcm_tag,
2368 0,
2369 &buf[sizeof(*kx)],
2370 sizeof(pbuf),
2371 pbuf))
2372 {
2373 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2374 "Unable to decrypt tag, dropping...\n");
2375 GNUNET_free (ss);
2376 GNUNET_STATISTICS_update (
2377 stats,
2378 "# messages dropped (no kid, AEAD decryption failed)",
2379 1,
2380 GNUNET_NO);
2381 return;
2382 }
2383 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2384 "Before VERIFY\n");
2385
2386 uc = (const struct UDPConfirmation *) pbuf;
2387 if (GNUNET_OK != verify_confirmation (&kx->ephemeral, uc))
2388 {
2389 GNUNET_break_op (0);
2390 GNUNET_free (ss);
2391 GNUNET_STATISTICS_update (stats,
2392 "# messages dropped (sender signature invalid)",
2393 1,
2394 GNUNET_NO);
2395 return;
2396 }
2397 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2398 "Before SETUP_SENDER\n");
2399
2400 calculate_cmac (ss);
2401 sender = setup_sender (&uc->sender, (const struct sockaddr *) &sa, salen);
2402 ss->sender = sender;
2403 GNUNET_CONTAINER_DLL_insert (sender->ss_head, sender->ss_tail, ss);
2404 sender->num_secrets++;
2405 GNUNET_STATISTICS_update (stats, "# Secrets active", 1, GNUNET_NO);
2406 GNUNET_STATISTICS_update (stats,
2407 "# messages decrypted without BOX",
2408 1,
2409 GNUNET_NO);
2410 try_handle_plaintext (sender, &uc[1], sizeof(pbuf) - sizeof(*uc));
2411 if ((GNUNET_NO == kx->rekeying) && (GNUNET_YES == ss->sender->rekeying))
2412 {
2413 ss->sender->rekeying = GNUNET_NO;
2414 sender->ss_rekey = NULL;
2415 // destroy_all_secrets (ss, GNUNET_NO);
2416 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2417 "Receiver stopped rekeying.\n");
2418 }
2419 else if (GNUNET_NO == kx->rekeying)
2420 consider_ss_ack (ss, GNUNET_YES);
2421 else
2422 {
2423 ss->sender->rekeying = GNUNET_YES;
2424 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2425 "Got KX: Receiver doing rekeying.\n");
2426 }
2427 /*if (sender->num_secrets > MAX_SECRETS)
2428 secret_destroy (sender->ss_tail);*/
2429 }
2430}
2431
2432
2433/**
2434 * Convert UDP bind specification to a `struct sockaddr *`
2435 *
2436 * @param bindto bind specification to convert
2437 * @param[out] sock_len set to the length of the address
2438 * @return converted bindto specification
2439 */
2440static struct sockaddr *
2441udp_address_to_sockaddr (const char *bindto, socklen_t *sock_len)
2442{
2443 struct sockaddr *in;
2444 unsigned int port;
2445 char dummy[2];
2446 char *colon;
2447 char *cp;
2448
2449 if (1 == sscanf (bindto, "%u%1s", &port, dummy))
2450 {
2451 /* interpreting value as just a PORT number */
2452 if (port > UINT16_MAX)
2453 {
2454 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2455 "BINDTO specification `%s' invalid: value too large for port\n",
2456 bindto);
2457 return NULL;
2458 }
2459 if ((GNUNET_NO == GNUNET_NETWORK_test_pf (PF_INET6)) ||
2460 (GNUNET_YES ==
2461 GNUNET_CONFIGURATION_get_value_yesno (cfg,
2462 COMMUNICATOR_CONFIG_SECTION,
2463 "DISABLE_V6")))
2464 {
2465 struct sockaddr_in *i4;
2466
2467 i4 = GNUNET_malloc (sizeof(struct sockaddr_in));
2468 i4->sin_family = AF_INET;
2469 i4->sin_port = htons ((uint16_t) port);
2470 *sock_len = sizeof(struct sockaddr_in);
2471 in = (struct sockaddr *) i4;
2472 }
2473 else
2474 {
2475 struct sockaddr_in6 *i6;
2476
2477 i6 = GNUNET_malloc (sizeof(struct sockaddr_in6));
2478 i6->sin6_family = AF_INET6;
2479 i6->sin6_port = htons ((uint16_t) port);
2480 *sock_len = sizeof(struct sockaddr_in6);
2481 in = (struct sockaddr *) i6;
2482 }
2483 return in;
2484 }
2485 cp = GNUNET_strdup (bindto);
2486 colon = strrchr (cp, ':');
2487 if (NULL != colon)
2488 {
2489 /* interpret value after colon as port */
2490 *colon = '\0';
2491 colon++;
2492 if (1 == sscanf (colon, "%u%1s", &port, dummy))
2493 {
2494 /* interpreting value as just a PORT number */
2495 if (port > UINT16_MAX)
2496 {
2497 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2498 "BINDTO specification `%s' invalid: value too large for port\n",
2499 bindto);
2500 GNUNET_free (cp);
2501 return NULL;
2502 }
2503 }
2504 else
2505 {
2506 GNUNET_log (
2507 GNUNET_ERROR_TYPE_ERROR,
2508 "BINDTO specification `%s' invalid: last ':' not followed by number\n",
2509 bindto);
2510 GNUNET_free (cp);
2511 return NULL;
2512 }
2513 }
2514 else
2515 {
2516 /* interpret missing port as 0, aka pick any free one */
2517 port = 0;
2518 }
2519 {
2520 /* try IPv4 */
2521 struct sockaddr_in v4;
2522 if (1 == inet_pton (AF_INET, cp, &v4.sin_addr))
2523 {
2524 v4.sin_family = AF_INET;
2525 v4.sin_port = htons ((uint16_t) port);
2526#if HAVE_SOCKADDR_IN_SIN_LEN
2527 v4.sin_len = sizeof(struct sockaddr_in);
2528#endif
2529 in = GNUNET_memdup (&v4, sizeof(struct sockaddr_in));
2530 *sock_len = sizeof(struct sockaddr_in);
2531 GNUNET_free (cp);
2532 return in;
2533 }
2534 }
2535 {
2536 /* try IPv6 */
2537 struct sockaddr_in6 v6;
2538 const char *start;
2539
2540 start = cp;
2541 if (('[' == *cp) && (']' == cp[strlen (cp) - 1]))
2542 {
2543 start++; /* skip over '[' */
2544 cp[strlen (cp) - 1] = '\0'; /* eat ']' */
2545 }
2546 if (1 == inet_pton (AF_INET6, start, &v6.sin6_addr))
2547 {
2548 v6.sin6_family = AF_INET6;
2549 v6.sin6_port = htons ((uint16_t) port);
2550#if HAVE_SOCKADDR_IN_SIN_LEN
2551 v6.sin6_len = sizeof(sizeof(struct sockaddr_in6));
2552#endif
2553 in = GNUNET_memdup (&v6, sizeof(v6));
2554 *sock_len = sizeof(v6);
2555 GNUNET_free (cp);
2556 return in;
2557 }
2558 }
2559 /* #5528 FIXME (feature!): maybe also try getnameinfo()? */
2560 GNUNET_free (cp);
2561 return NULL;
2562}
2563
2564
2565/**
2566 * Pad @a dgram by @a pad_size using @a out_cipher.
2567 *
2568 * @param out_cipher cipher to use
2569 * @param dgram datagram to pad
2570 * @param pad_size number of bytes of padding to append
2571 */
2572static void
2573do_pad (gcry_cipher_hd_t out_cipher, char *dgram, size_t pad_size)
2574{
2575 char pad[pad_size];
2576
2577 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK, pad, sizeof(pad));
2578 if (sizeof(pad) > sizeof(struct GNUNET_MessageHeader))
2579 {
2580 struct GNUNET_MessageHeader hdr =
2581 { .size = htons (sizeof(pad)),
2582 .type = htons (GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_PAD) };
2583
2584 memcpy (pad, &hdr, sizeof(hdr));
2585 }
2586 GNUNET_assert (
2587 0 ==
2588 gcry_cipher_encrypt (out_cipher, dgram, sizeof(pad), pad, sizeof(pad)));
2589}
2590
2591
2592/**
2593 * Signature of functions implementing the sending functionality of a
2594 * message queue.
2595 *
2596 * @param mq the message queue
2597 * @param msg the message to send
2598 * @param impl_state our `struct ReceiverAddress`
2599 */
2600static void
2601mq_send_kx (struct GNUNET_MQ_Handle *mq,
2602 const struct GNUNET_MessageHeader *msg,
2603 void *impl_state)
2604{
2605 struct ReceiverAddress *receiver = impl_state;
2606 uint16_t msize = ntohs (msg->size);
2607 struct UdpHandshakeSignature uhs;
2608 struct UDPConfirmation uc;
2609 struct InitialKX kx;
2610 struct GNUNET_CRYPTO_EcdhePrivateKey epriv;
2611 char dgram[receiver->kx_mtu + sizeof(uc) + sizeof(kx)];
2612 size_t dpos;
2613 gcry_cipher_hd_t out_cipher;
2614 struct SharedSecret *ss;
2615
2616 GNUNET_assert (mq == receiver->kx_mq);
2617 if (msize > receiver->kx_mtu)
2618 {
2619 GNUNET_break (0);
2620 if (GNUNET_YES != receiver->receiver_destroy_called)
2621 receiver_destroy (receiver);
2622 return;
2623 }
2624 reschedule_receiver_timeout (receiver);
2625
2626 /* setup key material */
2627 GNUNET_CRYPTO_ecdhe_key_create (&epriv);
2628
2629 ss = setup_shared_secret_enc (&epriv, receiver, GNUNET_YES);
2630
2631 if (receiver->num_secrets > MAX_SECRETS)
2632 {
2633 destroy_all_secrets (ss, GNUNET_YES);
2634 }
2635
2636 setup_cipher (&ss->master, 0, &out_cipher);
2637 /* compute 'uc' */
2638 uc.sender = my_identity;
2639 uc.monotonic_time =
2640 GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get_monotonic (cfg));
2641 uhs.purpose.purpose = htonl (GNUNET_SIGNATURE_COMMUNICATOR_UDP_HANDSHAKE);
2642 uhs.purpose.size = htonl (sizeof(uhs));
2643 uhs.sender = my_identity;
2644 uhs.receiver = receiver->target;
2645 GNUNET_CRYPTO_ecdhe_key_get_public (&epriv, &uhs.ephemeral);
2646 uhs.monotonic_time = uc.monotonic_time;
2647 GNUNET_CRYPTO_eddsa_sign (my_private_key,
2648 &uhs,
2649 &uc.sender_sig);
2650 /* Leave space for kx */
2651 dpos = sizeof(kx);
2652 /* Append encrypted uc to dgram */
2653 GNUNET_assert (0 == gcry_cipher_encrypt (out_cipher,
2654 &dgram[dpos],
2655 sizeof(uc),
2656 &uc,
2657 sizeof(uc)));
2658 dpos += sizeof(uc);
2659 /* Append encrypted payload to dgram */
2660 GNUNET_assert (
2661 0 == gcry_cipher_encrypt (out_cipher, &dgram[dpos], msize, msg, msize));
2662 dpos += msize;
2663 do_pad (out_cipher, &dgram[dpos], sizeof(dgram) - dpos);
2664 /* Datagram starts with kx */
2665 kx.ephemeral = uhs.ephemeral;
2666 GNUNET_assert (
2667 0 == gcry_cipher_gettag (out_cipher, kx.gcm_tag, sizeof(kx.gcm_tag)));
2668 gcry_cipher_close (out_cipher);
2669 if (GNUNET_NO == receiver->rekeying)
2670 kx.rekeying = GNUNET_NO;
2671 else
2672 kx.rekeying = GNUNET_YES;
2673 memcpy (dgram, &kx, sizeof(kx));
2674 if (-1 == GNUNET_NETWORK_socket_sendto (udp_sock,
2675 dgram,
2676 sizeof(dgram),
2677 receiver->address,
2678 receiver->address_len))
2679 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "send");
2680 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2681 "Sending KX to %s\n", GNUNET_a2s (receiver->address,
2682 receiver->address_len));
2683 GNUNET_MQ_impl_send_continue (mq);
2684}
2685
2686
2687static void
2688check_for_rekeying (struct ReceiverAddress *receiver, struct UDPBox *box)
2689{
2690
2691 struct GNUNET_TIME_Relative rt;
2692
2693 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2694 "Timeout is %llu\n.",
2695 (unsigned long long) receiver->rekey_timeout.abs_value_us);
2696
2697 if (0 == receiver->rekey_timeout.abs_value_us)
2698 {
2699 receiver->rekey_timeout = GNUNET_TIME_relative_to_absolute (
2700 rekey_interval);
2701 }
2702 else
2703 {
2704 rt = GNUNET_TIME_absolute_get_remaining (receiver->rekey_timeout);
2705 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2706 "Relative time is %llu and timeout is %llu\n.",
2707 (unsigned long long) rt.rel_value_us,
2708 (unsigned long long) receiver->rekey_timeout.abs_value_us);
2709
2710 if ((0 == rt.rel_value_us) || (receiver->rekey_send_bytes >
2711 rekey_max_bytes) )
2712 {
2713 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2714 "Bytes send %llu greater than %llu max bytes\n.",
2715 (unsigned long long) receiver->rekey_send_bytes,
2716 rekey_max_bytes);
2717 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2718 "Relative time is %llu and timeout is %llu\n.",
2719 (unsigned long long) rt.rel_value_us,
2720 (unsigned long long) receiver->rekey_timeout.abs_value_us);
2721
2722 receiver->rekey_timeout.abs_value_us = 0;
2723 receiver->rekey_send_bytes = 0;
2724 receiver->ss_rekey = NULL;
2725 // destroy_all_secrets (ss, GNUNET_NO);
2726 receiver->rekeying = GNUNET_YES;
2727 receiver->rekey_acks_available = receiver->acks_available;
2728 box->rekeying = GNUNET_YES;
2729 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2730 "Sender started rekeying.\n");
2731 if (GNUNET_YES == box->rekeying)
2732 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2733 "Sending rekeying with kid %s\n",
2734 GNUNET_sh2s (&box->kid));
2735 }
2736 }
2737}
2738
2739
2740static void
2741send_UDPRekey (struct ReceiverAddress *receiver, struct SharedSecret *ss)
2742{
2743 uint8_t is_ss_rekey_sequence_allowed_zero = GNUNET_NO;
2744 uint8_t is_acks_available_below = GNUNET_NO;
2745 uint8_t send_rekey = GNUNET_NO;
2746 uint16_t not_below;
2747 struct GNUNET_CRYPTO_EcdhePrivateKey epriv;
2748 struct UDPRekey *rekey;
2749 size_t dpos;
2750
2751 char rekey_dgram[sizeof(struct UDPRekey) + receiver->d_mtu];
2752
2753 if (NULL != receiver->ss_rekey)
2754 {
2755 not_below = (receiver->rekey_acks_available
2756 - (receiver->rekey_acks_available % 3)) / 3;
2757 is_ss_rekey_sequence_allowed_zero = (0 ==
2758 receiver->ss_rekey->sequence_allowed);
2759 is_acks_available_below = (receiver->acks_available >= not_below);
2760 send_rekey = (0 == (receiver->acks_available - not_below) % not_below) &&
2761 is_acks_available_below && is_ss_rekey_sequence_allowed_zero;
2762 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2763 "send_rekey: %u, %u, %u\n",
2764 send_rekey,
2765 receiver->rekey_acks_available,
2766 receiver->acks_available);
2767 }
2768 else if (NULL == receiver->ss_rekey)
2769 {
2770 /* setup key material */
2771 GNUNET_CRYPTO_ecdhe_key_create (&epriv);
2772 receiver->ss_rekey = setup_shared_secret_enc (&epriv, receiver,
2773 GNUNET_NO);
2774 receiver->ss_rekey->sequence_allowed = 0;
2775 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2776 "Setup secret with cmac %s\n",
2777 GNUNET_h2s (&(receiver->ss_rekey->cmac)));
2778 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2779 "Setup secret with master %s.\n",
2780 GNUNET_h2s (&(receiver->ss_rekey->master)));
2781 }
2782
2783 if (send_rekey)
2784 {
2785 GNUNET_assert (0 != receiver->number_rekeying_kce);
2786 gcry_cipher_hd_t rekey_out_cipher;
2787
2788 while (NULL != ss && ss->sequence_used >= ss->sequence_allowed)
2789 {
2790 ss = ss->prev;
2791 }
2792
2793 if (NULL != ss)
2794 {
2795 rekey = (struct UDPRekey *) rekey_dgram;
2796 rekey->sender = my_identity;
2797 ss->sequence_used++;
2798 get_kid (&ss->master, ss->sequence_used, &rekey->kid);
2799 receiver->number_rekeying_kce--;
2800 setup_cipher (&ss->master, ss->sequence_used, &rekey_out_cipher);
2801 /* Append encrypted payload to dgram */
2802 dpos = sizeof(struct UDPRekey);
2803
2804 GNUNET_assert (
2805 0 == gcry_cipher_encrypt (rekey_out_cipher, &rekey_dgram[dpos],
2806 sizeof(receiver->ss_rekey->master),
2807 &(receiver->ss_rekey->master),
2808 sizeof(receiver->ss_rekey->master)));
2809 dpos += sizeof(receiver->ss_rekey->master);
2810 /* GNUNET_assert ( */
2811 /* 0 == gcry_cipher_encrypt (rekey_out_cipher, &rekey_dgram[dpos], */
2812 /* /\*sizeof(receiver->ss_rekey->cmac), */
2813 /* &(receiver->ss_rekey->cmac), */
2814 /* sizeof(receiver->ss_rekey->cmac))); */
2815 /* dpos += sizeof(receiver->ss_rekey->cmac);*\/ */
2816 /* sizeof(receiver->ss_rekey), */
2817 /* receiver->ss_rekey, */
2818 /* sizeof(receiver->ss_rekey))); */
2819 /* dpos += sizeof(receiver->ss_rekey); */
2820 do_pad (rekey_out_cipher, &rekey_dgram[dpos], sizeof(rekey_dgram)
2821 - dpos);
2822 GNUNET_assert (0 == gcry_cipher_gettag (rekey_out_cipher,
2823 rekey->gcm_tag,
2824 sizeof(rekey->gcm_tag)));
2825 gcry_cipher_close (rekey_out_cipher);
2826
2827 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2828 "Sending rekey with kid %s and master %s\n",
2829 GNUNET_sh2s (&rekey->kid),
2830 GNUNET_h2s (&(receiver->ss_rekey->master)));
2831 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2832 "Sending rekey with cmac %s\n",
2833 GNUNET_h2s (&(receiver->ss_rekey->cmac)));
2834 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2835 "%u rekey kces left.\n",
2836 receiver->number_rekeying_kce);
2837
2838 if (-1 == GNUNET_NETWORK_socket_sendto (udp_sock,
2839 rekey_dgram,
2840 sizeof(rekey_dgram),
2841 receiver->address,
2842 receiver->address_len))
2843 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "send");
2844
2845 receiver->acks_available--;
2846 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2847 "%u receiver->acks_available 1\n",
2848 receiver->acks_available);
2849 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2850 "Sending UDPRekey to %s\n", GNUNET_a2s (receiver->address,
2851 receiver->
2852 address_len));
2853 }
2854 }
2855}
2856
2857
2858/**
2859 * Signature of functions implementing the sending functionality of a
2860 * message queue.
2861 *
2862 * @param mq the message queue
2863 * @param msg the message to send
2864 * @param impl_state our `struct ReceiverAddress`
2865 */
2866static void
2867mq_send_d (struct GNUNET_MQ_Handle *mq,
2868 const struct GNUNET_MessageHeader *msg,
2869 void *impl_state)
2870{
2871 struct ReceiverAddress *receiver = impl_state;
2872 uint16_t msize = ntohs (msg->size);
2873
2874 GNUNET_assert (mq == receiver->d_mq);
2875 if ((msize > receiver->d_mtu) ||
2876 (0 == receiver->acks_available))
2877 {
2878 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2879 "msize: %u, mtu: %lu, acks: %u\n",
2880 msize,
2881 receiver->d_mtu,
2882 receiver->acks_available);
2883
2884 GNUNET_break (0);
2885 if (GNUNET_YES != receiver->receiver_destroy_called)
2886 receiver_destroy (receiver);
2887 return;
2888 }
2889 reschedule_receiver_timeout (receiver);
2890
2891 /* begin "BOX" encryption method, scan for ACKs from tail! */
2892 for (struct SharedSecret *ss = receiver->ss_tail; NULL != ss; ss = ss->prev)
2893 {
2894 if (0 < ss->sequence_used)
2895 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2896 "Trying to send UDPBox with shared secrect %s sequence_used %u and ss->sequence_allowed %u\n",
2897 GNUNET_h2s (&ss->master),
2898 ss->sequence_used,
2899 ss->sequence_allowed);
2900 // Uncomment this for alternativ 1 of backchannel functionality
2901 if (ss->sequence_used >= ss->sequence_allowed)
2902 // Until here for alternativ 1
2903 // Uncomment this for alternativ 2 of backchannel functionality
2904 // if (0 == ss->sequence_allowed)
2905 // Until here for alternativ 2
2906 {
2907 continue;
2908 }
2909 char dgram[sizeof(struct UDPBox) + receiver->d_mtu];
2910 struct UDPBox *box;
2911 gcry_cipher_hd_t out_cipher;
2912 size_t dpos;
2913
2914 box = (struct UDPBox *) dgram;
2915 ss->sequence_used++;
2916 get_kid (&ss->master, ss->sequence_used, &box->kid);
2917 setup_cipher (&ss->master, ss->sequence_used, &out_cipher);
2918 /* Append encrypted payload to dgram */
2919 dpos = sizeof(struct UDPBox);
2920 GNUNET_assert (
2921 0 == gcry_cipher_encrypt (out_cipher, &dgram[dpos], msize, msg, msize));
2922 dpos += msize;
2923 do_pad (out_cipher, &dgram[dpos], sizeof(dgram) - dpos);
2924 GNUNET_assert (0 == gcry_cipher_gettag (out_cipher,
2925 box->gcm_tag,
2926 sizeof(box->gcm_tag)));
2927 gcry_cipher_close (out_cipher);
2928
2929 receiver->rekey_send_bytes += sizeof(struct UDPBox) + receiver->d_mtu;
2930
2931 if (GNUNET_NO == receiver->rekeying)
2932 box->rekeying = GNUNET_NO;
2933 else
2934 box->rekeying = GNUNET_YES;
2935
2936 if (-1 == GNUNET_NETWORK_socket_sendto (udp_sock,
2937 dgram,
2938 sizeof(dgram),
2939 receiver->address,
2940 receiver->address_len))
2941 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "send");
2942 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2943 "Sending UDPBox %u acks left\n",
2944 receiver->acks_available);
2945 GNUNET_MQ_impl_send_continue (mq);
2946 receiver->acks_available--;
2947 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2948 "%u receiver->acks_available 2\n",
2949 receiver->acks_available);
2950 check_for_rekeying (receiver, box);
2951 if (0 == receiver->acks_available - receiver->number_rekeying_kce)
2952 {
2953 /* We have no more ACKs */
2954 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2955 "No more acks\n");
2956 if (GNUNET_YES == receiver->rekeying)
2957 {
2958 receiver->rekeying = GNUNET_NO;
2959 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2960 "Sender stopped rekeying\n");
2961
2962 if ((NULL != receiver->ss_rekey) && (0 <
2963 receiver->ss_rekey->
2964 sequence_allowed) )
2965 add_acks_rekey (receiver);
2966 }
2967 }
2968 else if ((GNUNET_YES == receiver->rekeying) )
2969 {
2970 send_UDPRekey (receiver, ss);
2971 }
2972
2973 return;
2974 }
2975}
2976
2977
2978/**
2979 * Signature of functions implementing the destruction of a message
2980 * queue. Implementations must not free @a mq, but should take care
2981 * of @a impl_state.
2982 *
2983 * @param mq the message queue to destroy
2984 * @param impl_state our `struct ReceiverAddress`
2985 */
2986static void
2987mq_destroy_d (struct GNUNET_MQ_Handle *mq, void *impl_state)
2988{
2989 struct ReceiverAddress *receiver = impl_state;
2990 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2991 "Default MQ destroyed\n");
2992 if (mq == receiver->d_mq)
2993 {
2994 receiver->d_mq = NULL;
2995 if (GNUNET_YES != receiver->receiver_destroy_called)
2996 receiver_destroy (receiver);
2997 }
2998}
2999
3000
3001/**
3002 * Signature of functions implementing the destruction of a message
3003 * queue. Implementations must not free @a mq, but should take care
3004 * of @a impl_state.
3005 *
3006 * @param mq the message queue to destroy
3007 * @param impl_state our `struct ReceiverAddress`
3008 */
3009static void
3010mq_destroy_kx (struct GNUNET_MQ_Handle *mq, void *impl_state)
3011{
3012 struct ReceiverAddress *receiver = impl_state;
3013 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3014 "KX MQ destroyed\n");
3015 if (mq == receiver->kx_mq)
3016 {
3017 receiver->kx_mq = NULL;
3018 if (GNUNET_YES != receiver->receiver_destroy_called)
3019 receiver_destroy (receiver);
3020 }
3021}
3022
3023
3024/**
3025 * Implementation function that cancels the currently sent message.
3026 *
3027 * @param mq message queue
3028 * @param impl_state our `struct RecvierAddress`
3029 */
3030static void
3031mq_cancel (struct GNUNET_MQ_Handle *mq, void *impl_state)
3032{
3033 /* Cancellation is impossible with UDP; bail */
3034 GNUNET_assert (0);
3035}
3036
3037
3038/**
3039 * Generic error handler, called with the appropriate
3040 * error code and the same closure specified at the creation of
3041 * the message queue.
3042 * Not every message queue implementation supports an error handler.
3043 *
3044 * @param cls our `struct ReceiverAddress`
3045 * @param error error code
3046 */
3047static void
3048mq_error (void *cls, enum GNUNET_MQ_Error error)
3049{
3050 struct ReceiverAddress *receiver = cls;
3051
3052 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3053 "MQ error in queue to %s: %d\n",
3054 GNUNET_i2s (&receiver->target),
3055 (int) error);
3056 receiver_destroy (receiver);
3057}
3058
3059
3060/**
3061 * Setup the MQ for the @a receiver. If a queue exists,
3062 * the existing one is destroyed. Then the MTU is
3063 * recalculated and a fresh queue is initialized.
3064 *
3065 * @param receiver receiver to setup MQ for
3066 */
3067static void
3068setup_receiver_mq (struct ReceiverAddress *receiver)
3069{
3070 size_t base_mtu;
3071
3072 /*if (NULL != receiver->kx_qh)
3073 {
3074 GNUNET_TRANSPORT_communicator_mq_del (receiver->kx_qh);
3075 receiver->kx_qh = NULL;
3076 }
3077 if (NULL != receiver->d_qh)
3078 {
3079 GNUNET_TRANSPORT_communicator_mq_del (receiver->d_qh);
3080 receiver->d_qh = NULL;
3081 }*/
3082 // GNUNET_assert (NULL == receiver->mq);
3083 switch (receiver->address->sa_family)
3084 {
3085 case AF_INET:
3086 base_mtu = 1480 /* Ethernet MTU, 1500 - Ethernet header - VLAN tag */
3087 - sizeof(struct GNUNET_TUN_IPv4Header) /* 20 */
3088 - sizeof(struct GNUNET_TUN_UdpHeader) /* 8 */;
3089 break;
3090
3091 case AF_INET6:
3092 base_mtu = 1280 /* Minimum MTU required by IPv6 */
3093 - sizeof(struct GNUNET_TUN_IPv6Header) /* 40 */
3094 - sizeof(struct GNUNET_TUN_UdpHeader) /* 8 */;
3095 break;
3096
3097 default:
3098 GNUNET_assert (0);
3099 break;
3100 }
3101 /* MTU based on full KX messages */
3102 receiver->kx_mtu = base_mtu - sizeof(struct InitialKX) /* 48 */
3103 - sizeof(struct UDPConfirmation); /* 104 */
3104 /* MTU based on BOXed messages */
3105 receiver->d_mtu = base_mtu - sizeof(struct UDPBox);
3106
3107 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3108 "Setting up MQs and QHs\n");
3109 /* => Effective MTU for CORE will range from 1080 (IPv6 + KX) to
3110 1404 (IPv4 + Box) bytes, depending on circumstances... */
3111 if (NULL == receiver->kx_mq)
3112 receiver->kx_mq = GNUNET_MQ_queue_for_callbacks (&mq_send_kx,
3113 &mq_destroy_kx,
3114 &mq_cancel,
3115 receiver,
3116 NULL,
3117 &mq_error,
3118 receiver);
3119 if (NULL == receiver->d_mq)
3120 receiver->d_mq = GNUNET_MQ_queue_for_callbacks (&mq_send_d,
3121 &mq_destroy_d,
3122 &mq_cancel,
3123 receiver,
3124 NULL,
3125 &mq_error,
3126 receiver);
3127
3128 receiver->kx_qh =
3129 GNUNET_TRANSPORT_communicator_mq_add (ch,
3130 &receiver->target,
3131 receiver->foreign_addr,
3132 receiver->kx_mtu,
3133 GNUNET_TRANSPORT_QUEUE_LENGTH_UNLIMITED,
3134 0, /* Priority */
3135 receiver->nt,
3136 GNUNET_TRANSPORT_CS_OUTBOUND,
3137 receiver->kx_mq);
3138 receiver->d_qh =
3139 GNUNET_TRANSPORT_communicator_mq_add (ch,
3140 &receiver->target,
3141 receiver->foreign_addr,
3142 receiver->d_mtu,
3143 0, /* Initialize with 0 acks */
3144 1, /* Priority */
3145 receiver->nt,
3146 GNUNET_TRANSPORT_CS_OUTBOUND,
3147 receiver->d_mq);
3148
3149}
3150
3151
3152/**
3153 * Function called by the transport service to initialize a
3154 * message queue given address information about another peer.
3155 * If and when the communication channel is established, the
3156 * communicator must call #GNUNET_TRANSPORT_communicator_mq_add()
3157 * to notify the service that the channel is now up. It is
3158 * the responsibility of the communicator to manage sane
3159 * retries and timeouts for any @a peer/@a address combination
3160 * provided by the transport service. Timeouts and retries
3161 * do not need to be signalled to the transport service.
3162 *
3163 * @param cls closure
3164 * @param peer identity of the other peer
3165 * @param address where to send the message, human-readable
3166 * communicator-specific format, 0-terminated, UTF-8
3167 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the provided address is
3168 * invalid
3169 */
3170static int
3171mq_init (void *cls, const struct GNUNET_PeerIdentity *peer, const char *address)
3172{
3173 struct ReceiverAddress *receiver;
3174 const char *path;
3175 struct sockaddr *in;
3176 socklen_t in_len;
3177
3178 if (0 != strncmp (address,
3179 COMMUNICATOR_ADDRESS_PREFIX "-",
3180 strlen (COMMUNICATOR_ADDRESS_PREFIX "-")))
3181 {
3182 GNUNET_break_op (0);
3183 return GNUNET_SYSERR;
3184 }
3185 path = &address[strlen (COMMUNICATOR_ADDRESS_PREFIX "-")];
3186 in = udp_address_to_sockaddr (path, &in_len);
3187
3188 receiver = GNUNET_new (struct ReceiverAddress);
3189 receiver->address = in;
3190 receiver->address_len = in_len;
3191 receiver->target = *peer;
3192 receiver->nt = GNUNET_NT_scanner_get_type (is, in, in_len);
3193 (void) GNUNET_CONTAINER_multipeermap_put (
3194 receivers,
3195 &receiver->target,
3196 receiver,
3197 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
3198 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3199 "Added %s to receivers\n",
3200 GNUNET_i2s_full (&receiver->target));
3201 receiver->timeout =
3202 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
3203 receiver->hn = GNUNET_CONTAINER_heap_insert (receivers_heap,
3204 receiver,
3205 receiver->timeout.abs_value_us);
3206 GNUNET_STATISTICS_set (stats,
3207 "# receivers active",
3208 GNUNET_CONTAINER_multipeermap_size (receivers),
3209 GNUNET_NO);
3210 receiver->foreign_addr =
3211 sockaddr_to_udpaddr_string (receiver->address, receiver->address_len);
3212 setup_receiver_mq (receiver);
3213 if (NULL == timeout_task)
3214 timeout_task = GNUNET_SCHEDULER_add_now (&check_timeouts, NULL);
3215 return GNUNET_OK;
3216}
3217
3218
3219/**
3220 * Iterator over all receivers to clean up.
3221 *
3222 * @param cls NULL
3223 * @param target unused
3224 * @param value the queue to destroy
3225 * @return #GNUNET_OK to continue to iterate
3226 */
3227static int
3228get_receiver_delete_it (void *cls,
3229 const struct GNUNET_PeerIdentity *target,
3230 void *value)
3231{
3232 struct ReceiverAddress *receiver = value;
3233
3234 (void) cls;
3235 (void) target;
3236 receiver_destroy (receiver);
3237 return GNUNET_OK;
3238}
3239
3240
3241/**
3242 * Iterator over all senders to clean up.
3243 *
3244 * @param cls NULL
3245 * @param target unused
3246 * @param value the queue to destroy
3247 * @return #GNUNET_OK to continue to iterate
3248 */
3249static int
3250get_sender_delete_it (void *cls,
3251 const struct GNUNET_PeerIdentity *target,
3252 void *value)
3253{
3254 struct SenderAddress *sender = value;
3255
3256 (void) cls;
3257 (void) target;
3258
3259 if (NULL != sender->kce_task_rekey)
3260 {
3261 GNUNET_SCHEDULER_cancel (sender->kce_task_rekey);
3262 sender->kce_task_rekey = NULL;
3263 }
3264 if (NULL != sender->kce_task)
3265 {
3266 GNUNET_SCHEDULER_cancel (sender->kce_task);
3267 sender->kce_task = NULL;
3268 }
3269
3270 sender_destroy (sender);
3271 return GNUNET_OK;
3272}
3273
3274
3275/**
3276 * Shutdown the UNIX communicator.
3277 *
3278 * @param cls NULL (always)
3279 */
3280static void
3281do_shutdown (void *cls)
3282{
3283 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3284 "do_shutdown\n");
3285 if (NULL != nat)
3286 {
3287 GNUNET_NAT_unregister (nat);
3288 nat = NULL;
3289 }
3290 while (NULL != bi_head)
3291 bi_destroy (bi_head);
3292 if (NULL != broadcast_task)
3293 {
3294 GNUNET_SCHEDULER_cancel (broadcast_task);
3295 broadcast_task = NULL;
3296 }
3297 if (NULL != timeout_task)
3298 {
3299 GNUNET_SCHEDULER_cancel (timeout_task);
3300 timeout_task = NULL;
3301 }
3302 if (NULL != read_task)
3303 {
3304 GNUNET_SCHEDULER_cancel (read_task);
3305 read_task = NULL;
3306 }
3307 if (NULL != udp_sock)
3308 {
3309 GNUNET_break (GNUNET_OK ==
3310 GNUNET_NETWORK_socket_close (udp_sock));
3311 udp_sock = NULL;
3312 }
3313 GNUNET_CONTAINER_multipeermap_iterate (receivers,
3314 &get_receiver_delete_it,
3315 NULL);
3316 GNUNET_CONTAINER_multipeermap_destroy (receivers);
3317 GNUNET_CONTAINER_multipeermap_iterate (senders,
3318 &get_sender_delete_it,
3319 NULL);
3320 GNUNET_CONTAINER_multipeermap_destroy (senders);
3321 GNUNET_CONTAINER_multishortmap_destroy (key_cache);
3322 GNUNET_CONTAINER_heap_destroy (senders_heap);
3323 GNUNET_CONTAINER_heap_destroy (receivers_heap);
3324 if (NULL != timeout_task)
3325 {
3326 GNUNET_SCHEDULER_cancel (timeout_task);
3327 timeout_task = NULL;
3328 }
3329 if (NULL != ch)
3330 {
3331 GNUNET_TRANSPORT_communicator_disconnect (ch);
3332 ch = NULL;
3333 }
3334 if (NULL != ah)
3335 {
3336 GNUNET_TRANSPORT_application_done (ah);
3337 ah = NULL;
3338 }
3339 if (NULL != stats)
3340 {
3341 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
3342 stats = NULL;
3343 }
3344 if (NULL != my_private_key)
3345 {
3346 GNUNET_free (my_private_key);
3347 my_private_key = NULL;
3348 }
3349 if (NULL != is)
3350 {
3351 GNUNET_NT_scanner_done (is);
3352 is = NULL;
3353 }
3354 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3355 "do_shutdown finished\n");
3356}
3357
3358
3359/**
3360 * Function called when the transport service has received a
3361 * backchannel message for this communicator (!) via a different return
3362 * path. Should be an acknowledgement.
3363 *
3364 * @param cls closure, NULL
3365 * @param sender which peer sent the notification
3366 * @param msg payload
3367 */
3368static void
3369enc_notify_cb (void *cls,
3370 const struct GNUNET_PeerIdentity *sender,
3371 const struct GNUNET_MessageHeader *msg)
3372{
3373 const struct UDPAck *ack;
3374
3375 (void) cls;
3376 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3377 "Storing UDPAck received from backchannel from %s\n",
3378 GNUNET_i2s_full (sender));
3379 if ((ntohs (msg->type) != GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK) ||
3380 (ntohs (msg->size) != sizeof(struct UDPAck)))
3381 {
3382 GNUNET_break_op (0);
3383 return;
3384 }
3385 ack = (const struct UDPAck *) msg;
3386 GNUNET_CONTAINER_multipeermap_get_multiple (receivers,
3387 sender,
3388 &handle_ack,
3389 (void *) ack);
3390}
3391
3392
3393/**
3394 * Signature of the callback passed to #GNUNET_NAT_register() for
3395 * a function to call whenever our set of 'valid' addresses changes.
3396 *
3397 * @param cls closure
3398 * @param app_ctx[in,out] location where the app can store stuff
3399 * on add and retrieve it on remove
3400 * @param add_remove #GNUNET_YES to add a new public IP address,
3401 * #GNUNET_NO to remove a previous (now invalid) one
3402 * @param ac address class the address belongs to
3403 * @param addr either the previous or the new public IP address
3404 * @param addrlen actual length of the @a addr
3405 */
3406static void
3407nat_address_cb (void *cls,
3408 void **app_ctx,
3409 int add_remove,
3410 enum GNUNET_NAT_AddressClass ac,
3411 const struct sockaddr *addr,
3412 socklen_t addrlen)
3413{
3414 char *my_addr;
3415 struct GNUNET_TRANSPORT_AddressIdentifier *ai;
3416
3417 if (GNUNET_YES == add_remove)
3418 {
3419 enum GNUNET_NetworkType nt;
3420
3421 GNUNET_asprintf (&my_addr,
3422 "%s-%s",
3423 COMMUNICATOR_ADDRESS_PREFIX,
3424 GNUNET_a2s (addr, addrlen));
3425 nt = GNUNET_NT_scanner_get_type (is, addr, addrlen);
3426 ai =
3427 GNUNET_TRANSPORT_communicator_address_add (ch,
3428 my_addr,
3429 nt,
3430 GNUNET_TIME_UNIT_FOREVER_REL);
3431 GNUNET_free (my_addr);
3432 *app_ctx = ai;
3433 }
3434 else
3435 {
3436 ai = *app_ctx;
3437 GNUNET_TRANSPORT_communicator_address_remove (ai);
3438 *app_ctx = NULL;
3439 }
3440}
3441
3442
3443/**
3444 * Broadcast our presence on one of our interfaces.
3445 *
3446 * @param cls a `struct BroadcastInterface`
3447 */
3448static void
3449ifc_broadcast (void *cls)
3450{
3451 struct BroadcastInterface *bi = cls;
3452 struct GNUNET_TIME_Relative delay;
3453
3454 delay = BROADCAST_FREQUENCY;
3455 delay.rel_value_us =
3456 GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, delay.rel_value_us);
3457 bi->broadcast_task =
3458 GNUNET_SCHEDULER_add_delayed (INTERFACE_SCAN_FREQUENCY, &ifc_broadcast, bi);
3459
3460 switch (bi->sa->sa_family)
3461 {
3462 case AF_INET: {
3463 static int yes = 1;
3464 static int no = 0;
3465 ssize_t sent;
3466
3467 if (GNUNET_OK !=
3468 GNUNET_NETWORK_socket_setsockopt (udp_sock,
3469 SOL_SOCKET,
3470 SO_BROADCAST,
3471 &yes,
3472 sizeof(int)))
3473 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
3474 "setsockopt");
3475 sent = GNUNET_NETWORK_socket_sendto (udp_sock,
3476 &bi->bcm,
3477 sizeof(bi->bcm),
3478 bi->ba,
3479 bi->salen);
3480 if (-1 == sent)
3481 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
3482 "sendto");
3483 if (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (udp_sock,
3484 SOL_SOCKET,
3485 SO_BROADCAST,
3486 &no,
3487 sizeof(int)))
3488 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
3489 "setsockopt");
3490 break;
3491 }
3492
3493 case AF_INET6: {
3494 ssize_t sent;
3495 struct sockaddr_in6 dst;
3496
3497 dst.sin6_family = AF_INET6;
3498 dst.sin6_port = htons (my_port);
3499 dst.sin6_addr = bi->mcreq.ipv6mr_multiaddr;
3500 dst.sin6_scope_id = ((struct sockaddr_in6 *) bi->ba)->sin6_scope_id;
3501
3502 sent = GNUNET_NETWORK_socket_sendto (udp_sock,
3503 &bi->bcm,
3504 sizeof(bi->bcm),
3505 (const struct sockaddr *) &dst,
3506 sizeof(dst));
3507 if (-1 == sent)
3508 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
3509 break;
3510 }
3511
3512 default:
3513 GNUNET_break (0);
3514 break;
3515 }
3516}
3517
3518
3519/**
3520 * Callback function invoked for each interface found.
3521 * Activates/deactivates broadcast interfaces.
3522 *
3523 * @param cls NULL
3524 * @param name name of the interface (can be NULL for unknown)
3525 * @param isDefault is this presumably the default interface
3526 * @param addr address of this interface (can be NULL for unknown or unassigned)
3527 * @param broadcast_addr the broadcast address (can be NULL for unknown or
3528 * unassigned)
3529 * @param netmask the network mask (can be NULL for unknown or unassigned)
3530 * @param addrlen length of the address
3531 * @return #GNUNET_OK to continue iteration, #GNUNET_SYSERR to abort
3532 */
3533static int
3534iface_proc (void *cls,
3535 const char *name,
3536 int isDefault,
3537 const struct sockaddr *addr,
3538 const struct sockaddr *broadcast_addr,
3539 const struct sockaddr *netmask,
3540 socklen_t addrlen)
3541{
3542 struct BroadcastInterface *bi;
3543 enum GNUNET_NetworkType network;
3544 struct UdpBroadcastSignature ubs;
3545
3546 (void) cls;
3547 (void) netmask;
3548 if (NULL == addr)
3549 return GNUNET_YES; /* need to know our address! */
3550 network = GNUNET_NT_scanner_get_type (is, addr, addrlen);
3551 if (GNUNET_NT_LOOPBACK == network)
3552 {
3553 /* Broadcasting on loopback does not make sense */
3554 return GNUNET_YES;
3555 }
3556 for (bi = bi_head; NULL != bi; bi = bi->next)
3557 {
3558 if ((bi->salen == addrlen) && (0 == memcmp (addr, bi->sa, addrlen)))
3559 {
3560 bi->found = GNUNET_YES;
3561 return GNUNET_OK;
3562 }
3563 }
3564
3565 if ((AF_INET6 == addr->sa_family) && (NULL == broadcast_addr))
3566 return GNUNET_OK; /* broadcast_addr is required for IPv6! */
3567 if ((AF_INET6 == addr->sa_family) && (GNUNET_YES != have_v6_socket))
3568 return GNUNET_OK; /* not using IPv6 */
3569
3570 bi = GNUNET_new (struct BroadcastInterface);
3571 bi->sa = GNUNET_memdup (addr,
3572 addrlen);
3573 if ( (NULL != broadcast_addr) &&
3574 (addrlen == sizeof (struct sockaddr_in)) )
3575 {
3576 struct sockaddr_in *ba;
3577
3578 ba = GNUNET_memdup (broadcast_addr,
3579 addrlen);
3580 ba->sin_port = htons (2086); /* always GNUnet port, ignore configuration! */
3581 bi->ba = (struct sockaddr *) ba;
3582 }
3583 bi->salen = addrlen;
3584 bi->found = GNUNET_YES;
3585 bi->bcm.sender = my_identity;
3586 ubs.purpose.purpose = htonl (GNUNET_SIGNATURE_COMMUNICATOR_UDP_BROADCAST);
3587 ubs.purpose.size = htonl (sizeof(ubs));
3588 ubs.sender = my_identity;
3589 GNUNET_CRYPTO_hash (addr, addrlen, &ubs.h_address);
3590 GNUNET_CRYPTO_eddsa_sign (my_private_key,
3591 &ubs,
3592 &bi->bcm.sender_sig);
3593 if (NULL != bi->ba)
3594 {
3595 bi->broadcast_task = GNUNET_SCHEDULER_add_now (&ifc_broadcast, bi);
3596 GNUNET_CONTAINER_DLL_insert (bi_head, bi_tail, bi);
3597 }
3598 if ((AF_INET6 == addr->sa_family) && (NULL != broadcast_addr))
3599 {
3600 /* Create IPv6 multicast request */
3601 const struct sockaddr_in6 *s6 =
3602 (const struct sockaddr_in6 *) broadcast_addr;
3603
3604 GNUNET_assert (
3605 1 == inet_pton (AF_INET6, "FF05::13B", &bi->mcreq.ipv6mr_multiaddr));
3606
3607 /* http://tools.ietf.org/html/rfc2553#section-5.2:
3608 *
3609 * IPV6_JOIN_GROUP
3610 *
3611 * Join a multicast group on a specified local interface. If the
3612 * interface index is specified as 0, the kernel chooses the local
3613 * interface. For example, some kernels look up the multicast
3614 * group in the normal IPv6 routing table and using the resulting
3615 * interface; we do this for each interface, so no need to use
3616 * zero (anymore...).
3617 */bi->mcreq.ipv6mr_interface = s6->sin6_scope_id;
3618
3619 /* Join the multicast group */
3620 if (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (udp_sock,
3621 IPPROTO_IPV6,
3622 IPV6_JOIN_GROUP,
3623 &bi->mcreq,
3624 sizeof(bi->mcreq)))
3625 {
3626 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "setsockopt");
3627 }
3628 }
3629 return GNUNET_OK;
3630}
3631
3632
3633/**
3634 * Scan interfaces to broadcast our presence on the LAN.
3635 *
3636 * @param cls NULL, unused
3637 */
3638static void
3639do_broadcast (void *cls)
3640{
3641 struct BroadcastInterface *bin;
3642
3643 (void) cls;
3644 for (struct BroadcastInterface *bi = bi_head; NULL != bi; bi = bi->next)
3645 bi->found = GNUNET_NO;
3646 GNUNET_OS_network_interfaces_list (&iface_proc, NULL);
3647 for (struct BroadcastInterface *bi = bi_head; NULL != bi; bi = bin)
3648 {
3649 bin = bi->next;
3650 if (GNUNET_NO == bi->found)
3651 bi_destroy (bi);
3652 }
3653 broadcast_task = GNUNET_SCHEDULER_add_delayed (INTERFACE_SCAN_FREQUENCY,
3654 &do_broadcast,
3655 NULL);
3656}
3657
3658
3659/**
3660 * Setup communicator and launch network interactions.
3661 *
3662 * @param cls NULL (always)
3663 * @param args remaining command-line arguments
3664 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
3665 * @param c configuration
3666 */
3667static void
3668run (void *cls,
3669 char *const *args,
3670 const char *cfgfile,
3671 const struct GNUNET_CONFIGURATION_Handle *c)
3672{
3673 char *bindto;
3674 struct sockaddr *in;
3675 socklen_t in_len;
3676 struct sockaddr_storage in_sto;
3677 socklen_t sto_len;
3678
3679 (void) cls;
3680 cfg = c;
3681 if (GNUNET_OK !=
3682 GNUNET_CONFIGURATION_get_value_string (cfg,
3683 COMMUNICATOR_CONFIG_SECTION,
3684 "BINDTO",
3685 &bindto))
3686 {
3687 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
3688 COMMUNICATOR_CONFIG_SECTION,
3689 "BINDTO");
3690 return;
3691 }
3692
3693 if (GNUNET_OK !=
3694 GNUNET_CONFIGURATION_get_value_time (cfg,
3695 COMMUNICATOR_CONFIG_SECTION,
3696 "REKEY_INTERVAL",
3697 &rekey_interval))
3698 rekey_interval = DEFAULT_REKEY_TIME_INTERVAL;
3699
3700 if (GNUNET_OK !=
3701 GNUNET_CONFIGURATION_get_value_size (cfg,
3702 COMMUNICATOR_CONFIG_SECTION,
3703 "REKEY_MAX_BYTES",
3704 &rekey_max_bytes))
3705 rekey_max_bytes = DEFAULT_REKEY_MAX_BYTES;
3706
3707 in = udp_address_to_sockaddr (bindto, &in_len);
3708 if (NULL == in)
3709 {
3710 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3711 "Failed to setup UDP socket address with path `%s'\n",
3712 bindto);
3713 GNUNET_free (bindto);
3714 return;
3715 }
3716 udp_sock =
3717 GNUNET_NETWORK_socket_create (in->sa_family,
3718 SOCK_DGRAM,
3719 IPPROTO_UDP);
3720 if (NULL == udp_sock)
3721 {
3722 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "socket");
3723 GNUNET_free (in);
3724 GNUNET_free (bindto);
3725 return;
3726 }
3727 if (AF_INET6 == in->sa_family)
3728 have_v6_socket = GNUNET_YES;
3729 if (GNUNET_OK !=
3730 GNUNET_NETWORK_socket_bind (udp_sock,
3731 in,
3732 in_len))
3733 {
3734 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
3735 "bind",
3736 bindto);
3737 GNUNET_NETWORK_socket_close (udp_sock);
3738 udp_sock = NULL;
3739 GNUNET_free (in);
3740 GNUNET_free (bindto);
3741 return;
3742 }
3743
3744 /* We might have bound to port 0, allowing the OS to figure it out;
3745 thus, get the real IN-address from the socket */
3746 sto_len = sizeof(in_sto);
3747 if (0 != getsockname (GNUNET_NETWORK_get_fd (udp_sock),
3748 (struct sockaddr *) &in_sto,
3749 &sto_len))
3750 {
3751 memcpy (&in_sto, in, in_len);
3752 sto_len = in_len;
3753 }
3754 GNUNET_free (in);
3755 GNUNET_free (bindto);
3756 in = (struct sockaddr *) &in_sto;
3757 in_len = sto_len;
3758 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3759 "Bound to `%s'\n",
3760 GNUNET_a2s ((const struct sockaddr *) &in_sto, sto_len));
3761 switch (in->sa_family)
3762 {
3763 case AF_INET:
3764 my_port = ntohs (((struct sockaddr_in *) in)->sin_port);
3765 break;
3766
3767 case AF_INET6:
3768 my_port = ntohs (((struct sockaddr_in6 *) in)->sin6_port);
3769 break;
3770
3771 default:
3772 GNUNET_break (0);
3773 my_port = 0;
3774 }
3775 stats = GNUNET_STATISTICS_create ("C-UDP", cfg);
3776 senders = GNUNET_CONTAINER_multipeermap_create (32, GNUNET_YES);
3777 receivers = GNUNET_CONTAINER_multipeermap_create (32, GNUNET_YES);
3778 senders_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
3779 receivers_heap =
3780 GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
3781 key_cache = GNUNET_CONTAINER_multishortmap_create (1024, GNUNET_YES);
3782 GNUNET_SCHEDULER_add_shutdown (&do_shutdown, NULL);
3783 is = GNUNET_NT_scanner_init ();
3784 my_private_key = GNUNET_CRYPTO_eddsa_key_create_from_configuration (cfg);
3785 if (NULL == my_private_key)
3786 {
3787 GNUNET_log (
3788 GNUNET_ERROR_TYPE_ERROR,
3789 _ (
3790 "Transport service is lacking key configuration settings. Exiting.\n"));
3791 GNUNET_SCHEDULER_shutdown ();
3792 return;
3793 }
3794 GNUNET_CRYPTO_eddsa_key_get_public (my_private_key, &my_identity.public_key);
3795 /* start reading */
3796 read_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
3797 udp_sock,
3798 &sock_read,
3799 NULL);
3800 ch = GNUNET_TRANSPORT_communicator_connect (cfg,
3801 COMMUNICATOR_CONFIG_SECTION,
3802 COMMUNICATOR_ADDRESS_PREFIX,
3803 GNUNET_TRANSPORT_CC_UNRELIABLE,
3804 &mq_init,
3805 NULL,
3806 &enc_notify_cb,
3807 NULL);
3808 if (NULL == ch)
3809 {
3810 GNUNET_break (0);
3811 GNUNET_SCHEDULER_shutdown ();
3812 return;
3813 }
3814 ah = GNUNET_TRANSPORT_application_init (cfg);
3815 if (NULL == ah)
3816 {
3817 GNUNET_break (0);
3818 GNUNET_SCHEDULER_shutdown ();
3819 return;
3820 }
3821 /* start broadcasting */
3822 if (GNUNET_YES !=
3823 GNUNET_CONFIGURATION_get_value_yesno (cfg,
3824 COMMUNICATOR_CONFIG_SECTION,
3825 "DISABLE_BROADCAST"))
3826 {
3827 broadcast_task = GNUNET_SCHEDULER_add_now (&do_broadcast, NULL);
3828 }
3829 nat = GNUNET_NAT_register (cfg,
3830 COMMUNICATOR_CONFIG_SECTION,
3831 IPPROTO_UDP,
3832 1 /* one address */,
3833 (const struct sockaddr **) &in,
3834 &in_len,
3835 &nat_address_cb,
3836 NULL /* FIXME: support reversal: #5529 */,
3837 NULL /* closure */);
3838}
3839
3840
3841/**
3842 * The main function for the UNIX communicator.
3843 *
3844 * @param argc number of arguments from the command line
3845 * @param argv command line arguments
3846 * @return 0 ok, 1 on error
3847 */
3848int
3849main (int argc, char *const *argv)
3850{
3851 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
3852 GNUNET_GETOPT_OPTION_END
3853 };
3854 int ret;
3855
3856 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
3857 return 2;
3858
3859 ret = (GNUNET_OK == GNUNET_PROGRAM_run (argc,
3860 argv,
3861 "gnunet-communicator-udp",
3862 _ ("GNUnet UDP communicator"),
3863 options,
3864 &run,
3865 NULL))
3866 ? 0
3867 : 1;
3868 GNUNET_free_nz ((void *) argv);
3869 return ret;
3870}
3871
3872
3873/* end of gnunet-communicator-udp.c */