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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_PURPOSE_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_PURPOSE_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_PURPOSE_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_PURPOSE_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
1498 if (NULL == receiver->d_qh)
1499 {
1500 receiver->d_qh =
1501 GNUNET_TRANSPORT_communicator_mq_add (ch,
1502 &receiver->target,
1503 receiver->foreign_addr,
1504 receiver->d_mtu,
1505 acks_to_add,
1506 1, /* Priority */
1507 receiver->nt,
1508 GNUNET_TRANSPORT_CS_OUTBOUND,
1509 receiver->d_mq);
1510 }
1511 else
1512 {
1513 GNUNET_TRANSPORT_communicator_mq_update (ch,
1514 receiver->d_qh,
1515 acks_to_add,
1516 1);
1517 }
1518
1519 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1520 "Tell transport we have %u more acks!\n",
1521 acks_to_add);
1522 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1523 "%u kce for rekeying.\n",
1524 receiver->number_rekeying_kce);
1525
1526 // Until here for alternativ 1
1527
1528 /* move ss to head to avoid discarding it anytime soon! */
1529
1530 GNUNET_CONTAINER_DLL_remove (receiver->ss_head, receiver->ss_tail, ss);
1531 GNUNET_CONTAINER_DLL_insert (receiver->ss_head, receiver->ss_tail, ss);
1532 destroy_all_secrets (ss, GNUNET_YES);
1533}
1534
1535
1536static uint32_t
1537reset_rekey_kces (struct ReceiverAddress *receiver,
1538 uint32_t acks_to_add)
1539{
1540 int needed_for_rekeying;
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
1547 needed_for_rekeying = (3 - receiver->number_rekeying_kce);
1548 if (acks_to_add <= needed_for_rekeying)
1549 {
1550 receiver->number_rekeying_kce += acks_to_add;
1551 acks_to_add = 0;
1552 }
1553 else
1554 {
1555 acks_to_add -= (3 - receiver->number_rekeying_kce);
1556 receiver->number_rekeying_kce = 3;
1557 }
1558
1559 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1560 "%u kce for rekeying and %u acks_to_add\n",
1561 receiver->number_rekeying_kce,
1562 acks_to_add);
1563 return acks_to_add;
1564}
1565
1566
1567static void
1568add_acks_rekey (struct ReceiverAddress *receiver)
1569{
1570 uint32_t acks_to_add = receiver->ss_rekey->sequence_allowed;
1571
1572 if (receiver->number_rekeying_kce < 3)
1573 acks_to_add = reset_rekey_kces (receiver, acks_to_add);
1574 receiver->acks_available = receiver->ss_rekey->sequence_allowed;
1575 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1576 "%u receiver->acks_available 4\n",
1577 receiver->acks_available);
1578 /* add_acks (receiver->ss_rekey, acks_to_add - 3); */
1579 if (0 != acks_to_add)
1580 {
1581 add_acks (receiver->ss_rekey, acks_to_add);
1582 }
1583 receiver->ss_rekey = NULL;
1584 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1585 "# rekeying successful\n");
1586 GNUNET_STATISTICS_update (stats,
1587 "# rekeying successful",
1588 1,
1589 GNUNET_NO);
1590}
1591
1592
1593/**
1594 * We received an ACK for @a pid. Check if it is for
1595 * the receiver in @a value and if so, handle it and
1596 * return #GNUNET_NO. Otherwise, return #GNUNET_YES.
1597 *
1598 * @param cls a `const struct UDPAck`
1599 * @param pid peer the ACK is from
1600 * @param value a `struct ReceiverAddress`
1601 * @return #GNUNET_YES to continue to iterate
1602 */
1603static int
1604handle_ack (void *cls, const struct GNUNET_PeerIdentity *pid, void *value)
1605{
1606 const struct UDPAck *ack = cls;
1607 struct ReceiverAddress *receiver = value;
1608 uint32_t acks_to_add;
1609 uint32_t allowed;
1610 // int needed_for_rekeying;
1611
1612 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1613 "in handle ack with cmac %s\n",
1614 GNUNET_h2s (&ack->cmac));
1615
1616 if (NULL != receiver->ss_rekey)
1617 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1618 "We have rekey secret with cmac %s \n",
1619 GNUNET_h2s (&receiver->ss_rekey->cmac));
1620
1621 if ((NULL != receiver->ss_rekey) && (0 == memcmp (&ack->cmac,
1622 &receiver->ss_rekey->cmac,
1623 sizeof(struct
1624 GNUNET_HashCode))) )
1625 {
1626 allowed = ntohl (ack->sequence_max);
1627
1628 if (allowed > receiver->ss_rekey->sequence_allowed)
1629 {
1630 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1631 "%u > %u (%u %u) for rekey secrect %s\n", allowed,
1632 receiver->ss_rekey->sequence_allowed,
1633 receiver->acks_available,
1634 ack->acks_available,
1635 GNUNET_h2s (&receiver->ss_rekey->master));
1636
1637 receiver->ss_rekey->sequence_allowed = allowed;
1638
1639 if (GNUNET_NO == receiver->rekeying)
1640 add_acks_rekey (receiver);
1641
1642 return GNUNET_NO;
1643 }
1644 }
1645
1646 (void) pid;
1647 for (struct SharedSecret *ss = receiver->ss_head; NULL != ss; ss = ss->next)
1648 {
1649 if (0 == memcmp (&ack->cmac, &ss->cmac, sizeof(struct GNUNET_HashCode)))
1650 {
1651
1652 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1653 "Found matching mac\n");
1654
1655 allowed = ntohl (ack->sequence_max);
1656
1657 if (allowed > ss->sequence_allowed)
1658 {
1659 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1660 "%u > %u (%u %u) for secrect %s\n", allowed,
1661 ss->sequence_allowed,
1662 receiver->acks_available,
1663 ack->acks_available,
1664 GNUNET_h2s (&ss->master));
1665 // Uncomment this for alternativ 1 of backchannel functionality
1666 acks_to_add = (allowed - ss->sequence_allowed);
1667 if ((GNUNET_NO == receiver->rekeying) &&
1668 (receiver->number_rekeying_kce < 3) )
1669 acks_to_add = reset_rekey_kces (receiver, acks_to_add);
1670 /* if ((GNUNET_NO == receiver->rekeying) && */
1671 /* (receiver->number_rekeying_kce < */
1672 /* 3) ) */
1673 /* { */
1674 /* needed_for_rekeying = (3 - receiver->number_rekeying_kce); */
1675 /* if (acks_to_add <= needed_for_rekeying) */
1676 /* { */
1677 /* receiver->number_rekeying_kce += acks_to_add; */
1678 /* acks_to_add = 0; */
1679 /* } */
1680 /* else */
1681 /* { */
1682 /* acks_to_add -= (3 - receiver->number_rekeying_kce); */
1683 /* receiver->number_rekeying_kce = 3; */
1684 /* } */
1685 /* } */
1686 /* GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, */
1687 /* "%u kce for rekeying\n", */
1688 /* receiver->number_rekeying_kce); */
1689
1690 if ((0 != acks_to_add) && (GNUNET_NO == receiver->rekeying))
1691 {
1692 receiver->acks_available += (allowed - ss->sequence_allowed);
1693 ss->sequence_allowed = allowed;
1694 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1695 "%u receiver->acks_available 5\n",
1696 receiver->acks_available);
1697 add_acks (ss, acks_to_add);
1698 }
1699 }
1700 return GNUNET_NO;
1701 }
1702 }
1703 return GNUNET_YES;
1704}
1705
1706
1707/**
1708 * Test if we have received a valid message in plaintext.
1709 * If so, handle it.
1710 *
1711 * @param sender peer to process inbound plaintext for
1712 * @param buf buffer we received
1713 * @param buf_size number of bytes in @a buf
1714 */
1715static void
1716try_handle_plaintext (struct SenderAddress *sender,
1717 const void *buf,
1718 size_t buf_size)
1719{
1720 const struct GNUNET_MessageHeader *hdr =
1721 (const struct GNUNET_MessageHeader *) buf;
1722 const struct UDPAck *ack = (const struct UDPAck *) buf;
1723 uint16_t type;
1724
1725 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1726 "try_handle_plaintext of size %u (%u %u) and type %u\n",
1727 buf_size,
1728 ntohs (hdr->size),
1729 sizeof(*hdr),
1730 ntohs (hdr->type));
1731 if (sizeof(*hdr) > buf_size)
1732 return; /* not even a header */
1733 if (ntohs (hdr->size) > buf_size)
1734 return; /* not even a header */
1735 type = ntohs (hdr->type);
1736 switch (type)
1737 {
1738 case GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK:
1739 /* lookup master secret by 'cmac', then update sequence_max */
1740 GNUNET_CONTAINER_multipeermap_get_multiple (receivers,
1741 &sender->target,
1742 &handle_ack,
1743 (void *) ack);
1744 /* There could be more messages after the ACK, handle those as well */
1745 buf += ntohs (hdr->size);
1746 buf_size -= ntohs (hdr->size);
1747 pass_plaintext_to_core (sender, buf, buf_size);
1748 break;
1749
1750 case GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_PAD:
1751 /* skip padding */
1752 break;
1753
1754 default:
1755 pass_plaintext_to_core (sender, buf, buf_size);
1756 }
1757}
1758
1759
1760static void
1761kce_generate_cb (void *cls)
1762{
1763 struct SharedSecret *ss = cls;
1764
1765 ss->sender->kce_task = NULL;
1766
1767 if (((GNUNET_NO == ss->sender->rekeying) && (ss->sender->acks_available <
1768 KCN_TARGET) ) ||
1769 ((ss->sender->ss_rekey == ss) && (GNUNET_YES == ss->sender->rekeying) &&
1770 (ss->sender->acks_available < KCN_TARGET)))
1771 {
1772
1773 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1774 "Precomputing keys for master %s\n",
1775 GNUNET_h2s (&(ss->master)));
1776
1777 for (int i = 0; i < GENERATE_AT_ONCE; i++)
1778 kce_generate (ss, ++ss->sequence_allowed);
1779
1780 if (KCN_TARGET > ss->sender->acks_available)
1781 {
1782 ss->sender->kce_task = GNUNET_SCHEDULER_add_delayed (
1783 WORKING_QUEUE_INTERVALL,
1784 kce_generate_cb,
1785 ss);
1786 }
1787 else
1788 {
1789 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1790 "We have enough keys.\n");
1791 ss_finished = ss;
1792 ss->sender->kce_task_finished = GNUNET_YES;
1793 }
1794 }
1795
1796
1797
1798}
1799
1800
1801static void
1802kce_generate_rekey_cb (void *cls)
1803{
1804 struct SharedSecret *ss = cls;
1805
1806 ss->sender->kce_task_rekey = NULL;
1807
1808 if (NULL == ss->sender->kce_task)
1809 {
1810
1811 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1812 "Precomputing keys for rekey master %s\n",
1813 GNUNET_h2s (&(ss->master)));
1814
1815 for (int i = 0; i < GENERATE_AT_ONCE; i++)
1816 kce_generate (ss, ++ss->sequence_allowed);
1817
1818 ss->sender->kce_task = GNUNET_SCHEDULER_add_delayed (
1819 WORKING_QUEUE_INTERVALL,
1820 kce_generate_cb,
1821 ss);
1822 ss->sender->kce_task_rekey = NULL;
1823 }
1824 else
1825 {
1826 ss->sender->kce_task_rekey = GNUNET_SCHEDULER_add_delayed (
1827 WORKING_QUEUE_INTERVALL,
1828 kce_generate_rekey_cb,
1829 ss);
1830 }
1831}
1832
1833
1834/**
1835 * We established a shared secret with a sender. We should try to send
1836 * the sender an `struct UDPAck` at the next opportunity to allow the
1837 * sender to use @a ss longer (assuming we did not yet already
1838 * recently).
1839 *
1840 * @param ss shared secret to generate ACKs for
1841 * @param initial The SharedSecret came with initial KX.
1842 */
1843static void
1844consider_ss_ack (struct SharedSecret *ss, int initial)
1845{
1846 struct GNUNET_SCHEDULER_Task *kce_task_rekey;
1847 struct GNUNET_SCHEDULER_Task *kce_task;
1848 int kce_task_finished;
1849
1850 kce_task_rekey = ss->sender->kce_task_rekey;
1851 kce_task_finished = ss->sender->kce_task_finished;
1852 kce_task = ss->sender->kce_task;
1853
1854 GNUNET_assert (NULL != ss->sender);
1855 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1856 "Considering SS UDPAck %s\n",
1857 GNUNET_i2s_full (&ss->sender->target));
1858
1859 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1860 "We have %u acks available.\n",
1861 ss->sender->acks_available);
1862 /* drop ancient KeyCacheEntries */
1863 while ((NULL != ss->kce_head) &&
1864 (MAX_SQN_DELTA <
1865 ss->kce_head->sequence_number - ss->kce_tail->sequence_number))
1866 kce_destroy (ss->kce_tail);
1867
1868
1869 if (GNUNET_NO == initial)
1870 kce_generate (ss, ++ss->sequence_allowed);
1871
1872 /*if (0 == ss->sender->acks_available)
1873 {
1874 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1875 "Generating keys\n");
1876 while (ss->active_kce_count < KCN_TARGET)
1877 kce_generate (ss, ++ss->sequence_allowed);
1878 }*/
1879
1880 if (NULL != kce_task)
1881 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1882 "kce_task is not NULL\n");
1883 if (kce_task_finished)
1884 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1885 "kce_task_finished: GNUNET_YES\n");
1886 if (initial)
1887 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1888 "initial: GNUNET_YES\n");
1889
1890 if ( kce_task_finished || (GNUNET_NO == initial))
1891 {
1892 struct UDPAck ack;
1893 struct SharedSecret *ss_tell;
1894
1895 if (GNUNET_NO != initial)
1896 ss_tell = ss_finished;
1897 else
1898 ss_tell = ss;
1899
1900 ack.header.type = htons (GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK);
1901 ack.header.size = htons (sizeof(ack));
1902 ack.sequence_max = htonl (ss_tell->sequence_allowed);
1903 ack.acks_available = ss->sender->acks_available;
1904 ack.cmac = ss_tell->cmac;
1905 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1906 "Notifying transport of UDPAck %s with initial %u and master %s\n",
1907 GNUNET_i2s_full (&ss_tell->sender->target),
1908 initial,
1909 GNUNET_h2s (&(ss_tell->master)));
1910 GNUNET_TRANSPORT_communicator_notify (ch,
1911 &ss_tell->sender->target,
1912 COMMUNICATOR_ADDRESS_PREFIX,
1913 &ack.header);
1914 if (GNUNET_NO != initial)
1915 {
1916 destroy_all_secrets (ss, GNUNET_YES);
1917 ss->sender->kce_task_finished = GNUNET_NO;
1918 }
1919 }
1920 else if ((NULL == kce_task) && ((KCN_THRESHOLD >
1921 ss->sender->acks_available) ||
1922 (GNUNET_YES == ss->sender->rekeying) ||
1923 (ss->sender->num_secrets > MAX_SECRETS) ))
1924 {
1925
1926 // kce_generate (ss, ++ss->sequence_allowed);
1927 // kce_generate (ss, ++ss->sequence_allowed);
1928 // TODO This task must be per sender!
1929 kce_task = GNUNET_SCHEDULER_add_delayed (WORKING_QUEUE_INTERVALL,
1930 kce_generate_cb,
1931 ss);
1932 kce_task_finished = GNUNET_NO;
1933
1934 }
1935 else if ((NULL == kce_task_rekey) && (GNUNET_YES ==
1936 ss->sender->rekeying) )
1937 {
1938 kce_task_rekey = GNUNET_SCHEDULER_add_delayed (WORKING_QUEUE_INTERVALL,
1939 kce_generate_rekey_cb,
1940 ss);
1941 }
1942}
1943
1944
1945/**
1946 * We received a @a box with matching @a kce. Decrypt and process it.
1947 *
1948 * @param box the data we received
1949 * @param box_len number of bytes in @a box
1950 * @param kce key index to decrypt @a box
1951 */
1952static void
1953decrypt_box (const struct UDPBox *box,
1954 size_t box_len,
1955 struct KeyCacheEntry *kce)
1956{
1957 struct SharedSecret *ss = kce->ss;
1958 char out_buf[box_len - sizeof(*box)];
1959
1960 GNUNET_assert (NULL != ss->sender);
1961 if (GNUNET_OK != try_decrypt (ss,
1962 box->gcm_tag,
1963 kce->sequence_number,
1964 (const char *) &box[1],
1965 sizeof(out_buf),
1966 out_buf))
1967 {
1968 GNUNET_STATISTICS_update (stats,
1969 "# Decryption failures with valid KCE",
1970 1,
1971 GNUNET_NO);
1972 kce_destroy (kce);
1973 return;
1974 }
1975 kce_destroy (kce);
1976 GNUNET_STATISTICS_update (stats,
1977 "# bytes decrypted with BOX",
1978 sizeof(out_buf),
1979 GNUNET_NO);
1980 GNUNET_STATISTICS_update (stats,
1981 "# messages decrypted with BOX",
1982 1,
1983 GNUNET_NO);
1984 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1985 "decrypted UDPBox with kid %s\n",
1986 GNUNET_sh2s (&box->kid));
1987 try_handle_plaintext (ss->sender, out_buf, sizeof(out_buf));
1988 if ((GNUNET_NO == box->rekeying) && (GNUNET_YES == ss->sender->rekeying))
1989 {
1990 ss->sender->rekeying = GNUNET_NO;
1991 ss->sender->ss_rekey = NULL;
1992 // destroy_all_secrets (ss, GNUNET_NO);
1993 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1994 "Receiver stopped rekeying.\n");
1995 }
1996 else if (GNUNET_NO == box->rekeying)
1997 consider_ss_ack (ss, GNUNET_NO);
1998 else
1999 {
2000 ss->sender->rekeying = GNUNET_YES;
2001 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2002 "Got Box: Receiver doing rekeying.\n");
2003 }
2004}
2005
2006
2007/**
2008 * We received a @a rekey with matching @a kce. Decrypt and process it.
2009 *
2010 * @param rekey the data we received
2011 * @param rekey_len number of bytes in @a rekey
2012 * @param kce key index to decrypt @a rekey
2013 */
2014static void
2015decrypt_rekey (const struct UDPRekey *rekey,
2016 size_t rekey_len,
2017 struct KeyCacheEntry *kce,
2018 struct SenderAddress *sender)
2019{
2020 struct SharedSecret *ss = kce->ss;
2021 struct SharedSecret *ss_rekey;
2022 char out_buf[rekey_len - sizeof(*rekey)];
2023 struct GNUNET_HashCode *master;
2024
2025
2026 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2027 "decrypt_rekey.\n");
2028
2029 GNUNET_assert (NULL != ss->sender);
2030 if (GNUNET_OK != try_decrypt (ss,
2031 rekey->gcm_tag,
2032 kce->sequence_number,
2033 (const char *) &rekey[1],
2034 sizeof(out_buf),
2035 out_buf))
2036 {
2037 GNUNET_STATISTICS_update (stats,
2038 "# Decryption failures with valid KCE",
2039 1,
2040 GNUNET_NO);
2041 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2042 "Decryption with kid %s failed\n",
2043 GNUNET_sh2s (&rekey->kid));
2044 kce_destroy (kce);
2045 return;
2046 }
2047 kce_destroy (kce);
2048 GNUNET_STATISTICS_update (stats,
2049 "# bytes decrypted with Rekey",
2050 sizeof(out_buf),
2051 GNUNET_NO);
2052 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2053 "decrypted UDPRekey with kid %s\n",
2054 GNUNET_sh2s (&rekey->kid));
2055 /*cmac = (struct GNUNET_HashCode *) out_buf;
2056 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2057 "Received secret with cmac %s \n",
2058 GNUNET_h2s (&cmac));*/
2059 // ss_rekey = (struct SharedSecret *) out_buf;
2060 master = (struct GNUNET_HashCode *) out_buf;
2061 ss_rekey = GNUNET_new (struct SharedSecret);
2062 ss_rekey->master = *master;
2063 calculate_cmac (ss_rekey);
2064 ss_rekey->sender = sender;
2065 // ss_rekey->sequence_used = 0;
2066 // ss_rekey->sequence_allowed = 0;
2067 /* ss_rekey->active_kce_count = 0; */
2068 /* ss_rekey->prev = NULL; */
2069 /* ss_rekey->next = NULL; */
2070 /* GNUNET_assert (ss_rekey->prev == NULL && sender->ss_head != ss_rekey); */
2071 /* GNUNET_assert (ss_rekey->next == NULL && sender->ss_tail != ss_rekey); */
2072 GNUNET_CONTAINER_DLL_insert (sender->ss_head, sender->ss_tail, ss_rekey);
2073 sender->ss_rekey = ss_rekey;
2074 sender->num_secrets++;
2075 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2076 "Received secret with cmac %s\n",
2077 GNUNET_h2s (&(ss_rekey->cmac)));
2078 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2079 "Received secret with master %s.\n",
2080 GNUNET_h2s (&(ss_rekey->master)));
2081 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2082 "We have %u sequence_allowed.\n",
2083 ss_rekey->sequence_allowed);
2084 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2085 "We have a sender %p\n",
2086 ss_rekey->sender);
2087 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2088 "We have %u acks available.\n",
2089 ss_rekey->sender->acks_available);
2090 consider_ss_ack (ss_rekey, GNUNET_YES);
2091
2092}
2093
2094
2095/**
2096 * Closure for #find_sender_by_address()
2097 */
2098struct SearchContext
2099{
2100 /**
2101 * Address we are looking for.
2102 */
2103 const struct sockaddr *address;
2104
2105 /**
2106 * Number of bytes in @e address.
2107 */
2108 socklen_t address_len;
2109
2110 /**
2111 * Return value to set if we found a match.
2112 */
2113 struct SenderAddress *sender;
2114};
2115
2116
2117/**
2118 * Find existing `struct SenderAddress` by matching addresses.
2119 *
2120 * @param cls a `struct SearchContext`
2121 * @param key ignored, must match already
2122 * @param value a `struct SenderAddress`
2123 * @return #GNUNET_YES if not found (continue to search), #GNUNET_NO if found
2124 */
2125static int
2126find_sender_by_address (void *cls,
2127 const struct GNUNET_PeerIdentity *key,
2128 void *value)
2129{
2130 struct SearchContext *sc = cls;
2131 struct SenderAddress *sender = value;
2132
2133 if ((sender->address_len == sc->address_len) &&
2134 (0 == memcmp (sender->address, sc->address, sender->address_len)))
2135 {
2136 sc->sender = sender;
2137 return GNUNET_NO; /* stop iterating! */
2138 }
2139 return GNUNET_YES;
2140}
2141
2142
2143/**
2144 * Create sender address for @a target. Note that we
2145 * might already have one, so a fresh one is only allocated
2146 * if one does not yet exist for @a address.
2147 *
2148 * @param target peer to generate address for
2149 * @param address target address
2150 * @param address_len number of bytes in @a address
2151 * @return data structure to keep track of key material for
2152 * decrypting data from @a target
2153 */
2154static struct SenderAddress *
2155setup_sender (const struct GNUNET_PeerIdentity *target,
2156 const struct sockaddr *address,
2157 socklen_t address_len)
2158{
2159 struct SenderAddress *sender;
2160 struct SearchContext sc = { .address = address,
2161 .address_len = address_len,
2162 .sender = NULL };
2163
2164 GNUNET_CONTAINER_multipeermap_get_multiple (senders,
2165 target,
2166 &find_sender_by_address,
2167 &sc);
2168 if (NULL != sc.sender)
2169 {
2170 reschedule_sender_timeout (sc.sender);
2171 return sc.sender;
2172 }
2173 sender = GNUNET_new (struct SenderAddress);
2174 sender->target = *target;
2175 sender->address = GNUNET_memdup (address, address_len);
2176 sender->address_len = address_len;
2177 (void) GNUNET_CONTAINER_multipeermap_put (
2178 senders,
2179 &sender->target,
2180 sender,
2181 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
2182 GNUNET_STATISTICS_set (stats,
2183 "# senders active",
2184 GNUNET_CONTAINER_multipeermap_size (receivers),
2185 GNUNET_NO);
2186 sender->timeout =
2187 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
2188 sender->hn = GNUNET_CONTAINER_heap_insert (senders_heap,
2189 sender,
2190 sender->timeout.abs_value_us);
2191 sender->nt = GNUNET_NT_scanner_get_type (is, address, address_len);
2192 if (NULL == timeout_task)
2193 timeout_task = GNUNET_SCHEDULER_add_now (&check_timeouts, NULL);
2194 return sender;
2195}
2196
2197
2198/**
2199 * Check signature from @a uc against @a ephemeral.
2200 *
2201 * @param ephermal key that is signed
2202 * @param uc signature of claimant
2203 * @return #GNUNET_OK if signature is valid
2204 */
2205static int
2206verify_confirmation (const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral,
2207 const struct UDPConfirmation *uc)
2208{
2209 struct UdpHandshakeSignature uhs;
2210
2211 uhs.purpose.purpose = htonl (
2212 GNUNET_SIGNATURE_PURPOSE_COMMUNICATOR_UDP_HANDSHAKE);
2213 uhs.purpose.size = htonl (sizeof(uhs));
2214 uhs.sender = uc->sender;
2215 uhs.receiver = my_identity;
2216 uhs.ephemeral = *ephemeral;
2217 uhs.monotonic_time = uc->monotonic_time;
2218 return GNUNET_CRYPTO_eddsa_verify (
2219 GNUNET_SIGNATURE_PURPOSE_COMMUNICATOR_UDP_HANDSHAKE,
2220 &uhs,
2221 &uc->sender_sig,
2222 &uc->sender.public_key);
2223}
2224
2225
2226/**
2227 * Converts @a address to the address string format used by this
2228 * communicator in HELLOs.
2229 *
2230 * @param address the address to convert, must be AF_INET or AF_INET6.
2231 * @param address_len number of bytes in @a address
2232 * @return string representation of @a address
2233 */
2234static char *
2235sockaddr_to_udpaddr_string (const struct sockaddr *address,
2236 socklen_t address_len)
2237{
2238 char *ret;
2239
2240 switch (address->sa_family)
2241 {
2242 case AF_INET:
2243 GNUNET_asprintf (&ret,
2244 "%s-%s",
2245 COMMUNICATOR_ADDRESS_PREFIX,
2246 GNUNET_a2s (address, address_len));
2247 break;
2248
2249 case AF_INET6:
2250 GNUNET_asprintf (&ret,
2251 "%s-%s",
2252 COMMUNICATOR_ADDRESS_PREFIX,
2253 GNUNET_a2s (address, address_len));
2254 break;
2255
2256 default:
2257 GNUNET_assert (0);
2258 }
2259 return ret;
2260}
2261
2262
2263/**
2264 * Socket read task.
2265 *
2266 * @param cls NULL
2267 */
2268static void
2269sock_read (void *cls)
2270{
2271 struct sockaddr_storage sa;
2272 struct sockaddr_in *addr_verify;
2273 socklen_t salen = sizeof(sa);
2274 char buf[UINT16_MAX];
2275 ssize_t rcvd;
2276
2277 (void) cls;
2278 read_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
2279 udp_sock,
2280 &sock_read,
2281 NULL);
2282 rcvd = GNUNET_NETWORK_socket_recvfrom (udp_sock,
2283 buf,
2284 sizeof(buf),
2285 (struct sockaddr *) &sa,
2286 &salen);
2287 if (-1 == rcvd)
2288 {
2289 GNUNET_log_strerror (GNUNET_ERROR_TYPE_DEBUG, "recv");
2290 return;
2291 }
2292 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2293 "Read %lu bytes\n", rcvd);
2294
2295 if (rcvd > sizeof(struct UDPRekey))
2296 {
2297 const struct UDPRekey *rekey;
2298 const struct UDPBox *box;
2299 struct KeyCacheEntry *kce;
2300 struct SenderAddress *sender;
2301 int do_decrypt = GNUNET_NO;
2302
2303 rekey = (const struct UDPRekey *) buf;
2304 box = (const struct UDPBox *) buf;
2305 kce = GNUNET_CONTAINER_multishortmap_get (key_cache, &rekey->kid);
2306
2307 if ((GNUNET_YES == box->rekeying) || (GNUNET_NO == box->rekeying))
2308 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2309 "UDPRekey has rekeying %u\n",
2310 box->rekeying);
2311 else
2312 do_decrypt = GNUNET_YES;
2313
2314 if ((GNUNET_YES == do_decrypt) && (NULL != kce) && (GNUNET_YES ==
2315 kce->ss->sender->
2316 rekeying))
2317 {
2318 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2319 "UDPRekey with kid %s\n",
2320 GNUNET_sh2s (&rekey->kid));
2321 sender = setup_sender (&rekey->sender, (const struct sockaddr *) &sa,
2322 salen);
2323
2324 if (NULL != sender->ss_rekey)
2325 return;
2326
2327 decrypt_rekey (rekey, (size_t) rcvd, kce, sender);
2328 return;
2329 }
2330 }
2331
2332 /* first, see if it is a UDPBox */
2333 if (rcvd > sizeof(struct UDPBox))
2334 {
2335 const struct UDPBox *box;
2336 struct KeyCacheEntry *kce;
2337
2338 box = (const struct UDPBox *) buf;
2339 kce = GNUNET_CONTAINER_multishortmap_get (key_cache, &box->kid);
2340 if (NULL != kce)
2341 {
2342 decrypt_box (box, (size_t) rcvd, kce);
2343 return;
2344 }
2345 }
2346
2347 /* next, check if it is a broadcast */
2348 if (sizeof(struct UDPBroadcast) == rcvd)
2349 {
2350 const struct UDPBroadcast *ub;
2351 struct UdpBroadcastSignature uhs;
2352 struct GNUNET_PeerIdentity sender;
2353
2354 addr_verify = GNUNET_memdup (&sa, salen);
2355 addr_verify->sin_port = 0;
2356 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2357 "received UDPBroadcast from %s\n",
2358 GNUNET_a2s ((const struct sockaddr *) addr_verify, salen));
2359 ub = (const struct UDPBroadcast *) buf;
2360 uhs.purpose.purpose = htonl (
2361 GNUNET_SIGNATURE_PURPOSE_COMMUNICATOR_UDP_BROADCAST);
2362 uhs.purpose.size = htonl (sizeof(uhs));
2363 uhs.sender = ub->sender;
2364 sender = ub->sender;
2365 if (0 == memcmp (&sender, &my_identity, sizeof (struct
2366 GNUNET_PeerIdentity)))
2367 {
2368 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2369 "Received our own broadcast\n");
2370 return;
2371 }
2372 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2373 "checking UDPBroadcastSignature for %s\n",
2374 GNUNET_i2s (&sender));
2375 GNUNET_CRYPTO_hash ((struct sockaddr *) addr_verify, salen, &uhs.h_address);
2376 if (GNUNET_OK ==
2377 GNUNET_CRYPTO_eddsa_verify (
2378 GNUNET_SIGNATURE_PURPOSE_COMMUNICATOR_UDP_BROADCAST,
2379 &uhs,
2380 &ub->sender_sig,
2381 &ub->sender.public_key))
2382 {
2383 char *addr_s;
2384 enum GNUNET_NetworkType nt;
2385
2386 addr_s =
2387 sockaddr_to_udpaddr_string ((const struct sockaddr *) &sa, salen);
2388 GNUNET_STATISTICS_update (stats, "# broadcasts received", 1, GNUNET_NO);
2389 /* use our own mechanism to determine network type */
2390 nt =
2391 GNUNET_NT_scanner_get_type (is, (const struct sockaddr *) &sa, salen);
2392 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2393 "validating address %s received from UDPBroadcast\n",
2394 GNUNET_i2s (&sender));
2395 GNUNET_TRANSPORT_application_validate (ah, &sender, nt, addr_s);
2396 GNUNET_free (addr_s);
2397 return;
2398 }
2399 else
2400 {
2401 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2402 "VerifyingPeer %s is verifying UDPBroadcast\n",
2403 GNUNET_i2s (&my_identity));
2404 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2405 "Verifying UDPBroadcast from %s failed\n",
2406 GNUNET_i2s (&ub->sender));
2407 }
2408 GNUNET_free (addr_verify);
2409 /* continue with KX, mostly for statistics... */
2410 }
2411
2412
2413 /* finally, test if it is a KX */
2414 if (rcvd < sizeof(struct UDPConfirmation) + sizeof(struct InitialKX))
2415 {
2416 GNUNET_STATISTICS_update (stats,
2417 "# messages dropped (no kid, too small for KX)",
2418 1,
2419 GNUNET_NO);
2420 return;
2421 }
2422 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2423 "Got KX\n");
2424 {
2425 const struct InitialKX *kx;
2426 struct SharedSecret *ss;
2427 char pbuf[rcvd - sizeof(struct InitialKX)];
2428 const struct UDPConfirmation *uc;
2429 struct SenderAddress *sender;
2430
2431 kx = (const struct InitialKX *) buf;
2432 ss = setup_shared_secret_dec (&kx->ephemeral);
2433 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2434 "Before DEC\n");
2435
2436 if (GNUNET_OK != try_decrypt (ss,
2437 kx->gcm_tag,
2438 0,
2439 &buf[sizeof(*kx)],
2440 sizeof(pbuf),
2441 pbuf))
2442 {
2443 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2444 "Unable to decrypt tag, dropping...\n");
2445 GNUNET_free (ss);
2446 GNUNET_STATISTICS_update (
2447 stats,
2448 "# messages dropped (no kid, AEAD decryption failed)",
2449 1,
2450 GNUNET_NO);
2451 return;
2452 }
2453 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2454 "Before VERIFY\n");
2455
2456 uc = (const struct UDPConfirmation *) pbuf;
2457 if (GNUNET_OK != verify_confirmation (&kx->ephemeral, uc))
2458 {
2459 GNUNET_break_op (0);
2460 GNUNET_free (ss);
2461 GNUNET_STATISTICS_update (stats,
2462 "# messages dropped (sender signature invalid)",
2463 1,
2464 GNUNET_NO);
2465 return;
2466 }
2467 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2468 "Before SETUP_SENDER\n");
2469
2470 calculate_cmac (ss);
2471 sender = setup_sender (&uc->sender, (const struct sockaddr *) &sa, salen);
2472 ss->sender = sender;
2473 GNUNET_CONTAINER_DLL_insert (sender->ss_head, sender->ss_tail, ss);
2474 sender->num_secrets++;
2475 GNUNET_STATISTICS_update (stats, "# Secrets active", 1, GNUNET_NO);
2476 GNUNET_STATISTICS_update (stats,
2477 "# messages decrypted without BOX",
2478 1,
2479 GNUNET_NO);
2480 try_handle_plaintext (sender, &uc[1], sizeof(pbuf) - sizeof(*uc));
2481 if ((GNUNET_NO == kx->rekeying) && (GNUNET_YES == ss->sender->rekeying))
2482 {
2483 ss->sender->rekeying = GNUNET_NO;
2484 sender->ss_rekey = NULL;
2485 // destroy_all_secrets (ss, GNUNET_NO);
2486 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2487 "Receiver stopped rekeying.\n");
2488 }
2489 else if (GNUNET_NO == kx->rekeying)
2490 consider_ss_ack (ss, GNUNET_YES);
2491 else
2492 {
2493 ss->sender->rekeying = GNUNET_YES;
2494 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2495 "Got KX: Receiver doing rekeying.\n");
2496 }
2497 /*if (sender->num_secrets > MAX_SECRETS)
2498 secret_destroy (sender->ss_tail);*/
2499 }
2500}
2501
2502
2503/**
2504 * Convert UDP bind specification to a `struct sockaddr *`
2505 *
2506 * @param bindto bind specification to convert
2507 * @param[out] sock_len set to the length of the address
2508 * @return converted bindto specification
2509 */
2510static struct sockaddr *
2511udp_address_to_sockaddr (const char *bindto, socklen_t *sock_len)
2512{
2513 struct sockaddr *in;
2514 unsigned int port;
2515 char dummy[2];
2516 char *colon;
2517 char *cp;
2518
2519 if (1 == sscanf (bindto, "%u%1s", &port, dummy))
2520 {
2521 /* interpreting value as just a PORT number */
2522 if (port > UINT16_MAX)
2523 {
2524 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2525 "BINDTO specification `%s' invalid: value too large for port\n",
2526 bindto);
2527 return NULL;
2528 }
2529 if ((GNUNET_NO == GNUNET_NETWORK_test_pf (PF_INET6)) ||
2530 (GNUNET_YES ==
2531 GNUNET_CONFIGURATION_get_value_yesno (cfg,
2532 COMMUNICATOR_CONFIG_SECTION,
2533 "DISABLE_V6")))
2534 {
2535 struct sockaddr_in *i4;
2536
2537 i4 = GNUNET_malloc (sizeof(struct sockaddr_in));
2538 i4->sin_family = AF_INET;
2539 i4->sin_port = htons ((uint16_t) port);
2540 *sock_len = sizeof(struct sockaddr_in);
2541 in = (struct sockaddr *) i4;
2542 }
2543 else
2544 {
2545 struct sockaddr_in6 *i6;
2546
2547 i6 = GNUNET_malloc (sizeof(struct sockaddr_in6));
2548 i6->sin6_family = AF_INET6;
2549 i6->sin6_port = htons ((uint16_t) port);
2550 *sock_len = sizeof(struct sockaddr_in6);
2551 in = (struct sockaddr *) i6;
2552 }
2553 return in;
2554 }
2555 cp = GNUNET_strdup (bindto);
2556 colon = strrchr (cp, ':');
2557 if (NULL != colon)
2558 {
2559 /* interpret value after colon as port */
2560 *colon = '\0';
2561 colon++;
2562 if (1 == sscanf (colon, "%u%1s", &port, dummy))
2563 {
2564 /* interpreting value as just a PORT number */
2565 if (port > UINT16_MAX)
2566 {
2567 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2568 "BINDTO specification `%s' invalid: value too large for port\n",
2569 bindto);
2570 GNUNET_free (cp);
2571 return NULL;
2572 }
2573 }
2574 else
2575 {
2576 GNUNET_log (
2577 GNUNET_ERROR_TYPE_ERROR,
2578 "BINDTO specification `%s' invalid: last ':' not followed by number\n",
2579 bindto);
2580 GNUNET_free (cp);
2581 return NULL;
2582 }
2583 }
2584 else
2585 {
2586 /* interpret missing port as 0, aka pick any free one */
2587 port = 0;
2588 }
2589 {
2590 /* try IPv4 */
2591 struct sockaddr_in v4;
2592 if (1 == inet_pton (AF_INET, cp, &v4.sin_addr))
2593 {
2594 v4.sin_family = AF_INET;
2595 v4.sin_port = htons ((uint16_t) port);
2596#if HAVE_SOCKADDR_IN_SIN_LEN
2597 v4.sin_len = sizeof(struct sockaddr_in);
2598#endif
2599 in = GNUNET_memdup (&v4, sizeof(struct sockaddr_in));
2600 *sock_len = sizeof(struct sockaddr_in);
2601 GNUNET_free (cp);
2602 return in;
2603 }
2604 }
2605 {
2606 /* try IPv6 */
2607 struct sockaddr_in6 v6;
2608 const char *start;
2609
2610 start = cp;
2611 if (('[' == *cp) && (']' == cp[strlen (cp) - 1]))
2612 {
2613 start++; /* skip over '[' */
2614 cp[strlen (cp) - 1] = '\0'; /* eat ']' */
2615 }
2616 if (1 == inet_pton (AF_INET6, start, &v6.sin6_addr))
2617 {
2618 v6.sin6_family = AF_INET6;
2619 v6.sin6_port = htons ((uint16_t) port);
2620#if HAVE_SOCKADDR_IN_SIN_LEN
2621 v6.sin6_len = sizeof(sizeof(struct sockaddr_in6));
2622#endif
2623 in = GNUNET_memdup (&v6, sizeof(v6));
2624 *sock_len = sizeof(v6);
2625 GNUNET_free (cp);
2626 return in;
2627 }
2628 }
2629 /* #5528 FIXME (feature!): maybe also try getnameinfo()? */
2630 GNUNET_free (cp);
2631 return NULL;
2632}
2633
2634
2635/**
2636 * Pad @a dgram by @a pad_size using @a out_cipher.
2637 *
2638 * @param out_cipher cipher to use
2639 * @param dgram datagram to pad
2640 * @param pad_size number of bytes of padding to append
2641 */
2642static void
2643do_pad (gcry_cipher_hd_t out_cipher, char *dgram, size_t pad_size)
2644{
2645 char pad[pad_size];
2646
2647 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK, pad, sizeof(pad));
2648 if (sizeof(pad) > sizeof(struct GNUNET_MessageHeader))
2649 {
2650 struct GNUNET_MessageHeader hdr =
2651 { .size = htons (sizeof(pad)),
2652 .type = htons (GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_PAD) };
2653
2654 memcpy (pad, &hdr, sizeof(hdr));
2655 }
2656 GNUNET_assert (
2657 0 ==
2658 gcry_cipher_encrypt (out_cipher, dgram, sizeof(pad), pad, sizeof(pad)));
2659}
2660
2661
2662/**
2663 * Signature of functions implementing the sending functionality of a
2664 * message queue.
2665 *
2666 * @param mq the message queue
2667 * @param msg the message to send
2668 * @param impl_state our `struct ReceiverAddress`
2669 */
2670static void
2671mq_send_kx (struct GNUNET_MQ_Handle *mq,
2672 const struct GNUNET_MessageHeader *msg,
2673 void *impl_state)
2674{
2675 struct ReceiverAddress *receiver = impl_state;
2676 uint16_t msize = ntohs (msg->size);
2677 struct UdpHandshakeSignature uhs;
2678 struct UDPConfirmation uc;
2679 struct InitialKX kx;
2680 struct GNUNET_CRYPTO_EcdhePrivateKey epriv;
2681 char dgram[receiver->kx_mtu + sizeof(uc) + sizeof(kx)];
2682 size_t dpos;
2683 gcry_cipher_hd_t out_cipher;
2684 struct SharedSecret *ss;
2685
2686 GNUNET_assert (mq == receiver->kx_mq);
2687 if (msize > receiver->kx_mtu)
2688 {
2689 GNUNET_break (0);
2690 if (GNUNET_YES != receiver->receiver_destroy_called)
2691 receiver_destroy (receiver);
2692 return;
2693 }
2694 reschedule_receiver_timeout (receiver);
2695
2696 /* setup key material */
2697 GNUNET_CRYPTO_ecdhe_key_create (&epriv);
2698
2699 ss = setup_shared_secret_enc (&epriv, receiver, GNUNET_YES);
2700
2701 if (receiver->num_secrets > MAX_SECRETS)
2702 {
2703 destroy_all_secrets (ss, GNUNET_YES);
2704 }
2705
2706 setup_cipher (&ss->master, 0, &out_cipher);
2707 /* compute 'uc' */
2708 uc.sender = my_identity;
2709 uc.monotonic_time =
2710 GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get_monotonic (cfg));
2711 uhs.purpose.purpose = htonl (
2712 GNUNET_SIGNATURE_PURPOSE_COMMUNICATOR_UDP_HANDSHAKE);
2713 uhs.purpose.size = htonl (sizeof(uhs));
2714 uhs.sender = my_identity;
2715 uhs.receiver = receiver->target;
2716 GNUNET_CRYPTO_ecdhe_key_get_public (&epriv, &uhs.ephemeral);
2717 uhs.monotonic_time = uc.monotonic_time;
2718 GNUNET_CRYPTO_eddsa_sign (my_private_key,
2719 &uhs,
2720 &uc.sender_sig);
2721 /* Leave space for kx */
2722 dpos = sizeof(kx);
2723 /* Append encrypted uc to dgram */
2724 GNUNET_assert (0 == gcry_cipher_encrypt (out_cipher,
2725 &dgram[dpos],
2726 sizeof(uc),
2727 &uc,
2728 sizeof(uc)));
2729 dpos += sizeof(uc);
2730 /* Append encrypted payload to dgram */
2731 GNUNET_assert (
2732 0 == gcry_cipher_encrypt (out_cipher, &dgram[dpos], msize, msg, msize));
2733 dpos += msize;
2734 do_pad (out_cipher, &dgram[dpos], sizeof(dgram) - dpos);
2735 /* Datagram starts with kx */
2736 kx.ephemeral = uhs.ephemeral;
2737 GNUNET_assert (
2738 0 == gcry_cipher_gettag (out_cipher, kx.gcm_tag, sizeof(kx.gcm_tag)));
2739 gcry_cipher_close (out_cipher);
2740 if (GNUNET_NO == receiver->rekeying)
2741 kx.rekeying = GNUNET_NO;
2742 else
2743 kx.rekeying = GNUNET_YES;
2744 memcpy (dgram, &kx, sizeof(kx));
2745 if (-1 == GNUNET_NETWORK_socket_sendto (udp_sock,
2746 dgram,
2747 sizeof(dgram),
2748 receiver->address,
2749 receiver->address_len))
2750 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "send");
2751 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2752 "Sending KX with payload size %u to %s\n",
2753 msize,
2754 GNUNET_a2s (receiver->address,
2755 receiver->address_len));
2756 GNUNET_MQ_impl_send_continue (mq);
2757}
2758
2759
2760static void
2761check_for_rekeying (struct ReceiverAddress *receiver, struct UDPBox *box)
2762{
2763
2764 struct GNUNET_TIME_Relative rt;
2765
2766 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2767 "Timeout is %llu\n.",
2768 (unsigned long long) receiver->rekey_timeout.abs_value_us);
2769
2770 if (0 == receiver->rekey_timeout.abs_value_us)
2771 {
2772 receiver->rekey_timeout = GNUNET_TIME_relative_to_absolute (
2773 rekey_interval);
2774 }
2775 else
2776 {
2777 rt = GNUNET_TIME_absolute_get_remaining (receiver->rekey_timeout);
2778 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2779 "Relative time is %llu and timeout is %llu\n.",
2780 (unsigned long long) rt.rel_value_us,
2781 (unsigned long long) receiver->rekey_timeout.abs_value_us);
2782
2783 if ((0 == rt.rel_value_us) || (receiver->rekey_send_bytes >
2784 rekey_max_bytes) )
2785 {
2786 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2787 "Bytes send %llu greater than %llu max bytes\n.",
2788 (unsigned long long) receiver->rekey_send_bytes,
2789 rekey_max_bytes);
2790 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2791 "Relative time is %llu and timeout is %llu\n.",
2792 (unsigned long long) rt.rel_value_us,
2793 (unsigned long long) receiver->rekey_timeout.abs_value_us);
2794
2795 receiver->rekey_timeout.abs_value_us = 0;
2796 receiver->rekey_send_bytes = 0;
2797 receiver->ss_rekey = NULL;
2798 // destroy_all_secrets (ss, GNUNET_NO);
2799 receiver->rekeying = GNUNET_YES;
2800 receiver->rekey_acks_available = receiver->acks_available;
2801 box->rekeying = GNUNET_YES;
2802 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2803 "Sender started rekeying.\n");
2804 if (GNUNET_YES == box->rekeying)
2805 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2806 "Sending rekeying with kid %s\n",
2807 GNUNET_sh2s (&box->kid));
2808 }
2809 }
2810}
2811
2812
2813static void
2814send_UDPRekey (struct ReceiverAddress *receiver, struct SharedSecret *ss)
2815{
2816 uint8_t is_ss_rekey_sequence_allowed_zero = GNUNET_NO;
2817 uint8_t is_acks_available_below = GNUNET_NO;
2818 uint8_t send_rekey = GNUNET_NO;
2819 uint16_t not_below;
2820 struct GNUNET_CRYPTO_EcdhePrivateKey epriv;
2821 struct UDPRekey *rekey;
2822 size_t dpos;
2823
2824 char rekey_dgram[sizeof(struct UDPRekey) + receiver->d_mtu];
2825
2826 if (NULL != receiver->ss_rekey)
2827 {
2828 not_below = (receiver->rekey_acks_available
2829 - (receiver->rekey_acks_available % 3)) / 3;
2830 is_ss_rekey_sequence_allowed_zero = (0 ==
2831 receiver->ss_rekey->sequence_allowed);
2832 is_acks_available_below = (receiver->acks_available >= not_below);
2833 send_rekey = (0 == (receiver->acks_available - not_below) % not_below) &&
2834 is_acks_available_below && is_ss_rekey_sequence_allowed_zero;
2835 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2836 "send_rekey: %u, %u, %u\n",
2837 send_rekey,
2838 receiver->rekey_acks_available,
2839 receiver->acks_available);
2840 }
2841 else if (NULL == receiver->ss_rekey)
2842 {
2843 /* setup key material */
2844 GNUNET_CRYPTO_ecdhe_key_create (&epriv);
2845 receiver->ss_rekey = setup_shared_secret_enc (&epriv, receiver,
2846 GNUNET_NO);
2847 receiver->ss_rekey->sequence_allowed = 0;
2848 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2849 "Setup secret with cmac %s\n",
2850 GNUNET_h2s (&(receiver->ss_rekey->cmac)));
2851 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2852 "Setup secret with master %s.\n",
2853 GNUNET_h2s (&(receiver->ss_rekey->master)));
2854 }
2855
2856 if (send_rekey)
2857 {
2858 GNUNET_assert (0 != receiver->number_rekeying_kce);
2859 gcry_cipher_hd_t rekey_out_cipher;
2860
2861 while (NULL != ss && ss->sequence_used >= ss->sequence_allowed)
2862 {
2863 ss = ss->prev;
2864 }
2865
2866 if (NULL != ss)
2867 {
2868 rekey = (struct UDPRekey *) rekey_dgram;
2869 rekey->sender = my_identity;
2870 ss->sequence_used++;
2871 get_kid (&ss->master, ss->sequence_used, &rekey->kid);
2872 receiver->number_rekeying_kce--;
2873 setup_cipher (&ss->master, ss->sequence_used, &rekey_out_cipher);
2874 /* Append encrypted payload to dgram */
2875 dpos = sizeof(struct UDPRekey);
2876
2877 GNUNET_assert (
2878 0 == gcry_cipher_encrypt (rekey_out_cipher, &rekey_dgram[dpos],
2879 sizeof(receiver->ss_rekey->master),
2880 &(receiver->ss_rekey->master),
2881 sizeof(receiver->ss_rekey->master)));
2882 dpos += sizeof(receiver->ss_rekey->master);
2883 /* GNUNET_assert ( */
2884 /* 0 == gcry_cipher_encrypt (rekey_out_cipher, &rekey_dgram[dpos], */
2885 /* /\*sizeof(receiver->ss_rekey->cmac), */
2886 /* &(receiver->ss_rekey->cmac), */
2887 /* sizeof(receiver->ss_rekey->cmac))); */
2888 /* dpos += sizeof(receiver->ss_rekey->cmac);*\/ */
2889 /* sizeof(receiver->ss_rekey), */
2890 /* receiver->ss_rekey, */
2891 /* sizeof(receiver->ss_rekey))); */
2892 /* dpos += sizeof(receiver->ss_rekey); */
2893 do_pad (rekey_out_cipher, &rekey_dgram[dpos], sizeof(rekey_dgram)
2894 - dpos);
2895 GNUNET_assert (0 == gcry_cipher_gettag (rekey_out_cipher,
2896 rekey->gcm_tag,
2897 sizeof(rekey->gcm_tag)));
2898 gcry_cipher_close (rekey_out_cipher);
2899
2900 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2901 "Sending rekey with kid %s and master %s\n",
2902 GNUNET_sh2s (&rekey->kid),
2903 GNUNET_h2s (&(receiver->ss_rekey->master)));
2904 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2905 "Sending rekey with cmac %s\n",
2906 GNUNET_h2s (&(receiver->ss_rekey->cmac)));
2907 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2908 "%u rekey kces left.\n",
2909 receiver->number_rekeying_kce);
2910
2911 if (-1 == GNUNET_NETWORK_socket_sendto (udp_sock,
2912 rekey_dgram,
2913 sizeof(rekey_dgram),
2914 receiver->address,
2915 receiver->address_len))
2916 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "send");
2917
2918 receiver->acks_available--;
2919 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2920 "%u receiver->acks_available 1\n",
2921 receiver->acks_available);
2922 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2923 "Sending UDPRekey to %s\n", GNUNET_a2s (receiver->address,
2924 receiver->
2925 address_len));
2926 }
2927 }
2928}
2929
2930
2931/**
2932 * Signature of functions implementing the sending functionality of a
2933 * message queue.
2934 *
2935 * @param mq the message queue
2936 * @param msg the message to send
2937 * @param impl_state our `struct ReceiverAddress`
2938 */
2939static void
2940mq_send_d (struct GNUNET_MQ_Handle *mq,
2941 const struct GNUNET_MessageHeader *msg,
2942 void *impl_state)
2943{
2944 struct ReceiverAddress *receiver = impl_state;
2945 uint16_t msize = ntohs (msg->size);
2946
2947 GNUNET_assert (mq == receiver->d_mq);
2948 if ((msize > receiver->d_mtu) ||
2949 (0 == receiver->acks_available))
2950 {
2951 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2952 "msize: %u, mtu: %lu, acks: %u\n",
2953 msize,
2954 receiver->d_mtu,
2955 receiver->acks_available);
2956
2957 GNUNET_break (0);
2958 if (GNUNET_YES != receiver->receiver_destroy_called)
2959 receiver_destroy (receiver);
2960 return;
2961 }
2962 reschedule_receiver_timeout (receiver);
2963
2964 /* begin "BOX" encryption method, scan for ACKs from tail! */
2965 for (struct SharedSecret *ss = receiver->ss_tail; NULL != ss; ss = ss->prev)
2966 {
2967 if (0 < ss->sequence_used)
2968 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2969 "Trying to send UDPBox with shared secrect %s sequence_used %u and ss->sequence_allowed %u\n",
2970 GNUNET_h2s (&ss->master),
2971 ss->sequence_used,
2972 ss->sequence_allowed);
2973 // Uncomment this for alternativ 1 of backchannel functionality
2974 if (ss->sequence_used >= ss->sequence_allowed)
2975 // Until here for alternativ 1
2976 // Uncomment this for alternativ 2 of backchannel functionality
2977 // if (0 == ss->sequence_allowed)
2978 // Until here for alternativ 2
2979 {
2980 continue;
2981 }
2982 char dgram[sizeof(struct UDPBox) + receiver->d_mtu];
2983 struct UDPBox *box;
2984 gcry_cipher_hd_t out_cipher;
2985 size_t dpos;
2986
2987 box = (struct UDPBox *) dgram;
2988 ss->sequence_used++;
2989 get_kid (&ss->master, ss->sequence_used, &box->kid);
2990 setup_cipher (&ss->master, ss->sequence_used, &out_cipher);
2991 /* Append encrypted payload to dgram */
2992 dpos = sizeof(struct UDPBox);
2993 GNUNET_assert (
2994 0 == gcry_cipher_encrypt (out_cipher, &dgram[dpos], msize, msg, msize));
2995 dpos += msize;
2996 do_pad (out_cipher, &dgram[dpos], sizeof(dgram) - dpos);
2997 GNUNET_assert (0 == gcry_cipher_gettag (out_cipher,
2998 box->gcm_tag,
2999 sizeof(box->gcm_tag)));
3000 gcry_cipher_close (out_cipher);
3001
3002 receiver->rekey_send_bytes += sizeof(struct UDPBox) + receiver->d_mtu;
3003
3004 if (GNUNET_NO == receiver->rekeying)
3005 box->rekeying = GNUNET_NO;
3006 else
3007 box->rekeying = GNUNET_YES;
3008
3009 if (-1 == GNUNET_NETWORK_socket_sendto (udp_sock,
3010 dgram,
3011 sizeof(dgram),
3012 receiver->address,
3013 receiver->address_len))
3014 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "send");
3015 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3016 "Sending UDPBox with payload size %u, %u acks left\n",
3017 msize,
3018 receiver->acks_available);
3019 GNUNET_MQ_impl_send_continue (mq);
3020 receiver->acks_available--;
3021 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3022 "%u receiver->acks_available 2\n",
3023 receiver->acks_available);
3024 check_for_rekeying (receiver, box);
3025 if (0 == receiver->acks_available - receiver->number_rekeying_kce)
3026 {
3027 /* We have no more ACKs */
3028 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3029 "No more acks\n");
3030 if (GNUNET_YES == receiver->rekeying)
3031 {
3032 receiver->rekeying = GNUNET_NO;
3033 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3034 "Sender stopped rekeying\n");
3035
3036 if ((NULL != receiver->ss_rekey) && (0 <
3037 receiver->ss_rekey->
3038 sequence_allowed) )
3039 add_acks_rekey (receiver);
3040 }
3041 }
3042 else if ((GNUNET_YES == receiver->rekeying) )
3043 {
3044 send_UDPRekey (receiver, ss);
3045 }
3046
3047 return;
3048 }
3049}
3050
3051
3052/**
3053 * Signature of functions implementing the destruction of a message
3054 * queue. Implementations must not free @a mq, but should take care
3055 * of @a impl_state.
3056 *
3057 * @param mq the message queue to destroy
3058 * @param impl_state our `struct ReceiverAddress`
3059 */
3060static void
3061mq_destroy_d (struct GNUNET_MQ_Handle *mq, void *impl_state)
3062{
3063 struct ReceiverAddress *receiver = impl_state;
3064 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3065 "Default MQ destroyed\n");
3066 if (mq == receiver->d_mq)
3067 {
3068 receiver->d_mq = NULL;
3069 if (GNUNET_YES != receiver->receiver_destroy_called)
3070 receiver_destroy (receiver);
3071 }
3072}
3073
3074
3075/**
3076 * Signature of functions implementing the destruction of a message
3077 * queue. Implementations must not free @a mq, but should take care
3078 * of @a impl_state.
3079 *
3080 * @param mq the message queue to destroy
3081 * @param impl_state our `struct ReceiverAddress`
3082 */
3083static void
3084mq_destroy_kx (struct GNUNET_MQ_Handle *mq, void *impl_state)
3085{
3086 struct ReceiverAddress *receiver = impl_state;
3087 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3088 "KX MQ destroyed\n");
3089 if (mq == receiver->kx_mq)
3090 {
3091 receiver->kx_mq = NULL;
3092 if (GNUNET_YES != receiver->receiver_destroy_called)
3093 receiver_destroy (receiver);
3094 }
3095}
3096
3097
3098/**
3099 * Implementation function that cancels the currently sent message.
3100 *
3101 * @param mq message queue
3102 * @param impl_state our `struct RecvierAddress`
3103 */
3104static void
3105mq_cancel (struct GNUNET_MQ_Handle *mq, void *impl_state)
3106{
3107 /* Cancellation is impossible with UDP; bail */
3108 GNUNET_assert (0);
3109}
3110
3111
3112/**
3113 * Generic error handler, called with the appropriate
3114 * error code and the same closure specified at the creation of
3115 * the message queue.
3116 * Not every message queue implementation supports an error handler.
3117 *
3118 * @param cls our `struct ReceiverAddress`
3119 * @param error error code
3120 */
3121static void
3122mq_error (void *cls, enum GNUNET_MQ_Error error)
3123{
3124 struct ReceiverAddress *receiver = cls;
3125
3126 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3127 "MQ error in queue to %s: %d\n",
3128 GNUNET_i2s (&receiver->target),
3129 (int) error);
3130 receiver_destroy (receiver);
3131}
3132
3133
3134/**
3135 * Setup the MQ for the @a receiver. If a queue exists,
3136 * the existing one is destroyed. Then the MTU is
3137 * recalculated and a fresh queue is initialized.
3138 *
3139 * @param receiver receiver to setup MQ for
3140 */
3141static void
3142setup_receiver_mq (struct ReceiverAddress *receiver)
3143{
3144 size_t base_mtu;
3145
3146 /*if (NULL != receiver->kx_qh)
3147 {
3148 GNUNET_TRANSPORT_communicator_mq_del (receiver->kx_qh);
3149 receiver->kx_qh = NULL;
3150 }
3151 if (NULL != receiver->d_qh)
3152 {
3153 GNUNET_TRANSPORT_communicator_mq_del (receiver->d_qh);
3154 receiver->d_qh = NULL;
3155 }*/
3156 // GNUNET_assert (NULL == receiver->mq);
3157 switch (receiver->address->sa_family)
3158 {
3159 case AF_INET:
3160 base_mtu = 1480 /* Ethernet MTU, 1500 - Ethernet header - VLAN tag */
3161 - sizeof(struct GNUNET_TUN_IPv4Header) /* 20 */
3162 - sizeof(struct GNUNET_TUN_UdpHeader) /* 8 */;
3163 break;
3164
3165 case AF_INET6:
3166 base_mtu = 1280 /* Minimum MTU required by IPv6 */
3167 - sizeof(struct GNUNET_TUN_IPv6Header) /* 40 */
3168 - sizeof(struct GNUNET_TUN_UdpHeader) /* 8 */;
3169 break;
3170
3171 default:
3172 GNUNET_assert (0);
3173 break;
3174 }
3175 /* MTU based on full KX messages */
3176 receiver->kx_mtu = base_mtu - sizeof(struct InitialKX) /* 48 */
3177 - sizeof(struct UDPConfirmation); /* 104 */
3178 /* MTU based on BOXed messages */
3179 receiver->d_mtu = base_mtu - sizeof(struct UDPBox);
3180
3181 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3182 "Setting up MQs and QHs\n");
3183 /* => Effective MTU for CORE will range from 1080 (IPv6 + KX) to
3184 1404 (IPv4 + Box) bytes, depending on circumstances... */
3185 if (NULL == receiver->kx_mq)
3186 receiver->kx_mq = GNUNET_MQ_queue_for_callbacks (&mq_send_kx,
3187 &mq_destroy_kx,
3188 &mq_cancel,
3189 receiver,
3190 NULL,
3191 &mq_error,
3192 receiver);
3193 if (NULL == receiver->d_mq)
3194 receiver->d_mq = GNUNET_MQ_queue_for_callbacks (&mq_send_d,
3195 &mq_destroy_d,
3196 &mq_cancel,
3197 receiver,
3198 NULL,
3199 &mq_error,
3200 receiver);
3201
3202 receiver->kx_qh =
3203 GNUNET_TRANSPORT_communicator_mq_add (ch,
3204 &receiver->target,
3205 receiver->foreign_addr,
3206 receiver->kx_mtu,
3207 GNUNET_TRANSPORT_QUEUE_LENGTH_UNLIMITED,
3208 0, /* Priority */
3209 receiver->nt,
3210 GNUNET_TRANSPORT_CS_OUTBOUND,
3211 receiver->kx_mq);
3212}
3213
3214
3215/**
3216 * Function called by the transport service to initialize a
3217 * message queue given address information about another peer.
3218 * If and when the communication channel is established, the
3219 * communicator must call #GNUNET_TRANSPORT_communicator_mq_add()
3220 * to notify the service that the channel is now up. It is
3221 * the responsibility of the communicator to manage sane
3222 * retries and timeouts for any @a peer/@a address combination
3223 * provided by the transport service. Timeouts and retries
3224 * do not need to be signalled to the transport service.
3225 *
3226 * @param cls closure
3227 * @param peer identity of the other peer
3228 * @param address where to send the message, human-readable
3229 * communicator-specific format, 0-terminated, UTF-8
3230 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the provided address is
3231 * invalid
3232 */
3233static int
3234mq_init (void *cls, const struct GNUNET_PeerIdentity *peer, const char *address)
3235{
3236 struct ReceiverAddress *receiver;
3237 const char *path;
3238 struct sockaddr *in;
3239 socklen_t in_len;
3240
3241 if (0 != strncmp (address,
3242 COMMUNICATOR_ADDRESS_PREFIX "-",
3243 strlen (COMMUNICATOR_ADDRESS_PREFIX "-")))
3244 {
3245 GNUNET_break_op (0);
3246 return GNUNET_SYSERR;
3247 }
3248 path = &address[strlen (COMMUNICATOR_ADDRESS_PREFIX "-")];
3249 in = udp_address_to_sockaddr (path, &in_len);
3250
3251 receiver = GNUNET_new (struct ReceiverAddress);
3252 receiver->address = in;
3253 receiver->address_len = in_len;
3254 receiver->target = *peer;
3255 receiver->nt = GNUNET_NT_scanner_get_type (is, in, in_len);
3256 (void) GNUNET_CONTAINER_multipeermap_put (
3257 receivers,
3258 &receiver->target,
3259 receiver,
3260 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
3261 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3262 "Added %s to receivers\n",
3263 GNUNET_i2s_full (&receiver->target));
3264 receiver->timeout =
3265 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT);
3266 receiver->hn = GNUNET_CONTAINER_heap_insert (receivers_heap,
3267 receiver,
3268 receiver->timeout.abs_value_us);
3269 GNUNET_STATISTICS_set (stats,
3270 "# receivers active",
3271 GNUNET_CONTAINER_multipeermap_size (receivers),
3272 GNUNET_NO);
3273 receiver->foreign_addr =
3274 sockaddr_to_udpaddr_string (receiver->address, receiver->address_len);
3275 setup_receiver_mq (receiver);
3276 if (NULL == timeout_task)
3277 timeout_task = GNUNET_SCHEDULER_add_now (&check_timeouts, NULL);
3278 return GNUNET_OK;
3279}
3280
3281
3282/**
3283 * Iterator over all receivers to clean up.
3284 *
3285 * @param cls NULL
3286 * @param target unused
3287 * @param value the queue to destroy
3288 * @return #GNUNET_OK to continue to iterate
3289 */
3290static int
3291get_receiver_delete_it (void *cls,
3292 const struct GNUNET_PeerIdentity *target,
3293 void *value)
3294{
3295 struct ReceiverAddress *receiver = value;
3296
3297 (void) cls;
3298 (void) target;
3299 receiver_destroy (receiver);
3300 return GNUNET_OK;
3301}
3302
3303
3304/**
3305 * Iterator over all senders to clean up.
3306 *
3307 * @param cls NULL
3308 * @param target unused
3309 * @param value the queue to destroy
3310 * @return #GNUNET_OK to continue to iterate
3311 */
3312static int
3313get_sender_delete_it (void *cls,
3314 const struct GNUNET_PeerIdentity *target,
3315 void *value)
3316{
3317 struct SenderAddress *sender = value;
3318
3319 (void) cls;
3320 (void) target;
3321
3322 if (NULL != sender->kce_task_rekey)
3323 {
3324 GNUNET_SCHEDULER_cancel (sender->kce_task_rekey);
3325 sender->kce_task_rekey = NULL;
3326 }
3327 if (NULL != sender->kce_task)
3328 {
3329 GNUNET_SCHEDULER_cancel (sender->kce_task);
3330 sender->kce_task = NULL;
3331 }
3332
3333 sender_destroy (sender);
3334 return GNUNET_OK;
3335}
3336
3337
3338/**
3339 * Shutdown the UNIX communicator.
3340 *
3341 * @param cls NULL (always)
3342 */
3343static void
3344do_shutdown (void *cls)
3345{
3346 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3347 "do_shutdown\n");
3348 if (NULL != nat)
3349 {
3350 GNUNET_NAT_unregister (nat);
3351 nat = NULL;
3352 }
3353 while (NULL != bi_head)
3354 bi_destroy (bi_head);
3355 if (NULL != broadcast_task)
3356 {
3357 GNUNET_SCHEDULER_cancel (broadcast_task);
3358 broadcast_task = NULL;
3359 }
3360 if (NULL != timeout_task)
3361 {
3362 GNUNET_SCHEDULER_cancel (timeout_task);
3363 timeout_task = NULL;
3364 }
3365 if (NULL != read_task)
3366 {
3367 GNUNET_SCHEDULER_cancel (read_task);
3368 read_task = NULL;
3369 }
3370 if (NULL != udp_sock)
3371 {
3372 GNUNET_break (GNUNET_OK ==
3373 GNUNET_NETWORK_socket_close (udp_sock));
3374 udp_sock = NULL;
3375 }
3376 GNUNET_CONTAINER_multipeermap_iterate (receivers,
3377 &get_receiver_delete_it,
3378 NULL);
3379 GNUNET_CONTAINER_multipeermap_destroy (receivers);
3380 GNUNET_CONTAINER_multipeermap_iterate (senders,
3381 &get_sender_delete_it,
3382 NULL);
3383 GNUNET_CONTAINER_multipeermap_destroy (senders);
3384 GNUNET_CONTAINER_multishortmap_destroy (key_cache);
3385 GNUNET_CONTAINER_heap_destroy (senders_heap);
3386 GNUNET_CONTAINER_heap_destroy (receivers_heap);
3387 if (NULL != timeout_task)
3388 {
3389 GNUNET_SCHEDULER_cancel (timeout_task);
3390 timeout_task = NULL;
3391 }
3392 if (NULL != ch)
3393 {
3394 GNUNET_TRANSPORT_communicator_disconnect (ch);
3395 ch = NULL;
3396 }
3397 if (NULL != ah)
3398 {
3399 GNUNET_TRANSPORT_application_done (ah);
3400 ah = NULL;
3401 }
3402 if (NULL != stats)
3403 {
3404 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
3405 stats = NULL;
3406 }
3407 if (NULL != my_private_key)
3408 {
3409 GNUNET_free (my_private_key);
3410 my_private_key = NULL;
3411 }
3412 if (NULL != is)
3413 {
3414 GNUNET_NT_scanner_done (is);
3415 is = NULL;
3416 }
3417 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3418 "do_shutdown finished\n");
3419}
3420
3421
3422/**
3423 * Function called when the transport service has received a
3424 * backchannel message for this communicator (!) via a different return
3425 * path. Should be an acknowledgement.
3426 *
3427 * @param cls closure, NULL
3428 * @param sender which peer sent the notification
3429 * @param msg payload
3430 */
3431static void
3432enc_notify_cb (void *cls,
3433 const struct GNUNET_PeerIdentity *sender,
3434 const struct GNUNET_MessageHeader *msg)
3435{
3436 const struct UDPAck *ack;
3437
3438 (void) cls;
3439 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3440 "Storing UDPAck received from backchannel from %s\n",
3441 GNUNET_i2s_full (sender));
3442 if ((ntohs (msg->type) != GNUNET_MESSAGE_TYPE_COMMUNICATOR_UDP_ACK) ||
3443 (ntohs (msg->size) != sizeof(struct UDPAck)))
3444 {
3445 GNUNET_break_op (0);
3446 return;
3447 }
3448 ack = (const struct UDPAck *) msg;
3449 GNUNET_CONTAINER_multipeermap_get_multiple (receivers,
3450 sender,
3451 &handle_ack,
3452 (void *) ack);
3453}
3454
3455
3456/**
3457 * Signature of the callback passed to #GNUNET_NAT_register() for
3458 * a function to call whenever our set of 'valid' addresses changes.
3459 *
3460 * @param cls closure
3461 * @param app_ctx[in,out] location where the app can store stuff
3462 * on add and retrieve it on remove
3463 * @param add_remove #GNUNET_YES to add a new public IP address,
3464 * #GNUNET_NO to remove a previous (now invalid) one
3465 * @param ac address class the address belongs to
3466 * @param addr either the previous or the new public IP address
3467 * @param addrlen actual length of the @a addr
3468 */
3469static void
3470nat_address_cb (void *cls,
3471 void **app_ctx,
3472 int add_remove,
3473 enum GNUNET_NAT_AddressClass ac,
3474 const struct sockaddr *addr,
3475 socklen_t addrlen)
3476{
3477 char *my_addr;
3478 struct GNUNET_TRANSPORT_AddressIdentifier *ai;
3479
3480 if (GNUNET_YES == add_remove)
3481 {
3482 enum GNUNET_NetworkType nt;
3483
3484 GNUNET_asprintf (&my_addr,
3485 "%s-%s",
3486 COMMUNICATOR_ADDRESS_PREFIX,
3487 GNUNET_a2s (addr, addrlen));
3488 nt = GNUNET_NT_scanner_get_type (is, addr, addrlen);
3489 ai =
3490 GNUNET_TRANSPORT_communicator_address_add (ch,
3491 my_addr,
3492 nt,
3493 GNUNET_TIME_UNIT_FOREVER_REL);
3494 GNUNET_free (my_addr);
3495 *app_ctx = ai;
3496 }
3497 else
3498 {
3499 ai = *app_ctx;
3500 GNUNET_TRANSPORT_communicator_address_remove (ai);
3501 *app_ctx = NULL;
3502 }
3503}
3504
3505
3506/**
3507 * Broadcast our presence on one of our interfaces.
3508 *
3509 * @param cls a `struct BroadcastInterface`
3510 */
3511static void
3512ifc_broadcast (void *cls)
3513{
3514 struct BroadcastInterface *bi = cls;
3515 struct GNUNET_TIME_Relative delay;
3516
3517 delay = BROADCAST_FREQUENCY;
3518 delay.rel_value_us =
3519 GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, delay.rel_value_us);
3520 bi->broadcast_task =
3521 GNUNET_SCHEDULER_add_delayed (delay, &ifc_broadcast, bi);
3522
3523 switch (bi->sa->sa_family)
3524 {
3525 case AF_INET: {
3526 static int yes = 1;
3527 static int no = 0;
3528 ssize_t sent;
3529
3530 if (GNUNET_OK !=
3531 GNUNET_NETWORK_socket_setsockopt (udp_sock,
3532 SOL_SOCKET,
3533 SO_BROADCAST,
3534 &yes,
3535 sizeof(int)))
3536 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
3537 "setsockopt");
3538 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3539 "creating UDPBroadcast from %s\n",
3540 GNUNET_i2s (&(bi->bcm.sender)));
3541 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3542 "sending UDPBroadcast to add %s\n",
3543 GNUNET_a2s (bi->ba, bi->salen));
3544 sent = GNUNET_NETWORK_socket_sendto (udp_sock,
3545 &bi->bcm,
3546 sizeof(bi->bcm),
3547 bi->ba,
3548 bi->salen);
3549 if (-1 == sent)
3550 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
3551 "sendto");
3552 if (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (udp_sock,
3553 SOL_SOCKET,
3554 SO_BROADCAST,
3555 &no,
3556 sizeof(int)))
3557 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
3558 "setsockopt");
3559 break;
3560 }
3561
3562 case AF_INET6: {
3563 ssize_t sent;
3564 struct sockaddr_in6 dst;
3565
3566 dst.sin6_family = AF_INET6;
3567 dst.sin6_port = htons (my_port);
3568 dst.sin6_addr = bi->mcreq.ipv6mr_multiaddr;
3569 dst.sin6_scope_id = ((struct sockaddr_in6 *) bi->ba)->sin6_scope_id;
3570
3571 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3572 "sending UDPBroadcast\n");
3573 sent = GNUNET_NETWORK_socket_sendto (udp_sock,
3574 &bi->bcm,
3575 sizeof(bi->bcm),
3576 (const struct sockaddr *) &dst,
3577 sizeof(dst));
3578 if (-1 == sent)
3579 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
3580 break;
3581 }
3582
3583 default:
3584 GNUNET_break (0);
3585 break;
3586 }
3587}
3588
3589
3590/**
3591 * Callback function invoked for each interface found.
3592 * Activates/deactivates broadcast interfaces.
3593 *
3594 * @param cls NULL
3595 * @param name name of the interface (can be NULL for unknown)
3596 * @param isDefault is this presumably the default interface
3597 * @param addr address of this interface (can be NULL for unknown or unassigned)
3598 * @param broadcast_addr the broadcast address (can be NULL for unknown or
3599 * unassigned)
3600 * @param netmask the network mask (can be NULL for unknown or unassigned)
3601 * @param addrlen length of the address
3602 * @return #GNUNET_OK to continue iteration, #GNUNET_SYSERR to abort
3603 */
3604static int
3605iface_proc (void *cls,
3606 const char *name,
3607 int isDefault,
3608 const struct sockaddr *addr,
3609 const struct sockaddr *broadcast_addr,
3610 const struct sockaddr *netmask,
3611 socklen_t addrlen)
3612{
3613 struct BroadcastInterface *bi;
3614 enum GNUNET_NetworkType network;
3615 struct UdpBroadcastSignature ubs;
3616
3617 (void) cls;
3618 (void) netmask;
3619 if (NULL == addr)
3620 return GNUNET_YES; /* need to know our address! */
3621 network = GNUNET_NT_scanner_get_type (is, addr, addrlen);
3622 if (GNUNET_NT_LOOPBACK == network)
3623 {
3624 /* Broadcasting on loopback does not make sense */
3625 return GNUNET_YES;
3626 }
3627 for (bi = bi_head; NULL != bi; bi = bi->next)
3628 {
3629 if ((bi->salen == addrlen) && (0 == memcmp (addr, bi->sa, addrlen)))
3630 {
3631 bi->found = GNUNET_YES;
3632 return GNUNET_OK;
3633 }
3634 }
3635
3636 if ((AF_INET6 == addr->sa_family) && (NULL == broadcast_addr))
3637 return GNUNET_OK; /* broadcast_addr is required for IPv6! */
3638 if ((AF_INET6 == addr->sa_family) && (GNUNET_YES != have_v6_socket))
3639 return GNUNET_OK; /* not using IPv6 */
3640
3641 bi = GNUNET_new (struct BroadcastInterface);
3642 bi->sa = GNUNET_memdup (addr,
3643 addrlen);
3644 if ( (NULL != broadcast_addr) &&
3645 (addrlen == sizeof (struct sockaddr_in)) )
3646 {
3647 struct sockaddr_in *ba;
3648
3649 ba = GNUNET_memdup (broadcast_addr,
3650 addrlen);
3651 ba->sin_port = htons (2086); /* always GNUnet port, ignore configuration! */
3652 bi->ba = (struct sockaddr *) ba;
3653 }
3654 bi->salen = addrlen;
3655 bi->found = GNUNET_YES;
3656 bi->bcm.sender = my_identity;
3657 ubs.purpose.purpose = htonl (
3658 GNUNET_SIGNATURE_PURPOSE_COMMUNICATOR_UDP_BROADCAST);
3659 ubs.purpose.size = htonl (sizeof(ubs));
3660 ubs.sender = my_identity;
3661 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3662 "creating UDPBroadcastSignature for %s\n",
3663 GNUNET_a2s (addr, addrlen));
3664 GNUNET_CRYPTO_hash (addr, addrlen, &ubs.h_address);
3665 GNUNET_CRYPTO_eddsa_sign (my_private_key,
3666 &ubs,
3667 &bi->bcm.sender_sig);
3668 if (NULL != bi->ba)
3669 {
3670 bi->broadcast_task = GNUNET_SCHEDULER_add_now (&ifc_broadcast, bi);
3671 GNUNET_CONTAINER_DLL_insert (bi_head, bi_tail, bi);
3672 }
3673 if ((AF_INET6 == addr->sa_family) && (NULL != broadcast_addr))
3674 {
3675 /* Create IPv6 multicast request */
3676 const struct sockaddr_in6 *s6 =
3677 (const struct sockaddr_in6 *) broadcast_addr;
3678
3679 GNUNET_assert (
3680 1 == inet_pton (AF_INET6, "FF05::13B", &bi->mcreq.ipv6mr_multiaddr));
3681
3682 /* http://tools.ietf.org/html/rfc2553#section-5.2:
3683 *
3684 * IPV6_JOIN_GROUP
3685 *
3686 * Join a multicast group on a specified local interface. If the
3687 * interface index is specified as 0, the kernel chooses the local
3688 * interface. For example, some kernels look up the multicast
3689 * group in the normal IPv6 routing table and using the resulting
3690 * interface; we do this for each interface, so no need to use
3691 * zero (anymore...).
3692 */bi->mcreq.ipv6mr_interface = s6->sin6_scope_id;
3693
3694 /* Join the multicast group */
3695 if (GNUNET_OK != GNUNET_NETWORK_socket_setsockopt (udp_sock,
3696 IPPROTO_IPV6,
3697 IPV6_JOIN_GROUP,
3698 &bi->mcreq,
3699 sizeof(bi->mcreq)))
3700 {
3701 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "setsockopt");
3702 }
3703 }
3704 return GNUNET_OK;
3705}
3706
3707
3708/**
3709 * Scan interfaces to broadcast our presence on the LAN.
3710 *
3711 * @param cls NULL, unused
3712 */
3713static void
3714do_broadcast (void *cls)
3715{
3716 struct BroadcastInterface *bin;
3717
3718 (void) cls;
3719 for (struct BroadcastInterface *bi = bi_head; NULL != bi; bi = bi->next)
3720 bi->found = GNUNET_NO;
3721 GNUNET_OS_network_interfaces_list (&iface_proc, NULL);
3722 for (struct BroadcastInterface *bi = bi_head; NULL != bi; bi = bin)
3723 {
3724 bin = bi->next;
3725 if (GNUNET_NO == bi->found)
3726 bi_destroy (bi);
3727 }
3728 broadcast_task = GNUNET_SCHEDULER_add_delayed (INTERFACE_SCAN_FREQUENCY,
3729 &do_broadcast,
3730 NULL);
3731}
3732
3733
3734/**
3735 * Setup communicator and launch network interactions.
3736 *
3737 * @param cls NULL (always)
3738 * @param args remaining command-line arguments
3739 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
3740 * @param c configuration
3741 */
3742static void
3743run (void *cls,
3744 char *const *args,
3745 const char *cfgfile,
3746 const struct GNUNET_CONFIGURATION_Handle *c)
3747{
3748 char *bindto;
3749 struct sockaddr *in;
3750 socklen_t in_len;
3751 struct sockaddr_storage in_sto;
3752 socklen_t sto_len;
3753
3754 (void) cls;
3755 cfg = c;
3756 if (GNUNET_OK !=
3757 GNUNET_CONFIGURATION_get_value_string (cfg,
3758 COMMUNICATOR_CONFIG_SECTION,
3759 "BINDTO",
3760 &bindto))
3761 {
3762 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
3763 COMMUNICATOR_CONFIG_SECTION,
3764 "BINDTO");
3765 return;
3766 }
3767
3768 if (GNUNET_OK !=
3769 GNUNET_CONFIGURATION_get_value_time (cfg,
3770 COMMUNICATOR_CONFIG_SECTION,
3771 "REKEY_INTERVAL",
3772 &rekey_interval))
3773 rekey_interval = DEFAULT_REKEY_TIME_INTERVAL;
3774
3775 if (GNUNET_OK !=
3776 GNUNET_CONFIGURATION_get_value_size (cfg,
3777 COMMUNICATOR_CONFIG_SECTION,
3778 "REKEY_MAX_BYTES",
3779 &rekey_max_bytes))
3780 rekey_max_bytes = DEFAULT_REKEY_MAX_BYTES;
3781
3782 in = udp_address_to_sockaddr (bindto, &in_len);
3783 if (NULL == in)
3784 {
3785 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3786 "Failed to setup UDP socket address with path `%s'\n",
3787 bindto);
3788 GNUNET_free (bindto);
3789 return;
3790 }
3791 udp_sock =
3792 GNUNET_NETWORK_socket_create (in->sa_family,
3793 SOCK_DGRAM,
3794 IPPROTO_UDP);
3795 if (NULL == udp_sock)
3796 {
3797 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "socket");
3798 GNUNET_free (in);
3799 GNUNET_free (bindto);
3800 return;
3801 }
3802 if (AF_INET6 == in->sa_family)
3803 have_v6_socket = GNUNET_YES;
3804 if (GNUNET_OK !=
3805 GNUNET_NETWORK_socket_bind (udp_sock,
3806 in,
3807 in_len))
3808 {
3809 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
3810 "bind",
3811 bindto);
3812 GNUNET_NETWORK_socket_close (udp_sock);
3813 udp_sock = NULL;
3814 GNUNET_free (in);
3815 GNUNET_free (bindto);
3816 return;
3817 }
3818
3819 /* We might have bound to port 0, allowing the OS to figure it out;
3820 thus, get the real IN-address from the socket */
3821 sto_len = sizeof(in_sto);
3822 if (0 != getsockname (GNUNET_NETWORK_get_fd (udp_sock),
3823 (struct sockaddr *) &in_sto,
3824 &sto_len))
3825 {
3826 memcpy (&in_sto, in, in_len);
3827 sto_len = in_len;
3828 }
3829 GNUNET_free (in);
3830 GNUNET_free (bindto);
3831 in = (struct sockaddr *) &in_sto;
3832 in_len = sto_len;
3833 GNUNET_log_from_nocheck (GNUNET_ERROR_TYPE_DEBUG,
3834 "transport",
3835 "Bound to `%s'\n",
3836 GNUNET_a2s ((const struct sockaddr *) &in_sto,
3837 sto_len));
3838 switch (in->sa_family)
3839 {
3840 case AF_INET:
3841 my_port = ntohs (((struct sockaddr_in *) in)->sin_port);
3842 break;
3843
3844 case AF_INET6:
3845 my_port = ntohs (((struct sockaddr_in6 *) in)->sin6_port);
3846 break;
3847
3848 default:
3849 GNUNET_break (0);
3850 my_port = 0;
3851 }
3852 stats = GNUNET_STATISTICS_create ("C-UDP", cfg);
3853 senders = GNUNET_CONTAINER_multipeermap_create (32, GNUNET_YES);
3854 receivers = GNUNET_CONTAINER_multipeermap_create (32, GNUNET_YES);
3855 senders_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
3856 receivers_heap =
3857 GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
3858 key_cache = GNUNET_CONTAINER_multishortmap_create (1024, GNUNET_YES);
3859 GNUNET_SCHEDULER_add_shutdown (&do_shutdown, NULL);
3860 is = GNUNET_NT_scanner_init ();
3861 my_private_key = GNUNET_CRYPTO_eddsa_key_create_from_configuration (cfg);
3862 if (NULL == my_private_key)
3863 {
3864 GNUNET_log (
3865 GNUNET_ERROR_TYPE_ERROR,
3866 _ (
3867 "Transport service is lacking key configuration settings. Exiting.\n"));
3868 GNUNET_SCHEDULER_shutdown ();
3869 return;
3870 }
3871 GNUNET_CRYPTO_eddsa_key_get_public (my_private_key, &my_identity.public_key);
3872 /* start reading */
3873 read_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
3874 udp_sock,
3875 &sock_read,
3876 NULL);
3877 ch = GNUNET_TRANSPORT_communicator_connect (cfg,
3878 COMMUNICATOR_CONFIG_SECTION,
3879 COMMUNICATOR_ADDRESS_PREFIX,
3880 GNUNET_TRANSPORT_CC_UNRELIABLE,
3881 &mq_init,
3882 NULL,
3883 &enc_notify_cb,
3884 NULL);
3885 if (NULL == ch)
3886 {
3887 GNUNET_break (0);
3888 GNUNET_SCHEDULER_shutdown ();
3889 return;
3890 }
3891 ah = GNUNET_TRANSPORT_application_init (cfg);
3892 if (NULL == ah)
3893 {
3894 GNUNET_break (0);
3895 GNUNET_SCHEDULER_shutdown ();
3896 return;
3897 }
3898 /* start broadcasting */
3899 if (GNUNET_YES !=
3900 GNUNET_CONFIGURATION_get_value_yesno (cfg,
3901 COMMUNICATOR_CONFIG_SECTION,
3902 "DISABLE_BROADCAST"))
3903 {
3904 broadcast_task = GNUNET_SCHEDULER_add_now (&do_broadcast, NULL);
3905 }
3906 nat = GNUNET_NAT_register (cfg,
3907 COMMUNICATOR_CONFIG_SECTION,
3908 IPPROTO_UDP,
3909 1 /* one address */,
3910 (const struct sockaddr **) &in,
3911 &in_len,
3912 &nat_address_cb,
3913 NULL /* FIXME: support reversal: #5529 */,
3914 NULL /* closure */);
3915}
3916
3917
3918/**
3919 * The main function for the UNIX communicator.
3920 *
3921 * @param argc number of arguments from the command line
3922 * @param argv command line arguments
3923 * @return 0 ok, 1 on error
3924 */
3925int
3926main (int argc, char *const *argv)
3927{
3928 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
3929 GNUNET_GETOPT_OPTION_END
3930 };
3931 int ret;
3932
3933 GNUNET_log_from_nocheck (GNUNET_ERROR_TYPE_DEBUG,
3934 "transport",
3935 "Starting udp communicator\n");
3936 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
3937 return 2;
3938
3939 ret = (GNUNET_OK == GNUNET_PROGRAM_run (argc,
3940 argv,
3941 "gnunet-communicator-udp",
3942 _ ("GNUnet UDP communicator"),
3943 options,
3944 &run,
3945 NULL))
3946 ? 0
3947 : 1;
3948 GNUNET_free_nz ((void *) argv);
3949 return ret;
3950}
3951
3952
3953/* end of gnunet-communicator-udp.c */
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-18 04:12:01 +0000