2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
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 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 #include "gnunet_util_lib.h"
24 #include "gnunet_signatures.h"
25 #include "gnunet_statistics_service.h"
27 #include "cadet_protocol.h"
28 #include "cadet_path.h"
30 #include "gnunet-service-cadet_tunnel.h"
31 #include "gnunet-service-cadet_connection.h"
32 #include "gnunet-service-cadet_channel.h"
33 #include "gnunet-service-cadet_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"cadet-tun",__VA_ARGS__)
37 #define REKEY_WAIT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)
39 #define CONNECTIONS_PER_TUNNEL 3
41 #if !defined(GNUNET_CULL_LOGGING)
42 #define DUMP_KEYS_TO_STDERR GNUNET_YES
44 #define DUMP_KEYS_TO_STDERR GNUNET_NO
47 /******************************************************************************/
48 /******************************** STRUCTS **********************************/
49 /******************************************************************************/
53 struct CadetTChannel *next;
54 struct CadetTChannel *prev;
55 struct CadetChannel *ch;
60 * Connection list and metadata.
62 struct CadetTConnection
67 struct CadetTConnection *next;
72 struct CadetTConnection *prev;
77 struct CadetConnection *c;
80 * Creation time, to keep oldest connection alive.
82 struct GNUNET_TIME_Absolute created;
85 * Connection throughput, to keep fastest connection alive.
91 * Structure used during a Key eXchange.
93 struct CadetTunnelKXCtx
96 * Encryption ("our") old key, for encrypting traffic sent by us
97 * end before the key exchange is finished or times out.
99 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
102 * Decryption ("their") old key, for decrypting traffic sent by the
103 * other end before the key exchange started.
105 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
108 * Challenge to send in a ping and expect in the pong.
113 * When the rekey started. One minute after this the new key will be used.
115 struct GNUNET_TIME_Absolute rekey_start_time;
118 * Task for delayed destruction of the Key eXchange context, to allow delayed
119 * messages with the old key to be decrypted successfully.
121 GNUNET_SCHEDULER_TaskIdentifier finish_task;
125 * Struct containing all information regarding a tunnel to a peer.
130 * Endpoint of the tunnel.
132 struct CadetPeer *peer;
135 * State of the tunnel connectivity.
137 enum CadetTunnelCState cstate;
140 * State of the tunnel encryption.
142 enum CadetTunnelEState estate;
145 * Key eXchange context.
147 struct CadetTunnelKXCtx *kx_ctx;
150 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
153 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
156 * Encryption ("our") key.
158 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
161 * Decryption ("their") key.
163 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
166 * Task to start the rekey process.
168 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
171 * Paths that are actively used to reach the destination peer.
173 struct CadetTConnection *connection_head;
174 struct CadetTConnection *connection_tail;
177 * Next connection number.
182 * Channels inside this tunnel.
184 struct CadetTChannel *channel_head;
185 struct CadetTChannel *channel_tail;
188 * Channel ID for the next created channel.
190 CADET_ChannelNumber next_chid;
193 * Destroy flag: if true, destroy on last message.
195 GNUNET_SCHEDULER_TaskIdentifier destroy_task;
198 * Queued messages, to transmit once tunnel gets connected.
200 struct CadetTunnelDelayed *tq_head;
201 struct CadetTunnelDelayed *tq_tail;
206 * Struct used to save messages in a non-ready tunnel to send once connected.
208 struct CadetTunnelDelayed
213 struct CadetTunnelDelayed *next;
214 struct CadetTunnelDelayed *prev;
219 struct CadetTunnel *t;
222 * Tunnel queue given to the channel to cancel request. Update on send_queued.
224 struct CadetTunnelQueue *tq;
229 /* struct GNUNET_MessageHeader *msg; */
234 * Handle for messages queued but not yet sent.
236 struct CadetTunnelQueue
239 * Connection queue handle, to cancel if necessary.
241 struct CadetConnectionQueue *cq;
244 * Handle in case message hasn't been given to a connection yet.
246 struct CadetTunnelDelayed *tqd;
249 * Continuation to call once sent.
254 * Closure for @c cont.
260 /******************************************************************************/
261 /******************************* GLOBALS ***********************************/
262 /******************************************************************************/
265 * Global handle to the statistics service.
267 extern struct GNUNET_STATISTICS_Handle *stats;
270 * Local peer own ID (memory efficient handle).
272 extern GNUNET_PEER_Id myid;
275 * Local peer own ID (full value).
277 extern struct GNUNET_PeerIdentity my_full_id;
281 * Don't try to recover tunnels if shutting down.
283 extern int shutting_down;
287 * Set of all tunnels, in order to trigger a new exchange on rekey.
288 * Indexed by peer's ID.
290 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
293 * Default TTL for payload packets.
295 static unsigned long long default_ttl;
300 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
303 * Own ephemeral private key.
305 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
308 * Cached message used to perform a key exchange.
310 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
313 * Task to generate a new ephemeral key.
315 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
320 static struct GNUNET_TIME_Relative rekey_period;
322 /******************************************************************************/
323 /******************************** STATIC ***********************************/
324 /******************************************************************************/
327 * Get string description for tunnel connectivity state.
329 * @param cs Tunnel state.
331 * @return String representation.
334 cstate2s (enum CadetTunnelCState cs)
340 case CADET_TUNNEL3_NEW:
341 return "CADET_TUNNEL3_NEW";
342 case CADET_TUNNEL3_SEARCHING:
343 return "CADET_TUNNEL3_SEARCHING";
344 case CADET_TUNNEL3_WAITING:
345 return "CADET_TUNNEL3_WAITING";
346 case CADET_TUNNEL3_READY:
347 return "CADET_TUNNEL3_READY";
350 sprintf (buf, "%u (UNKNOWN STATE)", cs);
358 * Get string description for tunnel encryption state.
360 * @param es Tunnel state.
362 * @return String representation.
365 estate2s (enum CadetTunnelEState es)
371 case CADET_TUNNEL3_KEY_UNINITIALIZED:
372 return "CADET_TUNNEL3_KEY_UNINITIALIZED";
373 case CADET_TUNNEL3_KEY_SENT:
374 return "CADET_TUNNEL3_KEY_SENT";
375 case CADET_TUNNEL3_KEY_PING:
376 return "CADET_TUNNEL3_KEY_PING";
377 case CADET_TUNNEL3_KEY_OK:
378 return "CADET_TUNNEL3_KEY_OK";
379 case CADET_TUNNEL3_KEY_REKEY:
380 return "CADET_TUNNEL3_KEY_REKEY";
382 sprintf (buf, "%u (UNKNOWN STATE)", es);
390 * @brief Check if tunnel is ready to send traffic.
392 * Tunnel must be connected and with encryption correctly set up.
394 * @param t Tunnel to check.
396 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
399 is_ready (struct CadetTunnel *t)
403 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
404 ready = CADET_TUNNEL3_READY == t->cstate
405 && (CADET_TUNNEL3_KEY_OK == t->estate
406 || CADET_TUNNEL3_KEY_REKEY == t->estate);
407 ready = ready || GCT_is_loopback (t);
413 * Ephemeral key message purpose size.
415 * @return Size of the part of the ephemeral key message that must be signed.
418 ephemeral_purpose_size (void)
420 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
421 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
422 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
423 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
424 sizeof (struct GNUNET_PeerIdentity);
429 * Size of the encrypted part of a ping message.
431 * @return Size of the encrypted part of a ping message.
434 ping_encryption_size (void)
436 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
441 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
443 * @param tch Tunnel's channel handle.
445 * @return Amount of messages the channel can still buffer towards the client.
448 get_channel_buffer (const struct CadetTChannel *tch)
452 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
453 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
455 return GCCH_get_buffer (tch->ch, fwd);
460 * Get the channel's allowance status.
462 * @param tch Tunnel's channel handle.
464 * @return #GNUNET_YES if we allowed the client to send data to us.
467 get_channel_allowed (const struct CadetTChannel *tch)
471 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
472 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
474 return GCCH_get_allowed (tch->ch, fwd);
479 * Get the connection's buffer.
481 * @param tc Tunnel's connection handle.
483 * @return Amount of messages the connection can still buffer.
486 get_connection_buffer (const struct CadetTConnection *tc)
490 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
491 fwd = GCC_is_origin (tc->c, GNUNET_YES);
493 return GCC_get_buffer (tc->c, fwd);
498 * Get the connection's allowance.
500 * @param tc Tunnel's connection handle.
502 * @return Amount of messages we have allowed the next peer to send us.
505 get_connection_allowed (const struct CadetTConnection *tc)
509 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
510 fwd = GCC_is_origin (tc->c, GNUNET_YES);
512 return GCC_get_allowed (tc->c, fwd);
517 * Check that a ephemeral key message s well formed and correctly signed.
519 * @param t Tunnel on which the message came.
520 * @param msg The ephemeral key message.
522 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
525 check_ephemeral (struct CadetTunnel *t,
526 const struct GNUNET_CADET_KX_Ephemeral *msg)
528 /* Check message size */
529 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
530 return GNUNET_SYSERR;
532 /* Check signature size */
533 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
534 return GNUNET_SYSERR;
537 if (0 != memcmp (&msg->origin_identity,
538 GCP_get_id (t->peer),
539 sizeof (struct GNUNET_PeerIdentity)))
540 return GNUNET_SYSERR;
542 /* Check signature */
544 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
547 &msg->origin_identity.public_key))
548 return GNUNET_SYSERR;
555 * Select the best key to use for encryption (send), based on KX status.
557 * Normally, return the current key. If there is a KX in progress and the old
558 * key is fresh enough, return the old key.
560 * @param t Tunnel to choose the key from.
562 * @return The optimal key to encrypt/hmac outgoing traffic.
564 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
565 select_key (const struct CadetTunnel *t)
567 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
569 if (NULL != t->kx_ctx
570 && GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
572 struct GNUNET_TIME_Relative age;
574 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
575 LOG (GNUNET_ERROR_TYPE_DEBUG,
576 " key exchange in progress, started %s ago\n",
577 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
578 // FIXME make duration of old keys configurable
579 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
581 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
582 key = &t->kx_ctx->e_key_old;
586 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key\n");
601 * @param plaintext Content to HMAC.
602 * @param size Size of @c plaintext.
603 * @param iv Initialization vector for the message.
604 * @param key Key to use.
605 * @param hmac[out] Destination to store the HMAC.
608 t_hmac (const void *plaintext, size_t size,
609 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
610 struct GNUNET_CADET_Hash *hmac)
612 static const char ctx[] = "cadet authentication key";
613 struct GNUNET_CRYPTO_AuthKey auth_key;
614 struct GNUNET_HashCode hash;
616 #if DUMP_KEYS_TO_STDERR
617 LOG (GNUNET_ERROR_TYPE_DEBUG, " HMAC with key %s\n",
618 GNUNET_h2s ((struct GNUNET_HashCode *) key));
620 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
625 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
626 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
627 memcpy (hmac, &hash, sizeof (*hmac));
632 * Encrypt daforce_newest_keyta with the tunnel key.
634 * @param t Tunnel whose key to use.
635 * @param dst Destination for the encrypted data.
636 * @param src Source of the plaintext. Can overlap with @c dst.
637 * @param size Size of the plaintext.
638 * @param iv Initialization Vector to use.
639 * @param force_newest_key Force the use of the newest key, otherwise
640 * CADET will use the old key when allowed.
641 * This can happen in the case when a KX is going on
642 * and the old one hasn't expired.
645 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
646 size_t size, uint32_t iv, int force_newest_key)
648 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
649 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
652 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
654 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
655 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
656 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
657 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
658 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
665 * Decrypt and verify data with the appropriate tunnel key.
667 * @param key Key to use.
668 * @param dst Destination for the plaintext.
669 * @param src Source of the encrypted data. Can overlap with @c dst.
670 * @param size Size of the encrypted data.
671 * @param iv Initialization Vector to use.
673 * @return Size of the decrypted data, -1 if an error was encountered.
676 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
677 void *dst, const void *src, size_t size, uint32_t iv)
679 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
682 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
683 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
684 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
685 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
686 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
687 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
694 * Decrypt and verify data with the most recent tunnel key.
696 * @param t Tunnel whose key to use.
697 * @param dst Destination for the plaintext.
698 * @param src Source of the encrypted data. Can overlap with @c dst.
699 * @param size Size of the encrypted data.
700 * @param iv Initialization Vector to use.
702 * @return Size of the decrypted data, -1 if an error was encountered.
705 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
706 size_t size, uint32_t iv)
710 #if DUMP_KEYS_TO_STDERR
711 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
712 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
714 if (t->estate == CADET_TUNNEL3_KEY_UNINITIALIZED)
716 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
717 LOG (GNUNET_ERROR_TYPE_WARNING,
718 "got data on %s without a valid key\n",
720 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
724 out_size = decrypt (&t->d_key, dst, src, size, iv);
731 * Decrypt and verify data with the appropriate tunnel key and verify that the
732 * data has not been altered since it was sent by the remote peer.
734 * @param t Tunnel whose key to use.
735 * @param dst Destination for the plaintext.
736 * @param src Source of the encrypted data. Can overlap with @c dst.
737 * @param size Size of the encrypted data.
738 * @param iv Initialization Vector to use.
739 * @param msg_hmac HMAC of the message, cannot be NULL.
741 * @return Size of the decrypted data, -1 if an error was encountered.
744 t_decrypt_and_validate (struct CadetTunnel *t,
745 void *dst, const void *src,
746 size_t size, uint32_t iv,
747 const struct GNUNET_CADET_Hash *msg_hmac)
749 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
750 struct GNUNET_CADET_Hash hmac;
753 /* Try primary (newest) key */
755 decrypted_size = decrypt (key, dst, src, size, iv);
756 t_hmac (src, size, iv, key, &hmac);
757 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
758 return decrypted_size;
760 /* If no key exchange is going on, we just failed */
761 if (NULL == t->kx_ctx)
763 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
764 "Failed checksum validation on tunnel %s with no KX\n",
766 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
770 /* Try secondary (from previous KX period) key */
771 key = &t->kx_ctx->d_key_old;
772 decrypted_size = decrypt (key, dst, src, size, iv);
773 t_hmac (src, size, iv, key, &hmac);
774 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
775 return decrypted_size;
777 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
778 "Failed checksum validation on tunnel %s with KX\n",
780 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
786 * Create key material by doing ECDH on the local and remote ephemeral keys.
788 * @param key_material Where to store the key material.
789 * @param ephemeral_key Peer's public ephemeral key.
792 derive_key_material (struct GNUNET_HashCode *key_material,
793 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
796 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
806 * Create a symmetic key from the identities of both ends and the key material
809 * @param key Destination for the generated key.
810 * @param sender ID of the peer that will encrypt with @c key.
811 * @param receiver ID of the peer that will decrypt with @c key.
812 * @param key_material Hash created with ECDH with the ephemeral keys.
815 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
816 const struct GNUNET_PeerIdentity *sender,
817 const struct GNUNET_PeerIdentity *receiver,
818 const struct GNUNET_HashCode *key_material)
820 const char salt[] = "CADET kx salt";
822 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
824 key_material, sizeof (struct GNUNET_HashCode),
825 sender, sizeof (struct GNUNET_PeerIdentity),
826 receiver, sizeof (struct GNUNET_PeerIdentity),
832 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
834 * @param t Tunnel for which to create the keys.
837 create_keys (struct CadetTunnel *t)
839 struct GNUNET_HashCode km;
841 derive_key_material (&km, &t->peers_ephemeral_key);
842 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
843 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
844 #if DUMP_KEYS_TO_STDERR
845 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
846 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
847 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
848 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
849 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
850 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
851 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
852 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
853 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
859 * Pick a connection on which send the next data message.
861 * @param t Tunnel on which to send the message.
863 * @return The connection on which to send the next message.
865 static struct CadetConnection *
866 tunnel_get_connection (struct CadetTunnel *t)
868 struct CadetTConnection *iter;
869 struct CadetConnection *best;
871 unsigned int lowest_q;
873 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
876 for (iter = t->connection_head; NULL != iter; iter = iter->next)
878 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
879 GCC_2s (iter->c), GCC_get_state (iter->c));
880 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
882 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
883 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
891 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
897 * Callback called when a queued message is sent.
899 * Calculates the average time and connection packet tracking.
901 * @param cls Closure (TunnelQueue handle).
902 * @param c Connection this message was on.
903 * @param q Connection queue handle (unused).
904 * @param type Type of message sent.
905 * @param fwd Was this a FWD going message?
906 * @param size Size of the message.
909 tun_message_sent (void *cls,
910 struct CadetConnection *c,
911 struct CadetConnectionQueue *q,
912 uint16_t type, int fwd, size_t size)
914 struct CadetTunnelQueue *qt = cls;
915 struct CadetTunnel *t;
917 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
919 GNUNET_assert (NULL != qt->cont);
920 t = NULL == c ? NULL : GCC_get_tunnel (c);
921 qt->cont (qt->cont_cls, t, qt, type, size);
927 count_queued_data (const struct CadetTunnel *t)
929 struct CadetTunnelDelayed *iter;
932 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
939 * Delete a queued message: either was sent or the channel was destroyed
940 * before the tunnel's key exchange had a chance to finish.
942 * @param tqd Delayed queue handle.
945 unqueue_data (struct CadetTunnelDelayed *tqd)
947 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
953 * Cache a message to be sent once tunnel is online.
955 * @param t Tunnel to hold the message.
956 * @param msg Message itself (copy will be made).
958 static struct CadetTunnelDelayed *
959 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
961 struct CadetTunnelDelayed *tqd;
962 uint16_t size = ntohs (msg->size);
964 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
966 if (GNUNET_YES == is_ready (t))
972 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
975 memcpy (&tqd[1], msg, size);
976 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
982 * Sends an already built message on a tunnel, encrypting it and
983 * choosing the best connection.
985 * @param message Message to send. Function modifies it.
986 * @param t Tunnel on which this message is transmitted.
987 * @param c Connection to use (autoselect if NULL).
988 * @param force Force the tunnel to take the message (buffer overfill).
989 * @param cont Continuation to call once message is really sent.
990 * @param cont_cls Closure for @c cont.
991 * @param existing_q In case this a transmission of previously queued data,
992 * this should be TunnelQueue given to the client.
995 * @return Handle to cancel message. NULL if @c cont is NULL.
997 static struct CadetTunnelQueue *
998 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
999 struct CadetTunnel *t, struct CadetConnection *c,
1000 int force, GCT_sent cont, void *cont_cls,
1001 struct CadetTunnelQueue *existing_q)
1003 struct CadetTunnelQueue *tq;
1004 struct GNUNET_CADET_Encrypted *msg;
1005 size_t size = ntohs (message->size);
1006 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1012 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1014 if (GNUNET_NO == is_ready (t))
1016 struct CadetTunnelDelayed *tqd;
1017 /* A non null existing_q indicates sending of queued data.
1018 * Should only happen after tunnel becomes ready.
1020 GNUNET_assert (NULL == existing_q);
1021 tqd = queue_data (t, message);
1024 tq = GNUNET_new (struct CadetTunnelQueue);
1028 tq->cont_cls = cont_cls;
1032 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1034 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1035 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1036 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1038 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO) == size);
1039 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1040 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1043 c = tunnel_get_connection (t);
1046 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
1047 || CADET_TUNNEL3_SEARCHING != t->cstate)
1050 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1056 type = ntohs (message->type);
1059 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1060 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1061 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1062 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1064 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1066 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1067 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1068 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1069 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1070 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1071 msg->cid = *GCC_get_id (c);
1072 msg->ttl = htonl (default_ttl);
1077 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1079 fwd = GCC_is_origin (c, GNUNET_YES);
1083 GNUNET_break (NULL ==
1084 GCC_send_prebuilt_message (&msg->header, type, mid,
1085 c, fwd, force, NULL, NULL));
1088 if (NULL == existing_q)
1090 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1097 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1098 &tun_message_sent, tq);
1100 tq->cont_cls = cont_cls;
1107 * Send all cached messages that we can, tunnel is online.
1109 * @param t Tunnel that holds the messages. Cannot be loopback.
1112 send_queued_data (struct CadetTunnel *t)
1114 struct CadetTunnelDelayed *tqd;
1115 struct CadetTunnelDelayed *next;
1118 LOG (GNUNET_ERROR_TYPE_DEBUG,
1119 "GCT_send_queued_data on tunnel %s\n",
1122 if (GCT_is_loopback (t))
1128 if (GNUNET_NO == is_ready (t))
1130 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1131 estate2s (t->estate), cstate2s (t->cstate));
1135 room = GCT_get_connections_buffer (t);
1136 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1137 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1138 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1140 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1143 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1144 tqd->t, NULL, GNUNET_YES,
1145 NULL != tqd->tq ? tqd->tq->cont : NULL,
1146 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1150 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1155 * Sends key exchange message on a tunnel, choosing the best connection.
1156 * Should not be called on loopback tunnels.
1158 * @param t Tunnel on which this message is transmitted.
1159 * @param message Message to send. Function modifies it.
1162 send_kx (struct CadetTunnel *t,
1163 const struct GNUNET_MessageHeader *message)
1165 struct CadetConnection *c;
1166 struct GNUNET_CADET_KX *msg;
1167 size_t size = ntohs (message->size);
1168 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1172 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1174 /* Avoid loopback. */
1175 if (GCT_is_loopback (t))
1177 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1182 /* Even if tunnel is being destroyed, send anyway.
1183 * Could be a response to a rekey initiated by remote peer,
1184 * who is trying to create a new channel!
1187 /* Must have a connection. */
1188 if (NULL == t->connection_head)
1190 GNUNET_break (CADET_TUNNEL3_SEARCHING == t->cstate);
1191 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1195 msg = (struct GNUNET_CADET_KX *) cbuf;
1196 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1197 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1198 c = tunnel_get_connection (t);
1201 GNUNET_break (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
1202 || CADET_TUNNEL3_READY != t->cstate);
1203 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1206 type = ntohs (message->type);
1209 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1210 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1211 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1212 memcpy (&msg[1], message, size);
1215 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1220 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1221 /* TODO save handle and cancel in case of a unneeded retransmission */
1222 GCC_send_prebuilt_message (&msg->header, GNUNET_MESSAGE_TYPE_CADET_KX,
1223 message->type, c, fwd, GNUNET_YES, NULL, NULL);
1228 * Send the ephemeral key on a tunnel.
1230 * @param t Tunnel on which to send the key.
1233 send_ephemeral (struct CadetTunnel *t)
1235 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1237 kx_msg.sender_status = htonl (t->estate);
1238 send_kx (t, &kx_msg.header);
1242 * Send a ping message on a tunnel.
1244 * @param t Tunnel on which to send the ping.
1247 send_ping (struct CadetTunnel *t)
1249 struct GNUNET_CADET_KX_Ping msg;
1251 LOG (GNUNET_ERROR_TYPE_INFO, "===> PING for %s\n", GCT_2s (t));
1252 msg.header.size = htons (sizeof (msg));
1253 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PING);
1254 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1255 msg.target = *GCP_get_id (t->peer);
1256 msg.nonce = t->kx_ctx->challenge;
1258 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1259 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
1260 t_encrypt (t, &msg.target, &msg.target,
1261 ping_encryption_size(), msg.iv, GNUNET_YES);
1262 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1263 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
1265 send_kx (t, &msg.header);
1270 * Send a pong message on a tunnel.
1272 * @param t Tunnel on which to send the pong.
1273 * @param challenge Value sent in the ping that we have to send back.
1276 send_pong (struct CadetTunnel *t, uint32_t challenge)
1278 struct GNUNET_CADET_KX_Pong msg;
1280 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1281 msg.header.size = htons (sizeof (msg));
1282 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1283 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1284 msg.nonce = challenge;
1285 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1286 t_encrypt (t, &msg.nonce, &msg.nonce,
1287 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1288 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1290 send_kx (t, &msg.header);
1295 * Initiate a rekey with the remote peer.
1297 * @param cls Closure (tunnel).
1298 * @param tc TaskContext.
1301 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1303 struct CadetTunnel *t = cls;
1305 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1307 LOG (GNUNET_ERROR_TYPE_DEBUG, "Re-key Tunnel %s\n", GCT_2s (t));
1308 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1311 if (NULL == t->kx_ctx)
1313 LOG (GNUNET_ERROR_TYPE_DEBUG, " new kx ctx\n");
1314 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1315 t->kx_ctx->challenge =
1316 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1317 t->kx_ctx->d_key_old = t->d_key;
1318 t->kx_ctx->e_key_old = t->e_key;
1320 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1321 LOG (GNUNET_ERROR_TYPE_DEBUG, " new challenge for %s: %u\n",
1322 GCT_2s (t), t->kx_ctx->challenge);
1326 struct GNUNET_TIME_Relative duration;
1328 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1329 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1330 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1332 // FIXME make duration of old keys configurable
1333 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1335 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1336 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1344 case CADET_TUNNEL3_KEY_UNINITIALIZED:
1345 t->estate = CADET_TUNNEL3_KEY_SENT;
1347 case CADET_TUNNEL3_KEY_SENT:
1349 case CADET_TUNNEL3_KEY_OK:
1350 t->estate = CADET_TUNNEL3_KEY_REKEY;
1352 case CADET_TUNNEL3_KEY_PING:
1353 case CADET_TUNNEL3_KEY_REKEY:
1357 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1360 // FIXME exponential backoff
1361 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1362 GNUNET_STRINGS_relative_time_to_string (REKEY_WAIT, GNUNET_YES));
1363 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
1368 * Our ephemeral key has changed, create new session key on all tunnels.
1370 * Each tunnel will start the Key Exchange with a random delay between
1371 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1372 * per second, on average.
1374 * @param cls Closure (size of the hashmap).
1375 * @param key Current public key.
1376 * @param value Value in the hash map (tunnel).
1378 * @return #GNUNET_YES, so we should continue to iterate,
1381 rekey_iterator (void *cls,
1382 const struct GNUNET_PeerIdentity *key,
1385 struct CadetTunnel *t = value;
1386 struct GNUNET_TIME_Relative delay;
1387 long n = (long) cls;
1390 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1393 if (GNUNET_YES == GCT_is_loopback (t))
1396 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1397 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1398 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1405 * Create a new ephemeral key and key message, schedule next rekeying.
1407 * @param cls Closure (unused).
1408 * @param tc TaskContext.
1411 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1413 struct GNUNET_TIME_Absolute time;
1416 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1418 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1421 GNUNET_free_non_null (my_ephemeral_key);
1422 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1424 time = GNUNET_TIME_absolute_get ();
1425 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1426 time = GNUNET_TIME_absolute_add (time, rekey_period);
1427 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1428 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1429 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1431 GNUNET_assert (GNUNET_OK ==
1432 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1434 &kx_msg.signature));
1436 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1437 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1439 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1444 * Called only on shutdown, destroy every tunnel.
1446 * @param cls Closure (unused).
1447 * @param key Current public key.
1448 * @param value Value in the hash map (tunnel).
1450 * @return #GNUNET_YES, so we should continue to iterate,
1453 destroy_iterator (void *cls,
1454 const struct GNUNET_PeerIdentity *key,
1457 struct CadetTunnel *t = value;
1459 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1466 * Notify remote peer that we don't know a channel he is talking about,
1467 * probably CHANNEL_DESTROY was missed.
1469 * @param t Tunnel on which to notify.
1470 * @param gid ID of the channel.
1473 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1475 struct GNUNET_CADET_ChannelManage msg;
1477 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1478 msg.header.size = htons (sizeof (msg));
1479 msg.chid = htonl (gid);
1481 LOG (GNUNET_ERROR_TYPE_DEBUG,
1482 "WARNING destroying unknown channel %u on tunnel %s\n",
1484 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1489 * Demultiplex data per channel and call appropriate channel handler.
1491 * @param t Tunnel on which the data came.
1492 * @param msg Data message.
1493 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1494 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1495 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1496 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1499 handle_data (struct CadetTunnel *t,
1500 const struct GNUNET_CADET_Data *msg,
1503 struct CadetChannel *ch;
1507 size = ntohs (msg->header.size);
1509 sizeof (struct GNUNET_CADET_Data) +
1510 sizeof (struct GNUNET_MessageHeader))
1515 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1516 GC_m2s (ntohs (msg[1].header.type)));
1519 ch = GCT_get_channel (t, ntohl (msg->chid));
1522 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1524 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1526 send_channel_destroy (t, ntohl (msg->chid));
1530 GCCH_handle_data (ch, msg, fwd);
1535 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1537 * @param t Tunnel on which the DATA ACK came.
1538 * @param msg DATA ACK message.
1539 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1540 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1541 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1542 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1545 handle_data_ack (struct CadetTunnel *t,
1546 const struct GNUNET_CADET_DataACK *msg,
1549 struct CadetChannel *ch;
1553 size = ntohs (msg->header.size);
1554 if (size != sizeof (struct GNUNET_CADET_DataACK))
1561 ch = GCT_get_channel (t, ntohl (msg->chid));
1564 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1566 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1571 GCCH_handle_data_ack (ch, msg, fwd);
1576 * Handle channel create.
1578 * @param t Tunnel on which the data came.
1579 * @param msg Data message.
1582 handle_ch_create (struct CadetTunnel *t,
1583 const struct GNUNET_CADET_ChannelCreate *msg)
1585 struct CadetChannel *ch;
1589 size = ntohs (msg->header.size);
1590 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1597 ch = GCT_get_channel (t, ntohl (msg->chid));
1598 if (NULL != ch && ! GCT_is_loopback (t))
1600 /* Probably a retransmission, safe to ignore */
1601 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1603 ch = GCCH_handle_create (t, msg);
1605 GCT_add_channel (t, ch);
1611 * Handle channel NACK: check correctness and call channel handler for NACKs.
1613 * @param t Tunnel on which the NACK came.
1614 * @param msg NACK message.
1617 handle_ch_nack (struct CadetTunnel *t,
1618 const struct GNUNET_CADET_ChannelManage *msg)
1620 struct CadetChannel *ch;
1624 size = ntohs (msg->header.size);
1625 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1632 ch = GCT_get_channel (t, ntohl (msg->chid));
1635 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1637 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1642 GCCH_handle_nack (ch);
1647 * Handle a CHANNEL ACK (SYNACK/ACK).
1649 * @param t Tunnel on which the CHANNEL ACK came.
1650 * @param msg CHANNEL ACK message.
1651 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1652 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1653 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1654 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1657 handle_ch_ack (struct CadetTunnel *t,
1658 const struct GNUNET_CADET_ChannelManage *msg,
1661 struct CadetChannel *ch;
1665 size = ntohs (msg->header.size);
1666 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1673 ch = GCT_get_channel (t, ntohl (msg->chid));
1676 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1678 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1683 GCCH_handle_ack (ch, msg, fwd);
1688 * Handle a channel destruction message.
1690 * @param t Tunnel on which the message came.
1691 * @param msg Channel destroy message.
1692 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1693 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1694 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1695 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1698 handle_ch_destroy (struct CadetTunnel *t,
1699 const struct GNUNET_CADET_ChannelManage *msg,
1702 struct CadetChannel *ch;
1706 size = ntohs (msg->header.size);
1707 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1714 ch = GCT_get_channel (t, ntohl (msg->chid));
1717 /* Probably a retransmission, safe to ignore */
1721 GCCH_handle_destroy (ch, msg, fwd);
1726 * The peer's ephemeral key has changed: update the symmetrical keys.
1728 * @param t Tunnel this message came on.
1729 * @param msg Key eXchange message.
1732 handle_ephemeral (struct CadetTunnel *t,
1733 const struct GNUNET_CADET_KX_Ephemeral *msg)
1735 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
1737 if (GNUNET_OK != check_ephemeral (t, msg))
1739 GNUNET_break_op (0);
1742 if (NULL == t->kx_ctx)
1744 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1745 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1746 t->kx_ctx->e_key_old = t->e_key;
1747 t->kx_ctx->d_key_old = t->d_key;
1748 t->kx_ctx->challenge =
1749 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1751 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
1752 sizeof (msg->ephemeral_key)))
1754 t->peers_ephemeral_key = msg->ephemeral_key;
1756 if (CADET_TUNNEL3_KEY_OK == t->estate)
1758 t->estate = CADET_TUNNEL3_KEY_REKEY;
1761 if (CADET_TUNNEL3_KEY_SENT == t->estate)
1763 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending ping\n");
1765 t->estate = CADET_TUNNEL3_KEY_PING;
1771 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1772 * Answer with by retransmitting the challenge with the "opposite" key.
1774 * @param t Tunnel this message came on.
1775 * @param msg Key eXchange Ping message.
1778 handle_ping (struct CadetTunnel *t,
1779 const struct GNUNET_CADET_KX_Ping *msg)
1781 struct GNUNET_CADET_KX_Ping res;
1783 if (ntohs (msg->header.size) != sizeof (res))
1785 GNUNET_break_op (0);
1789 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PING for %s\n", GCT_2s (t));
1790 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1791 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1793 GNUNET_STATISTICS_update (stats, "# malformed PINGs", 1, GNUNET_NO);
1794 LOG (GNUNET_ERROR_TYPE_WARNING, " malformed PING on %s\n", GCT_2s (t));
1795 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1796 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1797 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1798 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1804 send_pong (t, res.nonce);
1807 * @brief Finish the Key eXchange and destory the old keys.
1809 * @param cls Closure (Tunnel for which to finish the KX).
1810 * @param tc Task context.
1813 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1815 struct CadetTunnel *t = cls;
1817 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1820 GNUNET_free (t->kx_ctx);
1826 * Peer has answer to our challenge.
1827 * If answer is successful, consider the key exchange finished and clean
1828 * up all related state.
1830 * @param t Tunnel this message came on.
1831 * @param msg Key eXchange Pong message.
1834 handle_pong (struct CadetTunnel *t,
1835 const struct GNUNET_CADET_KX_Pong *msg)
1839 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
1840 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1842 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1845 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1847 if (challenge != t->kx_ctx->challenge)
1849 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
1850 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1851 challenge, msg->nonce, t->kx_ctx->challenge);
1856 GNUNET_SCHEDULER_cancel (t->rekey_task);
1857 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1859 /* Don't free the old keys right away, but after a delay.
1860 * Rationale: the KX could have happened over a very fast connection,
1861 * with payload traffic still signed with the old key stuck in a slower
1863 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
1866 if (GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
1868 struct GNUNET_TIME_Relative delay;
1870 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
1871 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
1872 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
1874 GCT_change_estate (t, CADET_TUNNEL3_KEY_OK);
1879 * Demultiplex by message type and call appropriate handler for a message
1880 * towards a channel of a local tunnel.
1882 * @param t Tunnel this message came on.
1883 * @param msgh Message header.
1884 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1885 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1886 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1887 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1890 handle_decrypted (struct CadetTunnel *t,
1891 const struct GNUNET_MessageHeader *msgh,
1896 type = ntohs (msgh->type);
1897 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
1901 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1902 /* Do nothing, connection aleady got updated. */
1903 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
1906 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1907 /* Don't send hop ACK, wait for client to ACK */
1908 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
1911 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1912 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1915 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1916 handle_ch_create (t,
1917 (struct GNUNET_CADET_ChannelCreate *) msgh);
1920 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1922 (struct GNUNET_CADET_ChannelManage *) msgh);
1925 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1927 (struct GNUNET_CADET_ChannelManage *) msgh,
1931 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1932 handle_ch_destroy (t,
1933 (struct GNUNET_CADET_ChannelManage *) msgh,
1938 GNUNET_break_op (0);
1939 LOG (GNUNET_ERROR_TYPE_WARNING,
1940 "end-to-end message not known (%u)\n",
1941 ntohs (msgh->type));
1942 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1946 /******************************************************************************/
1947 /******************************** API ***********************************/
1948 /******************************************************************************/
1951 * Decrypt and demultiplex by message type. Call appropriate handler
1952 * for every message.
1954 * @param t Tunnel this message came on.
1955 * @param msg Encrypted message.
1958 GCT_handle_encrypted (struct CadetTunnel *t,
1959 const struct GNUNET_CADET_Encrypted *msg)
1961 size_t size = ntohs (msg->header.size);
1962 size_t payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
1964 char cbuf [payload_size];
1965 struct GNUNET_MessageHeader *msgh;
1968 decrypted_size = t_decrypt_and_validate (t, cbuf, &msg[1], payload_size,
1969 msg->iv, &msg->hmac);
1971 if (-1 == decrypted_size)
1973 GNUNET_break_op (0);
1978 while (off < decrypted_size)
1982 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1983 msize = ntohs (msgh->size);
1984 if (msize < sizeof (struct GNUNET_MessageHeader))
1986 GNUNET_break_op (0);
1989 handle_decrypted (t, msgh, GNUNET_SYSERR);
1996 * Demultiplex an encapsulated KX message by message type.
1998 * @param t Tunnel on which the message came.
1999 * @param message Payload of KX message.
2002 GCT_handle_kx (struct CadetTunnel *t,
2003 const struct GNUNET_MessageHeader *message)
2007 type = ntohs (message->type);
2008 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
2011 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2012 handle_ephemeral (t, (struct GNUNET_CADET_KX_Ephemeral *) message);
2015 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
2016 handle_ping (t, (struct GNUNET_CADET_KX_Ping *) message);
2019 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2020 handle_pong (t, (struct GNUNET_CADET_KX_Pong *) message);
2024 GNUNET_break_op (0);
2025 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
2031 * Initialize the tunnel subsystem.
2033 * @param c Configuration handle.
2034 * @param key ECC private key, to derive all other keys and do crypto.
2037 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2038 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2040 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2042 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2045 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2046 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2050 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2053 rekey_period = GNUNET_TIME_UNIT_DAYS;
2056 my_private_key = key;
2057 kx_msg.header.size = htons (sizeof (kx_msg));
2058 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2059 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2060 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2061 kx_msg.origin_identity = my_full_id;
2062 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
2064 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2069 * Shut down the tunnel subsystem.
2074 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
2076 GNUNET_SCHEDULER_cancel (rekey_task);
2077 rekey_task = GNUNET_SCHEDULER_NO_TASK;
2079 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2080 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2087 * @param destination Peer this tunnel is towards.
2089 struct CadetTunnel *
2090 GCT_new (struct CadetPeer *destination)
2092 struct CadetTunnel *t;
2094 t = GNUNET_new (struct CadetTunnel);
2096 t->peer = destination;
2099 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2100 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2111 * Change the tunnel's connection state.
2113 * @param t Tunnel whose connection state to change.
2114 * @param cstate New connection state.
2117 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2121 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2122 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2123 if (myid != GCP_get_short_id (t->peer) &&
2124 CADET_TUNNEL3_READY != t->cstate &&
2125 CADET_TUNNEL3_READY == cstate)
2128 if (CADET_TUNNEL3_KEY_OK == t->estate)
2130 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2131 send_queued_data (t);
2133 else if (CADET_TUNNEL3_KEY_UNINITIALIZED == t->estate)
2135 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2136 rekey_tunnel (t, NULL);
2141 if (CADET_TUNNEL3_READY == cstate
2142 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2144 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2145 GCP_stop_search (t->peer);
2150 * Change the tunnel encryption state.
2152 * @param t Tunnel whose encryption state to change.
2153 * @param state New encryption state.
2156 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2160 LOG (GNUNET_ERROR_TYPE_DEBUG,
2161 "Tunnel %s estate was %s\n",
2162 GCP_2s (t->peer), estate2s (t->estate));
2163 LOG (GNUNET_ERROR_TYPE_DEBUG,
2164 "Tunnel %s estate is now %s\n",
2165 GCP_2s (t->peer), estate2s (state));
2166 if (myid != GCP_get_short_id (t->peer) &&
2167 CADET_TUNNEL3_KEY_OK != t->estate && CADET_TUNNEL3_KEY_OK == state)
2170 send_queued_data (t);
2178 * @brief Check if tunnel has too many connections, and remove one if necessary.
2180 * Currently this means the newest connection, unless it is a direct one.
2181 * Implemented as a task to avoid freeing a connection that is in the middle
2182 * of being created/processed.
2184 * @param cls Closure (Tunnel to check).
2185 * @param tc Task context.
2188 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2190 struct CadetTunnel *t = cls;
2192 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2195 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2197 struct CadetTConnection *iter;
2198 struct CadetTConnection *c;
2200 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2202 if ((NULL == c || iter->created.abs_value_us > c->created.abs_value_us)
2203 && GNUNET_NO == GCC_is_direct (iter->c))
2210 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2212 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2225 * Add a connection to a tunnel.
2228 * @param c Connection.
2231 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2233 struct CadetTConnection *aux;
2235 GNUNET_assert (NULL != c);
2237 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2238 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2239 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2243 aux = GNUNET_new (struct CadetTConnection);
2245 aux->created = GNUNET_TIME_absolute_get ();
2247 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2249 GNUNET_SCHEDULER_add_now (&trim_connections, t);
2254 * Mark a path as no longer valid for this tunnel: has been tried and failed.
2256 * @param t Tunnel to update.
2257 * @param path Invalid path to remove. Is destroyed after removal.
2260 GCT_remove_path (struct CadetTunnel *t, struct CadetPeerPath *path)
2262 GCP_remove_path (t->peer, path);
2267 * Remove a connection from a tunnel.
2270 * @param c Connection.
2273 GCT_remove_connection (struct CadetTunnel *t,
2274 struct CadetConnection *c)
2276 struct CadetTConnection *aux;
2277 struct CadetTConnection *next;
2279 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2280 GCC_2s (c), GCT_2s (t));
2281 for (aux = t->connection_head; aux != NULL; aux = next)
2286 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2291 /* Start new connections if needed */
2292 if (CONNECTIONS_PER_TUNNEL < GCT_count_connections (t)
2293 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2294 && CADET_TUNNEL3_SHUTDOWN != t->cstate
2295 && GNUNET_NO == shutting_down)
2297 LOG (GNUNET_ERROR_TYPE_DEBUG, " no more connections, getting new ones\n");
2298 t->cstate = CADET_TUNNEL3_SEARCHING;
2299 GCP_connect (t->peer);
2303 /* If not marked as ready, no change is needed */
2304 if (CADET_TUNNEL3_READY != t->cstate)
2307 /* Check if any connection is ready to maintaing cstate */
2308 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2309 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2312 t->cstate = CADET_TUNNEL3_WAITING;
2317 * Add a channel to a tunnel.
2320 * @param ch Channel.
2323 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2325 struct CadetTChannel *aux;
2327 GNUNET_assert (NULL != ch);
2329 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2331 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2333 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2338 aux = GNUNET_new (struct CadetTChannel);
2340 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2341 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2343 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2345 GNUNET_SCHEDULER_cancel (t->destroy_task);
2346 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2347 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2353 * Remove a channel from a tunnel.
2356 * @param ch Channel.
2359 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2361 struct CadetTChannel *aux;
2363 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2364 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2368 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2369 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2378 * Search for a channel by global ID.
2380 * @param t Tunnel containing the channel.
2381 * @param chid Public channel number.
2383 * @return channel handler, NULL if doesn't exist
2385 struct CadetChannel *
2386 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2388 struct CadetTChannel *iter;
2393 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2395 if (GCCH_get_id (iter->ch) == chid)
2399 return NULL == iter ? NULL : iter->ch;
2404 * @brief Destroy a tunnel and free all resources.
2406 * Should only be called a while after the tunnel has been marked as destroyed,
2407 * in case there is a new channel added to the same peer shortly after marking
2408 * the tunnel. This way we avoid a new public key handshake.
2410 * @param cls Closure (tunnel to destroy).
2411 * @param tc Task context.
2414 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2416 struct CadetTunnel *t = cls;
2417 struct CadetTConnection *iter;
2419 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2420 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2422 LOG (GNUNET_ERROR_TYPE_WARNING,
2423 "Not destroying tunnel, due to shutdown. "
2424 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2427 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2428 t->cstate = CADET_TUNNEL3_SHUTDOWN;
2430 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2432 GCC_send_destroy (iter->c);
2439 * Tunnel is empty: destroy it.
2441 * Notifies all connections about the destruction.
2443 * @param t Tunnel to destroy.
2446 GCT_destroy_empty (struct CadetTunnel *t)
2448 if (GNUNET_YES == shutting_down)
2449 return; /* Will be destroyed immediately anyway */
2451 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2453 LOG (GNUNET_ERROR_TYPE_DEBUG,
2454 "Tunnel %s is already scheduled for destruction\n",
2457 /* should never happen, tunnel can only become empty once, and the
2458 * task identifier should be NO_TASK (cleaned when the tunnel was created
2459 * or became un-empty)
2464 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2467 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2468 &delayed_destroy, t);
2469 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llX\n",
2470 t, t->destroy_task);
2475 * Destroy tunnel if empty (no more channels).
2477 * @param t Tunnel to destroy if empty.
2480 GCT_destroy_if_empty (struct CadetTunnel *t)
2482 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2483 if (1 < GCT_count_channels (t))
2486 GCT_destroy_empty (t);
2491 * Destroy the tunnel.
2493 * This function does not generate any warning traffic to clients or peers.
2496 * Cancel messages belonging to this tunnel queued to neighbors.
2497 * Free any allocated resources linked to the tunnel.
2499 * @param t The tunnel to destroy.
2502 GCT_destroy (struct CadetTunnel *t)
2504 struct CadetTConnection *iter_c;
2505 struct CadetTConnection *next_c;
2506 struct CadetTChannel *iter_ch;
2507 struct CadetTChannel *next_ch;
2512 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
2514 GNUNET_break (GNUNET_YES ==
2515 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2516 GCP_get_id (t->peer), t));
2518 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2520 next_c = iter_c->next;
2521 GCC_destroy (iter_c->c);
2523 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2525 next_ch = iter_ch->next;
2526 GCCH_destroy (iter_ch->ch);
2527 /* Should only happen on shutdown, but it's ok. */
2530 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2532 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling %llX\n", t->destroy_task);
2533 GNUNET_SCHEDULER_cancel (t->destroy_task);
2534 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2537 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2538 GCP_set_tunnel (t->peer, NULL);
2540 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2542 GNUNET_SCHEDULER_cancel (t->rekey_task);
2543 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2545 if (NULL != t->kx_ctx)
2547 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
2548 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
2549 GNUNET_free (t->kx_ctx);
2556 * @brief Use the given path for the tunnel.
2557 * Update the next and prev hops (and RCs).
2558 * (Re)start the path refresh in case the tunnel is locally owned.
2560 * @param t Tunnel to update.
2561 * @param p Path to use.
2563 * @return Connection created.
2565 struct CadetConnection *
2566 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
2568 struct CadetConnection *c;
2569 struct GNUNET_CADET_Hash cid;
2570 unsigned int own_pos;
2572 if (NULL == t || NULL == p)
2578 if (CADET_TUNNEL3_SHUTDOWN == t->cstate)
2584 for (own_pos = 0; own_pos < p->length; own_pos++)
2586 if (p->peers[own_pos] == myid)
2589 if (own_pos >= p->length)
2591 GNUNET_break_op (0);
2595 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2596 c = GCC_new (&cid, t, p, own_pos);
2599 /* Path was flawed */
2602 GCT_add_connection (t, c);
2608 * Count established (ready) connections of a tunnel.
2610 * @param t Tunnel on which to count.
2612 * @return Number of connections.
2615 GCT_count_connections (struct CadetTunnel *t)
2617 struct CadetTConnection *iter;
2623 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2624 if (CADET_CONNECTION_DESTROYED != GCC_get_state (iter->c))
2631 * Count channels of a tunnel.
2633 * @param t Tunnel on which to count.
2635 * @return Number of channels.
2638 GCT_count_channels (struct CadetTunnel *t)
2640 struct CadetTChannel *iter;
2643 for (count = 0, iter = t->channel_head;
2645 iter = iter->next, count++) /* skip */;
2652 * Get the connectivity state of a tunnel.
2656 * @return Tunnel's connectivity state.
2658 enum CadetTunnelCState
2659 GCT_get_cstate (struct CadetTunnel *t)
2664 return (enum CadetTunnelCState) -1;
2671 * Get the encryption state of a tunnel.
2675 * @return Tunnel's encryption state.
2677 enum CadetTunnelEState
2678 GCT_get_estate (struct CadetTunnel *t)
2683 return (enum CadetTunnelEState) -1;
2689 * Get the maximum buffer space for a tunnel towards a local client.
2693 * @return Biggest buffer space offered by any channel in the tunnel.
2696 GCT_get_channels_buffer (struct CadetTunnel *t)
2698 struct CadetTChannel *iter;
2699 unsigned int buffer;
2700 unsigned int ch_buf;
2702 if (NULL == t->channel_head)
2704 /* Probably getting buffer for a channel create/handshake. */
2709 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2711 ch_buf = get_channel_buffer (iter);
2712 if (ch_buf > buffer)
2720 * Get the total buffer space for a tunnel for P2P traffic.
2724 * @return Buffer space offered by all connections in the tunnel.
2727 GCT_get_connections_buffer (struct CadetTunnel *t)
2729 struct CadetTConnection *iter;
2730 unsigned int buffer;
2732 if (GNUNET_NO == is_ready (t))
2734 if (count_queued_data (t) > 3)
2741 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2743 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2747 buffer += get_connection_buffer (iter);
2755 * Get the tunnel's destination.
2759 * @return ID of the destination peer.
2761 const struct GNUNET_PeerIdentity *
2762 GCT_get_destination (struct CadetTunnel *t)
2764 return GCP_get_id (t->peer);
2769 * Get the tunnel's next free global channel ID.
2773 * @return GID of a channel free to use.
2776 GCT_get_next_chid (struct CadetTunnel *t)
2778 CADET_ChannelNumber chid;
2779 CADET_ChannelNumber mask;
2782 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2783 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2784 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2786 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2791 t->next_chid |= mask;
2793 while (NULL != GCT_get_channel (t, t->next_chid))
2795 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2796 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2797 t->next_chid |= mask;
2799 chid = t->next_chid;
2800 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2801 t->next_chid |= mask;
2808 * Send ACK on one or more channels due to buffer in connections.
2810 * @param t Channel which has some free buffer space.
2813 GCT_unchoke_channels (struct CadetTunnel *t)
2815 struct CadetTChannel *iter;
2816 unsigned int buffer;
2817 unsigned int channels = GCT_count_channels (t);
2818 unsigned int choked_n;
2819 struct CadetChannel *choked[channels];
2821 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
2822 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2823 if (NULL != t->channel_head)
2824 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2826 /* Get buffer space */
2827 buffer = GCT_get_connections_buffer (t);
2833 /* Count and remember choked channels */
2835 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2837 if (GNUNET_NO == get_channel_allowed (iter))
2839 choked[choked_n++] = iter->ch;
2843 /* Unchoke random channels */
2844 while (0 < buffer && 0 < choked_n)
2846 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
2848 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
2851 choked[r] = choked[choked_n];
2857 * Send ACK on one or more connections due to buffer space to the client.
2859 * Iterates all connections of the tunnel and sends ACKs appropriately.
2864 GCT_send_connection_acks (struct CadetTunnel *t)
2866 struct CadetTConnection *iter;
2869 uint32_t allow_per_connection;
2871 unsigned int buffer;
2873 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
2882 buffer = GCT_get_channels_buffer (t);
2883 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
2885 /* Count connections, how many messages are already allowed */
2886 cs = GCT_count_connections (t);
2887 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2889 allowed += get_connection_allowed (iter);
2891 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
2893 /* Make sure there is no overflow */
2894 if (allowed > buffer)
2899 /* Authorize connections to send more data */
2900 to_allow = buffer; /* - allowed; */
2902 for (iter = t->connection_head;
2903 NULL != iter && to_allow > 0;
2906 allow_per_connection = to_allow/cs;
2907 to_allow -= allow_per_connection;
2909 if (get_connection_allowed (iter) > 64 / 3)
2913 GCC_allow (iter->c, allow_per_connection,
2914 GCC_is_origin (iter->c, GNUNET_NO));
2917 GNUNET_break (to_allow == 0);
2922 * Cancel a previously sent message while it's in the queue.
2924 * ONLY can be called before the continuation given to the send function
2925 * is called. Once the continuation is called, the message is no longer in the
2928 * @param q Handle to the queue.
2931 GCT_cancel (struct CadetTunnelQueue *q)
2936 /* tun_message_sent() will be called and free q */
2938 else if (NULL != q->tqd)
2940 unqueue_data (q->tqd);
2942 if (NULL != q->cont)
2943 q->cont (q->cont_cls, NULL, q, 0, 0);
2954 * Sends an already built message on a tunnel, encrypting it and
2955 * choosing the best connection if not provided.
2957 * @param message Message to send. Function modifies it.
2958 * @param t Tunnel on which this message is transmitted.
2959 * @param c Connection to use (autoselect if NULL).
2960 * @param force Force the tunnel to take the message (buffer overfill).
2961 * @param cont Continuation to call once message is really sent.
2962 * @param cont_cls Closure for @c cont.
2964 * @return Handle to cancel message. NULL if @c cont is NULL.
2966 struct CadetTunnelQueue *
2967 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2968 struct CadetTunnel *t, struct CadetConnection *c,
2969 int force, GCT_sent cont, void *cont_cls)
2971 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
2976 * Is the tunnel directed towards the local peer?
2980 * @return #GNUNET_YES if it is loopback.
2983 GCT_is_loopback (const struct CadetTunnel *t)
2985 return (myid == GCP_get_short_id (t->peer));
2990 * Is the tunnel this path already?
2995 * @return #GNUNET_YES a connection uses this path.
2998 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3000 struct CadetTConnection *iter;
3002 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3003 if (GCC_get_path (iter->c) == p)
3011 * Get a cost of a path for a tunnel considering existing connections.
3014 * @param path Candidate path.
3016 * @return Cost of the path (path length + number of overlapping nodes)
3019 GCT_get_path_cost (const struct CadetTunnel *t,
3020 const struct CadetPeerPath *path)
3022 struct CadetTConnection *iter;
3023 const struct CadetPeerPath *aux;
3024 unsigned int overlap;
3032 GNUNET_assert (NULL != t);
3034 for (i = 0; i < path->length; i++)
3036 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3038 aux = GCC_get_path (iter->c);
3042 for (j = 0; j < aux->length; j++)
3044 if (path->peers[i] == aux->peers[j])
3052 return path->length + overlap;
3057 * Get the static string for the peer this tunnel is directed.
3061 * @return Static string the destination peer's ID.
3064 GCT_2s (const struct CadetTunnel *t)
3069 return GCP_2s (t->peer);
3073 /******************************************************************************/
3074 /***************************** INFO/DEBUG *******************************/
3075 /******************************************************************************/
3078 * Log all possible info about the tunnel state.
3080 * @param t Tunnel to debug.
3081 * @param level Debug level to use.
3084 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3086 struct CadetTChannel *iterch;
3087 struct CadetTConnection *iterc;
3089 LOG (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3090 LOG (level, "TTT cstate %s, estate %s\n",
3091 cstate2s (t->cstate), estate2s (t->estate));
3092 LOG (level, "TTT kx_ctx %p, rekey_task %u\n", t->kx_ctx, t->rekey_task);
3093 LOG (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3094 LOG (level, "TTT destroy %u\n", t->destroy_task);
3096 LOG (level, "TTT channels:\n");
3097 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3099 LOG (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3102 LOG (level, "TTT connections:\n");
3103 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3105 LOG (level, "TTT - %s [%u] buf: %u/%u (qn %u/%u)\n",
3106 GCC_2s (iterc->c), GCC_get_state (iterc->c),
3107 GCC_get_buffer (iterc->c, GNUNET_YES),
3108 GCC_get_buffer (iterc->c, GNUNET_NO),
3109 GCC_get_qn (iterc->c, GNUNET_YES),
3110 GCC_get_qn (iterc->c, GNUNET_NO));
3113 LOG (level, "TTT DEBUG TUNNEL END\n");
3118 * Iterate all tunnels.
3120 * @param iter Iterator.
3121 * @param cls Closure for @c iter.
3124 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3126 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3131 * Count all tunnels.
3133 * @return Number of tunnels to remote peers kept by this peer.
3136 GCT_count_all (void)
3138 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3143 * Iterate all connections of a tunnel.
3145 * @param t Tunnel whose connections to iterate.
3146 * @param iter Iterator.
3147 * @param cls Closure for @c iter.
3150 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3152 struct CadetTConnection *ct;
3154 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3160 * Iterate all channels of a tunnel.
3162 * @param t Tunnel whose channels to iterate.
3163 * @param iter Iterator.
3164 * @param cls Closure for @c iter.
3167 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3169 struct CadetTChannel *cht;
3171 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3172 iter (cls, cht->ch);