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__)
36 #define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-tun",__VA_ARGS__)
38 #define REKEY_WAIT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)
40 #if !defined(GNUNET_CULL_LOGGING)
41 #define DUMP_KEYS_TO_STDERR GNUNET_YES
43 #define DUMP_KEYS_TO_STDERR GNUNET_NO
46 /******************************************************************************/
47 /******************************** STRUCTS **********************************/
48 /******************************************************************************/
52 struct CadetTChannel *next;
53 struct CadetTChannel *prev;
54 struct CadetChannel *ch;
59 * Connection list and metadata.
61 struct CadetTConnection
66 struct CadetTConnection *next;
71 struct CadetTConnection *prev;
76 struct CadetConnection *c;
79 * Creation time, to keep oldest connection alive.
81 struct GNUNET_TIME_Absolute created;
84 * Connection throughput, to keep fastest connection alive.
90 * Structure used during a Key eXchange.
92 struct CadetTunnelKXCtx
95 * Encryption ("our") old "confirmed" key, for encrypting traffic sent by us
96 * end before the key exchange is finished or times out.
98 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
101 * Decryption ("their") old "confirmed" key, for decrypting traffic sent by
102 * the other end before the key exchange started.
104 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
107 * Challenge to send in a ping and expect in the pong.
112 * When the rekey started. One minute after this the new key will be used.
114 struct GNUNET_TIME_Absolute rekey_start_time;
117 * Task for delayed destruction of the Key eXchange context, to allow delayed
118 * messages with the old key to be decrypted successfully.
120 GNUNET_SCHEDULER_TaskIdentifier finish_task;
124 * Struct containing all information regarding a tunnel to a peer.
129 * Endpoint of the tunnel.
131 struct CadetPeer *peer;
134 * State of the tunnel connectivity.
136 enum CadetTunnelCState cstate;
139 * State of the tunnel encryption.
141 enum CadetTunnelEState estate;
144 * Key eXchange context.
146 struct CadetTunnelKXCtx *kx_ctx;
149 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
152 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
155 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
157 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
160 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
162 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
165 * Task to start the rekey process.
167 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
170 * Paths that are actively used to reach the destination peer.
172 struct CadetTConnection *connection_head;
173 struct CadetTConnection *connection_tail;
176 * Next connection number.
181 * Channels inside this tunnel.
183 struct CadetTChannel *channel_head;
184 struct CadetTChannel *channel_tail;
187 * Channel ID for the next created channel.
189 CADET_ChannelNumber next_chid;
192 * Destroy flag: if true, destroy on last message.
194 GNUNET_SCHEDULER_TaskIdentifier destroy_task;
197 * Queued messages, to transmit once tunnel gets connected.
199 struct CadetTunnelDelayed *tq_head;
200 struct CadetTunnelDelayed *tq_tail;
203 * Task to trim connections if too many are present.
205 GNUNET_SCHEDULER_TaskIdentifier trim_connections_task;
210 * Struct used to save messages in a non-ready tunnel to send once connected.
212 struct CadetTunnelDelayed
217 struct CadetTunnelDelayed *next;
218 struct CadetTunnelDelayed *prev;
223 struct CadetTunnel *t;
226 * Tunnel queue given to the channel to cancel request. Update on send_queued.
228 struct CadetTunnelQueue *tq;
233 /* struct GNUNET_MessageHeader *msg; */
238 * Handle for messages queued but not yet sent.
240 struct CadetTunnelQueue
243 * Connection queue handle, to cancel if necessary.
245 struct CadetConnectionQueue *cq;
248 * Handle in case message hasn't been given to a connection yet.
250 struct CadetTunnelDelayed *tqd;
253 * Continuation to call once sent.
258 * Closure for @c cont.
264 /******************************************************************************/
265 /******************************* GLOBALS ***********************************/
266 /******************************************************************************/
269 * Global handle to the statistics service.
271 extern struct GNUNET_STATISTICS_Handle *stats;
274 * Local peer own ID (memory efficient handle).
276 extern GNUNET_PEER_Id myid;
279 * Local peer own ID (full value).
281 extern struct GNUNET_PeerIdentity my_full_id;
285 * Don't try to recover tunnels if shutting down.
287 extern int shutting_down;
291 * Set of all tunnels, in order to trigger a new exchange on rekey.
292 * Indexed by peer's ID.
294 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
297 * Default TTL for payload packets.
299 static unsigned long long default_ttl;
304 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
307 * Own ephemeral private key.
309 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
312 * Cached message used to perform a key exchange.
314 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
317 * Task to generate a new ephemeral key.
319 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
324 static struct GNUNET_TIME_Relative rekey_period;
326 /******************************************************************************/
327 /******************************** STATIC ***********************************/
328 /******************************************************************************/
331 * Get string description for tunnel connectivity state.
333 * @param cs Tunnel state.
335 * @return String representation.
338 cstate2s (enum CadetTunnelCState cs)
344 case CADET_TUNNEL_NEW:
345 return "CADET_TUNNEL_NEW";
346 case CADET_TUNNEL_SEARCHING:
347 return "CADET_TUNNEL_SEARCHING";
348 case CADET_TUNNEL_WAITING:
349 return "CADET_TUNNEL_WAITING";
350 case CADET_TUNNEL_READY:
351 return "CADET_TUNNEL_READY";
352 case CADET_TUNNEL_SHUTDOWN:
353 return "CADET_TUNNEL_SHUTDOWN";
355 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
363 * Get string description for tunnel encryption state.
365 * @param es Tunnel state.
367 * @return String representation.
370 estate2s (enum CadetTunnelEState es)
376 case CADET_TUNNEL_KEY_UNINITIALIZED:
377 return "CADET_TUNNEL_KEY_UNINITIALIZED";
378 case CADET_TUNNEL_KEY_SENT:
379 return "CADET_TUNNEL_KEY_SENT";
380 case CADET_TUNNEL_KEY_PING:
381 return "CADET_TUNNEL_KEY_PING";
382 case CADET_TUNNEL_KEY_OK:
383 return "CADET_TUNNEL_KEY_OK";
384 case CADET_TUNNEL_KEY_REKEY:
385 return "CADET_TUNNEL_KEY_REKEY";
387 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
395 * @brief Check if tunnel is ready to send traffic.
397 * Tunnel must be connected and with encryption correctly set up.
399 * @param t Tunnel to check.
401 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
404 is_ready (struct CadetTunnel *t)
408 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
409 ready = CADET_TUNNEL_READY == t->cstate
410 && (CADET_TUNNEL_KEY_OK == t->estate
411 || CADET_TUNNEL_KEY_REKEY == t->estate);
412 ready = ready || GCT_is_loopback (t);
418 * Check if a key is invalid (NULL pointer or all 0)
420 * @param key Key to check.
422 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
425 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
427 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
432 memset (&null_key, 0, sizeof (null_key));
433 if (0 == memcmp (key, &null_key, sizeof (null_key)))
440 * Ephemeral key message purpose size.
442 * @return Size of the part of the ephemeral key message that must be signed.
445 ephemeral_purpose_size (void)
447 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
448 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
449 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
450 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
451 sizeof (struct GNUNET_PeerIdentity);
456 * Size of the encrypted part of a ping message.
458 * @return Size of the encrypted part of a ping message.
461 ping_encryption_size (void)
463 return sizeof (uint32_t);
468 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
470 * @param tch Tunnel's channel handle.
472 * @return Amount of messages the channel can still buffer towards the client.
475 get_channel_buffer (const struct CadetTChannel *tch)
479 /* If channel is incoming, is terminal in the FWD direction and fwd is YES */
480 fwd = GCCH_is_terminal (tch->ch, GNUNET_YES);
482 return GCCH_get_buffer (tch->ch, fwd);
487 * Get the channel's allowance status.
489 * @param tch Tunnel's channel handle.
491 * @return #GNUNET_YES if we allowed the client to send data to us.
494 get_channel_allowed (const struct CadetTChannel *tch)
498 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
499 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
501 return GCCH_get_allowed (tch->ch, fwd);
506 * Get the connection's buffer.
508 * @param tc Tunnel's connection handle.
510 * @return Amount of messages the connection can still buffer.
513 get_connection_buffer (const struct CadetTConnection *tc)
517 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
518 fwd = GCC_is_origin (tc->c, GNUNET_YES);
520 return GCC_get_buffer (tc->c, fwd);
525 * Get the connection's allowance.
527 * @param tc Tunnel's connection handle.
529 * @return Amount of messages we have allowed the next peer to send us.
532 get_connection_allowed (const struct CadetTConnection *tc)
536 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
537 fwd = GCC_is_origin (tc->c, GNUNET_YES);
539 return GCC_get_allowed (tc->c, fwd);
544 * Check that a ephemeral key message s well formed and correctly signed.
546 * @param t Tunnel on which the message came.
547 * @param msg The ephemeral key message.
549 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
552 check_ephemeral (struct CadetTunnel *t,
553 const struct GNUNET_CADET_KX_Ephemeral *msg)
555 /* Check message size */
556 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
557 return GNUNET_SYSERR;
559 /* Check signature size */
560 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
561 return GNUNET_SYSERR;
564 if (0 != memcmp (&msg->origin_identity,
565 GCP_get_id (t->peer),
566 sizeof (struct GNUNET_PeerIdentity)))
567 return GNUNET_SYSERR;
569 /* Check signature */
571 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
574 &msg->origin_identity.public_key))
575 return GNUNET_SYSERR;
582 * Select the best key to use for encryption (send), based on KX status.
584 * Normally, return the current key. If there is a KX in progress and the old
585 * key is fresh enough, return the old key.
587 * @param t Tunnel to choose the key from.
589 * @return The optimal key to encrypt/hmac outgoing traffic.
591 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
592 select_key (const struct CadetTunnel *t)
594 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
596 if (NULL != t->kx_ctx
597 && GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
599 struct GNUNET_TIME_Relative age;
601 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
602 LOG (GNUNET_ERROR_TYPE_DEBUG,
603 " key exchange in progress, started %s ago\n",
604 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
605 // FIXME make duration of old keys configurable
606 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
608 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
609 key = &t->kx_ctx->e_key_old;
613 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
619 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
629 * @param plaintext Content to HMAC.
630 * @param size Size of @c plaintext.
631 * @param iv Initialization vector for the message.
632 * @param key Key to use.
633 * @param hmac[out] Destination to store the HMAC.
636 t_hmac (const void *plaintext, size_t size,
637 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
638 struct GNUNET_CADET_Hash *hmac)
640 static const char ctx[] = "cadet authentication key";
641 struct GNUNET_CRYPTO_AuthKey auth_key;
642 struct GNUNET_HashCode hash;
644 #if DUMP_KEYS_TO_STDERR
645 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC with key %s\n",
646 GNUNET_h2s ((struct GNUNET_HashCode *) key));
648 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
653 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
654 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
655 memcpy (hmac, &hash, sizeof (*hmac));
660 * Encrypt daforce_newest_keyta with the tunnel key.
662 * @param t Tunnel whose key to use.
663 * @param dst Destination for the encrypted data.
664 * @param src Source of the plaintext. Can overlap with @c dst.
665 * @param size Size of the plaintext.
666 * @param iv Initialization Vector to use.
667 * @param force_newest_key Force the use of the newest key, otherwise
668 * CADET will use the old key when allowed.
669 * This can happen in the case when a KX is going on
670 * and the old one hasn't expired.
673 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
674 size_t size, uint32_t iv, int force_newest_key)
676 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
677 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
680 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
682 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
683 #if DUMP_KEYS_TO_STDERR
684 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
685 GNUNET_h2s ((struct GNUNET_HashCode *) key));
687 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
688 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
689 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
690 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
697 * Decrypt and verify data with the appropriate tunnel key.
699 * @param key Key to use.
700 * @param dst Destination for the plaintext.
701 * @param src Source of the encrypted data. Can overlap with @c dst.
702 * @param size Size of the encrypted data.
703 * @param iv Initialization Vector to use.
705 * @return Size of the decrypted data, -1 if an error was encountered.
708 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
709 void *dst, const void *src, size_t size, uint32_t iv)
711 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
714 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
715 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
716 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
717 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
718 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
719 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
726 * Decrypt and verify data with the most recent tunnel key.
728 * @param t Tunnel whose key to use.
729 * @param dst Destination for the plaintext.
730 * @param src Source of the encrypted data. Can overlap with @c dst.
731 * @param size Size of the encrypted data.
732 * @param iv Initialization Vector to use.
734 * @return Size of the decrypted data, -1 if an error was encountered.
737 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
738 size_t size, uint32_t iv)
742 #if DUMP_KEYS_TO_STDERR
743 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
744 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
746 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
748 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
749 LOG (GNUNET_ERROR_TYPE_WARNING,
750 "got data on %s without a valid key\n",
752 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
756 out_size = decrypt (&t->d_key, dst, src, size, iv);
763 * Decrypt and verify data with the appropriate tunnel key and verify that the
764 * data has not been altered since it was sent by the remote peer.
766 * @param t Tunnel whose key to use.
767 * @param dst Destination for the plaintext.
768 * @param src Source of the encrypted data. Can overlap with @c dst.
769 * @param size Size of the encrypted data.
770 * @param iv Initialization Vector to use.
771 * @param msg_hmac HMAC of the message, cannot be NULL.
773 * @return Size of the decrypted data, -1 if an error was encountered.
776 t_decrypt_and_validate (struct CadetTunnel *t,
777 void *dst, const void *src,
778 size_t size, uint32_t iv,
779 const struct GNUNET_CADET_Hash *msg_hmac)
781 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
782 struct GNUNET_CADET_Hash hmac;
785 /* Try primary (newest) key */
787 decrypted_size = decrypt (key, dst, src, size, iv);
788 t_hmac (src, size, iv, key, &hmac);
789 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
790 return decrypted_size;
792 /* If no key exchange is going on, we just failed */
793 if (NULL == t->kx_ctx)
795 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
796 "Failed checksum validation on tunnel %s with no KX\n",
798 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
802 /* Try secondary (from previous KX period) key */
803 key = &t->kx_ctx->d_key_old;
804 decrypted_size = decrypt (key, dst, src, size, iv);
805 t_hmac (src, size, iv, key, &hmac);
806 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
807 return decrypted_size;
809 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
810 "Failed checksum validation on tunnel %s with KX\n",
812 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
818 * Create key material by doing ECDH on the local and remote ephemeral keys.
820 * @param key_material Where to store the key material.
821 * @param ephemeral_key Peer's public ephemeral key.
824 derive_key_material (struct GNUNET_HashCode *key_material,
825 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
828 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
838 * Create a symmetic key from the identities of both ends and the key material
841 * @param key Destination for the generated key.
842 * @param sender ID of the peer that will encrypt with @c key.
843 * @param receiver ID of the peer that will decrypt with @c key.
844 * @param key_material Hash created with ECDH with the ephemeral keys.
847 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
848 const struct GNUNET_PeerIdentity *sender,
849 const struct GNUNET_PeerIdentity *receiver,
850 const struct GNUNET_HashCode *key_material)
852 const char salt[] = "CADET kx salt";
854 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
856 key_material, sizeof (struct GNUNET_HashCode),
857 sender, sizeof (struct GNUNET_PeerIdentity),
858 receiver, sizeof (struct GNUNET_PeerIdentity),
864 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
866 * @param t Tunnel for which to create the keys.
869 create_keys (struct CadetTunnel *t)
871 struct GNUNET_HashCode km;
873 derive_key_material (&km, &t->peers_ephemeral_key);
874 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
875 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
876 #if DUMP_KEYS_TO_STDERR
877 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
878 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
879 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
880 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
881 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
882 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
883 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
884 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
885 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
891 * Create a new Key eXchange context for the tunnel.
893 * If the old keys were verified, keep them for old traffic. Create a new KX
894 * timestamp and a new nonce.
896 * @param t Tunnel for which to create the KX ctx.
899 create_kx_ctx (struct CadetTunnel *t)
901 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
903 if (NULL != t->kx_ctx)
905 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
907 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
908 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
909 t->kx_ctx->finish_task = GNUNET_SCHEDULER_NO_TASK;
914 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
915 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
919 if (CADET_TUNNEL_KEY_OK == t->estate)
921 LOG (GNUNET_ERROR_TYPE_INFO, " backing up keys\n");
922 t->kx_ctx->d_key_old = t->d_key;
923 t->kx_ctx->e_key_old = t->e_key;
926 LOG (GNUNET_ERROR_TYPE_INFO, " old keys not valid, not saving\n");
927 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
933 * @brief Finish the Key eXchange and destroy the old keys.
935 * @param cls Closure (Tunnel for which to finish the KX).
936 * @param tc Task context.
939 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
941 struct CadetTunnel *t = cls;
943 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
945 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
947 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
951 GNUNET_free (t->kx_ctx);
957 * Destroy a Key eXchange context for the tunnel. This function only schedules
958 * the destruction, the freeing of the memory (and clearing of old key material)
959 * happens after a delay!
961 * @param t Tunnel whose KX ctx to destroy.
964 destroy_kx_ctx (struct CadetTunnel *t)
966 struct GNUNET_TIME_Relative delay;
968 if (NULL == t->kx_ctx || GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
971 if (is_key_null (&t->kx_ctx->e_key_old))
973 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
977 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
978 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
980 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
986 * Pick a connection on which send the next data message.
988 * @param t Tunnel on which to send the message.
990 * @return The connection on which to send the next message.
992 static struct CadetConnection *
993 tunnel_get_connection (struct CadetTunnel *t)
995 struct CadetTConnection *iter;
996 struct CadetConnection *best;
998 unsigned int lowest_q;
1000 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
1002 lowest_q = UINT_MAX;
1003 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1005 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1006 GCC_2s (iter->c), GCC_get_state (iter->c));
1007 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1009 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1010 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1018 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1024 * Callback called when a queued message is sent.
1026 * Calculates the average time and connection packet tracking.
1028 * @param cls Closure (TunnelQueue handle).
1029 * @param c Connection this message was on.
1030 * @param q Connection queue handle (unused).
1031 * @param type Type of message sent.
1032 * @param fwd Was this a FWD going message?
1033 * @param size Size of the message.
1036 tun_message_sent (void *cls,
1037 struct CadetConnection *c,
1038 struct CadetConnectionQueue *q,
1039 uint16_t type, int fwd, size_t size)
1041 struct CadetTunnelQueue *qt = cls;
1042 struct CadetTunnel *t;
1044 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1046 GNUNET_assert (NULL != qt->cont);
1047 t = NULL == c ? NULL : GCC_get_tunnel (c);
1048 qt->cont (qt->cont_cls, t, qt, type, size);
1054 count_queued_data (const struct CadetTunnel *t)
1056 struct CadetTunnelDelayed *iter;
1059 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1066 * Delete a queued message: either was sent or the channel was destroyed
1067 * before the tunnel's key exchange had a chance to finish.
1069 * @param tqd Delayed queue handle.
1072 unqueue_data (struct CadetTunnelDelayed *tqd)
1074 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1080 * Cache a message to be sent once tunnel is online.
1082 * @param t Tunnel to hold the message.
1083 * @param msg Message itself (copy will be made).
1085 static struct CadetTunnelDelayed *
1086 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1088 struct CadetTunnelDelayed *tqd;
1089 uint16_t size = ntohs (msg->size);
1091 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1093 if (GNUNET_YES == is_ready (t))
1099 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1102 memcpy (&tqd[1], msg, size);
1103 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1109 * Sends an already built message on a tunnel, encrypting it and
1110 * choosing the best connection.
1112 * @param message Message to send. Function modifies it.
1113 * @param t Tunnel on which this message is transmitted.
1114 * @param c Connection to use (autoselect if NULL).
1115 * @param force Force the tunnel to take the message (buffer overfill).
1116 * @param cont Continuation to call once message is really sent.
1117 * @param cont_cls Closure for @c cont.
1118 * @param existing_q In case this a transmission of previously queued data,
1119 * this should be TunnelQueue given to the client.
1122 * @return Handle to cancel message.
1123 * NULL if @c cont is NULL or an error happens and message is dropped.
1125 static struct CadetTunnelQueue *
1126 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1127 struct CadetTunnel *t, struct CadetConnection *c,
1128 int force, GCT_sent cont, void *cont_cls,
1129 struct CadetTunnelQueue *existing_q)
1131 struct CadetTunnelQueue *tq;
1132 struct GNUNET_CADET_Encrypted *msg;
1133 size_t size = ntohs (message->size);
1134 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1140 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1142 if (GNUNET_NO == is_ready (t))
1144 struct CadetTunnelDelayed *tqd;
1145 /* A non null existing_q indicates sending of queued data.
1146 * Should only happen after tunnel becomes ready.
1148 GNUNET_assert (NULL == existing_q);
1149 tqd = queue_data (t, message);
1152 tq = GNUNET_new (struct CadetTunnelQueue);
1156 tq->cont_cls = cont_cls;
1160 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1162 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1163 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1164 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1166 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO) == size);
1167 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1168 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1171 c = tunnel_get_connection (t);
1174 /* Why is tunnel 'ready'? Should have been queued! */
1175 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
1178 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1180 return NULL; /* Drop... */
1184 type = ntohs (message->type);
1187 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1188 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1189 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1190 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1192 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1194 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1195 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1196 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1197 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1198 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1199 msg->cid = *GCC_get_id (c);
1200 msg->ttl = htonl (default_ttl);
1204 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1206 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1208 fwd = GCC_is_origin (c, GNUNET_YES);
1212 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1213 fwd, force, NULL, NULL));
1216 if (NULL == existing_q)
1218 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1225 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1226 &tun_message_sent, tq);
1227 GNUNET_assert (NULL != tq->cq);
1229 tq->cont_cls = cont_cls;
1236 * Send all cached messages that we can, tunnel is online.
1238 * @param t Tunnel that holds the messages. Cannot be loopback.
1241 send_queued_data (struct CadetTunnel *t)
1243 struct CadetTunnelDelayed *tqd;
1244 struct CadetTunnelDelayed *next;
1247 LOG (GNUNET_ERROR_TYPE_INFO, "Send queued data, tunnel %s\n", GCT_2s (t));
1249 if (GCT_is_loopback (t))
1255 if (GNUNET_NO == is_ready (t))
1257 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1258 estate2s (t->estate), cstate2s (t->cstate));
1262 room = GCT_get_connections_buffer (t);
1263 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1264 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1265 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1267 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1270 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1271 tqd->t, NULL, GNUNET_YES,
1272 NULL != tqd->tq ? tqd->tq->cont : NULL,
1273 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1277 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1282 * Sends key exchange message on a tunnel, choosing the best connection.
1283 * Should not be called on loopback tunnels.
1285 * @param t Tunnel on which this message is transmitted.
1286 * @param message Message to send. Function modifies it.
1289 send_kx (struct CadetTunnel *t,
1290 const struct GNUNET_MessageHeader *message)
1292 struct CadetConnection *c;
1293 struct GNUNET_CADET_KX *msg;
1294 size_t size = ntohs (message->size);
1295 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1299 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1301 /* Avoid loopback. */
1302 if (GCT_is_loopback (t))
1304 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1308 type = ntohs (message->type);
1310 /* Even if tunnel is being destroyed, send anyway.
1311 * Could be a response to a rekey initiated by remote peer,
1312 * who is trying to create a new channel!
1315 /* Must have a connection, or be looking for one. */
1316 if (NULL == t->connection_head)
1318 if (CADET_TUNNEL_SEARCHING != t->cstate)
1320 LOG (GNUNET_ERROR_TYPE_ERROR, "\n\n\n");
1322 LOG (GNUNET_ERROR_TYPE_ERROR, "no connection, sending %s\n", GC_m2s (type));
1323 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1324 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
1325 LOG (GNUNET_ERROR_TYPE_ERROR, "\n\n\n");
1330 msg = (struct GNUNET_CADET_KX *) cbuf;
1331 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1332 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1333 c = tunnel_get_connection (t);
1336 if (GNUNET_SCHEDULER_NO_TASK == t->destroy_task
1337 && CADET_TUNNEL_READY == t->cstate)
1340 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1346 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1347 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1348 memcpy (&msg[1], message, size);
1352 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1357 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1358 /* TODO save handle and cancel in case of a unneeded retransmission */
1359 GNUNET_assert (NULL == GCC_send_prebuilt_message (&msg->header, type, 0, c,
1366 * Send the ephemeral key on a tunnel.
1368 * @param t Tunnel on which to send the key.
1371 send_ephemeral (struct CadetTunnel *t)
1373 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1375 kx_msg.sender_status = htonl (t->estate);
1376 kx_msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1377 kx_msg.nonce = t->kx_ctx->challenge;
1378 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce c %u\n", kx_msg.nonce);
1379 t_encrypt (t, &kx_msg.nonce, &kx_msg.nonce,
1380 ping_encryption_size(), kx_msg.iv, GNUNET_YES);
1381 LOG (GNUNET_ERROR_TYPE_DEBUG, " send nonce e %u\n", kx_msg.nonce);
1382 send_kx (t, &kx_msg.header);
1387 * Send a pong message on a tunnel.
1389 * @param t Tunnel on which to send the pong.
1390 * @param challenge Value sent in the ping that we have to send back.
1393 send_pong (struct CadetTunnel *t, uint32_t challenge)
1395 struct GNUNET_CADET_KX_Pong msg;
1397 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1398 msg.header.size = htons (sizeof (msg));
1399 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1400 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1401 msg.nonce = challenge;
1402 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1403 t_encrypt (t, &msg.nonce, &msg.nonce,
1404 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1405 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1407 send_kx (t, &msg.header);
1412 * Initiate a rekey with the remote peer.
1414 * @param cls Closure (tunnel).
1415 * @param tc TaskContext.
1418 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1420 struct CadetTunnel *t = cls;
1422 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1424 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1425 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1428 GNUNET_assert (NULL != t->kx_ctx);
1429 struct GNUNET_TIME_Relative duration;
1431 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1432 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1433 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1435 // FIXME make duration of old keys configurable
1436 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1438 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
1439 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1440 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1447 case CADET_TUNNEL_KEY_UNINITIALIZED:
1448 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
1451 case CADET_TUNNEL_KEY_SENT:
1454 case CADET_TUNNEL_KEY_OK:
1456 * - state should have changed during rekey_iterator
1457 * - task should have been canceled at pong_handle
1460 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1463 case CADET_TUNNEL_KEY_PING:
1464 case CADET_TUNNEL_KEY_REKEY:
1468 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1471 // FIXME exponential backoff
1472 struct GNUNET_TIME_Relative delay;
1474 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1475 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1476 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1477 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1478 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1483 * Our ephemeral key has changed, create new session key on all tunnels.
1485 * Each tunnel will start the Key Exchange with a random delay between
1486 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1487 * per second, on average.
1489 * @param cls Closure (size of the hashmap).
1490 * @param key Current public key.
1491 * @param value Value in the hash map (tunnel).
1493 * @return #GNUNET_YES, so we should continue to iterate,
1496 rekey_iterator (void *cls,
1497 const struct GNUNET_PeerIdentity *key,
1500 struct CadetTunnel *t = value;
1501 struct GNUNET_TIME_Relative delay;
1502 long n = (long) cls;
1505 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1508 if (GNUNET_YES == GCT_is_loopback (t))
1511 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1512 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1513 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1515 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1522 * Create a new ephemeral key and key message, schedule next rekeying.
1524 * @param cls Closure (unused).
1525 * @param tc TaskContext.
1528 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1530 struct GNUNET_TIME_Absolute time;
1533 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1535 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1538 GNUNET_free_non_null (my_ephemeral_key);
1539 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1541 time = GNUNET_TIME_absolute_get ();
1542 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1543 time = GNUNET_TIME_absolute_add (time, rekey_period);
1544 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1545 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1546 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1547 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL RE-KEY, NEW EPHM: %s\n",
1548 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1550 GNUNET_assert (GNUNET_OK ==
1551 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1553 &kx_msg.signature));
1555 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1556 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1558 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1563 * Called only on shutdown, destroy every tunnel.
1565 * @param cls Closure (unused).
1566 * @param key Current public key.
1567 * @param value Value in the hash map (tunnel).
1569 * @return #GNUNET_YES, so we should continue to iterate,
1572 destroy_iterator (void *cls,
1573 const struct GNUNET_PeerIdentity *key,
1576 struct CadetTunnel *t = value;
1578 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1585 * Notify remote peer that we don't know a channel he is talking about,
1586 * probably CHANNEL_DESTROY was missed.
1588 * @param t Tunnel on which to notify.
1589 * @param gid ID of the channel.
1592 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1594 struct GNUNET_CADET_ChannelManage msg;
1596 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1597 msg.header.size = htons (sizeof (msg));
1598 msg.chid = htonl (gid);
1600 LOG (GNUNET_ERROR_TYPE_DEBUG,
1601 "WARNING destroying unknown channel %u on tunnel %s\n",
1603 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1608 * Demultiplex data per channel and call appropriate channel handler.
1610 * @param t Tunnel on which the data came.
1611 * @param msg Data message.
1612 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1613 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1614 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1615 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1618 handle_data (struct CadetTunnel *t,
1619 const struct GNUNET_CADET_Data *msg,
1622 struct CadetChannel *ch;
1626 size = ntohs (msg->header.size);
1628 sizeof (struct GNUNET_CADET_Data) +
1629 sizeof (struct GNUNET_MessageHeader))
1634 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1635 GC_m2s (ntohs (msg[1].header.type)));
1638 ch = GCT_get_channel (t, ntohl (msg->chid));
1641 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1643 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1645 send_channel_destroy (t, ntohl (msg->chid));
1649 GCCH_handle_data (ch, msg, fwd);
1654 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1656 * @param t Tunnel on which the DATA ACK came.
1657 * @param msg DATA ACK message.
1658 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1659 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1660 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1661 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1664 handle_data_ack (struct CadetTunnel *t,
1665 const struct GNUNET_CADET_DataACK *msg,
1668 struct CadetChannel *ch;
1672 size = ntohs (msg->header.size);
1673 if (size != sizeof (struct GNUNET_CADET_DataACK))
1680 ch = GCT_get_channel (t, ntohl (msg->chid));
1683 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1685 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1690 GCCH_handle_data_ack (ch, msg, fwd);
1695 * Handle channel create.
1697 * @param t Tunnel on which the data came.
1698 * @param msg Data message.
1701 handle_ch_create (struct CadetTunnel *t,
1702 const struct GNUNET_CADET_ChannelCreate *msg)
1704 struct CadetChannel *ch;
1708 size = ntohs (msg->header.size);
1709 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1716 ch = GCT_get_channel (t, ntohl (msg->chid));
1717 if (NULL != ch && ! GCT_is_loopback (t))
1719 /* Probably a retransmission, safe to ignore */
1720 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1722 ch = GCCH_handle_create (t, msg);
1724 GCT_add_channel (t, ch);
1730 * Handle channel NACK: check correctness and call channel handler for NACKs.
1732 * @param t Tunnel on which the NACK came.
1733 * @param msg NACK message.
1736 handle_ch_nack (struct CadetTunnel *t,
1737 const struct GNUNET_CADET_ChannelManage *msg)
1739 struct CadetChannel *ch;
1743 size = ntohs (msg->header.size);
1744 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1751 ch = GCT_get_channel (t, ntohl (msg->chid));
1754 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1756 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1761 GCCH_handle_nack (ch);
1766 * Handle a CHANNEL ACK (SYNACK/ACK).
1768 * @param t Tunnel on which the CHANNEL ACK came.
1769 * @param msg CHANNEL ACK message.
1770 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1771 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1772 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1773 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1776 handle_ch_ack (struct CadetTunnel *t,
1777 const struct GNUNET_CADET_ChannelManage *msg,
1780 struct CadetChannel *ch;
1784 size = ntohs (msg->header.size);
1785 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1792 ch = GCT_get_channel (t, ntohl (msg->chid));
1795 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1797 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1802 GCCH_handle_ack (ch, msg, fwd);
1807 * Handle a channel destruction message.
1809 * @param t Tunnel on which the message came.
1810 * @param msg Channel destroy message.
1811 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1812 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1813 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1814 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1817 handle_ch_destroy (struct CadetTunnel *t,
1818 const struct GNUNET_CADET_ChannelManage *msg,
1821 struct CadetChannel *ch;
1825 size = ntohs (msg->header.size);
1826 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1833 ch = GCT_get_channel (t, ntohl (msg->chid));
1836 /* Probably a retransmission, safe to ignore */
1840 GCCH_handle_destroy (ch, msg, fwd);
1845 * The peer's ephemeral key has changed: update the symmetrical keys.
1847 * @param t Tunnel this message came on.
1848 * @param msg Key eXchange message.
1851 handle_ephemeral (struct CadetTunnel *t,
1852 const struct GNUNET_CADET_KX_Ephemeral *msg)
1854 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
1856 if (GNUNET_OK != check_ephemeral (t, msg))
1858 GNUNET_break_op (0);
1863 * If the key is different from what we know, derive the new E/D keys.
1864 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
1866 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
1867 sizeof (msg->ephemeral_key)))
1869 #if DUMP_KEYS_TO_STDERR
1870 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
1871 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1872 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
1873 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
1875 t->peers_ephemeral_key = msg->ephemeral_key;
1879 if (CADET_TUNNEL_KEY_OK == t->estate)
1881 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1883 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1884 GNUNET_SCHEDULER_cancel (t->rekey_task);
1885 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
1887 if (CADET_TUNNEL_KEY_SENT == t->estate)
1889 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending challenge\n");
1891 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
1894 if (CADET_TUNNEL_KEY_UNINITIALIZED != ntohl(msg->sender_status))
1898 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce e %u\n", msg->nonce);
1899 t_decrypt (t, &nonce, &msg->nonce, ping_encryption_size (), msg->iv);
1900 LOG (GNUNET_ERROR_TYPE_DEBUG, " recv nonce c %u\n", nonce);
1901 send_pong (t, nonce);
1907 * Peer has answer to our challenge.
1908 * If answer is successful, consider the key exchange finished and clean
1909 * up all related state.
1911 * @param t Tunnel this message came on.
1912 * @param msg Key eXchange Pong message.
1915 handle_pong (struct CadetTunnel *t,
1916 const struct GNUNET_CADET_KX_Pong *msg)
1920 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
1921 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1923 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1926 if (NULL == t->kx_ctx)
1928 GNUNET_STATISTICS_update (stats, "# stray PONG messages", 1, GNUNET_NO);
1932 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1933 if (challenge != t->kx_ctx->challenge)
1935 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
1936 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1937 challenge, msg->nonce, t->kx_ctx->challenge);
1941 GNUNET_SCHEDULER_cancel (t->rekey_task);
1942 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1944 /* Don't free the old keys right away, but after a delay.
1945 * Rationale: the KX could have happened over a very fast connection,
1946 * with payload traffic still signed with the old key stuck in a slower
1948 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
1952 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
1957 * Demultiplex by message type and call appropriate handler for a message
1958 * towards a channel of a local tunnel.
1960 * @param t Tunnel this message came on.
1961 * @param msgh Message header.
1962 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1963 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1964 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1965 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1968 handle_decrypted (struct CadetTunnel *t,
1969 const struct GNUNET_MessageHeader *msgh,
1974 type = ntohs (msgh->type);
1975 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
1979 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1980 /* Do nothing, connection aleady got updated. */
1981 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
1984 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1985 /* Don't send hop ACK, wait for client to ACK */
1986 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
1989 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1990 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1993 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1994 handle_ch_create (t,
1995 (struct GNUNET_CADET_ChannelCreate *) msgh);
1998 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2000 (struct GNUNET_CADET_ChannelManage *) msgh);
2003 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2005 (struct GNUNET_CADET_ChannelManage *) msgh,
2009 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2010 handle_ch_destroy (t,
2011 (struct GNUNET_CADET_ChannelManage *) msgh,
2016 GNUNET_break_op (0);
2017 LOG (GNUNET_ERROR_TYPE_WARNING,
2018 "end-to-end message not known (%u)\n",
2019 ntohs (msgh->type));
2020 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2024 /******************************************************************************/
2025 /******************************** API ***********************************/
2026 /******************************************************************************/
2029 * Decrypt and demultiplex by message type. Call appropriate handler
2030 * for every message.
2032 * @param t Tunnel this message came on.
2033 * @param msg Encrypted message.
2036 GCT_handle_encrypted (struct CadetTunnel *t,
2037 const struct GNUNET_CADET_Encrypted *msg)
2039 size_t size = ntohs (msg->header.size);
2040 size_t payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2042 char cbuf [payload_size];
2043 struct GNUNET_MessageHeader *msgh;
2046 decrypted_size = t_decrypt_and_validate (t, cbuf, &msg[1], payload_size,
2047 msg->iv, &msg->hmac);
2049 if (-1 == decrypted_size)
2051 GNUNET_break_op (0);
2056 while (off < decrypted_size)
2060 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2061 msize = ntohs (msgh->size);
2062 if (msize < sizeof (struct GNUNET_MessageHeader))
2064 GNUNET_break_op (0);
2067 handle_decrypted (t, msgh, GNUNET_SYSERR);
2074 * Demultiplex an encapsulated KX message by message type.
2076 * @param t Tunnel on which the message came.
2077 * @param message Payload of KX message.
2080 GCT_handle_kx (struct CadetTunnel *t,
2081 const struct GNUNET_MessageHeader *message)
2085 type = ntohs (message->type);
2086 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
2089 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2090 handle_ephemeral (t, (struct GNUNET_CADET_KX_Ephemeral *) message);
2093 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2094 handle_pong (t, (struct GNUNET_CADET_KX_Pong *) message);
2098 GNUNET_break_op (0);
2099 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
2105 * Initialize the tunnel subsystem.
2107 * @param c Configuration handle.
2108 * @param key ECC private key, to derive all other keys and do crypto.
2111 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2112 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2114 int expected_overhead;
2116 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2119 sizeof (struct GNUNET_CADET_Encrypted) + sizeof (struct GNUNET_CADET_Data);
2120 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
2123 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2126 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2127 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2131 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2134 rekey_period = GNUNET_TIME_UNIT_DAYS;
2137 my_private_key = key;
2138 kx_msg.header.size = htons (sizeof (kx_msg));
2139 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2140 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2141 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2142 kx_msg.origin_identity = my_full_id;
2143 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
2145 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2150 * Shut down the tunnel subsystem.
2155 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
2157 GNUNET_SCHEDULER_cancel (rekey_task);
2158 rekey_task = GNUNET_SCHEDULER_NO_TASK;
2160 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2161 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2168 * @param destination Peer this tunnel is towards.
2170 struct CadetTunnel *
2171 GCT_new (struct CadetPeer *destination)
2173 struct CadetTunnel *t;
2175 t = GNUNET_new (struct CadetTunnel);
2177 t->peer = destination;
2180 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2181 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2192 * Change the tunnel's connection state.
2194 * @param t Tunnel whose connection state to change.
2195 * @param cstate New connection state.
2198 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2202 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2203 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2204 if (myid != GCP_get_short_id (t->peer) &&
2205 CADET_TUNNEL_READY != t->cstate &&
2206 CADET_TUNNEL_READY == cstate)
2209 if (CADET_TUNNEL_KEY_OK == t->estate)
2211 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2212 send_queued_data (t);
2214 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2216 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2217 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2218 GNUNET_SCHEDULER_cancel (t->rekey_task);
2220 rekey_tunnel (t, NULL);
2225 if (CADET_TUNNEL_READY == cstate
2226 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2228 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2229 GCP_stop_search (t->peer);
2235 * Change the tunnel encryption state.
2237 * @param t Tunnel whose encryption state to change, or NULL.
2238 * @param state New encryption state.
2241 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2243 enum CadetTunnelEState old;
2250 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
2251 GCP_2s (t->peer), estate2s (old));
2252 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
2253 GCP_2s (t->peer), estate2s (t->estate));
2255 /* Send queued data if enc state changes to OK */
2256 if (myid != GCP_get_short_id (t->peer) &&
2257 CADET_TUNNEL_KEY_OK != old && CADET_TUNNEL_KEY_OK == t->estate)
2259 send_queued_data (t);
2265 * @brief Check if tunnel has too many connections, and remove one if necessary.
2267 * Currently this means the newest connection, unless it is a direct one.
2268 * Implemented as a task to avoid freeing a connection that is in the middle
2269 * of being created/processed.
2271 * @param cls Closure (Tunnel to check).
2272 * @param tc Task context.
2275 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2277 struct CadetTunnel *t = cls;
2279 t->trim_connections_task = GNUNET_SCHEDULER_NO_TASK;
2281 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2284 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2286 struct CadetTConnection *iter;
2287 struct CadetTConnection *c;
2289 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2291 if ((iter->created.abs_value_us > c->created.abs_value_us)
2292 && GNUNET_NO == GCC_is_direct (iter->c))
2299 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2301 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2314 * Add a connection to a tunnel.
2317 * @param c Connection.
2320 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2322 struct CadetTConnection *aux;
2324 GNUNET_assert (NULL != c);
2326 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2327 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2328 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2332 aux = GNUNET_new (struct CadetTConnection);
2334 aux->created = GNUNET_TIME_absolute_get ();
2336 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2338 if (CADET_TUNNEL_SEARCHING == t->cstate)
2339 GCT_change_estate (t, CADET_TUNNEL_WAITING);
2341 if (GNUNET_SCHEDULER_NO_TASK != t->trim_connections_task)
2342 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2347 * Remove a connection from a tunnel.
2350 * @param c Connection.
2353 GCT_remove_connection (struct CadetTunnel *t,
2354 struct CadetConnection *c)
2356 struct CadetTConnection *aux;
2357 struct CadetTConnection *next;
2360 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2361 GCC_2s (c), GCT_2s (t));
2362 for (aux = t->connection_head; aux != NULL; aux = next)
2367 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2372 conns = GCT_count_connections (t);
2374 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2375 && CADET_TUNNEL_SHUTDOWN != t->cstate
2376 && GNUNET_NO == shutting_down)
2378 if (0 == GCT_count_any_connections (t))
2379 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2381 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2384 /* Start new connections if needed */
2385 if (CONNECTIONS_PER_TUNNEL > conns
2386 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2387 && CADET_TUNNEL_SHUTDOWN != t->cstate
2388 && GNUNET_NO == shutting_down)
2390 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2391 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
2395 /* If not marked as ready, no change is needed */
2396 if (CADET_TUNNEL_READY != t->cstate)
2399 /* Check if any connection is ready to maintain cstate */
2400 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2401 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2407 * Add a channel to a tunnel.
2410 * @param ch Channel.
2413 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2415 struct CadetTChannel *aux;
2417 GNUNET_assert (NULL != ch);
2419 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2421 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2423 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2428 aux = GNUNET_new (struct CadetTChannel);
2430 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2431 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2433 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2435 GNUNET_SCHEDULER_cancel (t->destroy_task);
2436 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2437 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2443 * Remove a channel from a tunnel.
2446 * @param ch Channel.
2449 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2451 struct CadetTChannel *aux;
2453 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2454 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2458 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2459 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2468 * Search for a channel by global ID.
2470 * @param t Tunnel containing the channel.
2471 * @param chid Public channel number.
2473 * @return channel handler, NULL if doesn't exist
2475 struct CadetChannel *
2476 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2478 struct CadetTChannel *iter;
2483 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2485 if (GCCH_get_id (iter->ch) == chid)
2489 return NULL == iter ? NULL : iter->ch;
2494 * @brief Destroy a tunnel and free all resources.
2496 * Should only be called a while after the tunnel has been marked as destroyed,
2497 * in case there is a new channel added to the same peer shortly after marking
2498 * the tunnel. This way we avoid a new public key handshake.
2500 * @param cls Closure (tunnel to destroy).
2501 * @param tc Task context.
2504 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2506 struct CadetTunnel *t = cls;
2507 struct CadetTConnection *iter;
2509 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2510 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2512 LOG (GNUNET_ERROR_TYPE_WARNING,
2513 "Not destroying tunnel, due to shutdown. "
2514 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2517 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2518 t->cstate = CADET_TUNNEL_SHUTDOWN;
2520 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2522 GCC_send_destroy (iter->c);
2529 * Tunnel is empty: destroy it.
2531 * Notifies all connections about the destruction.
2533 * @param t Tunnel to destroy.
2536 GCT_destroy_empty (struct CadetTunnel *t)
2538 if (GNUNET_YES == shutting_down)
2539 return; /* Will be destroyed immediately anyway */
2541 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2543 LOG (GNUNET_ERROR_TYPE_WARNING,
2544 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
2546 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2548 /* should never happen, tunnel can only become empty once, and the
2549 * task identifier should be NO_TASK (cleaned when the tunnel was created
2550 * or became un-empty)
2555 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2558 // FIXME make delay a config option
2559 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2560 &delayed_destroy, t);
2561 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llX\n",
2562 t, t->destroy_task);
2567 * Destroy tunnel if empty (no more channels).
2569 * @param t Tunnel to destroy if empty.
2572 GCT_destroy_if_empty (struct CadetTunnel *t)
2574 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2575 if (1 < GCT_count_channels (t))
2578 GCT_destroy_empty (t);
2583 * Destroy the tunnel.
2585 * This function does not generate any warning traffic to clients or peers.
2588 * Cancel messages belonging to this tunnel queued to neighbors.
2589 * Free any allocated resources linked to the tunnel.
2591 * @param t The tunnel to destroy.
2594 GCT_destroy (struct CadetTunnel *t)
2596 struct CadetTConnection *iter_c;
2597 struct CadetTConnection *next_c;
2598 struct CadetTChannel *iter_ch;
2599 struct CadetTChannel *next_ch;
2604 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
2606 GNUNET_break (GNUNET_YES ==
2607 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2608 GCP_get_id (t->peer), t));
2610 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2612 next_c = iter_c->next;
2613 GCC_destroy (iter_c->c);
2615 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2617 next_ch = iter_ch->next;
2618 GCCH_destroy (iter_ch->ch);
2619 /* Should only happen on shutdown, but it's ok. */
2622 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2624 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
2625 GNUNET_SCHEDULER_cancel (t->destroy_task);
2626 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2629 if (GNUNET_SCHEDULER_NO_TASK != t->trim_connections_task)
2631 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
2632 t->trim_connections_task);
2633 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
2634 t->trim_connections_task = GNUNET_SCHEDULER_NO_TASK;
2637 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2638 GCP_set_tunnel (t->peer, NULL);
2640 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2642 GNUNET_SCHEDULER_cancel (t->rekey_task);
2643 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2645 if (NULL != t->kx_ctx)
2647 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
2648 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
2649 GNUNET_free (t->kx_ctx);
2656 * @brief Use the given path for the tunnel.
2657 * Update the next and prev hops (and RCs).
2658 * (Re)start the path refresh in case the tunnel is locally owned.
2660 * @param t Tunnel to update.
2661 * @param p Path to use.
2663 * @return Connection created.
2665 struct CadetConnection *
2666 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
2668 struct CadetConnection *c;
2669 struct GNUNET_CADET_Hash cid;
2670 unsigned int own_pos;
2672 if (NULL == t || NULL == p)
2678 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
2684 for (own_pos = 0; own_pos < p->length; own_pos++)
2686 if (p->peers[own_pos] == myid)
2689 if (own_pos >= p->length)
2691 GNUNET_break_op (0);
2695 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2696 c = GCC_new (&cid, t, p, own_pos);
2699 /* Path was flawed */
2702 GCT_add_connection (t, c);
2708 * Count all created connections of a tunnel. Not necessarily ready connections!
2710 * @param t Tunnel on which to count.
2712 * @return Number of connections created, either being established or ready.
2715 GCT_count_any_connections (struct CadetTunnel *t)
2717 struct CadetTConnection *iter;
2723 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2731 * Count established (ready) connections of a tunnel.
2733 * @param t Tunnel on which to count.
2735 * @return Number of connections.
2738 GCT_count_connections (struct CadetTunnel *t)
2740 struct CadetTConnection *iter;
2746 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2747 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
2755 * Count channels of a tunnel.
2757 * @param t Tunnel on which to count.
2759 * @return Number of channels.
2762 GCT_count_channels (struct CadetTunnel *t)
2764 struct CadetTChannel *iter;
2767 for (count = 0, iter = t->channel_head;
2769 iter = iter->next, count++) /* skip */;
2776 * Get the connectivity state of a tunnel.
2780 * @return Tunnel's connectivity state.
2782 enum CadetTunnelCState
2783 GCT_get_cstate (struct CadetTunnel *t)
2788 return (enum CadetTunnelCState) -1;
2795 * Get the encryption state of a tunnel.
2799 * @return Tunnel's encryption state.
2801 enum CadetTunnelEState
2802 GCT_get_estate (struct CadetTunnel *t)
2807 return (enum CadetTunnelEState) -1;
2813 * Get the maximum buffer space for a tunnel towards a local client.
2817 * @return Biggest buffer space offered by any channel in the tunnel.
2820 GCT_get_channels_buffer (struct CadetTunnel *t)
2822 struct CadetTChannel *iter;
2823 unsigned int buffer;
2824 unsigned int ch_buf;
2826 if (NULL == t->channel_head)
2828 /* Probably getting buffer for a channel create/handshake. */
2829 LOG (GNUNET_ERROR_TYPE_DEBUG, " no channels, allow max\n");
2834 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2836 ch_buf = get_channel_buffer (iter);
2837 if (ch_buf > buffer)
2845 * Get the total buffer space for a tunnel for P2P traffic.
2849 * @return Buffer space offered by all connections in the tunnel.
2852 GCT_get_connections_buffer (struct CadetTunnel *t)
2854 struct CadetTConnection *iter;
2855 unsigned int buffer;
2857 if (GNUNET_NO == is_ready (t))
2859 if (count_queued_data (t) > 3)
2866 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2868 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2872 buffer += get_connection_buffer (iter);
2880 * Get the tunnel's destination.
2884 * @return ID of the destination peer.
2886 const struct GNUNET_PeerIdentity *
2887 GCT_get_destination (struct CadetTunnel *t)
2889 return GCP_get_id (t->peer);
2894 * Get the tunnel's next free global channel ID.
2898 * @return GID of a channel free to use.
2901 GCT_get_next_chid (struct CadetTunnel *t)
2903 CADET_ChannelNumber chid;
2904 CADET_ChannelNumber mask;
2907 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2908 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2909 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2911 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2916 t->next_chid |= mask;
2918 while (NULL != GCT_get_channel (t, t->next_chid))
2920 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2921 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2922 t->next_chid |= mask;
2924 chid = t->next_chid;
2925 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2926 t->next_chid |= mask;
2933 * Send ACK on one or more channels due to buffer in connections.
2935 * @param t Channel which has some free buffer space.
2938 GCT_unchoke_channels (struct CadetTunnel *t)
2940 struct CadetTChannel *iter;
2941 unsigned int buffer;
2942 unsigned int channels = GCT_count_channels (t);
2943 unsigned int choked_n;
2944 struct CadetChannel *choked[channels];
2946 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
2947 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2948 if (NULL != t->channel_head)
2949 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2951 /* Get buffer space */
2952 buffer = GCT_get_connections_buffer (t);
2958 /* Count and remember choked channels */
2960 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2962 if (GNUNET_NO == get_channel_allowed (iter))
2964 choked[choked_n++] = iter->ch;
2968 /* Unchoke random channels */
2969 while (0 < buffer && 0 < choked_n)
2971 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
2973 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
2976 choked[r] = choked[choked_n];
2982 * Send ACK on one or more connections due to buffer space to the client.
2984 * Iterates all connections of the tunnel and sends ACKs appropriately.
2989 GCT_send_connection_acks (struct CadetTunnel *t)
2991 struct CadetTConnection *iter;
2994 uint32_t allow_per_connection;
2996 unsigned int buffer;
2998 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3007 if (CADET_TUNNEL_READY != t->cstate)
3010 buffer = GCT_get_channels_buffer (t);
3011 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3013 /* Count connections, how many messages are already allowed */
3014 cs = GCT_count_connections (t);
3015 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3017 allowed += get_connection_allowed (iter);
3019 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3021 /* Make sure there is no overflow */
3022 if (allowed > buffer)
3025 /* Authorize connections to send more data */
3026 to_allow = buffer - allowed;
3028 for (iter = t->connection_head;
3029 NULL != iter && to_allow > 0;
3032 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
3033 || get_connection_allowed (iter) > 64 / 3)
3037 allow_per_connection = to_allow/cs;
3038 to_allow -= allow_per_connection;
3040 GCC_allow (iter->c, allow_per_connection,
3041 GCC_is_origin (iter->c, GNUNET_NO));
3046 /* Since we don't allow if it's allowed to send 64/3, this can happen. */
3047 LOG (GNUNET_ERROR_TYPE_DEBUG, " reminding to_allow: %u\n", to_allow);
3053 * Cancel a previously sent message while it's in the queue.
3055 * ONLY can be called before the continuation given to the send function
3056 * is called. Once the continuation is called, the message is no longer in the
3059 * @param q Handle to the queue.
3062 GCT_cancel (struct CadetTunnelQueue *q)
3067 /* tun_message_sent() will be called and free q */
3069 else if (NULL != q->tqd)
3071 unqueue_data (q->tqd);
3073 if (NULL != q->cont)
3074 q->cont (q->cont_cls, NULL, q, 0, 0);
3085 * Sends an already built message on a tunnel, encrypting it and
3086 * choosing the best connection if not provided.
3088 * @param message Message to send. Function modifies it.
3089 * @param t Tunnel on which this message is transmitted.
3090 * @param c Connection to use (autoselect if NULL).
3091 * @param force Force the tunnel to take the message (buffer overfill).
3092 * @param cont Continuation to call once message is really sent.
3093 * @param cont_cls Closure for @c cont.
3095 * @return Handle to cancel message. NULL if @c cont is NULL.
3097 struct CadetTunnelQueue *
3098 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3099 struct CadetTunnel *t, struct CadetConnection *c,
3100 int force, GCT_sent cont, void *cont_cls)
3102 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3106 * Sends an already built and encrypted message on a tunnel, choosing the best
3107 * connection. Useful for re-queueing messages queued on a destroyed connection.
3109 * @param message Message to send. Function modifies it.
3110 * @param t Tunnel on which this message is transmitted.
3113 GCT_resend_message (const struct GNUNET_MessageHeader *message,
3114 struct CadetTunnel *t)
3116 struct CadetConnection *c;
3119 c = tunnel_get_connection (t);
3122 /* TODO queue in tunnel, marked as encrypted */
3123 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
3126 fwd = GCC_is_origin (c, GNUNET_YES);
3127 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
3128 GNUNET_YES, NULL, NULL));
3133 * Is the tunnel directed towards the local peer?
3137 * @return #GNUNET_YES if it is loopback.
3140 GCT_is_loopback (const struct CadetTunnel *t)
3142 return (myid == GCP_get_short_id (t->peer));
3147 * Is the tunnel this path already?
3152 * @return #GNUNET_YES a connection uses this path.
3155 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3157 struct CadetTConnection *iter;
3159 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3160 if (path_equivalent (GCC_get_path (iter->c), p))
3168 * Get a cost of a path for a tunnel considering existing connections.
3171 * @param path Candidate path.
3173 * @return Cost of the path (path length + number of overlapping nodes)
3176 GCT_get_path_cost (const struct CadetTunnel *t,
3177 const struct CadetPeerPath *path)
3179 struct CadetTConnection *iter;
3180 const struct CadetPeerPath *aux;
3181 unsigned int overlap;
3189 GNUNET_assert (NULL != t);
3191 for (i = 0; i < path->length; i++)
3193 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3195 aux = GCC_get_path (iter->c);
3199 for (j = 0; j < aux->length; j++)
3201 if (path->peers[i] == aux->peers[j])
3209 return path->length + overlap;
3214 * Get the static string for the peer this tunnel is directed.
3218 * @return Static string the destination peer's ID.
3221 GCT_2s (const struct CadetTunnel *t)
3226 return GCP_2s (t->peer);
3230 /******************************************************************************/
3231 /***************************** INFO/DEBUG *******************************/
3232 /******************************************************************************/
3235 * Log all possible info about the tunnel state.
3237 * @param t Tunnel to debug.
3238 * @param level Debug level to use.
3241 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3243 struct CadetTChannel *iterch;
3244 struct CadetTConnection *iterc;
3247 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3249 __FILE__, __FUNCTION__, __LINE__);
3253 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3254 LOG2 (level, "TTT cstate %s, estate %s\n",
3255 cstate2s (t->cstate), estate2s (t->estate));
3256 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
3257 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
3258 #if DUMP_KEYS_TO_STDERR
3259 LOG2 (level, "TTT my EPHM\t %s\n",
3260 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
3261 LOG2 (level, "TTT peers EPHM:\t %s\n",
3262 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
3263 LOG2 (level, "TTT ENC key:\t %s\n",
3264 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
3265 LOG2 (level, "TTT DEC key:\t %s\n",
3266 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
3269 LOG2 (level, "TTT OLD ENC key:\t %s\n",
3270 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
3271 LOG2 (level, "TTT OLD DEC key:\t %s\n",
3272 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
3275 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3276 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3278 LOG2 (level, "TTT channels:\n");
3279 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3281 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3284 LOG2 (level, "TTT connections:\n");
3285 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3287 GCC_debug (iterc->c, level);
3290 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3295 * Iterate all tunnels.
3297 * @param iter Iterator.
3298 * @param cls Closure for @c iter.
3301 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3303 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3308 * Count all tunnels.
3310 * @return Number of tunnels to remote peers kept by this peer.
3313 GCT_count_all (void)
3315 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3320 * Iterate all connections of a tunnel.
3322 * @param t Tunnel whose connections to iterate.
3323 * @param iter Iterator.
3324 * @param cls Closure for @c iter.
3327 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3329 struct CadetTConnection *ct;
3331 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3337 * Iterate all channels of a tunnel.
3339 * @param t Tunnel whose channels to iterate.
3340 * @param iter Iterator.
3341 * @param cls Closure for @c iter.
3344 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3346 struct CadetTChannel *cht;
3348 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3349 iter (cls, cht->ch);