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 #define CONNECTIONS_PER_TUNNEL 3
42 #if !defined(GNUNET_CULL_LOGGING)
43 #define DUMP_KEYS_TO_STDERR GNUNET_YES
45 #define DUMP_KEYS_TO_STDERR GNUNET_NO
48 /******************************************************************************/
49 /******************************** STRUCTS **********************************/
50 /******************************************************************************/
54 struct CadetTChannel *next;
55 struct CadetTChannel *prev;
56 struct CadetChannel *ch;
61 * Connection list and metadata.
63 struct CadetTConnection
68 struct CadetTConnection *next;
73 struct CadetTConnection *prev;
78 struct CadetConnection *c;
81 * Creation time, to keep oldest connection alive.
83 struct GNUNET_TIME_Absolute created;
86 * Connection throughput, to keep fastest connection alive.
92 * Structure used during a Key eXchange.
94 struct CadetTunnelKXCtx
97 * Encryption ("our") old "confirmed" key, for encrypting traffic sent by us
98 * end before the key exchange is finished or times out.
100 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
103 * Decryption ("their") old "confirmed" key, for decrypting traffic sent by
104 * the other end before the key exchange started.
106 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
109 * Challenge to send in a ping and expect in the pong.
114 * When the rekey started. One minute after this the new key will be used.
116 struct GNUNET_TIME_Absolute rekey_start_time;
119 * Task for delayed destruction of the Key eXchange context, to allow delayed
120 * messages with the old key to be decrypted successfully.
122 GNUNET_SCHEDULER_TaskIdentifier finish_task;
126 * Struct containing all information regarding a tunnel to a peer.
131 * Endpoint of the tunnel.
133 struct CadetPeer *peer;
136 * State of the tunnel connectivity.
138 enum CadetTunnelCState cstate;
141 * State of the tunnel encryption.
143 enum CadetTunnelEState estate;
146 * Key eXchange context.
148 struct CadetTunnelKXCtx *kx_ctx;
151 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
154 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
157 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
159 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
162 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
164 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
167 * Task to start the rekey process.
169 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
172 * Paths that are actively used to reach the destination peer.
174 struct CadetTConnection *connection_head;
175 struct CadetTConnection *connection_tail;
178 * Next connection number.
183 * Channels inside this tunnel.
185 struct CadetTChannel *channel_head;
186 struct CadetTChannel *channel_tail;
189 * Channel ID for the next created channel.
191 CADET_ChannelNumber next_chid;
194 * Destroy flag: if true, destroy on last message.
196 GNUNET_SCHEDULER_TaskIdentifier destroy_task;
199 * Queued messages, to transmit once tunnel gets connected.
201 struct CadetTunnelDelayed *tq_head;
202 struct CadetTunnelDelayed *tq_tail;
205 * Task to trim connections if too many are present.
207 GNUNET_SCHEDULER_TaskIdentifier trim_connections_task;
212 * Struct used to save messages in a non-ready tunnel to send once connected.
214 struct CadetTunnelDelayed
219 struct CadetTunnelDelayed *next;
220 struct CadetTunnelDelayed *prev;
225 struct CadetTunnel *t;
228 * Tunnel queue given to the channel to cancel request. Update on send_queued.
230 struct CadetTunnelQueue *tq;
235 /* struct GNUNET_MessageHeader *msg; */
240 * Handle for messages queued but not yet sent.
242 struct CadetTunnelQueue
245 * Connection queue handle, to cancel if necessary.
247 struct CadetConnectionQueue *cq;
250 * Handle in case message hasn't been given to a connection yet.
252 struct CadetTunnelDelayed *tqd;
255 * Continuation to call once sent.
260 * Closure for @c cont.
266 /******************************************************************************/
267 /******************************* GLOBALS ***********************************/
268 /******************************************************************************/
271 * Global handle to the statistics service.
273 extern struct GNUNET_STATISTICS_Handle *stats;
276 * Local peer own ID (memory efficient handle).
278 extern GNUNET_PEER_Id myid;
281 * Local peer own ID (full value).
283 extern struct GNUNET_PeerIdentity my_full_id;
287 * Don't try to recover tunnels if shutting down.
289 extern int shutting_down;
293 * Set of all tunnels, in order to trigger a new exchange on rekey.
294 * Indexed by peer's ID.
296 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
299 * Default TTL for payload packets.
301 static unsigned long long default_ttl;
306 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
309 * Own ephemeral private key.
311 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
314 * Cached message used to perform a key exchange.
316 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
319 * Task to generate a new ephemeral key.
321 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
326 static struct GNUNET_TIME_Relative rekey_period;
328 /******************************************************************************/
329 /******************************** STATIC ***********************************/
330 /******************************************************************************/
333 * Get string description for tunnel connectivity state.
335 * @param cs Tunnel state.
337 * @return String representation.
340 cstate2s (enum CadetTunnelCState cs)
346 case CADET_TUNNEL_NEW:
347 return "CADET_TUNNEL_NEW";
348 case CADET_TUNNEL_SEARCHING:
349 return "CADET_TUNNEL_SEARCHING";
350 case CADET_TUNNEL_WAITING:
351 return "CADET_TUNNEL_WAITING";
352 case CADET_TUNNEL_READY:
353 return "CADET_TUNNEL_READY";
354 case CADET_TUNNEL_SHUTDOWN:
355 return "CADET_TUNNEL_SHUTDOWN";
357 sprintf (buf, "%u (UNKNOWN STATE)", cs);
365 * Get string description for tunnel encryption state.
367 * @param es Tunnel state.
369 * @return String representation.
372 estate2s (enum CadetTunnelEState es)
378 case CADET_TUNNEL_KEY_UNINITIALIZED:
379 return "CADET_TUNNEL_KEY_UNINITIALIZED";
380 case CADET_TUNNEL_KEY_SENT:
381 return "CADET_TUNNEL_KEY_SENT";
382 case CADET_TUNNEL_KEY_PING:
383 return "CADET_TUNNEL_KEY_PING";
384 case CADET_TUNNEL_KEY_OK:
385 return "CADET_TUNNEL_KEY_OK";
386 case CADET_TUNNEL_KEY_REKEY:
387 return "CADET_TUNNEL_KEY_REKEY";
389 sprintf (buf, "%u (UNKNOWN STATE)", es);
397 * @brief Check if tunnel is ready to send traffic.
399 * Tunnel must be connected and with encryption correctly set up.
401 * @param t Tunnel to check.
403 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
406 is_ready (struct CadetTunnel *t)
410 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
411 ready = CADET_TUNNEL_READY == t->cstate
412 && (CADET_TUNNEL_KEY_OK == t->estate
413 || CADET_TUNNEL_KEY_REKEY == t->estate);
414 ready = ready || GCT_is_loopback (t);
420 * Check if a key is invalid (NULL pointer or all 0)
422 * @param key Key to check.
424 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
427 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
429 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
434 memset (&null_key, 0, sizeof (null_key));
435 if (0 == memcmp (key, &null_key, sizeof (null_key)))
442 * Ephemeral key message purpose size.
444 * @return Size of the part of the ephemeral key message that must be signed.
447 ephemeral_purpose_size (void)
449 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
450 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
451 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
452 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
453 sizeof (struct GNUNET_PeerIdentity);
458 * Size of the encrypted part of a ping message.
460 * @return Size of the encrypted part of a ping message.
463 ping_encryption_size (void)
465 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
470 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
472 * @param tch Tunnel's channel handle.
474 * @return Amount of messages the channel can still buffer towards the client.
477 get_channel_buffer (const struct CadetTChannel *tch)
481 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
482 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
484 return GCCH_get_buffer (tch->ch, fwd);
489 * Get the channel's allowance status.
491 * @param tch Tunnel's channel handle.
493 * @return #GNUNET_YES if we allowed the client to send data to us.
496 get_channel_allowed (const struct CadetTChannel *tch)
500 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
501 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
503 return GCCH_get_allowed (tch->ch, fwd);
508 * Get the connection's buffer.
510 * @param tc Tunnel's connection handle.
512 * @return Amount of messages the connection can still buffer.
515 get_connection_buffer (const struct CadetTConnection *tc)
519 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
520 fwd = GCC_is_origin (tc->c, GNUNET_YES);
522 return GCC_get_buffer (tc->c, fwd);
527 * Get the connection's allowance.
529 * @param tc Tunnel's connection handle.
531 * @return Amount of messages we have allowed the next peer to send us.
534 get_connection_allowed (const struct CadetTConnection *tc)
538 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
539 fwd = GCC_is_origin (tc->c, GNUNET_YES);
541 return GCC_get_allowed (tc->c, fwd);
546 * Check that a ephemeral key message s well formed and correctly signed.
548 * @param t Tunnel on which the message came.
549 * @param msg The ephemeral key message.
551 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
554 check_ephemeral (struct CadetTunnel *t,
555 const struct GNUNET_CADET_KX_Ephemeral *msg)
557 /* Check message size */
558 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
559 return GNUNET_SYSERR;
561 /* Check signature size */
562 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
563 return GNUNET_SYSERR;
566 if (0 != memcmp (&msg->origin_identity,
567 GCP_get_id (t->peer),
568 sizeof (struct GNUNET_PeerIdentity)))
569 return GNUNET_SYSERR;
571 /* Check signature */
573 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
576 &msg->origin_identity.public_key))
577 return GNUNET_SYSERR;
584 * Select the best key to use for encryption (send), based on KX status.
586 * Normally, return the current key. If there is a KX in progress and the old
587 * key is fresh enough, return the old key.
589 * @param t Tunnel to choose the key from.
591 * @return The optimal key to encrypt/hmac outgoing traffic.
593 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
594 select_key (const struct CadetTunnel *t)
596 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
598 if (NULL != t->kx_ctx
599 && GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
601 struct GNUNET_TIME_Relative age;
603 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
604 LOG (GNUNET_ERROR_TYPE_DEBUG,
605 " key exchange in progress, started %s ago\n",
606 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
607 // FIXME make duration of old keys configurable
608 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
610 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
611 key = &t->kx_ctx->e_key_old;
615 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key\n");
621 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
631 * @param plaintext Content to HMAC.
632 * @param size Size of @c plaintext.
633 * @param iv Initialization vector for the message.
634 * @param key Key to use.
635 * @param hmac[out] Destination to store the HMAC.
638 t_hmac (const void *plaintext, size_t size,
639 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
640 struct GNUNET_CADET_Hash *hmac)
642 static const char ctx[] = "cadet authentication key";
643 struct GNUNET_CRYPTO_AuthKey auth_key;
644 struct GNUNET_HashCode hash;
646 #if DUMP_KEYS_TO_STDERR
647 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC with key %s\n",
648 GNUNET_h2s ((struct GNUNET_HashCode *) key));
650 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
655 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
656 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
657 memcpy (hmac, &hash, sizeof (*hmac));
662 * Encrypt daforce_newest_keyta with the tunnel key.
664 * @param t Tunnel whose key to use.
665 * @param dst Destination for the encrypted data.
666 * @param src Source of the plaintext. Can overlap with @c dst.
667 * @param size Size of the plaintext.
668 * @param iv Initialization Vector to use.
669 * @param force_newest_key Force the use of the newest key, otherwise
670 * CADET will use the old key when allowed.
671 * This can happen in the case when a KX is going on
672 * and the old one hasn't expired.
675 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
676 size_t size, uint32_t iv, int force_newest_key)
678 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
679 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
682 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
684 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
685 #if DUMP_KEYS_TO_STDERR
686 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
687 GNUNET_h2s ((struct GNUNET_HashCode *) key));
689 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
690 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
691 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
692 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
699 * Decrypt and verify data with the appropriate tunnel key.
701 * @param key Key to use.
702 * @param dst Destination for the plaintext.
703 * @param src Source of the encrypted data. Can overlap with @c dst.
704 * @param size Size of the encrypted data.
705 * @param iv Initialization Vector to use.
707 * @return Size of the decrypted data, -1 if an error was encountered.
710 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
711 void *dst, const void *src, size_t size, uint32_t iv)
713 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
716 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
717 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
718 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
719 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
720 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
721 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
728 * Decrypt and verify data with the most recent tunnel key.
730 * @param t Tunnel whose key to use.
731 * @param dst Destination for the plaintext.
732 * @param src Source of the encrypted data. Can overlap with @c dst.
733 * @param size Size of the encrypted data.
734 * @param iv Initialization Vector to use.
736 * @return Size of the decrypted data, -1 if an error was encountered.
739 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
740 size_t size, uint32_t iv)
744 #if DUMP_KEYS_TO_STDERR
745 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
746 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
748 if (t->estate == CADET_TUNNEL_KEY_UNINITIALIZED)
750 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
751 LOG (GNUNET_ERROR_TYPE_WARNING,
752 "got data on %s without a valid key\n",
754 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
758 out_size = decrypt (&t->d_key, dst, src, size, iv);
765 * Decrypt and verify data with the appropriate tunnel key and verify that the
766 * data has not been altered since it was sent by the remote peer.
768 * @param t Tunnel whose key to use.
769 * @param dst Destination for the plaintext.
770 * @param src Source of the encrypted data. Can overlap with @c dst.
771 * @param size Size of the encrypted data.
772 * @param iv Initialization Vector to use.
773 * @param msg_hmac HMAC of the message, cannot be NULL.
775 * @return Size of the decrypted data, -1 if an error was encountered.
778 t_decrypt_and_validate (struct CadetTunnel *t,
779 void *dst, const void *src,
780 size_t size, uint32_t iv,
781 const struct GNUNET_CADET_Hash *msg_hmac)
783 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
784 struct GNUNET_CADET_Hash hmac;
787 /* Try primary (newest) key */
789 decrypted_size = decrypt (key, dst, src, size, iv);
790 t_hmac (src, size, iv, key, &hmac);
791 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
792 return decrypted_size;
794 /* If no key exchange is going on, we just failed */
795 if (NULL == t->kx_ctx)
797 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
798 "Failed checksum validation on tunnel %s with no KX\n",
800 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
804 /* Try secondary (from previous KX period) key */
805 key = &t->kx_ctx->d_key_old;
806 decrypted_size = decrypt (key, dst, src, size, iv);
807 t_hmac (src, size, iv, key, &hmac);
808 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
809 return decrypted_size;
811 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
812 "Failed checksum validation on tunnel %s with KX\n",
814 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
820 * Create key material by doing ECDH on the local and remote ephemeral keys.
822 * @param key_material Where to store the key material.
823 * @param ephemeral_key Peer's public ephemeral key.
826 derive_key_material (struct GNUNET_HashCode *key_material,
827 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
830 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
840 * Create a symmetic key from the identities of both ends and the key material
843 * @param key Destination for the generated key.
844 * @param sender ID of the peer that will encrypt with @c key.
845 * @param receiver ID of the peer that will decrypt with @c key.
846 * @param key_material Hash created with ECDH with the ephemeral keys.
849 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
850 const struct GNUNET_PeerIdentity *sender,
851 const struct GNUNET_PeerIdentity *receiver,
852 const struct GNUNET_HashCode *key_material)
854 const char salt[] = "CADET kx salt";
856 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
858 key_material, sizeof (struct GNUNET_HashCode),
859 sender, sizeof (struct GNUNET_PeerIdentity),
860 receiver, sizeof (struct GNUNET_PeerIdentity),
866 * Create a new Key eXchange context for the tunnel.
868 * Initializes the key copies, KX start timestamp and creates a new nonce.
870 * @param t Tunnel for which to create the KX ctx.
873 create_kx_ctx (struct CadetTunnel *t)
875 if (NULL != t->kx_ctx)
877 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
879 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
880 t->kx_ctx->finish_task = GNUNET_SCHEDULER_NO_TASK;
885 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
886 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
887 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
889 t->kx_ctx->d_key_old = t->d_key;
890 t->kx_ctx->e_key_old = t->e_key;
891 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
896 * @brief Finish the Key eXchange and destroy the old keys.
898 * @param cls Closure (Tunnel for which to finish the KX).
899 * @param tc Task context.
902 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
904 struct CadetTunnel *t = cls;
906 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
909 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
911 GNUNET_free (t->kx_ctx);
917 * Destroy a Key eXchange context for the tunnel. This function only schedules
918 * the destruction, the freeing of the memory (and clearing of old key material)
919 * happens after a delay!
921 * @param t Tunnel whose KX ctx to destroy.
924 destroy_kx_ctx (struct CadetTunnel *t)
926 struct GNUNET_TIME_Relative delay;
928 if (NULL == t->kx_ctx || GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
931 if (is_key_null (&t->kx_ctx->e_key_old))
933 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
937 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
938 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
940 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
945 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
947 * @param t Tunnel for which to create the keys.
950 create_keys (struct CadetTunnel *t)
952 struct GNUNET_HashCode km;
954 derive_key_material (&km, &t->peers_ephemeral_key);
955 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
956 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
957 #if DUMP_KEYS_TO_STDERR
958 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
959 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
960 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
961 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
962 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
963 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
964 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
965 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
966 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
972 * Pick a connection on which send the next data message.
974 * @param t Tunnel on which to send the message.
976 * @return The connection on which to send the next message.
978 static struct CadetConnection *
979 tunnel_get_connection (struct CadetTunnel *t)
981 struct CadetTConnection *iter;
982 struct CadetConnection *best;
984 unsigned int lowest_q;
986 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
989 for (iter = t->connection_head; NULL != iter; iter = iter->next)
991 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
992 GCC_2s (iter->c), GCC_get_state (iter->c));
993 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
995 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
996 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1004 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1010 * Callback called when a queued message is sent.
1012 * Calculates the average time and connection packet tracking.
1014 * @param cls Closure (TunnelQueue handle).
1015 * @param c Connection this message was on.
1016 * @param q Connection queue handle (unused).
1017 * @param type Type of message sent.
1018 * @param fwd Was this a FWD going message?
1019 * @param size Size of the message.
1022 tun_message_sent (void *cls,
1023 struct CadetConnection *c,
1024 struct CadetConnectionQueue *q,
1025 uint16_t type, int fwd, size_t size)
1027 struct CadetTunnelQueue *qt = cls;
1028 struct CadetTunnel *t;
1030 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1032 GNUNET_assert (NULL != qt->cont);
1033 t = NULL == c ? NULL : GCC_get_tunnel (c);
1034 qt->cont (qt->cont_cls, t, qt, type, size);
1040 count_queued_data (const struct CadetTunnel *t)
1042 struct CadetTunnelDelayed *iter;
1045 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1052 * Delete a queued message: either was sent or the channel was destroyed
1053 * before the tunnel's key exchange had a chance to finish.
1055 * @param tqd Delayed queue handle.
1058 unqueue_data (struct CadetTunnelDelayed *tqd)
1060 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1066 * Cache a message to be sent once tunnel is online.
1068 * @param t Tunnel to hold the message.
1069 * @param msg Message itself (copy will be made).
1071 static struct CadetTunnelDelayed *
1072 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1074 struct CadetTunnelDelayed *tqd;
1075 uint16_t size = ntohs (msg->size);
1077 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1079 if (GNUNET_YES == is_ready (t))
1085 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1088 memcpy (&tqd[1], msg, size);
1089 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1095 * Sends an already built message on a tunnel, encrypting it and
1096 * choosing the best connection.
1098 * @param message Message to send. Function modifies it.
1099 * @param t Tunnel on which this message is transmitted.
1100 * @param c Connection to use (autoselect if NULL).
1101 * @param force Force the tunnel to take the message (buffer overfill).
1102 * @param cont Continuation to call once message is really sent.
1103 * @param cont_cls Closure for @c cont.
1104 * @param existing_q In case this a transmission of previously queued data,
1105 * this should be TunnelQueue given to the client.
1108 * @return Handle to cancel message.
1109 * NULL if @c cont is NULL or an error happens and message is dropped.
1111 static struct CadetTunnelQueue *
1112 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1113 struct CadetTunnel *t, struct CadetConnection *c,
1114 int force, GCT_sent cont, void *cont_cls,
1115 struct CadetTunnelQueue *existing_q)
1117 struct CadetTunnelQueue *tq;
1118 struct GNUNET_CADET_Encrypted *msg;
1119 size_t size = ntohs (message->size);
1120 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1126 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1128 if (GNUNET_NO == is_ready (t))
1130 struct CadetTunnelDelayed *tqd;
1131 /* A non null existing_q indicates sending of queued data.
1132 * Should only happen after tunnel becomes ready.
1134 GNUNET_assert (NULL == existing_q);
1135 tqd = queue_data (t, message);
1138 tq = GNUNET_new (struct CadetTunnelQueue);
1142 tq->cont_cls = cont_cls;
1146 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1148 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1149 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1150 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1152 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO) == size);
1153 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1154 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1157 c = tunnel_get_connection (t);
1160 /* Why is tunnel 'ready'? Should have been queued! */
1161 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
1164 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1166 return NULL; /* Drop... */
1170 type = ntohs (message->type);
1173 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1174 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1175 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1176 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1178 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1180 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1181 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1182 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1183 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1184 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1185 msg->cid = *GCC_get_id (c);
1186 msg->ttl = htonl (default_ttl);
1190 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1192 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1194 fwd = GCC_is_origin (c, GNUNET_YES);
1198 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1199 fwd, force, NULL, NULL));
1202 if (NULL == existing_q)
1204 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1211 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1212 &tun_message_sent, tq);
1213 GNUNET_assert (NULL != tq->cq);
1215 tq->cont_cls = cont_cls;
1222 * Send all cached messages that we can, tunnel is online.
1224 * @param t Tunnel that holds the messages. Cannot be loopback.
1227 send_queued_data (struct CadetTunnel *t)
1229 struct CadetTunnelDelayed *tqd;
1230 struct CadetTunnelDelayed *next;
1233 LOG (GNUNET_ERROR_TYPE_DEBUG,
1234 "GCT_send_queued_data on tunnel %s\n",
1237 if (GCT_is_loopback (t))
1243 if (GNUNET_NO == is_ready (t))
1245 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1246 estate2s (t->estate), cstate2s (t->cstate));
1250 room = GCT_get_connections_buffer (t);
1251 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1252 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1253 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1255 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1258 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1259 tqd->t, NULL, GNUNET_YES,
1260 NULL != tqd->tq ? tqd->tq->cont : NULL,
1261 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1265 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1270 * Sends key exchange message on a tunnel, choosing the best connection.
1271 * Should not be called on loopback tunnels.
1273 * @param t Tunnel on which this message is transmitted.
1274 * @param message Message to send. Function modifies it.
1277 send_kx (struct CadetTunnel *t,
1278 const struct GNUNET_MessageHeader *message)
1280 struct CadetConnection *c;
1281 struct GNUNET_CADET_KX *msg;
1282 size_t size = ntohs (message->size);
1283 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1287 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1289 /* Avoid loopback. */
1290 if (GCT_is_loopback (t))
1292 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1296 type = ntohs (message->type);
1298 /* Even if tunnel is being destroyed, send anyway.
1299 * Could be a response to a rekey initiated by remote peer,
1300 * who is trying to create a new channel!
1303 /* Must have a connection, or be looking for one. */
1304 if (NULL == t->connection_head)
1306 if (CADET_TUNNEL_SEARCHING != t->cstate)
1308 LOG (GNUNET_ERROR_TYPE_ERROR, "\n\n\n");
1310 LOG (GNUNET_ERROR_TYPE_ERROR, "no connection, sending %s\n", GC_m2s (type));
1311 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1312 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
1313 LOG (GNUNET_ERROR_TYPE_ERROR, "\n\n\n");
1318 msg = (struct GNUNET_CADET_KX *) cbuf;
1319 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1320 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1321 c = tunnel_get_connection (t);
1324 GNUNET_break (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
1325 || CADET_TUNNEL_READY != t->cstate);
1326 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1331 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1332 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1333 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1334 memcpy (&msg[1], message, size);
1337 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1342 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1343 /* TODO save handle and cancel in case of a unneeded retransmission */
1344 GNUNET_assert (NULL == GCC_send_prebuilt_message (&msg->header, type, 0, c,
1351 * Send the ephemeral key on a tunnel.
1353 * @param t Tunnel on which to send the key.
1356 send_ephemeral (struct CadetTunnel *t)
1358 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1360 kx_msg.sender_status = htonl (t->estate);
1361 send_kx (t, &kx_msg.header);
1365 * Send a ping message on a tunnel.
1367 * @param t Tunnel on which to send the ping.
1370 send_ping (struct CadetTunnel *t)
1372 struct GNUNET_CADET_KX_Ping msg;
1374 LOG (GNUNET_ERROR_TYPE_INFO, "===> PING for %s\n", GCT_2s (t));
1375 msg.header.size = htons (sizeof (msg));
1376 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PING);
1377 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1378 msg.target = *GCP_get_id (t->peer);
1379 msg.nonce = t->kx_ctx->challenge;
1381 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1382 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
1383 t_encrypt (t, &msg.target, &msg.target,
1384 ping_encryption_size(), msg.iv, GNUNET_YES);
1385 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1386 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
1388 send_kx (t, &msg.header);
1393 * Send a pong message on a tunnel.
1395 * @param t Tunnel on which to send the pong.
1396 * @param challenge Value sent in the ping that we have to send back.
1399 send_pong (struct CadetTunnel *t, uint32_t challenge)
1401 struct GNUNET_CADET_KX_Pong msg;
1403 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1404 msg.header.size = htons (sizeof (msg));
1405 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1406 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1407 msg.nonce = challenge;
1408 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1409 t_encrypt (t, &msg.nonce, &msg.nonce,
1410 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1411 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1413 send_kx (t, &msg.header);
1418 * Initiate a rekey with the remote peer.
1420 * @param cls Closure (tunnel).
1421 * @param tc TaskContext.
1424 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1426 struct CadetTunnel *t = cls;
1428 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1430 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1431 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1434 if (NULL == t->kx_ctx)
1441 struct GNUNET_TIME_Relative duration;
1443 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
1445 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1446 t->kx_ctx->finish_task = GNUNET_SCHEDULER_NO_TASK;
1449 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1450 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1451 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1453 // FIXME make duration of old keys configurable
1454 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1456 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1457 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1465 case CADET_TUNNEL_KEY_UNINITIALIZED:
1466 t->estate = CADET_TUNNEL_KEY_SENT;
1468 case CADET_TUNNEL_KEY_SENT:
1470 case CADET_TUNNEL_KEY_OK:
1471 t->estate = CADET_TUNNEL_KEY_REKEY;
1473 case CADET_TUNNEL_KEY_PING:
1474 case CADET_TUNNEL_KEY_REKEY:
1478 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1481 // FIXME exponential backoff
1482 struct GNUNET_TIME_Relative delay;
1484 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1485 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1486 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1487 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1488 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1493 * Our ephemeral key has changed, create new session key on all tunnels.
1495 * Each tunnel will start the Key Exchange with a random delay between
1496 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1497 * per second, on average.
1499 * @param cls Closure (size of the hashmap).
1500 * @param key Current public key.
1501 * @param value Value in the hash map (tunnel).
1503 * @return #GNUNET_YES, so we should continue to iterate,
1506 rekey_iterator (void *cls,
1507 const struct GNUNET_PeerIdentity *key,
1510 struct CadetTunnel *t = value;
1511 struct GNUNET_TIME_Relative delay;
1512 long n = (long) cls;
1515 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1518 if (GNUNET_YES == GCT_is_loopback (t))
1521 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1522 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1523 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1530 * Create a new ephemeral key and key message, schedule next rekeying.
1532 * @param cls Closure (unused).
1533 * @param tc TaskContext.
1536 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1538 struct GNUNET_TIME_Absolute time;
1541 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1543 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1546 GNUNET_free_non_null (my_ephemeral_key);
1547 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1549 time = GNUNET_TIME_absolute_get ();
1550 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1551 time = GNUNET_TIME_absolute_add (time, rekey_period);
1552 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1553 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1554 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1556 GNUNET_assert (GNUNET_OK ==
1557 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1559 &kx_msg.signature));
1561 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1562 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1564 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1569 * Called only on shutdown, destroy every tunnel.
1571 * @param cls Closure (unused).
1572 * @param key Current public key.
1573 * @param value Value in the hash map (tunnel).
1575 * @return #GNUNET_YES, so we should continue to iterate,
1578 destroy_iterator (void *cls,
1579 const struct GNUNET_PeerIdentity *key,
1582 struct CadetTunnel *t = value;
1584 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1591 * Notify remote peer that we don't know a channel he is talking about,
1592 * probably CHANNEL_DESTROY was missed.
1594 * @param t Tunnel on which to notify.
1595 * @param gid ID of the channel.
1598 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1600 struct GNUNET_CADET_ChannelManage msg;
1602 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1603 msg.header.size = htons (sizeof (msg));
1604 msg.chid = htonl (gid);
1606 LOG (GNUNET_ERROR_TYPE_DEBUG,
1607 "WARNING destroying unknown channel %u on tunnel %s\n",
1609 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1614 * Demultiplex data per channel and call appropriate channel handler.
1616 * @param t Tunnel on which the data came.
1617 * @param msg Data message.
1618 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1619 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1620 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1621 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1624 handle_data (struct CadetTunnel *t,
1625 const struct GNUNET_CADET_Data *msg,
1628 struct CadetChannel *ch;
1632 size = ntohs (msg->header.size);
1634 sizeof (struct GNUNET_CADET_Data) +
1635 sizeof (struct GNUNET_MessageHeader))
1640 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1641 GC_m2s (ntohs (msg[1].header.type)));
1644 ch = GCT_get_channel (t, ntohl (msg->chid));
1647 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1649 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1651 send_channel_destroy (t, ntohl (msg->chid));
1655 GCCH_handle_data (ch, msg, fwd);
1660 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1662 * @param t Tunnel on which the DATA ACK came.
1663 * @param msg DATA ACK message.
1664 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1665 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1666 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1667 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1670 handle_data_ack (struct CadetTunnel *t,
1671 const struct GNUNET_CADET_DataACK *msg,
1674 struct CadetChannel *ch;
1678 size = ntohs (msg->header.size);
1679 if (size != sizeof (struct GNUNET_CADET_DataACK))
1686 ch = GCT_get_channel (t, ntohl (msg->chid));
1689 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1691 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1696 GCCH_handle_data_ack (ch, msg, fwd);
1701 * Handle channel create.
1703 * @param t Tunnel on which the data came.
1704 * @param msg Data message.
1707 handle_ch_create (struct CadetTunnel *t,
1708 const struct GNUNET_CADET_ChannelCreate *msg)
1710 struct CadetChannel *ch;
1714 size = ntohs (msg->header.size);
1715 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1722 ch = GCT_get_channel (t, ntohl (msg->chid));
1723 if (NULL != ch && ! GCT_is_loopback (t))
1725 /* Probably a retransmission, safe to ignore */
1726 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1728 ch = GCCH_handle_create (t, msg);
1730 GCT_add_channel (t, ch);
1736 * Handle channel NACK: check correctness and call channel handler for NACKs.
1738 * @param t Tunnel on which the NACK came.
1739 * @param msg NACK message.
1742 handle_ch_nack (struct CadetTunnel *t,
1743 const struct GNUNET_CADET_ChannelManage *msg)
1745 struct CadetChannel *ch;
1749 size = ntohs (msg->header.size);
1750 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1757 ch = GCT_get_channel (t, ntohl (msg->chid));
1760 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1762 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1767 GCCH_handle_nack (ch);
1772 * Handle a CHANNEL ACK (SYNACK/ACK).
1774 * @param t Tunnel on which the CHANNEL ACK came.
1775 * @param msg CHANNEL ACK message.
1776 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1777 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1778 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1779 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1782 handle_ch_ack (struct CadetTunnel *t,
1783 const struct GNUNET_CADET_ChannelManage *msg,
1786 struct CadetChannel *ch;
1790 size = ntohs (msg->header.size);
1791 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1798 ch = GCT_get_channel (t, ntohl (msg->chid));
1801 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1803 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1808 GCCH_handle_ack (ch, msg, fwd);
1813 * Handle a channel destruction message.
1815 * @param t Tunnel on which the message came.
1816 * @param msg Channel destroy message.
1817 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1818 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1819 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1820 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1823 handle_ch_destroy (struct CadetTunnel *t,
1824 const struct GNUNET_CADET_ChannelManage *msg,
1827 struct CadetChannel *ch;
1831 size = ntohs (msg->header.size);
1832 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1839 ch = GCT_get_channel (t, ntohl (msg->chid));
1842 /* Probably a retransmission, safe to ignore */
1846 GCCH_handle_destroy (ch, msg, fwd);
1851 * The peer's ephemeral key has changed: update the symmetrical keys.
1853 * @param t Tunnel this message came on.
1854 * @param msg Key eXchange message.
1857 handle_ephemeral (struct CadetTunnel *t,
1858 const struct GNUNET_CADET_KX_Ephemeral *msg)
1860 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
1862 if (GNUNET_OK != check_ephemeral (t, msg))
1864 GNUNET_break_op (0);
1869 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
1870 sizeof (msg->ephemeral_key)))
1872 t->peers_ephemeral_key = msg->ephemeral_key;
1874 if (CADET_TUNNEL_KEY_OK == t->estate)
1876 t->estate = CADET_TUNNEL_KEY_REKEY;
1878 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1879 GNUNET_SCHEDULER_cancel (t->rekey_task);
1880 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
1882 else if (CADET_TUNNEL_KEY_OK == t->estate)
1886 if (CADET_TUNNEL_KEY_SENT == t->estate)
1888 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending ping\n");
1890 t->estate = CADET_TUNNEL_KEY_PING;
1896 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1897 * Answer with by retransmitting the challenge with the "opposite" key.
1899 * @param t Tunnel this message came on.
1900 * @param msg Key eXchange Ping message.
1903 handle_ping (struct CadetTunnel *t,
1904 const struct GNUNET_CADET_KX_Ping *msg)
1906 struct GNUNET_CADET_KX_Ping res;
1908 if (ntohs (msg->header.size) != sizeof (res))
1910 GNUNET_break_op (0);
1914 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PING for %s\n", GCT_2s (t));
1915 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1916 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1918 /* probably peer hasn't got our new EPHM yet and derived the wrong keys */
1919 GNUNET_STATISTICS_update (stats, "# malformed PINGs", 1, GNUNET_NO);
1920 LOG (GNUNET_ERROR_TYPE_INFO, " malformed PING on %s\n", GCT_2s (t));
1921 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1922 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1923 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1924 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1931 send_pong (t, res.nonce);
1936 * Peer has answer to our challenge.
1937 * If answer is successful, consider the key exchange finished and clean
1938 * up all related state.
1940 * @param t Tunnel this message came on.
1941 * @param msg Key eXchange Pong message.
1944 handle_pong (struct CadetTunnel *t,
1945 const struct GNUNET_CADET_KX_Pong *msg)
1949 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
1950 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1952 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1955 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1957 if (challenge != t->kx_ctx->challenge)
1959 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
1960 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1961 challenge, msg->nonce, t->kx_ctx->challenge);
1966 GNUNET_SCHEDULER_cancel (t->rekey_task);
1967 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1969 /* Don't free the old keys right away, but after a delay.
1970 * Rationale: the KX could have happened over a very fast connection,
1971 * with payload traffic still signed with the old key stuck in a slower
1973 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
1977 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
1982 * Demultiplex by message type and call appropriate handler for a message
1983 * towards a channel of a local tunnel.
1985 * @param t Tunnel this message came on.
1986 * @param msgh Message header.
1987 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1988 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1989 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1990 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1993 handle_decrypted (struct CadetTunnel *t,
1994 const struct GNUNET_MessageHeader *msgh,
1999 type = ntohs (msgh->type);
2000 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2004 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2005 /* Do nothing, connection aleady got updated. */
2006 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2009 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2010 /* Don't send hop ACK, wait for client to ACK */
2011 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2014 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2015 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2018 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2019 handle_ch_create (t,
2020 (struct GNUNET_CADET_ChannelCreate *) msgh);
2023 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2025 (struct GNUNET_CADET_ChannelManage *) msgh);
2028 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2030 (struct GNUNET_CADET_ChannelManage *) msgh,
2034 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2035 handle_ch_destroy (t,
2036 (struct GNUNET_CADET_ChannelManage *) msgh,
2041 GNUNET_break_op (0);
2042 LOG (GNUNET_ERROR_TYPE_WARNING,
2043 "end-to-end message not known (%u)\n",
2044 ntohs (msgh->type));
2045 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2049 /******************************************************************************/
2050 /******************************** API ***********************************/
2051 /******************************************************************************/
2054 * Decrypt and demultiplex by message type. Call appropriate handler
2055 * for every message.
2057 * @param t Tunnel this message came on.
2058 * @param msg Encrypted message.
2061 GCT_handle_encrypted (struct CadetTunnel *t,
2062 const struct GNUNET_CADET_Encrypted *msg)
2064 size_t size = ntohs (msg->header.size);
2065 size_t payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2067 char cbuf [payload_size];
2068 struct GNUNET_MessageHeader *msgh;
2071 decrypted_size = t_decrypt_and_validate (t, cbuf, &msg[1], payload_size,
2072 msg->iv, &msg->hmac);
2074 if (-1 == decrypted_size)
2076 GNUNET_break_op (0);
2081 while (off < decrypted_size)
2085 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2086 msize = ntohs (msgh->size);
2087 if (msize < sizeof (struct GNUNET_MessageHeader))
2089 GNUNET_break_op (0);
2092 handle_decrypted (t, msgh, GNUNET_SYSERR);
2099 * Demultiplex an encapsulated KX message by message type.
2101 * @param t Tunnel on which the message came.
2102 * @param message Payload of KX message.
2105 GCT_handle_kx (struct CadetTunnel *t,
2106 const struct GNUNET_MessageHeader *message)
2110 type = ntohs (message->type);
2111 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
2114 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2115 handle_ephemeral (t, (struct GNUNET_CADET_KX_Ephemeral *) message);
2118 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
2119 handle_ping (t, (struct GNUNET_CADET_KX_Ping *) message);
2122 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2123 handle_pong (t, (struct GNUNET_CADET_KX_Pong *) message);
2127 GNUNET_break_op (0);
2128 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
2134 * Initialize the tunnel subsystem.
2136 * @param c Configuration handle.
2137 * @param key ECC private key, to derive all other keys and do crypto.
2140 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2141 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2143 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2145 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2148 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2149 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2153 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2156 rekey_period = GNUNET_TIME_UNIT_DAYS;
2159 my_private_key = key;
2160 kx_msg.header.size = htons (sizeof (kx_msg));
2161 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2162 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2163 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2164 kx_msg.origin_identity = my_full_id;
2165 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
2167 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2172 * Shut down the tunnel subsystem.
2177 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
2179 GNUNET_SCHEDULER_cancel (rekey_task);
2180 rekey_task = GNUNET_SCHEDULER_NO_TASK;
2182 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2183 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2190 * @param destination Peer this tunnel is towards.
2192 struct CadetTunnel *
2193 GCT_new (struct CadetPeer *destination)
2195 struct CadetTunnel *t;
2197 t = GNUNET_new (struct CadetTunnel);
2199 t->peer = destination;
2202 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2203 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2214 * Change the tunnel's connection state.
2216 * @param t Tunnel whose connection state to change.
2217 * @param cstate New connection state.
2220 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2224 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2225 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2226 if (myid != GCP_get_short_id (t->peer) &&
2227 CADET_TUNNEL_READY != t->cstate &&
2228 CADET_TUNNEL_READY == cstate)
2231 if (CADET_TUNNEL_KEY_OK == t->estate)
2233 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2234 send_queued_data (t);
2236 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2238 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2239 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2240 GNUNET_SCHEDULER_cancel (t->rekey_task);
2241 rekey_tunnel (t, NULL);
2246 if (CADET_TUNNEL_READY == cstate
2247 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2249 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2250 GCP_stop_search (t->peer);
2255 * Change the tunnel encryption state.
2257 * @param t Tunnel whose encryption state to change.
2258 * @param state New encryption state.
2261 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2265 LOG (GNUNET_ERROR_TYPE_DEBUG,
2266 "Tunnel %s estate was %s\n",
2267 GCP_2s (t->peer), estate2s (t->estate));
2268 LOG (GNUNET_ERROR_TYPE_DEBUG,
2269 "Tunnel %s estate is now %s\n",
2270 GCP_2s (t->peer), estate2s (state));
2271 if (myid != GCP_get_short_id (t->peer) &&
2272 CADET_TUNNEL_KEY_OK != t->estate && CADET_TUNNEL_KEY_OK == state)
2275 send_queued_data (t);
2283 * @brief Check if tunnel has too many connections, and remove one if necessary.
2285 * Currently this means the newest connection, unless it is a direct one.
2286 * Implemented as a task to avoid freeing a connection that is in the middle
2287 * of being created/processed.
2289 * @param cls Closure (Tunnel to check).
2290 * @param tc Task context.
2293 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2295 struct CadetTunnel *t = cls;
2297 t->trim_connections_task = GNUNET_SCHEDULER_NO_TASK;
2299 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2302 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2304 struct CadetTConnection *iter;
2305 struct CadetTConnection *c;
2307 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2309 if ((NULL == c || iter->created.abs_value_us > c->created.abs_value_us)
2310 && GNUNET_NO == GCC_is_direct (iter->c))
2317 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2319 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2332 * Add a connection to a tunnel.
2335 * @param c Connection.
2338 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2340 struct CadetTConnection *aux;
2342 GNUNET_assert (NULL != c);
2344 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2345 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2346 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2350 aux = GNUNET_new (struct CadetTConnection);
2352 aux->created = GNUNET_TIME_absolute_get ();
2354 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2356 if (GNUNET_SCHEDULER_NO_TASK != t->trim_connections_task)
2357 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2362 * Mark a path as no longer valid for this tunnel: has been tried and failed.
2364 * @param t Tunnel to update.
2365 * @param path Invalid path to remove. Is destroyed after removal.
2368 GCT_remove_path (struct CadetTunnel *t, struct CadetPeerPath *path)
2370 GCP_remove_path (t->peer, path);
2375 * Remove a connection from a tunnel.
2378 * @param c Connection.
2381 GCT_remove_connection (struct CadetTunnel *t,
2382 struct CadetConnection *c)
2384 struct CadetTConnection *aux;
2385 struct CadetTConnection *next;
2388 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2389 GCC_2s (c), GCT_2s (t));
2390 for (aux = t->connection_head; aux != NULL; aux = next)
2395 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2400 conns = GCT_count_connections (t);
2402 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2403 && CADET_TUNNEL_SHUTDOWN != t->cstate
2404 && GNUNET_NO == shutting_down)
2406 if (0 == GCT_count_any_connections (t))
2407 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2409 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2412 /* Start new connections if needed */
2413 if (CONNECTIONS_PER_TUNNEL > conns
2414 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2415 && CADET_TUNNEL_SHUTDOWN != t->cstate
2416 && GNUNET_NO == shutting_down)
2418 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2419 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
2423 /* If not marked as ready, no change is needed */
2424 if (CADET_TUNNEL_READY != t->cstate)
2427 /* Check if any connection is ready to maintain cstate */
2428 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2429 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2435 * Add a channel to a tunnel.
2438 * @param ch Channel.
2441 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2443 struct CadetTChannel *aux;
2445 GNUNET_assert (NULL != ch);
2447 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2449 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2451 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2456 aux = GNUNET_new (struct CadetTChannel);
2458 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2459 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2461 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2463 GNUNET_SCHEDULER_cancel (t->destroy_task);
2464 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2465 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2471 * Remove a channel from a tunnel.
2474 * @param ch Channel.
2477 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2479 struct CadetTChannel *aux;
2481 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2482 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2486 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2487 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2496 * Search for a channel by global ID.
2498 * @param t Tunnel containing the channel.
2499 * @param chid Public channel number.
2501 * @return channel handler, NULL if doesn't exist
2503 struct CadetChannel *
2504 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2506 struct CadetTChannel *iter;
2511 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2513 if (GCCH_get_id (iter->ch) == chid)
2517 return NULL == iter ? NULL : iter->ch;
2522 * @brief Destroy a tunnel and free all resources.
2524 * Should only be called a while after the tunnel has been marked as destroyed,
2525 * in case there is a new channel added to the same peer shortly after marking
2526 * the tunnel. This way we avoid a new public key handshake.
2528 * @param cls Closure (tunnel to destroy).
2529 * @param tc Task context.
2532 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2534 struct CadetTunnel *t = cls;
2535 struct CadetTConnection *iter;
2537 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2538 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2540 LOG (GNUNET_ERROR_TYPE_WARNING,
2541 "Not destroying tunnel, due to shutdown. "
2542 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2545 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2546 t->cstate = CADET_TUNNEL_SHUTDOWN;
2548 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2550 GCC_send_destroy (iter->c);
2557 * Tunnel is empty: destroy it.
2559 * Notifies all connections about the destruction.
2561 * @param t Tunnel to destroy.
2564 GCT_destroy_empty (struct CadetTunnel *t)
2566 if (GNUNET_YES == shutting_down)
2567 return; /* Will be destroyed immediately anyway */
2569 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2571 LOG (GNUNET_ERROR_TYPE_WARNING,
2572 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
2574 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2576 /* should never happen, tunnel can only become empty once, and the
2577 * task identifier should be NO_TASK (cleaned when the tunnel was created
2578 * or became un-empty)
2583 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2586 // FIXME make delay a config option
2587 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2588 &delayed_destroy, t);
2589 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llX\n",
2590 t, t->destroy_task);
2595 * Destroy tunnel if empty (no more channels).
2597 * @param t Tunnel to destroy if empty.
2600 GCT_destroy_if_empty (struct CadetTunnel *t)
2602 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2603 if (1 < GCT_count_channels (t))
2606 GCT_destroy_empty (t);
2611 * Destroy the tunnel.
2613 * This function does not generate any warning traffic to clients or peers.
2616 * Cancel messages belonging to this tunnel queued to neighbors.
2617 * Free any allocated resources linked to the tunnel.
2619 * @param t The tunnel to destroy.
2622 GCT_destroy (struct CadetTunnel *t)
2624 struct CadetTConnection *iter_c;
2625 struct CadetTConnection *next_c;
2626 struct CadetTChannel *iter_ch;
2627 struct CadetTChannel *next_ch;
2632 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
2634 GNUNET_break (GNUNET_YES ==
2635 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2636 GCP_get_id (t->peer), t));
2638 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2640 next_c = iter_c->next;
2641 GCC_destroy (iter_c->c);
2643 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2645 next_ch = iter_ch->next;
2646 GCCH_destroy (iter_ch->ch);
2647 /* Should only happen on shutdown, but it's ok. */
2650 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2652 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
2653 GNUNET_SCHEDULER_cancel (t->destroy_task);
2654 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2657 if (GNUNET_SCHEDULER_NO_TASK != t->trim_connections_task)
2659 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
2660 t->trim_connections_task);
2661 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
2662 t->trim_connections_task = GNUNET_SCHEDULER_NO_TASK;
2665 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2666 GCP_set_tunnel (t->peer, NULL);
2668 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2670 GNUNET_SCHEDULER_cancel (t->rekey_task);
2671 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2673 if (NULL != t->kx_ctx)
2675 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
2676 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
2677 GNUNET_free (t->kx_ctx);
2684 * @brief Use the given path for the tunnel.
2685 * Update the next and prev hops (and RCs).
2686 * (Re)start the path refresh in case the tunnel is locally owned.
2688 * @param t Tunnel to update.
2689 * @param p Path to use.
2691 * @return Connection created.
2693 struct CadetConnection *
2694 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
2696 struct CadetConnection *c;
2697 struct GNUNET_CADET_Hash cid;
2698 unsigned int own_pos;
2700 if (NULL == t || NULL == p)
2706 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
2712 for (own_pos = 0; own_pos < p->length; own_pos++)
2714 if (p->peers[own_pos] == myid)
2717 if (own_pos >= p->length)
2719 GNUNET_break_op (0);
2723 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2724 c = GCC_new (&cid, t, p, own_pos);
2727 /* Path was flawed */
2730 GCT_add_connection (t, c);
2736 * Count all created connections of a tunnel. Not necessarily ready connections!
2738 * @param t Tunnel on which to count.
2740 * @return Number of connections created, either being established or ready.
2743 GCT_count_any_connections (struct CadetTunnel *t)
2745 struct CadetTConnection *iter;
2751 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2759 * Count established (ready) connections of a tunnel.
2761 * @param t Tunnel on which to count.
2763 * @return Number of connections.
2766 GCT_count_connections (struct CadetTunnel *t)
2768 struct CadetTConnection *iter;
2774 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2775 if (CADET_CONNECTION_DESTROYED != GCC_get_state (iter->c))
2783 * Count channels of a tunnel.
2785 * @param t Tunnel on which to count.
2787 * @return Number of channels.
2790 GCT_count_channels (struct CadetTunnel *t)
2792 struct CadetTChannel *iter;
2795 for (count = 0, iter = t->channel_head;
2797 iter = iter->next, count++) /* skip */;
2804 * Get the connectivity state of a tunnel.
2808 * @return Tunnel's connectivity state.
2810 enum CadetTunnelCState
2811 GCT_get_cstate (struct CadetTunnel *t)
2816 return (enum CadetTunnelCState) -1;
2823 * Get the encryption state of a tunnel.
2827 * @return Tunnel's encryption state.
2829 enum CadetTunnelEState
2830 GCT_get_estate (struct CadetTunnel *t)
2835 return (enum CadetTunnelEState) -1;
2841 * Get the maximum buffer space for a tunnel towards a local client.
2845 * @return Biggest buffer space offered by any channel in the tunnel.
2848 GCT_get_channels_buffer (struct CadetTunnel *t)
2850 struct CadetTChannel *iter;
2851 unsigned int buffer;
2852 unsigned int ch_buf;
2854 if (NULL == t->channel_head)
2856 /* Probably getting buffer for a channel create/handshake. */
2861 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2863 ch_buf = get_channel_buffer (iter);
2864 if (ch_buf > buffer)
2872 * Get the total buffer space for a tunnel for P2P traffic.
2876 * @return Buffer space offered by all connections in the tunnel.
2879 GCT_get_connections_buffer (struct CadetTunnel *t)
2881 struct CadetTConnection *iter;
2882 unsigned int buffer;
2884 if (GNUNET_NO == is_ready (t))
2886 if (count_queued_data (t) > 3)
2893 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2895 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2899 buffer += get_connection_buffer (iter);
2907 * Get the tunnel's destination.
2911 * @return ID of the destination peer.
2913 const struct GNUNET_PeerIdentity *
2914 GCT_get_destination (struct CadetTunnel *t)
2916 return GCP_get_id (t->peer);
2921 * Get the tunnel's next free global channel ID.
2925 * @return GID of a channel free to use.
2928 GCT_get_next_chid (struct CadetTunnel *t)
2930 CADET_ChannelNumber chid;
2931 CADET_ChannelNumber mask;
2934 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2935 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2936 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2938 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2943 t->next_chid |= mask;
2945 while (NULL != GCT_get_channel (t, t->next_chid))
2947 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2948 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2949 t->next_chid |= mask;
2951 chid = t->next_chid;
2952 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2953 t->next_chid |= mask;
2960 * Send ACK on one or more channels due to buffer in connections.
2962 * @param t Channel which has some free buffer space.
2965 GCT_unchoke_channels (struct CadetTunnel *t)
2967 struct CadetTChannel *iter;
2968 unsigned int buffer;
2969 unsigned int channels = GCT_count_channels (t);
2970 unsigned int choked_n;
2971 struct CadetChannel *choked[channels];
2973 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
2974 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2975 if (NULL != t->channel_head)
2976 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2978 /* Get buffer space */
2979 buffer = GCT_get_connections_buffer (t);
2985 /* Count and remember choked channels */
2987 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2989 if (GNUNET_NO == get_channel_allowed (iter))
2991 choked[choked_n++] = iter->ch;
2995 /* Unchoke random channels */
2996 while (0 < buffer && 0 < choked_n)
2998 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3000 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3003 choked[r] = choked[choked_n];
3009 * Send ACK on one or more connections due to buffer space to the client.
3011 * Iterates all connections of the tunnel and sends ACKs appropriately.
3016 GCT_send_connection_acks (struct CadetTunnel *t)
3018 struct CadetTConnection *iter;
3021 uint32_t allow_per_connection;
3023 unsigned int buffer;
3025 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3034 buffer = GCT_get_channels_buffer (t);
3035 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3037 /* Count connections, how many messages are already allowed */
3038 cs = GCT_count_connections (t);
3039 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3041 allowed += get_connection_allowed (iter);
3043 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3045 /* Make sure there is no overflow */
3046 if (allowed > buffer)
3051 /* Authorize connections to send more data */
3052 to_allow = buffer; /* - allowed; */
3054 for (iter = t->connection_head;
3055 NULL != iter && to_allow > 0;
3058 allow_per_connection = to_allow/cs;
3059 to_allow -= allow_per_connection;
3061 if (get_connection_allowed (iter) > 64 / 3)
3065 GCC_allow (iter->c, allow_per_connection,
3066 GCC_is_origin (iter->c, GNUNET_NO));
3069 GNUNET_break (to_allow == 0);
3074 * Cancel a previously sent message while it's in the queue.
3076 * ONLY can be called before the continuation given to the send function
3077 * is called. Once the continuation is called, the message is no longer in the
3080 * @param q Handle to the queue.
3083 GCT_cancel (struct CadetTunnelQueue *q)
3088 /* tun_message_sent() will be called and free q */
3090 else if (NULL != q->tqd)
3092 unqueue_data (q->tqd);
3094 if (NULL != q->cont)
3095 q->cont (q->cont_cls, NULL, q, 0, 0);
3106 * Sends an already built message on a tunnel, encrypting it and
3107 * choosing the best connection if not provided.
3109 * @param message Message to send. Function modifies it.
3110 * @param t Tunnel on which this message is transmitted.
3111 * @param c Connection to use (autoselect if NULL).
3112 * @param force Force the tunnel to take the message (buffer overfill).
3113 * @param cont Continuation to call once message is really sent.
3114 * @param cont_cls Closure for @c cont.
3116 * @return Handle to cancel message. NULL if @c cont is NULL.
3118 struct CadetTunnelQueue *
3119 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3120 struct CadetTunnel *t, struct CadetConnection *c,
3121 int force, GCT_sent cont, void *cont_cls)
3123 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3127 * Sends an already built and encrypted message on a tunnel, choosing the best
3128 * connection. Useful for re-queueing messages queued on a destroyed connection.
3130 * @param message Message to send. Function modifies it.
3131 * @param t Tunnel on which this message is transmitted.
3134 GCT_resend_message (const struct GNUNET_MessageHeader *message,
3135 struct CadetTunnel *t)
3137 struct CadetConnection *c;
3140 c = tunnel_get_connection (t);
3143 /* TODO queue in tunnel, marked as encrypted */
3144 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
3147 fwd = GCC_is_origin (c, GNUNET_YES);
3148 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
3149 GNUNET_YES, NULL, NULL));
3154 * Is the tunnel directed towards the local peer?
3158 * @return #GNUNET_YES if it is loopback.
3161 GCT_is_loopback (const struct CadetTunnel *t)
3163 return (myid == GCP_get_short_id (t->peer));
3168 * Is the tunnel this path already?
3173 * @return #GNUNET_YES a connection uses this path.
3176 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3178 struct CadetTConnection *iter;
3180 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3181 if (GCC_get_path (iter->c) == p)
3189 * Get a cost of a path for a tunnel considering existing connections.
3192 * @param path Candidate path.
3194 * @return Cost of the path (path length + number of overlapping nodes)
3197 GCT_get_path_cost (const struct CadetTunnel *t,
3198 const struct CadetPeerPath *path)
3200 struct CadetTConnection *iter;
3201 const struct CadetPeerPath *aux;
3202 unsigned int overlap;
3210 GNUNET_assert (NULL != t);
3212 for (i = 0; i < path->length; i++)
3214 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3216 aux = GCC_get_path (iter->c);
3220 for (j = 0; j < aux->length; j++)
3222 if (path->peers[i] == aux->peers[j])
3230 return path->length + overlap;
3235 * Get the static string for the peer this tunnel is directed.
3239 * @return Static string the destination peer's ID.
3242 GCT_2s (const struct CadetTunnel *t)
3247 return GCP_2s (t->peer);
3251 /******************************************************************************/
3252 /***************************** INFO/DEBUG *******************************/
3253 /******************************************************************************/
3256 * Log all possible info about the tunnel state.
3258 * @param t Tunnel to debug.
3259 * @param level Debug level to use.
3262 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3264 struct CadetTChannel *iterch;
3265 struct CadetTConnection *iterc;
3268 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3270 __FILE__, __FUNCTION__, __LINE__);
3274 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3275 LOG2 (level, "TTT cstate %s, estate %s\n",
3276 cstate2s (t->cstate), estate2s (t->estate));
3277 LOG2 (level, "TTT kx_ctx %p, rekey_task %u\n", t->kx_ctx, t->rekey_task);
3278 #if DUMP_KEYS_TO_STDERR
3279 LOG2 (level, "TTT my EPHM\t %s\n",
3280 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
3281 LOG2 (level, "TTT peers EPHM:\t %s\n",
3282 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
3283 LOG (level, "TTT ENC key:\t %s\n",
3284 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
3285 LOG (level, "TTT DEC key:\t %s\n",
3286 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
3288 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3289 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3291 LOG2 (level, "TTT channels:\n");
3292 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3294 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3297 LOG2 (level, "TTT connections:\n");
3298 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3300 GCC_debug (iterc->c, level);
3303 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3308 * Iterate all tunnels.
3310 * @param iter Iterator.
3311 * @param cls Closure for @c iter.
3314 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3316 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3321 * Count all tunnels.
3323 * @return Number of tunnels to remote peers kept by this peer.
3326 GCT_count_all (void)
3328 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3333 * Iterate all connections of a tunnel.
3335 * @param t Tunnel whose connections to iterate.
3336 * @param iter Iterator.
3337 * @param cls Closure for @c iter.
3340 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3342 struct CadetTConnection *ct;
3344 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3350 * Iterate all channels of a tunnel.
3352 * @param t Tunnel whose channels to iterate.
3353 * @param iter Iterator.
3354 * @param cls Closure for @c iter.
3357 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3359 struct CadetTChannel *cht;
3361 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3362 iter (cls, cht->ch);