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;
207 * Struct used to save messages in a non-ready tunnel to send once connected.
209 struct CadetTunnelDelayed
214 struct CadetTunnelDelayed *next;
215 struct CadetTunnelDelayed *prev;
220 struct CadetTunnel *t;
223 * Tunnel queue given to the channel to cancel request. Update on send_queued.
225 struct CadetTunnelQueue *tq;
230 /* struct GNUNET_MessageHeader *msg; */
235 * Handle for messages queued but not yet sent.
237 struct CadetTunnelQueue
240 * Connection queue handle, to cancel if necessary.
242 struct CadetConnectionQueue *cq;
245 * Handle in case message hasn't been given to a connection yet.
247 struct CadetTunnelDelayed *tqd;
250 * Continuation to call once sent.
255 * Closure for @c cont.
261 /******************************************************************************/
262 /******************************* GLOBALS ***********************************/
263 /******************************************************************************/
266 * Global handle to the statistics service.
268 extern struct GNUNET_STATISTICS_Handle *stats;
271 * Local peer own ID (memory efficient handle).
273 extern GNUNET_PEER_Id myid;
276 * Local peer own ID (full value).
278 extern struct GNUNET_PeerIdentity my_full_id;
282 * Don't try to recover tunnels if shutting down.
284 extern int shutting_down;
288 * Set of all tunnels, in order to trigger a new exchange on rekey.
289 * Indexed by peer's ID.
291 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
294 * Default TTL for payload packets.
296 static unsigned long long default_ttl;
301 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
304 * Own ephemeral private key.
306 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
309 * Cached message used to perform a key exchange.
311 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
314 * Task to generate a new ephemeral key.
316 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
321 static struct GNUNET_TIME_Relative rekey_period;
323 /******************************************************************************/
324 /******************************** STATIC ***********************************/
325 /******************************************************************************/
328 * Get string description for tunnel connectivity state.
330 * @param cs Tunnel state.
332 * @return String representation.
335 cstate2s (enum CadetTunnelCState cs)
341 case CADET_TUNNEL_NEW:
342 return "CADET_TUNNEL_NEW";
343 case CADET_TUNNEL_SEARCHING:
344 return "CADET_TUNNEL_SEARCHING";
345 case CADET_TUNNEL_WAITING:
346 return "CADET_TUNNEL_WAITING";
347 case CADET_TUNNEL_READY:
348 return "CADET_TUNNEL_READY";
351 sprintf (buf, "%u (UNKNOWN STATE)", cs);
359 * Get string description for tunnel encryption state.
361 * @param es Tunnel state.
363 * @return String representation.
366 estate2s (enum CadetTunnelEState es)
372 case CADET_TUNNEL_KEY_UNINITIALIZED:
373 return "CADET_TUNNEL_KEY_UNINITIALIZED";
374 case CADET_TUNNEL_KEY_SENT:
375 return "CADET_TUNNEL_KEY_SENT";
376 case CADET_TUNNEL_KEY_PING:
377 return "CADET_TUNNEL_KEY_PING";
378 case CADET_TUNNEL_KEY_OK:
379 return "CADET_TUNNEL_KEY_OK";
380 case CADET_TUNNEL_KEY_REKEY:
381 return "CADET_TUNNEL_KEY_REKEY";
383 sprintf (buf, "%u (UNKNOWN STATE)", es);
391 * @brief Check if tunnel is ready to send traffic.
393 * Tunnel must be connected and with encryption correctly set up.
395 * @param t Tunnel to check.
397 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
400 is_ready (struct CadetTunnel *t)
404 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
405 ready = CADET_TUNNEL_READY == t->cstate
406 && (CADET_TUNNEL_KEY_OK == t->estate
407 || CADET_TUNNEL_KEY_REKEY == t->estate);
408 ready = ready || GCT_is_loopback (t);
414 * Ephemeral key message purpose size.
416 * @return Size of the part of the ephemeral key message that must be signed.
419 ephemeral_purpose_size (void)
421 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
422 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
423 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
424 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
425 sizeof (struct GNUNET_PeerIdentity);
430 * Size of the encrypted part of a ping message.
432 * @return Size of the encrypted part of a ping message.
435 ping_encryption_size (void)
437 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
442 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
444 * @param tch Tunnel's channel handle.
446 * @return Amount of messages the channel can still buffer towards the client.
449 get_channel_buffer (const struct CadetTChannel *tch)
453 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
454 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
456 return GCCH_get_buffer (tch->ch, fwd);
461 * Get the channel's allowance status.
463 * @param tch Tunnel's channel handle.
465 * @return #GNUNET_YES if we allowed the client to send data to us.
468 get_channel_allowed (const struct CadetTChannel *tch)
472 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
473 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
475 return GCCH_get_allowed (tch->ch, fwd);
480 * Get the connection's buffer.
482 * @param tc Tunnel's connection handle.
484 * @return Amount of messages the connection can still buffer.
487 get_connection_buffer (const struct CadetTConnection *tc)
491 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
492 fwd = GCC_is_origin (tc->c, GNUNET_YES);
494 return GCC_get_buffer (tc->c, fwd);
499 * Get the connection's allowance.
501 * @param tc Tunnel's connection handle.
503 * @return Amount of messages we have allowed the next peer to send us.
506 get_connection_allowed (const struct CadetTConnection *tc)
510 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
511 fwd = GCC_is_origin (tc->c, GNUNET_YES);
513 return GCC_get_allowed (tc->c, fwd);
518 * Check that a ephemeral key message s well formed and correctly signed.
520 * @param t Tunnel on which the message came.
521 * @param msg The ephemeral key message.
523 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
526 check_ephemeral (struct CadetTunnel *t,
527 const struct GNUNET_CADET_KX_Ephemeral *msg)
529 /* Check message size */
530 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
531 return GNUNET_SYSERR;
533 /* Check signature size */
534 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
535 return GNUNET_SYSERR;
538 if (0 != memcmp (&msg->origin_identity,
539 GCP_get_id (t->peer),
540 sizeof (struct GNUNET_PeerIdentity)))
541 return GNUNET_SYSERR;
543 /* Check signature */
545 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
548 &msg->origin_identity.public_key))
549 return GNUNET_SYSERR;
556 * Select the best key to use for encryption (send), based on KX status.
558 * Normally, return the current key. If there is a KX in progress and the old
559 * key is fresh enough, return the old key.
561 * @param t Tunnel to choose the key from.
563 * @return The optimal key to encrypt/hmac outgoing traffic.
565 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
566 select_key (const struct CadetTunnel *t)
568 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
570 if (NULL != t->kx_ctx
571 && GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
573 struct GNUNET_TIME_Relative age;
575 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
576 LOG (GNUNET_ERROR_TYPE_DEBUG,
577 " key exchange in progress, started %s ago\n",
578 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
579 // FIXME make duration of old keys configurable
580 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
582 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
583 key = &t->kx_ctx->e_key_old;
587 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key\n");
593 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
603 * @param plaintext Content to HMAC.
604 * @param size Size of @c plaintext.
605 * @param iv Initialization vector for the message.
606 * @param key Key to use.
607 * @param hmac[out] Destination to store the HMAC.
610 t_hmac (const void *plaintext, size_t size,
611 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
612 struct GNUNET_CADET_Hash *hmac)
614 static const char ctx[] = "cadet authentication key";
615 struct GNUNET_CRYPTO_AuthKey auth_key;
616 struct GNUNET_HashCode hash;
618 #if DUMP_KEYS_TO_STDERR
619 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC with key %s\n",
620 GNUNET_h2s ((struct GNUNET_HashCode *) key));
622 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
627 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
628 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
629 memcpy (hmac, &hash, sizeof (*hmac));
634 * Encrypt daforce_newest_keyta with the tunnel key.
636 * @param t Tunnel whose key to use.
637 * @param dst Destination for the encrypted data.
638 * @param src Source of the plaintext. Can overlap with @c dst.
639 * @param size Size of the plaintext.
640 * @param iv Initialization Vector to use.
641 * @param force_newest_key Force the use of the newest key, otherwise
642 * CADET will use the old key when allowed.
643 * This can happen in the case when a KX is going on
644 * and the old one hasn't expired.
647 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
648 size_t size, uint32_t iv, int force_newest_key)
650 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
651 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
654 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
656 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
657 #if DUMP_KEYS_TO_STDERR
658 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
659 GNUNET_h2s ((struct GNUNET_HashCode *) key));
661 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
662 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
663 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
664 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
671 * Decrypt and verify data with the appropriate tunnel key.
673 * @param key Key to use.
674 * @param dst Destination for the plaintext.
675 * @param src Source of the encrypted data. Can overlap with @c dst.
676 * @param size Size of the encrypted data.
677 * @param iv Initialization Vector to use.
679 * @return Size of the decrypted data, -1 if an error was encountered.
682 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
683 void *dst, const void *src, size_t size, uint32_t iv)
685 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
688 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
689 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
690 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
691 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
692 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
693 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
700 * Decrypt and verify data with the most recent tunnel key.
702 * @param t Tunnel whose key to use.
703 * @param dst Destination for the plaintext.
704 * @param src Source of the encrypted data. Can overlap with @c dst.
705 * @param size Size of the encrypted data.
706 * @param iv Initialization Vector to use.
708 * @return Size of the decrypted data, -1 if an error was encountered.
711 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
712 size_t size, uint32_t iv)
716 #if DUMP_KEYS_TO_STDERR
717 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
718 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
720 if (t->estate == CADET_TUNNEL_KEY_UNINITIALIZED)
722 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
723 LOG (GNUNET_ERROR_TYPE_WARNING,
724 "got data on %s without a valid key\n",
726 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
730 out_size = decrypt (&t->d_key, dst, src, size, iv);
737 * Decrypt and verify data with the appropriate tunnel key and verify that the
738 * data has not been altered since it was sent by the remote peer.
740 * @param t Tunnel whose key to use.
741 * @param dst Destination for the plaintext.
742 * @param src Source of the encrypted data. Can overlap with @c dst.
743 * @param size Size of the encrypted data.
744 * @param iv Initialization Vector to use.
745 * @param msg_hmac HMAC of the message, cannot be NULL.
747 * @return Size of the decrypted data, -1 if an error was encountered.
750 t_decrypt_and_validate (struct CadetTunnel *t,
751 void *dst, const void *src,
752 size_t size, uint32_t iv,
753 const struct GNUNET_CADET_Hash *msg_hmac)
755 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
756 struct GNUNET_CADET_Hash hmac;
759 /* Try primary (newest) key */
761 decrypted_size = decrypt (key, dst, src, size, iv);
762 t_hmac (src, size, iv, key, &hmac);
763 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
764 return decrypted_size;
766 /* If no key exchange is going on, we just failed */
767 if (NULL == t->kx_ctx)
769 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
770 "Failed checksum validation on tunnel %s with no KX\n",
772 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
776 /* Try secondary (from previous KX period) key */
777 key = &t->kx_ctx->d_key_old;
778 decrypted_size = decrypt (key, dst, src, size, iv);
779 t_hmac (src, size, iv, key, &hmac);
780 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
781 return decrypted_size;
783 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
784 "Failed checksum validation on tunnel %s with KX\n",
786 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
792 * Create key material by doing ECDH on the local and remote ephemeral keys.
794 * @param key_material Where to store the key material.
795 * @param ephemeral_key Peer's public ephemeral key.
798 derive_key_material (struct GNUNET_HashCode *key_material,
799 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
802 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
812 * Create a symmetic key from the identities of both ends and the key material
815 * @param key Destination for the generated key.
816 * @param sender ID of the peer that will encrypt with @c key.
817 * @param receiver ID of the peer that will decrypt with @c key.
818 * @param key_material Hash created with ECDH with the ephemeral keys.
821 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
822 const struct GNUNET_PeerIdentity *sender,
823 const struct GNUNET_PeerIdentity *receiver,
824 const struct GNUNET_HashCode *key_material)
826 const char salt[] = "CADET kx salt";
828 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
830 key_material, sizeof (struct GNUNET_HashCode),
831 sender, sizeof (struct GNUNET_PeerIdentity),
832 receiver, sizeof (struct GNUNET_PeerIdentity),
838 * Create a new Key eXchange context for the tunnel.
840 * Initializes the key copies, KX start timestamp and creates a new nonce.
842 * @param t Tunnel for which to create the KX ctx.
845 create_kx_ctx (struct CadetTunnel *t)
847 if (NULL != t->kx_ctx)
849 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
851 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
852 t->kx_ctx->finish_task = GNUNET_SCHEDULER_NO_TASK;
857 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
858 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
859 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
861 t->kx_ctx->d_key_old = t->d_key;
862 t->kx_ctx->e_key_old = t->e_key;
863 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
868 * @brief Finish the Key eXchange and destroy the old keys.
870 * @param cls Closure (Tunnel for which to finish the KX).
871 * @param tc Task context.
874 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
876 struct CadetTunnel *t = cls;
878 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
881 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
883 GNUNET_free (t->kx_ctx);
889 * Destroy a Key eXchange context for the tunnel. This function only schedules
890 * the destruction, the freeing of the memory (and clearing of old key material)
891 * happens after a delay!
893 * @param t Tunnel whose KX ctx to destroy.
896 destroy_kx_ctx (struct CadetTunnel *t)
898 struct GNUNET_TIME_Relative delay;
900 if (NULL == t->kx_ctx || GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
903 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
904 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
906 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
911 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
913 * @param t Tunnel for which to create the keys.
916 create_keys (struct CadetTunnel *t)
918 struct GNUNET_HashCode km;
920 derive_key_material (&km, &t->peers_ephemeral_key);
921 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
922 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
923 #if DUMP_KEYS_TO_STDERR
924 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
925 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
926 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
927 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
928 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
929 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
930 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
931 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
932 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
938 * Pick a connection on which send the next data message.
940 * @param t Tunnel on which to send the message.
942 * @return The connection on which to send the next message.
944 static struct CadetConnection *
945 tunnel_get_connection (struct CadetTunnel *t)
947 struct CadetTConnection *iter;
948 struct CadetConnection *best;
950 unsigned int lowest_q;
952 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
955 for (iter = t->connection_head; NULL != iter; iter = iter->next)
957 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
958 GCC_2s (iter->c), GCC_get_state (iter->c));
959 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
961 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
962 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
970 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
976 * Callback called when a queued message is sent.
978 * Calculates the average time and connection packet tracking.
980 * @param cls Closure (TunnelQueue handle).
981 * @param c Connection this message was on.
982 * @param q Connection queue handle (unused).
983 * @param type Type of message sent.
984 * @param fwd Was this a FWD going message?
985 * @param size Size of the message.
988 tun_message_sent (void *cls,
989 struct CadetConnection *c,
990 struct CadetConnectionQueue *q,
991 uint16_t type, int fwd, size_t size)
993 struct CadetTunnelQueue *qt = cls;
994 struct CadetTunnel *t;
996 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
998 GNUNET_assert (NULL != qt->cont);
999 t = NULL == c ? NULL : GCC_get_tunnel (c);
1000 qt->cont (qt->cont_cls, t, qt, type, size);
1006 count_queued_data (const struct CadetTunnel *t)
1008 struct CadetTunnelDelayed *iter;
1011 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1018 * Delete a queued message: either was sent or the channel was destroyed
1019 * before the tunnel's key exchange had a chance to finish.
1021 * @param tqd Delayed queue handle.
1024 unqueue_data (struct CadetTunnelDelayed *tqd)
1026 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1032 * Cache a message to be sent once tunnel is online.
1034 * @param t Tunnel to hold the message.
1035 * @param msg Message itself (copy will be made).
1037 static struct CadetTunnelDelayed *
1038 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1040 struct CadetTunnelDelayed *tqd;
1041 uint16_t size = ntohs (msg->size);
1043 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1045 if (GNUNET_YES == is_ready (t))
1051 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1054 memcpy (&tqd[1], msg, size);
1055 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1061 * Sends an already built message on a tunnel, encrypting it and
1062 * choosing the best connection.
1064 * @param message Message to send. Function modifies it.
1065 * @param t Tunnel on which this message is transmitted.
1066 * @param c Connection to use (autoselect if NULL).
1067 * @param force Force the tunnel to take the message (buffer overfill).
1068 * @param cont Continuation to call once message is really sent.
1069 * @param cont_cls Closure for @c cont.
1070 * @param existing_q In case this a transmission of previously queued data,
1071 * this should be TunnelQueue given to the client.
1074 * @return Handle to cancel message.
1075 * NULL if @c cont is NULL or an error happens and message is dropped.
1077 static struct CadetTunnelQueue *
1078 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1079 struct CadetTunnel *t, struct CadetConnection *c,
1080 int force, GCT_sent cont, void *cont_cls,
1081 struct CadetTunnelQueue *existing_q)
1083 struct CadetTunnelQueue *tq;
1084 struct GNUNET_CADET_Encrypted *msg;
1085 size_t size = ntohs (message->size);
1086 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1092 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1094 if (GNUNET_NO == is_ready (t))
1096 struct CadetTunnelDelayed *tqd;
1097 /* A non null existing_q indicates sending of queued data.
1098 * Should only happen after tunnel becomes ready.
1100 GNUNET_assert (NULL == existing_q);
1101 tqd = queue_data (t, message);
1104 tq = GNUNET_new (struct CadetTunnelQueue);
1108 tq->cont_cls = cont_cls;
1112 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1114 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1115 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1116 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1118 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO) == size);
1119 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1120 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1123 c = tunnel_get_connection (t);
1126 /* Why is tunnel 'ready'? Should have been queued! */
1127 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
1130 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1132 return NULL; /* Drop... */
1136 type = ntohs (message->type);
1139 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1140 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1141 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1142 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1144 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1146 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1147 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1148 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1149 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1150 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1151 msg->cid = *GCC_get_id (c);
1152 msg->ttl = htonl (default_ttl);
1156 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1158 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1160 fwd = GCC_is_origin (c, GNUNET_YES);
1164 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1165 fwd, force, NULL, NULL));
1168 if (NULL == existing_q)
1170 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1177 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1178 &tun_message_sent, tq);
1179 GNUNET_assert (NULL != tq->cq);
1181 tq->cont_cls = cont_cls;
1188 * Send all cached messages that we can, tunnel is online.
1190 * @param t Tunnel that holds the messages. Cannot be loopback.
1193 send_queued_data (struct CadetTunnel *t)
1195 struct CadetTunnelDelayed *tqd;
1196 struct CadetTunnelDelayed *next;
1199 LOG (GNUNET_ERROR_TYPE_DEBUG,
1200 "GCT_send_queued_data on tunnel %s\n",
1203 if (GCT_is_loopback (t))
1209 if (GNUNET_NO == is_ready (t))
1211 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1212 estate2s (t->estate), cstate2s (t->cstate));
1216 room = GCT_get_connections_buffer (t);
1217 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1218 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1219 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1221 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1224 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1225 tqd->t, NULL, GNUNET_YES,
1226 NULL != tqd->tq ? tqd->tq->cont : NULL,
1227 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1231 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1236 * Sends key exchange message on a tunnel, choosing the best connection.
1237 * Should not be called on loopback tunnels.
1239 * @param t Tunnel on which this message is transmitted.
1240 * @param message Message to send. Function modifies it.
1243 send_kx (struct CadetTunnel *t,
1244 const struct GNUNET_MessageHeader *message)
1246 struct CadetConnection *c;
1247 struct GNUNET_CADET_KX *msg;
1248 size_t size = ntohs (message->size);
1249 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1253 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1255 /* Avoid loopback. */
1256 if (GCT_is_loopback (t))
1258 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1262 type = ntohs (message->type);
1264 /* Even if tunnel is being destroyed, send anyway.
1265 * Could be a response to a rekey initiated by remote peer,
1266 * who is trying to create a new channel!
1269 /* Must have a connection. */
1270 if (NULL == t->connection_head && CADET_TUNNEL_SEARCHING != t->cstate)
1272 LOG (GNUNET_ERROR_TYPE_WARNING, "\n\n\n");
1274 LOG (GNUNET_ERROR_TYPE_WARNING, "sending %s\n", GC_m2s (type));
1275 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1276 GCP_debug (t->peer, GNUNET_ERROR_TYPE_WARNING);
1277 LOG (GNUNET_ERROR_TYPE_WARNING, "\n\n\n");
1281 msg = (struct GNUNET_CADET_KX *) cbuf;
1282 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1283 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1284 c = tunnel_get_connection (t);
1287 GNUNET_break (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
1288 || CADET_TUNNEL_READY != t->cstate);
1289 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1294 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1295 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1296 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1297 memcpy (&msg[1], message, size);
1300 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1305 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1306 /* TODO save handle and cancel in case of a unneeded retransmission */
1307 GNUNET_assert (NULL == GCC_send_prebuilt_message (&msg->header, type, 0, c,
1314 * Send the ephemeral key on a tunnel.
1316 * @param t Tunnel on which to send the key.
1319 send_ephemeral (struct CadetTunnel *t)
1321 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1323 kx_msg.sender_status = htonl (t->estate);
1324 send_kx (t, &kx_msg.header);
1328 * Send a ping message on a tunnel.
1330 * @param t Tunnel on which to send the ping.
1333 send_ping (struct CadetTunnel *t)
1335 struct GNUNET_CADET_KX_Ping msg;
1337 LOG (GNUNET_ERROR_TYPE_INFO, "===> PING for %s\n", GCT_2s (t));
1338 msg.header.size = htons (sizeof (msg));
1339 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PING);
1340 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1341 msg.target = *GCP_get_id (t->peer);
1342 msg.nonce = t->kx_ctx->challenge;
1344 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1345 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
1346 t_encrypt (t, &msg.target, &msg.target,
1347 ping_encryption_size(), msg.iv, GNUNET_YES);
1348 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1349 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
1351 send_kx (t, &msg.header);
1356 * Send a pong message on a tunnel.
1358 * @param t Tunnel on which to send the pong.
1359 * @param challenge Value sent in the ping that we have to send back.
1362 send_pong (struct CadetTunnel *t, uint32_t challenge)
1364 struct GNUNET_CADET_KX_Pong msg;
1366 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1367 msg.header.size = htons (sizeof (msg));
1368 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1369 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1370 msg.nonce = challenge;
1371 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1372 t_encrypt (t, &msg.nonce, &msg.nonce,
1373 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1374 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1376 send_kx (t, &msg.header);
1381 * Initiate a rekey with the remote peer.
1383 * @param cls Closure (tunnel).
1384 * @param tc TaskContext.
1387 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1389 struct CadetTunnel *t = cls;
1391 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1393 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1394 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1397 if (NULL == t->kx_ctx)
1404 struct GNUNET_TIME_Relative duration;
1406 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
1408 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
1409 t->kx_ctx->finish_task = GNUNET_SCHEDULER_NO_TASK;
1412 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1413 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1414 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1416 // FIXME make duration of old keys configurable
1417 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1419 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1420 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1428 case CADET_TUNNEL_KEY_UNINITIALIZED:
1429 t->estate = CADET_TUNNEL_KEY_SENT;
1431 case CADET_TUNNEL_KEY_SENT:
1433 case CADET_TUNNEL_KEY_OK:
1434 t->estate = CADET_TUNNEL_KEY_REKEY;
1436 case CADET_TUNNEL_KEY_PING:
1437 case CADET_TUNNEL_KEY_REKEY:
1441 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1444 // FIXME exponential backoff
1445 struct GNUNET_TIME_Relative delay;
1447 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1448 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1449 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1450 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1451 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1456 * Our ephemeral key has changed, create new session key on all tunnels.
1458 * Each tunnel will start the Key Exchange with a random delay between
1459 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1460 * per second, on average.
1462 * @param cls Closure (size of the hashmap).
1463 * @param key Current public key.
1464 * @param value Value in the hash map (tunnel).
1466 * @return #GNUNET_YES, so we should continue to iterate,
1469 rekey_iterator (void *cls,
1470 const struct GNUNET_PeerIdentity *key,
1473 struct CadetTunnel *t = value;
1474 struct GNUNET_TIME_Relative delay;
1475 long n = (long) cls;
1478 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1481 if (GNUNET_YES == GCT_is_loopback (t))
1484 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1485 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1486 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1493 * Create a new ephemeral key and key message, schedule next rekeying.
1495 * @param cls Closure (unused).
1496 * @param tc TaskContext.
1499 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1501 struct GNUNET_TIME_Absolute time;
1504 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1506 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1509 GNUNET_free_non_null (my_ephemeral_key);
1510 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1512 time = GNUNET_TIME_absolute_get ();
1513 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1514 time = GNUNET_TIME_absolute_add (time, rekey_period);
1515 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1516 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1517 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1519 GNUNET_assert (GNUNET_OK ==
1520 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1522 &kx_msg.signature));
1524 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1525 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1527 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1532 * Called only on shutdown, destroy every tunnel.
1534 * @param cls Closure (unused).
1535 * @param key Current public key.
1536 * @param value Value in the hash map (tunnel).
1538 * @return #GNUNET_YES, so we should continue to iterate,
1541 destroy_iterator (void *cls,
1542 const struct GNUNET_PeerIdentity *key,
1545 struct CadetTunnel *t = value;
1547 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1554 * Notify remote peer that we don't know a channel he is talking about,
1555 * probably CHANNEL_DESTROY was missed.
1557 * @param t Tunnel on which to notify.
1558 * @param gid ID of the channel.
1561 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1563 struct GNUNET_CADET_ChannelManage msg;
1565 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1566 msg.header.size = htons (sizeof (msg));
1567 msg.chid = htonl (gid);
1569 LOG (GNUNET_ERROR_TYPE_DEBUG,
1570 "WARNING destroying unknown channel %u on tunnel %s\n",
1572 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1577 * Demultiplex data per channel and call appropriate channel handler.
1579 * @param t Tunnel on which the data came.
1580 * @param msg Data message.
1581 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1582 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1583 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1584 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1587 handle_data (struct CadetTunnel *t,
1588 const struct GNUNET_CADET_Data *msg,
1591 struct CadetChannel *ch;
1595 size = ntohs (msg->header.size);
1597 sizeof (struct GNUNET_CADET_Data) +
1598 sizeof (struct GNUNET_MessageHeader))
1603 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1604 GC_m2s (ntohs (msg[1].header.type)));
1607 ch = GCT_get_channel (t, ntohl (msg->chid));
1610 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1612 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1614 send_channel_destroy (t, ntohl (msg->chid));
1618 GCCH_handle_data (ch, msg, fwd);
1623 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1625 * @param t Tunnel on which the DATA ACK came.
1626 * @param msg DATA ACK message.
1627 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1628 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1629 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1630 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1633 handle_data_ack (struct CadetTunnel *t,
1634 const struct GNUNET_CADET_DataACK *msg,
1637 struct CadetChannel *ch;
1641 size = ntohs (msg->header.size);
1642 if (size != sizeof (struct GNUNET_CADET_DataACK))
1649 ch = GCT_get_channel (t, ntohl (msg->chid));
1652 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1654 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1659 GCCH_handle_data_ack (ch, msg, fwd);
1664 * Handle channel create.
1666 * @param t Tunnel on which the data came.
1667 * @param msg Data message.
1670 handle_ch_create (struct CadetTunnel *t,
1671 const struct GNUNET_CADET_ChannelCreate *msg)
1673 struct CadetChannel *ch;
1677 size = ntohs (msg->header.size);
1678 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1685 ch = GCT_get_channel (t, ntohl (msg->chid));
1686 if (NULL != ch && ! GCT_is_loopback (t))
1688 /* Probably a retransmission, safe to ignore */
1689 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1691 ch = GCCH_handle_create (t, msg);
1693 GCT_add_channel (t, ch);
1699 * Handle channel NACK: check correctness and call channel handler for NACKs.
1701 * @param t Tunnel on which the NACK came.
1702 * @param msg NACK message.
1705 handle_ch_nack (struct CadetTunnel *t,
1706 const struct GNUNET_CADET_ChannelManage *msg)
1708 struct CadetChannel *ch;
1712 size = ntohs (msg->header.size);
1713 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1720 ch = GCT_get_channel (t, ntohl (msg->chid));
1723 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1725 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1730 GCCH_handle_nack (ch);
1735 * Handle a CHANNEL ACK (SYNACK/ACK).
1737 * @param t Tunnel on which the CHANNEL ACK came.
1738 * @param msg CHANNEL ACK message.
1739 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1740 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1741 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1742 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1745 handle_ch_ack (struct CadetTunnel *t,
1746 const struct GNUNET_CADET_ChannelManage *msg,
1749 struct CadetChannel *ch;
1753 size = ntohs (msg->header.size);
1754 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1761 ch = GCT_get_channel (t, ntohl (msg->chid));
1764 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1766 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1771 GCCH_handle_ack (ch, msg, fwd);
1776 * Handle a channel destruction message.
1778 * @param t Tunnel on which the message came.
1779 * @param msg Channel destroy message.
1780 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1781 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1782 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1783 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1786 handle_ch_destroy (struct CadetTunnel *t,
1787 const struct GNUNET_CADET_ChannelManage *msg,
1790 struct CadetChannel *ch;
1794 size = ntohs (msg->header.size);
1795 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1802 ch = GCT_get_channel (t, ntohl (msg->chid));
1805 /* Probably a retransmission, safe to ignore */
1809 GCCH_handle_destroy (ch, msg, fwd);
1814 * The peer's ephemeral key has changed: update the symmetrical keys.
1816 * @param t Tunnel this message came on.
1817 * @param msg Key eXchange message.
1820 handle_ephemeral (struct CadetTunnel *t,
1821 const struct GNUNET_CADET_KX_Ephemeral *msg)
1823 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
1825 if (GNUNET_OK != check_ephemeral (t, msg))
1827 GNUNET_break_op (0);
1832 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
1833 sizeof (msg->ephemeral_key)))
1835 t->peers_ephemeral_key = msg->ephemeral_key;
1837 if (CADET_TUNNEL_KEY_OK == t->estate)
1839 t->estate = CADET_TUNNEL_KEY_REKEY;
1841 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1842 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
1844 else if (CADET_TUNNEL_KEY_OK == t->estate)
1848 if (CADET_TUNNEL_KEY_SENT == t->estate)
1850 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending ping\n");
1852 t->estate = CADET_TUNNEL_KEY_PING;
1858 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1859 * Answer with by retransmitting the challenge with the "opposite" key.
1861 * @param t Tunnel this message came on.
1862 * @param msg Key eXchange Ping message.
1865 handle_ping (struct CadetTunnel *t,
1866 const struct GNUNET_CADET_KX_Ping *msg)
1868 struct GNUNET_CADET_KX_Ping res;
1870 if (ntohs (msg->header.size) != sizeof (res))
1872 GNUNET_break_op (0);
1876 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PING for %s\n", GCT_2s (t));
1877 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1878 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1880 GNUNET_STATISTICS_update (stats, "# malformed PINGs", 1, GNUNET_NO);
1881 LOG (GNUNET_ERROR_TYPE_WARNING, " malformed PING on %s\n", GCT_2s (t));
1882 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1883 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1884 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1885 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1892 send_pong (t, res.nonce);
1897 * Peer has answer to our challenge.
1898 * If answer is successful, consider the key exchange finished and clean
1899 * up all related state.
1901 * @param t Tunnel this message came on.
1902 * @param msg Key eXchange Pong message.
1905 handle_pong (struct CadetTunnel *t,
1906 const struct GNUNET_CADET_KX_Pong *msg)
1910 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
1911 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1913 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1916 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1918 if (challenge != t->kx_ctx->challenge)
1920 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
1921 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1922 challenge, msg->nonce, t->kx_ctx->challenge);
1927 GNUNET_SCHEDULER_cancel (t->rekey_task);
1928 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1930 /* Don't free the old keys right away, but after a delay.
1931 * Rationale: the KX could have happened over a very fast connection,
1932 * with payload traffic still signed with the old key stuck in a slower
1934 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
1938 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
1943 * Demultiplex by message type and call appropriate handler for a message
1944 * towards a channel of a local tunnel.
1946 * @param t Tunnel this message came on.
1947 * @param msgh Message header.
1948 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1949 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1950 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1951 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1954 handle_decrypted (struct CadetTunnel *t,
1955 const struct GNUNET_MessageHeader *msgh,
1960 type = ntohs (msgh->type);
1961 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
1965 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1966 /* Do nothing, connection aleady got updated. */
1967 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
1970 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1971 /* Don't send hop ACK, wait for client to ACK */
1972 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
1975 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1976 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1979 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1980 handle_ch_create (t,
1981 (struct GNUNET_CADET_ChannelCreate *) msgh);
1984 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1986 (struct GNUNET_CADET_ChannelManage *) msgh);
1989 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1991 (struct GNUNET_CADET_ChannelManage *) msgh,
1995 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1996 handle_ch_destroy (t,
1997 (struct GNUNET_CADET_ChannelManage *) msgh,
2002 GNUNET_break_op (0);
2003 LOG (GNUNET_ERROR_TYPE_WARNING,
2004 "end-to-end message not known (%u)\n",
2005 ntohs (msgh->type));
2006 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2010 /******************************************************************************/
2011 /******************************** API ***********************************/
2012 /******************************************************************************/
2015 * Decrypt and demultiplex by message type. Call appropriate handler
2016 * for every message.
2018 * @param t Tunnel this message came on.
2019 * @param msg Encrypted message.
2022 GCT_handle_encrypted (struct CadetTunnel *t,
2023 const struct GNUNET_CADET_Encrypted *msg)
2025 size_t size = ntohs (msg->header.size);
2026 size_t payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2028 char cbuf [payload_size];
2029 struct GNUNET_MessageHeader *msgh;
2032 decrypted_size = t_decrypt_and_validate (t, cbuf, &msg[1], payload_size,
2033 msg->iv, &msg->hmac);
2035 if (-1 == decrypted_size)
2037 GNUNET_break_op (0);
2042 while (off < decrypted_size)
2046 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2047 msize = ntohs (msgh->size);
2048 if (msize < sizeof (struct GNUNET_MessageHeader))
2050 GNUNET_break_op (0);
2053 handle_decrypted (t, msgh, GNUNET_SYSERR);
2060 * Demultiplex an encapsulated KX message by message type.
2062 * @param t Tunnel on which the message came.
2063 * @param message Payload of KX message.
2066 GCT_handle_kx (struct CadetTunnel *t,
2067 const struct GNUNET_MessageHeader *message)
2071 type = ntohs (message->type);
2072 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
2075 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2076 handle_ephemeral (t, (struct GNUNET_CADET_KX_Ephemeral *) message);
2079 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
2080 handle_ping (t, (struct GNUNET_CADET_KX_Ping *) message);
2083 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2084 handle_pong (t, (struct GNUNET_CADET_KX_Pong *) message);
2088 GNUNET_break_op (0);
2089 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
2095 * Initialize the tunnel subsystem.
2097 * @param c Configuration handle.
2098 * @param key ECC private key, to derive all other keys and do crypto.
2101 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2102 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2104 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2106 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2109 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2110 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2114 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2117 rekey_period = GNUNET_TIME_UNIT_DAYS;
2120 my_private_key = key;
2121 kx_msg.header.size = htons (sizeof (kx_msg));
2122 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2123 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2124 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2125 kx_msg.origin_identity = my_full_id;
2126 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
2128 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2133 * Shut down the tunnel subsystem.
2138 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
2140 GNUNET_SCHEDULER_cancel (rekey_task);
2141 rekey_task = GNUNET_SCHEDULER_NO_TASK;
2143 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2144 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2151 * @param destination Peer this tunnel is towards.
2153 struct CadetTunnel *
2154 GCT_new (struct CadetPeer *destination)
2156 struct CadetTunnel *t;
2158 t = GNUNET_new (struct CadetTunnel);
2160 t->peer = destination;
2163 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2164 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2175 * Change the tunnel's connection state.
2177 * @param t Tunnel whose connection state to change.
2178 * @param cstate New connection state.
2181 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2185 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2186 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2187 if (myid != GCP_get_short_id (t->peer) &&
2188 CADET_TUNNEL_READY != t->cstate &&
2189 CADET_TUNNEL_READY == cstate)
2192 if (CADET_TUNNEL_KEY_OK == t->estate)
2194 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2195 send_queued_data (t);
2197 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2199 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2200 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2201 GNUNET_SCHEDULER_cancel (t->rekey_task);
2202 rekey_tunnel (t, NULL);
2207 if (CADET_TUNNEL_READY == cstate
2208 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2210 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2211 GCP_stop_search (t->peer);
2216 * Change the tunnel encryption state.
2218 * @param t Tunnel whose encryption state to change.
2219 * @param state New encryption state.
2222 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2226 LOG (GNUNET_ERROR_TYPE_DEBUG,
2227 "Tunnel %s estate was %s\n",
2228 GCP_2s (t->peer), estate2s (t->estate));
2229 LOG (GNUNET_ERROR_TYPE_DEBUG,
2230 "Tunnel %s estate is now %s\n",
2231 GCP_2s (t->peer), estate2s (state));
2232 if (myid != GCP_get_short_id (t->peer) &&
2233 CADET_TUNNEL_KEY_OK != t->estate && CADET_TUNNEL_KEY_OK == state)
2236 send_queued_data (t);
2244 * @brief Check if tunnel has too many connections, and remove one if necessary.
2246 * Currently this means the newest connection, unless it is a direct one.
2247 * Implemented as a task to avoid freeing a connection that is in the middle
2248 * of being created/processed.
2250 * @param cls Closure (Tunnel to check).
2251 * @param tc Task context.
2254 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2256 struct CadetTunnel *t = cls;
2258 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2261 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2263 struct CadetTConnection *iter;
2264 struct CadetTConnection *c;
2266 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2268 if ((NULL == c || iter->created.abs_value_us > c->created.abs_value_us)
2269 && GNUNET_NO == GCC_is_direct (iter->c))
2276 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2278 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2291 * Add a connection to a tunnel.
2294 * @param c Connection.
2297 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2299 struct CadetTConnection *aux;
2301 GNUNET_assert (NULL != c);
2303 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2304 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2305 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2309 aux = GNUNET_new (struct CadetTConnection);
2311 aux->created = GNUNET_TIME_absolute_get ();
2313 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2315 GNUNET_SCHEDULER_add_now (&trim_connections, t);
2320 * Mark a path as no longer valid for this tunnel: has been tried and failed.
2322 * @param t Tunnel to update.
2323 * @param path Invalid path to remove. Is destroyed after removal.
2326 GCT_remove_path (struct CadetTunnel *t, struct CadetPeerPath *path)
2328 GCP_remove_path (t->peer, path);
2333 * Remove a connection from a tunnel.
2336 * @param c Connection.
2339 GCT_remove_connection (struct CadetTunnel *t,
2340 struct CadetConnection *c)
2342 struct CadetTConnection *aux;
2343 struct CadetTConnection *next;
2345 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2346 GCC_2s (c), GCT_2s (t));
2347 for (aux = t->connection_head; aux != NULL; aux = next)
2352 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2357 /* Start new connections if needed */
2358 if (CONNECTIONS_PER_TUNNEL > GCT_count_connections (t)
2359 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2360 && CADET_TUNNEL_SHUTDOWN != t->cstate
2361 && GNUNET_NO == shutting_down)
2363 LOG (GNUNET_ERROR_TYPE_DEBUG, " no more connections, getting new ones\n");
2364 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2365 GCP_connect (t->peer);
2369 /* If not marked as ready, no change is needed */
2370 if (CADET_TUNNEL_READY != t->cstate)
2373 /* Check if any connection is ready to maintain cstate */
2374 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2375 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2378 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2383 * Add a channel to a tunnel.
2386 * @param ch Channel.
2389 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2391 struct CadetTChannel *aux;
2393 GNUNET_assert (NULL != ch);
2395 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2397 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2399 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2404 aux = GNUNET_new (struct CadetTChannel);
2406 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2407 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2409 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2411 GNUNET_SCHEDULER_cancel (t->destroy_task);
2412 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2413 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2419 * Remove a channel from a tunnel.
2422 * @param ch Channel.
2425 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2427 struct CadetTChannel *aux;
2429 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2430 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2434 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2435 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2444 * Search for a channel by global ID.
2446 * @param t Tunnel containing the channel.
2447 * @param chid Public channel number.
2449 * @return channel handler, NULL if doesn't exist
2451 struct CadetChannel *
2452 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2454 struct CadetTChannel *iter;
2459 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2461 if (GCCH_get_id (iter->ch) == chid)
2465 return NULL == iter ? NULL : iter->ch;
2470 * @brief Destroy a tunnel and free all resources.
2472 * Should only be called a while after the tunnel has been marked as destroyed,
2473 * in case there is a new channel added to the same peer shortly after marking
2474 * the tunnel. This way we avoid a new public key handshake.
2476 * @param cls Closure (tunnel to destroy).
2477 * @param tc Task context.
2480 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2482 struct CadetTunnel *t = cls;
2483 struct CadetTConnection *iter;
2485 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2486 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2488 LOG (GNUNET_ERROR_TYPE_WARNING,
2489 "Not destroying tunnel, due to shutdown. "
2490 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2493 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2494 t->cstate = CADET_TUNNEL_SHUTDOWN;
2496 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2498 GCC_send_destroy (iter->c);
2505 * Tunnel is empty: destroy it.
2507 * Notifies all connections about the destruction.
2509 * @param t Tunnel to destroy.
2512 GCT_destroy_empty (struct CadetTunnel *t)
2514 if (GNUNET_YES == shutting_down)
2515 return; /* Will be destroyed immediately anyway */
2517 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2519 LOG (GNUNET_ERROR_TYPE_WARNING,
2520 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
2522 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2524 /* should never happen, tunnel can only become empty once, and the
2525 * task identifier should be NO_TASK (cleaned when the tunnel was created
2526 * or became un-empty)
2531 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2534 // FIXME make delay a config option
2535 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2536 &delayed_destroy, t);
2537 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llX\n",
2538 t, t->destroy_task);
2543 * Destroy tunnel if empty (no more channels).
2545 * @param t Tunnel to destroy if empty.
2548 GCT_destroy_if_empty (struct CadetTunnel *t)
2550 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2551 if (1 < GCT_count_channels (t))
2554 GCT_destroy_empty (t);
2559 * Destroy the tunnel.
2561 * This function does not generate any warning traffic to clients or peers.
2564 * Cancel messages belonging to this tunnel queued to neighbors.
2565 * Free any allocated resources linked to the tunnel.
2567 * @param t The tunnel to destroy.
2570 GCT_destroy (struct CadetTunnel *t)
2572 struct CadetTConnection *iter_c;
2573 struct CadetTConnection *next_c;
2574 struct CadetTChannel *iter_ch;
2575 struct CadetTChannel *next_ch;
2580 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
2582 GNUNET_break (GNUNET_YES ==
2583 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2584 GCP_get_id (t->peer), t));
2586 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2588 next_c = iter_c->next;
2589 GCC_destroy (iter_c->c);
2591 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2593 next_ch = iter_ch->next;
2594 GCCH_destroy (iter_ch->ch);
2595 /* Should only happen on shutdown, but it's ok. */
2598 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2600 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling %llX\n", t->destroy_task);
2601 GNUNET_SCHEDULER_cancel (t->destroy_task);
2602 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2605 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2606 GCP_set_tunnel (t->peer, NULL);
2608 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2610 GNUNET_SCHEDULER_cancel (t->rekey_task);
2611 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2613 if (NULL != t->kx_ctx)
2615 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
2616 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
2617 GNUNET_free (t->kx_ctx);
2624 * @brief Use the given path for the tunnel.
2625 * Update the next and prev hops (and RCs).
2626 * (Re)start the path refresh in case the tunnel is locally owned.
2628 * @param t Tunnel to update.
2629 * @param p Path to use.
2631 * @return Connection created.
2633 struct CadetConnection *
2634 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
2636 struct CadetConnection *c;
2637 struct GNUNET_CADET_Hash cid;
2638 unsigned int own_pos;
2640 if (NULL == t || NULL == p)
2646 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
2652 for (own_pos = 0; own_pos < p->length; own_pos++)
2654 if (p->peers[own_pos] == myid)
2657 if (own_pos >= p->length)
2659 GNUNET_break_op (0);
2663 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2664 c = GCC_new (&cid, t, p, own_pos);
2667 /* Path was flawed */
2670 GCT_add_connection (t, c);
2676 * Count created connections of a tunnel. Not necessarily ready connections!
2678 * @param t Tunnel on which to count.
2680 * @return Number of connections created, either being established or ready.
2683 GCT_count_connections (struct CadetTunnel *t)
2685 struct CadetTConnection *iter;
2691 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2692 if (CADET_CONNECTION_DESTROYED != GCC_get_state (iter->c))
2699 * Count channels of a tunnel.
2701 * @param t Tunnel on which to count.
2703 * @return Number of channels.
2706 GCT_count_channels (struct CadetTunnel *t)
2708 struct CadetTChannel *iter;
2711 for (count = 0, iter = t->channel_head;
2713 iter = iter->next, count++) /* skip */;
2720 * Get the connectivity state of a tunnel.
2724 * @return Tunnel's connectivity state.
2726 enum CadetTunnelCState
2727 GCT_get_cstate (struct CadetTunnel *t)
2732 return (enum CadetTunnelCState) -1;
2739 * Get the encryption state of a tunnel.
2743 * @return Tunnel's encryption state.
2745 enum CadetTunnelEState
2746 GCT_get_estate (struct CadetTunnel *t)
2751 return (enum CadetTunnelEState) -1;
2757 * Get the maximum buffer space for a tunnel towards a local client.
2761 * @return Biggest buffer space offered by any channel in the tunnel.
2764 GCT_get_channels_buffer (struct CadetTunnel *t)
2766 struct CadetTChannel *iter;
2767 unsigned int buffer;
2768 unsigned int ch_buf;
2770 if (NULL == t->channel_head)
2772 /* Probably getting buffer for a channel create/handshake. */
2777 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2779 ch_buf = get_channel_buffer (iter);
2780 if (ch_buf > buffer)
2788 * Get the total buffer space for a tunnel for P2P traffic.
2792 * @return Buffer space offered by all connections in the tunnel.
2795 GCT_get_connections_buffer (struct CadetTunnel *t)
2797 struct CadetTConnection *iter;
2798 unsigned int buffer;
2800 if (GNUNET_NO == is_ready (t))
2802 if (count_queued_data (t) > 3)
2809 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2811 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2815 buffer += get_connection_buffer (iter);
2823 * Get the tunnel's destination.
2827 * @return ID of the destination peer.
2829 const struct GNUNET_PeerIdentity *
2830 GCT_get_destination (struct CadetTunnel *t)
2832 return GCP_get_id (t->peer);
2837 * Get the tunnel's next free global channel ID.
2841 * @return GID of a channel free to use.
2844 GCT_get_next_chid (struct CadetTunnel *t)
2846 CADET_ChannelNumber chid;
2847 CADET_ChannelNumber mask;
2850 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2851 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2852 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2854 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2859 t->next_chid |= mask;
2861 while (NULL != GCT_get_channel (t, t->next_chid))
2863 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2864 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2865 t->next_chid |= mask;
2867 chid = t->next_chid;
2868 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2869 t->next_chid |= mask;
2876 * Send ACK on one or more channels due to buffer in connections.
2878 * @param t Channel which has some free buffer space.
2881 GCT_unchoke_channels (struct CadetTunnel *t)
2883 struct CadetTChannel *iter;
2884 unsigned int buffer;
2885 unsigned int channels = GCT_count_channels (t);
2886 unsigned int choked_n;
2887 struct CadetChannel *choked[channels];
2889 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
2890 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2891 if (NULL != t->channel_head)
2892 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2894 /* Get buffer space */
2895 buffer = GCT_get_connections_buffer (t);
2901 /* Count and remember choked channels */
2903 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2905 if (GNUNET_NO == get_channel_allowed (iter))
2907 choked[choked_n++] = iter->ch;
2911 /* Unchoke random channels */
2912 while (0 < buffer && 0 < choked_n)
2914 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
2916 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
2919 choked[r] = choked[choked_n];
2925 * Send ACK on one or more connections due to buffer space to the client.
2927 * Iterates all connections of the tunnel and sends ACKs appropriately.
2932 GCT_send_connection_acks (struct CadetTunnel *t)
2934 struct CadetTConnection *iter;
2937 uint32_t allow_per_connection;
2939 unsigned int buffer;
2941 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
2950 buffer = GCT_get_channels_buffer (t);
2951 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
2953 /* Count connections, how many messages are already allowed */
2954 cs = GCT_count_connections (t);
2955 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2957 allowed += get_connection_allowed (iter);
2959 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
2961 /* Make sure there is no overflow */
2962 if (allowed > buffer)
2967 /* Authorize connections to send more data */
2968 to_allow = buffer; /* - allowed; */
2970 for (iter = t->connection_head;
2971 NULL != iter && to_allow > 0;
2974 allow_per_connection = to_allow/cs;
2975 to_allow -= allow_per_connection;
2977 if (get_connection_allowed (iter) > 64 / 3)
2981 GCC_allow (iter->c, allow_per_connection,
2982 GCC_is_origin (iter->c, GNUNET_NO));
2985 GNUNET_break (to_allow == 0);
2990 * Cancel a previously sent message while it's in the queue.
2992 * ONLY can be called before the continuation given to the send function
2993 * is called. Once the continuation is called, the message is no longer in the
2996 * @param q Handle to the queue.
2999 GCT_cancel (struct CadetTunnelQueue *q)
3004 /* tun_message_sent() will be called and free q */
3006 else if (NULL != q->tqd)
3008 unqueue_data (q->tqd);
3010 if (NULL != q->cont)
3011 q->cont (q->cont_cls, NULL, q, 0, 0);
3022 * Sends an already built message on a tunnel, encrypting it and
3023 * choosing the best connection if not provided.
3025 * @param message Message to send. Function modifies it.
3026 * @param t Tunnel on which this message is transmitted.
3027 * @param c Connection to use (autoselect if NULL).
3028 * @param force Force the tunnel to take the message (buffer overfill).
3029 * @param cont Continuation to call once message is really sent.
3030 * @param cont_cls Closure for @c cont.
3032 * @return Handle to cancel message. NULL if @c cont is NULL.
3034 struct CadetTunnelQueue *
3035 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3036 struct CadetTunnel *t, struct CadetConnection *c,
3037 int force, GCT_sent cont, void *cont_cls)
3039 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3044 * Is the tunnel directed towards the local peer?
3048 * @return #GNUNET_YES if it is loopback.
3051 GCT_is_loopback (const struct CadetTunnel *t)
3053 return (myid == GCP_get_short_id (t->peer));
3058 * Is the tunnel this path already?
3063 * @return #GNUNET_YES a connection uses this path.
3066 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3068 struct CadetTConnection *iter;
3070 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3071 if (GCC_get_path (iter->c) == p)
3079 * Get a cost of a path for a tunnel considering existing connections.
3082 * @param path Candidate path.
3084 * @return Cost of the path (path length + number of overlapping nodes)
3087 GCT_get_path_cost (const struct CadetTunnel *t,
3088 const struct CadetPeerPath *path)
3090 struct CadetTConnection *iter;
3091 const struct CadetPeerPath *aux;
3092 unsigned int overlap;
3100 GNUNET_assert (NULL != t);
3102 for (i = 0; i < path->length; i++)
3104 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3106 aux = GCC_get_path (iter->c);
3110 for (j = 0; j < aux->length; j++)
3112 if (path->peers[i] == aux->peers[j])
3120 return path->length + overlap;
3125 * Get the static string for the peer this tunnel is directed.
3129 * @return Static string the destination peer's ID.
3132 GCT_2s (const struct CadetTunnel *t)
3137 return GCP_2s (t->peer);
3141 /******************************************************************************/
3142 /***************************** INFO/DEBUG *******************************/
3143 /******************************************************************************/
3146 * Log all possible info about the tunnel state.
3148 * @param t Tunnel to debug.
3149 * @param level Debug level to use.
3152 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3154 struct CadetTChannel *iterch;
3155 struct CadetTConnection *iterc;
3158 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3160 __FILE__, __FUNCTION__, __LINE__);
3164 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3165 LOG2 (level, "TTT cstate %s, estate %s\n",
3166 cstate2s (t->cstate), estate2s (t->estate));
3167 LOG2 (level, "TTT kx_ctx %p, rekey_task %u\n", t->kx_ctx, t->rekey_task);
3168 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3169 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3171 LOG2 (level, "TTT channels:\n");
3172 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3174 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3177 LOG2 (level, "TTT connections:\n");
3178 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3180 GCC_debug (iterc->c, level);
3183 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3188 * Iterate all tunnels.
3190 * @param iter Iterator.
3191 * @param cls Closure for @c iter.
3194 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3196 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3201 * Count all tunnels.
3203 * @return Number of tunnels to remote peers kept by this peer.
3206 GCT_count_all (void)
3208 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3213 * Iterate all connections of a tunnel.
3215 * @param t Tunnel whose connections to iterate.
3216 * @param iter Iterator.
3217 * @param cls Closure for @c iter.
3220 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3222 struct CadetTConnection *ct;
3224 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3230 * Iterate all channels of a tunnel.
3232 * @param t Tunnel whose channels to iterate.
3233 * @param iter Iterator.
3234 * @param cls Closure for @c iter.
3237 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3239 struct CadetTChannel *cht;
3241 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3242 iter (cls, cht->ch);