2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 #include "gnunet_util_lib.h"
24 #include "gnunet_signatures.h"
25 #include "gnunet_statistics_service.h"
27 #include "cadet_protocol.h"
28 #include "cadet_path.h"
30 #include "gnunet-service-cadet_tunnel.h"
31 #include "gnunet-service-cadet_connection.h"
32 #include "gnunet-service-cadet_channel.h"
33 #include "gnunet-service-cadet_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"cadet-tun",__VA_ARGS__)
36 #define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-tun",__VA_ARGS__)
38 #define REKEY_WAIT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)
40 #if !defined(GNUNET_CULL_LOGGING)
41 #define DUMP_KEYS_TO_STDERR GNUNET_YES
43 #define DUMP_KEYS_TO_STDERR GNUNET_NO
46 /******************************************************************************/
47 /******************************** STRUCTS **********************************/
48 /******************************************************************************/
52 struct CadetTChannel *next;
53 struct CadetTChannel *prev;
54 struct CadetChannel *ch;
59 * Connection list and metadata.
61 struct CadetTConnection
66 struct CadetTConnection *next;
71 struct CadetTConnection *prev;
76 struct CadetConnection *c;
79 * Creation time, to keep oldest connection alive.
81 struct GNUNET_TIME_Absolute created;
84 * Connection throughput, to keep fastest connection alive.
90 * Structure used during a Key eXchange.
92 struct CadetTunnelKXCtx
95 * Encryption ("our") old "confirmed" key, for encrypting traffic sent by us
96 * end before the key exchange is finished or times out.
98 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
101 * Decryption ("their") old "confirmed" key, for decrypting traffic sent by
102 * the other end before the key exchange started.
104 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
107 * Challenge to send in a ping and expect in the pong.
112 * When the rekey started. One minute after this the new key will be used.
114 struct GNUNET_TIME_Absolute rekey_start_time;
117 * Task for delayed destruction of the Key eXchange context, to allow delayed
118 * messages with the old key to be decrypted successfully.
120 GNUNET_SCHEDULER_TaskIdentifier finish_task;
124 * Struct containing all information regarding a tunnel to a peer.
129 * Endpoint of the tunnel.
131 struct CadetPeer *peer;
134 * State of the tunnel connectivity.
136 enum CadetTunnelCState cstate;
139 * State of the tunnel encryption.
141 enum CadetTunnelEState estate;
144 * Key eXchange context.
146 struct CadetTunnelKXCtx *kx_ctx;
149 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
152 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
155 * Encryption ("our") key. It is only "confirmed" if kx_ctx is NULL.
157 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
160 * Decryption ("their") key. It is only "confirmed" if kx_ctx is NULL.
162 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
165 * Task to start the rekey process.
167 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
170 * Paths that are actively used to reach the destination peer.
172 struct CadetTConnection *connection_head;
173 struct CadetTConnection *connection_tail;
176 * Next connection number.
181 * Channels inside this tunnel.
183 struct CadetTChannel *channel_head;
184 struct CadetTChannel *channel_tail;
187 * Channel ID for the next created channel.
189 CADET_ChannelNumber next_chid;
192 * Destroy flag: if true, destroy on last message.
194 GNUNET_SCHEDULER_TaskIdentifier destroy_task;
197 * Queued messages, to transmit once tunnel gets connected.
199 struct CadetTunnelDelayed *tq_head;
200 struct CadetTunnelDelayed *tq_tail;
203 * Task to trim connections if too many are present.
205 GNUNET_SCHEDULER_TaskIdentifier trim_connections_task;
210 * Struct used to save messages in a non-ready tunnel to send once connected.
212 struct CadetTunnelDelayed
217 struct CadetTunnelDelayed *next;
218 struct CadetTunnelDelayed *prev;
223 struct CadetTunnel *t;
226 * Tunnel queue given to the channel to cancel request. Update on send_queued.
228 struct CadetTunnelQueue *tq;
233 /* struct GNUNET_MessageHeader *msg; */
238 * Handle for messages queued but not yet sent.
240 struct CadetTunnelQueue
243 * Connection queue handle, to cancel if necessary.
245 struct CadetConnectionQueue *cq;
248 * Handle in case message hasn't been given to a connection yet.
250 struct CadetTunnelDelayed *tqd;
253 * Continuation to call once sent.
258 * Closure for @c cont.
264 /******************************************************************************/
265 /******************************* GLOBALS ***********************************/
266 /******************************************************************************/
269 * Global handle to the statistics service.
271 extern struct GNUNET_STATISTICS_Handle *stats;
274 * Local peer own ID (memory efficient handle).
276 extern GNUNET_PEER_Id myid;
279 * Local peer own ID (full value).
281 extern struct GNUNET_PeerIdentity my_full_id;
285 * Don't try to recover tunnels if shutting down.
287 extern int shutting_down;
291 * Set of all tunnels, in order to trigger a new exchange on rekey.
292 * Indexed by peer's ID.
294 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
297 * Default TTL for payload packets.
299 static unsigned long long default_ttl;
304 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
307 * Own ephemeral private key.
309 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
312 * Cached message used to perform a key exchange.
314 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
317 * Task to generate a new ephemeral key.
319 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
324 static struct GNUNET_TIME_Relative rekey_period;
326 /******************************************************************************/
327 /******************************** STATIC ***********************************/
328 /******************************************************************************/
331 * Get string description for tunnel connectivity state.
333 * @param cs Tunnel state.
335 * @return String representation.
338 cstate2s (enum CadetTunnelCState cs)
344 case CADET_TUNNEL_NEW:
345 return "CADET_TUNNEL_NEW";
346 case CADET_TUNNEL_SEARCHING:
347 return "CADET_TUNNEL_SEARCHING";
348 case CADET_TUNNEL_WAITING:
349 return "CADET_TUNNEL_WAITING";
350 case CADET_TUNNEL_READY:
351 return "CADET_TUNNEL_READY";
352 case CADET_TUNNEL_SHUTDOWN:
353 return "CADET_TUNNEL_SHUTDOWN";
355 SPRINTF (buf, "%u (UNKNOWN STATE)", cs);
363 * Get string description for tunnel encryption state.
365 * @param es Tunnel state.
367 * @return String representation.
370 estate2s (enum CadetTunnelEState es)
376 case CADET_TUNNEL_KEY_UNINITIALIZED:
377 return "CADET_TUNNEL_KEY_UNINITIALIZED";
378 case CADET_TUNNEL_KEY_SENT:
379 return "CADET_TUNNEL_KEY_SENT";
380 case CADET_TUNNEL_KEY_PING:
381 return "CADET_TUNNEL_KEY_PING";
382 case CADET_TUNNEL_KEY_OK:
383 return "CADET_TUNNEL_KEY_OK";
384 case CADET_TUNNEL_KEY_REKEY:
385 return "CADET_TUNNEL_KEY_REKEY";
387 SPRINTF (buf, "%u (UNKNOWN STATE)", es);
395 * @brief Check if tunnel is ready to send traffic.
397 * Tunnel must be connected and with encryption correctly set up.
399 * @param t Tunnel to check.
401 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
404 is_ready (struct CadetTunnel *t)
408 GCT_debug (t, GNUNET_ERROR_TYPE_DEBUG);
409 ready = CADET_TUNNEL_READY == t->cstate
410 && (CADET_TUNNEL_KEY_OK == t->estate
411 || CADET_TUNNEL_KEY_REKEY == t->estate);
412 ready = ready || GCT_is_loopback (t);
418 * Check if a key is invalid (NULL pointer or all 0)
420 * @param key Key to check.
422 * @return #GNUNET_YES if key is null, #GNUNET_NO if exists and is not 0.
425 is_key_null (struct GNUNET_CRYPTO_SymmetricSessionKey *key)
427 struct GNUNET_CRYPTO_SymmetricSessionKey null_key;
432 memset (&null_key, 0, sizeof (null_key));
433 if (0 == memcmp (key, &null_key, sizeof (null_key)))
440 * Ephemeral key message purpose size.
442 * @return Size of the part of the ephemeral key message that must be signed.
445 ephemeral_purpose_size (void)
447 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
448 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
449 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
450 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
451 sizeof (struct GNUNET_PeerIdentity);
456 * Size of the encrypted part of a ping message.
458 * @return Size of the encrypted part of a ping message.
461 ping_encryption_size (void)
463 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
468 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
470 * @param tch Tunnel's channel handle.
472 * @return Amount of messages the channel can still buffer towards the client.
475 get_channel_buffer (const struct CadetTChannel *tch)
479 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
480 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
482 return GCCH_get_buffer (tch->ch, fwd);
487 * Get the channel's allowance status.
489 * @param tch Tunnel's channel handle.
491 * @return #GNUNET_YES if we allowed the client to send data to us.
494 get_channel_allowed (const struct CadetTChannel *tch)
498 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
499 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
501 return GCCH_get_allowed (tch->ch, fwd);
506 * Get the connection's buffer.
508 * @param tc Tunnel's connection handle.
510 * @return Amount of messages the connection can still buffer.
513 get_connection_buffer (const struct CadetTConnection *tc)
517 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
518 fwd = GCC_is_origin (tc->c, GNUNET_YES);
520 return GCC_get_buffer (tc->c, fwd);
525 * Get the connection's allowance.
527 * @param tc Tunnel's connection handle.
529 * @return Amount of messages we have allowed the next peer to send us.
532 get_connection_allowed (const struct CadetTConnection *tc)
536 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
537 fwd = GCC_is_origin (tc->c, GNUNET_YES);
539 return GCC_get_allowed (tc->c, fwd);
544 * Check that a ephemeral key message s well formed and correctly signed.
546 * @param t Tunnel on which the message came.
547 * @param msg The ephemeral key message.
549 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
552 check_ephemeral (struct CadetTunnel *t,
553 const struct GNUNET_CADET_KX_Ephemeral *msg)
555 /* Check message size */
556 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
557 return GNUNET_SYSERR;
559 /* Check signature size */
560 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
561 return GNUNET_SYSERR;
564 if (0 != memcmp (&msg->origin_identity,
565 GCP_get_id (t->peer),
566 sizeof (struct GNUNET_PeerIdentity)))
567 return GNUNET_SYSERR;
569 /* Check signature */
571 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
574 &msg->origin_identity.public_key))
575 return GNUNET_SYSERR;
582 * Select the best key to use for encryption (send), based on KX status.
584 * Normally, return the current key. If there is a KX in progress and the old
585 * key is fresh enough, return the old key.
587 * @param t Tunnel to choose the key from.
589 * @return The optimal key to encrypt/hmac outgoing traffic.
591 static const struct GNUNET_CRYPTO_SymmetricSessionKey *
592 select_key (const struct CadetTunnel *t)
594 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
596 if (NULL != t->kx_ctx
597 && GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
599 struct GNUNET_TIME_Relative age;
601 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
602 LOG (GNUNET_ERROR_TYPE_DEBUG,
603 " key exchange in progress, started %s ago\n",
604 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
605 // FIXME make duration of old keys configurable
606 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
608 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
609 key = &t->kx_ctx->e_key_old;
613 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key (old key too old)\n");
619 LOG (GNUNET_ERROR_TYPE_DEBUG, " no KX: using current key\n");
629 * @param plaintext Content to HMAC.
630 * @param size Size of @c plaintext.
631 * @param iv Initialization vector for the message.
632 * @param key Key to use.
633 * @param hmac[out] Destination to store the HMAC.
636 t_hmac (const void *plaintext, size_t size,
637 uint32_t iv, const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
638 struct GNUNET_CADET_Hash *hmac)
640 static const char ctx[] = "cadet authentication key";
641 struct GNUNET_CRYPTO_AuthKey auth_key;
642 struct GNUNET_HashCode hash;
644 #if DUMP_KEYS_TO_STDERR
645 LOG (GNUNET_ERROR_TYPE_INFO, " HMAC with key %s\n",
646 GNUNET_h2s ((struct GNUNET_HashCode *) key));
648 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
653 /* Two step: CADET_Hash is only 256 bits, HashCode is 512. */
654 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
655 memcpy (hmac, &hash, sizeof (*hmac));
660 * Encrypt daforce_newest_keyta with the tunnel key.
662 * @param t Tunnel whose key to use.
663 * @param dst Destination for the encrypted data.
664 * @param src Source of the plaintext. Can overlap with @c dst.
665 * @param size Size of the plaintext.
666 * @param iv Initialization Vector to use.
667 * @param force_newest_key Force the use of the newest key, otherwise
668 * CADET will use the old key when allowed.
669 * This can happen in the case when a KX is going on
670 * and the old one hasn't expired.
673 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
674 size_t size, uint32_t iv, int force_newest_key)
676 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
677 const struct GNUNET_CRYPTO_SymmetricSessionKey *key;
680 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
682 key = GNUNET_YES == force_newest_key ? &t->e_key : select_key (t);
683 #if DUMP_KEYS_TO_STDERR
684 LOG (GNUNET_ERROR_TYPE_INFO, " ENC with key %s\n",
685 GNUNET_h2s ((struct GNUNET_HashCode *) key));
687 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
688 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
689 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, key, &siv, dst);
690 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
697 * Decrypt and verify data with the appropriate tunnel key.
699 * @param key Key to use.
700 * @param dst Destination for the plaintext.
701 * @param src Source of the encrypted data. Can overlap with @c dst.
702 * @param size Size of the encrypted data.
703 * @param iv Initialization Vector to use.
705 * @return Size of the decrypted data, -1 if an error was encountered.
708 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
709 void *dst, const void *src, size_t size, uint32_t iv)
711 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
714 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
715 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
716 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
717 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
718 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
719 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
726 * Decrypt and verify data with the most recent tunnel key.
728 * @param t Tunnel whose key to use.
729 * @param dst Destination for the plaintext.
730 * @param src Source of the encrypted data. Can overlap with @c dst.
731 * @param size Size of the encrypted data.
732 * @param iv Initialization Vector to use.
734 * @return Size of the decrypted data, -1 if an error was encountered.
737 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
738 size_t size, uint32_t iv)
742 #if DUMP_KEYS_TO_STDERR
743 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt with %s\n",
744 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
746 if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
748 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
749 LOG (GNUNET_ERROR_TYPE_WARNING,
750 "got data on %s without a valid key\n",
752 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
756 out_size = decrypt (&t->d_key, dst, src, size, iv);
763 * Decrypt and verify data with the appropriate tunnel key and verify that the
764 * data has not been altered since it was sent by the remote peer.
766 * @param t Tunnel whose key to use.
767 * @param dst Destination for the plaintext.
768 * @param src Source of the encrypted data. Can overlap with @c dst.
769 * @param size Size of the encrypted data.
770 * @param iv Initialization Vector to use.
771 * @param msg_hmac HMAC of the message, cannot be NULL.
773 * @return Size of the decrypted data, -1 if an error was encountered.
776 t_decrypt_and_validate (struct CadetTunnel *t,
777 void *dst, const void *src,
778 size_t size, uint32_t iv,
779 const struct GNUNET_CADET_Hash *msg_hmac)
781 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
782 struct GNUNET_CADET_Hash hmac;
785 /* Try primary (newest) key */
787 decrypted_size = decrypt (key, dst, src, size, iv);
788 t_hmac (src, size, iv, key, &hmac);
789 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
790 return decrypted_size;
792 /* If no key exchange is going on, we just failed */
793 if (NULL == t->kx_ctx)
795 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
796 "Failed checksum validation on tunnel %s with no KX\n",
798 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
802 /* Try secondary (from previous KX period) key */
803 key = &t->kx_ctx->d_key_old;
804 decrypted_size = decrypt (key, dst, src, size, iv);
805 t_hmac (src, size, iv, key, &hmac);
806 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
807 return decrypted_size;
809 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
810 "Failed checksum validation on tunnel %s with KX\n",
812 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
818 * Create key material by doing ECDH on the local and remote ephemeral keys.
820 * @param key_material Where to store the key material.
821 * @param ephemeral_key Peer's public ephemeral key.
824 derive_key_material (struct GNUNET_HashCode *key_material,
825 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
828 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
838 * Create a symmetic key from the identities of both ends and the key material
841 * @param key Destination for the generated key.
842 * @param sender ID of the peer that will encrypt with @c key.
843 * @param receiver ID of the peer that will decrypt with @c key.
844 * @param key_material Hash created with ECDH with the ephemeral keys.
847 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
848 const struct GNUNET_PeerIdentity *sender,
849 const struct GNUNET_PeerIdentity *receiver,
850 const struct GNUNET_HashCode *key_material)
852 const char salt[] = "CADET kx salt";
854 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
856 key_material, sizeof (struct GNUNET_HashCode),
857 sender, sizeof (struct GNUNET_PeerIdentity),
858 receiver, sizeof (struct GNUNET_PeerIdentity),
864 * Create a new Key eXchange context for the tunnel.
866 * If the old keys were verified, keep them for old traffic. Create a new KX
867 * timestamp and a new nonce.
869 * @param t Tunnel for which to create the KX ctx.
872 create_kx_ctx (struct CadetTunnel *t)
874 LOG (GNUNET_ERROR_TYPE_INFO, " new kx ctx for %s\n", GCT_2s (t));
876 if (NULL != t->kx_ctx)
878 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
880 LOG (GNUNET_ERROR_TYPE_INFO, " resetting exisiting finish task\n");
881 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
882 t->kx_ctx->finish_task = GNUNET_SCHEDULER_NO_TASK;
887 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
890 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
892 if (CADET_TUNNEL_KEY_OK == t->estate)
894 t->kx_ctx->d_key_old = t->d_key;
895 t->kx_ctx->e_key_old = t->e_key;
897 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
902 * @brief Finish the Key eXchange and destroy the old keys.
904 * @param cls Closure (Tunnel for which to finish the KX).
905 * @param tc Task context.
908 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
910 struct CadetTunnel *t = cls;
912 LOG (GNUNET_ERROR_TYPE_INFO, "finish KX for %s\n", GCT_2s (t));
914 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
916 LOG (GNUNET_ERROR_TYPE_INFO, " shutdown\n");
920 GNUNET_free (t->kx_ctx);
926 * Destroy a Key eXchange context for the tunnel. This function only schedules
927 * the destruction, the freeing of the memory (and clearing of old key material)
928 * happens after a delay!
930 * @param t Tunnel whose KX ctx to destroy.
933 destroy_kx_ctx (struct CadetTunnel *t)
935 struct GNUNET_TIME_Relative delay;
937 if (NULL == t->kx_ctx || GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
940 if (is_key_null (&t->kx_ctx->e_key_old))
942 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_now (finish_kx, t);
946 delay = GNUNET_TIME_relative_divide (rekey_period, 4);
947 delay = GNUNET_TIME_relative_min (delay, GNUNET_TIME_UNIT_MINUTES);
949 t->kx_ctx->finish_task = GNUNET_SCHEDULER_add_delayed (delay, finish_kx, t);
954 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
956 * @param t Tunnel for which to create the keys.
959 create_keys (struct CadetTunnel *t)
961 struct GNUNET_HashCode km;
963 derive_key_material (&km, &t->peers_ephemeral_key);
964 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
965 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
966 #if DUMP_KEYS_TO_STDERR
967 LOG (GNUNET_ERROR_TYPE_INFO, "ME: %s\n",
968 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
969 LOG (GNUNET_ERROR_TYPE_INFO, "PE: %s\n",
970 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
971 LOG (GNUNET_ERROR_TYPE_INFO, "KM: %s\n", GNUNET_h2s (&km));
972 LOG (GNUNET_ERROR_TYPE_INFO, "EK: %s\n",
973 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
974 LOG (GNUNET_ERROR_TYPE_INFO, "DK: %s\n",
975 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
981 * Pick a connection on which send the next data message.
983 * @param t Tunnel on which to send the message.
985 * @return The connection on which to send the next message.
987 static struct CadetConnection *
988 tunnel_get_connection (struct CadetTunnel *t)
990 struct CadetTConnection *iter;
991 struct CadetConnection *best;
993 unsigned int lowest_q;
995 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
998 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1000 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
1001 GCC_2s (iter->c), GCC_get_state (iter->c));
1002 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
1004 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
1005 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
1013 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
1019 * Callback called when a queued message is sent.
1021 * Calculates the average time and connection packet tracking.
1023 * @param cls Closure (TunnelQueue handle).
1024 * @param c Connection this message was on.
1025 * @param q Connection queue handle (unused).
1026 * @param type Type of message sent.
1027 * @param fwd Was this a FWD going message?
1028 * @param size Size of the message.
1031 tun_message_sent (void *cls,
1032 struct CadetConnection *c,
1033 struct CadetConnectionQueue *q,
1034 uint16_t type, int fwd, size_t size)
1036 struct CadetTunnelQueue *qt = cls;
1037 struct CadetTunnel *t;
1039 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
1041 GNUNET_assert (NULL != qt->cont);
1042 t = NULL == c ? NULL : GCC_get_tunnel (c);
1043 qt->cont (qt->cont_cls, t, qt, type, size);
1049 count_queued_data (const struct CadetTunnel *t)
1051 struct CadetTunnelDelayed *iter;
1054 for (count = 0, iter = t->tq_head; iter != NULL; iter = iter->next)
1061 * Delete a queued message: either was sent or the channel was destroyed
1062 * before the tunnel's key exchange had a chance to finish.
1064 * @param tqd Delayed queue handle.
1067 unqueue_data (struct CadetTunnelDelayed *tqd)
1069 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
1075 * Cache a message to be sent once tunnel is online.
1077 * @param t Tunnel to hold the message.
1078 * @param msg Message itself (copy will be made).
1080 static struct CadetTunnelDelayed *
1081 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
1083 struct CadetTunnelDelayed *tqd;
1084 uint16_t size = ntohs (msg->size);
1086 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
1088 if (GNUNET_YES == is_ready (t))
1094 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
1097 memcpy (&tqd[1], msg, size);
1098 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
1104 * Sends an already built message on a tunnel, encrypting it and
1105 * choosing the best connection.
1107 * @param message Message to send. Function modifies it.
1108 * @param t Tunnel on which this message is transmitted.
1109 * @param c Connection to use (autoselect if NULL).
1110 * @param force Force the tunnel to take the message (buffer overfill).
1111 * @param cont Continuation to call once message is really sent.
1112 * @param cont_cls Closure for @c cont.
1113 * @param existing_q In case this a transmission of previously queued data,
1114 * this should be TunnelQueue given to the client.
1117 * @return Handle to cancel message.
1118 * NULL if @c cont is NULL or an error happens and message is dropped.
1120 static struct CadetTunnelQueue *
1121 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1122 struct CadetTunnel *t, struct CadetConnection *c,
1123 int force, GCT_sent cont, void *cont_cls,
1124 struct CadetTunnelQueue *existing_q)
1126 struct CadetTunnelQueue *tq;
1127 struct GNUNET_CADET_Encrypted *msg;
1128 size_t size = ntohs (message->size);
1129 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
1135 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
1137 if (GNUNET_NO == is_ready (t))
1139 struct CadetTunnelDelayed *tqd;
1140 /* A non null existing_q indicates sending of queued data.
1141 * Should only happen after tunnel becomes ready.
1143 GNUNET_assert (NULL == existing_q);
1144 tqd = queue_data (t, message);
1147 tq = GNUNET_new (struct CadetTunnelQueue);
1151 tq->cont_cls = cont_cls;
1155 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
1157 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1158 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
1159 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
1161 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO) == size);
1162 t_hmac (&msg[1], size, iv, select_key (t), &msg->hmac);
1163 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
1166 c = tunnel_get_connection (t);
1169 /* Why is tunnel 'ready'? Should have been queued! */
1170 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
1173 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
1175 return NULL; /* Drop... */
1179 type = ntohs (message->type);
1182 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1183 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1184 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1185 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1187 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1189 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1190 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1191 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1192 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1193 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1194 msg->cid = *GCC_get_id (c);
1195 msg->ttl = htonl (default_ttl);
1199 LOG (GNUNET_ERROR_TYPE_ERROR, "type %s not valid\n", GC_m2s (type));
1201 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1203 fwd = GCC_is_origin (c, GNUNET_YES);
1207 GNUNET_break (NULL == GCC_send_prebuilt_message (&msg->header, type, mid, c,
1208 fwd, force, NULL, NULL));
1211 if (NULL == existing_q)
1213 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1220 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1221 &tun_message_sent, tq);
1222 GNUNET_assert (NULL != tq->cq);
1224 tq->cont_cls = cont_cls;
1231 * Send all cached messages that we can, tunnel is online.
1233 * @param t Tunnel that holds the messages. Cannot be loopback.
1236 send_queued_data (struct CadetTunnel *t)
1238 struct CadetTunnelDelayed *tqd;
1239 struct CadetTunnelDelayed *next;
1242 LOG (GNUNET_ERROR_TYPE_DEBUG,
1243 "GCT_send_queued_data on tunnel %s\n",
1246 if (GCT_is_loopback (t))
1252 if (GNUNET_NO == is_ready (t))
1254 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1255 estate2s (t->estate), cstate2s (t->cstate));
1259 room = GCT_get_connections_buffer (t);
1260 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1261 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1262 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1264 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1267 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1268 tqd->t, NULL, GNUNET_YES,
1269 NULL != tqd->tq ? tqd->tq->cont : NULL,
1270 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1274 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1279 * Sends key exchange message on a tunnel, choosing the best connection.
1280 * Should not be called on loopback tunnels.
1282 * @param t Tunnel on which this message is transmitted.
1283 * @param message Message to send. Function modifies it.
1286 send_kx (struct CadetTunnel *t,
1287 const struct GNUNET_MessageHeader *message)
1289 struct CadetConnection *c;
1290 struct GNUNET_CADET_KX *msg;
1291 size_t size = ntohs (message->size);
1292 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1296 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1298 /* Avoid loopback. */
1299 if (GCT_is_loopback (t))
1301 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1305 type = ntohs (message->type);
1307 /* Even if tunnel is being destroyed, send anyway.
1308 * Could be a response to a rekey initiated by remote peer,
1309 * who is trying to create a new channel!
1312 /* Must have a connection, or be looking for one. */
1313 if (NULL == t->connection_head)
1315 if (CADET_TUNNEL_SEARCHING != t->cstate)
1317 LOG (GNUNET_ERROR_TYPE_ERROR, "\n\n\n");
1319 LOG (GNUNET_ERROR_TYPE_ERROR, "no connection, sending %s\n", GC_m2s (type));
1320 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1321 GCP_debug (t->peer, GNUNET_ERROR_TYPE_ERROR);
1322 LOG (GNUNET_ERROR_TYPE_ERROR, "\n\n\n");
1327 msg = (struct GNUNET_CADET_KX *) cbuf;
1328 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1329 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1330 c = tunnel_get_connection (t);
1333 if (GNUNET_SCHEDULER_NO_TASK == t->destroy_task
1334 && CADET_TUNNEL_READY == t->cstate)
1337 GCT_debug (t, GNUNET_ERROR_TYPE_ERROR);
1343 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1344 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1345 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1346 memcpy (&msg[1], message, size);
1349 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1354 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1355 /* TODO save handle and cancel in case of a unneeded retransmission */
1356 GNUNET_assert (NULL == GCC_send_prebuilt_message (&msg->header, type, 0, c,
1363 * Send the ephemeral key on a tunnel.
1365 * @param t Tunnel on which to send the key.
1368 send_ephemeral (struct CadetTunnel *t)
1370 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1372 kx_msg.sender_status = htonl (t->estate);
1373 send_kx (t, &kx_msg.header);
1377 * Send a ping message on a tunnel.
1379 * @param t Tunnel on which to send the ping.
1382 send_ping (struct CadetTunnel *t)
1384 struct GNUNET_CADET_KX_Ping msg;
1386 LOG (GNUNET_ERROR_TYPE_INFO, "===> PING for %s\n", GCT_2s (t));
1387 msg.header.size = htons (sizeof (msg));
1388 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PING);
1389 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1390 msg.target = *GCP_get_id (t->peer);
1391 msg.nonce = t->kx_ctx->challenge;
1393 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1394 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
1395 t_encrypt (t, &msg.target, &msg.target,
1396 ping_encryption_size(), msg.iv, GNUNET_YES);
1397 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1398 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
1400 send_kx (t, &msg.header);
1405 * Send a pong message on a tunnel.
1407 * @param t Tunnel on which to send the pong.
1408 * @param challenge Value sent in the ping that we have to send back.
1411 send_pong (struct CadetTunnel *t, uint32_t challenge)
1413 struct GNUNET_CADET_KX_Pong msg;
1415 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1416 msg.header.size = htons (sizeof (msg));
1417 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1418 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1419 msg.nonce = challenge;
1420 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1421 t_encrypt (t, &msg.nonce, &msg.nonce,
1422 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1423 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1425 send_kx (t, &msg.header);
1430 * Initiate a rekey with the remote peer.
1432 * @param cls Closure (tunnel).
1433 * @param tc TaskContext.
1436 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1438 struct CadetTunnel *t = cls;
1440 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1442 LOG (GNUNET_ERROR_TYPE_INFO, "Re-key Tunnel %s\n", GCT_2s (t));
1443 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1448 if (NULL == t->kx_ctx)
1454 struct GNUNET_TIME_Relative duration;
1456 duration = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
1457 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx started %s ago\n",
1458 GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
1460 // FIXME make duration of old keys configurable
1461 if (duration.rel_value_us >= GNUNET_TIME_UNIT_MINUTES.rel_value_us)
1463 LOG (GNUNET_ERROR_TYPE_DEBUG, " deleting old keys\n");
1464 memset (&t->kx_ctx->d_key_old, 0, sizeof (t->kx_ctx->d_key_old));
1465 memset (&t->kx_ctx->e_key_old, 0, sizeof (t->kx_ctx->e_key_old));
1473 case CADET_TUNNEL_KEY_UNINITIALIZED:
1474 GCT_change_estate (t, CADET_TUNNEL_KEY_SENT);
1476 case CADET_TUNNEL_KEY_SENT:
1478 case CADET_TUNNEL_KEY_OK:
1479 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1481 case CADET_TUNNEL_KEY_PING:
1482 case CADET_TUNNEL_KEY_REKEY:
1486 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1489 // FIXME exponential backoff
1490 struct GNUNET_TIME_Relative delay;
1492 delay = GNUNET_TIME_relative_divide (rekey_period, 16);
1493 delay = GNUNET_TIME_relative_min (delay, REKEY_WAIT);
1494 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1495 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1496 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1501 * Our ephemeral key has changed, create new session key on all tunnels.
1503 * Each tunnel will start the Key Exchange with a random delay between
1504 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1505 * per second, on average.
1507 * @param cls Closure (size of the hashmap).
1508 * @param key Current public key.
1509 * @param value Value in the hash map (tunnel).
1511 * @return #GNUNET_YES, so we should continue to iterate,
1514 rekey_iterator (void *cls,
1515 const struct GNUNET_PeerIdentity *key,
1518 struct CadetTunnel *t = value;
1519 struct GNUNET_TIME_Relative delay;
1520 long n = (long) cls;
1523 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1526 if (GNUNET_YES == GCT_is_loopback (t))
1529 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1530 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1531 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1538 * Create a new ephemeral key and key message, schedule next rekeying.
1540 * @param cls Closure (unused).
1541 * @param tc TaskContext.
1544 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1546 struct GNUNET_TIME_Absolute time;
1549 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1551 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1554 GNUNET_free_non_null (my_ephemeral_key);
1555 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1557 time = GNUNET_TIME_absolute_get ();
1558 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1559 time = GNUNET_TIME_absolute_add (time, rekey_period);
1560 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1561 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1562 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1563 LOG (GNUNET_ERROR_TYPE_INFO, "GLOBAL RE-KEY, NEW EPHM: %s\n",
1564 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
1566 GNUNET_assert (GNUNET_OK ==
1567 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1569 &kx_msg.signature));
1571 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1572 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1574 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1579 * Called only on shutdown, destroy every tunnel.
1581 * @param cls Closure (unused).
1582 * @param key Current public key.
1583 * @param value Value in the hash map (tunnel).
1585 * @return #GNUNET_YES, so we should continue to iterate,
1588 destroy_iterator (void *cls,
1589 const struct GNUNET_PeerIdentity *key,
1592 struct CadetTunnel *t = value;
1594 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1601 * Notify remote peer that we don't know a channel he is talking about,
1602 * probably CHANNEL_DESTROY was missed.
1604 * @param t Tunnel on which to notify.
1605 * @param gid ID of the channel.
1608 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1610 struct GNUNET_CADET_ChannelManage msg;
1612 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1613 msg.header.size = htons (sizeof (msg));
1614 msg.chid = htonl (gid);
1616 LOG (GNUNET_ERROR_TYPE_DEBUG,
1617 "WARNING destroying unknown channel %u on tunnel %s\n",
1619 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1624 * Demultiplex data per channel and call appropriate channel handler.
1626 * @param t Tunnel on which the data came.
1627 * @param msg Data message.
1628 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1629 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1630 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1631 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1634 handle_data (struct CadetTunnel *t,
1635 const struct GNUNET_CADET_Data *msg,
1638 struct CadetChannel *ch;
1642 size = ntohs (msg->header.size);
1644 sizeof (struct GNUNET_CADET_Data) +
1645 sizeof (struct GNUNET_MessageHeader))
1650 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1651 GC_m2s (ntohs (msg[1].header.type)));
1654 ch = GCT_get_channel (t, ntohl (msg->chid));
1657 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1659 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1661 send_channel_destroy (t, ntohl (msg->chid));
1665 GCCH_handle_data (ch, msg, fwd);
1670 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1672 * @param t Tunnel on which the DATA ACK came.
1673 * @param msg DATA ACK message.
1674 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1675 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1676 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1677 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1680 handle_data_ack (struct CadetTunnel *t,
1681 const struct GNUNET_CADET_DataACK *msg,
1684 struct CadetChannel *ch;
1688 size = ntohs (msg->header.size);
1689 if (size != sizeof (struct GNUNET_CADET_DataACK))
1696 ch = GCT_get_channel (t, ntohl (msg->chid));
1699 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1701 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1706 GCCH_handle_data_ack (ch, msg, fwd);
1711 * Handle channel create.
1713 * @param t Tunnel on which the data came.
1714 * @param msg Data message.
1717 handle_ch_create (struct CadetTunnel *t,
1718 const struct GNUNET_CADET_ChannelCreate *msg)
1720 struct CadetChannel *ch;
1724 size = ntohs (msg->header.size);
1725 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1732 ch = GCT_get_channel (t, ntohl (msg->chid));
1733 if (NULL != ch && ! GCT_is_loopback (t))
1735 /* Probably a retransmission, safe to ignore */
1736 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1738 ch = GCCH_handle_create (t, msg);
1740 GCT_add_channel (t, ch);
1746 * Handle channel NACK: check correctness and call channel handler for NACKs.
1748 * @param t Tunnel on which the NACK came.
1749 * @param msg NACK message.
1752 handle_ch_nack (struct CadetTunnel *t,
1753 const struct GNUNET_CADET_ChannelManage *msg)
1755 struct CadetChannel *ch;
1759 size = ntohs (msg->header.size);
1760 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1767 ch = GCT_get_channel (t, ntohl (msg->chid));
1770 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1772 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1777 GCCH_handle_nack (ch);
1782 * Handle a CHANNEL ACK (SYNACK/ACK).
1784 * @param t Tunnel on which the CHANNEL ACK came.
1785 * @param msg CHANNEL ACK message.
1786 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1787 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1788 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1789 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1792 handle_ch_ack (struct CadetTunnel *t,
1793 const struct GNUNET_CADET_ChannelManage *msg,
1796 struct CadetChannel *ch;
1800 size = ntohs (msg->header.size);
1801 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1808 ch = GCT_get_channel (t, ntohl (msg->chid));
1811 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1813 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1818 GCCH_handle_ack (ch, msg, fwd);
1823 * Handle a channel destruction message.
1825 * @param t Tunnel on which the message came.
1826 * @param msg Channel destroy message.
1827 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1828 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1829 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1830 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1833 handle_ch_destroy (struct CadetTunnel *t,
1834 const struct GNUNET_CADET_ChannelManage *msg,
1837 struct CadetChannel *ch;
1841 size = ntohs (msg->header.size);
1842 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1849 ch = GCT_get_channel (t, ntohl (msg->chid));
1852 /* Probably a retransmission, safe to ignore */
1856 GCCH_handle_destroy (ch, msg, fwd);
1861 * The peer's ephemeral key has changed: update the symmetrical keys.
1863 * @param t Tunnel this message came on.
1864 * @param msg Key eXchange message.
1867 handle_ephemeral (struct CadetTunnel *t,
1868 const struct GNUNET_CADET_KX_Ephemeral *msg)
1870 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
1872 if (GNUNET_OK != check_ephemeral (t, msg))
1874 GNUNET_break_op (0);
1879 * If the key is different from what we know, derive the new E/D keys.
1880 * Else destroy the rekey ctx (duplicate EPHM after successful KX).
1882 if (0 != memcmp (&t->peers_ephemeral_key, &msg->ephemeral_key,
1883 sizeof (msg->ephemeral_key)))
1885 #if DUMP_KEYS_TO_STDERR
1886 LOG (GNUNET_ERROR_TYPE_INFO, "OLD: %s\n",
1887 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
1888 LOG (GNUNET_ERROR_TYPE_INFO, "NEW: %s\n",
1889 GNUNET_h2s ((struct GNUNET_HashCode *) &msg->ephemeral_key));
1891 t->peers_ephemeral_key = msg->ephemeral_key;
1894 if (CADET_TUNNEL_KEY_OK == t->estate)
1896 GCT_change_estate (t, CADET_TUNNEL_KEY_REKEY);
1898 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1899 GNUNET_SCHEDULER_cancel (t->rekey_task);
1900 t->rekey_task = GNUNET_SCHEDULER_add_now (rekey_tunnel, t);
1902 if (CADET_TUNNEL_KEY_SENT == t->estate)
1904 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending ping\n");
1906 GCT_change_estate (t, CADET_TUNNEL_KEY_PING);
1912 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1913 * Answer with by retransmitting the challenge with the "opposite" key.
1915 * @param t Tunnel this message came on.
1916 * @param msg Key eXchange Ping message.
1919 handle_ping (struct CadetTunnel *t,
1920 const struct GNUNET_CADET_KX_Ping *msg)
1922 struct GNUNET_CADET_KX_Ping res;
1924 if (ntohs (msg->header.size) != sizeof (res))
1926 GNUNET_break_op (0);
1930 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PING for %s\n", GCT_2s (t));
1931 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1932 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1934 /* probably peer hasn't got our new EPHM yet and derived the wrong keys */
1935 GNUNET_STATISTICS_update (stats, "# malformed PINGs", 1, GNUNET_NO);
1936 LOG (GNUNET_ERROR_TYPE_INFO, " malformed PING on %s\n", GCT_2s (t));
1937 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1938 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1939 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1940 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1947 send_pong (t, res.nonce);
1952 * Peer has answer to our challenge.
1953 * If answer is successful, consider the key exchange finished and clean
1954 * up all related state.
1956 * @param t Tunnel this message came on.
1957 * @param msg Key eXchange Pong message.
1960 handle_pong (struct CadetTunnel *t,
1961 const struct GNUNET_CADET_KX_Pong *msg)
1965 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
1966 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1968 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1971 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1973 if (challenge != t->kx_ctx->challenge)
1975 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
1976 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1977 challenge, msg->nonce, t->kx_ctx->challenge);
1982 GNUNET_SCHEDULER_cancel (t->rekey_task);
1983 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1985 /* Don't free the old keys right away, but after a delay.
1986 * Rationale: the KX could have happened over a very fast connection,
1987 * with payload traffic still signed with the old key stuck in a slower
1989 * Don't keep the keys longer than 1/4 the rekey period, and no longer than
1993 GCT_change_estate (t, CADET_TUNNEL_KEY_OK);
1998 * Demultiplex by message type and call appropriate handler for a message
1999 * towards a channel of a local tunnel.
2001 * @param t Tunnel this message came on.
2002 * @param msgh Message header.
2003 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2004 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2005 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2006 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2009 handle_decrypted (struct CadetTunnel *t,
2010 const struct GNUNET_MessageHeader *msgh,
2015 type = ntohs (msgh->type);
2016 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
2020 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2021 /* Do nothing, connection aleady got updated. */
2022 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
2025 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2026 /* Don't send hop ACK, wait for client to ACK */
2027 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
2030 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2031 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
2034 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2035 handle_ch_create (t,
2036 (struct GNUNET_CADET_ChannelCreate *) msgh);
2039 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2041 (struct GNUNET_CADET_ChannelManage *) msgh);
2044 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2046 (struct GNUNET_CADET_ChannelManage *) msgh,
2050 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2051 handle_ch_destroy (t,
2052 (struct GNUNET_CADET_ChannelManage *) msgh,
2057 GNUNET_break_op (0);
2058 LOG (GNUNET_ERROR_TYPE_WARNING,
2059 "end-to-end message not known (%u)\n",
2060 ntohs (msgh->type));
2061 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2065 /******************************************************************************/
2066 /******************************** API ***********************************/
2067 /******************************************************************************/
2070 * Decrypt and demultiplex by message type. Call appropriate handler
2071 * for every message.
2073 * @param t Tunnel this message came on.
2074 * @param msg Encrypted message.
2077 GCT_handle_encrypted (struct CadetTunnel *t,
2078 const struct GNUNET_CADET_Encrypted *msg)
2080 size_t size = ntohs (msg->header.size);
2081 size_t payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
2083 char cbuf [payload_size];
2084 struct GNUNET_MessageHeader *msgh;
2087 decrypted_size = t_decrypt_and_validate (t, cbuf, &msg[1], payload_size,
2088 msg->iv, &msg->hmac);
2090 if (-1 == decrypted_size)
2092 GNUNET_break_op (0);
2097 while (off < decrypted_size)
2101 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
2102 msize = ntohs (msgh->size);
2103 if (msize < sizeof (struct GNUNET_MessageHeader))
2105 GNUNET_break_op (0);
2108 handle_decrypted (t, msgh, GNUNET_SYSERR);
2115 * Demultiplex an encapsulated KX message by message type.
2117 * @param t Tunnel on which the message came.
2118 * @param message Payload of KX message.
2121 GCT_handle_kx (struct CadetTunnel *t,
2122 const struct GNUNET_MessageHeader *message)
2126 type = ntohs (message->type);
2127 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
2130 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
2131 handle_ephemeral (t, (struct GNUNET_CADET_KX_Ephemeral *) message);
2134 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
2135 handle_ping (t, (struct GNUNET_CADET_KX_Ping *) message);
2138 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
2139 handle_pong (t, (struct GNUNET_CADET_KX_Pong *) message);
2143 GNUNET_break_op (0);
2144 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
2150 * Initialize the tunnel subsystem.
2152 * @param c Configuration handle.
2153 * @param key ECC private key, to derive all other keys and do crypto.
2156 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
2157 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
2159 int expected_overhead;
2161 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2164 sizeof (struct GNUNET_CADET_Encrypted) + sizeof (struct GNUNET_CADET_Data);
2165 GNUNET_assert (GNUNET_CONSTANTS_CADET_P2P_OVERHEAD == expected_overhead);
2168 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
2171 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
2172 "CADET", "DEFAULT_TTL", "USING DEFAULT");
2176 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
2179 rekey_period = GNUNET_TIME_UNIT_DAYS;
2182 my_private_key = key;
2183 kx_msg.header.size = htons (sizeof (kx_msg));
2184 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
2185 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
2186 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
2187 kx_msg.origin_identity = my_full_id;
2188 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
2190 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
2195 * Shut down the tunnel subsystem.
2200 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
2202 GNUNET_SCHEDULER_cancel (rekey_task);
2203 rekey_task = GNUNET_SCHEDULER_NO_TASK;
2205 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
2206 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
2213 * @param destination Peer this tunnel is towards.
2215 struct CadetTunnel *
2216 GCT_new (struct CadetPeer *destination)
2218 struct CadetTunnel *t;
2220 t = GNUNET_new (struct CadetTunnel);
2222 t->peer = destination;
2225 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
2226 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2237 * Change the tunnel's connection state.
2239 * @param t Tunnel whose connection state to change.
2240 * @param cstate New connection state.
2243 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2247 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2248 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2249 if (myid != GCP_get_short_id (t->peer) &&
2250 CADET_TUNNEL_READY != t->cstate &&
2251 CADET_TUNNEL_READY == cstate)
2254 if (CADET_TUNNEL_KEY_OK == t->estate)
2256 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2257 send_queued_data (t);
2259 else if (CADET_TUNNEL_KEY_UNINITIALIZED == t->estate)
2261 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2262 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2263 GNUNET_SCHEDULER_cancel (t->rekey_task);
2264 rekey_tunnel (t, NULL);
2269 if (CADET_TUNNEL_READY == cstate
2270 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2272 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2273 GCP_stop_search (t->peer);
2279 * Change the tunnel encryption state.
2281 * @param t Tunnel whose encryption state to change, or NULL.
2282 * @param state New encryption state.
2285 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2290 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate was %s\n",
2291 GCP_2s (t->peer), estate2s (t->estate));
2292 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s estate is now %s\n",
2293 GCP_2s (t->peer), estate2s (state));
2295 /* Send queued data if enc state changes to OK */
2296 if (myid != GCP_get_short_id (t->peer) &&
2297 CADET_TUNNEL_KEY_OK != t->estate && CADET_TUNNEL_KEY_OK == state)
2299 send_queued_data (t);
2307 * @brief Check if tunnel has too many connections, and remove one if necessary.
2309 * Currently this means the newest connection, unless it is a direct one.
2310 * Implemented as a task to avoid freeing a connection that is in the middle
2311 * of being created/processed.
2313 * @param cls Closure (Tunnel to check).
2314 * @param tc Task context.
2317 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2319 struct CadetTunnel *t = cls;
2321 t->trim_connections_task = GNUNET_SCHEDULER_NO_TASK;
2323 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2326 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2328 struct CadetTConnection *iter;
2329 struct CadetTConnection *c;
2331 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2333 if ((iter->created.abs_value_us > c->created.abs_value_us)
2334 && GNUNET_NO == GCC_is_direct (iter->c))
2341 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2343 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2356 * Add a connection to a tunnel.
2359 * @param c Connection.
2362 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2364 struct CadetTConnection *aux;
2366 GNUNET_assert (NULL != c);
2368 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2369 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2370 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2374 aux = GNUNET_new (struct CadetTConnection);
2376 aux->created = GNUNET_TIME_absolute_get ();
2378 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2380 if (CADET_TUNNEL_SEARCHING == t->cstate)
2381 GCT_change_estate (t, CADET_TUNNEL_WAITING);
2383 if (GNUNET_SCHEDULER_NO_TASK != t->trim_connections_task)
2384 t->trim_connections_task = GNUNET_SCHEDULER_add_now (&trim_connections, t);
2389 * Remove a connection from a tunnel.
2392 * @param c Connection.
2395 GCT_remove_connection (struct CadetTunnel *t,
2396 struct CadetConnection *c)
2398 struct CadetTConnection *aux;
2399 struct CadetTConnection *next;
2402 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2403 GCC_2s (c), GCT_2s (t));
2404 for (aux = t->connection_head; aux != NULL; aux = next)
2409 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2414 conns = GCT_count_connections (t);
2416 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2417 && CADET_TUNNEL_SHUTDOWN != t->cstate
2418 && GNUNET_NO == shutting_down)
2420 if (0 == GCT_count_any_connections (t))
2421 GCT_change_cstate (t, CADET_TUNNEL_SEARCHING);
2423 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
2426 /* Start new connections if needed */
2427 if (CONNECTIONS_PER_TUNNEL > conns
2428 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2429 && CADET_TUNNEL_SHUTDOWN != t->cstate
2430 && GNUNET_NO == shutting_down)
2432 LOG (GNUNET_ERROR_TYPE_DEBUG, " too few connections, getting new ones\n");
2433 GCP_connect (t->peer); /* Will change cstate to WAITING when possible */
2437 /* If not marked as ready, no change is needed */
2438 if (CADET_TUNNEL_READY != t->cstate)
2441 /* Check if any connection is ready to maintain cstate */
2442 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2443 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2449 * Add a channel to a tunnel.
2452 * @param ch Channel.
2455 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2457 struct CadetTChannel *aux;
2459 GNUNET_assert (NULL != ch);
2461 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2463 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2465 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2470 aux = GNUNET_new (struct CadetTChannel);
2472 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2473 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2475 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2477 GNUNET_SCHEDULER_cancel (t->destroy_task);
2478 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2479 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2485 * Remove a channel from a tunnel.
2488 * @param ch Channel.
2491 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2493 struct CadetTChannel *aux;
2495 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2496 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2500 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2501 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2510 * Search for a channel by global ID.
2512 * @param t Tunnel containing the channel.
2513 * @param chid Public channel number.
2515 * @return channel handler, NULL if doesn't exist
2517 struct CadetChannel *
2518 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2520 struct CadetTChannel *iter;
2525 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2527 if (GCCH_get_id (iter->ch) == chid)
2531 return NULL == iter ? NULL : iter->ch;
2536 * @brief Destroy a tunnel and free all resources.
2538 * Should only be called a while after the tunnel has been marked as destroyed,
2539 * in case there is a new channel added to the same peer shortly after marking
2540 * the tunnel. This way we avoid a new public key handshake.
2542 * @param cls Closure (tunnel to destroy).
2543 * @param tc Task context.
2546 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2548 struct CadetTunnel *t = cls;
2549 struct CadetTConnection *iter;
2551 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2552 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2554 LOG (GNUNET_ERROR_TYPE_WARNING,
2555 "Not destroying tunnel, due to shutdown. "
2556 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2559 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2560 t->cstate = CADET_TUNNEL_SHUTDOWN;
2562 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2564 GCC_send_destroy (iter->c);
2571 * Tunnel is empty: destroy it.
2573 * Notifies all connections about the destruction.
2575 * @param t Tunnel to destroy.
2578 GCT_destroy_empty (struct CadetTunnel *t)
2580 if (GNUNET_YES == shutting_down)
2581 return; /* Will be destroyed immediately anyway */
2583 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2585 LOG (GNUNET_ERROR_TYPE_WARNING,
2586 "Tunnel %s is already scheduled for destruction. Tunnel debug dump:\n",
2588 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
2590 /* should never happen, tunnel can only become empty once, and the
2591 * task identifier should be NO_TASK (cleaned when the tunnel was created
2592 * or became un-empty)
2597 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2600 // FIXME make delay a config option
2601 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2602 &delayed_destroy, t);
2603 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llX\n",
2604 t, t->destroy_task);
2609 * Destroy tunnel if empty (no more channels).
2611 * @param t Tunnel to destroy if empty.
2614 GCT_destroy_if_empty (struct CadetTunnel *t)
2616 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2617 if (1 < GCT_count_channels (t))
2620 GCT_destroy_empty (t);
2625 * Destroy the tunnel.
2627 * This function does not generate any warning traffic to clients or peers.
2630 * Cancel messages belonging to this tunnel queued to neighbors.
2631 * Free any allocated resources linked to the tunnel.
2633 * @param t The tunnel to destroy.
2636 GCT_destroy (struct CadetTunnel *t)
2638 struct CadetTConnection *iter_c;
2639 struct CadetTConnection *next_c;
2640 struct CadetTChannel *iter_ch;
2641 struct CadetTChannel *next_ch;
2646 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
2648 GNUNET_break (GNUNET_YES ==
2649 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2650 GCP_get_id (t->peer), t));
2652 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2654 next_c = iter_c->next;
2655 GCC_destroy (iter_c->c);
2657 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2659 next_ch = iter_ch->next;
2660 GCCH_destroy (iter_ch->ch);
2661 /* Should only happen on shutdown, but it's ok. */
2664 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2666 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling dest: %llX\n", t->destroy_task);
2667 GNUNET_SCHEDULER_cancel (t->destroy_task);
2668 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2671 if (GNUNET_SCHEDULER_NO_TASK != t->trim_connections_task)
2673 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling trim: %llX\n",
2674 t->trim_connections_task);
2675 GNUNET_SCHEDULER_cancel (t->trim_connections_task);
2676 t->trim_connections_task = GNUNET_SCHEDULER_NO_TASK;
2679 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2680 GCP_set_tunnel (t->peer, NULL);
2682 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2684 GNUNET_SCHEDULER_cancel (t->rekey_task);
2685 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2687 if (NULL != t->kx_ctx)
2689 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
2690 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
2691 GNUNET_free (t->kx_ctx);
2698 * @brief Use the given path for the tunnel.
2699 * Update the next and prev hops (and RCs).
2700 * (Re)start the path refresh in case the tunnel is locally owned.
2702 * @param t Tunnel to update.
2703 * @param p Path to use.
2705 * @return Connection created.
2707 struct CadetConnection *
2708 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
2710 struct CadetConnection *c;
2711 struct GNUNET_CADET_Hash cid;
2712 unsigned int own_pos;
2714 if (NULL == t || NULL == p)
2720 if (CADET_TUNNEL_SHUTDOWN == t->cstate)
2726 for (own_pos = 0; own_pos < p->length; own_pos++)
2728 if (p->peers[own_pos] == myid)
2731 if (own_pos >= p->length)
2733 GNUNET_break_op (0);
2737 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2738 c = GCC_new (&cid, t, p, own_pos);
2741 /* Path was flawed */
2744 GCT_add_connection (t, c);
2750 * Count all created connections of a tunnel. Not necessarily ready connections!
2752 * @param t Tunnel on which to count.
2754 * @return Number of connections created, either being established or ready.
2757 GCT_count_any_connections (struct CadetTunnel *t)
2759 struct CadetTConnection *iter;
2765 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2773 * Count established (ready) connections of a tunnel.
2775 * @param t Tunnel on which to count.
2777 * @return Number of connections.
2780 GCT_count_connections (struct CadetTunnel *t)
2782 struct CadetTConnection *iter;
2788 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2789 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
2797 * Count channels of a tunnel.
2799 * @param t Tunnel on which to count.
2801 * @return Number of channels.
2804 GCT_count_channels (struct CadetTunnel *t)
2806 struct CadetTChannel *iter;
2809 for (count = 0, iter = t->channel_head;
2811 iter = iter->next, count++) /* skip */;
2818 * Get the connectivity state of a tunnel.
2822 * @return Tunnel's connectivity state.
2824 enum CadetTunnelCState
2825 GCT_get_cstate (struct CadetTunnel *t)
2830 return (enum CadetTunnelCState) -1;
2837 * Get the encryption state of a tunnel.
2841 * @return Tunnel's encryption state.
2843 enum CadetTunnelEState
2844 GCT_get_estate (struct CadetTunnel *t)
2849 return (enum CadetTunnelEState) -1;
2855 * Get the maximum buffer space for a tunnel towards a local client.
2859 * @return Biggest buffer space offered by any channel in the tunnel.
2862 GCT_get_channels_buffer (struct CadetTunnel *t)
2864 struct CadetTChannel *iter;
2865 unsigned int buffer;
2866 unsigned int ch_buf;
2868 if (NULL == t->channel_head)
2870 /* Probably getting buffer for a channel create/handshake. */
2875 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2877 ch_buf = get_channel_buffer (iter);
2878 if (ch_buf > buffer)
2886 * Get the total buffer space for a tunnel for P2P traffic.
2890 * @return Buffer space offered by all connections in the tunnel.
2893 GCT_get_connections_buffer (struct CadetTunnel *t)
2895 struct CadetTConnection *iter;
2896 unsigned int buffer;
2898 if (GNUNET_NO == is_ready (t))
2900 if (count_queued_data (t) > 3)
2907 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2909 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2913 buffer += get_connection_buffer (iter);
2921 * Get the tunnel's destination.
2925 * @return ID of the destination peer.
2927 const struct GNUNET_PeerIdentity *
2928 GCT_get_destination (struct CadetTunnel *t)
2930 return GCP_get_id (t->peer);
2935 * Get the tunnel's next free global channel ID.
2939 * @return GID of a channel free to use.
2942 GCT_get_next_chid (struct CadetTunnel *t)
2944 CADET_ChannelNumber chid;
2945 CADET_ChannelNumber mask;
2948 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2949 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2950 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2952 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2957 t->next_chid |= mask;
2959 while (NULL != GCT_get_channel (t, t->next_chid))
2961 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2962 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2963 t->next_chid |= mask;
2965 chid = t->next_chid;
2966 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2967 t->next_chid |= mask;
2974 * Send ACK on one or more channels due to buffer in connections.
2976 * @param t Channel which has some free buffer space.
2979 GCT_unchoke_channels (struct CadetTunnel *t)
2981 struct CadetTChannel *iter;
2982 unsigned int buffer;
2983 unsigned int channels = GCT_count_channels (t);
2984 unsigned int choked_n;
2985 struct CadetChannel *choked[channels];
2987 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
2988 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2989 if (NULL != t->channel_head)
2990 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2992 /* Get buffer space */
2993 buffer = GCT_get_connections_buffer (t);
2999 /* Count and remember choked channels */
3001 for (iter = t->channel_head; NULL != iter; iter = iter->next)
3003 if (GNUNET_NO == get_channel_allowed (iter))
3005 choked[choked_n++] = iter->ch;
3009 /* Unchoke random channels */
3010 while (0 < buffer && 0 < choked_n)
3012 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
3014 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
3017 choked[r] = choked[choked_n];
3023 * Send ACK on one or more connections due to buffer space to the client.
3025 * Iterates all connections of the tunnel and sends ACKs appropriately.
3030 GCT_send_connection_acks (struct CadetTunnel *t)
3032 struct CadetTConnection *iter;
3035 uint32_t allow_per_connection;
3037 unsigned int buffer;
3039 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
3048 buffer = GCT_get_channels_buffer (t);
3049 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
3051 /* Count connections, how many messages are already allowed */
3052 cs = GCT_count_connections (t);
3053 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
3055 allowed += get_connection_allowed (iter);
3057 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
3059 /* Make sure there is no overflow */
3060 if (allowed > buffer)
3065 /* Authorize connections to send more data */
3066 to_allow = buffer; /* FIXME (- allowed;) */
3068 for (iter = t->connection_head;
3069 NULL != iter && to_allow > 0;
3072 if (CADET_CONNECTION_READY != GCC_get_state (iter->c)
3073 || get_connection_allowed (iter) > 64 / 3)
3077 allow_per_connection = to_allow/cs;
3078 to_allow -= allow_per_connection;
3080 GCC_allow (iter->c, allow_per_connection,
3081 GCC_is_origin (iter->c, GNUNET_NO));
3087 GCT_debug (t, GNUNET_ERROR_TYPE_WARNING);
3088 LOG (GNUNET_ERROR_TYPE_WARNING, " reminding to_allow: %u\n", to_allow);
3094 * Cancel a previously sent message while it's in the queue.
3096 * ONLY can be called before the continuation given to the send function
3097 * is called. Once the continuation is called, the message is no longer in the
3100 * @param q Handle to the queue.
3103 GCT_cancel (struct CadetTunnelQueue *q)
3108 /* tun_message_sent() will be called and free q */
3110 else if (NULL != q->tqd)
3112 unqueue_data (q->tqd);
3114 if (NULL != q->cont)
3115 q->cont (q->cont_cls, NULL, q, 0, 0);
3126 * Sends an already built message on a tunnel, encrypting it and
3127 * choosing the best connection if not provided.
3129 * @param message Message to send. Function modifies it.
3130 * @param t Tunnel on which this message is transmitted.
3131 * @param c Connection to use (autoselect if NULL).
3132 * @param force Force the tunnel to take the message (buffer overfill).
3133 * @param cont Continuation to call once message is really sent.
3134 * @param cont_cls Closure for @c cont.
3136 * @return Handle to cancel message. NULL if @c cont is NULL.
3138 struct CadetTunnelQueue *
3139 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3140 struct CadetTunnel *t, struct CadetConnection *c,
3141 int force, GCT_sent cont, void *cont_cls)
3143 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
3147 * Sends an already built and encrypted message on a tunnel, choosing the best
3148 * connection. Useful for re-queueing messages queued on a destroyed connection.
3150 * @param message Message to send. Function modifies it.
3151 * @param t Tunnel on which this message is transmitted.
3154 GCT_resend_message (const struct GNUNET_MessageHeader *message,
3155 struct CadetTunnel *t)
3157 struct CadetConnection *c;
3160 c = tunnel_get_connection (t);
3163 /* TODO queue in tunnel, marked as encrypted */
3164 LOG (GNUNET_ERROR_TYPE_DEBUG, "No connection available, dropping.\n");
3167 fwd = GCC_is_origin (c, GNUNET_YES);
3168 GNUNET_break (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
3169 GNUNET_YES, NULL, NULL));
3174 * Is the tunnel directed towards the local peer?
3178 * @return #GNUNET_YES if it is loopback.
3181 GCT_is_loopback (const struct CadetTunnel *t)
3183 return (myid == GCP_get_short_id (t->peer));
3188 * Is the tunnel this path already?
3193 * @return #GNUNET_YES a connection uses this path.
3196 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
3198 struct CadetTConnection *iter;
3200 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3201 if (GCC_get_path (iter->c) == p)
3209 * Get a cost of a path for a tunnel considering existing connections.
3212 * @param path Candidate path.
3214 * @return Cost of the path (path length + number of overlapping nodes)
3217 GCT_get_path_cost (const struct CadetTunnel *t,
3218 const struct CadetPeerPath *path)
3220 struct CadetTConnection *iter;
3221 const struct CadetPeerPath *aux;
3222 unsigned int overlap;
3230 GNUNET_assert (NULL != t);
3232 for (i = 0; i < path->length; i++)
3234 for (iter = t->connection_head; NULL != iter; iter = iter->next)
3236 aux = GCC_get_path (iter->c);
3240 for (j = 0; j < aux->length; j++)
3242 if (path->peers[i] == aux->peers[j])
3250 return path->length + overlap;
3255 * Get the static string for the peer this tunnel is directed.
3259 * @return Static string the destination peer's ID.
3262 GCT_2s (const struct CadetTunnel *t)
3267 return GCP_2s (t->peer);
3271 /******************************************************************************/
3272 /***************************** INFO/DEBUG *******************************/
3273 /******************************************************************************/
3276 * Log all possible info about the tunnel state.
3278 * @param t Tunnel to debug.
3279 * @param level Debug level to use.
3282 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level)
3284 struct CadetTChannel *iterch;
3285 struct CadetTConnection *iterc;
3288 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3290 __FILE__, __FUNCTION__, __LINE__);
3294 LOG2 (level, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
3295 LOG2 (level, "TTT cstate %s, estate %s\n",
3296 cstate2s (t->cstate), estate2s (t->estate));
3297 LOG2 (level, "TTT kx_ctx %p, rekey_task %u, finish task %u\n",
3298 t->kx_ctx, t->rekey_task, t->kx_ctx ? t->kx_ctx->finish_task : 0);
3299 #if DUMP_KEYS_TO_STDERR
3300 LOG2 (level, "TTT my EPHM\t %s\n",
3301 GNUNET_h2s ((struct GNUNET_HashCode *) &kx_msg.ephemeral_key));
3302 LOG2 (level, "TTT peers EPHM:\t %s\n",
3303 GNUNET_h2s ((struct GNUNET_HashCode *) &t->peers_ephemeral_key));
3304 LOG2 (level, "TTT ENC key:\t %s\n",
3305 GNUNET_h2s ((struct GNUNET_HashCode *) &t->e_key));
3306 LOG2 (level, "TTT DEC key:\t %s\n",
3307 GNUNET_h2s ((struct GNUNET_HashCode *) &t->d_key));
3310 LOG2 (level, "TTT OLD ENC key:\t %s\n",
3311 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->e_key_old));
3312 LOG2 (level, "TTT OLD DEC key:\t %s\n",
3313 GNUNET_h2s ((struct GNUNET_HashCode *) &t->kx_ctx->d_key_old));
3316 LOG2 (level, "TTT tq_head %p, tq_tail %p\n", t->tq_head, t->tq_tail);
3317 LOG2 (level, "TTT destroy %u\n", t->destroy_task);
3319 LOG2 (level, "TTT channels:\n");
3320 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
3322 LOG2 (level, "TTT - %s\n", GCCH_2s (iterch->ch));
3325 LOG2 (level, "TTT connections:\n");
3326 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
3328 GCC_debug (iterc->c, level);
3331 LOG2 (level, "TTT DEBUG TUNNEL END\n");
3336 * Iterate all tunnels.
3338 * @param iter Iterator.
3339 * @param cls Closure for @c iter.
3342 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3344 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3349 * Count all tunnels.
3351 * @return Number of tunnels to remote peers kept by this peer.
3354 GCT_count_all (void)
3356 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3361 * Iterate all connections of a tunnel.
3363 * @param t Tunnel whose connections to iterate.
3364 * @param iter Iterator.
3365 * @param cls Closure for @c iter.
3368 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3370 struct CadetTConnection *ct;
3372 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3378 * Iterate all channels of a tunnel.
3380 * @param t Tunnel whose channels to iterate.
3381 * @param iter Iterator.
3382 * @param cls Closure for @c iter.
3385 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3387 struct CadetTChannel *cht;
3389 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3390 iter (cls, cht->ch);