2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 #include "gnunet_util_lib.h"
24 #include "gnunet_signatures.h"
25 #include "gnunet_statistics_service.h"
27 #include "cadet_protocol.h"
28 #include "cadet_path.h"
30 #include "gnunet-service-cadet_tunnel.h"
31 #include "gnunet-service-cadet_connection.h"
32 #include "gnunet-service-cadet_channel.h"
33 #include "gnunet-service-cadet_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"cadet-tun",__VA_ARGS__)
37 #define REKEY_WAIT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)
39 #define CONNECTIONS_PER_TUNNEL 3
41 /******************************************************************************/
42 /******************************** STRUCTS **********************************/
43 /******************************************************************************/
47 struct CadetTChannel *next;
48 struct CadetTChannel *prev;
49 struct CadetChannel *ch;
54 * Connection list and metadata.
56 struct CadetTConnection
61 struct CadetTConnection *next;
66 struct CadetTConnection *prev;
71 struct CadetConnection *c;
74 * Creation time, to keep oldest connection alive.
76 struct GNUNET_TIME_Absolute created;
79 * Connection throughput, to keep fastest connection alive.
85 * Structure used during a Key eXchange.
87 struct CadetTunnelKXCtx
90 * Encryption ("our") old key, for encrypting traffic sent by us
91 * end before the key exchange is finished or times out.
93 struct GNUNET_CRYPTO_SymmetricSessionKey e_key_old;
96 * Decryption ("their") old key, for decrypting traffic sent by the
97 * other end before the key exchange started.
99 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
102 * Challenge to send in a ping and expect in the pong.
107 * When the rekey started. One minute after this the new key will be used.
109 struct GNUNET_TIME_Absolute rekey_start_time;
112 * Task for delayed destruction of the Key eXchange context, to allow delayed
113 * messages with the old key to be decrypted successfully.
115 GNUNET_SCHEDULER_TaskIdentifier finish_task;
119 * Struct containing all information regarding a tunnel to a peer.
124 * Endpoint of the tunnel.
126 struct CadetPeer *peer;
129 * State of the tunnel connectivity.
131 enum CadetTunnelCState cstate;
134 * State of the tunnel encryption.
136 enum CadetTunnelEState estate;
139 * Key eXchange context.
141 struct CadetTunnelKXCtx *kx_ctx;
144 * Peer's ephemeral key, to recreate @c e_key and @c d_key when own ephemeral
147 struct GNUNET_CRYPTO_EcdhePublicKey peers_ephemeral_key;
150 * Encryption ("our") key.
152 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
155 * Decryption ("their") key.
157 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
160 * Task to start the rekey process.
162 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
165 * Paths that are actively used to reach the destination peer.
167 struct CadetTConnection *connection_head;
168 struct CadetTConnection *connection_tail;
171 * Next connection number.
176 * Channels inside this tunnel.
178 struct CadetTChannel *channel_head;
179 struct CadetTChannel *channel_tail;
182 * Channel ID for the next created channel.
184 CADET_ChannelNumber next_chid;
187 * Destroy flag: if true, destroy on last message.
189 GNUNET_SCHEDULER_TaskIdentifier destroy_task;
192 * Queued messages, to transmit once tunnel gets connected.
194 struct CadetTunnelDelayed *tq_head;
195 struct CadetTunnelDelayed *tq_tail;
200 * Struct used to save messages in a non-ready tunnel to send once connected.
202 struct CadetTunnelDelayed
207 struct CadetTunnelDelayed *next;
208 struct CadetTunnelDelayed *prev;
213 struct CadetTunnel *t;
216 * Tunnel queue given to the channel to cancel request. Update on send_queued.
218 struct CadetTunnelQueue *tq;
223 /* struct GNUNET_MessageHeader *msg; */
228 * Handle for messages queued but not yet sent.
230 struct CadetTunnelQueue
233 * Connection queue handle, to cancel if necessary.
235 struct CadetConnectionQueue *cq;
238 * Handle in case message hasn't been given to a connection yet.
240 struct CadetTunnelDelayed *tqd;
243 * Continuation to call once sent.
248 * Closure for @c cont.
254 /******************************************************************************/
255 /******************************* GLOBALS ***********************************/
256 /******************************************************************************/
259 * Global handle to the statistics service.
261 extern struct GNUNET_STATISTICS_Handle *stats;
264 * Local peer own ID (memory efficient handle).
266 extern GNUNET_PEER_Id myid;
269 * Local peer own ID (full value).
271 extern struct GNUNET_PeerIdentity my_full_id;
275 * Don't try to recover tunnels if shutting down.
277 extern int shutting_down;
281 * Set of all tunnels, in order to trigger a new exchange on rekey.
282 * Indexed by peer's ID.
284 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
287 * Default TTL for payload packets.
289 static unsigned long long default_ttl;
294 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
297 * Own ephemeral private key.
299 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
302 * Cached message used to perform a key exchange.
304 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
307 * Task to generate a new ephemeral key.
309 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
314 static struct GNUNET_TIME_Relative rekey_period;
316 /******************************************************************************/
317 /******************************** STATIC ***********************************/
318 /******************************************************************************/
321 * Get string description for tunnel connectivity state.
323 * @param cs Tunnel state.
325 * @return String representation.
328 cstate2s (enum CadetTunnelCState cs)
330 static char buf[128];
334 case CADET_TUNNEL3_NEW:
335 return "CADET_TUNNEL3_NEW";
336 case CADET_TUNNEL3_SEARCHING:
337 return "CADET_TUNNEL3_SEARCHING";
338 case CADET_TUNNEL3_WAITING:
339 return "CADET_TUNNEL3_WAITING";
340 case CADET_TUNNEL3_READY:
341 return "CADET_TUNNEL3_READY";
344 sprintf (buf, "%u (UNKNOWN STATE)", cs);
352 * Get string description for tunnel encryption state.
354 * @param es Tunnel state.
356 * @return String representation.
359 estate2s (enum CadetTunnelEState es)
361 static char buf[128];
365 case CADET_TUNNEL3_KEY_UNINITIALIZED:
366 return "CADET_TUNNEL3_KEY_UNINITIALIZED";
367 case CADET_TUNNEL3_KEY_SENT:
368 return "CADET_TUNNEL3_KEY_SENT";
369 case CADET_TUNNEL3_KEY_PING:
370 return "CADET_TUNNEL3_KEY_PING";
371 case CADET_TUNNEL3_KEY_OK:
372 return "CADET_TUNNEL3_KEY_OK";
375 sprintf (buf, "%u (UNKNOWN STATE)", es);
383 * @brief Check if tunnel is ready to send traffic.
385 * Tunnel must be connected and with encryption correctly set up.
387 * @param t Tunnel to check.
389 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
392 is_ready (struct CadetTunnel *t)
397 ready = (CADET_TUNNEL3_READY == t->cstate && CADET_TUNNEL3_KEY_OK == t->estate);
398 ready = ready || GCT_is_loopback (t);
404 * Ephemeral key message purpose size.
406 * @return Size of the part of the ephemeral key message that must be signed.
409 ephemeral_purpose_size (void)
411 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
412 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
413 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
414 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
415 sizeof (struct GNUNET_PeerIdentity);
420 * Size of the encrypted part of a ping message.
422 * @return Size of the encrypted part of a ping message.
425 ping_encryption_size (void)
427 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
432 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
434 * @param tch Tunnel's channel handle.
436 * @return Amount of messages the channel can still buffer towards the client.
439 get_channel_buffer (const struct CadetTChannel *tch)
443 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
444 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
446 return GCCH_get_buffer (tch->ch, fwd);
451 * Get the channel's allowance status.
453 * @param tch Tunnel's channel handle.
455 * @return #GNUNET_YES if we allowed the client to send data to us.
458 get_channel_allowed (const struct CadetTChannel *tch)
462 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
463 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
465 return GCCH_get_allowed (tch->ch, fwd);
470 * Get the connection's buffer.
472 * @param tc Tunnel's connection handle.
474 * @return Amount of messages the connection can still buffer.
477 get_connection_buffer (const struct CadetTConnection *tc)
481 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
482 fwd = GCC_is_origin (tc->c, GNUNET_YES);
484 return GCC_get_buffer (tc->c, fwd);
489 * Get the connection's allowance.
491 * @param tc Tunnel's connection handle.
493 * @return Amount of messages we have allowed the next peer to send us.
496 get_connection_allowed (const struct CadetTConnection *tc)
500 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
501 fwd = GCC_is_origin (tc->c, GNUNET_YES);
503 return GCC_get_allowed (tc->c, fwd);
508 * Check that a ephemeral key message s well formed and correctly signed.
510 * @param t Tunnel on which the message came.
511 * @param msg The ephemeral key message.
513 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
516 check_ephemeral (struct CadetTunnel *t,
517 const struct GNUNET_CADET_KX_Ephemeral *msg)
519 /* Check message size */
520 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
521 return GNUNET_SYSERR;
523 /* Check signature size */
524 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
525 return GNUNET_SYSERR;
528 if (0 != memcmp (&msg->origin_identity,
529 GCP_get_id (t->peer),
530 sizeof (struct GNUNET_PeerIdentity)))
531 return GNUNET_SYSERR;
533 /* Check signature */
535 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
538 &msg->origin_identity.public_key))
539 return GNUNET_SYSERR;
548 * @param t Tunnel to get keys from.
549 * @param plaintext Content to HMAC.
550 * @param size Size of @c plaintext.
551 * @param iv Initialization vector for the message.
552 * @param outgoing Is this an outgoing message that we encrypted?
553 * @param hmac Destination to store the HMAC.
556 t_hmac (struct CadetTunnel *t, const void *plaintext, size_t size, uint32_t iv,
557 int outgoing, struct GNUNET_CADET_Hash *hmac)
559 struct GNUNET_CRYPTO_AuthKey auth_key;
560 static const char ctx[] = "cadet authentication key";
561 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
562 struct GNUNET_HashCode hash;
564 key = outgoing ? &t->e_key : &t->d_key;
565 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
570 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
571 memcpy (hmac, &hash, sizeof (*hmac));
576 * Encrypt data with the tunnel key.
578 * @param t Tunnel whose key to use.
579 * @param dst Destination for the encrypted data.
580 * @param src Source of the plaintext. Can overlap with @c dst.
581 * @param size Size of the plaintext.
582 * @param iv Initialization Vector to use.
583 * @param force_newest_key Force the use of the newest key, otherwise
584 * CADET will use the old key when allowed.
585 * This can happen in the case when a KX is going on
586 * and the old one hasn't expired.
589 t_encrypt (struct CadetTunnel *t, void *dst, const void *src,
590 size_t size, uint32_t iv, int force_newest_key)
592 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
593 struct GNUNET_CRYPTO_SymmetricSessionKey *e_key;
596 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
597 if (GNUNET_NO == force_newest_key
599 && GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
601 struct GNUNET_TIME_Relative age;
603 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
604 LOG (GNUNET_ERROR_TYPE_DEBUG,
605 " key exchange in progress, started %s ago\n",
606 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
607 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
609 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
610 e_key = &t->kx_ctx->e_key_old;
614 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key\n");
622 GNUNET_CRYPTO_symmetric_derive_iv (&siv, e_key, &iv, sizeof (iv), NULL);
623 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
624 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, e_key, &siv, dst);
625 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
632 * Decrypt and verify data with the appropriate tunnel key.
634 * @param key Key to use.
635 * @param dst Destination for the plaintext.
636 * @param src Source of the encrypted data. Can overlap with @c dst.
637 * @param size Size of the encrypted data.
638 * @param iv Initialization Vector to use.
640 * @return Size of the decrypted data, -1 if an error was encountered.
643 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
644 void *dst, const void *src, size_t size, uint32_t iv)
646 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
649 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
650 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
651 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
652 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
653 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
654 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
661 * Decrypt and verify data with the most recent tunnel key.
663 * @param t Tunnel whose key to use.
664 * @param dst Destination for the plaintext.
665 * @param src Source of the encrypted data. Can overlap with @c dst.
666 * @param size Size of the encrypted data.
667 * @param iv Initialization Vector to use.
669 * @return Size of the decrypted data, -1 if an error was encountered.
672 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
673 size_t size, uint32_t iv)
675 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
678 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt start\n");
679 if (t->estate == CADET_TUNNEL3_KEY_OK || t->estate == CADET_TUNNEL3_KEY_PING)
685 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
686 LOG (GNUNET_ERROR_TYPE_WARNING,
687 "got data on %s without a valid key\n",
693 out_size = decrypt (key, dst, src, size, iv);
700 * Decrypt and verify data with the appropriate tunnel key and verify that the
701 * data has not been altered since it was sent by the remote peer.
703 * @param t Tunnel whose key to use.
704 * @param dst Destination for the plaintext.
705 * @param src Source of the encrypted data. Can overlap with @c dst.
706 * @param size Size of the encrypted data.
707 * @param iv Initialization Vector to use.
708 * @param msg_hmac HMAC of the message, cannot be NULL.
710 * @return Size of the decrypted data, -1 if an error was encountered.
713 t_decrypt_and_validate (struct CadetTunnel *t,
714 void *dst, const void *src,
715 size_t size, uint32_t iv,
716 const struct GNUNET_CADET_Hash *msg_hmac)
718 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
719 struct GNUNET_CADET_Hash hmac;
722 /* Try primary (newest) key */
724 decrypted_size = decrypt (key, dst, src, size, iv);
725 t_hmac (t, src, size, iv, GNUNET_NO, &hmac);
726 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
727 return decrypted_size;
729 /* If no key exchange is going on, we just failed */
730 if (NULL == t->kx_ctx)
732 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
733 "Failed checksum validation on tunnel %s with no KX\n",
735 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
739 /* Try secondary (from previous KX period) key */
740 key = &t->kx_ctx->d_key_old;
741 decrypted_size = decrypt (key, dst, src, size, iv);
742 t_hmac (t, src, size, iv, GNUNET_NO, &hmac);
743 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
744 return decrypted_size;
746 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
747 "Failed checksum validation on tunnel %s with KX\n",
749 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
755 * Create key material by doing ECDH on the local and remote ephemeral keys.
757 * @param key_material Where to store the key material.
758 * @param ephemeral_key Peer's public ephemeral key.
761 derive_key_material (struct GNUNET_HashCode *key_material,
762 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
765 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
775 * Create a symmetic key from the identities of both ends and the key material
778 * @param key Destination for the generated key.
779 * @param sender ID of the peer that will encrypt with @c key.
780 * @param receiver ID of the peer that will decrypt with @c key.
781 * @param key_material Hash created with ECDH with the ephemeral keys.
784 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
785 const struct GNUNET_PeerIdentity *sender,
786 const struct GNUNET_PeerIdentity *receiver,
787 const struct GNUNET_HashCode *key_material)
789 const char salt[] = "CADET kx salt";
791 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
793 key_material, sizeof (struct GNUNET_HashCode),
794 sender, sizeof (struct GNUNET_PeerIdentity),
795 receiver, sizeof (struct GNUNET_PeerIdentity),
801 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
803 * @param t Tunnel for which to create the keys.
806 create_keys (struct CadetTunnel *t)
808 struct GNUNET_HashCode km;
810 derive_key_material (&km, &t->peers_ephemeral_key);
811 LOG (GNUNET_ERROR_TYPE_INFO, "km %s\n", GNUNET_h2s_full (&km));
812 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
813 LOG (GNUNET_ERROR_TYPE_INFO, "ek %s\n", GNUNET_h2s_full (&t->e_key));
814 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
815 LOG (GNUNET_ERROR_TYPE_INFO, "dk %s\n", GNUNET_h2s_full (&t->d_key));
820 * Pick a connection on which send the next data message.
822 * @param t Tunnel on which to send the message.
824 * @return The connection on which to send the next message.
826 static struct CadetConnection *
827 tunnel_get_connection (struct CadetTunnel *t)
829 struct CadetTConnection *iter;
830 struct CadetConnection *best;
832 unsigned int lowest_q;
834 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
837 for (iter = t->connection_head; NULL != iter; iter = iter->next)
839 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
840 GCC_2s (iter->c), GCC_get_state (iter->c));
841 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
843 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
844 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
852 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
858 * Callback called when a queued message is sent.
860 * Calculates the average time and connection packet tracking.
862 * @param cls Closure (TunnelQueue handle).
863 * @param c Connection this message was on.
864 * @param q Connection queue handle (unused).
865 * @param type Type of message sent.
866 * @param fwd Was this a FWD going message?
867 * @param size Size of the message.
870 tun_message_sent (void *cls,
871 struct CadetConnection *c,
872 struct CadetConnectionQueue *q,
873 uint16_t type, int fwd, size_t size)
875 struct CadetTunnelQueue *qt = cls;
876 struct CadetTunnel *t;
878 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
880 GNUNET_assert (NULL != qt->cont);
881 t = NULL == c ? NULL : GCC_get_tunnel (c);
882 qt->cont (qt->cont_cls, t, qt, type, size);
888 * Delete a queued message: either was sent or the channel was destroyed
889 * before the tunnel's key exchange had a chance to finish.
891 * @param tqd Delayed queue handle.
894 unqueue_data (struct CadetTunnelDelayed *tqd)
896 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
902 * Cache a message to be sent once tunnel is online.
904 * @param t Tunnel to hold the message.
905 * @param msg Message itself (copy will be made).
907 static struct CadetTunnelDelayed *
908 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
910 struct CadetTunnelDelayed *tqd;
911 uint16_t size = ntohs (msg->size);
913 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
915 if (GNUNET_YES == is_ready (t))
921 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
924 memcpy (&tqd[1], msg, size);
925 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
931 * Sends an already built message on a tunnel, encrypting it and
932 * choosing the best connection.
934 * @param message Message to send. Function modifies it.
935 * @param t Tunnel on which this message is transmitted.
936 * @param c Connection to use (autoselect if NULL).
937 * @param force Force the tunnel to take the message (buffer overfill).
938 * @param cont Continuation to call once message is really sent.
939 * @param cont_cls Closure for @c cont.
940 * @param existing_q In case this a transmission of previously queued data,
941 * this should be TunnelQueue given to the client.
944 * @return Handle to cancel message. NULL if @c cont is NULL.
946 static struct CadetTunnelQueue *
947 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
948 struct CadetTunnel *t, struct CadetConnection *c,
949 int force, GCT_sent cont, void *cont_cls,
950 struct CadetTunnelQueue *existing_q)
952 struct CadetTunnelQueue *tq;
953 struct GNUNET_CADET_Encrypted *msg;
954 size_t size = ntohs (message->size);
955 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
961 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
963 if (GNUNET_NO == is_ready (t))
965 struct CadetTunnelDelayed *tqd;
966 /* A non null existing_q indicates sending of queued data.
967 * Should only happen after tunnel becomes ready.
969 GNUNET_assert (NULL == existing_q);
970 tqd = queue_data (t, message);
973 tq = GNUNET_new (struct CadetTunnelQueue);
977 tq->cont_cls = cont_cls;
981 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
983 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
984 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
985 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
987 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv, GNUNET_NO) == size);
988 t_hmac (t, &msg[1], size, iv, GNUNET_YES, &msg->hmac);
989 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
992 c = tunnel_get_connection (t);
995 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
996 || CADET_TUNNEL3_SEARCHING != t->cstate)
1005 type = ntohs (message->type);
1008 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1009 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1010 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1011 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1013 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1015 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1016 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1017 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1018 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1019 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1020 msg->cid = *GCC_get_id (c);
1021 msg->ttl = htonl (default_ttl);
1026 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1028 fwd = GCC_is_origin (c, GNUNET_YES);
1032 GNUNET_break (NULL ==
1033 GCC_send_prebuilt_message (&msg->header, type, mid,
1034 c, fwd, force, NULL, NULL));
1037 if (NULL == existing_q)
1039 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1046 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1047 &tun_message_sent, tq);
1049 tq->cont_cls = cont_cls;
1056 * Send all cached messages that we can, tunnel is online.
1058 * @param t Tunnel that holds the messages. Cannot be loopback.
1061 send_queued_data (struct CadetTunnel *t)
1063 struct CadetTunnelDelayed *tqd;
1064 struct CadetTunnelDelayed *next;
1067 LOG (GNUNET_ERROR_TYPE_DEBUG,
1068 "GCT_send_queued_data on tunnel %s\n",
1071 if (GCT_is_loopback (t))
1077 if (GNUNET_NO == is_ready (t))
1079 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1080 estate2s (t->estate), cstate2s (t->cstate));
1084 room = GCT_get_connections_buffer (t);
1085 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1086 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1087 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1089 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1092 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1093 tqd->t, NULL, GNUNET_YES,
1094 NULL != tqd->tq ? tqd->tq->cont : NULL,
1095 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1099 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1104 * Sends key exchange message on a tunnel, choosing the best connection.
1105 * Should not be called on loopback tunnels.
1107 * @param t Tunnel on which this message is transmitted.
1108 * @param message Message to send. Function modifies it.
1111 send_kx (struct CadetTunnel *t,
1112 const struct GNUNET_MessageHeader *message)
1114 struct CadetConnection *c;
1115 struct GNUNET_CADET_KX *msg;
1116 size_t size = ntohs (message->size);
1117 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1121 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1123 /* Avoid loopback. */
1124 if (GCT_is_loopback (t))
1126 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1131 /* Even if tunnel is being destroyed, send anyway.
1132 * Could be a response to a rekey initiated by remote peer,
1133 * who is trying to create a new channel!
1136 /* Must have a connection. */
1137 if (NULL == t->connection_head)
1139 GNUNET_break (CADET_TUNNEL3_SEARCHING == t->cstate);
1144 msg = (struct GNUNET_CADET_KX *) cbuf;
1145 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1146 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1147 c = tunnel_get_connection (t);
1150 GNUNET_break (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
1151 || CADET_TUNNEL3_READY != t->cstate);
1155 type = ntohs (message->type);
1158 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1159 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1160 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1161 memcpy (&msg[1], message, size);
1164 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1169 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1170 /* TODO save handle and cancel in case of a unneeded retransmission */
1171 GCC_send_prebuilt_message (&msg->header, GNUNET_MESSAGE_TYPE_CADET_KX,
1172 message->type, c, fwd, GNUNET_YES, NULL, NULL);
1177 * Send the ephemeral key on a tunnel.
1179 * @param t Tunnel on which to send the key.
1182 send_ephemeral (struct CadetTunnel *t)
1184 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1186 kx_msg.sender_status = htonl (t->estate);
1187 send_kx (t, &kx_msg.header);
1191 * Send a ping message on a tunnel.
1193 * @param t Tunnel on which to send the ping.
1196 send_ping (struct CadetTunnel *t)
1198 struct GNUNET_CADET_KX_Ping msg;
1200 LOG (GNUNET_ERROR_TYPE_INFO, "===> PING for %s\n", GCT_2s (t));
1201 msg.header.size = htons (sizeof (msg));
1202 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PING);
1203 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1204 msg.target = *GCP_get_id (t->peer);
1205 msg.nonce = t->kx_ctx->challenge;
1207 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1208 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
1209 t_encrypt (t, &msg.target, &msg.target,
1210 ping_encryption_size(), msg.iv, GNUNET_YES);
1211 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1212 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
1214 send_kx (t, &msg.header);
1219 * Send a pong message on a tunnel.
1221 * @param t Tunnel on which to send the pong.
1222 * @param challenge Value sent in the ping that we have to send back.
1225 send_pong (struct CadetTunnel *t, uint32_t challenge)
1227 struct GNUNET_CADET_KX_Pong msg;
1229 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1230 msg.header.size = htons (sizeof (msg));
1231 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1232 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1233 msg.nonce = challenge;
1234 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1235 t_encrypt (t, &msg.nonce, &msg.nonce,
1236 sizeof (msg.nonce), msg.iv, GNUNET_YES);
1237 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1239 send_kx (t, &msg.header);
1244 * Initiate a rekey with the remote peer.
1246 * @param cls Closure (tunnel).
1247 * @param tc TaskContext.
1250 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1252 struct CadetTunnel *t = cls;
1254 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1256 LOG (GNUNET_ERROR_TYPE_DEBUG, "Re-key Tunnel %s\n", GCT_2s (t));
1257 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1260 if (NULL == t->kx_ctx)
1262 LOG (GNUNET_ERROR_TYPE_DEBUG, " new kx ctx\n");
1263 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1264 t->kx_ctx->challenge =
1265 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1266 t->kx_ctx->d_key_old = t->d_key;
1267 t->kx_ctx->e_key_old = t->e_key;
1269 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1270 LOG (GNUNET_ERROR_TYPE_DEBUG, " new challenge for %s: %u\n",
1271 GCT_2s (t), t->kx_ctx->challenge);
1278 case CADET_TUNNEL3_KEY_UNINITIALIZED:
1279 t->estate = CADET_TUNNEL3_KEY_SENT;
1281 case CADET_TUNNEL3_KEY_SENT:
1283 case CADET_TUNNEL3_KEY_PING:
1284 case CADET_TUNNEL3_KEY_OK:
1286 t->estate = CADET_TUNNEL3_KEY_PING;
1289 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1292 // FIXME exponential backoff
1293 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1294 GNUNET_STRINGS_relative_time_to_string (REKEY_WAIT, GNUNET_YES));
1295 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
1300 * Our ephemeral key has changed, create new session key on all tunnels.
1302 * Each tunnel will start the Key Exchange with a random delay between
1303 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1304 * per second, on average.
1306 * @param cls Closure (size of the hashmap).
1307 * @param key Current public key.
1308 * @param value Value in the hash map (tunnel).
1310 * @return #GNUNET_YES, so we should continue to iterate,
1313 rekey_iterator (void *cls,
1314 const struct GNUNET_PeerIdentity *key,
1317 struct CadetTunnel *t = value;
1318 struct GNUNET_TIME_Relative delay;
1319 long n = (long) cls;
1322 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1325 if (GNUNET_YES == GCT_is_loopback (t))
1328 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1329 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1330 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1337 * Create a new ephemeral key and key message, schedule next rekeying.
1339 * @param cls Closure (unused).
1340 * @param tc TaskContext.
1343 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1345 struct GNUNET_TIME_Absolute time;
1348 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1350 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1353 GNUNET_free_non_null (my_ephemeral_key);
1354 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1356 time = GNUNET_TIME_absolute_get ();
1357 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1358 time = GNUNET_TIME_absolute_add (time, rekey_period);
1359 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1360 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1361 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1363 GNUNET_assert (GNUNET_OK ==
1364 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1366 &kx_msg.signature));
1368 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1369 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1371 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1376 * Called only on shutdown, destroy every tunnel.
1378 * @param cls Closure (unused).
1379 * @param key Current public key.
1380 * @param value Value in the hash map (tunnel).
1382 * @return #GNUNET_YES, so we should continue to iterate,
1385 destroy_iterator (void *cls,
1386 const struct GNUNET_PeerIdentity *key,
1389 struct CadetTunnel *t = value;
1391 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1398 * Notify remote peer that we don't know a channel he is talking about,
1399 * probably CHANNEL_DESTROY was missed.
1401 * @param t Tunnel on which to notify.
1402 * @param gid ID of the channel.
1405 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1407 struct GNUNET_CADET_ChannelManage msg;
1409 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1410 msg.header.size = htons (sizeof (msg));
1411 msg.chid = htonl (gid);
1413 LOG (GNUNET_ERROR_TYPE_DEBUG,
1414 "WARNING destroying unknown channel %u on tunnel %s\n",
1416 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1421 * Demultiplex data per channel and call appropriate channel handler.
1423 * @param t Tunnel on which the data came.
1424 * @param msg Data message.
1425 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1426 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1427 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1428 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1431 handle_data (struct CadetTunnel *t,
1432 const struct GNUNET_CADET_Data *msg,
1435 struct CadetChannel *ch;
1439 size = ntohs (msg->header.size);
1441 sizeof (struct GNUNET_CADET_Data) +
1442 sizeof (struct GNUNET_MessageHeader))
1447 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1448 GC_m2s (ntohs (msg[1].header.type)));
1451 ch = GCT_get_channel (t, ntohl (msg->chid));
1454 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1456 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1458 send_channel_destroy (t, ntohl (msg->chid));
1462 GCCH_handle_data (ch, msg, fwd);
1467 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1469 * @param t Tunnel on which the DATA ACK came.
1470 * @param msg DATA ACK message.
1471 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1472 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1473 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1474 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1477 handle_data_ack (struct CadetTunnel *t,
1478 const struct GNUNET_CADET_DataACK *msg,
1481 struct CadetChannel *ch;
1485 size = ntohs (msg->header.size);
1486 if (size != sizeof (struct GNUNET_CADET_DataACK))
1493 ch = GCT_get_channel (t, ntohl (msg->chid));
1496 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1498 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1503 GCCH_handle_data_ack (ch, msg, fwd);
1508 * Handle channel create.
1510 * @param t Tunnel on which the data came.
1511 * @param msg Data message.
1514 handle_ch_create (struct CadetTunnel *t,
1515 const struct GNUNET_CADET_ChannelCreate *msg)
1517 struct CadetChannel *ch;
1521 size = ntohs (msg->header.size);
1522 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1529 ch = GCT_get_channel (t, ntohl (msg->chid));
1530 if (NULL != ch && ! GCT_is_loopback (t))
1532 /* Probably a retransmission, safe to ignore */
1533 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1535 ch = GCCH_handle_create (t, msg);
1537 GCT_add_channel (t, ch);
1543 * Handle channel NACK: check correctness and call channel handler for NACKs.
1545 * @param t Tunnel on which the NACK came.
1546 * @param msg NACK message.
1549 handle_ch_nack (struct CadetTunnel *t,
1550 const struct GNUNET_CADET_ChannelManage *msg)
1552 struct CadetChannel *ch;
1556 size = ntohs (msg->header.size);
1557 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1564 ch = GCT_get_channel (t, ntohl (msg->chid));
1567 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1569 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1574 GCCH_handle_nack (ch);
1579 * Handle a CHANNEL ACK (SYNACK/ACK).
1581 * @param t Tunnel on which the CHANNEL ACK came.
1582 * @param msg CHANNEL ACK message.
1583 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1584 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1585 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1586 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1589 handle_ch_ack (struct CadetTunnel *t,
1590 const struct GNUNET_CADET_ChannelManage *msg,
1593 struct CadetChannel *ch;
1597 size = ntohs (msg->header.size);
1598 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1605 ch = GCT_get_channel (t, ntohl (msg->chid));
1608 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1610 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1615 GCCH_handle_ack (ch, msg, fwd);
1620 * Handle a channel destruction message.
1622 * @param t Tunnel on which the message came.
1623 * @param msg Channel destroy message.
1624 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1625 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1626 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1627 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1630 handle_ch_destroy (struct CadetTunnel *t,
1631 const struct GNUNET_CADET_ChannelManage *msg,
1634 struct CadetChannel *ch;
1638 size = ntohs (msg->header.size);
1639 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1646 ch = GCT_get_channel (t, ntohl (msg->chid));
1649 /* Probably a retransmission, safe to ignore */
1653 GCCH_handle_destroy (ch, msg, fwd);
1658 * The peer's ephemeral key has changed: update the symmetrical keys.
1660 * @param t Tunnel this message came on.
1661 * @param msg Key eXchange message.
1664 handle_ephemeral (struct CadetTunnel *t,
1665 const struct GNUNET_CADET_KX_Ephemeral *msg)
1667 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
1669 if (GNUNET_OK != check_ephemeral (t, msg))
1671 GNUNET_break_op (0);
1674 t->peers_ephemeral_key = msg->ephemeral_key;
1676 if (CADET_TUNNEL3_KEY_SENT == t->estate)
1678 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending ping\n");
1680 t->estate = CADET_TUNNEL3_KEY_PING;
1686 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1687 * Answer with by retransmitting the challenge with the "opposite" key.
1689 * @param t Tunnel this message came on.
1690 * @param msg Key eXchange Ping message.
1693 handle_ping (struct CadetTunnel *t,
1694 const struct GNUNET_CADET_KX_Ping *msg)
1696 struct GNUNET_CADET_KX_Ping res;
1698 if (ntohs (msg->header.size) != sizeof (res))
1700 GNUNET_break_op (0);
1704 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PING for %s\n", GCT_2s (t));
1705 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1706 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1708 GNUNET_STATISTICS_update (stats, "# malformed PINGs", 1, GNUNET_NO);
1709 LOG (GNUNET_ERROR_TYPE_WARNING, " malformed PING on %s\n", GCT_2s (t));
1710 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1711 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1712 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1713 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1719 send_pong (t, res.nonce);
1722 * @brief Finish the Key eXchange and destory the old keys.
1724 * @param cls Closure (Tunnel for which to finish the KX).
1725 * @param tc Task context.
1728 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1730 struct CadetTunnel *t = cls;
1732 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1735 GNUNET_free (t->kx_ctx);
1741 * Peer has answer to our challenge.
1742 * If answer is successful, consider the key exchange finished and clean
1743 * up all related state.
1745 * @param t Tunnel this message came on.
1746 * @param msg Key eXchange Pong message.
1749 handle_pong (struct CadetTunnel *t,
1750 const struct GNUNET_CADET_KX_Pong *msg)
1754 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
1755 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1757 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1760 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1762 if (challenge != t->kx_ctx->challenge)
1764 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
1765 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1766 challenge, msg->nonce, t->kx_ctx->challenge);
1771 GNUNET_SCHEDULER_cancel (t->rekey_task);
1772 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1774 /* Don't free the old keys right away, but after a delay.
1775 * Rationale: the KX could have happened over a very fast connection,
1776 * with payload traffic still signed with the old key stuck in a slower
1779 if (GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
1781 t->kx_ctx->finish_task =
1782 GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_MINUTES, finish_kx, t);
1784 GCT_change_estate (t, CADET_TUNNEL3_KEY_OK);
1789 * Demultiplex by message type and call appropriate handler for a message
1790 * towards a channel of a local tunnel.
1792 * @param t Tunnel this message came on.
1793 * @param msgh Message header.
1794 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1795 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1796 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1797 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1800 handle_decrypted (struct CadetTunnel *t,
1801 const struct GNUNET_MessageHeader *msgh,
1806 type = ntohs (msgh->type);
1807 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
1811 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1812 /* Do nothing, connection aleady got updated. */
1813 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
1816 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1817 /* Don't send hop ACK, wait for client to ACK */
1818 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
1821 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1822 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1825 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1826 handle_ch_create (t,
1827 (struct GNUNET_CADET_ChannelCreate *) msgh);
1830 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1832 (struct GNUNET_CADET_ChannelManage *) msgh);
1835 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1837 (struct GNUNET_CADET_ChannelManage *) msgh,
1841 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1842 handle_ch_destroy (t,
1843 (struct GNUNET_CADET_ChannelManage *) msgh,
1848 GNUNET_break_op (0);
1849 LOG (GNUNET_ERROR_TYPE_WARNING,
1850 "end-to-end message not known (%u)\n",
1851 ntohs (msgh->type));
1856 /******************************************************************************/
1857 /******************************** API ***********************************/
1858 /******************************************************************************/
1861 * Decrypt and demultiplex by message type. Call appropriate handler
1862 * for every message.
1864 * @param t Tunnel this message came on.
1865 * @param msg Encrypted message.
1868 GCT_handle_encrypted (struct CadetTunnel *t,
1869 const struct GNUNET_CADET_Encrypted *msg)
1871 size_t size = ntohs (msg->header.size);
1872 size_t payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
1874 char cbuf [payload_size];
1875 struct GNUNET_MessageHeader *msgh;
1878 decrypted_size = t_decrypt_and_validate (t, cbuf, &msg[1], payload_size,
1879 msg->iv, &msg->hmac);
1882 while (off < decrypted_size)
1884 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1885 handle_decrypted (t, msgh, GNUNET_SYSERR);
1886 off += ntohs (msgh->size);
1892 * Demultiplex an encapsulated KX message by message type.
1894 * @param t Tunnel on which the message came.
1895 * @param message Payload of KX message.
1898 GCT_handle_kx (struct CadetTunnel *t,
1899 const struct GNUNET_MessageHeader *message)
1903 type = ntohs (message->type);
1904 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1907 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1908 handle_ephemeral (t, (struct GNUNET_CADET_KX_Ephemeral *) message);
1911 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1912 handle_ping (t, (struct GNUNET_CADET_KX_Ping *) message);
1915 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1916 handle_pong (t, (struct GNUNET_CADET_KX_Pong *) message);
1920 GNUNET_break_op (0);
1921 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1927 * Initialize the tunnel subsystem.
1929 * @param c Configuration handle.
1930 * @param key ECC private key, to derive all other keys and do crypto.
1933 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1934 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1936 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1938 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
1941 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1942 "CADET", "DEFAULT_TTL", "USING DEFAULT");
1946 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
1949 rekey_period = GNUNET_TIME_UNIT_DAYS;
1952 my_private_key = key;
1953 kx_msg.header.size = htons (sizeof (kx_msg));
1954 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
1955 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
1956 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1957 kx_msg.origin_identity = my_full_id;
1958 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1960 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1965 * Shut down the tunnel subsystem.
1970 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1972 GNUNET_SCHEDULER_cancel (rekey_task);
1973 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1975 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
1976 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1983 * @param destination Peer this tunnel is towards.
1985 struct CadetTunnel *
1986 GCT_new (struct CadetPeer *destination)
1988 struct CadetTunnel *t;
1990 t = GNUNET_new (struct CadetTunnel);
1992 t->peer = destination;
1995 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
1996 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
2007 * Change the tunnel's connection state.
2009 * @param t Tunnel whose connection state to change.
2010 * @param cstate New connection state.
2013 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2017 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2018 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2019 if (myid != GCP_get_short_id (t->peer) &&
2020 CADET_TUNNEL3_READY != t->cstate &&
2021 CADET_TUNNEL3_READY == cstate)
2024 if (CADET_TUNNEL3_KEY_OK == t->estate)
2026 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2027 send_queued_data (t);
2029 else if (CADET_TUNNEL3_KEY_UNINITIALIZED == t->estate)
2031 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2032 rekey_tunnel (t, NULL);
2037 if (CADET_TUNNEL3_READY == cstate
2038 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2040 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2041 GCP_stop_search (t->peer);
2046 * Change the tunnel encryption state.
2048 * @param t Tunnel whose encryption state to change.
2049 * @param state New encryption state.
2052 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2056 LOG (GNUNET_ERROR_TYPE_DEBUG,
2057 "Tunnel %s estate was %s\n",
2058 GCP_2s (t->peer), estate2s (t->estate));
2059 LOG (GNUNET_ERROR_TYPE_DEBUG,
2060 "Tunnel %s estate is now %s\n",
2061 GCP_2s (t->peer), estate2s (state));
2062 if (myid != GCP_get_short_id (t->peer) &&
2063 CADET_TUNNEL3_KEY_OK != t->estate && CADET_TUNNEL3_KEY_OK == state)
2066 send_queued_data (t);
2074 * @brief Check if tunnel has too many connections, and remove one if necessary.
2076 * Currently this means the newest connection, unless it is a direct one.
2077 * Implemented as a task to avoid freeing a connection that is in the middle
2078 * of being created/processed.
2080 * @param cls Closure (Tunnel to check).
2081 * @param tc Task context.
2084 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2086 struct CadetTunnel *t = cls;
2088 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2091 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2093 struct CadetTConnection *iter;
2094 struct CadetTConnection *c;
2096 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2098 if ((NULL == c || iter->created.abs_value_us > c->created.abs_value_us)
2099 && GNUNET_NO == GCC_is_direct (iter->c))
2106 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2108 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2121 * Add a connection to a tunnel.
2124 * @param c Connection.
2127 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2129 struct CadetTConnection *aux;
2131 GNUNET_assert (NULL != c);
2133 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2134 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2135 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2139 aux = GNUNET_new (struct CadetTConnection);
2141 aux->created = GNUNET_TIME_absolute_get ();
2143 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2145 GNUNET_SCHEDULER_add_now (&trim_connections, t);
2150 * Mark a path as no longer valid for this tunnel: has been tried and failed.
2152 * @param t Tunnel to update.
2153 * @param path Invalid path to remove. Is destroyed after removal.
2156 GCT_remove_path (struct CadetTunnel *t, struct CadetPeerPath *path)
2158 GCP_remove_path (t->peer, path);
2163 * Remove a connection from a tunnel.
2166 * @param c Connection.
2169 GCT_remove_connection (struct CadetTunnel *t,
2170 struct CadetConnection *c)
2172 struct CadetTConnection *aux;
2173 struct CadetTConnection *next;
2175 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2176 GCC_2s (c), GCT_2s (t));
2177 for (aux = t->connection_head; aux != NULL; aux = next)
2182 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2187 /* Start new connections if needed */
2188 if (CONNECTIONS_PER_TUNNEL < GCT_count_connections (t)
2189 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2190 && CADET_TUNNEL3_SHUTDOWN != t->cstate
2191 && GNUNET_NO == shutting_down)
2193 LOG (GNUNET_ERROR_TYPE_DEBUG, " no more connections, getting new ones\n");
2194 t->cstate = CADET_TUNNEL3_SEARCHING;
2195 GCP_connect (t->peer);
2199 /* If not marked as ready, no change is needed */
2200 if (CADET_TUNNEL3_READY != t->cstate)
2203 /* Check if any connection is ready to maintaing cstate */
2204 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2205 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2208 t->cstate = CADET_TUNNEL3_WAITING;
2213 * Add a channel to a tunnel.
2216 * @param ch Channel.
2219 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2221 struct CadetTChannel *aux;
2223 GNUNET_assert (NULL != ch);
2225 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2227 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2229 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2234 aux = GNUNET_new (struct CadetTChannel);
2236 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2237 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2239 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2241 GNUNET_SCHEDULER_cancel (t->destroy_task);
2242 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2243 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2249 * Remove a channel from a tunnel.
2252 * @param ch Channel.
2255 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2257 struct CadetTChannel *aux;
2259 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2260 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2264 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2265 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2274 * Search for a channel by global ID.
2276 * @param t Tunnel containing the channel.
2277 * @param chid Public channel number.
2279 * @return channel handler, NULL if doesn't exist
2281 struct CadetChannel *
2282 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2284 struct CadetTChannel *iter;
2289 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2291 if (GCCH_get_id (iter->ch) == chid)
2295 return NULL == iter ? NULL : iter->ch;
2300 * @brief Destroy a tunnel and free all resources.
2302 * Should only be called a while after the tunnel has been marked as destroyed,
2303 * in case there is a new channel added to the same peer shortly after marking
2304 * the tunnel. This way we avoid a new public key handshake.
2306 * @param cls Closure (tunnel to destroy).
2307 * @param tc Task context.
2310 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2312 struct CadetTunnel *t = cls;
2313 struct CadetTConnection *iter;
2315 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2316 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2318 LOG (GNUNET_ERROR_TYPE_WARNING,
2319 "Not destroying tunnel, due to shutdown. "
2320 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2323 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2324 t->cstate = CADET_TUNNEL3_SHUTDOWN;
2326 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2328 GCC_send_destroy (iter->c);
2335 * Tunnel is empty: destroy it.
2337 * Notifies all connections about the destruction.
2339 * @param t Tunnel to destroy.
2342 GCT_destroy_empty (struct CadetTunnel *t)
2344 if (GNUNET_YES == shutting_down)
2345 return; /* Will be destroyed immediately anyway */
2347 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2349 LOG (GNUNET_ERROR_TYPE_DEBUG,
2350 "Tunnel %s is already scheduled for destruction\n",
2353 /* should never happen, tunnel can only become empty once, and the
2354 * task identifier should be NO_TASK (cleaned when the tunnel was created
2355 * or became un-empty)
2360 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2363 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2364 &delayed_destroy, t);
2365 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llX\n",
2366 t, t->destroy_task);
2371 * Destroy tunnel if empty (no more channels).
2373 * @param t Tunnel to destroy if empty.
2376 GCT_destroy_if_empty (struct CadetTunnel *t)
2378 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2379 if (1 < GCT_count_channels (t))
2382 GCT_destroy_empty (t);
2387 * Destroy the tunnel.
2389 * This function does not generate any warning traffic to clients or peers.
2392 * Cancel messages belonging to this tunnel queued to neighbors.
2393 * Free any allocated resources linked to the tunnel.
2395 * @param t The tunnel to destroy.
2398 GCT_destroy (struct CadetTunnel *t)
2400 struct CadetTConnection *iter_c;
2401 struct CadetTConnection *next_c;
2402 struct CadetTChannel *iter_ch;
2403 struct CadetTChannel *next_ch;
2408 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
2410 GNUNET_break (GNUNET_YES ==
2411 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2412 GCP_get_id (t->peer), t));
2414 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2416 next_c = iter_c->next;
2417 GCC_destroy (iter_c->c);
2419 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2421 next_ch = iter_ch->next;
2422 GCCH_destroy (iter_ch->ch);
2423 /* Should only happen on shutdown, but it's ok. */
2426 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2428 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling %llX\n", t->destroy_task);
2429 GNUNET_SCHEDULER_cancel (t->destroy_task);
2430 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2433 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2434 GCP_set_tunnel (t->peer, NULL);
2436 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2438 GNUNET_SCHEDULER_cancel (t->rekey_task);
2439 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2441 if (NULL != t->kx_ctx)
2443 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
2444 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
2445 GNUNET_free (t->kx_ctx);
2452 * @brief Use the given path for the tunnel.
2453 * Update the next and prev hops (and RCs).
2454 * (Re)start the path refresh in case the tunnel is locally owned.
2456 * @param t Tunnel to update.
2457 * @param p Path to use.
2459 * @return Connection created.
2461 struct CadetConnection *
2462 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
2464 struct CadetConnection *c;
2465 struct GNUNET_CADET_Hash cid;
2466 unsigned int own_pos;
2468 if (NULL == t || NULL == p)
2474 if (CADET_TUNNEL3_SHUTDOWN == t->cstate)
2480 for (own_pos = 0; own_pos < p->length; own_pos++)
2482 if (p->peers[own_pos] == myid)
2485 if (own_pos >= p->length)
2487 GNUNET_break_op (0);
2491 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2492 c = GCC_new (&cid, t, p, own_pos);
2495 /* Path was flawed */
2498 GCT_add_connection (t, c);
2504 * Count established (ready) connections of a tunnel.
2506 * @param t Tunnel on which to count.
2508 * @return Number of connections.
2511 GCT_count_connections (struct CadetTunnel *t)
2513 struct CadetTConnection *iter;
2519 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2520 if (CADET_CONNECTION_DESTROYED != GCC_get_state (iter->c))
2527 * Count channels of a tunnel.
2529 * @param t Tunnel on which to count.
2531 * @return Number of channels.
2534 GCT_count_channels (struct CadetTunnel *t)
2536 struct CadetTChannel *iter;
2539 for (count = 0, iter = t->channel_head;
2541 iter = iter->next, count++) /* skip */;
2548 * Get the connectivity state of a tunnel.
2552 * @return Tunnel's connectivity state.
2554 enum CadetTunnelCState
2555 GCT_get_cstate (struct CadetTunnel *t)
2560 return (enum CadetTunnelCState) -1;
2567 * Get the encryption state of a tunnel.
2571 * @return Tunnel's encryption state.
2573 enum CadetTunnelEState
2574 GCT_get_estate (struct CadetTunnel *t)
2579 return (enum CadetTunnelEState) -1;
2585 * Get the maximum buffer space for a tunnel towards a local client.
2589 * @return Biggest buffer space offered by any channel in the tunnel.
2592 GCT_get_channels_buffer (struct CadetTunnel *t)
2594 struct CadetTChannel *iter;
2595 unsigned int buffer;
2596 unsigned int ch_buf;
2598 if (NULL == t->channel_head)
2600 /* Probably getting buffer for a channel create/handshake. */
2605 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2607 ch_buf = get_channel_buffer (iter);
2608 if (ch_buf > buffer)
2616 * Get the total buffer space for a tunnel for P2P traffic.
2620 * @return Buffer space offered by all connections in the tunnel.
2623 GCT_get_connections_buffer (struct CadetTunnel *t)
2625 struct CadetTConnection *iter;
2626 unsigned int buffer;
2629 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2631 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2635 buffer += get_connection_buffer (iter);
2643 * Get the tunnel's destination.
2647 * @return ID of the destination peer.
2649 const struct GNUNET_PeerIdentity *
2650 GCT_get_destination (struct CadetTunnel *t)
2652 return GCP_get_id (t->peer);
2657 * Get the tunnel's next free global channel ID.
2661 * @return GID of a channel free to use.
2664 GCT_get_next_chid (struct CadetTunnel *t)
2666 CADET_ChannelNumber chid;
2667 CADET_ChannelNumber mask;
2670 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2671 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2672 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2674 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2679 t->next_chid |= mask;
2681 while (NULL != GCT_get_channel (t, t->next_chid))
2683 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2684 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2685 t->next_chid |= mask;
2687 chid = t->next_chid;
2688 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2689 t->next_chid |= mask;
2696 * Send ACK on one or more channels due to buffer in connections.
2698 * @param t Channel which has some free buffer space.
2701 GCT_unchoke_channels (struct CadetTunnel *t)
2703 struct CadetTChannel *iter;
2704 unsigned int buffer;
2705 unsigned int channels = GCT_count_channels (t);
2706 unsigned int choked_n;
2707 struct CadetChannel *choked[channels];
2709 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
2710 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2711 if (NULL != t->channel_head)
2712 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2714 /* Get buffer space */
2715 buffer = GCT_get_connections_buffer (t);
2721 /* Count and remember choked channels */
2723 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2725 if (GNUNET_NO == get_channel_allowed (iter))
2727 choked[choked_n++] = iter->ch;
2731 /* Unchoke random channels */
2732 while (0 < buffer && 0 < choked_n)
2734 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
2736 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
2739 choked[r] = choked[choked_n];
2745 * Send ACK on one or more connections due to buffer space to the client.
2747 * Iterates all connections of the tunnel and sends ACKs appropriately.
2752 GCT_send_connection_acks (struct CadetTunnel *t)
2754 struct CadetTConnection *iter;
2757 uint32_t allow_per_connection;
2759 unsigned int buffer;
2761 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
2770 buffer = GCT_get_channels_buffer (t);
2771 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
2773 /* Count connections, how many messages are already allowed */
2774 cs = GCT_count_connections (t);
2775 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2777 allowed += get_connection_allowed (iter);
2779 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
2781 /* Make sure there is no overflow */
2782 if (allowed > buffer)
2787 /* Authorize connections to send more data */
2788 to_allow = buffer; /* - allowed; */
2790 for (iter = t->connection_head;
2791 NULL != iter && to_allow > 0;
2794 allow_per_connection = to_allow/cs;
2795 to_allow -= allow_per_connection;
2797 if (get_connection_allowed (iter) > 64 / 3)
2801 GCC_allow (iter->c, allow_per_connection,
2802 GCC_is_origin (iter->c, GNUNET_NO));
2805 GNUNET_break (to_allow == 0);
2810 * Cancel a previously sent message while it's in the queue.
2812 * ONLY can be called before the continuation given to the send function
2813 * is called. Once the continuation is called, the message is no longer in the
2816 * @param q Handle to the queue.
2819 GCT_cancel (struct CadetTunnelQueue *q)
2824 /* tun_message_sent() will be called and free q */
2826 else if (NULL != q->tqd)
2828 unqueue_data (q->tqd);
2830 if (NULL != q->cont)
2831 q->cont (q->cont_cls, NULL, q, 0, 0);
2842 * Sends an already built message on a tunnel, encrypting it and
2843 * choosing the best connection if not provided.
2845 * @param message Message to send. Function modifies it.
2846 * @param t Tunnel on which this message is transmitted.
2847 * @param c Connection to use (autoselect if NULL).
2848 * @param force Force the tunnel to take the message (buffer overfill).
2849 * @param cont Continuation to call once message is really sent.
2850 * @param cont_cls Closure for @c cont.
2852 * @return Handle to cancel message. NULL if @c cont is NULL.
2854 struct CadetTunnelQueue *
2855 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2856 struct CadetTunnel *t, struct CadetConnection *c,
2857 int force, GCT_sent cont, void *cont_cls)
2859 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
2864 * Is the tunnel directed towards the local peer?
2868 * @return #GNUNET_YES if it is loopback.
2871 GCT_is_loopback (const struct CadetTunnel *t)
2873 return (myid == GCP_get_short_id (t->peer));
2878 * Is the tunnel this path already?
2883 * @return #GNUNET_YES a connection uses this path.
2886 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
2888 struct CadetTConnection *iter;
2890 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2891 if (GCC_get_path (iter->c) == p)
2899 * Get a cost of a path for a tunnel considering existing connections.
2902 * @param path Candidate path.
2904 * @return Cost of the path (path length + number of overlapping nodes)
2907 GCT_get_path_cost (const struct CadetTunnel *t,
2908 const struct CadetPeerPath *path)
2910 struct CadetTConnection *iter;
2911 const struct CadetPeerPath *aux;
2912 unsigned int overlap;
2920 GNUNET_assert (NULL != t);
2922 for (i = 0; i < path->length; i++)
2924 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2926 aux = GCC_get_path (iter->c);
2930 for (j = 0; j < aux->length; j++)
2932 if (path->peers[i] == aux->peers[j])
2940 return path->length + overlap;
2945 * Get the static string for the peer this tunnel is directed.
2949 * @return Static string the destination peer's ID.
2952 GCT_2s (const struct CadetTunnel *t)
2957 return GCP_2s (t->peer);
2961 /******************************************************************************/
2962 /***************************** INFO/DEBUG *******************************/
2963 /******************************************************************************/
2967 * Log all possible info about the tunnel state to stderr.
2969 * @param t Tunnel to debug.
2972 GCT_debug (const struct CadetTunnel *t)
2974 struct CadetTChannel *iterch;
2975 struct CadetTConnection *iterc;
2977 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
2978 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT cstate %s, estate %s\n",
2979 cstate2s (t->cstate), estate2s (t->estate));
2980 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT kx_ctx %p, rekey_task %u\n",
2981 t->kx_ctx, t->rekey_task);
2982 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT tq_head %p, tq_tail %p\n",
2983 t->tq_head, t->tq_tail);
2984 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT destroy %u\n", t->destroy_task);
2986 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT channels:\n");
2987 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
2989 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT - %s\n", GCCH_2s (iterch->ch));
2992 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT connections:\n");
2993 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
2995 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT - %s [%u] buf: %u/%u (qn %u/%u)\n",
2996 GCC_2s (iterc->c), GCC_get_state (iterc->c),
2997 GCC_get_buffer (iterc->c, GNUNET_YES),
2998 GCC_get_buffer (iterc->c, GNUNET_NO),
2999 GCC_get_qn (iterc->c, GNUNET_YES),
3000 GCC_get_qn (iterc->c, GNUNET_NO));
3003 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT DEBUG TUNNEL END\n");
3008 * Iterate all tunnels.
3010 * @param iter Iterator.
3011 * @param cls Closure for @c iter.
3014 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3016 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3021 * Count all tunnels.
3023 * @return Number of tunnels to remote peers kept by this peer.
3026 GCT_count_all (void)
3028 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3033 * Iterate all connections of a tunnel.
3035 * @param t Tunnel whose connections to iterate.
3036 * @param iter Iterator.
3037 * @param cls Closure for @c iter.
3040 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3042 struct CadetTConnection *ct;
3044 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3050 * Iterate all channels of a tunnel.
3052 * @param t Tunnel whose channels to iterate.
3053 * @param iter Iterator.
3054 * @param cls Closure for @c iter.
3057 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3059 struct CadetTChannel *cht;
3061 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3062 iter (cls, cht->ch);