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.
585 t_encrypt (struct CadetTunnel *t,
586 void *dst, const void *src,
587 size_t size, uint32_t iv)
589 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
590 struct GNUNET_CRYPTO_SymmetricSessionKey *e_key;
593 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
594 if (NULL != t->kx_ctx && GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
596 struct GNUNET_TIME_Relative age;
598 age = GNUNET_TIME_absolute_get_duration (t->kx_ctx->rekey_start_time);
599 LOG (GNUNET_ERROR_TYPE_DEBUG,
600 " key exchange in progress, started %s ago\n",
601 GNUNET_STRINGS_relative_time_to_string (age, GNUNET_YES));
602 if (age.rel_value_us < GNUNET_TIME_UNIT_MINUTES.rel_value_us)
604 LOG (GNUNET_ERROR_TYPE_DEBUG, " using old key\n");
605 e_key = &t->kx_ctx->e_key_old;
609 LOG (GNUNET_ERROR_TYPE_DEBUG, " using new key\n");
617 GNUNET_CRYPTO_symmetric_derive_iv (&siv, e_key, &iv, sizeof (iv), NULL);
618 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
619 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, e_key, &siv, dst);
620 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
627 * Decrypt and verify data with the appropriate tunnel key.
629 * @param key Key to use.
630 * @param dst Destination for the plaintext.
631 * @param src Source of the encrypted data. Can overlap with @c dst.
632 * @param size Size of the encrypted data.
633 * @param iv Initialization Vector to use.
635 * @return Size of the decrypted data, -1 if an error was encountered.
638 decrypt (const struct GNUNET_CRYPTO_SymmetricSessionKey *key,
639 void *dst, const void *src, size_t size, uint32_t iv)
641 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
644 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt start\n");
645 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv\n");
646 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
647 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt iv done\n");
648 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
649 LOG (GNUNET_ERROR_TYPE_DEBUG, " decrypt end\n");
656 * Decrypt and verify data with the most recent tunnel key.
658 * @param t Tunnel whose key to use.
659 * @param dst Destination for the plaintext.
660 * @param src Source of the encrypted data. Can overlap with @c dst.
661 * @param size Size of the encrypted data.
662 * @param iv Initialization Vector to use.
664 * @return Size of the decrypted data, -1 if an error was encountered.
667 t_decrypt (struct CadetTunnel *t, void *dst, const void *src,
668 size_t size, uint32_t iv)
670 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
673 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt start\n");
674 if (t->estate == CADET_TUNNEL3_KEY_OK || t->estate == CADET_TUNNEL3_KEY_PING)
680 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
681 LOG (GNUNET_ERROR_TYPE_WARNING,
682 "got data on %s without a valid key\n",
688 out_size = decrypt (key, dst, src, size, iv);
695 * Decrypt and verify data with the appropriate tunnel key and verify that the
696 * data has not been altered since it was sent by the remote peer.
698 * @param t Tunnel whose key to use.
699 * @param dst Destination for the plaintext.
700 * @param src Source of the encrypted data. Can overlap with @c dst.
701 * @param size Size of the encrypted data.
702 * @param iv Initialization Vector to use.
703 * @param msg_hmac HMAC of the message, cannot be NULL.
705 * @return Size of the decrypted data, -1 if an error was encountered.
708 t_decrypt_and_validate (struct CadetTunnel *t,
709 void *dst, const void *src,
710 size_t size, uint32_t iv,
711 const struct GNUNET_CADET_Hash *msg_hmac)
713 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
714 struct GNUNET_CADET_Hash hmac;
717 /* Try primary (newest) key */
719 decrypted_size = decrypt (key, dst, src, size, iv);
720 t_hmac (t, src, size, iv, GNUNET_NO, &hmac);
721 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
722 return decrypted_size;
724 /* If no key exchange is going on, we just failed */
725 if (NULL == t->kx_ctx)
727 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
728 "Failed checksum validation on tunnel %s with no KX\n",
730 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
734 /* Try secondary (from previous KX period) key */
735 key = &t->kx_ctx->d_key_old;
736 decrypted_size = decrypt (key, dst, src, size, iv);
737 t_hmac (t, src, size, iv, GNUNET_NO, &hmac);
738 if (0 == memcmp (msg_hmac, &hmac, sizeof (hmac)))
739 return decrypted_size;
741 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
742 "Failed checksum validation on tunnel %s with KX\n",
744 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
750 * Create key material by doing ECDH on the local and remote ephemeral keys.
752 * @param key_material Where to store the key material.
753 * @param ephemeral_key Peer's public ephemeral key.
756 derive_key_material (struct GNUNET_HashCode *key_material,
757 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
760 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
770 * Create a symmetic key from the identities of both ends and the key material
773 * @param key Destination for the generated key.
774 * @param sender ID of the peer that will encrypt with @c key.
775 * @param receiver ID of the peer that will decrypt with @c key.
776 * @param key_material Hash created with ECDH with the ephemeral keys.
779 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
780 const struct GNUNET_PeerIdentity *sender,
781 const struct GNUNET_PeerIdentity *receiver,
782 const struct GNUNET_HashCode *key_material)
784 const char salt[] = "CADET kx salt";
786 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
788 key_material, sizeof (struct GNUNET_HashCode),
789 sender, sizeof (struct GNUNET_PeerIdentity),
790 receiver, sizeof (struct GNUNET_PeerIdentity),
796 * Derive the tunnel's keys using our own and the peer's ephemeral keys.
798 * @param t Tunnel for which to create the keys.
801 create_keys (struct CadetTunnel *t)
803 struct GNUNET_HashCode km;
805 derive_key_material (&km, &t->peers_ephemeral_key);
806 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
807 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
812 * Pick a connection on which send the next data message.
814 * @param t Tunnel on which to send the message.
816 * @return The connection on which to send the next message.
818 static struct CadetConnection *
819 tunnel_get_connection (struct CadetTunnel *t)
821 struct CadetTConnection *iter;
822 struct CadetConnection *best;
824 unsigned int lowest_q;
826 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
829 for (iter = t->connection_head; NULL != iter; iter = iter->next)
831 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
832 GCC_2s (iter->c), GCC_get_state (iter->c));
833 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
835 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
836 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
844 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
850 * Callback called when a queued message is sent.
852 * Calculates the average time and connection packet tracking.
854 * @param cls Closure (TunnelQueue handle).
855 * @param c Connection this message was on.
856 * @param q Connection queue handle (unused).
857 * @param type Type of message sent.
858 * @param fwd Was this a FWD going message?
859 * @param size Size of the message.
862 tun_message_sent (void *cls,
863 struct CadetConnection *c,
864 struct CadetConnectionQueue *q,
865 uint16_t type, int fwd, size_t size)
867 struct CadetTunnelQueue *qt = cls;
868 struct CadetTunnel *t;
870 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
872 GNUNET_assert (NULL != qt->cont);
873 t = NULL == c ? NULL : GCC_get_tunnel (c);
874 qt->cont (qt->cont_cls, t, qt, type, size);
880 * Delete a queued message: either was sent or the channel was destroyed
881 * before the tunnel's key exchange had a chance to finish.
883 * @param tqd Delayed queue handle.
886 unqueue_data (struct CadetTunnelDelayed *tqd)
888 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
894 * Cache a message to be sent once tunnel is online.
896 * @param t Tunnel to hold the message.
897 * @param msg Message itself (copy will be made).
899 static struct CadetTunnelDelayed *
900 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
902 struct CadetTunnelDelayed *tqd;
903 uint16_t size = ntohs (msg->size);
905 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
907 if (GNUNET_YES == is_ready (t))
913 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
916 memcpy (&tqd[1], msg, size);
917 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
923 * Sends an already built message on a tunnel, encrypting it and
924 * choosing the best connection.
926 * @param message Message to send. Function modifies it.
927 * @param t Tunnel on which this message is transmitted.
928 * @param c Connection to use (autoselect if NULL).
929 * @param force Force the tunnel to take the message (buffer overfill).
930 * @param cont Continuation to call once message is really sent.
931 * @param cont_cls Closure for @c cont.
932 * @param existing_q In case this a transmission of previously queued data,
933 * this should be TunnelQueue given to the client.
936 * @return Handle to cancel message. NULL if @c cont is NULL.
938 static struct CadetTunnelQueue *
939 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
940 struct CadetTunnel *t, struct CadetConnection *c,
941 int force, GCT_sent cont, void *cont_cls,
942 struct CadetTunnelQueue *existing_q)
944 struct CadetTunnelQueue *tq;
945 struct GNUNET_CADET_Encrypted *msg;
946 size_t size = ntohs (message->size);
947 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
953 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
955 if (GNUNET_NO == is_ready (t))
957 struct CadetTunnelDelayed *tqd;
958 /* A non null existing_q indicates sending of queued data.
959 * Should only happen after tunnel becomes ready.
961 GNUNET_assert (NULL == existing_q);
962 tqd = queue_data (t, message);
965 tq = GNUNET_new (struct CadetTunnelQueue);
969 tq->cont_cls = cont_cls;
973 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
975 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
976 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
977 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
979 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv) == size);
980 t_hmac (t, &msg[1], size, iv, GNUNET_YES, &msg->hmac);
981 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
984 c = tunnel_get_connection (t);
987 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
988 || CADET_TUNNEL3_SEARCHING != t->cstate)
997 type = ntohs (message->type);
1000 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1001 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1002 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1003 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1005 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1007 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1008 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1009 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1010 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1011 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1012 msg->cid = *GCC_get_id (c);
1013 msg->ttl = htonl (default_ttl);
1018 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1020 fwd = GCC_is_origin (c, GNUNET_YES);
1024 GNUNET_break (NULL ==
1025 GCC_send_prebuilt_message (&msg->header, type, mid,
1026 c, fwd, force, NULL, NULL));
1029 if (NULL == existing_q)
1031 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1038 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1039 &tun_message_sent, tq);
1041 tq->cont_cls = cont_cls;
1048 * Send all cached messages that we can, tunnel is online.
1050 * @param t Tunnel that holds the messages. Cannot be loopback.
1053 send_queued_data (struct CadetTunnel *t)
1055 struct CadetTunnelDelayed *tqd;
1056 struct CadetTunnelDelayed *next;
1059 LOG (GNUNET_ERROR_TYPE_DEBUG,
1060 "GCT_send_queued_data on tunnel %s\n",
1063 if (GCT_is_loopback (t))
1069 if (GNUNET_NO == is_ready (t))
1071 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1072 estate2s (t->estate), cstate2s (t->cstate));
1076 room = GCT_get_connections_buffer (t);
1077 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1078 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1079 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1081 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1084 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1085 tqd->t, NULL, GNUNET_YES,
1086 NULL != tqd->tq ? tqd->tq->cont : NULL,
1087 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1091 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1096 * Sends key exchange message on a tunnel, choosing the best connection.
1097 * Should not be called on loopback tunnels.
1099 * @param t Tunnel on which this message is transmitted.
1100 * @param message Message to send. Function modifies it.
1103 send_kx (struct CadetTunnel *t,
1104 const struct GNUNET_MessageHeader *message)
1106 struct CadetConnection *c;
1107 struct GNUNET_CADET_KX *msg;
1108 size_t size = ntohs (message->size);
1109 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1113 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1115 /* Avoid loopback. */
1116 if (GCT_is_loopback (t))
1118 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1123 /* Even if tunnel is being destroyed, send anyway.
1124 * Could be a response to a rekey initiated by remote peer,
1125 * who is trying to create a new channel!
1128 /* Must have a connection. */
1129 if (NULL == t->connection_head)
1131 GNUNET_break (CADET_TUNNEL3_SEARCHING == t->cstate);
1136 msg = (struct GNUNET_CADET_KX *) cbuf;
1137 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1138 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1139 c = tunnel_get_connection (t);
1142 GNUNET_break (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
1143 || CADET_TUNNEL3_READY != t->cstate);
1147 type = ntohs (message->type);
1150 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1151 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1152 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1153 memcpy (&msg[1], message, size);
1156 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1161 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1162 /* TODO save handle and cancel in case of a unneeded retransmission */
1163 GCC_send_prebuilt_message (&msg->header, GNUNET_MESSAGE_TYPE_CADET_KX,
1164 message->type, c, fwd, GNUNET_YES, NULL, NULL);
1169 * Send the ephemeral key on a tunnel.
1171 * @param t Tunnel on which to send the key.
1174 send_ephemeral (struct CadetTunnel *t)
1176 LOG (GNUNET_ERROR_TYPE_INFO, "=> EPHM for %s\n", GCT_2s (t));
1178 kx_msg.sender_status = htonl (t->estate);
1179 send_kx (t, &kx_msg.header);
1183 * Send a ping message on a tunnel.
1185 * @param t Tunnel on which to send the ping.
1188 send_ping (struct CadetTunnel *t)
1190 struct GNUNET_CADET_KX_Ping msg;
1192 LOG (GNUNET_ERROR_TYPE_INFO, "=> PING for %s\n", GCT_2s (t));
1193 msg.header.size = htons (sizeof (msg));
1194 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PING);
1195 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1196 msg.target = *GCP_get_id (t->peer);
1197 msg.nonce = t->kx_ctx->challenge;
1199 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1200 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
1201 t_encrypt (t, &msg.target, &msg.target, ping_encryption_size(), msg.iv);
1202 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1203 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
1205 send_kx (t, &msg.header);
1210 * Send a pong message on a tunnel.
1212 * @param t Tunnel on which to send the pong.
1213 * @param challenge Value sent in the ping that we have to send back.
1216 send_pong (struct CadetTunnel *t, uint32_t challenge)
1218 struct GNUNET_CADET_KX_Pong msg;
1220 LOG (GNUNET_ERROR_TYPE_INFO, "=> PONG for %s\n", GCT_2s (t));
1221 msg.header.size = htons (sizeof (msg));
1222 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1223 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1224 msg.nonce = challenge;
1225 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1226 t_encrypt (t, &msg.nonce, &msg.nonce, sizeof (msg.nonce), msg.iv);
1227 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1229 send_kx (t, &msg.header);
1234 * Initiate a rekey with the remote peer.
1236 * @param cls Closure (tunnel).
1237 * @param tc TaskContext.
1240 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1242 struct CadetTunnel *t = cls;
1244 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1246 LOG (GNUNET_ERROR_TYPE_DEBUG, "Re-key Tunnel %s\n", GCT_2s (t));
1247 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1250 if (NULL == t->kx_ctx)
1252 LOG (GNUNET_ERROR_TYPE_DEBUG, " new kx ctx\n");
1253 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1254 t->kx_ctx->challenge =
1255 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1256 t->kx_ctx->d_key_old = t->d_key;
1257 t->kx_ctx->e_key_old = t->e_key;
1259 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1260 LOG (GNUNET_ERROR_TYPE_DEBUG, " new challenge for %s: %u\n",
1261 GCT_2s (t), t->kx_ctx->challenge);
1268 case CADET_TUNNEL3_KEY_UNINITIALIZED:
1269 t->estate = CADET_TUNNEL3_KEY_SENT;
1271 case CADET_TUNNEL3_KEY_SENT:
1273 case CADET_TUNNEL3_KEY_PING:
1274 case CADET_TUNNEL3_KEY_OK:
1276 t->estate = CADET_TUNNEL3_KEY_PING;
1279 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1282 // FIXME exponential backoff
1283 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1284 GNUNET_STRINGS_relative_time_to_string (REKEY_WAIT, GNUNET_YES));
1285 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
1290 * Our ephemeral key has changed, create new session key on all tunnels.
1292 * Each tunnel will start the Key Exchange with a random delay between
1293 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1294 * per second, on average.
1296 * @param cls Closure (size of the hashmap).
1297 * @param key Current public key.
1298 * @param value Value in the hash map (tunnel).
1300 * @return #GNUNET_YES, so we should continue to iterate,
1303 rekey_iterator (void *cls,
1304 const struct GNUNET_PeerIdentity *key,
1307 struct CadetTunnel *t = value;
1308 struct GNUNET_TIME_Relative delay;
1309 long n = (long) cls;
1312 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1315 if (GNUNET_YES == GCT_is_loopback (t))
1318 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1319 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1320 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1327 * Create a new ephemeral key and key message, schedule next rekeying.
1329 * @param cls Closure (unused).
1330 * @param tc TaskContext.
1333 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1335 struct GNUNET_TIME_Absolute time;
1338 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1340 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1343 GNUNET_free_non_null (my_ephemeral_key);
1344 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1346 time = GNUNET_TIME_absolute_get ();
1347 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1348 time = GNUNET_TIME_absolute_add (time, rekey_period);
1349 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1350 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1351 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1353 GNUNET_assert (GNUNET_OK ==
1354 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1356 &kx_msg.signature));
1358 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1359 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1361 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1366 * Called only on shutdown, destroy every tunnel.
1368 * @param cls Closure (unused).
1369 * @param key Current public key.
1370 * @param value Value in the hash map (tunnel).
1372 * @return #GNUNET_YES, so we should continue to iterate,
1375 destroy_iterator (void *cls,
1376 const struct GNUNET_PeerIdentity *key,
1379 struct CadetTunnel *t = value;
1381 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1388 * Notify remote peer that we don't know a channel he is talking about,
1389 * probably CHANNEL_DESTROY was missed.
1391 * @param t Tunnel on which to notify.
1392 * @param gid ID of the channel.
1395 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1397 struct GNUNET_CADET_ChannelManage msg;
1399 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1400 msg.header.size = htons (sizeof (msg));
1401 msg.chid = htonl (gid);
1403 LOG (GNUNET_ERROR_TYPE_DEBUG,
1404 "WARNING destroying unknown channel %u on tunnel %s\n",
1406 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1411 * Demultiplex data per channel and call appropriate channel handler.
1413 * @param t Tunnel on which the data came.
1414 * @param msg Data message.
1415 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1416 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1417 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1418 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1421 handle_data (struct CadetTunnel *t,
1422 const struct GNUNET_CADET_Data *msg,
1425 struct CadetChannel *ch;
1429 size = ntohs (msg->header.size);
1431 sizeof (struct GNUNET_CADET_Data) +
1432 sizeof (struct GNUNET_MessageHeader))
1437 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1438 GC_m2s (ntohs (msg[1].header.type)));
1441 ch = GCT_get_channel (t, ntohl (msg->chid));
1444 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1446 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1448 send_channel_destroy (t, ntohl (msg->chid));
1452 GCCH_handle_data (ch, msg, fwd);
1457 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1459 * @param t Tunnel on which the DATA ACK came.
1460 * @param msg DATA ACK message.
1461 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1462 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1463 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1464 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1467 handle_data_ack (struct CadetTunnel *t,
1468 const struct GNUNET_CADET_DataACK *msg,
1471 struct CadetChannel *ch;
1475 size = ntohs (msg->header.size);
1476 if (size != sizeof (struct GNUNET_CADET_DataACK))
1483 ch = GCT_get_channel (t, ntohl (msg->chid));
1486 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1488 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1493 GCCH_handle_data_ack (ch, msg, fwd);
1498 * Handle channel create.
1500 * @param t Tunnel on which the data came.
1501 * @param msg Data message.
1504 handle_ch_create (struct CadetTunnel *t,
1505 const struct GNUNET_CADET_ChannelCreate *msg)
1507 struct CadetChannel *ch;
1511 size = ntohs (msg->header.size);
1512 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1519 ch = GCT_get_channel (t, ntohl (msg->chid));
1520 if (NULL != ch && ! GCT_is_loopback (t))
1522 /* Probably a retransmission, safe to ignore */
1523 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1525 ch = GCCH_handle_create (t, msg);
1527 GCT_add_channel (t, ch);
1533 * Handle channel NACK: check correctness and call channel handler for NACKs.
1535 * @param t Tunnel on which the NACK came.
1536 * @param msg NACK message.
1539 handle_ch_nack (struct CadetTunnel *t,
1540 const struct GNUNET_CADET_ChannelManage *msg)
1542 struct CadetChannel *ch;
1546 size = ntohs (msg->header.size);
1547 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1554 ch = GCT_get_channel (t, ntohl (msg->chid));
1557 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1559 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1564 GCCH_handle_nack (ch);
1569 * Handle a CHANNEL ACK (SYNACK/ACK).
1571 * @param t Tunnel on which the CHANNEL ACK came.
1572 * @param msg CHANNEL ACK message.
1573 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1574 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1575 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1576 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1579 handle_ch_ack (struct CadetTunnel *t,
1580 const struct GNUNET_CADET_ChannelManage *msg,
1583 struct CadetChannel *ch;
1587 size = ntohs (msg->header.size);
1588 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1595 ch = GCT_get_channel (t, ntohl (msg->chid));
1598 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1600 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1605 GCCH_handle_ack (ch, msg, fwd);
1610 * Handle a channel destruction message.
1612 * @param t Tunnel on which the message came.
1613 * @param msg Channel destroy message.
1614 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1615 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1616 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1617 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1620 handle_ch_destroy (struct CadetTunnel *t,
1621 const struct GNUNET_CADET_ChannelManage *msg,
1624 struct CadetChannel *ch;
1628 size = ntohs (msg->header.size);
1629 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1636 ch = GCT_get_channel (t, ntohl (msg->chid));
1639 /* Probably a retransmission, safe to ignore */
1643 GCCH_handle_destroy (ch, msg, fwd);
1648 * The peer's ephemeral key has changed: update the symmetrical keys.
1650 * @param t Tunnel this message came on.
1651 * @param msg Key eXchange message.
1654 handle_ephemeral (struct CadetTunnel *t,
1655 const struct GNUNET_CADET_KX_Ephemeral *msg)
1657 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
1659 if (GNUNET_OK != check_ephemeral (t, msg))
1661 GNUNET_break_op (0);
1664 t->peers_ephemeral_key = msg->ephemeral_key;
1666 if (CADET_TUNNEL3_KEY_SENT == t->estate)
1668 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending ping\n");
1670 t->estate = CADET_TUNNEL3_KEY_PING;
1676 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1677 * Answer with by retransmitting the challenge with the "opposite" key.
1679 * @param t Tunnel this message came on.
1680 * @param msg Key eXchange Ping message.
1683 handle_ping (struct CadetTunnel *t,
1684 const struct GNUNET_CADET_KX_Ping *msg)
1686 struct GNUNET_CADET_KX_Ping res;
1688 if (ntohs (msg->header.size) != sizeof (res))
1690 GNUNET_break_op (0);
1694 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PING for %s\n", GCT_2s (t));
1695 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1696 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1698 GNUNET_STATISTICS_update (stats, "# malformed PINGs", 1, GNUNET_NO);
1699 LOG (GNUNET_ERROR_TYPE_WARNING, " malformed PING on %s\n", GCT_2s (t));
1700 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1701 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1702 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1703 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1709 send_pong (t, res.nonce);
1712 * @brief Finish the Key eXchange and destory the old keys.
1714 * @param cls Closure (Tunnel for which to finish the KX).
1715 * @param tc Task context.
1718 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1720 struct CadetTunnel *t = cls;
1722 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1725 GNUNET_free (t->kx_ctx);
1731 * Peer has answer to our challenge.
1732 * If answer is successful, consider the key exchange finished and clean
1733 * up all related state.
1735 * @param t Tunnel this message came on.
1736 * @param msg Key eXchange Pong message.
1739 handle_pong (struct CadetTunnel *t,
1740 const struct GNUNET_CADET_KX_Pong *msg)
1744 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
1745 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1747 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1750 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1752 if (challenge != t->kx_ctx->challenge)
1754 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
1755 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1756 challenge, msg->nonce, t->kx_ctx->challenge);
1761 GNUNET_SCHEDULER_cancel (t->rekey_task);
1762 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1764 /* Don't free the old keys right away, but after a delay.
1765 * Rationale: the KX could have happened over a very fast connection,
1766 * with payload traffic still signed with the old key stuck in a slower
1769 if (GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
1771 t->kx_ctx->finish_task =
1772 GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_MINUTES, finish_kx, t);
1774 GCT_change_estate (t, CADET_TUNNEL3_KEY_OK);
1779 * Demultiplex by message type and call appropriate handler for a message
1780 * towards a channel of a local tunnel.
1782 * @param t Tunnel this message came on.
1783 * @param msgh Message header.
1784 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1785 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1786 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1787 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1790 handle_decrypted (struct CadetTunnel *t,
1791 const struct GNUNET_MessageHeader *msgh,
1796 type = ntohs (msgh->type);
1797 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
1801 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1802 /* Do nothing, connection aleady got updated. */
1803 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
1806 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1807 /* Don't send hop ACK, wait for client to ACK */
1808 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
1811 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1812 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1815 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1816 handle_ch_create (t,
1817 (struct GNUNET_CADET_ChannelCreate *) msgh);
1820 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1822 (struct GNUNET_CADET_ChannelManage *) msgh);
1825 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1827 (struct GNUNET_CADET_ChannelManage *) msgh,
1831 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1832 handle_ch_destroy (t,
1833 (struct GNUNET_CADET_ChannelManage *) msgh,
1838 GNUNET_break_op (0);
1839 LOG (GNUNET_ERROR_TYPE_WARNING,
1840 "end-to-end message not known (%u)\n",
1841 ntohs (msgh->type));
1846 /******************************************************************************/
1847 /******************************** API ***********************************/
1848 /******************************************************************************/
1851 * Decrypt and demultiplex by message type. Call appropriate handler
1852 * for every message.
1854 * @param t Tunnel this message came on.
1855 * @param msg Encrypted message.
1858 GCT_handle_encrypted (struct CadetTunnel *t,
1859 const struct GNUNET_CADET_Encrypted *msg)
1861 size_t size = ntohs (msg->header.size);
1862 size_t payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
1864 char cbuf [payload_size];
1865 struct GNUNET_MessageHeader *msgh;
1868 decrypted_size = t_decrypt_and_validate (t, cbuf, &msg[1], payload_size,
1869 msg->iv, &msg->hmac);
1872 while (off < decrypted_size)
1874 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1875 handle_decrypted (t, msgh, GNUNET_SYSERR);
1876 off += ntohs (msgh->size);
1882 * Demultiplex an encapsulated KX message by message type.
1884 * @param t Tunnel on which the message came.
1885 * @param message Payload of KX message.
1888 GCT_handle_kx (struct CadetTunnel *t,
1889 const struct GNUNET_MessageHeader *message)
1893 type = ntohs (message->type);
1894 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1897 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1898 handle_ephemeral (t, (struct GNUNET_CADET_KX_Ephemeral *) message);
1901 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1902 handle_ping (t, (struct GNUNET_CADET_KX_Ping *) message);
1905 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1906 handle_pong (t, (struct GNUNET_CADET_KX_Pong *) message);
1910 GNUNET_break_op (0);
1911 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1917 * Initialize the tunnel subsystem.
1919 * @param c Configuration handle.
1920 * @param key ECC private key, to derive all other keys and do crypto.
1923 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1924 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1926 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1928 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
1931 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1932 "CADET", "DEFAULT_TTL", "USING DEFAULT");
1936 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
1939 rekey_period = GNUNET_TIME_UNIT_DAYS;
1942 my_private_key = key;
1943 kx_msg.header.size = htons (sizeof (kx_msg));
1944 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
1945 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
1946 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1947 kx_msg.origin_identity = my_full_id;
1948 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1950 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1955 * Shut down the tunnel subsystem.
1960 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1962 GNUNET_SCHEDULER_cancel (rekey_task);
1963 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1965 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
1966 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1973 * @param destination Peer this tunnel is towards.
1975 struct CadetTunnel *
1976 GCT_new (struct CadetPeer *destination)
1978 struct CadetTunnel *t;
1980 t = GNUNET_new (struct CadetTunnel);
1982 t->peer = destination;
1985 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
1986 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
1997 * Change the tunnel's connection state.
1999 * @param t Tunnel whose connection state to change.
2000 * @param cstate New connection state.
2003 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2007 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2008 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2009 if (myid != GCP_get_short_id (t->peer) &&
2010 CADET_TUNNEL3_READY != t->cstate &&
2011 CADET_TUNNEL3_READY == cstate)
2014 if (CADET_TUNNEL3_KEY_OK == t->estate)
2016 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2017 send_queued_data (t);
2019 else if (CADET_TUNNEL3_KEY_UNINITIALIZED == t->estate)
2021 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2022 rekey_tunnel (t, NULL);
2027 if (CADET_TUNNEL3_READY == cstate
2028 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2030 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2031 GCP_stop_search (t->peer);
2036 * Change the tunnel encryption state.
2038 * @param t Tunnel whose encryption state to change.
2039 * @param state New encryption state.
2042 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2046 LOG (GNUNET_ERROR_TYPE_DEBUG,
2047 "Tunnel %s estate was %s\n",
2048 GCP_2s (t->peer), estate2s (t->estate));
2049 LOG (GNUNET_ERROR_TYPE_DEBUG,
2050 "Tunnel %s estate is now %s\n",
2051 GCP_2s (t->peer), estate2s (state));
2052 if (myid != GCP_get_short_id (t->peer) &&
2053 CADET_TUNNEL3_KEY_OK != t->estate && CADET_TUNNEL3_KEY_OK == state)
2056 send_queued_data (t);
2064 * @brief Check if tunnel has too many connections, and remove one if necessary.
2066 * Currently this means the newest connection, unless it is a direct one.
2067 * Implemented as a task to avoid freeing a connection that is in the middle
2068 * of being created/processed.
2070 * @param cls Closure (Tunnel to check).
2071 * @param tc Task context.
2074 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2076 struct CadetTunnel *t = cls;
2078 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2081 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2083 struct CadetTConnection *iter;
2084 struct CadetTConnection *c;
2086 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2088 if ((NULL == c || iter->created.abs_value_us > c->created.abs_value_us)
2089 && GNUNET_NO == GCC_is_direct (iter->c))
2096 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2098 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2111 * Add a connection to a tunnel.
2114 * @param c Connection.
2117 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2119 struct CadetTConnection *aux;
2121 GNUNET_assert (NULL != c);
2123 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2124 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2125 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2129 aux = GNUNET_new (struct CadetTConnection);
2131 aux->created = GNUNET_TIME_absolute_get ();
2133 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2135 GNUNET_SCHEDULER_add_now (&trim_connections, t);
2140 * Mark a path as no longer valid for this tunnel: has been tried and failed.
2142 * @param t Tunnel to update.
2143 * @param path Invalid path to remove. Is destroyed after removal.
2146 GCT_remove_path (struct CadetTunnel *t, struct CadetPeerPath *path)
2148 GCP_remove_path (t->peer, path);
2153 * Remove a connection from a tunnel.
2156 * @param c Connection.
2159 GCT_remove_connection (struct CadetTunnel *t,
2160 struct CadetConnection *c)
2162 struct CadetTConnection *aux;
2163 struct CadetTConnection *next;
2165 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2166 GCC_2s (c), GCT_2s (t));
2167 for (aux = t->connection_head; aux != NULL; aux = next)
2172 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2177 /* Start new connections if needed */
2178 if (CONNECTIONS_PER_TUNNEL < GCT_count_connections (t)
2179 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2180 && CADET_TUNNEL3_SHUTDOWN != t->cstate
2181 && GNUNET_NO == shutting_down)
2183 LOG (GNUNET_ERROR_TYPE_DEBUG, " no more connections, getting new ones\n");
2184 t->cstate = CADET_TUNNEL3_SEARCHING;
2185 GCP_connect (t->peer);
2189 /* If not marked as ready, no change is needed */
2190 if (CADET_TUNNEL3_READY != t->cstate)
2193 /* Check if any connection is ready to maintaing cstate */
2194 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2195 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2198 t->cstate = CADET_TUNNEL3_WAITING;
2203 * Add a channel to a tunnel.
2206 * @param ch Channel.
2209 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2211 struct CadetTChannel *aux;
2213 GNUNET_assert (NULL != ch);
2215 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2217 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2219 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2224 aux = GNUNET_new (struct CadetTChannel);
2226 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2227 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2229 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2231 GNUNET_SCHEDULER_cancel (t->destroy_task);
2232 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2233 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2239 * Remove a channel from a tunnel.
2242 * @param ch Channel.
2245 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2247 struct CadetTChannel *aux;
2249 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2250 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2254 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2255 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2264 * Search for a channel by global ID.
2266 * @param t Tunnel containing the channel.
2267 * @param chid Public channel number.
2269 * @return channel handler, NULL if doesn't exist
2271 struct CadetChannel *
2272 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2274 struct CadetTChannel *iter;
2279 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2281 if (GCCH_get_id (iter->ch) == chid)
2285 return NULL == iter ? NULL : iter->ch;
2290 * @brief Destroy a tunnel and free all resources.
2292 * Should only be called a while after the tunnel has been marked as destroyed,
2293 * in case there is a new channel added to the same peer shortly after marking
2294 * the tunnel. This way we avoid a new public key handshake.
2296 * @param cls Closure (tunnel to destroy).
2297 * @param tc Task context.
2300 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2302 struct CadetTunnel *t = cls;
2303 struct CadetTConnection *iter;
2305 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2306 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2308 LOG (GNUNET_ERROR_TYPE_WARNING,
2309 "Not destroying tunnel, due to shutdown. "
2310 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2313 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2314 t->cstate = CADET_TUNNEL3_SHUTDOWN;
2316 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2318 GCC_send_destroy (iter->c);
2325 * Tunnel is empty: destroy it.
2327 * Notifies all connections about the destruction.
2329 * @param t Tunnel to destroy.
2332 GCT_destroy_empty (struct CadetTunnel *t)
2334 if (GNUNET_YES == shutting_down)
2335 return; /* Will be destroyed immediately anyway */
2337 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2339 LOG (GNUNET_ERROR_TYPE_DEBUG,
2340 "Tunnel %s is already scheduled for destruction\n",
2343 /* should never happen, tunnel can only become empty once, and the
2344 * task identifier should be NO_TASK (cleaned when the tunnel was created
2345 * or became un-empty)
2350 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2353 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2354 &delayed_destroy, t);
2355 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llX\n",
2356 t, t->destroy_task);
2361 * Destroy tunnel if empty (no more channels).
2363 * @param t Tunnel to destroy if empty.
2366 GCT_destroy_if_empty (struct CadetTunnel *t)
2368 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2369 if (1 < GCT_count_channels (t))
2372 GCT_destroy_empty (t);
2377 * Destroy the tunnel.
2379 * This function does not generate any warning traffic to clients or peers.
2382 * Cancel messages belonging to this tunnel queued to neighbors.
2383 * Free any allocated resources linked to the tunnel.
2385 * @param t The tunnel to destroy.
2388 GCT_destroy (struct CadetTunnel *t)
2390 struct CadetTConnection *iter_c;
2391 struct CadetTConnection *next_c;
2392 struct CadetTChannel *iter_ch;
2393 struct CadetTChannel *next_ch;
2398 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
2400 GNUNET_break (GNUNET_YES ==
2401 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2402 GCP_get_id (t->peer), t));
2404 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2406 next_c = iter_c->next;
2407 GCC_destroy (iter_c->c);
2409 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2411 next_ch = iter_ch->next;
2412 GCCH_destroy (iter_ch->ch);
2413 /* Should only happen on shutdown, but it's ok. */
2416 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2418 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling %llX\n", t->destroy_task);
2419 GNUNET_SCHEDULER_cancel (t->destroy_task);
2420 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2423 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2424 GCP_set_tunnel (t->peer, NULL);
2426 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2428 GNUNET_SCHEDULER_cancel (t->rekey_task);
2429 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2431 if (NULL != t->kx_ctx)
2433 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
2434 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
2435 GNUNET_free (t->kx_ctx);
2442 * @brief Use the given path for the tunnel.
2443 * Update the next and prev hops (and RCs).
2444 * (Re)start the path refresh in case the tunnel is locally owned.
2446 * @param t Tunnel to update.
2447 * @param p Path to use.
2449 * @return Connection created.
2451 struct CadetConnection *
2452 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
2454 struct CadetConnection *c;
2455 struct GNUNET_CADET_Hash cid;
2456 unsigned int own_pos;
2458 if (NULL == t || NULL == p)
2464 if (CADET_TUNNEL3_SHUTDOWN == t->cstate)
2470 for (own_pos = 0; own_pos < p->length; own_pos++)
2472 if (p->peers[own_pos] == myid)
2475 if (own_pos >= p->length)
2477 GNUNET_break_op (0);
2481 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2482 c = GCC_new (&cid, t, p, own_pos);
2485 /* Path was flawed */
2488 GCT_add_connection (t, c);
2494 * Count established (ready) connections of a tunnel.
2496 * @param t Tunnel on which to count.
2498 * @return Number of connections.
2501 GCT_count_connections (struct CadetTunnel *t)
2503 struct CadetTConnection *iter;
2509 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2510 if (CADET_CONNECTION_DESTROYED != GCC_get_state (iter->c))
2517 * Count channels of a tunnel.
2519 * @param t Tunnel on which to count.
2521 * @return Number of channels.
2524 GCT_count_channels (struct CadetTunnel *t)
2526 struct CadetTChannel *iter;
2529 for (count = 0, iter = t->channel_head;
2531 iter = iter->next, count++) /* skip */;
2538 * Get the connectivity state of a tunnel.
2542 * @return Tunnel's connectivity state.
2544 enum CadetTunnelCState
2545 GCT_get_cstate (struct CadetTunnel *t)
2550 return (enum CadetTunnelCState) -1;
2557 * Get the encryption state of a tunnel.
2561 * @return Tunnel's encryption state.
2563 enum CadetTunnelEState
2564 GCT_get_estate (struct CadetTunnel *t)
2569 return (enum CadetTunnelEState) -1;
2575 * Get the maximum buffer space for a tunnel towards a local client.
2579 * @return Biggest buffer space offered by any channel in the tunnel.
2582 GCT_get_channels_buffer (struct CadetTunnel *t)
2584 struct CadetTChannel *iter;
2585 unsigned int buffer;
2586 unsigned int ch_buf;
2588 if (NULL == t->channel_head)
2590 /* Probably getting buffer for a channel create/handshake. */
2595 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2597 ch_buf = get_channel_buffer (iter);
2598 if (ch_buf > buffer)
2606 * Get the total buffer space for a tunnel for P2P traffic.
2610 * @return Buffer space offered by all connections in the tunnel.
2613 GCT_get_connections_buffer (struct CadetTunnel *t)
2615 struct CadetTConnection *iter;
2616 unsigned int buffer;
2619 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2621 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2625 buffer += get_connection_buffer (iter);
2633 * Get the tunnel's destination.
2637 * @return ID of the destination peer.
2639 const struct GNUNET_PeerIdentity *
2640 GCT_get_destination (struct CadetTunnel *t)
2642 return GCP_get_id (t->peer);
2647 * Get the tunnel's next free global channel ID.
2651 * @return GID of a channel free to use.
2654 GCT_get_next_chid (struct CadetTunnel *t)
2656 CADET_ChannelNumber chid;
2657 CADET_ChannelNumber mask;
2660 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2661 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2662 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2664 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2669 t->next_chid |= mask;
2671 while (NULL != GCT_get_channel (t, t->next_chid))
2673 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2674 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2675 t->next_chid |= mask;
2677 chid = t->next_chid;
2678 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2679 t->next_chid |= mask;
2686 * Send ACK on one or more channels due to buffer in connections.
2688 * @param t Channel which has some free buffer space.
2691 GCT_unchoke_channels (struct CadetTunnel *t)
2693 struct CadetTChannel *iter;
2694 unsigned int buffer;
2695 unsigned int channels = GCT_count_channels (t);
2696 unsigned int choked_n;
2697 struct CadetChannel *choked[channels];
2699 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
2700 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2701 if (NULL != t->channel_head)
2702 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2704 /* Get buffer space */
2705 buffer = GCT_get_connections_buffer (t);
2711 /* Count and remember choked channels */
2713 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2715 if (GNUNET_NO == get_channel_allowed (iter))
2717 choked[choked_n++] = iter->ch;
2721 /* Unchoke random channels */
2722 while (0 < buffer && 0 < choked_n)
2724 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
2726 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
2729 choked[r] = choked[choked_n];
2735 * Send ACK on one or more connections due to buffer space to the client.
2737 * Iterates all connections of the tunnel and sends ACKs appropriately.
2742 GCT_send_connection_acks (struct CadetTunnel *t)
2744 struct CadetTConnection *iter;
2747 uint32_t allow_per_connection;
2749 unsigned int buffer;
2751 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
2760 buffer = GCT_get_channels_buffer (t);
2761 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
2763 /* Count connections, how many messages are already allowed */
2764 cs = GCT_count_connections (t);
2765 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2767 allowed += get_connection_allowed (iter);
2769 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
2771 /* Make sure there is no overflow */
2772 if (allowed > buffer)
2777 /* Authorize connections to send more data */
2778 to_allow = buffer; /* - allowed; */
2780 for (iter = t->connection_head;
2781 NULL != iter && to_allow > 0;
2784 allow_per_connection = to_allow/cs;
2785 to_allow -= allow_per_connection;
2787 if (get_connection_allowed (iter) > 64 / 3)
2791 GCC_allow (iter->c, allow_per_connection,
2792 GCC_is_origin (iter->c, GNUNET_NO));
2795 GNUNET_break (to_allow == 0);
2800 * Cancel a previously sent message while it's in the queue.
2802 * ONLY can be called before the continuation given to the send function
2803 * is called. Once the continuation is called, the message is no longer in the
2806 * @param q Handle to the queue.
2809 GCT_cancel (struct CadetTunnelQueue *q)
2814 /* tun_message_sent() will be called and free q */
2816 else if (NULL != q->tqd)
2818 unqueue_data (q->tqd);
2820 if (NULL != q->cont)
2821 q->cont (q->cont_cls, NULL, q, 0, 0);
2832 * Sends an already built message on a tunnel, encrypting it and
2833 * choosing the best connection if not provided.
2835 * @param message Message to send. Function modifies it.
2836 * @param t Tunnel on which this message is transmitted.
2837 * @param c Connection to use (autoselect if NULL).
2838 * @param force Force the tunnel to take the message (buffer overfill).
2839 * @param cont Continuation to call once message is really sent.
2840 * @param cont_cls Closure for @c cont.
2842 * @return Handle to cancel message. NULL if @c cont is NULL.
2844 struct CadetTunnelQueue *
2845 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2846 struct CadetTunnel *t, struct CadetConnection *c,
2847 int force, GCT_sent cont, void *cont_cls)
2849 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
2854 * Is the tunnel directed towards the local peer?
2858 * @return #GNUNET_YES if it is loopback.
2861 GCT_is_loopback (const struct CadetTunnel *t)
2863 return (myid == GCP_get_short_id (t->peer));
2868 * Is the tunnel this path already?
2873 * @return #GNUNET_YES a connection uses this path.
2876 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
2878 struct CadetTConnection *iter;
2880 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2881 if (GCC_get_path (iter->c) == p)
2889 * Get a cost of a path for a tunnel considering existing connections.
2892 * @param path Candidate path.
2894 * @return Cost of the path (path length + number of overlapping nodes)
2897 GCT_get_path_cost (const struct CadetTunnel *t,
2898 const struct CadetPeerPath *path)
2900 struct CadetTConnection *iter;
2901 const struct CadetPeerPath *aux;
2902 unsigned int overlap;
2910 GNUNET_assert (NULL != t);
2912 for (i = 0; i < path->length; i++)
2914 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2916 aux = GCC_get_path (iter->c);
2920 for (j = 0; j < aux->length; j++)
2922 if (path->peers[i] == aux->peers[j])
2930 return path->length + overlap;
2935 * Get the static string for the peer this tunnel is directed.
2939 * @return Static string the destination peer's ID.
2942 GCT_2s (const struct CadetTunnel *t)
2947 return GCP_2s (t->peer);
2951 /******************************************************************************/
2952 /***************************** INFO/DEBUG *******************************/
2953 /******************************************************************************/
2957 * Log all possible info about the tunnel state to stderr.
2959 * @param t Tunnel to debug.
2962 GCT_debug (const struct CadetTunnel *t)
2964 struct CadetTChannel *iterch;
2965 struct CadetTConnection *iterc;
2967 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
2968 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT cstate %s, estate %s\n",
2969 cstate2s (t->cstate), estate2s (t->estate));
2970 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT kx_ctx %p, rekey_task %u\n",
2971 t->kx_ctx, t->rekey_task);
2972 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT tq_head %p, tq_tail %p\n",
2973 t->tq_head, t->tq_tail);
2974 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT destroy %u\n", t->destroy_task);
2976 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT channels:\n");
2977 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
2979 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT - %s\n", GCCH_2s (iterch->ch));
2982 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT connections:\n");
2983 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
2985 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT - %s [%u] buf: %u/%u (qn %u/%u)\n",
2986 GCC_2s (iterc->c), GCC_get_state (iterc->c),
2987 GCC_get_buffer (iterc->c, GNUNET_YES),
2988 GCC_get_buffer (iterc->c, GNUNET_NO),
2989 GCC_get_qn (iterc->c, GNUNET_YES),
2990 GCC_get_qn (iterc->c, GNUNET_NO));
2993 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT DEBUG TUNNEL END\n");
2998 * Iterate all tunnels.
3000 * @param iter Iterator.
3001 * @param cls Closure for @c iter.
3004 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3006 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3011 * Count all tunnels.
3013 * @return Number of tunnels to remote peers kept by this peer.
3016 GCT_count_all (void)
3018 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3023 * Iterate all connections of a tunnel.
3025 * @param t Tunnel whose connections to iterate.
3026 * @param iter Iterator.
3027 * @param cls Closure for @c iter.
3030 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3032 struct CadetTConnection *ct;
3034 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3040 * Iterate all channels of a tunnel.
3042 * @param t Tunnel whose channels to iterate.
3043 * @param iter Iterator.
3044 * @param cls Closure for @c iter.
3047 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3049 struct CadetTChannel *cht;
3051 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3052 iter (cls, cht->ch);