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 LOG (GNUNET_ERROR_TYPE_INFO, "km %s\n", GNUNET_h2s_full (&km));
807 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
808 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
813 * Pick a connection on which send the next data message.
815 * @param t Tunnel on which to send the message.
817 * @return The connection on which to send the next message.
819 static struct CadetConnection *
820 tunnel_get_connection (struct CadetTunnel *t)
822 struct CadetTConnection *iter;
823 struct CadetConnection *best;
825 unsigned int lowest_q;
827 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
830 for (iter = t->connection_head; NULL != iter; iter = iter->next)
832 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
833 GCC_2s (iter->c), GCC_get_state (iter->c));
834 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
836 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
837 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
845 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
851 * Callback called when a queued message is sent.
853 * Calculates the average time and connection packet tracking.
855 * @param cls Closure (TunnelQueue handle).
856 * @param c Connection this message was on.
857 * @param q Connection queue handle (unused).
858 * @param type Type of message sent.
859 * @param fwd Was this a FWD going message?
860 * @param size Size of the message.
863 tun_message_sent (void *cls,
864 struct CadetConnection *c,
865 struct CadetConnectionQueue *q,
866 uint16_t type, int fwd, size_t size)
868 struct CadetTunnelQueue *qt = cls;
869 struct CadetTunnel *t;
871 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
873 GNUNET_assert (NULL != qt->cont);
874 t = NULL == c ? NULL : GCC_get_tunnel (c);
875 qt->cont (qt->cont_cls, t, qt, type, size);
881 * Delete a queued message: either was sent or the channel was destroyed
882 * before the tunnel's key exchange had a chance to finish.
884 * @param tqd Delayed queue handle.
887 unqueue_data (struct CadetTunnelDelayed *tqd)
889 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
895 * Cache a message to be sent once tunnel is online.
897 * @param t Tunnel to hold the message.
898 * @param msg Message itself (copy will be made).
900 static struct CadetTunnelDelayed *
901 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
903 struct CadetTunnelDelayed *tqd;
904 uint16_t size = ntohs (msg->size);
906 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
908 if (GNUNET_YES == is_ready (t))
914 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
917 memcpy (&tqd[1], msg, size);
918 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
924 * Sends an already built message on a tunnel, encrypting it and
925 * choosing the best connection.
927 * @param message Message to send. Function modifies it.
928 * @param t Tunnel on which this message is transmitted.
929 * @param c Connection to use (autoselect if NULL).
930 * @param force Force the tunnel to take the message (buffer overfill).
931 * @param cont Continuation to call once message is really sent.
932 * @param cont_cls Closure for @c cont.
933 * @param existing_q In case this a transmission of previously queued data,
934 * this should be TunnelQueue given to the client.
937 * @return Handle to cancel message. NULL if @c cont is NULL.
939 static struct CadetTunnelQueue *
940 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
941 struct CadetTunnel *t, struct CadetConnection *c,
942 int force, GCT_sent cont, void *cont_cls,
943 struct CadetTunnelQueue *existing_q)
945 struct CadetTunnelQueue *tq;
946 struct GNUNET_CADET_Encrypted *msg;
947 size_t size = ntohs (message->size);
948 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
954 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
956 if (GNUNET_NO == is_ready (t))
958 struct CadetTunnelDelayed *tqd;
959 /* A non null existing_q indicates sending of queued data.
960 * Should only happen after tunnel becomes ready.
962 GNUNET_assert (NULL == existing_q);
963 tqd = queue_data (t, message);
966 tq = GNUNET_new (struct CadetTunnelQueue);
970 tq->cont_cls = cont_cls;
974 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
976 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
977 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
978 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
980 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv) == size);
981 t_hmac (t, &msg[1], size, iv, GNUNET_YES, &msg->hmac);
982 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
985 c = tunnel_get_connection (t);
988 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
989 || CADET_TUNNEL3_SEARCHING != t->cstate)
998 type = ntohs (message->type);
1001 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1002 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1003 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
1004 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
1006 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
1008 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1009 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1010 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1011 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1012 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1013 msg->cid = *GCC_get_id (c);
1014 msg->ttl = htonl (default_ttl);
1019 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
1021 fwd = GCC_is_origin (c, GNUNET_YES);
1025 GNUNET_break (NULL ==
1026 GCC_send_prebuilt_message (&msg->header, type, mid,
1027 c, fwd, force, NULL, NULL));
1030 if (NULL == existing_q)
1032 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
1039 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
1040 &tun_message_sent, tq);
1042 tq->cont_cls = cont_cls;
1049 * Send all cached messages that we can, tunnel is online.
1051 * @param t Tunnel that holds the messages. Cannot be loopback.
1054 send_queued_data (struct CadetTunnel *t)
1056 struct CadetTunnelDelayed *tqd;
1057 struct CadetTunnelDelayed *next;
1060 LOG (GNUNET_ERROR_TYPE_DEBUG,
1061 "GCT_send_queued_data on tunnel %s\n",
1064 if (GCT_is_loopback (t))
1070 if (GNUNET_NO == is_ready (t))
1072 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
1073 estate2s (t->estate), cstate2s (t->cstate));
1077 room = GCT_get_connections_buffer (t);
1078 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
1079 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
1080 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
1082 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
1085 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
1086 tqd->t, NULL, GNUNET_YES,
1087 NULL != tqd->tq ? tqd->tq->cont : NULL,
1088 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
1092 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
1097 * Sends key exchange message on a tunnel, choosing the best connection.
1098 * Should not be called on loopback tunnels.
1100 * @param t Tunnel on which this message is transmitted.
1101 * @param message Message to send. Function modifies it.
1104 send_kx (struct CadetTunnel *t,
1105 const struct GNUNET_MessageHeader *message)
1107 struct CadetConnection *c;
1108 struct GNUNET_CADET_KX *msg;
1109 size_t size = ntohs (message->size);
1110 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
1114 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
1116 /* Avoid loopback. */
1117 if (GCT_is_loopback (t))
1119 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1124 /* Even if tunnel is being destroyed, send anyway.
1125 * Could be a response to a rekey initiated by remote peer,
1126 * who is trying to create a new channel!
1129 /* Must have a connection. */
1130 if (NULL == t->connection_head)
1132 GNUNET_break (CADET_TUNNEL3_SEARCHING == t->cstate);
1137 msg = (struct GNUNET_CADET_KX *) cbuf;
1138 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
1139 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
1140 c = tunnel_get_connection (t);
1143 GNUNET_break (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
1144 || CADET_TUNNEL3_READY != t->cstate);
1148 type = ntohs (message->type);
1151 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1152 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1153 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1154 memcpy (&msg[1], message, size);
1157 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1162 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1163 /* TODO save handle and cancel in case of a unneeded retransmission */
1164 GCC_send_prebuilt_message (&msg->header, GNUNET_MESSAGE_TYPE_CADET_KX,
1165 message->type, c, fwd, GNUNET_YES, NULL, NULL);
1170 * Send the ephemeral key on a tunnel.
1172 * @param t Tunnel on which to send the key.
1175 send_ephemeral (struct CadetTunnel *t)
1177 LOG (GNUNET_ERROR_TYPE_INFO, "===> EPHM for %s\n", GCT_2s (t));
1179 kx_msg.sender_status = htonl (t->estate);
1180 send_kx (t, &kx_msg.header);
1184 * Send a ping message on a tunnel.
1186 * @param t Tunnel on which to send the ping.
1189 send_ping (struct CadetTunnel *t)
1191 struct GNUNET_CADET_KX_Ping msg;
1193 LOG (GNUNET_ERROR_TYPE_INFO, "===> PING for %s\n", GCT_2s (t));
1194 msg.header.size = htons (sizeof (msg));
1195 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PING);
1196 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1197 msg.target = *GCP_get_id (t->peer);
1198 msg.nonce = t->kx_ctx->challenge;
1200 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1201 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
1202 t_encrypt (t, &msg.target, &msg.target, ping_encryption_size(), msg.iv);
1203 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1204 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
1206 send_kx (t, &msg.header);
1211 * Send a pong message on a tunnel.
1213 * @param t Tunnel on which to send the pong.
1214 * @param challenge Value sent in the ping that we have to send back.
1217 send_pong (struct CadetTunnel *t, uint32_t challenge)
1219 struct GNUNET_CADET_KX_Pong msg;
1221 LOG (GNUNET_ERROR_TYPE_INFO, "===> PONG for %s\n", GCT_2s (t));
1222 msg.header.size = htons (sizeof (msg));
1223 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1224 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1225 msg.nonce = challenge;
1226 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1227 t_encrypt (t, &msg.nonce, &msg.nonce, sizeof (msg.nonce), msg.iv);
1228 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1230 send_kx (t, &msg.header);
1235 * Initiate a rekey with the remote peer.
1237 * @param cls Closure (tunnel).
1238 * @param tc TaskContext.
1241 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1243 struct CadetTunnel *t = cls;
1245 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1247 LOG (GNUNET_ERROR_TYPE_DEBUG, "Re-key Tunnel %s\n", GCT_2s (t));
1248 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1251 if (NULL == t->kx_ctx)
1253 LOG (GNUNET_ERROR_TYPE_DEBUG, " new kx ctx\n");
1254 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1255 t->kx_ctx->challenge =
1256 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1257 t->kx_ctx->d_key_old = t->d_key;
1258 t->kx_ctx->e_key_old = t->e_key;
1260 t->kx_ctx->rekey_start_time = GNUNET_TIME_absolute_get ();
1261 LOG (GNUNET_ERROR_TYPE_DEBUG, " new challenge for %s: %u\n",
1262 GCT_2s (t), t->kx_ctx->challenge);
1269 case CADET_TUNNEL3_KEY_UNINITIALIZED:
1270 t->estate = CADET_TUNNEL3_KEY_SENT;
1272 case CADET_TUNNEL3_KEY_SENT:
1274 case CADET_TUNNEL3_KEY_PING:
1275 case CADET_TUNNEL3_KEY_OK:
1277 t->estate = CADET_TUNNEL3_KEY_PING;
1280 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1283 // FIXME exponential backoff
1284 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1285 GNUNET_STRINGS_relative_time_to_string (REKEY_WAIT, GNUNET_YES));
1286 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
1291 * Our ephemeral key has changed, create new session key on all tunnels.
1293 * Each tunnel will start the Key Exchange with a random delay between
1294 * 0 and number_of_tunnels*100 milliseconds, so there are 10 key exchanges
1295 * per second, on average.
1297 * @param cls Closure (size of the hashmap).
1298 * @param key Current public key.
1299 * @param value Value in the hash map (tunnel).
1301 * @return #GNUNET_YES, so we should continue to iterate,
1304 rekey_iterator (void *cls,
1305 const struct GNUNET_PeerIdentity *key,
1308 struct CadetTunnel *t = value;
1309 struct GNUNET_TIME_Relative delay;
1310 long n = (long) cls;
1313 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1316 if (GNUNET_YES == GCT_is_loopback (t))
1319 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1320 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1321 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1328 * Create a new ephemeral key and key message, schedule next rekeying.
1330 * @param cls Closure (unused).
1331 * @param tc TaskContext.
1334 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1336 struct GNUNET_TIME_Absolute time;
1339 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1341 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1344 GNUNET_free_non_null (my_ephemeral_key);
1345 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1347 time = GNUNET_TIME_absolute_get ();
1348 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1349 time = GNUNET_TIME_absolute_add (time, rekey_period);
1350 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1351 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1352 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1354 GNUNET_assert (GNUNET_OK ==
1355 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1357 &kx_msg.signature));
1359 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1360 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1362 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1367 * Called only on shutdown, destroy every tunnel.
1369 * @param cls Closure (unused).
1370 * @param key Current public key.
1371 * @param value Value in the hash map (tunnel).
1373 * @return #GNUNET_YES, so we should continue to iterate,
1376 destroy_iterator (void *cls,
1377 const struct GNUNET_PeerIdentity *key,
1380 struct CadetTunnel *t = value;
1382 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1389 * Notify remote peer that we don't know a channel he is talking about,
1390 * probably CHANNEL_DESTROY was missed.
1392 * @param t Tunnel on which to notify.
1393 * @param gid ID of the channel.
1396 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1398 struct GNUNET_CADET_ChannelManage msg;
1400 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1401 msg.header.size = htons (sizeof (msg));
1402 msg.chid = htonl (gid);
1404 LOG (GNUNET_ERROR_TYPE_DEBUG,
1405 "WARNING destroying unknown channel %u on tunnel %s\n",
1407 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1412 * Demultiplex data per channel and call appropriate channel handler.
1414 * @param t Tunnel on which the data came.
1415 * @param msg Data message.
1416 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1417 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1418 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1419 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1422 handle_data (struct CadetTunnel *t,
1423 const struct GNUNET_CADET_Data *msg,
1426 struct CadetChannel *ch;
1430 size = ntohs (msg->header.size);
1432 sizeof (struct GNUNET_CADET_Data) +
1433 sizeof (struct GNUNET_MessageHeader))
1438 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1439 GC_m2s (ntohs (msg[1].header.type)));
1442 ch = GCT_get_channel (t, ntohl (msg->chid));
1445 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1447 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1449 send_channel_destroy (t, ntohl (msg->chid));
1453 GCCH_handle_data (ch, msg, fwd);
1458 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1460 * @param t Tunnel on which the DATA ACK came.
1461 * @param msg DATA ACK message.
1462 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1463 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1464 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1465 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1468 handle_data_ack (struct CadetTunnel *t,
1469 const struct GNUNET_CADET_DataACK *msg,
1472 struct CadetChannel *ch;
1476 size = ntohs (msg->header.size);
1477 if (size != sizeof (struct GNUNET_CADET_DataACK))
1484 ch = GCT_get_channel (t, ntohl (msg->chid));
1487 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1489 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1494 GCCH_handle_data_ack (ch, msg, fwd);
1499 * Handle channel create.
1501 * @param t Tunnel on which the data came.
1502 * @param msg Data message.
1505 handle_ch_create (struct CadetTunnel *t,
1506 const struct GNUNET_CADET_ChannelCreate *msg)
1508 struct CadetChannel *ch;
1512 size = ntohs (msg->header.size);
1513 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1520 ch = GCT_get_channel (t, ntohl (msg->chid));
1521 if (NULL != ch && ! GCT_is_loopback (t))
1523 /* Probably a retransmission, safe to ignore */
1524 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1526 ch = GCCH_handle_create (t, msg);
1528 GCT_add_channel (t, ch);
1534 * Handle channel NACK: check correctness and call channel handler for NACKs.
1536 * @param t Tunnel on which the NACK came.
1537 * @param msg NACK message.
1540 handle_ch_nack (struct CadetTunnel *t,
1541 const struct GNUNET_CADET_ChannelManage *msg)
1543 struct CadetChannel *ch;
1547 size = ntohs (msg->header.size);
1548 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1555 ch = GCT_get_channel (t, ntohl (msg->chid));
1558 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1560 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1565 GCCH_handle_nack (ch);
1570 * Handle a CHANNEL ACK (SYNACK/ACK).
1572 * @param t Tunnel on which the CHANNEL ACK came.
1573 * @param msg CHANNEL ACK message.
1574 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1575 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1576 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1577 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1580 handle_ch_ack (struct CadetTunnel *t,
1581 const struct GNUNET_CADET_ChannelManage *msg,
1584 struct CadetChannel *ch;
1588 size = ntohs (msg->header.size);
1589 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1596 ch = GCT_get_channel (t, ntohl (msg->chid));
1599 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1601 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1606 GCCH_handle_ack (ch, msg, fwd);
1611 * Handle a channel destruction message.
1613 * @param t Tunnel on which the message came.
1614 * @param msg Channel destroy message.
1615 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1616 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1617 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1618 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1621 handle_ch_destroy (struct CadetTunnel *t,
1622 const struct GNUNET_CADET_ChannelManage *msg,
1625 struct CadetChannel *ch;
1629 size = ntohs (msg->header.size);
1630 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1637 ch = GCT_get_channel (t, ntohl (msg->chid));
1640 /* Probably a retransmission, safe to ignore */
1644 GCCH_handle_destroy (ch, msg, fwd);
1649 * The peer's ephemeral key has changed: update the symmetrical keys.
1651 * @param t Tunnel this message came on.
1652 * @param msg Key eXchange message.
1655 handle_ephemeral (struct CadetTunnel *t,
1656 const struct GNUNET_CADET_KX_Ephemeral *msg)
1658 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
1660 if (GNUNET_OK != check_ephemeral (t, msg))
1662 GNUNET_break_op (0);
1665 t->peers_ephemeral_key = msg->ephemeral_key;
1667 if (CADET_TUNNEL3_KEY_SENT == t->estate)
1669 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, sending ping\n");
1671 t->estate = CADET_TUNNEL3_KEY_PING;
1677 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1678 * Answer with by retransmitting the challenge with the "opposite" key.
1680 * @param t Tunnel this message came on.
1681 * @param msg Key eXchange Ping message.
1684 handle_ping (struct CadetTunnel *t,
1685 const struct GNUNET_CADET_KX_Ping *msg)
1687 struct GNUNET_CADET_KX_Ping res;
1689 if (ntohs (msg->header.size) != sizeof (res))
1691 GNUNET_break_op (0);
1695 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PING for %s\n", GCT_2s (t));
1696 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1697 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1699 GNUNET_STATISTICS_update (stats, "# malformed PINGs", 1, GNUNET_NO);
1700 LOG (GNUNET_ERROR_TYPE_WARNING, " malformed PING on %s\n", GCT_2s (t));
1701 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1702 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1703 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1704 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1710 send_pong (t, res.nonce);
1713 * @brief Finish the Key eXchange and destory the old keys.
1715 * @param cls Closure (Tunnel for which to finish the KX).
1716 * @param tc Task context.
1719 finish_kx (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1721 struct CadetTunnel *t = cls;
1723 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1726 GNUNET_free (t->kx_ctx);
1732 * Peer has answer to our challenge.
1733 * If answer is successful, consider the key exchange finished and clean
1734 * up all related state.
1736 * @param t Tunnel this message came on.
1737 * @param msg Key eXchange Pong message.
1740 handle_pong (struct CadetTunnel *t,
1741 const struct GNUNET_CADET_KX_Pong *msg)
1745 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
1746 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1748 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1751 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1753 if (challenge != t->kx_ctx->challenge)
1755 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
1756 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1757 challenge, msg->nonce, t->kx_ctx->challenge);
1762 GNUNET_SCHEDULER_cancel (t->rekey_task);
1763 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1765 /* Don't free the old keys right away, but after a delay.
1766 * Rationale: the KX could have happened over a very fast connection,
1767 * with payload traffic still signed with the old key stuck in a slower
1770 if (GNUNET_SCHEDULER_NO_TASK == t->kx_ctx->finish_task)
1772 t->kx_ctx->finish_task =
1773 GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_MINUTES, finish_kx, t);
1775 GCT_change_estate (t, CADET_TUNNEL3_KEY_OK);
1780 * Demultiplex by message type and call appropriate handler for a message
1781 * towards a channel of a local tunnel.
1783 * @param t Tunnel this message came on.
1784 * @param msgh Message header.
1785 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1786 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1787 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1788 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1791 handle_decrypted (struct CadetTunnel *t,
1792 const struct GNUNET_MessageHeader *msgh,
1797 type = ntohs (msgh->type);
1798 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
1802 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1803 /* Do nothing, connection aleady got updated. */
1804 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
1807 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1808 /* Don't send hop ACK, wait for client to ACK */
1809 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
1812 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1813 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1816 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1817 handle_ch_create (t,
1818 (struct GNUNET_CADET_ChannelCreate *) msgh);
1821 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1823 (struct GNUNET_CADET_ChannelManage *) msgh);
1826 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1828 (struct GNUNET_CADET_ChannelManage *) msgh,
1832 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1833 handle_ch_destroy (t,
1834 (struct GNUNET_CADET_ChannelManage *) msgh,
1839 GNUNET_break_op (0);
1840 LOG (GNUNET_ERROR_TYPE_WARNING,
1841 "end-to-end message not known (%u)\n",
1842 ntohs (msgh->type));
1847 /******************************************************************************/
1848 /******************************** API ***********************************/
1849 /******************************************************************************/
1852 * Decrypt and demultiplex by message type. Call appropriate handler
1853 * for every message.
1855 * @param t Tunnel this message came on.
1856 * @param msg Encrypted message.
1859 GCT_handle_encrypted (struct CadetTunnel *t,
1860 const struct GNUNET_CADET_Encrypted *msg)
1862 size_t size = ntohs (msg->header.size);
1863 size_t payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
1865 char cbuf [payload_size];
1866 struct GNUNET_MessageHeader *msgh;
1869 decrypted_size = t_decrypt_and_validate (t, cbuf, &msg[1], payload_size,
1870 msg->iv, &msg->hmac);
1873 while (off < decrypted_size)
1875 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1876 handle_decrypted (t, msgh, GNUNET_SYSERR);
1877 off += ntohs (msgh->size);
1883 * Demultiplex an encapsulated KX message by message type.
1885 * @param t Tunnel on which the message came.
1886 * @param message Payload of KX message.
1889 GCT_handle_kx (struct CadetTunnel *t,
1890 const struct GNUNET_MessageHeader *message)
1894 type = ntohs (message->type);
1895 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1898 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1899 handle_ephemeral (t, (struct GNUNET_CADET_KX_Ephemeral *) message);
1902 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1903 handle_ping (t, (struct GNUNET_CADET_KX_Ping *) message);
1906 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1907 handle_pong (t, (struct GNUNET_CADET_KX_Pong *) message);
1911 GNUNET_break_op (0);
1912 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1918 * Initialize the tunnel subsystem.
1920 * @param c Configuration handle.
1921 * @param key ECC private key, to derive all other keys and do crypto.
1924 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1925 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1927 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1929 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
1932 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1933 "CADET", "DEFAULT_TTL", "USING DEFAULT");
1937 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
1940 rekey_period = GNUNET_TIME_UNIT_DAYS;
1943 my_private_key = key;
1944 kx_msg.header.size = htons (sizeof (kx_msg));
1945 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
1946 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
1947 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1948 kx_msg.origin_identity = my_full_id;
1949 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1951 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1956 * Shut down the tunnel subsystem.
1961 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1963 GNUNET_SCHEDULER_cancel (rekey_task);
1964 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1966 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
1967 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1974 * @param destination Peer this tunnel is towards.
1976 struct CadetTunnel *
1977 GCT_new (struct CadetPeer *destination)
1979 struct CadetTunnel *t;
1981 t = GNUNET_new (struct CadetTunnel);
1983 t->peer = destination;
1986 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
1987 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
1998 * Change the tunnel's connection state.
2000 * @param t Tunnel whose connection state to change.
2001 * @param cstate New connection state.
2004 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
2008 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
2009 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
2010 if (myid != GCP_get_short_id (t->peer) &&
2011 CADET_TUNNEL3_READY != t->cstate &&
2012 CADET_TUNNEL3_READY == cstate)
2015 if (CADET_TUNNEL3_KEY_OK == t->estate)
2017 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
2018 send_queued_data (t);
2020 else if (CADET_TUNNEL3_KEY_UNINITIALIZED == t->estate)
2022 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
2023 rekey_tunnel (t, NULL);
2028 if (CADET_TUNNEL3_READY == cstate
2029 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
2031 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
2032 GCP_stop_search (t->peer);
2037 * Change the tunnel encryption state.
2039 * @param t Tunnel whose encryption state to change.
2040 * @param state New encryption state.
2043 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
2047 LOG (GNUNET_ERROR_TYPE_DEBUG,
2048 "Tunnel %s estate was %s\n",
2049 GCP_2s (t->peer), estate2s (t->estate));
2050 LOG (GNUNET_ERROR_TYPE_DEBUG,
2051 "Tunnel %s estate is now %s\n",
2052 GCP_2s (t->peer), estate2s (state));
2053 if (myid != GCP_get_short_id (t->peer) &&
2054 CADET_TUNNEL3_KEY_OK != t->estate && CADET_TUNNEL3_KEY_OK == state)
2057 send_queued_data (t);
2065 * @brief Check if tunnel has too many connections, and remove one if necessary.
2067 * Currently this means the newest connection, unless it is a direct one.
2068 * Implemented as a task to avoid freeing a connection that is in the middle
2069 * of being created/processed.
2071 * @param cls Closure (Tunnel to check).
2072 * @param tc Task context.
2075 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2077 struct CadetTunnel *t = cls;
2079 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
2082 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
2084 struct CadetTConnection *iter;
2085 struct CadetTConnection *c;
2087 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
2089 if ((NULL == c || iter->created.abs_value_us > c->created.abs_value_us)
2090 && GNUNET_NO == GCC_is_direct (iter->c))
2097 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
2099 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
2112 * Add a connection to a tunnel.
2115 * @param c Connection.
2118 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
2120 struct CadetTConnection *aux;
2122 GNUNET_assert (NULL != c);
2124 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
2125 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
2126 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2130 aux = GNUNET_new (struct CadetTConnection);
2132 aux->created = GNUNET_TIME_absolute_get ();
2134 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
2136 GNUNET_SCHEDULER_add_now (&trim_connections, t);
2141 * Mark a path as no longer valid for this tunnel: has been tried and failed.
2143 * @param t Tunnel to update.
2144 * @param path Invalid path to remove. Is destroyed after removal.
2147 GCT_remove_path (struct CadetTunnel *t, struct CadetPeerPath *path)
2149 GCP_remove_path (t->peer, path);
2154 * Remove a connection from a tunnel.
2157 * @param c Connection.
2160 GCT_remove_connection (struct CadetTunnel *t,
2161 struct CadetConnection *c)
2163 struct CadetTConnection *aux;
2164 struct CadetTConnection *next;
2166 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2167 GCC_2s (c), GCT_2s (t));
2168 for (aux = t->connection_head; aux != NULL; aux = next)
2173 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2178 /* Start new connections if needed */
2179 if (CONNECTIONS_PER_TUNNEL < GCT_count_connections (t)
2180 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2181 && CADET_TUNNEL3_SHUTDOWN != t->cstate
2182 && GNUNET_NO == shutting_down)
2184 LOG (GNUNET_ERROR_TYPE_DEBUG, " no more connections, getting new ones\n");
2185 t->cstate = CADET_TUNNEL3_SEARCHING;
2186 GCP_connect (t->peer);
2190 /* If not marked as ready, no change is needed */
2191 if (CADET_TUNNEL3_READY != t->cstate)
2194 /* Check if any connection is ready to maintaing cstate */
2195 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2196 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2199 t->cstate = CADET_TUNNEL3_WAITING;
2204 * Add a channel to a tunnel.
2207 * @param ch Channel.
2210 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2212 struct CadetTChannel *aux;
2214 GNUNET_assert (NULL != ch);
2216 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2218 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2220 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2225 aux = GNUNET_new (struct CadetTChannel);
2227 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2228 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2230 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2232 GNUNET_SCHEDULER_cancel (t->destroy_task);
2233 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2234 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2240 * Remove a channel from a tunnel.
2243 * @param ch Channel.
2246 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2248 struct CadetTChannel *aux;
2250 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2251 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2255 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2256 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2265 * Search for a channel by global ID.
2267 * @param t Tunnel containing the channel.
2268 * @param chid Public channel number.
2270 * @return channel handler, NULL if doesn't exist
2272 struct CadetChannel *
2273 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2275 struct CadetTChannel *iter;
2280 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2282 if (GCCH_get_id (iter->ch) == chid)
2286 return NULL == iter ? NULL : iter->ch;
2291 * @brief Destroy a tunnel and free all resources.
2293 * Should only be called a while after the tunnel has been marked as destroyed,
2294 * in case there is a new channel added to the same peer shortly after marking
2295 * the tunnel. This way we avoid a new public key handshake.
2297 * @param cls Closure (tunnel to destroy).
2298 * @param tc Task context.
2301 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2303 struct CadetTunnel *t = cls;
2304 struct CadetTConnection *iter;
2306 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2307 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2309 LOG (GNUNET_ERROR_TYPE_WARNING,
2310 "Not destroying tunnel, due to shutdown. "
2311 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2314 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2315 t->cstate = CADET_TUNNEL3_SHUTDOWN;
2317 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2319 GCC_send_destroy (iter->c);
2326 * Tunnel is empty: destroy it.
2328 * Notifies all connections about the destruction.
2330 * @param t Tunnel to destroy.
2333 GCT_destroy_empty (struct CadetTunnel *t)
2335 if (GNUNET_YES == shutting_down)
2336 return; /* Will be destroyed immediately anyway */
2338 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2340 LOG (GNUNET_ERROR_TYPE_DEBUG,
2341 "Tunnel %s is already scheduled for destruction\n",
2344 /* should never happen, tunnel can only become empty once, and the
2345 * task identifier should be NO_TASK (cleaned when the tunnel was created
2346 * or became un-empty)
2351 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2354 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2355 &delayed_destroy, t);
2356 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llX\n",
2357 t, t->destroy_task);
2362 * Destroy tunnel if empty (no more channels).
2364 * @param t Tunnel to destroy if empty.
2367 GCT_destroy_if_empty (struct CadetTunnel *t)
2369 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2370 if (1 < GCT_count_channels (t))
2373 GCT_destroy_empty (t);
2378 * Destroy the tunnel.
2380 * This function does not generate any warning traffic to clients or peers.
2383 * Cancel messages belonging to this tunnel queued to neighbors.
2384 * Free any allocated resources linked to the tunnel.
2386 * @param t The tunnel to destroy.
2389 GCT_destroy (struct CadetTunnel *t)
2391 struct CadetTConnection *iter_c;
2392 struct CadetTConnection *next_c;
2393 struct CadetTChannel *iter_ch;
2394 struct CadetTChannel *next_ch;
2399 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
2401 GNUNET_break (GNUNET_YES ==
2402 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2403 GCP_get_id (t->peer), t));
2405 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2407 next_c = iter_c->next;
2408 GCC_destroy (iter_c->c);
2410 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2412 next_ch = iter_ch->next;
2413 GCCH_destroy (iter_ch->ch);
2414 /* Should only happen on shutdown, but it's ok. */
2417 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2419 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling %llX\n", t->destroy_task);
2420 GNUNET_SCHEDULER_cancel (t->destroy_task);
2421 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2424 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2425 GCP_set_tunnel (t->peer, NULL);
2427 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2429 GNUNET_SCHEDULER_cancel (t->rekey_task);
2430 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2432 if (NULL != t->kx_ctx)
2434 if (GNUNET_SCHEDULER_NO_TASK != t->kx_ctx->finish_task)
2435 GNUNET_SCHEDULER_cancel (t->kx_ctx->finish_task);
2436 GNUNET_free (t->kx_ctx);
2443 * @brief Use the given path for the tunnel.
2444 * Update the next and prev hops (and RCs).
2445 * (Re)start the path refresh in case the tunnel is locally owned.
2447 * @param t Tunnel to update.
2448 * @param p Path to use.
2450 * @return Connection created.
2452 struct CadetConnection *
2453 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
2455 struct CadetConnection *c;
2456 struct GNUNET_CADET_Hash cid;
2457 unsigned int own_pos;
2459 if (NULL == t || NULL == p)
2465 if (CADET_TUNNEL3_SHUTDOWN == t->cstate)
2471 for (own_pos = 0; own_pos < p->length; own_pos++)
2473 if (p->peers[own_pos] == myid)
2476 if (own_pos >= p->length)
2478 GNUNET_break_op (0);
2482 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2483 c = GCC_new (&cid, t, p, own_pos);
2486 /* Path was flawed */
2489 GCT_add_connection (t, c);
2495 * Count established (ready) connections of a tunnel.
2497 * @param t Tunnel on which to count.
2499 * @return Number of connections.
2502 GCT_count_connections (struct CadetTunnel *t)
2504 struct CadetTConnection *iter;
2510 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2511 if (CADET_CONNECTION_DESTROYED != GCC_get_state (iter->c))
2518 * Count channels of a tunnel.
2520 * @param t Tunnel on which to count.
2522 * @return Number of channels.
2525 GCT_count_channels (struct CadetTunnel *t)
2527 struct CadetTChannel *iter;
2530 for (count = 0, iter = t->channel_head;
2532 iter = iter->next, count++) /* skip */;
2539 * Get the connectivity state of a tunnel.
2543 * @return Tunnel's connectivity state.
2545 enum CadetTunnelCState
2546 GCT_get_cstate (struct CadetTunnel *t)
2551 return (enum CadetTunnelCState) -1;
2558 * Get the encryption state of a tunnel.
2562 * @return Tunnel's encryption state.
2564 enum CadetTunnelEState
2565 GCT_get_estate (struct CadetTunnel *t)
2570 return (enum CadetTunnelEState) -1;
2576 * Get the maximum buffer space for a tunnel towards a local client.
2580 * @return Biggest buffer space offered by any channel in the tunnel.
2583 GCT_get_channels_buffer (struct CadetTunnel *t)
2585 struct CadetTChannel *iter;
2586 unsigned int buffer;
2587 unsigned int ch_buf;
2589 if (NULL == t->channel_head)
2591 /* Probably getting buffer for a channel create/handshake. */
2596 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2598 ch_buf = get_channel_buffer (iter);
2599 if (ch_buf > buffer)
2607 * Get the total buffer space for a tunnel for P2P traffic.
2611 * @return Buffer space offered by all connections in the tunnel.
2614 GCT_get_connections_buffer (struct CadetTunnel *t)
2616 struct CadetTConnection *iter;
2617 unsigned int buffer;
2620 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2622 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2626 buffer += get_connection_buffer (iter);
2634 * Get the tunnel's destination.
2638 * @return ID of the destination peer.
2640 const struct GNUNET_PeerIdentity *
2641 GCT_get_destination (struct CadetTunnel *t)
2643 return GCP_get_id (t->peer);
2648 * Get the tunnel's next free global channel ID.
2652 * @return GID of a channel free to use.
2655 GCT_get_next_chid (struct CadetTunnel *t)
2657 CADET_ChannelNumber chid;
2658 CADET_ChannelNumber mask;
2661 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2662 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2663 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2665 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2670 t->next_chid |= mask;
2672 while (NULL != GCT_get_channel (t, t->next_chid))
2674 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2675 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2676 t->next_chid |= mask;
2678 chid = t->next_chid;
2679 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2680 t->next_chid |= mask;
2687 * Send ACK on one or more channels due to buffer in connections.
2689 * @param t Channel which has some free buffer space.
2692 GCT_unchoke_channels (struct CadetTunnel *t)
2694 struct CadetTChannel *iter;
2695 unsigned int buffer;
2696 unsigned int channels = GCT_count_channels (t);
2697 unsigned int choked_n;
2698 struct CadetChannel *choked[channels];
2700 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
2701 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2702 if (NULL != t->channel_head)
2703 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2705 /* Get buffer space */
2706 buffer = GCT_get_connections_buffer (t);
2712 /* Count and remember choked channels */
2714 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2716 if (GNUNET_NO == get_channel_allowed (iter))
2718 choked[choked_n++] = iter->ch;
2722 /* Unchoke random channels */
2723 while (0 < buffer && 0 < choked_n)
2725 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
2727 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
2730 choked[r] = choked[choked_n];
2736 * Send ACK on one or more connections due to buffer space to the client.
2738 * Iterates all connections of the tunnel and sends ACKs appropriately.
2743 GCT_send_connection_acks (struct CadetTunnel *t)
2745 struct CadetTConnection *iter;
2748 uint32_t allow_per_connection;
2750 unsigned int buffer;
2752 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
2761 buffer = GCT_get_channels_buffer (t);
2762 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
2764 /* Count connections, how many messages are already allowed */
2765 cs = GCT_count_connections (t);
2766 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2768 allowed += get_connection_allowed (iter);
2770 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
2772 /* Make sure there is no overflow */
2773 if (allowed > buffer)
2778 /* Authorize connections to send more data */
2779 to_allow = buffer; /* - allowed; */
2781 for (iter = t->connection_head;
2782 NULL != iter && to_allow > 0;
2785 allow_per_connection = to_allow/cs;
2786 to_allow -= allow_per_connection;
2788 if (get_connection_allowed (iter) > 64 / 3)
2792 GCC_allow (iter->c, allow_per_connection,
2793 GCC_is_origin (iter->c, GNUNET_NO));
2796 GNUNET_break (to_allow == 0);
2801 * Cancel a previously sent message while it's in the queue.
2803 * ONLY can be called before the continuation given to the send function
2804 * is called. Once the continuation is called, the message is no longer in the
2807 * @param q Handle to the queue.
2810 GCT_cancel (struct CadetTunnelQueue *q)
2815 /* tun_message_sent() will be called and free q */
2817 else if (NULL != q->tqd)
2819 unqueue_data (q->tqd);
2821 if (NULL != q->cont)
2822 q->cont (q->cont_cls, NULL, q, 0, 0);
2833 * Sends an already built message on a tunnel, encrypting it and
2834 * choosing the best connection if not provided.
2836 * @param message Message to send. Function modifies it.
2837 * @param t Tunnel on which this message is transmitted.
2838 * @param c Connection to use (autoselect if NULL).
2839 * @param force Force the tunnel to take the message (buffer overfill).
2840 * @param cont Continuation to call once message is really sent.
2841 * @param cont_cls Closure for @c cont.
2843 * @return Handle to cancel message. NULL if @c cont is NULL.
2845 struct CadetTunnelQueue *
2846 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2847 struct CadetTunnel *t, struct CadetConnection *c,
2848 int force, GCT_sent cont, void *cont_cls)
2850 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
2855 * Is the tunnel directed towards the local peer?
2859 * @return #GNUNET_YES if it is loopback.
2862 GCT_is_loopback (const struct CadetTunnel *t)
2864 return (myid == GCP_get_short_id (t->peer));
2869 * Is the tunnel this path already?
2874 * @return #GNUNET_YES a connection uses this path.
2877 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
2879 struct CadetTConnection *iter;
2881 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2882 if (GCC_get_path (iter->c) == p)
2890 * Get a cost of a path for a tunnel considering existing connections.
2893 * @param path Candidate path.
2895 * @return Cost of the path (path length + number of overlapping nodes)
2898 GCT_get_path_cost (const struct CadetTunnel *t,
2899 const struct CadetPeerPath *path)
2901 struct CadetTConnection *iter;
2902 const struct CadetPeerPath *aux;
2903 unsigned int overlap;
2911 GNUNET_assert (NULL != t);
2913 for (i = 0; i < path->length; i++)
2915 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2917 aux = GCC_get_path (iter->c);
2921 for (j = 0; j < aux->length; j++)
2923 if (path->peers[i] == aux->peers[j])
2931 return path->length + overlap;
2936 * Get the static string for the peer this tunnel is directed.
2940 * @return Static string the destination peer's ID.
2943 GCT_2s (const struct CadetTunnel *t)
2948 return GCP_2s (t->peer);
2952 /******************************************************************************/
2953 /***************************** INFO/DEBUG *******************************/
2954 /******************************************************************************/
2958 * Log all possible info about the tunnel state to stderr.
2960 * @param t Tunnel to debug.
2963 GCT_debug (const struct CadetTunnel *t)
2965 struct CadetTChannel *iterch;
2966 struct CadetTConnection *iterc;
2968 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
2969 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT cstate %s, estate %s\n",
2970 cstate2s (t->cstate), estate2s (t->estate));
2971 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT kx_ctx %p, rekey_task %u\n",
2972 t->kx_ctx, t->rekey_task);
2973 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT tq_head %p, tq_tail %p\n",
2974 t->tq_head, t->tq_tail);
2975 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT destroy %u\n", t->destroy_task);
2977 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT channels:\n");
2978 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
2980 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT - %s\n", GCCH_2s (iterch->ch));
2983 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT connections:\n");
2984 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
2986 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT - %s [%u] buf: %u/%u (qn %u/%u)\n",
2987 GCC_2s (iterc->c), GCC_get_state (iterc->c),
2988 GCC_get_buffer (iterc->c, GNUNET_YES),
2989 GCC_get_buffer (iterc->c, GNUNET_NO),
2990 GCC_get_qn (iterc->c, GNUNET_YES),
2991 GCC_get_qn (iterc->c, GNUNET_NO));
2994 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT DEBUG TUNNEL END\n");
2999 * Iterate all tunnels.
3001 * @param iter Iterator.
3002 * @param cls Closure for @c iter.
3005 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
3007 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
3012 * Count all tunnels.
3014 * @return Number of tunnels to remote peers kept by this peer.
3017 GCT_count_all (void)
3019 return GNUNET_CONTAINER_multipeermap_size (tunnels);
3024 * Iterate all connections of a tunnel.
3026 * @param t Tunnel whose connections to iterate.
3027 * @param iter Iterator.
3028 * @param cls Closure for @c iter.
3031 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
3033 struct CadetTConnection *ct;
3035 for (ct = t->connection_head; NULL != ct; ct = ct->next)
3041 * Iterate all channels of a tunnel.
3043 * @param t Tunnel whose channels to iterate.
3044 * @param iter Iterator.
3045 * @param cls Closure for @c iter.
3048 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
3050 struct CadetTChannel *cht;
3052 for (cht = t->channel_head; NULL != cht; cht = cht->next)
3053 iter (cls, cht->ch);