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 * Decryption ("their") old key, for decrypting traffic sent by the
91 * other end before the key exchange started.
93 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
96 * Challenge to send in a ping and expect in the pong.
102 * Struct containing all information regarding a tunnel to a peer.
107 * Endpoint of the tunnel.
109 struct CadetPeer *peer;
112 * State of the tunnel connectivity.
114 enum CadetTunnelCState cstate;
117 * State of the tunnel encryption.
119 enum CadetTunnelEState estate;
122 * Key eXchange context.
124 struct CadetTunnelKXCtx *kx_ctx;
127 * Encryption ("our") key.
129 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
132 * Decryption ("their") key.
134 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
137 * Task to start the rekey process.
139 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
142 * Paths that are actively used to reach the destination peer.
144 struct CadetTConnection *connection_head;
145 struct CadetTConnection *connection_tail;
148 * Next connection number.
153 * Channels inside this tunnel.
155 struct CadetTChannel *channel_head;
156 struct CadetTChannel *channel_tail;
159 * Channel ID for the next created channel.
161 CADET_ChannelNumber next_chid;
164 * Destroy flag: if true, destroy on last message.
166 GNUNET_SCHEDULER_TaskIdentifier destroy_task;
169 * Queued messages, to transmit once tunnel gets connected.
171 struct CadetTunnelDelayed *tq_head;
172 struct CadetTunnelDelayed *tq_tail;
177 * Struct used to save messages in a non-ready tunnel to send once connected.
179 struct CadetTunnelDelayed
184 struct CadetTunnelDelayed *next;
185 struct CadetTunnelDelayed *prev;
190 struct CadetTunnel *t;
193 * Tunnel queue given to the channel to cancel request. Update on send_queued.
195 struct CadetTunnelQueue *tq;
200 /* struct GNUNET_MessageHeader *msg; */
205 * Handle for messages queued but not yet sent.
207 struct CadetTunnelQueue
210 * Connection queue handle, to cancel if necessary.
212 struct CadetConnectionQueue *cq;
215 * Handle in case message hasn't been given to a connection yet.
217 struct CadetTunnelDelayed *tqd;
220 * Continuation to call once sent.
225 * Closure for @c cont.
231 /******************************************************************************/
232 /******************************* GLOBALS ***********************************/
233 /******************************************************************************/
236 * Global handle to the statistics service.
238 extern struct GNUNET_STATISTICS_Handle *stats;
241 * Local peer own ID (memory efficient handle).
243 extern GNUNET_PEER_Id myid;
246 * Local peer own ID (full value).
248 extern struct GNUNET_PeerIdentity my_full_id;
252 * Don't try to recover tunnels if shutting down.
254 extern int shutting_down;
258 * Set of all tunnels, in order to trigger a new exchange on rekey.
259 * Indexed by peer's ID.
261 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
264 * Default TTL for payload packets.
266 static unsigned long long default_ttl;
271 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
274 * Own ephemeral private key.
276 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
279 * Cached message used to perform a key exchange.
281 static struct GNUNET_CADET_KX_Ephemeral kx_msg;
284 * Task to generate a new ephemeral key.
286 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
291 static struct GNUNET_TIME_Relative rekey_period;
293 /******************************************************************************/
294 /******************************** STATIC ***********************************/
295 /******************************************************************************/
298 * Get string description for tunnel connectivity state.
300 * @param cs Tunnel state.
302 * @return String representation.
305 cstate2s (enum CadetTunnelCState cs)
307 static char buf[128];
311 case CADET_TUNNEL3_NEW:
312 return "CADET_TUNNEL3_NEW";
313 case CADET_TUNNEL3_SEARCHING:
314 return "CADET_TUNNEL3_SEARCHING";
315 case CADET_TUNNEL3_WAITING:
316 return "CADET_TUNNEL3_WAITING";
317 case CADET_TUNNEL3_READY:
318 return "CADET_TUNNEL3_READY";
321 sprintf (buf, "%u (UNKNOWN STATE)", cs);
329 * Get string description for tunnel encryption state.
331 * @param es Tunnel state.
333 * @return String representation.
336 estate2s (enum CadetTunnelEState es)
338 static char buf[128];
342 case CADET_TUNNEL3_KEY_UNINITIALIZED:
343 return "CADET_TUNNEL3_KEY_UNINITIALIZED";
344 case CADET_TUNNEL3_KEY_SENT:
345 return "CADET_TUNNEL3_KEY_SENT";
346 case CADET_TUNNEL3_KEY_PING:
347 return "CADET_TUNNEL3_KEY_PING";
348 case CADET_TUNNEL3_KEY_OK:
349 return "CADET_TUNNEL3_KEY_OK";
352 sprintf (buf, "%u (UNKNOWN STATE)", es);
360 * @brief Check if tunnel is ready to send traffic.
362 * Tunnel must be connected and with encryption correctly set up.
364 * @param t Tunnel to check.
366 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
369 is_ready (struct CadetTunnel *t)
374 ready = (CADET_TUNNEL3_READY == t->cstate && CADET_TUNNEL3_KEY_OK == t->estate);
375 ready = ready || GCT_is_loopback (t);
381 * Ephemeral key message purpose size.
383 * @return Size of the part of the ephemeral key message that must be signed.
386 ephemeral_purpose_size (void)
388 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
389 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
390 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
391 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
392 sizeof (struct GNUNET_PeerIdentity);
397 * Size of the encrypted part of a ping message.
399 * @return Size of the encrypted part of a ping message.
402 ping_encryption_size (void)
404 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
409 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
411 * @param tch Tunnel's channel handle.
413 * @return Amount of messages the channel can still buffer towards the client.
416 get_channel_buffer (const struct CadetTChannel *tch)
420 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
421 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
423 return GCCH_get_buffer (tch->ch, fwd);
428 * Get the channel's allowance status.
430 * @param tch Tunnel's channel handle.
432 * @return #GNUNET_YES if we allowed the client to send data to us.
435 get_channel_allowed (const struct CadetTChannel *tch)
439 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
440 fwd = GCCH_is_origin (tch->ch, GNUNET_YES);
442 return GCCH_get_allowed (tch->ch, fwd);
447 * Get the connection's buffer.
449 * @param tc Tunnel's connection handle.
451 * @return Amount of messages the connection can still buffer.
454 get_connection_buffer (const struct CadetTConnection *tc)
458 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
459 fwd = GCC_is_origin (tc->c, GNUNET_YES);
461 return GCC_get_buffer (tc->c, fwd);
466 * Get the connection's allowance.
468 * @param tc Tunnel's connection handle.
470 * @return Amount of messages we have allowed the next peer to send us.
473 get_connection_allowed (const struct CadetTConnection *tc)
477 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
478 fwd = GCC_is_origin (tc->c, GNUNET_YES);
480 return GCC_get_allowed (tc->c, fwd);
485 * Check that a ephemeral key message s well formed and correctly signed.
487 * @param t Tunnel on which the message came.
488 * @param msg The ephemeral key message.
490 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
493 check_ephemeral (struct CadetTunnel *t,
494 const struct GNUNET_CADET_KX_Ephemeral *msg)
496 /* Check message size */
497 if (ntohs (msg->header.size) != sizeof (struct GNUNET_CADET_KX_Ephemeral))
498 return GNUNET_SYSERR;
500 /* Check signature size */
501 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
502 return GNUNET_SYSERR;
505 if (0 != memcmp (&msg->origin_identity,
506 GCP_get_id (t->peer),
507 sizeof (struct GNUNET_PeerIdentity)))
508 return GNUNET_SYSERR;
510 /* Check signature */
512 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_CADET_KX,
515 &msg->origin_identity.public_key))
516 return GNUNET_SYSERR;
523 * Encrypt data with the tunnel key.
525 * @param t Tunnel whose key to use.
526 * @param dst Destination for the encrypted data.
527 * @param src Source of the plaintext. Can overlap with @c dst.
528 * @param size Size of the plaintext.
529 * @param iv Initialization Vector to use.
532 t_encrypt (struct CadetTunnel *t,
533 void *dst, const void *src,
534 size_t size, uint32_t iv)
536 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
539 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
540 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->e_key, &iv, sizeof (iv), NULL);
541 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
542 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &t->e_key, &siv, dst);
543 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
550 * Decrypt data with the tunnel key.
552 * @param t Tunnel whose key to use.
553 * @param dst Destination for the plaintext.
554 * @param src Source of the encrypted data. Can overlap with @c dst.
555 * @param size Size of the encrypted data.
556 * @param iv Initialization Vector to use.
559 t_decrypt (struct CadetTunnel *t,
560 void *dst, const void *src,
561 size_t size, uint32_t iv)
563 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
564 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
567 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt start\n");
568 if (t->estate == CADET_TUNNEL3_KEY_OK || t->estate == CADET_TUNNEL3_KEY_PING)
572 else if (NULL != t->kx_ctx)
574 key = &t->kx_ctx->d_key_old;
578 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
579 LOG (GNUNET_ERROR_TYPE_DEBUG,
580 "WARNING got data on %s without a valid key\n",
586 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt iv\n");
587 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
588 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt iv done\n");
589 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
590 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt end\n");
597 * Create key material by doing ECDH on the local and remote ephemeral keys.
599 * @param key_material Where to store the key material.
600 * @param ephemeral_key Peer's public ephemeral key.
603 derive_key_material (struct GNUNET_HashCode *key_material,
604 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
607 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
616 * Create a symmetic key from the identities of both ends and the key material
619 * @param key Destination for the generated key.
620 * @param sender ID of the peer that will encrypt with @c key.
621 * @param receiver ID of the peer that will decrypt with @c key.
622 * @param key_material Hash created with ECDH with the ephemeral keys.
625 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
626 const struct GNUNET_PeerIdentity *sender,
627 const struct GNUNET_PeerIdentity *receiver,
628 const struct GNUNET_HashCode *key_material)
630 const char salt[] = "CADET kx salt";
632 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
634 key_material, sizeof (struct GNUNET_HashCode),
635 sender, sizeof (struct GNUNET_PeerIdentity),
636 receiver, sizeof (struct GNUNET_PeerIdentity),
641 * Pick a connection on which send the next data message.
643 * @param t Tunnel on which to send the message.
645 * @return The connection on which to send the next message.
647 static struct CadetConnection *
648 tunnel_get_connection (struct CadetTunnel *t)
650 struct CadetTConnection *iter;
651 struct CadetConnection *best;
653 unsigned int lowest_q;
655 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GCT_2s (t));
658 for (iter = t->connection_head; NULL != iter; iter = iter->next)
660 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
661 GCC_2s (iter->c), GCC_get_state (iter->c));
662 if (CADET_CONNECTION_READY == GCC_get_state (iter->c))
664 qn = GCC_get_qn (iter->c, GCC_is_origin (iter->c, GNUNET_YES));
665 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
673 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GCC_2s (best));
679 * Callback called when a queued message is sent.
681 * Calculates the average time and connection packet tracking.
683 * @param cls Closure (TunnelQueue handle).
684 * @param c Connection this message was on.
685 * @param q Connection queue handle (unused).
686 * @param type Type of message sent.
687 * @param fwd Was this a FWD going message?
688 * @param size Size of the message.
691 tun_message_sent (void *cls,
692 struct CadetConnection *c,
693 struct CadetConnectionQueue *q,
694 uint16_t type, int fwd, size_t size)
696 struct CadetTunnelQueue *qt = cls;
697 struct CadetTunnel *t;
699 LOG (GNUNET_ERROR_TYPE_DEBUG, "tun_message_sent\n");
701 GNUNET_assert (NULL != qt->cont);
702 t = NULL == c ? NULL : GCC_get_tunnel (c);
703 qt->cont (qt->cont_cls, t, qt, type, size);
709 * Delete a queued message: either was sent or the channel was destroyed
710 * before the tunnel's key exchange had a chance to finish.
712 * @param tqd Delayed queue handle.
715 unqueue_data (struct CadetTunnelDelayed *tqd)
717 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
723 * Cache a message to be sent once tunnel is online.
725 * @param t Tunnel to hold the message.
726 * @param msg Message itself (copy will be made).
728 static struct CadetTunnelDelayed *
729 queue_data (struct CadetTunnel *t, const struct GNUNET_MessageHeader *msg)
731 struct CadetTunnelDelayed *tqd;
732 uint16_t size = ntohs (msg->size);
734 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GCT_2s (t));
736 if (GNUNET_YES == is_ready (t))
742 tqd = GNUNET_malloc (sizeof (struct CadetTunnelDelayed) + size);
745 memcpy (&tqd[1], msg, size);
746 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
754 * @param t Tunnel to get keys from.
755 * @param plaintext Content to HMAC.
756 * @param size Size of @c plaintext.
757 * @param iv Initialization vector for the message.
758 * @param outgoing Is this an outgoing message that we encrypted?
759 * @param hmac Destination to store the HMAC.
762 t_hmac (struct CadetTunnel *t, const void *plaintext, size_t size, uint32_t iv,
763 int outgoing, struct GNUNET_CADET_Hash *hmac)
765 struct GNUNET_CRYPTO_AuthKey auth_key;
766 static const char ctx[] = "cadet authentication key";
767 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
768 struct GNUNET_HashCode hash;
770 key = outgoing ? &t->e_key : &t->d_key;
771 GNUNET_CRYPTO_hmac_derive_key (&auth_key, key,
776 GNUNET_CRYPTO_hmac (&auth_key, plaintext, size, &hash);
777 memcpy (hmac, &hash, sizeof (*hmac));
782 * Sends an already built message on a tunnel, encrypting it and
783 * choosing the best connection.
785 * @param message Message to send. Function modifies it.
786 * @param t Tunnel on which this message is transmitted.
787 * @param c Connection to use (autoselect if NULL).
788 * @param force Force the tunnel to take the message (buffer overfill).
789 * @param cont Continuation to call once message is really sent.
790 * @param cont_cls Closure for @c cont.
791 * @param existing_q In case this a transmission of previously queued data,
792 * this should be TunnelQueue given to the client.
795 * @return Handle to cancel message. NULL if @c cont is NULL.
797 static struct CadetTunnelQueue *
798 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
799 struct CadetTunnel *t, struct CadetConnection *c,
800 int force, GCT_sent cont, void *cont_cls,
801 struct CadetTunnelQueue *existing_q)
803 struct CadetTunnelQueue *tq;
804 struct GNUNET_CADET_Encrypted *msg;
805 size_t size = ntohs (message->size);
806 char cbuf[sizeof (struct GNUNET_CADET_Encrypted) + size];
812 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GCT_2s (t));
814 if (GNUNET_NO == is_ready (t))
816 struct CadetTunnelDelayed *tqd;
817 /* A non null existing_q indicates sending of queued data.
818 * Should only happen after tunnel becomes ready.
820 GNUNET_assert (NULL == existing_q);
821 tqd = queue_data (t, message);
824 tq = GNUNET_new (struct CadetTunnelQueue);
828 tq->cont_cls = cont_cls;
832 GNUNET_assert (GNUNET_NO == GCT_is_loopback (t));
834 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
835 msg = (struct GNUNET_CADET_Encrypted *) cbuf;
836 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED);
838 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv) == size);
839 t_hmac (t, &msg[1], size, iv, GNUNET_YES, &msg->hmac);
840 msg->header.size = htons (sizeof (struct GNUNET_CADET_Encrypted) + size);
843 c = tunnel_get_connection (t);
846 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
847 || CADET_TUNNEL3_SEARCHING != t->cstate)
856 type = ntohs (message->type);
859 case GNUNET_MESSAGE_TYPE_CADET_DATA:
860 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
861 if (GNUNET_MESSAGE_TYPE_CADET_DATA == type)
862 mid = ntohl (((struct GNUNET_CADET_Data *) message)->mid);
864 mid = ntohl (((struct GNUNET_CADET_DataACK *) message)->mid);
866 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
867 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
868 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
869 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
870 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
871 msg->cid = *GCC_get_id (c);
872 msg->ttl = htonl (default_ttl);
877 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s\n", GC_m2s (type));
879 fwd = GCC_is_origin (c, GNUNET_YES);
883 GNUNET_break (NULL ==
884 GCC_send_prebuilt_message (&msg->header, type, mid,
885 c, fwd, force, NULL, NULL));
888 if (NULL == existing_q)
890 tq = GNUNET_new (struct CadetTunnelQueue); /* FIXME valgrind: leak*/
897 tq->cq = GCC_send_prebuilt_message (&msg->header, type, mid, c, fwd, force,
898 &tun_message_sent, tq);
900 tq->cont_cls = cont_cls;
907 * Send all cached messages that we can, tunnel is online.
909 * @param t Tunnel that holds the messages. Cannot be loopback.
912 send_queued_data (struct CadetTunnel *t)
914 struct CadetTunnelDelayed *tqd;
915 struct CadetTunnelDelayed *next;
918 LOG (GNUNET_ERROR_TYPE_DEBUG,
919 "GCT_send_queued_data on tunnel %s\n",
922 if (GCT_is_loopback (t))
928 if (GNUNET_NO == is_ready (t))
930 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
931 estate2s (t->estate), cstate2s (t->cstate));
935 room = GCT_get_connections_buffer (t);
936 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
937 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
938 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
940 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
943 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
944 tqd->t, NULL, GNUNET_YES,
945 NULL != tqd->tq ? tqd->tq->cont : NULL,
946 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
950 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_send_queued_data end\n", GCP_2s (t->peer));
955 * Sends key exchange message on a tunnel, choosing the best connection.
956 * Should not be called on loopback tunnels.
958 * @param t Tunnel on which this message is transmitted.
959 * @param message Message to send. Function modifies it.
962 send_kx (struct CadetTunnel *t,
963 const struct GNUNET_MessageHeader *message)
965 struct CadetConnection *c;
966 struct GNUNET_CADET_KX *msg;
967 size_t size = ntohs (message->size);
968 char cbuf[sizeof (struct GNUNET_CADET_KX) + size];
972 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GCT_2s (t));
974 /* Avoid loopback. */
975 if (GCT_is_loopback (t))
977 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
982 /* Even if tunnel is being destroyed, send anyway.
983 * Could be a response to a rekey initiated by remote peer,
984 * who is trying to create a new channel!
987 /* Must have a connection. */
988 if (NULL == t->connection_head)
990 GNUNET_break (CADET_TUNNEL3_SEARCHING == t->cstate);
995 msg = (struct GNUNET_CADET_KX *) cbuf;
996 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX);
997 msg->header.size = htons (sizeof (struct GNUNET_CADET_KX) + size);
998 c = tunnel_get_connection (t);
1001 GNUNET_break (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
1002 || CADET_TUNNEL3_READY != t->cstate);
1006 type = ntohs (message->type);
1009 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1010 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1011 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1012 memcpy (&msg[1], message, size);
1015 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1020 fwd = GCC_is_origin (t->connection_head->c, GNUNET_YES);
1021 /* TODO save handle and cancel in case of a unneeded retransmission */
1022 GCC_send_prebuilt_message (&msg->header, GNUNET_MESSAGE_TYPE_CADET_KX,
1023 message->type, c, fwd, GNUNET_YES, NULL, NULL);
1028 * Send the ephemeral key on a tunnel.
1030 * @param t Tunnel on which to send the key.
1033 send_ephemeral (struct CadetTunnel *t)
1035 LOG (GNUNET_ERROR_TYPE_INFO, "=> EPHM for %s\n", GCT_2s (t));
1037 kx_msg.sender_status = htonl (t->estate);
1038 send_kx (t, &kx_msg.header);
1042 * Send a ping message on a tunnel.
1044 * @param t Tunnel on which to send the ping.
1047 send_ping (struct CadetTunnel *t)
1049 struct GNUNET_CADET_KX_Ping msg;
1051 LOG (GNUNET_ERROR_TYPE_INFO, "=> PING for %s\n", GCT_2s (t));
1052 msg.header.size = htons (sizeof (msg));
1053 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PING);
1054 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1055 msg.target = *GCP_get_id (t->peer);
1056 msg.nonce = t->kx_ctx->challenge;
1058 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1059 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
1060 t_encrypt (t, &msg.target, &msg.target, ping_encryption_size(), msg.iv);
1061 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1062 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
1064 send_kx (t, &msg.header);
1069 * Send a pong message on a tunnel.
1071 * @param t Tunnel on which to send the pong.
1072 * @param challenge Value sent in the ping that we have to send back.
1075 send_pong (struct CadetTunnel *t, uint32_t challenge)
1077 struct GNUNET_CADET_KX_Pong msg;
1079 LOG (GNUNET_ERROR_TYPE_INFO, "=> PONG for %s\n", GCT_2s (t));
1080 msg.header.size = htons (sizeof (msg));
1081 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_PONG);
1082 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1083 msg.nonce = challenge;
1084 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1085 t_encrypt (t, &msg.nonce, &msg.nonce, sizeof (msg.nonce), msg.iv);
1086 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1088 send_kx (t, &msg.header);
1093 * Initiate a rekey with the remote peer.
1095 * @param cls Closure (tunnel).
1096 * @param tc TaskContext.
1099 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1101 struct CadetTunnel *t = cls;
1103 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1105 LOG (GNUNET_ERROR_TYPE_DEBUG, "Re-key Tunnel %s\n", GCT_2s (t));
1106 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1109 if (NULL == t->kx_ctx)
1111 LOG (GNUNET_ERROR_TYPE_DEBUG, " new kx ctx\n");
1112 t->kx_ctx = GNUNET_new (struct CadetTunnelKXCtx);
1113 t->kx_ctx->challenge =
1114 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1115 t->kx_ctx->d_key_old = t->d_key;
1116 LOG (GNUNET_ERROR_TYPE_DEBUG, " new challenge for %s: %u\n",
1117 GCT_2s (t), t->kx_ctx->challenge);
1122 case CADET_TUNNEL3_KEY_UNINITIALIZED:
1123 t->estate = CADET_TUNNEL3_KEY_SENT;
1125 case CADET_TUNNEL3_KEY_SENT:
1127 case CADET_TUNNEL3_KEY_PING:
1128 case CADET_TUNNEL3_KEY_OK:
1130 t->estate = CADET_TUNNEL3_KEY_PING;
1133 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1136 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1137 GNUNET_STRINGS_relative_time_to_string (REKEY_WAIT, GNUNET_YES));
1138 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
1143 * Out ephemeral key has changed, create new session key on all tunnels.
1145 * @param cls Closure (size of the hashmap).
1146 * @param key Current public key.
1147 * @param value Value in the hash map (tunnel).
1149 * @return #GNUNET_YES, so we should continue to iterate,
1152 rekey_iterator (void *cls,
1153 const struct GNUNET_PeerIdentity *key,
1156 struct CadetTunnel *t = value;
1157 struct GNUNET_TIME_Relative delay;
1158 long n = (long) cls;
1161 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1164 if (GNUNET_YES == GCT_is_loopback (t))
1167 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1168 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1169 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1176 * Create a new ephemeral key and key message, schedule next rekeying.
1178 * @param cls Closure (unused).
1179 * @param tc TaskContext.
1182 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1184 struct GNUNET_TIME_Absolute time;
1187 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1189 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1192 GNUNET_free_non_null (my_ephemeral_key);
1193 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1195 time = GNUNET_TIME_absolute_get ();
1196 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1197 time = GNUNET_TIME_absolute_add (time, rekey_period);
1198 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1199 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1200 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1202 GNUNET_assert (GNUNET_OK ==
1203 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1205 &kx_msg.signature));
1207 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1208 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1210 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1215 * Called only on shutdown, destroy every tunnel.
1217 * @param cls Closure (unused).
1218 * @param key Current public key.
1219 * @param value Value in the hash map (tunnel).
1221 * @return #GNUNET_YES, so we should continue to iterate,
1224 destroy_iterator (void *cls,
1225 const struct GNUNET_PeerIdentity *key,
1228 struct CadetTunnel *t = value;
1230 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_shutdown destroying tunnel at %p\n", t);
1237 * Notify remote peer that we don't know a channel he is talking about,
1238 * probably CHANNEL_DESTROY was missed.
1240 * @param t Tunnel on which to notify.
1241 * @param gid ID of the channel.
1244 send_channel_destroy (struct CadetTunnel *t, unsigned int gid)
1246 struct GNUNET_CADET_ChannelManage msg;
1248 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
1249 msg.header.size = htons (sizeof (msg));
1250 msg.chid = htonl (gid);
1252 LOG (GNUNET_ERROR_TYPE_DEBUG,
1253 "WARNING destroying unknown channel %u on tunnel %s\n",
1255 send_prebuilt_message (&msg.header, t, NULL, GNUNET_YES, NULL, NULL, NULL);
1260 * Demultiplex data per channel and call appropriate channel handler.
1262 * @param t Tunnel on which the data came.
1263 * @param msg Data message.
1264 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1265 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1266 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1267 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1270 handle_data (struct CadetTunnel *t,
1271 const struct GNUNET_CADET_Data *msg,
1274 struct CadetChannel *ch;
1278 size = ntohs (msg->header.size);
1280 sizeof (struct GNUNET_CADET_Data) +
1281 sizeof (struct GNUNET_MessageHeader))
1286 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1287 GC_m2s (ntohs (msg[1].header.type)));
1290 ch = GCT_get_channel (t, ntohl (msg->chid));
1293 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1295 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1297 send_channel_destroy (t, ntohl (msg->chid));
1301 GCCH_handle_data (ch, msg, fwd);
1306 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1308 * @param t Tunnel on which the DATA ACK came.
1309 * @param msg DATA ACK message.
1310 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1311 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1312 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1313 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1316 handle_data_ack (struct CadetTunnel *t,
1317 const struct GNUNET_CADET_DataACK *msg,
1320 struct CadetChannel *ch;
1324 size = ntohs (msg->header.size);
1325 if (size != sizeof (struct GNUNET_CADET_DataACK))
1332 ch = GCT_get_channel (t, ntohl (msg->chid));
1335 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1337 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1342 GCCH_handle_data_ack (ch, msg, fwd);
1347 * Handle channel create.
1349 * @param t Tunnel on which the data came.
1350 * @param msg Data message.
1353 handle_ch_create (struct CadetTunnel *t,
1354 const struct GNUNET_CADET_ChannelCreate *msg)
1356 struct CadetChannel *ch;
1360 size = ntohs (msg->header.size);
1361 if (size != sizeof (struct GNUNET_CADET_ChannelCreate))
1368 ch = GCT_get_channel (t, ntohl (msg->chid));
1369 if (NULL != ch && ! GCT_is_loopback (t))
1371 /* Probably a retransmission, safe to ignore */
1372 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1374 ch = GCCH_handle_create (t, msg);
1376 GCT_add_channel (t, ch);
1382 * Handle channel NACK: check correctness and call channel handler for NACKs.
1384 * @param t Tunnel on which the NACK came.
1385 * @param msg NACK message.
1388 handle_ch_nack (struct CadetTunnel *t,
1389 const struct GNUNET_CADET_ChannelManage *msg)
1391 struct CadetChannel *ch;
1395 size = ntohs (msg->header.size);
1396 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1403 ch = GCT_get_channel (t, ntohl (msg->chid));
1406 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1408 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1413 GCCH_handle_nack (ch);
1418 * Handle a CHANNEL ACK (SYNACK/ACK).
1420 * @param t Tunnel on which the CHANNEL ACK came.
1421 * @param msg CHANNEL ACK message.
1422 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1423 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1424 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1425 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1428 handle_ch_ack (struct CadetTunnel *t,
1429 const struct GNUNET_CADET_ChannelManage *msg,
1432 struct CadetChannel *ch;
1436 size = ntohs (msg->header.size);
1437 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1444 ch = GCT_get_channel (t, ntohl (msg->chid));
1447 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1449 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1454 GCCH_handle_ack (ch, msg, fwd);
1460 * Handle a channel destruction message.
1462 * @param t Tunnel on which the message came.
1463 * @param msg Channel destroy message.
1464 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1465 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1466 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1467 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1470 handle_ch_destroy (struct CadetTunnel *t,
1471 const struct GNUNET_CADET_ChannelManage *msg,
1474 struct CadetChannel *ch;
1478 size = ntohs (msg->header.size);
1479 if (size != sizeof (struct GNUNET_CADET_ChannelManage))
1486 ch = GCT_get_channel (t, ntohl (msg->chid));
1489 /* Probably a retransmission, safe to ignore */
1493 GCCH_handle_destroy (ch, msg, fwd);
1498 * The peer's ephemeral key has changed: update the symmetrical keys.
1500 * @param t Tunnel this message came on.
1501 * @param msg Key eXchange message.
1504 handle_ephemeral (struct CadetTunnel *t,
1505 const struct GNUNET_CADET_KX_Ephemeral *msg)
1507 struct GNUNET_HashCode km;
1508 LOG (GNUNET_ERROR_TYPE_INFO, "<=== EPHM for %s\n", GCT_2s (t));
1510 if (GNUNET_OK != check_ephemeral (t, msg))
1512 GNUNET_break_op (0);
1515 derive_key_material (&km, &msg->ephemeral_key);
1516 LOG (GNUNET_ERROR_TYPE_DEBUG, " km is %s\n", GNUNET_h2s (&km));
1517 derive_symmertic (&t->e_key, &my_full_id, GCP_get_id (t->peer), &km);
1518 derive_symmertic (&t->d_key, GCP_get_id (t->peer), &my_full_id, &km);
1519 if (CADET_TUNNEL3_KEY_SENT == t->estate)
1521 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, send ping\n");
1523 t->estate = CADET_TUNNEL3_KEY_PING;
1529 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1530 * Answer with by retransmitting the challenge with the "opposite" key.
1532 * @param t Tunnel this message came on.
1533 * @param msg Key eXchange Ping message.
1536 handle_ping (struct CadetTunnel *t,
1537 const struct GNUNET_CADET_KX_Ping *msg)
1539 struct GNUNET_CADET_KX_Ping res;
1541 if (ntohs (msg->header.size) != sizeof (res))
1543 GNUNET_break_op (0);
1547 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PING for %s\n", GCT_2s (t));
1548 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1549 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1551 GNUNET_STATISTICS_update (stats, "# malformed PINGs", 1, GNUNET_NO);
1552 LOG (GNUNET_ERROR_TYPE_WARNING, " malformed PING on %s\n", GCT_2s (t));
1553 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1554 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1555 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1556 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1562 send_pong (t, res.nonce);
1567 * Peer has answer to our challenge.
1568 * If answer is successful, consider the key exchange finished and clean
1569 * up all related state.
1571 * @param t Tunnel this message came on.
1572 * @param msg Key eXchange Pong message.
1575 handle_pong (struct CadetTunnel *t,
1576 const struct GNUNET_CADET_KX_Pong *msg)
1580 LOG (GNUNET_ERROR_TYPE_INFO, "<=== PONG for %s\n", GCT_2s (t));
1581 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1583 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1586 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1588 if (challenge != t->kx_ctx->challenge)
1590 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge on %s\n", GCT_2s (t));
1591 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1592 challenge, msg->nonce, t->kx_ctx->challenge);
1597 GNUNET_SCHEDULER_cancel (t->rekey_task);
1598 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1599 GNUNET_free (t->kx_ctx);
1601 GCT_change_estate (t, CADET_TUNNEL3_KEY_OK);
1606 * Demultiplex by message type and call appropriate handler for a message
1607 * towards a channel of a local tunnel.
1609 * @param t Tunnel this message came on.
1610 * @param msgh Message header.
1611 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1612 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1613 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1614 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1617 handle_decrypted (struct CadetTunnel *t,
1618 const struct GNUNET_MessageHeader *msgh,
1623 type = ntohs (msgh->type);
1624 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s on %s\n", GC_m2s (type), GCT_2s (t));
1628 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
1629 /* Do nothing, connection aleady got updated. */
1630 GNUNET_STATISTICS_update (stats, "# keepalives received", 1, GNUNET_NO);
1633 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1634 /* Don't send hop ACK, wait for client to ACK */
1635 handle_data (t, (struct GNUNET_CADET_Data *) msgh, fwd);
1638 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1639 handle_data_ack (t, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1642 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1643 handle_ch_create (t,
1644 (struct GNUNET_CADET_ChannelCreate *) msgh);
1647 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1649 (struct GNUNET_CADET_ChannelManage *) msgh);
1652 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1654 (struct GNUNET_CADET_ChannelManage *) msgh,
1658 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1659 handle_ch_destroy (t,
1660 (struct GNUNET_CADET_ChannelManage *) msgh,
1665 GNUNET_break_op (0);
1666 LOG (GNUNET_ERROR_TYPE_WARNING,
1667 "end-to-end message not known (%u)\n",
1668 ntohs (msgh->type));
1673 /******************************************************************************/
1674 /******************************** API ***********************************/
1675 /******************************************************************************/
1678 * Decrypt and demultiplex by message type. Call appropriate handler
1679 * for every message.
1681 * @param t Tunnel this message came on.
1682 * @param msg Encrypted message.
1685 GCT_handle_encrypted (struct CadetTunnel *t,
1686 const struct GNUNET_CADET_Encrypted *msg)
1688 size_t size = ntohs (msg->header.size);
1689 size_t payload_size = size - sizeof (struct GNUNET_CADET_Encrypted);
1690 size_t decrypted_size;
1691 char cbuf [payload_size];
1692 struct GNUNET_MessageHeader *msgh;
1694 struct GNUNET_CADET_Hash hmac;
1696 decrypted_size = t_decrypt (t, cbuf, &msg[1], payload_size, msg->iv);
1697 t_hmac (t, &msg[1], payload_size, msg->iv, GNUNET_NO, &hmac);
1698 if (0 != memcmp (&hmac, &msg->hmac, sizeof (hmac)))
1700 /* checksum failed */
1701 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1702 "Failed checksum validation for a message on tunnel `%s'\n",
1704 GNUNET_STATISTICS_update (stats, "# wrong HMAC", 1, GNUNET_NO);
1708 while (off < decrypted_size)
1710 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1711 handle_decrypted (t, msgh, GNUNET_SYSERR);
1712 off += ntohs (msgh->size);
1718 * Demultiplex an encapsulated KX message by message type.
1720 * @param t Tunnel on which the message came.
1721 * @param message Payload of KX message.
1724 GCT_handle_kx (struct CadetTunnel *t,
1725 const struct GNUNET_MessageHeader *message)
1729 type = ntohs (message->type);
1730 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1733 case GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL:
1734 handle_ephemeral (t, (struct GNUNET_CADET_KX_Ephemeral *) message);
1737 case GNUNET_MESSAGE_TYPE_CADET_KX_PING:
1738 handle_ping (t, (struct GNUNET_CADET_KX_Ping *) message);
1741 case GNUNET_MESSAGE_TYPE_CADET_KX_PONG:
1742 handle_pong (t, (struct GNUNET_CADET_KX_Pong *) message);
1746 GNUNET_break_op (0);
1747 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1753 * Initialize the tunnel subsystem.
1755 * @param c Configuration handle.
1756 * @param key ECC private key, to derive all other keys and do crypto.
1759 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1760 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1762 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1764 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "DEFAULT_TTL",
1767 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1768 "CADET", "DEFAULT_TTL", "USING DEFAULT");
1772 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REKEY_PERIOD",
1775 rekey_period = GNUNET_TIME_UNIT_DAYS;
1778 my_private_key = key;
1779 kx_msg.header.size = htons (sizeof (kx_msg));
1780 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_KX_EPHEMERAL);
1781 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_CADET_KX);
1782 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1783 kx_msg.origin_identity = my_full_id;
1784 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1786 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1791 * Shut down the tunnel subsystem.
1796 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1798 GNUNET_SCHEDULER_cancel (rekey_task);
1799 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1801 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
1802 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1809 * @param destination Peer this tunnel is towards.
1811 struct CadetTunnel *
1812 GCT_new (struct CadetPeer *destination)
1814 struct CadetTunnel *t;
1816 t = GNUNET_new (struct CadetTunnel);
1818 t->peer = destination;
1821 GNUNET_CONTAINER_multipeermap_put (tunnels, GCP_get_id (destination), t,
1822 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
1833 * Change the tunnel's connection state.
1835 * @param t Tunnel whose connection state to change.
1836 * @param cstate New connection state.
1839 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate)
1843 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s cstate %s => %s\n",
1844 GCP_2s (t->peer), cstate2s (t->cstate), cstate2s (cstate));
1845 if (myid != GCP_get_short_id (t->peer) &&
1846 CADET_TUNNEL3_READY != t->cstate &&
1847 CADET_TUNNEL3_READY == cstate)
1850 if (CADET_TUNNEL3_KEY_OK == t->estate)
1852 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered send queued data\n");
1853 send_queued_data (t);
1855 else if (CADET_TUNNEL3_KEY_UNINITIALIZED == t->estate)
1857 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered rekey\n");
1858 rekey_tunnel (t, NULL);
1863 if (CADET_TUNNEL3_READY == cstate
1864 && CONNECTIONS_PER_TUNNEL <= GCT_count_connections (t))
1866 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate triggered stop dht\n");
1867 GCP_stop_search (t->peer);
1872 * Change the tunnel encryption state.
1874 * @param t Tunnel whose encryption state to change.
1875 * @param state New encryption state.
1878 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state)
1882 LOG (GNUNET_ERROR_TYPE_DEBUG,
1883 "Tunnel %s estate was %s\n",
1884 GCP_2s (t->peer), estate2s (t->estate));
1885 LOG (GNUNET_ERROR_TYPE_DEBUG,
1886 "Tunnel %s estate is now %s\n",
1887 GCP_2s (t->peer), estate2s (state));
1888 if (myid != GCP_get_short_id (t->peer) &&
1889 CADET_TUNNEL3_KEY_OK != t->estate && CADET_TUNNEL3_KEY_OK == state)
1892 send_queued_data (t);
1900 * @brief Check if tunnel has too many connections, and remove one if necessary.
1902 * Currently this means the newest connection, unless it is a direct one.
1903 * Implemented as a task to avoid freeing a connection that is in the middle
1904 * of being created/processed.
1906 * @param cls Closure (Tunnel to check).
1907 * @param tc Task context.
1910 trim_connections (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1912 struct CadetTunnel *t = cls;
1914 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1917 if (GCT_count_connections (t) > 2 * CONNECTIONS_PER_TUNNEL)
1919 struct CadetTConnection *iter;
1920 struct CadetTConnection *c;
1922 for (c = iter = t->connection_head; NULL != iter; iter = iter->next)
1924 if ((NULL == c || iter->created.abs_value_us > c->created.abs_value_us)
1925 && GNUNET_NO == GCC_is_direct (iter->c))
1932 LOG (GNUNET_ERROR_TYPE_DEBUG, "Too many connections on tunnel %s\n",
1934 LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying connection %s\n",
1947 * Add a connection to a tunnel.
1950 * @param c Connection.
1953 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c)
1955 struct CadetTConnection *aux;
1957 GNUNET_assert (NULL != c);
1959 LOG (GNUNET_ERROR_TYPE_DEBUG, "add connection %s\n", GCC_2s (c));
1960 LOG (GNUNET_ERROR_TYPE_DEBUG, " to tunnel %s\n", GCT_2s (t));
1961 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1965 aux = GNUNET_new (struct CadetTConnection);
1967 aux->created = GNUNET_TIME_absolute_get ();
1969 GNUNET_CONTAINER_DLL_insert (t->connection_head, t->connection_tail, aux);
1971 GNUNET_SCHEDULER_add_now (&trim_connections, t);
1976 * Mark a path as no longer valid for this tunnel: has been tried and failed.
1978 * @param t Tunnel to update.
1979 * @param path Invalid path to remove. Is destroyed after removal.
1982 GCT_remove_path (struct CadetTunnel *t, struct CadetPeerPath *path)
1984 GCP_remove_path (t->peer, path);
1989 * Remove a connection from a tunnel.
1992 * @param c Connection.
1995 GCT_remove_connection (struct CadetTunnel *t,
1996 struct CadetConnection *c)
1998 struct CadetTConnection *aux;
1999 struct CadetTConnection *next;
2001 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
2002 GCC_2s (c), GCT_2s (t));
2003 for (aux = t->connection_head; aux != NULL; aux = next)
2008 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
2013 /* Start new connections if needed */
2014 if (CONNECTIONS_PER_TUNNEL < GCT_count_connections (t)
2015 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
2016 && CADET_TUNNEL3_SHUTDOWN != t->cstate
2017 && GNUNET_NO == shutting_down)
2019 LOG (GNUNET_ERROR_TYPE_DEBUG, " no more connections, getting new ones\n");
2020 t->cstate = CADET_TUNNEL3_SEARCHING;
2021 GCP_connect (t->peer);
2025 /* If not marked as ready, no change is needed */
2026 if (CADET_TUNNEL3_READY != t->cstate)
2029 /* Check if any connection is ready to maintaing cstate */
2030 for (aux = t->connection_head; aux != NULL; aux = aux->next)
2031 if (CADET_CONNECTION_READY == GCC_get_state (aux->c))
2034 t->cstate = CADET_TUNNEL3_WAITING;
2039 * Add a channel to a tunnel.
2042 * @param ch Channel.
2045 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2047 struct CadetTChannel *aux;
2049 GNUNET_assert (NULL != ch);
2051 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
2053 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2055 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
2060 aux = GNUNET_new (struct CadetTChannel);
2062 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
2063 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
2065 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2067 GNUNET_SCHEDULER_cancel (t->destroy_task);
2068 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2069 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
2075 * Remove a channel from a tunnel.
2078 * @param ch Channel.
2081 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch)
2083 struct CadetTChannel *aux;
2085 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
2086 for (aux = t->channel_head; aux != NULL; aux = aux->next)
2090 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GCCH_2s (ch));
2091 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
2100 * Search for a channel by global ID.
2102 * @param t Tunnel containing the channel.
2103 * @param chid Public channel number.
2105 * @return channel handler, NULL if doesn't exist
2107 struct CadetChannel *
2108 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid)
2110 struct CadetTChannel *iter;
2115 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2117 if (GCCH_get_id (iter->ch) == chid)
2121 return NULL == iter ? NULL : iter->ch;
2126 * @brief Destroy a tunnel and free all resources.
2128 * Should only be called a while after the tunnel has been marked as destroyed,
2129 * in case there is a new channel added to the same peer shortly after marking
2130 * the tunnel. This way we avoid a new public key handshake.
2132 * @param cls Closure (tunnel to destroy).
2133 * @param tc Task context.
2136 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
2138 struct CadetTunnel *t = cls;
2139 struct CadetTConnection *iter;
2141 LOG (GNUNET_ERROR_TYPE_DEBUG, "delayed destroying tunnel %p\n", t);
2142 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
2144 LOG (GNUNET_ERROR_TYPE_WARNING,
2145 "Not destroying tunnel, due to shutdown. "
2146 "Tunnel at %p should have been freed by GCT_shutdown\n", t);
2149 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2150 t->cstate = CADET_TUNNEL3_SHUTDOWN;
2152 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2154 GCC_send_destroy (iter->c);
2161 * Tunnel is empty: destroy it.
2163 * Notifies all connections about the destruction.
2165 * @param t Tunnel to destroy.
2168 GCT_destroy_empty (struct CadetTunnel *t)
2170 if (GNUNET_YES == shutting_down)
2171 return; /* Will be destroyed immediately anyway */
2173 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2175 LOG (GNUNET_ERROR_TYPE_DEBUG,
2176 "Tunnel %s is already scheduled for destruction\n",
2179 /* should never happen, tunnel can only become empty once, and the
2180 * task identifier should be NO_TASK (cleaned when the tunnel was created
2181 * or became un-empty)
2186 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2189 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2190 &delayed_destroy, t);
2191 LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduled destroy of %p as %llX\n",
2192 t, t->destroy_task);
2197 * Destroy tunnel if empty (no more channels).
2199 * @param t Tunnel to destroy if empty.
2202 GCT_destroy_if_empty (struct CadetTunnel *t)
2204 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s destroy if empty\n", GCT_2s (t));
2205 if (1 < GCT_count_channels (t))
2208 GCT_destroy_empty (t);
2213 * Destroy the tunnel.
2215 * This function does not generate any warning traffic to clients or peers.
2218 * Cancel messages belonging to this tunnel queued to neighbors.
2219 * Free any allocated resources linked to the tunnel.
2221 * @param t The tunnel to destroy.
2224 GCT_destroy (struct CadetTunnel *t)
2226 struct CadetTConnection *iter_c;
2227 struct CadetTConnection *next_c;
2228 struct CadetTChannel *iter_ch;
2229 struct CadetTChannel *next_ch;
2234 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GCP_2s (t->peer));
2236 GNUNET_break (GNUNET_YES ==
2237 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2238 GCP_get_id (t->peer), t));
2240 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2242 next_c = iter_c->next;
2243 GCC_destroy (iter_c->c);
2245 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2247 next_ch = iter_ch->next;
2248 GCCH_destroy (iter_ch->ch);
2249 /* Should only happen on shutdown, but it's ok. */
2252 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2254 LOG (GNUNET_ERROR_TYPE_DEBUG, "cancelling %llX\n", t->destroy_task);
2255 GNUNET_SCHEDULER_cancel (t->destroy_task);
2256 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2259 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2260 GCP_set_tunnel (t->peer, NULL);
2262 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2264 GNUNET_SCHEDULER_cancel (t->rekey_task);
2265 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2266 if (NULL != t->kx_ctx)
2267 GNUNET_free (t->kx_ctx);
2277 * @brief Use the given path for the tunnel.
2278 * Update the next and prev hops (and RCs).
2279 * (Re)start the path refresh in case the tunnel is locally owned.
2281 * @param t Tunnel to update.
2282 * @param p Path to use.
2284 * @return Connection created.
2286 struct CadetConnection *
2287 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p)
2289 struct CadetConnection *c;
2290 struct GNUNET_CADET_Hash cid;
2291 unsigned int own_pos;
2293 if (NULL == t || NULL == p)
2299 if (CADET_TUNNEL3_SHUTDOWN == t->cstate)
2305 for (own_pos = 0; own_pos < p->length; own_pos++)
2307 if (p->peers[own_pos] == myid)
2310 if (own_pos >= p->length)
2312 GNUNET_break_op (0);
2316 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE, &cid, sizeof (cid));
2317 c = GCC_new (&cid, t, p, own_pos);
2320 /* Path was flawed */
2323 GCT_add_connection (t, c);
2329 * Count established (ready) connections of a tunnel.
2331 * @param t Tunnel on which to count.
2333 * @return Number of connections.
2336 GCT_count_connections (struct CadetTunnel *t)
2338 struct CadetTConnection *iter;
2344 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2345 if (CADET_CONNECTION_DESTROYED != GCC_get_state (iter->c))
2352 * Count channels of a tunnel.
2354 * @param t Tunnel on which to count.
2356 * @return Number of channels.
2359 GCT_count_channels (struct CadetTunnel *t)
2361 struct CadetTChannel *iter;
2364 for (count = 0, iter = t->channel_head;
2366 iter = iter->next, count++) /* skip */;
2373 * Get the connectivity state of a tunnel.
2377 * @return Tunnel's connectivity state.
2379 enum CadetTunnelCState
2380 GCT_get_cstate (struct CadetTunnel *t)
2385 return (enum CadetTunnelCState) -1;
2392 * Get the encryption state of a tunnel.
2396 * @return Tunnel's encryption state.
2398 enum CadetTunnelEState
2399 GCT_get_estate (struct CadetTunnel *t)
2404 return (enum CadetTunnelEState) -1;
2410 * Get the maximum buffer space for a tunnel towards a local client.
2414 * @return Biggest buffer space offered by any channel in the tunnel.
2417 GCT_get_channels_buffer (struct CadetTunnel *t)
2419 struct CadetTChannel *iter;
2420 unsigned int buffer;
2421 unsigned int ch_buf;
2423 if (NULL == t->channel_head)
2425 /* Probably getting buffer for a channel create/handshake. */
2430 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2432 ch_buf = get_channel_buffer (iter);
2433 if (ch_buf > buffer)
2441 * Get the total buffer space for a tunnel for P2P traffic.
2445 * @return Buffer space offered by all connections in the tunnel.
2448 GCT_get_connections_buffer (struct CadetTunnel *t)
2450 struct CadetTConnection *iter;
2451 unsigned int buffer;
2454 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2456 if (GCC_get_state (iter->c) != CADET_CONNECTION_READY)
2460 buffer += get_connection_buffer (iter);
2468 * Get the tunnel's destination.
2472 * @return ID of the destination peer.
2474 const struct GNUNET_PeerIdentity *
2475 GCT_get_destination (struct CadetTunnel *t)
2477 return GCP_get_id (t->peer);
2482 * Get the tunnel's next free global channel ID.
2486 * @return GID of a channel free to use.
2489 GCT_get_next_chid (struct CadetTunnel *t)
2491 CADET_ChannelNumber chid;
2492 CADET_ChannelNumber mask;
2495 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2496 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2497 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2499 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GCP_get_id (t->peer));
2504 t->next_chid |= mask;
2506 while (NULL != GCT_get_channel (t, t->next_chid))
2508 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2509 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2510 t->next_chid |= mask;
2512 chid = t->next_chid;
2513 t->next_chid = (t->next_chid + 1) & ~GNUNET_CADET_LOCAL_CHANNEL_ID_CLI;
2514 t->next_chid |= mask;
2521 * Send ACK on one or more channels due to buffer in connections.
2523 * @param t Channel which has some free buffer space.
2526 GCT_unchoke_channels (struct CadetTunnel *t)
2528 struct CadetTChannel *iter;
2529 unsigned int buffer;
2530 unsigned int channels = GCT_count_channels (t);
2531 unsigned int choked_n;
2532 struct CadetChannel *choked[channels];
2534 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCT_unchoke_channels on %s\n", GCT_2s (t));
2535 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2536 if (NULL != t->channel_head)
2537 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2539 /* Get buffer space */
2540 buffer = GCT_get_connections_buffer (t);
2546 /* Count and remember choked channels */
2548 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2550 if (GNUNET_NO == get_channel_allowed (iter))
2552 choked[choked_n++] = iter->ch;
2556 /* Unchoke random channels */
2557 while (0 < buffer && 0 < choked_n)
2559 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
2561 GCCH_allow_client (choked[r], GCCH_is_origin (choked[r], GNUNET_YES));
2564 choked[r] = choked[choked_n];
2570 * Send ACK on one or more connections due to buffer space to the client.
2572 * Iterates all connections of the tunnel and sends ACKs appropriately.
2577 GCT_send_connection_acks (struct CadetTunnel *t)
2579 struct CadetTConnection *iter;
2582 uint32_t allow_per_connection;
2584 unsigned int buffer;
2586 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
2595 buffer = GCT_get_channels_buffer (t);
2596 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
2598 /* Count connections, how many messages are already allowed */
2599 cs = GCT_count_connections (t);
2600 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2602 allowed += get_connection_allowed (iter);
2604 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
2606 /* Make sure there is no overflow */
2607 if (allowed > buffer)
2612 /* Authorize connections to send more data */
2613 to_allow = buffer; /* - allowed; */
2615 for (iter = t->connection_head;
2616 NULL != iter && to_allow > 0;
2619 allow_per_connection = to_allow/cs;
2620 to_allow -= allow_per_connection;
2622 if (get_connection_allowed (iter) > 64 / 3)
2626 GCC_allow (iter->c, allow_per_connection,
2627 GCC_is_origin (iter->c, GNUNET_NO));
2630 GNUNET_break (to_allow == 0);
2635 * Cancel a previously sent message while it's in the queue.
2637 * ONLY can be called before the continuation given to the send function
2638 * is called. Once the continuation is called, the message is no longer in the
2641 * @param q Handle to the queue.
2644 GCT_cancel (struct CadetTunnelQueue *q)
2649 /* tun_message_sent() will be called and free q */
2651 else if (NULL != q->tqd)
2653 unqueue_data (q->tqd);
2655 if (NULL != q->cont)
2656 q->cont (q->cont_cls, NULL, q, 0, 0);
2667 * Sends an already built message on a tunnel, encrypting it and
2668 * choosing the best connection if not provided.
2670 * @param message Message to send. Function modifies it.
2671 * @param t Tunnel on which this message is transmitted.
2672 * @param c Connection to use (autoselect if NULL).
2673 * @param force Force the tunnel to take the message (buffer overfill).
2674 * @param cont Continuation to call once message is really sent.
2675 * @param cont_cls Closure for @c cont.
2677 * @return Handle to cancel message. NULL if @c cont is NULL.
2679 struct CadetTunnelQueue *
2680 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2681 struct CadetTunnel *t, struct CadetConnection *c,
2682 int force, GCT_sent cont, void *cont_cls)
2684 return send_prebuilt_message (message, t, c, force, cont, cont_cls, NULL);
2689 * Is the tunnel directed towards the local peer?
2693 * @return #GNUNET_YES if it is loopback.
2696 GCT_is_loopback (const struct CadetTunnel *t)
2698 return (myid == GCP_get_short_id (t->peer));
2703 * Is the tunnel this path already?
2708 * @return #GNUNET_YES a connection uses this path.
2711 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p)
2713 struct CadetTConnection *iter;
2715 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2716 if (GCC_get_path (iter->c) == p)
2724 * Get a cost of a path for a tunnel considering existing connections.
2727 * @param path Candidate path.
2729 * @return Cost of the path (path length + number of overlapping nodes)
2732 GCT_get_path_cost (const struct CadetTunnel *t,
2733 const struct CadetPeerPath *path)
2735 struct CadetTConnection *iter;
2736 const struct CadetPeerPath *aux;
2737 unsigned int overlap;
2745 GNUNET_assert (NULL != t);
2747 for (i = 0; i < path->length; i++)
2749 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2751 aux = GCC_get_path (iter->c);
2755 for (j = 0; j < aux->length; j++)
2757 if (path->peers[i] == aux->peers[j])
2765 return path->length + overlap;
2770 * Get the static string for the peer this tunnel is directed.
2774 * @return Static string the destination peer's ID.
2777 GCT_2s (const struct CadetTunnel *t)
2782 return GCP_2s (t->peer);
2786 /******************************************************************************/
2787 /***************************** INFO/DEBUG *******************************/
2788 /******************************************************************************/
2792 * Log all possible info about the tunnel state to stderr.
2794 * @param t Tunnel to debug.
2797 GCT_debug (const struct CadetTunnel *t)
2799 struct CadetTChannel *iterch;
2800 struct CadetTConnection *iterc;
2802 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT DEBUG TUNNEL TOWARDS %s\n", GCT_2s (t));
2803 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT cstate %s, estate %s\n",
2804 cstate2s (t->cstate), estate2s (t->estate));
2805 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT kx_ctx %p, rekey_task %u\n",
2806 t->kx_ctx, t->rekey_task);
2807 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT tq_head %p, tq_tail %p\n",
2808 t->tq_head, t->tq_tail);
2809 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT destroy %u\n", t->destroy_task);
2811 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT channels:\n");
2812 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
2814 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT - %s\n", GCCH_2s (iterch->ch));
2817 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT connections:\n");
2818 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
2820 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT - %s [%u] buf: %u/%u (qn %u/%u)\n",
2821 GCC_2s (iterc->c), GCC_get_state (iterc->c),
2822 GCC_get_buffer (iterc->c, GNUNET_YES),
2823 GCC_get_buffer (iterc->c, GNUNET_NO),
2824 GCC_get_qn (iterc->c, GNUNET_YES),
2825 GCC_get_qn (iterc->c, GNUNET_NO));
2828 LOG (GNUNET_ERROR_TYPE_DEBUG, "TTT DEBUG TUNNEL END\n");
2833 * Iterate all tunnels.
2835 * @param iter Iterator.
2836 * @param cls Closure for @c iter.
2839 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls)
2841 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
2846 * Count all tunnels.
2848 * @return Number of tunnels to remote peers kept by this peer.
2851 GCT_count_all (void)
2853 return GNUNET_CONTAINER_multipeermap_size (tunnels);
2858 * Iterate all connections of a tunnel.
2860 * @param t Tunnel whose connections to iterate.
2861 * @param iter Iterator.
2862 * @param cls Closure for @c iter.
2865 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls)
2867 struct CadetTConnection *ct;
2869 for (ct = t->connection_head; NULL != ct; ct = ct->next)
2875 * Iterate all channels of a tunnel.
2877 * @param t Tunnel whose channels to iterate.
2878 * @param iter Iterator.
2879 * @param cls Closure for @c iter.
2882 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls)
2884 struct CadetTChannel *cht;
2886 for (cht = t->channel_head; NULL != cht; cht = cht->next)
2887 iter (cls, cht->ch);