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 "mesh_protocol.h"
28 #include "mesh_path.h"
30 #include "gnunet-service-mesh_tunnel.h"
31 #include "gnunet-service-mesh_connection.h"
32 #include "gnunet-service-mesh_channel.h"
33 #include "gnunet-service-mesh_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"mesh-tun",__VA_ARGS__)
37 #define REKEY_WAIT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)
39 /******************************************************************************/
40 /******************************** STRUCTS **********************************/
41 /******************************************************************************/
45 struct MeshTChannel *next;
46 struct MeshTChannel *prev;
47 struct MeshChannel *ch;
50 struct MeshTConnection
52 struct MeshTConnection *next;
53 struct MeshTConnection *prev;
54 struct MeshConnection *c;
58 * Structure used during a Key eXchange.
60 struct MeshTunnelKXCtx
63 * Decryption ("their") old key, for decrypting traffic sent by the
64 * other end before the key exchange started.
66 struct GNUNET_CRYPTO_SymmetricSessionKey d_key_old;
69 * Challenge to send in a ping and expect in the pong.
75 * Struct containing all information regarding a tunnel to a peer.
80 * Endpoint of the tunnel.
82 struct MeshPeer *peer;
85 * State of the tunnel connectivity.
87 enum MeshTunnel3CState cstate;
90 * State of the tunnel encryption.
92 enum MeshTunnel3EState estate;
95 * Key eXchange context.
97 struct MeshTunnelKXCtx *kx_ctx;
100 * Encryption ("our") key.
102 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
105 * Decryption ("their") key.
107 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
110 * Task to start the rekey process.
112 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
115 * Paths that are actively used to reach the destination peer.
117 struct MeshTConnection *connection_head;
118 struct MeshTConnection *connection_tail;
121 * Next connection number.
126 * Channels inside this tunnel.
128 struct MeshTChannel *channel_head;
129 struct MeshTChannel *channel_tail;
132 * Channel ID for the next created channel.
134 MESH_ChannelNumber next_chid;
137 * Destroy flag: if true, destroy on last message.
139 GNUNET_SCHEDULER_TaskIdentifier destroy_task;
142 * Queued messages, to transmit once tunnel gets connected.
144 struct MeshTunnelDelayed *tq_head;
145 struct MeshTunnelDelayed *tq_tail;
150 * Struct used to save messages in a non-ready tunnel to send once connected.
152 struct MeshTunnelDelayed
157 struct MeshTunnelDelayed *next;
158 struct MeshTunnelDelayed *prev;
163 struct MeshTunnel3 *t;
166 * Tunnel queue given to the channel to cancel request. Update on send_queued.
168 struct MeshTunnel3Queue *tq;
173 /* struct GNUNET_MessageHeader *msg; */
178 * Handle for messages queued but not yet sent.
180 struct MeshTunnel3Queue
183 * Connection queue handle, to cancel if necessary.
185 struct MeshConnectionQueue *cq;
188 * Handle in case message hasn't been given to a connection yet.
190 struct MeshTunnelDelayed *tqd;
193 * Continuation to call once sent.
198 * Closure for @c cont.
204 /******************************************************************************/
205 /******************************* GLOBALS ***********************************/
206 /******************************************************************************/
209 * Global handle to the statistics service.
211 extern struct GNUNET_STATISTICS_Handle *stats;
214 * Local peer own ID (memory efficient handle).
216 extern GNUNET_PEER_Id myid;
219 * Local peer own ID (full value).
221 extern struct GNUNET_PeerIdentity my_full_id;
225 * Don't try to recover tunnels if shutting down.
227 extern int shutting_down;
231 * Set of all tunnels, in order to trigger a new exchange on rekey.
232 * Indexed by peer's ID.
234 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
237 * Default TTL for payload packets.
239 static unsigned long long default_ttl;
244 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
247 * Own ephemeral private key.
249 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
252 * Cached message used to perform a key exchange.
254 static struct GNUNET_MESH_KX_Ephemeral kx_msg;
257 * Task to generate a new ephemeral key.
259 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
264 static struct GNUNET_TIME_Relative rekey_period;
266 /******************************************************************************/
267 /******************************** STATIC ***********************************/
268 /******************************************************************************/
271 * Get string description for tunnel connectivity state.
273 * @param cs Tunnel state.
275 * @return String representation.
278 cstate2s (enum MeshTunnel3CState cs)
280 static char buf[128];
284 case MESH_TUNNEL3_NEW:
285 return "MESH_TUNNEL3_NEW";
286 case MESH_TUNNEL3_SEARCHING:
287 return "MESH_TUNNEL3_SEARCHING";
288 case MESH_TUNNEL3_WAITING:
289 return "MESH_TUNNEL3_WAITING";
290 case MESH_TUNNEL3_READY:
291 return "MESH_TUNNEL3_READY";
294 sprintf (buf, "%u (UNKNOWN STATE)", cs);
302 * Get string description for tunnel encryption state.
304 * @param es Tunnel state.
306 * @return String representation.
309 estate2s (enum MeshTunnel3EState es)
311 static char buf[128];
315 case MESH_TUNNEL3_KEY_UNINITIALIZED:
316 return "MESH_TUNNEL3_KEY_UNINITIALIZED";
317 case MESH_TUNNEL3_KEY_SENT:
318 return "MESH_TUNNEL3_KEY_SENT";
319 case MESH_TUNNEL3_KEY_PING:
320 return "MESH_TUNNEL3_KEY_PING";
321 case MESH_TUNNEL3_KEY_OK:
322 return "MESH_TUNNEL3_KEY_OK";
325 sprintf (buf, "%u (UNKNOWN STATE)", es);
333 * @brief Check if tunnel is ready to send traffic.
335 * Tunnel must be connected and with encryption correctly set up.
337 * @param t Tunnel to check.
339 * @return #GNUNET_YES if ready, #GNUNET_NO otherwise
342 is_ready (struct MeshTunnel3 *t)
347 ready = (MESH_TUNNEL3_READY == t->cstate && MESH_TUNNEL3_KEY_OK == t->estate);
348 ready = ready || GMT_is_loopback (t);
354 * Ephemeral key message purpose size.
356 * @return Size of the part of the ephemeral key message that must be signed.
359 ephemeral_purpose_size (void)
361 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
362 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
363 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
364 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
365 sizeof (struct GNUNET_PeerIdentity);
370 * Size of the encrypted part of a ping message.
372 * @return Size of the encrypted part of a ping message.
375 ping_encryption_size (void)
377 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
382 * Get the channel's buffer. ONLY FOR NON-LOOPBACK CHANNELS!!
384 * @param tch Tunnel's channel handle.
386 * @return Amount of messages the channel can still buffer towards the client.
389 get_channel_buffer (const struct MeshTChannel *tch)
393 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
394 fwd = GMCH_is_origin (tch->ch, GNUNET_YES);
396 return GMCH_get_buffer (tch->ch, fwd);
401 * Get the channel's allowance status.
403 * @param tch Tunnel's channel handle.
405 * @return #GNUNET_YES if we allowed the client to send data to us.
408 get_channel_allowed (const struct MeshTChannel *tch)
412 /* If channel is outgoing, is origin in the FWD direction and fwd is YES */
413 fwd = GMCH_is_origin (tch->ch, GNUNET_YES);
415 return GMCH_get_allowed (tch->ch, fwd);
420 * Get the connection's buffer.
422 * @param tc Tunnel's connection handle.
424 * @return Amount of messages the connection can still buffer.
427 get_connection_buffer (const struct MeshTConnection *tc)
431 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
432 fwd = GMC_is_origin (tc->c, GNUNET_YES);
434 return GMC_get_buffer (tc->c, fwd);
439 * Get the connection's allowance.
441 * @param tc Tunnel's connection handle.
443 * @return Amount of messages we have allowed the next peer to send us.
446 get_connection_allowed (const struct MeshTConnection *tc)
450 /* If connection is outgoing, is origin in the FWD direction and fwd is YES */
451 fwd = GMC_is_origin (tc->c, GNUNET_YES);
453 return GMC_get_allowed (tc->c, fwd);
458 * Check that a ephemeral key message s well formed and correctly signed.
460 * @param t Tunnel on which the message came.
461 * @param msg The ephemeral key message.
463 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
466 check_ephemeral (struct MeshTunnel3 *t,
467 const struct GNUNET_MESH_KX_Ephemeral *msg)
469 /* Check message size */
470 if (ntohs (msg->header.size) != sizeof (struct GNUNET_MESH_KX_Ephemeral))
471 return GNUNET_SYSERR;
473 /* Check signature size */
474 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
475 return GNUNET_SYSERR;
478 if (0 != memcmp (&msg->origin_identity,
479 GMP_get_id (t->peer),
480 sizeof (struct GNUNET_PeerIdentity)))
481 return GNUNET_SYSERR;
483 /* Check signature */
485 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_MESH_KX,
488 &msg->origin_identity.public_key))
489 return GNUNET_SYSERR;
496 * Encrypt data with the tunnel key.
498 * @param t Tunnel whose key to use.
499 * @param dst Destination for the encrypted data.
500 * @param src Source of the plaintext. Can overlap with @c dst.
501 * @param size Size of the plaintext.
502 * @param iv Initialization Vector to use.
505 t_encrypt (struct MeshTunnel3 *t,
506 void *dst, const void *src,
507 size_t size, uint32_t iv)
509 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
512 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt start\n");
513 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->e_key, &iv, sizeof (iv), NULL);
514 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt IV derived\n");
515 out_size = GNUNET_CRYPTO_symmetric_encrypt (src, size, &t->e_key, &siv, dst);
516 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_encrypt end\n");
523 * Decrypt data with the tunnel key.
525 * @param t Tunnel whose key to use.
526 * @param dst Destination for the plaintext.
527 * @param src Source of the encrypted data. Can overlap with @c dst.
528 * @param size Size of the encrypted data.
529 * @param iv Initialization Vector to use.
532 t_decrypt (struct MeshTunnel3 *t,
533 void *dst, const void *src,
534 size_t size, uint32_t iv)
536 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
537 struct GNUNET_CRYPTO_SymmetricSessionKey *key;
540 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt start\n");
541 if (t->estate == MESH_TUNNEL3_KEY_OK || t->estate == MESH_TUNNEL3_KEY_PING)
545 else if (NULL != t->kx_ctx)
547 key = &t->kx_ctx->d_key_old;
551 GNUNET_STATISTICS_update (stats, "# non decryptable data", 1, GNUNET_NO);
552 LOG (GNUNET_ERROR_TYPE_DEBUG,
553 "WARNING got data on %s without a valid key\n",
559 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt iv\n");
560 GNUNET_CRYPTO_symmetric_derive_iv (&siv, key, &iv, sizeof (iv), NULL);
561 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt iv done\n");
562 out_size = GNUNET_CRYPTO_symmetric_decrypt (src, size, key, &siv, dst);
563 LOG (GNUNET_ERROR_TYPE_DEBUG, " t_decrypt end\n");
570 * Create key material by doing ECDH on the local and remote ephemeral keys.
572 * @param key_material Where to store the key material.
573 * @param ephemeral_key Peer's public ephemeral key.
576 derive_key_material (struct GNUNET_HashCode *key_material,
577 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
580 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
589 * Create a symmetic key from the identities of both ends and the key material
592 * @param key Destination for the generated key.
593 * @param sender ID of the peer that will encrypt with @c key.
594 * @param receiver ID of the peer that will decrypt with @c key.
595 * @param key_material Hash created with ECDH with the ephemeral keys.
598 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
599 const struct GNUNET_PeerIdentity *sender,
600 const struct GNUNET_PeerIdentity *receiver,
601 const struct GNUNET_HashCode *key_material)
603 const char salt[] = "MESH kx salt";
605 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
607 key_material, sizeof (struct GNUNET_HashCode),
608 sender, sizeof (struct GNUNET_PeerIdentity),
609 receiver, sizeof (struct GNUNET_PeerIdentity),
614 * Pick a connection on which send the next data message.
616 * @param t Tunnel on which to send the message.
618 * @return The connection on which to send the next message.
620 static struct MeshConnection *
621 tunnel_get_connection (struct MeshTunnel3 *t)
623 struct MeshTConnection *iter;
624 struct MeshConnection *best;
626 unsigned int lowest_q;
628 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GMP_2s (t->peer));
631 for (iter = t->connection_head; NULL != iter; iter = iter->next)
633 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
634 GMC_2s (iter->c), GMC_get_state (iter->c));
635 if (MESH_CONNECTION_READY == GMC_get_state (iter->c))
637 qn = GMC_get_qn (iter->c, GMC_is_origin (iter->c, GNUNET_YES));
638 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
646 LOG (GNUNET_ERROR_TYPE_DEBUG, " selected: connection %s\n", GMC_2s (best));
652 * Callback called when a queued message is sent.
654 * Calculates the average time and connection packet tracking.
656 * @param cls Closure (TunnelQueue handle).
657 * @param c Connection this message was on.
658 * @param q Connection queue handle (unused).
659 * @param type Type of message sent.
660 * @param fwd Was this a FWD going message?
661 * @param size Size of the message.
664 message_sent (void *cls,
665 struct MeshConnection *c,
666 struct MeshConnectionQueue *q,
667 uint16_t type, int fwd, size_t size)
669 struct MeshTunnel3Queue *qt = cls;
671 GNUNET_assert (NULL != qt->cont);
672 qt->cont (qt->cont_cls, GMC_get_tunnel (c), qt, type, size);
678 * Delete a queued message: either was sent or the channel was destroyed
679 * before the tunnel's key exchange had a chance to finish.
681 * @param tqd Delayed queue handle.
684 unqueue_data (struct MeshTunnelDelayed *tqd)
686 GNUNET_CONTAINER_DLL_remove (tqd->t->tq_head, tqd->t->tq_tail, tqd);
692 * Cache a message to be sent once tunnel is online.
694 * @param t Tunnel to hold the message.
695 * @param msg Message itself (copy will be made).
697 static struct MeshTunnelDelayed *
698 queue_data (struct MeshTunnel3 *t, const struct GNUNET_MessageHeader *msg)
700 struct MeshTunnelDelayed *tqd;
701 uint16_t size = ntohs (msg->size);
703 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue data on Tunnel %s\n", GMT_2s (t));
705 if (GNUNET_YES == is_ready (t))
711 tqd = GNUNET_malloc (sizeof (struct MeshTunnelDelayed) + size);
714 memcpy (&tqd[1], msg, size);
715 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tqd);
722 * Sends an already built message on a tunnel, encrypting it and
723 * choosing the best connection.
725 * @param message Message to send. Function modifies it.
726 * @param t Tunnel on which this message is transmitted.
727 * @param force Force the tunnel to take the message (buffer overfill).
728 * @param cont Continuation to call once message is really sent.
729 * @param cont_cls Closure for @c cont.
730 * @param existing_q In case this a transmission of previously queued data,
731 * this should be TunnelQueue given to the client.
734 * @return Handle to cancel message. NULL if @c cont is NULL.
736 static struct MeshTunnel3Queue *
737 send_prebuilt_message (const struct GNUNET_MessageHeader *message,
738 struct MeshTunnel3 *t, int force,
739 GMT_sent cont, void *cont_cls,
740 struct MeshTunnel3Queue *existing_q)
742 struct MeshTunnel3Queue *tq;
743 struct MeshConnection *c;
744 struct GNUNET_MESH_Encrypted *msg;
745 size_t size = ntohs (message->size);
746 char cbuf[sizeof (struct GNUNET_MESH_Encrypted) + size];
751 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GMT_2s (t));
753 if (GNUNET_NO == is_ready (t))
755 struct MeshTunnelDelayed *tqd;
756 /* A non null existing_q indicates sending of queued data.
757 * Should only happen after tunnel becomes ready.
759 GNUNET_assert (NULL == existing_q);
760 tqd = queue_data (t, message);
763 tq = GNUNET_new (struct MeshTunnel3Queue);
767 tq->cont_cls = cont_cls;
771 GNUNET_assert (GNUNET_NO == GMT_is_loopback (t));
773 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
774 msg = (struct GNUNET_MESH_Encrypted *) cbuf;
775 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED);
777 GNUNET_assert (t_encrypt (t, &msg[1], message, size, iv) == size);
778 msg->header.size = htons (sizeof (struct GNUNET_MESH_Encrypted) + size);
779 c = tunnel_get_connection (t);
782 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
783 || MESH_TUNNEL3_SEARCHING != t->cstate)
790 type = ntohs (message->type);
793 case GNUNET_MESSAGE_TYPE_MESH_DATA:
794 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
795 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
796 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
797 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
798 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
799 msg->cid = *GMC_get_id (c);
800 msg->ttl = htonl (default_ttl);
803 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
808 fwd = GMC_is_origin (c, GNUNET_YES);
812 (void) GMC_send_prebuilt_message (&msg->header, c, fwd, force, NULL, NULL);
815 if (NULL == existing_q)
817 tq = GNUNET_new (struct MeshTunnel3Queue); /* FIXME valgrind: leak*/
824 tq->cq = GMC_send_prebuilt_message (&msg->header, c, fwd, force,
827 tq->cont_cls = cont_cls;
834 * Send all cached messages that we can, tunnel is online.
836 * @param t Tunnel that holds the messages. Cannot be loopback.
839 send_queued_data (struct MeshTunnel3 *t)
841 struct MeshTunnelDelayed *tqd;
842 struct MeshTunnelDelayed *next;
845 LOG (GNUNET_ERROR_TYPE_DEBUG,
846 "GMT_send_queued_data on tunnel %s\n",
849 if (GMT_is_loopback (t))
855 if (GNUNET_NO == is_ready (t))
857 LOG (GNUNET_ERROR_TYPE_DEBUG, " not ready yet: %s/%s\n",
858 estate2s (t->estate), cstate2s (t->cstate));
862 room = GMT_get_connections_buffer (t);
863 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
864 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq head: %p\n", t->tq_head);
865 for (tqd = t->tq_head; NULL != tqd && room > 0; tqd = next)
867 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending queued data\n");
870 send_prebuilt_message ((struct GNUNET_MessageHeader *) &tqd[1],
872 NULL != tqd->tq ? tqd->tq->cont : NULL,
873 NULL != tqd->tq ? tqd->tq->cont_cls : NULL,
877 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT_send_queued_data end\n", GMP_2s (t->peer));
882 * Sends key exchange message on a tunnel, choosing the best connection.
883 * Should not be called on loopback tunnels.
885 * @param t Tunnel on which this message is transmitted.
886 * @param message Message to send. Function modifies it.
889 send_kx (struct MeshTunnel3 *t,
890 const struct GNUNET_MessageHeader *message)
892 struct MeshConnection *c;
893 struct GNUNET_MESH_KX *msg;
894 size_t size = ntohs (message->size);
895 char cbuf[sizeof (struct GNUNET_MESH_KX) + size];
899 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GMT_2s (t));
901 /* Avoid loopback. */
902 if (GMT_is_loopback (t))
904 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
909 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
911 LOG (GNUNET_ERROR_TYPE_DEBUG, " being destroyed, why bother\n");
915 /* Must have a connection. */
916 if (NULL == t->connection_head)
918 GNUNET_break (MESH_TUNNEL3_SEARCHING == t->cstate);
923 msg = (struct GNUNET_MESH_KX *) cbuf;
924 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX);
925 msg->header.size = htons (sizeof (struct GNUNET_MESH_KX) + size);
926 c = tunnel_get_connection (t);
929 GNUNET_break (GNUNET_SCHEDULER_NO_TASK != t->destroy_task
930 || MESH_TUNNEL3_READY != t->cstate);
934 type = ntohs (message->type);
937 case GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL:
938 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
939 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
940 msg->reserved = htonl (0);
941 memcpy (&msg[1], message, size);
944 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
949 fwd = GMC_is_origin (t->connection_head->c, GNUNET_YES);
950 /* TODO save handle and cancel in case of a unneeded retransmission */
951 GMC_send_prebuilt_message (&msg->header, c, fwd, GNUNET_YES, NULL, NULL);
956 * Send the ephemeral key on a tunnel.
958 * @param t Tunnel on which to send the key.
961 send_ephemeral (struct MeshTunnel3 *t)
963 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __FUNCTION__);
965 kx_msg.sender_status = htonl (t->estate);
966 send_kx (t, &kx_msg.header);
970 * Send a ping message on a tunnel.
972 * @param t Tunnel on which to send the ping.
975 send_ping (struct MeshTunnel3 *t)
977 struct GNUNET_MESH_KX_Ping msg;
979 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __FUNCTION__);
980 msg.header.size = htons (sizeof (msg));
981 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PING);
982 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
983 msg.target = *GMP_get_id (t->peer);
984 msg.nonce = t->kx_ctx->challenge;
986 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
987 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&msg.target));
988 t_encrypt (t, &msg.target, &msg.target, ping_encryption_size(), msg.iv);
989 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
990 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg.target));
992 send_kx (t, &msg.header);
997 * Send a pong message on a tunnel.
999 * @param t Tunnel on which to send the pong.
1000 * @param challenge Value sent in the ping that we have to send back.
1003 send_pong (struct MeshTunnel3 *t, uint32_t challenge)
1005 struct GNUNET_MESH_KX_Pong msg;
1007 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s()\n", __FUNCTION__);
1008 msg.header.size = htons (sizeof (msg));
1009 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PONG);
1010 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1011 msg.nonce = challenge;
1012 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending %u\n", msg.nonce);
1013 t_encrypt (t, &msg.nonce, &msg.nonce, sizeof (msg.nonce), msg.iv);
1014 LOG (GNUNET_ERROR_TYPE_DEBUG, " e sending %u\n", msg.nonce);
1016 send_kx (t, &msg.header);
1021 * Initiate a rekey with the remote peer.
1023 * @param cls Closure (tunnel).
1024 * @param tc TaskContext.
1027 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1029 struct MeshTunnel3 *t = cls;
1031 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1033 LOG (GNUNET_ERROR_TYPE_DEBUG, "Re-key Tunnel %s\n", GMT_2s (t));
1034 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1037 if (NULL == t->kx_ctx)
1039 LOG (GNUNET_ERROR_TYPE_DEBUG, " new kx ctx\n");
1040 t->kx_ctx = GNUNET_new (struct MeshTunnelKXCtx);
1041 t->kx_ctx->challenge =
1042 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1043 t->kx_ctx->d_key_old = t->d_key;
1044 LOG (GNUNET_ERROR_TYPE_DEBUG, " new challenge for %s: %u\n",
1045 GMT_2s (t), t->kx_ctx->challenge);
1050 case MESH_TUNNEL3_KEY_UNINITIALIZED:
1051 t->estate = MESH_TUNNEL3_KEY_SENT;
1053 case MESH_TUNNEL3_KEY_SENT:
1055 case MESH_TUNNEL3_KEY_PING:
1056 case MESH_TUNNEL3_KEY_OK:
1058 t->estate = MESH_TUNNEL3_KEY_PING;
1061 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->estate);
1064 LOG (GNUNET_ERROR_TYPE_DEBUG, " next call in %s\n",
1065 GNUNET_STRINGS_relative_time_to_string (REKEY_WAIT, GNUNET_YES));
1066 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
1071 * Out ephemeral key has changed, create new session key on all tunnels.
1073 * @param cls Closure (size of the hashmap).
1074 * @param key Current public key.
1075 * @param value Value in the hash map (tunnel).
1077 * @return #GNUNET_YES, so we should continue to iterate,
1080 rekey_iterator (void *cls,
1081 const struct GNUNET_PeerIdentity *key,
1084 struct MeshTunnel3 *t = value;
1085 struct GNUNET_TIME_Relative delay;
1086 long n = (long) cls;
1089 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1092 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
1093 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
1094 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
1101 * Create a new ephemeral key and key message, schedule next rekeying.
1103 * @param cls Closure (unused).
1104 * @param tc TaskContext.
1107 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1109 struct GNUNET_TIME_Absolute time;
1112 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1114 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
1117 GNUNET_free_non_null (my_ephemeral_key);
1118 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
1120 time = GNUNET_TIME_absolute_get ();
1121 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
1122 time = GNUNET_TIME_absolute_add (time, rekey_period);
1123 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
1124 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
1125 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
1127 GNUNET_assert (GNUNET_OK ==
1128 GNUNET_CRYPTO_eddsa_sign (my_private_key,
1130 &kx_msg.signature));
1132 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
1133 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
1135 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
1140 * Called only on shutdown, destroy every tunnel.
1142 * @param cls Closure (unused).
1143 * @param key Current public key.
1144 * @param value Value in the hash map (tunnel).
1146 * @return #GNUNET_YES, so we should continue to iterate,
1149 destroy_iterator (void *cls,
1150 const struct GNUNET_PeerIdentity *key,
1153 struct MeshTunnel3 *t = value;
1161 * Notify remote peer that we don't know a channel he is talking about,
1162 * probably CHANNEL_DESTROY was missed.
1164 * @param t Tunnel on which to notify.
1165 * @param gid ID of the channel.
1168 send_channel_destroy (struct MeshTunnel3 *t, unsigned int gid)
1170 struct GNUNET_MESH_ChannelManage msg;
1172 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY);
1173 msg.header.size = htons (sizeof (msg));
1174 msg.chid = htonl (gid);
1176 LOG (GNUNET_ERROR_TYPE_DEBUG,
1177 "WARNING destroying unknown channel %u on tunnel %s\n",
1179 send_prebuilt_message (&msg.header, t, GNUNET_YES, NULL, NULL, NULL);
1184 * Demultiplex data per channel and call appropriate channel handler.
1186 * @param t Tunnel on which the data came.
1187 * @param msg Data message.
1188 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1189 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1190 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1191 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1194 handle_data (struct MeshTunnel3 *t,
1195 const struct GNUNET_MESH_Data *msg,
1198 struct MeshChannel *ch;
1202 size = ntohs (msg->header.size);
1204 sizeof (struct GNUNET_MESH_Data) +
1205 sizeof (struct GNUNET_MessageHeader))
1210 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
1211 GM_m2s (ntohs (msg[1].header.type)));
1214 ch = GMT_get_channel (t, ntohl (msg->chid));
1217 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
1219 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel 0x%X unknown\n",
1221 send_channel_destroy (t, ntohl (msg->chid));
1225 GMCH_handle_data (ch, msg, fwd);
1230 * Demultiplex data ACKs per channel and update appropriate channel buffer info.
1232 * @param t Tunnel on which the DATA ACK came.
1233 * @param msg DATA ACK message.
1234 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1235 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1236 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1237 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1240 handle_data_ack (struct MeshTunnel3 *t,
1241 const struct GNUNET_MESH_DataACK *msg,
1244 struct MeshChannel *ch;
1248 size = ntohs (msg->header.size);
1249 if (size != sizeof (struct GNUNET_MESH_DataACK))
1256 ch = GMT_get_channel (t, ntohl (msg->chid));
1259 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
1261 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1266 GMCH_handle_data_ack (ch, msg, fwd);
1271 * Handle channel create.
1273 * @param t Tunnel on which the data came.
1274 * @param msg Data message.
1277 handle_ch_create (struct MeshTunnel3 *t,
1278 const struct GNUNET_MESH_ChannelCreate *msg)
1280 struct MeshChannel *ch;
1284 size = ntohs (msg->header.size);
1285 if (size != sizeof (struct GNUNET_MESH_ChannelCreate))
1292 ch = GMT_get_channel (t, ntohl (msg->chid));
1293 if (NULL != ch && ! GMT_is_loopback (t))
1295 /* Probably a retransmission, safe to ignore */
1296 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
1300 ch = GMCH_handle_create (t, msg);
1303 GMT_add_channel (t, ch);
1309 * Handle channel NACK: check correctness and call channel handler for NACKs.
1311 * @param t Tunnel on which the NACK came.
1312 * @param msg NACK message.
1315 handle_ch_nack (struct MeshTunnel3 *t,
1316 const struct GNUNET_MESH_ChannelManage *msg)
1318 struct MeshChannel *ch;
1322 size = ntohs (msg->header.size);
1323 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
1330 ch = GMT_get_channel (t, ntohl (msg->chid));
1333 GNUNET_STATISTICS_update (stats, "# channel NACK on unknown channel",
1335 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1340 GMCH_handle_nack (ch);
1345 * Handle a CHANNEL ACK (SYNACK/ACK).
1347 * @param t Tunnel on which the CHANNEL ACK came.
1348 * @param msg CHANNEL ACK message.
1349 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1350 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1351 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1352 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1355 handle_ch_ack (struct MeshTunnel3 *t,
1356 const struct GNUNET_MESH_ChannelManage *msg,
1359 struct MeshChannel *ch;
1363 size = ntohs (msg->header.size);
1364 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
1371 ch = GMT_get_channel (t, ntohl (msg->chid));
1374 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
1376 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
1381 GMCH_handle_ack (ch, msg, fwd);
1387 * Handle a channel destruction message.
1389 * @param t Tunnel on which the message came.
1390 * @param msg Channel destroy message.
1391 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1392 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1393 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1394 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1397 handle_ch_destroy (struct MeshTunnel3 *t,
1398 const struct GNUNET_MESH_ChannelManage *msg,
1401 struct MeshChannel *ch;
1405 size = ntohs (msg->header.size);
1406 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
1413 ch = GMT_get_channel (t, ntohl (msg->chid));
1416 /* Probably a retransmission, safe to ignore */
1420 GMCH_handle_destroy (ch, msg, fwd);
1425 * The peer's ephemeral key has changed: update the symmetrical keys.
1427 * @param t Tunnel this message came on.
1428 * @param msg Key eXchange message.
1431 handle_ephemeral (struct MeshTunnel3 *t,
1432 const struct GNUNET_MESH_KX_Ephemeral *msg)
1434 struct GNUNET_HashCode km;
1435 LOG (GNUNET_ERROR_TYPE_DEBUG, " ephemeral key message\n");
1437 if (GNUNET_OK != check_ephemeral (t, msg))
1439 GNUNET_break_op (0);
1442 derive_key_material (&km, &msg->ephemeral_key);
1443 LOG (GNUNET_ERROR_TYPE_DEBUG, " km is %s\n", GNUNET_h2s (&km));
1444 derive_symmertic (&t->e_key, &my_full_id, GMP_get_id (t->peer), &km);
1445 derive_symmertic (&t->d_key, GMP_get_id (t->peer), &my_full_id, &km);
1446 if (MESH_TUNNEL3_KEY_SENT == t->estate)
1448 LOG (GNUNET_ERROR_TYPE_DEBUG, " our key was sent, send ping\n");
1450 t->estate = MESH_TUNNEL3_KEY_PING;
1456 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
1457 * Answer with by retransmitting the challenge with the "opposite" key.
1459 * @param t Tunnel this message came on.
1460 * @param msg Key eXchange Ping message.
1463 handle_ping (struct MeshTunnel3 *t,
1464 const struct GNUNET_MESH_KX_Ping *msg)
1466 struct GNUNET_MESH_KX_Ping res;
1468 if (ntohs (msg->header.size) != sizeof (res))
1470 GNUNET_break_op (0);
1474 LOG (GNUNET_ERROR_TYPE_DEBUG, " ping message\n");
1475 t_decrypt (t, &res.target, &msg->target, ping_encryption_size (), msg->iv);
1476 if (0 != memcmp (&my_full_id, &res.target, sizeof (my_full_id)))
1478 GNUNET_STATISTICS_update (stats, "# malformed PINGs", 1, GNUNET_NO);
1479 LOG (GNUNET_ERROR_TYPE_WARNING, " malformed PING\n");
1480 LOG (GNUNET_ERROR_TYPE_DEBUG, " e got %u\n", msg->nonce);
1481 LOG (GNUNET_ERROR_TYPE_DEBUG, " e towards %s\n", GNUNET_i2s (&msg->target));
1482 LOG (GNUNET_ERROR_TYPE_DEBUG, " got %u\n", res.nonce);
1483 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s\n", GNUNET_i2s (&res.target));
1487 send_pong (t, res.nonce);
1492 * Peer has answer to our challenge.
1493 * If answer is successful, consider the key exchange finished and clean
1494 * up all related state.
1496 * @param t Tunnel this message came on.
1497 * @param msg Key eXchange Pong message.
1500 handle_pong (struct MeshTunnel3 *t,
1501 const struct GNUNET_MESH_KX_Pong *msg)
1505 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG received\n");
1506 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
1508 GNUNET_STATISTICS_update (stats, "# duplicate PONG messages", 1, GNUNET_NO);
1511 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
1513 if (challenge != t->kx_ctx->challenge)
1515 LOG (GNUNET_ERROR_TYPE_WARNING, "Wrong PONG challenge\n");
1516 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG: %u (e: %u). Expected: %u.\n",
1517 challenge, msg->nonce, t->kx_ctx->challenge);
1518 GNUNET_break_op (0);
1521 GNUNET_SCHEDULER_cancel (t->rekey_task);
1522 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1523 GNUNET_free (t->kx_ctx);
1525 GMT_change_estate (t, MESH_TUNNEL3_KEY_OK);
1530 * Demultiplex by message type and call appropriate handler for a message
1531 * towards a channel of a local tunnel.
1533 * @param t Tunnel this message came on.
1534 * @param msgh Message header.
1535 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1536 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1537 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1538 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1541 handle_decrypted (struct MeshTunnel3 *t,
1542 const struct GNUNET_MessageHeader *msgh,
1547 type = ntohs (msgh->type);
1548 LOG (GNUNET_ERROR_TYPE_DEBUG,
1549 "Got a %s message!\n",
1554 case GNUNET_MESSAGE_TYPE_MESH_DATA:
1555 /* Don't send hop ACK, wait for client to ACK */
1556 handle_data (t, (struct GNUNET_MESH_Data *) msgh, fwd);
1559 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
1560 handle_data_ack (t, (struct GNUNET_MESH_DataACK *) msgh, fwd);
1563 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
1564 handle_ch_create (t,
1565 (struct GNUNET_MESH_ChannelCreate *) msgh);
1568 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
1570 (struct GNUNET_MESH_ChannelManage *) msgh);
1573 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
1575 (struct GNUNET_MESH_ChannelManage *) msgh,
1579 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
1580 handle_ch_destroy (t,
1581 (struct GNUNET_MESH_ChannelManage *) msgh,
1586 GNUNET_break_op (0);
1587 LOG (GNUNET_ERROR_TYPE_DEBUG,
1588 "end-to-end message not known (%u)\n",
1589 ntohs (msgh->type));
1594 /******************************************************************************/
1595 /******************************** API ***********************************/
1596 /******************************************************************************/
1599 * Decrypt and demultiplex by message type. Call appropriate handler
1600 * for every message.
1602 * @param t Tunnel this message came on.
1603 * @param msg Encrypted message.
1606 GMT_handle_encrypted (struct MeshTunnel3 *t,
1607 const struct GNUNET_MESH_Encrypted *msg)
1609 size_t size = ntohs (msg->header.size);
1610 size_t payload_size = size - sizeof (struct GNUNET_MESH_Encrypted);
1611 size_t decrypted_size;
1612 char cbuf [payload_size];
1613 struct GNUNET_MessageHeader *msgh;
1616 decrypted_size = t_decrypt (t, cbuf, &msg[1], payload_size, msg->iv);
1618 while (off < decrypted_size)
1620 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1621 handle_decrypted (t, msgh, GNUNET_SYSERR);
1622 off += ntohs (msgh->size);
1628 * Demultiplex an encapsulated KX message by message type.
1630 * @param t Tunnel on which the message came.
1631 * @param message Payload of KX message.
1634 GMT_handle_kx (struct MeshTunnel3 *t,
1635 const struct GNUNET_MessageHeader *message)
1639 type = ntohs (message->type);
1640 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1643 case GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL:
1644 handle_ephemeral (t, (struct GNUNET_MESH_KX_Ephemeral *) message);
1647 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
1648 handle_ping (t, (struct GNUNET_MESH_KX_Ping *) message);
1651 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
1652 handle_pong (t, (struct GNUNET_MESH_KX_Pong *) message);
1656 GNUNET_break_op (0);
1657 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1663 * Initialize the tunnel subsystem.
1665 * @param c Configuration handle.
1666 * @param key ECC private key, to derive all other keys and do crypto.
1669 GMT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1670 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1672 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1674 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "DEFAULT_TTL",
1677 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1678 "MESH", "DEFAULT_TTL", "USING DEFAULT");
1682 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REKEY_PERIOD",
1685 rekey_period = GNUNET_TIME_UNIT_DAYS;
1688 my_private_key = key;
1689 kx_msg.header.size = htons (sizeof (kx_msg));
1690 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL);
1691 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_MESH_KX);
1692 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1693 kx_msg.origin_identity = my_full_id;
1694 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1696 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1701 * Shut down the tunnel subsystem.
1706 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1708 GNUNET_SCHEDULER_cancel (rekey_task);
1709 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1711 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &destroy_iterator, NULL);
1712 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1719 * @param destination Peer this tunnel is towards.
1721 struct MeshTunnel3 *
1722 GMT_new (struct MeshPeer *destination)
1724 struct MeshTunnel3 *t;
1726 t = GNUNET_new (struct MeshTunnel3);
1728 t->peer = destination;
1731 GNUNET_CONTAINER_multipeermap_put (tunnels, GMP_get_id (destination), t,
1732 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
1743 * Change the tunnel's connection state.
1745 * @param t Tunnel whose connection state to change.
1746 * @param cstate New connection state.
1749 GMT_change_cstate (struct MeshTunnel3* t, enum MeshTunnel3CState cstate)
1753 LOG (GNUNET_ERROR_TYPE_DEBUG,
1754 "Tunnel %s cstate was %s\n",
1755 GMP_2s (t->peer), cstate2s (t->cstate));
1756 LOG (GNUNET_ERROR_TYPE_DEBUG,
1757 "Tunnel %s cstate is now %s\n",
1758 GMP_2s (t->peer), cstate2s (cstate));
1759 if (myid != GMP_get_short_id (t->peer) &&
1760 MESH_TUNNEL3_READY != t->cstate &&
1761 MESH_TUNNEL3_READY == cstate)
1764 if (MESH_TUNNEL3_KEY_OK == t->estate)
1766 LOG (GNUNET_ERROR_TYPE_DEBUG, " triggered send queued data\n");
1767 send_queued_data (t);
1769 else if (MESH_TUNNEL3_KEY_UNINITIALIZED == t->estate)
1771 LOG (GNUNET_ERROR_TYPE_DEBUG, " triggered rekey\n");
1772 rekey_tunnel (t, NULL);
1777 if (MESH_TUNNEL3_READY == cstate && 3 <= GMT_count_connections (t))
1779 GMP_stop_search (t->peer);
1784 * Change the tunnel encryption state.
1786 * @param t Tunnel whose encryption state to change.
1787 * @param state New encryption state.
1790 GMT_change_estate (struct MeshTunnel3* t, enum MeshTunnel3EState state)
1794 LOG (GNUNET_ERROR_TYPE_DEBUG,
1795 "Tunnel %s estate was %s\n",
1796 GMP_2s (t->peer), estate2s (t->estate));
1797 LOG (GNUNET_ERROR_TYPE_DEBUG,
1798 "Tunnel %s estate is now %s\n",
1799 GMP_2s (t->peer), estate2s (state));
1800 if (myid != GMP_get_short_id (t->peer) &&
1801 MESH_TUNNEL3_KEY_OK != t->estate && MESH_TUNNEL3_KEY_OK == state)
1804 send_queued_data (t);
1812 * Add a connection to a tunnel.
1815 * @param c Connection.
1818 GMT_add_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1820 struct MeshTConnection *aux;
1822 GNUNET_assert (NULL != c);
1824 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1828 aux = GNUNET_new (struct MeshTConnection);
1830 GNUNET_CONTAINER_DLL_insert_tail (t->connection_head, t->connection_tail, aux);
1835 * Mark a path as no longer valid for this tunnel: has been tried and failed.
1837 * @param t Tunnel to update.
1838 * @param path Invalid path to remove. Is destroyed after removal.
1841 GMT_remove_path (struct MeshTunnel3 *t, struct MeshPeerPath *path)
1843 GMP_remove_path (t->peer, path);
1848 * Remove a connection from a tunnel.
1851 * @param c Connection.
1854 GMT_remove_connection (struct MeshTunnel3 *t,
1855 struct MeshConnection *c)
1857 struct MeshTConnection *aux;
1858 struct MeshTConnection *next;
1860 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing connection %s from tunnel %s\n",
1861 GMC_2s (c), GMT_2s (t));
1862 for (aux = t->connection_head; aux != NULL; aux = next)
1867 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
1872 /* Start new connections if needed */
1873 if (NULL == t->connection_head
1874 && GNUNET_SCHEDULER_NO_TASK == t->destroy_task
1875 && GNUNET_NO == shutting_down)
1877 LOG (GNUNET_ERROR_TYPE_DEBUG, " no more connections, getting new ones\n");
1878 GMP_connect (t->peer);
1879 t->cstate = MESH_TUNNEL3_SEARCHING;
1883 /* If not marked as ready, no change is needed */
1884 if (MESH_TUNNEL3_READY != t->cstate)
1887 /* Check if any connection is ready to maintaing cstate */
1888 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1889 if (MESH_CONNECTION_READY == GMC_get_state (aux->c))
1892 t->cstate = MESH_TUNNEL3_WAITING;
1897 * Add a channel to a tunnel.
1900 * @param ch Channel.
1903 GMT_add_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1905 struct MeshTChannel *aux;
1907 GNUNET_assert (NULL != ch);
1909 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
1911 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1913 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
1918 aux = GNUNET_new (struct MeshTChannel);
1920 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
1921 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
1923 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
1925 GNUNET_SCHEDULER_cancel (t->destroy_task);
1926 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
1927 LOG (GNUNET_ERROR_TYPE_DEBUG, " undo destroy!\n");
1933 * Remove a channel from a tunnel.
1936 * @param ch Channel.
1939 GMT_remove_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1941 struct MeshTChannel *aux;
1943 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
1944 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1948 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GMCH_2s (ch));
1949 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
1958 * Search for a channel by global ID.
1960 * @param t Tunnel containing the channel.
1961 * @param chid Public channel number.
1963 * @return channel handler, NULL if doesn't exist
1965 struct MeshChannel *
1966 GMT_get_channel (struct MeshTunnel3 *t, MESH_ChannelNumber chid)
1968 struct MeshTChannel *iter;
1973 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1975 if (GMCH_get_id (iter->ch) == chid)
1979 return NULL == iter ? NULL : iter->ch;
1984 * @brief Destroy a tunnel and free all resources.
1986 * Should only be called a while after the tunnel has been marked as destroyed,
1987 * in case there is a new channel added to the same peer shortly after marking
1988 * the tunnel. This way we avoid a new public key handshake.
1990 * @param cls Closure (tunnel to destroy).
1991 * @param tc Task context.
1994 delayed_destroy (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1996 struct MeshTunnel3 *t = cls;
1998 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2004 * Tunnel is empty: destroy it.
2006 * Notifies all connections about the destruction.
2008 * @param t Tunnel to destroy.
2011 GMT_destroy_empty (struct MeshTunnel3 *t)
2013 struct MeshTConnection *iter;
2015 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel %s empty: destroying scheduled\n",
2017 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2019 GMC_send_destroy (iter->c);
2022 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2024 t->estate = MESH_TUNNEL3_KEY_UNINITIALIZED;
2025 GNUNET_SCHEDULER_cancel (t->rekey_task);
2026 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
2027 GNUNET_free (t->kx_ctx);
2030 t->cstate = MESH_TUNNEL3_NEW;
2031 t->destroy_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
2032 &delayed_destroy, t);
2037 * Destroy tunnel if empty (no more channels).
2039 * @param t Tunnel to destroy if empty.
2042 GMT_destroy_if_empty (struct MeshTunnel3 *t)
2044 if (1 < GMT_count_channels (t))
2047 GMT_destroy_empty (t);
2052 * Destroy the tunnel.
2054 * This function does not generate any warning traffic to clients or peers.
2057 * Cancel messages belonging to this tunnel queued to neighbors.
2058 * Free any allocated resources linked to the tunnel.
2060 * @param t The tunnel to destroy.
2063 GMT_destroy (struct MeshTunnel3 *t)
2065 struct MeshTConnection *iter_c;
2066 struct MeshTConnection *next_c;
2067 struct MeshTChannel *iter_ch;
2068 struct MeshTChannel *next_ch;
2073 if (GNUNET_SCHEDULER_NO_TASK != t->destroy_task)
2075 GNUNET_SCHEDULER_cancel (t->destroy_task);
2076 t->destroy_task = GNUNET_SCHEDULER_NO_TASK;
2079 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GMP_2s (t->peer));
2081 GNUNET_break (GNUNET_YES ==
2082 GNUNET_CONTAINER_multipeermap_remove (tunnels,
2083 GMP_get_id (t->peer), t));
2085 for (iter_c = t->connection_head; NULL != iter_c; iter_c = next_c)
2087 next_c = iter_c->next;
2088 GMC_destroy (iter_c->c);
2090 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = next_ch)
2092 next_ch = iter_ch->next;
2093 GMCH_destroy (iter_ch->ch);
2094 /* Should only happen on shutdown, but it's ok. */
2097 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
2098 GMP_set_tunnel (t->peer, NULL);
2100 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
2101 GNUNET_SCHEDULER_cancel (t->rekey_task);
2108 * @brief Use the given path for the tunnel.
2109 * Update the next and prev hops (and RCs).
2110 * (Re)start the path refresh in case the tunnel is locally owned.
2112 * @param t Tunnel to update.
2113 * @param p Path to use.
2115 * @return Connection created.
2117 struct MeshConnection *
2118 GMT_use_path (struct MeshTunnel3 *t, struct MeshPeerPath *p)
2120 struct MeshConnection *c;
2121 struct GNUNET_HashCode cid;
2122 unsigned int own_pos;
2124 if (NULL == t || NULL == p)
2130 for (own_pos = 0; own_pos < p->length; own_pos++)
2132 if (p->peers[own_pos] == myid)
2135 if (own_pos > p->length - 1)
2137 GNUNET_break_op (0);
2141 GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE, &cid);
2142 c = GMC_new (&cid, t, p, own_pos);
2145 /* Path was flawed */
2148 GMT_add_connection (t, c);
2154 * Count established (ready) connections of a tunnel.
2156 * @param t Tunnel on which to count.
2158 * @return Number of connections.
2161 GMT_count_connections (struct MeshTunnel3 *t)
2163 struct MeshTConnection *iter;
2166 for (count = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2167 if (MESH_CONNECTION_DESTROYED != GMC_get_state (iter->c))
2174 * Count channels of a tunnel.
2176 * @param t Tunnel on which to count.
2178 * @return Number of channels.
2181 GMT_count_channels (struct MeshTunnel3 *t)
2183 struct MeshTChannel *iter;
2186 for (count = 0, iter = t->channel_head;
2188 iter = iter->next, count++) /* skip */;
2195 * Get the connectivity state of a tunnel.
2199 * @return Tunnel's connectivity state.
2201 enum MeshTunnel3CState
2202 GMT_get_cstate (struct MeshTunnel3 *t)
2207 return (enum MeshTunnel3CState) -1;
2214 * Get the encryption state of a tunnel.
2218 * @return Tunnel's encryption state.
2220 enum MeshTunnel3EState
2221 GMT_get_estate (struct MeshTunnel3 *t)
2226 return (enum MeshTunnel3EState) -1;
2232 * Get the maximum buffer space for a tunnel towards a local client.
2236 * @return Biggest buffer space offered by any channel in the tunnel.
2239 GMT_get_channels_buffer (struct MeshTunnel3 *t)
2241 struct MeshTChannel *iter;
2242 unsigned int buffer;
2243 unsigned int ch_buf;
2245 if (NULL == t->channel_head)
2247 /* Probably getting buffer for a channel create/handshake. */
2252 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2254 ch_buf = get_channel_buffer (iter);
2255 if (ch_buf > buffer)
2263 * Get the total buffer space for a tunnel for P2P traffic.
2267 * @return Buffer space offered by all connections in the tunnel.
2270 GMT_get_connections_buffer (struct MeshTunnel3 *t)
2272 struct MeshTConnection *iter;
2273 unsigned int buffer;
2276 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2278 if (GMC_get_state (iter->c) != MESH_CONNECTION_READY)
2282 buffer += get_connection_buffer (iter);
2290 * Get the tunnel's destination.
2294 * @return ID of the destination peer.
2296 const struct GNUNET_PeerIdentity *
2297 GMT_get_destination (struct MeshTunnel3 *t)
2299 return GMP_get_id (t->peer);
2304 * Get the tunnel's next free global channel ID.
2308 * @return GID of a channel free to use.
2311 GMT_get_next_chid (struct MeshTunnel3 *t)
2313 MESH_ChannelNumber chid;
2314 MESH_ChannelNumber mask;
2317 /* Set bit 30 depending on the ID relationship. Bit 31 is always 0 for GID.
2318 * If our ID is bigger or loopback tunnel, start at 0, bit 30 = 0
2319 * If peer's ID is bigger, start at 0x4... bit 30 = 1
2321 result = GNUNET_CRYPTO_cmp_peer_identity (&my_full_id, GMP_get_id (t->peer));
2327 while (NULL != GMT_get_channel (t, t->next_chid))
2329 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
2330 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
2331 t->next_chid |= mask;
2333 chid = t->next_chid;
2334 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
2335 t->next_chid |= mask;
2342 * Send ACK on one or more channels due to buffer in connections.
2344 * @param t Channel which has some free buffer space.
2347 GMT_unchoke_channels (struct MeshTunnel3 *t)
2349 struct MeshTChannel *iter;
2350 unsigned int buffer;
2351 unsigned int channels = GMT_count_channels (t);
2352 unsigned int choked_n;
2353 struct MeshChannel *choked[channels];
2355 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT_unchoke_channels on %s\n", GMT_2s (t));
2356 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
2357 if (NULL != t->channel_head)
2358 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
2360 /* Get buffer space */
2361 buffer = GMT_get_connections_buffer (t);
2367 /* Count and remember choked channels */
2369 for (iter = t->channel_head; NULL != iter; iter = iter->next)
2371 if (GNUNET_NO == get_channel_allowed (iter))
2373 choked[choked_n++] = iter->ch;
2377 /* Unchoke random channels */
2378 while (0 < buffer && 0 < choked_n)
2380 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
2382 GMCH_allow_client (choked[r], GMCH_is_origin (choked[r], GNUNET_YES));
2385 choked[r] = choked[choked_n];
2391 * Send ACK on one or more connections due to buffer space to the client.
2393 * Iterates all connections of the tunnel and sends ACKs appropriately.
2398 GMT_send_connection_acks (struct MeshTunnel3 *t)
2400 struct MeshTConnection *iter;
2403 uint32_t allow_per_connection;
2405 unsigned int buffer;
2407 LOG (GNUNET_ERROR_TYPE_DEBUG, "Tunnel send connection ACKs on %s\n",
2416 buffer = GMT_get_channels_buffer (t);
2417 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer %u\n", buffer);
2419 /* Count connections, how many messages are already allowed */
2420 cs = GMT_count_connections (t);
2421 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
2423 allowed += get_connection_allowed (iter);
2425 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowed %u\n", allowed);
2427 /* Make sure there is no overflow */
2428 if (allowed > buffer)
2433 /* Authorize connections to send more data */
2434 to_allow = buffer; /* - allowed; */
2436 for (iter = t->connection_head;
2437 NULL != iter && to_allow > 0;
2440 allow_per_connection = to_allow/cs;
2441 to_allow -= allow_per_connection;
2443 if (get_connection_allowed (iter) > 64 / 3)
2447 GMC_allow (iter->c, allow_per_connection,
2448 GMC_is_origin (iter->c, GNUNET_NO));
2451 GNUNET_break (to_allow == 0);
2456 * Cancel a previously sent message while it's in the queue.
2458 * ONLY can be called before the continuation given to the send function
2459 * is called. Once the continuation is called, the message is no longer in the
2462 * @param q Handle to the queue.
2465 GMT_cancel (struct MeshTunnel3Queue *q)
2470 /* message_sent() will be called and free q */
2472 else if (NULL != q->tqd)
2474 unqueue_data (q->tqd);
2476 if (NULL != q->cont)
2477 q->cont (q->cont_cls, NULL, q, 0, 0);
2488 * Sends an already built message on a tunnel, encrypting it and
2489 * choosing the best connection.
2491 * @param message Message to send. Function modifies it.
2492 * @param t Tunnel on which this message is transmitted.
2493 * @param force Force the tunnel to take the message (buffer overfill).
2494 * @param cont Continuation to call once message is really sent.
2495 * @param cont_cls Closure for @c cont.
2497 * @return Handle to cancel message. NULL if @c cont is NULL.
2499 struct MeshTunnel3Queue *
2500 GMT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2501 struct MeshTunnel3 *t, int force,
2502 GMT_sent cont, void *cont_cls)
2504 return send_prebuilt_message (message, t, force, cont, cont_cls, NULL);
2509 * Is the tunnel directed towards the local peer?
2513 * @return #GNUNET_YES if it is loopback.
2516 GMT_is_loopback (const struct MeshTunnel3 *t)
2518 return (myid == GMP_get_short_id (t->peer));
2523 * Is the tunnel this path already?
2528 * @return #GNUNET_YES a connection uses this path.
2531 GMT_is_path_used (const struct MeshTunnel3 *t, const struct MeshPeerPath *p)
2533 struct MeshTConnection *iter;
2535 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2536 if (GMC_get_path (iter->c) == p)
2544 * Get a cost of a path for a tunnel considering existing connections.
2547 * @param path Candidate path.
2549 * @return Cost of the path (path length + number of overlapping nodes)
2552 GMT_get_path_cost (const struct MeshTunnel3 *t,
2553 const struct MeshPeerPath *path)
2555 struct MeshTConnection *iter;
2556 const struct MeshPeerPath *aux;
2557 unsigned int overlap;
2565 GNUNET_assert (NULL != t);
2567 for (i = 0; i < path->length; i++)
2569 for (iter = t->connection_head; NULL != iter; iter = iter->next)
2571 aux = GMC_get_path (iter->c);
2575 for (j = 0; j < aux->length; j++)
2577 if (path->peers[i] == aux->peers[j])
2585 return (path->length + overlap) * (path->score * -1);
2590 * Get the static string for the peer this tunnel is directed.
2594 * @return Static string the destination peer's ID.
2597 GMT_2s (const struct MeshTunnel3 *t)
2602 return GMP_2s (t->peer);
2606 /******************************************************************************/
2607 /***************************** INFO/DEBUG *******************************/
2608 /******************************************************************************/
2612 * Log all possible info about the tunnel state.
2614 * @param t Tunnel to debug.
2617 GMT_debug (const struct MeshTunnel3 *t)
2619 struct MeshTChannel *iterch;
2620 struct MeshTConnection *iterc;
2622 LOG (GNUNET_ERROR_TYPE_DEBUG, "DEBUG TUNNEL TOWARDS %s\n", GMT_2s (t));
2623 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate %s, estate %s\n",
2624 cstate2s (t->cstate), estate2s (t->estate));
2625 LOG (GNUNET_ERROR_TYPE_DEBUG, " kx_ctx %p, rekey_task %u\n",
2626 t->kx_ctx, t->rekey_task);
2627 LOG (GNUNET_ERROR_TYPE_DEBUG, " tq_head %p, tq_tail %p\n",
2628 t->tq_head, t->tq_tail);
2629 LOG (GNUNET_ERROR_TYPE_DEBUG, " destroy %u\n", t->destroy_task);
2631 LOG (GNUNET_ERROR_TYPE_DEBUG, " channels:\n");
2632 for (iterch = t->channel_head; NULL != iterch; iterch = iterch->next)
2634 LOG (GNUNET_ERROR_TYPE_DEBUG, " - %s\n", GMCH_2s (iterch->ch));
2637 LOG (GNUNET_ERROR_TYPE_DEBUG, " connections:\n");
2638 for (iterc = t->connection_head; NULL != iterc; iterc = iterc->next)
2640 LOG (GNUNET_ERROR_TYPE_DEBUG, " - %s [%u] buf: %u/%u (qn %u/%u)\n",
2641 GMC_2s (iterc->c), GMC_get_state (iterc->c),
2642 GMC_get_buffer (iterc->c, GNUNET_YES),
2643 GMC_get_buffer (iterc->c, GNUNET_NO),
2644 GMC_get_qn (iterc->c, GNUNET_YES),
2645 GMC_get_qn (iterc->c, GNUNET_NO));
2648 LOG (GNUNET_ERROR_TYPE_DEBUG, "DEBUG TUNNEL END\n");
2653 GMT_iterate_all (void *cls, GNUNET_CONTAINER_PeerMapIterator iter)
2655 GNUNET_CONTAINER_multipeermap_iterate (tunnels, iter, cls);
2659 GMT_count_all (void)
2661 return GNUNET_CONTAINER_multipeermap_size (tunnels);
2665 GMT_iterate_connections (struct MeshTunnel3 *t, GMT_conn_iter iter, void *cls)
2667 struct MeshTConnection *ct;
2669 for (ct = t->connection_head; NULL != ct; ct = ct->next)
2674 GMT_iterate_channels (struct MeshTunnel3 *t, GMT_chan_iter iter, void *cls)
2676 struct MeshTChannel *cht;
2678 for (cht = t->channel_head; NULL != cht; cht = cht->next)
2679 iter (cls, cht->ch);