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_enc.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, 30)
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.
87 enum MeshTunnel3State state;
90 * Key eXchange context.
92 struct MeshTunnelKXCtx *kx_ctx;
95 * Encryption ("our") key.
97 struct GNUNET_CRYPTO_SymmetricSessionKey e_key;
100 * Decryption ("their") key.
102 struct GNUNET_CRYPTO_SymmetricSessionKey d_key;
105 * Task to start the rekey process.
107 GNUNET_SCHEDULER_TaskIdentifier rekey_task;
110 * Paths that are actively used to reach the destination peer.
112 struct MeshTConnection *connection_head;
113 struct MeshTConnection *connection_tail;
116 * Next connection number.
121 * Channels inside this tunnel.
123 struct MeshTChannel *channel_head;
124 struct MeshTChannel *channel_tail;
127 * Channel ID for the next created channel.
129 MESH_ChannelNumber next_chid;
132 * Destroy flag: if true, destroy on last message.
137 * Queued messages, to transmit once tunnel gets connected.
139 struct MeshTunnelQueue *tq_head;
140 struct MeshTunnelQueue *tq_tail;
145 * Struct used to queue messages in a tunnel.
147 struct MeshTunnelQueue
152 struct MeshTunnelQueue *next;
153 struct MeshTunnelQueue *prev;
158 struct MeshChannel *ch;
163 /* struct GNUNET_MessageHeader *msg; */
167 /******************************************************************************/
168 /******************************* GLOBALS ***********************************/
169 /******************************************************************************/
172 * Global handle to the statistics service.
174 extern struct GNUNET_STATISTICS_Handle *stats;
177 * Local peer own ID (memory efficient handle).
179 extern GNUNET_PEER_Id myid;
182 * Local peer own ID (full value).
184 extern struct GNUNET_PeerIdentity my_full_id;
188 * Set of all tunnels, in order to trigger a new exchange on rekey.
189 * Indexed by peer's ID.
191 static struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
194 * Default TTL for payload packets.
196 static unsigned long long default_ttl;
201 const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
204 * Own ephemeral private key.
206 static struct GNUNET_CRYPTO_EcdhePrivateKey *my_ephemeral_key;
209 * Cached message used to perform a key exchange.
211 static struct GNUNET_MESH_KX_Ephemeral kx_msg;
214 * Task to generate a new ephemeral key.
216 static GNUNET_SCHEDULER_TaskIdentifier rekey_task;
221 static struct GNUNET_TIME_Relative rekey_period;
223 /******************************************************************************/
224 /******************************** STATIC ***********************************/
225 /******************************************************************************/
228 * Get string description for tunnel state.
230 * @param s Tunnel state.
232 * @return String representation.
235 GMT_state2s (enum MeshTunnel3State s)
237 static char buf[128];
241 case MESH_TUNNEL3_NEW:
242 return "MESH_TUNNEL3_NEW";
243 case MESH_TUNNEL3_SEARCHING:
244 return "MESH_TUNNEL3_SEARCHING";
245 case MESH_TUNNEL3_WAITING:
246 return "MESH_TUNNEL3_WAITING";
247 case MESH_TUNNEL3_KEY_SENT:
248 return "MESH_TUNNEL3_KEY_SENT";
249 case MESH_TUNNEL3_PING_SENT:
250 return "MESH_TUNNEL3_PING_SENT";
251 case MESH_TUNNEL3_READY:
252 return "MESH_TUNNEL3_READY";
253 case MESH_TUNNEL3_RECONNECTING:
254 return "MESH_TUNNEL3_RECONNECTING";
255 case MESH_TUNNEL3_REKEY:
256 return "MESH_TUNNEL3_REKEY";
259 sprintf (buf, "%u (UNKNOWN STATE)", s);
266 * Ephemeral key message purpose size.
268 * @return Size of the part of the ephemeral key message that must be signed.
271 ephemeral_purpose_size (void)
273 return sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) +
274 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
275 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
276 sizeof (struct GNUNET_CRYPTO_EcdhePublicKey) +
277 sizeof (struct GNUNET_PeerIdentity);
282 * Size of the encrypted part of a ping message.
284 * @return Size of the encrypted part of a ping message.
287 ping_encryption_size (void)
289 return sizeof (struct GNUNET_PeerIdentity) + sizeof (uint32_t);
294 * Check that a ephemeral key message s well formed and correctly signed.
296 * @param t Tunnel on which the message came.
297 * @param msg The ephemeral key message.
299 * @return GNUNET_OK if message is fine, GNUNET_SYSERR otherwise.
302 check_ephemeral (struct MeshTunnel3 *t,
303 const struct GNUNET_MESH_KX_Ephemeral *msg)
305 /* Check message size */
306 if (ntohs (msg->header.size) != sizeof (struct GNUNET_MESH_KX_Ephemeral))
307 return GNUNET_SYSERR;
309 /* Check signature size */
310 if (ntohl (msg->purpose.size) != ephemeral_purpose_size ())
311 return GNUNET_SYSERR;
314 if (0 != memcmp (&msg->origin_identity,
315 GMP_get_id (t->peer),
316 sizeof (struct GNUNET_PeerIdentity)))
317 return GNUNET_SYSERR;
319 /* Check signature */
321 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_MESH_KX,
324 &msg->origin_identity.public_key))
325 return GNUNET_SYSERR;
332 * Encrypt data with the tunnel key.
334 * @param t Tunnel whose key to use.
335 * @param dst Destination for the encrypted data.
336 * @param src Source of the plaintext. Can overlap with @c dst.
337 * @param size Size of the plaintext.
338 * @param iv Initialization Vector to use.
341 t_encrypt (struct MeshTunnel3 *t,
342 void *dst, const void *src,
343 size_t size, uint32_t iv)
345 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
347 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->e_key, &iv, sizeof (uint32_t), NULL);
348 return GNUNET_CRYPTO_symmetric_encrypt (src, size, &t->e_key, &siv, dst);
353 * Decrypt data with the tunnel key.
355 * @param t Tunnel whose key to use.
356 * @param dst Destination for the plaintext.
357 * @param src Source of the encrypted data. Can overlap with @c dst.
358 * @param size Size of the encrypted data.
359 * @param iv Initialization Vector to use.
362 t_decrypt (struct MeshTunnel3 *t,
363 void *dst, const void *src,
364 size_t size, uint32_t iv)
366 struct GNUNET_CRYPTO_SymmetricInitializationVector siv;
368 GNUNET_CRYPTO_symmetric_derive_iv (&siv, &t->e_key, &iv, sizeof (uint32_t), NULL);
369 return GNUNET_CRYPTO_symmetric_decrypt (src, size, &t->d_key, &siv, dst);
374 * Create key material by doing ECDH on the local and remote ephemeral keys.
376 * @param key_material Where to store the key material.
377 * @param ephemeral_key Peer's public ephemeral key.
380 derive_key_material (struct GNUNET_HashCode *key_material,
381 const struct GNUNET_CRYPTO_EcdhePublicKey *ephemeral_key)
384 GNUNET_CRYPTO_ecc_ecdh (my_ephemeral_key,
393 * Create a symmetic key from the identities of both ends and the key material
396 * @param key Destination for the generated key.
397 * @param sender ID of the peer that will encrypt with @c key.
398 * @param receiver ID of the peer that will decrypt with @c key.
399 * @param key_material Hash created with ECDH with the ephemeral keys.
402 derive_symmertic (struct GNUNET_CRYPTO_SymmetricSessionKey *key,
403 const struct GNUNET_PeerIdentity *sender,
404 const struct GNUNET_PeerIdentity *receiver,
405 const struct GNUNET_HashCode *key_material)
407 const char salt[] = "MESH kx salt";
409 GNUNET_CRYPTO_kdf (key, sizeof (struct GNUNET_CRYPTO_SymmetricSessionKey),
411 key_material, sizeof (struct GNUNET_HashCode),
412 sender, sizeof (struct GNUNET_PeerIdentity),
413 receiver, sizeof (struct GNUNET_PeerIdentity),
418 * Pick a connection on which send the next data message.
420 * @param t Tunnel on which to send the message.
422 * @return The connection on which to send the next message.
424 static struct MeshConnection *
425 tunnel_get_connection (struct MeshTunnel3 *t)
427 struct MeshTConnection *iter;
428 struct MeshConnection *best;
430 unsigned int lowest_q;
432 LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel_get_connection %s\n", GMP_2s (t->peer));
435 for (iter = t->connection_head; NULL != iter; iter = iter->next)
437 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s: %u\n",
438 GNUNET_h2s (GMC_get_id (iter->c)), GMC_get_state (iter->c));
439 if (MESH_CONNECTION_READY == GMC_get_state (iter->c))
441 qn = GMC_get_qn (iter->c, GMC_is_origin (iter->c, GNUNET_YES));
442 LOG (GNUNET_ERROR_TYPE_DEBUG, " q_n %u, \n", qn);
455 * Send all cached messages that we can, tunnel is online.
457 * @param t Tunnel that holds the messages.
458 * @param fwd Is this fwd?
461 send_queued_data (struct MeshTunnel3 *t, int fwd)
463 struct MeshTunnelQueue *tq;
464 struct MeshTunnelQueue *next;
467 LOG (GNUNET_ERROR_TYPE_DEBUG,
468 "GMT_send_queued_data on tunnel %s\n",
471 if (NULL == t->channel_head ||
472 GNUNET_NO == GMCH_is_origin (t->channel_head->ch, fwd))
475 room = GMT_get_buffer (t, fwd);
476 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space: %u\n", room);
477 for (tq = t->tq_head; NULL != tq && room > 0; tq = next)
479 LOG (GNUNET_ERROR_TYPE_DEBUG, " data on channel %s\n", GMCH_2s (tq->ch));
482 GNUNET_CONTAINER_DLL_remove (t->tq_head, t->tq_tail, tq);
483 GMCH_send_prebuilt_message ((struct GNUNET_MessageHeader *) &tq[1],
488 LOG (GNUNET_ERROR_TYPE_DEBUG,
489 "GMT_send_queued_data end\n",
497 * Cache a message to be sent once tunnel is online.
499 * @param t Tunnel to hold the message.
500 * @param ch Channel the message is about.
501 * @param msg Message itself (copy will be made).
504 queue_data (struct MeshTunnel3 *t,
505 struct MeshChannel *ch,
506 const struct GNUNET_MessageHeader *msg)
508 struct MeshTunnelQueue *tq;
509 uint16_t size = ntohs (msg->size);
511 if (MESH_TUNNEL3_READY == t->state)
517 tq = GNUNET_malloc (sizeof (struct MeshTunnelQueue) + size);
520 memcpy (&tq[1], msg, size);
521 GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tq);
527 * Sends key exchange message on a tunnel, choosing the best connection.
528 * Should not be called on loopback tunnels.
530 * @param t Tunnel on which this message is transmitted.
531 * @param message Message to send. Function modifies it.
534 send_kx (struct MeshTunnel3 *t,
535 const struct GNUNET_MessageHeader *message)
537 struct MeshConnection *c;
538 struct GNUNET_MESH_KX *msg;
539 size_t size = ntohs (message->size);
540 char cbuf[sizeof (struct GNUNET_MESH_KX) + size];
544 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT KX on Tunnel %s\n", GMT_2s (t));
546 /* Avoid loopback. */
547 if (myid == GMP_get_short_id (t->peer))
549 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
554 /* Must have a connection. */
555 if (NULL == t->connection_head)
561 msg = (struct GNUNET_MESH_KX *) cbuf;
562 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX);
563 msg->header.size = htons (sizeof (struct GNUNET_MESH_KX) + size);
564 c = tunnel_get_connection (t);
567 GNUNET_break (GNUNET_YES == t->destroy);
570 type = ntohs (message->type);
573 case GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL:
574 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
575 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
576 msg->cid = *GMC_get_id (c);
577 msg->reserved = htonl (0);
578 memcpy (&msg[1], message, size);
581 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
582 GNUNET_MESH_DEBUG_M2S (type));
586 fwd = GMC_is_origin (t->connection_head->c, GNUNET_YES);
587 GMC_send_prebuilt_message (&msg->header, c, fwd);
592 * Send the ephemeral key on a tunnel.
594 * @param t Tunnel on which to send the key.
597 send_ephemeral (struct MeshTunnel3 *t)
599 kx_msg.sender_status = htonl (t->state);
601 send_kx (t, &kx_msg.header);
605 * Send a ping message on a tunnel.
607 * @param t Tunnel on which to send the ping.
610 send_ping (struct MeshTunnel3 *t)
612 struct GNUNET_MESH_KX_Ping msg;
614 msg.header.size = htons (sizeof (msg));
615 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PING);
616 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
617 msg.target = *GMP_get_id (t->peer);
618 msg.nonce = t->kx_ctx->challenge;
619 t_encrypt (t, &msg.target, &msg.target, ping_encryption_size(), msg.iv);
621 send_kx (t, &msg.header);
626 * Send a pong message on a tunnel.
628 * @param t Tunnel on which to send the pong.
629 * @param challenge Value sent in the ping that we have to send back.
632 send_pong (struct MeshTunnel3 *t, uint32_t challenge)
634 struct GNUNET_MESH_KX_Pong msg;
636 msg.header.size = htons (sizeof (msg));
637 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_PONG);
638 msg.iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
639 msg.nonce = challenge;
640 t_encrypt (t, &msg.nonce, &msg.nonce, sizeof (msg.nonce), msg.iv);
642 send_kx (t, &msg.header);
647 * Initiate a rekey with the remote peer.
649 * @param cls Closure (tunnel).
650 * @param tc TaskContext.
653 rekey_tunnel (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
655 struct MeshTunnel3 *t = cls;
657 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
659 if (NULL != tc && 0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
662 t->kx_ctx = GNUNET_new (struct MeshTunnelKXCtx);
663 t->kx_ctx->challenge = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
665 t->kx_ctx->d_key_old = t->d_key;
667 if (MESH_TUNNEL3_READY == t->state)
670 t->state = MESH_TUNNEL3_REKEY;
672 else if (MESH_TUNNEL3_WAITING == t->state)
674 t->state = MESH_TUNNEL3_KEY_SENT;
678 LOG (GNUNET_ERROR_TYPE_DEBUG, "Unexpected state %u\n", t->state);
681 t->rekey_task = GNUNET_SCHEDULER_add_delayed (REKEY_WAIT, &rekey_tunnel, t);
686 * Out ephemeral key has changed, create new session key on all tunnels.
688 * @param cls Closure (size of the hashmap).
689 * @param key Current public key.
690 * @param value Value in the hash map (tunnel).
692 * @return #GNUNET_YES, so we should continue to iterate,
695 rekey_iterator (void *cls,
696 const struct GNUNET_PeerIdentity *key,
699 struct MeshTunnel3 *t = value;
700 struct GNUNET_TIME_Relative delay;
704 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
707 r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, (uint32_t) n * 100);
708 delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, r);
709 t->rekey_task = GNUNET_SCHEDULER_add_delayed (delay, &rekey_tunnel, t);
716 * Create a new ephemeral key and key message, schedule next rekeying.
718 * @param cls Closure (unused).
719 * @param tc TaskContext.
722 rekey (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
724 struct GNUNET_TIME_Absolute time;
727 rekey_task = GNUNET_SCHEDULER_NO_TASK;
729 if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
732 GNUNET_free_non_null (my_ephemeral_key);
733 my_ephemeral_key = GNUNET_CRYPTO_ecdhe_key_create ();
735 time = GNUNET_TIME_absolute_get ();
736 kx_msg.creation_time = GNUNET_TIME_absolute_hton (time);
737 time = GNUNET_TIME_absolute_add (time, rekey_period);
738 time = GNUNET_TIME_absolute_add (time, GNUNET_TIME_UNIT_MINUTES);
739 kx_msg.expiration_time = GNUNET_TIME_absolute_hton (time);
740 GNUNET_CRYPTO_ecdhe_key_get_public (my_ephemeral_key, &kx_msg.ephemeral_key);
742 GNUNET_assert (GNUNET_OK ==
743 GNUNET_CRYPTO_eddsa_sign (my_private_key,
747 n = (long) GNUNET_CONTAINER_multipeermap_size (tunnels);
748 GNUNET_CONTAINER_multipeermap_iterate (tunnels, &rekey_iterator, (void *) n);
750 rekey_task = GNUNET_SCHEDULER_add_delayed (rekey_period, &rekey, NULL);
755 * Demultiplex data per channel and call appropriate channel handler.
757 * @param t Tunnel on which the data came.
758 * @param msg Data message.
759 * @param fwd Is this FWD data? (root -> dest)
762 handle_data (struct MeshTunnel3 *t,
763 const struct GNUNET_MESH_Data *msg,
766 struct MeshChannel *ch;
771 size = ntohs (msg->header.size);
773 sizeof (struct GNUNET_MESH_Data) +
774 sizeof (struct GNUNET_MessageHeader))
779 type = ntohs (msg->header.type);
780 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message\n",
781 GNUNET_MESH_DEBUG_M2S (type));
782 LOG (GNUNET_ERROR_TYPE_DEBUG, " payload of type %s\n",
783 GNUNET_MESH_DEBUG_M2S (ntohs (msg[1].header.type)));
786 ch = GMT_get_channel (t, ntohl (msg->chid));
789 GNUNET_STATISTICS_update (stats, "# data on unknown channel",
791 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
796 GMT_change_state (t, MESH_TUNNEL3_READY);
797 GMCH_handle_data (ch, msg, fwd);
801 handle_data_ack (struct MeshTunnel3 *t,
802 const struct GNUNET_MESH_DataACK *msg,
805 struct MeshChannel *ch;
809 size = ntohs (msg->header.size);
810 if (size != sizeof (struct GNUNET_MESH_DataACK))
817 ch = GMT_get_channel (t, ntohl (msg->chid));
820 GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
822 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
827 GMCH_handle_data_ack (ch, msg, fwd);
831 handle_ch_create (struct MeshTunnel3 *t,
832 const struct GNUNET_MESH_ChannelCreate *msg,
835 struct MeshChannel *ch;
839 size = ntohs (msg->header.size);
840 if (size != sizeof (struct GNUNET_MESH_ChannelCreate))
847 ch = GMT_get_channel (t, ntohl (msg->chid));
850 /* Probably a retransmission, safe to ignore */
851 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists...\n");
855 ch = GMCH_handle_create (t, msg, fwd);
857 GMT_add_channel (t, ch);
861 handle_ch_ack (struct MeshTunnel3 *t,
862 const struct GNUNET_MESH_ChannelManage *msg,
865 struct MeshChannel *ch;
869 size = ntohs (msg->header.size);
870 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
877 ch = GMT_get_channel (t, ntohl (msg->chid));
880 GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
882 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING channel %u unknown\n",
887 GMCH_handle_ack (ch, msg, fwd);
891 handle_ch_destroy (struct MeshTunnel3 *t,
892 const struct GNUNET_MESH_ChannelManage *msg,
895 struct MeshChannel *ch;
899 size = ntohs (msg->header.size);
900 if (size != sizeof (struct GNUNET_MESH_ChannelManage))
907 ch = GMT_get_channel (t, ntohl (msg->chid));
910 /* Probably a retransmission, safe to ignore */
914 GMCH_handle_destroy (ch, msg, fwd);
919 * The peer's ephemeral key has changed: update the symmetrical keys.
921 * @param t Tunnel this message came on.
922 * @param msg Key eXchange message.
925 handle_ephemeral (struct MeshTunnel3 *t,
926 const struct GNUNET_MESH_KX_Ephemeral *msg)
928 struct GNUNET_HashCode km;
929 LOG (GNUNET_ERROR_TYPE_DEBUG, " ephemeral key message\n");
931 if (GNUNET_OK != check_ephemeral (t, msg))
936 derive_key_material (&km, &msg->ephemeral_key);
937 derive_symmertic (&t->e_key, &my_full_id, GMP_get_id (t->peer), &km);
938 derive_symmertic (&t->d_key, GMP_get_id (t->peer), &my_full_id, &km);
939 if (MESH_TUNNEL3_KEY_SENT == t->state)
942 t->state = MESH_TUNNEL3_PING_SENT;
948 * Peer wants to check our symmetrical keys by sending an encrypted challenge.
949 * Answer with by retransmitting the challenge with the "opposite" key.
951 * @param t Tunnel this message came on.
952 * @param msg Key eXchange Ping message.
955 handle_ping (struct MeshTunnel3 *t,
956 const struct GNUNET_MESH_KX_Ping *msg)
958 struct GNUNET_MESH_KX_Ping res;
960 LOG (GNUNET_ERROR_TYPE_DEBUG, " ping message\n");
961 t_decrypt (t, &res.target, &msg->target, ping_encryption_size(), msg->iv);
962 if (0 != memcmp (&my_full_id, &msg->target, sizeof (my_full_id)))
965 LOG (GNUNET_ERROR_TYPE_DEBUG, " at %s\n", GNUNET_i2s (&my_full_id));
966 LOG (GNUNET_ERROR_TYPE_DEBUG, " for %s\n", GNUNET_i2s (&msg->target));
970 send_pong (t, res.iv);
975 * Peer has answer to our challenge.
976 * If answer is successful, consider the key exchange finished and clean
977 * up all related state.
979 * @param t Tunnel this message came on.
980 * @param msg Key eXchange Pong message.
983 handle_pong (struct MeshTunnel3 *t,
984 const struct GNUNET_MESH_KX_Pong *msg)
988 LOG (GNUNET_ERROR_TYPE_DEBUG, "PONG received\n");
989 if (GNUNET_SCHEDULER_NO_TASK == t->rekey_task)
994 t_decrypt (t, &challenge, &msg->nonce, sizeof (uint32_t), msg->iv);
996 if (challenge != t->kx_ctx->challenge)
998 LOG (GNUNET_ERROR_TYPE_DEBUG,
999 "Wrong PONG challenge: %u. Expected: %u.\n",
1000 challenge, t->kx_ctx->challenge);
1001 GNUNET_break_op (0);
1004 GNUNET_SCHEDULER_cancel (t->rekey_task);
1005 t->rekey_task = GNUNET_SCHEDULER_NO_TASK;
1006 GNUNET_free (t->kx_ctx);
1008 t->state = MESH_TUNNEL3_READY;
1009 send_queued_data (t, GNUNET_YES);
1010 send_queued_data (t, GNUNET_NO);
1015 * Demultiplex by message type and call appropriate handler for a message
1016 * towards a channel of a local tunnel.
1018 * @param t Tunnel this message came on.
1019 * @param msgh Message header.
1020 * @param fwd Is this message fwd?
1023 handle_decrypted (struct MeshTunnel3 *t,
1024 const struct GNUNET_MessageHeader *msgh,
1029 type = ntohs (msgh->type);
1030 LOG (GNUNET_ERROR_TYPE_DEBUG,
1031 "Got a %s message!\n",
1032 GNUNET_MESH_DEBUG_M2S (type));
1036 case GNUNET_MESSAGE_TYPE_MESH_DATA:
1037 /* Don't send hop ACK, wait for client to ACK */
1038 handle_data (t, (struct GNUNET_MESH_Data *) msgh, fwd);
1041 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
1042 handle_data_ack (t, (struct GNUNET_MESH_DataACK *) msgh, fwd);
1045 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
1046 handle_ch_create (t,
1047 (struct GNUNET_MESH_ChannelCreate *) msgh,
1051 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
1053 (struct GNUNET_MESH_ChannelManage *) msgh,
1057 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
1058 handle_ch_destroy (t,
1059 (struct GNUNET_MESH_ChannelManage *) msgh,
1064 GNUNET_break_op (0);
1065 LOG (GNUNET_ERROR_TYPE_DEBUG,
1066 "end-to-end message not known (%u)\n",
1067 ntohs (msgh->type));
1071 /******************************************************************************/
1072 /******************************** API ***********************************/
1073 /******************************************************************************/
1076 * Decrypt and demultiplex by message type. Call appropriate handler
1077 * for every message.
1079 * @param t Tunnel this message came on.
1080 * @param msg Encrypted message.
1081 * @param fwd Is this message fwd?
1084 GMT_handle_encrypted (struct MeshTunnel3 *t,
1085 const struct GNUNET_MESH_Encrypted *msg,
1088 size_t size = ntohs (msg->header.size);
1089 size_t payload_size = size - sizeof (struct GNUNET_MESH_Encrypted);
1090 size_t decrypted_size;
1091 char cbuf [payload_size];
1092 struct GNUNET_MessageHeader *msgh;
1095 decrypted_size = t_decrypt (t, cbuf, &msg[1], payload_size, msg->iv);
1097 while (off < decrypted_size)
1099 msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
1100 handle_decrypted (t, msgh, fwd);
1101 off += ntohs (msgh->size);
1107 * Demultiplex an encapsulated KX message by message type.
1109 * @param t Tunnel on which the message came.
1110 * @param message Payload of KX message.
1113 GMT_handle_kx (struct MeshTunnel3 *t,
1114 const struct GNUNET_MessageHeader *message)
1118 type = ntohs (message->type);
1119 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message received\n", type);
1122 case GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL:
1123 handle_ephemeral (t, (struct GNUNET_MESH_KX_Ephemeral *) message);
1126 case GNUNET_MESSAGE_TYPE_MESH_KX_PING:
1127 handle_ping (t, (struct GNUNET_MESH_KX_Ping *) message);
1130 case GNUNET_MESSAGE_TYPE_MESH_KX_PONG:
1131 handle_pong (t, (struct GNUNET_MESH_KX_Pong *) message);
1135 GNUNET_break_op (0);
1136 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx message not known (%u)\n", type);
1142 * Initialize the tunnel subsystem.
1144 * @param c Configuration handle.
1145 * @param key ECC private key, to derive all other keys and do crypto.
1148 GMT_init (const struct GNUNET_CONFIGURATION_Handle *c,
1149 const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
1151 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1153 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "DEFAULT_TTL",
1156 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1157 "MESH", "DEFAULT_TTL", "USING DEFAULT");
1161 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REKEY_PERIOD",
1164 rekey_period = GNUNET_TIME_UNIT_DAYS;
1167 my_private_key = key;
1168 kx_msg.header.size = htons (sizeof (kx_msg));
1169 kx_msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_KX_EPHEMERAL);
1170 kx_msg.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_MESH_KX);
1171 kx_msg.purpose.size = htonl (ephemeral_purpose_size ());
1172 kx_msg.origin_identity = my_full_id;
1173 rekey_task = GNUNET_SCHEDULER_add_now (&rekey, NULL);
1175 tunnels = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
1180 * Shut down the tunnel subsystem.
1185 if (GNUNET_SCHEDULER_NO_TASK != rekey_task)
1187 GNUNET_SCHEDULER_cancel (rekey_task);
1188 rekey_task = GNUNET_SCHEDULER_NO_TASK;
1190 GNUNET_CONTAINER_multipeermap_destroy (tunnels);
1197 * @param destination Peer this tunnel is towards.
1199 struct MeshTunnel3 *
1200 GMT_new (struct MeshPeer *destination)
1202 struct MeshTunnel3 *t;
1204 t = GNUNET_new (struct MeshTunnel3);
1206 t->peer = destination;
1209 GNUNET_CONTAINER_multipeermap_put (tunnels, GMP_get_id (destination), t,
1210 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
1221 * Change the tunnel state.
1223 * @param t Tunnel whose state to change.
1224 * @param state New state.
1227 GMT_change_state (struct MeshTunnel3* t, enum MeshTunnel3State state)
1231 LOG (GNUNET_ERROR_TYPE_DEBUG,
1232 "Tunnel %s state was %s\n",
1234 GMT_state2s (t->state));
1235 LOG (GNUNET_ERROR_TYPE_DEBUG,
1236 "Tunnel %s state is now %s\n",
1238 GMT_state2s (state));
1239 if (myid != GMP_get_short_id (t->peer) &&
1240 MESH_TUNNEL3_WAITING == t->state && MESH_TUNNEL3_READY == state)
1242 LOG (GNUNET_ERROR_TYPE_DEBUG, " triggered rekey\n");
1243 rekey_tunnel (t, NULL);
1244 LOG (GNUNET_ERROR_TYPE_DEBUG,
1245 "Tunnel %s state is now %s\n",
1247 GMT_state2s (t->state));
1253 if (MESH_TUNNEL3_READY == state && 3 <= GMT_count_connections (t))
1255 GMP_stop_search (t->peer);
1261 * Add a connection to a tunnel.
1264 * @param c Connection.
1267 GMT_add_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1269 struct MeshTConnection *aux;
1271 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1275 aux = GNUNET_new (struct MeshTConnection);
1277 GNUNET_CONTAINER_DLL_insert_tail (t->connection_head, t->connection_tail, aux);
1282 * Remove a connection from a tunnel.
1285 * @param c Connection.
1288 GMT_remove_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
1290 struct MeshTConnection *aux;
1292 for (aux = t->connection_head; aux != NULL; aux = aux->next)
1295 GNUNET_CONTAINER_DLL_remove (t->connection_head, t->connection_tail, aux);
1303 * Add a channel to a tunnel.
1306 * @param ch Channel.
1309 GMT_add_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1311 struct MeshTChannel *aux;
1313 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding channel %p to tunnel %p\n", ch, t);
1315 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1317 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there %p\n", aux->ch);
1322 aux = GNUNET_new (struct MeshTChannel);
1324 LOG (GNUNET_ERROR_TYPE_DEBUG, " adding %p to %p\n", aux, t->channel_head);
1325 GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
1330 * Remove a channel from a tunnel.
1333 * @param ch Channel.
1336 GMT_remove_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
1338 struct MeshTChannel *aux;
1340 LOG (GNUNET_ERROR_TYPE_DEBUG, "Removing channel %p from tunnel %p\n", ch, t);
1341 for (aux = t->channel_head; aux != NULL; aux = aux->next)
1345 LOG (GNUNET_ERROR_TYPE_DEBUG, " found! %s\n", GMCH_2s (ch));
1346 GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
1355 * Search for a channel by global ID.
1357 * @param t Tunnel containing the channel.
1358 * @param chid Public channel number.
1360 * @return channel handler, NULL if doesn't exist
1362 struct MeshChannel *
1363 GMT_get_channel (struct MeshTunnel3 *t, MESH_ChannelNumber chid)
1365 struct MeshTChannel *iter;
1370 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1372 if (GMCH_get_id (iter->ch) == chid)
1376 return NULL == iter ? NULL : iter->ch;
1381 * Tunnel is empty: destroy it.
1383 * Notifies all connections about the destruction.
1385 * @param t Tunnel to destroy.
1388 GMT_destroy_empty (struct MeshTunnel3 *t)
1390 struct MeshTConnection *iter;
1392 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1394 GMC_send_destroy (iter->c);
1397 t->destroy = GNUNET_YES;
1402 * Destroy tunnel if empty (no more channels).
1404 * @param t Tunnel to destroy if empty.
1407 GMT_destroy_if_empty (struct MeshTunnel3 *t)
1409 if (1 < GMT_count_channels (t))
1412 GMT_destroy_empty (t);
1417 * Destroy the tunnel.
1419 * This function does not generate any warning traffic to clients or peers.
1422 * Cancel messages belonging to this tunnel queued to neighbors.
1423 * Free any allocated resources linked to the tunnel.
1425 * @param t The tunnel to destroy.
1428 GMT_destroy (struct MeshTunnel3 *t)
1430 struct MeshTConnection *iter;
1431 struct MeshTConnection *next;
1436 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying tunnel %s\n", GMP_2s (t->peer));
1438 // if (GNUNET_YES != GNUNET_CONTAINER_multihashmap_remove (tunnels, &t->id, t))
1439 // GNUNET_break (0);
1441 for (iter = t->connection_head; NULL != iter; iter = next)
1444 GMC_destroy (iter->c);
1447 GNUNET_STATISTICS_update (stats, "# tunnels", -1, GNUNET_NO);
1448 GMP_set_tunnel (t->peer, NULL);
1450 if (GNUNET_SCHEDULER_NO_TASK != t->rekey_task)
1451 GNUNET_SCHEDULER_cancel (t->rekey_task);
1458 * @brief Use the given path for the tunnel.
1459 * Update the next and prev hops (and RCs).
1460 * (Re)start the path refresh in case the tunnel is locally owned.
1462 * @param t Tunnel to update.
1463 * @param p Path to use.
1465 * @return Connection created.
1467 struct MeshConnection *
1468 GMT_use_path (struct MeshTunnel3 *t, struct MeshPeerPath *p)
1470 struct MeshConnection *c;
1471 struct GNUNET_HashCode cid;
1472 unsigned int own_pos;
1474 if (NULL == t || NULL == p)
1480 for (own_pos = 0; own_pos < p->length; own_pos++)
1482 if (p->peers[own_pos] == myid)
1485 if (own_pos > p->length - 1)
1491 GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE, &cid);
1492 c = GMC_new (&cid, t, p, own_pos);
1493 GMT_add_connection (t, c);
1499 * Count established (ready) connections of a tunnel.
1501 * @param t Tunnel on which to count.
1503 * @return Number of connections.
1506 GMT_count_connections (struct MeshTunnel3 *t)
1508 struct MeshTConnection *iter;
1511 for (count = 0, iter = t->connection_head;
1513 iter = iter->next, count++);
1519 * Count channels of a tunnel.
1521 * @param t Tunnel on which to count.
1523 * @return Number of channels.
1526 GMT_count_channels (struct MeshTunnel3 *t)
1528 struct MeshTChannel *iter;
1531 for (count = 0, iter = t->channel_head;
1533 iter = iter->next, count++) /* skip */;
1540 * Get the state of a tunnel.
1544 * @return Tunnel's state.
1546 enum MeshTunnel3State
1547 GMT_get_state (struct MeshTunnel3 *t)
1550 return (enum MeshTunnel3State) -1;
1555 * Get the total buffer space for a tunnel.
1557 * If terminal, use the biggest channel buffer (or 64) if no channel exists.
1558 * If not terminal, use the sum of all connection buffers.
1561 * @param fwd Is this for FWD traffic?
1563 * @return Buffer space offered by all entities (c/ch) in the tunnel.
1566 GMT_get_buffer (struct MeshTunnel3 *t, int fwd)
1568 struct MeshTConnection *iter;
1569 unsigned int buffer;
1571 iter = t->connection_head;
1574 /* If terminal, return biggest channel buffer */
1575 if (NULL == iter || GMC_is_terminal (iter->c, fwd))
1577 struct MeshTChannel *iter_ch;
1578 unsigned int ch_buf;
1580 if (NULL == t->channel_head)
1582 /* Probably getting buffer for a channel create/handshake. */
1586 for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = iter_ch->next)
1588 ch_buf = GMCH_get_buffer (iter_ch->ch, fwd);
1589 if (ch_buf > buffer)
1595 /* If not terminal, return sum of connection buffers */
1596 while (NULL != iter)
1598 if (GMC_get_state (iter->c) != MESH_CONNECTION_READY)
1604 buffer += GMC_get_buffer (iter->c, fwd);
1613 * Get the tunnel's destination.
1617 * @return ID of the destination peer.
1619 const struct GNUNET_PeerIdentity *
1620 GMT_get_destination (struct MeshTunnel3 *t)
1622 return GMP_get_id (t->peer);
1627 * Get the tunnel's next free global channel ID.
1631 * @return GID of a channel free to use.
1634 GMT_get_next_chid (struct MeshTunnel3 *t)
1636 MESH_ChannelNumber chid;
1638 while (NULL != GMT_get_channel (t, t->next_chid))
1640 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
1641 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
1643 chid = t->next_chid;
1644 t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
1651 * Send ACK on one or more channels due to buffer in connections.
1653 * @param t Channel which has some free buffer space.
1654 * @param fwd Is this for FWD traffic? (ACK goes to root)
1657 GMT_unchoke_channels (struct MeshTunnel3 *t, int fwd)
1659 struct MeshTChannel *iter;
1660 unsigned int buffer;
1661 unsigned int channels = GMT_count_channels (t);
1662 unsigned int choked_n;
1663 struct MeshChannel *choked[channels];
1665 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT_unchoke_channels on %s\n", GMT_2s (t));
1666 LOG (GNUNET_ERROR_TYPE_DEBUG, " head: %p\n", t->channel_head);
1667 if (NULL != t->channel_head)
1668 LOG (GNUNET_ERROR_TYPE_DEBUG, " head ch: %p\n", t->channel_head->ch);
1676 /* Get buffer space */
1677 buffer = GMT_get_buffer (t, fwd);
1683 /* Count and remember choked channels */
1685 for (iter = t->channel_head; NULL != iter; iter = iter->next)
1687 if (GNUNET_NO == GMCH_get_allowed (iter->ch, fwd))
1689 choked[choked_n++] = iter->ch;
1693 /* Unchoke random channels */
1694 while (0 < buffer && 0 < choked_n)
1696 unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1698 GMCH_allow_client (choked[r], fwd);
1701 choked[r] = choked[choked_n];
1707 * Send ACK on one or more connections due to buffer space to the client.
1709 * Iterates all connections of the tunnel and sends ACKs appropriately.
1712 * @param fwd Is this in for FWD traffic? (ACK goes dest->root)
1715 GMT_send_acks (struct MeshTunnel3 *t, int fwd)
1717 struct MeshTConnection *iter;
1720 uint32_t allow_per_connection;
1722 unsigned int buffer;
1724 LOG (GNUNET_ERROR_TYPE_DEBUG,
1725 "Tunnel send %s ACKs on %s\n",
1726 fwd ? "FWD" : "BCK", GMT_2s (t));
1733 if (NULL == t->channel_head ||
1734 GNUNET_NO == GMCH_is_origin (t->channel_head->ch, !fwd))
1740 buffer = GMT_get_buffer (t, fwd);
1742 /* Count connections, how many messages are already allowed */
1743 cs = GMT_count_connections (t);
1744 for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
1746 allowed += GMC_get_allowed (iter->c, fwd);
1749 /* Make sure there is no overflow */
1750 if (allowed > buffer)
1756 /* Authorize connections to send more data */
1757 to_allow = buffer; /* - allowed; */
1759 for (iter = t->connection_head; NULL != iter && to_allow > 0; iter = iter->next)
1761 allow_per_connection = to_allow/cs;
1762 to_allow -= allow_per_connection;
1764 if (GMC_get_allowed (iter->c, fwd) > 64 / 3)
1768 GMC_allow (iter->c, buffer, fwd);
1771 GNUNET_break (to_allow == 0);
1776 * Sends an already built message on a tunnel, encrypting it and
1777 * choosing the best connection.
1779 * @param message Message to send. Function modifies it.
1780 * @param t Tunnel on which this message is transmitted.
1781 * @param ch Channel on which this message is transmitted.
1782 * @param fwd Is this a fwd message on @c ch?
1785 GMT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1786 struct MeshTunnel3 *t,
1787 struct MeshChannel *ch,
1790 struct MeshConnection *c;
1791 struct GNUNET_MESH_Encrypted *msg;
1792 size_t size = ntohs (message->size);
1793 size_t encrypted_size;
1794 char cbuf[sizeof (struct GNUNET_MESH_Encrypted) + size];
1798 if (MESH_TUNNEL3_READY != t->state)
1800 queue_data (t, ch, message);
1803 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GMT_2s (t));
1805 if (myid == GMP_get_short_id (t->peer))
1807 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback!\n");
1808 handle_decrypted (t, message, fwd);
1812 iv = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
1813 msg = (struct GNUNET_MESH_Encrypted *) cbuf;
1814 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED);
1816 encrypted_size = t_encrypt (t, &msg[1], message, size, iv);
1817 msg->header.size = htons (sizeof (struct GNUNET_MESH_Encrypted) + encrypted_size);
1818 c = tunnel_get_connection (t);
1821 GNUNET_break (GNUNET_YES == t->destroy);
1824 type = ntohs (message->type);
1827 case GNUNET_MESSAGE_TYPE_MESH_DATA:
1828 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
1829 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
1830 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
1831 msg->cid = *GMC_get_id (c);
1832 msg->ttl = htonl (default_ttl);
1835 LOG (GNUNET_ERROR_TYPE_DEBUG, "unkown type %s\n",
1836 GNUNET_MESH_DEBUG_M2S (type));
1840 fwd = GMC_is_origin (c, GNUNET_YES);
1841 GMC_send_prebuilt_message (&msg->header, c, fwd);
1845 * Is the tunnel directed towards the local peer?
1849 * @return #GNUNET_YES if it is loopback.
1852 GMT_is_loopback (const struct MeshTunnel3 *t)
1854 return (myid == GMP_get_short_id(t->peer));
1859 * Is the tunnel using this path already?
1864 * @return #GNUNET_YES a connection uses this path.
1867 GMT_is_path_used (const struct MeshTunnel3 *t, const struct MeshPeerPath *p)
1869 struct MeshTConnection *iter;
1871 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1872 if (GMC_get_path (iter->c) == p)
1880 * Get a cost of a path for a tunnel considering existing connections.
1883 * @param path Candidate path.
1885 * @return Cost of the path (path length + number of overlapping nodes)
1888 GMT_get_path_cost (const struct MeshTunnel3 *t,
1889 const struct MeshPeerPath *path)
1891 struct MeshTConnection *iter;
1892 unsigned int overlap;
1900 GNUNET_assert (NULL != t);
1902 for (i = 0; i < path->length; i++)
1904 for (iter = t->connection_head; NULL != iter; iter = iter->next)
1906 for (j = 0; j < GMC_get_path (iter->c)->length; j++)
1908 if (path->peers[i] == GMC_get_path (iter->c)->peers[j])
1916 return (path->length + overlap) * (path->score * -1);
1921 * Get the static string for the peer this tunnel is directed.
1925 * @return Static string the destination peer's ID.
1928 GMT_2s (const struct MeshTunnel3 *t)
1930 return GMP_2s (t->peer);